Abiotic control on the dissipation of chlorpyrifos spiked in an Udic Ferrisol at a lower dosage

The dissipation routes of chlorpyrifos spiked in an Udic Ferrisol at the dosage of 400 ng g^?1, which represents a residual level after an agricultural application, were studied in a laboratory, using the natural soil under three moisture regimes, sterilised, and organic matter-free soils in the dark at 20°C. The obtained results showed that higher soil moisture caused faster dissipation, and the abiotic and biotic contributions to the total dissipated amount of the applied chlorpyrifos in the soil accounted for 77.3–85.2% and 14.7–22.7%, respectively. In the sterilised soil, the contribution of organic matter to chlorpyrifos dissipation was noticed to account for 95% in the earlier two weeks, and was nearly equal to that of soil minerals two weeks after the incubation.     

O3对水稻叶片氮代谢、脯氨酸和谷胱甘肽含量的影响

臭氧(O3)被认为是重要的气污染物之一,水稻又是主要的粮食作物,因而准确地评估O3浓度升高对水稻生长发育的影响具有十分重要的意义。采用开顶式气室法模拟研究了O3对水稻叶片可见伤害症状、氮代谢、脯氨酸和谷胱甘肽含量的影响。结果显示,O3污染胁迫会导致水稻叶片产生明显的伤害症状,具体表现为:老叶叶鞘褪绿,有褐斑,直至完全干枯;稻穗小且黄化,籽粒不饱满;水稻成熟期提前等。O3浓度升高对水稻叶片的硝酸还原酶活性有显著影响。当O3浓度为40、80和120nL.L-1时,水稻叶片硝酸还原酶活性与对照组相比均降低,其中,分蘖期分别降低了25.3%、67.4%和86.3%;拔节期分别降低了57.4%、75.7%和97.8%;抽穗期分别降低了91.0%、97.2%和99.3%;乳熟期分别降低了89.5%、89.5%和96.7%。水稻叶片铵态氮和硝态氮含量随着O3浓度的升高而显著地降低,例如当O3浓度为40、80和120nL.L-1时,与对照相比,水稻叶片硝态氮含量分别降低46.3%、52.7%和65.7%,铵态氮含量分别降低6.5%、12.9%和43.4%。O3污染胁迫下水稻叶片脯氨酸含量在不同生长期变化不同,分蘖期、拔节期和抽穗期脯氨酸含量在40nL.L-1浓度O3熏蒸下急剧地提高,但是随着O3浓度的增加,脯氨酸含量又不断地降低。在水稻乳熟期,脯氨酸含量均随着O3浓度的增加而显著地下降。O3污染胁迫导致水稻叶片还原型谷胱甘肽(GSH)含量显著低于对照组,而氧化型谷胱甘肽(GSSG)含量显著高于对照组。当O3浓度为40、80和120nL.L-1时,乳熟期水稻叶片GSH含量分别比对照组降低68.7%、80.2%和78.2%,GSSG含量分别比对照提高494.4%、527.2%和439.8%。研究表明,O3污染胁迫对水稻叶片氮代谢和抗氧化系统产生了极显著的影响。     

Emission factors of gaseous carbonaceous species from residential combustion of coal and crop residue briquettes

Experiments were performed to measure the emission factors (EFs) of gaseous carbonaceous species, such as CO₂, CO, CH₄, and non-methane volatile organic compounds (NMVOCs), from the combustion of five types of coal of varying organic maturity and two types of biomass briquettes under residential burning conditions. Samples were collected in stainless steel canisters and 2,4-dinitrophenylhydrazine (DNPH) cartridges and were analyzed by GC-FID/MS and HPLC, respectively. The EFs from crop residue briquette burning were generally higher than those from coals, with the exception of CO₂. The dominant NMVOC species identified in coal smoke were carbonyls (41.7%), followed by C2 unsaturated hydrocarbons (29.1%) and aromatics (12.1%), while C2 unsaturated hydrocarbons were the dominant species (68.9%) emitted from the combustion of crop residue briquettes, followed by aromatics (14.4%). A comparison of burning normal crop residues in stoves and the open field indicated that briquettes emitted a larger proportion of ethene and acetylene. Both combustion efficiency and coal organic maturity had a significant impact on NMVOC EFs from burning coal: NMVOC emissions increased with increasing coal organic maturity but decreased as the combustion efficiency improved. Emissions from the combustion of crop residue briquettes from stoves occurred mainly during the smoldering process, with low combustion efficiency. Therefore, an improved stove design to allow higher combustion efficiency would be beneficial for reducing emissions of carbonaceous air pollutants.     

