六硝基菧的紫外光解

采用紫外-可见光谱、X-射线光电子能谱、电子自旋共振谱及质谱等实验手段研究了固态含能材料六硝基菧（HNS）在365 nm紫外光照下的光解机理。HNS的乙腈溶液被紫外光照射后,在310 nm和350 nm处出现了两个新的吸收峰。X-射线光电子能谱实验中,N元素和O元素的窄谱图分别在401 eV和528 eV处出现了新峰。质谱分析则显示在质荷比403和329处出现了两个新的特征离子峰。实验结果表明:CNO2键断裂、分子中NO2基团异构化为亚硝基,以及随后的NO消去等过程均可能发生在六硝基菧的紫外光解反应过程中。     

Numerical Study on Hypersonic Flow and Aerodynamic Heating北大核心CSCD

基于有限差分法开发了高超声速流动与换热问题气热耦合仿真求解器,运用该求解器对三种典型高超声速流动与换热问题开展了仿真研究,得到了相应的气动参数、热流密度分布。高超声速后台阶的存在使表面气动参数、热流分布不再连续;随着缝深的提高,缝隙局部流速迅速降低,对流换热效应减弱;高超声速无限长圆管绕流中,边界层外部区域气动参数随时间变化不大,边界层内存在较大的温度梯度,壁面温度随时间升高。三个算例的仿真结果均与试验测量值进行了对比,验证了所开发的求解器的计算能力。     

TATB表面的傅里叶红外光声光谱与光电子能谱研究

1,3,5-三氨基-2,4,6-三硝基苯(TATB)具有优良的热安定性、非常钝感,在接近理论密度时对外界刺激表现出近乎木头的特点[1],是目前唯一通过美国能源部钝感炸药(insensitive highexplosive,IHE)标准的单质炸药。因TATB在核武器主炸药中的重要作用,对其性能的研究一直受到广泛关注,     

氟硅结构对UV涂料疏水疏油性的影响

UV防污助剂主要包括有机氟和有机硅等，前者结构主要是全氟聚醚链段，后者结构主要是聚二甲基硅氧烷链，利用氟硅的低表面张力起到防污作用，所以主要链段结构的细微差异会导致性能的明显变化。本文选取C1607、C1603和KY1203分别代表聚二甲基硅氧烷、K型全氟聚醚链段和Z型全氟聚醚链段，并与UV涂料复配和固化，研究不同氟硅链段对UV涂料的疏水疏油性能的影响规律。结果证明，聚二甲基硅氧烷链段具有较强的迁移性，低添加量就可达到疏水效果，但仅能应用于低端的防水防油需求。全氟聚醚类UV防污助剂的疏水疏油性能要远优于有机硅，在较高添加量时K型全氟聚醚类UV防污助剂具有更强的疏水疏油性能。     

蛋白质结构建模的后期优化策略

以Lip8为研究对象, 以分级开放式优化和组合优化为优化策略, 分别采取四种不同的优化手段对相同的初始模型进行了优化, 同时比较了含水体系与不含水体系的优化过程, 最终获得8个相应优化后的蛋白模型. 采用Procheck, Errat, Profile 3D及Ramachandran 图等方法对上述8个模型进行评估. 通过比较各项评估结果, 研究了不同优化方法对最终模型准确性的影响, 结果表明, 优化过程中采用分级开放式策略, 同时考虑显性溶剂(水)体系和加入分子动力学优化的优化方法可以获得相对最优结构.     

