排序方式: 共有62条查询结果,搜索用时 390 毫秒
21.
言杰 孙胜森 李澄 何康林 安琪 边渐鸣 曹国富 曹学香 陈宏芳 邓子艳 封常青 傅成栋 何苗 衡月昆 黄彬 郭建华 贾卢魁 季晓斌 李卫东 梁羽铁 刘春秀 刘怀民 刘树彬 刘曙东 刘勇 罗涛 马秋梅 马想 毛泽普 莫晓虎 邱进发 邵明 孙晓东 孙勇杰 孙永昭 孙志嘉 田浩来 王纪科 文硕频 吴金杰 伍灵慧 吴智 谢宇广 徐敏 严亮 杨桂安 袁野 张长春 张建勇 张瑶 赵川 赵雷 朱永生 邹佳恒 《中国物理 C》2010,34(3):368-373
The principle of the method for the BESIII TOF calibration using cosmic ray data without magnetic field are reported in this paper. After applying calibration constants, the single-end readout time resolution could reach about 150 ps, and the time resolution for one layer is achieved to be about 110 ps. The paper also described the extraction scheme for the event start time of cosmic events. 相似文献
22.
光纤陀螺仪已成为惯性导航系统中最重要的新兴器件.本文对干涉型光纤陀螺的国内外进展国内现有水平和技术状况进行了分析探讨.最后介绍了光纤陀螺仪的发展方向. 相似文献
23.
Supramolecular assemblies of 2,2'-biimidazole with 5-sulfosalicylic acid and 3,4,5-trihydroxybenzoic acid, have been synthesized and characterized by single-crystal X-ray diffraction methods. Both the two proton-transfer compounds of 2,2'-biimidazole with 3-carboxy-4-hydroxybenzenesulfonic acid (5-sulfosalicylic acid, 5-SSA) [namely bis(2-(2-1H-imidazolyl)-1H-imidazolium) 4-hydroxybenzene-3-carboxylate-1-sulfonate monohydrate, 2(C6HTN4)^+· CTH4068^2-.H2O, (Ⅰ)] and 3,4,5-trihydroxybenzoic acid [namely 2,2'-bi-1H-imidazolium bis(3,4,5-trihydroxybenzoate) tetrahydrate, C6H8N4^2+ ·2(C7H5O5)^-·4(H20), (Ⅱ)] feature extensively hydrogen-bonded three-dimensional network structures having significant interlayer n-n interactions between the cation and anion species. In Ⅰ, a 5-SSA^2- dianionic species results from deprotonation of both the sulfonic and the carboxylic acid groups, all available O-atom acceptors interact with all cation and water molecule donors by hydrogen bonds. In Ⅱ, the formula unit displays a crystallographic inversion symmetry. The structural information about the two complexes between 2,2'-biimidazole compound and benzenecarboxylic acids obtained in this work will be particularly important for the rational design of supramolecular organic functional materials. 相似文献
24.
阿霉素—铁(Ⅲ)配合物的电化学特征及其与DNA结合作用研究 总被引:6,自引:0,他引:6
采用示波极谱法环伏安法研究了3价铁离子Fe(Ⅲ)与阿霉素(ADM)配合物 电化学特性。在生理pH条件下,Fe(Ⅲ)与ADM形成2:1的稳定配合物,Fe(Ⅲ)配位使ADM在更负的电势下才能还原,这与其心脏毒性减轻密切相关,采用线性扫描,吸收光谱和凝胶电泳法研究了ADM-Fe(Ⅲ)配合物与DNA的结合作用,ADM-Fe(Ⅱ)栩合物仍保留了ADM插入结合的特征,并形成一种稳定的DNA-Fe(Ⅲ)-ADM 相似文献
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进入"十一五"以来,陕西省图书馆通过系统地回顾新馆开馆后的事业发展状况,将发展思路定位为:进一步强化公共服务职能,带动全省公共图书馆事业的发展.陕西省图书馆坚持"读者第一,竭诚服务"的基本宗旨,在增强服务意识、创新服务理念、扩大服务范围、延伸服务链条、完善服务手段、改进服务质量、提升服务层次、构建服务网络、提高服务效益等方面进行了不懈的努力,随着我国信息资源共享机制的建设不断发展,在这个层面上我省公共图书馆考虑到了现代学习技术平台的打造与公共服务体系需求的结合,所以在技术引进、阅读管理、场地设施等层面展开了基本性建设并取得了可观的成果. 相似文献
26.
研究了二氯二苯基锡(Ph_2SnCl_2)与核酸的基本组成单元──单核苷酸在水相中的配位作用,并用热分析、傅利叶变换红外光谱和 ̄1H、 ̄(31)P超导核磁共振谱对新配合物Ph_2Sn(5'-AMP)·H_2O、Ph_2Sn(5'-CMP)·H_2O和Ph_2Sn(5'-GMP)进行了详细的表征。结果表明,在配合物中锡仅与单核苷酸的磷酸根结合,给出了配合物的可能结构。 相似文献
27.
环丁烷嘧啶二聚体(Cyclobutane Pyrimidine Dimer,CPD)是紫外线对DNA损伤导致皮肤癌的首要环节,XPC-hHR23B是最早作为对CPD的损伤识别剂的,但其识别效率很低.首次采用分子力学方法模拟了手性金属配合物D,L-[Ru(phen)2dppz]^2+(phen=1,10phenanthroline,dppz—dipyrido[3,2-a:2’,3'-c]phenazine)对含G:T错配的CPD双螺旋DNA的识别作用.模拟结果显示:该配合物的左手异构体优先从小沟方向识别与G:T错配相邻的4T5/T7G6区域,而右手异构体则优先从大沟方向识别与G:T错配相邻的另一区域T6A7/C5T4.由于CPD的形成,该DNA螺旋高度扭曲,使得识别过程体现了手性选择性和位点特异性,左手异构体更占优势.详细的能量分析发现:在配合物插入碱基堆积过程中的空间位阻状况决定了识别作用的结果,静电相互作用也在一定程度上产生了影响.此外,我们还发现,金属配合物插入CPD相邻的区域后,能将形成CPD的两个T碱基由原来的敞口形状部分地转为近平行状,使其得到构型上的部分修复. 相似文献
28.
A new model of a quantum refrigeration cycle composed of two adiabatic and
two isomagnetic field processes is established. The working substance in the
cycle consists of many non-interacting spin-1/2 systems. The performance of
the cycle is investigated, based on the quantum master equation and
semi-group approach. The general expressions of several important
performance parameters, such as the coefficient of performance, cooling
rate, and power input, are given. It is found that the coefficient of
performance of this cycle is in the closest analogy to that of the classical
Carnot cycle. Furthermore, at high temperatures the optimal relations of the
cooling rate and the maximum cooling rate are analysed in detail. Some
performance characteristic curves of the cycle are plotted, such as the
cooling rate versus the maximum ratio between high and low ``temperatures'
of the working substances, the maximum cooling rate versus the ratio between
high and low ``magnetic fields' and the ``temperature' ratio between high
and low reservoirs. The obtained results are further generalized and
discussed, so that they may be directly applied to describing the performance
of the quantum refrigerator using spin-$J$ systems as the working substance.
Finally, the optimum characteristics of the quantum Carnot and Ericsson
refrigeration cycles are derived by analogy. 相似文献
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