Movement and Distribution of Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) Adults Under Different Temperature Differences in Different Lengths of Horizontal Grain Columns

Understanding insect movement and distribution is critical for developing an effective insect pest management protocol. Movement and distribution of adult Cryptolestes ferrugineus (Stephens) in response to nominal temperature differences of 5, 10, 15, and 20°C in 1- and 2-m horizontal columns filled with 12.5% moisture content wheat were studied in 24, 48, and 72 h of movement times. In the wheat columns without temperature differences, adults had a diffusion distribution pattern caused by their random movement. Adults showed bias movement to the warmer grain in wheat columns with temperature differences and preferred the warmer grain regardless of the magnitude of temperature differences in less than 24 h. Their distribution did not have significant differences among different movement times in 1- or 2-m columns. About 40% of adults moved to the warmer wheat located at 0.4 to 0.5 m in the 1 m column but did not move to the warmer wheat located at 0.9 to 1 m in the 2-m column. Therefore, length of grain column influenced detection of warmer grain by insects. Adults under different temperatures had a similar response as that under linear temperature gradients.     

Dissecting the genetic basis of maize deep-sowing tolerance by combining association mapping and gene expression analysis

Deep-sowing is an important method for avoiding drought stress in crop species,including maize.Identifying candidate genes is the groundwork for investigating the molecular mechanism underlying maize deep-sowing tolerance.This study evaluated four traits(mesocotyl length at 10 and 20 cm planting depths and seedling emergence rate on days 6 and 12) related to deep-sowing tolerance using a large maize population containing 386 inbred lines genotyped with 0.5 million high-quality single nucleotide ...     

鱼游泳能力对体长的响应及其在鱼道设计中的应用

为了探讨鱼类体长对游泳能力的影响并为鱼道水流的设计提供参考,该研究在封闭水槽中使用"递增流速法"测试了海南省某水利枢纽鱼道目标对象的游泳能力,并用Origin软件进行了数据统计分析,得到了试验鱼感应流速、临界游泳速度和爆发游泳速度的直线回归方程和Kaplan-Meier曲线.结果表明:1)随着试验鱼体长增大,相对感应流...     

内毒素对大鼠小肠黏膜组织的影响及多价阳离子A的保护效应

旨在揭示大肠埃希菌内毒素(ET)对大鼠小肠黏膜的结构、绒毛长度、上皮内淋巴细胞(IEL)的数量和分布的影响,并探讨多价阳离子A(CA)对上述指标的保护效应。选用72只140g~150g SPF级SD大鼠随机分为3组,即对照组、ET组和CA保护组,经相应处理后分别在3、4、8、12h采集十二指肠、空肠组织作为检测样本,制备病理组织切片,HE染色并利用图像分析系统进行分析。ET组十二指肠和空肠绒毛长度在3、4、8、12h均显著低于对照组和CA保护组(P0.01),ET组十二指肠、空肠IEL数量在3、4、8、12h均显著低于对照组(P0.01);CA保护组十二指肠和空肠IEL数量在4、8、12h均显著高于ET组(P0.01)。结果显示,ET在不同程度上能够破坏小肠黏膜的正常组织结构,降低小肠绒毛长度,减少IEL的数量,从而影响小肠正常的吸收和免疫功能,而CA则能明显降低ET所导致的毒性作用,发挥其保护效应。     

电车接触网腕臂的计算

电气化铁道的“三大元件”分为接触网、电力机车和牵引变电所。本论文论述时速200Km/h高速电气化铁路的接触网电车接触网腕臂的计算,接触网的计算精确程度就关系到接触线悬挂的可靠程度,故接触网计算是设计中基础的工作内容,其计算主要分为腕臂的计算和接触网的负载计算。文章详细分析了腕臂长度的计算方法,重点介绍了路基曲线区段腕臂长度、转换柱和中心柱腕臂长度的计算。     

Study on Length Polymorphism of KAP1 Family Genes in Yak (Bos gurnniens)

