袖子与前衣片对条对格关系的研究

本文主要研究袖子结构与前衣片对条对格的关系。研究表明，要使得袖子与前衣片的条格对位，其结构应先确定袖子的袖山高为＋2．5cm，取前袖山斜线长为前AH－1．5cm，后袖山斜线长为后AH，在该袖上找到对条对格的对应点，然后保持袖肥不变，再将袖子的袖山增高0．3cm，这时袖山上总缝缩量的大小符合一般面料的需要，且分布均匀，能保证袖子与前衣片的对条对格。     

Password memorability and security: empirical results

Users rarely choose passwords that are both hard to guess and easy to remember. To determine how to help users choose good passwords, the authors performed a controlled trial of the effects of giving users different kinds of advice. Some of their results challenge the established wisdom.     

某型内燃机闭环控制减振的仿真研究

内燃机自身的振动是重型军用车辆主要的振动和噪声源,对其进行有效的振动控制十分重要.但由于内燃机系统结构的复杂性,研究其振动和噪声控制比较困难.针对某型内燃机系统,采用Matlab软件的Simulink工具,建立了整个系统的动力学仿真模型,并分别对该模型进行简谐、白噪声信号扰动下的减振控制研究,控制方法采用闭环数字PI策略.系统输出转矩和转速的曲线结果表明减振具有明显的效果.     

Effect of synthesis temperature on density and microstructure of MgB2 superconductor at ambient pressure

The experimental thermodynamic of MgB₂ synthesis process and phase compositions have been investigated by diffraction thermal analysis (DTA) technology and X-ray diffraction. The fabrication of MgB₂ bulks and superconducting properties at the temperatures range from 600 to 800°C were reported. And microstructure of MgB₂ bulks were observed by scanning electron microscope (SEM). A method was developed to determine the porosity of MgB₂ and the highest density can be obtained in MgB₂ prepared at 650°C at ambient pressure. It is found that the vapor pressure of Mg increases remarkably at high temperature, leading to the high porosity in MgB₂ samples. MgB₂ bulk with good superconducting property and fine microstructure was synthesized at 750°C.     

An accurate analytical approach to electron crystallography

A much more accurate analytical expression of dynamical electron diffraction than the phase object approximation (POA) formula has been derived in this paper which decreases the restriction of sample thickness up to almost one order of magnitude compared to POA theory. The importance of the new expression is twofold. First, a sample with such a thickness that new expression remains valid can be prepared experimentally. Second, the new expression reveals a clear and straightforward relationship between the wave function and crystal potential. In the expression, the effect of dynamical diffraction on wave function can be simply attributed to two factors TP(D) = (sin(lambda pi zg2))/(4pi2g2) and TA(D) = [1 - cos(lambda pi zg2)]/4pi2g2. Compared to the effect of transfer functions of an electron microscope on wave function, we found that TP(d) and TA(d) play the same role as transfer function but are independent of the instrument.For this reason, we here call the former as "extrinsic transfer functions" and the latter as "intrinsic" ones. In principle, one should correct not only extrinsic transfer functions but also intrinsic ones if one desires to achieve higher resolution.     

Preserving global features of fluid animation from a single image using video examples

We synthesize animations from a single image by transferring fluid motion of a video example globally.Given a target image of a fluid scene,an alpha matte is required to extract the fluid region.Our me...     

Role of ERAB/L-3-hydroxyacyl-coenzyme A dehydrogenase type II activity in Abeta-induced cytotoxicity

