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A simple model for two-proton radioactivity

Chinese Physics C 2024年第10期48卷 247-255页

作者： Jie-Dong jiang xiao Liu Dong-Meng Zhang Ming Li Xi-Jun Wu xiao-Hua Li School of Nuclear Science and Technology University of South ChinaHengyang 421001China School of Math and Physics University of South ChinaHengyang 421001China National Exemplary Base for International Sci&Tech.Collaboration of Nuclear Energy and Nuclear Safety University of South ChinaHengyang 421001China Cooperative Innovation Center for Nuclear Fuel Cycle Technology&Equipment University of South ChinaHengyang 421001China Key Laboratory of Low Dimensional Quantum Structures and Quantum Control Hunan Normal UniversityChangsha 410081China

In this work,considering the preformation factor of the emitted two protons in parent nucleus S_(2p) and the effect of the parent nucleus deformation,based on the Wentzel-Kramers-Brillouin approximation and Bohr-Sommerfeld quantization condition,we improve a simple phenomenological model proposed by Bayrak[***.G:47,025102(2020)]to systematically study 2p radioactivity *** model contains two adjustable parameters V_(0) and a_(β),which are related to the depth of nuclear potential and effect of *** calculated results show that this model can effectively reproduce the experimental data with a corresponding root-mean-square(RMS)standard deviation of σ=*** comparison,we include the Gamow-like model(GLM)proposed by Liu et al.[***.C 45,044110(2021)],generalized liquid drop model(GLDM)proposed by Cui et al.[***.C 101,014301(2020)],effective liquid drop model(ELDM)proposed by *** et al.[***.B 774,14(2017)],two-potential approach with Skyrme-Hartree-Fock(TPASHF)proposed by Pan et al.[***.C 45,124104(2021)],phenomenological model with a screened electrostatic barrier(SEB)propoesed by Zou et al.[***.C 45,104101(2021)],unified fission model(UFM)proposed by Xing et al.[***.C 45,124105(2021)],Coulomb and proximity potential model for deformed nuclei(CPPMDN)proposed by Santhosh[***.C 104,064613(2021)],two-parameter empirical formula proposed by Liu et al.[***.C 45,024108(2021)],and four-parameter empirical formula proposed by Sreeja et al.[***.J.A 55,33(2019)].In addition,we use this model to 2p predict the radioactive half-lives of some possible potential nuclei whose 2p radioactivity are energetically allowed or observed but not yet quantified in NUBASE2020.

关键词： two-proton radioactivity half-lives Wentzel-Kramers-Brillouin approximation

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大而显著的苞片影响了笋兰的繁殖成功

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Journal of Plant Ecology 2024年第1期17卷 50-56页

作者： Shi-Mao Wu jiang-yun Gao Institute of Biodiversity School of Ecology and Environmental ScienceYunnan UniversityKunmingYunnan 650500China

在被子植物中,多样的花部特征是为了适应各种选择压力和生态功能。到目前为止,对兰科植物花部特征的生态功能研究主要集中在唇瓣,而从未有对苞片的研究。本研究以一种熊蜂授粉并且提供花蜜报酬的地生或附生兰科植物笋兰(Thunia alba)为... 详细信息

在被子植物中,多样的花部特征是为了适应各种选择压力和生态功能。到目前为止,对兰科植物花部特征的生态功能研究主要集中在唇瓣,而从未有对苞片的研究。本研究以一种熊蜂授粉并且提供花蜜报酬的地生或附生兰科植物笋兰(Thunia alba)为研究材料,其大而显著形似舟状的苞片包裹着花蜜距和花梗。我们猜想显著的大苞片能够保护蜜距,抵御盗蜜者。为了验证这一假设,我们通过实验去除苞片,记录传粉者和盗蜜者访花行为的变化,并评估了它们对笋兰繁殖成功的影响。研究结果表明,当苞片被去除后,唯一的传粉者短头熊蜂(Bombus breviceps)转变为盗蜜者,并且被盗蜜的花的比例也显著增加。无论是花苞片被去除的处理组还是未处理的对照组,笋兰都是受传粉者限制的。去除苞片对传粉者的访花频率并没有影响,但是显著降低了笋兰雄性和雌性的繁殖成功率。本研究表明,在复杂的授粉限制的环境压力下,大而显著的苞片可以防止花被盗蜜者盗蜜从而提高笋兰的整体适合度。

