渔用HDPE/淀粉复合材料的结构与性能

采用熔融共混法制备高密度聚乙烯(HDPE)/淀粉复合材料,研究了淀粉含量(w淀粉)对HDPE/淀粉复合材料的流变性、微观结构、热性能、力学性能与动态力学性能的影响。结果显示,淀粉含量为20 wt%时淀粉在HDPE基体中呈微米级均匀分布,淀粉含量增加到30 wt%和50 wt%时呈球状聚集体,其平均粒径从0.6μm增加到0.8μm。随淀粉含量增加,HDPE/淀粉复合材料的断裂强力和断裂伸长率显著降低。不同淀粉含量的HDPE/淀粉复合材料均被检测到3个转变峰。HDPE低温下的γ转变峰对应为聚乙烯的玻璃化转变峰,对应于非晶态链段的运动,淀粉含量对γ转变峰影响不大。纯HDPE不存在β峰,β转变与淀粉分散相有关,随淀粉含量增加,复合材料的β峰变宽。高温区出现的α转变与聚乙烯结晶区附近受限链段的运动有关,是一个复杂的多重松弛过程。研究表明,引入一定含量的淀粉可以改善HDPE的加工流变性和韧性,为制备高性能可降解淀粉基渔用材料提供了理论和技术支撑。     

2016年天津主要陆源入海排污口排污状况综合评价

为更好地保护海洋环境与海洋渔业资源,了解陆源入海排污口对海域的有机物污染物、重金属等有毒有害物质的输入状况以及对近岸海洋生态损害的状况与程度,掌握天津市近岸海域陆源入海排污口排放入海的污水量、污染物种类和数量以及各种污染物的浓度状况,2016年对天津12个主要陆源入海排污口的排污情况进行监测,通过单因子评价法确定排污口主要污染物;并通过超标率、污染程度、污水生物毒性对排污状况进行综合评价。结果表明,2016年天津市主要陆源入海排污口超标污染物为化学需氧量(CODCr)、五日生化需氧量(BOD5)和粪大肠菌群。各排污口年超标率为7.29%~17.86%,年平均污染程度指数为5~7分,排污口等级为黄色到橙色,生物毒性均为低毒性风险。其中大沽排污河入海口、泰达市政排污口Ⅰ、泰达市政排污口Ⅱ、海河入海口四个排污口污染程度最高。     

白色水果玉米申雪甜1号的选育

为了改变当前白色水果玉米以进口为主,缺乏自主知识产权品种的现状,以WS02为母本,WS01为父本,在国内首次以SRG基因为遗传背景,选育出杂交白色超甜玉米新品种申雪甜1号。申雪甜1号春播出苗至采收77 d,株高156 cm,穗位高27 cm,果穗长锥形,穗长19.3 cm,穗粗4.5 cm,穗行数15.7行,行粒数32.4粒,籽粒白色,排列整齐,单穗净质量220～250 g,鲜百粒质量31 g,鲜出籽率63.9%,平均667 m2产量高达788 kg;鲜食糖度可以达到18%～20%,综合品质评价90.3分,尤其蒸煮品质方面的风味、色泽、甜度、果皮厚度均优于对照金菲,与对照雪甜7401相当,是可以生吃的水果甜玉米,且皮薄渣少,适口性好;抗大斑病、小斑病和茎腐病,轻感纹枯病、南方锈病,综合抗性优于对照金菲和雪甜7401。适宜在上海、浙江等地区种植。     

MMT改性淀粉基纳米复合纤维的海水降解性能

不可降解渔具造成的“白色污染”和“幽灵捕捞”问题已严重威胁到海洋的生态环境,开发可降解渔具材料已经成为我国渔业可持续发展的有效途径之一。本实验采用熔融纺丝法制备淀粉(STR)/高密度聚乙烯(HDPE)/纳米蒙脱土(MMT)纳米复合纤维,研究MMT对纳米复合纤维的热学性能、力学性能、动态力学性能与海水降解性能的影响。结果显示,引入MMT后,纳米复合纤维的熔融温度(Tm)移向低温,结晶度增加,而断裂强度下降。此外,MMT的加入显著降低了聚乙烯的玻璃态储能模量和内部损耗,但对淀粉相影响不显著。4个月海水降解结果显示,与STR/HDPE纤维相比,STR/HDPE/MMT纳米复合纤维失重率增加了约5%,纤维直径减小了约11%,这表明MMT加快了STR/HDPE纤维的降解过程。本实验系统研究了MMT改性淀粉基纳米复合纤维的海水降解性能,可为渔业等海洋产业用降解新材料的开发与应用提供参考。     

