稳定苯乙烯/丙烯酸丁酯细乳液的制备

以十二烷基硫酸钠（SDS）作乳化剂,不同链长的脂肪烃或脂肪醇作共乳化剂,分别用搅拌和超声乳化方法制备一系列苯乙烯（St)／丙烯酸丁酯（BA）细乳液,测定细乳液稳定性的结构表明,SDS／十六烷（HDE）的乳化效果最佳,HDE先与单体混合结构超声波制备的细乳液最稳定,乳化剂,共乳化剂的种类和沈度,乳化温度,超声时间等对细乳液的稳定性均有影响。     

挤压油膜阻尼器失效的判据

 挤压油膜阻尼器(简称SFD)设计不当,会导致功能失效.对弹支-挤压油膜阻尼器来说,失效有2种形式:一是过不了临界,即转子系统的振幅随转速的上升而一直增大;二是出现双稳态特性.2帧失效判据图已经作出:一是双稳态区域图,只要轴承参数和质量偏心率数组不选在双稳态区域内,便不致产生双稳态特性;二是减振失效边界图,只要前述数据组不在失效边界的一侧,便不致产生过不了临界的现象.经实验证明,上述结论从正反2个方面看都是正确的.实验也进一步确认了挤压油膜阻尼器优越的减振功能.     

氧化剂含氧浓度对甲烷反扩散火焰光谱特性影响实验研究

为了研究氧化剂的含氧浓度对同轴射流甲烷反扩散火焰光谱特性分布的影响,采用光纤光谱仪对富氧层流甲烷反扩散火焰中发射谱线分别为314nm和430nm的激发态自由基OH*和CH*进行了光谱特性实验研究,分析了OH*,CH*辐射强度随氧化剂含氧浓度X_(O_2)的变化规律,及其沿反扩散火焰轴向与径向的分布特征。研究表明:甲烷反扩散火焰具有明显的内外双层结构,当氧化剂含氧浓度从21%增加到50%,反扩散火焰反应核心区直径增宽75%,而对火焰高度的变化却非常微弱。OH*和CH*辐射强度沿火焰轴向与径向均呈现先增后减的趋势。随着氧化剂含氧浓度增加,OH*辐射强度呈指数型增加,在距喷嘴出口2/3直径高度处处出现OH*和CH*辐射强度峰值,且峰值的轴向位置不随氧化剂含氧浓度X_(O_2)的增大而改变。     

A new stationary droplet evaporation model and its validation

The liquid droplet evaporation character is important for not only combustion chamber design process but also high-accuracy spray combustion simulation.In this paper,the suspended droplets' evaporation character was measured in a quiescent high-temperature environment by micro high-speed camera system.The gasoline and kerosene experimental results are consistent with the reference data.Methanol,common kerosene and aviation kerosene droplet evaporation characteristics,as well as their evaporation rate changing with temperature,were obtained.The evaporation rate experimental data were compared with the prediction result of Ranz-Marshall boiling temperature model (RMB),Ranz-Marshall low-temperature model (RML),drift flux model (DFM),mass analogy model (MAM),and stagnant film model (SFM).The disparity between the experimental data and the model prediction results was mainly caused by the neglect of the nat ural convection effect,which was never introduced into the droplet evaporation concept.A new droplet evaporation model with consideration of natural convection buoyancy force effect was proposed in this paper.Under the experimental conditions in this paper,the calculation results of the new droplet evaporation model were agreed with the experimental data for kerosene,methanol and other fuels,with less than 20％ relative deviations.The relative deviations between the new evaporation model predictions for kerosene and the experimental data from the references were within 10％.     

复方金钱草颗粒抑制草酸钙结石形成的化学模拟

本文研究了不同剂量的复方金钱草溶液对草酸钙亚稳溶液中可溶性钙离子浓度的影响,当加入剂量从0 mL增加到35.0 mL时,草酸钙亚稳溶液中钙离子浓度从0.1966 mmol/L增加至0.5564 mmol/L,且草酸钙亚稳溶液中的钙离子浓度与复方金钱草的加入量呈线性关系。而且,随着复方金钱草浓度的增加,一水草酸钙晶体生长抑制指数增大。     

数据链作战使用性能试验方法研究

分析了数据链在现代战争中的重要作用,提出了表征数据链作战使用性能的指标体系、试验数据链作战使用性能的试验方法以及试验数据录取方法,并给出了相应的试验数据处理方法。     

机载设备电磁兼容性设计方法

根据机载电子设备的使用环境和工作性质,分析了机载电磁环境的固有特性,并阐述了具体的电磁兼容性要求;针对机载电子设备的电磁兼容性问题,总结了工程实践巾在研制初期,从电路、印制板、设备内部走线、接地以及屏蔽5个方面相应的经验和方法.     

球齿轮传动齿廓接触特性分析

 对球齿轮齿廓进行了接触特性研究。在建立了球齿轮齿廓曲面方程和啮合模型基础上,利用计算机仿真的方法对其进行了齿面接触分析研究。针对球齿轮啮合传动时接触形式表现为轮齿凸面与马鞍面之间的点接触,对啮合齿面的接触椭圆进行了分析计算,确定了接触椭圆的方向和尺寸,得到了球齿轮机构在任一偏摆平面内啮合传动时接触椭圆的变化规律：在轮齿根部和顶部啮合时,接触椭圆较小,因而接触应力较大;而在轮齿中部啮合时,接触椭圆较大,所以接触应力较小。上述结论对进一步研究球齿轮的传动理论与实际应用具有重要的指导意义。     

Analysis of the brightness temperature features of the lunar surface using 37 GHz channel data from the Chang'E-2 microwave radiometer

Compared with other remote observations, brightness temperatures (T_B) derived from microwave emission measurements provide a unique means to characterize the physical properties of the lunar surface. Using Chang’E-2 microwave radiometer data, we produced 12 global T_B images of the lunar surface during a diurnal cycle with different local times separated by approximately 2?h. There are two types of remarkable T_B units on the lunar surface, the “hot regions” occurring during the lunar day in the lunar Maria regions and the “microwave cold spots” occurring during the nighttime typically related to young craters. Compared with their surroundings, the hot regions are much warmer during the lunar day and slightly colder at night, while the microwave cold spots are much colder during the lunar night and slightly warmer in the daytime. Moreover, the T_B heating and cooling rates of these two units are larger than others at the same average latitude where they are located during the lunar day, especially after sunrise and before sunset. The hot regions have a good agreement with the mare regions with high TiO₂ abundance. Besides, brightness temperatures in the lunar Maria correlate closely with their TiO₂ abundance. For most microwave cold spots, they agree with the young craters, and their brightness temperature distributions have a significant negative correlation with the lunar surface nighttime temperature and rock abundance.