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Influence of sintering time on microstructure and properties of hot oscillatory pressing sintered W–Cu refractory alloys

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Tungsten 2024年第2期6卷 323-332页

作者： zi-Qian Wu Wei Zhao Ka gao Shi-hao Du Qing-Quan Kong De-Jian Sun Yang gao School of Materials Science and Engineering Zhengzhou University of AeronauticsZhengzhou 450015China School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China Department of General Medicine Changhai HospitalShanghai 200000China Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of Science and TechnologyWuhan 430081China Sichuan Province Engineering Technology Research Center of Powder Metallurgy Chengdu UniversityChengdu 610106China

W–Cu refractory alloys are widely used in aerospace,aviation,electronics,power,and other fi elds.However,because of its large melting point diff erence between alloy elements,the conventional powder metallurgy method required a long time of high temperature sintering is very likely to cause low density and abnormal grain size growth.Therefore,90W-10Cu refractory alloys were successfully prepared by hot oscillatory pressing(HOP)under diff erent sintering time in this work.Then the infl uence of sintering time on the microstructure,grain size,density,Vickers hardness,room-tensile property,and electrical conductivity of the W–Cu refractory alloy was systematically invested.The results showed that during the short sintering time(30–90 min),the density,Vickers hardness,tensile strength,and electrical conductivity of the W–Cu refractory alloy increased signifi cantly to 98.7%,163.29 HV 30,507.3 MPa,and 14.2%International Annealed Copper Standard with the sintering time increasing,respectively,while its grain size showed no obvious change.When the sintering time further increased to 120 min,the density was basically consistent with the sintering time of 90 min.Nevertheless,the prolonged high temperature sintering resulted in the grain growth of the samples,which caused the deterioration of the Vickers hardness,room-tensile strength,and conductivity properties of the W–Cu refractory alloy.At the same sintering time,the density,Vickers hardness,and electrical conductivity of the HOP sintered W–Cu refractory alloy were signifi cantly higher than those of the HP sintered sample.It was indicated that high density,fi ne-grain,and excellent properties W–Cu refractory alloys could be prepared by hot oscillatory pressing under appropriate sintering time.

关键词： W–Cu refractory alloy Hot oscillatory pressing Sintering time Microstructure Property

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Weyl Type Theorem for Bounded Linear Operator and Its Functional Calculus

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Acta Mathematica Sinica,English Series 2024年第2期40卷 528-536页

作者： gao Hui zi FENG Peng Tong LI School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

Let H be a complex infinite dimensional Hilbert space and B(H)be the algebra of all bounded linear operators on H.In this paper,we mainly study the operators that satisfy both a-Weyl's theorem and property(R).Also,the operators whose functional calculus satisfies the two properties are also explored.We give the features for the operator or its functional calculus for which both a-Weyl's theorem and property(R)hold.

关键词： a-Weyl's theorem property(R) functional calculus

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Antiviral treatment standards for hepatitis B:An urgent need for expansion

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World Journal of Gastroenterology 2024年第4期30卷 418-420页

作者： zi-Hong Bao Zhi-Kun Dai hao-Xian Tang Department of Infectious Diseases The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041Guangdong ProvinceChina Medical College Shantou University Medical CollegeShantou 515041Guangdong ProvinceChina Department of Cardiology The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041Guangdong ProvinceChina

The present letter to the editor is related to the review with the title“Past,present,and future of long-term treatment for hepatitis B virus.”Chronic hepatitis B(CHB)represents an important and pressing public health concern.Timely identification and effective antiviral therapy hold the potential to reduce liver-related mortality attributable to chronic infection with hepatitis B virus(HBV)substantially.However,the current global treatment rates for CHB remain conspicuously low,with the excessively stringent treatment criteria advocated by national CHB guidelines being a contributing factor to these low rates.Nevertheless,recent strides in comprehending this malady and the emergence of novel antiviral agents prompt the imperative re-evaluation of treatment standards to extend the sphere of potential beneficiaries.An impending need arises for a novel paradigm for the classification of patients with CHB,the expansion of antiviral treatment eligibility for HBV-infected individuals,and even the streamlining of the diagnostic process for CHB to amplify cost-effectiveness and augment survival prospects.

