植被覆盖作用下的水土流失效应研究

通过对延庆县上辛庄径流试验站两年监测数据的分析,结果表明,植被覆盖度的提高可以明显抑制径流、土壤的流失强度,并且可消弱坡度、降雨对水土流失的影响程度．同时,30％的植被覆盖可能是该区能有效控制水土流失的临界值;污染物的流失强度随植被覆盖度的变化规律与径流与植被覆盖度的变化规律一致,即随着植被覆盖度增加而降低,说明植被措施对污染物流失的控制主要是通过减少径流泥沙而起作用的,但植被措施对不同污染物的抑制效果存在差异．     

耕地资源安全内涵与构成研究

耕地资源安全不同于粮食安全、土地安全等,具有独特的内涵和构成,耕地资源安全具有社会、环境、经济的属性,包含数量安全、质量安全、生态安全、布局安全四个有机构成,任何一部分存在脆弱性都会妨碍耕地资源安全的实现。在当前耕地资源快速非农化导致耕地资源安全威胁加剧的情况下,研究为耕地资源安全保障提供理论依据和支撑。     

基于CA-MAS模型的城市保障房用地演变模拟(英文)

为了模拟保障房用地的演变过程,建立了元胞自动机(CA)和多智能体(MAS)相结合的模型.通过文献综述法,对保障房选址的决策因素进行梳理,构建关于保障房选址决策因素的层次结构模型,运用层次分析法(AHP)得出各层次因素的权重;基于各因素及其权重,建立CA和MAS相结合的模型;最后,以南京市主城区为例,验证模型的可行性.结果表明:CA-MAS模型能够对保障房建设用地进行有效的演化模拟,对于认识、理解保障房的发展和城市化进程具有重要的理论和实践意义.     

湖南省失地农民社会保障问题调查研究

近年来,随着我国工业化、城市化的进程加快,农村土地被大量征用,催生出了一个数量庞大的失地农民群体。大多数失地农民的社会保障引起社会各界的高度关注。研究表明,湖南省失地农民社会保障还存在社会保障制度尚不健全、再就业困难、城市生活融入差等问题。针对这些问题,笔者提出征地补偿市场化、强化社会保障、对失地农民有针对性地培训,促进失地农民再就业、鼓励农民创业等加强和改善失地农民社会保障的对策与建议。     

劳伦斯与沈从文乡土情怀之比较

英国作家D.H.劳伦斯与中国作家沈从文都以自己的家乡为背景创作了大批优秀的"乡土作品"。稍事比较,不难看出劳伦斯与沈从文有着截然不同的乡土情怀:劳伦斯以犀利的笔调贬斥家乡习气之庸俗;沈从文以溢美之言赞颂故里民风之淳朴。然而,这种迥然不同的乡土情怀背后,却深藏着两位作家对生命本真回归作为的向往。     

国内农用地适宜性评价研究综述

农用地适宜性评价是土地利用规划的重要环节.目前,国内对农用地适宜性评价进行了广泛而深入的研究,评价范围区域性特征明显、评价指标综合化与多样化;农用地适宜性评价技术方法不断更新,模型化趋势明显;GIS技术与数学方法、模型结合,保证了农用地适宜性评价的准确性、科学性.随着景观生态学理论的引入,农用地生态适宜性评价将进一步得到重视,研究理论与方法的更新是关键点.     

马克思土地资本理论与我国土地经济学创新

马克思土地资本理论是马克思资本理论的重要组成部分,这一理论不仅具有十分丰富的内涵,而且具有较强的现实意义。土地资本是为改良土地而投入土地并附着在土地上的资本。土地资本作为产业资本,运动和增殖是它的本性。土地资本在社会生产关系体系中,代表的是土地经营者的利益。在我国广大农村实行土地联产承包责任制之后,土地资本积累归承包者还是归土地所有者,需要深入研究。当前土地问题和房地产问题日益突出,各种矛盾交织而生,土地资本运动规律、运行规则、操作规程值得探讨。建议把＂土地资本＂概念纳入土地经济学理论体系,用土地资本概念统领土地经济学,以土地产权、土地价值、土地市场、土地财政、土地金融、土地经济发展等为基本概念,构建具有中国特色的社会主义土地经济学研究范式。     

城市近郊统筹城乡改革的经验、困难与深化——重庆“陶家模式”和“海龙模式”的比较与启示

重庆市统筹城乡发展改革在九龙坡区陶家镇和海龙村的试点较为成功,其共同点在于注重以工促农、社会保障和土地集约,而在改革主导角色、农民身份转变和土地流转方式上各具特色。"陶家模式"和"海龙模式"的实践证明:中小企业是统筹城乡发展的纽带,农民增收是统筹城乡改革顺利推进的关键,土地政策是统筹城乡发展的核心问题,统筹城乡发展需要系统思考与政策创新。目前,两种模式的深化发展,面临土地政策供给不足、社会保障推力不够、城乡规划视野不宽、政策落实不到位、资源要素流通不畅、管理体制不顺等困难。应进一步探索土地集约利用的新机制,加快城乡一体的社会保障体系建设,充分保障农转城人员的利益,推进城乡科学规划,破除农村投资樊篱,并提升各级政府的统筹发展能力。     

The application of inertial measurement units and functional principal component analysis to evaluate movement in the forward 3½ pike somersault springboard dive

Based on technological and analytical advances, the capability to more accurately and finitely examine biomechanical and skill characteristics of movement has improved. The purpose of this study was to use Inertial Measurement Units (IMUs) and Functional Principal Components Analysis (fPCA) to examine the role of movement variability (assessed via angular velocity), on 2 divers (1 international level; 1 national) performing the forward 3½ pike somersault dive. Analysis of angular velocity curves during ive-flight identified 5 fPCs, accounting for 96.5% of movement variability. The national diver’s scatter plots and standard deviation of fPC scores illustrated larger magnitudes of angular velocity variability across dive flight. For fPC1 and fPC3, magnitudes of SD variability were 282.6 and 201.5, respectively. The international diver illustrated more consistent angular velocity profiles, with clustering of fPCs scores (e.g., fPC1 & 3 = SD’s of 75.2 & 68.0). To account for lower variability in the international diver, the ability to better coordinate movement sequences and functionally utilise feedback in response to initiation of the somersault position is highlighted. Overall, findings highlight how both IMUs and fPCA can more holistically and finitely examine the biomechanical and skill characteristics of movement sequences with the capability to inform athlete development.     

A rule induction framework for the determination of representative learning design in skilled performance

Representative learning design provides a framework for the extent to which practice simulates key elements of a performance setting. Improving both the measurement and analysis of representative learning design would allow for the refinement of sports training environments that seek to replicate competition conditions and provide additional context to the evaluation of athlete performance. Using rule induction, this study aimed to develop working models for the determination of high frequency, representative events in Australian Rules football kicking. A sample of 9005 kicks from the 2015 Australian Football League season were categorised and analysed according to the following constraints: type of pressure, kick distance, possession source, time in possession, velocity and kick target. The Apriori algorithm was used to develop two models. The first consisted of 10 rules containing the most commonly occurring constraint sets occurring during the kick in AF, with support values ranging from 0.15 to 0.22. None of the rules contained more than three constraints and confidence values ranged from 0.63 to 0.84. The second model considered ineffective and effective kick outcomes and displayed 70% classification accuracy. This research provides a measurement approach to determine the degree of representativeness of sports practice and is directly applicable to various team sports.