低温外科手术器械的现状和展望

本文从工程应用角度出发,综述了目前使用的各种低温外科手术器械的性能特点和适用场合。以当前使用最普遍的LN_2式冷疗仪为例对其原理、结构作了简要说明,着重指出其制造的关键和存在的不足,并对冷疗仪的进一步发展作了展望。     

350keV Yb~＋注入Si（100）的射程分布和晶格损伤研究

用３５０ｋｅＶＹｂ~＋在室温下注入了单晶硅，并用卢瑟福背散射／沟道技术测量了注入离子在硅中的射程分布谱和晶格损伤谱。用表面能量近似和平均能量近似从背散射谱上计算了射程深度和射程分布的标准偏差。实验和计算结果表明，大部分注入离子都处于非替位位置。表面能量近似方法已能给出相当理想的计算精度，它与更精确的平均能量近似所得出的结果相差甚微。晶体与非晶体界面附近的损伤并由Ｙｂ~＋直接产生，它是一种次级级联碰撞效应。     

Improving flexibility and efficiency by adding parallelism to genetic algorithms

In this paper we develop a study on several types of parallel genetic algorithms (PGAs). Our motivation is to bring some uniformity to the proposal, comparison, and knowledge exchange among the traditionally opposite kinds of serial and parallel GAs. We comparatively analyze the properties of steady-state, generational, and cellular genetic algorithms. Afterwards, this study is extended to consider a distributed model consisting in a ring of GA islands. The analyzed features are the time complexity, selection pressure, schema processing rates, efficacy in finding an optimum, efficiency, speedup, and resistance to scalability. Besides that, we briefly discuss how the migration policy affects the search. Also, some of the search properties of cellular GAs are investigated. The selected benchmark is a representative subset of problems containing real world difficulties. We often conclude that parallel GAs are numerically better and faster than equivalent sequential GAs. Our aim is to shed some light on the advantages and drawbacks of various sequential and parallel GAs to help researchers using them in the very diverse application fields of the evolutionary computation.     

对运动竞技中运动心理学的再认识

文章通过分析运动员身体能量和心理能量的关系 ,认为主客观都要求运动员赛前将心理能量和身体能量调控到相对较高点 ,以发挥其最大的竞争力。由于心理技能的训练和发展有赖于各心理技能间的相互发展 ,因此 ,对运动员必须从心理能量有效调控关联的技能训练着手进行心理技能训练     

平行数据模型单位根的非参数检验方法——截面内误差项存在L阶自相关关系

时间序列单位根检验问题是现代经济计量学研究的一个焦点问题。由于平行数据模型研究的是跨横截面的时间序列问题,因此单位根检验问题对它来说也非常重要。这个问题目前在平行数据模型的研究领域备受关注。本文通过研究时间序列单位根的非参数Z检验方法与平行数据模型单位根的IPS检验方法,针对横截面内误差项存在L阶自相关关系的平行数据模型,提出了非参数单位根检验方法;并利用Monte-Carlo方法模拟比较了本文提出方法与LL单位根检验方法的效果。一、时间序列单位根的非参数Z检验方法Phillips(1988)考虑了时间序列可能出现的自相关关系…     

数学建模与大学生素质拓展

从培养大学生思维能力，创新意识和团队精神等几个方面阐述了数学建模与大学生素质拓展的关系，提出了开展数学建模活动的具体方法。     

房地产企业留住人才的博弈分析

本文通过建立博弈矩阵模型,并利用线性规划理论进行分析,指出房地产企业在提高工资待遇吸引人才的同时,建立有效的动态激励机制才是留住人才的关键.     

小议"类词缀"的判别标准

本文主要讨论类词缀的判别标准和类词缀“意义虚化”的内涵 ,认为只有“意义虚化”才是类词缀与词根的区别性特征 ,而类词缀“意义的虚化”主要有“类化”和“泛化”两个表征。定位性、变性功能以及能产性是类词缀的重要特征 ,但不能单独地把它们作为判定标准 ,尤其是能产性不能作为判定标准     

高校学生思想政治工作进公寓初探

高校完全学分制与高校后勤社会化改革的逐步实施,使学生公寓正日渐取代班级而上升为学生生活、学习、思想、情感交流的基本空间及日常教育管理的基本载体。唯有树立依法管理、学生是消费者、师生平等交往的观念,建立由学生考核、实行责任联带追究的高素质管理队伍,以交流、对话、感染的基本方式营造民主和谐的教育管理氛围,探索以辅导员进驻学生公寓为主体的一系列工作新机制,坚持服务意识,强化设施建设,才能真正使公寓成为学生全面发展、成长成才的有效载体。     

Applicability of a Neuroprobabilistic Integral Risk Index for the Environmental Management of Polluted Areas: A Case Study

Recently, we developed a GIS-Integrated Integral Risk Index (IRI) to assess human health risks in areas with presence of environmental pollutants. Contaminants were previously ranked by applying a self-organizing map (SOM) to their characteristics of persistence, bioaccumulation, and toxicity in order to obtain the Hazard Index (HI). In the present study, the original IRI was substantially improved by allowing the entrance of probabilistic data. A neuroprobabilistic HI was developed by combining SOM and Monte Carlo analysis. In general terms, the deterministic and probabilistic HIs followed a similar pattern: polychlorinated biphenyls (PCBs) and light polycyclic aromatic hydrocarbons (PAHs) were the pollutants showing the highest and lowest values of HI, respectively. However, the bioaccumulation value of heavy metals notably increased after considering a probability density function to explain the bioaccumulation factor. To check its applicability, a case study was investigated. The probabilistic integral risk was calculated in the chemical/petrochemical industrial area of Tarragona (Catalonia, Spain), where an environmental program has been carried out since 2002. The risk change between 2002 and 2005 was evaluated on the basis of probabilistic data of the levels of various pollutants in soils. The results indicated that the risk of the chemicals under study did not follow a homogeneous tendency. However, the current levels of pollution do not mean a relevant source of health risks for the local population. Moreover, the neuroprobabilistic HI seems to be an adequate tool to be taken into account in risk assessment processes.