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First Passage Density of Brownian Motion with Two-sided Piecewise Linear Boundaries

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1505-1520页

作者： zhen yu Mao Zai TIAN Center for Applied Statistics School of StatisticsRenmin University of ChinaBeijing 100872P.R.China School of Mathematics and Data Science Changji UniversityChangji 831100P.R.China

The first passage time has many applications in fields like finance,econometrics,statistics,and ***,explicit formulas for the first passage density have only been obtained for a few *** paper derives an explicit formula for the first passage density of Brownian motion with twosided piecewise continuous boundaries which may have some points of *** are used to obtain a simplified formula for estimating the first passage ***,the results are also generalized to the case of two-sided general nonlinear *** can be easily carried out with Monte Carlo method and it is demonstrated for several typical two-sided boundaries that the proposed approximation method offers a highly accurate approximation of first passage density.

关键词： Boundary non-crossing probability first density passage density two-sided piecewise continuous boundaries Brownian motion

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The breaking of spin symmetry in the single-particle resonances in deformed nuclei

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Nuclear Science and Techniques 2024年第3期35卷 237-245页

作者： zhen-yu zheng Shou-Wan Chen Quan Liu School of Physics and Optoelectronic Engineering Anhui UniversityHefei 230601China

The exploration of spin symmetry (SS) in nuclear physics has been instrumental in identifying atomic nucleus *** this study,we solve the Dirac equation from the relativistic mean field (RMF) in complex momentum *** investigated SS and its breaking in single-particle resonant states within deformed nuclei,with a focus on the illustrative *** was the initial discovery of a resonant spin doublet in a deformed nucleus,with the expectation of the SS approaching the continuum *** increasing single-particle energy,the splitting of the resonant spin doublets widened *** escalating splitting implies diminishing adherence to the SS,indicating a departure from the expected behavior as the energy levels *** also analyzed the width of the resonant states,showing that lower orbital angular momentum resonances possess shorter decay times and that SS is preserved within broad resonant doublets,as opposed to narrow resonant *** the radial density of the upper components for the bound-state and resonant-state doublets,it becomes evident that while SS is well-preserved in the bound states,it deteriorates in the resonant *** impact of nuclear deformation (β_(2)) on SS was examined,demonstrating that an increase in β_(2) resulted in higher energy and width splitting in the resonant spin doublets,which is attributed to increased component ***,the sensitivity of spin doublets to various potential parameters such as surface diffuseness (a),radius (R),and depth (Σ0) is discussed,emphasizing the role of these parameters in *** study provides valuable insights into the behavior of spin doublets in deformed nuclei and their interplay with the nuclear structure,thereby advancing our understanding of SS in the resonance state.

关键词： Spin symmetry Resonant states Deformed nuclei Complex-momentum representation

New Vacuum Solar Telescope Achieves Narrowband Infrared Solar Imaging Observation at He I 10830 A

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Research in Astronomy and Astrophysics 2024年第5期24卷 76-84页

作者： Wei-Jie Meng Fang-yu Xu zhen-yu Jin yunnan Observatories Chinese Academy of SciencesKunming 650011China yunnan Key Laboratory of Solar Physics and Space Science Kunming 650216China University of Chinese Academy of Sciences Beijing 100049China

The near-infrared imaging channel constitutes a crucial component of the multichannel high-resolution imaging system of the New Vacuum Solar Telescope(NVST). We have successfully achieved high-resolution, narrowband imaging of the chromosphere using He I 10830 A triplet within this channel, which significantly enhances the imaging observation capabilities of NVST. This paper provides a concise overview of the optical system associated with the near-infrared imaging channel, detailing data processing procedures and presenting several observed images. Leveraging a high-resolution image reconstruction algorithm, we were able to generate a narrowband image near the diffraction limit at 10830 A with a temporal resolution of less than 10 s.

