福建农村生态文明监测体系构建及测评

在对农村生态文明的含义和内容进行辨析的基础上,选取了30个反映自然生态保护、农村经济发展和生态文明管理体制的代表性指标,使用主成分分析法和层次分析法,构建了福建农村生态文明建设监测体系。并通过实际数据的测算,对福建9个设区市的农村生态文明情况进行了比较。在此基础上,提出了加强福建农村生态文明建设的若干政策建议

Synthesis and characterization of cellulose acetate with high degree of substitution from miscanthus

以芒草为原料,用Na OH/H_2O_2溶液体系预处理制备芒草纤维,在冰醋酸环境下,以浓硫酸为催化剂与醋酸酐酯化制备芒草醋酸纤维素。优化了预处理条件:温度、时间、次数和酯化条件:催化剂量、温度、时间、醋酸酐量,最佳条件下制备出的芒草纤维的纤维素、半纤维素和木质素的质量分数分别为75.3%、17.3%、5.1%,制备出芒草醋酸纤维素的取代度DS=2.8,特性黏度[η]=1.24 d L/g,达到美国联邦贸易委员会指南认定的三醋酸纤维素标准。利用扫描电镜(SEM)和热分析(TG、DSC)对制得样品进行表征。结果表明,可以利用Na OH/H_2O_2水溶液体系预处理芒草原料制备芒草纤维,并进一步酯化制备出高取代度的醋酸纤维素。A procedure for synthesizing cellulose acetate with high degree of substitution from miscanthus biomass is developed. The miscanthus fiber is prepared by pretreatment of miscanthus biomass with Na OH / H_2O_2,which is then reacted with acetic anhydride in an acetic acid solvent to synthesize cellulose acetate by using concentrated sulfuric acid as catalyst. The effects of the pretreatment factors( such as pretreatment temperature,time and number of times) and the esterification factors( such as catalyst volume,reaction temperature,reaction time and acetic anhydride volume) are studied. Under the optimal conditions,the contents of cellulose,hemicellulose and lignin for prepared miscanthus fiber are75. 3%,17. 3% and 5. 1%,respectively. The degree of substitution( DS) and the intrinsic viscosity( [η ]) of the obtained miscanthus cellulose acetate are 2. 8 and 1. 24 d L / g,respectively. The miscanthus biomass,fiber and cellulose acetate are characterized by SEM,TG and DSC. This study shows that cellulose acetate with high degree of substitution can be prepared from miscanthus biomass pretreated with Na OH / H_2O_2.国家自然科学基金(21303142;31170067);; 福建省中青年教师教育科研项目(JA14010);; 厦门市海洋经济发展专项资金项目(14GZP59HJ29);; 福建省海洋高新产业发展专项项目(闽海洋高新[2014]25号);; 厦门大学校长基金(20720150090

Cloning and heterologous expression of a novel GH10 xylanase gene from Hypocrea orientalis EU7-22

木聚糖酶是降解半纤维素最主要的酶,对于开发可再生生物能源具有重要的应用价值。分别以东方肉座菌(HyPOCrEA OrIEnTAlIS)Eu7-22的基因组dnA和C dnA为模板,利用染色体步移和PCr技术首次克隆获得该菌gH10家族木聚糖酶Ⅲ的基因(XynⅢ),并对其进行生物信息学分析。结果表明:该基因全长1283 bP(gXynⅢ),含有3个内含子;CdS序列为1044 bP(CXynⅢ),编码347个氨基酸,n端含有一个16 AA的信号肽序列;XynⅢ氨基酸序列与TrICHOdErMA PSEudOkOnIngII的EndOXylAnASE具有较高的同源性。经生物信息学分析,XynⅢ成熟蛋白可能含有18个n-糖基化位点,其理论等电点(P I)为6.14,蛋白质分子质量为36.55 ku,属于亲水性蛋白;SWISS-MOdEl建模预测,XynⅢ成熟蛋白中含有11个α螺旋,其核心结构为8个β折叠片围成一个柱状结构。同时将编码成熟蛋白的基因片段MXynⅢ与P PIC9k质粒连接构建表达载体后转化毕赤酵母,对重组子表达产物进行酶活检测显示该基因能在毕赤酵母中表达有生物活性的XynⅢ并分泌到胞外,发酵液中的木聚糖酶活在诱导培养168 H后可达到127.5 Iu/M l。Endo-1,4-xylanase( E.C.3.2.1.8) is the major enzyme to the conversion of hemicelluloses into xylo-oligosaccharide.In this research,a novel GH10 xylanase Ⅲ( xyn Ⅲ) gene was cloned from Hypocrea orientalis EU7-22 by chromosome walking and PCR.The results showed that the DNA fragment( 1283 bp) encoding xynⅢ( gxynⅢ) contained three introns.The CDS of xynⅢ( cxynⅢ) encoded 331 amino acids of putative mature protein and a 16 aa signal in N terminator.The amino acid sequence of xynⅢ is highly homologous with the endoxylanase of Trichoderma pseudokoningii.The bioinformatics analysis showed that the theoretical isoelectric point and the molecular weight of putative mature protein of XYNⅢ were 6.14 and 36.55 ku,respectively.It is a soluble hydrophilic protein containing 18 N-glycosylation sites.The 3D structure predicted with SWISS-Model showed that XYNⅢ protein contained11 alpha helices and 8 extended strands.A recombinant plasmid p PIC9K-xynⅢ was constructed and then transformed into Pichia pastoris.The transformant identified by PCR was induced to produce XYNⅢ enzyme with 1% methanol.And after 168 hours induced expression,the produced crude enzyme was detected to reach a high enzymatic activity of 127.5 IU / m L.国家自然科学基金(21303142;31170067); 福建省海洋高新产业发展专项项目(闽海洋高新[2014]25号); 厦门市海洋经济发展专项资金项目(14GZP59HJ29

