这项工作得到了 nasa/SSERVI 建模等离子体、大气层和宇宙尘埃 (撞击) 和 nasa 太阳能系统工作计划 (赠款号: NNX16AO81G) 的支持。

1. 真空室设置
<ol><li>将绝缘橡胶板 (直径为0.2 厘米, 5 厘米) 与一个中心孔1.9 厘米直径在绝缘板上 (2 厘米厚和20厘米直径) (图 2a, b)。负载绝缘, 不规则形状的尘埃粒子 (直径在10和50微米之间) 在洞中。</li>
	<li>将绝缘板放置在真空室中间的金属板上。用陶瓷支架将金属板从腔室中电隔离。</li>
	<li>打开真空泵 (由机械粗加工泵支持的涡轮泵), 以达到 10-6乇的基本压力。演示实验是在圆柱形不锈钢真空室, 直径50厘米和28厘米高 (图 2c) 中进行的。</li>
	<li>用摄像机以30帧/秒 (fps) 或高速 (> 2000 fps) 相机的速度记录尘埃运动和放样。使用 LED 灯的最大照明相当于 > 500W incandesce 光, 以产生足够的照明粉尘颗粒, 以高质量的视频记录。 注: 使用橡胶是因为它的深色, 最大限度地减少光反射到相机。浅色粉尘颗粒应用于更好的拍摄, 因为颜色对比的黑色橡胶表面。该厚绝缘板用于消除绝缘板表面与金属板之间的电场对粉尘充电和动员的影响。在这个示范, 火星模拟 (JSC-Mars-1, 筛到平均直径38-48 微米, 质量密度为1.9 克/厘米-3和主要组成的, 即2 28) 使用, 这类似于一般的壤粉尘的无气体在内部太阳系。还测试了各种其他类型的绝缘尘埃粒子, 如月球模拟 (JSC-1)、月球模拟高地 (LHT) 和纯二氧化硅粉尘。</li>
</ol>2. 与电子束电子接触热等离子体
<ol><li>将钍钨长丝 (0.1 毫米厚和3厘米长) 连接至电极馈并安装在燃烧室的顶部。然后将腔体泵入基压。</li>
	<li>用氩气将真空室填充到 0.5 mTorr 的压力。</li>
	<li>打开电源并将偏置电压设置为灯丝的-120 V。</li>
	<li>增加加热电流的发热电压为 2A, 直到发射电流达到所需值 (少量 mA)。能量为 120 eV 的电子将从灯丝中发出。 注意: 这些光束状的初级电子会影响中性氩原子, 导致它们被电离, 并产生一个电子温度约 2 eV 的等离子体。一大小部分的主光束电子直接到达尘土飞扬的表面, 而不会与中性原子发生碰撞。尘埃粒子因此暴露在热等离子体和电子束电子。</li>
	<li>为了显示高能束电子在尘埃传输中的作用, 在尘埃粒子上使用一种可替代的方法来创建热等离子体。<ol>
<li>打开房间底部的备用灯丝, 其偏置电压为-40 伏, 排放电流高达400毫安 (图 2a)。从灯丝发出的主要电子将被金属板阻挡在灰尘颗粒休息的侮辱板上 (图 2a, b)。</li>
		<li>变化的发射电流, 以改变表面上的电场。更高的电流产生更高的等离子密度, 更薄的鞘, 因而更大的电场。</li>
	</ol>
</li>
</ol>3. 只接触电子束电子
<ol><li>在上面的实验中, 用上面的灯丝来设置实验。</li>
	<li>在基压 10-6乇 (i. e) 下打开顶丝, 在会议厅中没有氩气。没有等离子被创造, 而只有 120 eV 光束电子发出的灯丝轰击尘埃粒子。</li>
	<li>用两种不同的模式操作灯丝。<ol>
<li>将偏置电压设置为-120 伏, 然后增加加热电压直至发射电流达到数毫安。</li>
		<li>增加加热电压达到所需的加热电流 ~ 2 a, 然后将偏压从0伏逐渐增加到-120 伏, 以少量 mA 的发射电流发射电子。</li>
	</ol>
</li>
</ol>4. 只接触紫外线辐射
<ol><li>用 UV 灯 (图 2b) 替换顶部灯丝, 并将该腔体向下泵入底座压力。使用氙准分子欧司朗灯, 它发出 172 nm 波长的紫外线光。相应的光子能是 7.2 eV, 大于灰尘表面的工作功能 (~ 5.5 eV) 为了发射光电子。 注: 辐射更高能量光子的波长较短的紫外线, 预计会在尘埃粒子上产生更多的电荷, 因此可以根据修补后的电荷模型26,27来增加更多的动员。</li>
	<li>打开紫外线灯辐射尘埃粒子。在演示中, 光子辐照度是40兆瓦/厘米-2在紫外线源和 ~ 16 兆瓦/cm-2在尘土飞扬的表面。</li>
</ol>

