Electron microscope studies of nano-domain structures in Ru-based magneto-superconductors: RuSr(2)Gd(1.5)Ce(0.5)Cu(2)O(10-delta) (Ru-1222) and RuSr(2)GdCu(2)O(8) (Ru-1212)

Microstructures of the RuSr(2)Gd(1.5)Ce(0.5)Cu(2)O(10-delta) (Ru-1222) and RuSr(2)GdCu(2)O(8) (Ru-1212) magneto-superconductors have been investigated by using selected-area electron diffraction, convergent-beam electron diffraction, dark-field electron microscopy and high-resolution electron microscopy at room temperature. Both Ru-1212 and Ru-1222 consist of nm-size domains stacked along the [Formula: see text] direction, where the domains are formed by two types of superstructures due to ordering of rotated RuO(6) octahedra about the c-axis. In Ru-1212, both primitive-and body-centered tetragonal superstructures (the possible space groups: P4/mbm and I4/mcm) are derived to form the corresponding nm-domains. It is of great interest that Ru-1212 consists of domains of two crystallographically different superstructures, while the similar domains observed in Ru-1222 have crystallographically identical superstructure with an orthorhombic symmetry (possible space group: Aeam), related by 90 degrees rotation around the c-axis (Yokosawa et al., 2003, submitted for publication).     

Antennal sensilla of Eucryptorrhynchus chinensis (Olivier) and Eucryptorrhynchus brandti (Harold) (Coleoptera: Curculionidae)

Eucryptorrhynchus chinensis (Olivier) (Coleoptera: Curculionidae) and E. brandti (Harold) (Coleoptera: Curculionidae) are the two most important pests of tree‐of‐heaven, Ailanthus altissima (Mill.) Swingle and its variety Ailanthus altissima var. Qiantouchun in China. They are also considered potential biological control agents for tree‐of‐heaven in North America. In this study, the external morphologies and antennal sensilla of both species were examined using scanning electron microscopy to better understand their host‐finding mechanisms. Eleven morphological sensilla types were recorded, that is, Böhm bristles, six types of sensilla chaetica (Sch. 1–6), two types of sensilla basiconica (Sb. 1–2), and two types of sensilla trichodea (St. 1–2). Sch. 5 were absent from the antennae of E. chinensis, while Sch. 2 were absent from the antennae of E. brandti. Abundant cuticular pores were present on the antennae of both species. Three types of sensilla on the antennae of E. chinensis that were not found in a previous study, and ten different types of sensilla on the antennae of E. brandti were identified for the first time. The possible functions of the sensilla types are discussed based on a comparison with previous studies. Four types of sensilla (Sb. 1, Sb. 2, St. 2, and Sch. 6) on the antennae of both species indicate chemoreception may play a significant role in host location. Microsc. Res. Tech. 76:968–978, 2013. © 2013 Wiley Periodicals, Inc.     

不同相变行为Ti_(50.6)Ni_(19.4)Pd_(30)合金的力学性能表征

制备了可以呈现两种相变行为的Ti_(50.6)Ni_(19.4)Pd_(30)高温形状记忆合金。力学性能试验结果表明,与B2-B19一阶相变的合金试样相比,当合金呈现B2-B19-B19’两阶相变时,试样的力学性能差异明显。在一阶相变的合金试样的断口形貌上观察到了较多的空洞和韧窝。两种合金试样在亚稳奥氏体状态下,都获得了完全的线性伪弹性。由于B19’相较大的弹性模量,B19’-B19相变使得两阶相变合金弹性模量曲线在相变区表现为一个台阶,B2-B19相变对应于曲线的凹谷。     

铁磁性形状记忆合金Ni_(50)Ga_(27)Fe_(17)Co_6的阻尼性能

采用低频扭摆仪研究了铁磁性形状记忆合金Ni50Ga27Fe17Co6的阻尼性能与应变振幅、频率及温度的关系.结果表明:当应变振幅小于7.5×10-5时,Ni50Ga27Fe17Co6合金的阻尼性能主要取决于频率,当应变振幅大于7.5×10-6时,其阻尼性能主要取决于应变振幅;当该合金处于马氏体相和奥氏体相共存时具有高阻尼性能,当应变振幅为5×10-5,频率为0.1 Hz时,合金最大阻尼值为0.11.     

