根癌农杆菌介导AtNHX1基因转化小麦

利用根癌农杆菌对 3种基因型小麦进行了转化研究 .发现基因型对转化有明显影响 .将小麦品种烟优 36 1、烟 10 3、核生 3号的胚性愈伤组织用含报告基因NPTⅡ和抗盐基因Na H 反向转运AtNHX1的农杆菌菌株pROK2AT GV310 1感染和共培养后 ,用巴龙霉素 5 0 - 15 0mg L筛选抗性愈伤组织及转化植株 .对抗性植株的总DNA用AtNHX1基因的特异引物进行PCR检测 ,目的基因的PCR阳性频率为 1.3(烟 10 3)和 2 .9% (核生 3号 ) .Southern杂交证实外源基因已经整合到小麦的基因组中     

椭圆周上的一类新的双正交级数

研究了椭圆周上一类新的双正交级数，给出了它的部分和与其诱导函数的Ｆｏｕｒｉｅｒ三角级数的部分和之间偏差的精确的渐近表达式．     

Frequent mtDNA mutations and its role in gastric carcinogenesis

In order to disclose the relationship between mutations of mitochondrial DNA (mtDNA) and gastric carcinogenesis, we screened the entire mtDNA sequence in 30 cases of human gastric cancer and matched normal tissues by using denaturing high-performance liquid chromatography (DHPLC) and DNA sequencing. Our data showed that high frequency (66.7%, 20/30) of mitochondrial genome mutation occurred in gastric cancer. Among these variants, 17 cases (56.7%, 17/30) were identified to be somatic mutation. High level mutant frequency was found in ND4, ND5 coding genes and D-loop control region, which was 36.7%, 26.7% and 30% respectively. Comparing with complexes Ⅲ, Ⅳ and Ⅴof the electron transport chain, we found that variants appeared to be more frequent in the subunit genes of complexⅠ. Most of mutations were base substitutions (85.4%, 41/48). Our results suggested that mutations of subunit genes encoding complexⅠ, especially ND3, ND4 and ND5 genes, might contribute to human gastric carcinogenesis.     

BioStarM-140s芯片基因信息查询系统的构建及应用

应用生物信息学数据库查询的方法,对B ioS tarM-140s小鼠基因表达芯片上的14 112个基因进行相应注释信息的查询和所对应蛋白质功能的分类.首先参照人类综合型芯片上基因的功能分类,设定了14个蛋白质类别,然后采用V isual C 编程语言,构建了基因信息查询系统.应用该查询系统,进行了网络生物学数据库信息资源的自动直接查询,共搜索到有注释信息的基因12 070个;进一步按照所设定的14个蛋白质类别对12 070个基因进行分类查询,搜索到了与这14个分类相符合的、具有详细蛋白质功能注释信息的基因共1 606个.     

TD-SCDMA系统中引入阈值信噪比的信道估计

采用联合检测和智能天线等技术是TD-SCDMA移动通信系统的优势之一,但这些技术的实现必须以准确的信道估计为前提.本文探讨了适合于TD-SCDMA系统的信道估计算法,分析了一种加入阈值信噪比的信道估计算法原理.通过上行链路的模拟仿真表明,该信道估计算法的信道响应更接近理想值,有利于提高系统性能.     

浅谈利用任务驱动法进行单片机教学与职业核心能力的培养

本文就任务驱动法在单片机教学中的应用与职业核心能力培养进行了阐述，并且以实例的形式得到了很好的验证。     

基于DSP的变频调速控制系统设计

应用矢量控制的原理，以DSP为核心，开发出一套基于DSP的变频调速系统。对整个系统的硬件电路和驱动软件实现作了详细的介绍，实现对异步电机的控制，提高了能量的利用效率。     

提升普通高校学报影响力的措施和方法

分析了普通高校学报影响因子低、影响力小的原因,重点论述了提高普通高校学报被引频次、影响因子和影响力的措施和方法.     

Study on the Predicting System of Breaking Chip When PCD Tool Cutting Aluminum Alloy

In the field of automobile manufacture, during the aluminum alloy cutting, chip forming and breaking process are very complicated. It is affected by many facto rs. Automatic machining process can not be carried through if the chip enlaces t he workpiece or the tool. So the chip control and breaking are key technology. P CD tool has many traits, such as high cutting efficiency, machining precision an d wearability. It is desired that it be used for machining coloured metals.The p aper present the study of p...