Two overrun phenomena and their effects on fusion yield in the Coulomb explosion of heteronuclear clusters

Two overrun effects in the Coulomb explosion dynamics of heteronuclear clusters have been investigated theoretically by the use of a simplified electrostatic model. When the charge-to-mass ratio of light ions is higher than that of heavy ions, the light ions can overtake the heavy ions inside the cluster and acquire a higher kinetic energy. Further, if the charge density of the heavy ions is twice as high as that of the light ions, i.e. a proposed competitive parameter xi = rho BqB/rho AqA > 2, the inner light ions can overtake those light ions on the surface of the cluster and form a shock shell during the explosion, which might drive the intracluster collision and fusion of the light ions. Different regimes of nuclear fusion are discussed and the corresponding neutron yields are estimated. Our analysis indicates that the probability of intracluster fusion is quite low even if deuterated heteronuclear clusters such as (DI)(n) with large size and high competitive parameter are employed. However, heteronuclear clusters are still a better candidate compared with homonuclear clusters for enhancing the total intercluster fusion yield because both a higher energy region and a higher proportion of deuterons distributing in the energy region can be created in the deuterated heteronuclear clusters.

Studies of magnetic interactions in Mn-doped β-Ga2O3 from first-principles calculations

The magnetic behavior of Mn-doped beta-Ga2O3 is Studied from first-principles calculations within the generalized gradient approximation method. Calculations show that ferromagnetic ordering is always favorable for configurations in which two Mn ions substitute either tetrahedral or octahedral sites, and the ferromagnetic ground state is also sometimes favorable for configurations where one Mn ion substitutes a tetrahedral site and another Mn ion substitutes an octahedral site. However, the configurations of the latter case are less stable than those of the former. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

SMC蛋白复合体的结构、功能和作用机制

染色体结构维持(SMC)蛋白是一类染色体ATP酶.以这类蛋白质为核心可形成三种多蛋白复合体:凝聚蛋白(condensin)、黏结蛋白(cohesin)和SMC5-SMC6复合体.这些复合体直接参与了染色质结构的组织、细胞分裂过程中遗传物质的准确分离和忠实遗传等重要功能活动,自发现至今,对该类复合体的结构、功能及作用机制等方面已有较多研究并取得一些重要进展.

利用耳石日轮技术研究长江中游草鱼幼鱼的孵化期及生长

根据耳石日轮对2004年采自洞庭湖和新滩口江段的草鱼幼鱼进行日龄(D)鉴定,孵化时间推算以及生长的研究。草鱼幼鱼所有样品体长(BL,mm)生长方程为BL=-53.4195+3.1650D,体重(W,g)生长方程为W=0.9816 e0.0633D,体长体重相关方程为W=0.00001BL3.1003。孵化时间最早为5月14日,最晚为7月11日,主要集中在5月下旬和6月份。研究发现三峡大坝在139m水位运行后长江中游仍有草鱼产卵,最早繁殖时间稍晚于历史记录。

柠檬酸对高岭石的溶解作用

采用间歇法(batch method)研究柠檬酸对高岭石溶解的影响。结果表明:低浓度(0.02mmolL-1)柠檬酸可促进高岭石中Ca2+、Mg2+、Na+少量的释放。当柠檬酸浓度分别为1.0mmolL-1和8mmolL-1时,Ca2+,Mg2+,K+,Na+,Si,Al3+阳离子的释放量也相应地增加。释放的Ca2+、Mg2+主要来自高岭石表面的吸附,而Na+、K+则来自高岭石的溶解。

中药处方配伍监控系统的设计与实现

医院信息系统(hospital information system,HIS)作为医院信息化建设的重要组成部分越来越受到社会的重视,已经进入一个高速发展的阶段。但是作为诊疗过程的一个重要组成部分-药物处方治疗,在HIS中却缺少必要的监控与指导。在HIS标准化推进的同时,更应该对其深度和广度进行研究,结合软件工程的设计思想,基于面向对象的开发方法,设计开发了“中药处方配伍”监控系统,提供了临床用药指导功能,使其作为HIS的一个子系统能够实时的对医生处方进行监控,使临床医药人员记得更多、更准、更细,以降低药源性疾病,提高用药质量,加强用药管理,避免医疗纠纷。

大带宽半导体光学放大器的理论分析

提出一种新型的半导体光学放大器结构，并从增益谱和能带结构等角度分析其特征，得出其大带宽内偏振不灵敏的原因和规律。通过剖析该结构中有源区各部分的作用，得出大的张应变的引入主要是用于提高TM模的材料增益，获得偏振不灵敏和大的TE模带宽，减小制备难度。厚的无应变层的引入主要是为了改善有源层晶体质量，获得大的偏振不灵敏模式增益。

As＋注入Si1-xGex中应就驰豫的双晶X射线衍射研究

国家自然科学基金

Ce-Si多层膜中铈硅化物的形成

国家自然科学基金