这项研究得到1000名中国青年科学家、国家自然科学基金 (51472164 号赠款)、A * 星航标灯方案 (赠款 152 70 00014) 和新加坡国立大学高级2D 技术中心提供的设施支持。材料.

注意: 这项工作中使用的一些化学剂和气体是有毒的、致癌的、易燃的和爆炸性的。在进行蒸汽输送沉积时, 请使用所有适当的安全措施, 包括使用工程控制 (油烟机) 和个人防护设备 (安全眼镜、专业防护口罩、手套、实验室大衣、全长裤子, 和封闭脚趾鞋)。
1. 温度控制器参数的自动调谐功能
注: 在合成 SnSe 片之前, 需要按照制造商的手册来校准炉子的加热系统。
<ol><li>将最常用温度的80% 设置为目标温度。这里, 将 560 oC 设置为1小时, 然后运行熔炉。</li>
	<li>当温度接近 560 oC 时, 按 2 s 的 "设置" 键, 注意参数 "HAL" 弹出, 然后按 1 s 的 "设置" 键转到下一个参数。</li>
	<li>继续按下 "设置" 键。出现 "Cont=3" 后, 将其设置为2。系统启动自动调谐功能, 以算出 Int、Pro 和 it 的值, 然后系统将转到3。当需要重新自动调整时, 将其设置为2。</li>
</ol>2. 石英管和陶瓷船的预处理
注: 在合成 SnSe 片之前, 需要一个高温清洗工艺, 新的陶瓷船和新的石英管被预处理。
<ol><li>在新的1英寸直径的石英管内放置一条新的陶瓷船。将1英寸直径的石英管放在水平管炉内, 用新的2英寸直径的石英管。确保管道两端牢固固定和支持。</li>
	<li>关闭炉盖, 加热管炉至 1000 oC 30 分钟以上。</li>
	<li>当加热炉中心的温度接近 1000 oc 时, 将炉子保持在 1000 oc 上30分钟。然后, 逐渐将管式炉从一端移到另一个端, 以加热整个管的长度, 以清洗石英管壁和陶瓷船。</li>
	<li>在此之后, 让管炉冷却到室温通过关闭炉。当炉冷却到室温, 打开炉盖, 取出新的陶瓷船和新的1英寸直径的石英管, 可用于后续实验。</li>
</ol>3. 预处理- 2 /Si 基板
<ol><li>在重掺杂 Si 上剪切2/Si 硅片 (300 nm 厚的 x2 ) (参见材料表), 使用菱形划线, 将其用作生长基质。</li>
	<li>在丙酮、异丙醇和水中清洁2/Si 基底, 然后氮气吹干。</li>
</ol>4. 大体积矩形 SnSe 片的合成
<ol><li>在清洁的陶瓷船上放置0.010 克 SnSe 粉 (参见材料表)。将干净的2/Si 衬底 (大约1.5 厘米 x 2 厘米) 放到陶瓷船上, 生长侧面对 SnSe 粉末。将陶瓷船放置在一个干净的1英寸直径的石英管内。</li>
	<li>将1英寸直径的石英管放在水平管式炉内, 外部有2英寸直径的石英管, 并确保陶瓷船位于管式炉加热区的上游。拧紧管两端的法兰, 关闭排气阀, 密封2英寸直径的石英管。</li>
	<li>打开连接到石英管的泵, 将管泵成 ~ 1×10-2毫巴的压力, 以去除管内的空气和湿气。压力实现后, 关闭泵。</li>
	<li>然后打开载气阀, 使用气体流量计控制气体流量。将40标准立方厘米每分钟 (sccm) Ar 和 10 sccm H2 (纯度: 99.9%) 引入石英管, 直到大气压达到。打开排气阀, 使石英管中的气体连续流动。</li>
	<li>关闭炉盖, 用 35 oC 每分钟加热速率快速加热管式炉。</li>
	<li>当炉膛中心的温度接近 700 oC 时, 快速移动管式炉, 将 SnSe 粉末放置在炉子的中心。SnSe 粉末将蒸发, 散装 SnSe 片将沉积在2/Si 表面。</li>
	<li>经过15分钟的生长时间, 打开炉盖, 快速冷却管炉的室温。同时, 将 Ar/H2的流量调整为最大值, 这将有助于将反应气体或粒子从管中驱动。当生长过程完成后, 将在2/Si 衬底的表面上获得大块 SnSe 薄片。</li>
</ol>5. 单层矩形 SnSe 片的制作
<ol><li>将已长大的散装 SnSe/2/Si 样品朝上一条新的清洁陶瓷船。将陶瓷船放置在一个新的干净的1英寸直径的石英管内。</li>
	<li>将1寸直径的石英管置于水平管炉内, 直径为2英寸的石英管, 与陶瓷船位于炉管加热区的上游。拧紧管两端的法兰, 并关闭排气阀以密封2英寸直径的石英管。</li>
	<li>打开连接到石英管的泵, 将管子向下泵入至 1×10-2毫巴的压力, 以去除管内的空气和湿气。完成后, 关闭泵。</li>
	<li>打开载气阀, 使用气体流量计控制气体流量。将 50 sccm N2 (纯度: 99.9%) 引入石英管, 直到大气压达到。打开排气阀, 使石英管中的气体连续流动。</li>
	<li>关闭炉盖, 并将管炉快速加热至 700 oC, 20 分钟。</li>
	<li>当加热炉中心的温度接近 700 oC 时, 快速移动管式炉, 将散装 SnSe/输出2/Si 样品放置在炉的中心。</li>
	<li>将炉子保持在 700 oC 的5-20 分钟内以完成蚀刻过程。然后, 打开炉盖, 快速冷却管炉到室温。同时, 将 N2气体的流量保持在最大值, 这将有助于将反应气体或粒子从管中驱动。当蚀刻过程完成后, 观察在2/Si 衬底表面获得的单层矩形 SnSe 片。 注: 蚀刻气体和蚀刻时间是该工艺的主要控制因素。在参考29中对蚀刻机理进行了研究, 因此请参阅参考29以了解更多细节。</li>
</ol>

