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151.
浅谈大学生社会实践活动的项目化管理 总被引:5,自引:0,他引:5
结合中国环境管理干部学院"千名学生绿色行"活动的项目化管理的具体组织和实践情况,在实际工作中探索大学生社会实践活动项目化管理的科学性和有效性,将项目化管理模式应用于大学生实践活动的管理中,最大限度地利用现有的学生活动资源、规范管理行为、降低管理成本、提高工作效率,实现培养大学生综合素质和创新能力的目的。 相似文献
152.
Kun Wang Maofa Ge Weigang Wang 《Atmospheric environment (Oxford, England : 1994)》2010,44(15):1847-1850
The relative rate method has been used to determine the rate constants for the gas-phase reactions of NO3 radicals with a series of acrylate esters: ethyl acrylate (k1), n-butyl acrylate (k2), methyl methacrylate (k3) and ethyl methacrylate (k4) at 298 ± 1 K and 760 Torr. The obtained rate constants are k1 = (1.8 ± 0.25) × 10?16 cm3 molecule?1 s?1, k2 = (2.1 ± 0.33) × 10?16 cm3 molecule?1 s?1, k3 = (3.6 ± 1.2) × 10?15 cm3 molecule?1 s?1, k4 = (4.9 ± 1.7) × 10?15 cm3 molecule?1 s?1. The experimental rate constants are in good agreement with theoretical rate constants calculated by an algorithm of the correlation between the rate constants and the orbital energies for the reactions of unsaturated VOCs with NO3 radicals. In addition, the atmospheric lifetimes of the compound against NO3 attack are estimated and the results show that NO3 reactions contribute little to the atmospheric losses of acrylate esters except in polluted regions. 相似文献
153.
154.
目前水环境系统脆弱性研究主要局限于水环境系统的单方面脆弱性研究,过于片面化,需要综合考虑水资源、水环境质量、旱涝灾害、社会经济以及生态环境等方面的脆弱性。根据水环境系统脆弱性是系统状态受到系统压力引起的敏感性以及系统状态对系统压力的适应性响应的观点,采用“压力-状态-响应”模式构建区域水环境系统脆弱性指标体系。区域水环境系统脆弱性研究中客观存在诸多不确定性,利用联系数描述上述不确定性过程中差异度系数在[-1,1]上取值仍存在不确定性,为此,构造三角模糊数刻画差异度系数取值的不确定性,给出三角模糊联系数的基本形式,取置信水平得出置信区间联系数,采用期望-方差排序法对置信区间联系数进行决策分析,建立基于三角模糊联系数的系统综合决策模型。此模型用于安徽省水环境系统脆弱性评价的结果表明,安徽省区域水环境系统脆弱等级介于[2.731 3.620]之间,脆弱性状况不容乐观,应采取相应措施改善区域水环境质量,降低区域水环境系统脆弱性,保障区域社会经济及生态环境的可持续发展 相似文献
155.
Huilun Chen Honghao Rao Pengzhen He Yongxiang Qiao Fei Wang Haijun Liu Minmin Cai Jun Yao 《Environmental science and pollution research international》2014,21(19):11340-11348
Antibiotics are widely used in daily life but their abuse has posed a potential threat to human health. To evaluate the toxicity of chloramphenicol (CAP) at the protein level, the interaction between CAP and human serum albumin (HSA) was investigated by fluorescence, Ultraviolet–visible (UV–Vis) absorption, Fourier transform infrared (FT-IR) spectroscopy and molecular docking methods. Fluorescence data revealed that the fluorescence quenching of HSA by CAP was the result of the formation of CAP–HSA complex, and the binding constant was determined to be 3.196?×?104 L mol?1 at 310 K. The thermodynamic determination indicated that the interaction was driven by enthalpy change and entropy change together, where the multiple hydrogen bonds (CAP and the residues Arg 222 and His 242 of HSA) and van der Waals forces were the dominant binding force. The site marker competition revealed that CAP bound into sub-domain IIA of HSA. The binding of CAP induced the drastic reduction in α-helix conformation and the significant enhancement in β-sheet conformation of HSA. Molecular docking study further confirmed the binding mode obtained by experimental study. This work provides a new quantitative evaluation method for antibiotics to cause the protein damage. 相似文献
156.
