森林雷击火的预报监测

本文介绍对森林雷击火预测的研究及其监测技术的进展与应用，以期作为大兴安岭雷电监测网全面开通后监测预报研究工作的新起点     

小型城市污水排放量预测模型研究——以楚雄市为例

针对小城市污水排放量历史数据较少,城市发展变化较大的特点,以楚雄市为例,提出了基于污水排放来源以及生成机理的预测方法。根据历史人口增长趋势以及城镇化率进行城区人口综合预测,运用定额法根据不同行业用水特点预测城市用水量,结合城市污水排放特点对楚雄市近期以及远期城市污水排放量进行科学合理的预测,并对预测结果进行了分析,可为城市发展规划提供决策参考。     

Fouling distribution in forward osmosis membrane process

Fouling behavior along the length of membrane module was systematically investigated by performing simple modeling and lab-scale experiments of forward osmosis （FO） membrane process. The flux distribution model developed in this study showed a good agreement with experimental results, validating the robustness of the model. This model demonstrated, as expected, that the permeate flux decreased along the membrane channel due to decreasing osmotic pressure differential across the FO membrane. A series of fouling experiments were conducted under the draw and feed solutions at various recoveries simulated by the model. The simulated fouling experiments revealed that higher organic （alginate） fouling and thus more flux decline were observed at the last section of a membrane channel, as foulants in feed solution became more concentrated. Furthermore, the water flux in FO process declined more severely as the recovery increased due to more foulants transported to membrane surface with elevated solute concentrations at higher recovery, which created favorable solution environments for organic adsorption. The fouling reversibility also decreased at the last section of the membrane channel, suggesting that fouling distribution on FO membrane along the module should be carefully examined to improve overall cleaning efficiency. Lastly, it was found that such fouling distribution observed with co-current flow operation became less pronounced in counter- current flow operation of FO membrane process.     

基于VR技术的机场应急救援虚拟演练平台

为解决机场实地应急演练中存在的成本消耗高、不安全、扩展性差等问题,研发基于VR技术的机场应急救援虚拟演练平台。平台采用模块化设计方案,并通过定义平台操作流程支持虚拟演练操作。采取分细节度的场景构建方法,运用细节层次模型以3层不同细节度模型方案将虚拟灾害场景划分为3类,同时利用Unity3D粒子系统控制机制实现火灾及灭火粒子特效的模拟,运用双顶层本体模型构建机场应急预案本体模型（AERPO）,并利用XML Spy建立存储模型,且支持基于典型场景模型编辑形成整个灾害场景。结果表明:平台模块设置科学、场景效果合理,有助于提升演练人员应急处置能力。     

An isolated AC module for photovoltaic energy conversion

In this paper, an isolated ac module with pseudo dc-link and galvanic isolation is proposed for photovoltaic energy conversion. The studied grid-tie ac module can individually extract the maximum solar power from each photovoltaic panel and transfer to ac utility system. It consists of an interleaved active-clamping single-ended primary-inductive circuit (SEPIC) with a secondary voltage doubler, a full-bridge polarity selector operating under line frequency to achieve high efficiency. For the studied topology, key features such as reduced input current ripple, zero-voltage switching (ZVS) of primary switches, low reverse-recovery current of the output diodes, and lower switch voltage stress are obtained. Also, to reduce input current ripple, an interleaved control strategy is adopted. A simple control strategy is proposed to generate a rectified sinusoidal waveform voltage at the pseudo dc-link capacitors and achieve the high maximum power point tracking (MPPT) accuracy. The operation principles and design considerations of the studied ac module are analyzed and discussed. A prototype with 25–60 V dc input, 110 V/60 Hz ac output and 150 W power rating has been constructed for verifying the feasibility of the proposed ac module.     

