以人为本 开创高校工会工作新局面

认真落实科学发展观,以科学发展观统领工会工作,必须体现在党对工会工作的要求上,体现在准确全面履行好工会的职责上,从而充分发挥工会在支持改革开放、促进经济发展、推动社会进步中的积极作用。     

River channel network design for drought and flood control: A case study of Xiaoqinghe River basin, Jinan City, China

Vulnerability of river channels to urbanization has been lessened by the extensive construction of artificial water control improvements. The challenge, however, is that traditional engineering practices on isolated parts of a river may disturb the hydrologic continuity and interrupt the natural state of ecosystems. Taking the Xiaoqinghe River basin as a whole, we developed a river channel network design to mitigate river risks while sustaining the river in a state as natural as possible. The river channel risk from drought during low-flow periods and flood during high-flow periods as well as the potential for water diversion were articulated in detail. On the basis of the above investigation, a network with “nodes” and “edges” could be designed to relieve drought hazard and flood risk respectively. Subsequently, the shortest path algorithm in the graph theory was applied to optimize the low-flow network by searching for the shortest path. The effectiveness assessment was then performed for the low-flow and high-flow networks, respectively. For the former, the network connectedness was evaluated by calculating the “gamma index of connectivity” and “alpha index of circuitry”; for the latter, the ratio of flood-control capacity to projected flood level was devised and calculated. Results show that the design boosted network connectivity and circuitry during the low-flow periods, indicating a more fluent flow pathway, and reduced the flood risk during the high-flow periods.     

SO2对Ag/Al2O3催化剂上CH3OH还原NO性能的影响

用溶胶-凝胶混合法制备了Ag负载量为5%的Ag/A1₂O₃催化剂.研究了富氧条件下,SO₂对CH₃OH在催化剂上还原NO性能的影响.结果表明,反应气不含SO₂和H₂O时,NO还原活性温度较低,有显著量N₂O生成,这被归因为反应过程中,部分氧化态Ag被还原为金属Ag.添加SO₂或同时添加SO₂和H_{2相似文献}   

三江源生态移民对草地资源依赖性分析

基于移民、牧民访谈和问卷调查,对青海三江源泽库县生态移民的生活情况进行调查,分析移民对草地资源依赖性变化,以了解生态移民政策的成效与不足,并探讨现有政策中存在的相关问题,对三江源生态补偿政策和制度的制定完善提供参考和研究基础。研究结果显示:生态移民家庭经济收入有所提高,畜牧业收入占家庭总收入比例下降,生态补偿、务工、经商对于家庭收入的作用已明显显现。移民家庭从事畜牧业降为20.1%,务工家庭增加到37%,30.5%的移民参加过技能培训,但能源使用经济负担有所增加。53.90%的牧民愿意移民,但对移民后就业及生活设施建设仍有较大顾虑。总体而言,生态移民生活整体情况有所改观,移民后草地资源不再是家庭主要收入的基础。政府应完善技能培训体系,加快后续产业培育,重视生态移民工程前期规划,加大生态补偿资金支持力度。     

东北农牧交错带典型区土地利用变化及其生态效应

东北农牧交错带是典型的生态环境脆弱区，具有敏感性强、退化趋势明显等生态脆弱性特征。本文利用1986、2002年两期TM/ETM影像，揭示了吉林西部16年来土地利用／覆被的时空变化规律，并依据Costanza R．等人对全球生态系统服务价值的评估方法。分析了土地利用变化对区域生态系统服务价值的影响。结果表明：16年来，吉林西部土地利用／覆被发生了剧烈变化。耕地、盐碱地面积大幅度增加，草地、水域和湿地的面积大幅度减少，区域生态系统服务功能出现明显的衰退。生态系统服务价值显著地减少。吉林西部生态系统服务价值由1986年的767．1亿元／a下降到2002年的624．1亿元／a，减少幅度达18．6％，年均递减速率达1．6％。16年来该区域生态环境恶化和以经济利益为目的的土地利用结构调整，给区域生态系统服务功能和可持续发展能力带来巨大负面影响。     

国内外可持续发展评价方法对比分析

国际、国内很多组织都对可持续性评价方法进行过研究分析,但大多是特定的案例研究.目前国内外对可持续发展评价方法没有一个全面系统的分析比较,使得不同地区比较起来很困难.本文对各种评价方法如环境可持续性指数法、生态足迹法、能值分析法和指标综合评价法的来源、理论和应用作了介绍.得出各方法适用范围:可持续性指数法适合于国家间的综合评价;生态足迹和能值分析法适合于各种范围,包括国家、区域、地区和小系统;指标体系综合评价法对于小范围更合适.同时对各种方法的优势和缺陷进行了分析讨论,得出:可持续性指数法信息量大,但是计算复杂;生态足迹法计算过程简单,但是缺失一些可持续性信息;能值分析法考虑问题全面,但是其原理涉及热力学知识,很难被一些学者认同;指标体系评价法变通性较大,可随着评价系统的变化而进行调整,但是主观性较强.通过分析指出不同方法适用范围并指出每种分析方法的优势和不足,为以后选择合适的分析方法评价对象的可持续性提供依据.     

