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1.
The balance principle of the strain gauge arrays observation is analyzed in detail according to the first invariant of the stress. A partly damaged strain gauge arrays' strain conversion is discussed. The stress computation through the strain gauge arrays under different condition is confirmed. A method for determining the validity of the strain gauge arrays is studied and summarized. A collection procedure containing the strain gauge arrays' validity judgment, strain conversion, and stress computation is established based on the causal relation model.  相似文献   

2.
采用在瘤胃背囊、皱胃幽门部和十二指肠近端安装有双极胃肠电极及应力传感器的土种公山羊 5头 ,按自身对照设计 ,研究了双氯醇胺对山羊胃肠电活动及运动的影响。结果表明 ,β 激动剂双氯醇胺在功能上有与肾上腺素相似的作用 ,即可直接或间接地抑制山羊胃肠道电活动和运动。与对照期相比 ,给山羊皮下注射双氯醇胺后 ,其瘤胃背囊、皱胃幽门部及十二指肠近端的快、慢波电位振幅显著降低 (p <0 0 5) ,瘤胃运动的应力波值极显著减小 (p <0 0 1) ,但快、慢波频率无明显变化。瘤胃运动的应力波值与瘤胃快波电位振幅以及应力波延续时间与快波峰电位数间呈强正相关 (R值分别为 0 94± 0 32和 0 85± 0 2 7)。体外试验结果亦显示 ,双氯醇胺可使离体十二指肠段的快、慢波电位振幅减小 ,张力波值大幅度下降 ,张力曲线变得平滑  相似文献   

3.
谷胱甘肽S-转移酶(glutathione S-transferase,GST)是谷胱甘肽结合反应的关键酶,催化谷胱甘肽结合反应的起始步骤,主要存在于胞液中,有多种形式,其在病理学上有一定的重要性。本研究通过克隆GST基因以及对其进行相关的生物信息学分析。利用聚合酶链式反应(polymerase chain reaction,PCR)技术扩增该基因,经分析该基因可编码219个氨基酸,并且通过相关分析得到这219个氨基酸组成的蛋白为稳定的亲水性蛋白,有一个明显的区段存在信号肽,在该蛋白中α-螺旋和无规则卷曲是主要的二级结构方式,根据序列同源比对,蓖麻、麻疯树和榴莲聚类到一起,说明相对于其他物种,它们的同源性较高。这些分析结果为蓖麻谷胱甘肽S-转移酶生物合成及其功能的进一步研究提供一定的理论与实践依据。  相似文献   

4.
Analyzes the potentials of natural resource to improve the indoor thermal environment in Chongqing through the statistical analysis of natural resource including solar energy, wind, water and earth etc. The building forms, systems and principle of usage of natural resources are briefly analyzed through the building site-decision, building form design and computer simulation which will be the real reference for the design of building energy efficiency.  相似文献   

5.
热平衡式茎流计在测定植物蒸腾耗水中的应用进展   总被引:1,自引:0,他引:1  
热平衡式茎流计是用于测量植物蒸腾耗水速率的仪器,该茎流计以其精确、方便、无损和数字化等优点已经得到广泛的应用和比较深入的研究。旨在对近年来热平衡式茎流计在国内测定植物蒸腾耗水中的运用和发展进行相关的分析和讨论,为以后科学地运用和方法的改进提供理论依据。分析了热平衡茎流计的工作原理,归纳了植物液流速率日、生长季的变化规律,总结了植物蒸腾速率的影响因素,对热平衡式茎流计的应用做了详细的介绍,最后提出了热平衡式茎流计在实际应用中的优点、注意的问题和发展展望。  相似文献   

6.
以口蹄疫病毒株OA/58 RNA为模板,反转录并扩增目的cDNA,然后与pMD18-T载体连接并转化JM109菌株,提取的重组质粒用凝胶电泳、PCR和BamH I,Hind III双酶切法鉴定。运用同源模建得到OA/58 VP2蛋白三维空间结构,并结合理化性质、亲水性、可塑性和免疫原性进行分析,找出OA/58 VP2蛋白的B细胞抗原表位。结果表明,OA/58 VP2蛋白存在多个潜在的抗原表位,可能的蛋白质抗原表位区域:1~23,40~63,71~78,82~91,102~106,113~119,131~138,148~154,166~177,189~196,212~218。应用同源模建得到的OA/58 VP2蛋白三维空间结构来预测其B细胞表位,为进一步研究OA/58 VP2蛋白在引起易感宿主体液免疫应答方面提供了一种可视化的技术平台,并且为选择表达其他口蹄疫病毒株的VP2蛋白分子提供有参考价值的信息。  相似文献   

