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Influence of Nd^(3+) concentration on mid-infrared emission in PbF_(2. crystal co-doped with Ho^(3+) and Nd^(3+) ions

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Journal of Rare Earths 2024年第3期42卷 479-487,I0002页

作者： Yan chen Juncheng Tan Peixiong {2. Weibi Zheng lin li lianhan {2. Zhen li Yin Hang Zhenqiang chen department of Optoelectronic Engineering Jinan UniversityGuangzhou510632China Guangdong Provincial Engineering Research Centerof Crystal and Laser Technology.Guangzhou 510632China Research Center of Laser Crystal Key Laboratory of High Power Laser MaterialsShanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai201800China

A promising series of Ho_(y)Nd_(x)Pb_((1-x-y))F_2.x = 0, 0.01, 0.02. 0.03, 0.04;y = 0.02. crystals was grown by the Bridgman method. The influence of the Nd^(3+)ions concentration on mid-infrared(~2.0, ~2.9 and ~3.9 μm)fluorescence emissions of Ho^(3+)ions in the PbF_(2. crystal excited by 808 nm laser diode was investigated in this work. The energy transfer mechanism between Nd^(3+)ions and Ho~(3+)ions under different concentrations of the Nd^(3+)ions was systematically analyzed. The results show that the Nd^(3+)ions have good sensitization and deactivation effect on the Ho^(3+)ions to stimulate the mid-infrared fluorescence emissions. The experimental analysis proves that the sensitization efficiency of the Nd^(3+)ions is relatively stable at around 93.45% with varying Nd^(3+)-doping concentrations. Concentration dependence studies indicate that the concentration of the Nd^(3+)ions has significant influence on mid-infrared *** the doping concentration of the Nd^(3+)ions is up to 2.0 at%, the intensity of ~2.0, ~2.9 and ~3.9 μm emissions all reach the maximum. The output characteristics of a 3.9 μm laser are simulated, and it is found that with the increase of the Nd^(3+)-doping concentration, the peak power, pulse width, and peak energy all meet the trend of first increasing and then decreasing, and Ho_(0.02.Nd_(0.02.Pb_(0.96)F_(2. crystal displays the best performance. All the results show that the Nd^(3+)/Ho^(3+)co-doped PbF_(2. crystals might act as a useful optical medium for mid-infrared laser applications.

关键词： Crystal growth Mid-infrared PbF_(2. Rare earth ions

Simulation of nuclei morphologies for binary alloy

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Science China mathematics 2010年第11期53卷 2927-2936页

作者： li DaMing1, & zhang PingWen2.1{2. of {2., shanghai jiaotong university, shanghai 2.02.0, China 2.ey Lab of {2. and Applied {2., Center for Applied Physics and Technology and School of Mathematical Sciences, Peking university, Beijing 100871, China 1. department of mathematics Shanghai Jiaotong University Shanghai 200240 China2. Key Lab of Mathematics and Applied Mathematics Center for Applied Physics and Technology and School of Mathematical Sciences Peking University Beijing 100871 China

We study the critical nuclei morphologies of a binary alloy by the string method. The dynamic equation of the string, connecting the metastable phase (liquid) and stable phase (solid), is governed by Helmholtz free energy for the binary alloy system at a given temperature. The stationary string through the critical nucleus (saddle point) is obtained if the relaxation time of the string is su?ciently large. The critical nucleus radius and energy barrier to nucleation of a pure alloy with isotropic interface energy in two and three dimensions are calculated, which are consistent with the classical nucleation theory. The critical nuclei morphologies are sensitive to the anisotropy strength of interface energy and interface thickness of alloy in two and three dimensions. The critical nucleus and energy barrier to nucleation become smaller if the anisotropy strength of the interface energy is increased, which means that it is much easier to form a stable nucleus if the anisotropy of the interface energy is considered.

