作者承认迈克尔 Pluchinsky 的帮助与高速摄影工作

使用适当的个人防护设备如安全眼镜、手套等执行本手稿中提到的任何任务。这里使用的起始材料是否, 为测量弯曲的力量, 碰撞, 长宽比或大块粉碎总挤出物从实验室研究或试验性设备研究或是商业材料获得。催化剂挤出强度取决于预处理条件, 因此对用户选择合适的处理方法是很重要的。测量结果允许从强度角度决定在进一步研究中使用哪些材料。
1. 抗弯强度
<ol><li>
弯曲强度试样制备
	<ol>
<li>浅滩的挤出样品的兴趣, 以代表性的大小为25粒子最小。使用旋转 riffler 或浅滩式采样分隔线。 注意:催化剂强度依赖于热预处理, 因此样品要求使用者在预处理方面做出一定的选择。</li>
		<li>执行以下两个典型预处理之一, 但它们的条件可能会根据用户的需要而改变。<ol>
<li>将样品煅烧538摄氏度, 1 小时。<ol>
<li>在瓷碟或耐热烧杯中放置至少25花纹催化剂挤出物。</li>
				<li>将该盘与催化剂放入一个耐火型的消音器烤箱在538°c 1 小时。</li>
				<li>煅烧后, 将热样品放入干燥, 使其冷却到环境条件。</li>
			</ol>
</li>
			<li>将样品干燥121摄氏度, 最低为2小时。<ol>
<li>在瓷碟或耐热烧杯中放置至少25花纹催化剂挤出物。</li>
				<li>将该盘与催化剂放在烘干烤箱中, 设置为121摄氏度, 最低为2小时。</li>
				<li>从烘干烤箱中取出热样品, 放入干燥, 使其冷却到环境条件下。</li>
			</ol>
</li>
		</ol>
</li>
	</ol>
</li>
	<li>
弯曲强度仪表安装 注:破裂模量的误差线为 +/-10%。根据制造商提出的程序, 每天校准设备。选择正确匹配样本形状的方法, 因为铁道部的计算取决于形状因子。<ol>
<li>启动弯曲测试框架, 并允许系统在使用前至少预热20分钟。然后打开所需的软件。</li>
		<li>根据制造商的说明附加 10 N (10 牛顿力) 负载单元。</li>
		<li>选择一个 0.2 mm/秒的铁砧速度与5毫米的支撑跨度。 注意:据观察, 对于这种速度, 催化剂不是在应变率敏感区域和断裂力是可再生的。</li>
		<li>选择 "结果" 选项卡中的 "破裂模数" 和 "最大力"。</li>
		<li>通过在框架控制台上牢牢按下 "返回" 按钮, 确保铁道部车架上的十字头处于 "零" 位置。如有必要, 可以改变十字头和铁砧的位置, 以适应不同直径的挤出物。</li>
	</ol>
</li>
	<li>
弯曲强度测量
	<ol>
<li>从干燥中抽取催化剂挤出样品, 并将其放入5-6 厘米直径的反向过滤器中, N2通过它向上吹, 形成一条干气毯。</li>
		<li>使用镊子从过滤器托盘中取一个挤出标本, 并将其放在支撑梁上。尽量减少挤出试样放置和测量的时间, 以尽量减少水分的提取。</li>
		<li>中心的催化剂挤出试样尽可能最好的左到右和前背部的支持梁</li>
		<li>单击右侧工具栏上的 "开始" 图标。 注意:在这一步, 挤出是弯曲超越了突破点, 因此测试是破坏性的, 在这个意义上。</li>
		<li>确保十字头停止, 并返回到起始位置时, 经历了40% 下降的负载力。 注意:这通常发生在挤出破损。</li>
		<li>选择右侧工具栏上的 "下一步" 图标, 继续下一个挤出。</li>
		<li>点击 "后退" 查看图表上和结果表上的数据点。</li>
		<li>在测量第二十五挤出标本后, 选择 "完成样品"。 注意:软件生成具有强度属性的报告</li>
	</ol>
</li>
</ol>2. 碰撞试验
注意:将催化剂送入滴管的进给速率保持在较低的速度, 使单个催化剂挤出物与底部的空表面发生碰撞, 而不会相互阻碍。
<ol><li>
碰撞设备准备
	<ol>
<li>将下拉管 (0.15 米直径和1.83 米长塑料管) 装配在底部的回收板 (316 SS) 上。设置进纸器放电在正确的高度选择 (这里 1.83m) 中心在下降管。改变跌落高度以改变碰撞的严重性。</li>
		<li>将振动馈线的共振频率设置为250赫兹, 电源关闭。</li>
		<li>在进料斗上放置局部通风。</li>
	</ol>
</li>
	<li>
碰撞样品准备
	<ol>
<li>浅滩的催化剂样品的兴趣, 以代表性的大小为50粒子最小。使用旋转 riffler 或浅滩式采样分隔线。</li>
		<li>轻轻筛好所制备的样品, 以避免粒径比小于或等于1的小颗粒。</li>
		<li>使用协议节3测量样本的初始纵横比。</li>
	</ol>
</li>
	<li>
碰撞催化剂下落做法
	<ol>
<li>手动将整个样品转移到进料斗。</li>
		<li>确保进纸槽出口位于下拉管的中心。</li>
		<li>打开切换开关以打开进纸器并设置为 "开始"。</li>
		<li>允许所有粒子自由地落入下拉管并撞击底板。</li>
		<li>一旦所有粒子都被喂食和丢弃, 关闭电源给馈线。</li>
		<li>从回收板中转移所有微粒, 并通过筛分轻轻地去除样品中的罚款, 以去除灰尘和碎屑。</li>
		<li>使用协议部分3测量样本的纵横比, 以完成指定1X 的第一个跌落测量。</li>
		<li>使用步骤2.3.7 的示例, 重复步骤 2.3.1 2.3.6, 并使用协议节3来测量长宽比, 以完成指定2X 的第二个跌落测量。</li>
		<li>重复上述步骤以完成多达5X 和10X 的跌落测量。 注意:你可以选择跳过中间长宽比测量, 因为长宽比在多次下落以后只改变少许。</li>
	</ol>
</li>
</ol>3. 催化剂长宽比
<ol><li>
纵横比样品准备
	<ol>
<li>浅滩的催化剂样品的兴趣, 有代表性的大小为50到250粒子。使用旋转 riffler 或浅滩式采样分隔线来获取具有代表性的样本。</li>
		<li>筛选准备好的样品, 以避免小于或等于1的小颗粒, l 代表挤出的长度, 而 D 代表挤出的直径。</li>
	</ol>
</li>
	<li>
纵横比软件与设置
	<ol>
<li>打开软件并选择屏幕顶部的 "扫描" 工具栏按钮。</li>
		<li>用超细纤维布擦拭玻璃, 除去灰尘。在扫描仪上放置一个干净的透明纸。</li>
		<li>将挤出物洒在透明度之上, 避免粒子相互接触。将粒子放在一个矩形区域内, 测量最大10厘米20厘米。</li>
		<li>在要扫描的区域内随机分布挤出物。用一双镊子将粒子相互滑动, 或者将它们放在更开阔的区域。</li>
		<li>关闭扫描仪盖。</li>
		<li>选择粒子的形状</li>
		<li>在软件设置中启用消息功能, 对于触摸粒子 (屏幕上的红色突出显示), 重叠 (或刷牙) 扫描区域边缘的粒子被自动删除, 任何具有过度曲率的粒子, 任何粒子太小 (例如尘埃斑点), 以及任何相互接触的粒子。</li>
		<li>单击 "扫描" 工具栏按钮。 注意:扫描仪将开始扫描粒子。这将需要2-3 分钟。表格结果和光学扫描图像显示在屏幕上。</li>
	</ol>
</li>
	<li>
纵横比分析
	<ol>
<li>检查扫描结果并确保扫描中包含所有合法粒子。 注意:合法的粒子有和 L/D > 1, 休息在一个自然的位置扫描和不接触其他挤出物。</li>
		<li>检查每个被怀疑接触相邻粒子的粒子, 因为计算算法不完善。</li>
		<li>消除因拥挤 (接触或躺在对方之上) 而不适当的微粒, 并在软件中消除。或者, 用镊子调整粒子的位置, 可以重新扫描整个样品。</li>
		<li>保存结果并记录以下信息: 平均直径、平均长度和粒子数。</li>
	</ol>
</li>
</ol>4. 散装粉碎试验
<ol><li>
散装粉碎样品准备
	<ol>
<li>应花纹催化剂挤出样品, 以获得总金额的合适代表。</li>
		<li>热处理的催化剂样品在538°c 至少1小时在一个消音器烤箱或类似的, 并把它热在一个干燥, 让它冷却到环境条件。</li>
	</ol>
</li>
	<li>
大块粉碎过程
	<ol>
<li>将催化剂样品容器 (杯) 装满, 用催化剂填充, 使容器中有多余的催化剂。</li>
		<li>小心水平的杯子与金属直边没有过度包装床。</li>
		<li>称量含机油的容器与一个水平的催化剂, 以获得样品的重量。</li>
		<li>将样品小心地放在负载块和活塞总成中。将负载块放在试样的顶部, 而不粉碎催化剂。</li>
		<li>将球轴承放在负载块的中心, 用小木匠的水平在滚珠轴承上均匀地调整锁臂到适当的高度。把手臂锁到位。</li>
		<li>检查压力调节器是否按用户指定的压力设置, 以应用于催化剂样品。 注意:通常情况下, 它是在 5-1, 000 帕范围, 它通常是由试验和错误的特定应用。</li>
		<li>检查负载控制阀和压力阀是否打开, 然后关闭排气阀。 注意:负载块将上升到其设定的压力。</li>
		<li>等待六十年代的样品平衡。</li>
		<li>打开排气阀, 关闭压力阀, 释放压力。观察负载块回到原来的位置。</li>
		<li>松开可调节的锁臂, 并将轴承球和负载块小心地取出。</li>
		<li>在粉碎测试后测量并记录样品的压痕。</li>
		<li>把罚款筛出来。记录所收集的罚款, 并根据协议第3条测量样品的纵横比。</li>
	</ol>
</li>
</ol>