7.
The rock property difference of bedded composite rock often does not lead to ideal Pre-splitting blasting effect. The influence factor of Pre-splitting such as the dynamite quantity and explosive structure was studied by experiment with transient dynamic strain gauge testing system. At the same time, the damaged rock reduced by blasting was examined with RS-STOIC ultrasonic gauge. The results indicate that different dynamite densities are taken for considering especially property of bedded composite rock. The conclusion for cite.  相似文献   

8.
随着栽培年限的延长,昆明地区香石竹栽培中的枯萎病害发生日愈严重。本文通过田间调查及病原菌分离、鉴定、田间接种确定香石竹枯萎病的病原菌为立枯丝核菌。并以真菌通用ITS引物对所分离的三株病原菌进行PCR扩增,结果表明扩增片段为750bp,测序后去除引物序列长度为505bp,所分离3株立枯丝核菌的序列完全一致,该序列与马铃薯、西红柿、水稻、棉花立枯丝核菌的同源性在85%以上,表明所分离于香石竹枯萎病的3个病原菌为立枯丝核菌。利用DNAMAN4.0进行系统进化树分析,表明分离菌株与大麦、四季豆、马铃薯、西红柿、水稻、棉花等的立枯丝核菌归为一类,而落叶松、柠檬、青椒、剑兰、苹果、咖啡等的立枯丝核菌为另一类。在前茬作物交配类型无法确定的情况下,前茬作物的致病菌不仅存在交叉感染的可能,同时还可能产生新的变异类型。因此,在香石竹栽培过程中,应尽量避免在前茬作物为遗传学上相对较近的作物栽培土壤中种植。  相似文献   

9.
For light gauge steel floor,the structure testing and finite element method were applied to study the junior beam's inflection capability influenced by steel floor sheet.Analysis results show that the thin steel floor sheet affects junior beam's deflection very strongly.This conclusion has value for design of new structure or evaluating load support capability to the steel floors.  相似文献   

10.
从农业生态系统承载力看全球生态经济系统前景   总被引:1,自引:1,他引:0  
本研究运用3种方法预测作物产量潜力,结果表明:(1)利用作物历年单产回归拟合后进行趋势外推,得出多数作物的未来产量潜力极限大约是现在单产的2~3倍;(2)运用“国际应用系统研究所”(IIASA)与“联合国粮农组织”(FAO)共同开发的“农业生态区划”(AEZ)模型计算中国主要粮油作物的区域单产最高潜力,得出水稻、小麦、玉米、马铃薯、油菜和大豆的单产潜力分别是它们2005年全国平均单产的1.2倍、2.2倍、2.2倍、2.9倍、2.0倍、1.9倍;(3)运用自然界中植物的最大光能利用率计算世界主要粮油作物单产的光合潜力,得出水稻、小麦、玉米、马铃薯、油菜、大豆产量的最大光合生产潜力大约分别是目前高产地区单产的1.4倍、2.5倍、1.2倍、1.8倍、1.9倍、2.2倍。据此:从作物产量潜力极限出发,阐述了农业生态系统的承载力;再从“封闭”系统特性出发,论述了全球生态经济系统的不可持续性。  相似文献   

11.
During the Snellius-II Expedition Lower Pilocene coral material was collected near Salayer, and Quaternary reefs were sampled on Ambon and Sumba. Coral collections from the Pliocene of Nias were also available for study. This new material is presented together with earlier data. Preservation potentials of different coral growth forms are reviewed. The absence of Acropora and Montipora from Quaternary coral faunae is striking. This is interpreted with the model of Potts (1983), on the disturbance by Pleistocene sea level fluctuations in the reef coral fauna. Diversification within both genera is apparently very recent, which may explain their complex taxonomy. Given the dominant role of Acropora and Montipora in many present day Indonesian reefs, these are better described as transitional assemblages of corals than as established coral communities.  相似文献   

