H_2O_2对Apg-2与BCR/ABL蛋白亚细胞定位的影响

目的观察H2O2对Apg-2与BCR/ABL蛋白亚细胞定位的影响。方法用50μmol/L H2O2分别处理BaF3-BCR/ABL、BaF3-MIGR1及过表达Apg-2蛋白的BaF3-BCR/ABL细胞,激光共聚焦显微镜观察细胞内Apg-2、BCR/ABL蛋白的亚细胞定位变化。结果 Apg-2和BCR/ABL蛋白在细胞中定位于胞浆,H2O2损伤可致Apg-2和BCR/ABL蛋白在BaF3-BCR/ABL细胞中发生核转位,Apg-2蛋白过表达可引起BCR/ABL蛋白核转位。结论 Apg-2蛋白在H2O2诱导的损伤后发生核转位,可能与BCR/ABL蛋白相互作用,保护H2O2诱导的细胞损伤。     

机载激光武器技术发展探讨

美国的ABL系统是一个集成了大气补偿技术的兆瓦级机载激光武器系统,ABL的设计目标是击毁敌方的弹道导弹。本文对ABL的作战使用方法、系统组成以及主要关键技术进行了介绍,分析了其发展过程中遇到的技术困难,探讨了我国机载激光武器的发展思路。     

Improved k-ε model and wall function formulation for the RANS simulation of ABL flows

The simulation of Atmospheric Boundary Layer (ABL) flows is usually performed using the commercial CFD codes with RANS turbulence modelling and standard sand-grain rough wall functions. Such approach generally results in the undesired decay of the velocity and turbulent profiles specified at the domain inlet, before they reach the section of interest within the computational domain. This behaviour is a direct consequence of the inconsistency between the fully developed ABL inlet profiles and the wall function formulation.The present paper addresses the aforementioned issue and proposes a solution to it. A modified formulation of the Richards and Hoxey wall function for turbulence production is presented to avoid the well-documented over-prediction of the turbulent kinetic energy at the wall. Moreover, a modification of the standard k-ε turbulence model is proposed to allow specific arbitrary sets of fully developed profiles at the inlet section of the computational domain.The methodology is implemented and tested in the commercial code FLUENT v6.3 by means of the User Defined Functions (UDF). Results are presented for two neutral boundary layers over flat terrain, at wind tunnel and full scale, and for the flow around a bluff-body immersed into a wind-tunnel ABL. The potential of the proposed methodology in ensuring the homogeneity of velocity and turbulence quantities throughout the computational domain is demonstrated.     

基于大涡模拟的大气边界层湍流强度对低矮房屋风荷载特性影响研究

对德州理工大学(Texas tech university,TTU)低矮房屋标准模型,以已有现场实测以及缩尺模型风洞实验数据为验证对比,基于大涡模拟(Large-eddy simulation,LES)方法研究了大气边界层湍流强度对低矮房屋风荷载特征的影响机理。采用CDRFG (Consistent discretizing random flow generation) 人工合成湍流方法生成大气边界层湍流,研究了来流湍流度对低矮建筑表面的平均、脉动以及极小值风压分布以及风压非高斯特性的影响,并利用LES能提供非常场流动全流域信息的优势,结合瞬态湍流场结构对大气边界层湍流对低矮房屋风荷载特征的影响机理进行了阐释。结果表明:LES数值模拟得到的平均、脉动及极小值风压系数与实验以及实测结果一致,平均风压结果包络在实测误差范围以内,极小值风压系数最大误差小于10%,脉动风压系数最大误差小于20%且误差区域较小。在来流湍流度增大的过程中,低矮房屋屋面平均风压系数变化较小,脉动风压系数呈显著的线性增加;极小值风压系数变化规律相对复杂,呈现出非线性减小的趋势,风压系数极小值可达?5.0;屋面涡脱强度逐渐被抑制,锥形涡迹线与屋面迎风前缘的夹角由14.4°下降至8.7°。屋面风压非高斯特性主要与屋面形成的涡旋结构相关,表现出典型的右偏软化非高斯过程,且随着来流湍流度的增加风压非高斯特性逐渐减弱。从流场的角度来看,湍流度的增加抑制屋面迎风前缘柱状涡以及锥形涡的形成,加快流动分离的再附,减少分离泡尺度,同时提高了屋盖周围的湍流高频能量成分,从而使脉动风压增加,极小值风压减小以及风压非高斯特性减弱。该研究阐明了大气边界层湍流对低矮房屋风荷载特性的影响机理,有助于进一步理解低矮房屋风致破坏机理,并且为低矮房屋的抗风设计及抗风性能优化提供重要参考。     

