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Search Results: 1 - 10 of 30806 matches for " 韩召 "
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棉铃虫3种蜕皮相关基因的RNA干扰效应比较
杨静,
南京农业大学学报 , 2014, DOI: 10.7685/j.issn.1000-2030.2014.01.014
Abstract: 利用表达dsRNA的细菌液连续喂食棉铃虫,比较热激同源蛋白70基因(Hsc70)、几丁质酶基因(Chi)和蜕皮激素受体基因(EcR)的沉默效应。结果表明dsHsc70处理后试虫热激同源蛋白70基因的表达量为对照的115%,无显著差异,试虫的生长发育也没有显著变化。但dsChi和dsEcR处理后,棉铃虫几丁质酶和蜕皮激素受体基因的表达量分别下降到对照的37.2%和80.3%,且化蛹成功率也显著降低,分别为对照的53.2%和79.1%。此外,dsChi处理棉铃虫的体质量增长缓慢,幼虫死亡率(49.3%)显著高于对照(11.1%),但发育异常率没有显著变化。而dsEcR处理试虫的发育异常率(14.6%)显著高于对照(2.8%),但体质量增长速率和幼虫死亡率与对照没有显著差异。综合分析表明,在RNA干扰研究中,并不是所有的被干扰基因都会表现出明显的沉默效应。因此,为了获得显著的沉默效应,靶基因的选择至关重要。本研究表明棉铃虫几丁质酶基因较其他两种基因更适合作为研究RNAi防治害虫的靶基因。
量子Büchi自动机的代数及逻辑刻画