12.
外源激素对棉纤维超超结构及纤维强度的影响   总被引:12,自引:1,他引:11  
刘继华  贾景农 《作物学报》1994,20(1):120-125
对发育棉铃加施外源GA3、IAA的研究表明:低强度类型的鲁棉一号型陆地棉品种,可通过人为改善激素状况的方法,调节其纤维发育,尤其在其纤维素合成速度的低值期施用,可明显提高纤维强度,甚至改善纤维结构,使取向参数发生较大改变。高强度型的海岛棉型品种,仅通过增施外源GA3、IAA是无效的,甚至对纤维结构及强度都是有害  相似文献   

13.
The pastures and rangelands of the semi-arid region of Nigeria wherein is the bulk of the livestock in the country, provide sufficient nutrients for livestock for no more than three to five months of the year. There is therefore need to have high yielding and good quality forages to ensure adequate all-year-round forage supply for the livestock. The objective of this study was to evaluate the forage potentials of pearl millet ( Pennistetum americanum [L.] K. Schum.) which is well adapted to the region. Twenty cultivars were evaluated for their growth, forage yield and mineral content potentials.
The cultivars were significantly different in the number of leaves per plant, plant height, dry matter yield and potassium content in each cutting. Differences in crude protein and crude fibre contents were significant only between cuttings. Variations in crude protein and crude fibre contents ranged from 14.1 to 20.3 % and from 28 to 30.8 %, respectively. Cultivars had a progressive dimunition in growth, yield and mineral content potentials after the first or second cutting. Pearl millet therefore seems less suited to forage production in the semi-arid region of Nigeria since no cultivar showed the potentials for adequate supply of all-year-round forage.  相似文献   

14.
采用cDNA-AFLP差异显示技术对大豆细胞质雄性不育系NJCMS2A与其保持系NJCMS2B间基因差异表达进行研究,结果从NJCMS2A花蕾中分离到一个差异表达片段,对该差异片段进行克隆、测序和序列比对分析,Blast检索结果显示它与大豆基因组中Gm13上g29510.1 cDNA片段的同源性达98.7%,与大豆中一个MADS-box基因的同源性达98%,氨基酸序列比对结果表明它与大豆中一个MADS-box蛋白有96%的同源性,与豌豆中MADS-box M7蛋白有83%的同源性,与苦瓜中MADS-box2蛋白有88%的同源性,与海岛棉典型的MADS-box基因编码的AGAMOUS蛋白保守区有83%的同源性,进一步对其氨基酸序列进行结构和功能预测显示该差异片段具有MADS-box转录因子的典型结构域K-box,证明其编码蛋白为一MADS-box转录因子,半定量RT-PCR分析结果显示其在NJCMS2A花蕾中表达量很高,而在NJCMS2B花蕾中表达量很低,推测该差异片段可能与大豆细胞质雄性不育有关。  相似文献   

15.
粉蕉ACC氧化酶cDNA的克隆及其序列分析   总被引:1,自引:1,他引:0  
本研究根据GeneBank公布的ACC氧化酶(ACO)基因的保守序列设计一对引物,通过RT-PCR方法从成熟粉蕉果实(ABBgroup)中克隆到一条新的香蕉ACO基因全序列。该氧化酶cDNA全长1172bp,基因编码区共957bp,推测其编码318个氨基酸。分析发现,该基因除了与登录号为X95599的香蕉ACO基因核苷酸序列一致性为84%外,与其它基因库上公布的香蕉ACO基因核苷酸序列一致性为94% ̄98%,而且,这些香蕉ACO基因核苷酸推导出的氨基酸序列总体一致性为95.81%。聚类分析结果表明,相同基因型的果实克隆出的香蕉ACO氨基酸具有更多的同源性。另外,将该香蕉ACO氨基酸与其它12种重要的果实的ACO氨基酸相比较,其序列一致性也很高。其与芒果一致性高达98%,与菠萝、番木瓜、葡萄、苹果,桃、梨、柑、橙等一致性也在68% ̄76%之间。同时发现这13种ACO氨基酸有9个较长的保守结构域。系统树分析结果表明,具有相似的生长环境和相似的生理特性的果实ACO基因具有更多的同源性。  相似文献   

