Finite element mode analysis and experiment ofcombine harvester chassis

针对联合收获机正常工作时的振动与噪音问题,为减少共振的发生,利用三维软件UG对沃得巨龙280型稻麦联合收获机底盘机架进行了参数化建模,采用NX Nastran模块求解出了底盘机架的模态频率和振型,并对底盘机架进行了模态试验,验证了理论分析的准确性。在分析了外部激振频率特点的基础上,为使底盘机架的固有频率避开外部激振频率范围,对机架进行了结构优化。结果表明：在底盘机架质量增加3.77%的条件下,机架的前4阶模态频率分别调整到21.70、36.61、43.64和46.33 Hz,均避开了脱粒滚筒激振频率范围15～18.3 Hz和发动机的激振频率范围38.3～41.7 Hz,可以有效避免共振的产生。该研究为联合收获机底盘结构的设计与优化提供了参考。     

修正碳赤字视阈下京津冀县域生态补偿时空格局及其驱动因素

[目的]建立兼顾区域本底差异的生态补偿模型,进一步明确京津冀生态补偿时空分异格局及其主导驱动因子,为政府部门制定环境保护与宏观经济政策提供参考。[方法]基于修正碳赤字,利用模型构建、空间相关性分析与地理探测器技术等方法构建了合理的生态补偿框架,分析和研究了2007—2020年的京津冀县域生态补偿的时空变异格局、空间自相关性、驱动因子排序和交互作用等内容。[结果](1)京津冀县域2007—2020年碳排放量呈现“先增后减”的变化趋势,碳吸收量大体呈现持续增加的变化趋势。(2)修正前的京津冀县域碳赤字呈现东、南、西部高,而北部较低的U形格局,而修正后的碳赤字由于兼顾了区域间本底差异,在时空分布上更加均匀。(3)生态补偿额度冷点区域基本分布在京津冀东北部,热点区域分布在京津冀西南部,两者之间存在个别冷热点区域,整体呈现热点区域向东北方向移动,冷点显著区域向西南方向移动的趋势。(4)不同年份内影响生态补偿额变化的主要因子不同,2007,2012,2017和2020年这4 a中影响京津冀县域生态补偿变化的主导影响因子分别为第三产业产值、财政收入、第二产业产值和人均生产总值;不同年份导致生态补偿变...     

Successful <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of <Emphasis Type="Italic">Populus tomentosa</Emphasis> with apple <Emphasis Type="Italic">SPDS</Emphasis> gene

The problem of salinized soils has become one of the most serious constraints to agricultural and forest productivity. With the purpose of enhancing salt stress tolerance of Populus tomentosa, we transformed this tree species with spermidine synthase （SPDS） genes derived from an apple by an Agrobacterium-mediated method. Four transgenic clones were confu＇med by PCR and Southern blot analysis. As well, the expression of introduced SPDS genes was analyzed by real-time quantitative PCR.     

重庆市50年来小麦主栽品种高分子量谷蛋白亚基分析

采用十二烷基硫酸钠聚丙烯酰胺凝胶电泳技术（SDS-PAGE）．对重庆市近50年来主要推广的50个小麦品种的高分子量谷蛋白亚基遗传变异进行分析,检测到13种亚基和17种亚基组合类型,其中,Glu-A1有3种类型（1、null和2^＊）。分别占50％、46％和4％;Glu-B1有7种类型,主要有7＋8、14＋15和7＋9。分别占54％、18％和12％;Glu-D1有3种类型,主要是2＋12、5＋10。分别占76％、20％;品质评分在5-10之间,平均7．3分;20世纪90年代以后育成品种中优质亚基5＋10、17＋18出现频率明显增加。说明育种单位已重视利用具有优质遗传背景的材料。     

CHRIS数据几何校正精度改善研究(英文)

This paper deals with a new type of multi-angle remotely sensed data--CHRIS （the Compact High Resolution Imaging Spec- trometer）, by using rational function models （RFM） and rigorous sensor models （RSM）. For ortho-rectifying an image set, a rigorous sen- sor model-Toutin＇s model was employed and a set of reported parameters including across track angle, along track angle, IFOV, altitude, period, eccentricity and orbit inclination were input, then, the orbit calculation was started and the track information was given to the raw data. The images were ortho-rectified with geocoded ASTER images and digital elevation （DEM） data. Results showed that with 16 ground control points （GCPs）, the correction accuracy decreased with view zenith angle, and the RMSE value increased to be over one pixel at 36 degree off-nadir. When the GCPs were approximately chosen as in Toutin＇s model, a RFM with three coefficients produced the same accuracy trend versus view zenith angle while the RMSEs for all angles were improved and within about one pixel.     

