“铱”系统及其业务进展

“铱”（Iridium）系统是美国摩托罗拉公司于1987年提出的一种利用低轨道（LEO）卫星群实现全球个人卫星移动通信的系统，它与现有的通信网相结合，可以实现全球数字化个人通信。“铱”系统区别于其它卫星移动通信系统的特点之一是卫星载有处理器，采用星间交换链路技术，因而，系统的性能极为先进、复杂、投资费用较高。此外，“铱”系统的漫游方案设计解决了卫星网与地面蜂窝网之间以及地面蜂窝网之间的跨协议漫游，这是“铱”系统有别于其它卫星移动通信系统的又一大特点。“铱”系统市场主要定位于国际旅行、商务活动、工业开发、政府…     

Improved efficiency and stability of perovskite solar cells with molecular ameliorating of ZnO nanorod/perovskite interface and Mg-doping ZnO

Despite the advanced efficiency of perovskite solar cells(PSCs),electron transportation is still a pending issue.Here the polymer polyvinylpyrrolidone(PVP)is used to enhance the electron injection,which is thanks to the passivation of the defects at the interface between the ZnO electron transporting layer(ETL)and the perovskite.The application of the PVP layer inhibits the device degradation,and 80%of the primary efficiency is kept after 30 d storage in air condition.Additionally,the efficiency of the device is further enhanced by improving the conductivity and crystallinity of the ZnO ETL via Magnesium(Mg)doping in the ZnO nanorods(ZnO NRs).Moreover,the preparation parameters of the ZnO NRs are optimized.By employing the high-crystallinity ZnO ETL and the PVP layer,the power conversion efficiency(PCE)of the champion device is increased from 16.29%to 19.63%.These results demonstrate the advantages of combining mesoscale manipulation with interface modification and doping together.     

超高清电视技术在中国的专利申请分析

超高清电视技术是当前电视技术的热点研究领域之一,为了解涉及超高清电视技术的专利在中国的发展和布局状况,在对中国范围的超高清电视领域的专利申请进行检索基础上,分析了超高清电视技术在中国的专利申请量变化趋势、主要申请人等方面的特点,对超高清电视技术的发展特点做出一个整体的论述,以供国内超高清电视领域的申请人参考.     

基于主题发布-订阅的分布式通信总线设计与实现

参考数据分发服务(Data Distribute Service,DDS)规范模型,基于组播通信和ZMQ通信库,设计并实现了一个高效、实时的主题发布订阅通信总线库(Topic Publish Subscibe Bus Library,TPSBLIB).该通信总线库采用发布-订阅工作模式,有效降低数据发送及获取节点之间的...     

Circular shallow spherical shells with central circular hole under simultaneous actions of arbitrary unsteady temperature field and arbitrary dynamic normal load

In this paper, under assumption that tempeature is linearly distributed along the thickness of the shell, we deal with problems as indicated in the title and obtain general solutions of them which are expressed in analytic form.In the first part, we investigate free vibration of circular shallow spherical shells with circular holes at the center under usual arbitrary boundary conditions. As an example, we calculate fundamental natural frequency of a circular shallow spherical shell whose edge is fixed (m=0). Results we get are expressed in analytic form and check well with E. Reissner’s [1]. Method for calculating frequency equation is recently suggested by Chien Wei-zang and is to be introduced in appendix 3.In the second part, we investigate forced vibration of shells as indicated in the title under arbitrary harmonic temperature field and arbitrary harmonic dynamic normal load.In the third part, we investigate forced vibration of the above mentioned shells with initial conditions under arbitrary unsteady temperature field and arbitrary normal load.In appendix 1 and 2, we discuss how to express displacement boundary conditions with stress function and boundary conditions in the case m=1.     

同轴静电纺丝技术制备药物缓释载体的研究进展

由于纳米纤维在组织工程支架材料,药物传递载体等方面的潜在应用,使得具有高比表面积的静电纺丝纳米纤维得到了很大的关注。静电纺丝技术是一种简单、有效的微／纳米技术,而同轴静电纺丝则是在传统静电纺丝技术上发展起来的新方法,单步即可制备连续的壳一芯结构纳米纤维或中空纳米纤维。这也使得静电纺丝纳米纤维在组织工程和药物缓释等领域有...     

我国电子商务网站的定位和栏目设计技巧

在网络技术快速发展的今天,电子商务网站已经逐渐渗透到我国各行各业,但是它存在很多问题,尤其是在网站的栏目和定位两个方面较为明显,笔者通过对这些问题的分析,提出一些自己的观点和看法,旨在为我国电子商务网站正确定位提供参考。     

一种无线语音传输系统设计

利用锁相环技术,通过调频方式,实现音频信号的调制、解调,设计一种可以选择使用耳机或扬声器的无线语音传输系统.系统利用电路实现语音的通信和信息转发,可实现对语音实时无失真传输,系统实现对音频信号的无线通信的功能.     

亚硝酸三(乙二胺)合镍的合成和性质

关于三(乙二胺)合镍的亚硝酸盐,Bandyopadhayay^[1]曾使醋酸镍、亚硝酸钠和乙二胺作用,得到顺磁性物质Ni₂en₂(NO₂)₃(OH),并认为它是无机高聚物.Бабаева和张守纲^[2]在合成[Nien₂(NO₂)₂]络合物时,观察到紫红色晶体,认为是亚硝酸三(乙二胺)合镍,但未列出化学分析和性质测定的数据.我们用醋酸镍、亚硝酸钠和过量的乙二胺作用,合成亚硝酸三(乙二胺)合镍(Ⅱ),并测定其若干物理化学性质.     

我国三网融合背景下的技术专利分析

从2010年开始,我国开始推行三网融合.经过几年的试点工作,目前三网融合进入外推广阶段.从专利分析的角度,介绍了三网融合技术的专利申请的数量、技术趋势等方面的分布情况,通过介绍这一领域专利的现状和发展趋势,希望能对国内相关行业提供一定的参考.