上海人口自然变动负增长与社会经济发展

1993年上海人口自然变动在全国率先进入负增长,自然增长率为-0.78‰,并将持续一个较长的时期。这是长期以来本市经济和社会发展以及计划生育工作共同作用的必然结果,其中计划生育政策的成功推行起着重要的作用。上海除了继续控制人口增长的数量外,还要调节人口规模和人口结构,大力提高人口素质,不断使人口与社会经济发展、生态平衡、资源利用等方面达到协调发展。由负增长引发的劳动力短缺和老龄化程度加剧要采取相应的对策。     

浅谈我国逆反射材料现状及其发展趋势展望

随着逆反射材料的广泛应用 ,其带来的安全警示效果、产品质量、生产工艺、检测方法及规范管理等方面的问题被日趋重视 ,笔者通过对逆反射材料的基本构造及反光特性的分析 ,论述了其对人和物的安全防护作用 ,并对我国目前逆反射材料的应用领域、产品质量及检测设备、检测标准等方面的问题进行探讨和评述 ,根据国内外的发展趋势 ,对我国开发及发展逆反射材料产业提出了笔者观点 ,为政府决策提供科学依据     

Surface runoff losses of copper and zinc in sandy soils

Increased anthropogenic inputs of Cu and Zn in soils have caused considerable concern relative to their effect on water contamination. Copper and Zn contents in surface soil directly influence the movement of Cu and Zn. However, minimal information is available on runoff losses of Cu and Zn in agricultural soils, and soil-extractable Cu and Zn in relation to runoff water quality. Field experiments were conducted in 2001 to study dissolved Cu and Zn losses in runoff in Florida sandy soils under commercial citrus and vegetable production and the relationship between soil-extractable Cu and Zn forms and dissolved Cu and Zn concentrations in runoff water. Five extraction methods were compared for extracting soil available Cu and Zn. Concentrations of dissolved Cu and Zn in runoff were measured and runoff discharge was monitored. Mean dissolved Cu in field runoff water was significantly correlated with the extractable Cu obtained only by 0.01 mol L(-1) CaCl2, Mehlich 1, or DTPA-TEA methods. Dissolved Zn in runoff water was only significantly correlated with extractable Zn by 0.01 mol L(-1) CaCl2. The highest correlations to dissolved Cu in runoff were obtained when soil-available Cu was extracted by 0.01 mol L(-1) CaCl2. The results indicate that 0.01 mol L(-1) CaCl2-extractable Cu and Zn are the best soil indexes for predicting readily released Cu and Zn in the sandy soils. Both runoff discharge and 0.01 mol L(-1) CaCl2-extractable Cu and Zn levels had significant influences on Cu and Zn loads in surface runoff.     

EMMC process for combined removal of organics, nitrogen and an odor producing substance

In order to improve the process performance regarding the removal of organics, nitrogen, and an odor-causing compound (sulfide) contained in domestic wastewater, an entrapped-mixed-microbial cell (EMMC) with and without humic substances for both fixed and moving carrier reactors and conventional suspended growth culture (i.e. conventional activated sludge process) were investigated simultaneously. Both synthetic (simulated to the organics concentration of general domestic sewage) and actual domestic wastewater were investigated under operational conditions of 12 h of hydraulic retention time (HRT) with 1 h of aeration and 1 h of non-aeration, and 6 h of HRT with continuous aeration, at a room temperature of 25 +/- 2 degrees C. It was found that entrapping humic substances in the EMMC carriers had no impact on the removal of organics, nitrogen, and the odor-producing compound. Additionally, the performance of the EMMC moving carrier system for the removal of these pollutants is similar to that of the EMMC fixed carrier system. In general, the EMMC associated systems which provide high solids retention time achieve a better removal of chemical oxygen demand (COD), nitrogen, and the odor-producing substance than the suspended growth system for both HRTs of 6 h (continuous aeration) and 12 h (1 h of aeration and 1 h of non-aeration). Both the fixed and moving carrier EMMC processes, therefore, have the potential for improvement or replacement of the existing conventional activated sludge process with regard to improving the effluent qualities (such as COD, nitrogen and odor-producing compound) for reuse/disposal.     

Removal of copper ions and dissolved phenol from water using micellar-enhanced ultrafiltration with mixed surfactants

A laboratory study was conducted to evaluate the effects of composition and concentration of mixed anionic/nonionic surfactants on the efficiency of a micellar-enhanced ultrafiltration (MEUF) operation in removing metal ions/organic solutes from aqueous solutions. Based on the analysis of surface tensions and micelle sizes, it was found that for mixed sodium dodecylsulfate (SDS)/Triton X-100 surfactants, the critical micelle concentration (cmc) was significantly lower than that of SDS and mixed micelles formed. The mixed surfactant system was then applied in a cross-flow mode of MEUF, in which the concentration polarization can be neglected, to remove Cu2+ from aqueous solutions. With a surfactant concentration of 10 mM, the Cu2+ rejection was negligible by using pure Triton X-100 and increased with increasing SDS mole fraction with a value as high as 85%, which suggests that the rejection of Cu2+ was due to the electrostatic attraction between Cu2+ and SDS. Furthermore, pronounced Cu2+ rejection was obtained for a 5 mM SDS solution, which was attributable to a decrease in the cmc of SDS by the existence of Cu2+. When the MEUF technique was applied to remove Cu2+ and phenol simultaneously from aqueous solutions, the Cu2+ rejection was slightly enhanced in the presence of phenol. However, the rejection of phenol was comparatively low, approximately 27%, which may be caused by its relatively hydrophilic characteristic.     

基于3S技术的地质灾害易损性面评价研究

以等面积法作为基本手段,结合3S(GIS、RS、GPS)技术探讨地质灾害易损性面评价的实现方法。提出了为实现易损性面评估而确立的评价对象的分类方法、空间数据库的建设方法、基于空间数据库的空间分析方法以及信息的集成方法。最后探讨了在GIS环境下的数据可视化表达方式和实现地质灾害易损性面评价的一般操作流程。     

循环经济的过程和工作重点

循环经济分为3个连续的阶段或环节：生产阶段、消费阶段和废旧物品再制造阶段。在生产阶段促进清洁技术的开发勺应用是实施循环经济的根本举措。当前实施循环经济的重点是：在宏观经济中实施循环经济；在宏观经济方针政策中体现循环经济原则、可持续发展原则和环境保护原则；将保护环境的基本国策纳入进出口政策；以循环经济的原则规划、建设、改造现存的化学工业同区。     

防护用品质量管理的发展趋势

据最新研究表明．用户的满意程度和企业的盈利能力与产品和服务的质量紧密相关。较高的产品质量和服务质量，能使用户满意，同时也能维持较高的价格。因此，质量改进方案通常会增加企业的盈利能力。     

乌鲁木齐市燃煤点源现状分析

对乌鲁木齐市燃煤点派数量、耗煤量、污染物的排放量以及在各功能区的分布分别进行了统计分析，对污染物的排放量在不同高度空间的分布也进行了统计分析，从而得出了确切的结论并提出了相应的建议。     

世界旅游精品建设目标下的张家界旅游环境管理对策研究

建设世界旅游精品是张家界制定的旅游业发展的战略目标，一流的旅游环境条件是实现这一目标的必备条件。然而，张家界目前的旅游环境与世界旅游精品存在差距，环境管理中存在基础性工作、基础性研究比较薄弱、制度不够健全等方面的问题，影响了环境管理效率。在分析研究张家界环境管理中存在问题的基础上，针对性地提出保护、改善环境的对策，是实现世界旅游精品战略目标的基础工作。