应用大鼠全胚胎培养方法探讨偏钒酸铵的致畸作用及其机理

本文通过ＮＨ４ＶＯ３体外大鼠全胚胎培养致畸实验研究，发现ＮＨ４ＶＯ３对大鼠胚胎具有直接胚胎毒性和致畸性，且具有显的剂量一反应和时间一效应关系，其作用机理可能与卵黄囊的功能受到钒化物的损害有关。     

微生物传感器技术原理及其在水环境监测中的应用

微生物传感器技术产生于７０年代，并且，已在水环境监测中得到应用，例如，ＢＯＤ、ＮＨ３、ＮＨ４＾＋、ＮＯ２＾－、ＮＯ３＾－等项目分析；毒物测定和毒性评价；致突变物的筛选等。实践证明，该项技术具有快速、灵敏、易于自动控制、成本低廉等优点；可以相信，它必定会越来越多的应用于环境监测。     

酸性降水研究

本文对降水酸度的变化规律，降水ｐＨ值与电导率的关系，以及ｐＨ值与降水量，降水时间的关系等方面进行了研究，建立了ｐＨ值与ＳＯ＾２－４，Ｃａ＾２＋，ＮＨ＾＋４的三元线性回归模式。     

信息窗

信息窗石油化工污水ＮＨ３－Ｎ达标的探讨随着石油化工产品的增加及深度加工，其排放污水中ＮＨ３－Ｎ经中和沉淀，生化处理后仍达不到国家排放标准，为促使石油化工外排污水ＮＨ３－Ｎ达标提出了Ａ／０生物膜脱氮、过氧化脱氮、碱化曝气吹脱氮及程序间歇式多级生物氧化法...     

简易流动注射仪化学发光法测定水环境中的铵态氮

在０．１Ｍ的碱性条件下，ＮＢＳ（Ｎ—溴代丁二酰亚　胺）在荧光素的增敏作用下氧化氯化铵，产生强的化学发光。基于此本文详细研究了其反应　的特性和影响因素，在优化的实验条件下体系对氯化铵的测定范围为１．０×１０－７～１　．５×１０－５ｇ／ｍＬ，检出限为３．６×１０－８ｇ／ｍＬ，对５．０×１０－６ｇ／ｍＬ氯化铵　进行１１次平行测定，其ＲＳＤ为２．８％。将本法用于环境水样中ＮＨ＋４的分析，并与常规的　方法进行对照，获得了满意的结果。     

脉冲电晕等离子法烟气脱硫脱硝的研究

本文探讨了脉冲电晕等离子法脱硫脱硝的基本原理，较系统地研究了影响脉冲电晕等离子烟气脱硫脱硝的主要因素，进行了加ＮＨ３脱硝的探索试验。实验表明：该法能有效地去除烟气中的ＳＯ２，但脱硝效果不明显，加ＮＨ３后可大量提高脱硝的效率；湿度对脱硫影响较大，湿度越高，脱硫效率也越高，当相对湿度达８０％时，脱硫率基本达到最大，而湿度对脱硝的影响不如脱硫明显；脉冲电压越高，功率越大，脱硫脱硝效率越高；增加放电极长度     

AAS与ICP—AES间接测定天然水中硫酸盐

本文以ＳＯ４＾２－与过量Ｂａ＾２＋形成ＢａＳＯ４沉淀反应为基础，较详细地讨论了反应条件，从而拟定了用ＡＡＳ和ＩＣＰ－ＡＥＳ间接测定天然水中ＳＯ４＾２－的方法、确定了方法的精密度，ＡＡＳ法的ＲＳＤ％为１．５，ＩＣＰ－ＡＥＳ法为３．２， 两种方法对比分析的结果接近，误差为１．０％（相对）。用于天然水中ＳＯ４＾２－的测定，获得满意的结果。     

双流区域地下水污染现状及评价

本文在双流区域地下水污染调查基础之上，选用了主要反映工业生活污染的综合指标ＣＯＤ、ＢＯＤ５和反映农业污染程度的ＮＨ３－Ｎ，ＮＯ３－Ｎ，ＮＯ２－Ｎ作为评价因子，研究了双流地下水污染现状，采用了综合指数法和点群分析法分类并评价了区域地下水污染对饮用水源地的影响程度。     