Boundary Lubrication of Oxide Surfaces by Poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) in Aqueous Media

In this work, we have explored the application of poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) as an additive to improve the lubricating properties of water for metal-oxide-based tribo-systems. The adsorption behavior of the polymer onto both silicon oxide and iron oxide has been characterized by optical waveguide lightmode spectroscopy (OWLS). Several tribological approaches, including ultra-thin-film interferometry, the mini traction machine (MTM), and pin-on-disk tribometry, have been employed to characterize the frictional properties of the oxide tribo-systems in various contact regimes. The polymer appears to form a protective layer on the tribological interface in aqueous buffer solution and improves both the load-carrying and boundary-layer-lubrication properties of water.     

Proteomics of brain extracellular fluid (ECF) and cerebrospinal fluid (CSF)

Mass spectrometry has become the gold standard for the identification of proteins in proteomics. In this review, I will discuss the available literature on proteomic experiments that analyze human cerebrospinal fluid (CSF) and brain extracellular fluid (ECF), mostly obtained by cerebral microdialysis. Both materials are of high diagnostic value in clinical neurology, for example, in cerebrovascular disorders like stroke, neurodegenerative diseases like Alzheimer's Disease, Parkinson's Disease, amyotrophic lateral sclerosis (ALS), traumatic brain injury and cerebral infectious and inflammatory disease, such as multiple sclerosis. Moreover, there are standard procedures for sampling. In a number of studies in recent years, biomarkers have been proposed in CSF and ECF for improved diagnosis or to control therapy, based on proteomics and mass spectrometry. I will also discuss the needs for a transition of research‐based experimental screening with mass spectrometry to fast and reliable diagnostic instrumentation for clinical use. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 29:17–28, 2010     

Electric field-induced changes of W(110) and W(111) tips

Using field emission and scanning electron microscopy we have studied the influence of strong electric fields on the thermally induced growth behaviour of field emission tips. For smaller fields (i.e. smaller than needed for a satisfactory field emission image) we observe an enlargement of low-index faces, which for higher fields develops into a building-up of micro-structures and roughening on the initially spherical part of the tip surface. In an intermediate state only the region near the (111) directions contributes to the field emission pattern. For the highest fields employed the results indicate the growth of local protrusions preferentially near (100) faces. Our results show that in scanning tunnelling microscopy W(111) tips should be superior to the commonly used W(110) tips.     

先进生产力展览会HOUSTEX(R)2002

由美国制造工程师学会(SME)和美国机床分销商协会(AMTDA)联合主办,美国制造技术协会(AMT)参加的先进生产力展览会HOUSTEX将于2002年4月9—11日在美国得克萨斯州的休斯顿George R.Brown会议中心举行。这是休斯顿最时兴的机床和金属加工展览会。靠展会旁边举办由SME负责的技术项目主要聚焦于先进     

Morphology of immature stages of Dohrniphora cornuta (Bigot) (Diptera: Phoridae)

Morphology of all larval instars and puparium of Dohrniphora cornuta (Bigot), a most common phorid fly species indoors in China, is presented using scanning electron microscopy. The first instar larva was composed of 12 segments, each of segments 3–11 with six slender tubercles situated dorsally, dorsolaterally, and laterally in transverse row. These tubercles divided into two segments, of which the basal one was smooth, and the brush‐shaped distal one was comprised of a cluster of fine spines. Antennae and maxillary palp complex were visible. Two slits could be seen at the posterior spiracle. Besides the presence of anterior spiracle, the tubercles of second instar became stouter than those of first instar and were covered by numerous long bristles from the base to top. The posterior spiracle contained four slits. Third larval instar was similar to second instar. The bubble membrane comprised of ≈120 globules with a pointed tip on their top presented at the segment 5 of third instar larvae. Puparia showed a retracted cephalic region and a pair of distinct pupal respiratory horns on the dorsum. The respiratory horns were long and bore numerous branches from base to apex. The apex of branch with two longitudinal slits was relatively broad and curled dorsally. Microsc. Res. Tech. © 2012 Wiley Periodicals, Inc.     

关于F(s)和F(z)对应性的研究

在计算机测控系统上应用控制理论,首先要建立被控对象的时间离散的数学模型.把s传递函数近似转换成z传递函数的方法很多,用"L变换和Z变换表"得到的z传递函数对于脉冲输入的响应性能相当满意,然而对于阶跃输入的响应虽然形状相似而幅度相差太大以至于不能用.反之,用MATLAB的control-tools得到的z传递函数对于阶跃输入的响应性能相当满意,然而对于脉冲输入的响应虽然形状相似而幅度相差太大以至于不能用.这是每个应用计算机控制理论的工程师必须知道的知识.     

