聚类分析和因子分析对深井软岩软化系数的预测

为了预测深井软岩巷道开挖后不同水环境下的岩石软化系数,将深井软岩软化系数定义为含水率的函数,利用聚类分析和因子分析理论研究影响其软化系数的因子之间的相关性,并建立分析模型。结果表明：深井软岩的干密度、颗粒密度、孔隙率对其软化系数的影响具有共性,可归为一类因子;含水率和黏土矿物质量分数分别为一类。文中提出的分析模型与实验结果相吻合,对矿山深井巷道施工和支护设计具有一定的指导意义。     

2013 年我国对外贸易形势及政策建议

2013年前三季度,在2012年同期进出口增速基数较低基础上,我国进出口增速进一步放缓,贸易结构悄然变化。预计2013年第四季度进口、出口增速均在7%左右,而全年出口增速在7.5%左右,全年进口增速均在7%左右。针对我国未来外贸增长面临问题和挑战,结合我国贸易结构调整的需求,本文建议我国对外贸易优化出口市场、加大对民营企业的支持力度、促进升级消费和产业结构调整,积极应对贸易摩擦。     

科学基金管理系统多层次决策分析

本文利用层次分析法(Analytic Hierarchy Process)和德尔菲群组判断概念,分析了科学基金管理系统的决策问题,讨论了系统的递阶层次结构,层次指标体系和系统判断矩阵的数学模型。通过计算处理和综合,对决策对象和方案进行优劣排序,为决策者提供决策依据。本文的方法可推广应用于其他涉及优化排序的管理系统中。     

A Fuzzy Negotiation Model of E-commerce

We usually decide to accept or reject the offer based on the utility function in the traditional automatic negotiation of E-commerce so that we reject the offers whose utility is lower than a specified value. Here we evaluate the acceptability based on the fuzzy set theory and the membership function. Since different issues have different effect on the negotiators, we state the combined concession in the multi-issue negotiation for the negotiators. We put forward a more practical negotiation model than the traditional negotiation model and give an example of its application in E-commerce.     

Facile immobilization of heparin on bioabsorbable iron via mussel adhesive protein (MAPs)

Motivated by adhesive proteins in mussels, strategies using dopamine to modified surface have become particularly attractive. In the present work, we developed a novel and convenient method to modify the biodegradable Fe plates with heparin. Iron was first treated by a facile one-step p H-induced polymerization of dopamine, and then a high density heparin was successfully grafted onto the surface via coupling with polydopamine(PDA) active layer. Heparin immobilization contributed much longer blood clotting coagulation time than the pure Fe sample, and hence reduced the risk of thrombosis. Cell viability tests suggested that the heparin modified Fe plates were more favorable to the proliferation of ECV304 cells. In summary, the heparin modified Fe plates with good anti-thrombus properties and inhibiting the proliferation of VSMC cells provide great prospects for biodegradable iron.     

131I治疗Graves病43例疗效分析

目的：探讨^131I治疗Graves病的临床应用价值。方法：通过对43例确诊Graves病具有适应症患者，采用以^131I为主的综合治疗，治疗后定期随访并进行疗效评价。结果：均无早期不良反应发生，随访4～19月，治愈27例，治愈率62.8％，明显好转15例，有效率97．7％，无效1例，无效率2.3％。甲状腺体积明显缩小。结论：^131I治疗Graves病安全高效，有良好的应用前景。     

浅析建筑工程材料造价的有效控制

文章针对工程材料造价的重要性以及目前管理中存在的问题,探讨了加强材料造价管理的有效措施,以供同行参考.     

浅谈公路工程计量

本文介绍公路工程有关计量原则及应注意的主要事项     

Responses of ground-dwelling spiders to four hedgerow species on sloped agricultural fields in Southwest

Spiders are important predators in aeroecosystems and contribute to the control of agricultural nect nnnulatinns.Hahitat manage-ment such as the creation of new semi-natural habitats around or within fields enhances spider abundance and species diversity.Using pitfall traps,we investigated the effects of four hedgerow plant svecies.which serve as undisturhed and permanent semi-narimal habitats,on ground-dwelling spider activity density(a parameter of nonulation density and relative activitv)and species richness.Samples were ollected over two winter wheat and two summer maize growing seasons druing 2005-2007 in trial field 1(slope gradient of 20%)and field 2(slope gradient of 12%)at the Ziyane Experimental Site in Sichuan Province,China.The hedgerow species evaluated were Amorpha fruticosa(field 1).Vetiveria zizanioides(field 1),EulahODsis binata (field 2),and Afediraon sativa(field 2).CnmnareA to rnntrnl plots,hedgerow plots had significantly higher activity density and species richness of ground-dwelling spiders within strips in both fields 1 and 2 during the wheat growing season.The presence of hedgerow strins did not augment the activity density and species richness of ground-dwelling spiders within the crop fields during the wheat or maize growing seasons.The ground-dwelling spider activity density within hedgerow strips was significantly higher in the Vetiveria than in the AmorDha nlots and in the Medicago than in the Eulaliopsis plots,and the species richness was significantly higher in the Vetiveria than in the Amornha plots during the wheat season. Our results suggest that hedgerows may serve as important overwinterine sites for ground-dwelling spiders durinjthe wheat growing season.In addition,the diversification of agroecosystems by using hedgerow strips may be a viable strategy for maintaining ground-dwelling spider populations in agricultural areas.However,ground-dwelling spiders did not move into adiacent crop fields;therefore,future work should address the mechanisms of attracting spiders into crop fields,thereby contributing to the bio-control of pests.     

中小学生科学推理能力发展现状研究——以北京市中小学生为样本

以北京市部分中小学生为样本,采用LCTSR量表(2000版)中的部分题目进行测试,得出了科学推理能力随年级发展的规律,用Logistics回归曲线描述了不同年级学生在5个主要能力维度上的发展情况;指出教学因素对科学推理能力在不同维度上的发展具有显著影响,教学模式与能力属性的匹配程度影响其发展水平.