高职院校计算机应用专业《JSP动态网站设计》课程改革探析

通过分析当前社会需求，结合高职高专院校目前的教学模式，提出计算机应用专业的《JSP动态网站设计》课程的教学改革方案。在基于工作任务的lAPP（导入-分析-实践-项目）教学情境中，开展“课堂实训＋虚拟公司＋校外实训基地”三位一体的实践模式教学，同时，将对工作过程的考核纳入课程的整个考核体系之中，使学生在课程中能够获得真实的职业体验和完善的实践能力。     

基于方波溶出伏安法的电化学传感器检测水体中痕量铅

基于方波溶出伏安法运用丝网印刷电极探索了一种利用电化学传感器检测水样中痕量铅的方法.得到了该检测方法的最佳参数:方波频率30 Hz,振幅80 mV,电位增量5 mV;0.5 mol/L的支持电解质(KCl);沉积电位-1.1 V,沉积时间400 s.在该优化条件下,在浓度为25 ～ 500μg/L范围内溶出峰电流与铅离子浓度呈良好的线性关系(R2=0.9945).对于几种其他金属离子的干扰实验结果表明,Mn2的存在严重抑制铅离子的峰电流.     

Evaluation on the toxicity of ionic liquid mixture with antagonism and synergism to Vibrio qinghaiensis sp.-Q67

Ionic liquids (ILs) are a fascinating group of new chemicals with the potential to replace the classical volatile organic solvents, stimulating many applications in chemical industry. In case ILs are released to the environment, possible combined toxicity should be taken into account and it is, however, often neglected up to now. In this paper, therefore, the concentration-response curves (CRCs) of four groups of IL mixtures with various mixture ratios to Vibrio qinghaiensis sp.-Q67 were determined using the microplate toxicity analysis and were compared to the CRCs predicted by an additive reference model, the concentration addition (CA) or independent action (IA), to identify the toxicity interaction. It is showed that most of the IL mixture rays displayed the classical addition while the remaining rays exhibited antagonism or synergism. Moreover, it is found that the pEC₅₀ values of the mixture rays exhibiting antagonism or synergism are well correlated with the mixture ratio of a certain IL therein.     

Concentration and health risk evaluation of heavy metals in market-sold vegetables and fishes based on questionnaires in Beijing,China

Concentrations of heavy metals (As, Cd, Pb, Cu, Ni, Fe, Mn, and Zn) in market vegetables and fishes in Beijing, China, are investigated, and their health risk to local consumers is evaluated by calculating the target hazard quotient (THQ). The heavy metal concentrations in vegetables and fishes ranged from not detectable (ND) to 0.21 mg/kg fresh weight (f.w.) (As), ND to 0.10 mg/kg f.w. (Cd), and n.d to 0.57 mg/kg f.w. (Pb), with average concentrations of 0.17, 0.04, and 0.24 mg/kg f.w., respectively. The measured concentrations of As, Cd, Pb, Cu, Ni, Fe, Mn, and Zn are generally lower than the safety limits given by the Chinese regulation safety and quality standards of agriculture products (GB2762-2012). As, Cd, and Pb contaminations are found in vegetables and fishes. The exceeding standard rates are 19 % for As, 3 % for Cd, and 25 % for Pb. Pb contaminations are found quite focused on the fish samples from traditional agri-product markets. The paper further analyzed the health risk of heavy metals in vegetables and fishes respectively from supermarkets and traditional agri-product markets; the results showed that the fishes of traditional agri-product markets have higher health risk, while the supermarkets have vegetables of higher heavy metal risk, and the supervision should be strengthened in the fish supply channels in traditional agri-product markets.     

Estimating the impact of seawater on the production of soil water-extractable organic carbon during coastal erosion

The production of water-extractable organic carbon (WEOC) during arctic coastal erosion and permafrost degradation may contribute significantly to C fluxes under warming conditions, but it remains difficult to quantify. A tundra soil collected near Barrow, AK, was selected to evaluate the effects of soil pretreatments (oven drying vs. freeze drying) as well as extraction solutions (pure water vs. seawater) on WEOC yields. Both oven drying and freeze drying significantly increased WEOC release compared with the original moist soil samples; dried samples released, on average, 18% more WEOC than did original moist samples. Similar results were observed for the production of low-molecular-weight dissolved organic C. However, extractable OC released from different soil horizons exhibited differences in specific UV absorption, suggesting differences in WEOC quality. Furthermore, extractable OC yields were significantly less in samples extracted with seawater compared with those extracted with pure water, likely due to the effects of major ions on extractable OC flocculation. Compared with samples from the active horizons, upper permafrost samples released more WEOC, suggesting that continuously frozen samples were more sensitive than samples that had experienced more drying-wetting cycles in nature. Specific UV absorption of seawater-extracted OC was significantly lower than that of OC extracted using pure water, suggesting more aromatic or humic substances were flocculated during seawater extraction. Our results suggest that overestimation of total terrestrial WEOC input to the Arctic Ocean during coastal erosion could occur if estimations were based on WEOC extracted from dried soil samples using pure water.     

