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Mantle avalanches in a Venus-like stagnant lid planet

Earth and Planetary Physics 2024年第5期8卷 686-702页

作者： Madeleine C.Kerr Dave R.Stegman Institute of Geophysics and Planetary Physics Scripps Institution of Oceanography University of California

Stagnant lid planets are characterized by a globe-encircling, conducting lid that is thick and strong, which leads to reduced global surface heat flows. Consequently, the mantles of such planets can have warmer interiors than Earth, and interestingly, a pyrolitic mantle composition under warmer conditions is predicted to have a distinctly different mantle transition zone compared to the present-day Earth(Hirose, 2002; Stixrude and Lithgow-Bertelloni, 2011; Ichikawa et al., 2014; Dannberg et al, 2022). Instead of olivine primarily transforming into its higher-pressure polymorphs such as wadsleyite and then ringwoodite, at pressures corresponding to410 km and 520 km depth in Earth, respectively, it instead transforms into a mineral assemblage of wadsleyite, majorite, and ferropericlase(WMF), and then to majorite + ferropericlase(MF), before finally transforming into bridgmanite at pressures corresponding to 660 km depth in Earth(Stixrude and Lithgow-Bertelloni, 2011; Ichikawa et al., 2014). Convective motions in stagnant lid planets are dominated by small-scale instabilities(cold drips) forming within the mobile rheological sublayer under the rigid lid. Using ASPECT and a thermodynamic model of a pyrolitic mantle composition generated by HeFESTo, we show that under certain conditions, the small drips can pond atop the WMF-MF mineral phase transition. The barrier to convective flow arises from the WMF mineral phase assemblage having an effective negative thermal expansivity(Stixrude and Lithgow-Bertelloni, 2022). Although large-scale downwellings that typically occur within mobile lid planets are able to pass through the WMF zone without difficulty(Dannberg et al., 2022; Li RP et al.,2024), the smaller and less negatively buoyant nature of downwelling drips in stagnant lid planets are more susceptible to these effects,which leads to an ephemeral layering of the mantle. Our numerical models show that in stagnant lid planets with mantle potential temperatures that exceed

关键词： Venus mantle avalanches numerical modelling phase transitions

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Recent advances in post-chiroptical manipulation of supramolecular aggregates assembled with molecular modules

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Science China Chemistry 2024年第9期67卷 2842-2863页

作者： Yanling Shen Wanhua Wu Zhipeng Yu Cheng Yang Key Laboratory of Green Chemistry&Technology of Ministry of Education College of Chemistry InstitutionSichuan UniversityChengdu 610064China

Recently,various supramolecular assembly systems have been identified where the pre-existing chiral supramolecular structure can be manipulated through environmental adjustments,such as temperature,solvent,and *** changes result in diverse microscopic morphologies during the assembly process and induce chiroptical variations,particularly in circular dichroism(CD)and circularly polarized luminescence(CPL)*** chiroptical properties serve as direct indicators of the chiral supramolecular structure and hold promise for applications in sensing,molecular recognition,asymmetric synthesis,and material *** review focuses on research published in the last five years,highlighting instances where assembled structures aggregated by small organic molecular modules demonstrate in-situ chiroptical changes through external condition *** categorizes and discusses different modes of regulation,aiming to offer insights and guidelines for exploring dynamic changes in assembly processes and designing in-situ adjustable structures of assembly modules.

