持续农业：内涵,定义及反思

持续农业带来现代农业的新方向，但仅局限于物理环境的改善不能实现农业的持续性。只有重视环境问题的社会性因素，寻求解决社会与环境问题的新方法，才能真正保持农业的持续发展。     

德国发展循环经济对中国的启迪

德国吸取了片面强调经济增长导致生态环境破坏的惨痛教训,率先在国际上实行发展循环经济政策,在发展循环经济方面积累了丰富的经验,形成了独具特色的循环经济管理体系.借鉴德国先进经验,认为转变经济发展模式,发展循环经济是中国实现全面可持续发展的战略选择,介绍了德国在理论、实践方面的经验,对正处于经济水平与环境保护有待于进一步协调发展的中国而言,具有现实的参考意义.     

Hydraulic model for multi-sources reclaimed water pipe network based on EPANET and its applications in Beijing, China

Water shortage is one of the major water related problems for many cities in the world. The planning for utilization of reclaimed water has been or would be drafted in these cities. For using the reclaimed water soundly, Beijing planned to build a large scale reclaimed water pipe networks with multi-sources. In order to support the plan, the integrated hydraulic model of planning pipe network was developed based on EPANET supported by geographic information system (GIS). The complicated pipe network was divided into four weak conjunction subzones according to the distribution of reclaimed water plants and the elevation. It could provide a better solution for the problem of overhigh pressure in several regions of the network. Through the scenarios analysis in different subzones, some of the initial diameter of pipes in the network was adjusted. At last the pipe network planning scheme of reclaimed water was proposed. The proposed planning scheme could reach the balances between reclaimed water requirements and reclaimed water supplies, and provided a scientific basis for the reclaimed water utilization in Beijing. Now the scheme had been adopted by Beijing municipal government.     

生物炭输入对碳酸钙调控油菜生长及重金属富集的影响

采用油菜盆栽试验,研究了1%和5%水稻秸秆生物炭投加量配施碳酸钙对重金属污染的郴州和龙岩土壤的pH值、有机质、油菜可食生物量、重金属累积和富集系数等的影响.结果表明,适量生物炭输入可以促进碳酸钙的调控效果.相比对照,单施碳酸钙可提高土壤pH值,但对有机质没有显著影响.而生物炭配施比单施碳酸钙处理最大可提高土壤pH值0.66个单位,增加有机质含量223.0%.碳酸钙单施可以显著提高油菜可食部分生物量,适量配施生物炭可强化增产作用,与对照相比,郴州土壤中配施5%生物炭的强化效果最好,可提高油菜可食部分生物量36.5%;而龙岩土壤配施1%生物炭效果最好,油菜生物量提高67.4倍.在郴州和龙岩土壤中,碳酸钙单施或与生物炭配施对重金属富集的影响不同.相对而言,碳酸钙在偏酸性的龙岩土壤中配施适量生物炭可更有效地降低土壤Cd、As、Pb在油菜可食部分的富集,降低重金属从土壤向油菜的迁移.总体来看,生物炭配施碳酸钙可以较好地改良土壤、促进植物生长和减少Cd、Pb的富集.     

Spatial distribution of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in soil around a municipal solid waste incinerator

Municipal solid waste incinerators (MSWIs) are usually considered to be important sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). To examine the influence of PCDD/Fs emissions from a MSWI on the surrounding environment, 21 soil samples were collected from various sampling sites distributed at distances of 300–1,700 m away from the stack of a MSWI. International Toxic Equivalent (I-TEQ) concentrations ranged from 0.47 to 2.07 pg I-TEQ g^?1, with average and median concentrations of 1.08 and 1.05 pg I-TEQ g^?1, respectively. Comparison of the results presented herein with other worldwide studies suggested that the concentrations of PCDD/Fs in the ambient soil were relatively low, indicating a limited impact on the surrounding environment. The emission concentrations from the incinerator were the critical factor in generating an environmental impact on the surrounding environment. An exponential function was developed, indicating a slight decline in TEQs of PCDD/Fs with increasing distance from the MSWI stack. The ordinary kriging interpolation technique was selected to create a contour map, which intuitively showed that a limited surrounding area (≤1,000 m from the stack) was obviously influenced by the MSWI.     

财务集约化管理体系下的“一键式”报表管理

针对宁夏电力公司原有财务报表系统存在的业务标准不统一、内部交易手工抵消、 “以表汇表”编报方式等问题,采用财务集约化管理体系下的集团对账功能、协同平台抵销功能及集团内部合并抵销账务处理,实现合并报表“一键式”出具、合并口径及供电局各级报表实时查询分析,确保了“账、证、表”一致及快报数据的实效性和准确性。应用结果表明:“一键式”报表管理模式减少了加工和报送环节,缩短了编制周期,优化了公司财务报告模式,集团报表编报效率和质量大幅提高,会计信息的时效性、透明度显著增强,实现了财务报表编报方式的创新。     

氨法脱硫研究进展

介绍钢铁企业脱硫现状、氨法脱硫工艺流程、反应原理、技术特点和应用情况,分析利用氨法脱除烧结烟气中二氧化硫的优缺点,提出采用焦化氨源可大幅降低成本,并提出烧结脱硫技术发展趋势及建议。     

ZSM-5沸石分子筛吸附-脱附VOCs的性能研究

以不同Si/Al比的ZSM-5分子筛为吸附剂,考察了硅铝比对其疏水性和吸附性能的影响.结果表明,随着Si/Al比的增加,其微孔孔体积和微孔表面积变大,当Si/Al100时,ZSM-5分子筛均具有良好的疏水性和对甲苯的选择性吸附能力,但脱附温度随之升高.同时,以4类VOCs(醇类、酯类、烃类、酮类)为吸附质,研究了ZSM-5分子筛吸附-脱附不同VOCs的性能.发现ZSM-5分子筛由于具有丰富的微孔结构更适合吸附小分子VOCs,对于同类VOCs分子,随着碳数的增加,分子大小和极性均增大,其与分子筛的作用力越强,热脱附温度越高,但VOCs在ZSM-5分子筛表面300℃左右就能脱附完全.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans and polychlorinated biphenyls in surface soil from the Tibetan Plateau

Concentrations of Polychlorinated dibenzo-p-dioxins and dibenzofurans（PCDD/Fs） and polychlorinated biphenyls（PCBs） in soil samples from Tibetan Plateau were determined. The average concentration of total 2,3,7,8-PCDD/Fs was（2.30 ± 1.02） pg/g, and World Health Organization Toxicity Equivalency（WHO-TEQ） average concentration was（0.013 ± 0.010）pg WHO-TEQ/g. The average concentration of ∑PCBs（7 indicator PCB and 12 dioxin like-PCB congeners） was（16.2 ± 9.25） pg/g, and WHO-TEQ average concentration was 0.043 ±0.049 pg WHO-TEQ/g. Comparing to previous studies in similar environmental conditions,PCDD/Fs and PCBs in this study showed a relatively lower concentration. The altitude dependences of PCDD/Fs and PCBs were also studied. Total organic carbon（TOC） normalized concentrations presented a quadratic relation with the altitudes, and an inflection could be found on the parabola of the total concentrations and some congeners of high concentration.The concentrations decreased with altitudes below about 4500 m above sea level（a.s.l.）, while they increased with altitudes above it. These phenomena indicate that cold condensation of PCDD/Fs and PCBs would happen above 4500 m a.s.l, on the Tibetan Plateau.