关键词： Hepatitis B virus Chronic hepatitis B Antiviral treatment criteria Serum alanine aminotransferase Liver-related mortality Letter to the Editor

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Enhancing force sensing in a squeezed optomechanical system with quantum nondemolition measurement

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Communications in Theoretical Physics 2024年第1期76卷 49-60页

作者： Shi-Lei Chao zi-hao Li Xin-You Lü School of Physics Huazhong University of Science and Technology430074 WuhanChina

A theoretical scheme is proposed to enhance the sensitivity of force sensors with quantum nondemolition measurement(QND)in an optomechanical setup assisted by four-tone optical driving and an optical parametric amplifier(OPA).With the help of special drive,the system can be simplified as the typical type of QND for force sensing,so that the backaction noise can be evaded to surpass the standard quantum limit.Besides,the added noise can be suppressed owing to the modified optical susceptibility resulting from the OPA.By introducing two oscillators coupling with two charged bodies respectively,the signal can be enhanced with the nonlinearity caused by Coulomb interaction,while the noise presents an exponential decrease.Moreover,considering the homodyne detection effect,the range of system parameters and frequency bands will be broadened.The present investigation may provide a route toward simultaneously evading backaction noise,reducing the mechanical thermal noise,and enhancing the external signal,which can be an alternative design for sensitive devices.

关键词： force sensing optical parametric amplifier quantum non-demolition measurement optomechanical system

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Nonreciprocal generation of Schrodinger cat state induced by topology

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 23-30页

作者： zi-hao Li Li-Li Zheng Ying Wu Xin-You Lü School of Physics and Institute for Quantum Science and Engineering Huazhong University of Science and Technologyand Wuhan Institute of Quantum TechnologyWuhan 430074China Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education Jianghan UniversityWuhan 430074China

The Schrodinger cat state produced differently in two directions is anticipated to be a critical quantum resource in quantum information technologies.By exploring the interplay between quantum nonreciprocity and topology in a one-dimensional microcavity array,we obtain the Schrodinger cat state(a pure quantum state)in a chosen direction at the edge cavity,whereas a classical state in the other direction.This nonreciprocal generation of the cat state originates from the topologically protected chiralitymode excitation in the nontrivial phase,but in the trivial phase,the nonreciprocal generation of cat state vanishes.Thus,our proposal is switchable by tuning the parameters so that a topological phase transition occurs.Moreover,the obtained cat state has nonreciprocal high fidelity,nonclassicality,and quantum coherence,which are sufficient to be used in various one-way quantum technologies,e.g.,invisible quantum sensing,noise-tolerant quantum computing,and chiral quantum networks.Our work provides a general approach to control quantum nonreciprocities with the topological effect,which substantially broadens the fields of nonreciprocal photonics and topological physics.

关键词： Schr?dinger cat state nonreciprocity topology

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Intermittent Theta Burst Stimulation Attenuates Cognitive Deficits and Alzheimer’s Disease-Type Pathologies via ISCA1-Mediated Mitochondrial Modulation in APP/PS1 Mice

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Neuroscience Bulletin 2024年第2期40卷 182-200页

作者： Yang Zhu hao Huang Zhi Chen Yong Tao Ling-Yi Liao Shi-hao gao Yan-Jiang Wang Chang-Yue gao Department of Rehabilitation Medicine Daping HospitalArmy Medical UniversityChongqing 400042China Department of Neurology and Center for Clinical Neuroscience Daping HospitalArmy Medical UniversityChongqing 400042China Department of Special Medicine Daping HospitalArmy Medical UniversityChongqing 400042China

Intermittent theta burst stimulation(iTBS),a time-saving and cost-effective repetitive transcranial magnetic stimulation regime,has been shown to improve cognition in patients with Alzheimer’s disease(AD).However,the specific mechanism underlying iTBS-induced cognitive enhancement remains unknown.Previous studies suggested that mitochondrial functions are modulated by magnetic stimulation.Here,we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1(ISCA1,an essential regulatory factor for mitochondrial respiration)in the brain of APP/PS1 mice.In vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function,which is required for ISCA1.Moreover,iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 mice.The present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in AD.We provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.

