整体合建倒置A^2O氧化沟中试试验及参数优化

以处理20m^3／d城镇生活污水的深沟型气升推流立体循环倒置A^2O整体合建氧化沟中试装置为研究平台,通过对影响该工艺运行的有机物的去除效果、硝化反应与反硝化反应效果及除磷效果等因素进行探索及最佳工况的正交试验设计,实验结果表明该工艺对BOD,、COD、SS、NH4^-N、TN、TP的平均去除率分别为94．25％、90...     

重组大肠杆菌产CotA漆酶的发酵条件优化

CotA漆酶在环境保护、食品工业和纸浆漂白等工业中具有重要的应用价值.将重组表达载体pET-22b/CotA转入大肠杆菌BL21(DE3),得到工程菌株,采用单因素实验和正交实验相结合的方法,研究诱导表达条件和发酵培养基对重组大肠杆菌产CotA漆酶量的影响.结果表明,初始pH 7.5的培养基中,添加0.6 mmol L-1 Cu2+,1 g L-1葡萄糖作碳源、15 g L-1蛋白胨和2 g L-1硫酸铵作氮源,以10%的接种量,37℃、200 r/min,直到菌液的D600 nm值为1.0,加入终浓度为1.0 mmol L-1的IPTG,25℃诱导12 h,漆酶的产量最高.优化前发酵液的粗提液的漆酶活性仅为1 190 U mL-1,优化后达到3 526 U mL-1,正交实验优化后漆酶活性提高了2.96倍.纯化的CotA漆酶最适反应温度为45℃,最适pH值为7.2.CotA漆酶对RBBR的脱色率在90%以上,此CotA漆酶在短时间内对染料能够有效地脱色,能够成为有潜力的工业用酶.图6表3参17     

基于GIS技术及模糊物元分析法的南京市仙林新市区生态安全评价

运用压力-状态-响应模型和层次分析法构建生态安全评价指标体系,综合运用GIS技术及模糊物元分析方法对南京市仙林新市区建设前后(2003和2007年)的生态安全状况进行评价。结果表明,2003—2007年,仙林生态安全状况主要向2个方向发展,生态安全和不安全区域面积均有所增加,占区域总面积比例分别由9.6%和12.9%增加至22.3%和15.0%。由于各区域发展模式不同,生态安全状况区域差异明显。具体表现为仙鹤片区与白象片区生态安全区域面积明显增加,占研究区总面积比例分别由2.6%和3.9%增加至10.1%和9.3%;麒麟片区生态安全状况以临界安全为主,部分片区由临界安全状态向较安全状态转化;青龙片区生态安全状况变化不大。     

2株石油降解菌生长和降解石油条件的优化

对2株石油降解菌DH-5和DH-9生长的最适培养基成分以及降解石油的最佳环境条件进行了筛选。结果表明,DH-5的最佳培养基成分为ρ(原油)1 g.L-1、ρ(氮源)400 mg.L-1、ρ(磷源)200 mg.L-1、ρ(酵母浸出液)20 mg.L-1,最有效利用的氨基酸为精氨酸,最适环境条件为pH 7.0、盐度20、温度15～30℃;DH-9的最佳培养基成分为ρ(原油)1 g.L-1、ρ(氮源)400 mg.L-1、ρ(磷源)100 mg.L-1、ρ(酵母浸出液)20 mg.L-1,最有效利用的氨基酸为天冬氨酸,最适环境条件为pH 7.5、盐度20、温度30℃。当ρ(原油)为20 g.L-1时,DH-9的生物量和原油降解率分别是DH-5的2.58倍和2.29倍。研究表明,DH-9对高浓度原油的耐受性明显强于DH-5,而DH-5对低温的适应性优于DH-9,2个菌株对高盐度的适应性均较强。     

The moderating effects of job control and selection,optimization, and compensation strategies on the age–work ability relationship