<ol>
	<li>Le Page, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Applied Heterogeneous Catalysis. , (1987).</li><li>Woodcock, C. R., Mason, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Bulk Solids Handling: An Introduction to the Practice and Technology. , (1987).</li><li>Bertolacini, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+and+Physical+Testing+of+Catalysts.">Mechanical and Physical Testing of Catalysts.</a> ACS Symposium series. , 380-383 (1989).</li><li>Wu, D. F., Zhou, J. C., Li, Y. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distribution+of+the+mechanical+strength+of+solid+catalysts.">Distribution of the mechanical strength of solid catalysts.</a> Chem Eng Res Des. 84 (12), 1152-1157 (2006).</li><li>Li, Y., Wu, D., Chang, L., Shi, Y., Wu, D., Fang, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+model+for+bulk+crushing+strength+of+spherical+catalysts.">A model for bulk crushing strength of spherical catalysts.</a> Ind Eng Chem Res. 38, 1911-1916 (1999).</li><li>Li, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+and+statistics+of+single+pellet+mechanical+strength+of+differently+shaped+catalysts.">Measurement and statistics of single pellet mechanical strength of differently shaped catalysts.</a> Powder Technol. 113, 176-184 (2000).</li><li>Staub, D., Meille, S., Le Corre, V., Chevalier, J., Rouleau, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Revisiting+the+side+crushing+test+using+the+three-point+bending+test+for+the+strength+measurement+of+catalyst+supports.">Revisiting the side crushing test using the three-point bending test for the strength measurement of catalyst supports.</a> Oil Gas Sci Technol. 70, 475-486 (2015).</li><li>Bridgwater, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+3,+Particle+Breakage+due+to+Bulk+Shear.">Chapter 3, Particle Breakage due to Bulk Shear.</a> Handbook of Powder Technology, 1st ed. 12, (2007).</li><li>Farsi, A., Xiang, J., Latham, J. P., Carlsson, M., Stitt, E. H., Marigo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Does+Shape+Matter?+FEMDEM+Estimations+of+Strength+and+Post+Failure+Behaviour+of+Catalyst+Supports.">Does Shape Matter? FEMDEM Estimations of Strength and Post Failure Behaviour of Catalyst Supports.</a> 5th International Conference on Particle-Based methods. , (2017).</li><li>Beeckman, J. W. L., Fassbender, N. A., Datz, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Length+to+Diameter+Ratio+of+Extrudates+in+Catalyst+Technology,+I.+Modeling+Catalyst+Breakage+by+Impulsive+Forces.">Length to Diameter Ratio of Extrudates in Catalyst Technology, I. Modeling Catalyst Breakage by Impulsive Forces.</a> AIChE J. 62, 639-647 (2016).</li><li>Beeckman, J. W. L., Fassbender, N. A., Datz, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Length+to+Diameter+Ratio+of+Extrudates+in+Catalyst+Technology,+II.+Bending+strength+versus+Impulsive+Forces.">Length to Diameter Ratio of Extrudates in Catalyst Technology, II. Bending strength versus Impulsive Forces.</a> AIChE J. 62, 2658-2669 (2016).</li><li>Beeckman, J. W. L., Cunningham, M., Fassbender, N. A., Datz, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Length-to-Diameter+Ratio+of+Extrudates+in+Catalyst+Technology:+III.+Catalyst+Breakage+in+a+Fixed+Bed.">Length-to-Diameter Ratio of Extrudates in Catalyst Technology: III. Catalyst Breakage in a Fixed Bed.</a> Chem. Eng. Technol. , 1844-1851 (2017).</li></ol>