超声波改善大蒜秸秆不溶性膳食纤维结构及吸附性

为了增强大蒜秸秆膳食纤维的功能特性,采用超声波对大蒜秸秆的不溶性膳食纤维(insoluble dietary fiber,IDF)进行改性处理。以提高葡萄糖吸附能力为目标,利用单因素试验和响应面法优化大蒜秸秆IDF的超声改性条件,通过胆固醇结合力、吸水性、持油性及膨胀能力等来评价改性后IDF的功能特性,并通过扫描电镜和红外光谱分析其结构变化。结果表明:液料质量比30:1、超声功率700 W和超声时间40 min时,大蒜秸秆IDF的葡萄糖吸附能力明显提高,比对照组提高了12.8%,胆固醇吸附力则提高了45.0%(P0.05);超声处理所得IDF的色泽品质和物理化学特性也明显优于对照组(P0.05);超声处理和对照IDF的红外吸收光谱基本相同,电镜结果显示超声波处理使IDF的组织结构变得更加疏松,其表面呈现蜂窝状,有助于表现出较强的吸附性,从而赋予大蒜秸秆IDF更强的功能品质和物理化学特性。     

区域人口—经济—生态环境耦合协调空间分异规律研究

以安徽省16个地级市为研究对象,通过ArcGIS的空间分析工具和Geoda1.0.6软件,分析各市人口、经济、生态环境耦合协调发展的空间分布特征及空间集聚效应。研究表明：人口—经济—生态环境耦合度分布较为均衡,除亳州外都处于拮抗阶段;人口—经济—生态环境耦合协调度空间分布较不均衡,皖北和江淮地区主要属于轻度失调衰退类,皖南地区主要属于濒临失调衰退类;人口—经济—生态环境耦合协调度的空间集聚特征显著,其中H—H集聚现象主要分布在皖南地区,L—L集聚现象主要分布在皖北地区。     

Influence of Drawing and Annealing on the Crystallization,Viscoelasticity, and Mechanical Properties for Middle-molecular-weight Polyethylene Fishing Monofilaments

The influence of drawing and annealing on the crystallization, viscoelasticity and mechanical properties for middle-molecular-weight polyethylene (MMWPE) fishing monofilaments was investigated. It was found that the drawing procedure had a positive effect on the crystallization of the MMWPE fishing monofilaments. Meanwhile, the glass transition temperature of the MMWPE monofilaments shifted to higher temperature, and the α-relaxation associated with crystalline phases became higher and broader with the increase in the drawing ratio. Moreover, the breaking strength of MMWPE fishing monofilaments can be effectively improved by increasing the drawing ratio. Meanwhile, the knot strength increased first and then decreased. However, the increase in annealing temperature improved the knot strength. With increasing annealing temperature, the orientation factor decreased and induced the γ-relaxation peak at high magnitude. This indicated that the amorphous structure could become disordered during annealing treatment. In addition, the annealing temperature can clearly influence the working temperature dependence of the stress-strain behavior. When the working temperature rose from 20 °C to 30 °C, the MMWPE monofilaments after annealing at 120 °C exhibited low modulus loss due to their high α- transition temperature. Thus, an important method for improving the mechanical properties by controlling the drawing and annealing conditions was established.     

动物流行病学正态样本异常值的判断和处理

讨论动物流行病学调查分析数据正态样本的判断和处理。描述格拉布斯检验法和偏度-峰度检验法在处理正态样本中的步骤。以仔猪市场价格为例,阐述格拉布斯检验法的运用方法。说明样本异常值的处理技术。     

大豆F3’H基因植物表达载体的构建及拟南芥的遗传转化

通过RT-PCR方法扩增了大豆F3'H基因并构建含大豆荚皮绒毛色基因的重组质粒pBI121/F3'H的植物表达载体,转化到根癌农杆菌LBA4404菌株中形成工程菌株,通过根癌农杆菌介导的方法转化拟南芥.为进一步研究大豆荚皮绒毛色基因(F3'H)作为植物基因工程的报告基因的可能性奠定基础.     

Surface coating as a key parameter in engineering neuronal network structures in vitro

By quantitatively comparing a variety of macromolecular surface coating agents, we discovered that surface coating strongly modulates the adhesion and morphogenesis of primary hippocampal neurons and serves as a switch of somata clustering and neurite fasciculation in vitro. The kinetics of neuronal adhesion on poly-lysine-coated surfaces is much faster than that on laminin and Matrigel-coated surfaces, and the distribution of adhesion is more homogenous on poly-lysine. Matrigel and laminin, on the other hand, facilitate neuritogenesis more than poly-lysine does. Eventually, on Matrigel-coated surfaces of self-assembled monolayers, neurons tend to undergo somata clustering and neurite fasciculation. By replacing coating proteins with cerebral astrocytes, and patterning neurons on astrocytes through self-assembled monolayers, microfluidics and micro-contact printing, we found that astrocyte promotes soma adhesion and astrocyte processes guide neurites. There, astrocytes could be a versatile substrate in engineering neuronal networks in vitro. Besides, quantitative measurements of cellular responses on various coatings would be valuable information for the neurobiology community in the choice of the most appropriate coating strategy.