检索结果-南通市图书馆

Systematic study of the synthesis of heavy and superheavy nuclei in 48Ca-induced fusion-evaporation reactions

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 157-172页

作者： Shi-Hao Zhu tian-liang Zhao xiao-Jun Bao Department of Physics Collaborative Innovation Center for Quantum EffectsKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationHunan Normal UniversityChangsha410081China School of Nuclear Science and Technology Lanzhou UniversityLanzhou730000China School of Physics Xi’an Jiaotong UniversityXi’an710049China

We systematically studied the evaporation residue cross sections of ^(48)Ca-induced reactions on lanthanide and actinide target nuclei under the Dinuclear System(DNS)model framework to check the reliability and applicability of the *** produce new proton-rich Fl and Lv isotopes through hot fusion reactions in the superheavy element region with Z≥104,we utilized the reactions ^(48)Ca+^(236,238,239) Pu and ^(48)Ca+^(242,243,244,250) ***,owing to the detection limit of available equipment(0.1 pb),only 283Fl and 287−289Lv,which have the maximum evaporation residue cross section values of 0.149,0.130,9.522,and 0.309 pb,respectively,can be ***,to produce neutron-deficient isotopes of actinides near the proton drip line with Z=93−100,we attempted to generate the new isotopes(224−227Pu,228−232,237Cm)using the reactions ^(48)Ca+180,182,183 W and ^(48)Ca+^(184,186,187,192) *** maximum evaporation residue cross section values are 0.07,0.06,0.26,and 0.30 nb for the former set of reactions,and 1.96 pb,5.73 pb,12.16 pb,19.39 pb,54.79 pb,and 6.45 nb for the latter,*** results are expected to provide new information for the future synthesis of unknown neutron-deficient isotopes.

关键词： Dinuclear system(DNS)model Evaporation residue cross section Neutron-deficient isotopes

A compact route for efficient production of high-purity β-Ga_(2)O_(3) powder

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4573-4584页

作者： xiao-Wei Zhou Gao-Jie chen liang Xu Zhi-Jun Shao cheng Yang Yong-Pan tian Zhuo Zhao School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243032China Low-Carbon Research Institute Anhui University of TechnologyMa'anshan 243032China

The present study has proposed a compact process for the production of high-purity β-Ga_(2)O_(3)powder by simply using gallium metal and water as the raw *** process basically consists of two essential steps including hydrothermal synthesis of Ga OOH and calcination of Ga OOH for the production of the target product of β-Ga_(2)O_(3).Thermodynamic evaluation and systematic experiments were conducted for process parameter optimization.X-ray diffractometer(XRD),scanning electron microscopy(SEM),thermogravimetryDdifferential scanning calorimetry(TG-DSC)and X-ray photoelectron spectroscopy(XPS)were utilized to clarify the reaction mechanisms of the hydrothermal synthesis and transformation of Ga OOH to β-Ga_(2)O_(3)by *** analysis of the final product of β-Ga_(2)O_(3)obtained under the optimal conditions was carried out with inductively coupled plasma mass spectrometry(ICP-MS),and the results showed that the contents of the representative impurities such as Ni,Cu,In,Mn,Co,Zn and Cr are obviously lower than the requirement of 5N β-Ga_(2)O_(3)standard,exhibiting excellent application prospect of the proposed process to produce high-purity β-Ga_(2)O_(3).

关键词： β-Ga_(2)O_(3) Hydrothermal synthesis Calcination Purity Reaction mechanism

Development of lithium-free P2-type high-sodium content cathode materials with enhanced cycle and air stability for sodium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第1期43卷 113-123页

作者： Jin-Lv tian Lin-Rong Wu Hai-Jun Zhao Shou-Dong Xu liang chen Ding Zhang xiao-Chuan Duan College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China School of Chemical Engineering and Pharmacy Wuhan Institute of TechnologyWuhan 430205China

The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na_(45/54)Mg_(6)/_(54)Ni_(12/54)Mn_(34/54)O_(2) cathode with high initial Coulombic efficiency and excellent cyclic stability has been investigated in this *** on the crystal structural analysis,the Mg doping can retain the P2 structure up to 4.3 V,thus restraining the detrimental phase transformation of P2-02during the Na-ion intercalation/deintercalation ***,the obtained Mg-doped P2-type cathode exhibits a reversible specific capacity of 109 mAh·g^(-1) at 0.1C between 2.0 and 4.3 V and a retention rate of 81.5% after 200cycles at *** addition,the full cell consisting of Mg-doped P2-type cathode and hard carbon anode shows a capacity retention rate of 85.6% after 100 *** study provides new insight into the development of durable cathode materials for sodium-ion batteries.