Work ability describes employees' capability to carry out their work with respect to physical and psychological job demands. This study investigated direct and interactive effects of age, job control, and the use of successful aging strategies called selection, optimization, and compensation (SOC) in predicting work ability. We assessed SOC strategies and job control by using employee self‐reports, and we measured employees' work ability using supervisor ratings. Data collected from 173 health‐care employees showed that job control was positively associated with work ability. Additionally, we found a three‐way interaction effect of age, job control, and use of SOC strategies on work ability. Specifically, the negative relationship between age and work ability was weakest for employees with high job control and high use of SOC strategies. These results suggest that the use of successful aging strategies and enhanced control at work are conducive to maintaining the work ability of aging employees. We discuss theoretical and practical implications regarding the beneficial role of the use of SOC strategies utilized by older employees and enhanced contextual resources at work for aging employees. Copyright © 2012 John Wiley & Sons, Ltd.     

Evaluation and Optimization of Handle Design Parameters of a Grass Trimming Machine

The grass trimming machine is a widely used agricultural machine for cutting grass by the roadside and in other areas in Malaysia. Hand-arm vibration (HAV) syndrome is very common among workers operating power tools and performing similar work for extended periods. Grass trimming involves the use of a motorized cutter spinning at high speed, resulting in high levels of HAV among its operators. The existing D-shape handle causes HAV-related stress and operational load in operators. This research proposes a new design of a handle of the grass trimming machine. When this new design was compared with the old one, it was found that the new handle resulted in 18% lower HAV. To find the lowest HAV, 3 critical parameters of the new handle (length, angle and material of the cap of the handle) were optimized using the Taguchi quality tool. Appropriately selected parameters of the new handle significantly reduced the occurrence of HAV among grass trimmers.     

基于个体脆弱性区域疏散最佳路径

针对危险化学品、生化制剂、放射性或核物质（ CBRN）事故情景,建立区域疏散路径优化模型。基于个体脆弱性模型,提出了适合求解模型算法,包括静态最优路径算法和动态最优路径算法。最后用随机路网测试算法的应用效果,结果表明,所提算法可以满足区域疏散路径双目标优化的需求,并能根据外部环境变化动态更新当前最优路径,是一种近似、快速的算法。区域疏散路径的确定可为CBRN事故救灾提供有力的技术支持。     

邛海水体富营养化的综合评价

为了研究近年来邛海水质的富营养化状况,本文以2010年邛海4个水质监测点水质监测资料为基础,采用模糊数学的方法对邛海营养状态进行综合评价。结果表明,邛海水质在青龙寺、二水厂和海河口属于贫营养,在公园属于中营养,说明近年来随着邛海及周边环境治理工程的加强,水体富营养化得到一定的遏制。     

输水水质保障下南四湖流域产业结构优化调整研究

通过对南四湖流域产业结构现状、水污染现状以及两者动态演化趋势的解析,结合对流域经济与环保政策导向的梳理,综合权衡三次产业发展对流域经济支撑度、水污染影响潜在威胁与现实效应,汇总形成了南四湖流域三次产业结构优化调整分析矩阵。在此基础上,探讨了不同产业结构优化调整的方案模式,提出南四湖流域三次产业中不同行业的结构优化方案。     

Optimum Heat Conductance Distribution for Power Optimization of a Regenerated Closed Brayton Cycle

In this paper, the power output of the cycle is taken as objective for performance optimization of an irreversible regenerated closed Brayton cycle coupled to constant-temperature thermal energy reservoirs in the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM). The analytical formulae about the relations between power output and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers and the regenerator, the irreversible compression and expansion losses in the compressor and turbine, and the pressure drop loss in the piping. The maximum power output optimization is performed by searching the optimum heat conductance distribution corresponding to the optimum power output among the hot- and cold-side heat exchangers and the regenerator for the fixed total heat exchanger inventory. The influence of some design parameters, including the temperature ratio of the heat reservoirs, the total heat exchanger inventory, the efficiencies of the compressor and the turbine, and the pressure recovery coefficient, on the optimum heat conductance distribution and the maximum power output are provided. The power plant design with optimization leads to smaller size including the compressor, turbine, and the hot- and cold-side heat exchangers and the regenerator.