基于欧玛技术的大学英语考试总评成绩计算方法

以基于欧玛技术的阅卷系统为例,介绍了用Excel实现大学英语分类成绩的接口及合并计算总评成绩的基本方法与步骤.     

Failure analysis and wear mechanism study of a heavily loaded gear

Failure analysis and a study of the wear mechanism were performed on a heavily loaded carburized gear with some unusual features. The analysis showed that the different failure forms on the tooth surface of the gear were dependent on the sub-surface shearing stress, the lubrication conditions and the surface roughness. Delaminations formed on the addendum surface were the main reason for the gear failure. A suggestion for improvement has been tried, and a desirable result has been obtained.     

Microstructures and Plastic Anisotropy of As—Cast Low Carbon Steel Strips

对比研究了低碳钢带铸材不同处理状态钢带和薄板铸坯中不同位置切片的组织特征、晶体学织构和15％工程应变条件下的塑性异向性．结果表明，带铸材试样中存在{111}与{114}特征织构，织构强度均较弱；铸坯切片中存在{111}与{001}特征织构，并且因局部凝固冷速不同存在明显的织构强度差异．两组低碳钢的法向异向性与平均晶粒尺寸的对数之间尽管均存在线性关系，但斜率明显不同．分析表明法向异向性的晶粒尺寸依存性与钢带中织构的强弱有关，由此提出了“有效织构强度比”的概念，从塑性变形理论的角度解释了微观组织对塑性异向性的影响．     

对二甲苯直接电解氧化反应的研究

研究了在有机溶剂、支持电解质和碳棒存在下，对二甲苯的直接电解氧化反应，使用GC－MS方法分析鉴定了主要电解氧化产物，讨论了电解氧化产物成分随电解时间的变化规律，提出了对二甲苯的直接电解氧化反应过程。     

Oily wastewater treatment by porous ceramics mediums with surface lipophilic modification

Aiming at the treatment of difficult-to-handle oily wastewater, the ceramics filter mediums made from the iron and steel plant sludge were adopted to surface lipophilic modification so as to remove oil efficiently. The hydrolysis technique by FTIR and conductivity test indicated that under acid conditions hydrogen silicon oil did not hydrolyze but release hydrogen by chemical reaction under alkaline conditions. The results of the experiments including contact angle measurement, FTIR analysis, and SEM analysis illustrate that a layer of lipophile coating indeed exists evenly on the surface of filter mediums after modification. Furthermore, the hydrogen-containing silicone oil was combined through dehydration of Si-H bond with the -OH on the surface of ceramic filter medium.     

红外相机三态隔热冷却装置的设计及分析北大核心

红外相机工作环境温度不能超过50℃,但在某些工业高温场合,它需在约300℃的环境中持续工作。针对此问题,设计一种适用于某型号红外相机的三态隔热冷却装置。该装置结合隔热材料阻滞热量传递、水冷却、空气冷却的三态物质的隔热冷却效果,同时具有自清洁石英玻璃的作用。通过COMSOL中的传热模块对传热性能进行验证,分析其内部空间的温度场。结果表明:所设计的三态隔热冷却装置能够在约300℃的环境温度下使红外相机所处空间的温度保持在50℃以下,保证红外相机能正常工作。     

Simple and cost-effective fabrication of two-dimensional plastic nanochannels from silica nanowire templates

Nanofluidic systems are attracting a great deal of interest due to their fundamental significance and potential applications in chemistry, biology and physics. However, high fabrication cost, expensive equipments and complicated fabrication process of most current fabrication techniques prevent lots of researchers from entering the nanofluidic field. Here we present a quick, simple and cost-effective method for fabricating two-dimensional (2D) nanochannel in polycarbonate (PC) substrates. Silica nanowires, taper-drawn from commercially available single-mode fiber were used as templates and embedded in the PC substrate by hot embossing. The nanochannels were created after removing the nanowires by hydrofluoric acid (HF) etching. Poly(dimethylsiloxane) (PDMS) was used to seal the nanochannel reversibly. Nanochannels with widths range from 100 to 900 nm and lengths up to several millimeters were obtained. Various nanostructures including integrated micro and nanochannels, nanochannel array, bent nanochannel and cross-shaped nanochannel were fabricated and characterized by fluorescent microscope, scanning electron microscope (SEM) and atomic force microscope (AFM).     

避雷器放电电流在线监测装置的研制与开发

本文论述了避雷器放电电流在线测量的可行性，并围绕装置研制过程中的有关问题进行了讨论，尤其针对避雷器放电瞬高地电位及变电站强干扰等问题进行了研究和处理。     

GB/T12606钢管漏磁探伤方法述评

根据标准制定过程,结合国际、国外标准情况,对新制定的国家标准ＧＢ／Ｔ１２６０６钢管漏磁探伤方法进行述评。     

用正电子湮没研究含砷α黄铜的脱锌机制

分别测量了含０．００、０．０１、０．０３、０．０５、００７、０．１０ｗｔ％Ａｓ的６８ｗｔ％Ｃｕ－Ｚｎ合金在１％ＣｕＣｌ２水溶液中脱锌后的正电子寿命谱。讨论了黄铜脱锌及砷抑制脱锌的空位体扩散机制。