就业与税收关系

目前，我国的劳动就业形式依然严峻。如何破解这个难题，已经成为我国能否顺利推进改革进程的一个关键性问题。我们应该注意到，劳动就业问题的产生是社会经济生活中众多相关因素共同影响的结果。因此，在我们探讨劳动就业问题的时候，必须找到影响劳动就业问题的相关因素并着力研究它们之间的联系，以综合的，全局的目光对就业问题加以审视，才能真正把握我国劳动就业问题的实质，才能使解决劳动就业问题的措施取得预期的效果，才能使劳动就业问题的解决走出简单应对的“陷阱”。     

气升回流一体化工艺处理生活污水简

针对分散型生活污水处理开发了气升回流一体化工艺，以校园生活污水为对象，研究其对生活污水中污染物的去除效果。该系统由好氧区、厌氧区、沉淀区和气升室组成，以曝气的剩余气体的气升作用实现混合液的回流，节省动力消耗。结果表明，本工艺对COD、氨氮及悬浮物（SS）有较好的去除效果，去除率分别达到80%、90%和75%左右，出水COD、NH₄⁺-N及SS平均浓度在40 mg/L、6.5 mg/L和10 mg/L左右。当进水COD在100~1 000 mg/L之间波动时，出水水质稳定。该工艺有较强的抗冲击负荷能力，且可实现剩余污泥的自消解。本工艺具有结构紧凑、占地少，运行费用低，维护简单的特点。     

Microbial community composition and electricity generation in cattle manure slurry treatment using microbial fuel cells: effects of inoculum addition

Environmental Science and Pollution Research - Microbial fuel cell (MFC) is a sustainable technology to treat cattle manure slurry (CMS) for converting chemical energy to bioelectricity. In this...     

Economic dispatch of power system containing wind power and photovoltaic considering carbon trading and spare capacity variation

The drying up of the fossil energy sources and the damage from unchecked carbon emissions demand the development of low carbon economy, which promotes the development of new energy sources, such as wind power and photovoltaic. However, the direct connections of wind/photovoltaic power into power grid bring great impacts on power systems, thus affecting the security and stability of power system operations, which challenges the power system dispatching. In despite of many methods for power system dispatch, lack of the models, for power system containing wind power and photovoltaic considering carbon trading and spare capacity variation (PSCWPCCTSCV), restricts the further optimal operations of power systems. This paper studies the economic dispatch modeling problem of power system containing wind power and photovoltaic, establishes the model of economic dispatch of PSCWPCCTSCV. On this basis, adaptive immune genetic algorithm is applied to conduct the economic operation optimization, which can provide the optimal carbon trading price and the optimal power distribution coefficient. Finally, simulations based on the newly proposed models are made to illustrate the economic dispatch of PSCWPCCTSCV. The results show that optimization with the proposed model can not only weaken the volatility of the new energy effectively, but also reduce carbon emissions and reduce power generation costs.     

基于机器视觉的鱼类行为特征提取与分析

近年来,水污染问题备受关注。生物式水质监测成为目前国家环境保护工作的重要任务之一。为准确监测水质污染情况,本文以青鳉鱼(Oryzias latipes)为研究对象,采用非接触式的机器视觉监测技术,提取青鳉鱼的生理特征(呼吸频率)和运动特征(胸鳍和尾鳍的摆动频率),并分析这些特征与水质之间的关系。本文采用支持向量机(Support Vector Machine,SVM)准确提取鱼鳃,并根据鱼鳃呼吸面积大小变化计算出鱼的呼吸频率。基于形态学细化算法提取青鳉鱼骨架,求出胸鳍和尾鳍的摆动频率。结果显示:不同浓度铜离子暴露实验测得的青鳉鱼生理特征和运动特征与实际情况一致;通过对不同铜离子浓度下的毒性实验数据对比,发现了青鳉鱼的生理特征和运动特征会随不同的铜离子浓度发生相应变化,可以作为水质监测的评价标准。     

