Influence of nitrogen plasma post-treatment on diamond-like carbon films synthesized by RF plasma enhanced chemical vapor deposition

DLC films were synthesized by RF plasma enhanced chemical vapor deposition and the effects of nitrogen plasma post-treatment at different pressures on the structure and properties of DLC films were investigated. Higher roughness was obtained after plasma post-treatment at higher pressures (0.3 and 0.9 torr) and plasma post-treatment at a lower pressure (0.15 torr) resulted in lower roughness than that of original films. The hardness of DLC films decreased with the decrease of post-treatment pressure, which is consistent with the Raman results of I_D/I_G ratio and G peak position. Compared to the original DLC film, the residual stress after plasma post-treatment decreased slightly due to the relatively thin region involved in the plasma post-treatment.     

Performance characteristic studies of glucose biosensors modified by (3-mercaptopropyl)trimethoxysilane sol–gel and non-conducting polyaniline

The materials (3-mercaptopropyl)trimethoxysilane (MPTMS) sol–gel and non-conducting polyaniline (PAn) were prepared for coating on two different amperometric biosensors fabricated by the immobilization of glucose oxidase (GOx) in conducting polyaniline (PA) as permselective membranes. A few performance characteristics of the MPTMS and the PAn-modified glucose sensors are comparable. In detecting 1 mM glucose, the biosensors’ response times were 11 and 12 s, respectively, and results from the repeating measurements (N = 10) showed that R.S.D. = 2.09 and 1.70%, respectively. The detection linearity of the two biosensors was up to 12.5 mM with R = 0.9989 and 0.9969. When they were used to detect 0.5 mM of ascorbic acid (AA), uric acid (UA), and acetaminophen at an anodic potential of 0.4 V, current signals were either insignificant or invisible. The PAn-coated glucose sensor exhibited superior sensitivity at 18.91 μA/(mM cm²), and a maximum current density of 3.70 mA/cm². GOx in the MPTMS-modified biosensor presented a stronger affinity to glucose with K_m = 48.87. More importantly, the stability of this biosensor is superior to that of the PAn-modified biosensor and has lasted for almost 5 months.     

某矿用特种车辆全轮转向机构的仿真及优化

在动力学仿真软件环境中建立全轮转向机构的参数化模型,通过优化确定该机构中各个铰接点的最佳空间位置,使得车轮在转向过程中的滑移率较小,从而达到减小轮胎磨损和降低能耗的目的。     

Surface characterization and nanomechanical properties of diamond-like carbon films synthesized by RF plasma enhanced chemical vapor deposition

Diamond-like carbon (DLC) films were synthesized by RF plasma enhanced chemical vapor deposition using acetylene as the carbon source and the effects of acetylene/nitrogen ratio in the reaction atmosphere, deposition pressure, and plasma post-treatment using different atmospheres on the surface roughness and mechanical properties of DLC films were investigated. Although the surface roughness, characterized by AFM, decreased as the acetylene/nitrogen ratio in the reaction atmosphere decreased, the hardness of DLC films measured by nanoindentation also decreased with the decrease of the acetylene/nitrogen ratio, which is consistent with the Raman results of the I_D/I_G ratio. Rougher films with higher residual stress were obtained when using a deposition pressure higher than 40.0 Pa (0.3 torr). For the effect of plasma post-treatment using different atmospheres, surface smoothing was found for the hydrogen plasma post-treatment, whereas nitrogen and argon plasma post-treatments resulted in surface roughening. Hydrogen plasma post-treatment was found to lower the surface roughness without significantly sacrificing the hardness.     

图论中最短路径问题算法程序的开发

研究了图论中的最短路径问题算法程序的开发。首先,介绍了最短路径问题的概念和最短路径问题的算法。然后在Delphi7．0环境下开发目前最短路径问题算法的流程。最后,通过实例对最短路径问题的算法程序进行了验证。所开发的算法程序直观简捷,方便工程人员的使用。     

物理场技术在水产品冷冻冷链中的应用

在冷链流通过程中, 对新鲜水产品进行冷冻处理能够大大提高其保质期。然而, 传统的冷冻和解冻方法有传热效率低、耗时较长的缺陷, 且难以控制冰晶对食品原料的损伤。所以冷冻水产品经常会面临一系列的质量问题, 如质构劣化、蛋白质变性、持水能力下降等。因此有必要采用高效的冷冻/解冻技术以防止品质劣变。相比于传统方法, 基于物理场(如高压、超声、电场等)的新型冷冻和解冻技术具有高冷冻/解冻速率、低能耗、对产品品质维持更好等优点。本文综述了近年来物理场技术在水产品中的应用, 分析了它们各自的原理、特点、缺陷及未来的发展趋势, 为这些新技术在水产品冷冻冷链中的应用提供相关参考。     

球笼万向节在某型矿车轮边减速器上的应用

介绍了球笼万向节结构特征,通过Hertz接触理论得出各规格球笼式万向节的理论计算转矩,-根据某型矿车实际工况选用了合适的球笼万向节,实现了轮边减速器传动、转向和承栽的功能。     

高速旋转非对称支撑结构的有限元分析

目前,对高速旋转的非对称结构的离心变形分析尚停留在常规计算阶段,结构轻量化和抗变形能力的矛盾体现—最佳宽厚比难以确定,使得设计裕度较大.本文对此类结构的一个典型算例-偏心光刀组件进行了有限元分析,通过参数化设计建立了一系列光刀组件模型,计算了不同宽度、厚度、材料的多种光刀组件模型的离心变形,分析了变形趋势,确定了光刀的...     

某矿用特种车转向油缸参数的确定

分析了该矿车全轮转向机构的工作特点,介绍了该型矿车转向半径和转向阻力矩的计算方法,并运用动力学仿真的方法确定该型矿车转向油缸的主要参数。