尼龙6表面金属(Ni)化膜材料的制备及性能研究

用化学还原法制得了尼龙６表面金属（Ｎｉ）化膜材料。研究了还原条件，金属盐浓度对膜材料电性能的影响，以及膜材料的电发热性能，用光电子能谱和扫描电子显微镜对其表面及形貌进行了表征。     

Nitrogen dioxide effect in the reduction of nitric oxide by propane in oxidizing atmosphere

The role of nitrogen dioxide in the selective reduction of NO by propane over a Cu-MFI zeolite is investigated. NO₂ and NO reductions were carried out under similar conditions of reaction. In the presence of oxygen, the reduction of NO by C₃H₈ does not differ significantly from that of NO₂. In the absence of oxygen, the reduction of NO₂ by propane occurs with a partial decomposition of the nitric dioxide molecule. Such a decomposition leads to the formation of oxygen, which is responsible for the increase in catalytic activity by comparison with the same reaction performed with NO. NO₂ formed and released in the gas phase during the reduction of NO by propane in the presence of oxygen does not play a predominant role in the catalytic process.     

Evaluation of rainfall networks using entropy: II. Application

This paper, the second in the series, applies the entropy approach to space and time evaluation of rainfall networks in Louisiana. The evaluation is made for five sampling intervals: daily, 2-day, weekly, monthly, and yearly, and for two separate seasons. In each case, the best combination of raingages is suggested and the lines of equal information (isoinformation contours) are constructed showing the areas of greater or less information transfer. The isoinformation lines are especially suitable in decisions concerning the expansion of the existing network or deleting the unnecessary raingages.     

Parallel associative combinator evaluation II

A new evaluation model for SK combinator expressions is presented and used as a basis for the design of a novel processor. The resulting machine architecture resembles a dataflow ring, but executions are constrained to be fully lazy. An automatic dynamic load sharing mechanism for a distributed multiprocessor architecture is suggested, and initial simulation results are presented.     

植物油、脂肪酸和植物油甲酯在塔河稠油掺稀降黏中的应用评价

稠油由于富含沥青质、胶质等重质组分而具有很高的黏度，给稠油的开采和运输带来了很大的困难。降低稠油黏度进而改善其流动性成为一项十分重要的工作。以植物油、脂肪酸及植物油甲酯为掺稀介质，以塔河油田稠油为研究对象，考察对比了3种不同的掺稀介质对稠油的掺稀降黏效果。研究结果表明，3种掺稀介质对稠油具有良好的掺稀降黏效果，在同一掺稀比下，植物油甲酯对稠油的降黏效果最显著，其次是脂肪酸，再次是植物油。通过斑点试验考察了掺稀介质和稠油的相容性和体系稳定性。结果显示，植物油甲酯与稠油相容性和稳定性最好，脂肪酸和植物油与稠油的相容性和稳定性相对较差。     

一种8毫米波变张角,半径突变多模圆锥馈源

我们研制了一种8毫米波变张角、半径突变的多模圆锥馈源。计算出其模比并推导出其辐射方向图公式;给出其在两个主平面——E平面与H平面上的辐射方向图和波束场分布特性的测试结果以及电压驻波比VSWR的测量结果;同时给出频带和旁瓣特性。分析与测试共同表明,在34.5GHz～37GHz频带里,该多模馈源的辐射图在大于24dB范围内获得幅度等化且不出现旁瓣,因此具有一定的应用价值。     

Differences in the structure of copper active sites for decomposition and selective reduction of nitric oxide with hydrocarbons and ammonia

Cu ion co-ordination-location in zeolites of MFI, erionite, mordenite matrices has been determined and the activity of the individual Cu sites compared for NO decomposition and its selective reduction by hydrocarbons or ammonia. It appears that Cu ions in the vicinity of one framework Al (site II), able to form stable Cu⁺-dinitrosyl complexes, and abundant in MFI structure, are responsible for high activity in NO decomposition. The Cu ions neighbouring two framework Al atoms (site I), and forming mostly mononitrosyl complexes, which dominate in erionite structure, provide a high activity in selective reduction of NO.     

Development of damage in a 2D woven C/SiC composite under mechanical loading: I. Mechanical characterization

An investigation has been undertaken to determine the damage mechanisms and the associated mechanical response of a 2D reinforced composite of carbon fibers in an SiC CVI-processed matrix subjected to uniaxial tensile and compressive loadings at room temperature. Under tension loading, an extended non-linear stress/strain response was evidenced and related to a multi-stage development of damage involving transverse matrix microcracking, bundle/matrix and inter-bundle debonding as well as thermal residual stress release. This tensile behavior proved to be damageable-elastic with respect to a fictitious thermalstress-free origin of the stress/strain axis lying in the compression domain. In compression, after an initial stage involving closure of the thermal microcracks present from processing, the composite displayed a linear-elastic behavior until failure. The extent of damage over the material was characterized quantitatively at the microscale by the decrease of the average transverse microcrack spacing and at the macroscale by the decrease of both the longitudinal Young's modulus and the in-plane Poisson's ratio.     

Preparation of ultra fine nickel-copper bimetallic powder for BME-MLCC

The preparation of ultra fine nickel-copper bimetallic powder with two-stage chemical reduction method was investigated. Reductive sugar and hydrazine hydrate were employed as reducing agent in different reductive stage, respectively. Reaction of CuSO₄·5H₂O with reductive sugar at 70 °C gives cuprous oxide and copper particles, then as-prepared mixture and nickelous hydroxide were reduced by hydrazine hydrate, and nickel-copper powder having excellent dispersibility was prepared. Influences of nickel added on composition and dispersibility of powder were studied. TG/DTG/DTA of nickel-copper powder, which is stable in room temperature, were discussed with thermal analyzer. Relation of nickel content to oxidation temperature was investigated. Ni-Cu bimetallic powder particles have a fully coated structure when nickel content is up to 30%. As-prepared nickel-copper powder was applied in base metal electrode-multilayer ceramic capacitor (BME-MLCC). The end termination has high adhesion force, fairly good densification, low resistivity, excellent solderibility behavior and resistance behavior to soldering.     

双极性步进电机细分驱动器的设计与实现

论述了一种双极性步进电动机驱动器的工作原理，该驱动器能较好地改善步进电动机的运行性能，具有实用性强，结构简单，成本低的优点。针对实际调试中出现的问题进行分析后，提出了对策；最后给出了试验结果。