全球生态系统服务价值评估研究进展

随着人类对生态系统功能不可替代性的认识愈来愈深刻，生态系统服务功能研究愈来愈受到人们的重视。近年来，这一领域的研究已经取得了令人注目的进展。研究的重点主要集中在采用各种方法对自然资本的边际服务价值进行估计。评估的方法大都直接或间接地基于对生态系统服务的个人偿付意愿进行计量。对全球生态系统服务价值评估的代表是基于全球静态总平衡输入输出模型的评估和基于全球静态部分平衡的评估，中国对区域生态系统服务价值也进行了初步估算。生态系统功能与服务的复杂性、价值的多重认识、市场失效及价格空缺、实证的困难与自然资本总价值得无限至今还制约着生态系统服务价值研究的发展，今后需要研究的领域及发展趋势是：1、不同生态类型的各种服务价值研究；2、生态系统服务空间异质性研究；3、包含非线性及阈值的动态地区模型和全球模型；4、改变账户系统和制定相应政策；5、考虑生态系统服务损失的项目评估；6、大规模的小幅度变化和小规模的大幅度变化边际研究.     

泾河流域近五年来植被变化分析

本文使用2004年10月和2001年10月的MODIS(MODerate resolution lmaging Spectroradiometer)数据研究了泾河流域实行退耕还林还草以来的植被变化,结果表明近5年来植被指数大幅度增加,而且出现了2001年所没有的NDVI高值区(0.6＜NDVI＜0.8).因此可以认为在退耕还林还草政策以及自然条件综合影响下植被得到较好的恢复.分析结果表明本区的纬向分异以及垂直分异明显.纬向分异表现为自南向北随着纬度升高NDVI逐渐变小;山区因海拔高而降水较多,植被长势良好;经向分异在北纬36度以北的草地地区较为明显,表现为NDVI自西向东逐渐升高,而在36度以南农地地区NDVI变化趋势不明显.     

中国水资源对发展的承载能力研究

本文对我国目前水资源承载能力进行了明确的定义,在此基础上估算了水资源人口承载力、水资源对居民生活、工业和农业的承载力、水资源环境承载能力及水资源承载能力超载率.结果表明,如果我国保持现有耗水水平,那么我国水资源理论上的自然承载力为63×108人,我国能够实现的水资源实际人口承载力为25×108人.在今后20年间,我国大陆地区水资源有效人口承载力在15×108～18×108人之间,总体上我国的人口数量在水资源人口承载能力范围之内,承载力盈余约在2.5×108～5.1×108人.但由于各地人口和水资源分布极不均衡,一些地区表现出水资源人口严重超载,超载达50%以上,而一些地区具有极高的水资源人口承载力盈余.水资源人口超载区域的用水主要来自于该区域之外.此外,现有经济发展的规模及趋势均在水资源经济承载力范围之内,农村居民的生活用水支持能力除华北地区之外,普遍有所剩余.随着人口的增长,水资源承载力状况将成为经济发展的重要影响因素,跨区域调水等一系列战略措施将会在全国广泛实施.     

大城市居民生活消费的生态占用初探——对北京、上海的案例研究

生态占用方法是通过跟踪人类利用的大多数消费品和产生的废弃物，来计算生产和维持这些消费及同化废弃物所需要的生物生产性土地面积，并与生态承载力进行比较，以此衡量可持续发展的程度。该文运用生态占用分析方法，以北京市、上海市为例，估计了1999年两市居民的食物、衣着、生活用品、生活用能等主要生活消费占用的生态空间。两市居民人均生态占用面积分别为1.62hm2和1.33hm2,其中存在由于地方生活习惯差异造成的生态占用面积及类型的差异。虽然估计相对保守，但全市居民生态占用的总面积已经数十倍于城市实际面积。城市显然是“生态赤字”区，城市居民依赖于城市边界之外的生态系统满足基本生活需求。随着我国今后城市化步伐的加快，城市可持续发展问题将越来越重要，开展城市生态占用这一科学问题的研究也变得十分紧迫和重要。     

The influence of core affect on cyclo-ergometer endurance performance: Effects on performance outcomes and perceived exertion