作者没有什么可透露的。

碰撞引起的冲击力断裂: 在实验室跌落试验中可以测量与表面碰撞时挤出长宽比的减小。在这个测试中, 挤出物是从一个降落伞, 下降和加速由于重力, 也经历了阻力与周围的空气。
上文概述的方法仅在文献中可用, 如 Beeckman15、16中所述。直到最近, 高度的沉闷做手工测量的卡尺为大量的挤出物可能是一个贡献的因素。暴露时间的环境空气, 因此湿度应尽量减少在测量期间和之间。如果需要, 可能需要使用 N2清除或在气缸中进行干空气清除来执行 drop 测试的协议。你也可以选择让催化剂平衡在周围空气中过夜之前, 采取任何测量, 以使水分回升较少的问题。这里使用的协议和方法有好处, 它迅速地产生长宽比为超过100-300 挤出物, 因此它采取多数可变性, 可以观察与小样品从争论。
由于形状识别软件可以错误地分配此类催化剂件的长度和直径, 因此从样品中去除长度与直径比小于统一的挤出物是很重要的。因此, 最小化和更好地消除这种短挤出物的数量也很重要。因此, 建议在测试开始时与具有足够大的纵横比的挤出物一起工作, 并限制测试的影响严重性。
对于未来的工作和从一个基本的角度来看, 这将是非常有趣的研究的碰撞, 单挤出物作为一个函数的长度, 作为一个函数的下降高度, 作为一个函数的冲击角和作为角动量的功能, 提 j只有几个变量破损时, 根据原始挤出的长度确定破裂面的位置是很有趣的。这种方法也可以适用于不挤压的材料, 而是通过挤压或球形颗粒获得的, 因此可能会应用于制药工业和食品工业。
固定床应力破坏 以上概述的方法迄今为止仅在文献中提供, 如 Beeckman18中所述。对于批量粉碎强度, 必须遵循 ASTM D7084-0417中概述的标准操作协议, 以重复性为理由。
暴露时间的环境空气, 因此湿度应尽量减少在测量期间和之间。如有必要, 该协议可能需要在手套箱中进行, 以适用于散装粉碎强度。
与碰撞情况一样, 这种方法也可以适用于不挤压的材料, 而是通过按颗粒状或通过滴水或造粒获得的球形颗粒获得的。

