Concentric Ring Pattern Formation in a Competing Crystallization and Phase Separation Process

Spherulitic patterns usually form in the single process of crystallization in polymer blends. But when phase separation intervenes under deep quench, the radial growth of the initial spherulitic patterns tends to invert into concentric alternating crystalline‐/amorphous‐rich ring structures. Within crystalline‐rich regions, lateral lamellae orient in the tangential direction rather than in the usual radial direction. We demonstrate the determining factor for this first observed phenomenon is the concentration deviation enhanced phase separation dynamics at the growth interface of crystals.     

大口径模拟导弹发射装置简介

介绍了大口径模拟导弹发射装置的设计思想、工作原理、装置的组成、达到的技术指标、主体结构及应用情况。     

超高速发射中缓冲层材料对钽飞片速度影响的数值分析

 在超高速发射技术研究中,缓冲层材料起着十分重要的作用。通过数值计算,分析了TPX缓冲层材料的厚度对高阻抗钽飞片超高速发射速度的影响,给出了最优的缓冲层材料厚度,对于0.3和0.5 mm厚的钽飞片,选取不同厚度的TPX缓冲层材料,钽飞片中心速度的相对误差达到5%～6%;为了比较不同缓冲层材料对钽飞片速度的影响,还给出了相同厚度的TPX和Lexan材料作缓冲层时,钽飞片的中心速度和压力历史的二维计算结果。     

自制微透析探针性能评价

以自制微透析探针为研究对象,通过体外芍药苷微透析实验,评估灌注液流速、人工细胞外液中药物浓度、回收率测定方法及半透膜性质对自制同轴型微透析探针取样回收率的影响。实验结果表明,自制探针的回收率随灌注液流速升高呈近似指数曲线降低。当灌注流速为8.0μL/min时,回收率表现出浓度依赖性。采用直接透析法或反向透析法所得同一探针回收率存在显著差异。回收率因探针不同而存在差异。探针在体内连续取样6h,半透膜的通量未见衰减。实验室自制探针性能稳定,可用于体内微透析研究。     

任意分配比的微波功率分配器

圆波导中TE11模式波的电场在波导壁上随角度按正弦(或余弦)变化.如果在其侧壁上沿径向接两根互相垂直的波导,波导绕轴转动时两根波导中所分配的功率将随旋转角度而变化.这样就可以设计出任意分配比的微波功率分配器.通过HFSS的模拟计算完成了该功分器的设计,同时设计了一个新型的圆波导TE11模式转换器.     

电磁发射器的原理与应用

传统的化学推进技术已不能满足人类的进一步要求，从原理和能源上变革发射技术势在必行，因此电磁发射技术便应运而生。因其在国防、航天等领域应用前景广阔，目前国内外电磁发射技术发展迅速。文章论述了电磁发射技术的发展历史、现状和电磁发射器的基本原理和广阔的应用前景。     

Breathing air from protein foam

Protein foams can be used to extinguish fires. If foams are to be used to extinguish fires where people are present, such as in high-rise buildings or ships, then a method for allowing people to breathe in a foam-filled environment is needed. It is proposed that the air, used to create the foam be used for breathing. A canister that will break incoming air-filled foam has been designed for attachment to a standard gas mask, in order to provide breathable air to a trapped person. Preliminary results for the modified mask indicate feasibility of breathing air from air-filled protein foam.     

Denisov-type quasi-optical mode converter forhigher-order asymmetric volume mode gyrotron北大核心CSCD

The principle and design method of Denisov-type quasi-optical mode converter is investigated indetail. The operation process of the Denisov-type launcher is analyzed by applying the geometrical optics, andthe Gaussian-like field distribution achieved on the waveguide wall is also derived. The method for designing arippled-wall launcher is proposed on the basis of coupled mode theory. A simulation code for Denisov-type qua-si-optical mode converter GQOMC-D is developed based on coupled mode theory, vector diffraction integrationand physical optics, which is compared to the design parameters and experimental results reported in literaturefor its validity. According to this code, a Denisov-type quasi-optical mode converter used in 110 GHz TE22.6mode gyrotron oscillators is designed. Simulation results indicate that a Gaussian-like beam is obtained at theoutput window with a scalar content of 98.4 % and a conversion efficiency of 94.7 %.     

三同心球光学系统跟瞄误差分析

针对独有的跟踪方式,具体讨论了激光通信三同心球光学系统的跟瞄方案,并进行了具体规划。通过对通信跟踪光路和通信接收光路的视场和精度分析,给出了二者的相关参数,作为Matlab理论计算跟踪像面轨道的依据。利用Tracepro软件模拟了引入相关误差量后的通信跟踪和通信接收像面光斑质心偏移和光斑大小变化情况。仿真结果显示:随着角度的旋转,通信接收的质心偏差在±4μm范围内,通信跟踪的质心偏差在±50μm范围内;通信接收像面光斑直径小于80μm,通信跟踪像面光斑直径均在400μm以内。系统所引入的误差在允许范围之内,不影响相关跟踪通信功能。     

有限长大间隙环流中同心转子动特性系数研究

基于作者建立的大间隙环流中转子运动理论模型,用摄动法推导了有限长大间隙环流流场非线性控制方程的零阶和一阶摄动方程,研究了摄动方程的数值求解方法,并用该数值方法深入研究了有限长大间隙环流中同心转子的动特性系数以及壁面粗糙度、入口压力、长径比和入口预旋等参数的影响,研究结果表明,系统参数对有限长大间隙环流中同心转子动特性系数的影响是流体惯性效应、旋流效应、摩擦耗散效应和Lomakin效应综合影响的因素。