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Physics of cavitation near particles

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Journal of Hydrodynamics 2024年第1期36卷 102-118页

作者： Jia-xin Yu Xiao-yu Wang Jun-wei Shen Jin-sen Hu Xiang-qing Zhang Da-qing he Yu-ning Zhang Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China

The combined effect of cavitation and silt abrasion presents a great challenge and threat to secure the operation and the efficiency of hydraulic machineries working in sediment-laden *** present paper critically reviews the current research progress on the interaction mechanisms of the bubbles and the ***,the analytical models including boundary treatment methods for predicting the jet dynamics of the bubble collapse near particles are ***,the bubble collapsing dynamics,jet dynamics and shock wave characteristics near particles are revealed both experimentally and ***,the bubble-particle-wall system is investigated with a focus on microjets.

关键词： Cavitation bubble particle jet shock wave

Relaxor antiferroelectric-relaxor ferroelectric crossover in NaNbO_(3)-based lead-free ceramics for high-efficiency large-capacitive energy storage

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Chinese Chemical Letters 2024年第7期35卷 465-469页

作者： Shuangliang Xie Yuyue Chen qing he Liang Chen Jikun Yang Shiqing Deng Yimei Zhu he Qi School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering Department of Physical ChemistryUniversity of Science and Technology BeijingBeijing 100083China School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China Department of Condensed Matter Physics and Materials Science Brookhaven National LaboratoryUptonNew York 11973United States

Relaxor ferroic dielectrics have garnered increasing attention in the past decade as promising materials for energy *** them,relaxor antiferroelectrics(AFEs)and relaxor ferroelectrics(FEs)have shown great promise in term of high energy storage density and efficiency,*** this study,a unique phase transition from relaxor AFE to relaxor FE was achieved for the first time by introducing strong-ferroelectricity BaTiO_(3)into NaNbO_(3)-BiFeO_(3)system,leading to an evolution from AFE R hierarchical nanodomains to FE polar nanoregions.A novel medium state,consisting of relaxor AFE and relaxor FE,was identified in the crossover of 0.88NaNbO_(3)–0.07BiFeO_(3)–0.05BaTiO_(3)ceramic,exhibiting a distinctive core-shell grain structure due to the composition *** harnessing the advantages of high energy storage density from relaxor AFE and large efficiency from relaxor FE,the ceramic showcased excellent overall energy storage *** achieved a substantial recoverable energy storage density W_(rec)~13.1 J/cm^(3)and an ultrahigh efficiencyη~88.9%.These remarkable values shattered the trade-off relationship typically observed in most dielectric capacitors between W_(rec)andη.The findings of this study provide valuable insights for the design of ceramic capacitors with enhanced performance,specifically targeting the development of next generation pulse power devices.

关键词： Relaxor ferroelectric Antiferroelectric Core-shell Energy storage High efficiency

Accurate Shortwave Radiation Simulation with a Two-Layer Aerosol Model in Xinjiang Region

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Journal of Meteorological Research 2024年第1期38卷 69-87页

作者： Guan HUANG Yonghang CheN Qiong LIU Pengtao WANG Qianshan he qing he Shuai LI Weiling SHAO Ting FAN School of Tourism&Research Institute of Human Geography Xi’an International Studies UniversityXi’an 710128 Center for Silk Road and Eurasian Civilization Studies Xi’an International Studies UniversityXi’an 710128 College of Environmental Science and Engineering Donghua UniversityShanghai 201620 Shanghai Meteorological Service Shanghai 200030 Shanghai Key Laboratory of Meteorology and health Shanghai 200030 Taklimakan Desert Meteorology Field Experiment Station of China Meteorological Administration Institute of Desert MeteorologyUrumqi 830002 Xinjiang Climate Centre Xinjiang Meteorological ServiceUrumqi 830002

To harness the rich solar energy resources in Xinjiang Region of Northwest China,this study tries to address the issue of lack of downward surface shortwave radiation(DSSR)observations and the need to improve the accuracy of satellite retrieval and numerical simulation of DSSR under varied sky and meteorological conditions.(1)A two-layer aerosol model specific to Xinjiang was developed to capture the vertical distributions of aerosols based on multiple data sources including lidar,GPS sounding,ground meteorological observations,and profiles from the ECMWF reanalysis version 5(ERA5)*** results show that the ERA5/PBLH(planetary boundary layer height)and ERA5/ALH(aerosol layer height)could be used to establish the two-layer aerosol model and characterize the vertical distribution of aerosols in Xinjiang Region.(2)Using the Santa Barbara Discrete Atmospheric Radiative Transfer(SBDART)model,a localized inverse model of clear-sky DSSR was *** parameter adjustment and using the optimal combination of input parameters for DSSR simulation together with the two-layer aerosol model,the model-simulated DSSR(DSSRSBD)under clear-sky conditions improved significantly compared to the initial results,with all fitting indices greatly improved.(3)In addition,the study demonstrated that the impact of the two-layer aerosol model on DSSR was more pronounced under dust conditions than clear-sky conditions.(4)Using the localized clear-sky DSSR inversion model and its required parameters,simulations were also conducted to capture the spatiotemporal distribution of DSSR under clear-sky conditions in Xinjiang from 2017 to *** annual average DSSR_(SBD)under clear-sky conditions in Xinjiang during 2017–2019 was 606.78 W m^(-2),while DSSR from CERES(DSSR_(CER))under the same conditions was generally higher(703.95 W m^(-2)).(5)It is found that satellite remote sensing products experienced data loss in high-altitude snow areas,where numerical simulation technology could ser