关键词： nucleation crystal morphology string method

Anisotropic phonon dynamics in Dirac semimetal PtTe2.thin films enabled by helicity-dependent ultrafast light excitation

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light(Science & Applications) 2024年第9期13卷 1888-1897页

作者： Ziyang li Yequan chen Anke Song Jinzhong {2. Rong {2. Zongzhi {2. Xuefeng Wang Key Laboratory of Micro and Nano Photonic Structures(MOE) School of Information Science and TechnologyFudan UniversityShanghaiChina Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials State Key Laboratory of Spintronics Devices and TechnologiesSchool of Electronic Science and EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjingChina department of Physics School of Physics and Electronic ScienceEast China Normal UniversityShanghaiChina department of Physics Xiamen UniversityXiamenChina

Coherent phonons have aroused considerable attention in condensed matter physics owing to their extraordinary capacity of reflecting and controlling the physical properties of ***,the investigation on the interaction between coherent phonons and other microscopic particles on the ultrafast timescale within topological systems continues to be an active and unresolved ***,we show the energy transfer of coherent optical phonons(COP)in Dirac semimetal PtTe2.thin films using ultrafast optical pump-probe ***,the helicitydependent light-driven anisotropic COP signals disclose their direct connection with the light-excited anisotropic spinpolarized electrons via an angular momentum ***,we observe the notable decreases in the COP oscillation frequency and the decay rate with increasing temperatures due to the anharmonic phonon-phonon scattering and electron-phonon scattering in the COP dissipation process,*** work paves the way for uncovering the coherent phonons in Dirac semimetals for the potential applications in optoelectronics and optospintronics.

关键词： spectroscopy. phonon Dirac

SEMI-DEFINITE RELAXATION ALGORITHM FOR SINGLE MACHINE SCHEDUliNG WITH CONTROLLABLE PROCESSING TIMES

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Chinese Annals of mathematics,Series B 2005年第1期26卷 153-158页

作者： chenFENG zhang{2.ANSHENG departmentofmathematics ShanghaiUniversityShanghai200436China／／DepartmentofIndustrialEngineeringandManagementShanghaiJiaotongUniversityShanghai200030China. departmentofmathematics ShanghaiUniversityShanghai200436China

The authors present a semi-definite relaxation algorithm for the scheduling problem with controllable times on a single machine. Their approach shows how to relate this problem with the maximum vertex-cover problem with kernel constraints (MKVC).The established relationship enables to transfer the approximate solutions of MKVCinto the approximate solutions for the scheduling problem. Then, they show how to obtain an integer approximate solution for MKVC based on the semi-definite relaxation and randomized rounding technique.

关键词： Scheduling with controllable times Semi-definite programming Approximation algorithm

A universal non-Hermitian platform for bound state in the continuum enhanced wireless power transfer

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Frontiers of physics 2024年第4期19卷 37-46页

作者： Haiyan zhang Zhiwei Guo Yunhui li Yaping Yang Yuguang {2. Hong {2. School of Physics Science and Engineering Tongji UniversityShanghai 200092China department of Electrical Engineering Tongji UniversityShanghai 201804China

Non-Hermitian systems with parity–time(PT)-symmetry have been extensively studied and rapidly developed in resonance wireless power transfer(WPT).The WPT system that satisfies PT-symmetry always has real eigenvalues,which promote efficient energy ***,meeting the condition of PT-symmetry is one of the most puzzling *** power transfer under different transmission conditions is also a great *** state in the continuum(BIC)supporting extreme quality-factor mode provides an opportunity for efficient ***,we propose theoretically and demonstrate experimentally that BIC widely exists in resonance-coupled systems without PT-symmetry,and it can even realize more stable and efficient power transfer than PT-symmetric ***,BIC for efficient WPT is universal and suitable in standard second-order and even high-order WPT *** results not only extend non-Hermitian physics beyond PT-symmetry,but also bridge the gap between BIC and practical application engineering,such as highperformance WPT,wireless sensing and communications.

关键词： non-Hermitian physics parity-time asymmetry bound state in the continuum wireless power transfer

Large contributions of emission reductions and meteorological conditions to the abatement of PM_(2.5)in Beijing during the 2.th Winter Olympic Games in 2.2.