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我们没有什么可透露的。

本文首次报道了气体输送沉积法和氮气蚀刻技术在常压系统中的结合。在该协议中, 关键步骤是制作单层 SnSe 片的部分。
虽然可以将散装试样蚀刻成高质量的单层样品, 但散装试样的厚度应均匀, 试样的分解温度应高于蚀刻温度。由于大多数散装样品完全蚀刻, 因此所得到的样品的覆盖率很低。
对于扫描隧道显微术 (STM) 的应用, 单层样品的覆盖密度不够。?...

近年来, 由于石墨烯的成功分离, 对二维 (2D) 材料的研究已经绽放, 这是因为2D 材料在其散装对应物上具有优异的电学、光学和机械性能1,2,3,4,5. 2D 材料在光电和电子设备中显示有前途的应用6,7, 催化和水分裂8,9, 表面增强拉曼散射传感10、11、等等可剥离成2D 材料的大量分层材料显示出巨大的多样性, 包括从半金属石墨烯到半导体过渡金属 dichalcogenides (TMDs) 和黑色磷 (BP) 对绝缘六角氮化硼 (h BN)。这些材料及其异质结构近年来得到了很好的研究, 并展示了许多新颖的特性和应用12。其他研究较少, 但同样有希望的2D 分层材料, 在通过 (气体, 气体, 和 InSe)13,14和伊娃通过 (GeS, 考试, 和 SnS)15,16,17家庭有最近也受到关注。
SnSe 属于正交结构, 由在pnma空间群中排列的原子组成, 并在层内屈曲, 就像 phosphorene 的晶体结构一样。SnSe 是一个窄隙半导体与带隙 0.6 eV, 但更著名的是其更独特的热电性能, 因为它被报告有一个非常高的 ZT (热电图的优点) 值2.6 在 923 K18,19, 由于其独特的电子结构和低导热性。虽然散装 SnSe 晶体是商用的, 并且可以通过已知的方法来增长, 如布里奇曼-Stockbarger 方法20或化学蒸气传输方法21, 在介电上生长大尺寸的少量层和单层 SnSe基板更具挑战性。有许多支持2D 材料生长的基板, 如高定向热解石墨 (HOPG)、云母、2、Si3N4和玻璃。低成本的2电介质是最常用的基板, 因为它们允许制造场效应晶体管, 其中介质作为电气后门的一部分。根据我们的经验, 与石墨烯和 TMDs 不同, 很难获得少量层或单层 SnSe 片的微机械剥离方法, 因为散装 SnSe 有一个高夹层结合能22 32 兆伏特/Å2, 这导致厚层, 甚至沿剥落片的边缘。因此, 为了研究少量层和单层 SnSe 的新型电子性质, 需要一种新的、简单的、低成本的合成方法, 在绝缘衬底上制备高质量的大型单层 SnSe 晶体, 特别是由于 SnSe 具有作为热电应用的候选者, 在低和中温范围内的能量转换方面表现出很大的希望19。
一些研究人员开发了合成高质量 SnSe 晶体的方法。刘等。23和 Franzman et 。24使用解决方案阶段方法合成不同形状的 SnSe 纳米晶, 如量子点、nanoplates、单晶薄片、nanoflowers 和 nanopolyhedra, 使用 SnCl2和烷基磷化膦硒或二烷基二diselenium 为前体。Baumgardner et 。25通过将双 [双 (三甲基硅) 氨基] 锡 (II) 注入热 trioctylphosphine, 合成了胶体 SnSe 纳米粒子, 并获得了直径为4-10 纳米的纳米晶。Boscher et 。26使用常压化学气相沉积技术, 利用四氯化锡和硒化二元前体, 在玻璃基底上获得 SnSe 薄膜, 其氯化锡比为硒化二乙酯, 其合成SnSe 薄膜约100纳米厚, 银色黑色的外观。赵等。27在低真空系统中使用了蒸气输送沉积, 在云母基体上合成了单晶 SnSe nanoplates, 得到了1-6 µm 的平方 nanoplates。然而, 使用这些技术不可能获得单层 SnSe 晶体。李等。28使用 SnCl4和 SeO2前体的一壶合成方法成功合成单层单晶 SnSe 薄片。然而, 他们只能获得大约300毫微米的横向大小为他们的薄片。我们最近发布了我们的方法, 以发展高质量的, 大型的单层 SnSe 晶体, 这是阶段纯29。这项详细的协议旨在帮助新的从业者使用这种方法种植其他大型高品质的超薄2D 材料。

