13 research outputs found

    一种导电超高分子量聚乙烯纤维的制备方法

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    本发明涉及一种导电超高分子量聚乙烯纤维的制备方法。现有方法工艺复杂、污染环境。本发明方法首先将超高分子量聚乙烯纤维浸泡在丙酮、乙醇或四氢呋喃溶液中,超声洗涤后晾干;然后将多巴胺类物质溶解在缓冲溶液中,配成活化溶液,将超高分子量聚乙烯纤维置于活化溶液中,在搅拌下进行活化;将活化后的超高分子量聚乙烯纤维浸入镀液中,10~60℃下浸0.5~10小时,完成镀银。本发明利用多巴胺类聚合物强黏附作用活化表面,用化学镀实现表面金属化,得到导电性极佳的超高分子量聚乙烯纤维,整个过程对环境友好无污染

    利用界面缩聚改性超高分子量聚乙烯粉末表面的方法

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    本发明公开了一种利用界面缩聚改性超高分子量聚乙烯表面的方法,该方法包括将超高分子量聚乙烯粉末浸泡在含两个或两个以上酰氯基团或异氰酸酯基团的反应单体溶液中,再加入到含有两个或两个以上胺基或羟基的反应单体溶液中,经搅拌分散,通过界面缩聚在超高分子量聚乙烯粉末表面生成一层聚脲和/或聚氨酯和/或聚酰胺薄膜,从而有效地改善UHMWPE粉末表面的相容性和粘结性,同时不改变UHMWPE粉末本身性能。另外,本发明的UHMWPE粉末表面改性方法操作简单、对设备要求低、处理速度快而且处理效果好,是一种易于进行工业化生产的UHMWPE粉末表面改性方法

    Genetic variation in three farmed Plectorhinchus cinctus stocks with various body color using AFLP analysis

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    通过AFLP技术对中国东南沿海的3个不同体色花尾胡椒鲷(Plectorhinchus cinctus)养殖群体进行了遗传分析。6对引物组合从3个群体中扩增出370个位点,其中多态位点比例为49.5%,每对引物组合扩增的片段为51~71条,平均61.3条,每对引物组合多态位点检出率为39.4%~56.5%。正常群体、白色和灰色变异群体的多态位点比例分别为41.4%、36.3%、34.3%,平均杂合度分别为0.1145、0.0887和0.0837。遗传多样性衡量指标表明,正常花尾胡椒鲷养殖群体的遗传变异量相对最大,遗传多样性相对较高,白色变异群体次之,而灰色变异群体最低,白色变异群体和灰色变异群体两者间遗传多样性差异并不显著(P>0.05),显示变异群体的遗传多样性降低。正常群体与白色群体之间的遗传距离(0.0354)最大,遗传相似系数最小(0.9652)。同时,遗传分化系数Fst(0.1362)和AMOVA方差分量百分比(10.68%)也表明群体间存在着一定程度的遗传结构分化,说明对体色这一特定表型性状的人为定向选育对花尾胡椒鲷养殖群体的遗传变异产生一定的影响。Yellow-spotted grunt Plectorhinchus cinctus is a commercially important marine fish cultured in both southeast coast and Taiwan Province of China. At present,the technology on mass seed production and grow-out in a large scale are well established for this species in these areas. During the period of artificial breeding,the stock of morphs with white body and black eyes appeared in normal stock first,and then grey-morph stock differentiated from white stock. In order to assess genetic variation in these different Plectorhinchus cinctus stocks with different body color,to investigate their genetic structure,to evaluate the impact of artificial breeding on their genetic diversity and provide a baseline for further study of genetic breeding and population evolution as well,a total of 90 yellow-spotted grunt were collected from three different localities in both Fujian and Guangdong Provinces in 2004. Among them,12 randomly sampled fish from each stock were used for genomic DNA isolation,and then the amplified fragment length polymorphic (AFLP) technique was employed to analyze genomic DNA polymorphism. The results showed that a total of 370 DNA amplification bands ranging from 100 to 900 bp were produced using 6 pairs of primer combinations selected for the three stocks,including EcoRI-ACC/MseI-CAG,EcoRI-ACC/MseI-CTC,EcoRI-ACC/MseI-CAC,EcoRI-ACT/MseI-CTC,EcoRI-AAC/MseI-CAT and EcoRI-AAC/MseI-CAC,of which 183 were polymorphic and the proportion of polymorphic loci was 49.5%. The amplified bands ranged from 51 to 57 with an average of 61.3 for each primer combination,and the detecting rate of each primer varied from 39.4% to 56.5%. These 6 primer combinations yielded 353 bands,317 bands and 327 bands,respectively,with 146,115 and 112 polymorphic loci for normal,white morph and grey morph stocks. Percent polymorphic loci of 41.4%,36.3% and 34.3% and average heterozygosity of 0.114 5,0.088 7 and 0.083 7 were determined in normal stock,white morph stock and grey morph stock respectively,which clearly showed the trend in the reduction of genetic diversity in morph stocks in comparisons with normal stock. The maximum genetic distance(0.035 4)was also detected between normal and white morph stocks with minimum genetic coefficient(0.965 2). At the same time,genetic division coefficient Fst(0.136 2)and percent variance component of AMOVA(10.68%)also indicated that some genetic differentiation occurred in these three stocks. There existed a certain genetic structure differenciation among them,but there was still more genetic divergence within the stocks than that between the stocks. Either NJ cluster analysis or UPGMA cluster analysis classified normal stock and grey stock into the same category,and white stock was another cluster. It is concluded that genetic divergence is higher in normal stock than that in white or grey stock;the former has rich genetic diversity and grey stock possesses low genetic divergence and diversity compared with the two others. Selective breeding in terms of body color as a specifically phenotypic trait has some impacts on genetic variation of farmed stocks of P. cinctus. However,due to a comparatively short time of isolation in each stock,there has been no significant genetic difference between them so far(P>0.05).福建省海洋与渔业局重点项目(闽渔科0371)