关键词： supramolecular assemblies post-chiroptical manipulation in-situ structural changes

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Effectively improved piezoelectricityyinhigh-temperature Arrhenius CBT ceramics by modifying potential energy profile and spontaneous polarization

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Journal of Advanced Ceramics 2024年第8期13卷 1143-1152页

作者： Jingwen Xi Linlin Liu Hongwei Qiao Jiacheng Luo Xin Su Xin Zhao Yugen Xu Hao Chen Zhi Tan Jianguo Zhu Nuclear Power institution of China Chengdu 610213China College of Materials Science and Engineering Sichuan UniversityChengdu 610064China

Enhancing the piezoelectricity of CaBi_(4)Ti_(4)O_(15)(CBT)ceramics is crucial for improving their application potential in high-temperature piezoelectric ***,we propose a strategy involving the introduction of larger Na/Bi ions at the A-site,effectively inhibiting the tilt of oxygen octahedra and flattening the potential energy *** flattening enhances the variation in polarization under external ***,substituting Nb/Mn at the B-site increases the deviation between positive and negative ionic centers,leading to stronger spontaneous polarization,while the induced defect dipoles restrict oxygen vacancy migration and increase the direct current resistivity(ρ_(dc)).The flattened potential energy profile and increased spontaneous polarization significantly enhance the overall performance of cBT ceramics,with the piezoelectric constant(d_(33))reaching 25 pC/N when the Curie temperature(Tc)=752℃.Piezoresponse force microscopy(PFM)and transmission electron microscopy(TEM)revealed submicron-long rectangular domains and nanoscale domains in the modified composition,indicating a high density of domain *** study presents an effective approach for enhancing the piezoelectric properties of bismuth layered-structured ferroelectrics(BLSFs),thereby improving the application potential of BLSFsathightemperatures.

关键词： piezoelectricity bismuth layered-structured ferroelectrics(BLSFs) potential energy profile spontaneous polarization high temperatures

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A critical review on solid-state welding of high entropy alloys-processing,microstructural characteristics and mechanical properties of joints

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Defence Technology（防务技术） 2024年第4期34卷 78-133页

作者： Tushar Sonar Mikhail Ivanov Evgeny Trofimov Aleksandr Tingaev Ilsiya Suleymanova Department of Welding Engineering Institution of Engineering and TechnologySouth Ural State University(National Research University)Chelyabinsk454080Russia Department of Materials Science Physical and Chemical Properties of MaterialsInstitution of Engineering and TechnologySouth Ural State University(National Research University)Chelyabinsk454080Russia

The high entropy alloys(HEAs)are the newly developed high-performance materials that have gained significant importance in defence,nuclear and aerospace sector due to their superior mechanical properties,heat resistance,high temperature strength and corrosion *** alloys are manufactured by the equal mixing or larger proportions of five or more alloying *** exhibit superior mechanical performance compared to traditional engineering alloys because of the extensive alloying composition and higher entropy of *** state welding(SSW)techniques such as friction stir welding(FSW),rotary friction welding(RFW),diffusion bonding(DB)and explosive welding(EW)have been efficiently deployed for improving the microstructural integrity and mechanical properties of welded HEA *** HEA interlayers revealed greater potential in supressing the formation of deleterious intermetallic phases and maximizing the mechanical properties of HEAs *** similar and dissimilar joining of HEAs has been manifested to be viable for HEA systems which further expands their industrial ***,the main objective of this review paper is to present a critical review of current state of research,challenges and opportunities and main directions in SSW of HEAs mainly CoCrFeNiMn and Al_xCoCrFeNi *** state of the art of problems,progress and future outlook in SSW of HEAs are critically reviewed by considering the formation of phases,microstructural evolution and mechanical properties of HEAs joints.

关键词： High entropy alloys Solid state welding Microstructure Mechanical properties

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Alternative splicing and related RNA binding proteins in human health and disease

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Signal Transduction and Targeted Therapy 2024年第3期9卷 839-871页

作者： Yining Tao Qi Zhang Haoyu Wang Xiyu Yang Haoran Mu Department of Orthopedics Shanghai General HospitalShanghai Jiao Tong University School of Medicine200000 ShanghaiChina Shanghai Bone Tumor institution 200000 ShanghaiChina Department of Biochemistry and Molecular Cell Biology Shanghai Key Laboratory for Tumor Microenvironment and InflammationShanghai Jiao Tong University School of Medicine200000 ShanghaiChina

