非线性光学晶体δ-LiZnPO4的制备、结构及光学性能

研究了LiF为助熔剂体系下的δ-LiZnPO4的结晶特性,通过自发结晶得到了尺寸为1~3 mm的透明块状δ-LiZnPO4和Li4Zn(PO4)2共晶体,通过PXRD衍射分析和元素分析确定了共晶体的相组成,并对从共晶体中分离出的δ-LiZnPO4晶体结构进行了分析.结果表明:δ-LiZnPO4晶体具有非中心对称结构,属于正交晶系,空间群为Pna21,晶格常数a=1.00085 nm,b=0.49390 nm,c=0.66545 nm,Z=4;δ-LiZnPO4是由PO4、ZnO4和LiO4四面体构筑成的具有类似ABW型分子筛结构的化合物.采用水热法制备了尺寸约为10 μm的纯相透明的δ-LiZnPO4晶体.粉末倍频测试表明,δ-LiZnPO4晶体倍频效应约为KDP的1.7倍,紫外截止边约为218 nm,是一种有潜在应用价值的紫外非线性光学晶体.     

基于不平等厌恶函数的RCEP合作的网络博弈仿真北大核心

RCEP同我国倡导的“一带一路”具有战略协同性,对提高区域民众生活水平、带动经济发展具有重要意义．以RCEP成员国双边货物贸易数据为基础,确定RCEP的贸易合作网络,并将不平等厌恶函数引入到RCEP的网络博弈模型中,深入分析邻居奖励、合作的社会舆论压力、成本净收益比、对他人收益高于自身的厌恶程度、对自身收益高于他人的厌恶程度对合作的影响;在此基础上,讨论促进RCEP合作的措施,为我国推进RCEP的建设提供科学的依据．     

Geometries and electronic structures of the hydrogenated diamond (100) surface upon exposure to active ions: A first principles study

To elucidate the effects of physisorbed active ions on the geometries and electronic structures of hydrogenated diamond films, models of HCO⁻₃ , H₃O⁺, and OH⁻ ions physisorbed on hydrogenated diamond (100) surfaces were constructed. Density functional theory was used to calculate the geometries, adsorption energies, and partial density of states. The results showed that the geometries of the hydrogenated diamond (100) surfaces all changed to different degrees after ion adsorption. Among them, the H₃O⁺ ion affected the geometry of the hydrogenated diamond (100) surfaces the most. This is well consistent with the results of the calculated adsorption energies, which indicated that a strong electrostatic attraction occurs between the hydrogenated diamond (100) surface and H₃O⁺ ions. In addition, electrons transfer significantly from the hydrogenated diamond (100) surface to the adsorbed H₃O⁺ ion, which induces a downward shift in the HOMO and LUMO energy levels of the H₃O⁺ ion. However, for active ions like OH⁻ and HCO⁻₃ , no dramatic change appears for the electronic structures of the adsorbed ions.     

Dominant ferromagnetic coupling over antiferromagnetic in Ni doped ZnO: First-principles calculations

Frontiers of Physics - This article presents a review of our present understanding of the spin structure of the unpolarized hadron. Particular attention is paid to the quark sector at leading...