基于神经网络的结构地震反应仿真研究进展

总结了利用神经网络进行结构地震反应仿真的研究进展,针对线性结构地震仿真的网络模型选择、网络结构确定及仿真精度控制等关键问题进行了探讨并提出了建议,指出了非线性结构地震反应仿真研究所面临的主要问题及解决方向。     

基于计算机图像处理的冲压床保护技术研究

本文用图像处理方法对冲压床保护技术进行了比较深入的研究。从两种角度对其进行了分析：对未带手套的手与工件的识别,采用了HSI颜色系统并利用了模糊技术进行处理;对带手套的手与工件的识别,利用了图像纹理形成的灰度共生矩阵并提取其特征参数来进行识别。实验结果表明：该方法能有效地区分手和工件,达到了预期目标,结果是可以接受的,为下一步进行有效的控制提供了依据。     

The Study of Plasma Nitriding of AISI304 Stainless Steel

This paper presents results on the plasma nitriding of AISI 304 stainless steel at different temperatures in NH3gas. The working pressure was 100～200 Pa and the discharge voltage was 700～800V. The phase of nltrided layer formed on the surface was confirmed by X-ray diffraction. The hardness of the samples was measured by using a Vickers microhardness tester with the load of 50g. After nitriding at about 400℃ for two hours a nitrided layer consisting of single γN phase with thickness of 51.tm was obtained. Microhardness measurements showed significant increase in the hardness from 240 HV (for untreated samples) up to 950 HV (for nltrided samples at temperature of 420℃). The phase composition, the thickness, the microstructure and the surface topography of the nltrided layer as well as its properties depend essentially on the process parameters.     

Preparation and electrochemical study of cerium–silica sol–gel thin films

Design and development of suitable multilayered systems for delaying corrosion advance in metals requires that both the alteration mechanisms of the metal and the behaviour and properties of the protective coatings be known. Coatings prepared by the sol–gel method provide a good approach as protective layers on metallic surfaces. This kind of coatings can be prepared from pure chemical reagents at room temperature and atmospheric pressure, with compositions in a very wide range of environmentally non-aggressive precursors. Sol–gel coatings based on siloxane bonded units were prepared starting from an organic–inorganic hybrid system. The precursors were γ-methacryloxypropyltrimethoxysilane (MAP) and tetramethoxysilane (TMOS). Cerium nitrate hexahydrate in three different concentrations was added. Cerium salts may perform a similar protective effect to that carried out by the well-known lead oxides and chromium salts, even though in this case a negative environmental impact is not expected. Application of coatings upon pure zinc substrates and common glass slides were performed by spinning. Coated samples were heat treated at 40 °C for 6 days. Optical measurements (UV-Vis absorption and diffuse reflectance spectroscopies) pointed out that the coatings were colourless and transparent, reducing the diffuse reflectance of the metallic surface up to 60%. Optical and scanning electron microscopies (SEM) allowed observation of the texture and microstructure of the coated samples, both before and after the corrosion tests were carried out. Likewise, the remaining sols were kept to gelify at 60 °C for 4 days and then powdered to obtain suitable samples for analysing them by other characterisation techniques (Fourier transformed infrared, FTIR and differential thermal analysis, DTA). Electrochemical measurements were performed by impedance spectroscopy. This technique was used to clarify the anticorrosive protection role of cerium ions incorporated into the hybrid sol–gel network. The effect of cerium concentration on the impedance spectra was analysed, as well as the system behaviour against the corrosive medium (0.6 M NaCl aqueous solutions), as a function of exposure time. From the electrochemical point of view, the sol–gel films behave as a conversion coating on the metallic surface.     

内皮素受体拮抗剂CPU-0213 血药浓度的HPLC 测定法和药动学研究

目的: 建立内皮素受体拮抗剂CPU-0213 在小鼠和大鼠血清中的检测方法, 测定单次静脉注射(iv) CPU-0213 80 mg·kg^-1后在小鼠和大鼠体内的药代动力学。方法: 用HPLC 测定小鼠和大鼠血清中的药物浓度, 3P97 程序拟合药动学参数。结果: CPU-0213 在0.4～200 μg·L^-1的范围内呈良好的线性关系(r=0.9998), 最低检测浓度为35 μg·L^-1。日内差小于2.7 %, 日间差小于6.3 %, 方法回收率大于95.9 %。CPU-0213 在小鼠和大鼠体内的药-时数据均符合二室模型, 消除半衰期分别为83.0±1.8 min 和96.6±11.5 min 。结论: 该方法灵敏、简单, 专属性强, 重现性好。单次iv CPU-021380 mg·kg^-1后, 在小鼠和大鼠体内的药代动力学未见种属差异性。     

添加剂对Cu/Co多层膜电结晶成核机理及磁性的影响

在硼酸镀液中以单晶S i(111)为基底用双槽法制备Cu/Co多层膜,在镀液中分别加入了镀铜添加剂2000#和镀钴添加剂5#。探讨了镀层电结晶成核机理,在基础镀液中铜电结晶为三维连续成核过程,钴电结晶在较低电位下为三维连续成核,在较高电位下为三维瞬时成核过程。加入添加剂后,铜、钴电结晶均为三维瞬时成核过程。测试了Cu/Co多层膜的磁性能;添加剂能提高多层膜的磁性能,无添加剂的Cu/Co多层膜的巨磁阻(GMR)值约为5%,而在加入了添加剂后,其GMR值高达52%。     

水热法一步合成核壳型TiO2/Al2O3纳米粉体的热力学分析

水热法一步合成核壳结构的工艺路线具有简化生产工艺、大大缩短生产时间的特点.所以研究制备具有核壳结构的前驱体热力学条件有重要的指导意义.热力学分析表明,在纳米Ti(OH)4表面包覆Al(OH)3的过程中,存在核包覆和膜包覆的竞争;而在其它条件不变的情况下,包覆物的过饱和度对包覆形态起到了决定性的影响.在较低的过饱和度下,可形成膜包覆;如果过饱和度过高,则形成核包覆.     

碳化硅基材料抗氧化涂层的研究进展

碳化硅基材料具有优良的高温性能,但作为非氧化物陶瓷,碳化硅材料的高温氧化造成的性能衰减限制了其进一步的广泛应用.本文通过分析碳化硅的氧化机理,对比和总结了碳化硅抗氧化涂层的制备方法和涂层体系,并结合实际工作对碳化硅抗氧化涂层的研究提出了具体的见解.     

低温下跌水曝气接触氧化处理乡村生活污水

简述了在低温时以跌水曝气接触氧化法为主体的污水处理工程对低浓度农村生活污水的处理效果,该工艺出水COD、TN、TP分别低于70mg／L、5mg／L、0．1mg/L,均能达到城镇污水处理厂污染物排放的一级标准（GB18918-2002）,对富营养化水体流域内农村生活污水的处理具有指导意义。     

无泡曝气膜生物反应器在废水处理中的研究及应用

概述了新型生物膜反应器一无泡曝气膜生物反应器（MABR）的工作原理、技术特点，探讨了膜材料和气液操作条件等因素对MABR运行的影响，并着重介绍了其在有机废水和含氮废水处理中的应用和研究进展。最后指出当前该技术存在的问题，并展望了其广阔的发展前景。