1.06μm连续激光辐照TiO_2/SiO_2/K_9薄膜元件温升规律研究

利用1.06μm连续激光在不同强度下辐照TiO2/SiO2/K9薄膜元件,实验中用红外热像仪测量激光辐照在TiO2/SiO2/K9元件表面引起的温升随时间的变化,通过数据处理,获得激光辐照区域最高温度随辐照时间的增加而增加。同时,给出材料温升随材料发射率的变化关系。并用程序模拟不同激光强度下薄膜温度场的分布,通过实验测量数据校正数值模拟计算结果,给出TiO2/SiO2/K9薄膜元件温度随激光辐照强度和辐照时间的变化规律。并且获得在薄膜厚度方向:薄膜表面温度最高,基底与薄膜接触处温度最低;沿径向:激光辐照中心温度最高,边沿温度最低。     

稳定波长反馈引起的失谐对自由电子激光的影响

利用修改的一维非定态程序,基于美国杰弗逊实验室（JLab）Demo自由电子激光装置的参数,对高功率自由电子激光振荡器稳定波长的反馈系统进行了数值模拟。电子微脉冲为高斯型分布,每个纵向网格中取16个模拟宏电子,不考虑电子束的能散度。结果表明：当无反馈时,腔内光功率和波长都可以在一定范围内稳定;加入反馈后,由于电子束能量的变化所引起的等效失谐对整个系统有着重要的影响,甚至可能导致电子和光场失去相互作用,从而使得装置不能工作。提出应该在光场达到饱和以后再启动稳定波长反馈系统。模拟结果证明,该实施方案是合理有效的,可以避免其对FEL运行的严重影响。     

高温超导线圈在大电流下稳定性的数值仿真

在电力应用中,超导磁体可能会因为线圈工作于过流状态而失超,也可能会因为交流损耗而导致失超.为此,我们模拟了一个磁体在大电流过载下的稳定性情况.我们使用了一个建立在热传导方程和麦克斯韦方程基础上的差分数值计算方法来得出磁体内部的温度分布.我们对各种不同的电流冲击情况进行了考察,我们的模型可以使磁体设计者在实际制作之前能够估计一个比较安全的操作电流水平,有着广泛的实用价值.     

高功率微波器件2.5维通用粒子模拟软件——尤普

利用体积加权宏粒子模型,考虑了阴极形状的爆炸电子发射模型、散度校正完全匹配层边界等新型和改进型电磁粒子模拟算法模型,提高了粒子模拟算法的计算精度,并有效降低数值噪声。在此基础上开发出2.5维全电磁通用粒子模拟软件——尤普,可在x-y,z-r和r-φ3种坐标系下应用于高功率微波器件的2.5维数值模拟研究和结构设计。对相对论磁控管、磁绝缘线振荡器和虚阴极振荡器等高功率微波器件的模拟结果表明：尤普软件得到了正确的物理图像和物理规律。     

中国工程物理研究院FEL-THz束线从头至尾模拟设计(英文)

中国工程物理研究院正在开展自由电子激光太赫兹源(FEL-THz)的研究。介绍了中物院FEL-THz束线的设计,通过PARMELA和TRANSPORT等程序优化了束线参数,并通过IMPACT-T和ELEGANT程序核对了模拟结果。优化结果表明,电子束在摇摆器入口处能量7～8MeV、平均电流5mA、横向归一化发射度小于10mm·mrad,满足设计要求。     

Monte carlo simulations of microemulsions

Summary We describe the Larson-Stauffer model of a microemulsion and report results which strongly indicate that this is a successful model. Particular attention is paid to the structure of the surfactant which appears to be the decisive factor for modelling a microemulsion. We study the kinetics of micelle formation, the miscibility gap of oil and water, the coexistence of various phases, the segregation of three phases (oil rich, water rich and the bicontinuous surfactant rich) as a function of temperature, the relative interaction strengths of hydrophobic and hydrophilic monomers of the surfactant with oil and water, and concentration of surfactant. The model is capable of describing most of the observed properties of a microemulsion. In addition, we are now in the position to study the properties of ?designer? surfactant,e.g., ?bola-form?. Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994.     

Comparison of Intermolecular Interactions of Irreversible and Reversible Inhibitors with Bruton’s Tyrosine Kinase via Molecular Dynamics Simulations

Bruton’s tyrosine kinase (BTK) is a key protein from the TEC family and is involved in B-cell lymphoma occurrence and development. Targeting BTK is therefore an effective strategy for B-cell lymphoma treatment. Since previous studies on BTK have been limited to structure-function analyses of static protein structures, the dynamics of conformational change of BTK upon inhibitor binding remain unclear. Here, molecular dynamics simulations were conducted to investigate the molecular mechanisms of association and dissociation of a reversible (ARQ531) and irreversible (ibrutinib) small-molecule inhibitor to/from BTK. The results indicated that the BTK kinase domain was found to be locked in an inactive state through local conformational changes in the DFG motif, and P-, A-, and gatekeeper loops. The binding of the inhibitors drove the outward rotation of the C-helix, resulting in the upfolded state of Trp395 and the formation of the salt bridge of Glu445-Arg544, which maintained the inactive conformation state. Met477 and Glu475 in the hinge region were found to be the key residues for inhibitor binding. These findings can be used to evaluate the inhibitory activity of the pharmacophore and applied to the design of effective BTK inhibitors. In addition, the drug resistance to the irreversible inhibitor Ibrutinib was mainly from the strong interaction of Cys481, which was evidenced by the mutational experiment, and further confirmed by the measurement of rupture force and rupture times from steered molecular dynamics simulation. Our results provide mechanistic insights into resistance against BTK-targeting drugs and the key interaction sites for the development of high-quality BTK inhibitors. The steered dynamics simulation also offers a means to rapidly assess the binding capacity of newly designed inhibitors.     

管肋式辐射器排热特性的数值分析与优化设计

为得到按单面辐射方式布置的管肋式空间辐射器的排热特性，建立了相应的数学模型．采用数值模拟方法分析了管内流体温度、肋片几何尺寸和等效热沉温度对辐射器排热特性的影响，得到了不同参数值下辐射器单位面积排热量以及特定参数范围内的辐射器肋片最佳宽度和肋片效率．数值模拟结果对辐射器的工程结构设计以及空间站热管理方案的优化分析具有一定的参考价值．     

反应堆核泵浦~3He-Ar-Xe气体激光腔内能量沉积数值模拟研究

在 TRIM软件计算结果的基础上利用蒙卡方法编制了能量沉积效率与损失率的 EDL计算软件 ,模拟计算了泵浦腔尺寸、混合气体中 3 He分压等参数与能量沉积密度之间的关系 ,研究了反应堆核泵浦激光腔内的能量沉积问题 ,推导出了能量沉积密度的函数关系式。     

激光诱导击穿空气等离子体光谱及半经验理论模拟

利用Nd∶YAG激光器输出的1 064 nm激光进行了激光诱导击穿空气光谱实验,测量了空气等离子体的时间分辨光谱。基于局域热动力学平衡模型,建立了模拟激光诱导击穿光谱的方法。对700~900 nm波段的空气等离子体光谱进行了模拟。通过模拟结果与实验结果的比较,进一步估算出了空气中氮、氧和氩的相对含量。