The Atmospheric Scanning Electron Microscope with open sample space observes dynamic phenomena in liquid or gas

Although conventional electron microscopy (EM) requires samples to be in vacuum, most chemical and physical reactions occur in liquid or gas. The Atmospheric Scanning Electron Microscope (ASEM) can observe dynamic phenomena in liquid or gas under atmospheric pressure in real time. An electron-permeable window made of pressure-resistant 100 nm-thick silicon nitride (SiN) film, set into the bottom of the open ASEM sample dish, allows an electron beam to be projected from underneath the sample. A detector positioned below captures backscattered electrons. Using the ASEM, we observed the radiation-induced self-organization process of particles, as well as phenomena accompanying volume change, including evaporation-induced crystallization. Using the electrochemical ASEM dish, we observed tree-like electrochemical depositions on the cathode. In silver nitrate solution, we observed silver depositions near the cathode forming incidental internal voids. The heated ASEM dish allowed observation of patterns of contrast in melting and solidifying solder. Finally, to demonstrate its applicability for monitoring and control of industrial processes, silver paste and solder paste were examined at high throughput. High resolution, imaging speed, flexibility, adaptability, and ease of use facilitate the observation of previously difficult-to-image phenomena, and make the ASEM applicable to various fields.     

Deuterium trapping by irradiation damage in tungsten induced by different displacement processes

The deuterium trapping behaviors in tungsten damaged by light ions with lower energy (10 keV C⁺ and 3 keV He⁺) or a heavy ion with higher energy (2.8 MeV Fe²⁺) were compared by means of TDS to understand the effects of cascade collisions on deuterium retention in tungsten. By light ion irradiation, most of deuterium was trapped by vacancies, whose retention was almost saturated at the damage level of 0.2 dpa. For the heavy ion irradiation, the deuterium trapping by voids was found, indicating that cascade collisions by the heavy ion irradiation would create the voids in tungsten. Most of deuterium trapped by the voids was desorbed in higher temperature region compared to that trapped by vacancies. It was also found that deuterium could accumulate in the voids, resulting in the formation of blisters in tungsten.     

一种直流微电网多光伏变换器新型功率分配策略

为了解决光伏单元在运行过程中因工作模式切换造成的母线电压波动问题,提出一种新型平滑切换控制策略。根据光伏电池的输出特性曲线,将输出功率对输出电流的微分作为控制变量。通过跟踪不同的dp/di指令值来实现光伏单元最大功率点跟踪模式、恒压下垂模式的控制以及两种模式间的平滑切换。在此基础上,针对多光伏变换器工作在恒压下垂控制时因线路阻抗差异造成功率分配精度较低的问题,提出一种基于二次调节的自适应下垂控制策略。此外,构建相邻光伏单元间的稀疏通信网络,并采用动态一致性算法实现相关平均信息的全局稳定收敛。仿真和实验结果表明,所提控制策略可以实现光伏单元工作模式切换过程平滑过渡和负荷功率的精确分配。     

Fe-Ni-Si基奥氏体时效合金的马氏体相变和形状记忆效应

It is well known that the morphologies of the α martensite formed from the γ phase in ferrous alloys are classified into five types of lath, butterfly, (225)A type plate,lenticular and thin-plate. Among those α martensites, onlythe thinplate martensite, which is characterized by containing a high density of transformation twins, has a potential of exhibiting a perfect shape memory (SM) effect.Recently the present authors found in Fe-Ni-Si alloys that the thin-plate martensite is formed by the introduction of fine and coherent γ-(Ni,Fe)3Si particles with a L12 ordered structure in the austenite matrix due to ausaging. In the present study, the SM properties of the ausaged Fe-Ni-Si alloys with the thin-plate martensite are investigated by a conventional bending-test. The effects of the addition of Co to the Fe-Ni-Si alloys on the martensitic transformation and the SM properties are also investigated. It is shown that while the ausaged Fe-Ni-Si ternary alloys exhibit an imperfect SM effect due to reverse transformation from stress-induced thin-plate martensite to austenite, the SM properties are improved by the addition of Co. An almost perfect SM effect is confirmed in the Fe-Ni-Si-Co alloys by heating to 1 100 ℃ after deformation at -196 ℃.     