<table border="0" cellpadding="0" cellspacing="0" width="1083">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">SnSe powder&#160;&#160;</td>
			<td style="width:295px;">Sigma-Aldrich</td>
			<td style="width:159px;">1315-06-6</td>
			<td style="width:347px;">(99.999%) toxic, carcinogenic</td>
		</tr>
		<tr height="28">
			<td height="28" style="height:28px;width:283px;">Ar gas</td>
			<td style="width:295px;"></td>
			<td style="width:159px;"></td>
			<td>explosive</td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:283px;">H2 gas</td>
			<td style="width:295px;"></td>
			<td style="width:159px;"></td>
			<td>flammable, explosive</td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;">SiO2/Si wafer</td>
			<td style="width:295px;"></td>
			<td style="width:159px;"></td>
			<td>300 nm thick SiO2 on heavily doped Si</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Acetone</td>
			<td style="width:295px;">Sigma-Aldrich</td>
			<td>67-64-1</td>
			<td>toxic, flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isopropanol</td>
			<td style="width:295px;">Sigma-Aldrich</td>
			<td>67-63-0</td>
			<td>flammable</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Quartz tube</td>
			<td>Dongjing Quartz Company, China</td>
			<td style="width:159px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Ceramic boat</td>
			<td style="width:295px;">Dongjing Quartz Company, China</td>
			<td style="width:159px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Optical microscope</td>
			<td style="width:295px;">Olympus, BX51</td>
			<td style="width:159px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Atomic force microscopy</td>
			<td style="width:295px;">Bruker&#160;</td>
			<td style="width:159px;"></td>
			<td>Using FastScan-A probe type&#160; and ScanAsyst-air</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Scanning electron microscopy&#160;</td>
			<td style="width:295px;">JEOL JSM-6700F</td>
			<td style="width:159px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">transmission electron microscopy</td>
			<td style="width:295px;">FEI Titan</td>
			<td style="width:159px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Tube furnace</td>
			<td style="width:295px;">MTI Corporation</td>
			<td style="width:159px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

atmospheric pressure fabrication of large-sized single-layer rectangular snse flakes