关键词： Intermittent theta burst stimulation Alzheimer’s disease Iron-sulfur cluster assembly 1 Mitochondrial dysfunction Neurodegeneration

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Study of the multi-physics field-coupled model of the two-stage electrostatic precipitator

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Building Simulation 2024年第3期17卷 387-398页

作者： Wenjia hao Yu Guo Yukun Wang Tao Yu hao gao Zhengwei Long Tianjin Key Laboratory of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityWeijin Road 92Tianjin300072China Wuhan Second Ship Design and Research Institute WuhanChin

The two-stage electrostatic precipitator is widely used to purify oil mist particles.However,there is limited research on the influences of relative humidity,particle deposition characteristics,and the generation of gaseous pollutants.Therefore,this paper established a numerical model of the electrostatic oil mist purifier and applied it to a two-stage electrostatic precipitator.Then the model was used to investigate the corona discharge characteristics under different relative humidity conditions in the charged zone,the particle deposition characteristics,the purification efficiency,the ozone concentration distribution,and the oil vapor concentration distribution in the collection zone.The results indicate that,with a constant temperature,the corona current decreases as relative humidity increase,and there is a quadratic relationship between relative humidity and current.The variation in relative humidity has little impact on the purification efficiency.The maximum ozone concentration occurs near the electrode line,and its concentration is influenced by the discharge current and inlet airflow velocity.The oil vapor concentration reaches its maximum value at the side plates,with a value of 19 ppb,while it reaches the minimum value at the collecting zone electrode plate,with a value of 2 ppb.The temperature is the main factor affecting the volatilization of the oil film,with higher temperatures resulting in higher oil vapor.

关键词： two-stage ESPs particle deposition corona discharge oil vapor

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Experimental research on the launching system of auxiliary charge with filter cartridge structure

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Defence Technology（防务技术） 2024年第1期31卷 41-48页

作者： zi-Jun Chen Ze He Hong-hao Ma Lu-Qing Wang Zhao-Wu Shen CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefeiAnhui230027PR China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefeiAnhui230026PR China

A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the projectile.The combustion chamber of the launching system is divided into two fixed chambers,one is located in the breech chamber,and the other is arranged in the barrel.The breech chamber charge was ignited first,and the charges in the auxiliary chambers were ignited by the high-temperature,highpressure combustible gas trailing the projectile.In this way,the combustible gas in the auxiliary chambers could compensate for the pressure drop caused by the movement of the projectile.The proposed device features the advantage of launching a projectile with high muzzle velocity without exceeding the maximum pressure in the chamber.In order to obtain some internal ballistic characteristics of the launch system,some critical structure,such as the length of the filter cartridge auxiliary charge,the combustion degree of the propellant in the chamber,and the length of the barrel,are discussed.The experimental results show that with the increased auxiliary charge length,a pressure plateau or even a secondary peak pressure can be formed,which is less than the peak pressure.The projectile velocity increased by 23.57%,14.64%,and 7.65%when the diaphragm thickness was 0 mm,1 mm,and2 mm,respectively.The muzzle velocity of the projectile can be increased by 13.42%by increasing the length of the barrel.Under the same charge condition,with the increase of barrel length,the energy utilization rate of propellant increases by 28.64%.

