Grafting of N,N-dimethylacrylamide onto silk fibers via a RAFT agent controlled radical transformation process

RAFT-mediated silk graft copolymerizations with DMAAm (N,N-Dimethylacrylamide) were studied. Three types of macromolecular RAFT agents which released different R group radicals, namely, polyacrylic acid-b-polystyrene radical (PAA-b-PSt^?), polyacrylic acid-b-polybutyl acrylate radical (PAA-b-PBA^?) and polystyrene-b-polyacrylic acid radical (PSt-b-PAA^?), were chosen as the transfer agents. During the graft copolymerizations, the newly born PAA-b-PSt^? in the aqueous phase enhanced the formation of silk macroradicals, consequently accelerated the copolymerization rate and improved monomer grafting efficiency (Ge) greatly. The Ge was less improved when the RAFT agent capable of producing PAA-b-PBA^? were substituted for the one producing PAA-b-PSt^?. In addition, Ge also benefited from an increase in the chain length of PSt block in PAA-b-PSt^?, as well as PBA block in PAA-b-PBA^?. However, the addition of RAFT agent giving rise to PSt-b-PAA^? had negligible effects on Ge. The reasons were ascribed to both the radical reactivity and capacity of radical adsorption onto silk fibers.     

Study on the creep and recovery behaviors of UHMWPE/CNTs composite fiber

The creep and recovery behaviors of UHMWPE and UHMWPE/CNTs composite fibers at different temperature were studied using Dynamic Mechanical Analysis (DMA). It was found that the creep strain of the UHMWPE and the UHMWPE/CNTs fibers increased with temperature rising. And creep strain of the composite fibers was always lower than that of the neat UHMWPE fiber. Burger’s model and Weibull distribution are employed to simulate the creep and recovery behaviors of the two fibers. The results show elasticity, stiffness and the recovery property of the composite fiber were improved by adding multi walled carton nanotubes.     

比较中华大蟾蜍不同个体间galectin-3 cDNA分子多样性

从中华大蟾蜍(Bufo gargarizans)某一个体的皮肤第一链cDNA中克隆到多个编码半乳糖凝聚素3(Gal-3)的cDNA。为分析该现象在中华大蟾蜍中的普遍性,分离并纯化3个不同个体的皮肤总RNA并合成其第一链cDNA,然后以此为模板,通过DNA聚合酶链式反应(PCR)扩增gal-3的开放阅读框序列。序列分析结果表明,从3个不同个体中均克隆到多个不同的gal-3 cDNA的ORF,在3组不同的试验中,出现完全相同的克隆或者完全相同的缺失以及相同的多核苷酸多态性位点,支持gal-3 cDNA多样性的客观存在,揭示gal-3cDNA的多样性是该物种的特征。     

荧光蛋白的研究进展与应用

绿色荧光蛋白(green fluorescent protein,GFP)于1962年被发现,由于它可以发出稳定的荧光,不具有物种专一性,且易于在细胞内表达,已作为标记物广泛地应用于生命科学领域。本文对荧光蛋白的发现、作用机理及其应用进展进行了综述。最后,本文阐述了GFP在动物营养相关领域的研究和应用。     

应急生存设备的情感化设计与研究

探讨了应急生存设备情感化设计产生的背景,分析了灾害中人的情感。从造型、色彩、材质三个层面探寻情感化设计在应急生存设备应用中的具体形式,从而帮助设计者设计出人性心理关怀的产品,以彰显出应急生存设备的情感化设计是对人类的终极关怀。     

西溪湿地底泥质量现状与生态风险初步评价

为了解西溪湿地底泥质量现状,2012年9月采集保护区内不同干扰类型的底泥样本,测试了底泥中重金属和POPs中PCBs、OCPs和PAHs的含量,并对湿地底泥污染进行了生态风险初步评价。结果表明,底泥中未检出PCBs和OCPs,但检测出14种EPA优控PAHs,总PAHs的浓度范围为115.9～217.8 ng·g^-1,低于潜在生态风险的效应区间低值ERL,其中列入中国"水中优先控制污染黑名单"的7种PAHs均有检出并且其总量占∑PAHs 1/2左右(平均为50.08%);底泥中8种重金属含量平均值低于《土壤环境质量标准》(GB 15618-1995)的二级标准,但Hg、Zn、Pb、Ni含量在多个位点已超过一级标准;分别采用土壤背景值和国家一级标准为参比值对湿地底泥中重金属进行单因子污染风险指数评价,发现分别有7种和4种元素的污染指数大于1;综合分析不同干扰类型的底泥质量,发现底泥疏浚能有效降低有机质含量、全氮和PAHs含量,但对全磷、重金属含量则无明显效果,封闭水体的干塘措施能显著减少污泥量和有机物含量。研究结果表明,西溪湿地底泥中高环PAHs和重金属污染水平可能对西溪湿地生物具有潜在的生物毒性作用及不利的生态影响效应,其疏浚底泥农用则无生态风险。     

