酸浸改性无烟煤填充PE复合材料的力学性能研究

将酸浸和表面改性的无烟煤粉体,与聚乙烯(PE)共混,制备了煤基聚合物复合材料,并表征了煤粉粒度、疏水性以及填充性能.结果表明,改性无烟煤粒度得到明显改善,疏水性明显增强,具有良好的增强作用.1.5％的硅烷湿法改性粉体相容性较好,其填充量为10％时,复合材料的拉伸强度、屈服应力分别为18.27MPa和12.24MPa,与...     

强夯法在湿陷性黄土地基中的应用

强夯法是在重锤夯实法基础上发展起来的,具有工期短、费用低、效果显著等优点。由于地质复杂,在施工前必须通过现场试验,确定其适用性和处理效果。通过黄河尼那左岸副坝工程实例,分析了强夯法相关试验的结果,确定相关技术参数,实践证明强夯法是处理湿陷性黄土地基较经济合理的方法。     

Enhanced friction model for high-speed right-angle gear dynamics

The modeling of elastohydrodynamic lubrication friction and the analysis of its dynamic effect on right-angle gears, such as hypoid and spiral bevel types are performed in the present study. Unlike the classically applied empirical constant coefficient of friction at the contacting tooth surfaces, the enhanced physics-based gear mesh friction model is both spatial and time-varying. The underlying formulation assumes mixed elastohydrodynamic lubrication (EHL) condition in which the division and load distribution between the full film and asperity contact zones are determined by the film thickness ratio and load sharing coefficient. In the proposed time-varying friction model, the calculation of friction coefficient is performed at each contact grid inside the instantaneous contact area that is being subjected to mineral oil lubrication. The effective friction coefficient and directional parameters synthesized from the net frictional and normal contact forces are then incorporated into a nonlinear time-varying right-angle gear dynamic model. Using this model, the effect of friction on the gear dynamic response due to the transmission error and mesh excitations is analyzed. Also, parametric studies are performed by varying torque, surface roughness and lubrication properties to understand the salient role of tooth sliding friction in gear dynamics. The simulation results are included. But experimental verification is needed.     

一种实时监测系统的体系结构及软件设计

本文介绍了监测点多、面广、距离远、采用无线通讯方式的实时监测系统的体系结构,阐述了其软件结构和功能,讨论了系统实时性、可靠性、灵活扩充性和数据库系统的设计和实现。本文工作对新型实时监测系统的设计与实现有一定参考价值。     

马脊梁矿用国产综采设备实现高产高效

1　概况大同煤矿集团公司马脊梁矿综采一队于 1997年 10月 2 0日组建 ,12月 18日正式投产出煤 ,是全部使用国产设备的综采队。投产以来 ,先后开采了11#层 4 0 6盘区 86 0 2工作面、86 0 4工作面 ,现开采86 0 6工作面 ,截止目前已累计生产原煤 5 0 0 37万ｔ ,设备状况良好 ,运行正常 ,实现了高产高效。1 1　工作面参数及设备配备86 0 6工作面长度为 180ｍ ,可采走向长度2 180ｍ ,煤层厚度 3 0～ 4 0ｍ ,回采期间采高为3 0～ 3 3ｍ ,地质构造简单 ,整体为单斜构造 ,煤层平均倾角为 2°左右 ,属近水平煤层 ,工作面有两条落差为 1 3ｍ的正断层…     

数字HDTV发射管的发展及其应用

本文主要论述了英国ＥＥＶ，美国Ｖａｒｉａｎ和法国ＴｈｏｍｓｏｎＴｕｂｅｓＥｌｅｃｔｒｏｎｉｑｕｅｓ三家公司推出的数字ＨＤＴＶ发射管ＩＯＴ（ＩｎｄｕｃｔｉｖｅＯｕｔｐｕｔＴｕｂｅ）以及ＴｈｏｍｓｏｎＴｕｂｅｓＥｌｅｃｔｒｏｎｉｑｕｅｓ新近推向市场的ＨＤＴＶ发射管ＴＨ５６３四极管和双端四极管（Ｄｉａｃｒｏｄｅ—Ｄｏｕｂｌｅ－ｅｎｄｅｄｔｅｔｒｏｄｅ）ＴＨ６８０所达到的技术水平；特别着重介绍了上述三种数字ＨＤＴＶ发射管的整机应用情况，同时也展望了ＩＯＴ，尤其是ＴＨ５６３和ＴＨ６８０的美好应用前景。     

