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Worldvolume fermions as baryons in holographic quantum chromodynamics with instantons

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Communications in Theoretical Physics 2025年第1期77卷 106-121页

作者： Si-wen Li Hao-qian Li Yi-peng Zhang Department of Physics School of ScienceDalian Maritime UniversityDalian 116026China

In this study,we investigated worldvolume fermions on the flavor brane in the D0-D4/D8 model,which is holographically equivalent to four-dimensional quantum chromodynamics with instantons or equivalently with a theta *** action involving the worldvolume fermions was obtained by the T-duality rules in string theory,and we accordingly derived their effective five-dimensional and canonical four-dimensional forms by using the systematic dimensional reduction and decomposition of the ***,we used the AdS/CFT dictionary to evaluate the two-point correlation function as the spectral function for the worldvolume fermions and interpreted the fermions as baryons by analyzing their quantum number with the baryon vertex in *** this sense,the interacted action involving the worldvolume fermions and gauge field on the flavor brane was finally derived in holography,which describes the various interactions of mesons and baryons with instantons in the large-N ***,this study provides a holographic picture to describe baryons and their interactions based on string theory,particularly in the presence of instantons or a theta angle.

关键词： gauge-gravity duality AdS/CFT holographic QCD

Discovery of a new family member of arsenic–vanadium polyoxometalates with high catalytic performance for one-pot coupling of CO2, epoxides and amines

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Tungsten 2025年第1期7卷 80-87页

作者： Fang-qian Wang Yin Zhang Wei-Wei Wang Mei-qian Fu Hong-bing Mo Wei-Dong Yu Chao Liu Jun Yan College of Chemistry and Chemical Engineering Central South University Junior Education Department Changsha Normal University School of Science Hunan University of Technology and Business

Arsenic-vanadium polyoxometalates（POMs） represent a family of tremendous potential catalysts owing to their peculiar physical and chemical *** in CO2conversion,using POMs to catalyze the conversion of CO2and epoxide into chemical intermediates is the research ***,A new family number of arsenic-vanadium POMs,[N（CH3）4]4[As8V12O38（H2O）]·2H2O({As8V12O38}),was reported and characterized by single-crystal X-ray diffraction,fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,*** from other allotropicity,{As8V12O38}shows a different structure pattern with an I-43d *** obtained {As8V12O38} was employed as a catalyst for the *** initial catalytic reaction confirmed that {As8V12O38} can catalyze the formation of epoxy carbonate by using 1.01 kPa CO2and epoxide at 70℃.Furtherly,when added amine in the catalytic system,oxazolidinone could be obtained by high yields,which provides an efficient way to convert CO2into profitable ***,a possible catalytic reaction mechanism was proposed by using different characterization analyses.{As8V12O38} first catalyzes the epoxide and CO2to form an epoxy carbonate and then catalyzes epoxy carbonate and benzylamine into oxazolidinone.

关键词： Arsenic CO2 conversion Oxazolidinone Polyoxometalates Vanadium

New poly-types of LPSO structures in a non-equilibrium Mg_(97)Zn_(1)Y_(1.6)Ca_(0.4)alloy

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China Foundry 2025年第1期22卷 83-89页

作者： qian-qian Jin Zi-hui Tang wen-long Xiao Xiu-yu Qu Xu-hao Han Lin Mei Xiao-hong Shao Xiu-liang Ma School of Biological and Chemical Engineering Guangxi University of Science and TechnologyLiuzhou 545006GuangxiChina Center for the Structure of Advanced Matter School of Electronic EngineeringGuangxi University of Science and TechnologyLiuzhou 545006GuangxiChina Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Bay Area Center for Electron Microscopy Songshan Lake Materials LaboratoryDongguan 523808GuangdongChina

In this study,a comprehensive analysis of microstructural features,morphology,crystal structures,and interface structures of long-period stacking ordered(LPSO)structures in a non-equilibrium Mg_(97)Zn_(1)Y_(16)Ca_(0.4)alloy cast in a steel mold was carried *** addition of Ca element plays an important role in the refinement of LPSO *** result reveals new poly-types including 20H F2F2F4,60R(F2F3F3)_(3),and 66H F2F3F3F2(F6)_(4)featuring a 6-Mg structure,alongside the prevalent 18R and 14H LPSO *** incoherent interface between 20H and the Mg matrix is split into two dislocation arrays,leading to the formation of a segment of 60R_(1).Moreover,the superstructure 116L,designated as(F2)_(18)F4,is formed through the ordered distribution of F4 stacking faults in 18R.