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Journal of Environmental Sciences 2024年第2期136卷 172-188页

作者： Yaping Jiang Shaocai Yu Xue chen Yibo zhang Mengying {2. Zhen {2. Zhe Song Pengfei {2. Xiaoye zhang Eric {2.chtfouse Daniel Rosenfeld Key Laboratory of Environmental Remediation and Ecological Health Ministry of EducationResearch Center for Air Pollution and HealthCollege of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China College of Science and Technology Hebei Agricultural UniversityBaoding 071000China Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081China Aix-Marseille Univ CNRSColl FranceCNRSIRDINRAEEuropole Mediterraneen de l’ArboisAvenue Louis Philibert13100 Aix en ProvenceFrance Xi’an jiaotong university State Key Laboratory of Multiphase Flow in Power EngineeringXi’an 710049China Institute of Earth Sciences The Hebrew University of JerusalemJerusalemIsrael

To guarantee the blue skies for the 2.2. Winter Olympics held in Beijing and zhangjiakou from February 4 to 2.,Beijing and its surrounding areas adopted a series of emission control *** provides an opportunity to determine the impacts of large-scale temporary control measures on the air quality in Beijing during this special ***,we applied the WRF-CMAQ model to quantify the contributions of emission reduction measures and meteorological *** show that meteorological conditions in 2.2. decreased PM_(2.5)in Beijing by 6.9 and 11.8μg/m^(3)relative to 2.2. under the scenarios with and without emission reductions,*** emission reduction measures implemented in Beijing and seven neighboring provinces resulted in an average decrease of 13.0μg/m^(3)(-41.2.)in PM_(2.5)in *** the entire period,local emission reductions contributed more to good air quality in Beijing than nonlocal emission *** the emission reduction scenario,local,controlled regions,other regions,and boundary conditions contributed 47.7%,42.0%,5.3%,and 5.0%to the PM_(2.5)concentrations in Beijing,*** results indicate that during the cleaning period with the air masses from the northwest,the abatements of PM_(2.5)were mainly caused by local emission ***,during the potential pollution period with the air masses from the east-northeast and west-southwest,the abatements of PM_(2.5)were caused by both local and nonlocal emission reductions almost *** implies that regional coordinated prevention and control strategies need to be arranged scientifically and rationally when heavy pollution events are forecasted.

关键词： PM_(2.5) WRF-CMAQ Meteorological conditions Emission reductions Winter Olympic games

Tissue adhesive,ROS scavenging and injectable PRP-based‘plasticine’for promoting cartilage repair

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Regenerative Biomaterials 2024年第1期3卷 94-107页

作者： Shiao li Dawei Niu Haowei Fang Yancheng chen Jinyan li Kunxi {2. Jingbo Yin Peiliang Fu department of Orthopedics Shanghai Changzheng HospitalNaval Medical UniversityShanghai 200003P.R.China department of Polymer Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444P.R.China

Platelet-rich plasma(PRP)that has various growth factors has been used clinically in cartilage ***,the short residence time and release time at the injury site limit its therapeutic *** present study fabricated a granular hydrogel that was assembled from gelatin microspheres and tannic acid through their abundant hydrogen *** microspheres with the gelatin concentration of 10wt%and the diameter distribution of 1-10 lm were used to assemble by tannic acid to form the granular hydrogel,which exhibited elasticity under low shear strain,but flowability under higher shear *** viscosity decreased with the increase in shear ***,the granular hydrogel exhibited self-healing feature during rheology ***,granular hydrogel carrying PRP not only exhibited well-performed injectability but also performed like a‘plasticine’that possessed good *** granular hydrogel showed tissue adhesion ability and reactive oxygen species scavenging *** hydrogel carrying PRP transplanted to full-thickness articular cartilage defects could integrate well with native cartilage,resulting in newly formed cartilage articular fully filled in defects and well-integrated with the native cartilage and subchondral *** unique features of the present granular hydrogel,including injectability,plasticity,porous structure,tissue adhesion and reactive oxygen species scavenging provided an ideal PRP carrier toward cartilage tissue engineering.