二段生物接触氧化工艺在中水回用中的特性研究

以规模小区生活污水为水源,对采用聚丙烯网状填料和强化炉渣组合填料的二段生物接触氧化工艺（以下简称二段法）进行了试验研究,试验针对本工艺的各项技术指标、影响因素以及各相关参数进行了较系统的试验测试。结果表明,反应器在第一接触氧池HRT为20 min、气水比为6∶1和第二接触氧池HRT为25 min、气水比为5∶1条件下,接触氧化池达到最佳降碳条件;反应器在第一接触沉池上升流速5.5 m/h和第二接触沉池上升流速4.5 m/h条件下,接触沉淀池达到最佳处理条件。     

Eco-environmental water demands for the Baiyangdian Wetland

In recent years, the hydrological characters of Baiyangdian Wetland have changed greatly, which, in turn, influence the biotic component, the structure and function of the wetland ecosystem. In order to determine the demands for water resources of ecological wetland system, a method of ecological water level coefficient was suggested to calculate the water resources demands for wetland environment use. This research showed that the minimum coefficient is 0.94 and the optimal coefficient is more than 1.10. According to these two coefficients, the ecological water level and water quantity can be estimated. The results indicate that the amount of the minimal and optimal eco-environmental water requirements are 0.87 × 10⁸ and 2.78 × 10⁸ m³ in average monthly, respectively, with the maximum eco-environmental water requirement in summer and the minimum in winter. The annual change of eco-environment water demand is in according with the climate change and hydrological characters. The method of ecological water level emphasizes that wetland ecosystem adapts to the hydrological conditions, so it can be used in practice well.     

Interspecific association among main plant species in the unstable slope with high-frequency debris flow北大核心CSCD

To determine the characteristics of vegetation community structure and the relationship between species in the frequent watersheds of debris flow in fragile ecological environments, based on sample survey and 2 × 2 joint table techniques, we used analysis of variance test, χ2 test, Jaccard index, Pearson correlation coefficient, and Spearman's rank correlation coefficient test to study the main plant species correlations in the stable zone, instable zone, and deposit zone of the unstable slope. The analysis of variance test showed that all 45 species pairs had a significant negative correlation in the stable zone and instable zone, whereas there was no significant negative correlation in the deposit zone, which showed that the species had an independent distribution trend. The results from the different tests showed that there were 1 pair, 4 pairs, and 4 pairs from the stable zone, instable zone, and deposit zone, respectively, which had significant interspecific association under the χ2 test and the ratios of positive correlation pairs to negative correlation pairs were 0.55, 0.67, and 0.67 in the stable zone, instable zone, and deposit zone, respectively. There were 8 pairs, 5 pairs, and 5 pairs from the stable zone, instable zone, and deposit zone, respectively, which had significant interspecific association from the Pearson correlation analysis test, and the ratios of positive correlation pairs to negative correlation pairs were 0.36, 0.45, and 0.45 in the stable zone, instable zone, and deposit zone, respectively. There were 10 pairs, 6 pairs, and 9 pairs from the stable zone, instable zone, and deposit zone, respectively, which had significant interspecific association from the Spearman's rank correlation analysis test and the ratios of positive correlation pairs to negative correlation pairs were 0.5, 0.55, and 0.6 in the stable zone, instable zone, and deposit zone, respectively. The three test results showed general similarities but there were some differences. Most species pairs did not reach a significant level in the three zones and the number of negatively related species was more than the number of positively related species. In brief, this loose interspecific relationship indicates that the entire plant community was not stable, and the interspecific relationships among species are susceptible to environmental interference in the ecologically fragile areas of the debris flow basin. Therefore, rational selection and configuration of species should be applied to promote community structure development and ecological environmental improvement in vegetation restoration process areas with high-frequency debris flow. © 2018 Science Press. All rights reserved.     

Arsenic sorption by red mud-modified biochar produced from rice straw

Red mud-modified biochar (RM-BC) has been produced to be utilized as a novel adsorbent to remove As because it can effectively combine the beneficial features of red mud (rich metal oxide composition and porous structure) and biochar (large surface area and porous structure properties). SEM-EDS and XRD analyses demonstrated that red mud had loaded successfully on the surface of biochar. With the increasing of pH in solution, arsenate (As(V)) adsorption on RM-BC decreased while arsenite (As(III)) increased. Arsenate adsorption kinetics process on RM-BC fitted the pseudo-second-order model, while that of As(III) favored the Elovich model. All sorption isotherms produced superior fits with the Langmuir model. RM-BC exhibited improved As removal capabilities, with a maximum adsorption capacity (Q_max) for As(V) of 5923 μg g^?1, approximately ten times greater than that of the untreated BC (552.0 μg g^?1). Furthermore, it has been indicated that the adsorption of As(V) on RM-BC may be strongly associated with iron oxides (hematite and magnetite) and aluminum oxides (gibbsite) by X-ray absorption near-edge spectroscopy (XANES), which was possibly because of surface complexation and electrostatic interactions. RM-BC may be used as a valuable adsorbent for removing As in the environment due to the waste materials being relatively abundant.