关键词： Interior ballistics Charge structures Launch system Charge design

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Realizing high initial Coulombic efficiency in manganese-based layered oxide cathodes for sodium-ion batteries via P2/O'3 biphasic structure optimization

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Rare Metals 2024年第5期43卷 2093-2102页

作者： Bo Peng zi-hao Zhou Ping Xuan Jie Xu Lian-Bo Ma School of Materials Science and Engineering Anhui University of Technology Anhui Product Quality Supervision&Inspection Research Institute

Abstract Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmenta friendliness,low cost and high specific capacity.P2 and O'3 are two representative structures of Mn-based layered oxides.However,the P2 structure containing insufficien Na generally exhibits low initial charge capacity,while O'3structure with sufficient Na delivers high initial charge capacity but poor cycle stability.This study prepared a multitude of NaxMnO2（x=0.7,0.8,0.9） cathode materials with varying P2/O'3 ratios and further investigated their electrochemical performances.The optimized Na0.8MnO2comprising 69.9 wt%O'3 and 30.1 wt% P2 phase,exhibited relatively balanced specific capacity,Coulombic efficiency and cycle stability.Specifically,it achieved a high specific capacity of 128.9 mAh·g-1with an initia Coulombic efficiency of 98.2%in half-cell configuration The Na0.8MnO2// hard carbon full cell also achieved a high specific capacity of 126.7 mAh·g-1with an initia Coulombic efficiency of 98.9%.Moreover,the capacity fading mechanism was revealed by combining in-situ and ex-situ X-ray diffraction.The findings of this study provide theoretical guidance for further modification design of Mnbased layered cathodes.

关键词： Sodium-ion batteries Cathode materials Mn-based layered oxides P2/O′3 composites

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Cellular atlases of ovarian microenvironment alterations by diet and genetically-induced obesity

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Science China(Life Sciences) 2024年第1期67卷 51-66页

作者： Yonghui Jiang Xueying gao Yue Liu Xueqi Yan Huangcong Shi Rusong Zhao zi-Jiang Chen Fei gao Han Zhao Shigang Zhao Center for Reproductive Medicine Shandong UniversityJinan 250012China Research Unit of Gametogenesis and Health of ART-Offspring Chinese Academy of Medical Sciences(No.2021RU001)Jinan 250012China Key Laboratory of Reproductive Endocrinology of Ministry of Education Shandong UniversityJinan 250012China Shandong Key Laboratory of Reproductive Medicine Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250012China Shandong Provincial Clinical Research Center for Reproductive Health Jinan 250012China National Research Center of Assisted Reproductive Technology and Reproductive Genetics Shandong UniversityJinan 250012China The Affiliated Suzhou Hospital of Nanjing Medical University Suzhou Municipal HospitalGusu SchoolNanjing Medical UniversitySuzhou 215000China Center for reproductive medicine Ren Ji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200127China Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics Shanghai 200127China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of ScienceBeijing 100101China

Obesity,which can arise from genetic or environmental factors,has been shown to cause serious damages to the reproductive system.The ovary,as one of the primary regulators of female fertility,is a complex organ comprised of heterogeneous cell types that work together to maintain a normal ovarian microenvironment(OME).Despite its importance,the effect of obesity on the entire ovary remains poorly documented.In this study,we performed ovary single-cell and nanoscale spatial RNA sequencing to investigate how the OME changed under different kinds of obesity,including high-fat diet(HFD)induced obesity and Leptin ablation induced obesity(OB).Our results demonstrate that OB,but not HFD,dramatically altered the proportion of ovarian granulosa cells,theca-interstitial cells,luteal cells,and endothelial cells.Furthermore,based on the spatial dynamics of follicular development,we defined four subpopulations of granulosa cell and found that obesity drastically disrupted the differentiation of mural granulosa cells from small to large antral follicles.Functionally,HFD enhanced follicle-stimulating hormone(FSH)sensitivity and hormone conversion,while OB caused decreased sensitivity,inadequate steroid hormone conversion,and impaired follicular development.These differences can be explained by the differential expression pattern of the transcription factor Foxo1.Overall,our study provides a powerful and high-resolution resource for profiling obesity-induced OME and offers insights into the diverse effects of obesity on female reproductive disorders.

关键词： obesity ovarian microenvironment snRNA-seq Stereo-seq Foxo1

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