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First-principles study on persistent luminescence mechanism of LiYGeO_(4):Eu^(3+)

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Journal of Rare Earths 2023年第10期41卷 1519-1524,I0002页

作者： Shihang Zhou Bibo Lou chong-Geng ma Min Yin Xinjiang Key Laboratory for Luminescence Minerals and Optical Functional materials School of Physics and Electronic EngineeringXinjiang Normal UniversityUrumqi830054China CAS Key Laboratory of Strongly-Coupled Quantum matter Physics and School of Physical SciencesUniversity of Science and Technology of ChinaHefei230026China School of Optoelectronic Engineering&CQUPT-BUL Innovation Institute Chongqing University of Posts and TelecommunicationsChongqing400065China

LiYGeO_(4):Eu^(3+)is a red persistent luminescent material with a duration of more than 21 *** its persistent luminescence phenomenon has been fully studied,its detailed mechanism is still the subject of ***,we performed first-principles study on the intrinsic point defects and the charge transfer processes in LiYGeO_(4):Eu^(3+)to reveal the mechanism of persistent *** results show that,under charge transfer excitation,the electron is promoted from the valence band(oxygen ion ligand)to the central Eu^(3+)ion to form Eu^(2+)ion in LiYGeO_(4):Eu^(3+),leaving a hole *** charge transfer excitation can relax quickly to the excited state of the Eu^(3+)ion,which produces the characteristic^(5)D_(0)→^(7)F_(J)(J=0-6)*** Li vacancies(V_(Li))and the antisite defects of Li replacing Y site(Li_(Y))and Y replacing Li site(YLi)are main defects,while O vacancies(V_(O))are less important in concentration due to high formation *** and Liy can serve as hole-type traps,with the trap depths suitable for trapping the holes produced by *** delayed release holes can combine with the Eu^(2+)left behind by the illumination,leading to persistent *** VLi trap is shallower than Li_(Y),and the latter is responsible for the long duration of persistent luminescence.A schematic based on the calculation results is constructed to illustrate the mechanism of persistent luminescence.

关键词： Persistent Iuminescence Eu^(3+) Charge transfer Point defects First-principles Rare earths

A new shear rheological model for a soft interlayer with varying water content

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Water Science and Engineering 2018年第2期11卷 131-138页

作者： chong ma Hong-bin Zhan Wen-min Yao Hua-zhou Li School of mathematics and Physics China University of Geosciences Faculty of Engineering China University of Geosciences Department of Geology and Geophysics Texas A&M University College Station

The rheological behavior of a soft interlayer is critical to understanding slope stability, which is closely related to the water content of the soft interlayer. This study used the soft interlayer of the Permian maokou Formation in Southwest China as an example to perform ring shear creep tests with different water content amounts. The effect of water content on the creep properties of the soft interlayer was analyzed, and a new shear rheological model was established. This research produced several findings. First, the ring shear creep deformation of the soft interlayer samples varied with the water content and the maximum instantaneous shear strain increment occurred near the saturated water content. As the water content increased, the cumulative creep increment of the samples increased. Second, the water content significantly affected the long-term strength of the soft interlayer, which decreased with the increase of water content, exhibiting a negative linear correlation. Third, a constitutive equation for the new rheological model was derived, and through fitting of the ring shear creep test data, the validity and applicability of the constitutive equation were proven. This study has developed an important foundation for studying the long-term deformation characteristics of a soft interlayer with varying water content.

关键词： Soft interlayer Ring shear creep test Rheological constitutive model Water content

Interfacial Properties Modification of Carbon Fiber/Polyarylacetylene Composites

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Chinese Journal of Aeronautics 2007年第2期20卷 124-128页

作者： FU Hong-jun ma chong-qi KUANG Nai-hang LUAN Shi-lin School of Textile Tianjin Polytechnic University Tianjin 300160 China Harbin FRP Institute Harbin 150001 China

This work was dedicated to performing surface oxidation and coating treatments on carbon fibers （CF） and investigating the changes of fiber surface properties after these treatments, including surface composition, relative volume of functional groups, and surface topography with X-ray photoelectron spectroscopy （XPS） and atom force microscopy （AFM） technology. The results show that, after oxidation treatments, interfacial properties between CF and non-polar polyarylacetylene （PAA） resin are remarkably modified by removing weak surface layers and increasing fiber surface roughness. Coating treatment by high char phenolic resin solution after oxidation makes interface of CF/PAA composites to be upgraded and the interfacial properties further bettered.

