Investigation of environmental and land use impacts in forested permafrost headwaters of the Selenga-Baikal river system,Mongolia - Effects on discharge,water quality and macroinvertebrate diversity

Headwater streams play a major role for provision of ecosystem services, e.g. drinking water. We investigated a high-altitude headwater catchment of the Kharaa River (including 41 1st-order rivers) to understand the impact of land cover (especially forest cover), environment and human usage on runoff, chemical water quality and macroinvertebrate fauna in a river basin under discontinuous permafrost conditions in an arid, sparsely populated region of Mongolia. To verify our hypotheses that different landuses and environmental impacts in permafrost headwaters influence water quality, we investigated 105 sampling sites, 37 of them at intermittent stream sections without water flow. Discharge was positively impacted by land cover types steppe, grassland and forest and negatively by shrubland, forest burnt by wild fires (indicating a reduction of permafrost) and slope. Water quality was affected by altitude, longitude and latitude, shrub growth and water temperature. Shannon diversity of macroinvertebrates was driven by water temperature, iron content of the water, flow velocity, and subbasin size (adjusted R² = 0.54). Sample plots clustered in three groups that differed in water chemistry, macroinvertebrate diversity, species composition and bio-indicators. Our study confirms that steppes and grasslands have a higher contribution to runoff than forests, forest cover has a positive impact on water quality, and diversity of macroinvertebrates is higher in sites with less nutrients and pollutants. The excellent ecological status of the upper reaches of the Kharaa is severely threatened by forest fires and human-induced climate change and urgently needs to be conserved.     

独立学院“生物化学”综合性实验的开设

从综合性实验内容、综合性实验开设对人才培养目标的体现、综合性实验实施过程中的注意事项等方面阐述如何在“生物化学”课程中开设综合性实验“聚丙烯酰胺凝胶电泳分离蛋白及蛋白质含量的测定”。此实验的开设,可使学生将理论知识融会贯通,对培养学生的动手能力和创新能力有积极作用。     

浅谈修购专项实施方案编制常见的问题及建议

中央级科学事业单位修缮购置专项项目实施方案是项目预算执行、监督检查、项目验收和绩效考评的重要依据。因此，编制实施方案是一项非常重要的基础性工作，其编制质量直接影响项目获批的金额、后期实施和项目验收。文章阐述了修购专项实施方案、基建项目初步设计和修购专项申报书的区别，结合项目实施方案编制实践，简单分析了实施方案编制中的常见问题、原因并针对原因提出了针对性的建议。     

空气罐与超压泄压阀联合水锤防护特性

提出了一种空气罐与超压泄压阀联合设置的停泵水锤防护方案,并基于瞬变流计算的特征线法建立了空气罐、液控蝶阀、超压泄压阀等边界条件的数学模型,模拟了停泵工况下系统的压力变化过程.结合工程实例,对比分析了空气罐单独防护、空气罐与两阶段关闭泵后液控蝶阀联合防护以及空气罐与超压泄压阀联合防护对停泵水锤的影响.在空气罐体型一定时,对超压泄压阀的启闭规律进行了敏感性分析.计算结果表明,空气罐与两阶段关闭泵后液控蝶阀联合防护方案对输水系统正负水锤防护均不利;而空气罐与超压泄压阀联合防护方案对输水系统正负水锤均有较好的防护效果,与空气罐单独防护方案相比,泵后高压管段最高压应力由1.343 MPa降至1.087 MPa,在满足承压标准1.2 MPa的基础上安全裕度提高了9.4%,空气罐体型也由200 m³缩减至160 m³.超压泄压阀应在5 s内开启至全开度,且开启后持续时间应接近1个相长.     

农业生产基地项目环境影响评价要点分析及探讨

农业生产基地项目具有影响范围大、产品服务多元化等特点，涉及行业类别较多，其环境影响评价文件也相对复杂。环境影响评价报告编制单位应充分与建设方进行沟通，熟悉项目建设内容，挖掘项目可能的产生污染的环节和设施，明确环境影响范围和环境敏感点，并对项目损益进行两方面的分析。     

Phosphorous accumulation and distribution of two ecotypes of Pilea sinofasciata grown in phosphorous-enriched soils

Water eutrophication and poultry manure require an efficacious remediation technology to decrease phosphorous (P) concentration. In this study, the P phytoremediation potential of a mining (ME) and nonmining ecotype (NME) of Pilea sinofasciata were analyzed by pot experiments employing different concentrations of P treatments (CK, P100, P200, P400, P800 and P1600) in tested soil. Growth, P accumulation and P-relevant enzyme activities of P. sinofasciata in ME and NME were assessed after 10 weeks’ plantation. The results showed that there was no significant difference between the shoot biomass of the ME and NME. Higher P concentration and accumulation were observed in the ME than NME for all treatments. Stem P concentration of the ME were 117%, 189%, 152%, 153%, 140% and 139% higher than the NME, and leaf P concentration were 122%, 146%, 138%, 144%, 137% and 113%. Maximum P uptake and phytoextraction was observed at P400 for the ME of P. sinofasciata. Elevated activities of acid phosphatase and phytase in roots were examined in P-enriched soil, and the ME presented higher activities compared with the NME. The results in this paper provide a theoretical basis for the use of ME of P. sinofasciata for phosphorus accumulators and suggest that ME of P. sinofasciata is a promising species for the excess P phytoextraction of P-enriched soils.     

秸秆沼气集中供气工程运行管理维护研究

文章针对凤凰村秸秆沼气集中供气工程运行管理维护中存在的问题,进行分析并提出了相应的解决办法,为今后秸秆沼气集中供气工程建设及运营提供经验和借鉴。     

论继续推进沿海防护林体系工程建设的必要性

全国沿海防护林体系二期工程建设规划将于2015年完成,通过二期规划建设,工程取得了巨大成就,但依然存在较大增长空间和发展潜力,为了贯彻落实生态文明建设总体要求,进一步推动沿海防护林持续快速发展,充分发挥其生态、经济和社会效益,从八个方面对继续推进沿海防护林体系工程建设的必要性进行了论述,以期引起各级政府部门的高度重视和全社会关注,并尽早出台沿海防护林体系工程后期有关建设规划。     

对提高农业院校科技成果转化效率的若干思考

首先分析了现阶段中国农业院校提高农业科技成果转化效率的现实意义,在此基础上以中国H农业大学为例,深入研究了中国农业院校在农业科技成果转化工作中存在的问题,并针对性地提出了解决对策。     

基于自压滴灌工程过滤装置尺寸的确定及应用

由于新疆牧业灌区无电供应,水源无法过滤,实现滴灌工程难,目前采用地面灌溉。地形坡度大、灌水量多、大量水土流失。灌区下游排水不畅,洼地沼泽化面积剧增,地下水位上升导致土壤盐碱化,弃田面积逐渐扩大、种植面积萎缩。为了解决上述问题,充分利用地形落差,研制了自压滴灌工程过滤装置。同时渠道进水流量、调水池的调节流量、集水桶流量及系统流量之间建立了平衡关系。用实例说明不同地形落差与自压滴灌工程系统流量及过滤装置尺寸的计算过程。解决了自压滴灌工程水源的过滤、排沙、冲沙及自行冲洗等问题。为无电牧业灌区实现节水灌溉技术提供依据。