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选择定则的分类与计算

陕西师大学报(自然科学版) 1987年第2期 28-36页

作者：王天真付克德陕西师大物理系

选择定则在原子物理、量子力学、原子光谱、量子化学等多门学科中都有涉及但都未能较细致地讨论。本文首先从四个方面把选择定则加以分类:从计算条件把它分为严格的与近似的选择定则;从等效模型把它分为电偶极、磁偶极与电四极跃迁选择... 详细信息

选择定则在原子物理、量子力学、原子光谱、量子化学等多门学科中都有涉及但都未能较细致地讨论。本文首先从四个方面把选择定则加以分类:从计算条件把它分为严格的与近似的选择定则;从等效模型把它分为电偶极、磁偶极与电四极跃迁选择定则;从参与一次跃迁的光子数分为单光子、双光子、多光子选择定则;从一次跃迁时原子单电子态改变数分为单电子、双电子选择定则。然后从光与物质相互作用出发,利用 SO(3)群的不可约张量算符特性及维格纳——爱卡特定理,根据微扰理论,计算了原子的单光子电偶极、磁偶极及电四极跃迁的选择定则,并作了必要的讨论。

关键词：宇称选择定则光子数四极分量多极跃迁不可约张量算符磁偶极电子态

p-CoFe_2O_4/n-TiO_2可见光催化分解水制氢的研究

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化工新型材料 2016年第7期44卷 87-89,92页

作者：王田珍杜湘云王晟黄集森刘福生柯旭胡海龙南京工业大学化工学院南京210009 南京林业大学理学院南京210037

水热法制备了系列p-CoFe_2O_4/n-TiO_2复合光催化剂,采用XRD,UV-Vis DRS,SEM和Mott-Schottky分析对制备的光催化剂进行了结构和性能表征。研究了p-CoFe_2O_4/n-TiO_2复合光催化剂可见光催化分解水制氢性能。结果表明:由于CoFe_2O_4的导... 详细信息

水热法制备了系列p-CoFe_2O_4/n-TiO_2复合光催化剂,采用XRD,UV-Vis DRS,SEM和Mott-Schottky分析对制备的光催化剂进行了结构和性能表征。研究了p-CoFe_2O_4/n-TiO_2复合光催化剂可见光催化分解水制氢性能。结果表明:由于CoFe_2O_4的导带电势比TiO_2的导带电势更负,以及CoFe_2O_4和TiO_2界面形成的p-n结所产生的内建电场的双重作用,使得CoFe_2O_4导带上的电子能迅速迁移到TiO_2的导带上,减少了电子-空穴对复合的概率,提高了光催化活性。

关键词： CoFe2O4 TiO2 p-n结光催化制氢

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双光子自发跃迁几率计算

陕西师大学报(自然科学版) 1988年第1期 31-34页

作者：付克德王天真陕西师大物理系

本文探讨平衡态下的双光子跃迁过程,建立了双光子黑体辐射公式;给出爱因斯坦几率系数的新定义;进而计算了双光子自发跃迁几率,并对结果作了分析讨论.

关键词：普朗克辐射双光子自发跃迁跃迁几率

An Iterated Greedy Algorithm with Memory and Learning Mechanisms for the Distributed Permutation Flow Shop Scheduling Problem

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Computers, Materials & Continua 2025年第1期82卷 371-388页

作者： Binhui wang Hongfeng wang College of Information Science and Engineering Northeastern UniversityShenyang110819China