Alternative splicing(AS)serves as a pivotal mechanism in transcriptional regulation,engendering transcript diversity,and modifications in protein structure and *** varying tissues,developmental stages,or under specific conditions,AS gives rise to distinct splice *** implies that these isoforms possess unique temporal and spatial roles,thereby associating AS with standard biological activities and *** these,AS-related RNA-binding proteins(RBPs)play an instrumental role in regulating alternative splicing *** physiological conditions,the diversity of proteins mediated by AS influences the structure,function,interaction,and localization of proteins,thereby participating in the differentiation and development of an array of tissues and *** pathological conditions,alterations in AS are linked with various diseases,particularly *** changes can lead to modifications in gene splicing patterns,culminating in changes or loss of protein *** instance,in cancer,abnormalities in AS and RBPs may result in aberrant expression of cancer-associated genes,thereby promoting the onset and progression of *** and RBPs are also associated with numerous neurodegenerative diseases and autoimmune ***,the study of AS across different tissues holds significant *** review provides a detailed account of the recent advancements in the study of alternative splicing and AS-related RNA-binding proteins in tissue development and diseases,which aids in deepening the understanding of gene expression complexity and offers new insights and methodologies for precision medicine.

关键词： organs alterations thereby

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Comparison between Liver Cancer Mortality Rates in China and Spain

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Journal of Clinical and Translational Hepatology 2024年第10期12卷 831-833页

作者： Javier Guinea-Castanares Jesus Maria Iturralde Iriso Irune Natalia Elizondo Pinillos Gloria Martinez Iniesta Osakidetza Basque Health Service Ringgold Standard institution(16651) Vitoria-GasteizSpain

Dear Editors,We have read with interest the article by Liu H et al.1 published in your journal regarding liver cancer mortality in China and would like to compare it with that of our country,Spain,which is a European ... 详细信息

关键词： al. mortality Cancer

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Experimental investigation of junction growth of rough contacts using X-ray computed tomography

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Friction 2024年第11期12卷 2519-2531页

作者： Runliang WANG Jianhua LIU Bo LIU Duo JIA Xiaoyu DING School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China AECC Shenyang Engine Research institution Shenyang 110000China

The real contact area(RCA)of randomly rough contacts has received a great deal of attention because it correlates strongly with friction,lubrication,sealing,and *** have revealed that the RCA associated with deterministic normal squeezing loads increases when tangential loads are also applied,in a phenomenon called junction ***,experimental investigations of the junction growth of randomly rough contacts are ***,we used X-ray computed tomography(CT)to measure junction growth when two aluminum alloy surfaces were in contact.A high-resolution experimental setup was used to apply loads and observe contact behaviors at a resolution of 4μ*** RCA and average contact gaps were computed using a three-dimensional(3D)geometric model constructed from gray CT images using the Otsu thresholding *** results showed that the RCA increased as the normal load *** RCA increased by 22.67%after a tangential load was applied(junction growth),and the average gap decreased by 14.01%after a tangential load was ***,X-ray CT accurately measured the junction growth as a novel quantitative method.

关键词： three-dimensional(3D)contact analyses real contact area(RCA),junction growth X-ray computed tomography(CT) assembly interfaces

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Effective Identity Authentication Based on Multiattribute Centers for Secure Government Data Sharing

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Tsinghua Science and Technology 2024年第3期29卷 736-752页

作者： Meiquan Wang Junhua Wu Tongdui Zhang Junhao Wu Guangshun Li School of Computer Science Qufu Normal UniversityRizhao 276800China Science and Technology Innovation Service institution of Rizhao Rizhao 276800China

As one of the essential steps to secure government data sharing,Identity Authentication(IA)plays a vital role in the processing of large ***,the centralized IA scheme based on a trusted third party presents problems of information leakage and single point of failure,and those related to key ***,herein,an effective IA model based on multiattribute centers is ***,a private key of each attribute of a data requester is generated by the attribute authorization *** obtaining the private key of attribute,the data requester generates a personal private ***,a dynamic key generation algorithm is proposed,which combines blockchain and smart contracts to periodically update the key of a data requester to prevent theft by external attackers,ensure the traceability of IA,and reduce the risk of privacy ***,the combination of blockchain and interplanetary file systems is used to store attribute field information of the data requester to further reduce the cost of blockchain information storage and improve the effectiveness of information *** results show that the proposed model ensures the privacy and security of identity information and outperforms similar authentication models in terms of computational and communication costs.

