国际贸易实务教学内容的探讨

《国际贸易实务》是一门专门研究国际间商品交换具体过程的学科,是一门具有涉外活动特点的实践性很强的综合性应用科学。本文对《国际贸易实务》的教学内容进行了一些探讨,主要包括:正确处理《国际贸易实务》与其它相关课程之间的关系;按照业务流程调整教学内容的结构安排;合理安排理论教学与实践教学的比例;不断更新教学内容;突出教学重点与难点;树立风险防范意识,有效防范风险。     

国际贸易实务教学内容的探讨

《国际贸易实务》是一门专门研究国际间商品交换具体过程的学科，是一门具有涉外活动特点的实践性很强的综合性应用科学。本文对《国际贸易实务》的教学内容进行了一些探讨，主要包括：正确处理《国际贸易实务》与其它相关课程之间的关系；按照业务流程调整教学内容的结构安排；合理安排理论教学与实践教学的比例；不断更新教学内容；突出教学重点与难点；树立风险防范意识，有效防范风险。     

北京市环境政策评价研究

选取北京市 1985— 1999年环境经济数据 ,建立北京市经济增长与环境污染水平计量模型 ,为评价北京市环境政策提供依据。此实证研究得出两个重要结论 :北京市环境指标与人均GDP演替轨迹呈现显著的环境库兹涅茨曲线特征 ;但比发达国家较早实现了其环境库兹涅茨曲线转折点     

The derivation of species response curves with Gaussian logistic regression is sensitive to sampling intensity and curve characteristics

We investigated quantitatively the sensitivity of plant species response curves to sampling characteristics (number of plots, occurrence and frequency of species), along a simulated pH gradient. We defined 54 theoretical unimodal response curves, issued from combinations of six values for optimum (opt = 3, 4, …, 8), three values for tolerance (tol = 0.5, 1.0, and 1.5, sensu ter Braak and Looman [ter Braak, C.J.F., Looman, C.W.N., 1986. Weighted averaging, logistic regression and the Gaussian response model. Vegetatio 65, 3–11]), and three values for maximum probability of presence (p_max = 0.05, 0.20, and 0.50). For each of these 54 theoretical response curves, we built artificial binary data sets (presence/absence) to test the influence of species occurrence, frequency, or number of available plots. With real data extracted from EcoPlant, a phytoecological database for French forests [Gégout, J.-C., Coudun, Ch., Bailly, G., Jabiol, B., 2005. EcoPlant: a forest sites database linking floristic data with soil characteristics and climatic conditions. J. Veg. Sci. 16, 257–260], we compared the ecological response of 50 plant species to soil pH, based first on a small data set (100 randomly sampled plots), and then based on the whole data set available (3810 plots).     

劳资关系的分配视角分析

从历史发展进程的角度分析了劳资关系及其变化问题,并重点探讨劳动与资本之间分配关系的动态变化．“资本雇佣劳动”这种制度安排有其历史发展过程中的“路径依赖”特征,各种不同经济与法律环境对其形成与存在提供基础,而今后经济发展的复杂化将对传统的劳资关系产生重要的影响．劳资之间分配关系是劳资关系中最为重要而根本性的体现,劳资关系的变迁对于其分配关系也将产生影响,使劳资之间的分配模式从传统的“以物质资本为中心”的分配模式向新型的“以人力资本为中心”的分配模式转化．     

生态生产：一种重要的生产形式

生态生产指构成生态系统的各要素在相互依存、制约和作用过程中的物质循环和能量流动。一个健全的生态生产须具备两个基本条件，一是构成要素的不可缺少性或构成要素应有足够的数量保证，二是生态生产各要素之间要有一种优化协调的关系。长期以来，人们关注的主要是生态生产的社会化，而忽视了社会生产的生态化要求，结果造成社会生产与生态生产之间尖锐的矛盾，处理地社会生产与生态生产的相互关系，必须遵循物质生产和人口生产一定     

社会、经济与环境协调发展指数评价模型

为了建立合理和实用的社会、经济与环境协调发展的评价指标体系和评价模型，分析了社会经济和环境指标体系具有的确定性和不确定性特征，应用集对分析中联系度的同异反态势排序法，给出了社会、经济发展和环境功能损害态势度表示，并提出了社会经济与环境之间协调发展满足的生长曲线指数计算公式。对大理市评价的实例表胆：基于联系度的同异的同异反态势排序的社会、经济与环境协调发展的评价指标体系和评价模型具有简单、实用的特点     

A COMPLEMENTARY TOOL TO WATER QUALITY INDEX: FUZZY CLUSTERING ANALYSIS1

ABSTRACT: A general methodology for fuzzy clustering analysis is developed and illustrated with a case study of water quality evaluation for Dianshan Lake, Shanghai, China. Fuzzy clustering analysis may be used whenever a composite classification of water quality incorporates multiple parameters. In such cases, the technique may be used as a complement or an alternative to comprehensive assessment. In fuzzy clustering analysis, the classification is determined by a fuzzy relation. After a fuzzy similarity matrix has been established and the fuzzy relation stabilized, a dynamic clustering chart can be developed. Given a suitable threshold, the appropriate classification is worked out. The methodology is relatively simple, and the results can be interpreted to provide valuable information to support decision making and to aid water quality management.     

MODELING WATER BALANCE WITH THE ERHYM MODEL ON SOUTH TEXAS RANGELANDS1

ABSTRACT: Understanding the hydrologic processes of rangeland plant communities is essential to determine if water augmentation through shrub management is feasible. Vegetation manipulation studies are costly, difficult to accurately replicate, and often require more than 10 years to determine treatment effect on the water budget. If properly applied, hydrologic simulation models are an attractive alternative for assessing vegetation manipulation practices. The ERHYM-II model was evaluated to determine if it was capable of simulating the water balance for honey mesquite shrub clusters, grass interspaces, and bare soil in south Texas. The simulated water budget was within 2 percent of the measured evapotranspiration for the shrub clusters and grass interspaces. The model underestimated the number of runoff events and overestimated runoff volume for the grass interspace and shrub clusters. Simulated runoff was overestimated by approximately twofold for the grass interspace and threefold for the shrub clusters. Although simulated runoff was substantially overestimated, observed and simulated runoff only accounted for 3 to 6 percent of annual rainfall for the grass and shrub dominated areas, respectively. Simulated evapotranspiration was underestimated by 18 percent and soil water content was overestimated by 82 percent for the bare soil. The model underestimated evapotranspiration for the bare soil as a result of restricting evaporative losses to the first soil layer. Based on our analysis, the ERHYM-II model has the potential for simulating the annual water balance for semiarid rangeland plant communities where runoff and deep drainage are limited components of the water balance.     

呼吸性粉尘浓度测定值的采用与统计

通过对刘冲矿大量测试数据的解析，论证了矿山各工人群呼吸性粉尘浓度对数值遵从正态分布规律，并在此基础上提出了工人群呼吸性粉尘浓度测定值的采用与统计应遵循的原则和方法，对正确推行呼吸性粉尘监测新技术具有重要意义。