关键词： downward surface shortwave radiation(DSSR) aerosol vertical distribution Clouds and the Earth’s Radiant Energy System(CERES) Santa Barbara Discrete Atmospheric Radiative Transfer(SBDART) Xinjiang

Microstructural evolution,mechanical properties and degradation mechanism of PS-PVD quasi-columnar thermal barrier coatings exposed to glassy CMAS deposits

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Rare Metals 2024年第7期43卷 3329-3340页

作者： Zi-Yue Yu Liang-Liang Wei Xing-Ye Guo Bao-Peng Zhang qing he Hong-Bo Guo School of Materials Science and Engineering Beihang UniversityBeijing100191China Key Laboratory of High-Temperature Structure Materials and Protective Coatings(Ministry of Industry and Information Technology) Beihang UniversityBeijing 100191China Surface Engineering Research Institute Chinese Academy of Agricultural Mechanization SciencesBeijing 100083China

Thermal barrier coatings(TBCs) applied in aeroengines tend to be attacked by molten calcia-magnesiaalumino-silicate(CMAS) at high operating ***-stabilized zirconia(YSZ) coatings with quasicolumnar microstructure were fabricated by plasma spray physical vapor deposition(PS-PVD) *** chemic al changes,micros tructural transform ation,mechanical properties and degradation mechanisms of the CM AS-interacted TBCs in the thermal cycling tests were *** YSZ grains were dissolved in the CMAS melts,and then the ZrO_(2) grains were reprecipitated with spherical shape,accompanying with phase transformation from tetragonal(t) to monoclinic(m).The thermal cycling tests reveal that the YSZ coating fails at the early stage due to the attack of *** fractures in intracolumns lead to partial spallation of the *** failure of the coating occurs at the interfaces between thermally grown oxides(TGO) layer and YSZ topcoat;especially,the hardness and Young's modulus of the YSZ coatings increase intensively,as the coatings were infiltrated by the CMAS for a long time.

关键词： CMAS Thermal barrier coatings Young's modulus Thermal cycling behavior PS-PVD

Model Checking Computation Tree Logic over Multi-Valued Decision Processes and Its Reduction Techniques

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Chinese Journal of Electronics 2024年

作者： Wuniu LIU Junmei WANG qing he Yongming LI The School of Mathematics and Statistics Shaanxi Normal University The School of Computer Science Shaanxi Normal University

Model checking computation tree logic(CTL) based on multi-valued possibility measures has been studied by Li et al. in 2019. However, the previous work did not consider the nondeterministic choices inherent in systems represented by multi-valued Kripke structures(MvKSs). This nondeterminism is crucial for accurate system modeling, decision making, and control capabilities. To address this limitation, we draw inspiration from the generalization of Markov chains(MCs) to Markov decision processes(MDPs) in probabilistic systems. By integrating nondeterminism into MvKS, we introduce multi-valued decision processes(MvDPs) as a framework for modeling MvKSs with nondeterministic choices. We investigate the challenges of model checking over MvDPs. Verifying properties are expressed by using multi-valued computation tree logic(MvCTL) based on schedulers. Our primary objective is to leverage fixpoint techniques to determine the maximum and minimum possibilities of the system satisfying temporal properties. This allows us to identify the optimal or worst-case schedulers for decision making or control *** aim to develop reduction techniques that enhance the efficiency of model checking, thereby reducing the associated time complexity.

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Meromorphic Solutions to Higher Order Nonlinear Delay Differential Equations

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Acta Mathematicae Applicatae Sinica 2024年

作者： Ye-zhou LI Ming-yue WU he-qing SUN School of Science Beijing University of Posts and Telecommunications Key Laboratory of Mathematics and Information Networks (Beijing University of Posts and Telecommunications) Ministry of Education Beijing University of Posts and Telecommunications

Let w（z） be non-rational meromorphic solutions with hyper-order less than 1 to a family of higher order nonlinear delay differential equations w（z+1）w（z-1）+a（z）w（k）（z）/w（z）=R(z,w（z）),k∈N+,where a（z） is rational,R(z,w（z）)=P(z,w（z）)/Q(z,w（z）) is an irreducible rational function in w with rational coefficients in *** paper mainly show the relationships of the degree of P(z,w（z）) and Q(z,w（z）) when the above equations exist such solutions w（z）.There are also some examples to show that our results are sharp.