关键词： Sodium-ion batteries Cathode material High sodium content Air stability

Global convergence in terrestrial gross primary production response to atmospheric vapor pressure deficit

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第9期67卷 2016-2025页

作者： Chao Huang Jingfeng Huang Jingfeng xiao Xing Li Hong SHe Yu liang Fusheng chen Hanqin tian Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed College of ForestryJiangxi Agricultural UniversityNanchang 330045China CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Institute of Applied Remote Sensing&Information Technology College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China Key Laboratory of Agricultural Remote Sensing and Information Systems Zhejiang ProvinceZhejiang UniversityHangzhou 310058China Earth Systems Research Center Institute for the Study of EarthOceansand SpaceUniversity of New HampshireDurham NH 03824USA Research Institute of Agriculture and Life Sciences Seoul National UniversitySeoul 08826South Korea School of Natural Resources University of Missouri203 ABNR BuildingColumbiaMO 65211USA Schiller Institute for Integrated Science and Society Department of Earth and Environmental SciencesBoston CollegeChestnut HillMA 02467USA

Atmospheric vapor pressure deficit(VPD)increases with climate warming and may limit plant ***,gross primary production(GPP)responses to VPD remain a mystery,offering a significant source of uncertainty in the estimation of global terrestrial ecosystems carbon *** this study,in-situ measurements,satellite-derived data,and Earth System Models(ESMs)simulations were analysed to show that the GPP of most ecosystems has a similar threshold in response to VPD:first increasing and then *** VPD exceeds these thresholds,atmospheric drought stress reduces soil moisture and stomatal conductance,thereby decreasing the productivity of terrestrial *** ESMs underscore CO_(2) fertilization effects but predict significant GPP decline in low-latitude ecosystems when VPD exceeds the *** results emphasize the impacts of climate warming on VPD and propose limitations to future ecosystems productivity caused by increased atmospheric water *** VPD,soil moisture,and canopy conductance interactions into ESMs enhances the prediction of terrestrial ecosystem responses to climate change.

关键词： atmospheric water demands soil moisture stomatal conductance photosynthesis climate warming

Bending Analysis of Circular Piezoelectric Semiconductor Plates Incorporating Flexoelectricity

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第4期37卷 613-621页

作者： liang Sun Zhengguang xiao Chunli Zhang Weiqiu chen Department of Engineering Mechanics Zhejiang UniversityHangzhou310027China Department of Basic Courses Naval University of EngineeringWuhan430033China Huanjiang Laboratory Zhuji311816China

Based on the three-dimensional(3D)basic equations of piezoelectric semiconductors(PSs),we establish a two-dimensional(2D)deformation-polarization-carrier coupling bending model for PS structures,taking flexoelectricity into *** analytical solutions to classical flexure of a clamped circular PS thin plate are *** the derived analytical model,we numerically investigate the distributions of electromechanical fields and the concentration of electrons in the circular PS thin plate under an upward concentrated *** effect of flexoelectricity on the multi-field coupling responses of the circular PS plate is *** obtained results provide theoretical guidance for the design of novel PS devices.

关键词： Piezoelectric semiconductor Plate model Flexoelectricity Multi-field coupling

Effect of land use on soil nematode community composition and co-occurrence network relationship

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第8期23卷 2807-2819页

作者： xiaotong Liu Siwei liang Yijia tian xiao Wang Wenju liang xiaoke Zhang Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China Tillage and Cultivation Research Institute Liaoning Academy of Agricultural SciencesShenyang 110161China University of Chinese Academy of Sciences Beijing 100049China Key Lab of Conservation Tillage and Ecological Agriculture in Liaoning Province Shenyang 110016China

Land use influences soil biota community composition and diversity,and then belowground ecosystem processes and *** characterize the effect of land use on soil biota,soil nematode communities in crop land,forest land and fallow land were investigated in six regions of northern *** richness,diversity,abundance and biomass of soil nematodes was the lowest in crop *** richness and diversity of soil nematodes were 28.8and 15.1%higher in fallow land than in crop land,*** significant differences in soil nematode indices were found between forest land and fallow land,but their network keystone genera composition was *** the keystone genera,50%of forest land genera were omnivores-predators and 36%of fallow land genera were *** proportion of fungivores in forest land was 20.8%lower than in fallow *** network complexity and the stability were lower in crop land than forest land and fallow *** pH,NH_(4)^(+)-N and NO_(3)^(–)-N were the major factors influencing the soil nematode community in crop land while soil organic carbon and moisture were the major factors in forest *** nematode communities in crop land influenced by artificial management practices were more dependent on the soil environment than communities in forest land and fallow *** use induced soil environment variation and altered network relationships by influencing trophic group proportions among keystone nematode genera.

