新疆伊犁托海水电站拱坝坝体变形监测分析

根据托海拱坝5号坝段、7号坝段例垂线实测资料分析，说明了新疆寒冷地区坝体采取聚胺脂喷涂施工措施后对坝体变形的影响，以及右坝肩渗漏对右坝肩岩体的影响，分析结果为托海水电站通过国家电力公司大坝安全监察中心大坝安全首次定检提供了科学依据。     

类胡萝卜素的生物利用率

本文论述了作为维生素A前体的类胡萝卜素在体内的吸收代谢过程、类胡萝卜素生物利用率的定义、影响生物利用率的因素以及测定新方法。     

Interfacial reactions in In-Sn/Ni couples and phase equilibria of the In-Sn-Ni system

The In-Sn-Ni alloys of various compositions were prepared and annealed at 160°C and 240°C. No ternary compounds were found; however, most of the binary compounds had extensive ternary solubility. There was a continuous solid solution between the Ni₃Sn phase and Ni₃In phase. The Sn-In/Ni couples, made of Sn-In alloys with various compositions, were reacted at 160°C and 240°C and formed only one compound for all the Sn-In alloys/Ni couples reacted up to 8 h. At 240°C, Ni₂₈In₇₂ phase formed in the couples made with pure indium, In-10at.%Sn and In-11at.%Sn alloys, while Ni₃Sn₄ phase formed in the couples made of alloys with compositions varied from pure Sn to In-12at.%Sn. At 160°C, except in the In/Ni couple, Ni₃Sn₄ formed by interfacial reaction.     

LDPC-based space-time coded OFDM systems over correlated fadingchannels: Performance analysis and receiver design

We consider a space-time coded (STC) orthogonal frequency-division multiplexing (OFDM) system with multiple transmitter and receiver antennas over correlated frequency- and time-selective fading channels. It is shown that the product of the time-selectivity order and the frequency-selectivity order is a key parameter to characterize the outage capacity of the correlated fading channel. It is also observed that STCs with large effective lengths and ideal built-in interleavers are more effective in exploiting the natural diversity in multiple-antenna correlated fading channels. We then propose a low-density parity-check (LDPC)-code-based STC-OFDM system. Compared with the conventional space-time trellis code (STTC), the LDPC-based STC can significantly improve the system performance by exploiting both the spatial diversity and the selective-fading diversity in wireless channels. Compared with the previously proposed turbo-code-based STC scheme, LDPC-based STC exhibits lower receiver complexity and more flexible scalability. We also consider receiver design for LDPC-based STC-OFDM systems in unknown fast fading channels and propose a novel turbo receiver employing a maximum a posteriori expectation-maximization (MAP-EM) demodulator and a soft LDPC decoder, which can significantly reduce the error floor in fast fading channels with a modest computational complexity. With such a turbo receiver, the proposed LDPC-based STC-OFDM system is a promising solution to highly efficient data transmission over selective-fading mobile wireless channels     

职业技能鉴定质量分析初探

职业技能鉴定是推行职业资格证书制度的重要环节,鉴定的质量直接关系到职业资格证书的真实性、权威性。通过对试卷的有效性和可靠性的分析,以及对试题难度、区分度的分析,对职业技能鉴定质量的分析方法进行了探讨,阐述了质量分析在职业技能鉴定中的作用。     

WLAN网管系统的现状和发展

2001年以来，全球WLAN（无线局域网）市场应用的瓶颈被打破，中国也迎来了WLAN商业化运作和服务的春天，WLAN为我们带来了一种全新的、灵活的工作方式，同时也带来了新的挑战，本文将对WLAN网络管理的主要内容和具体指标进行阐述，并对各大厂商的WLAN网管产品进行简单介绍和比较。     

试论融资租赁项下的进口贸易

阐述了当前跨国公司在合同中普遍采用的融资租赁的性质及融资租赁项下的进口贸易特点。     

Using motion from orthographic views to verify 3-D point matches

The specific problem addressed by the authors is how to detect the true match of a fourth point from among candidate matches in a situation in which three points have already been matched. The two sets of points to be matched are both subject to measurement errors. The depth error is more dominant than errors in the other two coordinates; however, the exact statistical distribution of the measurement errors is not known. The authors present a new method for solving the problem. The method is based on the technique of motion analysis using orthographic views. It discards the noisy z (depth) coordinates and uses only the x and y coordinates of the points to verify the match. The effect of depth errors on the motion estimate is completely prevented. Results show that this method is substantially more effective than previous methods that use all three coordinates