Heavy metal (Cu,Cd, Pb,Cr) washing from river sediment using biosurfactant rhamnolipid

Heavy metal-contaminated sediments posed a serious threat to both human beings and environment. A biosurfactant, rhamnolipid, was employed as the washing agent to remove heavy metals in river sediment. Batch experiments were conducted to test the removal capability. The effects of rhamnolipid concentration, washing time, solution pH, and liquid/solid ratio were investigated. The speciation of heavy metals before and after washing in sediment was also analyzed. Heavy metal washing was favored at high concentration, long washing time, and high pH. In addition, the efficiency of washing was closely related to the original speciation of heavy metals in sediment. Rhamnolipid mainly targeted metals in exchangeable, carbonate-bound or Fe-Mn oxide-bound fractions. Overall, rhamnolipid biosurfactant as a washing agent could effectively remove heavy metals from sediment.

     

Concentrations and accumulation rates of polychlorinated biphenyls in soil along an urban–rural gradient in Shanghai

Environmental Science and Pollution Research - This study proposed an in situ soil experimental system to quantify concentration and accumulation rates of polychlorinated biphenyl (PCB) congeners...     

基于超效率DEA模型的三峡库区生态效率评价及空间演化格局分析

本文基于2010—2017年的统计数据,首先采用超效率DEA模型对三峡库区26个区县的生态效率进行测算,然后运用空间自相关分析方法对三峡库区生态效率的演化格局进行了实证分析,探索三峡库区生态效率的时空动态演变特征。研究表明:2010—2017年三峡库区生态效率平均水平处于0.5601～1.1920,整体呈现波动性变化趋势,生态效率在一定程度上有所改善,但是整体水平仍然较低;从区域层面看,各个区县间生态效率水平不平衡,空间分布上呈现"西高东低"的非均衡性特征。局部空间自相关分析表明,三峡库区2010—2017年集聚性呈逐渐减弱态势,空间异质性逐渐增加,整体的生态效率差异变大。最后依据实证研究分析结果,本文对如何提升三峡库区生态效率提出了相应的政策建议。     

基于TiO2载体的锰铈系低温SCR脱硝催化剂研究进展

开发低温、高活性、高抗硫抗水性能的选择性催化还原(SCR)脱硝催化剂已成为国内外的研究热点。综述了基于TiO2载体的锰铈系低温脱硝催化剂的脱硝性能,探讨了助剂掺杂改性、制备方法、反应条件等对催化剂脱硝性能的影响,总结了现有低温脱硝催化剂的技术难点,指出SCR催化剂的研究需要着重考虑以下几方面:深入研究催化剂的反应机理和中毒机理;研究催化剂的循环再生;探究拓宽催化剂温度窗口,使其适应不同的温度条件。     

桂林市城区大气VOCs污染特征及对O3和SOA的生成潜势

对桂林市城区大气中挥发性有机物(VOCs)的污染特征,以及VOCs对臭氧(O3)和二次有机气溶胶(SOA)的生成潜势进行了研究。结果显示,研究期间,共检出VOCs物种78种,平均体积分数为21.32×10-9,表现为芳香烃(67.82%)烷烃(19.56%)卤代烃(7.50%)烯烃(2.86%)含氧挥发性有机物(1.41%)。VOCs体积分数空间分布呈现市中心和下风向郊区两个高值区。通过苯与甲苯的浓度比值发现,林科所VOCs主要来自交通源和生物源,师专甲山校区VOCs主要是来自交通源,其余测点VOCs主要来自交通源、工业源和外来传输源。分析乙苯和间/对二甲苯的浓度比值发现,电子科大尧山校区气团光化学年龄较大,光化学反应活性相对较强烈;旅游学院、华侨旅游经开区、大埠中心校气团光化学年龄较小,光化学反应活性相对较弱。VOCs对O3生成潜势最大的为芳香烃(93.81%),其次是烷烃(7.22%)和烯烃(4.75%);对SOA生成潜势最大的为芳香烃(97.45%),其次是烷烃(2.55%)。