Endoplasmic reticulum-associated amyloid beta-peptide (Abeta)-binding protein (ERAB)/L-3-hydroxyacyl-CoA dehydrogenase type II (HADH II) is expressed at high levels in Alzheimer's disease (AD)-affected brain, binds Abeta, and contributes to Abeta-induced cytotoxicity. Purified recombinant ERAB/HADH II catalyzed the NADH-dependent reduction of S-acetoacetyl-CoA with a Km of approximately 68 microM and a Vmax of approximately 430 micromol/min/mg. The contribution of ERAB/HADH II enzymatic activity to Abeta-mediated cellular dysfunction was studied by site-directed mutagenesis in the catalytic domain (Y168G/K172G). Although COS cells cotransfected to overexpress wild-type ERAB/HADH II and variant beta-amyloid precursor protein (betaAPP(V717G)) showed DNA fragmentation, cotransfection with Y168G/K172G-altered ERAB and betaAPP(V717G) was without effect. We thus asked whether the enzyme might recognize alcohol substrates of which the aldehyde products could be cytotoxic; ERAB/HADH II catalyzed oxidation of a variety of simple alcohols (C2-C10) to their respective aldehydes in the presence of NAD+ and NAD-dependent oxidation of 17beta-estradiol. Addition of micromolar levels of synthetic Abeta(1-40) to purified ERAB/HADH II inhibited, in parallel, reduction of S-acetoacetyl-CoA (Ki approximately 1.6 microM), as well as oxidation of 17beta-estradiol (Ki approximately 3.2 microM) and (-)-2-octanol (Ki approximately 2.6 microM). Because micromolar levels of Abeta were required to inhibit ERAB/HADH II activity, whereas Abeta binding to ERAB/HADH II occurred at much lower concentrations (Km approximately 40-70 nM), the latter more closely simulating Abeta levels within cells, Abeta perturbation of ERAB/HADH II was likely to result from mechanisms other than the direct modulation of enzymatic activity. Cells cotransfected to overexpress ERAB/HADH II and betaAPP(V717G) generated malondialdehyde-protein and 4-hydroxynonenal-protein epitopes, which were detectable only at the lowest levels in cells overexpressing either ERAB/HADH II or betaAPP(V717G) alone. Generation of such toxic aldehydes was not observed in cells contransfected to overexpress Y168G/K172G-altered ERAB and betaAPP(V717G). We conclude that the generalized alcohol dehydrogenase activity of ERAB/HADH II is central to the cytotoxicity observed in an Abeta-rich environment.     

Cu(Ⅱ)-3,5-diCl-DMPAP-OP 显色反应及其应用研究

研究了在非离子表面活性剂ＯＰ存在下，２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯酚（３，５－ｄｉＣｌ－ＤＭＰＡＰ）与Ｃｕ（Ⅱ）的显色反应。实验表明，在ｐＨ７．５～１０．０的硼砂缓冲介质中，铜（Ⅱ）与试剂形成１∶２的稳定的红色配合物，其表观摩尔吸光系数ε５５８＝９．７×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，铜浓度在０～６．５μｇ／１０ｍＬ范围内符合比尔定律。在柠檬酸三钠和二酮肟的存在下，可直接用于铝合金和纯铝中微量铜的测定，获得满意结果。     

Effect of H_2 dilution on the structure and properties of nc-CrC/a-C:H coatings deposited by a hybrid beams system

Nanocomposite Cr C/hydrogenated amorphous carbon(nc-CrC/a-C:H) coatings were deposited by a hybrid beams system comprised of a hollow cathode ion source and a cathodic arc ion-plating unit with varying H_2 flow rates. The influences of H_2 flow rates on the morphologies, microstructures, and properties of the coatings were systematically studied. The morphologies and microstructures of the coatings were characterized by SEM, AFM, XPS, Raman spectroscopy, GIXRD, and HRTEM. The mechanical and tribological properties were measured by a nano-indenter, scratch tester, and ball-ondisk tribometer. The wear tracks were evaluated using 3D profilometer, optical microscope, and EDS analysis. It has been found that a moderate H_2 flow rate can effectively smooth the surface, enlarge the fraction of a sp~3 bond, and improve the properties. The coating exhibits the highest hardness and elastic modulus at the H_2 flow rate of 40 sccm. A superior combination of adhesion strength,friction coefficient, and wear resistance can be achieved at the H_2 flow rate of 80 sccm.