Modeling watershed-scale effectiveness of agricultural best management practices to reduce phosphorus loading

Planners advocate best management practices (BMPs) to reduce loss of sediment and nutrients in agricultural areas. However, the scientific community lacks tools that use readily available data to investigate the relationships between BMPs and their spatial locations and water quality. In rural, humid regions where runoff is associated with saturation-excess processes from variable source areas (VSAs), BMPs are potentially most effective when they are located in areas that produce the majority of the runoff. Thus, two critical elements necessary to predict the water quality impact of BMPs include correct identification of VSAs and accurate predictions of nutrient reduction due to particular BMPs. The objective of this research was to determine the effectiveness of BMPs using the Variable Source Loading Function (VSLF) model, which captures the spatial and temporal evolutions of VSAs in the landscape. Data from a long-term monitoring campaign on a 164-ha farm in the New York City source watersheds in the Catskills Mountains of New York state were used to evaluate the effectiveness of a range of BMPs. The data spanned an 11-year period over which a suite of BMPs, including a nutrient management plan, riparian buffers, filter strips and fencing, was installed to reduce phosphorus (P) loading. Despite its simplicity, VSLF predicted the spatial distribution of runoff producing areas well. Dissolved P reductions were simulated well by using calibrated reduction factors for various BMPs in the VSLF model. Total P losses decreased only after cattle crossings were installed in the creek. The results demonstrated that BMPs, when sited with respect to VSAs, reduce P loss from agricultural watersheds, providing useful information for targeted water quality management.     

煤低温氧化热解的热分析实验研究

在热分析动力学的基础上,对阳泉煤样运用同步热分析仪进行150℃下的氧化以及热解实验,得出该煤样相应的TG-DSC曲线。通过两者的TG-DSC曲线,对比分析煤样的热量释放情况,并结合曲线设定多项式形式的机理函数以分析其动力学特性。实验研究得出:该煤的低温氧化过程较之热解过程是个明显的氧化放热过程;该煤低温氧化和热解过程的最佳机理函数都为多项式,并且相应过程中的TG曲线和DSC曲线适用于同一个机理函数,这与一般所定义的机理函数不同;热解过程较之氧化过程所需的表观活化能较大,相同条件下较易发生煤的氧化自燃。     

安全生产责任的制度整合与伦理道德建设

在分析安全生产责任危机含义和安全生产责任概念基础上,指明安全生产责任体系的"四要素",即道德责任、政治责任、法律责任与管理责任,重点阐明道德责任是该体系的基础要素及其意义。根据对我国现有安全生产责任制度的分析,提出一个关于安全生产责任制度建设的伦理框架:强化安全生产责任意识;用人权伦理原则对安全生产责任制度伦理化;以特定的安全生产责任的伦理规范和准则构建责任规则系统;强化责任主体道德素质培养与监察制度建设,促使其自觉履行好自身应负的安全生产责任。总之,该理论框架为安全生产责任制度建立提供一个新的伦理学基础。     

金属非金属矿山安全标准化信息管理平台的开发

按照《金属非金属矿山安全标准化规范》的要求,为便于信息管理,建立了矿山安全标准化信息管理系统;该系统根据安全标准化规范的14个要素,将安全标准化管理信息平台划分为13个子系统,并研讨了安全标准化信息管理系统的各个功能模块;结合矿山实际,把信息系统平台分为系统管理模块,统一信息发布平台前台管理模块,后台管理模块等。该信息系统平台采用NET的技术开发信息系统平台,充分运用其基于组件开发的技术,为企业提供一个规范化、标准化管理平台,实现安全动态管理模式,使安全标准化在企业得以实现。     

Using Measurements of Nitrogen Oxides to Estimate the Emission Controls Required to Meet the UK Nitrogen Dioxide Standard

In this paper we introduce a new method of analysing the relationship between nitrogen dioxide (NO₂) and oxides of nitrogen (NO_x) concentrations using data from the UK National Air Quality Archive. The study includes analyses of measurements from two different types of site in London, a kerbside site: Cromwell Rd, and three background sites: Bridge Place, London Bloomsbury and West London, over several years (1991–7). The data in some years showed that hourly NO₂ concentrations exceeded the UK Standard of 150 ppb. Data were binned, averaged, and polynomials fitted at each site. Analysis of the resulting polynomials was used to estimate reductions in NO_x emission required to achieve the National Air Quality Strategy Objective. Examination of the empirical ratio NO₂:NO_x (the 'yield') gives an indication of the sensitivity of the NO₂ to NO_x controls and the amount of NO₂ that would arise from modelled values of total oxides of nitrogen. The response of NO₂ to emission changes is very non-linear, implying 30–45% controls on NO_x may be required.     

