外卖配送公共交通违法行为影响因素分析

通过问卷调查研究外卖配送公共交通违法行为影响因素，将外卖配送员分为曾经发生过和未发生过公共交通违法行为2组样本。通过Logistic回归对比分析，发现影响外卖配送员是否会发生公共交通违法行为的因素为平均每月送餐收入和平均每单配送距离；接着对其中发生过公共交通违法行为的1组样本，运用灰色关联分析法判断外卖配送员发生公共交通违法行为的主要驱动因素是平均每日接单数量、平均每月送餐收入以及平均每单配送时长，并根据影响因素提出了解决该问题的针对性长期建议。     

关于在太子河源头建设生态功能保护区的思考

针对对太子河上游水质现状及污染趋势进行了调查分析，并提出了在太子河源头建立生态功能保护区的构想及相应的保护措施。     

高效酶促进剂Accell应用于SBR处理畜禽废水的研究

为了进一步在工艺基础上提升畜禽废水污染物的处理效果,在畜禽废水治理工艺的生化段SBR反应器进水中投加高效酶促进剂Accell。两套相同装置平行运行的效果对比表明:投加Accell可使得COD的去除在SBR反应器基础上再减少40%以上,对NH_3-N的去除可进一步再减少25%以上。此外,投加高效酶促进剂Accell可促进微生物的代谢速率,增加溶氧效率,强化污染物的去除效果。     

Modelling the motion of an internal solitary wave over a bottom ridge in a stratified fluid

A series of laboratory experiments has been carried out to investigate the passage of an internal solitary wave of depression over a bottom ridge, in a two-layer fluid system for which the upper and lower layer is linearly-stratified and homogeneous respectively. Density, velocity and vorticity fields induced by the wave propagation over the ridge have been measured simultaneously at three locations, namely upstream, downstream and over the ridge crest, for a wide range of model parameters. Results are presented to show that wave breaking may occur for a sufficiently large wave amplitude and a strong ridge blockage factor, with accompanying mixing and overturning. Density field data are presented (i) to illustrate the overturning and mixing processes that accompany the wave breaking and (ii) to quantify the degree of mixing in terms of the wave and ridge parameters. For weak encounters, good agreement is obtained between the laboratory experimental results (velocity and vorticity fields induced by the wave propagation) and the predictions of a recently-developed fully nonlinear theory. Discrepancies between theory and experiment are discussed for cases in which breaking and mixing occur.     

从工业废料制取化学建材石膏的研究

研究了以造纸白泥、电石渣及工业废硫酸为原料化学建材石膏的原料二水石膏的工艺条件和影响因素，同时采用废水闭路循环回用工艺流程，防止二次污染的产生。实验表明，将废渣配成１０％浓度的浆液与低浓度废硫酸进行反应，控制一定的反应时间及终点ＰＨ值可制得含量达９０％以上的优质二水石膏。     

温带湖泊周边湿地原生草地与人工林土壤碳释放差异性分析

采用红外气体分析法对东平湖湿地人工杨树林和自然草地土壤碳通量进行测定,分析了6:00到18:00两种生境下群落土壤碳通量日变化规律,及其对温度、水分等环境因子的响应。结果表明:(1)两种生境群落的土壤碳通量日动态都呈单峰曲线,但人为耕作过的土壤碳通量明显高于原生草地,土壤碳通量均在6:00达到最小值,杨树林土壤碳通量的最大值出现在12:00,而草地群落土壤碳通量最大值在14:00左右;(2)人工林土壤碳通量与近地面大气温度、土壤温度的相关性均低于草地,且两种生境群落土壤呼吸与近地面大气温度的相关性(P<0.01)均好于与土壤温度的相关性(P<0.05)。土壤碳通量对近地面大气温度的敏感性Q10值大于土壤温度的敏感性,人工林土壤呼吸温度敏感性Q10值小于草地。土壤碳通量与近地面大气相对湿度之间具有显著线性方程关系(P<0.01),人工杨树林和草地的相关系数分别为:0.399、0.29。杨树林土壤碳通量与土壤体积含水量相关性差(P<0.05),湿地草地土壤CO2释放量与土壤体积含水量的相关性不显著(P>0.05),这可能由于土壤体积含水量日变化较小,而不能很好的解释日变化尺度上的土壤呼吸变化;(3)对湿地地土壤碳通量的日变化与土壤养分和盐分相关分析得出,人工林土壤中的有机质和全盐与土壤碳通量具有显著关系(P<0.05),而草地土壤碳通量与土壤养分和盐分相关性均非常差,说明人工林生境土壤有机质和全盐是影响土壤碳通量的一个重要因素,而对草地的影响较小。该结果可以为华北平原东部地区以及温带湖泊湿地的土壤碳通量研究提供参考。     

Dental caries in fluorine exposure areas in China

In this study, fluorine concentrations in drinking water and in urine of residents from a fluorine exposure area in China were tested. DMFT (average number of decayed, missing and filled teeth) of local residents in four age groups were also determined. The results of the study indicate that in fluorine exposure areas, there is a strictly positive correlation between fluorine content in urine and the fluorine content in drinking water. Effect of dental caries by high fluorine content drinking water is different for the different age groups. High fluorine content drinking water is more dangerous for 15-and 18-year-old groups than 5- and 12-year-old groups.     

Household solid fuel use with diabetes and fasting blood glucose levels among middle-aged and older adults in China

Environmental Science and Pollution Research - To explore the impacts of household solid fuel use for cooking and heating on diabetes and fasting blood glucose (FBG) levels, we used data from the...