The distributed permutation flow shop scheduling problem(DPFSP)has received increasing attention in recent *** iterated greedy algorithm(IGA)serves as a powerful optimizer for addressing such a problem because of its straightforward,single-solution evolution ***,a potential draw-back of IGA is the lack of utilization of historical information,which could lead to an imbalance between exploration and exploitation,especially in large-scale *** a consequence,this paper develops an IGA with memory and learning mechanisms(MLIGA)to efficiently solve the DPFSP targeted at the ***,we incorporate a memory mechanism to make a more informed selection of the initial solution at each stage of the search,by extending,reconstructing,and reinforcing the information from previous *** addition,we design a twolayer cooperative reinforcement learning approach to intelligently determine the key parameters of IGA and the operations of the memory ***,to ensure that the experience generated by each perturbation operator is fully learned and to reduce the prior parameters of MLIGA,a probability curve-based acceptance criterion is proposed by combining a cube root function with custom *** last,a discrete adaptive learning rate is employed to enhance the stability of the memory and *** ablation experiments are utilized to verify the effectiveness of the memory mechanism,and the results show that this mechanism is capable of improving the performance of IGA to a large ***,through comparative experiments involving MLIGA and five state-of-the-art algorithms on 720 benchmarks,we have discovered that MLI-GA demonstrates significant potential for solving large-scale *** indicates that MLIGA is well-suited for real-world distributed flow shop scheduling.

关键词： Distributed permutation flow shop scheduling makespan iterated greedy algorithm memory mechanism cooperative reinforcement learning

Controlled cationic ring-opening polymerization of L-lactide by organic ion pair: novel approach to isotactic-rich and crystalline polylactide

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Science China Chemistry 2025年第1期68卷 394-402页

作者： Zhiqiang Ding Mingqian wang Zijing Zhou Bin wang Yuesheng Li Tianjin Key Laboratory of Composite & Functional Materials School of Materials Science and Engineering Tianjin University

Living/controlled cationic ring-opening polymerization （ROP） of L-lactide is a promising approach to isotactic-rich and crystalline poly（L-lactide）.In contrast with the unsubstituted lactones,L-LA can not be polymerized by organic Lewis acids or carbenium ions,and the state of the art in this field is the cationic ROP of L-LA catalyzed by Br?nsted acid/alcohol system via activated monomer ***,we reported the first example of controlled cationic ROP of L-LA by using Meerweintype ion pair[Me3O]+[B（C6F5）4]-as the catalyst.[Me3O]+[B（C6F5）4]-promoted rapid L-LA cationic polymerization in the absence of alcohol,producing isotactic-rich and crystalline PLLA without transesterification and epimerization side *** activated chain end mechanism,involving twice SN2 substitution and configuration-inversion （S→R→S） with the assistance of released Me2O,was proposed and further verified by density functional theory and control *** work expands the catalytic toolbox of isotactic-rich and crystalline polylactide *** represents a unique example of cationic-controlled polymerization of L-LA catalyzed by an organic ion pair.

关键词： organic ion pair controlled cationic ring-opening polymerization activated chain end mechanism isotactic-rich polylactide

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基于多级特征提取的并网逆变器故障诊断策略

电源学报 2022年第4期20卷 28-36页

作者：耿俊超王天真韩金刚陈国栋汤天浩上海海事大学物流工程学院上海201306 上海电气输配电集团技术中心上海200042

由于降低了谐波含量,减少了开关损耗,且易于模块化,级联型H桥多电平逆变器在可再生能源并网系统中得到了广泛的应用。随着电平数的增加,其使用的开关器件(IGBT)数量随之增多,相应的故障概率与故障类型也在增加。在多种故障情况下,传统... 详细信息

由于降低了谐波含量,减少了开关损耗,且易于模块化,级联型H桥多电平逆变器在可再生能源并网系统中得到了广泛的应用。随着电平数的增加,其使用的开关器件(IGBT)数量随之增多,相应的故障概率与故障类型也在增加。在多种故障情况下,传统的故障特征提取方法不能有效地提取故障的关键特征,从而造成诊断精度的下降。针对这一问题,提出了一种基于多级特征提取的故障诊断策略。首先利用PCA对故障特征进行初步提取,然后基于欧氏距离阈值提取关键故障特征,最后使用ELM分类器完成故障诊断。实验结果表明,所提出的诊断策略具有更少的输入特征向量维度和更高的故障诊断精度。