关键词： instrumentation detectors-instrumentation high angular resolution-Sun chromosphere-Sun infrared

Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： zhen-yu ZHOU Qiu-Yang zhenG yu LI Cong DING Guang-Jian PENG Zhong-yu PIAO College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2D-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is *** mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and *** effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(MD)*** characterization results show that the 2D-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 *** optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5,10,and 15 N loads,*** gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

Deliberate self-harm among pediatric psychiatric inpatients in China:A single-center retrospective study

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World Journal of Psychiatry 2024年第3期14卷 398-408页

作者： Xing-Zhi Jiang Huan-Huan Li zhen-zhen yu Chen Wang Department of Child and Adolescent Psychiatry Shenzhen Kangning HospitalShenzhen Mental Health CenterShenzhen Key Laboratory for Psychological Healthcare and Shenzhen Institute of Mental HealthShenzhen 518020Guangdong ProvinceChina Department of Psychiatry Xiamen Xianyue HospitalXiamen 361012Fujian ProvinceChina Department of Geriatric Medicine Dalian Medical UniversityDalian 116000Liaoning ProvinceChina Department of Neurology The Second Affiliated Hospital of Xiamen Medical CollegeXiamen 361000Fujian ProvinceChina Department of Neurology and Department of Neuroscience The First Affiliated Hospital of Xiamen UniversitySchool of MedicineXiamen UniversityXiamen 361000Fujian ProvinceChina

BACKGROUND For children and adolescents,deliberate self-harm(DSH)is becoming a mental health problem of *** several studies on the prevalence and factors of DSH in the world,there is little information on DSH among children and adolescents in *** study explores the prevalence,types,associated risk factors and tendency of DSH in pediatric psychiatric inpatients in *** To understand the situation of DSH among hospitalized children and adolescents and its related *** In this study,we retrospectively studied 1414 hospitalized children and adolescents with mental illness at Xiamen Mental Health Center from 2014 to 2019,extracted the demographic and clinical data of all patients,and analyzed clinical risk factors of *** A total of 239(16.90%)patients engaged in at least one type of DSH in our ***(n=115,48.12%)was the most common type of ***(n=171,71.55%)were more likely to engage in DSH than males(n=68,28.45%).DSH was positively associated with depressive disorders[OR=3.845(2.196-6.732);P<0.01],female[OR=2.536(1.815-3.542);P<0.01],parental marital status[OR=5.387(2.254-12.875);P<0.01]and negative family history of psychiatric illness[OR=7.767(2.952-20.433);P<0.01],but not with occupation,substance use and history of physical *** Our findings suggest that for patients with depression,females,an abnormal marriage of parents,and no history of mental illness,attention should be paid to the occurrence of DSH.

关键词： Deliberate self-harm Children Adolescent Psychiatric inpatients Retrospective study

Climatic impacts induced by winter wheat irrigation over North China simulated by the nonhydrostatic RegCM4.7

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Advances in Climate Change Research 2024年第2期15卷 197-210页

作者： Jia WU zhen-yu HAN Xue-Jie GAO zheng-Jia LIU National Climate Centre China Meteorological AdministrationBeijing 100081China Key Laboratory for Climate Studies China Meteorological AdministrationBeijing 100081China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation *** related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate ***,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation *** experiments were conducted with and without winter wheat irrigation to isolate the effects of *** showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil ***,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation *** wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum ***,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the *** analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and ***,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated ***,no notable change was found in terms of heavy rainfall events and precipitation intensity

关键词： Nonhydrostatic regional climate model Irrigation effect Extreme events North China

SPNS1 ablation drives skeletal muscle atrophy by disrupting mitophagy,mitochondrial function,and apoptosis in mice

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Genes & Diseases 2024年第5期11卷 25-28页

作者： Xianzhong Zhang Fengmin Zhang Haofan Wu zhen yu Chengle Zhuang Department of Gastrointestinal Surgery Shanghai Tenth People's HospitalSchool of MedicineTongji UniversityShanghai200092China Colorectal Cancer Center Shanghai Tenth People's HospitalSchool of MedicineTongji UniversityShanghai 200072China

Sarcopenia is characterized by a dramatic decline in muscle mass and function during aging,which of ten leads to reduced mobility,diminished quality of life,and shortened *** recent advances in sarcopenia,the mechanisms that mediate skeletal muscle dysfunction remain unclear.1 Lysosomal plays a vital role in digesting and recycling macromolecules,and several studies have shown that lysosomal acidification and autophagy decrease with age,which may impair the clearance of damaged mitochondria.