4－AAP萃取光度法以蒸馏水代替无酚水测定地面水中挥发酚

４－氨基安替比林（简称４－ＡＡＰ）萃取光度法测酚是灵敏度很高的标准分析方法。该方法要求使用无酚水。本文经过实验分析提出以蒸馏水代替无酚水测定地面水中挥发酚，结果表明，本方法检出限为０．０１７ｍｇ／ｌ，具有较高的精密度和准确度。本法省略了制备无酚水的程序，从而使实验分析得到简化。     

4阶导数光谱法同时测定酚类及芳胺的统计性检验

介绍４阶导数光谱法同时测定污水中酚类及芳胺方法的统计性检验，通过样品加标回收实验以及Ｆ检验和ｔ检验证明该方法的精密度和准确度均优于国家环保局推荐的４－氨基安替比林先度法删酚和萘乙二胺偶氮光度法测芳胺的实验方法。     

A COMPARATIVE STUDY OF A SWEDISH AND A CHINESE HYDROLOGICAL MODEL1

ABSTRACT: There are a large number of conceptual hydrological models available today. It is not easy to immediately identify the similarities and differences between the different models. The Swedish HBV model and the Chinese Xinanjiang model are two examples of conceptual, semi-distributed, rainfall-runoff models. The Xinanjiang model was designed for use in humid and semi-humid regions, with no routine for the snowmelt runoff, whereas the snow routine is an important part of the HBV model in many applications. The model structures of the two models may be described in four routines, compared in this paper. The integral structures of them are similar, but there are some differences, especially in the runoff production routine. The physical significance and physical definitions of some model parameters were analyzed. Both models were tested in two basins. Both models gave similar results, and both models performed well in the application. The similarity of the results obtained by different model structures leads to the following two conclusions. First, more effort should probably be spent on the improvement of input data quality and coverage than on the development of more detailed model structures only. Second, inference about basin behavior and characteristics from the values of calibrated model parameters must be made with great caution.     

Empirical Comparison of Temperature-Distribution Models for Energy and Exergy Analyses of Stratified Thermal Energy Storages

Five previously developed temperature-distribution models are compared using data from actual thermal energy storage (TES) systems, and the advantages and disadvantages of each model are identified. These models are used for evaluating the energy and exergy in a TES. Furthermore, the accuracy and simplicity of the temperature-distribution models (Linear, Stepped, Continuous-linear, Three-zone and General-linear) are compared in order to determine which model has the greatest accuracy and simplicity regarding computational effort, while providing physical understanding. After fitting the models to temperature data for 35 stratified TES samples, it was observed that some models are easy to use but relatively inaccurate, while others are relatively accurate but complicated to use. As a trade-off, the Three-zone model provides physical understanding, yields acceptable accuracy and is relatively simple to use, especially in computing the parameters needed for energy and exergy assessments of stratified TESs.     

毒害污染物生态风险评价模型研究进展

随着化学品的使用种类和数量日益增加,有毒有害污染物的生态效应逐渐受到重视.生态风险评价模型作为较好的科研和管理技术工具,被越来越广泛地用于扩散到环境中化学物质的生态风险评价中;欧美等发达国家和地区已经建立了多个生态风险评价的模型,并投入到实际应用中.本研究系统综述和总结了毒害污染物生态风险评价模型的构建方法、种类、结构以及特征,归纳了重金属和有机污染物等主要毒害物质的风险评价模型发展状况,比较了几种较为成熟的风险评价模型的具体模块和特点,分析了模型在生态风险评价中的应用以及不足之处,在总结我国生态风险评价模型的研究方向和趋势的基础上,提出模型研究和发展的具体建议.     

