载人航天高可靠伺服技术

回顾了载人航天高可靠伺服技术的研制道路，介绍了用于载人航天火箭推力矢量控制中的新型三余度伺服机构的技术特点，对载人航天伺服技术的未来发展进行了分析和展望。     

后桥壳的可靠性优化设计

该文讨论了后桥壳的可靠性优化设计问题.在基本随机变量的概率特性已知的情况下,应用随机摄动法和约束随机方向法对后桥壳进行可靠性优化设计,并编制了实用的计算机程序,可以迅速准确地得到后桥壳的可靠性设计参数.     

再论“用离心机作静力结构模型试验”

 本文通过最近所作的两个离心模型试验,进一步探讨了用离心机作静力结构模型试验的有关问题,试验结果进一步证明用离心机作静力结构模型试验,无论在理论上和试验技术上都是可行的,最后将有关问题作了进一步的讨论。     

Increasing Reliability in Cable-Free Radio LANs Low Level Forwarding in HIPERLAN

Radio LANs are emerging in the computing world. They are supported by distinct configurations: on the one hand radio LANs with base stations and a wired backbone, on the other hand radio LANs implementing Intra-forwarding. Adding a new node in a radio LAN with Intra-forwarding, increases the reliability, while this reliability decreases with ad hoc or hub configurations. This advantage of Intra-forwarding is quantified. Intra-forwarding, as defined in the HIPERLAN standard, is based on a hop-by-hop policy and link check procedures. It is shown how point-to-point packets and broadcast packets are forwarded. The three basic components of Intra-forwarding needed to build and update the Intra-forwarding database are described. The originality of this approach is the use of multipoint relays which enable better scalability. The correctness of the Intra-forwarding protocol is proved and its cost is evaluated.     

竹坑水库大坝安全鉴定分析

在竹坑水库大坝安全鉴定中,认真分析了该工程存在的主要问题,并针对大坝的结构稳定和渗流稳定作了详细的分析论证.     

包头市万友商城结构方案优化设计分析

本文提出了改进型离散变量组合形算法并研制开发了结构优化设计程序,可用于高层建筑结构优化,并对包头市万友商城结构方案进行了优化设计分析.     

Effect of oxygen flow rate on the structural and electrochemical properties of lithium nickel oxides synthesized by the sol–gel method

The structural and electrochemical properties of LiNiO₂ powders were investigated as a function of the oxygen flow rate employed in the preparation of lithium nickel oxide. It was found that oxygen played an important role in the synthesis of highly crystallized LiNiO₂(R3¯m). In the crystallization process of LiNiO₂, a deficiency of oxygen in the calcination reactor induced the formation of impurities and cubic rock-salt structure (Fm3m) in LiNiO₂ powders. For LiNiO₂ prepared at higher oxygen flow rates, the electrode delivered high discharge capacities with relatively good retention rates. But very low electrode capacity was obtained from LiNiO₂ prepared at lower oxygen flow rates.     

Experimental evaluation of fishway modifications on the passage behaviour of adult Chinook salmon and steelhead at Lower Granite Dam,Snake River,USA

Previous studies of Pacific salmonid passage over Snake River dams indicated slowed passage at transition pools, the transition area between the fishway entrance and the fish ladder. In 2001 and 2002, we conducted an experiment to determine if modified weirs affected adult salmon and steelhead passage times and route selection through the Lower Granite Dam transition pool. Fish attraction flows through the lower ladder weirs were experimentally increased using removable panels. During the experiment we monitored radio‐tagged adult Chinook salmon and steelhead to determine passage routes and times through the transition pool. The weir treatment increased the number of spring–summer Chinook salmon passing straight through the transition pool compared to those exiting the transition pool to the collection channel or tailrace. Mean passage times through the transition pool differed among routes and were significantly lower during treatment periods for the exit‐to‐collection channel route in spring‐summer Chinook salmon, but not for other routes. Passage times among routes differed in steelhead, but there was no evidence of treatment effects on route use or passage time. Fall Chinook exhibited similar trends in route use and passage time to spring–summer Chinook, but differences were not significant, perhaps because of relatively small sample size. Total dam passage times did not differ by treatment or route for any run. Fish depth during passage of the transition pool suggested that most fish passed through submerged orifices and supported the hypothesis that increased water velocity through these orifices caused the increase in straight‐through passage in spring–summer Chinook. Collectively, the results suggested the weir modifications provided improvement to passage through the transition pool for spring–summer Chinook and no evidence of negative effects on other runs. The results from this study were used to develop new design criteria and modifications of the Lower Granite Dam fishway. Copyright © 2006 John Wiley & Sons, Ltd.     

发育有切割井眼结构面的井壁稳定性评价研究

切割井眼结构面的存在弱化了井壁的稳定性，常规完整井眼的井壁稳定分析理论已不能完全适用于受结构面切割的井眼。基于摩尔-库仑理论，在分析结构面应力状态的基础上，给出了井眼受结构面切割的井壁稳定性评价方法，并研究分析了结构面产状对井壁失稳的影响。结果表明，井壁的稳定性与原地应力状态、结构面产状以及结构面的力学性质有关，在其它因素一定的情况下，结构面的走向与倾角对井壁的稳定与失稳方位有着较大的影响。因此，准确评价结构面产出状态是提高井壁稳定性评价精度的前提。     

Breaking of structural dormancy in seeds of Tetrapleura tetraptera by Aspergillus niger

Aspergillus niger (strain UUF9202) significantly reduced the dormancy period and boosted aggregate germination percentage (AGP) in seeds of Tetrapleura tetraptera. A net reduction in mean germination time (MGT) to 12 days and an increase from 0 to 42% AGP were obtained in 32 days. The optimal spore inoculum of the fungus was 8.5 × 10≥10 ml^?1 per 100 seeds in 96 h pregermination incubation. The potential of some physical factors in combination with this fungal concentration in enhancing AGP was evaluated. The treatments were as follows: (i) hot water scarification at 30°C, 50°C, 80°C and 100°C plus A niger; and (ii) nicking by decoating at either the micropylar or chalazal ends plus A niger. Micropylar scarification plus A niger gave the highest AGP (94%) followed by chalazal scarification plus A niger (86%) and hot water dip at 80°C + A niger (82%). The control seeds which were soaked in presterilised (by autoclaving at 121°C for 15 min) A niger spore suspension at 30°C gave zero germination.