氮分子激光器放电电流的测量

本文从理论上计算了电容转移式氮分子激光器放电电流的变化规律，并用罗氏线圈测量了其波形，这为设计激光器放电回路提供了依据．     

矿山边坡稳定性的弹性分析

利用弹性力学理论分析法，给出在自重应力作用下的矿山边坡内最大剪应力作用面的分布规律和最大剪应力迹线，为分析边坡稳定性提供了一定的理论依据。     

Finite Element Analysis of Diamond Saw Blades to Prevent Steel Base Wear

The FEM analysis of stress and deformation of steel base of the special diamond saw blades are carried out.The small carbide round segments are welded on the side of blades in order to increase the side wear re sistance of blade.Comparing with conventional saw blade,the maximum stress val ues of reasonable special saw blade are reduced respectively about 17 % 33%,and the maximum deformation values are reduced respectively about 26" D.7%in thetangential(X),radial(Y)and axial(Z)direction.The stress co...     

Thermodynamic Parameters of Temperature‐Induced Phase Transition for Brushes onto Nanoparticles: Hydrophilic versus Hydrophobic End‐Groups Functionalization

Quantification of the stimuli‐responsive phase transition in polymers is topical and important for the understanding and development of novel stimuli‐responsive materials. The temperature‐induced phase transition of poly(N‐isopropylacrylamide) (PNIPAm) with one thiol end group depends on the confinement—free polymer or polymer brush—on the molecular weight and on the nature of the second end. This paper describes the synthesis of heterotelechelic PNIPAm of different molecular weights with a thiol end group—that specifically binds to gold nanorods and a hydrophilic NIPAm end group by reversible addition‐fragmentation chain‐transfer polymerization. Proton high‐resolution magic angle sample spinning NMR spectra are used as an indicator of the polymer chain conformations. The characteristics of phase transition given by the transition temperature, entropy, and width of transition are obtained by a two‐state model. The dependence of thermodynamic parameters on molecular weight is compared for hydrophilic and hydrophobic end functional‐free polymers and brushes.     

Effects of alkyl side chains positioning and presence of fused aromatic units in the backbone of low‐bandgap diketopyrrolopyrrole copolymers on the optoelectronic properties of organic solar cells

The systematic optimization of the chemical structure of low‐bandgap (LBG) donor‐acceptor polymeric semiconductors is a challenging task for which accurate guidelines are yet to be determined. Several different structural and molecular parameters are crucial ingredients for obtaining LBG polymers that simultaneously possess high power conversion efficiencies, good processability in common organic solvents, and enhanced stability in organic photovoltaic devices. In this work, we present an extensive structure–optoelectronic properties–solar cell performance study on the emerging class of diketopyrrolopyrrole‐based LBG polymers. In particular, we investigate alkyl side chain positioning by introducing linear alkyl side chains into two different positions (α‐ and β‐), and the distance of the electron rich and electron deficient monomers within the repeat units of the polymer chain. We demonstrate that anchoring linear alkyl side chains to the α‐positions and introducing fused moieties into the polymer backbone, can be beneficial toward maintaining photocurrents similar to the unsubstituted derivative, and concurrently exhibit better processabiliy in common organic solvents. These results can provide a design rationale towards further optimization of semiconducting polymers. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 138–146     

Wirelessly powered dielectrophoresis of metal oxide particles using spark-gap Tesla coil

Wirelessly powered dielectrophoresis (DEP) of metal oxide particles was performed using a spark-gap Tesla coil (TC). The main contribution of this work is the simplification of the conventional DEP setup that requires attaching wires directly to the electrodes. Wireless power from the TC generates a high output frequency and voltage, which corresponds to that used for the DEP. Therefore, a spark-gap TC was built and utilized to conduct the DEP process. Metal oxides (ZnO and Fe₂O₃) were used as targets for the assembly. The results showed that the wirelessly powered DEP technique via a TC was successful in assembling the metal oxide particles. Positive and negative DEP phenomena were observed. Positive DEP occurred during ZnO assembly, making particles chain grow 0.92 mm toward the sparks within 60 s. Negative DEP was observed during Fe₂O₃ assembly, where the repulsion of particles formed a void around the sparks with a 1.45 mm radius. The mechanism of this wireless DEP system is discussed.     

微分环在强流陡脉冲测量中的抗干扰研究

论述了测量强流陡脉冲的微分环存在不可避免的内部电感应干扰信号,采用中部开缝屏蔽的微分环对降低这种干扰效果是明显的,其微分信号测量信噪比为２７,而双微分环差动平衡抗干扰技术的采用,更使微全测量信噪比达５７。     

右端项为L~1时具退化强制椭圆方程弱解的存在性

利用方程零阶项系数与右端项的正则化效应,考虑一类具退化强制和低阶项的椭圆型方程.当方程的右端项f仅在L~1时,得到了其弱解的先验一致L∞估计,并证明了其弱解的存在性.     

聚乙烯丙纶双层双面复合防水卷材 在屋面防水工程中的施工工艺

介绍新型防水材料聚乙烯丙纶双层双面复合防水卷材的结构特点、技术性能及施工方法和施工中的注意事项，并对其作出效益分析.     

闭式组合机身拉紧螺栓的可靠性设计理论研究

在分析了闭式组合机身拉紧螺栓传统设计方法存在问题的基础上，指出了对其进行可靠性设计的必要性．深入地分析了其受力及失效机理，首次建立了机械压力机闭式组合机身拉紧螺栓在压力机工作时的应力波动范围、应力幅、平均应力及其循环特性的表达式，建立了闭式组合机身拉紧螺栓完整的可靠性设计理论．