Research Progress of α-Glucuronidase, an Enzyme for Degrading Hemicellulose Side-Chain

半纤维素是自然界中最丰富的可再生资源之一,将半纤维素降解为单糖并转化为燃料或化学品一直是科学界研究的热点。半纤维素是由木糖基主链以及α-葡萄糖醛酸等侧链共同组成的异质多聚体。α-葡萄糖醛酸酶是半纤维素完全降解过程中的关键酶之一,能够水解4-O-甲基葡萄糖醛酸与木糖之间的α-1,2-糖苷键。本文综述了α-葡萄糖醛酸酶的分类、催化机制及晶体结构、酶学性质和基因克隆表达等方面的研究进展,同时对该研究进行了展望。Hemicellulose is one of the most abundant renewable resources in nature.The bioconversion of hemicellulose into biofuels or chemicals is a research hotspot in the world.Hemicellulose consists of a backbone of xylan residues and some branches like glucuronic acid.α-Glucuronidase, which is capable to hydrolysis the α-1,2-glycosidic bond between xylan and glucuronic acid, is one of the key enzyme to degrade hemicellulose completely.The recent research progresses on catalysis mechanism, structure, charaterization, and gene cloning of α-glucuronidase are summarized in this paper.国家自然科学基金(31170067;21303142); 国家重点基础研究发展计划(973计划;2010CB732201); 福建省自然科学基金(2012J05029); 农业部“引进国际先进农业科学技术”项目(2013-Z70

高速超低功耗16QAM发射装置

 一种高速超低功耗16QAM发射装置,包括：一锁相环频率综合器,其输出端与除四分频器的输入端连接；一除四分频器,其输入端与锁相环频率综合器的输出端连接；一四选一相位选通器,其输入端与除四分频器的输出端连接；一四选一相位选通器,其输入端与除四分频器的输出端连接；一相位调制器,其输入端分别与四选一相位选通器的输出端连接,用于产生相位已调信号,并驱动变增益功率放大器；一变增益功率放大器,其输入端与相位调制器的输出端连接,用于产生两种不同的信号幅度并驱动天线欧姆负载；一16QAM数字调制器,其输出端分别与四选一相位选通器,相位调制器,变增益功率放大器的输入端相连接,用来将串行输入的基带数据进行串并转换,形成16QAM调制所需要的四位并行数据

一种高密度低寄生的电容装置

本发明公开了一种电容装置，包括：一个由多晶硅栅、栅氧及连接到一起的源、漏和N阱构成的PMOS电容，其中源、漏和N阱连接到电容装置的A端口，多晶硅栅连接到电容装置的B端口；同一层金属之间的第一电容，该同一层金属由两个连接到电容装置A端口和B端口的金属叉指构成；相邻层金属之间的第二电容，其中上层金属叉指与其投影下方的金属叉指分别连接到电容装置的A端口和B端口；MIM电容，具有上极板和下极板，上极板和下极板分别连接到电容装置的A端口和B端口。本发明通过在MOS电容上实现同层金属之间的电容、相邻金属层之间的电容、MIM电容等，最大限度的实现了单位面积上的电容

一种高密度低寄生的电容装置

本发明公开了一种高密度低寄生的电容装置，包括：一个由多晶硅栅、栅氧及连接到一起的源、漏和N阱构成的PMOS电容；多晶硅栅与第一层金属之间的第一电容；同一层金属之间的第二电容，其中该同一层金属由金属方块阵列构成，且每一个金属方块与其相邻的金属方块分别连接到电容装置的A端口和B端口；通孔与通孔之间的第三电容，其中每个通孔与其相邻的通孔分别连接到电容装置的A端口和B端口；MIM电容，具有上极板和下极板，上极板和下极板分别连接到电容装置的A端口和B端口。本发明通过在MOS电容上实现多晶硅栅与金属层之间的电容、同层金属之间的电容、通孔与通孔之间的电容、MIM电容等，最大限度的实现了单位面积上的电容