<ol>
	<li>Criswell, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Horizon-glow+and+the+motion+of+lunar+dust.">Horizon-glow and the motion of lunar dust.</a> Photon and Particle Interactions with Surfaces in Space. , 545-556 (1973).</li><li>Rennilson, J. J., Criswell, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surveyor+observations+of+lunar+horizon-glow.">Surveyor observations of lunar horizon-glow.</a> Moon. 10 (2), 121-142 (1974).</li><li>Colwell, J. E., Batiste, S., Hor&#225;nyi, M., Robertson, S., Sture, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lunar+surface:+Dust+dynamics+and+regolith+mechanics.">Lunar surface: Dust dynamics and regolith mechanics.</a> Rev. Geophys. 45, RG2006 (2007).</li><li>McCoy, J. E., Criswell, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+for+a+high+latitude+distribution+of+lunar+dust.">Evidence for a high latitude distribution of lunar dust.</a> The 5th Proc. Lunar Sci. Conf. , 2991 (1974).</li><li>Zook, H. A., McCoy, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+scale+lunar+horizon+glow+and+a+high+altitude+lunar+dust+exosphere.">Large scale lunar horizon glow and a high altitude lunar dust exosphere.</a> Geophys. Res. Lett. 18 (11), 2117-2120 (1991).</li><li>Smith, B. A., 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=Encounter+with+Saturn+-+Voyager-1+imaging+science+results.">Encounter with Saturn - Voyager-1 imaging science results.</a> Science. 212 (4491), 163-191 (1981).</li><li>Smith, B. A., 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=A+new+look+at+the+Saturn+system+-+the+Voyager-2+images.">A new look at the Saturn system - the Voyager-2 images.</a> Science. 215 (4532), 504-537 (1982).</li><li>Mitchell, C. J., Hor&#225;nyi, M., Havnes, O., Porco, C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Saturn's+spokes:+Lost+and+found.">Saturn's spokes: Lost and found.</a> Science. 311 (5767), 1587-1589 (2006).</li><li>Robinson, M. S., Thomas, P. C., Veverka, J., Murchie, S., Carcich, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+nature+of+ponded+deposits+on+Eros.">The nature of ponded deposits on Eros.</a> Nature. 413 (6854), 396-400 (2001).</li><li>Thomas, N., 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=Redistribution+of+particles+across+the+nucleus+of+comet+67P/Churyumov-Gerasimenko.">Redistribution of particles across the nucleus of comet 67P/Churyumov-Gerasimenko.</a> Astron. Astrophys. 583, A17 (2015).</li><li>Vernazza, P., 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=High+surface+porosity+as+the+origin+of+emissivity+features+in+asteroid+spectra.">High surface porosity as the origin of emissivity features in asteroid spectra.</a> Icarus. 221 (2), 1162-1172 (2012).</li><li>Hirata, N., Miyamoto, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dust+levitation+as+a+major+resurfacing+process+on+the+surface+of+a+saturnian+icy+satellite+Atlas.">Dust levitation as a major resurfacing process on the surface of a saturnian icy satellite Atlas.</a> Icarus. 220 (1), 106-113 (2012).</li><li>Garrick-Bethell, I., Head, J. W., Pieters, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectral+properties,+magnetic+fields,+and+dust+transport+at+lunar+swirls.">Spectral properties, magnetic fields, and dust transport at lunar swirls.</a> Icarus. 212 (2), 480-492 (2011).</li><li>Murphy, T. W., 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=Long-term+degradation+of+optical+devices+on+the+Moon.">Long-term degradation of optical devices on the Moon.</a> Icarus. 208 (1), 31-35 (2010).</li><li>Sheridan, T. E., Goree, J., Chiu, Y. T., Rairden, R. L., Kiessling, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Observation+of+dust+shedding+from+material+bodies+in+a+plasma.">Observation of dust shedding from material bodies in a plasma.</a> J. Geophys. Res. 97 (A3), 2935-2942 (1992).</li><li>Flanagan, T. M., Goree, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dust+release+from+surfaces+exposed+to+plasma.">Dust release from surfaces exposed to plasma.</a> Phys. Plasmas. 13 (12), 123504 (2006).</li><li>Sickafoose, A. A., Colwell, J. E., Hor&#225;nyi, M., Robertson, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+levitation+of+dust+grains+in+a+plasma+sheath.">Experimental levitation of dust grains in a plasma sheath.</a> J. Geophys. Res. 107 (A11), 1408 (2002).</li><li>Wang, X., Hor&#225;nyi, M., Robertson, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experiments+on+dust+transport+in+plasma+to+investigate+the+origin+of+the+lunar+horizon+glow.">Experiments on dust transport in plasma to investigate the origin of the lunar horizon glow.</a> J. Geophys. Res. 114, A05103 (2009).</li><li>Wang, X., Hor&#225;nyi, M., Robertson, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+of+dust+transport+on+the+lunar+surface+in+a+laboratory+plasma+with+an+electron+beam.">Investigation of dust transport on the lunar surface in a laboratory plasma with an electron beam.</a> J. Geophys. Res. 115, A11102 (2010).</li><li>Wang, X., Hor&#225;nyi, M., Robertson, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dust+transport+near+electron+beam+impact+and+shadow+boundaries.">Dust transport near electron beam impact and shadow boundaries.</a> Planet. Space Sci. 59 (14), 1791-1794 (2011).</li><li>Hartzell, C. M., Wang, X., Scheeres, D. J., Hor&#225;nyi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+demonstration+of+the+role+of+cohesion+in+electrostatic+dust+lofting.">Experimental demonstration of the role of cohesion in electrostatic dust lofting.</a> Geophys. Res. Lett. 40 (6), 1038-1042 (2013).</li><li>Wang, X., Hor&#225;nyi, M., Sternovsky, Z., Robertson, S., Morfill, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+laboratory+model+of+the+lunar+surface+potential+near+boundaries+between+sunlit+and+shadowed+regions.">A laboratory model of the lunar surface potential near boundaries between sunlit and shadowed regions.</a> Geophys. Res. Lett. 34 (16), L16104 (2007).</li><li>Ding, N., Wang, J., Polansky, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+dust+charging+on+a+lunar+regolith+simulant+surface.">Measurement of dust charging on a lunar regolith simulant surface.</a> IEEE Trans. Plasma Sci. 41 (12), 3498-3504 (2013).</li><li>Sheridan, T. E., Hayes, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Charge+fluctuations+for+particles+on+a+surface+exposed+to+plasma.">Charge fluctuations for particles on a surface exposed to plasma.</a> Appl. Phys. Lett. 98 (9), 091501 (2011).</li><li>Heijmans, L. C. J., Nijdam, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dust+on+a+surface+in+a+plasma:+A+charge+simulation.">Dust on a surface in a plasma: A charge simulation.</a> Phys. Plasmas. 23 (6), 043703 (2016).</li><li>Wang, X., Schwan, J., Hsu, H. -. W., Gr&#252;n, E., Hor&#225;nyi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dust+charging+and+transport+on+airless+planetary+bodies.">Dust charging and transport on airless planetary bodies.</a> Geophys. Res. Lett. 43 (12), 6103-6110 (2016).</li><li>Schwan, J., Wang, X., Hsu, H. -. W., Gr&#252;n, E., Hor&#225;nyi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+charge+state+of+electrostatically+transported+dust+on+regolith+surfaces.">The charge state of electrostatically transported dust on regolith surfaces.</a> Geophys. Res. Lett. 44 (7), 3059-3065 (2017).</li><li>Allen, C. C., 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=Martian+Regolith+Simulant+JSC-Mars-1.">Martian Regolith Simulant JSC-Mars-1.</a> The 29th Lunar and Planetary Science Conference. , (1998).</li><li>Martin, N. L. S., von Engel, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+reflection+of+slow+electrons+from+a+soot-covered+surface.">The reflection of slow electrons from a soot-covered surface.</a> J. Phys DAppl Phys. 10 (6), 863-868 (1977).</li><li>Halekas, J. S., Delory, G. T., Lin, R. P., Stubbs, T. J., Farrell, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lunar+Prospector+measurements+of+secondary+electron+emission+from+lunar+regolith.">Lunar Prospector measurements of secondary electron emission from lunar regolith.</a> Planet. Space Sci. 57 (1), 78-82 (2009).</li><li>Wiese, R., Sushkov, V., Kersten, H., Ikkurthi, V. R., Schneider, R., Hippler, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavior+of+a+porous+particle+in+a+radiofrequency+plasma+under+pulsed+argon+ion+beam+bombardment.">Behavior of a porous particle in a radiofrequency plasma under pulsed argon ion beam bombardment.</a> New J. Phys. 12, 033036 (2010).</li><li>Richterov&#225;, I., N&#277;me&#269;ek, Z., Ber&#225;nek, M., &#352;afr&#225;nkov&#225;, J., Pavl&#367;, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Secondary+emission+from+non-spherical+dust+grains+with+rough+surfaces:+Applications+to+lunar+dust.">Secondary emission from non-spherical dust grains with rough surfaces: Applications to lunar dust.</a> Astrophys. J. 761 (2), 108 (2012).</li><li>Ma, Q., Matthews, L. S., Land, V., Hyde, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Charging+of+aggregate+grains+in+astrophysical+environments.">Charging of aggregate grains in astrophysical environments.</a> Astrophys. J. 763 (2), 77 (2013).</li><li>Dove, A., Hor&#225;nyi, M., Wang, X., Piquette, M., Poppe, A. R., Robertson, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+study+of+a+photoelectron+sheath.">Experimental study of a photoelectron sheath.</a> Phys. Plasmas. 19 (4), 043502 (2012).</li><li>Zimmerman, M. I., 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=Grain-scale+supercharging+and+breakdown+on+airless+regoliths.">Grain-scale supercharging and breakdown on airless regoliths.</a> J. Geophys. Res.-Planet. 121 (10), 2150-2165 (2016).</li><li>Wang, X., Pilewskie, J., Hsu, H. -. W., Hor&#225;nyi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasma+potential+in+the+sheaths+of+electron-emitting+surfaces+in+space.">Plasma potential in the sheaths of electron-emitting surfaces in space.</a> Geophys. Res. Lett. 43 (12), 525-531 (2016).</li></ol>

