考虑火场环境实时作用下的人群疏散仿真研究

在现行的性能化防火设计中,通常将火灾发展与人员疏散两个过程分开考虑,从而忽略了火场环境对人员疏散过程的实时作用。该方法与实际情况有很大差异。笔者借助火灾模拟程序CFAST和人员疏散仿真软件buildingEXODUS,以某地铁车站为例,进行了火场环境实时作用下的人群疏散仿真研究。结果表明,火场环境会降低人群的判断和活动能力,延长疏散时间并产生其他的不利后果。因此,在防火设计中考虑火场环境对人群疏散的实时影响是十分必要的。     

全干式煤气布袋除尘在大中型高炉中的应用

高炉煤气全干式布袋除尘净化技术,应用于大中型高炉效果显著,目前此技术已使用成熟且具备推广条件,指出了推广该技术需要完善解决的问题.     

ANALYSIS OF NEW TECHNIQUES FOR PUBLIC INVOLVEMENT IN WATER PLANNING1

ABSTRACT: The growing demands by the public for a more active role in planning have recently generated considerable interest among researchers and planners in the subject of public involvement techniques. Numerous surveys have found that standard public participation techniques (e.g., public hearings) by themselves are considered inadequate. Several techniques that have potential for overcoming some of the limitations of standard public involvement techniques have recently been developed. This paper describes several of these new techniques and analyzes each of them in terms of their potential utility in water resources planning.     

REDUCING THE COST OF CONTINUOUS HYDROLOGIC-HYDRAULIC SIMULATION1

ABSTRACT: The use of continuous hydrologic-hydraulic-water quality models is inhibited by their large computer run costs relative to cost incurred with discrete event models. The fixed recurrence interval transfer (FRIT) technique is a means of achieving substantial reductions in computer costs associated with continuous models while retaining their technical advantages. The FRIT technique is applicable where it is reasonable to assume that the recurrence interval of the response of a watershed to a causative meteorologic event is the same for both “before” and “after” conditions. Example applications of the FRIT technique to the hydrologic-hydraulic modeling of floodwater storage, land use changes, and channel modifications are presented to demonstrate the procedure, to suggest the expected accuracy, and to illustrate how computer run costs might be reduced by 99% or more. The FRIT technique is intended for preliminary assessment of the impact of alternative land use conditions and structural water control measures.     

APPLICATION OF ADVANCES IN FLOOD FREQUENCY ANALYSIS1

ABSTRACT: Flood frequency analyses are frequently being made using widely available computer programs. Serious errors can result from blind acceptance of such results. Visual interpretation of observed flood series can be used for evaluation on frequency paper with compatible scales. Such frequency papers are presented in the paper. In ephemeral streams, more infrequent floods may constitute a separate set from the more frequent floods because (a) runoff producing storms cover only a portion of the contributing area, (b) transmission losses in the normally dry streambed may reduce the peak flow, and (c) some runoff may be stored in stock water ponds which therefore leads to partial area runoff. The Cunnane plotting position used in this paper is superior to the more widely used Weibull equation, having a mathematically sound basis for locating observed floods on an assumed probability.     

COST REDUCTIONS DUE TO SEASONAL VARIATION IN MUNICIPAL WASTE WATER TREATMENT LEVELS1

ABSTRACT: Varying treatment levels to meet seasonal variation in assimilative capacity of streams can reduce total costs of treatment. A mathematical model of a Pennsylvania stream based on a theoretically sound approximation of the physical relationships underlying the distribution of DO in a river system was used to determine discharge constraints for an economic optimization model which produced estimates of sewage treatment cost savings. Increasing the number of flow periods during the year enhances cost reducing opportunities even when land application processes are considered. Also, the least cost treatment process for year around operation may not be the least costly under multiple flow period management.     

