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Robustness of the octupole collectivity in 144Ba within the cranking covariant density functional theory in 3D lattice

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Nuclear Science and Techniques 2024年第8期35卷 124-131页

作者： Ze‑kai Li yuan‑yuan Wang Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China Hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000China

The octupole deformation and collectivity in octupole double-magic nucleus 144Ba are investigated using the Cranking covariant density functional theory in a three-dimensional lattice *** reduced B(E3)transition probability is implemented for the first time in semiclassical approximation based on the microscopically calculated electric octupole *** available data,including the I-ωrelation and electric transitional probabilities B(E2)and B(E3)are well ***,it is shown that the ground state of 144Ba exhibits axial octupole and quadrupole deformations that persist up to high spins(I≈24h).

关键词： Octupole collectivity Cranking covariant density functional theory Rotational spectrum Electric transitional probabilities

Reconstruct recent multi-population migration history by using identical-by-descent sharing

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Journal of Genetics and Genomics 2024年第6期51卷 642-651页

作者： Wenxiao zhang kai yuan Ru Wen Haifang Li Xumin Ni School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044China The Stanley Center for Psychiatric Research Broad Institute of MIT and HarvardCambridgeMA 02142USA Baidu Incorporated Beijing 100085China

Identical-by-descent(IBD)is a fundamental genomic characteristic in population genetics and has been widely used for population history ***,limited by the nature of IBD,which could only capture the relationship between two individuals/haplotypes,existing IBD-based history inference is constrained to two *** this study,we propose a framework by leveraging IBD sharing in multipopulation and develop a method,MatrixiBD,to reconstruct recent multi-population migration ***,we employ the structured coalescent theory to precisely model the genealogical process and then estimate the IBD sharing across multiple *** our model,we establish a theoretical connection between migration history and IBD *** method is rigorously evaluated through simulations,revealing its remarkable accuracy and ***,we apply MatrixiBD to Central and South Asia in the Human Genome Diversity Project and successfully reconstruct the recent migration history of three closely related populations in South *** taking into account the IBD sharing across multiple populations simultaneously,MatrixlBD enables us to attain clearer and more comprehensive insights into the history of regions characterized by complex migration dynamics,providing a holistic perspective on intricate patterns embedded within the recent population migration history.

关键词： Population genetics IBD sharing Migration history Structured coalescent theory Gene flow

Knoevenagel Condensation Catalyzed by DBU Brnsted Ionic Liquid without Solvent

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Chemical Research in Chinese Universities 2009年第6期25卷 876-881页

作者： YING An-guo LIU Luo WU Guo-feng CHEN Xin-zhi YE Wei-dong CHEN Jian-hui zhang kai-yuan Department of Chemical and BiOlogical Engineering Zhejiang University Hangzhou 310027 P. R. China Xinchang Pharmaceuticals Factory Zhejiang Medicine Co. Ltd. Xinchang 312500 P. R. China

A protocol for the Knoevenagel condensation of aromatic aldehydes with methylene compounds catalyzed by task specifed ionic liquid 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium lactate under solvent-free conditions has been developed. The reactions proceed at ambient temperature and the work-up procedures are very simple. Good to excellent yields could be obtained. The ionic liuid could be simply prepared and recycled efficiently.

关键词： Knoevenagel condensation [DBU][Lac] Ionic liquid Aromatic aldehydes Active methylene compound

Highly Red Emissive Conjugated Homopolymers Based on Double B←N Bridged Bipyridine Unit

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Chinese Journal of Polymer Science 2024年第8期42卷 1029-1037页

作者： Yu-Yue Gao kai-yuan zhang Shu-Meng Wang Hui Tong Jun Liu State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Conjugated homopolymers based on six-member rings,e.g.,polyfluorene,always exhibit blue emission and conjugated homopolymers based on five-member rings,e.g.,polythiophene,can give red emission with low *** this work,we report a series of new conjugated homopolymers based on six-member rings with high-efficiency deep-red *** repeating units of the red light emitting homopolymers are double B←N bridged bipyridine(BNBP)with the boron atoms functionalized with diphenyl,borafluorene,and 2,7-di-tert-butyl-borafluorene groups,*** relationship between the chemical structures and the opto-electronic properties of the monomers and the homopolymers has been systematically *** three polymers emit pure red light(λ_(max)=656 nm)or deep red light(λ_(max)=693 nm)with fluorescence quantum efficiency in solution higher than 60%.The polymers can be used as the emitters in solution-processed organic light-emitting diodes with red emission and decent device *** work indicates a new strategy to design highly efficient light emitting conjugated polymers.