雏鸡在感染IBDV后血浆cAMP、cGMP和IL-2水平变化

在经ＩＢＤ弱毒苗免疫和未免疫的３０～５９日龄ＡＡ鸡研究了感染ＩＢＤＶ后血浆ｃＡＭＰ、ｃＧＭＰ和ＩＬ２水平动态变化。结果表明：未免疫攻毒鸡（Ａ组）、免疫攻毒鸡（Ｂ组）和未免疫未攻毒鸡（Ｃ组）在ＩＢＤＶ攻毒前１天血浆ｃＡＭＰ和ｃＧＭＰ水平Ｂ组明显高于Ａ和Ｃ组,ｃＡＭＰ／ｃＧＭＰ比值同样是Ｂ组高于或明显高于Ａ和Ｃ组,ＩＬ２水平三组之间无明显差异。在攻毒后的头５天内,Ｂ和Ｃ组ｃＡＭＰ明显升高,而Ａ组没有类似的变化,第５天明显低于Ｂ和Ｃ组,以后Ｂ和Ｃ组仍高于或显著高于攻毒前和同期Ａ组水平。在攻毒后Ａ和Ｂ组ｃＧＭＰ均呈波动性上升趋势,第７天明显高于攻毒前水平并高于Ｃ组,以后Ａ、Ｂ、Ｃ三组均下降,但Ａ组比Ｂ和Ｃ组下降更快。在攻毒后２８天内,Ａ组ｃＡＭＰ／ｃＧＭＰ比值无明显变化,Ｂ组波动上升,Ｃ组处于高水平上,Ｂ和Ｃ组均高于或明显高于Ａ组。血浆ＩＬ２水平Ａ和Ｂ组在ＩＢＤＶ攻毒后的头７天内呈逐渐下降趋势,但Ａ组下降的更剧烈,Ｃ组无明显差异性变化,三组相比,Ｂ和Ｃ组均高于或明显高于Ａ组,以后Ａ和Ｂ组逐渐回升。     

红纹凤蝶半合成人工饲料研究

应用正交试验设计,考察了半合成人工饲料中马兜铃叶粉、麦胚粉加酵母粉、藻粉和防腐剂４因素３水平的不同组合对红纹风蝶幼虫历期、蛹重和化蛹率的影响,筛选出一个可用于大量繁殖的半合成人工饲料配方,在该配方中,幼虫期、蛹重与对照差异不显著,化蛹率极显著高于其它半合成人工饲料配方,各因素不同水平的极差分析表明：防腐剂的含量是影响红纹凤蝶幼虫生长发育的主要因素,此外,寄分呈的变化主要影响幼虫发育历期和蛹重,麦胚     

改善生态环境防治长江上游水土流失

长江上游长约４５００ｋｍ,流域面积约１００万ｋｍ＾２。本区域地理条件特征。水力、矿产、动植物和旅游资源部十分丰富,具有巨大的经济发展潜力。近几十来,由于本区域森林植被遭到严重破坏,垦殖率不断增高以及对资源的不合理开发利用,致使长江上游地区生态环境日益恶化,水土流失不断加剧。在长江上游地区自然生态系统遭到严重破坏的同时,也给长江中下游地区带来了巨大的危害,改善长江上游生态环境和防治水土流失,是实现流     

Molecular analysis of Lathyrus sativus L. (grasspea) and related Lathyrus species

Eight Lathyrus sativus L. accessions from a variety of geographic origins were used to study intraspecific genetic diversity using RAPD analysis. Fourteen decamer primers produced 64 amplification products, 50% of which were polymorphic between the samples. Jaccard's coefficient of genetic similarity was calculated between samples and a dendrogram was constructed by an unweighted pair-group method with arithmetical averages (UPGMA). The dendrogram showed that most of the L. sativus plants clustered into accessions or common geographical areas. The average genetic similarity coefficient within accessions was 0.12 and between accessions was 0.20, indicating a low level of intraspecific genetic variation. Interspecific genetic diversity and phylogenetic relationships of eight Lathyrus species, including L. sativus and Pisum sativum L. (field pea) were examined using 14 decamer primers which produced 283 amplification products. All amplification products were polymorphic across the nine species. In the dendrogram the Lathyrus species clustered into three distinct groups which correlated with the Sections Lathyrus, Clymenum and Linearicarpus. This supports traditional taxonomic classifications of the genus Lathyrus which are based on morphological traits. Of the species from Section Lathyrus, L. gorgoni and L. cicera were the most similar to L. sativus. The results suggest that a strategy of breeding for producing lines of L. sativus with increased genetic variation would be effectively achieved through hybrid production between accessions from wide geographic areas particularly the Mediterranean area and the Indian subcontinent. However, the most effective method would be introgression of germplasm from other species in Section Lathyrus. This revised version was published online in July 2006 with corrections to the Cover Date.     

犬精液冷冻与人工授精的进展

详述了国内外大精液冷冻与人工授精（AI）技术的研究及利用现状,针对大精液的采集、稀释、平衡、冷冻、解冻和输精等主要技术环节进行了总结分析,试图概括本领域已有的成果和经验,找出存在的问题,以利该技术在我国的进一步研究和推广。