催化剂制造是支持石化行业和相关产业的骨干。商业催化剂, 参见 Le 页1, 典型地被挤出根据被保护的商业秘密的食谱或有专利的制造方法。典型的催化剂大小范围从1毫米到大约5毫米直径和在各种各样的形状象圆筒, trilobe 或 quadrulobe 一起也与他们的空心同行的各种各样。虽然挤出催化剂的直径和截面通常控制得很好, 但单个挤出物的长度有一个更高斯的分布, 而个体长度通常范围从大约等于一直径到几个直径。一个例外是有足够大直径的挤出催化剂, 允许它们在出口模面时被切割, 而且它们的长度分布更紧。石油化工行业典型的1毫米至3毫米直径挤出催化剂的长度分布通常是由自然破损或因其内在强度而造成的强迫破碎而获得的。
Le 页1, 伍德考克2, Bertolacini3, 吴4和 Li5显示典型的催化剂性能和复杂的强度测量。在文学和商业环境中, 典型的强度测量包括单一挤出物的平均粉碎强度和大块粉碎强度。两种强度特性都用于判断催化剂是否有足够的强度在过程中生存和使用。通常也增加磨损测试, 以判断催化剂的耐磨性在过程中。尽管在商业植物中存在着催化剂强度和使用的大型数据库, 但在公开文献中很少能获得这种信息。此外, 许多催化剂配方是临时性的, 并已建立了大量的试验和错误。对催化剂制造这方面的建模仍然是一个挑战, 至少可以说。
这里应用的是从一个三点弯曲试验中获得的欧拉-伯努利模量测量所得的催化剂的弯曲强度。Li6和凯西·斯道博7关于催化剂弯曲强度的评述但它们的工作是在相当大的直径挤出物上进行的, 没有直接应用于模型催化剂断裂。弯曲强度在文献中很少被测量和报告为典型的商业催化剂大小。此外, 在催化剂制造中, 弯曲强度往往不应用于指导。
在其制造过程中或在使用期间, 对催化剂的破损进行测量和建模是很困难的。通常, 催化剂挤出长直径比是建模的基础上的经验方法, 它与强度通过幂律, 然而, 这在许多情况下仍然有一个强大的特设组件。布里奇沃特8提供了对剪切造成的颗粒破损的全面概述, 但挤出物的长度与直径比在讨论的挤出物商业范围之外。离散元方法 (DEM) 和有限元法 (FEM) 现在也被用来研究颗粒的破损, 这些方法在一个基本水平上接近这个问题。此方法的详细信息, 请参阅 Heinrich9、Wassgren10、Potyondy11、Potapov12、卡森13和波斯语14 。本文所采用的方法和技术试图通过牛顿第二定律来帮助改进建模催化剂断裂, 以确定撞击力, 并以欧拉-伯努利模量表示的强度平衡。对于固定床的荷载应力破坏, 采用了负载力和床面弯曲强度的平衡, 从而可以预测床的纵横比作为荷载的函数。重要的是测量方法本身, 必须在良好的控制条件下应用, 这一方面是本文详细的全面。例如, 众所周知的是, 催化剂的强度受到了热处理的强烈影响, 并根据使用条件, 当催化剂可以提取水分。较高的热处理温度通常会增强催化剂的含量, 而高水分的回升通常会削弱其效果。因此, 重要的是, 强度是衡量在一个催化剂, 已经看到了适当的热处理和水分是控制在必要的地方, 以便使其代表使用的催化剂, 无论是在其制造或在使用过程中。在文献中发现的很少, 具体衡量和模型的长度到直径比的催化剂挤出物, 是典型的石化行业。最近, Beeckman15,16使用了催化剂的弯曲强度来预测由于碰撞而导致的自然断裂和催化剂的强迫断裂。这里给出了催化剂长宽比 (升/D) 的具体注意, 它定义为一个代表性样品中单个催化剂挤出物的长度与直径比值的算术平均值。本文所描述的实验方法比较简单, 可以从根本上研究和比较实验测量与理论处理。
催化剂的断裂模量是衡量其抗弯强度的一种方法。莱昂哈德·欧拉欧拉和丹尼尔伯努利开发了第一个理论上酣然的方法在断裂的弹性行为和力量在1750。图 1显示了弯曲测试和断裂力Fr的示意图。对于圆柱形挤出的具体情况, 可通过以下方法计算断裂模量:
<img alt="Equation 1" src="/files/ftp_upload/57163/57163eq1.jpg">(1)
其中, σ称为破裂模量, 并具有应力维数 (Pa)。D代表挤出的直径, 而w是两个支持点之间的距离。变量s为圆柱形因子, 等于 8/π。为全面解释在实验过程中的作用力和应力, 以及如何处理不同截面形状的参考, 给出了 Beeckman16。具体地说, σ是垂直于挤出横截面的断裂的拉伸应力, 位于两个支撑点中间的极光纤中。
对于挤出与曲面的冲突, Beeckman15显示了关于挤出纵横比的两个渐近线。在多次重复的影响下, 第一个称为Φ∞的渐近线被到达。这种渐近行为很容易理解, 因为在碰撞后断裂后, 较短的催化剂动量较小, 因此在撞击过程中的作用力较小。同时, 较短的催化剂也需要更多的力从扭矩的角度来打破, 因此, 在许多影响下, 催化剂有望达到渐近长宽比Φ∞ 。当丢弃的挤出物时间足够长时, 第二个称为Φα的渐近线在一次撞击后到达. 长挤出物有比例更高的动量和断裂在几个地方沿他们的长度的第一个冲击和纵横比后碰撞到达第二个渐近线指定的Φα. 两个渐近线都可以通过回归的碰撞数据来发现, 测量长宽比作为重复撞击次数的函数:
<img alt="Equation 2" src="/files/ftp_upload/57163/57163eq2.jpg">(2)
其中Φ0是初始长宽比, Φj 是j下降后的长宽比。参数Φ∞和Φα 都具有物理机械意义, 这与影响的严重性和催化剂的强度有关。撞击的严重性可以通过改变跌落高度来改变, 尽管对于大的跌落高度, 催化剂接近终点速度, 因此严重程度会降低。
颗粒长度和粒径是催化剂在生产和使用过程中的重要特性。催化剂颗粒的大小和形状也是决定其填料特性的因素, 影响催化剂床的压降。在早期, 这些属性通常是手工测量的, 这是一个非常繁琐的过程。现在, 这些性能可以很容易获得的第一次光学扫描一个大样本的催化剂挤出物。然后, 用成像软件确定单个粒子的大小。这样可以快速准确地分析大量的粒子, 请参见 Beeckman15。这些系统被调整, 以有效地识别和测量直径在0.8 到4.0 毫米范围内的粒子, 长度可以是几个直径长。此方法使用催化剂的 "自上而下" 视图, 从而产生 "光" 直径。对于某些形状, 在将光学直径与用卡尺手动确定的直径值进行比较时, 必须注意。
催化剂和催化剂载体的大块粉碎强度试验, ASTM D7084-0417在这里使用的是公认的标准测试方法。催化剂是加载在圆柱细胞和压力 (压力) 通常适用于 5-1, 000 帕范围内, 并允许平衡。在每个压力点之后, 催化剂被卸载。催化剂的细度从催化剂样品中筛选出来, 在催化剂样品的大部分花纹, 以获得具有代表性的样品以精确测量长宽比。虽然标准散装粉碎强度试验程序集中为衡量催化剂强度而创建的罚款量, 这篇手稿集中在削减的纵横比后, 破碎作为负载的功能, 也请参见 Beeckman18.

<table border="0" cellpadding="0" cellspacing="0" style="width:799px;" width="798">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:173px;">Modulus of rupture (MOR)</td>
			<td style="width:152px;">INSTRON</td>
			<td style="width:311px;">MODEL 5942 SINGLE COLUMN TABLE TOP</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Modulus of rupture (MOR)</td>
			<td>INSTRON</td>
			<td>10 NEWTON LOAD CELL</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Modulus of rupture (MOR)</td>
			<td>INSTRON</td>
			<td>50 NEWTON LOAD CELL</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Modulus of rupture (MOR)</td>
			<td>INSTRON</td>
			<td>BLEUHILL 3 SOFTWARE</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Filter</td>
			<td>VWR</td>
			<td>BUCHNER FILTER</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:20px;">Aspect ratio (avg L/D)</td>
			<td>EPSON</td>
			<td style="width:311px;">PERFECTION V700 PHOTO INSTRUMENT</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Software</td>
			<td>CASCADE DATA SYSTEMS</td>
			<td>ALIAS 3-4 SOFTWARE</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Riffling</td>
			<td>HUMBOLDT MFG. Co</td>
			<td>SPINNING RIFFLER</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Riffling</td>
			<td>HUMBOLDT MFG. Co</td>
			<td>RIFFLE -TYPE SAMPLE DIVIDER</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sieve screen</td>
			<td>VWR</td>
			<td>US MESH SIEVE SCREEN, # 16</td>
			<td></td>
		</tr>
	</tbody>
</table>

predicting catalyst extrudate breakage based on the modulus of rupture

挤压催化剂的机械强度及其在固定床上的碰撞对表面或受压载荷的自然或强迫断裂是催化剂技术中的重要现象。以其弯曲强度或弯曲强度来测量催化剂的机械强度。该技术在应用于工业用典型尺寸的商用催化剂方面相对较新。在挤出物通过垂直管道中的环境空气后, 对表面碰撞后的催化剂破损进行测量。运用牛顿第二定律, 从理论上对冲击力进行量化。根据散装粉碎强度试验的标准程序, 对固定床内应力引起的催化剂破损进行了测量。这里的小说重点是测量挤出物的长度和直径比的减少作为应力的函数。