抗癌药物3-吖啶氨基-5羟甲基苯胺(AHMA)的晶体结构分析

本文用X射线晶体衍射法分析了抗癌药物3-吖啶氨基-5羟甲基苯胺(3-(9-acridiny-lamino)-5-(hydroxymethyl)aniline,AHMA)的分子结构。AHMA的化学式为C_(20)H_(17)N_3O,Mr=315.37。晶体属三斜晶系,空间群为P-1。晶胞参数晶胞参数:α=8.043(2),b=9.949(2),c=11.631(3)A,α=69.78(1)°,β=84.02(1)°,γ=65.70(1)°。经最小二乘修正后得到的R_1值为0.051。在晶体结构中,吖啶环和苯胺环几乎相互垂直,两个环平面之间的两面角为66.5°。这种结构有利于AHMA以嵌插于DNA碱基对的形式与DNA结合。     

0.95K_(0.47)Na_(0.47)Li_(0.06)NbO_3-0.05Ba_xSr_(1-x)TiO_3无铅压电陶瓷的微观结构与性能

采用传统的陶瓷制备技术制备了0.95K0.47Na0.47Li0.06NbO3-0.05BaxSr1-xTiO3体系无铅压电陶瓷,研究了该体系陶瓷的微观结构与压电、介电性能。结果表明:在1 165℃烧结4 h的条件下,该体系陶瓷能形成单一的钙钛矿型结构;随着x值的增大,陶瓷的压电、介电性能先增后降,并在x为0.85时性能达到最佳,其压电常数为136 pC/N,机电耦合系数为39%,机械品质因数为146,介电常数为1 327,介质损耗为0.021。     

Ethanol (C(2)H(5)OH) spray of sub-micron droplets for laser driven negative ion source

Liquid ethanol (C(2)H(5)OH) was used to generate a spray of sub-micron droplets. Sprays with different nozzle geometries have been tested and characterised using Mie scattering to find scaling properties and to generate droplets with different diameters within the spray. Nozzles having throat diameters of 470 μm and 560 μm showed generation of ethanol spray with droplet diameters of (180 ± 10) nm and (140 ± 10) nm, respectively. These investigations were motivated by the observation of copious negative ions from these target systems, e.g., negative oxygen and carbon ions measured from water and ethanol sprays irradiated with ultra-intense (5 × 10(19) W∕cm(2)), ultra short (40 fs) laser pulses. It is shown that the droplet diameter and the average atomic density of the spray have a significant effect on the numbers and energies of accelerated ions, both positive and negative. These targets open new possibilities for the creation of efficient and compact sources of different negative ion species.     

LON-LAN-WAN开放式控制系统与数据的网络集成

数据的网络集成是在网络中实现信息共享的关键，采用开放式控制系统是实现数据网络集成的最佳途径。我们先介绍一下开放式控制系统与封闭式控制系统的区别，然后讨论如何在LON、LAN（局域网）和WAN（广域网）之间实现数据的网络集成。     

块状Cu_(60)Zr_(30)Ti_(10)非晶合金激光熔凝层的组织和硬度

采用水冷铜模真空吸铸法制备了块状Cu60Zr30Ti10非晶合金,用Nd:YAG激光束(功率201.6 W)分别以20,40,60 mm·s-1的速度对合金表面进行重熔处理,采用X射线衍射仪、光学显微镜、显微硬度计和电子探针等研究了熔凝层的显微组织和不同深度的显微硬度.结果表明:经20 mm2·s-1的激光重熔后,在块状非晶合金基体表面形成了两层新的组织,其中位于中间厚度约200 μm第二层的硬度、耐腐蚀性均比基体的有明显改善,显微硬度达到873 HV,该区域铜原子在弥散分布的尺寸为0.2～1μm微区聚集.     

Surface Texture Effect on Friction of a Microtextured Poly(dimethylsiloxane) (PDMS)

The effect of surface textures on the friction of a poly(dimethylsiloxane) (PDMS) elastomer has been investigated at both macro and microscales using a nanoindentation-scratching system. Friction tests were conducted by a stainless-steel bearing ball with a diameter of 1.6 mm (macroscale tests) and a Rockwell diamond tip with a radius of curvature of 25 μm (microscale tests) under normal loads of 5, 10, and 25 mN and with a sliding speed of 1 μm/s. Coefficient of friction (COF) on the pillar-textured surface was found to be much lower than that on the smooth surface of the same material, and it was reduced by about 59% at the macroscale tests and 38% at the microscale tests. The reduction of COF can be attributed to the reduced contact areas. The use of the JKR model revealed that the adhesion force has less effect on contacts under higher normal loads. COFs in different sliding directions on the groove-textured surfaces were compared, and a friction anisotropic behavior was identified and analyzed.