关键词：苞片传粉者盗蜜繁殖成功笋兰(Thunia alba) 短头熊蜂(Bombus breviceps)

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Correlating dynamic relaxation and viscoelasticity in metallic glasses

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 81-90页

作者： GuangHui Xing Qi Hao Fan Zhu yun-jiang Wang Yong Yang Hidemi Kato Eloi Pineda Si Lan JiChao Qiao School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Department of Materials Science and Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Institute for Materials Research Tohoku UniversitySendai 980-8577Japan Department of Physics Institute of Energy TechnologiesUniversitat Politècnica de CatalunyaBarceona 9Spain School of Material Science and Engineering Herbert Gleiter Institute of NanoscienceNanjing University of Science and Technology.Nanjing 210094China State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment Northwestern Polytechnical UniversityXi'an 710072China

Relaxation dynamics,essential for the structural evolution of non-equilibrium systems like glassy materials,remain ***,we explore relaxation dynamics and viscoelastic properties in three types of metallic glasses with distinctβrelaxation *** systems with significantβrelaxation,stress relaxation and creep experiments reveal a transition from two-step to one-step relaxation with rising ***,such a phenomenon is absent in systems with weakerβ*** model the two-step relaxation process using a double Kohlrausch-Williams-Watts equation,and the obtained relaxation times elegantly adhere to the Arrhenius *** combining fitted activation energies with theoretical analysis,we conclusively attribute these relaxation processes toβrelaxation andαrelaxation,***,we analyze the relaxation time spectra of two processes and establish a comprehensive picture linking dynamic relaxation with *** study provides new strategies for probing the complex relaxation behaviors of glasses from the perspective of viscoelasticity.

关键词： creep relaxation glasses

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Multiomics analyses of two Leonurus species illuminate leonurine biosynthesis and its evolution

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Molecular Plant 2024年第1期17卷 158-177页

作者： Peng Li Meng-xiao Yan Pan Liu Dan-Jie Yang Ze-Kun He yun Gao Yan jiang Yu Kong Xin Zhong Sheng Wu Jun Yang Hong-Xia Wang Yan-Bo Huang Le Wang xiao-Ya Chen Yong-Hong Hu Qing Zhao Ping Xu shanghai Key Laboratory of Plant Functional Genomics and Resources Shanghai Chenshan Botanical GardenShanghai Chenshan Plant Science Research CenterChineseAcademy of SciencesShanghaiChina College of Life Sciences Shanghai Normal UniversityShanghai 200234China State Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghaiChina University of the Chinese Academy of Sciences Beijing 100049China The Research Center of Chiral Drugs Innovation Research Institute of Traditional Chinese MedicineShanghai University of Traditional Chinese Medicine1200 Cailun RoadShanghai 201203China College of Chemistry and Chemical Engineering Shanghai University of Engineering ScienceShanghai 201620China

The Lamiaceae family is renowned for its terpenoid-based medicinal components,but Leonurus,which has traditional medicinal uses,stands out for its alkaloid-rich ***,the principal active compound found in Leonurus,has demonstrated promising effects in reducing blood lipids and treating ***,the biosynthetic pathway of leonurine remains largely ***,we present the chromosome-level genome sequence assemblies of Leonurus japonicus,known for its high leonurine production,and Leonurus sibiricus,characterized by very limited leonurine *** integrating genomics,RNA sequencing,metabolomics,and enzyme activity assay data,we constructed the leonurine biosynthesis pathway and identified the arginine decarboxylase(ADC),uridine diphosphate glucosyltransferase(UGT),and serine carboxypeptidase-like(SCPL)acyltransferase enzymes that catalyze key reactions in this *** analyses revealed that the UGT–SCPL gene cluster evolved by gene duplication in the ancestor of Leonurus and neofunctionalization of SCPL in ***,which contributed to the accumulation of leonurine specifically in ***,our comprehensive study illuminates leonurine biosynthesis and its evolution in Leonurus.

