No enhancement of fusion probability by the neutron halo of 6He

Quantum tunnelling through a potential barrier (such as occurs in nuclear fusion) is very sensitive to the detailed structure of the system and its intrinsic degrees of freedom. A strong increase of the fusion probability has been observed for heavy deformed nuclei. In light exotic nuclei such as 6He, 11Li and 11Be (termed 'halo' nuclei), the neutron matter extends much further than the usual nuclear interaction scale. However, understanding the effect of the neutron halo on fusion has been controversial--it could induce a large enhancement of fusion, but alternatively the weak binding energy of the nuclei could inhibit the process. Other reaction channels known as direct processes (usually negligible for ordinary nuclei) are also important: for example, a fragment of the halo nucleus could transfer to the target nucleus through a diminished potential barrier. Here we study the reactions of the halo nucleus 6He with a 238U target, at energies near the fusion barrier. Most of these reactions lead to fission of the system, which we use as an experimental signature to identify the contribution of the fusion and transfer channels to the total cross-section. At energies below the fusion barrier, we find no evidence for a substantial enhancement of fusion. Rather, the (large) fission yield is due to a two-neutron transfer reaction, with other direct processes possibly also involved.     

分布式选举算法

提出了一种基于任意网络拓扑的分布式选举领导人算法。每一处理机既不知道系统的网络拓扑，也不知道系统中处理机的台数。对于由ｎ台处理机组成的分布式系统，算法的消息复杂度最好为３＃Ｅ，最坏不超过＃Ｅ（２Ｎ＋１）－Ｎ＋ｎ；对于同步分布式系统，其时间复杂度最好不超过３（ｎ－１）△ｔ，最坏不超过４（ｎ－１）△ｔ。     

Mitochondrial dynamics as regulators of cancer biology

Mitochondria are dynamic organelles that supply energy required to drive key cellular processes, such as survival, proliferation, and migration. Critical to all of these processes are changes in mitochondrial architecture, a mechanical mechanism encompassing both fusion and fragmentation (fission) of the mitochondrial network. Changes to mitochondrial shape, size, and localization occur in a regulated manner to maintain energy and metabolic homeostasis, while deregulation of mitochondrial dynamics is associated with the onset of metabolic dysfunction and disease. In cancers, oncogenic signals that drive excessive proliferation, increase intracellular stress, and limit nutrient supply are all able to alter the bioenergetic and biosynthetic requirements of cancer cells. Consequently, mitochondrial function and shape rapidly adapt to these hostile conditions to support cancer cell proliferation and evade activation of cell death programs. In this review, we will discuss the molecular mechanisms governing mitochondrial dynamics and integrate recent insights into how changes in mitochondrial shape affect cellular migration, differentiation, apoptosis, and opportunities for the development of novel targeted cancer therapies.     

数控设备E-服务技术研究

针对数控设备售后服务与技术支持问题,提出基于Web的服务保障系统．系统由E-服务平台、数控机床网关和远程终端三部分组成．E-服务平台是一个特殊网站,它通过Internet向客户提供技术支持与服务．数控机床网关是一个移动PC,当机床发生故障时将其带到现场,采集机床PLC信息、视频信息和传感器信息,并将信息传送到E-服务平台供诊断分析．远程终端可以是连接在Internet上的任何PC机,客户通过远程终端访问E-服务平台,获得快速和高质量的产品售后服务．     

数控加工中心误差G代码补偿技术

提出了数控加工中心误差的G代码补偿方法，应用刚体运动学理论和齐次坐标变换技术建立了多轴数控加工中心空间误差的通用模型，把加工患具相对工件的终端误差表示为各个误差源和刀具位置的函数，给出了全部运动误差参数的激光干涉仪识别方法，提出了数控加工中心三种基本运动的误差补偿算法，在立式加工中心上进行了该方法的实验，结果表明引入误差补偿后使加工中心的系统误差减小80％－90％。     

可重构的虚拟数控远程操作面板生成系统研究

介绍了虚拟数控系统软件芯片的构建方法，研究了基于可重构的虚拟数控操作面板设计原理和实现技术；利用COM／DOOM技术，开发实现了可重构的、可定制的虚拟数控操作面板生成系统，采用ASP，ActiveX等技术和通用的协议标准TCP／IP，实现了了基于Web的虚拟数控系统的远程操作与监控，并给出了系统的运行实例。     

螺旋锥齿轮空间曲面NC加工插补误差分析

基于空间曲面共轭原理，建立螺旋锥齿轮的齿面矢量方程，由空间坐标系的变换，确定出刀具相对工件的位置和姿态，实现刀具与工件的相对运动，在综合考虑齿面形状、刀具形态及机床结构等因素的基础上，分析了五坐标螺旋锥齿轮面NC过程插补误差，建立考虑齿面NC插补误差的螺旋齿轮数控加工方法，计算结果与加工实验结果基本一致。