关键词： composites carbon fiber polyarylacetylene interface

Bright and tunable emissive monodisperse CsPbI3@Cs4PbI6 nanocomposites via a precise and controllable dissolution−recrystallization method

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Nano Research 2023年第1期16卷 1586-1594页

作者： Luyu Cao Bomei Liu Lin Huang Zhi Zhou chong-Geng ma Jian Zhang Jing Wang Ministry of Education Key Laboratory of Bioinorganic and Synthetic Chemistry State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of ChemistrySun Yat-Sen UniversityGuangzhou 510275China School of materials Science and Engineering Sun Yat-Sen UniversityGuangzhou 510275China College of Science Hunan Optical Agriculture Engineering Technology Research CenterHunan Agricultural UniversityChangsha 410128China CQUPT-BUL Innovation Institute Chongqing University of Posts and TelecommunicationsChongqing 400065China Engineering Research Center of Electronic Information materials and Devices(Ministry of Education) Guangxi Key Laboratory of Information MaterialsGuangxi Collaborative Innovation Center of Structure and Property for New Energy and MaterialsSchool of Materials Science and EngineeringGuilin University of Electronic TechnologyGuilin 541004China

Nowadays,due to uncontrolled synthesis and lack of more direct and systematic evidences,the photoluminescence origin of“zero-dimensional”Cs4PbI6 remains great controversy and the luminescence cannot be *** we propose a controllable dissolution-recrystallization method to synthesize“emissive”and“non-emissive”Cs4PbI6 nanocrystals(NCs)*** comparing“emissive”and“non-emissive”Cs4PbI6 NCs,it is clearly proved that the visible emission in“emissive”Cs4PbI6 NCs comes from embedded CsPbI3 quantum dots(QDs).It is found for CsPbI3@Cs4PbI6 nanocomposites,methyl acetate(MeAC)and cyclohexane play an important role in dissolution and recrystallization respectively to obtain Cs4PbI6 matrix and CsPbI3 *** from this two-step method,the as-synthesized CsPbI3@Cs4PbI6 nanocomposites with CsPbI3 QDs uniformly distributed in Cs4PbI6 matrix are bright with photoluminescence quantum yield(PLQY)up to 71.4%and exhibit improved stability than CsPbI3 ***,utilizing its formation mechanism,the size of embedded CsPbI3 QDs can be controlled by reasonable designing the“dissolution”process,so that the luminescence of this CsPbI3@Cs4PbI6 nanocomposites can be adjusted in a wide range from green to red(554–630 nm).Our finding not only provides a novel method for synthesizing tunable“emissive”Cs4PbI6 NCs,but also makes clear the photoluminescence origin of“emissive”Cs4PbI6.

关键词： CsPbI3@Cs4PbI6 dissolution-recrystallization nanocomposites tunable emission

Successful diagnosis and treatment of jejunal diverticular haemorrhage by full-thickness enterotomy: A case report

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World Journal of Clinical Cases 2021年第19期9卷 5232-5237页

作者： Hua-chong ma Hui Xiao Hao Qu Zhen-Jun Wang Department of General Surgery Beijing Chaoyang HospitalCapital Medical UniversityBeijing 100020China

BACKGROUND Jejunal diverticula are the rarest of all small bowel diverticula and usually have no classic clinical *** diverticular haemorrhage(JDH)is a rare complication and can be difficult to identify and manage,hence it always resulting in a diagnostic delay and unsatisfactory clinical *** with the advances in endoscopic technology,no consensus have been reached on the diagnosis and management of JDH,the conventional surgical intervention still remains the mainstream for the management of *** report an unique case of a 63-year-old male who presented with massive haemorrhage from jejunal diverticula,which was successfully managed by initial resuscitation and definitive *** SUMmaRY A 63-year-old male was admitted as an emergency with 6 h history of haematemesis and *** haematemesis appeared to be bright red,with volume exceeding 100 *** amount of melena was estimated to be 200 ***,the patient received fluid resuscitation and three unit blood ***,in order to localize the bleeding sites,colonoscopy,upper gastrointestinal endoscopy,and mesenteric angiography were utilized but failed to identify the source of *** consent form was obtained for further treatment,and he was treated with an exploratory laparotomy and the bleeding site was successfully located during the *** was diagnosed with *** postoperative period was uneventful,and he was discharged on day 18 after *** rebleeding occurred at the 1-year *** In patients with gastrointestinal bleeding,if various techniques fail to identify the cause of haemorrhage in small bowel and haemodynamic instability is sustained with continuous resuscitation,we recommend surgical intervention should be the ultimate treatment of choice.

