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151.
单清  钱焕文  张杰  任华  焦振宇 《激光技术》1999,23(6):335-338
重组人碱性成纤维细胞生长因子(rhbFGF)具有刺激血管生长,加速创伤愈合,以及促进神经损伤修复等功能.作者以青紫蓝灰兔为试验材料,以不同剂量和不同注射部位与地塞米松相对照,通过检眼镜、眼底照相、组织学观察、超微结构观察、损伤斑定量分析及ERG-b波分析等项测试得出结论:地塞米松有一定疗效,而受试药物rhbFGF对激光视网膜损伤的治疗作用更明显.  相似文献   
152.
In this paper, the subspace fitting models for direction-of-arrival (DOA) estimation is analyzed, an effective algorithmic approach is given. As the initialization value is so critical to the global convergence, the continuation theory is also used to develop a new framework which solves the initialization problem powerfully. Some numerical evidence will be given to show that the performance of the new algorithm is very promising.  相似文献   
153.
Ren  Shenyuan  He  Ligang  Li  Junyu  Chen  Zhiyan  Jiang  Peng  Li  Chang-Tsun 《Wireless Networks》2022,28(3):1293-1300
Wireless Networks - In this paper, we investigate the influential factors that impact on the performance when the tasks are co-running on a multicore computers. Further, we propose the machine...  相似文献   
154.
任修坤  耿欣  胡捍英 《光通信研究》2007,33(3):42-44,61
在研究了主公共控制物理信道(P-CCPCH)同步原理、介绍了现有的同步法的基础上,提出了一种新的P-CCPCH同步法.该方法基于SYNC-DL调制相位和载波频偏,可以非常好地克服由于载波频偏而引起的捕获概率降低的现象.仿真结果表明,该方法具有很好的抗载波频偏的性能,且检测概率高,运算量小,操作性强,易于实现.  相似文献   
155.
All-solid-state Li batteries (ASSLBs) with solid-polymer electrolytes are considered promising battery systems to achieve improved safety and high energy density. However, Li dendrite formation at the Li anode under high charging current density/capacity has limited their development. To tackle the issue, Li-metal alloying has been proposed as an alternative strategy to suppress Li dendrite growth in ASSLBs. One drawback of alloying is the relatively lower operating cell voltages, which will inevitably lower energy density compared to cells with pure Li anode. Herein, a Li-rich Li13In3 alloy electrode (LiRLIA) is proposed, where the Li13In3 alloy scaffold guides Li nucleation and hinders Li dendrite formation. Meanwhile, the free Li can recover Li's potential and facilitate fast charge transfer kinetics to realize high-energy-density ASSLBs. Benefitting from the stronger adsorption energy and lower diffusion energy barrier of Li on a Li13In3 substrate, Li prefers to deposit in the 3D Li13In3 scaffold selectively. Therefore, the Li–Li symmetric cell constructed with LiRLIA can operate at a high current density/capacity of 5 mA cm−2/5 mAh cm−2 for almost 1000 h.  相似文献   
156.
研究了无场调制板结构、有场调制板结构但无凹槽栅、结合场调制板结构和凹槽栅工艺三种AlGaN/GaN HEMT的动态I-V特性和微波特性,认为场调制板结构和凹槽栅工艺可以有效改善AlGaN/GaN HEMT器件沟道内电场分布,显著减小电流崩塌现象,提高器件的微波输出功率特性.利用此技术研制的1mm栅宽AlGaN/GaNHEMT输出功率大于10W.  相似文献   
157.
本论文介绍了一个带定制电容阵列的低功耗9bit,100MS/s逐次比较型模数转换器。其电容阵列的基本电容单元是一个新型3D,电容值为1fF的MOM电容。除此之外,改进后的电容阵列结构和开关转换方式也降低了不少功耗。为了验证设计的有效性,该比较器在TSMC IP9M 65nm LP CMOS工艺下流片。测试结果如下:采样频率100MS/s,输入频率1MS/s时,有效位数(ENOB)为7.4,bit,信噪失真比(SNDR)为46.40dB,无杂散动态范围(SFDR)为62.31dB。整个芯片核面积为0.030mm2,在1.2V电源电压下功耗为0.43mW。该设计的品质因数(FOM)为23.75fJ/conv。  相似文献   
158.
The method of lines is extended to the multilayered inhomogenous dielectric layers by means of the additional transformation and the recurrence matrix. The computed dispersion diagrams for the multilayered planar waveguides agree very well with the results from other authors. New results for a six layer structure are given.  相似文献   
159.
Silicon is widely used as a raw material for production of solar cells. As a major impurity in silicon, phosphorus must be removed to 1 × 10?5 wt.%. In the present study, based on the distribution of phosphorus in a silicon ingot obtained by vacuum refining and directional solidification, the mechanism for removal of phosphorus from silicon is investigated. The results show that the distribution is controlled not only by segregation at the solid–liquid interface but also by evaporation at the gas–liquid interface, showing some deviation from Scheil’s equation. A modified model which considers both segregation and evaporation is used to simulate the distribution, matching quite well with the experimental results. The temperature and solidification rate are two important parameters that affect the overall mass transfer coefficient and the effective segregation coefficient and thus the distribution of phosphorus. A high removal efficiency and a homogeneous distribution can be obtained by adjusting these two parameters.  相似文献   
160.
Cooperative spectrum sensing has been shown to be an effective approach to improve the detection performance by exploiting the spatial diversity among multiple secondary users (or unlicensed users). However, due to correlated shadowing and cooperation overhead in practical cognitive radio networks, it is desired to select an appropriate set of secondary users which have little correlation with each other to participate in cooperation so as to achieve the effective tradeoff between detection performance and cooperation overhead. In this paper, we first study the hypothesis testing model and detection performance of cooperative spectrum sensing under the correlated log-normal shadowing scenario. Afterwards, based on whether the false-alarm and missed-detection probabilities are constrained, three optimization problems are formulated to find the optimal set of secondary users participating in cooperation, which take into account the tradeoff between detection performance and cooperation overhead. Then the solutions using adaptive genetic algorithms are presented for the optimization problems. Finally, simulation experiments demonstrate that our proposed schemes are very effective.  相似文献   
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