关键词： Lamiaceae Leonurus japonicus Leonurus sibiricus genome sequence alkaloids leonurine gene cluster biosynthetic pathway evolution

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Bright InP quantum dots by Ga-doping for red emitters

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Nano Research 2024年第7期17卷 6721-6733页

作者： Kai-Zheng Song xiao-Hang He Zhe-Yong Chen Ge Tang Jin-Zhao Huang Feng-Lei jiang College of Chemistry and Molecular Sciences Wuhan UniversityWuhan 430072China

Environment-friendly indium phosphide(InP)-based quantum dots(QDs)with efficient red-emitting properties are sufficiently needed to satisfy the requirement of burgeoning display and lighting ***,the syntheses of InP QDs using tris(trimethylsilyl)phosphine as the precursor are highly toxic and ***,we successfully introduced gallium(Ga)ions into tris(dimethylamino)phosphine-based red InP cores through thermally-promoted cation exchange,and the obtained Ga-doped InP cores exhibited significantly increased photoluminescence quantum yields(PLQY)of up to 26%.The existence of Ga was directly confirmed by energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy,and the functions of Ga were systematically *** subsequent coating of Ga-doped InP cores with ZnSeS and ZnS shells,the resulting Ga-InP/ZnSeS/ZnS QDs achieved a high PLQY of 62%with an emission maximum at 640 *** contrast,without Ga-doping,the PLQY only attained 36%using the same synthetic *** indicated an approximate 1.7-fold increase in *** enhancement of photoluminescence was related to the Ga^(3+),as it not only passivated surface defects of InP cores but also reduced core–shell interface *** Ga-InP/ZnSeS/ZnS QDs exhibited good stability towards heat treatment and ultraviolet(UV)***,the red light-emitting diode(LED)based on Ga-InP/ZnSeS/ZnS QDs performed well in a wide injected current range of 2 to 200 mA,with a maximum power efficiency of 0.68 lm/*** work showcases Ga-doping through cation exchange as a promising strategy for enhancing the efficiency of InP-based red emitters.

关键词： indium phosphide gallium doping optical properties light emitting diode

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Mechanism of Ta on the microstructure and properties of Fe-Mn damping alloys

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Tungsten 2024年第4期6卷 767-777页

作者： Gui-Xiang Liu Kun Zhang Chao Han xiao-Lin Shao Jun Lu Lin Zhang xiao-Song jiang Zi-Xuan Wu Liu Yang The Second Sub-Institute Nuclear Power Institute of China Key Laboratory of Advanced Technologies of Materials Ministry of Education School of Materials Science and Engineering Southwest Jiao tong University School of Engineering and Materials Science Queen Mary University of London Institute for Applied Materials (IAM-WK) Karlsruhe Institute of Technology (KIT)

Fe-Mn-Co-xTa alloys（x=0,1,2,3 wt.%） were fabricated using spark plasma sintering to explore the influence of Ta content on the microstructure,mechanical properties,and damping characteristics of Fe-17Mn-3Co damping *** micro structural analysis reveals the dominant presence of γ-austenite,ε-martensite,α'-martensite,and Co3Ta precipitates within the *** increments in Ta content exhibit proportional enhancements in hardness,tensile strength,and fracture elongation of the ***,these improvements in mechanical attributes are closely correlated with the generated second-phase *** the Ta content increases,there is a gradual augmentation in the formation of Co3Ta within the ***,the damping property initially experiences an ascent followed by a subsequent decline with rising Ta *** damping behavior finds its origins in multiple mechanisms,including grain boundary damping stemming from reduced grain size,interfacial damping induced by the generated Co3Ta,and dislocation *** is noteworthy that the emergence of the secondary phase wields a dual impact on damping *** the one hand,the proliferation of the second phase fosters increased interfaces for energy *** the other hand,these interfaces give rise to compressive stresses,constraining interface movement and thus impeding damping property enhancement.