以蚕蛹为主要原料制曲工艺的研究

以蚕蛹为主要原料,通过对米曲霉的培养筛选,确定了沪酿3.042是最佳的菌种.研究了培养时间、温度、曲料含水量、碳源、碳源添加量和接种量对制曲的影响.结果表明,当培养时间72h,培养温度30℃,曲料含水量40%,接种景为0.5%,以葡萄糖为主要碳源时,米曲霉产中性蛋白酶为2135U/g,孢子数为1.92×1099个/g,氨基酸态氮为1.212g/100g.制曲后蚕蛹的风味得到极大改善.     

瞬态温度变化对大口径光学元件的影响

温度瞬变是影响惯性约束聚变(ICF)驱动器中大口径光学元件结构稳定性的一个重要的激励因素.采用多通道高精度温度监测仪对原型装置中编组站大口径光学元件环境温度进行了24 h监测,得到了编组站光学元件环境温度24 h温度变化曲线;采用有限元分析软件建立了光学元件的有限元模型,把温度监测结果作为载荷,对光学元件进行了热结构耦合分析.分析得到了大口径光学元件面形在24 h内的变化曲线,光学元件环境温度24 h内最大变化范围为0.45 ℃,24 h光学元件最大转角变化为1.12 μrad.分析结果表明,光学元件转角最大变化已超过打靶对光学元件稳定性的要求,但通过调整打靶时间,缩短光路准直之后打靶的等待时间可有效提高打靶的成功率.     

10 Gb/s OEIC optical receiver front-end and 3.125 Gb/s PHEMT limiting amplifier

A 10 Gb/s OEIC (optoelectronic integrated circuit) optical receiver front-end has been studied and fab ricated based on the φ-76 mm GaAs PHEMT process; this is the first time that a limiting amplifier (LA) has been designed and realized using depletion mode PHEMT. An OEIC optical receiver front-end mode composed of an MSM photodiode and a current mode transimpedance amplifier (TIA) has been established and optimized by simu lation software ATLAS. The photodiode has a bandwidth of 10 GHz, a capacitance of 3 fF/μm and a photosensitive area of 50×50 μm~2. The whole chip has an area of 1511×666 μm~2. The LA bandwidth is expanded by spiral inductance which has been simulated by software HFSS. The chip area is 1950×1910μm~2 and the measured results demonstrate an input dynamic range of 34 dB (10-500 mVpp) with constant output swing of 500 tnVpp.     

掺铒钨碲酸盐玻璃光谱性质的研究

研究了掺铒钨碲酸盐玻璃的吸收光谱和荧光光谱。应用JuddOfelt理论计算了Er3+的光谱强度参数Ωt(t=2,4,6)、自发辐射跃迁几率、荧光分支比和辐射寿命。从光谱强度参数的计算说明掺铒钨碲酸盐玻璃中Er—O键的共价性强于碲酸盐玻璃中Er—O键的共价性。玻璃的荧光半高宽为52nm,大于Er3+在磷酸盐和硅酸盐玻璃中的荧光半高宽。应用McCumber理论,计算了钨碲酸盐玻璃中Er3+离子在峰值波长1532nm的受激发射截面,为0.91×10-20cm2,大于Er3+在碲酸盐玻璃中的受激发射截面0.75×10-20cm2。由于掺铒钨碲酸盐玻璃的玻璃转变温度高、有较大的声子能量、较宽的荧光半高宽和较大的受激发射截面,是制作高增益的光波导放大器的理想材料。