关键词：级联H桥多电平逆变器并网系统特征提取故障诊断

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Impact of Startup Strategy and Buffer Tank Volume on the Compressor Inlet State for a 3-MW sCO2 Brayton Cycle

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Journal of Thermal Science 2025年第1期34卷 159-175页

作者： ZHAO Decai wang Bo Key Laboratory of Advanced Energy and Power Institute of Engineering Thermophysics(IET)Chinese Academy of Sciences (CAS) University of Chinese Academy of Sciences

The supercritical carbon dioxide（sCO2） Brayton cycle system has become an emerging and highly promising method of thermal power conversion due to its efficiency advantage,system compactness,and excellent adaptability of the heat *** the low carbon sCO2Brayton cycle testbed with cycle output power approaching 3 MW,a relatively detailed dynamic simulation model of the entire system is constructed to explore the dynamic response characteristics of the system with different startup strategies and different buffer tank volumes during the startup *** simulation results indicate that the smaller the volume of the buffer tank,the more rapid and obvious the parameter fluctuation in the buffer tank during the *** the allowable relative deviation limit of density is 5%,then the ratio of the buffer tank volume to the volume of the entire closed loop should not be lower than 36.80%.The strategy of simultaneous temperature and speed increase during turbine bypass start can effectively reduce the fluctuation of compressor inlet parameters and reach the steady-state more *** paper provides the recommended matching table for the opening of the turbine bypass valve（TBV） and the main regulating valve（MGV） to reduce the parameter fluctuation during the bypass *** effectiveness of the proposed turbine bypass and bypass switching startup strategy is verified by simulation,which may be used as a reference for test bench's future debugging and operation.

关键词： buffer tank dynamic characteristic dynamic model sCO2 Brayton cycle startup strategy

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在近绝对零度时氦零振幅最大的量子力学证明

陕西师大学报(自然科学版) 1986年第1期 14-17页

作者：王天真付克德陕西师大物理系

氦是临界温界最低,最后一个被液化、电离能最大、最稳定的一种原子。本文用单原子分子谐振子近似模型,根据量子力学理论,得到单原子分子的零振幅公式:再根据光谱数据,利用上公式,指出了在接近绝对零度时,最可能以液态存在的只有氦原子... 详细信息

氦是临界温界最低,最后一个被液化、电离能最大、最稳定的一种原子。本文用单原子分子谐振子近似模型,根据量子力学理论,得到单原子分子的零振幅公式:再根据光谱数据,利用上公式,指出了在接近绝对零度时,最可能以液态存在的只有氦原子。最后利用原子的能级,讨论了氦原子电离能最大的原因。

关键词：量子力学绝对零度谐振子弹簧振子

The Hilbert expansion of the Boltzmann equation in the incompressible Euler level in a channel

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Science China Mathematics 2025年第1期68卷 39-88页

作者： Feimin Huang Weiqiang wang Yong wang Feng Xiao Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences Key Laboratory of Computing and Stochastic Mathematics (Ministry of Education) School of Mathematics and StatisticsHunan Normal University

The study of the hydrodynamic limit of the Boltzmann equation with physical boundary is a challenging problem due to the appearance of the viscous and Knudsen boundary *** this paper,the hydrodynamic limit from the Boltzmann equation with the specular reflection boundary condition to the incompressible Euler equations in a channel is *** on the multi-scaled Hilbert expansion,the equations with boundary conditions and compatibility conditions for interior solutions,and viscous and Knudsen boundary layers are derived under different scaling,***,some uniform estimates for the interior solutions,and viscous and Knudsen boundary layers are *** the help of the L2-L∞framework and the uniform estimates obtained above,the solutions to the Boltzmann equation are constructed by the truncated Hilbert expansion with multiscales,and hence the hydrodynamic limit in the incompressible Euler level is justified.

关键词： Boltzmann equation incompressible Euler equations hydrodynamic limit Hilbert expansion specular reflection boundary condition viscous boundary layer Knudsen boundary layer