关键词： Damping Fe–Mn–Co Mechanical properties Spark plasma sintering Ta

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Differences in and factors controlling organic matter enrichment in the Ziliujing Formation shale in the Sichuan Basin

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Petroleum Science 2024年第1期21卷 77-86页

作者： Peng Li Zhong-Bao Liu He Bi Tao jiang Rui-Kang Bian Peng-Wei Wang xiao-Yu Shang State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development Beijing102206China Key Laboratory of Shale Oil/Gas Exploration and Production Technology SINOPECBeijing102206China Petroleum Exploration and Production Research Institute SINOPECBeijing102206China Research Institute of Petroleum Exploration and Development PetroChinaBeijing100083China Chinese Academy of Geological Sciences Beijing100037China No.4 Oil Production Plant in Daqing Oilfield Co Ltd. Daqing163511HeilongjiangChina

Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon *** are two sets of shale,the Dongyuemiao and Da’anzhai Members,in the Ziliujing Formation in the Sichuan *** identify the differential enrichment characteristics of organic matter and clarify its controlling factors,geochemical analyses of organic and inorganic geochemical analyses were *** results showed that the total organic carbon content of the Dongyuemiao shale(1.36%)is slightly higher than that of the Da’anzhai shale(0.95%).The enrichment of organic matter in the two shales resulted from the comprehensive controls of paleoproductivity,paleoenvironment,and terrigenous input,but different factors have different *** addition,driven by climate,the change in the sulfate concentration in the bottom water further led to the different intensities of bacterial sulfate reduction in early *** made a great difference regarding organic matter accumulation in the two *** general,climate may have played a dominant role in organic matter enrichment in the two sets of shale.

关键词： Lacustrine shale Ziliujing Formation Sichuan Basin Enrichment mechanism of organic matter

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High-strength and thermally stable TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy fabricated via selective laser melting

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2221-2232页

作者： jiang Yu Yaoxiang Geng Yongkang Chen xiao Wang Zhijie Zhang Hao Tang Junhua Xu Hongbo Ju Dongpeng Wang School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China National Engineering Research Center of Near-Net Shape Forming for Metallic Materials Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic MaterialsSouth China University of TechnologyGuangzhou 510640China CEMMPRE-Centre for Mechanical Engineering Materials and Processes Department of Mechanical EngineeringUniversity of CoimbraRua Luís Reis SantosCoimbra 3030-788Portugal

To increase the processability and plasticity of the selective laser melting(SLM)fabricated Al-Mn-Mg-Er-Zr alloys,a novel TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy with a mixture of Al-Mn-Mg-Er-Zr and nano-TiB_(2) powders was fabricated by *** pro-cessability,microstructure,and mechanical properties of the alloy were systematically investigated by density measurement,microstruc-ture characterization,and mechanical properties *** alloys fabricated at 250 W displayed higher relative densities due to a uni-formly smooth top surface and appropriate laser energy *** maximum relative density value of the alloy reached(99.7±0.1)%,demonstrating good *** alloy exhibited a duplex grain microstructure consisting of columnar regions primarily and equiaxed regions with TiB_(2),Al6Mn,and Al3Er phases distributed along the grain *** directly aging treatment at a high tem-perature of 400℃,the strength of the SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy increased due to the precipitation of the secondary Al6Mn *** maximum yield strength and ultimate tensile strength of the aging alloy were measured to be(374±1)and(512±13)MPa,*** SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy demonstrates exceptional strength and thermal stability due to the synergistic effects of the inhibition of grain growth,the incorporation of TiB_(2) nanoparticles,and the precipitation of secondary Al6Mn nanoparticles.