空气污染对儿童肺功能指标影响的初步分析

报告中国 4城市 8所小学儿童肺功能指标受室外空气污染影响的结果。以 FVC/预测值 (85% )、FEV1 /预测值(85% )、FEV1 / FVC(实测值之比 ) (80 % )作为判断肺功能指标异常的参考标准 ,并将 8所小学按污染程度分为污染严重和污染较轻两类三组。污染严重组儿童肺功能指标的异常率均比污染较轻组要高。空气的严重污染 ,可使儿童肺功能FVC、FEV1 、FEV1 / FVC异常率的危险程度分别增高 3 0 %～ 78%、52 %～ 86%和 1 0 2 %～ 1 2 7%。异常组儿童的 FVC、FEV1 的平均值约下降 3 3 0～ 4 60 ml,FEV1 / FVC平均值约下降 1 3 %～ 1 5%。说明空气的严重污染对儿童肺功能生长发育可能有不利影响     

水质综合评价的径向基函数网络模型

针对目前水质综合评价中常规方法存在的问题 ,提出了径向基函数网络模型 (简记为 RBF-ANN)。以吉林省白城市地下潜水水质资料为例 ,运用该方法对监测样点进行了综合评价。通过与其它方法对比 ,结果表明 ,利用RBF-ANN模型进行水环境质量综合评价不仅方法简便 ,而且结论更接近客观实际。     

Alternative soil quality indices for evaluating the effect of intensive cropping, fertilisation and manuring for 31 years in the semi-arid soils of India

Soil quality assessment provides a tool for evaluating the sustainability of alternative soil management practices. Our objective was to develop the most sensitive soil quality index for evaluating fertilizer, farm yard manure (FYM), and crop management practices on a semiarid Inceptisol in India. Soil indicators and crop yield data from a long-term (31 years) fertilizer, manure, and crop rotation (maize, wheat, cowpea, pearl millet) study at the Indian Agricultural Research Institute (IARI) near New Delhi were used. Plots receiving optimum NPK, super optimum NPK and optimum NPK + FYM had better values for all the parameters analyzed. Biological, chemical, and physical soil quality indicator data were transformed into scores (0 to 1) using both linear and non-linear scoring functions, and combined into soil quality indices using unscreened transformations, regression equation, or principal component analysis (PCA). Long-term application of optimum inorganic fertilizers (NPK) resulted in higher soil quality ratings for all methods, although the highest values were obtained for treatment, which included FYM. Correlations between wheat (Triticum aestivum L.) yield and the various soil quality indices showed the best relationship (highest r) between yield and a PCA-derived SQI. Differences in SQI values suggest that the control (no NPK, no manure) and N only treatments were degrading, while soils receiving animal manure (FYM) or super optimum NPK fertilizer had the best soil quality, respectively. Lower ratings associated with the N only and NP treatments suggest that one of the most common soil management practices in India may not be sustainable. A framework for soil quality assessment is proposed.     

Snow-cover environmental monitoring and assessment in Northeast China using passive microwave emission models

In this study, we present the application of the passive microwave emission models to snow-cover environment monitoring and assessment in Northeast China. The study employs the radiative transfer function and strong fluctuation theory to develop the models. We used the exponential form of a spherical symmetric correlation function to describe random permittivity fluctuations. From strong fluctuation, we then obtained the phase matrix and extinction coefficients of snow-packs for the spherical symmetric correlation function. We also used the vector radiative transfer formula for the layer of a random medium by solving Gaussian quadrature and eigen analysis. By comparing the brightness temperatures at 5, 10.7, 18, and 37 GHz, the modelling results agreed with experimental data of dry-snow physical parameters as measured in the fieldwork.     

城市化对上海河网结构和功能的发育影响

城市化河网水系的演变产生了深刻的影响,也使城市化地区水系的界定变得模糊。基于水利片这一城市集排水的基本单元,借鉴上海水务部门河流等级管理系统,探讨了上海河网的结构特征以及城市化对河网发育的影响。研究表明,上海河网发育基本符合水系发育的一般规律;城市化已经成为改变城市地区河网结构发育趋势的主导因素,其影响集中地表现为河网长度发育能力的弱化、河网结构简单化和河道形态的人工化;河网结构与水网功能之间有着密切的关联;水面率、河面率、平均分枝比、平均长度比、单位面积槽蓄容量和单位面积可调蓄容量是上海城市河网结构和功能的主要表征指标。