关键词： LPSO structures crystal structure Mg alloys heterogeneous interface

Influence of heat treatment on microstructure of a newβ-solidifyingγ-TiAl alloy

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Journal of Iron and Steel Research International 2025年第1期32卷 239-248页

作者： Li Quan Xiao-bing Li Peng Xue Jun-jie Hao Kun qian Bo Chen Jian-zhong Li Kui Liu School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina Department of Materials Science and Technology Ji Hua LaboratoryFoshan528200GuangdongChina

The high strength and stability of the full-lamellar structure guarantee the industrial application of theβ-solidifyingγ-TiAl ***,it is a huge challenge to design an alloy with good hot-deformability as well as the full-lamellar *** low-cost Ti-42.5Al-2Mn-0.4Mo-0.1B-0.1C(at.%)alloy was designed,which undergoes bothβandαsingle-phase region during the *** is found that the full-lamellar structure can be obtained by the solution heat treatment at 1230℃ for 20 min and then aging treatment at 800℃ for 3 ***,a new microstructure,namely,the pearlitic-like microstructure(PM)induced by theα_(2)/γ→βo+γcellular reaction was observed when the aging temperature is increased to above 800℃.The volume fraction of the PM is gradually increased from 0%to 25.5%,65%,and 94%according to elevated aging temperature from 800 to 900,1000,and 1050℃,*** mechanism of the reducedα_(2)/γlamellae and PM formation was discussed regarding the heterogeneous distribution ofβstabilizing elements and the interface energy stored inα_(2)/γlamellae.

关键词： β-γ-TiAl Alloy design Two-step heat treatment Full-lamellar structure Cellular reaction

A single-pixel elemental imaging method using neutron-induced gamma-ray activation

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Nuclear Science and Techniques 2025年第1期36卷 1-12页

作者： Can Cheng Yong-Ji Xie Xun-Rong Xia Jia-Yu Gu Dong Zhao Yi-Ze Chen Ai-Yun Sun Xu-wen Liang wen-Bao Jia Da-qian Hei Department of Ionizing Radiation and Medical Engineering Jiangsu Institute of MetrologyNanjing 210023China Institute of Nuclear Analytical Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China China Nuclear Power Engineering Co. LtdBeijing 100840China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an ***,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating *** this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the *** of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization *** results demonstrate that the elemental imaging of the sample can be accurately determined using this *** proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.

关键词： Elemental imaging Neutron-induced gamma-ray activation Single-pixel imaging

Effects of aggregate size distribution and carbon nanotubes on the mechanical properties of cemented gangue backfill samples under true triaxial compression

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 311-324页

作者： qian Yin Fan wen Zhigang Tao Hai Pu Tianci Deng Yaoyao Meng Qingbin Meng Hongwen Jing Bo Meng Jiangyu Wu State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing 100083China Key Laboratory of Xinjiang Coal Resources Green Mining Ministry of EducationXinjiang Institute of EngineeringUrumqi 830023China

The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious ***,the true triaxial compression tests,CT scanning,SEM,and EDS tests were conducted on cemented gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied fractal theory for the PSD of *** mechanical properties,energy dissipations,and failure mechanisms of the CGBSs under true triaxial compression were systematically *** results indicate that appropriate carbon nanotubes(CNTs)effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging,and the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSD fractal dimension(D)of 2.500 as an example,compared to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy(Ue),and dissipated energy(U_(d))increased by 12.76%,29.60%,19.05%,and90.39%,***,excessive CNTs can reduce the mechanical properties of CGBSs due to CNT agglomeration,manifesting a decrease inρ_(p),ε_(1,p),and the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the addition of CNTs improved the integrity of CGBS after macroscopic failure,and crack extension in CGBSs appeared in two modes:detour and pass through the ***σ_(p)and U_(d)firstly increase and then decrease with increasing D,and porosity shows the opposite ***ε_(1,p)andΔε_(v)are negatively correlated with D,and CGBS with D=2.150 has the maximum deformation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)due to the frictional slip effect caused by coarse *** increasing D,the failure modes of CGBSs are sequentially manifested as oblique shear failure,"Y-shaped"shear failure,and conjugate shear failure.