作者没有什么可透露的。

数十年来, 静电尘埃在无气物体壤上的传输问题仍然是一个悬而未决的问题, 如何壤尘埃粒子获得足够大的电荷来动员或放样。最近的实验室研究26,27从根本上提高了对这个问题的理解。
在这里, 它被证明三最近开发的实验显示粉尘充电和动员在热等离子体与电子束电子, 仅电子束或紫外线辐射。这些实验的关键元素是创造二次电子或光电子从尘土飞扬的表面发出。如前面的工作26所示, 这些发射的电子很可能会导致尘埃粒子的负电荷大大增强, 因为它们在尘埃表面下面的微腔中重新吸收。详细的机制是用最近开发和成功验证的 "修补电荷模型" 26,27描述的。
在协议步骤1和2中, 尘埃粒子需要直接接触到 100 eV 以上能量的电子束电子, 以有效地创建二级电子36。应先设置灯丝的偏置电压, 然后增加加热电压, 直到达到所需的发射电流, 如协议3.3.1 所述。如果尘埃粒子没有移动或放样, 它可能表明尘埃表面电位跟随光束能量变得如此消极, 二次电子的创造被压制。这可能是由于在设置灯丝电压时发生错误的操作导致的, 如协议3.3.2 中所述。
在协议步骤3中, 紫外线灯的波长应为 170 nm 或更短, 这样 uv 光子的能量比尘埃表面的工作功能显著地大, 以便有效地发射光电子。粉尘的动员在很大程度上取决于尘埃粒子之间的凝聚力, 这可能随不同的成分而变化。火星模拟被证明是最容易移动。
这些实验表明, 尘埃粒子 (直径的微米) 可以跳到几厘米高。这个高度相当于月球表面上的几厘米, 类似于月球地平线的高度。目前尚不清楚发光是否是由弹道跳跃或尘埃粒子悬浮引起的。这些实验表明前者是一种更有可能的机制。结果表明, 静电粉尘的动员可以导致光滑表面的形成, 这可能与小行星爱神9和彗星 67P10上形成的尘埃池有关, 以及土星冰月亮阿特拉斯12的高度平滑表面。
最后, 这些实验表明, 静电粉尘运输预计将发挥重要作用, 形成无气行星体表面, 并可能负责一些不寻常的表面现象。这里所展示的方法为更先进的研究开辟了大门, 包括实验室实验和未来的建模。