FRP-混凝土界面剥离破坏过程并行数值模拟

FRP-混凝土界面粘结性能和抗拉裂能力是外贴FRP片材加固混凝土结构技术的关键问题。基于FRP与混凝土界面面内剪切试验的结果,采用材料真实破裂过程三维并行分析(RFPA3D-Parallel)系统,对FRP-混凝土界面的粘结性能进行了三维并行数值模拟研究。数值试验再现了FRP-混凝土构件的三维破裂过程演化过程,清晰地反映了拉伸载荷作用下FRP-混凝土构件界面剥离破坏的规律,FRP-混凝土界面剥离破坏是一个细观损伤不断产生和宏观裂缝形成的渐进过程,可通过监测FRP-混凝土结构损伤演化过程的声发射来揭示FRP-混凝土结构在外载荷作用下的损伤程度。FRP片材在加载过程中的变形剥离破坏过程大致可以划分为四个阶段：(1)弹性变形阶段;(2)弹性软化阶段;(3)弹性软化剥离阶段;(4)软化剥离阶段。本文的数值计算表明RFPA3D-Parallel并行数值模拟方法为FRP片材-混凝土界面剥离破坏过程和机理研究提供了一个很好的途径,同时也为研究FRP-混凝土工程结构等的损伤断裂机理提供了一个新的分析手段,这对于土木建筑工程中FRP-混凝土结构的工程设计施工、损伤断裂控制及混凝土结构加固等研究无疑具有重要的理论指导和实践意义。     

Diagnostic technique for measuring fusion reaction rate for inertial confinement fusion experiments at Shen Guang-III prototype laser facility

A study is conducted using a two-dimensional simulation program(Lared-s)with the goal of developing a technique to evaluate the effect of Rayleigh–Taylor growth in a neutron fusion reaction region.Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program(Lared-s)and confirmed by the experimental results.A neutron temporal diagnostic(NTD)system is developed with a high temporal resolution of~30 ps at the Shen Guang-III(SG-III)prototype laser facility in China,to measure the fusion reaction rate history.With the shape of neutron reaction rate curve and the spherical harmonic function in this paper,the degree of Rayleigh–Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively.This technique,including the diagnostic system and the simulation program,may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion.     

J-TEXT 装置等离子体平衡重建与集成运算

利用Matlab 语言将EFIT 程序反演计算过程进行优化整合,简化了程序操作步骤,并增加了对计算结果的分析与存储功能。利用整合后的EFIT 程序,计算分析了J-TXET 装置放电过程中等离子体磁场位形和其它参数的演变,绘制了等离子体压强剖面图、等离子体电流密度和安全因子分布等磁面信息的重建结果。此外,还将反演结果与软X 射线测算数据进行比对。结果表明,改善后的EFIT 程序能够初步满足对实验放电的反演计算分析要求,为J-TXET 装置的放电控制和运行提供重要的参考数据。     

Localized waves of the coupled cubic–quintic nonlinear Schrdinger equations in nonlinear optics

We investigate some novel localized waves on the plane wave background in the coupled cubic–quintic nonlinear Schr o¨dinger(CCQNLS) equations through the generalized Darboux transformation(DT). A special vector solution of the Lax pair of the CCQNLS system is elaborately constructed, based on the vector solution, various types of higherorder localized wave solutions of the CCQNLS system are constructed via the generalized DT. These abundant and novel localized waves constructed in the CCQNLS system include higher-order rogue waves, higher-order rogues interacting with multi-soliton or multi-breather separately. The first-and second-order semi-rational localized waves including several free parameters are mainly discussed:(i) the semi-rational solutions degenerate to the first-and second-order vector rogue wave solutions;(ii) hybrid solutions between a first-order rogue wave and a dark or bright soliton, a second-order rogue wave and two dark or bright solitons;(iii) hybrid solutions between a first-order rogue wave and a breather, a second-order rogue wave and two breathers. Some interesting and appealing dynamic properties of these types of localized waves are demonstrated, for example, these nonlinear waves merge with each other markedly by increasing the absolute value of α.These results further uncover some striking dynamic structures in the CCQNLS system.     

Higher-Order Rogue Wave Pairs in the Coupled Cubic-Quintic Nonlinear Schr?dinger Equations

We study some novel patterns of rogue wave in the coupled cubic-quintic nonlinear Schr?dinger equations.Utilizing the generalized Darboux transformation, the higher-order rogue wave pairs of the coupled system are generated.Especially, the first-and second-order rogue wave pairs are discussed in detail. It demonstrates that two classical fundamental rogue waves can be emerged from the first-order case and four or six classical fundamental rogue waves from the second-order case. In the second-order rogue wave solution, the distribution structures can be in triangle,quadrilateral and ring shapes by fixing appropriate values of the free parameters. In contrast to single-component systems, there are always more abundant rogue wave structures in multi-component ones. It is shown that the two higher-order nonlinear coefficients ρ_1 and ρ_2 make some skews of the rogue waves.