An asymmetric analysis of the impacts of energy use on carbon dioxide emissions in the G7 countries

Environmental Science and Pollution Research - The foremost theme of the paper is to explore the asymmetric/symmetric impact of energy consumption on the carbon dioxide emission of G7 countries...     

Preparation and Characterization of Collagens from the Skin of Northern Snakehead (<Emphasis Type="Italic">Channa argus)</Emphasis>

Channa argus, a type of snakehead fish native to China, is a popular food fish in certain Asian countries but is a known destructive invasive species in the US. In this study, the two collagens, i.e. acid-soluble collagen (ASC) and pepsin-solubilized collagen (PSC), were obtained from C. argus skin. The yield of ASC was 28.0% and that of PSC was 16.8% on the dry bases. The collagens were identified as the collagen of type I by SDS–PAGE patterns. The Tds were approximately 27.0?°C. Similar ultraviolet spectra of both collagens were observed. Fourier Transform infrared spectra indicated PSC structure had a little change due to the loss of terminal domains by pepsin digestion. The results of XRD proved that the two collagens retained their helical structures. The results suggest that the collagens isolated from C. argus can potentially be alternative sources of vertebrate collagens for use in the food and other industries.     

我国生态环境保护重大工程项目管理制度现状及存在的问题

生态环境重大工程项目是中国生态环境保护规划实施的重要抓手,工程实施与管理的科学性和可行性是提高资金使用效率和确保项目发挥环境效益的关键,因此,系统构建生态环境保护重大工程项目管理制度具有必要性和现实意义。结合国家现行政策,在实际调研的基础上,梳理了现有生态环境保护重大工程项目管理制度,分析了地方重大工程项目管理现状,识别了目前生态环境保护重大工程项目管理的存在问题,据此提出了完善生态环境保护重大工程项目制度的建议框架,以期为实现新时代生态环境保护目标提供支撑。     

Effect of Soybean Cultivation on Soil Collembola Community in Marshland of Sanjiang Plain,China

The Sanjiang Plain, the largest inland freshwater marshland in China, was extensive reclaimed into agricultural land. To assess the effects of marshland reclamation on Collembola, we investigated collembolan communities in a chronosequence of soybean plantations (2, 15, and 25 years) in Sanjiang marshland, Northeastern China. We found that: 1) the densities and species richness of Collembola were promoted after short-term (2 years) cultivation of soybean, but significantly decreased after medium-term cultivation (15 years); 2) the densities of epi-edaphic Collembola increased while the densities of hemi-edaphic Collembola decreased as the elongation of soybean cultivation; 3) compared with S0, two species of Collembola appeared while five species disappeared in S25. The changes of plant communities and the soil traits were supposed to be the key factors affecting the composition of soil Collembola. We thus suggest that original marshland should be saved for preserving high diversity and densities of Collembola in the Sanjiang Plain.

     

CePO4-TiO2固溶体的NH3-SCR活性

采用共沉淀法合成了不同Ce与Ti摩尔比的CePO₄-TiO₂复合材料,利用XRD、TEM、NH₃-TPD和H₂-TPR技术对其物理化学性质进行了表征,并对其NH₃-SCR活性进行了评价。实验结果表明：随着CePO₄含量的增加,催化剂的活性提高;当Ce与Ti的摩尔比为8:2时催化剂的活性最高,230 ℃的NO转化率达到100%,且具有更广的温度窗口,优于纯CePO₄。表征结果显示,CePO₄与TiO₂形成固溶体后,颗粒尺寸较为均匀,强酸位的数量增多,氧化还原性能提升,从而提高了催化剂的SCR反应活性,同时改善了其抗水抗硫性能。     

组织支持感对建筑业农民工不安全行为的影响*

为对建筑业农民工的不安全行为进行科学有效的管理，探讨组织支持感、自我效能感与建筑业农民工不安全行为之间的关系，防止因建筑业农民工不安全行为造成的不安全事件发生，从组织行为学和计划行为学视角出发，以218名一线建筑业农民工为研究对象，通过构建结构方程模型进行实证分析。结果表明:组织支持感的3个维度均可直接对建筑业农民工的不安全行为产生负向显著影响，其中关心利益维度影响最大，工作支持维度次之；建筑业农民工的自我效能感在其组织支持感与不安全行为的负向关系中起到中介作用。     

基于改进模体方法的国家应急组织合作网络基元比较

为分析和比较应对非常规突发事件过程中，由不同类型组织个体及其不同频次合作关系构成的应急复杂组织网络的微观结构特征，研究运用表征个体差异和关系强弱的改进模体分析方法，以中国和美国国家应急组织合作网络为例，比较分析其基元同构与异构特征。结果表明:中美应急组织系统不同类型的应急主导和支持组织构成的主要合作模式具有同构性，但子图结构数量分布具有异构性；考虑个体间关系频次差异，中美应急组织网络基元合作模式具有形式同构但相对数量分布异构的特征；比较而言，美国合作网络为分布式、分权化和关系型基元构型，中国合作网络具有集中式、集权化和契约型基元特征。     

液液萃取-气相色谱法测定水质可萃取性石油烃C10~C40

建立了以环己烷为萃取剂、气相色谱法(氢火焰离子化检测器,FID)测定水质样品中可萃取性石油烃(C_(10)～C_(40))的分析方法。以正构烷烃混合标准溶液为定性和定量校准标准,以色谱峰面积总和与混合标准溶液总浓度建立校准曲线进行外标法定量。方法检出限为0.01 mg/L,经验证方法精密度和准确度良好。同时,分别以气相色谱法和红外光度法测定了地表水、污水处理厂出水、海水和化工废水等实际样品,对比实验结果表明,在可萃取性石油烃C_(10)～C_(40)的碳数范围内,气相色谱法的测试结果与红外光度法无明显差异,有较好的可比性。     

MoS_2/Bi_2S_3异质结光催化剂的制备及其光催化性能

以五水硝酸铋为铋源、钼酸钠为钼源、硫脲为硫源,采用简单的一步水热法合成了MoS_2/Bi_2S_3异质结光催化剂,采用XRD,SEM,TEM,BET,UV-Vis DRS技术对其进行了表征。表征结果显示,MoS_2纳米片在Bi_2S_3微棒表面生长,增加了比表面积和活性位点,并形成异质结构,促进了光生载流子的迁移,抑制了电子-空穴对的再复合。实验结果表明:钼酸钠与五水硝酸铋的质量比为1∶2时制备的复合光催化剂性能最好,反应180min时对亚甲基蓝的去除率可达96.4%,明显高于MoS_2和Bi_2S_3,且具有较高的稳定性;该催化剂对罗丹明B、甲基橙和4-硝基苯酚的去除率分别为97.1%、93.1%和90.5%,表明其对污染物具有普适性。