无空气的行星体, 如月球和小行星, 被称为壤的细小尘埃粒子所覆盖。这些空气不通风的物体, 不像地球, 直接暴露于太阳风等离子体和太阳紫外线 (UV) 辐射, 导致壤尘埃被充电。因此, 这些带电的尘埃粒子可能会被动员, 放样, 运输, 甚至从表面上被逐出和丢失由于静电力量。这一静电过程的第一个建议证据是所谓的 "月球地平线辉光", 在日落后不久观察到的西部地平线上的一个明显的辉光, 由测量员 5, 6, 7 航天器五年前 (图 1a)1, 2,3。据推测, 这一辉光是由从静电放样尘埃粒子 (5 微米半径) 到高度 < 1 米以上的距离月球终结器1,2,3。静电释放的细粉尘也被建议负责的射线状的彩带达到高海拔的阿波罗宇航员4,5。
自从这些阿波罗观测, 许多对其他无气物体的观测也与静电尘埃的动员或放样机制联系在一起, 例如土星环中的径向辐条6,7,8, 在小行星爱神 (图 1b)9和彗星 67P10上的尘埃池, 从主带小行星谱11的多孔表面, 土星冰冷的月球地图集12的异常平滑表面, 以及壤在月球漩涡13。此外, 激光反光境在月球表面的退化也可能是由静电放样尘埃的积累引起的 14.
实验室研究的主要动机是这些不寻常的空间观测, 以了解粉尘充电和运输的物理过程。在各种等离子体条件下观察到粉尘的动员, 其中尘埃粒子从玻璃球表面脱落15,16, 在等离子鞘中悬浮17, 并记录在导电和绝缘上移动。表面18,19,20,21。然而, 尘埃粒子如何获得足够大的电荷来放样或动员仍然是很不清楚的。对光滑表面上单个尘埃粒子的电荷的测量22和在尘埃表面上的平均电荷密度23浸入等离子显示, 这些电荷太小, 不能放样或动员尘埃粒子。
在前面的理论16,24,25中, 充电只被认为发生在直接暴露于紫外线或等离子的顶面层上。电荷通常被认为是均匀分布在整个尘土飞扬的表面上, i. e., 每个单独的尘埃粒子获得相同的电荷量, 由所谓的 "共享电荷模型"16描述。然而, 从这个模型计算的电荷比单独的引力要小得多。电荷涨落理论, 将电子和离子通量的随机过程解释为表面的16,24显示了静电力的时间增强, 但相对于引力。
本文利用三新近研制的实验26对静电粉尘的放样和动员进行了论证, 对了解无气行星体壤的粉尘输送具有重要意义。这些实验是在热等离子体的条件下, 电子束电子, 仅电子束或紫外线辐射。这些实验证明了最近开发的 "修补电荷模型"26,27的有效性, 其中微腔在表面下面的相邻尘埃粒子之间形成, 可以重新吸收发出的照片和/或二次电子, 在相邻的尘埃粒子的表面产生大的负电荷。这些负电荷之间的排斥力可以变得足够大, 以动员或解除尘埃粒子。

<table>
	<tbody>
		<tr>
			<td>Vacuum chamber</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum electrode feedthrough</td>
			<td>Lesker</td>
			<td>EFT0113053</td>
			<td></td>
		</tr>
		<tr>
			<td>Tungsten filament (0.1 mm thick)</td>
			<td>Goodfellow</td>
			<td>W055250</td>
			<td>Thoriated</td>
		</tr>
		<tr>
			<td>Power supply #1 (0-8V, 3A)</td>
			<td>Agilent</td>
			<td>E3610A</td>
			<td>Or equivalent</td>
		</tr>
		<tr>
			<td>Power supply #2 (0-140V, 0.5A)</td>
			<td>Agilent</td>
			<td>E3612A</td>
			<td>Or equivalent</td>
		</tr>
		<tr>
			<td>UV lamp</td>
			<td>Osram</td>
			<td>XERADEX L40/120/SB-SX48/KF50HV</td>
			<td>Or equivalent</td>
		</tr>
		<tr>
			<td>Dust sample</td>
			<td>Any</td>
			<td>Mars or Lunar simulants or other types</td>
			<td>Irregularly-shaped, sieved, insulating</td>
		</tr>
		<tr>
			<td>Insulating plate</td>
			<td>Any</td>
			<td>NA</td>
			<td>Thickness &#62; 1 cm</td>
		</tr>
		<tr>
			<td>Rubber sheet</td>
			<td>Any</td>
			<td>NA</td>
			<td>Thickness &#62; 1 mm</td>
		</tr>
		<tr>
			<td>Metal plate</td>
			<td>Any</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>Ceramic stands</td>
			<td>McMaster</td>
			<td>94335A130</td>
			<td>1/2&#34; diameter</td>
		</tr>
		<tr>
			<td>Video camera (consumer)</td>
			<td>Panasonic</td>
			<td>HC-VX870</td>
			<td>Or equivalent</td>
		</tr>
		<tr>
			<td>Video camera (high-speed)</td>
			<td>Phantom</td>
			<td>V2512</td>
			<td>&#62; 1000 fps</td>
		</tr>
		<tr>
			<td>LED lamp</td>
			<td>Any</td>
			<td>NA</td>
			<td>&#62; 500W Tungsten Equivalent</td>
		</tr>
	</tbody>
</table>

experimental methods of dust charging and mobilization on surfaces with exposure to ultraviolet radiation or plasmas

