博弈树搜索算法的分析与实现     

危春波  王海瑞  文乔农 《科技广场》2007,6(5):15-17

α-β剪枝算法是博弈树搜索算法中成熟而重要的一枝。本文给出其各种改进策略及实现技术,并给出实验结果分析。B*算法是α-β剪枝算法的挑战者,它给我们以新的视角看待博弈树搜索,并能克服α-β剪枝算法的一些缺陷。  相似文献   

浙江东部凤仙花属一新种     

金孝锋  丁炳扬 《中国科学院研究生院学报》2002,40(2):167-169

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对我国B2B的一些思考     

王进  和金生 《研究与发展管理》2001,13(3):11-14

从B2B的现状入手,指出中国非常需要B2B;从B2B企业的内部环境对B2B出现的问题加以分析,并提出了相关对策,最后对B2B给予了展望。  相似文献   

留学回国人员创业载体建设问题的探讨   总被引：2，自引：0，他引：2  

段兴民  李涛 《科研管理》2003,24(3):86-91

本文描述了我国留学人员创业园的内涵及功能，考察了留学人员创业园的发展现状，分析了留学人员创业园建设存在的问题及制度障碍，提出了加速发展留学人员创业园的政策建议。  相似文献   

Brazil in the Age of Electronic Commerce     

Paulo Bastos Tigre 《The Information Society》2003,19(1):33-43

E-commerce is growing rapidly in Brazil, led by information-intensive and transaction-intensive sectors such as finance, manufacturing, and retail/wholesale. However, Brazil's highly uneven income distribution is a major barrier for B2C diffusion. Government policies have emphasized promotional or enabling initiatives such as e-procurement, tax filings, and providing Internet access to social institutions. E-commerce legislation is just now being developed, and decisions on taxation are being negotiated in the context of international agreements. E-commerce raises issues for Brazil in terms of its relationship to the global economy. Although most online purchases involve imported goods, e-commerce also offers opportunities to participate in international value chains.  相似文献   

在电子商务平台中Java和XML的整合应用     

梁一子  王自力  司崇占 《现代情报》2005,25(12):219-221

随着Internet的发展，传统的基于EDI的电子商务由于其成本过高，很大程度上限制了其应用范围，已经显露出越来越多的弊端。XML的出现．完全克服了EDI的缺点，再加上Java与XML的完美结合，极大地促进了电子商务尤其是B2B电子商务的发展。本文就如何利用Java与XML技术在基于XML的B2B电子商务的应用系统做了一些研究对应用系统中的关键技术作了阐述。  相似文献   

C/S结构与B/S结构的信息系统比较分析   总被引：37，自引：0，他引：37  

吴大刚  肖荣荣 《情报科学》2003,21(3):313-315

传统的C/S体系结构虽然采用的是开放模式。但这只是系统开发一级的开放性，在特定的应用中无论时Client端还是Server端都还需要特定的软件，没有提供用户真正期望的开放环境。B/S结构则不同，它的前端是以TCP/IP协议为基础的，企业内的WWW服务器可以接受安装有Web浏览器，各种处理任务都可以调用系统资源来完成。这样大大简化了客户端。减轻了系统维护与升级的成本和工作量，降低了用户的总体拥有成本（TCO）。  相似文献   

象山地区中国对虾白斑综合征病毒超微结构观察     

邓岳松  许梓荣  夏枚生  鲁兴萌 《科技通报》2003,19(4):327-329

从患病的中国对虾(Penaeus chinensis)头胸部分离提纯出一种杆状病毒,负染观察发现,病毒粒子的核衣壳呈杆状,大小约为(250～290) nm × (65～80) nm,每圈螺旋宽约20 nm,核衣壳的两个末端之间一般有13～15圈衣壳螺旋.个别病毒有较长的核衣壳,螺旋数达30圈,长度达到600 nm.有部分病毒核衣壳的一端有30～65 nm的凹陷.还有部分病毒核衣壳一端有30～60 nm的突出部分.  相似文献   

Effects of short-term hormone replacement on atherogenic indices in Indian postmenopausal women     

Sarika Arora  Anju Jain  R Chitra 《Indian journal of clinical biochemistry : IJCB》2006,21(1):41-47

Indian ethnicity by itself is a strong risk factor for development of CAD in Indian postmenopausal women due to lower HDL levels as compared to Whites and women of oriental origin. We evaluated and compared the short-term effects of menopause, estrogen replacement therapy and combined estrogen and progestin replacement therapy on various atherogenic indices. 40 postmenopausal women, both surgical and natural (20 each) were selected. 10 surgical postmenopausal women were given 0.625 mg conjugated estrogens daily for 6 months and 10 natural postmenopausal women were given 0.625 mg conjugated estrogen with 2.5 mg medroxyprogesterone acetate daily. 20 women were included in the control group and given placebo. Fasting venous blood samples were analyzed for extended lipid profile and calculated atherogenic indices before starting the therapy and after 1,3 and 6 months. LDL and Apolipoprotein B increased (p<0.05) and those of Apolipoprotein A1 and HDL decreased in the control groups. In both the study groups levels of serum cholesterol and LDL decreased (p<0.05) and those of HDL and Apolipoprotein A1 increased (p<0.01). LDL/HDL, Apo B/ApoA1, Total Cholesterol/HDL decreased significantly (p<0.05) in both the study groups compared to the control groups. The effect of estrogen alone was more significant as compared to combination therapy. Log Triglycerides (TG)/HDL ratio showed a decrease in women on estrogen alone but the difference was not significant. Our study confirms that short term HRT has a favorable effect on atherogenic indices in Indian postmenopausal women.  相似文献   

幽门螺杆菌CagA蛋白与CTB融合基因的克隆及其植物表达载体的构建   总被引：2，自引：0，他引：2  

姜云水  方平楚  付亚萍  朱诚 《科技通报》2004,20(3):189-193

目的　构建能在水稻胚乳中特异表达的幽门螺杆菌细胞毒素相关蛋白(CagA)和霍乱毒素B亚单位(CTB)的植物表达载体.方法　采用高保真PCR技术分别从质粒pGEM CTB和幽门螺杆菌基因组DNA中扩增出CTB和cagA基因,然后用PCR方法直接融合CTB基因和cagA基因.又用PCR法改造了水稻Wx启动子,在其3′端融合加入Ω序列和Kozak序列.通过一系列亚克隆最终将两个融合基因和NOS终止子插入根癌农杆菌双元载体pCAMBI A1300的表达框架内.结果　PCR验证和测序分析证明,CTB和cagA融合基因以正确的方向插入到载体pCAMBI A1300中,并位于水稻Wx启动子后.结论　成功构建CTB和cagA融合基因的植物表达载体,为幽门螺杆菌口服疫苗的研究奠定基础.  相似文献