关键词： Conjugated homopolymers Double B←N bridged bipyridine(BNBP) Deep-red emission High fluorescent efficiency

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作业车间调度的邻域单次搜索人工蜂群算法

制造业自动化 2024年第9期46卷 95-103页

作者：张开元杨火根夏小云庄鹤林陈泽丰江西理工大学理学院江西赣州341000 嘉兴大学信息科学与工程学院浙江嘉兴314001 嘉兴职业技术学院互联网学院浙江嘉兴314036 中山大学人工智能学院广东珠海519082

为了减少算法求解作业车间调度问题(Job Shop Scheduling Problem,JSP)时的无效重复搜索,以提高算法性能,提出一种邻域单次搜索人工蜂群算法(Single Neighborhood Search Artificial Bee Colony Algorithm,SNSABC)。在工序加工优先级的编码方式上结合JSP本身的特性设计邻域搜索策略,该策略采用了交换算子和路径重连算子配合搜索的方式。每次交换算子选择未被搜索过的位置搜索,在交换过程中跳过不能改变最大完工时间和已经做过的工序交换。若没有搜索到更优解,将搜索的位置标为已搜索。若搜索到更优解,将更优解进行路径重连。根据邻域搜索策略改进侦查蜂阶段,淘汰所有关键工序位置搜索完毕的解,用淘汰的解和种群中剩余的解分别交叉寻找更优解。在人工蜂群算法中加入所提策略,算法搜索效率和求解质量得到明显提升,能够快速搜索到可接受解,在大部分算例可以收敛到已知最优解。相比于对比算法,邻域单次搜索人工蜂群算法求得的最优解和均值具有更短的完工时间。实验结果表明所提策略有效提高了算法的性能。

关键词：作业车间调度人工蜂群算法邻域搜索策略关键路径路径重连

Theoretical study of superradiant masing with solid-state spins at room temperature

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 38-47页

作者： Qilong Wu yuan zhang Hao Wu Shi-Lei Su kai-kai Liu Mark Oxborrow Chong-Xin Shan Klaus Mølmer Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Material Physics Ministry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China Institute of Quantum Materials and Physics Henan Academy of SciencesZhengzhou 450046China Center for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements School of PhysicsBeijing Institute of TechnologyBeijing 100081China Beijing Academy of Quantum Information Sciences Beijing 100193China Department of Materials Imperial College LondonLondon SW72AZUK Niels Bohr Institute University of CopenhagenCopenhagen 2100Denmark

Steady-state superradiance and superradiant lasing attract significant attentions in the field of optical lattice clocks,but have not been achieved yet due to the technical challenges and atom loss *** this article,we propose that their counter-part may be observed in the microwave domain with solid-state spins,i.e.,nitrogen-vacancy center spins and pentacene molecular spins,coupled to microwave resonator at room temperature with realistic technical *** validate our proposal,we investigate systematically the system dynamics and steady-state by solving quantum master equations for the multi-level and multi-process dynamics of trillions of *** calculations show that the superradiant Rabi oscillations occur firstly due to transitions among different Dicke states,and the subsequent continuous-wave superradiant masing can achieve a linewidth well below *** work may guide further exploration of transient and steady-state superradiant masing with the mentioned and other solid-state spins *** ultra-narrow linewidth may find applications in deep-space communications,radio astronomy and high-precision metrology.

