首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9篇
  免费   0篇
化学   4篇
数学   1篇
物理学   4篇
  2018年   1篇
  2014年   1篇
  2012年   1篇
  2011年   2篇
  2009年   3篇
  2008年   1篇
排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
The direct proton capture and resonance proton capture properties of stellar reactions 22Mg(p,γ)23Al and 26Si(p,γ)27P are studied by employing a mean-field potential obtained from the Skyrme-Hartree-Fock(SHF) model.Calculations with the SHF potential reproduce well the loosely-bound structure of the ground states as well as the widths of the resonant states in these nuclei.With the obtained potential we estimate the reaction rates of direct proton capture and resonance proton capture to nuclei 23Al and 27P....  相似文献   
2.
An inclusion complex of cyclic bis(zinc porphyrin) 1 with 5,15-dipyridylporphyrin derivative 3 has been designed and constructed. The complex formation is induced by Zn-N coordination, and is robust (Kassoc ~ 106 L/mol) due to the presence of the cage effect of cyclic bis(zinc porphyrin). The cage-like complex as an entity is stable enough, and also convenient to achieve relative movement between the bis(zinc porphyrin) host and the dipyridylporphyrin guest connected by Zn-N coordination. The characteristic...  相似文献   
3.
酞菁的大π共轭体系使其具有良好的电子给予能力和对可见光的强烈吸收性质,可作为人工光合作用体系中的光捕捉单元.富勒烯具有独特的三维笼状结构,几乎所有反应中都具有低的重组能,是良好的电子或能量受体.将富勒烯与酞菁结合起来,集两个光活性实体于一身,由于酞菁和富勒烯给受体之间的电子相互作用,又赋予其新的性质,具有良好的应用前景,是富勒烯和酞菁领域中的研究热点.本文将酞菁.富勒烯给受体体系分为共价和非共价两种连接方式,介绍其结构与性质以及两者的相互关系,总结了其在有机太阳能电池、非线性光学和液晶性等方面的应用进展,展望了该体系的未来发展趋势.  相似文献   
4.
The surface diffusion of Pt dimers on Wulff polyhedral clusters with 586-12934 atoms was studied by the embedded atom method. The minimum energy diffusion path and the corresponding energy barrier for dimer diffusion on cluster surfaces were determined through a combination of the quenched Molecular Dynamics and the Nudged Elastic Band method. It was found that the diffusion of a dimer across the step-edge by dissociation and consecutive single-atom exchange with the edge atoms, rather than diffusion over t...  相似文献   
5.
Two methods currently available for evaluating the probability of Multiple Site Damage(MSD)occurrence were studied in this paper.One of the methods is a probabilistic analysis approach based on the statistical theory and fatigue characteristics of each structural detail,and the other is an approach which defines the initial damage scenario by means of Monte-Carlo simulation,and multiple initial crack scenarios are randomly generated.A modified method based on the Monte-Carlo simulation was proposed in this paper,in which the random fluctuation of the stress was considered to give more accurate evaluation results.In the presented method,the probability of MSD occurrence in a structural element containing multiple details was calculated based on the Monte-Carlo simulation and the p-S-N curve of a single structural detail.Fatigue tests were accomplished using specimens containing 21-similar-details to obtain the fatigue life corresponding to MSD occurrence.Tests on single-detail specimens and static calibration tests were also conducted to get the basic fatigue properties of the material and the degree of stress fluctuation.The aforementioned three methods were compared and validated via the test results.The influence of the stress random fluctuation degree on the probability of MSD occurrence and influence of the distribution types on evaluating the MSD occurrence probability were discussed.  相似文献   
6.
To develop the high-performance fluorescent bio-sensors, the metal nanoparticles were employed as nanoquenchers and at- tracted reasonable attention in the design of fluorescent biosensors. In this work, silver nanoparticles (AgNPs) were obtained via reduction of Ag+ on FAM-labeled DNA template. For the tight binding between AgNPs and DNA, the tem-plate-ynthesized AgNPs turned out high quenching efficiency and could be applied as super nanoquenchers to establish the biosensing platform for fluorescent detec...  相似文献   
7.
The new trust region subproblem with the conic model was proposed in 2005, and was divided into three different cases. The first two cases can be converted into a quadratic model or a convex problem with quadratic constraints, while the third one is a nonconvex problem. In this paper, first we analyze the nonconvex problem, and reduce it to two convex problems. Then we discuss some dual properties of these problems and give an algorithm for solving them. At last, we present an algorithm for solving the new trust region subproblem with the conic model and report some numerical examples to illustrate the efficiency of the algorithm.  相似文献   
8.
Recently we developed a technique of ozone/vacuum annealing to continuously change the doping level of the surface of Bi2Sr2CaCu2O8+x and measured a nearly whole superconducting dome on one surface by in-situ angle-resolved photoemission spectroscopy [arXiv: 1805.06450]. Here we study the evolution of the electronic structures of Bi2Sr2CaCu2O8+x using this technique together with tight binding fits. The tight binding parameters are extracted to study their evolution with doping.  相似文献   
9.
利用模板辅助合成的方法合成了一个环形双锌卟啉1,该分子具有灵活的空腔且能扩张到足够的大小以容纳5,15-双吡啶卟啉客体3,包合物13通过Zn—N弱作用力连接,因为笼子效应的存在而构筑成非常稳定的实体(Kassoc=1.45×10^6L/mol).对于主一客体之间作用力较小的包合物,笼子效应对它们的稳定性起着决定性的作用.这样的主.客体包合物体系具有类似于分子陀螺仪的特点,即主客体两构件之间能灵活地实现相对运动.研究中用1H NMR,UV-vis和荧光光谱滴定的手段对包合物的形成和组装特点进行了详细的研究,同时通过比较它们包合常数(Kassoc)的差异来定量地评价笼子效应在包合物形成中的贡献.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号