Landscape perception and recreation needs in urban green space in Fuyang,Hangzhou, China

This study analyzes the landscape characteristics and the residents’ recreational activities in the urban green spaces in Fuyang, Hangzhou, China. It explores the correlation of the desire to be in close proximity to urban green space to engage in recreational activities (the need for recreation) related to residents’ demographic and socio-economic factors: gender, education, monthly income and dwelling location. Residents’ preferences for landscape elements and attributes of urban green space are examined using principal components analysis. In addition, regression analysis identifies that coherence and vegetation are the most relevant factors correlated with perceived overall recreational appropriateness of the three most frequently visited urban parks. The purpose of the study is to attempt to quantify people's recreation needs in urban green space; identify the landscape components in urban green space which can encourage more outdoor visits and/or greater recreational activities; and provide proposals and strategies on planning, management and conservation for recreation-oriented urban green space which will enhance people's enjoyment and wellbeing by improving landscape esthetic quality, recreational and ecological function.     

超高效液相色谱-串联质谱法检测水稻及稻田环境中速灭威的残留

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)检测稻田土壤、田水、水稻植株、谷壳和糙米样品中速灭威残留的分析方法。样品经乙腈提取及盐析处理后,用乙二胺-N-丙基(PSA)和白炭黑(SiO2·nH2O)净化,UPLC-MS/MS 多离子反应监测模式下测定。结果表明,在0.005~1 mg/L 范围内,速灭威的仪器响应值与进样质量浓度间呈良好线性关系,相关系数(r)大于0.98。当添加水平为0.01~5 mg/kg(田水样品中为0.005~1 mg/L)时,速灭威在不同样品基质中的平均回收率为76.7% ~107.8%,相对标准偏差(RSD)为1.7% ~8.5%,最小检出量(LOD)均为2.0×10-13g,最低检测浓度(LOQ) 除在田水样品中为0.005 mg/L外,其余均为0.01 mg/kg。当按推荐剂量的1.5倍(有效成分45 g/hm2)分别施药2次和3次后,采用所建方法测得距最后一次施药10、14和21 d采收的糙米样品中速灭威的最终残留量均为未检出(低于0.01 mg/kg)。     

农药淡水水生生物水质基准研究进展

水环境质量基准(简称水质基准)是环境保护部门制定水质标准、进行水质管理的基础,其中,水生生物水质基准是保护水生生物物种多样性及充分发挥水生生物群落生态功能的保证,是制定水环境管理目标及措施的重要依据。目前用于推导淡水水生生物水质基准的方法主要有评价因子法、物种敏感度分布曲线法及毒性百分数排序法,综述了3种方法的推导过程、适用范围以及优缺点,并对我国农药淡水水生生物水质基准研究的现状及发展趋势进行了探讨。     

浙江省安吉县西苕溪流域非点源污染负荷研究

为探究浙江省安吉县西苕溪流域非点源污染现状,运用污染输出系数法对非点源污染负荷进行估算,并应用地理信息系统（GIS）技术对非点源污染负荷的空间分布特征进行分析。结果表明,2007年浙江省安吉县西苕溪流域非点源污染COD、TN、TP、NH3-N输出总量分别为2236.12t、1007.22t、78.11t、82.90t,分别占西苕溪流域污染物总量的71.91%、70.05%、83.52%、23.64%,其中农村生活污水、农林用地和村镇工业废水是COD的主要污染源,农林用地是TN的主要污染源,农村生活垃圾、畜禽养殖和农林用地是TP的主要污染源,畜禽养殖和村镇工业废水是NH3-N的主要污染源。在空间尺度上,非点源污染负荷主要集中在西苕溪流域中下游地区,COD、TP、NH3-N输出量从上游至下游逐渐增加,但TN输出量相近。