关键词： blockchain identity authentication distribution dynamic key generation

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Disparities in the Levels of Whole-Blood Epstein-Barr Virus between the Cancer and Non-Cancer Populations in Zhejiang,China

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Biomedical and Environmental Sciences 2024年第9期37卷 993-1002页

作者： Qingjun Jia Meichun Zeng Qi Chen Hangzhou Center for Disease Control and Prevention(Hangzhou Health Supervision institution) Hangzhou 310021ZhejiangChina Department of Pathology The First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhou 310003ZhejiangChina

Objective This study aimed to investigate the prevalence of Epstein-Barr virus(EBV)infection in patients with and without *** A total of 26,648 participants who underwent whole-blood EBV DNA(WBEBV)assays between January 1,2020,and August 31,2023,were *** chi-square test was used for categorical data analysis,and R software was used to analyze the differences in EBV DNA load levels and the diagnostic capabilities of *** Positive rates were 10.2%and 25.4%for healthy controls(HC)and patients,*** positivity rate for EBV-associated neoplasms(EN)was the highest at 7.53%,followed by leukemia(Le)at 5.49%.The subgroup analysis showed that the positivity rate for abnormal proliferation or hyperplasia(APH)was 31.9%,followed by 30.5%for *** WBEBV of patients with transplants(TP),especially living-related transplants(LT),was the highest among all *** at diagnosis was used to differentiate between infectious mononucleosis(IM)and chronic active Epstein-Barr virus(CAEBV),with a sensitivity of 67.4%(95%confidence interval[CI]:57.6-75.8)and specificity of 72%(95%CI:63.3-79.3).We conclude that the prevalence of EBV infection is low in the healthy population in this region and that a high EBV load at baseline is more common in LT,IM,and Lymphocyte Leukemia(LL).Conclusion This study used a large-sample survey to characterize the prevalence of whole-blood EBV levels in various diseases,including the stages and *** EBV detection rate was higher in patients with malignant disease than in those with benign *** study provides clinicians with baseline information regarding EBV-associated diseases.

关键词： Epstein-Barr virus Epstein-Barr virus DNA Whole blood Epstein-Barr virus DNA Viral load

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A Planning Method for Operational Test of UAV Swarm Based on Mission Reliability

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1889-1918页

作者： Jingyu Wang Ping Jiang Jianjun Qi College of Systems Engineering National University of Defense TechnologyChangsha410073China Beijing Special Engineering Design institution Beijing100028China

The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV *** to the high cost and long duration of operational tests,it is essential to plan the test in *** solve the problem of planning UAV swarm operational test,this study considers the multi-stage feature of a UAV swarm mission,composed of launch,flight and combat stages,and proposes a method to find test plans that can maximize mission ***,a multi-stage mission reliability model for a UAV swarm is proposed to ensure successful implementation of the mission.A multi-objective integer optimization method that considers both mission reliability and cost is then formulated to obtain the optimal test *** study first constructs a mission reliability model for the UAV swarm in the combat ***,the launch stage and flight stage are integrated to develop a complete PMS(Phased Mission Systems)reliability ***,the Binary Decision Diagrams(BDD)and Multi Objective Quantum Particle Swarm Optimization(MOQPSO)methods are proposed to solve the *** optimal plans considering both reliability and cost are *** proposed model supports the planning of UAV swarm operational tests and represents a meaningful exploration of UAV swarm test planning.

关键词： UAV swarm PMS MOQPSO BDD mission reliability operational test planning

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