O3浓度升高对棉蚜取食行为的影响

在加倍O3浓度的开顶式气室(OTC)中培养抗虫棉GK12幼苗30 d,正常O3浓度处理为对照。应用刺探电位图谱(EPG)技术,对棉蚜(Aphis gossypii Glover)在苗期棉花上的取食行为进行了比较研究。结果表明：蚜虫在加倍O3浓度下生长的棉苗上取食的过程中,C波数量显著减少,pd波首次出现时间明显提前,被动取食持续时间(E2波的总时间)明显拉长。棉蚜的取食适合度明显提高的原因可能是加倍O3浓度对棉花叶片组织结构和体内营养物质的变化有影响。     

一类6p2 阶群的非交换图及其对群结构的影响

研究一类固定阶非交换群G的非交换图和其结构之间的一些联系.证明了当p是奇素数,p≠3,且3(p-1)时,11个6p2阶非交换群G中,有5个可由其非交换图刻画,另外6个不能由其非交换图刻画.     

Graph theory in action: evaluating planned highway tracks based on connectivity measures

Maintaining connectivity among local populations in a fragmented landscape is crucial for the survival of many species. For isolated habitat patches, stochastic fluctuations and reduced gene flow can lead to high risk of extinction. The connectivity of the landscape is especially crucial for the carabid species living in the fragmented forests of the Bereg plain (NE Hungary and W Ukraine) because a highway will be constructed through the plain. Our purpose is to (1) evaluate the impacts of three possible highway tracks, (2) suggest a solution that is realistic with less impact on connectivity than other plans and (3) discuss how to decrease the disadvantageous effects of each track. Our results, based on a network analysis of landscape graph of patches and ecological corridors, indicate that the intended highway could have deleterious consequences on forest-living carabids. Relatively simple actions, like the establishment of stepping stones, could compensate for the loss of habitat connectivity and promote the survival of carabids, or minor modifications in one possible track could diminish its adverse effects. While many other studies would be needed for a comprehensive assessment of the biotic impact of the highway, we provide an example on the usefulness of network analysis for land use management. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

稀土元素示踪法探究坡面侵蚀进展与热点——基于CiteSpace计量分析

稀土元素示踪法从上世纪90年代开始逐渐被相关学者重视,并在坡面土壤侵蚀的研究中得到越来越广泛的应用。笔者采用CiteSpace软件和文献计量学方法,以Web of Science数据库核心合集和中国知网(CNKI)数据库核心期刊为数据源,分析了近30年国内外稀土元素示踪法在坡面侵蚀研究的发展历程。研究发现:①总体而言,国内稀土元素示踪法在坡面侵蚀中的应用在理论和实践层面已经从初步探索走向了成熟;②随着研究的深入,稀土元素示踪法的研究与相关学科交叉更加密切,并在微观探索和宏观调控方面取得一定进展;③未来发展趋势来看,宏观方面趋向和生态系统、气候变化等互相作用机理的研究,微观方向趋向对团聚体等微观颗粒的迁移研究;④在国际相关研究方面,对于稀土元素示踪法在坡面侵蚀的应用从多个方面和角度做了大量的研究,我国的相关研究相较于国外顶尖水平的研究仍存在一定差距。     

利用EPG技术分析西花蓟马在4种寄主植物上的取食行为

采用直流刺吸电位仪EPG(direct current electrical penetration graph, EPG)技术分析西花蓟马Frankliniella occidentalis雌雄虫在4种寄主植物上的取食行为,探讨西花蓟马雌雄虫取食行为差异及与寄主适合性的相关性。结果表明: (1)西花蓟马在辣椒上的非取食刺探次数显著少于其他寄主植物。雌虫在辣椒、番茄、曼陀罗和矮牵牛上的非取食刺探分别为2311,3289,3610和3044次,雄虫在辣椒、番茄、曼陀罗和矮牵牛上的非取食刺探分别为1527,2772,2214和1968次。西花蓟马在矮牵牛上的短取食刺探显著高于番茄,雌虫在番茄和矮牵牛上的短取食分别为688和1444次,雄虫在番茄和矮牵牛上的短取食分别为159和809次。西花蓟马在矮牵牛上的长取食刺探次数少于在其他寄主植物。(2)雌虫比雄虫产生更多的非取食刺探和短取食刺探,雄虫的长取食刺探显著高于雌虫。在矮牵牛上,雌虫的非取食刺探次数和非取食刺探总时间为雄虫的15倍。在番茄上,雌虫的短取食次数和短取食总时间分别为雄虫的4倍和2倍;雄虫的长取食次数和长取食总时间分别为雌虫的2倍和7倍。由此可见,西花蓟马的取食行为与寄主适宜性之间无显著的相关性。     

基于四分图模型的土地整理农民满意度评价——以江苏省涟水县为例

以江苏省涟水县为例,选取影响土地整理农民满意度的20项指标,通过问卷调查分析多指标的重要程度和农民的满意程度,运用四分图模型评价土地整理农民满意度。结果表明:农民对土地整理总体满意,其中对土地整理后的生活水平改善情况较为满意,对项目实施后的管护工作和基层干部的工作则普遍不满意。     