应用于高温干态过滤的三聚氰胺纤维过滤材料

ＬＦＢ是Ｂａｓｏｆｉｌ纤维与Ｍｅｔｍａｘ纤维混合制成的针刺毡，本文主要介绍Ｂａｓｏｆｉｌ纤维和ＬＦＢ的物理和化学特性。     

小麦-玉米轮作体系农田氮素淋失特征及氮素表观平衡

连续6年采用渗漏计法研究了不同施氮处理下陕西关中小麦-玉米轮作区农田土壤90 cm深度处氮素(N)淋失特征和土壤-作物体系氮素表观平衡状况.结果表明:该地区农田氮素淋溶主要发生在降雨量较多的玉米季,且集中在8月和9月.监测期内,TN和NO-3-N年平均流失量分别为2.72~23.07 kg·hm-2和1.53~18.72 kg·hm-2,年流失率分别为0.65%~3.44%和0.82%~3.32%,且年总氮、硝态氮流失量均随年施氮量增加呈指数增加.氮素淋失形态中,NO-3-N比例较高,可占总氮淋失量的56.00%~81.00%,且随着氮肥用量的降低,其占总氮淋失量的比例也随之减小.可见,施氮量的大小在一定程度上会影响淋失液中各形态氮的比例.氮素表观平衡结果显示,随着施氮量提高,氮素在土壤中的残留和表观氮盈余均呈现指数增加趋势.长期施氮条件下,土壤-作物体系氮素表观损失率的幅度为32.60%~55.20%,土壤表观残留率为-0.17%~8.20%.多年监测结果表明,优化施氮模式下,作物不仅可以获得较高的产量和氮肥利用率,农田氮素淋失量也大幅降低,在节约肥料资源的同时减轻了潜在的环境风险.     

赤潮灾害经济损失评估技术方法

为有效应对赤潮灾害防灾减灾、灾后救援及管理的需求,在综合分析前人提出的赤潮灾害损失评估技术方法的基础上,参考赤潮灾害对受灾体的危害特点,结合实际工作的需求及在实际中可获取的业务数据,提出了赤潮灾害经济损失评估指标体系;根据灾害经济学理论,借鉴其他自然灾害经济损失评估的先进思想,采用市场价格法,分别建立了包括海水养殖业经济损失、滨海旅游业经济损失、赤潮灾害业务与应急监测费用和赤潮灾害处置费用的赤潮灾害经济损失评估模型;最后,提出了赤潮灾害损失评估的技术流程。     

PBDEs的来源特征、环境分布及污染控制

多溴联苯醚(Polybrominated diphenyl ethers,PBDEs)生产应用、环境分布与生态风险之间的关系将如何影响我国的未来,具体涉及到工业、环境、健康、人类繁衍等的社会问题.由于PBDEs阻燃效率高,热稳定性好,价格便宜,作为添加剂被广泛应用在电子、电器、化工、交通、建材、纺织、石油等领域的阻燃产品中.PBDEs进入环境后迁移扩散并富集于沉积物和生物体内,进入人体后引起肝脏毒性、内分泌干扰、神经毒性和生育能力下降等而危害人类的健康.基于此,从生产应用、品种生产量、分子的物理化学特性以及毒性等的文献数据分析了PBDEs的来源特征与环境危害,分析这些性质对环境分布与污染控制的基础支持关系;从沉积物、水体、大气、水生生物、人体5个方面考察了PBDEs的环境本底浓度变化、分配关系、迁移规律、时间效应,分析了生产、应用与扩散的多因素影响关系,发现全球性PBDEs污染物蔓延的现象,沉积物是主要的归趋场所,室内空气中的浓度远高于室外,水中浓度较低,水生生物和人体均能富集PBDEs,通过饮食、母乳和呼吸摄入,可实现代际传播,污染的分布呈现介质与区域的不同特征;污染控制需要考虑点源技术与面源修复的联合,结合PBDEs的物理性质、分子结构及其化学特性,统计分析了微生物法、光化学降解法和零价铁还原法的原理及其有效性,根据PBDEs在产品中存在与分布的特点,提出收集-分离-富集-超临界催化还原和氧化毁毒的工艺,针对实际环境(以电子垃圾塑料和流域水体及沉积物为对象)中的PBDEs进行回收或处理,结合材料如催化剂的应用,从动力学和热力学方面提高PBDEs无害化的效率.最后,从生产管理、环境监测、风险评价、技术集成等方面提出了未来的努力方向.