关键词： soil nematode trophic groups community composition co-occurrence network land use

Development and application of novel high‐efficiency composite ultrafine cement grouts for roadway in fractured surrounding rocks

在线全文

学校读者我要写书评

暂无评论

Deep Underground Science and Engineering 2024年第1期3卷 53-69页

作者： Maolin tian Shaojie chen Lijun Han Hongtian xiao Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation Shandong University of Science and TechnologyQingdaoChina College of Civil Engineering and Architecture Shandong University of Science and TechnologyQingdaoChina College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdaoChina State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouChina

The fractured surrounding rocks of roadways pose major challenges to safe *** has often been used to reinforce the surrounding rocks to mitigate the safety risks associated with fractured *** aim of this study is to develop highly efficient composite ultrafine cement(CUC)grouts to reinforce the roadway in fractured surrounding *** materials used are ultrafine cement(UC),ultrafine fly ash(UF),ultrafine slag(US),and additives(superplasticizer[SUP],aluminate ultrafine expansion agent[AUA],gypsum,and retarder).The fluidity,bleeding,shrinkage,setting time,chemical composition,microstructure,degree of hydration,and mechanical property of grouting materials were evaluated in this ***,a suitable and effective CUC grout mixture was used to reinforce the roadway in the fractured surrounding *** results have shown that the addition of UF and US reduces the plastic viscosity of CUC,and the best fluidity can be obtained by adding 40%UF and 10%*** UC and UF particles are small,the pozzolanic effect of UF promotes the hydration reaction,which is conductive to the stability of CUC *** addition,fine particles of UC,UF,and US can effectively fill the pores,while the volumetric expansion of AUA and gypsum decreases the pores and thus affects the microstructure of the solidified *** compressive test results have shown that the addition of specific amounts of UF and US can ameliorate the mechanical properties of CUC ***,the CUC22‐8 grout was used to reinforce the No.20322 belt *** results of numerical simulation and field monitoring have indicated that grouting can efficaciously reinforce the surrounding rock of the *** this research,high‐performance CUC grouts were developed for surrounding rock reinforcement of underground engineering by utilizing UC and some additives.

关键词： broken surrounding rock composite ultrafine cement(CUC)grouts grouting material grouting performance grouting reinforcement

Deformation of Rigid Conjugate Self-dual Galois Representations

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第7期40卷 1599-1644页

作者： Yi Feng LIU Yi Chao tian liang xiao Wei ZHANG Xin Wen ZHU Institute for Advanced Study in Mathematics Zhejiang UniversityHangzhou 310058P.R.China Morningside Center of Mathematics AMSSChinese Academy of SciencesBeijing 100190P.R.China New Cornerstone Lab Beijing International Center for Mathematical ResearchPeking Ui Beijing 100871P.R.China Department of Mathematics Massachusetts Institute of TechnologyCambridge MA 02139United States Department of Mathematics Stanford UniversityStanfordCA 94305United States

In this article,we study deformations of conjugate self-dual Galois *** study is ***,we prove an R=T type theorem for a conjugate self-dual Galois representation with coefficients in a finite field,satisfying a certain property called ***,we study the rigidity property for the family of residue Galois representations attached to a symmetric power of an elliptic curve,as well as to a regular algebraic conjugate self-dual cuspidal representation.

关键词： Galois deformation rigid conjugate self-dual Galois representations

Research on aiming methods for small sample size shooting tests of two-dimensional trajectory correction fuse

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 506-517页

作者： chen liang Qiang Shen Zilong Deng Hongyun Li Wenyang Pu Lingyun tian Ziyang Lin School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse *** impact point easily deviates from the target,and thus the correction result cannot be readily ***,the cost of shooting tests is considerably high to conduct many tests for data *** address this issue,this study proposes an aiming method for shooting tests based on small sample *** proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion *** experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.

关键词： Two-dimensional trajectory correction fuse Small sample size test Compatibility test KL divergence Fusion bayesian estimation