关键词： selective laser melting aluminum alloy processability mechanical properties thermal stability

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Design of Ca-type todorokite catalysts with highly active for the selective reduction of NO_(x) by NH_(3) at low temperatures

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Journal of Environmental Sciences 2024年第4期138卷 697-708页

作者： Chuang Chang Zidi Yan Chunlei Zhang Yanshuang Zhang Miao jiang Luna Ruan Min xiao yunbo Yu Hong He School of Rare Earths University of Science and Technology of ChinaHefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Ca-type todorokite catalysts were designed and prepared by a simple redox method and applied to the selective reduction of NO_(x) by NH_(3)(NH_(3)-SCR)for the first *** with the Na-type manjiroite prepared by the same method,the todorokite catalysts with different Mn/Ca ratios showed greatly improved catalytic activity for NO_(x) *** them,Mn8Ca4 catalyst exhibited the best NH_(3)-SCR performance,achieving 90%NO_(x) conversion within temperature range of 70-275℃ and having a high sulphur *** to the Na-type manjiroite sample,Ca-type todorokite catalysts possessed an increased size of tunnel,resulting in a larger specific surface *** increased the amounts of Ca doping,the Na content in Ca-type todorokite catalysts significantly decreased,providing larger amounts of Bronsted acid sites for NH_(3) adsorption to produce NH_(4)^(+).The NH_(4)^(+)species were highly active for reaction with NO+O_(2),playing a determining role in NH_(3)-SCR process at low ***,larger amounts of surface adsorbed oxygen contained over the Ca-doping samples than that over Na-type manjiroite,promoting the oxidation of NO and fast SCR *** the Ca-type todorokite catalysts,furthermore,nitrates produced during the flow of NO+O_(2),were more active for reaction with NH_(3) than that over Na-type manjiroite,benefiting the occurrence of NH_(3)-SCR *** study provides novel insights into the design of NH_(3)-SCR catalysts with high performance.

关键词： NO_(x) NH_(3)-SCR Mn-based oxides Ca-type todorokite Bronsted acid sites

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Microstructure and mechanical properties of Co-28Cr-6Mo-0.22C investment castings by current solution treatment

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China Foundry 2024年第4期21卷 369-378页

作者： Ze-yu Dan Jun Liu Jian-lei Zhang Yan-hua Li Yuan-xin Deng yun-hu Zhang Chang-jiang Song Center for Advanced Solidification Technology School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Wuxi CastPro Precision Co. Ltd.Wuxi 214105JiangsuChina

This study examined the impact of current solution treatment on the microstructure and mechanical properties of the Co-28Cr-6Mo-0.22C alloy investment *** findings reveal that the current solution treatment significantly promotes the dissolution of carbides at a lower *** optimal conditions for solution treatment are determined as a solution temperature of 1,125°C and a holding time of 5.0 *** these parameters,the size and volume fraction of precipitated phases in the investment castings are measured as6.2μm and 1.1vol.%.The yield strength,ultimate tensile strength,and total elongation of the Co-28Cr-6Mo-0.22C investment castings are 535 MPa,760 MPa,and 12.6%,*** values exceed those obtained with the conventional solution treatment at 1,200°C for 4.0 *** findings suggest a phase transformation of M_(23)C_(6)→σ+C following the current solution treatment at 1,125°C for 5.0 *** comparison,the traditional solution treatment at 1,200°C for 4.0 h leads to the formation of M_(23)C_(6)and M_(6)C *** is noteworthy that the non-thermal effect of the current during the solution treatment modifies the free energy of both the matrix and precipitation *** modification lowers the phase transition temperature of the M_(23)C_(6)→σ+C reaction,thereby facilitating the dissolution of *** a result,the current solution treatment approach achieves carbide dissolution at a lower temperature and within a significantly shorter time when compared to the traditional solution treatment methods.

关键词： CoCrMo alloy investment castings current solution treatment microstructure mechanical property carbide

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