碰撞破坏: 为了给读者一个关于挤出对表面影响的复杂性的想法, 人们认为提供一些快照图片是有益的, 在当时我们已经有了最高的帧速度 (1万帧/秒)。图 2显示了这种高速摄影, 并捕获了单个挤出物在影响聚碳酸酯表面时的破损。这个表面有额外的优势, 它显示了挤出的方法之前, 反射率的影响, 从表面上, 并允许明确定义的接触实例。受影响的破损持续时间似乎小于 10-4 , 而完全影响历史记录显示为非常复杂。在碰撞过程中, 挤出作为时间函数所经历的力量是非常尖锐和不规则的。平均减速定义为撞击速度超过接触时间只是一个粗略的估计发生了什么。当乘以挤出的质量它再是力量的仅粗略的估计。
在25种不同的催化剂上确定了渐近长宽比Φ∞ , 并在 Beeckman16中给出了它们的性质。使用 Eq 进行非线性回归, 得到了每个催化剂的模型参数Φ∞ . (2) 介绍中所示。
图 3显示了同一催化剂批次中多次从不同高度跌落的典型新鲜催化剂的纵横比的降低。此序列清楚地显示了向渐近纵横比的行外, Φ∞为不同的降高度i. e。不同的严重性。Beeckman16表明, 在秋季, 由于环境空气的阻力减慢了挤出物的加速度, 最终达到了大落差的终点速度, 大跌落高度的纵横比差异变得越来越小。高度。研究还表明, 挤出物遵循二阶断裂定律, 解释了纵横比趋势曲线的形状与连续滴数的变化规律。图 4显示了与图 3中相同的催化剂的纵横比, 但现在从一个单一的影响 (每个数据点都是从一个挤出生成) 开始使用非常长的选择催化剂链。实体符号表示每组大小的纵横比的平均值。这显示了第二个渐近线Φα的存在, 以及当长度与直径比率从非常有限的挤出物中获得时所涉及的误差线的欣赏。
在碰撞过程中挤出的脉冲力可以通过牛顿第二定律来发现。结果表明, 在渐近长宽比Φ∞中, 将断裂力等同于脉冲力会导致以下相关性:
<img alt="Equation 3" src="/files/ftp_upload/57163/57163eq3.jpg">(3)
由以下所给出的归一化无量纲群:
<img alt="Equation 4" src="/files/ftp_upload/57163/57163eq4.jpg">(4)
其中σ、Ψ、 p、 D和g分别为断裂的催化剂模量、催化剂形状因子、催化剂密度、催化剂直径和重力加速度。影响S∞的规范化无量纲严重性可以表示为:
<img alt="Equation 5" src="/files/ftp_upload/57163/57163eq5.jpg">(5)
v的撞击速度在哪里, Δt是碰撞的持续时间, C是碰撞交互因子。进一步表明, 对于总共25种不同尺寸、形状和化学组成的催化剂, 在跌落试验中, 在第一近似下测试, 组实质上是一个常量. <img alt="Equation 5b" src="/files/ftp_upload/57163/57163eq5b.jpg">
固定床应力破坏: 对表 1中显示的五催化剂进行了各种压力下的大块粉碎试验研究。在一定的压力下, 这里称为临界压力, 在床的催化剂长宽比上没有发生根本性的变化。一旦压力增加到这个临界值之上, 催化剂挤出开始分解, 并且床的纵横比自然地调整, 直到床的弯曲的力量再能承受应用的重音。实验结果和预测结果的比较示例显示在图 5中。预测值将显示为实曲线, 并从挤出物催化剂的起始长宽比Φ0开始获得, 直到到达临界压力 P c 为止. 此后, 纵横比的值随荷载压力的负一第三幂减小。
找到一张床承受催化剂破损的最大允许载荷的方法是, 在破裂时利用负载力与催化剂床强度的平衡。
Beeckman18表明, 与负载力平衡的催化剂的纵横比可以用以下描述:
<img alt="Equation 6" src="/files/ftp_upload/57163/57163eq6.jpg">(6)
其中Φ是挤出长宽比, 而是r 是由以下内容提供的无量纲组:
<img alt="Equation 7" src="/files/ftp_upload/57163/57163eq7.jpg">(7)
如果σ是破裂的模量, 则s与碰撞时的挤出形状因子相同, 而P是应力。Ψ的值由床填料和床粒到颗粒力相互作用确定, 作者给出了 61/6或大约1.35 Ψ的理论值。
综上所述, 如果在大粉碎强度测试中加载了挤出物床, 并且应用了应力 p, 则挤出物将在应用 应力P 下的整个床上断裂, 以 Eq 给出平均值. (6)。因此, 具有起始长宽比Φ0的床具有临界压力Pc 它可以承受的:
<img alt="Equation 8" src="/files/ftp_upload/57163/57163eq8.jpg">(8)
<table fo:keep-together.within-page="1"><tbody>
<tr>
<td>催化剂</td>
			<td>形状</td>
			<td>D、直径</td>
			<td>Φ0 , 初始长宽比</td>
			<td>s, 形状因素</td>
			<td>ρ, 密度</td>
			<td>σ</td>
			<td>Pc, 临界应力</td>
		</tr>
<tr>
<td></td>
			<td></td>
			<td>m</td>
			<td>(-)</td>
			<td>(-)</td>
			<td>魔芋-3
</td>
			<td>M p a</td>
			<td>Kpa</td>
		</tr>
<tr>
<td>一个</td>
			<td>QUADRULOBE</td>
			<td>1.43E-03</td>
			<td>3.18</td>
			<td>2.20</td>
			<td>1250</td>
			<td>0.81</td>
			<td>27。9</td>
		</tr>
<tr>
<td>B</td>
			<td>缸</td>
			<td>9.50E-04</td>
			<td>5.92</td>
			<td>2.55</td>
			<td>750</td>
			<td>1.38</td>
			<td>6。4</td>
		</tr>
<tr>
<td>C</td>
			<td>缸</td>
			<td>8.30E-04</td>
			<td>7.48</td>
			<td>2.55</td>
			<td>1870</td>
			<td>2.83</td>
			<td>6。5</td>
		</tr>
<tr>
<td>D</td>
			<td>TRILOBE</td>
			<td>2.89E-03</td>
			<td>2.28</td>
			<td>2.28</td>
			<td>970</td>
			<td>0.76</td>
			<td>69。3</td>
		</tr>
<tr>
<td>电子邮件</td>
			<td>缸</td>
			<td>1.55E-03</td>
			<td>3.54</td>
			<td>2.55</td>
			<td>那</td>
			<td>1.37</td>
			<td>39。7</td>
		</tr>
</tbody></table>表 1:在大块粉碎研究中使用的催化剂及其性能.表1显示了催化剂的性质和衍生应力特性, 允许计算在压缩过程中, 在大块粉碎强度测量中的纵横比的降低。从 Beeckman et 201718中改编
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57163/57163fig1.jpg"> 图 1: 三点弯曲的催化剂挤出的外力 F.催化剂的示意图表示法和在两个支撑点中间应用的力的位置, 用于测定破裂的模量。弯曲的量是高度夸张的。根据弹性理论, 轴向应力在挤出的顶部是压缩的, 轴向应力在挤出的底部是拉伸的。因此, 有一个轴与零应力, 这被称为质心。当底部的拉应力达到材料的抗拉强度或破裂的模量时, 挤出断裂在极端纤维位于底部和传播非常快速完成挤出失败。从 Beeckman et . 2016 16改编而成。<a href="/files/ftp_upload/57163/57163fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/57163/57163fig2.jpg"> 图 2: 挤出物对空聚碳酸酯表面的影响。高速摄影显示一个序列的两个催化剂挤出 impingements 对聚碳酸酯表面。镜头是0.1 毫秒, 除了对方。从 Beeckman et . 2016 16改编而成。<a href="/files/ftp_upload/57163/57163fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/57163/57163fig3.jpg"> 图 3: 纵横比作为放置高度的函数和影响的数量.纵横比作为一个函数的下降高度或严重性和数量的影响。对于高降高度, 渐近长宽比变化仅小, 因为挤出物到达他们的终端速度。从 Beeckman et . 2016 15改编而成。<a href="/files/ftp_upload/57163/57163fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/57163/57163fig4.jpg"> 图 4: 在具有较大初始长宽比的催化剂 A 1 滴后长宽比.在下拉前有大纵横比的一滴挤出物后的纵横比。对于这样长的挤出物, 第二个渐近线变得明显地是可见的, 即使在存在大量的实验错误由于使用的挤出物的有限的数量。从 Beeckman et . 2016 15改编而成。<a href="/files/ftp_upload/57163/57163fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/57163/57163fig5.jpg"> 图 5: 催化剂长宽比与负载应力 A.将长宽比作为应用载荷应力在大体积粉碎强度测量中的作用根据方法 ASTM D7084-04。当压力增加时, 长宽比保持恒定直到临界压力达到随后催化剂断裂到更小和更小的价值。每一个数据点是一个单独的测量与新鲜的催化剂从一开始。改编自 Beeckman et 201718<a href="/files/ftp_upload/57163/57163fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

