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Search Results: 1 - 10 of 221132 matches for " 刘先 "
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不同生物型棉蚜对夏寄主葫芦科作物的选择
发表于《生态学报》2013年12期,引自
http://www.cnki.net/KCMS/detail/detail.aspx  [PDF]


QianRen Biology (QRB) , 2014, DOI: 10.12677/QRB.2014.11004
Abstract:
于2008、2009年连续两年采用模拟田间自然扩散法,系统地研究了棉花型棉蚜和甜瓜型棉蚜有翅蚜对11种夏寄主的选择性。结果表明,棉花型棉蚜对杂交葫芦、小西葫芦表现出强选择性及适应性,而对香瓜、黄瓜、西瓜及甜瓜均不选择,或即使选择其若蚜在其上也不能存活;甜瓜型棉蚜对甜瓜、香瓜、南瓜、黄西葫芦、大西葫芦、杂交葫芦等均表现较强选择性,而对棉花及小西葫芦表现不选择。但是,甜瓜型棉蚜在小西葫芦上也能产若蚜并存活。从而证明小西葫芦是两种寄主型棉蚜的共同寄主,有可能成为两者相互转换的桥梁寄主。
The cotton or melon aphid, Aphis gossypii (Glove), is one of the most important pests worldwide. The species has at least two specialized biotypes, one on cotton (Gossypium hirsutum), and one on cucurbitaceous plants. In this study, we determined the preference and the finite increase rates of A. gossypii on 10 host plants of Cucurbtaceae with winged adults. A. gossypii adults originally from cotton significantly preferred two cucurbits, hybrid squash (Cucurbita sp.) and zucchini (Cucurbi-tapepo zucchini), to other host plants; whereas A. gossypii adults originally from melon (Cucumis melo) preferred cucurbit plants, including melon, cantaloupe (Cucumis meloinodorus), pumpkin (Cucurbita moschata), yellow squash (Cucurbita pepo), tornado (Cucumis melo “tornado”), and hybrid squash (Cucurbita sp.) to cotton and zucchini. Interestingly, the aphids originally from melon did not prefer zucchini, but they could survive on this host well. Therefore, zucchini could be an intermediate or the mutual host of the two aphid biotypes, and they might be serving as a bridge host of the two biotype aphids.
表面等离子体增强型量子阱红外探测器光栅设计与模拟
Design and Simulation of the Surface Plasmon Enhanced Grating for Quantum-Well Infrared Detector
 [PDF]

张忆, 文杰
Optoelectronics (OE) , 2013, DOI: 10.12677/OE.2013.32005
Abstract: 本研究分析了目前量子阱红外探测器应用中的主要制约因素,从表面等离子体的激发和传输物理机制出发,将表面等离子体近场光增强效应引入量子阱红外探测器光栅设计中,通过模拟计算进一步分析了光栅结构参数对探测器吸收波长和强度的影响,为未来这项技术的进一步应用打下理论基础。
In this paper, the main restricting factors of quantum well infrared detector application were analyzed. Through studying on the physical mechanism of surface plasmon excitation and transmission, we developed a surface plasmon grating for quantum-well infrared detector. The influence on transmission intensity and wavelength with the constructor parameters of grating was discussed. The result is giving theoretical basis for future quantum well infrared detector application.
铁电极化调控CO在Pt表面的吸附
The CO Absorption on Pt Film Tuned by Ferroelectric Polarization
 [PDF]

, 曹觉
Advances in Condensed Matter Physics (CMP) , 2015, DOI: 10.12677/CMP.2015.42006
Abstract:
基于密度泛函理论的第一性原理,以BaTiO3和PbTiO3两种典型的铁电材料为例,我们探讨了铁电极化对CO在Pt薄膜表面吸附的影响。计算结果表明当极化方向为正时,CO在Pt/PbO/PbTiO3表面顶位的吸附能为?2.53 eV,而当极化方向反向时,CO的吸附能变为?1.39 eV。这表明铁电薄膜的铁电极化可有效调控CO在Pt表面的吸附。这种调控主要是由于极化所诱导的界面电场有效地改变了CO的4σ、1π、5σ轨道与Pt5d轨道之间的成键耦合。我们的研究为寻找抑制质子交换膜“CO中毒”的催化材料提供了新的方法。
We investigated the CO absorption on Pt film tuned by ferroelectric polarization of BaTiO3 and PbTiO3. Our results have demonstrated that the adsorption properties can be dramatically mod-ulated by the ferroelectric polarization. Especially, we found that the chemisorption energy are ?2.53 eV with positive ferroelectric polarization for CO adsorbed on the top site of Pt/PbO/PbTiO3 while the chemisorptions energy reduce to ?1.39 eV with inversion of the polarization direction. It is found that the coupling strength for the 4σ, 1π, 5σ orbital and 5d orbital of Pt can be tuned by the interfacial electric filed induced by the polarization of ferroelectric film. Our studies provide new approach for carbon monoxide poisoning resistant in proton exchange membrane catalytic material.
基于Data Matrix二维条码的汽车零件管理系统的研究
Research on Auto Parts Management System Based on Data Matrix Two-Dimensional Barcode Technology
 [PDF]

