滚子摆动从动杆盘状凸轮廓线的间接检测原理

本文提出了一种间接检测摆动从动杆盘状凸轮廓线的方法及其程序系统,论证了间接检测的基本原理,推导了直动滚子测头当量位移与摆动从动杆位移相互换算的公式,并编制了间接测量的程序系统,包括换算程序、样条插值程序及估计理论计算误差程序等。     

Interpenetrating polymer network structured thermosets prepared from epoxidized soybean oil/diglycidyl ether of bisphenol A

Epoxidized soybean oil (ESO)/diglycidyl ether of bisphenol A (DGEBA) in various blend ratios (i.e. 100/0, 90/10, 80/20, 70/30, 60/40, 50/50) was thermally cured using methylhexahydrophthalic anhydride in the presence of 2‐ethyl‐4‐methylimidazole catalyst. The tensile properties and fracture toughness of the ESO/DGEBA thermoset blends were determined. Thermal properties of the blends were characterized using dynamic mechanical analysis, differential scanning calorimetry and thermogravimetric analysis. Blending of ESO and DGEBA gave synergistic effects on the modulus, strength, glass transition temperature and thermal stability. However, the fracture toughness and elongation at break of ESO/DGEBA blends are lower than those of ESO, as expected. The enhancement in certain mechanical and thermal properties of ESO/DGEBA can be associated with the crosslink density, gel content and possible interpenetrating network of the resulting thermoset blends. © 2013 Society of Chemical Industry     

土体标度分布参数与其物理力学性质的关系研究

土体标度分布参数可以客观地表达土体颗粒组成的整体特征,便于建立其与土体物理力学性质之间的定量关系,具有重要的理论意义和实际应用价值.以土体的标度分布理论为基础,结合土体渗透实验和直剪实验,研究了土体标度分布参数与其渗透系数、抗剪强度指标(黏聚力、内摩擦角)的关系,结果表明:土体渗透系数K与标度分布参数μ呈负对数关系,与...     

慢性粒细胞白血病树突状细胞对T细胞增殖作用的研究

目的　体外诱导慢性粒细胞白血病 (CML)患者外周血单个核细胞 (PBMCs)为树突状细胞 (DCs) ,并对其形态、表型及对T细胞刺激增殖作用进行研究。方法　利用GM CSF、IL 4、TNF α体外定向诱导生成树突状细胞 ,对所诱生的细胞进行细胞表型及形态检测 ,用D FISH方法检测所诱生DCs的白血病源性 ,应用MTT法检测所诱生的DCs刺激T细胞增殖的能力。结果　CML患者PBMCs在体外可诱导生成bcr/abl融合基因阳性的DCs(CMLDCs)。CMLDCs对自体T细胞有明显刺激增殖作用 ,而CML细胞无此作用。CMLDCs刺激同一异体T细胞增殖能力弱于正常DCs,但当培养体系中加入 30 0U/ml干扰素 α(IFN α)时可使其刺激能力接近正常DCs。结论　CMLDCs具有刺激自体及异体T细胞增殖的能力 ,但对异体T细胞的刺激作用弱于正常DCs,IFN α可提高CMLDCs刺激T细胞增殖能力     

硅灰石/环氧树脂增强体系性能研究

通过对针状硅灰石粉进行干法表面化学改性,制成不同粒径的增强填料。并填充于环氧树脂中进行十字交叉法试验,探讨了硅灰石／环氧树脂体系的增强机理。力学性能测试结果表明：环氧树脂经硅灰石填充后．可显著提高机械强度和硬度;改性硅灰石与未改性硅灰石相比,改性后填充量增大,增强效果明显。同一粒径的硅灰石,随填充量的增加,环氧树脂的机械强度增大。硅灰石粒径越小。比表面积越大。与环氧树脂的结合力越强,强度越大。     

Synchrotron radiolysis and mass spectrometry: a new approach to research on the actin cytoskeleton

Hydroxyl radicals generated from millisecond exposure of aqueous solutions to synchrotron X-rays react with proteins to yield stable oxidative modifications of solvent-accessible amino acid side chains. Following proteolysis, HPLC/MS analysis is performed to quantitate the side chain reactivities, and MS/MS analysis is used to identify the modification site(s). Side chain reactivity is shown to be correlated with solvent accessibility; thus the method provides detailed site-specific information about protein structure. The application of these techniques to the study of the actin cytoskeleton is described in detail, including defining the binding sites of monomeric actin with gelsolin segment-1, the actin monomer binding surface on cofilin, the divalent cation-dependent structure changes of monomeric actin, and the conformational changes associated with actin filamentous assembly.     

水性聚氨酯/纳米二氧化硅杂化材料的研究进展

介绍了制备水性聚氨酯(WPU)/纳米Si O2(二氧化硅)杂化材料的几种方法(如纳米Si O2表面改性法、溶胶-凝胶法和原位聚合法等),特别综述了采用化学接枝改性法制备纳米Si O2和溶胶-凝胶法制备共价键连接的杂化材料的研究进展。最后对WPU/纳米Si O2杂化材料的发展方向提出了建议。     

填充聚合物的旋转成型

本文在理论上探讨了聚合物在旋转成型中填充的可能性。根据填料颗粒在熔体中的运动方程,求出其位移速度V(τ)的函数表达式: V(τ)=α(τ)+mα/6πηγ(e~(-(6πηγ/m)τ)-1) 列出斯托克斯力的平衡方程,在给出有关参数后,便得到模型的旋转极限频率(ω_c): ωc=3/2γ(η⊿b/ρ_1⊿τR)~(1/2) 当模型旋转达到此频率时,则填料颗粒就会均匀分布在整个制品体积中。实验证明,上述理论是合理的。