Enantioselective effects of imazethapyr residues on Arabidopsis thaliana metabolic profile and phyllosphere microbial communities

Imazethapyr (IM) is a widely used acetolactate synthase-inhibiting chiral herbicide. It has long-term residuals that may be absorbed by the human body through the edible parts of plants, such as vegetable leaves or fruits. Here, we selected a model plant, Arabidopsis thaliana, to determine the effects of R-IM and S-IM on its leaf structure, photosynthetic efficiency, and metabolites, as well as the structures of microorganisms in the phyllosphere, after 7 days of exposure. Our results indicated enantiomeric differences in plant growth between R-IM and S-IM; 133 µg/kg R-IM showed heavier inhibition of photosynthetic efficiency and greater changes to subcellular structure than S-IM. R-IM and S-IM also had different effects on metabolism and leaf microorganisms. S-IM mainly increased lipid compounds and decreased amino acids, while R-IM increased sugar accumulation. The relative abundance of Moraxellaceae human pathogenic bacteria was increased by R-IM treatment, indicating that R-IM treatment may increase leaf surface pathogenic bacteria. Our research provides a new perspective for evaluating the harmfulness of pesticide residues in soil, phyllosphere microbiome changes via the regulation of plant metabolism, and induced pathogenic bacterial accumulation risks.     

电磁防护技术和防护装备

电磁辐射(EMI)污染已被公认为大气污染、水质污染、噪音污染之外的第四大公害，电视广播发射塔、雷达站、通信发射台、变电站、高压电线，还有电脑、手机、微波炉、电磁灶，甚至我们乘坐的地铁列车等等都能制造电磁辐射污染。它无色、无味、无形，可以穿透包括人体在内的多种物质，人体如果长期暴露在超过安全的辐射剂量下，细胞就会被大面积杀伤或杀死，从而引发多种疾病。     

微生物法处理含铬(Ⅵ)废水的研究

采用硫酸盐还原菌处理含铬(Ⅵ)废水，研究了其去除铬(Ⅵ)的最适宜工艺条件。实验表明，该菌的适用范围广，处理含铬废水的能力强。在菌液与废液体积比为1．0：1、铬(Ⅵ)质量浓度为150mg／L条件下处理36h，铬(Ⅵ)去除率达99．9％。     

冷原子荧光法测定水中痕量汞的改进

对冷原子荧光法测定地表水及工业废水中汞的分析处理方法提出改进措施，改进的方法准，快，简，省，符合监测规范要求。     

水温及污泥龄对生物处理系统运行的影响

水温和污泥龄对硝化作用有着重要的影响；水温和污泥龄对污泥增长量也起着主导性作用。指出水温对难降解程度有重大影响。     

锌对酒精发育毒性的拮抗作用

孕期饮酒导致胚胎和胎儿出生前后一系列机体发育异常及功能缺陷，孕期饮酒还可导致微量元素锌大量丢失。该文应用已建立的体外酒精致畸模型，以全胚胎培养技术探讨了锌对酒精发育毒性的拮抗作用。结果表明，２μｇ／ｍｌ的锌，对２００ｍｇ／ｄｌ的酒精所致的胚胎生长发育指标无明显作用；５μｇ／ｍｌ锌，能显著改善胚胎的蛋白质、ＤＮＡ含量、ＶＹＳ直径等指标；１０μｇ／ｍｌ锌，对胚胎的生长发育和胚胎器官形态分化无明显改善作     

Purification function of the natural wetland in the Liaohe Delta

１ＩｎｔｒｏｄｕｃｔｉｏｎＳｔｒｕｃｔｕｒｅ，ｆｕｎｃｔｉｏｎａｎｄｃｈａｎｇｅａｒｅｔｈｒｅｅｉｍｐｏｒｔａｎｔａｓｐｅｃｔｓｏｆｌａｎｄｓｃａｐｅｅｃｏｌｏｇｙ（Ｆｏｒｍａｎ，１９８６）．Ｌａｎｄｓｃａｐｅｆｕｎｃｔｉｏｎｍｅａｎｓｔｈｅｉｎｔｅ...     

Plant-trait-based modeling assessment of ecosystem-service sensitivity to land-use change

Evidence is accumulating that the continued provision of essential ecosystem services is vulnerable to land-use change. Yet, we lack a strong scientific basis for this vulnerability as the processes that drive ecosystem-service delivery often remain unclear. In this paper, we use plant traits to assess ecosystem-service sensitivity to land-use change in subalpine grasslands. We use a trait-based plant classification (plant functional types, PFTs) in a landscape modeling platform to model community dynamics under contrasting but internally consistent land-use change scenarios. We then use predictive models of relevant ecosystem attributes, based on quantitative plant traits, to make projections of ecosystem-service delivery. We show that plant traits and PFTs are effective predictors of relevant ecosystem attributes for a range of ecosystem services including provisioning (fodder), cultural (land stewardship), regulating (landslide and avalanche risk), and supporting services (plant diversity). By analyzing the relative effects of the physical environment and land use on relevant ecosystem attributes, we also show that these ecosystem services are most sensitive to changes in grassland management, supporting current agri-environmental policies aimed at maintaining mowing of subalpine grasslands in Europe.     

浅析变压器发生火灾、爆炸的原因

变压器是利用电磁感应原理，把交流电能转变为不同电压、电流等参数的另一种电能的设备。油浸式变压器（以下变压器都指油浸式变压器）内部的绝缘衬垫和支架，大多采用纸、棉纱、布、木材等有机可燃物质，并有大量的绝缘油，     

The Impact of Changes of Property Rights on Farmland Use： An Empirical Study of China during Transition

In China, farmland property rights characterized by the household-responsibility system （HRS） have been improved since the reform and opening-up. The rights of use, transfer and gain become more stable, authorized and complete. This paper firstly analyzes the impact on farmland productivity, which comes from the improvement of farmland property rights. Then, an economet-ric model is built to test the above analysis. It concludes that changes of property rights will affect farmland performance in China. In the end, some policy implications are explored for fur-ther reforms.