光纤陀螺信号处理中SLD驱动电路设计

光纤陀螺用光源要求输出功率高、相干性低、稳定性好，超辐射发光二极管（SLD）是能满足这些要求的理想光源，目前国内光纤陀螺用的光源基本上主要选择超辐射发光二极管（SLD），从工程实际应用出发，介绍了超辐射发光二极管（SLD）驱动电路设计，以此来提高光纤陀螺性能。     

Average Range and Network Synchronizability

The influence of structural properties of a network on the network synchronizability is studied by introducing a new concept of average range of edges. For both small-world and scale-free networks, the effect of average range on the synchronizability of networks with bounded or unbounded synchronization regions is illustrated through numerical simulations. The relations between average range, range distribution, average distance, and maximum betweenness are also explored, revealing the effects of these factors on the network synchronizability of the small-world and scale-free networks, respectively.     

一类基于排斥吸引函数的离散混沌模型

利用排斥吸引函数容易实现有界离散映射的特点,提出了一类新的离散混沌映射,并利用理论推导对其分岔机理进行了研究.通过分岔图和Lyapunov指数谱清楚地展示了这个离散映射从有序到混沌的变化过程.可以看到这个简单的排斥吸引函数也能够象著名的Logistic模型一样产生复杂的动力学行为.     

温度对fcc铁中氦行为的影响研究

温度对fcc铁中的氦行为具有重要的影响,编写了居于fcc晶格的面向对象动力学蒙特卡罗程序（Object Kinetic Monte Carlo）,采用该程序结合分子动力学（MD）方法对fcc铁中的氦行为进行多尺度模拟,研究了温度对fcc铁中氦行为的影响,给出了不同温度退火过程中氦行为的原子细节。模拟结果表明引入一定量的非热平衡空位可以使模拟结果与文献实验结果有非常好的吻合;室温至1073K,温度对氦行为影响可以分为四个阶段：第一阶段,298-473K,正电子长寿命随退火温度增加略有减少,这主要由于非热平衡空位浓度降低;第二阶段,473-673K,正电子长寿命随退火温度增加而增加,主要由于晶粒内平均氦泡尺寸增加;第三阶段,673-873K,正电子长寿命随退火温度增加而迅速减少,主要是由于氦泡的平均尺寸减小和晶粒内的空位浓度降低;第四阶段,873-1073K,正电子长寿命随退火温度增加而迅速增加,与晶粒内氦泡的平均尺寸变大,且空位浓度随温度的增加而指数增加有关。     

温度对bcc铁中He行为影响的模拟研究

温度对bcc铁中的He行为有重要的影响,基于bcc晶格的晶格动力学蒙特卡罗（Lattice Kinetic Monte Carlo,LKMC）方法,模拟研究了298—1298 K范围内温度对bcc铁中He行为的影响.结果表明：温度对bcc铁中He行为的影响可以分为4个阶段：（1）298—598 K,（2）598—798 K,（3）798—998 K,（4）998—1298 K.第一阶段随着温度的增加,晶粒内He原子浓度略有降低,但He泡中平均He原子个数迅速增加;第二阶段随着温度的增加,晶粒内的He原子浓度迅速降低,但He泡中平均He原子个数几乎不变;第三阶段随着温度的增加,晶粒内的He原子浓度和He泡中平均He原子个数均迅速减少;第四阶段随着温度的增加,晶粒内He原子浓度以及He泡中平均He原子个数均有所增加,到1298 K时,晶粒内He原子浓度与室温时相近,几乎没有He原子从铁晶粒内逃逸出.模拟结果与文献正电子湮灭实验结果有很好的吻合. 关键词： bcc铁 He 晶格动力学蒙特卡罗 温度     

Epidemic spreading on networks with vaccination

In this paper, a new susceptible-infected-susceptible (SIS) model on complex networks with imperfect vaccination is proposed. Two types of epidemic spreading patterns (the recovered individuals have or have not immunity) on scale-free networks are discussed. Both theoretical and numerical analyses are presented. The epidemic thresholds related to the vaccination rate, the vaccination-invalid rate and the vaccination success rate on scale-free networks are demonstrated, showing different results from the reported observations. This reveals that whether or not the epidemic can spread over a network under vaccination control is determined not only by the network structure but also by the medicine's effective duration. Moreover, for a given infective rate, the proportion of individuals to vaccinate can be calculated theoretically for the case that the recovered nodes have immunity. Finally, simulated results are presented to show how to control the disease prevalence.     

Cost and effect of pinning control for network synchronization

The problem of pinning control for the synchronization of complex dynamical networks is discussed in this paper. A cost function of the controlled network is defined by the feedback gain and the coupling strength of the network. An interesting result is that a lower cost is achieved by using the control scheme of pinning nodes with smaller degrees. Some strict mathematical analyses are presented for achieving a lower cost in the synchronization of different star-shaped networks. Numerical simulations on some non-regular complex networks generated by the Barabási--Albert model and various star-shaped networks are performed for verification and illustration.     

氚老化对LaNi4.9Al0.1的动力学性能的影响

测定了不同材龄的LaNi4.9Al0.1氘化与去氘化动力学参数,评价了氚老化对LaNi4.9Al0.1动力学性能的影响.研究结果表明,氚老化不改变合金的氘化与去氘化的反应级数;反应速率随老化时间的增加而降低;活化能随老化时间的增加而增加.     

大气环境中铈氧物组成研究

采用X射线衍射仪(XRD)、扫描电镜(SEM)和X射线光电子能谱(EDS)研究了大气环境中铈氧化物的组成变化. 实验结果表明, 大气环境中铈的氧化物主要由Ce2O3, Ce7O12和CeO2构成, 氧化初期主要是Ce2O3, 随着氧化时间增加, 大部分Ce2O3逐渐转变为Ce7O12, 而在局部微裂纹集中处直接生成CeO2, 随着氧化过程的进行, Ce7O12逐渐转变为CeO2, 240 h后 Ce7O12几乎完全转变为CeO2;扫描电镜结合能谱分析表明Ce7O12主要以连续致密氧化膜存在, 而CeO2则出现大量微裂纹, 这种变化与两者密度上的差异有关.     

温度对bcc铁中He行为影响的模拟

介绍了一种模拟bee铁中长期He行为的晶格动力学蒙特卡罗方法（LKMC），它采用分子动力学或第一性原理计算方法计算得到的金属中缺陷的迁移能、形成能、离解能等数据作为输入参数，根据这些参数计算得到模拟体系的事件集，然后通过抽样方法得到体系的下一状态，从而实现对金属中He和缺陷相互作用过程的模拟。根据Robison等描述的LKMC模拟步骤，编写了用于模拟bee金属中He行为的LKMC程序，采用该程序模拟研究了温度对bee铁中He行为的影响。