16.
棉花叶绿体70S核糖体S7蛋白基因的克隆和序列分析   总被引:3,自引:0,他引:3  
樊卫华  沈燕新 《作物学报》1997,23(4):487-490
叶绿体基因组具有高度保守性,来源于不同植物的叶绿体基因同源性很高。应用PCR技术,从棉花叶绿体基因组扩增并克隆了长度为1.0kb的叶绿体DNA片段。该片段含有叶绿体核本小亚基S7蛋白基因rps7。采用限制性内切酶消化连接的策略构建亚克隆,并测定了该片段的含部核苷酸序列。结果表明,棉花叶绿体rpas7基因与烟草、不稻的相庆基因同源性高,分别为97.9%和89.5%,3非编码区的同源性分别为96.3%  相似文献   

17.
旨在从分子生物学角度进一步研究新城疫病毒La Sota株HN基因,探究NDV La Sota HN基因的遗传变异情况。研究以试验室冻存的p NDV-HN为模版,根据Gen Bank中登录的NDV La Sota株序列设计引物扩增HN基因,将其克隆到pMD18-T载体后进行鉴定,对鉴定正确的重组质粒p MD-NDV-HN进行测序分析。应用生物信息学软件对新城疫病毒Lasota株HN基因进行系统进化树分析、氨基酸序列同源性分析、糖基化位点、蛋白结构跨膜区分析及磷酸化位点预测分析。核苷酸序列测定结果表明:HN基因的序列长度为1743bp,该基因的开放阅读框(Open Reading Frame,ORF)总长为1716 bp,编码571个氨基酸。生物信息学表明:试验获得的HN基因具有6个潜在糖基化位点及12个半胱氨酸残基,第5个潜在糖基化位点(508-510 aa)发生缺失及第123位半胱氨酸残基被色氨酸残基取代。La Sota株HN基因编码的蛋白质中有29个丝氨酸、10个酪氨酸和16个苏氨酸可能成为蛋白激酶磷酸化位点。将试验获得的La Sota株HN基因序列和推导的氨基酸序列与新城疫毒株的HN基因相应序列比较后发现,它们的核苷酸序列同源性和氨基酸序列同源性最高均可达到99%,表明HN基因在种属间具有较高的保守性。研究为新城疫病毒的分子病毒学研究奠定了基础。  相似文献   

18.
根据Genbank已报道马铃薯卷叶病毒(PLRV)基因组序列,分析其基因间隔区(IS)两端的保守区,自行设计、合成一对特异性引物,以PLRV内蒙古分离物总RNA为模板,经RT-PCR扩增得到含PLRVIS的一段369 bp的cDNA,克隆于载体pBS-T中。重组质粒经PCR鉴定、酶切分析和核苷酸序列测定,并进一步与PLRV其他分离物的同源序列作比对。结果表明:克隆的PLRV内蒙古分离物的IS序列与其他全部已发表的13个全基因组中的IS核苷酸序列有很高的同源性,最高达到100%,平均为97.90%,高于这13个PLRV全基因组序列96.81%的同源性,说明IS序列不仅在PLRV的不同株系间比较保守,而且在PLRV的全基因组序列中也是相对保守的。研究结果预示,将IS构建成RNA干扰型结构导入马铃薯,将有可能获得抗PLRV多种株系且抗性更高的转基因植株。  相似文献   

19.
长白猪甘露聚糖结合凝集素-C基因的克隆与序列分析   总被引:2,自引:1,他引:1  
摘 要:从长白猪肝脏组织中提取总RNA,经RT-PCR技术扩增pMBL-C基因,与pMD18-T载体连接,获得pMBL-C基因。序列测定结果显示该基因编码区为723bp,编码241个氨基酸残基。与已发表的猪MBL-C具有99%同源性;进化树分析显示与哺乳动物的MBL-C基因,尤其是牛的亲缘关系最近,而与MBL-A基因相差较大,与禽类的最远。本研究为进一步研究猪MBL分子的遗传特征提供了依据。  相似文献   

20.
S.K. Hahn 《Euphytica》1982,31(1):13-18
Summary Screening sweet potato, Ipomoea batatas, L., for source potentials is more difficult than for sink capacities. Twenty clones were grafted to four tester varieties to screen them for source potentials in relation to sink capacities which are interdependent. Source potential of a clone was measured by its average scion effect when grafted on the four tester varieties. There were significant differences in source potentials among the twenty clones. Seven clones were selected for having high source potentials. Clone TIS 2498 was the best. Degrees of response of source to sink were estimated using the regression method for twenty clones showed significant differences and ranged from b–0.45 to b=2.06. Source potential showed significant relationship (r=0.62**) with response of source to sink. Implication of this approach to sweet potato breeding is discussed.  相似文献   

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