关键词： cartilage regeneration granular hydrogel gelatin tannic acid PRP

The molecular genetics of PI3K/PTEN/AKT/mTOR pathway in the malformations of cortical development

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Genes & Diseases 2024年第5期11卷 252-271页

作者： Qing Ma Guang chen Ying li Zhenming Guo Xue {2. NHC and CAMS Key Laboratory of Molecular Probe and Targeted Theranostics Harbin Medical UniversityHarbinHeilongjiang 150000China department of Urology The Fourth Hospital of Harbin Medical UniversityHarbinHeilongjiang 150000China department of Child and Adolescent Health School of Public HealthHarbin Medical UniversityHarbinHeilongjiang 150000China Institute for Regenerative Medicine Shanghai East HospitalFrontier Science Center for Stem Cell ResearchSchool of Life Sciences and TechnologyTongji UniversityShanghai 200120China

Malformations of cortical development(MCD)are a group of developmental disorders characterized by abnormal cortical structures caused by genetic or harmful environmental *** kinds of MCD are caused by genetic *** is the common cause of intellectual disability and intractable *** rapid advances in imaging and sequencing technologies,the diagnostic rate of MCD has been increasing,and many potential genes causing MCD have been successively ***,the high genetic heterogeneity of MCD makes it challenging to understand the molecular pathogenesis of MCD and to identify effective targeted ***,in this review,we outline important events of cortical *** we illustrate the progress of molecular genetic studies about MCD focusing on the PI3K/PTEN/AKT/mTOR ***,we briefly discuss the diagnostic methods,disease models,and therapeutic strategies for *** information will facilitate further research on *** the role of the PI3K/PTEN/AKT/mTOR pathway in MCD could lead to a novel strategy for treating MCD-related diseases.

关键词： Epilepsy Gene mutation Genetics Malformations of cortical development PI3K/PTEN/AKT/mTOR pathway

A personalized electronic textile for ultrasensitive pressure sensing enabled by biocompatible MXene/ PEDOT:PSS composite

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Carbon Energy 2024年第3期6卷 224-238页

作者： Yahua li Wentao Cao Zhi liu Yue {2. Ziyan chen Xianhong Zheng department of Interventional Radiology The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenanChina School of Textile and Garment Anhui Polytechnic UniversityWuhuAnhuiChina department of Prosthodontics Shanghai Stomatological Hospital and School of StomatologyFudan UniversityShanghaiChina College of Chemistry Chemical Engineering and BiotechnologyDonghua UniversityShanghaiChina

Flexible,breathable,and highly sensitive pressure sensors have increasingly become a focal point of interest due to their pivotal role in healthcare monitoring,advanced electronic skin applications,and disease ***,traditional methods,involving elastomer film-based substrates or encapsulation techniques,often fall short due to mechanical mismatches,discomfort,lack of breathability,and limitations in sensing ***,there is a pressing need,yet it remains a significant challenge to create pressure sensors that are not only highly breathable,flexible,and comfortable but also sensitive,durable,and ***,we present a biocompatible and breathable fabric-based pressure sensor,using nonwoven fabrics as both the sensing electrode(coated with MXene/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate[PEDOT:PSS])and the interdigitated electrode(printed with MXene pattern)via a scalable spray-coating and screen-coating *** resultant device exhibits commendable air permeability,biocompatibility,and pressure sensing performance,including a remarkable sensitivity(754.5 kPa^(−1)),rapid response/recovery time(180/110 ms),and robust cycling ***,the integration of PEDOT:PSS plays a crucial role in protecting the MXene nanosheets from oxidation,significantly enhancing the device's long-term *** outstanding features make this sensor highly suitable for applications in fullrange human activities detection and disease *** study underscores the promising future of flexible pressure sensors in the realm of intelligent wearable electronics,setting a new benchmark for the industry.

关键词： biocompatibility MXene pressure sensor screen printing textile