静电尘埃的传输已经被推测来解释一些异常行星现象的观测。在这里, 它被证明使用三最近开发的实验中, 尘埃粒子暴露在热等离子体与电子束电子, 只电子束, 或紫外线 (紫外线) 辐射。紫外线光源的波长以 172 nm 为中心, 带宽狭窄。光束电子与能量的 120 eV 是创建一个负偏热灯丝。当真空室充满氩气时, 除了电子束外, 还会产生热等离子体。实验中使用了直径几微米的绝缘粉尘微粒。尘埃粒子被记录为放样的高度, 最高可达几厘米, 发射速度可达1米/秒。这些实验表明, 灰尘表面的照片和/或二次电子发射改变了尘埃粒子的充电机制。根据最近开发的 "修补电荷模型", 发射的电子可以在微腔内的相邻尘埃粒子之间重新吸收, 从而导致周围尘埃的增强负电荷堆积。粒子.这些负电荷粒子之间的排斥力可能足够大, 可以动员并将它们从表面上提起。这些实验对尘土飞扬的表面进行了粉尘充放电和运输的深入认识, 为今后研究其在无气行星体表面演化中的作用打下了基础。

用顶部或底部的细丝进行了一系列实验。使用顶部灯丝设置, 记录了尘埃粒子的跳跃 (图 3a)。相比之下, 当使用底部灯丝时, 尘埃颗粒仍保持静止。测量了在协议步骤 226中描述的条件下, 在两个实验中, 表面的垂直电场近似相同 (16 伏/厘米)。这些结果表明, 由于鞘电场的静电力不够大, 无法调动粉尘颗粒。这两个实验的唯一区别是存在 (使用顶长灯丝) 或缺席 (使用底部灯丝) 的光束电子轰击表面。
在灰尘和外部橡胶表面的潜力测量由王et al。26表明, 二次电子是由于高能束电子的轰击而产生的, 在电子被热化的等离子体中最小化。更重要的是, 这些潜在的测量结果表明, 与固体表面26相比, 二次电子发射在尘土飞扬的表面上大大减少。这可能是由于表面粗糙度, 可以重新吸收发射电子20,29,30,31,32,33。
正如协议3.3.1 中所描述的, 一旦 120 eV 光束电子从灯丝上发射到表面, 就会产生二次电子, 从而使表面电位上升到比-120 v 更积极。在这种情况下, 从表面动员和放样尘埃粒子 (图 3b)。在 3.3.2, 没有记录尘埃运动。测得的是, 表面电位仅仅跟随灯丝偏压, 变成-120 V26。这是因为灯丝电压开始非常小, i. e, 相应的电子束电子能量非常低, 二次电子屈服几乎为零, 所以表面电位等于电子束电子 (eV) 的能量, 以阻止它们在平衡状态下保持零净电流。灯丝电压的增量是渐进的, 与等离子响应相比, 使电压增量太小, 不能产生任何二次电子。因此, 表面电位跟随灯丝电压, 导致电子束电子被停止到达表面, 从而抑制二次电子发射。实验表明, 二次电子的产生对粉尘的充放电和输送过程有显著的促进作用。
在 172 nm 紫外线辐射下记录了跳尘 (图 3c)。光电子鞘在表面之上被创造, 电场是非常小的 ~ 0.5 V/cm34。因此, 由于鞘电场的静电力是微不足道的。如 Schwan et al所示。27, 紫外线辐射下的放样尘埃粒子携带大量负电荷。这一结果与光电子的预期正电荷相抵触, 而与下面描述的 "修补电荷模型" 一致。
还对紫外线辐射下的尘埃粒子进行了长时间曝光。图 4显示了作为时间函数的曲面形态学的变化。表面变得更加平滑, 最终铺平了水面, 为在小行星爱神 (图 1b) 上形成的尘埃池提供了一个有效的过程。
上述三项实验表明, 当照片和/或二次电子从尘土飞扬的表面发出时, 灰尘的放样就会发生, 而这些发射的电子由于粗糙而可以在表面重新吸收。由王et开发的 "补丁充电模型"。26基于这两个结果, 并简要回顾如下。
如图 5所示, 与平滑的固体表面相反, 微腔是在壤表面下方的尘埃粒子之间形成的。顶部表面 (蓝色补丁) 是由光电离光的电荷, 由于紫外线辐射和/或等离子电子和离子。在顶面的尘埃颗粒之间有小开口。一些紫外线光子, 或电子和离子可以穿透这些小开口到尘埃颗粒下面的顶面, 创造光电子和/或二次电子。许多这些发射的电子不会逃脱, 并被重新吸收在微腔内, 并在周围粒子的表面沉积负电荷 (红色斑块)。
蓝色表面补丁的电荷是 Qb E<img alt="Equation" src="/files/ftp_upload/57072/57072eq1.jpg"> </img> b, 其中 Eb是尘埃表面上方的鞘电场。红色补丁被控于 Qr E<img alt="Equation" src="/files/ftp_upload/57072/57072eq1.jpg"> </img> r, 其中 Er是微腔内的电场。eb 1<img alt="Equation" src="/files/ftp_upload/57072/57072eq1.jpg"> </img> /λde, 其中λde是德拜长度, 而 Er 1/r, 其中是单独的尘埃粒子半径, 近似类似于微腔的特征大小.<img alt="Equation" src="/files/ftp_upload/57072/57072eq1.jpg"> </img>由于λDe > > r, Er > > Eb , 因此 Qr > > Qb。主要增强的负电荷 Qr可能在两个负电荷粒子之间产生足够大的排斥力, 从而将它们从表面上弹出。在计算机模拟35中也观察到, 由于光电子的重新吸收, 在尘土飞扬的表面上有大量的电荷沉积 (按0.5 微机/m2的顺序)。 
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57072/57072fig1.jpg"> 图1。照片中的两个例子的异常表面现象与静电粉尘运输有关.(a) 测量师7号航天器 (NASA 照片) 拍摄的月球地平线辉光.(b) 在火山口的细尘沉积, 即近鞋匠航天器所采取的小行星433爱神的所谓 "尘埃池"9。箭头和圆圈表示预先存在的 toporgraphies。正方形突出了一个小的孤立的尘埃池。<a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/57072/57072fig1large.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/57072/57072fig2.jpg"> 图2。实验设备和安装程序.(a) 实验装置的示意图, 它的粉尘暴露于热等离子体中, 电子束电子, 仅电子束或紫外线辐射仅为26。(b) 图片显示室内紫外线实验的设置和 (c) 真空室的图片。<a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/57072/57072fig2large.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/57072/57072fig3.jpg"> 图3。放样粉尘的轨迹图像26.暴露于 (a) 等离子体与 120 ev 电子束电子, (b) 120 ev 电子束电子和 (c) 紫外线辐射, 分别。(a) 中的一个蓝色盒子突出了放样尘埃粒子的轨迹。(c) 中的一个蓝色盒子突出了放样尘埃粒子的轨迹, 并放大了视图。放样粉尘颗粒包括直径为140米的骨料, 除单个颗粒 (直径 38-45 米)。这个数字已经从纸上被王等. 修改过了。26.<a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/57072/57072fig3large.jpg" target="_blank">请单击此处查看此图的更大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/57072/57072fig4.jpg"> 图4。表面变化的时间失效由于灰尘 moblization 在紫外线辐射下.紫外线波长是172毫微米与光子辐照度16兆瓦/cm2在尘土飞扬的表面。<a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/57072/57072fig4large.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/57072/57072fig5.jpg"> 图5。修补的充电模型26.中心显示的微腔由相邻的尘埃粒子 (灰色圆圈) 形成。蓝色表面贴片暴露于光子和/或电子和离子。它们被控 Qb , simultanously 发出照片和/或二次电子。这些发射的电子中的一小部分被重新吸收到微腔内, 并堆积在周围尘埃粒子的红色表面斑块上, 对 Qr进行负面的充电。<a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/57072/57072fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

