RKPM形状函数的矩式显式表述及快速计算

给出了计算再生核质点法(RKPM)形状函数及其导数的矩式显式处理方法。其特点是在计算形状函数及其导数时不涉及矩阵的求逆或者线性方程组的求解,从而减少计算误差的产生并提高了计算速度。二维及三维形状函数计算算例表明该方法是提高RKPM计算效率的一种有效途径。     

Vacuum Ultraviolet Free-Electron Laser Photoionization Mass Spectrometry of Alpha-pinene Ozonolysis

\begin{document}$\alpha$\end{document}-pinene is the most abundant monoterpene that represents an important family of volatile organic compounds. Molecular identification of key transient compounds during the \begin{document}$\alpha$\end{document}-pinene ozonolysis has been proven to be a challenging experimental target because of a large number of intermediates and products involved. Here we exploit the recently developed hybrid instruments that integrate aerosol mass spectrometry with a vacuum ultraviolet free-electron laser to study the \begin{document}$\alpha$\end{document}-pinene ozonolysis. The experiments of \begin{document}$\alpha$\end{document}-pinene ozonolysis are performed in an indoor smog chamber, with reactor having a volume of 2 m\begin{document}$^3$\end{document} which is made of fluorinated ethylene propylene film. Distinct mass spectral peaks provide direct experimental signatures of previously unseen compounds produced from the reaction of \begin{document}$\alpha$\end{document}-pinene with O\begin{document}$_3$\end{document}. With the aid of quantum chemical calculations, plausible mechanisms for the formation of these new compounds are proposed. These findings provide crucial information on fundamental understanding of the initial steps of \begin{document}$\alpha$\end{document}-pinene oxidation and the subsequent processes of new particle formation.     

新型表面活性剂类硫脲高效催化硝基烯烃的不对称Michael加成(英文)

由N-BOC-胺甲基吡咯烷和异硫氰酸盐反应合成了一种新型结构的硫脲分子,将该具有表面活性剂类型的硫脲分子用作有机催化剂来催化硝基烯烃的不对称Michael加成,条件实验探索结果表明,最优的实验条件是,10 mol%催化剂,10 mol%的苯甲酸作为添加剂,用水做溶剂以及在室温反应温度.在该最优条件下,可以非常顺利地实现各种硝基烯烃与各类醛和酮的Michael加成,得到较高的收率(76%~97%),良好的几何选择性(顺∶反=82∶18~99∶1)以及对映选择性(ee值达到97%).     

5000t油轮与人工岛之间碰撞力和缆索拉力试验研究

５０００ｔ油轮在停靠人工岛码头时，受到风浪流等外界载荷作用，油轮与人工码头的橡胶护舷部分发生碰撞，同时系泊缆索受到上力作用，文中通过实验求得碰撞力及系统拉力，为人工岛和５０００ｔ油轮提供结构设计的依据。     

Some Properties of Nonlinear Klein-Gordon Equation in the Non-Classical Variation Field

Using the non-classioal variational method,we prove the function of cosmos potential of the non-linear Klein-Gordon equation is a sign-function, and the coefficient g of KGE is not always positive. Furthermore, some more important properties are obtained.     

Multiple channel dynamics in the O(1D) reaction with alkanes

In this article, we briefly review the recent experimental studies of the multiple channel dynamics of the O((1)D) reaction with alkane molecules using the significantly improved universal crossed molecular beam technique. In these reactions, the dominant reaction mechanism is found to be an O atom insertion into the C-H bond, while a direct abstraction mechanism is also present in the OH formation channel. While the reaction mechanism is similar for all of these reactions, the product channels are quite different because of the significantly different energetics of these reaction channels. In the O((1)D) reaction with methane, OH formation is the dominant process while H atom formation is also a significant process. In the O((1)D) reaction with ethane, however, the CH(3) + CH(2)OH is the most important process, OH formation is still significant and H atom formation is of minor importance. A new type of O atom insertion mechanism (insertion into a C-C bond) is also inferred from the O((1)D) reaction with cyclopropane. Through these comprehensive studies, complete dynamical pictures of many multiple channel chemical reactions could be obtained. Such detailed studies could provide a unique bridge between dynamics and kinetics research.     

Acetate chitosan with CaCO3 doping form tough hydrogel for hemostasis and wound healing

In recent years, chitosan has been applied for wound management due to its properties of biocompatibility, biodegradability, antimicrobial activity, and low immunogenicity. But the poor water solubility in neutral pH limited its further application in clinical wound healing. To overcome this problem, acetate chitosan was developed and approved as commercial products for wound healing. However, the acidity of acetate chitosan was potentially allergenic, and the poor mechanical properties of its formed hydrogels also hindered the therapeutic efficacy in wound care. In this study, CaCO₃ was simply doped into acetate chitosan to form the wound dressing. After absorbing water, the H⁺ of acetate chitosan reacted with CaCO₃ to release Ca²⁺, resulting in acidity decreased. The production of Ca²⁺ and residue of CaCO₃ cross‐linked with chitosan to form a tough hydrogel by electrostatic interaction. The physical characteristics, swelling, mechanical testing, and blood clotting were evaluated. The results in vitro demonstrated that after doping CaCO₃ into acetate chitosan, the mechanical properties and blood clotting of the formed hydrogel were increased. Then, the evaluation of hydrogels in vivo revealed that it can also accelerate the wound healing by promoting re‐epithelization and collagen deposition. This simple way by doping CaCO₃ into acetate chitosan can increase wound healing, and it can also broad the application of acetate chitosan in clinical use.     

Temporal behavior of dark spatial solitons in closed-circuit photovoltaic media

We show that the time-dependent nonlinear wave equation in closed-circuit photovoltaic media can exhibit quasi-steady-state and steady-state spatial solitons. We demonstrate that the formation time of open-circuit quasi-steady-state and open-circuit steady-state dark solitons decreases with an increase in the intensity ratio of the soliton, which is the ratio between the soliton peak intensity and the dark irradiance. We find that for the time-dependent nonlinear wave equation that exhibits only an open-circuit steady-state dark soliton, changing the electric current density J₀ does not generate quasi-steady-state dark solitons and affects the formation time of steady-state dark solitons and that for the time-dependent nonlinear wave equation that exhibits an open-circuit quasi-steady-state dark soliton, changing J₀ gives rise to three different time evolution regimes of the full width half maximum of the soliton’s intensity. The first regime shows that the formation time of steady-state dark solitons increases with J₀ whereas the formation time of quasi-steady-state dark solitons is independent of J₀. The second regime shows that the formation time of steady-state dark solitons decreases with an increases in J₀ and the formation time of quasi-steady-state dark solitons increases with J₀. The third regime shows that changing J₀ enables only steady-state dark solitons in the time-dependent nonlinear wave equation, of which the formation time increases with J₀.