论美感增力性的生理和心理基础——美育科学化原理研究之一

美感的产生有着深刻的生理和心理原因,因而才能以其显著的增力性激发着人们去追求、去创造。美感增力性的生理基础具有强度适中和第二信号系统支持的特征;其心理基础在于美感合乎人的心理需要和人的充分创造性的本质,决定了它在人的精神生活中无所不在。要科学地建构和实施美育,还必须对有关问题作进一步的实验验证     

Evolutionary character changes and population responses in an insect host-parasitoid experimental system

In an insect host (the cowpea weevilCallosobruchus maculatus)- parasitoidHeterospilus prosopidis) experimental system, the population densities of the component species oscillated for the first 20 generations and then abruptly stabilized as the parasitoid density decreased. Examination of the host and parasitoid after the 40th generation in the long-term experiment showed that (1) host larvae exhibited contest-type competition (killing other larvae inhabiting the same bean), in contrast to the founder population being scramble-type competitors and (2) the parasitoid attack rate on the host did not change. There was also an evolutionary trade-off between body size and the rates of larval survival and development, suggesting a cost of contest competition on larval survivorship and development. I tested model predictions (Tuda and Iwasa 1998) that (1) host equilibrium population size should gradually decrease as the proportion of the contest type increases and that (2) random attacks of the parasitoid on the host should reduce the rate of increase in proportion of the contest type, and the effect should become manifest especially during the first 20 generations. Two of three host-only replicates showed significant decrease in population sizes. Although the density of emerging adults per bean did not differ between replicates of the host-only and host-parasitoid systems, comparison of the host body size between them on day 270 (at the 13th generation) showed that the host was more contest-type in the host-only system than in the host-parasitoid system, as the model predicted, and later on day 650 the effect of the parasitoid had disappeared.     

3D object recognition: Representation and matching

Three-dimensional object recognition entails a number of fundamental problems in computer vision: representation of a 3D object, identification of the object from its image, estimation of its position and orientation, and registration of multiple views of the object for automatic model construction. This paper surveys three of those topics, namely representation, matching, and pose estimation. It also presents an overview of the free-form surface matching problem, and describes COSMOS, our framework for representing and recognizing free-form objects. The COSMOS system recognizes arbitrarily curved 3D rigid objects from a single view using dense surface data. We present both the theoretical aspects and the experimental results of a prototype recognition system based on COSMOS.     

Improving Ratio Estimators of Second Order Point Process Characteristics

Ripley's K function, the L function and the pair correlation function are important second order characteristics of spatial point processes. These functions are usually estimated by ratio estimators, where the numerators are Horvitz–Thompson edge corrected estimators and the denominators estimate the intensity or its square. It is possible to improve these estimators with respect to bias and estimation variance by means of adapted distance dependent intensity estimators. Further improvement is possible by means of refined estimators of the square of intensity. All this is shown by statistical analysis of simulated Poisson, cluster and hard core processes.     

高校学生对教学、任课教师和课程满意度的调查

通过对重庆市院校合并前24所高校3266名学生的抽样调查及分析表明:高校学生对高校教学总的满意度分布有学校类型和年级的差异.比较起来,满意度分布最积极的是理工类高校,满意度分布最消极的是师范类高校;随着年级递增,高校学生对教学的满意度递减;满意度突减     

病原微生物实验室实验操作对室内空气产生微生物污染的研究

目的通过模拟病原微生物实验室实验操作产生的微生物气溶胶,对实验室产生微生物污染风险进行定量研究,为实验操作人员危害评估和防护措施提供科学依据。方法使用黏质沙雷菌作为指示细菌,在实验室内对多种实验操作如吹吸混匀、培养瓶意外跌落、正常离心、离心管破裂、注射攻毒、解剖动物和安全柜泄漏等进行正常操作和意外事故模拟,使用定量空气采样和沉降平皿的方法对各种操作造成的微生物气溶胶风险进行定量分析。结果在本实验条件下,局部环境产生的微生物气溶胶浓度差异较大。吹吸混匀、培养瓶意外跌落、正常离心、离心管破裂、注射攻毒、解剖动物和安全柜泄漏产生的最大源强分别为1409、9346、〈10、138、〉8232、〈4和〉801CFU／m3。结论病原微生物实验室各种实验操作产生的气溶胶源强差异较大,在局部环境中可以产生较高的气溶胶污染,应加强实验技能的培训和一级呼吸道防护装备的应用。     

数学建模竞赛队员的选拔与培训

介绍了数学建模的基本情况,给出一些选拔和培训数学建模竞赛队员的具体做法;结合近年来的实践与探索,明确指出搞好数学建模选拔和培训是在竞赛中取得好成绩的重要保障,并据此提出合理化建议.     

膜生物反应器在工业废水处理中的应用

文中综述了膜生物反应器在工业废水处理中的工艺特点,分析了影响膜生物反应器运行状态的因素：曝气强度、 有机负荷、污泥龄( SRT)、水力停留时间(HRT)、溶液pH、水温以及污泥浓度等。认为该种新型生物反应器具有处理效 率高、出水水质好、设备紧凑、体积小、运行管理简单的优点,且易与其他预处理方法结合实现自动控制,大大提高工业废 水处理的效率,在工业生产中表现出明显的优势。同时分析了膜生物反应器在实际应用中仍存在的膜的生产成本较高、 使用寿命较短、更换膜组件费用较高等问题,提出膜材料改性、与料液预处理技术有效结合、探索优化操作参数等方面是 今后研发的重点。     

农地产权强度对农户生产合作行为的影响

实现小农户与现代农业的有机衔接是中国农业长期面临的重要任务,基于大国小农的基本国情,党和国家多次强调要发展农户之间的生产合作。在此背景下,研究产权强度影响农户生产合作行为的机理,采用2020年黄淮冬麦区实地调研数据,运用双变量Probit模型实证考察产权强度与小麦种植户生产合作行为之间的关系。研究结果表明：(1)产权强度法律赋权维度正向影响农户联耕联种行为。(2)产权强度社会认同维度正向促进农户联耕联种行为。(3)产权强度产权主体行为能力维度中的排他能力与交易能力正向促进农户联耕联种行为与联户经营行为;处置能力正向增进联耕联种行为,负向影响联户经营行为。为此,必须改善赋权的稳定性与明确性,提高社会认同度,提升产权主体的行为能力,从而促进农户生产合作行为。     

大学生体育锻炼动机强度测评分析

通过对大学生体育锻炼强度的测评，其中包括体表型、健康型、竞技型、工作与学习质量型及心理型的体育锻炼的动机强度测评，从中可以看出大学生的体育锻炼目的、意识及兴趣，并提出了自己的不同看法，以期为加大高校体育教学改革力度提供参考。