锂离子电池用新型复合聚合物电解质膜的性能研究

聚合物电解质膜是影响锂离子电池性能的重要因素,通过对聚合物的改性,能够改善聚合物电解质膜综合性能.本文以偏氟乙烯-六氟丙烯共聚物[P(VDF-HFP)]为基,以N甲基吡咯烷酮(NMP)作溶剂,γ-丁内酯(γ-BL)作添加剂,用倒相湿法制备出复合聚合物电解质膜,并对其离子传递、膜结构和电化学性能进行了研究.用限制扩散方法测定了该电解质膜的锂离子扩散系数为5.68×10-10 cm2·s-1;用稳态极化法测定了该电解质膜的迁移数为0.61;用交流阻抗法测得该电解质膜的室温最高电导率可达1.73×10-3S·cm-1.测试结果表明,该聚合物电解质膜具有较好的离子传输性质和电化学性能.     

Regression model under skew-normal error with applications in predicting groundwater arsenic level in the Mekong Delta Region

Environmental and Ecological Statistics - Recently there has been some renewed interest in skew-normal distribution (SND) because it provides a nice and natural generalization (in terms of...     

中国民政救灾资金年度需求分析

在中国,由民政部门提供救灾专项资金是救灾的一项重要手段。民政救灾资金的实际支出与当年自然灾害的多寡、灾情的严重程度相关,进行当年预算时往往难以确定其具体额度。以1985-2009年全国救灾数据和灾情数据为基础,对除民政救灾储备与冬令春荒救助资金以外的历年救灾支出进行了统计建模,估计了在2009年的人口基数与社会经济发展水平下的年度民政救灾数量需求(实物单位)。通过设置不同的救灾标准情景,模拟了不同情景下中国民政救灾资金年度总需求。结果表明,在不同标准下,年度民政救灾资金的平均需求为157.9～477.1亿元。本研究估计的结果可为民政和财政部门制定有关预算提供参考。     

Kinetics of acetyl CoA: Arylamine N‐acetyltransferase from rapid and slow acetylator fish tissues

N‐acetyltransferase (NAT) activity was determined in 100 fish (Oreochromis mossambicus) livers using 2‐aminofluorene and p‐aminobenzoic acid as substrates. Overall, the liver NAT activity of the 50 females was higher than the liver NAT activity of the 50 males. The activities (mean ± SD) of NAT from kidney, blood, intestine, and liver of males was 0.42 ± 0.11, 0.12 ± 0.03, 0.12 ± 0.08, and 1.56 ± 0.54 nmol/min/mg protein for the acetylation of 2‐aminofluorene and 0.36 ± 0.09, 0.09 ± 0.01, 0.11 ± 0.04, and 0.46 ± 0.15 nmol/min/mg protein for the acetylation of p‐aminobenzoic acid. In kidney, blood, intestine, and liver from female fish, the activities obtained were 1.60 ± 0.12, 0.35 ± 0.07, 0.15 ± 0.09, and 1.89 ± 0.50 nmol/min/mg protein for 2‐aminofluorene and 0.95 ± 0.11, 0.27 ± 0.03, 0.13 ± 0.09, and 0.57 ± 0.12nmol/min/mg protein for p‐aminobenzoic acid. Kinetic constants for arylamine N‐acetyltransferase activity in kidney, blood, intestine, and liver from fish with rapid, intermediate, and slow acetylator activity were determined. Apparent K _m and V _max values for 2‐aminofluorene were 5.5 and 7‐fold higher for liver than for the other tissues. Apparent K _m and V _max values for p‐aminobenzoic acid were 3.5 and 4.7‐fold higher for liver than for the other tissues. Based on the 2‐aminofluorene NAT activity of liver, there appears to be a polymorphism in NAT activity with 16 rapid, 28 intermediate, and 56 slow acetylators among the 100 fish assayed. This is the first demonstration of acetyl CoA: arylamine N‐acetyltransferase activity in fresh water fish and could lead to the development of a fish model for monitoring the effect of pollution of water environments on native species.     

Paeonol promotes arylamine N‐acetyltransferase activity in human bladder tumor cells

Paeonol was used to determine effects of arylamine N‐acetyltransferase (NAT) activity in human bladder tumor cells. The NAT activity was measured by high performance liquid chromatography assaying for the amounts of N‐acetyl‐2‐aminofluorene (2‐AAF) and N‐acetyl‐p‐amino‐benzoic acid (N‐Ac‐PABA) and remaining 2‐aminofluorene (2‐AF) and p‐aminobenzoic acid (PABA). The NAT activity in human bladder tumor cells was promoted by paeonol in a dose‐dependent manner, i.e. the higher the concentration of paeonol, the higher the promotion of NAT activity. The data also indicated that paeonol increases the apparent values of K_m and K_max from human bladder tumor cells in cytosols and intact cells. This report is the first demonstration to show paeonol did promote human bladder tumor cell NAT activity.     