关键词： solid-state spins superradiance maser

Difluoromethyl phenoxathiinium salt: A new general and versatile difluoromethylating reagent with divergent ·CF_(2)H, CF_(2)H^(+), and :CF_(2) reactivities

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Science China Chemistry 2024年第3期67卷 953-962页

作者： yuan-Qing Gu Hong-Xin Long Dan-Dan zhang Mei-Feng Ruan Guo-kai Liu School of Pharmacy Shenzhen University Medical SchoolShenzhen UniversityShenzhen 518055China

Development of practical and versatile electrophilic difluoromethylating reagent is still a grand challenge so far due to its inherent instability or low ***,we report the design and synthesis of difluoromethyl phenoxathiinium tetrafluoroborate(PT-CF_(2)H^(+)BF_(4)^(-)) as a novel difluoromethylating reagent,which proves to be a bench-stable,general,powerful and versatile reagent with divergent·CF_(2)H,CF_(2)H^(+),and:CF_(2) *** use of this reagent,we demonstrated a vast array of difluoromethyl radical transfer reactions via diverse pathways involving photocatalyst-free visible-light induction,visible-light photoredox catalysis and visible-light mediation single electron transfer of EDA ***,the green and highly effective CF_(2)H^(+) and:CF_(2) transfer reactions were also readily accomplished.

关键词： difluoromethyl phenoxathiinium salt versatile difluoromethylating reagent difluoromethyl radical difluoromthyl cation difluorocarbene

Sn-decorated CeO_(2) with different morphologies for direct dehydrogenation of ethylbenzene

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Journal of Rare Earths 2024年第1期42卷 102-109,I0004页

作者： kai zhang Guoju Cui Mengzhen yuan Huiwen Huang Ning Li Jiale Xu Guowei Wang Chunyi Li State Key Laboratory of Heavy Oil Processing China University of Petroleum(East China)Qingdao266580China Petrochemical Plant of Sinopec Shengli Oilfield Company Dongying257237China College of Chemical and Biological Engineering Shandong University of Science and TechnologyQingdao266590China

Three Sn-decorated ceria catalysts with various morphologies(rods,particles,and cubes)were prepared and applied to the direct dehydrogenation of ***-technology characterizations,including X-ray photoelectro n spectroscopy(XPS),H_(2)-tempe rature programmed reduction(H_(2)-TPR),and Raman spectroscopy,prove that the oxygen vacancies are the active sites for ethylbenzene dehydrogenation,which can be regulated by engineering CeO_(2) morphology and enhanced via introducing metal *** the results of activity test,the catalytic activities for ethylbenzene dehydrogenation over different samples are closely dependent on the amount of oxygen *** reduced Sn-decorated CeO_(2) catalyst with nanoparticles morphology exhibits better dehydrogenation performance than the other two studied catalysts at 600℃.This work provides an effective approach to regulate the active oxygen vacancies and further enhance the dehydrogenation activities through engineering the surface morphology of the catalyst and introducing suitable additives.

关键词： Ethylbenzene dehydrogenation CeO_(2) Sn Morphology Oxygen vacancy Rare earths

Machine learning enabling prediction in mechanical performance of Ti6Al4V fabricated by large-scale laser powder bed fusion via a stacking model

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Frontiers of Mechanical Engineering 2024年第4期19卷 29-43页

作者： Changjun HAN Fubao YAN Daolin yuan kai LI Yongqiang YANG Jiong zhang Di WANG School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510641China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China

Determining appropriate process parameters in large-scale laser powder bed fusion(LPBF)additive manufacturing pose formidable challenges that necessitate advanced approaches to minimize trial-and-error during *** work proposed a data-driven approach based on stacking ensemble learning to predict the mechanical properties of Ti6Al4V alloy fabricated by large-scale LPBF for the first *** method can adapt to the complexity of large-scale LPBF data distribution and exhibits a more generalized predictive capability compared to base ***,the stacking model utilized artificial neural network(ANN),gradient boosting regressor,kernel ridge regression,and elastic net as base models,with the Lasso model serving as the *** optimization and cross-validation were utilized for model optimization and training based on a limited data set,resulting in higher predictive accuracy compared to traditional artificial neural network *** statistical analysis of the ANN and stacking models indicates that the stacking model exhibits superior performance on the test set,with a coefficient of determination value of 0.944,mean absolute percentage error of 2.51%,and root mean squared error of 27.64,surpassing that of the ANN *** statistical metrics demonstrate superiority over those obtained from the ANN *** results confirm that by integrating the base models,the stacking model exhibits superior predictive stability compared to individual base models alone,thereby providing a reliable assessment approach for predicting the mechanical properties of metal parts fabricated by the LPBF process.

关键词： machine learning laser powder bed fusion ensemble learning stacking algorithm additive manufacturing