左截尾双参数指数分布的可靠性评估(Ⅰ)

对左截尾双参数指数分布,给出了其分布参数(位置参数μ,尺度参数θ)、可靠性测度(失效率A,平均失效前时间(MTTF)M,可靠寿命tR,可靠度R(t))的UMVUE、Bayes估计与经典精确限和Bayes精确可信限,还给出了MTIF高精度的经典近似限.最后用数值例说明了这些方法.     

High Temperature Oxidation of FGH96 P/M Superalloy

High temperature oxidation behaviors of FGH96 P/M superalloy have been studied in air at temperatures ranging from 600 to 1000℃. By means of isothermal oxidation testing,X-ray diffraction,SEM(scanning electron microscopy),and EDS(energy dispersive X-ray spectroscopy) analyses,the oxidation kinetics as well as the composition and morphology of scales were investigated. Thermodynamic calculations were used to explain the oxidation mechanism. The results showed that as the oxidation temperature increased,the oxidation rate,the scale thickness,and scale spallation increased. FGH96 P/M superalloy exhibits good oxidation resistance at temperature below 800℃. The oxidation kinetics follows an approximately parabolic rate law,and the oxide layer was mainly composed of Cr2O3,TiO2,and a little amount of NiCr2O4. The oxidation is controlled by the transmission of chromium,titanium,and oxygen through the oxide scale.     

JAVA多线程机制在网络游戏中的应用与研究

网络游戏软件通常是针对某一种玩法而开发的,功能上缺乏多样性.采用Java多线程机制模拟实现网络扑克牌游戏,并基于软件复用思想,研究通过构件定制技术来灵活设置游戏人数,使用户在同一个游戏软件中选择不同的玩法,从而提高游戏的灵活性.     

THz Channel Modeling: Consolidating the Road to THz Communications

For the sake of meeting the demand of data rates at terabit (Tbit) per second scale in future networks,the terahertz (THz) band is widely accepted as one of the...     

基于Moodle和PhoneGap的移动学习客户端的设计与应用研究

本文将结合用户移动学习现状及偏好,确定移动学习客户端的系统需求,进而基于Moodle和PhoneGap平台,实现对移动学习客户端的设计,并将移动学习客户端应用到实际教学过程中,确定应用成效。     

大型污水处理工程预应力施工

介绍了某大型污水处理工程中预应力水池的结构方案和预应力施工技术,并进一步探讨了预应力技术在大型水池中的应用。     

极化冷冻机油添加剂的节能性分析

本文分析了极化冷冻机油添加剂（PROA）的节能机理,讨论了目前对极化冷冻机油添加剂研究中存在的一些争议。并结合工程实例对实际运行的冷水机组进行了现场测试,对添加前后系统的性能和能耗进行了比较分析。结果表明,极化冷冻机油添加剂节能效果并不显著。     

A Review of Toxicity Mechanism Studies of Electronic Cigarettes on Respiratory System

Electronic cigarettes (e-cigarettes) have attracted much attention as a new substitute for conventional cigarettes. E-cigarettes are first exposed to the respiratory system after inhalation, and studies on the toxicity mechanisms of e-cigarettes have been reported. Current research shows that e-cigarette exposure may have potentially harmful effects on cells, animals, and humans, while the safety evaluation of the long-term effects of e-cigarette use is still unknown. Similar but not identical to conventional cigarettes, the toxicity mechanisms of e-cigarettes are mainly manifested in oxidative stress, inflammatory responses, and DNA damage. This review will summarize the toxicity mechanisms and signal pathways of conventional cigarettes and e-cigarettes concerning the respiratory system, which could give researchers a better understanding and direction on the effects of e-cigarettes on our health.     

香港新机场航天广场屋面钢结构加工制作质量控制技术

介绍香港新机场航天广场屋面钢结构在结构构造比较复杂的情况下,通过建胎装配、复胎、工厂预拼装等方法,针对性地制定加工质量控制措施和检验方案,解决了质量控制的难题,营造了一个钢结构精品。