Watch this Scientific Journal Video about Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas at JoVE.com

Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas

在三实验中, 用电子束电子、电子束或紫外线 (UV) 辐射照射热等离子体, 证明了粉尘的充电和动员。这些实验对静电粉尘的传输及其在无气行星体表面成形中的作用提出了先进的认识。

紫外辐射或等离子体照射表面的粉尘充电和动员实验方法

Electrostatic dust transport has been hypothesized to explain a number of observations of unusual planetary phenomena. Here, it is demonstrated using ...

experimental-methods-dust-charging-mobilization-on-surfaces-with

Nanyang Technological University

Research

JoVE Journal

Environment

8.1K 次观看.  University of Colorado. 在三实验中, 用电子束电子、电子束或紫外线 (UV) 辐射照射热等离子体, 证明了粉尘的充电和动员。这些实验对静电粉尘的传输及其在无气行星体表面成形中的作用提出了先进的认识。

视频: Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas

Methods for Facilitating Microbial Growth on Pulp Mill Waste Streams and Characterization of the Biodegradation Potential of Cultured Microbes

The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chemical derivatives that constitute the majority of available organic carbon within black liquor, and its basic pH present challenges to microbial biodegradation of this waste material. Methods for the collection and modification of black liquor for microbial growth are aimed at utilization of this pulp waste to convert the lignin, organic acids, and polysaccharide degradation byproducts into valuable chemicals. The lignocellulose extraction techniques presented provide a reproducible method for preparation of lignocellulose growth substrates for understanding metabolic capacities of cultured microorganisms. Use of gas chromatography-mass spectrometry enables the identification and quantification of the fermentation products resulting from the growth of microorganisms on pulping waste. These methods when used together can facilitate the determination of the metabolic activity of microorganisms with potential to produce fermentation products that would provide greater value to the pulping system and reduce effluent waste, thereby increasing potential paper milling profits and offering additional uses for black liquor.

Industrial wastes can be collected and modified to analyze microbial growth. Lignocellulose extraction techniques provide components to analyze specific biodegradation ability. Gas chromatography-mass spectrometry identifies fermentation products of microorganisms grown on pulping waste. These methods determine the metabolic capacity of microorganisms to degrade pulping waste.

方法对纸浆厂污水流和培养微生物的生物降解能力的表征促进微生物生长

The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high ...

科研

环境科学

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.

EPA Method 1615 uses an electropositive filter to concentrate enteroviruses and noroviruses in environmental and drinking waters. This manuscript describes the procedure for collecting samples for Method 1615 analyses.

EPA方法1615测量肠道病毒和诺瓦克病毒发生水由文化和RT-qPCR的了。病毒样本的收集I.