Quantifying interactions between propranolol and dissolved organic matter (DOM) from different sources using fluorescence spectroscopy 总被引:1,自引:0,他引:1
Na Peng Kaifeng Wang Guoguang Liu Fuhua Li Kun Yao Wenying Lv 《Environmental science and pollution research international》2014,21(7):5217-5226
Beta blockers are widely used pharmaceuticals that have been detected in the environment. Interactions between beta blockers and dissolved organic matter (DOM) may mutually alter their environmental behaviors. To assess this potential, propranolol (PRO) was used as a model beta blocker to quantify the complexation with DOM from different sources using the fluorescence quenching titration method. The sources of studied DOM samples were identified by excitation–emission matrix spectroscopy (EEMs) combined with fluorescence regional integration analysis. The results show that PRO intrinsic fluorescence was statically quenched by DOM addition. The resulting binding constants (log K oc) ranged from 3.90 to 5.20, with the surface-water-filtered DOM samples claiming the lower log K oc and HA having the highest log K oc. Log K oc is negatively correlated with the fluorescence index, biological index, and the percent fluorescence response (P i,n) of protein-like region (P I,n) and the P i,n of microbial byproduct-like region (P II,n) of DOM EEMs, while it is correlated positively with humification index and the P i,n of UVC humic-like region (P III,n). These results indicate that DOM samples from allochthonous materials rich in aromatic and humic-like components would strongly bind PRO in aquatic systems, and autochthonous DOM containing high protein-like components would bind PRO more weakly. 相似文献
157.
158.
The purpose of this study was to investigate associations between pyrethroids occupational exposures, and risk of abnormal glucose regulation. Data from total of 3080 subjects in two pesticide factories were used. This was a population-based case-controlled study in China. In total, 18.3% of subjects with impaired glucose regulation (IGR) and 6.5% of subjects with diabetes, and the prevalence of abnormal glucose regulation was 24.8%, 86 subjects had known type 2 diabetes and 114 had newly diagnosed diabetes. The prevalence of subjects with abnormal glucose regulation increased from 21.3% in the controls to 29.3% in the exposures (χ2 = 33.182, P < 0.001). Multivariate logistic regression was used to control potential confounders and calculate odd ratios as the estimate of effect. An indication of increased risk for abnormal glucose regulation was noted for exposure to pyrethroids (OR = 1.482, 95%CI = 1.238-1.774). Abnormal glucose regulation is common in subjects exposed to pyrethroids. The present investigation indicates the adverse health effects of pyrethroids are underestimated. 相似文献
159.
城乡二元制度对农民工市民化影响的实证分析 总被引:4,自引:0,他引:4
黄锟 《中国人口.资源与环境》2011,21(3)
将影响农民工市民化的制度因素归结为城乡分割、城市偏向的城乡二元制度,分析了这一制度的内涵和基本特征,并运用Logistic回归模型和入户调查数据对这一制度对农民工市民化意愿、市民化能力和市民化进程的影响进行实证分析,结果发现,虽然农民工具有比较强烈的市民化愿望,但由于受到市民化能力的制约,绝大多数农民工无法转化为市民,因此尽快提离农民工的市民化能力成为促进农民工市民化的关键;在城乡二元制度中,除了城乡二元户籍制度之外,城乡二元就业制度、城乡二元社会保障制度、城乡二元土地制度和城乡二元教育制度对农民工市民化意愿和市民化能力,进而对农民工的市民化进程具有明显的阻碍作用:因此,未来城乡二元制度的创新重点不能再继续停留在形式化的城乡二元户籍制度层面,而应该尽快切换到对农民工的预期和收入等权利和待遇具有实质性影响的城乡二元就业制度、城乡二元社会保障制度、城乡二元土地制度和城乡二元教育制度上来. 相似文献
160.
喀纳斯自然保护区生态系统服务价值变化研究 总被引:1,自引:0,他引:1
生态系统可持续发展是随着全球范围内可持续发展研究的深入和人们对环境破坏和资源利用认识的不断加深而逐渐形成的.人类社会的可持续发展从根本上取决于生态系统及其服务的可持续性,本文应用喀纳斯自然保护区1980、2005年两期Landsat TM影像解译数据,参照谢高地等制定的中国生态系统单位面积生态服务当量因子和新疆布尔津县单位面积农田生态系统提供的食物生产服务的经济价值,确定喀纳斯自然保护区生态系统单位面积生态服务价值系数,对保护区生态系统服务价值及其变化进行了估算和比较.结果表明,林地和草地是喀纳斯自然保护区主要的土地利用类型,25年间土地利用总体上发生了明显变化,林地面积在减少,革地、水域、建设用地面积略有增加;保护区生态系统服务价值由1980年的37.289亿元减少至2005年的36.351亿元,有林地和离覆盖度草地的减少是服务价值降低的主要原因;主要由林地、草地和水域提供的维持生物多样性、水文调节、气候调节、保持土壤等单项功能服务价值均呈现不同程度地减少,说明保护区生态系统结构和功能已受到影响,保护区生态环境质量不断趋向退化. 相似文献