硒化锡 (SnSe) 属于具有 phosphorene 的屈曲结构的层状金属硫材料的家族, 并在二维电子学器件中显示了应用潜力。虽然已经开发了许多合成 SnSe 纳米晶的方法, 但制作大型单层 SnSe 片的简单方法仍然是一个巨大的挑战。在常压石英管中, 采用直接两步法制作方法, 给出了在常用的2/Si 绝缘衬底上使用普通的单层矩形 SnSe 片的实验方法。炉系统。采用气相输送沉积技术和氮蚀刻工艺相结合, 制备了平均厚度为6.8 Å的单层矩形 SnSe 片和大约30µm x 50 µm 的横向尺寸。对矩形 SnSe 片的形貌、显微结构和电学性能进行了表征, 获得了优良的结晶度和良好的电子性能。这篇文章的两步制作方法可以帮助研究人员发展其他类似的二维, 大型, 单层材料使用大气压系统。

实验仪器的示意图, 光学图像, 原子力显微镜 (AFM) 图像, 扫描电子显微镜 (SEM) 图像, 透射电镜 (TEM) 图像的捏造 SnSe 片显示在图 1中,图 2和图 3。光学图像由传统的光学显微镜完成。目镜透镜为 10X, 物镜为20X、50X 和100X。曝光时间约为0.3 秒。得到的光学图像的分辨率是1,376×1,038 的。扫描大小为30µm, 长宽比为1?...

Watch this Scientific Journal Video about Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes at JoVE.com

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

提出了一种在常压石英管炉系统中, 在低成本的2/Si 介质晶片上生长大型单层矩形 SnSe 片的两步法制造技术。

大型单层矩形 SnSe 片的常压制备

Tin selenide (SnSe) belongs to the family of layered metal chalcogenide materials with a buckled structure like phosphorene, and has shown potential for ...

atmospheric-pressure-fabrication-large-sized-single-layer-rectangular

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

8.1K 次观看.  Shenzhen University. 提出了一种在常压石英管炉系统中, 在低成本的2/Si 介质晶片上生长大型单层矩形 SnSe 片的两步法制造技术。

视频: Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

Fabrication of Spatially Confined Complex Oxides

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from the inherent strong electron correlations that reside within them. These materials can also possess electronic phase separation in which regions of vastly different resistive and magnetic behavior can coexist within a single crystal alloy material. By reducing the scale of these materials to length scales at and below the inherent size of the electronic domains, novel behaviors can be exposed. Because of this and the fact that spin-charge-lattice-orbital order parameters each involve correlation lengths, spatially reducing these materials for transport measurements is a critical step in understanding the fundamental physics that drives complex behaviors. These materials also offer great potential to become the next generation of electronic devices 1-3. Thus, the fabrication of low dimensional nano- or micro-structures is extremely important to achieve new functionality. This involves multiple controllable processes from high quality thin film growth to accurate electronic property characterization. Here, we present fabrication protocols of high quality microstructures for complex oxide manganite devices. Detailed descriptions and required equipment of thin film growth, photo-lithography, and wire-bonding are presented.

We describe the use of pulsed laser deposition (PLD), photolithography and wire-bonding techniques to create micrometer scale complex oxides devices. The PLD is utilized to grow epitaxial thin films. Photolithography and wire-bonding techniques are introduced to create practical devices for measurement purposes.

空间密闭的复合氧化物制备

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from ...

科研

工程学

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

在极端的压力和温度的合成和Microdiffraction

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

The application of femtosecond four-wave mixing to the study of fundamental properties of diluted magnetic semiconductors ((s,p)-d hybridization, spin-flip scattering) is described, using experiments on GaMnAs as a prototype III-Mn-V system.&#160; Spectrally-resolved and time-resolved experimental configurations are described, including the use of zero-background autocorrelation techniques for pulse optimization.&#160; The etching process used to prepare GaMnAs samples for four-wave mixing experiments is also highlighted.&#160; The high temporal resolution of this technique, afforded by the use of short (20 fsec) optical pulses, permits the rapid spin-flip scattering process in this system to be studied directly in the time domain, providing new insight into the strong exchange coupling responsible for carrier-mediated ferromagnetism.&#160; We also show that spectral resolution of the four-wave mixing signal allows one to extract clear signatures of (s,p)-d hybridization in this system, unlike linear spectroscopy techniques.&#160;&#160; This increased sensitivity is due to the nonlinearity of the technique, which suppresses defect-related contributions to the optical response. This method may be used to measure the time scale for coherence decay (tied to the fastest scattering processes) in a wide variety of semiconductor systems of interest for next generation electronics and optoelectronics.

The technique of femtosecond four-wave mixing is described, including spectrally-resolved and time-resolved configurations. We illustrate the utility of this technique for the investigation of crucial physical properties in the III-V diluted magnetic semiconductors, afforded by its nonlinearity and high temporal resolution.