潖江蓄滞洪区洪灾风险分析及避难转移安置研究

以潖江蓄滞洪区洪灾避难转移安置为研究对象,利用Mike21技术,建立潖江蓄滞洪区洪水演进数值模型,模拟北江遭遇300年一遇洪水时,在潖江口泄洪,潖江蓄滞洪区内洪水演进,分析潖江蓄滞洪区洪灾风险.通过实地调查,结合历史洪水情况,利用潖江蓄滞洪区DEM数据、Google地图及最快避难转移安置时间分析法,详细设计了潖江蓄滞洪区内各行政村落遭遇洪灾时避难转移与人员安置,为潖江蓄滞洪区启用预案科学编制及防洪减灾提供科学依据.     

零价纳米铁对大肠杆菌的毒性效应

以大肠杆菌为研究对象,通过检测尺寸为20 nm的零价纳米铁暴露下大肠杆菌形貌、生长曲线和细胞内酶活性的变化,研究了零价纳米铁对大肠杆菌的毒性效应,并探讨了其可能的毒性机制.用透射电镜(TEM)观察零价纳米铁与大肠杆菌(JM109)接触后细胞的形态变化;用0、112、560和1 120 mg·L-1的零价纳米铁染毒大肠杆...     

Municipal solid waste management in Dalian: practices and challenges

The fast growing of urban areas in developing countries has brought serious problems on municipal solid waste (MSW) management. It will be rational to adopt an integrated approach to deal with such a challenge so that the overall eco-efficiency of MSW management could be improved. To better examine how attributes of integrated MSW management are being interpreted and put into practice, and to explore what changes should be made to improve the application of integrated MSW management, we employ a case study method so that lessons learned could be used to inform initiatives in other cities and the potential solution may offer feasible strategies. The case study city is Dalian, a typical seaport city with fast growing rate in economy. The outcomes of this case study show us that fragmented management structure, ineffective and inefficient enforcement of relevant regulations, backward technologies, limited financial resources and lack of public participation are main barriers for the implementation of integrated MSW management. Consequently, in order to overcome these barriers, we propose an integrated management framework on MSW management, aiming to maximize the overall eco-efficiency of MSW management.     

长期棉花连作对北疆棉区土壤生物活性与酶学性状的影响

以长期连作棉田为研究对象,通过对5-15年连作棉田土壤理化性质和生物学性状的测定,揭示北疆长期连作对土壤主要肥力性质、土壤酶活性、微生物量碳氮以及土壤呼吸的影响。结果表明：长期棉花（Gossypium spp）连作对土壤肥力性状影响显著,表层土壤（0-20cm）肥力明显高于亚表层（20-40cm）。长期棉花连作对土壤酶活性、微生物量碳氮、土壤呼吸等生物活性有显著影响,脲酶、碱性磷酸酶、β-葡萄糖苷酶、纤维素酶和多酚氧化酶均随棉花连作年限增加而下降,棉花/苜蓿（Medicago sativa Linn）轮作（CtR-AR）处理各酶酶活性均高于棉花连作处理。微生物量碳（MBC）随棉花连作年限逐渐下降,而微生物量氮（MBN）随不同棉花连作年限并无一致性变化。不同棉花连作年限处理之间的呼吸商（q（CO2））有很大的差异,15年棉花连作非病区（CtN15）土壤呼吸商最高为19.00g？mg-1？h-1,CtR-AR处理的呼吸商最低为13.64g？mg-1？h-1。土壤微生物商随棉花连作年限延长呈现下降趋势,CtN15处理出现最低值,为0.81%。随棉花连作年限增加,土壤微生物活性降低,不利于土壤健康持续利用。     

The Effect of Protective Gloves on Manual Dexterity in the Cold Environments

This article presents a study on the effect of different protective gloves (which are commercially available and commonly used in the cold) on manual dexterity in cold environments. The experiments compared statistically four different types of gloves and two different types of gloving (outer or double) at +19 °C and -10 °C. Performance was determined both objectively and subjectively using two manual dexterity tasks: bolt-nut and pick-up tasks. The response measured was the time of performing each task. Statistical analysis showed that all independent factors such as glove type, participant, object size, and temperature had significant effects on the hand cooling reaction. A significant difference in the performance between the gloves was found in the bolt-nut task. It was also found that outer-inner combination gloving may be an approach to use for precision tasks.     

环保职业教育中环保行指委的角色期待

在分析目前环保职业教育存在问题的基础上,提出为进一步发挥环保行指委的作用,推动环保职业教育的发展与创新,环保职业院校对环保行指委的角色期待。环保行指委在环境保护职业教育中应该扮演专家、组织者、指导者、支持者、平台和桥梁以及监督者的角色。     

散装液体危化品码头的污染原因分析及防控对策

介绍了液体危化品的特点,对散装液体危化品码头的污染原因进行了分析,并提出了相应的防控对策,为确保码头安全稳定运行提供了保障.