洪涝灾害三参数损失函数的构建Ⅰ——基本原理

为把握快速城镇化、社会经济增长、防洪工程标准提高背景下暴雨洪涝灾害风险的演变趋势,基于洪水风险理论及城市洪涝灾害的连锁性与损失突变性特征,探讨了洪涝灾害风险演变驱动机制,构建了具有物理意义的三参数洪涝灾害损失-重现期(D-R)风险函数,明确了曲线形态中临界洪灾损失值Dc、临界重现期Rc、区域脆弱性综合指数k等控制参数的物理意义。该函数可作为洪涝灾害风险评估与预测的一种便捷手段,找到洪涝灾害风险演化的转折点,可为防灾减灾决策提供依据,同时也可应用于对防洪工程体系减灾效益的评估。     

高靶材利用率的新型磁控溅射器

在现代大型薄膜连续生产线中 ,其生产效率主要受以下两因数的影响 :溅射器的沉积速率和靶材的使用周期。本实验研制了一种圆筒形靶材绕溅射器中心轴线匀速旋转 ,并且与溅射器之间用螺丝固定连接的新型磁控溅射器。论述了新型溅射器的结构与组成 ,并给出实验结果与结论。其具有靶材利用率高、使用周期长、换靶时间短等优点。同时在反应溅射时避免在靶面上的形成介质层 ,提高了溅射过程的稳定性。     

发电机组同期并列问题研究

简要介绍了发电厂准同期系统及非同期并列的危害,并分析了在同期系统中如何进行同期系统待并侧电压的选择、同期系统电压核相及导前时间的整定。     

采用硫酸熟化—水浸工艺从锂云母中提取锂铷铯

采用硫酸熟化—水浸工艺进行综合提取锂云母中锂、铷、铯的研究,考察了硫酸浓度、酸矿比、熟化温度、熟化时间、浸出温度、液固比等对锂、铷、铯浸取率的影响。结果表明,提取锂、铷、铯的最优工艺条件为:酸矿比1∶1、硫酸浓度70%、120℃熟化8h、液固比4∶1、50℃浸出1h。在此条件下,锂、铷、铯的浸出率分别为91.42%、88.83%、90.09%。     

某型航空涡轴发动机燃油调节器建模与仿真

根据某型航空涡轴发动机燃油调节器的结构原理图,分析了该型燃油调节器的调节规律以及调节器基本工作原理.进而结合该型燃油调节器在试验台上得到的部分试验数据,在MATLAB软件的SIMULINK平台上采用LookUp-Table模块构建系统非线性环节,以模拟系统的非线性特性,进而建立了该型燃油调节器的简易数学模型.对建立的燃油调节器模型进行的静态校验结果表明,调节器模型满足了该型燃油调节器的各项性能指标的要求.并结合该型涡轴发动机的数学模型进行了动态联合仿真,通过对动态仿真结果的分析,获得了影响该型调节器性能的关键结构参数及将该型调节器数字化时的采样周期范围.     

基于生命期引导的生态进化模型

进化算法的一个很大的不足是个体进化本身没有一个明确的引导趋势.该文借鉴个体进化的生命周期性,提出了一种基于生命期引导的生态进化模型.基于此模型的算法在个体生命期的各个阶段设置了相应的引导算子,使个体在整个生命期都基于其生态特征而被引导进化.实验结果验证了其优越性.     

Dynamics of mechanical,acoustical, and electrical properties of epoxy‐amine compositions during cure

Dynamics of mechanical, acoustical, and electric properties is studied in the cure of three samples of polymeric compositions produced on the basis of epoxy oligomer with different content of the curing agent. The measurements were made in a parallel mode with an automated measuring complex. Variations in elastic modules, sound speed, attenuation coefficient, relaxation of the shear stress, electric resistance of the samples during the complete cure in the transition from a liquid into a glass state are considered. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

妊娠期肝内胆汁淤积症(intrahepatic cholestasis of pregnancy,ICP)的诊断及护理干预

目的探讨妊娠期肝内胆汁淤积症(ICP)的诊断及护理方法。方法对县级28例孕晚期妊娠期肝内胆汁淤积症的临床资料回顾性分析,诊断并进行护理干预。结果 75%以皮肤瘙痒为首发症状,黄疸及其它症状出现较皮肤瘙痒发病率低、发生晚,实验室无法进行血清肝胆酸测定,但肝功能测定、胎儿监护、胎盘功能测定均可进行,经过细心的治疗护理,23例足月产,1例早产,2例胎儿生长受限,2例胎儿宫内窘迫,无产后出血、新生儿颅内出血等,体征和生化异常在2周内恢复正常。结论早期确诊本病,积极护理干预,可降低孕产妇及胎婴儿发病率,改善妊娠结局。     

Development of a high curing latency no-flow underfill with self-fluxing ability for lead-free solder interconnects

Tin-lead solders have been used as joining materials in the electronics industry for many years. As present there are great concerns about the potential harm of lead-containing solders to human beings and many efforts have been made to remove the lead from the electronics packages. However, there is no no-flow underfill currently on the market that is compatible with the lead-free solder. In this study, a new no-flow underfill for flip chip bumped with lead-free solder has been developed based on a curing agent and catalysts with high curing latency. The curing agent itself has the fluxing ability, so the need of extra flux is eliminated. Compared with the underfill for lead-containing solder, the new underfill has a higher curing temperature, compatible with the melting profile of lead-free solder. The wetting compatibility of the underfill with the lead-free solder has been studied by wetting experiments. The material properties of the underfill have been investigated using DSC, TGA, TMA and DMA. The results show that the newly developed underfill material has the potential to be used in lead-free interconnects.     

给水加氧技术在节能降耗上的应用

通过对广东红海湾发电有限公司2#机组的给水加氧技术应用前后的各种参数对比,结果表明,给水加氧技术在节能降耗方面的空间比较大,值得推广。