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911.
针对石油机械制造企业现状,分析了利用电子商务加快我国石油机械制造业发展的必要性,探讨了整个市场环境下石油机械制造企业电子商务平台的应用模式及如何对企业传统的经营活动和组织模式进行改革和完善,将石油机械制造业由传统制造业转变为基于电子商务的现代制造业,提出了利用电子商务实现动态联盟,提升企业竞争能力,扩大营销渠道的策略,并对石油机械制造企业发展电子商务应注意的问题进行了论述。 相似文献
912.
WANGXufei WANGXiaohua CHENLianyun HUZhiwen LIJun WUYu CHENBin HUSuhua ZHANGJun XUMingliang WULijun WANGShaohu FENGHuiyun ZHANFuru PENGShixiang HUChundong ZHANGShuqing CHENGJianjun SHIZhongtao YUANHang YUANHaitao YUZengliang 《科学通报(英文版)》2004,49(17):1806-1811
A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). The system was designed to deliver a defined numbers of hydrogen ions, produced by a van de Graaff accelerator, in an energy range of 2.0-3.0 MeV, into an area smaller than that of the nucleus of an individual living cell. The beam is collimated by a borosilicate glass capillary that forms the beam-line exit. An integrated computer program recognizes the cells and locates them one by one over the microbeam exit for irradiation. We present technical details of the CAS-LIBB microbeam facility, particularly on the collimator, hardware, control program, as well as cell irradiation protocols available. Various factors contributing to the targeting and positioning precision are discussed along with accuracy measurement results. 相似文献
913.
Large Deflection Buckling Spring-Piece (LDBSP) refers to the deformation of an end-fixed flat spring-piece under normal loadings. Plastic deformation usually appears in LDBSP.The static characteristic curve is very particular, because within its linear deflection region, the spring constant can be designed to be any value from minus to plus. With its obvious advantages of large liner deflection range, low spring constant, etc., the LDBSP has now been extensively applied to the exciting device, low-frequency shock absorbers and so on. The static characteristic curve of LDBSP belongs to the nonlinear problem of an arch with varying section. Therefore, it is difficult to obtain it theoretically. The formulae for designing LDBSP have not been set up yet. In this study,the authors apply similarity theory to analyze the liner deflection range A and the spring constant K, and derive the relationship of similarity criterion, finally obtain a set of formulae for designing LDBSP by model test and the least square method, which can be applied in engineering design.Through the research, it is proved that it is unnecessary to keep geometrical similarity of spring-piece shape. This fact extends the application scope of the formulae. The proposed formulae for designing LDBSP thereby can be applied for any dimensions within the range allowed. 相似文献
914.
The optimum conditions of hydrolysis of cellulosic wastes by cellulase were studied. The results show that the optimum conditions of sulfuric acid pretreatment were sulfuric acid consistency 0.3M,pretreatment temperature 100℃, pretreatment time 4hours. After sulfuric acid pretreatment, the optimum conditions of hydrolysis by cellulase were enzymatic temperature 50℃ ,enzymatic time 48hours,pH4.8,the charge of cellulase 100IU/g and the substraste consistency 60g/l. Meanwhile this paper studies that the structural change of cellulose during sulfuric acid pretreatment and cellulase hydrolysis by analyzing the infrared spectra. 相似文献
915.
凉山州水土流失治理现状及对策 总被引:1,自引:0,他引:1
通过对凉山州水土流失严重的原因、治理的现状等进行调查分析和研究,笔者认为应采取以下措施加强凉山州水土流失治理:严格实行退耕还林草、荒山造林,增加地被覆盖加强生物措施治理;重视落实生态移民搬迁配套治理;重视农业科学化加强农业措施治理;结合农业生产加强工程措施治理。 相似文献
916.
20世纪90年代,随着IT产业的迅猛发展,计算机网络在世界范围内急剧膨胀,在全世界掀起了新的一轮信息革命,全球经济进入网络经济时代,而电子商务更是以其独特的魅力影响并改变着企业的整体运作、经营管理模式。 相似文献
917.
ZHAO Wei HU Ke KIMOTO Akitsu MIZUYAMA Takahisa . Institute of Environmental Science Beijing Normal University Beijing China . College of Earth Sciences Jilin University Changchun Jilin China . Laboratory of Erosion Control Graduate School of Agriculture Kyoto University Kyoto Japan 《武汉大学学报:自然科学英文版》2004,9(4):527-532
0 IntroductionManystudieshavebeendoneonthesedimentdischargeinMt.Tanakami .Thosestudiesconcerntheamountofsedi mentsandfewdiscussionsabouttheprocessonly .Andthesedi mentyieldmechanismindevastatedslopeinMt.Tanakamiisnotfullyunderstood.Inordertorecordthewholeprocessofsoilero sionfromthebeginningofprecipitation ,totheendofsedimentmovement,asimulatingexperimentbyusingartificialrainiscon ducted .Basedonthisexperiment,andbyfurthercomparingwiththepreviousdataofsedimentsinthisarea,somebasicdataaboutc… 相似文献
918.
Zhou Xingyu Zhang Jiang Liu Yang Xie Yanqing Zhang Ran Zhao Yang He Zhongxiong 《中国工程科学》2004,2(2):88-89
Based on the intelligent decision support system, a new method was presented to defense the catastrophic infectious disease such as SARS, Bird Flu, etc.. By using All Set theory, the decision support system (DSS) model can be built to analyze the noise information and forecast the trend of the catastrophe then to give the method or policy to defend the disease. The model system is composed of four subsystems: the noise analysis subsystem, forecast and simulation subsystem, diagnosis subsystem and second recovery subsystem. They are discussed briefly in this paper. This model can be used not only for SARS but also for other paroxysmal accidences. 相似文献
919.
基于集对分析的模糊逻辑研究 总被引:3,自引:0,他引:3
成科扬 《华中科技大学学报(自然科学版)》2004,(Z1)
介绍了一种新的解决模糊问题的途径 ,提出了一种模糊逻辑表示新形式 ,论证了其较之于传统模糊逻辑表示法的优点 . 相似文献
920.
基于出行者逐日路径选择过程,建立出行者路径选择模型和逐日路径选择学习模型. 在2条平行路径的简单路网中进行多次数值实验,结果表明:网络交通流演化是否稳定,以及能否达到随机用户均衡态,与出行者对昨日感知行程时间的依赖程度和先进的出行者信息系统市场占有率两者都有关系. 当出行者对昨日实际行程时间完全依赖时,路网系统始终偏离随机用户均衡态;当出行者对昨日感知行程时间完全依赖时,出行者集中选择一条路径,并且网络交通流演化稳定. 相似文献