This study was aimed to understand the characteristics of length polymorphism with repeat sequence of keratin associated protein 1 (KAP1) family genes in yak. KAP1 family genes of yak and cattle were sequenced, and compared with sheep KAP1 family gene sequences. The results showed that cattle KAP1 family genes were located in chromosome 19, according to location of sheep KAP1 family genes in the chromosome and similarity with cattle KAP1 family genes, renaming the cattle KAP1 family (according to the gene location of chromosome) B2D, B2A, KAP1-1 and B2C genes into KAP1-4, KAP1-1, KAP1-2 and KAP1-3 gene, respectively. KAP1 family genes in the 3'and 5' flank were highly conserved, the difference between family genes mainly in the the repeat sequence region, which yak KAP1 to KAP4 genes were found 30 bp length polymorphism. There were B(CCQTS)A₁(CCQPT) repeat sequence and a new repeat sequence C(SIQTS). The results indicated that the repeat sequence was the key of the polymorphism of KAP1 family genes, which might be relate to combination with keratin protein.     

Using of AFLP Marker to Predict the Hybrid Yield and Yield Heterosis in Rice

利用AFLP分子标记对46个水稻品种进行遗传多样性分析,继而研究分子标记遗传距离与按照NC设计获得的195个杂交组合的产量及特殊配合力的相关性,探讨预测杂种优势的可能性。结果表明:(1)通过UPGMA聚类分析(图3),可将供试材料分为16个类群,并把来源不明的品种(系)划分到相应类群中,从而对这些材料进行初步鉴定。可见,AFLP分子标记是检测类内品种间遗传差异的有效方法,为水稻品种(系)亲本选配提供理论依据。(2)分子标记遗传距离与杂种产量优势、F1产量、特殊配合力之间都呈显著正相关,相关系数介于0.3235-0.7713之间。但相关程度还不足以预测杂种优势。增效座位和减效座位以及使用与杂种优势有关的QTL连锁标记位点可能提高杂种优势的预测能力,但最终解决,将依赖于杂种优势遗传机理的研究。     

Experimental Study on the Extended Length of Negative Reinforcement Cut-in Phases in Continuous Beams

In this paper through the static loading tests of 6 inflexion zones and 2 cantilever zones in full-size constrained R/C beams, the stress performance in rebars cut-in-phases and subjected to negative moment is studied. The stress properties of extended length of rebars with different shear-span ratiosare analysed on basis of the full measurement of strain distributions combined with the investigation on state and regularity of the diagonal cracks development and series of new knowledge are obtained. It is found that current Concrete Design Code provisions on the extended length are inadequate for the high shear-span ratio and superfluous for the low shear-span ratio. The theoretical and experimental foundations are provided for determining proper value of extended length for rebars cut-in-phases.     

CALCULATING SYSTEM FOR SECOND-ORDER EFFECT IN THE COLUMNS OF REINFORCED CONCRETE FRAMES

This paper makes an analysis and comparison of the calculatingsystem for second-order effect in columns of reinforced concrete frames proposedby scholars at home and abroad,and the systems adopted by codes of manycountries.The focus is on explaining the conceptual error and deficiency in somemethods.After expounding the basic law of the second-order effect in framecolumns with different restraints,this paper suggests an improvement of thecalculating system for second-order effect in frame columns for China's DesignCode of Concrete Structures.     

低压射流不同喷嘴参数及压力下破碎过程实验

研究了不同低压下喷头喷嘴直径和喷嘴锥角对射流破碎的影响。采用高速摄像仪对低压圆柱射流的射流核心长度和射流破碎长度进行实验,测量了不同喷嘴结构的流量、射程和末端水滴直径。结果表明:同一压力下,当喷嘴锥角不变时,随着喷嘴直径的增大,喷头流量、射程和喷头末端水滴直径都变大,射流核心长度和破碎长度均增大;当喷嘴直径不变时,随着喷嘴锥角的增大,喷头流量逐渐减小,而喷头射程呈先增大后减小趋势,喷头末端水滴直径也变大,射流核心长度逐渐减小,射流破碎长度先减小后增大。综合考虑射程和雾化效果,直径为5 mm、锥角为45°的喷嘴为最优选择。同时通过对不同Re数和We数的实验和分析,给出了适合低压喷嘴的两种射流特征长度的拟合关联式。