The application of femtosecond four-wave mixing to the study of fundamental properties of diluted magnetic semiconductors ((s,p)-d hybridization, ...

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained.

Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations.

制造和微流控光机振荡器测试

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a stable and continuous operation of the plasma is possible and the plasma torch can be used for many different applications. On one hand, the hot (3,600 K gas temperature) plasma can be used for chemical processes and on the other hand the cold afterglow (temperatures down to almost RT) can be applied for surface processes. For example chemical syntheses are interesting volume processes. Here the microwave plasma torch can be used for the decomposition of waste gases which are harmful and contribute to the global warming but are needed as etching gases in growing industry sectors like the semiconductor branch. Another application is the dissociation of CO2. Surplus electrical energy from renewable energy sources can be used to dissociate CO2 to CO and O2. The CO can be further processed to gaseous or liquid higher hydrocarbons thereby providing chemical storage of the energy, synthetic fuels or platform chemicals for the chemical industry. Applications of the afterglow of the plasma torch are the treatment of surfaces to increase the adhesion of lacquer, glue or paint, and the sterilization or decontamination of different kind of surfaces. The movie will explain how to ignite the plasma solely by microwave power without any additional igniters, e.g., electric sparks. The microwave plasma torch is based on a combination of two resonators &#8212; a coaxial one which provides the ignition of the plasma and a cylindrical one which guarantees a continuous and stable operation of the plasma after ignition. The plasma can be operated in a long microwave transparent tube for volume processes or shaped by orifices for surface treatment purposes.

This movie shows how an atmospheric plasma torch can be ignited by microwaves with no additional igniters and provides a stable and continuous plasma operation suitable for plenty of applications.

如何点燃常压微波等离子体炬没有任何额外的点火器

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a ...

Atomically Traceable Nanostructure Fabrication

Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the entire fabrication process being used in order to maintain exquisite control over both feature size and feature density. Here, we demonstrate a method for tracking atomically resolved and controlled structures from initial template definition through final nanostructure metrology, opening up a pathway for top-down atomic control over nanofabrication. Hydrogen depassivation lithography is the first step of the nanoscale fabrication process followed by selective atomic layer deposition of up to 2.8 nm of titania to make a nanoscale etch mask. Contrast with the background is shown, indicating different mechanisms for growth on the desired patterns and on the H passivated background. The patterns are then transferred into the bulk using reactive ion etching to form 20 nm tall nanostructures with linewidths down to ~6 nm. To illustrate the limitations of this process, arrays of holes and lines are fabricated. The various nanofabrication process steps are performed at disparate locations, so process integration is discussed. Related issues are discussed including using fiducial marks for finding nanostructures on a macroscopic sample and protecting the chemically reactive patterned Si(100)-H surface against degradation due to atmospheric exposure.

We report a protocol for combining the atomic metrology of the Scanning Tunneling Microscope for surface patterning with selective Atomic Layer Deposition and Reactive Ion Etching. Using a robust process involving numerous atmospheric exposures and transport, 3D nanostructures with atomic metrology are fabricated.

原子纳米结构可追溯制造

Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the entire fabrication process ...

Blast Quantification Using Hopkinson Pressure Bars

Near-field blast load measurement presents an issue to many sensor types as they must endure very aggressive environments and be able to measure pressures up to many hundreds of megapascals. In this respect the simplicity of the Hopkinson pressure bar has a major advantage in that while the measurement end of the Hopkinson bar can endure and be exposed to harsh conditions, the strain gauge mounted to the bar can be affixed some distance away. This allows protective housings to be utilized which protect the strain gauge but do not interfere with the measurement acquisition. The use of an array of pressure bars allows the pressure-time histories at discrete known points to be measured. This article also describes the interpolation routine used to derive pressure-time histories at un-instrumented locations on the plane of interest. Currently the technique has been used to measure loading from high explosives in free air and buried shallowly in various soils.

This protocol details the use of Hopkinson pressure bars to measure reflected blast loading from near-field explosive events. It is capable of interpolating a pressure-time history at any point on a reflective boundary and as such can be used to fully characterize the spatial and temporal variations in loading produced.

高炉利用定量霍普金森杆

Near-field blast load measurement presents an issue to many sensor types as they must endure very aggressive environments and be able to measure pressures ...