电子学报 , 2013, DOI: 10.3969/j.issn.0372-2112.2013.06.009
Abstract: 提出量子Büchi自动机(简记为LVBA)的概念,利用量子状态构造方法证明了一般LVBA与状态转移为经典函数的LVSBA间的相互等价性,籍此研究了量子无穷正则语言的代数刻画、层次刻画和Büchi刻画以及对于正则运算的封闭性;通过引入单体二阶量子逻辑(简记为LVMSO)的概念,给出量子Büchi自动机所识别无穷语言的单体二阶逻辑描述,深化和推广了量子逻辑意义下的Büchi基本定理.
棉蚜饲养技术——笼罩法
李飞,
应用昆虫学报 , 2001,
Abstract: 在长期的试虫饲养过程中,摸索出一种新的棉蚜饲养方法———笼罩法。利用a4幅面的透明胶片和纱网制成笼罩。并于室内催芽,培育棉花种苗,可利用自制笼罩于光照培养箱内隔离饲养棉蚜,经与琼脂叶片法和自制blackmanbox方法比较,笼罩法具有省时省力、不受季节限制、棉蚜生长条
棉蚜对吡虫啉抗性的初步研究
李菁,
农药学学报 , 2007,
Abstract: 用吡虫啉对棉蚜进行室内抗性筛选,用药处理25次后抗性是筛选前的20.03倍;2007年对田间棉蚜进行抗性调查,发现不同地区种群对吡虫啉的抗性差异显著,江苏南京种群最为敏感,河南安阳、山东泰安和北京地区棉蚜与之相比,抗性分别为2.21、7.63和9.53倍;抗、感品系解毒酶活力分析发现,抗性品系的谷胱甘肽s-转移酶活性增加很少(比活力1.12倍),但酯酶活力显著高于敏感品系(比活力1.71倍);增效试验结果表明,顺丁烯二酸二乙酯(dem)在抗、感品系中对吡虫啉均没有明显的增效作用,而磷酸三苯酯(tpp)和增效醚(pbo)虽然在敏感品系中对吡虫啉的增效作用较小(sr1.24和1.29),但在抗性品系中的增效作用显著增高(sr2.13和1.74);此外还发现,吡虫啉处理可提高棉蚜群体的酯酶活力。由此认为,棉蚜至少具有对吡虫啉产生中等水平抗性的风险,其抗性可能是由于棉蚜的酯酶和p450单加氧酶的解毒能力提高所致。
灰飞虱水通道蛋白基因克隆及其与杀虫剂代谢的关系
周晨,
南京农业大学学报 , 2017, DOI: 10.7685/jnau.201703003
Abstract: [目的] 水通道蛋白是细胞膜内嵌蛋白超家族的主要成员,具有传输水分子以及小分子化合物进出细胞膜的功能,本研究目的是分析重要农业害虫灰飞虱体内水通道蛋白功能及其与杀虫剂代谢之间的关系。[方法] 根据转录组数据,采用PCR和RACE技术对灰飞虱体内的水通道蛋白基因进行了克隆,并利用进化树对获得的基因进行亲缘关系的分析验证,利用实时荧光定量PCR技术分析这些基因在灰飞虱抗、感品系间的表达量差异,利用体外表达技术分析其转运活性。[结果] 从灰飞虱体内克隆获得了6个灰飞虱水通道蛋白基因全长序列,分别命名为LsAQP1、LsAQP2、LsAQP3、LsAQP4、LsAQP5和LsAQP6,其中LsAQP6在灰飞虱的不同抗性品系里均高表达。体外功能表达试验显示:LsAQP6对水具有很强的转运能力,对灭多威也具有显著的转运能力,但对甘油和杀虫双的转运能力不显著。[结论] LsAQP6在灰飞虱体内对水和某些小分子农药具有转运作用。
[Objectives] Aquaporin, a member of the major intrinsic protein superfamily, functions mainly for transporting water and small molecule compounds across cell membrane, and the aim of this study was to analyze the function of the aquaporin and its possible contribution to insecticide metabolism in an important agricultural pest Laodelphax striatellus.[Methods] In this study, aquaporin genes in L. striatellus were cloned based on the transcriptome data and with PCR and RACE cloning techniques. The cloned genes were subjected to phylogenetic relationship analysis by constructing phylogenetic tree with previously reported insect aquaporin genes, tests of the expression level in the susceptible and resistant strains by real-time quantitative PCR, and functional verification for their transporting capability by combinant expression in vitro.[Results] Six full length aquaporin genes were cloned from L. striatellus and designated as LsAQP1, LsAQP2, LsAQP3, LsAQP4, LsAQP5 and LsAQP6, respectively. Among them, LsAQP6 was found expressed with higher level in all three resistant strains tested as compared to the susceptible strain. Furthermore, functional expression showed that LsAQP6 had strong transport capacity for water and significant transport capacity for methomyl, but not for glycerol and bisultap.[Conclusions] Thus, it is speculated that LsAQP6 plays a significant role in transporting water and some small molecule insecticides in L. striatellus
复杂应变路径下Q&P980超高强钢的非弹性回复行为
Inelastic recovery of Q&P980 ultra high strength steel with a complicated deformation path

,
- , 2018, DOI: 10.16511/j.cnki.qhdxxb.2018.26.038
Abstract: 板材成形过程中复杂加载路径的改变会影响其弹塑性流动行为。以超高强钢淬火—配分(quenching&partitioning,Q&P)980钢为研究对象,在室温下沿着轧制方向的不同角度进行2步拉伸实验,得到不同应力状态下的应力—应变曲线,并根据单位体积塑性功相等原则,确定了板材不同等效塑性应变(0%、1%、4%、6%)下的实验屈服轨迹。结果表明:在应变路径变化上,初始流动应力显著降低,特别在45°和90°方向上,瞬时时段之后的流动应力存在持续的偏移,较大应变条件下各向异性比较明显。实验屈服轨迹呈外凸性,部分屈服轨迹不对称,随变形程度的增加,屈服轨迹向外扩大。通过对比简单加载和循环加载,分析其弹塑性行为,并建立各自的卸载弦数学模型,指出弹性模量随应变的增加而降低,降低到一定程度后趋于平缓。在相同塑性应变下,循环加载时弹性模量的变化值比简单加载时要大。
Abstract:The loading paths used for sheet metal forming affect its elastic-plastic flow behavior. Quenching & partitioning (Q&P) 980 steel was used here as the research object. Two-step tensile tests using different angles relative to the rolling direction were conducted at room temperature to obtain the stress-strain curves for various stress states. The equal volume plasticity work principle was used to determine the experimental yield loci of different equivalent plastic strain (0%, 1%, 4%, 6%). The results show that the initial flow stress is significantly reduced by changing the strain path, especially in the 45° and 90° directions, the flow stress after the transient period various by a fixed amount, and the anisotropy is quite large for larger strains. The test yield loci line is convex and some of the yield loci are asymmetric. As the deformation increases, the yield loci expand outward. Simple loading and cyclic loading were compared to analyze the elasto-plastic behavior and develop unloading string mathematical models. The elastic modulus decreases quickly with increasing strain, then decreases slowly and then becomes constant. For a given plastic strain, the change in the elastic modulus during cyclic loading is greater than when simply loaded.
Cloning and Sequence of Nicotinic Acetylcholine Recepto r α Subunit from Chilo suppressalis
二化螟乙酰胆碱受体α亚基的基因克隆与序列分析

