21世纪中国的水问题及其对策

论述了 2 1世纪我国所面临的洪涝灾害、水资源短缺、水环境恶化等问题 ,并分析了应采取的对策。     

降低腹腔镜胆囊切除术并发症的对策

结合病例,探讨降低腹腔镜胆囊切除术(LC)并发症的对策。指出LC手术初期必须加强基本功训练;严格选择病例及适应症;精心操作,处理好胆囊动脉及胆囊管;遇到困难及时中转开腹手术;术后严密观察并及时处理。     

GPS/GIS车辆监控管理系统中的关键技术

简要论述了车辆监控管理系统的工作原理及通信链路的选择策略，针对一套实用的GPS／GIS车辆监控系统设计方案，详细阐述了系统设计中的关键技术．     

跨国公司技术转移研究评述

跨国公司是影响世界经济发展和技术进步的重要力量。本文通过对1960年代以来国内外学术界有关跨国公司技术转移影响东道国或地区经济增长和技术进步的理论和实证研究成果进行细致的分析和梳理发现:整体上看,跨国公司的直接投资对东道国或地区经济增长和技术进步的影响是不确定的。在很多情况下,跨国公司的技术控制会造成东道国或地区企业长期的技术依赖。更重要的是,学术界一直缺乏基于提高东道国或地区技术创新能力视角的研究,更缺乏精确度量技术转移程度的指标体系,而这正是我们全面、客观、科学评价跨国公司技术转移和技术扩散的出发点。     

趋势与前景:新世纪师范教育发展探寻

新世纪的中国师范教育将在以下方面出现新发展、新变化 :减少办学层次、开放培养体系、完善课程结构、促进一体化教育、提高专业化水平、掌握信息技术、加强高师教师队伍建设     

Perceived health problems in swimmers according to the chemical treatment of water in swimming pools

The objective of this study was to determine which chemical treatment used for disinfecting water in indoor swimming pools had the least impact on users' perceptions of health problems, and which generated the greatest satisfaction with the quality of the water. A survey on satisfaction and perceived health problems was given to 1001 users at 20 indoor swimming pools which used different water treatment methods [chlorine, bromine, ozone, ultraviolet lamps (UV) and salt electrolysis]. The findings suggest that there is a greater probability of perceived health problems, such as eye and skin irritation, respiratory problems and skin dryness, in swimming pools treated with chlorine than in swimming pools using other chemical treatment methods. Pools treated with bromine have similar, although slightly better, results. Other factors, such as age, gender, time of day of use (morning and afternoon) and type of user (competitive and recreational), can also affect the probability of suffering health problems. For all of the above, using combined treatment methods as ozone and UV, or salt electrolysis produces a lower probability of perceived health problems and greater satisfaction.     

水分胁迫下亚精胺对小麦幼苗蛋白质含量与蛋白酶活性的影响

研究了水分胁迫下亚精胺对小麦幼苗相对含水量、叶绿素总量、蛋白质含量和蛋白酶活性的影响。结果显示,亚精胺预处理延缓水分胁迫下小麦幼苗叶片含水量、叶绿素含量和蛋白质含量的下降,抑制蛋白酶活性的上升。表明亚精胺预处理对水分胁迫的小麦幼苗具有防衰抗旱的保护作用。     

A dynamic decision model for portfolio investment and assets management

This paper addresses a dynamic portfolio investment problem. It discusses how we can dynamically choose candidate assets, achieve the possible maximum revenue and reduce the risk to the minimum level. The paper generalizes Markowitz's portfolio selection theory and Sharpe's rule for investment decision. An analytical solution is presented to show how an institutional or individual investor can combine Markowitz's portfolio selection theory, generalized Sharpe's rule and Value-at-Risk(VaR) to find candidate assets and optimal level of position sizes for investment (dis-investment). The result shows that the generalized Markowitz's portfolio selection theory and generalized Sharpe's rule improve decision making for investment.     

线切割电参数的合理选择

分析了线切割参数对线切割加工工艺指标的影响,指明了怎样合理选择切割线参数。     

EBF网络特征映射和恢复及其在鲁棒话者识别中的应用

The performance of speaker verification systems is often compromised under real-world environments. For example, variations in handset characteristics could cause severe performance degradation. This paper presents a novel method to overcome this problem by using a non-linear handset mapper. Under this method, a mapper is constructed by training an elliptical basis function network using distorted speech features as inputs and the corresponding clean features as the desired outputs. During feature recuperation, clean features are recovered by feeding the distorted features to the feature mapper. The recovered features are then presented to a speaker model as if they were derived from clean speech. Experimental evaluations based on 258 speakers of the TIMIT and NTIMIT corpuses suggest that the feature mappers improve the verification performance remarkably.