民勤绿洲生态气候资源及其利用

民勤绿洲边缘 ,光照丰富、温差大 ,有利于农产品质量的提高。但是水资源缺乏 ,地下水位急剧下降和土地沙化是民勤绿洲农业生产的首要问题。如何充分利用现有生态资源 ,并充分提高其利用率是摆在我们面前的一个主要课题。只有通过引进优良品种 ,调整农业种植结构 ,大力推广节水灌溉技术 ,才是解决上述问题的有效途径     

The integration and insertion site of GbVe1 gene in the genome of transgenic cotton (Gossypium hirsutum)

[Objective] The aim of this study was to obtain the flanking sequences of T-DNA in the transgenic cotton containing a GbVe1 over-expression cassette. [Method] The T-DNA insertion copy number in the transgenic GbVe1 cotton was analyzed by southern blot. Flanking sequences of the transgenic lines with putative single T-DNA insertion copy were obtained using high-efficiency Thermal asymmetric interlaced polymerase chain reaction (hiTAIL-PCR). The T-DNA insertion sites were further confirmed by PCR with specific primers. [Result] RB-flanking sequences (119-1 018 bp) and LB-flanking sequences (243-516 bp) were obtained from three transgenic lines with low copy number of T-DNA insertion. The AT content was more than 63% in these flanking sequences. A same single insertion site in the intron of Gohir.D01G157600.1 was found in the two transgenic lines 7/100826-152 and 12/100826-393, while two separated insertion sites, one also in the intron of Gohir.-D01G157600.1 and the other in the intergenic region of A12 chromosome, were found in the transgenic line 1/w-ch14. A deletion of 21 bp was found in the insertion site in the intron of Gohir.D01G157600.1. The T-DNA insertion in the intron of Gohir.D01G157600.1 was further confirmed by the specific PCR. [Conclusion] The flanking sequences of T-DNA in the transgenic GbVe1 cotton were obtained and the specific transformation event in the intron of Gohir.D01G157600.1 was further confirmed by PCR.     

辽西北困难立地造林有关建议

辽西北地区造林成效很低究其根源,概括起来,困难立地造林主要问题也不少。     

Characterization of Genomic Integration and Transgene Organization in Six Transgenic Rapeseed Events

To characterize the DNA rearrangement of both the T-DNA region and the genomic insertion site during T-DNA insertion, the Genomewalker strategy was used to isolate the junctions between the inserted DNA and the plant genomic DNA in six rapeseed events as well as the genomic DNA at the sites before integration. During transformation in each of the six events, portions of both the right border（RB） and left border（LB） regions of the T-DNA were deleted, ranging from a 7 nucleotide deletion of the LB repeats in event RF1 to a 207 bp deletion of the LB region in event RF2. For the six events, T-DNA integration resulted in a deletion at the target site spanning less than 100 bp. Sequence analysis indicated that the T-DNA was integrated into the coding region of various native rapeseed genes in events RF1 and RF2. Duplications of the genomic DNA target site were observed in events RF2, RF3 and Topas 19/2. And multimerization of transgenes was found in event Topas 19/2, in which, the T-DNA was integrated as a head-to-head（RB-to-RB） concatemer into the recipient genome. In event MS1, chromosomal translocation or a large target-site deletion may have occurred during T-DNA integration, which was identified due to a failure to amplify the presumptive insertion site based on the flanking rapeseed DNA sequences. Our results provide comprehensive data concerning transgene organization and the genomic context of the T-DNA in six rapeseed events, which can aid in the developing of insert fingerprinting and the monitoring of long-term genetic stability and potential unintended effects of transgenic events.     

廊道景观边缘效应研究

运用景观生态学原理,依据绿色廊道的生态功能,对长沙市廊道景观边缘和内部的主要植物种类及其重要值进行了调查和分析。结果表明:在同一条件下,廊道景观边缘植物种类多于内部植物种类。这可为长沙市廊道景观的生态建设提供参考依据。     

河北省平原地区农村宅基地不合理利用的成因分析——基于河北省涿州市的调查研究

基于河北省平原地区宅基地不合理利用的现状,选取涿州市为研究对象,通过对案例、数据的分析,从理论与实证的角度,阐明了宅基地不合理利用的现状及成因,提出了解决问题的对策。     

论影响麻花钻切削因素之间的关系

学生搞不清楚麻花钻刃磨时几何角度之间的关系,导致麻花钻头的刃磨失败,最终使学生形成了麻花钻内容太难,麻花钻刃磨起来太麻烦的结论。用图示、口诀配合文字讲解的方式讲解标准麻花钻切削部分之间的关系,学生易于接受。     

级进模自动排样冲切刃口设计

针对级进模难于实现自动化的排样问题,通过对不满足悬臂和凹槽强度检验要求的多义线进行分析和对外形轮廓的分解与重组,对级进冲裁模排样系统中冲裁零件的冲切刃口进行了分析与设计;同时为保证凹模壁厚达到强度要求,在分析冲切刃口的干涉关系的基础上,根据分析结果设计了程序,该程序能够自动重新生成级进模各工位的冲切刃口和外形,以实现级进模的自动工序排样。     

45阶Kirkman三连系的构造与计数

给出了边矩阵和完全三分图的定义,提出了利用边矩阵、完全三分图构造45阶Kirkman三连系的思路。介绍了不同构的45阶Kirkman三连系构造的全过程,讨论了45阶Kirkman三连系的计数。