关键词： Case report Jejunal diverticular haemorrhage Colonoscopy Gastrointestinal bleeding Surgical intervention

Pesticide-induced photoluminescence quenching of ultra-small Eu3+-activated phosphate and vanadate nanoparticles

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Journal of materials Science & Technology 2020年第3期38卷 197-204页

作者： Jovana Perisa Zeljka Antic chong-Geng ma Jelena Papan Dragana Jovanovic Miroslav D.Dramicanin Vinca Institute of Nuclear Sciences University of BelgradeP.O.Box 52211001 BelgradeSerbia College of Sciences Chongqing University of Posts and TelecommunicationsChongqing 400065China

The aim of this research was to investigate the luminescent behavior of ultra-small Eu3+-activated phosphate and vanadate nanoparticles in the presence of *** have an average diameter of approximately 2 nm with a narrow size *** monazite crystal structure of phosphate-based particles(space group P121/n1)and single tetragonal zircon-type structure of vanadate-based particles(space group of I41/amd)have been confirmed using X-ray diffraction *** synthesized Eu3+-activated colloidal nanoparticles show sharp emission peaks in the red spectral *** measurements revealed emission quenching upon addition of millimolar concentrations of following pesticides:4-Chloro-2-methyl-phenoxyacetic acid(MCPA),2,4-Dichlorophenoxyacetic acid(2,4-D)and N-(phosphonomethyl)glycine(Glyphosate).In both phosphate and vanadate-based colloidal nanoparticles luminescence quenching is more evident in the presence of 2,4-D pesticide with the lowest limit of detection(0.7μM)obtained for phosphate-based nanoparticles.

关键词： Phosphate/vanadate based colloidal nanoparticles Eu3+ Emission quenching Pesticide

Precise delivery of obeticholic acid via nanoapproach for triggering natural killer T cell-mediated liver cancer immunotherapy

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Acta Pharmaceutica Sinica B 2020年第11期10卷 2171-2182页

作者： Guofeng Ji Lushun ma Haochen Yao Sheng ma Xinghui Si Yalin Wang Xin Bao Lili ma Fangfang Chen chong ma Leaf Huang Xuedong Fang Wantong Song Department of Gastrointestinal and Colorectal Surgery China-Japan Union Hospital of Jilin UniversityChangchun 130033China Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Division of Pharmacoengineering and Molecular Pharmaceutics Eshelman School of PharmacyUniversity of North Carolina at Chapel HillChapel HillNC 27599USA Key Laboratory of Zoonosis Chinese Ministry of EducationCollege of Basic Medical ScienceJilin UniversityChangchun 130021China Second Hospital of Shandong University Jinan 250000China Second Hospital of Jilin University Changchun 130041China Jilin Biomedical Polymers Engineering Laboratory Changchun 130022China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China

Primary bile acids were reported to augment secretion of chemokine(C-X-C motif)ligand16(CXCL16)from liver sinusoidal endothelial cells(LSECs)and trigger natural killer T(NKT)cellbased immunotherapy for liver ***,abundant expression of receptors for primary bile acids across the gastrointestinal tract overwhelms the possibility of using agonists against these receptors for liver cancer *** advantage of the intrinsic property of LSECs in capturing circulating nanoparticles in the circulation,we proposed a strategy using nanoemulsion-loaded obeticholic acid(OCA),a clinically approved selective farnesoid X receptor(FXR)agonist,for precisely manipulating LSECs for triggering NKT cell-mediated liver cancer *** OCA-nanoemulsion(OCA-NE)was prepared via ultrasonic emulsification method,with a diameter of 184 nm and good *** vivo biodistribution studies confirmed that the injected OCA-NE mainly accumulated in the liver and especially in LSECs and Kupffer *** a result,OCA-NE treatment significantly suppressed hepatic tumor growth in a murine orthotopic H22 tumor model,which performed much better than oral medication of free *** analysis revealed that the OCA-NE resulted in augmented secretion of CXCL16 and IFN-g,as well as increased NKT cell populations inside the ***,our research provides a new evidence for the antitumor effect of receptors for primary bile acids,and should inspire using nanotechnology for precisely manipulating LSECs for liver cancer therapy.