Watch this Scientific Journal Video about Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture at JoVE.com

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

在这里, 我们提出了一个协议, 以测量一个挤压催化剂的断裂模数和断裂的催化剂挤出物的碰撞表面或压缩在固定床上。

基于断裂模量的催化剂挤出断裂预测

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...

predicting-catalyst-extrudate-breakage-based-on-the-modulus-of-rupture

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8.2K 次观看.  ExxonMobil Research and Engineering Company. 在这里, 我们提出了一个协议, 以测量一个挤压催化剂的断裂模数和断裂的催化剂挤出物的碰撞表面或压缩在固定床上。

视频: Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

The customized techniques developed in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators are presented. The protocols to obtain and characterize these resonators are detailed, and an explanation of some of their applications in microwave photonics is given.

基于微波光子系统回音壁模式谐振器

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various ...

科研

工程学

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75&#176;. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm2, respectively, has decreased the CA to near 15&#176;, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer&#8217;s surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of&#160;the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm2 and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103&#176;. The XPS results indicate ArF laser induced formation of Si&#8211;(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

We report on a process of in situ alteration of HF treated Si (001) surface into a hydrophilic or hydrophobic state by irradiating samples in microfluidic chambers filled with&#160;H2O2/H2O solution (0.01%-0.5%) or methanol solutions using pulsed UV laser of a relative low pulse fluence.

硅表面润湿性的选择区域改性脉冲紫外激光照射在液体环境

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of ...

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior

For slender and lightweight structures, vibration serviceability is a matter of growing concern, often constituting the critical design requirement. With designs governed by the dynamic performance under human-induced loads, a strong demand exists for the verification and refinement of currently available load models. The present contribution uses a 3D inertial motion tracking technique for the characterization of the in-field pedestrian behavior. The technique is first tested in laboratory experiments with simultaneous registration of the corresponding ground reaction forces. The experiments include walking persons as well as rhythmical human activities such as jumping and bobbing. It is shown that the registered motion allows for the identification of the time variant pacing rate of the activity. Together with the weight of the person and the application of generalized force models available in literature, the identified time-variant pacing rate allows to characterize the human-induced loads. In addition, time synchronization among the wireless motion trackers allows identifying the synchronization rate among the participants. Subsequently, the technique is used on a real footbridge where both the motion of the persons and the induced structural vibrations are registered. It is shown how the characterized in-field pedestrian behavior can be applied to simulate the induced structural response. It is demonstrated that the in situ identified pacing rate and synchronization rate constitute an essential input for the simulation and verification of the human-induced loads. The main potential applications of the proposed methodology are the estimation of human-structure interaction phenomena and the development of suitable models for the correlation among pedestrians in real traffic conditions.

A protocol is presented for the characterization of the in-field pedestrian behavior and the simulation of the resulting structural response. Field-tests demonstrate that the in situ identified pacing rate and synchronization rate among the participants constitute an essential input for the simulation and verification of the human-induced loads.