Fabrication and Characterization of Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors (MKIDs) for the detection of faint astrophysical signatures, as well as for quantum computing applications and materials characterization. In this paper, procedures are presented for the fabrication and characterization of thin-film superconducting microwave resonators. The fabrication methodology allows for the realization of superconducting transmission-line resonators with features on both sides of an atomically smooth single-crystal silicon dielectric. This work describes the procedure for the installation of resonator devices into a cryogenic microwave testbed and for cool-down below the superconducting transition temperature. The set-up of the cryogenic microwave testbed allows one to do careful measurements of the complex microwave transmission of these resonator devices, enabling the extraction of the properties of the superconducting lines and dielectric substrate (e.g., internal quality factors, loss and kinetic inductance fractions), which are important for device design and performance.

Superconducting microwave resonators are of interest for detection of light, quantum computing applications and materials characterization. This work presents a detailed procedure for fabrication and characterization of superconducting microwave resonator scattering parameters.

制备与表征超导谐振器的

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors ...

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. The reactions of cold plasma with the surrounding atmosphere yield a variety of reactive species, which can define its effectiveness. While efficient development of cold plasma therapy requires kinetic models, model benchmarking needs empirical data. Experimental studies of the source of reactive species detected in aqueous solutions exposed to plasma are still scarce. Biomedical plasma is often operated with He or Ar feed gas, and a specific interest lies in investigation of the reactive species generated by plasma with various gas admixtures (O2, N2, air, H2O vapor, etc.) Such investigations are very complex due to difficulties in controlling the ambient atmosphere in contact with the plasma effluent. In this work, we addressed common issues of &#39;high&#39; voltage kHz frequency driven plasma jet experimental studies. A reactor was developed allowing the exclusion of ambient atmosphere from the plasma-liquid system. The system thus comprised the feed gas with admixtures and the components of the liquid sample. This controlled atmosphere allowed the investigation of the source of the reactive oxygen species induced in aqueous solutions by He-water vapor plasma. The use of isotopically labelled water allowed distinguishing between the species originating in the gas phase and those formed in the liquid. The plasma equipment was contained inside a Faraday cage to eliminate possible influence of any external field. The setup is versatile and can aid in further understanding the cold plasma-liquid interactions chemistry.

An experimental setup was created for the helium-operated kHz frequency plasma jet. The setup includes a cage for the plasma power supply and jet and an in-house built reactor to monitor plasma-induced reactive species without the interference of the ambient atmosphere.

大气压等离子体设置调查活性物种形成

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. ...

New Application of an Atmospheric Pressure Plasma Jet as a Neuro-protective Agent Against Glucose Deprivation-induced Injury of SH-SY5Y Cells

The atmospheric pressure plasma jet (APPJ) has attracted the attention of many researchers from multiple disciplines in recent years because its emissions include multiple types of reactive nitrogen species (RNS) and reactive oxygen species (ROS). Our previous study has shown the cytoprotective effect of the APPJ against oxidative stress-induced injuries. The aim of the present study is to provide a detailed in vitro treatment protocol regarding the neuroprotective applications of helium APPJs on glucose deprivation-induced injury in SH-SY5Y cells. The SH-SY5Y human neuroblastoma-derived cell line was maintained in RPMI 1640 medium supplemented with 15% fetal calf serum. The culture medium was then changed to RPMI 1640 without glucose before APPJ treatment. After a 1 h incubation in a cell incubator, cell viability was determined using Cell Counting Kit 8. The results showed that, compared to the glucose deprivation group, cells treated with APPJ exhibited significantly increased cell viability in a dose-dependent manner, with 8 s/well observed as an optimal dose. Meanwhile, helium flow had no effect on the glucose deprivation-induced cell impairment. Our results indicated that APPJ could be potentially used as a treatment method for the diseases in the central nervous system related to glucose deprivation. This protocol could also be used as a cytoprotective application for other cells with different impairments, but the cell culture and APPJ treatment conditions should be readjusted, and the treatment dose must be relatively low.

A protocol for the neuroprotective application of low-dose atmospheric pressure plasma treatment on glucose deprivation-induced SH-SY5Y injuries.

常压等离子体射流作为神经保护剂抗葡萄糖剥夺诱导 SH-SY5Y 细胞损伤的新应用

The atmospheric pressure plasma jet (APPJ) has attracted the attention of many researchers from multiple disciplines in recent years because its emissions ...