高度城市化地区碳汇资源基本特征及其提升策略

作为全球碳循环和当前低碳发展的重要组成内容之一,城市碳汇资源研究受到广泛关注.以高度城市化的深圳市为例,利用IPCC缺省碳汇系数法和相关研究模型,分析了城市碳汇资源的基本特征.结果显示:深圳市2005年碳汇总量约为347.85×104 t,其中林地、耕地、草地、湿地和海洋的碳汇总量分别为317.52×104、4.50×104、2.10×104、12.60×104和11.13×104 t.碳汇资源持续减少、碳汇资源量较低、碳汇品质较差、碳汇资源保护形势严峻、碳汇能力提升压力较大等是当前深圳碳汇资源的主要特征,表明要推动高度城市化地区低碳生态城市建设,必须重视城市碳汇资源相关工作的开展,促进碳汇资源持续增加和碳汇品质持续提升.结合深圳城市发展实际,从碳汇资源保护、碳汇资源建设、碳汇品质提升、碳汇服务交易等角度提出了深圳城市碳汇资源提升的主要策略.      

多重复合加强型石膏材料的研制

从石膏的水化及硬化原理出发,通过添加有机物和无机物对石膏粉进行改性,并以石膏为基体,讨论了石膏与各种加强材料所形成的复合材料的抗压及抗折性能,从而寻找一种新型材料以解决当前化工产业生产的大量副产品——石膏的回收利用问题。     

CFD modeling and simulation of turbulent fluid flow and dust dispersion in the 20-L explosion vessel equipped with the perforated annular nozzle

A three-dimensional CFD model was developed to simulate the turbulent flow field induced by dust feeding and the associated dust dispersion within the 20-L explosion vessel equipped with the perforated annular nozzle. The model was validated against experimental data for pressure and root mean square velocity.Simulation results have shown that the turbulent kinetic energy is rather uniformly distributed and its values are significantly lower than those attained with the rebound nozzle. Furthermore, the perforated annular nozzle is able to generate a uniform dust/air cloud. However, a consistent fraction of the dust remains trapped inside the nozzle and, thus, it does not contribute to the explosion process.     

中新生态城土壤质量现状及改良利用途径

对中新生态城区域内土壤的紧实度、有机质、碱解氮、土壤盐分、酸碱度、地表水、地下水进行了调查取样分析,结果表明该区土壤容重在1.3～1.7g/cm3,有机质含量大多为中等或低水平（5.5～19.1g/kg）,速效氮与土壤有机质含量相关性达显著水平（r=0.98）。盐分垂直分布上表现为果园、农田土壤盐分含量小于1.5g/kg,荒地和水库含量在5.0～6.4g/kg之间,垫土区、养殖池和盐场盐池土壤通体盐分含量高（大于10g/kg）,且存在表聚现象,超出了一般植物生长的极限。土壤酸碱度为7.81～9.05,水库、养殖池、盐场、荒地、沟塘水的矿化度均在10g/L以上,蓟运河水和农田沟渠为5000mg/L～8500mg/L,果园灌溉水的矿化度也在2000mg/L以上,地下水矿化度高,埋藏浅。并针对以上特点提出其土壤改良利用途径和绿化建设模式。     

Problem driver remediation: a meta-analysis of the driver improvement literature

PROBLEM: Given the public safety risk posed by violation and crash repeaters and the substantial costs for state driver improvement programs, it is important that their effectiveness be scientifically demonstrated and that intervention programs are based on sound research findings. METHOD: Crash and traffic violation standardized effect sizes (d) representing 106 individual interventions were coded from 35 methodologically sound studies and analyzed using meta-analysis. RESULTS: Driver improvement intervention in general was associated with small but significant reductions in both crashes (dw = 0.03) and violations (dw = 0.06). Significant effects were found on both measures for warning letters, group meetings, individual hearings, and license suspense/revocation. Of the driver improvement interventions studied, license suspension/revocation was by far the most effective treatment for both crashes and violations (dw = 0.11 and 0.19). Since one of the objectives of license suspension/revocation is to eliminate driving for the period of suspension, it is possible that much or all of the effect is due to reduced exposure and/or more careful driving during the suspension interval. Results were mixed for other types of interventions, although distributing educational or informational material was not associated with any reductions. Interventions associated with violation reduction tended to also be associated with crash reduction, although the relationship was not very strong (r = .30). DISCUSSION: Although interpretation of the effect size estimates was complicated by almost ubiquitous heterogeneity, the results do suggest an overall positive impact of driver improvement interventions in general. IMPACT ON INDUSTRY: The results support the continued use of driver improvement interventions, chiefly warning letters, group meetings, individual hearings, and especially license suspension/revocation. The results also suggest that court-triggered traffic violator programs are less effective than interventions triggered by drivers license agencies.     