招久,
动物学研究 , 2002,
Abstract: 烟碱型乙酰胆碱受体(nAChR)在昆虫的兴奋性突触传递中起着重要的作用,同时也是杀虫剂作用的重要靶标。近年来,二化螟对作用于昆虫nAChR的沙蚕毒素类杀虫剂杀虫单产生了高抗性。为了研究可能存在的靶标不敏感机制,我们采用RT-PCR技术,对二化螟nAChR-α亚 基全长cDNA进行了分子克隆。序分析表明,这是1个新的α亚基基因,定名为Cs α 1。基 因全长为1997个核苷酸,包含了1个开放阅读框,编码1个509氨基酸的成熟蛋白和1个24氨基酸的信号肽。Cs α 1与其他昆虫nAChR α亚基之间有52%-94%的同源性,高于与脊椎动物nAChR α亚基之间的同源性。
Cloning and Sequencing of Two Acetylcholinesterase cDNA Fragments from Cotton Aphid, Aphis gossypii Glover
棉蚜2个乙酰胆碱酯酶cDNA片段的基因克隆与序列分析

Abstract,
李飞
,

动物学研究 , 2002,
Abstract: Two acetylcholinesterase (AChE) genes cDNA fragments,Ag.acel and Ag.ace2,have been cloned from cotton aphid,Aphis gossypii Glover using degenerate primers with RT-PCR technique.Ag.acel gene cDNA fragment is of 282?bp encoding 94 amino acids,and Ag.ace2 gene cDNA fragment is of 264?bp encoding 88 amino acids.Both two putative AChE genes cDNA fragments share numerous similarities with those cloned from other insects.This is the first report of two AChE cDNA fragment sequences in the insect species,which provided the direct evidence of multiple AChE existence in insects.
褐飞虱生物型研究进展:致害性变异的遗传机制
周亦红,
应用昆虫学报 , 2003,
Abstract: 能够“克服”水稻抗性的褐飞虱生物型的出现,是目前水稻育种及害虫防治工作中面临的重大难题。为探明褐飞虱生物型的形成机制,许多学者致力于生物型致害性的遗传学研究,然而得出的结论却不尽一致。该文综述了有关褐飞虱生物型研究中争论较多的3个方面,即生物型致害性的稳
褐飞虱对抗性水稻品种Mudgo个体致害性指标
周亦红,
昆虫学报 , 2003,
Abstract: 在28±1℃下,观测了褐飞虱Nilaparvatalugens羽化24?h内短翅型雌成虫在敏感水稻品种TN1及抗性品种Mudgo上的寿命及体重增量。结果表明,取食抗性品种时,试虫的平均增重与寿命之间表现出明显的正相关。寿命在7天内的个体,存活期间平均体重增量为负值,而存活7天以上的个体则平均增重明显。进一步研究了初羽化的褐飞虱长翅型雌成虫在TN1及Mudgo上取食第1~4天的体重增量、寿命及产卵量,结果发现试虫在Mudgo上的这3个生物学参数之间存在明显正相关。其中,寿命及体重增量较好地反映出害虫个体对抗性品种的致害能力,可作为个体致害性指标。根据研究结果,提出将羽化后在Mudgo上存活7天以上或最初4天内体重增量大于0.1mg的雌成虫定为能够致害该抗性品种的个体。
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