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An Outbreak of Serogroup Y Meningococcal Meningitis in a Private Secondary Vocational School-Guangzhou City,Guangdong Province,China,2023

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China CDC weekly 2024年第12期6卷 242-246,I0005页

作者： Xiang Zeng qing he Yilan Li Yong Zhou Xiaoping Shao Pei Hu Jian Liang Yudan Song Chao Ma Lijie Zhang Limei Sun Lei Luo Chinese Field Epidemiology Training Program Chinese Center for Disease Control and PreventionBeijingChina Zhuhai Center for Disease Control and Prevention Zhuhai CityGuangdong ProvinceChina Guangdong Center for Disease Control and Prevention Guangzhou CityGuangdong ProvinceChina Guangzhou Center for Disease Control and Prevention Guangzhou CityGuangdong ProvinceChina Institute of Public health Guangzhou Medical University&Guangzhou Center for Disease Control and PreventionGuangzhou CityGuangdong ProvinceChina Department of the National Immunization Programme Chinese Center for Disease Control and PreventionBeijingChina

What is already known about this topic?The inclusion of meningococcal vaccines in the National Immunization Program(NIP)over several years has significantly reduced the incidence of meningococcal meningitis in China to historic ***,there has been a diversification of meningococcal serogroups,leading to a shift in dominant serogroups in China from serogroup A to serogroups C and B,accompanied by a rise in reports of serogroups Y and *** is added by this report?An outbreak of serogroup Y Neisseria meningitidis(Nm)in a secondary vocational school involved a single confirmed severe case and 24 individuals with laboratory-confirmed Nm *** investigation revealed that the outbreak was localized to the classroom of the confirmed *** close contact within a confined space was identified as a significant risk factor for Nm *** genotype sequence identified was type 1655(ST-1655),which is categorized under clonal complex 23(CC-23)and bears resemblance to 8 previously confirmed cases of serogroup Y meningococcal meningitis within Guangdong *** suggests that serogroup Y infections continue to sporadically emerge and have become prevalent *** are the implications for public health practice?This outbreak underscores the critical need to enhance surveillance of meningococcal serogroups and population carrier,and advocate for vaccination with MenY-containing vaccines.

关键词： break Secondary Guangdong

Lymphovenous anastomosis and complex decongestive therapy for severe deformed lymphedema with recurrent infection:A case report

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World Journal of Clinical Cases 2024年第22期12卷 5159-5167页

作者： he-Jun Wang qing-qing he Chang-Rui Liu Ying-Ying Wang Xun-Wei Liu Department of Thyroid and Breast Surgery The 960th Hospital of People’s Liberation ArmyJinan 250000Shandong ProvinceChina Department of Oncology The 960th Hospital of People’s Liberation ArmyJinan 250000Shandong ProvinceChina

BACKGROUND Lower extremity lymphedema is a common complication following treatment for gynecological *** incidence rate can reach up to 70%,affecting~20 million people ***,specialized treatment centers are scarce,and there is a lack of consensus on treatment ***,there are even fewer reports on the systematic and effective treatment of severe lymphedema with *** management of this condition remains a significant challenge for *** SUMMARY A 40-year-old woman developed bilateral leg swelling 6 years after receiving treatment for endometrial *** August 2018,she experienced>30 episodes of *** presentation,she exhibited bilateral leg swelling and deformation,with four large swellings in the posterior thigh that impeded movement,and pain in the *** manifestations included lichenoid lesions and features of deep *** lymphoscintigraphy confirmed the diagnosis of lower limb *** 6 mo of complex decongestive therapy(CDT)and three lymphaticovenous anastomosis(LVA)treatments,the patient lost 49 kg in *** also experienced a maximum circumference reduction of 35.2 cm in the left lower limb and 37.5 cm in the right lower *** leg pain disappeared,her swelling significantly decreased,and she regained the ability to walk,cycle,and run *** The combined application of CDT and LVA therapy demonstrates significant positive effects in the treatment of severe,deformed stage III lymphedema.

关键词： Lower extremity lymphedema Endometrial cancer Lymphaticovenous anastomosis Complex decongestive therapy Gynecological malignancies Recurrent infection Case report

Characteristic changes in astrocyte properties during astrocyte-to-neuron conversion induced by NeuroD1/Ascl1/Dlx2

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Neural Regeneration Research 2025年第6期20卷 1801-1815页

作者： qing he Zhen Wang Yuchen Wang Mengjie Zhu Zhile Liang Kanghong Zhang Yuge Xu Gong Chen GHM Institute of CNS Regeneration Jinan UniversityGuangzhouGuangdong ProvinceChina

Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.

关键词： aquaporin-4 Ascl1 astrocyte cortex Dlx2 gap junction glia-to-neuron conversion neural regeneration NeuroD1 reprogramming