    尿嘧啶分子振动性质研究

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    页岩气开采中的若干力学前沿问题

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    页岩气的开采涉及破裂和收集输运两个关键过程.如何实现2000 m以下、复杂地应力作用下、多相复杂介质组分的页岩层内网状裂纹的形成,同时将孔洞、缝隙中的游离、吸附气体进行高效收集,涉及到诸多的核心力学问题.这一工程过程涵盖了力学前沿研究的诸多领域:介质和裂纹从纳米尺度到千米尺度的空间跨越,游离、吸附气体输运过程中微秒以下的时间尺度事件到历经数年开采的时间尺度跨越,不同尺度上流体固体的相互作用,以及压裂过程中通过监测信息反演内部破坏状态等.针对近年来我们国家页岩气勘探开发工作所取得的成就及后续发展中面临的前沿力学问题,在综合介绍页岩气藏的基本特征和开发技术的基础上,以页岩气开采中的若干力学前沿问题为主线,从页岩力学性质及其表征方法、页岩气藏实验模拟技术、页岩气微观流动机制及流固耦合特征、水力压裂过程数值模拟方法、水力压裂过程微地震监测技术、高效环保的无水压裂技术等6个方面的最新研究进展进行了总结和展望,结合页岩气藏开发的工程实践,深入探究了其中力学关键问题,以期对从事页岩气领域的开发和研究的从业人员提供理论基础,同时,该方面的内容对力学学科、尤其是岩土力学领域的科研工作也具有重要指导价值.</p

    页岩气开采中的若干力学前沿问题

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    页岩气的开采涉及破裂和收集输运两个关键过程.如何实现2000 m以下、复杂地应力作用下、多相复杂介质组分的页岩层内网状裂纹的形成,同时将孔洞、缝隙中的游离、吸附气体进行高效收集,涉及到诸多的核心力学问题.这一工程过程涵盖了力学前沿研究的诸多领域:介质和裂纹从纳米尺度到千米尺度的空间跨越,游离、吸附气体输运过程中微秒以下的时间尺度事件到历经数年开采的时间尺度跨越,不同尺度上流体固体的相互作用,以及压裂过程中通过监测信息反演内部破坏状态等.针对近年来我们国家页岩气勘探开发工作所取得的成就及后续发展中面临的前沿力学问题,在综合介绍页岩气藏的基本特征和开发技术的基础上,以页岩气开采中的若干力学前沿问题为主线,从页岩力学性质及其表征方法、页岩气藏实验模拟技术、页岩气微观流动机制及流固耦合特征、水力压裂过程数值模拟方法、水力压裂过程微地震监测技术、高效环保的无水压裂技术等6个方面的最新研究进展进行了总结和展望,结合页岩气藏开发的工程实践,深入探究了其中力学关键问题,以期对从事页岩气领域的开发和研究的从业人员提供理论基础,同时,该方面的内容对力学学科、尤其是岩土力学领域的科研工作也具有重要指导价值

    产量与经济效益共赢的高效生态农业模式:以弘毅生态农场为例

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    化学物质的大量投入以及元素不能循环导致农田生态系统退化,耕地质量和产量均呈下降趋势,食物链受到污染.本研究从低产田开始,通过秸秆养牛、腐熟牛粪还田恢复地力;以物理+生物方法控制虫害;以人工+机械管理杂草,停用农药、化肥和除草剂,同时不用地膜、人工合成激素、转基因种子生产优质安全食品,并在线上与线下销售.10年的长期实验结果表明,所在村庄农田生态环境改善,减少农药用量58.3%;物理+生物控虫效果明显,每盏灯年捕获量从2009年的33 kg下降到2014年的2.1 kg,下降93.8%;年消耗秸秆1000 t,秸秆利用率从1.1%提高到62.5%.有机肥还田提高了土壤生物多样性,有机果园蚯蚓数量317条m~(-2),而普通果园只有16条m~(-2);大量有机肥还田(75 t hm~(-2)),土壤有机质从实验初期的0.7%提高到2.4%.粮食产量从最初的11.43 t hm~(-2)提高到目前的17.43 t hm~(-2),其中冬小麦(Triticum aestivum)、夏玉米(Zea mays)、大豆(Glycine max(Linn.)Merr.)和花生(Arachis hypogaea Linn.)产量分别超出山东省平均水平42.6%,60.9%,32.2%和38.1%.由于质量好,产品已销售往除西藏以外的30个省、市、自治区,经济效益明显,平均每公顷效益是普通农田的3~5倍,带动所在村庄67户农民从事高效生态农业.本研究可为国家制定生态农业发展规划、精准扶贫、农村环境保护等提供科学依据
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