基于该特征场行人行为人类引起的振动模拟

For slender and lightweight structures, vibration serviceability is a matter of growing concern, often constituting the critical design requirement. With ...

Strain Sensing Based on Multiscale Composite Materials Reinforced with Graphene Nanoplatelets

The electrical response of NH2-functionalized graphene nanoplatelets composite materials under strain was studied. Two different manufacturing methods are proposed to create the electrical network in this work: (a) the incorporation of the nanoplatelets into the epoxy matrix and (b) the coating of the glass fabric with a sizing filled with the same nanoplatelets. Both types of multiscale composite materials, with an in-plane electrical conductivity of ~10-3 S/m, showed an exponential growth of the electrical resistance as the strain increases due to distancing between adjacent functionalized graphene nanoplatelets and contact loss between overlying ones. The sensitivity of the materials analyzed during this research, using the described procedures, has been shown to be higher than commercially available strain gauges. The proposed procedures for self-sensing of the structural composite material would facilitate the structural health monitoring of components in difficult to access emplacements such as offshore wind power farms. Although the sensitivity of the multiscale composite materials was considerably higher than the sensitivity of metallic foils used as strain gauges, the value reached with NH2 functionalized graphene nanoplatelets coated fabrics was nearly an order of magnitude superior. This result elucidated their potential to be used as smart fabrics to monitor human movements such as bending of fingers or knees. By using the proposed method, the smart fabric could immediately detect the bending and recover instantly. This fact permits precise monitoring of the time of bending as well as the degree of bending.

The integration of conductive nanoparticles, such as graphene nanoplatelets, into glass fiber composite materials creates an intrinsic electrical network susceptible to strain. Here, different methods to obtain strain sensors based on the addition of graphene nanoplatelets into the epoxy matrix or as a coating on glass fabrics are proposed.

基于多尺度复合材料的增强与石墨烯纳米片应变传感

The electrical response of NH2-functionalized graphene nanoplatelets composite materials under strain was studied. Two different manufacturing methods are ...

Effect of Bending on the Electrical Characteristics of Flexible Organic Single Crystal-based Field-effect Transistors

The charge transport in an organic semiconductor depends highly on the molecular packing in the crystal, which influences the electronic coupling immensely. However, in soft electronics, in which organic semiconductors play a critical role, the devices will be bent or folded repeatedly. The effect of bending on the crystal packing and thus the charge transport is crucial to the performance of the device. In this manuscript, we describe the protocol to bend a single crystal of 5,7,12,16-tetrachloro-6,13-diazapentacene (TCDAP) in the field-effect transistor configuration and to obtain reproducible I-V characteristics upon bending the crystal. The results show that bending a field-effect transistor prepared on a flexible substrate results in nearly reversible yet opposite trends in charge mobility, depending on the bending direction. The mobility increases when the device is bent toward the top gate/dielectric layer (upward, compressive state) and decreases when bent toward the crystal/substrate side (downward, tensile state). The effect of bending curvature was also observed, with greater mobility change resulting from higher bending curvature. It is suggested that the intermolecular &#960;-&#960; distance changes upon bending, thereby influencing the electronic coupling and the subsequent carrier transport ability.

This manuscript describes the bending process of an organic single crystal-based field-effect transistor to maintain a functioning device for electronic property measurement. The results suggest that bending causes changes in the molecular spacing in the crystal and thus in the charge hopping rate, which is important in flexible electronics.

弯曲对基于晶体的柔性有机单场效应晶体管的电气特性的影响

The charge transport in an organic semiconductor depends highly on the molecular packing in the crystal, which influences the electronic coupling ...

The Modular Design and Production of an Intelligent Robot Based on a Closed-Loop Control Strategy

Intelligent robots are part of a new generation of robots that are able to sense the surrounding environment, plan their own actions and eventually reach their targets. In recent years, reliance upon robots in both daily life and industry has increased. The protocol proposed in this paper describes the design and production of a handling robot with an intelligent search algorithm and an autonomous identification function.
First, the various working modules are mechanically assembled to complete the construction of the work platform and the installation of the robotic manipulator. Then, we design a closed-loop control system and a four-quadrant motor control strategy, with the aid of debugging software, as well as set steering gear identity (ID), baud rate and other working parameters to ensure that the robot achieves the desired dynamic performance and low energy consumption. Next, we debug the sensor to achieve multi-sensor fusion to accurately acquire environmental information. Finally, we implement the relevant algorithm, which can recognize the success of the robot&#39;s function for a given application.
The advantage of this approach is its reliability and flexibility, as the users can develop a variety of hardware construction programs and utilize the comprehensive debugger to implement an intelligent control strategy. This allows users to set personalized requirements based on their needs with high efficiency and robustness.

We present a protocol on modular design and production of intelligent robots to help scientific and technical workers design intelligent robots with special production tasks based on personal needs and individualized design.

基于闭环控制策略的智能机器人模块化设计与制作

Intelligent robots are part of a new generation of robots that are able to sense the surrounding environment, plan their own actions and eventually reach ...

Fabrication of Flexible Image Sensor Based on Lateral NIPIN Phototransistors

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, but several challenging points remain, such as a low absorption efficiency due to a thin active layer and low flexibility. We present an advanced method to fabricate a flexible phototransistor array with an improved electrical performance. The outstanding electrical performance is driven by a low dark current owing to deep impurity doping. Stretchable and flexible metal interconnectors simultaneously offer electrical and mechanical stabilities in a highly deformed state. The protocol explicitly describes the fabrication process of the phototransistor using a thin silicon membrane. By measuring I-V characteristics of the completed device in deformed states, we demonstrate that this approach improves the mechanical and electrical stabilities of the phototransistor array. We expect that this approach to a flexible phototransistor can be widely used for the applications of not only next-generation imaging systems/optoelectronics but also wearable devices such as tactile/pressure/temperature sensors and health monitors.

We present a detailed method to fabricate a deformable lateral NIPIN phototransistor array for curved image sensors. The phototransistor array with an open mesh form, which is composed of thin silicon islands and stretchable metal interconnectors, provides flexibility and stretchability. The parameter analyzer characterizes the electrical property of the fabricated phototransistor.

基于侧向 NIPIN Phototransistors 的柔性图像传感器的研制

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, ...