积极参加’97年全国“安全生产周”活动

积极参加’９７年全国“安全生产周”活动安全生产与劳动保护是企业和整个经济生活的一个重要环节，每一个从事生产、经营的企业都无不面临这个问题。搞好安全生产与劳动保护工作，对于减少生产过程中的危险和事故；减少由此造成的经济损失和降低生产经营成本；对于保护劳...     

四川省中低产田土的综合治理

本文以四川中低产田土综合治理实况为例,着重论述了自然灾害对农业生态系统的严重危害,从而阐明了改造中低产田土对提高经济、生态、社会三大效益的重要性和紧迫性,并从省情出发,总结提出当前乃至今后相当一个时期,农业部门所应采取的几项行之有效的措施,展望了2000年前景。     

Regeneration of industrial district wastewater using a combination of Fenton process and ion exchange—A case study

Regeneration studies of wastewater effluent from an organized industrial district (OID) for possible reuse in textile industry as process water was investigated. Advanced treatment methods including Fenton process, polyaluminium chloride (PAC) coagulation and ion exchange were applied on OID effluent. In Fenton process removal efficiencies for suspended solids (SS), chemical oxygen demand (COD), SAC₄₃₆ (spectral absorption coefficient), SAC₅₂₅ and SAC₆₂₀ were determined 61%, 36%, 35%, 49% and 67%, respectively. After Fenton process, wastewater samples were coagulated with PAC. Optimum removal efficiencies for SS, COD, Fe ion, SAC₄₃₆, SAC₅₂₅ and SAC₆₂₀ were determined 83%, 18%, 93%, 32%, 36% and 58%, respectively. Ion exchange experiments were conducted on chemically coagulated wastewater samples to improve the quality of wastewater. Optimum dosage of resins was determined. The experiments revealed that 1:1 resin ratio (20 mL H-type resin:20 mL OH-type resin) gave the best removal rates for the parameters considered in this study. Study results indicated that quality of the wastewater was suitable for the process water characteristics of textile industry and unit wastewater treatment cost was determined as 2.54 €/m³.     

A process model to estimate the cost of industrial scale biodiesel production from waste cooking oil by supercritical transesterification

This paper describes the conceptual design of a production process in which waste cooking oil is converted via supercritical transesterification with methanol to methyl esters (biodiesel).Since waste cooking oil contains water and free fatty acids, supercritical transesterification offers great advantage to eliminate the pre-treatment capital and operating cost.A supercritical transesterification process for biodiesel continuous production from waste cooking oil has been studied for three plant capacities (125,000; 80,000 and 8000 tonnes biodiesel/year). It can be concluded that biodiesel by supercritical transesterification can be scaled up resulting high purity of methyl esters (99.8%) and almost pure glycerol (96.4%) attained as by-product.The economic assessment of the biodiesel plant shows that biodiesel can be sold at US$ 0.17/l (125,000 tonnes/year), US$ 0.24/l (80,000 tonnes/year) and US$ 0.52/l for the smallest capacity (8000 tonnes/year).The sensitive key factors for the economic feasibility of the plant are: raw material price, plant capacity, glycerol price and capital cost.Overall conclusion is that the process can compete with the existing alkali and acid catalyzed processes.Especially for the conversion of waste cooking oil to biodiesel, the supercritical process is an interesting technical and economical alternative.     

焦化废水厌氧氨氧化污泥培养影响因素的研究

针对煤化行业高含氮焦化污水,采用厌氧氨氧化工艺进行脱氮污泥培养、驯化,对可能制约厌氧氨氧化菌生长的因素进行研究分析。结果发现:得出适宜于厌氧氨氧化污泥培养的水力停留时间、温度、p H及为保持污泥活性要求限制反应器进水氨氮和亚硝酸盐氮的最大负荷值。