BackgroundCore affect is defined as the most general affective construct consciously accessible that is experienced constantly. It can be experienced as free-floating (mood) or related to prototypical emotional episodes. The aim of this study was to examine the influence of pleasant and unpleasant core affect on cyclo-ergometer endurance performance. Specifically, we considered the influence of pleasant and unpleasant core affect on performance outcomes (i.e., time to task completion) and rate of perceived exertion (RPE; Borg Scale, category ratio-10) collected during the task.MethodsThirty-one participants aged 20–28 years were recruited. Core affect was randomly elicited by 2 sets of pleasant and unpleasant pictures chosen from the international affective picture system. Pictures were displayed to participants during a cyclo-ergometer performance in 2 days in a counterbalanced order. RPE was collected every minute to detect volunteers’ exhaustion.ResultsThe study sample was split into 2 groups. Group 1 comprised participants who performed better with pleasant core affect, whereas Group 2 included participants who performed better with unpleasant core affect. Mixed between-within subjects analysis of variance revealed a significant 2 (group) × 2 (condition) × 5 (isotime) interaction (p = 0.002, η_p² = 0.158). Post hoc comparisons showed that participants who obtained better performance with pleasant core affect (pleasant pictures; Group 1) reported lower RPE values at 75% of time to exhaustion in a pleasant core affect condition compared to an unpleasant core affect condition. On the other hand, participants who obtained better performance with unpleasant core affect (unpleasant pictures; Group 2) reported lower RPE values at 75% and 100% of time to exhaustion in an unpleasant core affect condition.ConclusionFindings suggest differential effects of pleasant and unpleasant core affect on performance. Moreover, core affect was found to influence perceived exertion and performance according to participants’ preferences for pleasant or unpleasant core affect.     

PIC16C71微控制器在水分快速检测中的应用

介绍一种以PIC系列微控制器为核心构成的水分快速测定仪的数据处理系统,该系统结构简单,工作可靠,宜于便携式仪器。     

对跨栏跑快速节奏培养的研究

分析了构成跨栏跑快速节奏的主要因素及其对跨栏跑快速节奏形成的影响, 并提出了培养跨栏跑快速节奏的方法     

高校法学课程课堂教学模式改革探究——以电子商务法律课程为例

高校法学课程课堂教学具有理论性和职业性的双重属性,现行的课堂教学模式存在着内容滞后性和局限性、交流单向性、方法单一性、评价重结果轻过程的缺陷。本文通过对课堂教学模式改革效果的调查分析,围绕教学前、教学中和教学后三个阶段,提出以培养学生的创新能力为宗旨,以建立平等的师生关系为基础,借鉴德、美等国的经验,构建创新型立体式课堂教学模式。     

Knowledge of general practitioners on dementia and mild cognitive impairment: a cross-sectional,questionnaire study from Hungary

General practitioners (GPs) play a pivotal role in dementia recognition, yet research suggests that dementia often remains undetected in primary care. Lack of knowledge might be a major contributing factor to low recognition rates. Our objective was to address a gap in the scientific literature by exploring GPs’ knowledge on dementia and mild cognitive impairment (MCI) for the first time in Hungary by conducting a cross-sectional, questionnaire study among practicing GPs. Recruitment of the participants (n = 402) took place at mandatory postgraduate training courses and at national GP-conferences; the applied questionnaire was self-administered and contained both open-ended and fixed-response questions.

Results showed that GPs highlighted vascular and metabolic factors (38.3% of the answer items) and unhealthy lifestyle (29.1% of the answer items) as dementia risk factors. They perceived vascular dementia as the most common dementia form, followed by Alzheimer’s disease. Almost half of the respondents (44.9%) were not familiar with MCI. Most GPs identified memory problems (98.4%) and personality change (83.2%) as the leading symptoms of dementia.

In summary, GPs demonstrated adequate knowledge on areas more relevant to their practices and scope of duties (risk and preventive factors, main types and symptoms of dementia); however, uncertainties were uncovered regarding epidemiology, MCI, and pharmacological therapy. As only one-fifth (19.4%) of the GPs could participate recently in dementia-focused trainings, continued education might be beneficial to improve dementia detection rates in primary care.