Water quality management worldwide

This article analyzes water quality on a global scale. An overview of the global water supply and demand situation is presented first, including regional and country information, as well as data on selected water use patterns. The focus then shifts to a discussion of water pollution, its various causes, impact, and remedies, with emphasis on legal and administrative solutions. Water pollution control expenditures and the resultant achievements are dealt with in the final third of the article, with projections to 1995. A wide variety of published sources was dovetailed to obtain a composite picture and most likely scenario; this was supplemented with primary interviews by the author conducted in North America, Western and Eastern Europe, and Oceania at the start of the 1980s.     

Household size and composition and implications for housing need in Kumasi,Ghana: a research note

A simple method of calculating the scale of housing need for Kumasi, Ghana, uses two likely variations in household size distribution and an overcrowding threshold of 3 p.p.r., and a measure of preference. The two household size distributions take account both of trends and of changes which may occur if and when new housing is provided. At that time, released from the current constraints, household formation along traditional lines may again be possible. The preferred supply equates households’ perceived need to their ability to pay at current rents. The resulting range of rooms required is wide but even the lowest need is so far in excess of supply that conventional approaches are self‐evidently inadequate and greater client involvement must be encouraged.     

天津市城区暴雨沥涝仿真模拟系统的研究

天津市位于黄河水系尾闾，是我国北方重要的工业和港口城市。该市历史上一直遭受洪涝灾害的威胁，加之近几年市区范围不断扩大，不透水面积增加，排水能力远远不能适应城市的发展要求，城市沥涝问题日趋严重。为了掌握天津市暴雨沥涝的规律，减轻洪涝灾害对该市的影响，作者利用二维不恒定流水动力学模型和计算机信息管理及图形技术，采用Power Station Fortran 4.0和Visual Basic5.0编程语言，在Widows98环境下开发了天津市暴雨沥涝仿真模拟系统。该系统首次实现了从城市暴雨预报、监测到城市暴雨沥涝仿真模拟的研究， 不仅能够处理实时的不均匀的降雨信息，还能处理数值预报模型的预报降雨信息。系统的信息前后处理模块用图形方式管理仿真模型的各类信息，方便用户显示、查询和修改，使系统更加完整、实用。     

脉冲激光发射模块电磁屏蔽效能仿真分析

目的 提高脉冲激光发射模块的电磁兼容性。方法 基于腔体的电磁屏蔽机理,使用HFSS软件,建立脉冲激光发射模块腔体模型,以电磁敏感度、电磁干扰2个方面对腔体电磁屏蔽效能进行仿真分析。结果 设计的双层屏蔽腔体在电磁波辐照频率为1~100 kHz时,屏蔽效能达到28 dB;电磁波辐照频率为0.2~18 GHz时,屏蔽效能达到47 dB。结论 当电磁波辐照频率在1~100 kHz时,腔体的屏蔽效能随频率的增加而增大。辐射源外部激励时,双层屏蔽腔体使用外层铁内层铜屏蔽效能较高。电磁波辐照频率在0.2～18 GHz时,腔体的屏蔽效能随频率的增大而减小,且发生了谐振效应。当腔体厚度相等时,双层屏蔽的屏蔽效能高于单层屏蔽。使用电缆连接器代替孔洞进行信号传输时,腔体屏蔽效能增加。     

公众参与环境保护制度属性及制度模块构建

民主政治是公众参与制度的出发点和归宿,通过公众的有效参与,环境执法权得到监督;有序是公众参与制度的自然属性,有序才能使参与变得顺畅;利益均衡是公众参与制度的价值准则,环境矛盾最终体现为环境利益和经济利益之争,解决环境纠纷的最佳手段是寻找利益均衡点;政府居于环境执法的主导地位,同时发挥指导、引导、疏导公众和企业的作用;多重沟通平台是公众参与制度的效率保证,政府、企业、公众在执法前后的多重沟通,才能达到参与的最终目标。与公众参与环境执法制度属性相对应的是制度模块建设,如监督制度、程序制度、纠纷调处制度、润性执法制度以及沟通制度等。这些制度既能准确反映公众参与环境执法制度属性,又能完成制度赋予的使命。