地下车库采用HRB400级钢筋的技术经济分析和优化研究

以同一个地下车库采用HRB335级和HR．B400级钢筋的两种方案，作出技术经济分析和对比，并进一步优化。结论认为：有选择地采用HRB400级钢筋，能较好地节省钢材和资金。     

多关节鱼水中救援策略

针对多关节鱼水中救援项目,在单关节鱼的基础上,对多关节鱼在尽可能短的时间内完成救援任务提出了一种救援策略.策略在多关节鱼能够全部撞击到目标物的前提下,保证了在规定时间内即使多关节鱼未能完成任务,也可以取得一个相对高效的救援效果.策略中设计出了迪杰斯特拉路径规划方案的救援路线,采用了直接撞击函数和鱼头甩动函数相结合的救援方法.实验结果表明:该策略能够灵活调用多关节鱼,大大缩短了救援用时,增加了策略的稳定性,提高了救援效率,在实际应用中取得了较好的效果.     

Multi-field coupling thermo-acoustic radiation using free-standing nano-thin films in a static magnetic field

Abstract

Thermo-acoustic radiation from nano-thin film has been widely reported these years. In this paper, a static magnetic field is introduced to enhance the acoustic power in the multi-field thermo-acoustic generation. The coupled thermo-acoustic system in a static magnetic field shares the same acoustical unit with very few additional components. In the presence of a static magnetic field, thin-film vibration is excited instead of being still in the classical thermo-acoustic system. Not surprisingly, a steady magnetic field has very little impact on the thermo-acoustic generation system when a constant amplitude sinusoidal current is introduced. The oscillation perpendicular to the nano-thin film is driven by the electromagnetic force. The system response of thermo-acoustics and magneto-acoustics can be generally matched when suitable parameters are introduced. The acoustical pressure output can be significantly improved in the presence of a static magnetic field although more electrical input power should be provided in the multi-field thermo-acoustic system. Evidently, the coupled multi-field acoustical system is able to handle more electrical power input and the power input can be more easily dissipated relatively. The results show that the acoustic response of this new multi-filed coupled system can be significantly improved as compared to the classical system without magnetic effects.     

一种最小电压应力的软开关无桥PFC技术研究

针对传统桥式整流升压功率因数校正(PFC)电路效率较低的缺点,提出了一种最小电压应力的软开关无桥PFC电路拓扑.在理论分析和仿真验证的基础上,研制了一台300 W的实验样机.结果表明,改进的无桥PFC电路拓扑具有通态损耗低、电流采样简单,能实现开关管零电压关断和零电流开通,同时实现整流二极管零电压导通和接近零电流软关断...     

北极涛动对华北沙尘暴频次的影响

This study has investigated the influence of Arctic Oscillation (AO) on dust storm frequency in North China in spring seasons during 1961-2007. There is a significant linkagebetween dust storm frequency and AO; a negative (positive) AO phase is related to an in-creased (decreased) dust storm frequency in North China. This relationship is closely related to changes in the cold air activity in Mongolia. The cold air activity exerts large impacts on the dust storm frequency; the frequency of cold air activity over Mongolia not only positively cor-relates with the dust storm frequency in North China, but also shows a long-term decreasing trend that is an important reason for the long-term decreasing of dust storm frequency in North China. The AO has large influence on the frequency of cold air activity over Mongolia; a negative (positive) AO phase is highly related to an increased (decreased) frequency of cold air activity over Mongolia, which results in an increased (decreased) dust storm frequency in North China.     

