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991.
在分析J2EE体系结构及EJB组件技术的基础上,提出一种基于EJB组件的分布式电子商务应用系统框架;并对其中各部分所采用技术进行了分析及合理选择;最后讨论了应用服务器选取、负载均衡等关键技术问题。该系统框架具有较好的可扩展性、可重用性、开放性和兼容性。 相似文献
992.
传统的水流流量计多数采用RS232接口设备作为数据转存的方式,设备体积较大,携带不便,且存储空间有限,防震性能不好.为此,介绍一种利用CH375实现明渠流量计海量数据存储系统的方法,该方法运用USB移动存储设备,实现明渠流量计系统的数据存储,以此实现与微机管理系统的数据交换. 相似文献
993.
Owing to imperfect boundary conditions in laboratory soil tests and the possibility of water diffusion inside the soil specimen in undrained tests, the assumption of uniform stress/strain over the sample is not valid. This study presents a qualitative assessment of the effects of non‐uniformities in stresses and strains, as well as effects of water diffusion within the soil sample on the global results of undrained cyclic simple shear tests. The possible implications of those phenomena on the results of liquefaction strength assessment are also discussed. A state‐of‐the‐art finite element code for transient analysis of multi‐phase systems is used to compare results of the so‐called ‘element tests’ (numerical constitutive experiments assuming uniform stress/strain/pore pressure distribution throughout the sample) with results of actual simulations of undrained cyclic simple shear tests using a finite element mesh and realistic boundary conditions. The finite element simulations are performed under various conditions, covering the entire range of practical situations: (1) perfectly drained soil specimen with constant volume, (2) perfectly undrained specimen, and (3) undrained test with possibility of water diffusion within the sample. The results presented here are restricted to strain‐driven tests performed for a loose uniform fine sand with relative density Dr=40%. Effects of system compliance in undrained laboratory simple shear tests are not investigated here. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
994.
本文介绍一种无线数据传接口及控制装置。装置中采用计算机软件实现串—并、并—串变换及频率调制、其硬件成本低廉,工作可靠,可用于速率为50、300、600或1200bps的数传通信。 相似文献
995.
Average slip rate,earthquake rupturing segmentation and recurrence behavior on the Litang fault zone,western Sichuan Province,China 总被引:3,自引:0,他引:3
XU Xiwei WEN Xueze YU Guihua ZHENG Rongzhang LUO Haiyuan & ZHENG Bin . Institute of Geology China Earthquake Administration Beijing China . Earthquake Administration of Sichuan Province Chengdu China 《中国科学D辑(英文版)》2005,48(8):1183-1196
The Litang fault zone (LFZ) is an important active fault within the northwestern Sichuan sub-block. To-gether with the Garzê-Yushu, Xianshuihe, and An-ninghe fault zones on its northern, eastern and south-eastern sides, the LFZ constitutes the lateral extrusion tectonic system in the southeastern part of the Qing-hai-Tibetan Plateau[1,2] (Fig. 1). According to instru-mental records, historical recordings and field investi- gation, an earthquake (Ms7.3) occurred on its middle to south se… 相似文献
996.
LIU Xuhua WANG Jinfeng LIU Mingliang & MENG Bin . Institute of Geographic Sciences Natural Resources Research Chinese Academy of Sciences Beijing China . Graduate School of the Chinese Academy of Sciences Beijing China . College of Arts Sciences of Beijing Union University Beijing China . School of Forestry Wildlife Sciences Auburn University Auburn Alabama AL USA 《中国科学D辑(英文版)》2005,48(12):2231-2240
Along with the increasing problems of rapid popu-lation increase, resources scarcity and environment deterioration, the interaction between human devel-opment and natural environment changes, especially the Land-Use/Land-Cover, LUCC issue is becoming a frontier and hot field[1], in which investigation on the mechanisms of land use change is one of the three core issues. Deficient natural resources, in particular the shortage of cropland resource in China, are the important constraints to Ch… 相似文献
997.
The effects of recombinant eel growth hormone (reGH).methyltestosterone (MT)and L-thyroxine (T4)on the growth of red sea bream. Pagrosomus major.were investigated.Administration of reGH to fry by immersion at 2 mg 1 for 2 hevery 5 dsys resulted in significant increase in both weight and length.but the condition factor (CF) diminished relative to that of similarly treated controls over the 37day treatment period.Immersion in 0.1 mg:1 T4 also resulted in significant increase in both weight and length and higher survival rate of test fry compared to the controls. Immersion in MT had less effect on growth and high-dose resulted in high mortality.In the second study.injection of 2 μg reGH(gwk)caused a significant increase in the specific growth rate (SGR) of test red sea bream fingerlings relative to that of the controls during the 4-week treatment period and maintained the increasing trend over the post-treatment period (weeks 4-6).Injection of MT at a dosage of 1μg (gwk) resulted in a significant in-creas 相似文献
998.
黑龙江省三江平原地下水资源潜力与生态环境地质研究综述 总被引:1,自引:0,他引:1
黑龙江省三江平原地下水资源潜力与生态环境地质调查评价项目,是首批国土资源大调查项目之一。此项目已经完成,在水工环境方面取得了重要的成绩。本文对三江平原地下水资源潜力与生态环境地质进行了综合研究;提出了本次研究的目的任务及预期目标;对以往工作进行了评述;阐释了研究思路及主要研究方法;系统地总结了本次工作的成果;最后提出了下一步工作建议。 相似文献
999.
1000.