Molecular beam epitaxial growth of SrO and CaO with RHEED intensity oscillation

SrO and CaO, related compounds of BSCCO superconductor, are grown onto SrTiO₃(100) substrates with molecular beam epitaxy(MBE) technique. During growth, the specular spots of RHEED patterns show intensity oscillations, indicating two dimensional growth. The periods of oscillations are utilized to calculate the atom fluxes. It is shown that sublimation processes of both Sr and Ca metals in the effusion cells are stable under the growth condition of oxide films. The periods of oscillations during the SrO growth are independent of substrate temperature, confirming that Sr atoms are oxidized immediately and stay on the substrate surface without re-evaporation. These informations are practically available for precise control of the atomic layer controlled MBE of BSCCO superconductor thin films.On leave from Superconductiivity Research Laboratory, ISTEC.     

Psychological Stress Exacerbates Inflammation of the Ileum via the Corticotropin-Releasing Hormone-Mast Cell Axis in a Mouse Model of Eosinophilic Enteritis

The effects of psychological stress on eosinophilic gastrointestinal disorders have not been elucidated. This study investigated the effects of psychological stress in a mouse model of eosinophilic enteritis (EoN). BALB/c mice were treated with ovalbumin (OVA) to create an EoN model and subjected to either water avoidance stress (WAS) or sham stress (SS). Microscopic inflammation, eosinophil and mast cell counts, mRNA expression, and protein levels of type 2 helper T cell (Th2) cytokines in the ileum were compared between groups. We evaluated ex vivo intestinal permeability using an Ussing chamber. A corticotropin-releasing hormone type 1 receptor (CRH-R1) antagonist was administered before WAS, and its effects were analyzed. WAS significantly increased diarrhea occurrence and, eosinophil and mast cell counts, and decreased the villus/crypt ratio compared to those in the SS group. The mRNA expression of CRH, interleukin IL-4, IL-5, IL-13, eotaxin-1, and mast cell tryptase β2 significantly increased, and the protein levels of IL-5, IL-13, and OVA-specific immunoglobulin E (IgE) also significantly increased in the WAS group. Moreover, WAS significantly increased the intestinal permeability. The CRH-R1 antagonist significantly inhibited all changes induced by WAS. Psychological stress exacerbated ileal inflammation via the CRH-mast cell axis in an EoN mouse model.     

不同含盐量挂面食品的离子释放与存留研究

运用等离子体发射光谱仪和离子色谱仪检测干基挂面及其煮制后的钾离子、钠离子在固液两相中的含量.煮制之后,钠存留率与干基挂面横截面积呈线性正方向关系,钠流失率与干基挂面横截面积呈线性反方向关系;与之相反,钾存留率与干基挂面横截面积呈线性反方向关系,钾流失率与干基挂面横截面积呈线性正方向关系.干基挂面横截面积对钠元素溶出行为...     

DRTE:面向基础教育的术语抽取方法

术语抽取从非结构化文本中自动抽取专业术语。该工作在中文分词、信息抽取、知识库构建中发挥着重要的作用。当前术语抽取方法很大程度上依赖于词的统计信息,由于基础教育学科中术语具有极强的长尾特性,导致基于统计的术语抽取方法很难抽取出处于尾端的术语。该文结合基础教育的学科特点,提出了DRTE: 一种利用术语定义与术语关系挖掘,综合构词规则与边界检测的术语抽取方法。该文以初高中的数学课本为数据源进行术语抽取,实验结果表明我们的术语抽取方法F1值达到82.7％,相比目前的方法提高了40.8％,能够有效地在中文基础教育领域进行自动化的术语抽取。     

The characteristics of the external‐electrode mercury fluorescent lamp for backlighting liquid‐crystal‐television displays

Abstract— A reliable external‐electrode mercury fluorescent lamp (EEFL) has been developed for backlighting a liquid‐crystal‐television (LC‐TV) display. This involved the investigation of the EEFL characteristics and the improvement in the construction of the EEFL and drive waveforms, in the frequency range of 50–200 kHz, that affects the EEFL characteristics. The results showed that a sinusoidal waveform is suitable for driving the EEFL, and EEFL's voltage decreases when the frequency of the drive waveform is increased.     

应对脱离配电网情况的单三相多微网组合分析及切换控制

考虑单相及三相微网两者在地域上接入较为相近,互联而形成单三相多微网系统。由于其复杂的运行方式,亟待解决如何实现多微网灵活无缝切换的问题。介绍了单三相多微网系统拓扑结构;当多微网系统为应对脱离配电网情况时,即常规主动并转离,通过互联方案预筛选得到初始方案后,基于模糊多目标决策得到多微网互联方案;通过给定的互联方案目标进行系统状态平滑切换。所提策略经算例验证可行,为多微网切换控制技术提供建议性方案。