电能表自动化检定系统监控功能的完善

针对电能表自动化检定系统工作过程中的异常现象,通过对其产生原因和影响因素的分析,提出了采用增加触点检测、温度监测、各工位信息实时集中监控的方法对监控功能进行完善。应用结果表明:改进方法实现了对各检定工位的实时监控,系统异常现象减少,合格率得到了提升,保证了检定系统的高效稳定运行。     

新疆阿克苏地区地下水优先控制污染物的确定

为确定新疆阿克苏地区地下水优先控制污染物,结合潜在危害指数法和综合评分法对新疆阿克苏地区地下水中9项评价指标进行了优先控制污染物筛选,利用GIS软件分析了阿克苏地区地下水优先控制污染物的空间分布规律,并将地下水中各优先控制污染物与土地利用类型在空间上进行叠加,结合土地利用类型与主成因分析法确定了阿克苏地区地下水优先控制...     

施氏矿物协同Cu（II）活化过硫酸盐去除水中土霉素的效果

畜禽粪污排放致使水体遭受土霉素（OTC）及重金属污染已成为环境领域的热点问题.本研究考察了施氏矿物协同Cu（II）活化过硫酸盐去除水中OTC的效果及施氏矿物循环利用效果.结果表明,在施氏矿物（Sch）加入量为0.8 g·L^-1,过硫酸钠（PS）浓度为180 μmol·L^-1,Cu（II）浓度为40 mmol·L^-1的条件下作用3 h,水中OTC（60 μmol·L^-1）去除率为74.3%.当用100 W功率紫外灯照射OTC+Cu（II）+PS+Sch处理体系,OTC在3 h时的去除率为98.5%,TOC去除率达到78.2%.施氏矿物循环第4批与首批结果相比较,体系OTC与TOC去除率无明显差异,OTC+ Cu（II）+PS+Sch体系在暗反应条件下首批与循环利用第4批对OTC的去除率分别为74.3%、78.4%,相应TOC的去除率分别为39.1%、39.8%;当用100 W功率紫外灯照射该体系,首批与循环第4批对OTC的去除率分别为98.5%、98.6%,相应TOC的去除率分别为78.2%、80.7%.本研究结果可为含有抗生素及铜离子废水的高级氧化处理提供一定的参数支撑.     

Biofilm-overproducing Bacillus subtilis B12ΔYwcc decreases Cd uptake in Chinese cabbage through increasing Cd-immobilizing related gene abundance and root surface colonization

Biofilm-producing bacteria can decrease Cd uptake in vegetables, but mechanisms underlying this effect are poorly characterized. In this study, two mutant strains B12ΔYwcc and B12ΔSlrR were constructed from a biofilm-producing Bacillus subtilis strain B12. Then, the impacts of strain B12 and its high biofilm-producing mutant strain B12ΔYwcc and low biofilm-producing mutant strain B12ΔSlrR on Cd availability and uptake in Chinese cabbage and the related mechanisms were investigated in the Cd-polluted soil. Strain B12 and its mutants B12ΔYwcc and B12ΔSlrR increased the dry biomasses of edible tissues by 54%–130% compared with the controls. Strain B12 and its mutant B12ΔYwcc reduced the soil available Cd content by 36%–50% and root and edible tissue Cd contents by 23%–50% compared with the controls. Furthermore, the mutant strain B12ΔYwcc reduced the edible tissue Cd content by 40% and increased the polysaccharide content by 23%, invertase activity by 139%, and gene copies of the cumA by 4.5-fold, epsA by 7.1-fold, and cadA by 4.3-fold, which were involved in Cd adsorption in the rhizosphere soils, respectively, compared with strain B12. The polysaccharide content and cumA, epsA, and cadA gene copy numbers showed significantly reverse correlations with the available Cd content. Notably, the mutant strain B12ΔYwcc showed better ability to colonize the vegetable root surface than strain B12. These findings demonstrated that the biofilm-overproducing mutant strain B12ΔYwcc increased the polysaccharide production and Cd-immobilizing related cumA, epsA, and cadA gene copies, resulting in lower Cd availability and accumulation in Chinese cabbage in the Cd-polluted soil.     

P(AM-DMDAAC-VAM)共聚物的合成及其絮凝性能

以丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC)、乙酸乙烯酯(VAM)为单体,采用水溶液自由基胶束共聚合法合成了疏水缔合阳离子型共聚物P(AM-DMDAAC-VAM),并对其进行了红外光谱和核磁共振氢谱表征。实验结果表明:在P(AM-DMDAAC-VAM)加入量为14 mg/L、絮凝温度为30~60℃、硅藻土悬浊液pH为8~11时,P(AM-DMDAAC-VAM)对硅藻土悬浊液的絮凝效果最好,上清液透光率高达97.5%。