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. II. Total Culturable Virus Assay

A standardized method is required when national studies on virus occurrence in environmental and drinking waters utilize multiple analytical laboratories. The U.S Environmental Protection Agency&#8217;s (USEPA) Method 1615 was developed with the goal of providing such a standard for measuring Enterovirus and Norovirus in these waters. Virus is concentrated from water using an electropositive filter, eluted from the filter surface with beef extract, and then concentrated further using organic flocculation. Herein we present the protocol from Method 1615 for filter elution, secondary concentration, and measurement of total culturable viruses. A portion of the concentrated eluate from each sample is inoculated onto ten replicate flasks of Buffalo Green Monkey kidney cells. The number of flasks demonstrating cytopathic effects is used to quantify the most probable number (MPN) of infectious units per liter. The method uses a number of quality controls to increase data quality and to reduce interlaboratory and intralaboratory variation. Laboratories must meet defined performance standards. Method 1615 was evaluated by examining virus recovery from reagent-grade and ground waters seeded with Sabin poliovirus type 3. Mean poliovirus recoveries with the total culturable assay were 111% in reagent grade water and 58% in groundwaters.

Here we present a procedure to measure total culturable viruses using the Buffalo Green Monkey kidney cell line. The procedure provides a standardized tool for measuring the occurrence of infectious viruses in environmental and drinking waters.

EPA方法1615年测量和肠道病毒水中诺如病毒发生由文化部和RT-qPCR的的。 II。总可培养病毒试验

A standardized method is required when national studies on virus occurrence in environmental and drinking waters utilize multiple analytical laboratories. ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. Part III. Virus Detection by RT-qPCR

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a standardized method for use in multiple analytical laboratories during monitoring period 3 of the Unregulated Contaminant Monitoring Rule. Herein we present the protocol for extraction of viral ribonucleic acid (RNA) from water sample concentrates and for quantitatively measuring enterovirus and norovirus concentrations using reverse transcription-quantitative PCR (RT-qPCR). Virus concentrations for the molecular assay are calculated in terms of genomic copies of viral RNA per liter based upon a standard curve. The method uses a number of quality controls to increase data quality and to reduce interlaboratory and intralaboratory variation. The method has been evaluated by examining virus recovery from ground and reagent grade waters seeded with poliovirus type 3 and murine norovirus as a surrogate for human noroviruses. Mean poliovirus recoveries were 20% in groundwaters and 44% in reagent grade water. Mean murine norovirus recoveries with the RT-qPCR assay were 30% in groundwaters and 4% in reagent grade water.

Here we present a procedure to quantify enterovirus and norovirus in environmental and drinking waters using reverse transcription-quantitative PCR. Mean virus recovery from groundwater with this standardized procedure from EPA Method 1615 was 20% for poliovirus and 30% for murine norovirus.

EPA方法1615测量肠道病毒和诺瓦克病毒发生水由文化和RT-qPCR的了。第三部分。病毒检测用RT-qPCR的

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a ...

Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface

Evaporation is directly influenced by the interactions between the atmosphere, land surface and soil subsurface. This work aims to experimentally study evaporation under various surface boundary conditions to improve our current understanding and characterization of this multiphase phenomenon as well as to validate numerical heat and mass transfer theories that couple Navier-Stokes flow in the atmosphere and Darcian flow in the porous media. Experimental data were collected using a unique soil tank apparatus interfaced with a small climate controlled wind tunnel. The experimental apparatus was instrumented with a suite of state of the art sensor technologies for the continuous and autonomous collection of soil moisture, soil thermal properties, soil and air temperature, relative humidity, and wind speed. This experimental apparatus can be used to generate data under well controlled boundary conditions, allowing for better control and gathering of accurate data at scales of interest not feasible in the field. Induced airflow at several distinct wind speeds over the soil surface resulted in unique behavior of heat and mass transfer during the different evaporative stages.

A protocol for the design and construction of a soil tank interfaced to a small climate controlled wind tunnel to study the effects of atmospheric forcings on evaporation is presented. Both the soil tank and wind tunnel are instrumented with sensor technologies for the continuous in situ measurement of environmental conditions.

在探索大气蒸发强迫的影响:大气边界层和浅地层的实验整合

Evaporation is directly influenced by the interactions between the atmosphere, land surface and soil subsurface. This work aims to experimentally study ...

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory by using pumps and automating delivery of sediment and water to simulate suspension of sediment. FLEES data are used to develop exposure-response curves between the effects on aquatic organisms and suspended sediment concentrations at the desired exposure duration. The effects data are used to evaluate management practices used to reduce the interactions between aquatic organisms and anthropogenic causes of suspended sediments. The FLEES is capable of generating total suspended solids (TSS) concentrations as low as 30 to as high as 800 mg/L, making this system an ideal choice for evaluating the effects of TSS resulting from many activities including simulating low ambient levels of TSS to evaluating sources of suspended sediments from dredging operations, vessel traffic, freshets, and storms.

A robust and flexible flow-through exposure system designed to maintain sediment in suspension is presented. The system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory.

对水生生命值评价悬浮泥沙影响的流通系统曝光

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended ...

