Soil water characteristics in mountain poplar stand and its benefits to soil and water conservation in loess hilly region

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Impacts of climate change on wheat development and production in the northern China

In this paper, impacts of climate change on wheat development rate and production in the northern China are discussed. The results show that the temperature is a controlling factor of development rate but the precipitation is not. The higher the temperature is. the faster the development and the shorter development period will be. Without consideration to varieties and cropping system, meteorological yield of winter wheat would decrease 170.40, 134.25, 98.70 and 97.20 kg/hm2 in the north China and 13.97, 7.95, 39.60 and 19.80 kg/hm2 in the northwest China compared with that in 1950s, 1960s, 1970s and 1980s, respectively, when the CO2 concentration in the atmosphere is doubled. In drought and semi-drought regions, the spring wheat yield would drop with the temperature rise in and raise with the precipitation increase. The influence of temperature on weight of leaf and stalk is also remarkable.     

灌溉水库群优化调度的AD模型

随着国民经济的不断发展,工农业用水日益增长,但可供利用的水资源有限,使得供水与需水矛盾加剧。因此,对流域内或流域间的水库进行联合调度和管理,将有限的水资源统筹安排、挖掘潜力、充分发挥现有工程的效益、提高供水的保证程度即对水库实施优化调度很有现实意义。本文应用系统分析方法,建立了灌溉水库群优化调度的聚合分解(AD)模型,以保证在系统整体效益最优条件下得出各库的最佳运行策略,从而使水库的运行管理建立在科学的基础之上。     

锰砂表面改性去除酚类化合物的研究

本文叙述了锰砂表面改性(以下简称旧锰砂)处理含酚饮用水的实验研究,陈酚率可达99％。本实验对除酚因素(温度、pH值、流速和接触时间等)进行了实验研究。当进水酚浓度≤2.0mg/l时,经旧锰砂的吸附,可使酚浓度≤0.002mg/l。     

Effect of sorbed and desorbed Zn(Ⅱ) on the growth of a green alga (Chlorella pyrenoidosa)

Toxic effect of Zn(Ⅱ)on a green alga(ChloreUa pyrenoidosa)in the presence of sepiolite and kaolinite was investigated.The Zn-free clays were found to have a negative impact on the growth of C.pyrenoidosa in comparison with control samples(without adding any clay or Zn(Ⅱ)).When Zn(Ⅱ)was added,the algae in the presence of clays could be better survived than the control samples,which was actually caused by a decrease in Zn(Ⅱ)concentration in the solution owing to the adsorption of Zn(Ⅱ)on the clays.When the solution system was diluted,the growth of algae could be further inhibited as compared to that in a system which had the same initial Zn(Ⅱ)concentration as in the diluted system.This in fact resulted from desorption of Zn(Ⅱ)from the zinc-contaminated clays,although the effect varied according to the different desorption capabilities of sepiolite and kaolinite.Therefore the adsorption and desorption processes of Zn(Ⅱ)played an important part in its toxicity,and adsorption and desorption of pollutants on soils/sediments should be well considered in natural eco-environmental systems before their risk of toxicity to aquatic organisms was assessed objectively.     

沈阳市中水回用对策研究及前景分析

为了解决全市水资源严重短缺问题，缓解污水排放对生态环境造成的破坏，沈阳市在今后5～10a内将建成中水回用系统，使城市中水回用率达到50％。结合沈阳市中水回用现状，分析了目前全市中水供应能力及市场需求，进行了2010年相应指标的预测，同时探讨了沈阳市中水回用存在的问题和解决方法。     

位场反演在相山火山岩型铀矿中的应用研究

相山矿田是我国最主要的铀矿资源基地之一,本文介绍了综合利用位、场及场的垂直梯度的物性反演方法的原理与实施,反演计算了相山盆地不同深度下的磁性结构分布特征,最后对相山盆地地下岩层结构及界面变化趋势进行了半定量和定性分析,这对指导相山的铀资源勘查有着重要意义。     

泡沫分离--臭氧消毒装置的水处理效果研究

对闭合循环水产养殖系统中泡沫分离—臭氧消毒装置及泡沫分离装置的水处理效果进行研究。结果表明,泡沫分离—臭氧消毒装置对养殖水体中异养细菌去除率为93.58％,NH_4~ -N、NO_2~--N去除率分别为39.00％、38.10％,能明显提高水体pH和DO,对COD的去除效果不明显;连续运行24h,能有效控制养殖水体中的NO_2~--N浓度和异养细菌数量。泡沫分离装置出水口比进水口的NH_4~ -N、NO_2~--N和COD分别降低42.45％、24.71％、11.00％,能明显提高出水pH和DO;连续运行24h,对养殖系统中的NH_4~ -N和NO_2~--N有一定的处理效果。     

三峡库区小城镇水环境与工业产业结构优化模型——以万州区分水镇为例

以长江上游三峡库区腹部的重庆市万州区分水镇为研究对象,根据2005年分水镇工业各行业的结构特点及各行业对水环境的污染特点,建立水环境--经济工业结构多目标优化模型,选取工业生产总值最大和COD排放量最小作为优化目标,量化分水镇2010年工业结构,选择出符合当地经济发展"十一五"规划目标和水环境保护目标的工业结构优化方案,提出具体的工业产业发展建议,达到减少工业污染物对境内长江次级河流瀼渡河的污染,有效地改善瀼渡河水质状况,同时保证分水镇社会、经济、水环境的可持续发展的目的.文章同时也对三峡库区小城镇的工业产业结构优化调整,获得既符合经济发展目标又满足水环境保护要求的合理的工业产业结构,提供可借鉴的思路和方法.     

利用PCR-DGGE技术分析生物陶粒硝化反应器中微生物群落动态

为了揭示生物陶粒硝化反应器中活性污泥的微生物种群多样性,从运行不同时期的反应器中提取活性污泥,利用PCR-DGGE技术初步分析了生物陶粒反应器细菌的种群演替情况.结果表明,随着进水COD值的逐阶段降低,氨氮去除率逐步提高到64.38%.群落结构和优势种群的数量具有时序动态性,微生物多样性与废水的处理效果出现协同变化的特征.测序结果表明,生物陶粒反应器中运行第21天的优势种群除了自养细菌,还有异养细菌存在.其中自养细菌为Nitrosospira.sp和Nitrobacter.sp,异养细菌为Bacillus.sp、Pseudomonas.sp和Pseudochrobactrum.sp.