O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression

Unlike macroscopic process variables, near-infrared spectroscopy provides process information at the molecular level and can significantly improve the prediction of the components in industrial processes. The ability to record spectra for solid and liquid samples without any pretreatment is advantageous and the method is widely used. However, the disadvantages of analyzing high-dimensional near-infrared spectral data include information redundancy and multicollinearity of the spectral data. Thus, we propose to use partial least squares regression method, which has traditionally been used to reduce the data dimensionality and eliminate the collinearity between the original features. We implement the method for predicting the o-cresol concentration during the production of polyphenylene ether. The proposed approach offers the following advantages over component regression prediction methods: 1) partial least squares regression solves the multicollinearity problem of the independent variables and effectively avoids overfitting, which occurs in a regression analysis due to the high correlation between the independent variables; 2) the use of the near-infrared spectra results in high accuracy because it is a non-destructive and non-polluting method to obtain information at microscopic and molecular scales.

The protocol describes a method of predicting o-cresol concentration during the production of polyphenylene ether using near-infrared spectroscopy and partial least squares regression. To describe the process more clearly and completely, an example of predicting the o-cresol concentration during the production of polyphenylene is used to clarify the steps.

O-cresol 浓度在线测量基于近红外光谱通过部分最小平方回归

Unlike macroscopic process variables, near-infrared spectroscopy provides process information at the molecular level and can significantly improve the ...

Implementation of a Nonlinear Microscope Based on Stimulated Raman Scattering

Stimulated Raman scattering (SRS) microscopy uses near-infrared excitation light; therefore, it shares many multi-photon microscopic imaging properties. SRS imaging modality can be obtained using commercial laser-scanning microscopes by equipping with a non-descanned forward detector with proper bandpass filters and lock-in amplifier (LIA) detection scheme. A schematic layout of a typical SRS microscope includes the following: two pulsed laser beams, (i.e., the pump and probe directed in a scanning microscope), which must be overlapped in both space and time at the image plane, then focused by a microscope objective into the sample through two scanning mirrors (SMs), which raster the focal spot across an x-y plane. After interaction with the sample, transmitted output pulses are collected by an upper objective and measured by a forward detection system inserted in an inverted microscope. Pump pulses are removed by a stack of optical filters, whereas the probe pulses that are the result of the SRS process occurring in the focal volume of the specimen are measured by a photodiode (PD). The readout of the PD is demodulated by the LIA to extract the modulation depth. A two-dimensional (2D) image is obtained by synchronizing the forward detection unit with the microscope scanning unit. In this paper, the implementation of an SRS microscope is described and successfully demonstrated, as well as the reporting of label-free images of polystyrene beads with diameters of 3 &#181;m. It is worth noting that SRS microscopes are not commercially available, so in order to take advantage of these characteristics, the homemade construction is the only option. Since SRS microscopy is becoming popular in many fields, it is believed that this careful description of the SRS microscope implementation can be very useful for the scientific community.

In this manuscript, the implementation of a stimulated Raman scattering (SRS) microscope, obtained by the integration of an SRS experimental set-up with a laser scanning microscope, is described. The SRS microscope is based on two femtosecond (fs) laser sources, a Ti-Sapphire (Ti:Sa) and synchronized optical parametric oscillator (OPO).

基于刺激拉曼散射的非线性显微镜的实现

Stimulated Raman scattering (SRS) microscopy uses near-infrared excitation light; therefore, it shares many multi-photon microscopic imaging properties. ...

In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx

Resistive switching crossbar architecture is highly desired in the field of digital memories due to low cost and high-density benefits. Different materials show variability in resistive switching properties due to the intrinsic nature of the material used, leading to discrepancies in the field because of underlying operation mechanisms. This highlights a need for a reliable technique to understand mechanisms using nanostructural observations. This protocol explains a detailed process and methodology of in&#160;situ nanostructural analysis as a result of electrical biasing using transmission electron microscopy (TEM). It provides visual and reliable evidence of underlying nanostructural changes in real time memory operations. Also included is the methodology of fabrication and electrical characterizations for asymmetric crossbar structures incorporating amorphous vanadium oxide. The protocol explained here for vanadium oxide films can be easily extended to any other materials in a metal-dielectric-metal sandwiched structure. Resistive switching crossbars are predicted to serve the programmable logic and neuromorphic circuits for next-generation memory devices, given the understanding of the operation mechanisms. This protocol reveals the switching mechanism in a reliable, timely, and cost-effective way in any type of resistive switching materials, and thereby predicts the device&#39;s applicability.

In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx

Presented here is a protocol for analyzing nanostructural changes during in&#160;situ biasing with transmission electron microscopy (TEM) for a stacked metal-insulator-metal structure. It has significant applications in resistive switching crossbars for the next generation of programmable logic circuits and neuromimicking hardware, to reveal their underlying operation mechanisms and practical applicability.

基于断裂模量的催化剂挤出断裂预测

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基于微波光子系统回音壁模式谐振器

硅表面润湿性的选择区域改性脉冲紫外激光照射在液体环境

基于该特征场行人行为人类引起的振动模拟

基于多尺度复合材料的增强与石墨烯纳米片应变传感

弯曲对基于晶体的柔性有机单场效应晶体管的电气特性的影响

基于闭环控制策略的智能机器人模块化设计与制作

基于侧向 NIPIN Phototransistors 的柔性图像传感器的研制

O-cresol 浓度在线测量基于近红外光谱通过部分最小平方回归

基于刺激拉曼散射的非线性显微镜的实现

基于混合相位a-VO_x的不对称横杆的偏置和制造现场传输电子显微镜

基于断裂模量的催化剂挤出断裂预测

摘要

探索更多视频

此视频中的章节

基于微波光子系统回音壁模式谐振器

硅表面润湿性的选择区域改性脉冲紫外激光照射在液体环境

基于该特征场行人行为人类引起的振动模拟

基于多尺度复合材料的增强与石墨烯纳米片应变传感

弯曲对基于晶体的柔性有机单场效应晶体管的电气特性的影响

基于闭环控制策略的智能机器人模块化设计与制作

基于侧向 NIPIN Phototransistors 的柔性图像传感器的研制

O-cresol 浓度在线测量基于近红外光谱通过部分最小平方回归

基于刺激拉曼散射的非线性显微镜的实现

基于混合相位a-VOx的不对称横杆的偏置和制造现场传输电子显微镜

基于混合相位a-VO_x的不对称横杆的偏置和制造现场传输电子显微镜