关键词： cemented gangue backfill materials particle size distribution true triaxial compression test carbon nanotubes mechanical properties failure modes

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高温高压液氢离解效应研究

北京理工大学学报 2014年第6期34卷 632-637页

作者：李名锐周刚李明钱秉文范如玉马坤清华大学工程物理系北京100084 西北核技术研究所陕西西安710024

在ab-initio理论基础上,利用前期获得的与实验吻合较好的CEIMC法模拟结果,采取配位数分析法详细研究了高温高压液氢的离解过程,确定了不同状态下液氢的离解度数值,系统讨论了分子离解对液氘冲击特性的影响.当冲击压力低于20 GPa时,液氘... 详细信息

在ab-initio理论基础上,利用前期获得的与实验吻合较好的CEIMC法模拟结果,采取配位数分析法详细研究了高温高压液氢的离解过程,确定了不同状态下液氢的离解度数值,系统讨论了分子离解对液氘冲击特性的影响.当冲击压力低于20 GPa时,液氘分子主要为双原子分子态;冲击压力大于53 GPa时,主要为单原子分子态;压力处于两者之间时为D2与D的共存态.在T-p面及T-P面内划分出了液氢分子开始离解及完全离解的临界线,认为高温高压液氢金属化应至少有50%氢分子离解.

关键词：高温高压液氢离解配位数

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海口市市售牡蛎中诺如病毒的分子检测

中国病原生物学杂志 2017年第5期12卷 447-449,455页

作者：李平黄涵余倩钟汶兵四川大学华西公共卫生学院四川成都610041 海口市疾病预防控制中心海南海口570000

目的检测海口市售牡蛎感染诺如病毒的情况,为诺如病毒防治提供参考。方法 2015年9月-2016年5月,在海口市随机抽样,采集牡蛎标本,提取病毒核酸,应用实时荧光定量PCR检测诺如病毒核酸,进行诺如病毒GⅠ群或GⅡ群基因分型。以脊髓灰质炎疫... 详细信息

目的检测海口市售牡蛎感染诺如病毒的情况,为诺如病毒防治提供参考。方法 2015年9月-2016年5月,在海口市随机抽样,采集牡蛎标本,提取病毒核酸,应用实时荧光定量PCR检测诺如病毒核酸,进行诺如病毒GⅠ群或GⅡ群基因分型。以脊髓灰质炎疫苗中的病毒作为标准品检测病毒的回收率。结果牡蛎标本220份,分别来自广东湛江、广西北海、海南海口和儋州。经实时荧光定量PCR检测6份标本诺如病毒核酸阳性,阳性率为2.73%;其中4份标本同时携带诺如病毒GⅠ群和GⅡ群,2份仅GⅡ群阳性。冬季和春季采集的标本阳性率分别为5.88%(4/68)和3.64%(2/55)。广东湛江和海南海口的牡蛎诺如病毒阳性率分别为9.80%(5/51)和1.28%(1/78),其他两地的牡蛎未检出诺如病毒。以脊髓灰质炎疫苗作为标准品验证诺如病毒的平均回收率为11.46%。结论海口市市售牡蛎受到诺如病毒污染,有关部门应采取相应措施,加强市售海产品管理,降低人群感染诺和病毒的风险。

关键词：牡蛎诺如病毒 RT-PCR 海口

Global patterns of taxonomic and phylogenetic endemism in liverwort assemblages

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Plant Diversity 2025年第1期47卷 82-88页

作者： Hong qian Shenhua qian Research and Collections Center Illinois State Museum1011 East Ash StreetSpringfieldIL 62703USA Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment Ministry of EducationChongqing UniversityChongqing 400045China College of Environment and Ecology Chongqing UniversityChongqing 400045China

Exploring the worldwide patterns of endemism and the processes that lead to the formation of highendemism centers is crucial in *** study examines the geographic distribution and ecological influences on the endemism of liverworts across 390 regions *** assess phylogenetic endemism and relative phylogenetic endemism in relation to eleven environmental factors,which represent current and Quaternary climate variations,as well as topographic and environmental *** with higher endemism in liverworts tend to have higher temperatures,precipitation,and environmental heterogeneity,but lower temperature seasonality and lesser impacts from Quaternary climate *** exhibiting notably high endemism are predominantly found in tropical Asia,Madagascar,eastern Australia,and the Andes,while those with notably low endemism are generally in temperate Eurasia and North America,parts of Africa,and eastern South *** of neo-endemism are mainly in southern Africa,whereas centers of paleo-endemism are in southern South America,tropical Asia,and New *** variability is a more significant predictor of phylogenetic endemism than current climate conditions,which are themselves more predictive than variables related to Quaternary climate ***,these three types of explanatory variables combined explain only about one-third of the variance in phylogenetic endemism.

关键词： Bryophyte Quaternary climate change Current climate Topographic heterogeneity Endemism