人与自然关系的主体原因探析

人作为主体,在人与自然关系中起着至关重要的作用。人口因素对自然环境的影响,主要 包括人口数量因素对自然环境的影响和人口质量因素对自然环境的影响。要改善人对自然环境的影 响,必须从人的自身去寻找对策,变不利因素为有利因素,实现人与自然的和谐统一。     

Organismic integration as a dynamic process: a systematic review of empirical studies on change in behavioral regulations in exercise in adults

In facilitating the adoption of exercise behavior, attention should be directed towards the dynamic nature of behavioral regulations. Organismic integration theory presents a suitable framework for investigating fluctuations in behavioral regulations. However, current results pertaining to this issue revealed mixed findings. The aim of this review is to examine the empirical literature on the dynamic nature of organismic integration theory in exercise settings over time in adults. A systematic review of English articles using PsycINFO, PsycARTICLES, ScienceDirect, and SPORTDiscus was conducted including keywords of organismic integration theory, longitudinal designs, change in behavioral regulations, and exercise. Findings are summarized through quantitative analysis of the evidence. Regarding autonomous regulations, steady increases in regulations are observable that originate within the first weeks and persist for up to one year. Most studies reported no changes in controlled regulations, although in a few cases changes were observed six weeks after baseline or later. The review adds to the theoretical understanding of how behavioral regulations are internalized. However, whether changes in regulation occur depends on both the type of regulation and on contextual characteristics. Future research of longitudinal design is warranted to identify optimal periods in which individuals seek for increased support during exercise adoption.     

城市外来人口宏观调控政策研究之新视角

在外来人口宏观调控问题上,政府作用和市场作用同样不可或缺.外来人口的宏观调控不仅仅是数量上的调控,也不仅仅是人口准入制度的建立,而是一个如何让外来人口和本地社会经济协调发展的过程.我们应该正确评估城市合理人口规模对城市人口调控的指导意义,充分认识到城市合理人口规模只是一个理论概念,而不是一种操作手段.在市场经济条件下,产业结构调整、完善城市功能定位和优化城市空间结构、提高城市承载能力是实现外来人口和城市协调发展的长远措施.城市政府应该以劳动力市场干预为主要手段,合理引导劳动力流动,切实保障外来人口权益;同时以建立和完善外来人口社会福利制度和社会管理制度为抓手,消除市场经济所带来的各种负的外部性,特别是外来人口的社会不适应性及其不良社会后果.     

非晶团簇Au19的熔化特征研究

介绍了分子动力学的基本原理和计算过程,模拟了Au19团簇从类固相到类液相的相变过程.将所得的数据绘制成图线,并进行了分析与讨论,结果发现Au19这种不规则的非晶团簇的熔化过程是分步完成的:首先是外层某些不稳定原子开始熔化,其次是其他外层原子也随能量的升高熔化,最后是随能量的不断升高,中心原子也完成了熔化过程,整个体系完成从类固相到类液相的相变过程.由此可以看出,Au19的熔化过程是分步完成的,有别于晶体团簇和其他结构规则的非晶团簇,是一个比较特殊的过程.     

硇洲岛沿海腹足类的种类组成和生态分布

本文报道了广东湛江硇洲岛沿海的腹足类软体动物１１４种，隶属于６８属４２科；介绍了硇洲岛的自然环境及潮汐；对腹足类的种类组成、生态分布、优势种和区系特点等进行了分析．     

论郴州人口的可持续发展与和谐社会的建构

人口问题是长期制约我国经济社会发展的关键因素,它与社会的可持续发展、与和谐社会的建构有着密切的关系。郴州是一个人口增长较快、人口居住密度较大、经济社会发展相对滞后的农业市,要实施可持续发展战略,构建和谐社会,就必须有效控制人口增长速度,提高人口质量,改善人口结构。     

民国时期山西农村人口迁徙之分析

民国时期山西农村人口的迁徙流动在整个中国农村 ,特别是北方各省农村具有相当的代表性 ,此乃当时农村社会结构发生变动的主要特征之一。民国时期山西农村人口迁徙之因主要有灾荒、人祸及其各种经济压力等 ;其迁徙情势是复杂多变的 ,流动是多方位多层面的 ,而这种人口迁徙则对社会影响极大。     

转变教育思想:知识经济的呼唤

本文拟从知识经济这一视角,审视我国高等教育,指出必须转变过于大一统的教育思想,以学生主体性和个性的培养为教育的出发点和落脚点,才能培养与知识经济时代具有本质联系的创新型人才,改变培养的人才脱离和滞后经济建设的社会发展需要的现象。     

Transient Responses of Flexible Non—uniform Spinning Shaft with Nonlinear and Asymmetric Supports

In this paper ,a hybrid approach was developed to investigate the transient responses of a multi-span non-uniform flexble spinning shaft with nonlinear and asymmetric supports.The non-uniform spinning shaft with variable parmeters was modeled as a Bernoulli-Euler beam column with sectional constant cross-section properties by the finite element method.The supporting stiffness behavior of the nonlinear supports was described as a piecewise-linear and asymmetric model.The equations of motion in the matrix form of a multi-span non-uniform spinning shaft with nonlinear and asymmetric supports were formulated using Hamilton‘s principle and the assumed mode method.As an example,a spinning rocket with many variable stiffness supports was numerically simulated by the direct integration method.The transient response and dynamic behavior of this rotate-dynamic system are analyzed.     

统计学中几个容易混淆的问题

统计学是一门重要的学科,在日常生活中有着极其广泛的应用。本文对统计学教学中几个容易混淆的问题进行阐明,旨在帮助学生对统计学中的一些概念有个正确的理解。