关键词： skeletal function spite

Highly Aligned Graphene Aerogels for Multifunctional Composites

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Nano-Micro Letters 2024年第6期16卷 276-342页

作者： Ying Wu Chao An Yaru Guo Yangyang Zong Naisheng Jiang Qingbin zheng Zhong‑zhen yu Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004People’s Republic of China School of Science and Engineering The Chinese University of Hong KongShenzhenShenzhenGuangdong 518172People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

Stemming from the unique in-plane honeycomb lattice structure and the sp^(2)hybridized carbon atoms bonded by exceptionally strong carbon–carbon bonds,graphene exhibits remarkable anisotropic electrical,mechanical,and thermal *** maximize the utilization of graphene’s in-plane properties,pre-constructed and aligned structures,such as oriented aerogels,films,and fibers,have been *** unique combination of aligned structure,high surface area,excellent electrical conductivity,mechanical stability,thermal conductivity,and porous nature of highly aligned graphene aerogels allows for tailored and enhanced performance in specific directions,enabling advancements in diverse *** review provides a comprehensive overview of recent advances in highly aligned graphene aerogels and their *** highlights the fabrication methods of aligned graphene aerogels and the optimization of alignment which can be estimated both qualitatively and *** oriented scaffolds endow graphene aerogels and their composites with anisotropic properties,showing enhanced electrical,mechanical,and thermal properties along the alignment at the sacrifice of the perpendicular *** review showcases remarkable properties and applications of aligned graphene aerogels and their composites,such as their suitability for electronics,environmental applications,thermal management,and energy *** and potential opportunities are proposed to offer new insights into prospects of this material.

关键词： Highly aligned graphene aerogels Quantitative characterization of alignment Multifunctional composites Anisotropic properties Multifunctional applications

Patient-derived induced pluripotent stem cells with a MERTK mutation exhibit cell junction abnormalities and aberrant cellular differentiation potential

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World Journal of Stem Cells 2024年第5期16卷 512-524页

作者： Hang Zhang Ling-Zi Wu zhen-yu Liu Zi-Bing Jin Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing 100730China

BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease ***,iPSCs carrying specific mutations may limit their clinical applications due to certain inherent *** To investigate the impact of MERTK mutations on hiPSCs and determine whether hiPSC-derived extracellular vesicles(EVs)influence anomalous cell junction and differentiation *** We employed a non-integrating reprogramming technique to generate peripheral blood-derived hiPSCs with and hiPSCs without a MERTK ***-somal karyotype analysis,flow cytometry,and immunofluorescent staining were utilized for hiPSC *** and proteomics were employed to elucidate the expression patterns associated with cell junction abnormalities and cellular differentiation ***,EVs were isolated from the supernatant,and their RNA and protein cargos were examined to investigate the involvement of hiPSC-derived EVs in stem cell junction and *** The generated hiPSCs,both with and without a MERTK mutation,exhibited normal karyotype and expressed pluripotency markers;however,hiPSCs with a MERTK mutation demonstrated anomalous adhesion capability and differentiation potential,as confirmed by transcriptomic and proteomic ***,hiPSC-derived EVs were involved in various biological processes,including cell junction and *** HiPSCs with a MERTK mutation displayed altered junction characteristics and aberrant differentiation ***,hiPSC-derived EVs played a regulatory role in various biological processes,including cell junction and differentiation.

关键词： Cell junction Cellular differentiation Extracellular vesicle Human induced pluripotent stem cells Transcriptomics Proteomics