机载激光武器仿真系统与分析

在分析机载激光武器(ABL)战技术指标和作战过程的基础上,建立了机载激光武器仿真系统,该系统由弹道导弹、载机、测距激光、跟瞄系统、激光大气传输和高能激光毁伤评估模块组成。重点研究了机载激光武器的建模,包括测距激光探测概率计算、复合轴跟瞄系统设计、大气对激光造成的衰减和扩散以及高能激光毁伤计算等。最后,搭建了仿真系统进行反导拦截试验,从攻防两方面对影响机载激光武器毁伤效果的主要因素进行了分析,并给出了仿真结果。该仿真系统可以为机载激光武器反导效能的分析评估提供平台和依据。     

建筑结构风荷载与风环境数值模拟仿真研究与工程应用

本文首先对建筑结构风工程数值模拟方法的特点做了简明介绍; 接着提炼了风工程数值模拟研究的几个基础问题包括湍流模型与数值参数影响、平衡边界层的数值模拟、复杂建筑结构的数值风洞建模等, 介绍了这方面的最新研究进展和成果; 然后, 结合建筑工程实践, 概述了风工程教值模拟方法在解决复杂建筑结构风荷栽与风环境等问题中研究和应用成果; 最后, 对风工程数值模拟研究做了展望。其中许多成果为作者在研究和实践中的提炼和总结。对从事建筑结构风工程数值模拟研究具有一定参考价值。     

Performance and wake comparison of horizontal and vertical axis wind turbines under varying surface roughness conditions

A numerical study of both a horizontal axis wind turbine (HAWT) and a vertical axis wind turbine (VAWT) with similar size and power rating is presented. These large scale turbines have been tested when operating stand‐alone at their optimal tip speed ratio (TSR) within a neutrally stratified atmospheric boundary layer (ABL). The impact of three different surface roughness lengths on the turbine performance is studied for the both turbines. The turbines performance, the response to the variation in the surface roughness of terrain, and the most relevant phenomena involved on the resulting wake were investigated. The main goal was to evaluate the differences and similarities of these two different types of turbine when they operate under the same atmospheric flow conditions. An actuator line model (ALM) was used together with the large eddy simulation (LES) approach for predicting wake effects, and it was implemented using the open‐source computational fluid dynamics (CFD) library OpenFOAM to solve the governing equations and to compute the resulting flow fields. This model was first validated using wind tunnel measurements of power coefficients and wake of interacting HAWTs, and then employed to study the wake structure of both full scale turbines. A preliminary study test comparing the forces on a VAWT blades against measurements was also investigated. These obtained results showed a better performance and shorter wake (faster recovery) for an HAWT compared with a VAWT for the same atmospheric conditions.     

美国研制的高能激光武器系统

综述了美国研制的机载、车载和舰载激光武器系统以及地基激光反卫星武器和未来的天基激光武器系统,并给出了武器的性能和有关的技术参数。     

关注美国机载激光武器(ABL)计划

机载激光武器（ABL）是拦截处于助推段弹道导弹的激光武器。介绍了ABL汁划的由来并根据其作战任务,分析了其系统组成和各部分担负的任务,系统阐述了其发展计划,并对项目进展进行了预测。