2种藻菌固定化改进方法的比较及优化研究

研究了替换固定液及壳聚糖覆膜2种藻菌固定化改进方法,并对比2种改进方法对固定化效果及废水处理效果的影响.结果表明,2种方法都可增强固定化小球的稳定性与机械强度.4个周期后,经前种方法制备的固定化小球对COD, NH3-N, PO43--P的去除率分别为75.8%,42.5%,47.5%,后种方法制备的小球对2种污染物的去除率分别为73.8%,51.8%,54.5%.与改进前相比,前者降低了废水处理效果,而后者对处理效果影响不大.以壳聚糖覆膜作为改进方法,考察壳聚糖溶液的质量浓度,pH值和覆膜时间对固定化小球处理废水能力的影响,得到最佳浓度,pH值以及覆膜时间分别为1%,5.5,15min.     

焦化废水中溶解性有机物组分的特征分析

焦化废水是典型的具有复杂有机质的工业废水,其复杂的有机构成制约了水处理的水质达标,且可能对排入水体构成危害.为了探明其溶解性有机物的组成,采用XAD-8大孔树脂将焦化废水中的溶解性有机物分为亲水性组分(HIS)、疏水酸性组分(HOA)、疏水碱性组分(HOB)和疏水中性组分(HON),分析了各组分的溶解性有机物(DOC)、紫外-可见光谱、色度,并采用GC/MS对各组分中有机物进行定性分析.结果表明,焦化废水中的有机物主要为HIS和HOA组分,其DOC含量分别占总DOC的44.3%和32.4%;焦化废水在200—250 nm和300—400 nm范围内有特征吸收峰,且吸收光强度顺序为HIS>HOA>HON>HOB;焦化废水的色度主要由HOA和HON构成,其在525 nm和436 nm处的吸光度分别占焦化废水吸光度的42.9%(HON)、42.1%(HON)和21.4%(HOA)、15.8%(HOA);焦化废水中亲水性物质主要是苯胺、苯酚、喹啉、异喹啉,疏水酸性物质中主要是各种甲基取代的酚类物质,疏水碱性物质主要是各种胺类和含氮杂环化合物,疏水中性物质主要是吲哚及其衍生物.     

化肥和有机肥配施生物炭对土壤磷酸酶活性和微生物群落的影响

研究化肥和有机肥配施生物炭处理下植株根际、非根际土壤磷酸酶活性和phoC、phoD基因微生物群落多样性变化的规律,可为土壤磷库中难溶性磷素向植物根系可吸收的无机态磷酸根离子转化提供一定的理论指导,同时也为土壤中磷素有效性的提高和生物炭的农业利用提供一定的试验依据.本研究以玉米秸秆和稻壳秸秆为供试材料,采用盆栽试验的方法...     

上海大气中花粉与颗粒物的复合污染特征

于2009~2010年,利用风标式花粉采集器,采集了上海不同区域春、秋、冬季的飞散花粉和大气颗粒物样品,并于春季(2010年4月)利用重力花粉采集器在不同高度采集了飞散花粉样品,以及不同区域悬铃木的花粉.对风标花粉采样器采集的样品进行溶酸处理后进行花粉鉴定;对重力法采集的花粉样品染色后直接进行观察.利用高分辨的扫描电镜(SEM)对悬铃木花粉上吸附的大气颗粒物进行了微观表征.结果显示,上海春季大气中的花粉以木本植物花粉为主.不同区域悬铃木花粉上所吸附的颗粒物组分有所差异.冬季和春季大气颗粒物(总悬浮颗粒物)中的SO42-的浓度均为所检测离子(Na+、K+、Ca2+、Mg2+、NH4+、NO3-、SO42-、Cl-)中浓度最高的,NO3-、SO42-、NH4+在冬季样品中要比春季样品中的浓度高.上海大气颗粒物中的地壳元素的质量浓度从高到低为Ca >Na>Mg>K.     

絮凝剂对污泥脱水性能的改善

指出好氧强曝气后污泥的沉降性能,并着重以APAM、CPAM和ciba7635三种絮凝剂对剩余污泥的SV值和比阻值进行了考察,最终在此基础上分析了每一种絮凝剂絮凝机理和絮凝能力差别的原因。研究分别指出了每一种絮凝剂的最佳投药量。