Reviews of selected 100 recent papers for lithium batteries （Aug. 1,2015 to Sept. 30,2015）

该文是一篇近两个月的锂电池文献评述,我们以“lithium”和“batter*”为关键词检索了Web of Science 从2015年8月1日至2015年9月30日上线的锂电池研究论文,共有2432篇,选择其中100篇加以评论。正极材料主要研究了富锂相材料、三元材料和尖晶石材料的掺杂和表面包覆及界面层改进对其循环寿命的影响。高容量的硅、锡基复合负极材料研究侧重于SEI界面层、复合材料、黏线剂及反应机理研究,电解液添加剂、固态电解质、锂空电池、锂硫电池的论文也有多篇。理论模拟工作包括电极材料体相和界面结构以及电解质的输运性质,除了以材料为主的研究之外,针对电池的状态估计、失效分析、热安全分析的研究论文也有多篇。     

Reviews of selected 100recent papers for lithium batteries (Oct. 1, 2015 to Nov. 30, 2015)

该文是一篇近两个月的锂电池文献评述,以“lithium”和“batter*”为关键词检索了Web of Science从2015年10月1日至2015年11月30日上线的锂电池研究论文,共有2318篇,选择其中100篇加以评论。正极材料主要研究了富锂相材料、三元材料和尖晶石材料的掺杂和表面包覆及界面层改进对其循环寿命的影响。高容量的硅、锡基复合负极材料研究侧重于SEI界面层、复合材料、黏结剂及反应机理研究,电解液添加剂、固态电解质、锂空电池、锂硫电池的论文也有多篇。理论模拟工作包括电极材料体相、界面结构以及电解质的输运性质。除了以材料为主的研究之外,针对电池的状态估计、失效分析、热安全分析的研究论文也有多篇。     

Reviews of selected 100 recent papers for lithium batteries#br# （Oct. 1，2017 to Nov. 30，2017）

该文是一篇近两个月的锂电池文献评述,我们以“lithium”和“batter*”为关键词检索了Web of Science从2017年10月1日至2017年11月30日上线的锂电池研究论文,共3750篇,选择其中100篇加以评论。正极材料主要研究了层状结构材料和高压尖晶石材料充放电过程中的结构演变和表面修饰作用。高容量的硅、硅基负极材料研究侧重于纳米材料、复合材料及反应机理研究。金属锂负极的研究侧重于通过表面覆盖层的设计来提高其循环性能。固态电解质方面制备方法和离子输运机理是研究重点,电解液添加剂的研究目标是提高电池充电至高电压时的稳定性。锂空电池、锂硫电池侧重于改进电池的循环性能。理论模拟工作包括材料体相、界面结构和输运性质,除了以材料为主的研究之外,针对电池分析、理论模拟和电池模型的研究论文也有多篇。     

Vapor Phase Synthesis and Optic Properties of MoO2 Micro/nanosheet

以MoO₃粉末和石墨为原料, 用气相传输方法制备MoO₂微/纳米片, 并对其形貌、结构及光学性能进行了分析和表征。结果表明, 用气相法制备的矩形薄片状MoO₂, 长和宽在几微米到几十微米之间, 厚度约为200 nm。MoO₂微/纳米片在波长200--300 nm的紫外光范围内有较强的吸收带, 在304.6 nm、343.4 nm和359.6 nm处有较强的发光峰。根据实验分析和热力学理论, 探讨了MoO₂微/纳米片的生长机理。     

Integration of microsensor for microsurgery robot’s end-effector

To enhance the effect of robotic microsurgery, the microsensors are integrated on the robot s end-effector. On the basis of the requirements presented for the integration design, measuring mechanism for the robotic end trephine s force and cutting depth are studied. Force microsensor and position microsensor are used to measure surgical information of the force and depth. Measuring mechanism was achieved by means of linear sliding bearing and differential measuring structure. The sensor data board was developed. With the power spectral estimation of sensor data, two digital filtering methods are proposed, to help eliminate the interference to the original microsensor signal. They are the filtering method of lowpass-bandstop serial structure suitable for a PC, and a shift average filtering algorithm suitable for the sensor data board, respectively. The experimental results show that the integration of microsensors for microsurgery robot s end-effector can satisfy the design requirements, and the robotic end trephine can accurately fulfill the surgical task of corneal cutting.