石英灯辐射加热条件下低密度碳/酚醛复合材料高温响应及分析

目的研究低密度碳/酚醛复合材料在不同地面加热实验测试响应的差异性,指导材料在实际应用环境下的高温响应分析。方法对低密度碳/酚醛复合材料开展了热流为400 kW/m~2的单侧石英灯辐射加热实验,利用热电偶测温系统测量试件在加热过程中不同位置的温度时间历程,并对试件的烧蚀形貌和微观结构进行观测。同时与热流为464k W/m~2的氧乙炔加热陶瓷板辐射加热实验结果进行对比分析,并且采用有限元方法对材料的传热传质多场耦合计算进行分析。结果对于石英灯辐射加热,在测量点升温到接近200℃时,温度响应拐点都依次出现。由于加热的辐射热源不同,在不同的辐射波段下,多孔材料吸收和发射的热量不同,短时间内氧乙炔加热陶瓷板辐射加热使材料内部升温速率比石英灯辐射加热实验的要快,但长时间加热时现象刚好相反。结论进行传热传质多场耦合计算材料高温响应时,合理确定材料宏观性能随温度的变化至关重要。     

我国饲料粮区域产消平衡特征及政策启示

我国饲料粮消耗量大且增长迅速,已经成为我国粮食安全的首要影响因素,准确判断我国饲料粮的区域产消平衡特征对农业相关政策的制订具有重要的现实意义。论文在详细分析各省区不同畜牧产品粮食转化系数的基础上,对区域饲料粮的产消平衡状态及其原因进行了研究。结果显示：1）近年来我国饲料粮消费量快速上升,由2000年的21 730万t增长到2015年的30 549万t,15 a间增长了8 819万t。2）2015年生猪饲料粮消耗量最大,比例达到了44.4%,占据了我国饲料消耗总量的半壁江山。其次为禽蛋与禽肉消耗,消费占比分别为15.8%与12.7%;牛肉、羊肉、牛奶与水产品的饲料粮消费量比例均在5%~9%之间。3）2015年全国饲料粮总计短缺4 276万t,区域上呈现“北余南缺”的格局,东北黑龙江、吉林、内蒙古三省（区）成为我国最重要的饲料粮供应区域。从粮食转换系数与饲养结构来看,“北粮南运”现象是粮食资源的合理配置。论文提出三点政策建议：1）转变消费结构,增加牛肉与牛奶的消费量;2）推动“以粮为纲”向“粮经饲”三元种植结构转变;3）充分利用国际市场,从全球视角保护粮食安全。     

Prediction of Leachate Level in Kimpo Metropolitan Landfill Site by Total Water Balance

Kimpo metropolitan landfill has received various kinds of wastessince January 1992. The leachate level was measured to be 10.3 m in May 1995 and the level increased to 12.2 m in August 1996. Therefore, to prove the reason for the increasing leachate level, we calibrated hydraulic conductivity of each waste andintermediate layer using the HELP (Hydrologic Evaluation ofLandfill Performance) model. The leachate generation data measured from February 1993 to October 1995 was used in the model calibration. As a result of a model calibration, we obtained anaverage infiltration ratio and used this in analysis of the total water balance to predict elevation of leachate level. Main causes of the elevation of the leachate level were the high water content of the waste and the degradation of the leachate-drainage system caused by the subsidence of a naturalbarrier layer.     

对熏烟扩散模式应用的探讨

工程上应用的大气污染物扩散模式中 ,熏烟模式由于其非定常性而与其他扩散模式有很大的区别。正确处理模式中各参数及变量的相互关系才能客观地反映污染物对环境影响的结果。本研究通过对熏烟模式的非定常性和各参数、变量相互关系的分析 ,提出了正确使用该模式的方法     

乙酸型顶极群落的内平衡与反馈调节机制研究

通过产酸脱硫反应器处理高浓度硫酸盐有机废水的连续流试验，从“动态”角度考察COD／SO4^2-比改变引起的pH值、氧化还原电位（ORP）、碱度（ALK）和末端产物（VFAs）等的变动及生态因子的叠加效应引发的优势种群变迁，分析了乙酸型顶极群落的稳定性及其发生定向性生态演替的规律，进而阐明了乙酸型顶极群落抵抗环境压力的内平衡与反馈调节机制，并指出乙酸型代谢和乙酸型顶极群落是产酸脱硫生态系统的典型特征。     

骆马湖的氮磷平衡及实施截污工程对水质改善效果的研究

骆马湖“九五”期间的氮磷平衡分析结果表明：氮磷在骆马湖湖体中的滞留量分别为1188.89t/a和193.36t/a。根据骆马湖的水质要求，在骆马湖截污工程完成后，没有新的污染进入水体的前提下，对骆马湖水体通过自然净化恢复到要求状态所需的时间进行了详细的数学推导和科学论证，结果表明，在不考虑底泥营养物质的情况下，只需0.19年左右的时间就能恢复，如果考虑底泥的影响。也只需0.59年左右的时间就能恢复，因此得出结论：对骆马湖实施截污是加速骆马湖水体改善的最佳途径。     

市场经济体制下的企业环境行为及调控

市场经济体制和现代企业制度也逐步建立，企业将表现出三类不同的环境行为，为矫正，引导企业的环境行为，必须建立有效的经济调控手段和强有力的法制保障手段。     

选择性离子交换法脱除水中NH3-N

采用储量较大的黑龙江省嫩江天然斜发沸石,对其脱除NH_3-N的能力、预处理及洗脱再生方法、交换平衡、交换动力学等进行系统的研究,并对沸石床层的交换过程进行数学模型计算。     

Waste minimization and its ecological evaluation A case study in printed circuit board manufacture

The printed circuit board (PCB) manufacturers face several problems regarding the waste they generate. In Austria, a detailed study for waste minimization was carried out with three PCB manufacturers and one electroplating company. In this project a lot of ecologically and economically effective options were found and implemented. The ecological evaluation of processes is still an unsolved problem. Several evaluation models are tested on selected processes of the project.     

Carbon Dioxide Balance of Wood Substitution: Comparing Concrete- and Wood-Framed Buildings

In this study a method is suggested to compare the net carbon dioxide (CO₂) emission from the construction of concrete- and wood-framed buildings. The method is then applied to two buildings in Sweden and Finland constructed with wood frames, compared with functionally equivalent buildings constructed with concrete frames. Carbon accounting includes: emissions due to fossil fuel use in the production of building materials; the replacement of fossil fuels by biomass residues from logging, wood processing, construction and demolition; carbon stock changes in forests and buildings; and cement process reactions. The results show that wood-framed construction requires less energy, and emits less CO₂ to the atmosphere, than concrete-framed construction. The lifecycle emission difference between the wood- and concrete-framed buildings ranges from 30 to 130 kg C per m² of floor area. Hence, a net reduction of CO₂ emission can be obtained by increasing the proportion of wood-based building materials, relative to concrete materials. The benefits would be greatest if the biomass residues resulting from the production of the wood building materials were fully used in energy supply systems. The carbon mitigation efficiency, expressed in terms of biomass used per unit of reduced carbon emission, is considerably better if the wood is used to replace concrete building material than if the wood is used directly as biofuel.