关键词： Obeticholic acid Farnesoid X receptor Nanoemulsion Liver sinusoidal endothelial cells Liver cancer

Penile vascular anomalies:A retrospective single center study and cumulative analysis of studies from China

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Asian Journal of Urology 2023年第4期10卷 555-562页

作者： chong ma Feng Gao Ran An Yawei Guan Jingfei Teng Xing Ai Department of Urology The Third Medical Center of PLA General HospitalBeijingChina Department of Urology The Seventh Medical Center of PLA General HospitalBeijingChina Department of Pathology The Seventh Medical Center of PLA General HospitalBeijingChina

Objective Penile vascular anomalies(PVAs)or hemangioma can arouse patient concern about aesthetics and cause symptoms like bleeding and sexual ***,its low incidence and the deficiency of large-volume studies hinder urologists from making informed *** study aimed to investigate the clinical features and treatment experience of PVAs at the Seventh Medical Center of PLA General Hospital,Beijing,***,by systematically analysis of studies on PVAs in Chinese people,we aimed to provide novel insights on the management of this *** We retrospectively investigated clinical features and pathology of surgery-treated PVAs at our ***,by systemically reviewing the literature from PubMed and the three largest medical databases(China National Knowledge Infrastructure,Wan Fang,and Chinese Medical Journal Database)in China,we analyzed the clinical features and various therapies of PVAs in Chinese *** Between march 1,2018 and march 1,2023,a total of 356 cases with vascular anomalies were treated with surgery at out *** seven(2.0%)cases had lesions involving the perineum and external *** the seven cases were pathologically benign and demonstrated no recurrence over a follow-up period of 1-52 months(median 14 months).A total of 410 cases from 44 studies were selected in the cumulative *** patients(92.4%)diagnosed with PVAs were asymptomatic,and 68.8%of the patients were treated with *** to the pathology,57.1%were venous *** The most common PVA is venous malformation and the majority of patients are *** and laser have emerged as viable options for treating small *** still has its role in treating large lesions and obtaining *** PVAs often relapse or demand multiple treatments,the prognosis is favorable.

关键词： Hemangioma Laser irradiation Penis Surgery Vascular anomaly

Influencing factors and mechanism of high-temperature oxidation of high-entropy alloys: A review

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International Journal of Minerals,Metallurgy and materials 2021年第6期28卷 915-930页

作者： Ya Wei Yu Fu Zhi-min Pan Yi-chong ma Hong-xu Cheng Qian-cheng Zhao Hong Luo Xiao-gang Li National materials Corrosion and Protection Data Center Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Key Laboratory for Corrosion and Protection of The Ministry of Education(MOE) Beijing 100083China BRI Southeast Asia Network for Corrosion and Protection(MOE) Shunde Graduate School of University of Science and Technology BeijingFoshan 528000China

High-temperature oxidation is a common failure in high-temperature environments,which widely occur in aircraft engines and aerospace thrusters;as a result,the development of anti-high-temperature oxidation materials has been ***-based alloys are a common high-temperature material;however,they are too ***-entropy alloys are alternatives for the anti-oxidation property at high temperatures because of their special structure and *** recent achievements of high-temperature oxidation are reviewed in this *** high-temperature oxidation environment,temperature,phase structure,alloy elements,and preparation methods of high-entropy alloys are *** reason why high-entropy alloys have anti-oxidation ability at high temperatures is *** research,material selection,and application prospects of high-temperature oxidation are introduced.

关键词： high-entropy alloy high-temperature oxidation influencing factors oxidation mechanism