高速图像采集系统与中性粒子计数系统的实现以及对RTX的初步研究

在HL-2A装置实验中，高速图像采集系统在实验期间完成了对等离子体放电图像的实时采集与显示，提供对放电状态的监视，可以作为分析实验结果的直观参照。中性粒子计数系统主要在实验期间完成对等离子体辐射出的中性粒子数量的计数，以便提供对离子能量计算所需要的数据。     

An active control synchronization for two modified Chua circuits

From modern control theory, an active control method to synchronize two modified Chua circuits with each other,which exhibit chaos, is presented. Some sufficient conditions of linear stability of the chaotic synchronization are obtained from rigorous mathematic justification. On the basis of the state-observer, the controller is analytically deduced using the active control. It is shown that this technique can be applied to achieve synchronization of the two systems with each other, whether they are identical or not. Finally, numerical simulations show the effectiveness of the proposed control scheme.     

Radiation-induced resistance oscillation and instability in GaAS/AlGaAS heterostructure under transverse magnetic fields

This paper studies dynamics of a modulation-doped GaAs/AlGaAs heterostructure under transverse magnetic fields and microwave radiations. It finds that negative differential conductivity, due to the real-space electron transfer and delayed dielectric relaxation of the interface potential barrier, can lead to complex behaviours when a relatively small magnetic field is applied. Quasiperiodicity, frequency-locking and the routes from period-doubling to chaos are found. Under a large magnetic field, however, two time-independent homogeneous steady states exist; and the longitudinal resistance of the system shows an interesting oscillation with period tuned by the ratio of microwave radiation frequency w to the cyclotron frequency Wc and local minima at ω/ωc = integer ＋ 1/4.     

基于AMOEBA可极化力场研究蛋白二聚化对于gramicidin A通道电导的影响

在离子通道性质的研究中,由于可极化力场计算量巨大,长期以来使用最广泛的依旧是经典力场. 本文考察了可极化力场在描述离子通道gramicidin A(gA)二聚状态下离子输运性质方面的可靠性. 利用AMOEBA可极化力场对单通道gA和双通道gA进行增强采样模拟,从电导、扩散系数和自由能等方面描述了gA二聚化对钾离子和钠离子穿越通道过程的影响. 计算结果显示,可极化力场模拟获得的钾离子和钠离子穿越通道的电导与实验数值吻合. 进一步的数据分析揭示了蛋白质二聚化影响gA通道离子输运性质的分子机制,即蛋白二聚化通过调整gA蛋白周围的环境(磷脂头基、通道外离子和体相水分子的分布)而不是直接调整gA蛋白的构象来加速钾离子和钠离子穿越通道.     

生物细胞中的能量学和力学

世界上的生物总是在不停地运动着。动物在奔跑、飞翔、游泳。植物日复一日追逐着太阳。即使是微生物,也在不停地运动。我们体内的细胞的各个部分也在不停地运动,这些运动使我们的细胞可以生长、分裂、改变形状、甚至运动。除了运动之外,我们的身体还必须能够感知到周围的世界。活体细胞可以对周围很多种机械刺激产生反馈,比如伸展,液体的流动,渗透压的改变,周围环境的硬度。我们的触觉和听觉要求细胞能够感知非常细微的机械力。我们对血压的调节能力依赖于分布在体内动脉和静脉的机械敏感性。     

基于图像分析法的水稻茎秆力学性能测量与分析

水稻茎秆力学性能的准确描述是水稻抗倒伏力学分析的关键。由于茎秆是由生物活性材料组成的形状不规则柔性结构,传统的测试方法难以对其力学性能进行准确测量。以南方水稻为研究对象,采用拉伸试验机对水稻茎秆进行了拉伸试验。首先采用传统的应变片方法测量应变,继而探索采用图像分析法实现非接触、高精度地测量水稻茎秆的截面尺寸、拉伸变形。用数字摄像机记录不同荷载水平下试件表面的数字图像,采用数字图像相关分析法(DIC)进行分析,通过两种方法计算茎秆的轴向应变;将完成拉伸实验的试件切片,采集其横截面的数字图像,通过数字图像分析技术得到其几何特性,并对大量实验数据进行了统计分析,实现了对水稻茎秆弹性模量、抗弯刚度等的合理描述。实验结果表明,采用传统的应变片测量求得的水稻茎秆的弹性模量的离散性极大,超出样本差异性的范围,而采用数字图像分析方法得到的弹性模量、抗弯刚度的结果有一定的离散性,但分布比较合理,比较准确地反映了水稻茎秆相关的力学性能。     

新添加剂下KDP晶体快速生长及其性能表征

我们使用优级纯的KH2PO4和超纯水(电阻率≥18.2MΩ·cm)为原料,采用新的添加剂KCl(氯化钾)及EDTA钾盐,使生长溶液的稳定性得到提高,在5L生长槽内生长出51mm×54mm×40mm的KDP单晶,生长速度达到15～20mm/d,并检测了快速生长晶体的重要的应用性能,发现与高质量慢速生长晶体性能相当,可以达到使用要求.     

A critical pattern of crossflow around a slender

IntroductionModernhigh_performancefightersoftenrequiretobeoperatedunderafairlylargeangleofattacksoastoachieveexcellentmaneuverabilityandagility .Atsuchlargeangleofattack ,asymmetricallee_sidevortexflowwillformatthefrontpartofthefuselage .Sothatsuchagreats…     

溶液法生长氘化磷酸二氢铵(DADP)晶体及其性能研究

使用优级纯的NH4H2PO4(含量＞99.5;)和重水(纯度＞99.5;)为原料,在重水中经过三次氘化重结晶,获得含氘量＞95;的结晶原料.上述DADP晶体作为原料配成1000ml的饱和溶液,用降温转动法生长出22mm×23mm×78mm尺寸的透明大晶体,并且测定其晶体结构、透过光谱和激光损伤阈值.从数据分析来看在最重要的光谱应用波段(1.06μm附近)DADP晶体综合性能是很优越的,这使得DADP有利于作为电光晶体材料和制作高频高灵敏度的电光器件.     

Stability of the crossflow pattern around a slender and influence of disturbance

Topological structure and stability of a slender cross flow is discussed by the stability theory of dynamic system. The inner boundary of flow field was limiting streamline and it was proved that the topological structure connected saddles by limiting streamline is stable. It is proved that the development of slender vortices leads to the change of topological structure about cross flow. And it is the change from stable and symmetrical vortices flow pattern to unstable and symmetrical vortices flow pattern, and then to stable and asymmetrical vortices flow pattern due to little disturbance which leads to the development of asymmetrical slender vortices. The influence of disturbance to flowfield structure was discussed by unfolding theory too.