Experimental System of Solar Adsorption Refrigeration with Concentrated Collector

To improve the performance of solar adsorption refrigeration, an experimental system with a solar concentration collector was set up and investigated. The main components of the system were the adsorbent bed, the condenser, the evaporator, the cooling sub-system, and the solar collector. In the first step of the experiment, the vapor-saturated bed was heated by the solar radiation under closed conditions, which caused the bed temperature and pressure to increase. When the bed pressure became high enough, the bed was switched to connect to the condenser, thus water vapor flowed continually from the bed to the condenser to be liquefied. Next, the bed needed to cool down after the desorption. In the solar-shielded condition, achieved by aluminum foil, the circulating water loop was opened to the bed. With the water continually circulating in the bed, the stored heat in the bed was took out and the bed pressure decreased accordingly. When the bed pressure dropped below the saturation pressure at the evaporation temperature, the valve to the evaporator was opened. A mass of water vapor rushed into the bed and was adsorbed by the zeolite material. With the massive vaporization of the water in the evaporator, the refrigeration effect was generated finally. The experimental result has revealed that both the COP (coefficient of the performance of the system) and the SCP (specific cooling power of the system) of the SAPO-34 zeolite was greater than that of the ZSM-5 zeolite, no matter whether the adsorption time was longer or shorter. The system of the SAPO-34 zeolite generated a maximum COP of 0.169.

With solar energy as the driving force, a novel adsorption refrigeration system has been developed and experimentally investigated. Water vapor and zeolite formed the working pair of the adsorption system. This manuscript describes the setup of the experimental rig, the operation procedure, and the important results.

聚光集热器太阳能吸附制冷实验系统

To improve the performance of solar adsorption refrigeration, an experimental system with a solar concentration collector was set up and investigated. The ...

Adherence of Bacteria to Plant Surfaces Measured in the Laboratory

This manuscript describes a method to measure bacterial binding to axenic plant surfaces in the light microscope and through the use of viable cell counts. Plant materials used include roots, sprouts, leaves, and cut fruits. The methods described are inexpensive, easy, and suitable for small sample sizes. Binding is measured in the laboratory and a variety of incubation media and conditions can be used. The effect of inhibitors can be determined. Situations that promote and inhibit binding can also be assessed. In some cases it is possible to distinguish whether various conditions alter binding primarily due to their effects on the plant or on the bacteria.

An easy method for measuring and characterizing bacterial adhesion to plants, particularly roots and sprouts, is described in this article.

细菌附着在实验室测量的植物表面

This manuscript describes a method to measure bacterial binding to axenic plant surfaces in the light microscope and through the use of viable cell ...

Preparation of DMMTAV and DMDTAV Using DMAV for Environmental Applications: Synthesis, Purification, and Confirmation

Dimethylated thioarsenicals such as dimethylmonothioarsinic acid (DMMTAV) and dimethyldithioarsinic acid (DMDTAV), which are produced by the metabolic pathway of dimethylarsinic acid (DMAV) thiolation, have been recently found in the environment as well as human organs. DMMTAV and DMDTAV can be quantified to determine the ecological effects of dimethylated thioarsenicals and their stability in environmental media. The synthesis method for these compounds is unstandardized, making replicating previous studies challenging. Furthermore, there is a lack of information about storage techniques, including storage of compounds without species transformation. Moreover, because only limited information about synthesis methods is available, there may be experimental difficulties in synthesizing standard chemicals and performing quantitative analysis. The protocol presented herein provides a practically modified synthesis method for the dimethylated thioarsenicals, DMMTAV and DMDTAV, and will help in the quantification of species separation analysis using high performance liquid chromatography in conjunction with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The experimental steps of this procedure were modified by focusing on the preparation of chemical reagents, filtration methods, and storage.

Preparation of DMMTAV and DMDTAV Using DMAV for Environmental Applications: Synthesis, Purification, and Confirmation

This article presents modified experimental protocols for dimethylmonothioarsinic acid (DMMTAV) and dimethyldithioarsinic acid (DMDTAV) synthesis, inducing dimethylarsinic acid (DMAV) thiolation through mixing of DMAV, Na2S, and H2SO4. The modified protocol provides an experimental guideline, thereby overcoming limitations of the synthesis steps that could have caused experimental failures in quantitative analysis.

使用 DMAv为环境应用 DMMTAv和 DMDTAv的准备: 合成、纯化和确认

Dimethylated thioarsenicals such as dimethylmonothioarsinic acid (DMMTAV) and dimethyldithioarsinic acid (DMDTAV), which are produced by the metabolic ...

Bioindication Testing of Stream Environment Suitability for Young Freshwater Pearl Mussels Using In Situ Exposure Methods

Knowledge of habitat suitability for freshwater mussels is an important step in the conservation of this endangered species group. We describe a protocol for performing in situ juvenile exposure tests within oligotrophic river catchments over one-month and three-month periods. Two methods (in both modifications) are presented to evaluate the juvenile growth and survival rate. The methods and modifications differ in value for the locality bioindication and each has its benefits as well as limitations. The sandy cage method works with a large set of individuals, but only some of the individuals are measured and the results are evaluated in bulk. In the mesh cage method, the individuals are kept and measured separately, but a low individual number is evaluated. The open water exposure modification is relatively easy to apply; it shows the juvenile growth potential of sites and can also be effective for water toxicity testing. The within-bed exposure modification needs a high workload but is closer to the conditions of a natural juvenile environment and it is better for reporting the real suitability of localities. On the other hand, more replications are needed in this modification due to its high-hyporheic environment variability.

Bioindication Testing of Stream Environment Suitability for Young Freshwater Pearl Mussels Using In Situ Exposure Methods

In situ bioindications enable determination of the suitability of an environment for endangered mussel species. We describe two methods based on the juvenile exposure of freshwater pearl mussels in cages to oligotrophic river habitats. Both methods are implemented in variants for open water and hyporheic water environments.

用原位曝光法测定淡水珍珠贻贝 Bioindication 的流环境适宜性

Knowledge of habitat suitability for freshwater mussels is an important step in the conservation of this endangered species group. We describe a protocol ...