μC／OS-Ⅱ中消息队列通信的数据安全问题

μC/OS-Ⅱ是一个可移植、可裁剪的占先式多任务实时内核,且源码开放.便于学习、移植和维护.消息队列是一种广泛使用且灵活的任务间通信机制.分析了μO/OS-Ⅱ的消息队列通信机制中存在的数据安全性问题,然后通过改进消息队列通信所涉及的数据结构,同时增加消息队列测试函数OSQTest(),以提供应用程序对消息队列中消息访问是否安全的测试途径,从而提高了应用程序间通过消息队列进行通信的数据安全性.通过模拟实验证明此改进在实际应用中的有效性.     

基于J2ME和J2EE的城市公交查询系统的设计与实现

J2ME和J2EE技术是目前Java两大主要技术,并在应用中取得了成功。本文基于J2ME和J2EE技术实现了一个移动手机版的城市公交查询系统。其中,J2ME技术拥有移动手机客户端的开发,而J2EE技术则用于后台服务器和手机客户端的交互,以及后台服务器信息的发布。本系统实现了三种查询功能:路线查询、站点查询和站站查询。通过本系统将极大地方便手机用户对公交信息的查询。     

外语类院校《操作系统》课程设置及教学探索

由于学生的生源特征、知识背景和所处大环境的不同,外语类学校中<操作系统>的教学并非易事,是专业教学中的难点.为了能够让学生掌握操作系统的有关知识,应正视与理工院校存在的差异和距离,在课程设王、教学方法教学组织、实践环节等方面进行了探索,取得了一定效果.     

基于PIC单片机的测井系统激励信号源研制

设计了一种基于HC单片机的井下仪器发射信号源,单片机利用内部功能模块产生PWM脉冲序列,经过D类功放放大,然后将滤波解调出的标准正弦波作为微电阻率扫描成像（简称FMI）测井系统极板的激励信号源。该基于PIC单片机的集成化模块为测井仪器中信号源的研制提供了新的方法。     

优化SVPWM及其DSP变频调速系统的设计

电压空间矢量脉宽调制技术(SVPWM)在当今的变频调速领域得到了广泛的应用,本文住要通过对SVPWM基本原理的介绍和分析,对该技术进行优化,得到一个优化过的SVPWM系统,然后基于优化过的SVPWM技术,设计出一种由TI公司生产的DSP微处理器TMS320F2812控制的变频调速系统,并给出实验结论.     

可融合遥感信息的植被场景仿真模拟

在通过遥感信息构造针对目标植被的仿真模拟过程中,其植被所在地表、空间场景是关键组成.场景空间直接影响植被生长过程,因此是融合遥感信息和相关辐射计、传感器植被仿真模拟的重要组成部分.本文依托实验数据.给出了实现植被所在场景空间的构造方法,使植被的仿真模拟具备高可信度和极近逼真效果,从而服务于计算机远程、异地的农作物监测、估产工作.     

An investigation of 2'-deoxyribonucleoside cyanoboranes in mice for therapeutic safety

A standard acute toxicity study was undertaken to assess 2'-deoxyribonucleoside cyanoboranes for therapeutic safety. 2'-Deoxyribonucleoside cyanoboranes and related derivatives were nontoxic at doses required for anti-neoplastic and hypolipidemic activities. At higher doses (50 and 100 mg/kg/day IP for 7 days), all treated animals survived with slight reductions in total body weight and small decrements in daily food consumption. No clinical chemistry value was elevated to a magnitude suggesting onset of organ specific toxicity. However, agents appeared to modulate subpopulations of white blood cells, i.e., more lymphocytes than PMNs were present in blood from treated animals as determined by differential cell counts. This modulation is correlated with increases in granulomatous foci in the spleen and mesentery of treated animals after 7 days. The kidney was damaged only by Compound 5 at 50 and 100 mg/kg/day; Compound 5 had the most potent anti-neoplastic activity. The compounds demonstrated no in vitro toxicity against human HCT-8 ileum cells. LD(50) values were greater than 1000 mg/kg, IP, for all compounds.     

Substrate-mode holographic polarization-division multi/demultiplexer for optical communications

Based on the diffractive properties of a transmission-type phase volume hologram, a new type of polarization-division multi/demultiplexer for optical communications is presented.     

Interactions between Al-1 wt% Si thin film and W-Ti barrier layer

The interaction of Al-1 wt% Si with a W-Ti barrier layer in the Al/Ti₃W₇/SiO₂/Si system was studied over the temperature range of 400–500 °C for reaction times up to 300 h. The interaction was found to be diffusion-controlled, and to occur in a layer-by-layer fashion. The first reaction product is always Al₁₂W, which forms at the Al/Ti₃W₇ interface. With excess W in the system, Al will eventually be completely converted to Al₁₂W, and further interactions result in the formation of an Al₄W layer at the Al₁₂W/Ti₃W₇ interface. The amount of Al₄W increases at the expense of Al₁₂W. Ti plays a minor role in the interaction and forms a small amount of Al₃Ti precipitates in the Al₁₂W matrix. Decomposition of the Ti₃W₇ pseudoalloy into W and Ti phases is not significant, and is not detected by X-ray diffraction even after annealing at 500 °C for 300 h. The kinetics of the Al₁₂W formation follows a parabolic reaction law with an activation energy of 2.53 eV. The sheet resistance of the film is insensitive to compound formation as long as a continuous Al film exists in the system. The sheet resistance increases dramatically when Al is consumed to the extent that it is no longer a continuous film. The sheet resistance of the Al₁₂W layer is estimated to be 570 m ^–1.     

Preparation and characterization of poly(2,6-dimethyl-1,4-phenylene oxide) and Nylon 6 graft copolymer

Summary A poly(2,6-dimethyl-1,4-phenylene oxide) (PPO, 1) macroinitiator having carbonylcaprolactam groups was prepared through metalation of methyl group of PPO and subsequent modification to introduce carboxyl group, acid chloride group, and finally carbonylcaprolactam group. Anionic ring opening copolymerization of -caprolactam took place onto the macroinitiator to give a graft copolymer of PPO and Nylon 6. The structure of intermediate materials and the graft copolymer were characterized by ¹H NMR, ¹³C NMR, and IR spectroscopy. Glass transition temperatures and melting temperatures of these materials are also reported. It is found that the copolymer has a microphase-separated morphology even with segment molecular weight as low as 3000.