, 幺和
Computer Science and Application (CSA) , 2011, DOI: 10.12677/csa.2011.13025
Abstract: 本文讨论了基于Data Matrix二维条码的汽车零件管理系统的重要性,介绍了当前软件系统的两种结构,对整个管理系统从需求分析、系统结构到重要功能模块都进行了阐述,并对系统的安全性进行了分析。运用该系统可以提高企业的质量和管理效率,并为售后服务提供有力的保障。
This paper discusses the importance of the Auto Parts Management System which based on Data Matrix two-dimensional barcode technology, introduces two kinds software structure of current software sys- tem, explains entire management system from requirements analysis, system architecture to important fun- ction modules, and analyzes system security. Using this system can improve the quality and management effi- ciency, and provide strong protection for the service.
对一个环Zn上圆锥曲线数字签名的分析与改进
Analysis and Improvement of a Digital Signature Based on Conic Curve over Zn
 [PDF]

军霞,
Software Engineering and Applications (SEA) , 2012, DOI: 10.12677/SEA.2012.12008
Abstract:

杨慧等人基于环Zn上的圆锥曲线构造了一个ElGamal型数字签名方案,文章分析指出,该方案的私钥可以从公钥和签名中恢复出来,因而该签名方案是不安全的。对杨慧等人的签名方案进行了改进,通过分析可知改进方案能够抵抗密钥恢复攻击。基于改进数字签名方案构造了一个多重数字签名方案,该多重数字签名方案无需进行多次交换数据以获得同一个参数,减少了通信量。

Under the analyses of an ElGamal digital signature scheme based on conic curve over Zn proposed by Yang Hui et al., this paper reveals that the secret key can be gained by the public key and the signature, so Yang et al.’s scheme is not security. An improved digital signature scheme is given, and it can resist the secret key gaining attack. Moreover, a multi-signature digital scheme is supplied based on the improved digital signature scheme. The multi- signature digital scheme has the advantage not to exchange many times among singers to get the same parameter, and therefore reduces the communication traffic.

 

斜拉桥在不可压缩流中的颤振稳定性条件分析

力学与实践 , 1987,
Abstract: 本文通过对既包括竖直运动又包括扭转运动的气动耦合的颤振分析,拟建立斜拉桥在不可压缩流中的颤振稳定性条件。
近距离薄煤层上行开采实践

煤炭工程 , 2010,
Abstract: 摘要针对近距离薄煤层能否进行上行综合机械开采进行了论证分析,通过现场试验,取得成功,并对近距离煤层上行开采进行了总结。
几种弧形倒角变直径轴段的柔度或刚度的积分算法

力学学报 , 1977, DOI: 10.6052/0459-1879-1977-3-1977-030
Abstract: 一、引言在研究往复内燃机的扭转振动时,常先把曲轴连杆活塞机构化成带薄盘的等径轴模型系统。机器直轴有时需分成直径大小不同的几段,因而其诸段的扭转弹簧系数也就依径变而有所区别。为了简化计算,在上述情形中,也需要先把这样的轴按照预先选定
半无限弹性体内球型热源所激起的热应力及变形

力学学报 , 1959, DOI: 10.6052/0459-1879-1959-3-1959-016
Abstract: 众所周知,一般而諭,若有不均匀的温度在一个物体的表面或內部存在,就必然会产生热应力。若該物体是一部机器,热应力也常常会达到使机件破裂的程度。因此,研究某种情况下的热应力分布是具有实际意义的一件工作;例如,无論是在蒸汽涡輪机、燃汽涡輪机、往复內燃机、高压压气机,以及許多别的只要是与高温有关系的机具及装置中均发生热应力。把在某种高温分布情况下的热应力变化規律探討清楚以后,一方面,如对机器的性能沒有妨碍的話,就可以借改变設計来根本避免或是部分的避免过高应力的产生;
矩形截面异质柱体在半无限弹性体内的热应力问题

力学学报 , 1965, DOI: 10.6052/0459-1879-1965-4-1965-030
Abstract: 一、含有矩形截面异质柱的无限弹性体的热应力问题如图1所示,无限弹性体内装有矩形截面异质柱,柱轴平行于z轴,设c>0,异质性的热胀系数α_i大于无限弹性体的热胀系数α_a,但两种材料有相同的弹性系数.当温度等
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