轴向柱塞泵全局耦合动力学建模

轴向柱塞泵内部子系统强耦合作用下柱塞泵呈明显的全局耦合特性,而柱塞泵传统局部动力学模型普遍存在恒压力、定转速等假设条件,缺乏对全局耦合特性的综合分析能力,为此在分析子系统间结构关系及耦合情况的基础上,提出一种基于数组的键合图建模方法,建立了斜盘式轴向柱塞泵键合图模型。进行了柱塞-滑靴子系统摩擦学-动力学耦合机理分析,并定义能量损耗因子,综合包含非线性因素的各子系统动力学方程参数,最终导出柱塞泵全局耦合动力学模型。对模型进行了仿真,仿真结果与实际情况吻合,验证了模型的有效性和正确性。     

烟粉虱B型和Q型竞争能力的室内比较分析

【目的】烟粉虱（Bemisia tabaci）B型和Q型均为外来入侵种类。近年田间调查表明,Q型在中国大部分地区已经取代B型成为优势种,有必要研究烟粉虱生物型之间的取代机制及其影响因素。论文在实验室条件下比较这两种生物型的取食能力及竞争能力,以期为烟粉虱有效治理提供依据。【方法】利用刺吸电位（electrical penetration graph,EPG）技术测定烟粉虱B型和Q型雌、雄成虫在黄瓜叶片上的取食行为,并在室内黄瓜上混合饲养两种烟粉虱生物型,多代监测其种群动态和雌雄比例,以比较其在室内无农药压力条件下的竞争力。【结果】 EPG结果显示,（i）总体上,烟粉虱B型的总刺探次数（P=0.020）和刺探的总持续时间（P=0.048）显著高于Q型;在第2阶段B型E波时间百分比显著低于Q型（P=0.001）,刺探时间百分比差异不显著;B型Pd波总次数（P=0.012）和Pd波总持续时间（P=0.016）均显著高于Q型;（ii）烟粉虱B型雌性非刺探波Np的时间百分比显著低于雄性（P=0.035）;而第2阶段刺探时间的百分比显著大于雄性（P=0.011）,与唾液分泌相关的第2阶段E波百分比却显著短于雄性（P＜0.001）;但B型雌、雄性成虫在第3阶段吸食韧皮部汁液的时间则差异不显著（P＞0.05）。Q型雌性不仅在第2阶段刺探的百分比显著高于雄性（P=0.031）,而且在整个记录时间内的总持续时间也显著高于雄性（P=0.039）,而雌性的非刺探时间Np波却显著短于雄性（P=0.038）;（iii）对于雌性,烟粉虱B型被动吸食植物汁液的E2＞10 min的个数显著多于Q型（P=0.036）;但是,烟粉虱Q型雌性第2阶段E波百分比显著高于B型雌性（P＜0.001）。两种生物型混合饲养结果显示,随烟粉虱世代增加,B型和Q型所占比例逐步出现分化。第1代时,B型种群数量在混合种群中所占比例已接近80%;而第5代和第6代时,B型所占比例已达到98%,Q型近乎完全被B型取代。同种生物型烟粉虱两性间的比例变化趋势一致,且同种生物型烟粉虱雌性所占比例均略高于其雄性。【结论】室内EPG记录和多代混养种群动态结果都表明,在室内没有农药压力的环境下,烟粉虱B型在黄瓜上的取食能力和种群竞争能力均高于Q型,而且两种生物型雌性的取食和竞争能力均高于雄性。     

傅立叶红外光谱仪分析膨化羽毛粉的结构变化

利用傅立叶红外光谱方法对膨化羽毛粉结构进行分析,结果表明,膨化处理后,羽毛角蛋白中多肽链形成的索状结构发生解链,部分氢键断裂,羽毛的致密结构变得疏松,从而使其易于被消化。     

Identification of a Group of Novel y-Gliadin Genes

γ-Gliadins are an important component of wheat seed storage proteins. Four novel γ-gliadin genes （Gli-ngl to Gli-ng4） were cloned from wheat （Triticum aestivum） and Aegilops species. The novel γ-gliadins were much smaller in molecular size when compared to the typical γ-gliadins, which was caused by deletion of the non-repetitive domain, glutamine-rich region, 3＂ part of the repetitive domain, and 5＇ part of the C-terminal, possibly due to illegitimate recombination between the repetitive domain and the C-terminal. As a result, Gli-ngl and Gli-ng4 only contained two and three cysteine residues, respectively. Gli-ngl, as the representative of novel γ-gliadin genes, has been sub-cloned into an Escherichia coli expression system. SDS- PAGE indicated that the both cysteine residues of Gli-ngl could participate in the formation of intermolecular disulphide bonds in vitro. Successful cloning of Gli-ngl from seed cDNA of T. aestivum cv. Chinese Spring suggested that these novel γ-gliadin genes were normally transcribed during the development of seeds. Phylogenic analysis indicated that the four novel γ-gliadin genes had a closer relationship with those from the B （S） genome of wheat.