MODEL STUDIES OF SALT WATER INTRUSION1

Model studies were and are still being used to verify certain theories in ground-water flow systems in general. In complex cases, the model studies may be extremely useful especially when a theoretical rigorous analysis does not exist. The models cannot be considered entirely satisfactory due to the several drawbacks in each type in addition to the normal human errors in experimentation. This paper is concerned only with the viscous flow models. However, a brief summary of the other types of models, which may possibly be used in connection with salt water intrusion problems is given. It should be noted that some of such experiments are not directly related to the field of salt water intrusion. Two main types lie within this category: The gravity flow systems which are analogous to some phases of salt intrusion problems and problems in oil fields which bear general similarities to sea water intrusion zones. In oil fields, gas cycling studies give valuable information to sea water problems. Model studies are used by hydraulic engineers, geologists, petroleum engineers, physicists, foundation engineers and several other professional groups.     

STOCHASTIC MODELING OF MONTHLY AND DAILY RAINFALL SEQUENCES1

ABSTRACT: A monthly model and two daily models (I and II) are presented for the purpose of generating monthly and daily rainfall sequences in the Quae Yai river basin in Thailand. Performance of the models are evaluated by comparing the statistical parameters of the generated sequences with those from historical data. For monthly generation, Thomas-Fiering model worked satisfactorily in spite of the monthly correlations being weak, if any. Daily Model I, which assumes no persistence between daily rainfall amounts within the wet spells, could not preserve some important parameters regardless of the simplicity in model construction. Application of multi-state transition probability matrix model gave good results, although the user has to modify some parameters looking at the performance of the model for each historical record.     

污水处理厂优化设计研究进展

本文对城市污水处理厂优化设计研究发展的历史作了回顾 ,对不同时期的几个系统模型作了简单的介绍 ,并提出了城市污水处理厂优化设计研究中几个有待进一步研究的问题。     

Limitations of model-fitting methods for kinetic analysis: Polystyrene thermal degradation

In this paper, some clarifications regarding the use of model-fitting methods of kinetic analysis are provided in response to the lack of plot linearity and dispersion in the activation energy values for the thermal degradation of polystyrene found in the literature and some results proposing an nth order model as the most suitable one. In the present work, two model-fitting methods based on the differential and integral forms of the general kinetic equation are evaluated using both simulated and experimental data, showing that the differential method is recommended due to its higher discrimination power. Moreover, the intrinsic limitations of model-fitting methods are highlighted: the use of a limited set of kinetic models to fit experimental data and the ideal nature of such models. Finally, it is concluded that a chain scission model is more appropriate than first order.     

AN APPLICATION RUNOFF MODEL STRATEGY FOR UNGAGED WATERSHEDS1

ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m²) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft³/sec (0.085 to 3.34 m³/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.     

Resampling methods for evaluating classification accuracy of wildlife habitat models

Predictive models of wildlife-habitat relationships often have been developed without being tested The apparent classification accuracy of such models can be optimistically biased and misleading. Data resampling methods exist that yield a more realistic estimate of model classification accuracy These methods are simple and require no new sample data. We illustrate these methods (cross-validation, jackknife resampling, and bootstrap resampling) with computer simulation to demonstrate the increase in precision of the estimate. The bootstrap method is then applied to field data as a technique for model comparison We recommend that biologists use some resampling procedure to evaluate wildlife habitat models prior to field evaluation.     

A COMPARISON OF SOME DYNAMIC,LINEAR AND POLICY ITERATION METHODS FOR RESERVOIR OPERATION1

Within the past few years, a number of papers have been published in which stochastic mathematical programming models, incorporating first order Markov chains, have been used to derive alternative sequential operating policies for a multiple purpose reservoir. This paper attempts to review and compare three such mathematical modeling and solution techniques, namely dynamic programming, policy iteration, and linear programming. It is assumed that the flows into the reservoir are serially correlated stochastic quantities. The design parameters are assumed fixed, i.e., the reservoir capacity and the storage and release targets, if any, are predetermined. The models are discrete since the continuous variables of time, volume, and flow are approximated by discrete units. The problem is to derive an optimal operating policy. Such a policy defines the reservoir release as a function of the current storage volume and inflow. The form of the solution and some of the advantages, limitations and computational efficiencies of each of the models and their algorithms are compared using a simplified numerical example.