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91.
Thelwall  Mike  Tang  Rong 《Scientometrics》2003,58(1):155-181
The Web has become an important means of academic information exchange and can be used to give new insights into patterns of informal scholarly communication. This study develops new methods to examine patterns of university Web linking, focusing on Mainland China and Taiwan, and including language considerations. Multiple exploratory investigations into Web links were conducted between universities in these two places. Firstly, inlinks were counted to each university Web site from its national peers using four alternative Web document models. The results were shown to correlate significantly with research productivity in Taiwan but not in the Mainland, although in the latter case less reliable institutional data could have been the cause. For Taiwan, this is the first evidence of a scholarly association with academic linking for a non-English speaking region. It was then ascertained that the same link counts associated more strongly with scientific than social scientific research productivity in Taiwan. This confirms the general assumption of greater Web use by the hard sciences. We then investigated Taiwan-Mainland university cross-links, and found that although English is extensively used on the Web, there was no evidence that it was the language of preference for informal scholarly communication between the two areas. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
92.
This paper proposes a novel low-leakage BiCMOS deep-trench (DT) diode in a 0.18-/spl mu/m silicon germanium (SiGe) BiCMOS process. By means of the DT and an n/sup +/ buried layer in the SiGe BiCMOS process, a parasitic vertical p-n-p bipolar transistor with an open-base configuration is formed in the BiCMOS DT diode. Based on the two-dimensional (2-D) simulation and measured results, the BiCMOS DT diode indeed has the lowest substrate leakage current as compared to the conventional p/sup +//n-well diode even at high temperature conditions, which mainly results from the existence of the parasitic open-base bipolar transistor. Considering the applications of the diode string in electrostatic discharge (ESD) protection circuit designs, the BiCMOS DT diode string also provides a good ESD performance. Owing to the characteristics of the low leakage current and high ESD robustness, it is very convenient for circuit designers to use the BiCMOS DT diode string in their IC designs.  相似文献   
93.
为减少勘探费用,缩短施工周期,取全取准各项地质资料,采取中途测试工艺。随着深井中途测试不断增多,特别是跨隔支撑测试具有一定施工风险和难度,要求测试质量不断提高。结合油田生产实际,合理选配了地层测试工具仪表,不断改进测试管串和优化施工设计,经盐22井中途跨隔测试应用,获得成功。  相似文献   
94.
In the all-IP wireless networks beyond the third generation, mobility management can be effectively achieved by applying mobile IP (MIP) and the session initiation protocol (SIP) jointly. Nevertheless, an efficient combination of both protocols remains an open research issue. Conventional hybrid MIP-SIP mobility architectures operate MIP and SIP almost independently, resulting in significant redundant costs. This article investigates the representative hybrid MIP-SIP architectures and explores the joint optimizations between MIP and SIP for a more cost-efficient mobility support whilst utilizing their complementary power. Two novel design approaches are presented. The first approach culminates in a tightly integrated architecture, which merges the redundant mobility entities in MIP and SIP to yield maximum system efficiency. The other approach leads to a loosely integrated architecture, where necessary interactions are introduced between MIP and SIP mobility servers while their physical entities are kept intact. Major mobility procedures, including location update, session setup and handoff, are discussed in these architectures. The analytical results demonstrate that both proposed architectures outperform typical hybrid MIP-SIP architectures in terms of clear-cut reduced signaling costs  相似文献   
95.
不同注F剂量与CMOS运放电路辐照损伤的相关性   总被引:1,自引:1,他引:0  
在不同注F剂量条件下,对P沟和N沟两种不同差分对输入CMOS运放电路的电离辐照响应进行了研究.分析比较了注F和未注F运放电路电离辐照响应之间的差异.结果表明,在栅场介质注入适量的F,可有效抑制辐照感生的氧化物电荷尤其是界面态的增长,从而提高CMOS运放电路的抗辐照特性.  相似文献   
96.
下一代无线通信(NextG:Next-generationwireless)的主流是随时随地的无线通信系统和无缝的高质量无线业务。概述了随时随地的无线通信和业务发展情况,并且介绍了为下一代无线通信的发展提供基础的关键技术。  相似文献   
97.
研究了垂直腔面发射激光器 (VCSEL)及其列阵器件的光谱特性、调制特性、高频特性及与微电子电路的兼容性 ,将 1× 16的VCSEL与CMOS专用集成电路进行多芯片组装 (MCM ) ,混合集成为 16信道VCSEL光发射功能模块 .测试过程中 ,功能模块的光电特性及其均匀性良好 ,测量的 - 3dB频带宽度大于 2GHz.  相似文献   
98.
无线监测示功仪的研制与应用   总被引:2,自引:0,他引:2  
针对常规示功仪资料储存的容量有限和对油井不能长时间连续监测的不足,研制了无线监测示功仪。该示功仪将载荷和位移传感器、无线传输以及太阳能供电等多种技术集于一体(1)采用加速度传感器,实现了光杆无线位移检测,解决了常规位移传感器寿命短、可靠性差的问题;(2)应用CC1000无线模块,实现了油井示功图短距离数据无线交换,屏弃了常规仪器电缆通讯的方式;(3)通过增加仪器储存容量和移植USB接口,解决了常规示功仪储存数据量少的问题,极大地方便了数据交换;(4)将太阳能电池与充电电池有机结合,圆满解决了仪器供电问题。  相似文献   
99.
Recent years have witnessed a rapid growth of interest in the study of the dynamic behavior of replenishment rules of bullwhip effect. We prove that bullwhip effect and butterfly effect share a same the self-oscillation amplifying mechanism that is the ordering decisions the supplier self-oscillation amplify the perturbations brought by the errors in the processing of retailers' demand information. This results as an explicit self-similar structure of the sensitivity of the system to the initial values duty to the nonlinear mechanism. In this paper, the causes process of the bullwhip effect is described as the internal nonlinear mechanism and study on the complexity of bullwhip effect for order-up-to policy under demand signal processing. The methodology is based on fractal and chaotic theory and allows important insights to be gained about the complexity behavior of bullwhip effect.  相似文献   
100.
石膏转化制硫酸钾结晶动力学及结晶添加剂研究   总被引:2,自引:0,他引:2  
研究了浓氨介质中石膏与氯化钾直接转化制硫酸钾的结晶动力学及结晶添加剂的作用效果。结果表明 ,硫酸钾在氨介质中的成核速率与晶体生长速率、悬浮密度、搅拌速率存在如下关联式 :B0 =5 .64 13×10 8G3.32 0 8Mt0 .0 559np0 .2 92 8。加入异丙醇、OP乳化剂及十二烷基苯磺酸钠等添加剂 ,可使硫酸钾结晶产品纯度提高 ,晶体形态整齐均匀  相似文献   
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