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Surface modification of tungsten oxide by oxygen vacancies for hydrogen adsorption

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Journal of Materials Science & Technology 2022年第22期117卷 23-35页

作者： Q.Zhang F.w.tang Z.Zhao Z.R.Nie X.Y.Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing the adsorption process of hydrogen on surface of tungsten oxide was proposed based on the first-principle calculations. Multiple factors such as type of active surface, adsorption site and distribution of oxygen vacancies were considered to evaluate the hydrogen adsorption capability of tungsten oxide. The adsorption Gibbs free energies, electronic structures and bonding characteristics under various conditions were examined to reveal the influence of oxygen vacancies on the surface. It is found that the capability of hydrogen adsorption of tungsten oxide can be significantly enhanced by adjusting the oxygen vacancy on the outermost layer of certain active surfaces. The modeling predicts that the surface structure stability and gas adsorption ability of tungsten oxide can be simultaneously improved through the formation of w–h bonds. The proposed strategy for moderating surface provides a new approach to obtain excellent gas-sensitive metal oxide materials.

关键词： Metal oxide Gas-sensitive material Surface adsorption Oxygen vacancy First-principles calculation

In-situ generation of poly(quinolizine)s via catalyst-free polyannulations of activated diyne and pyridines

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Science China Chemistry 2022年第4期65卷 789-795页

作者： Benzhao he Jiachang huang Jing Zhang Xinyue Liu Dong wang herman h.Y.Sung Yajun Liu Anjun Qin Jacky w.Y.Lam Ben Zhong tang Center for Advanced Materials Research Science and Technology Experimental PlatformAdvanced Institute of Natural SciencesBeijing Normal University at ZhuhaiZhuhai 519085China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstructionand Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional MaterialsThe Hong Kong University of Science&TechnologyKowloonHong KongChina Center for AIE Research College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China Department of Laboratory Medicine Nanfang HospitalSouthern Medical UniversityGuangzhou 510515China State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesCenter for Aggregation-Induced EmissionSouth China University of TechnologyGuangzhou 510640China hKUST-Shenzhen Research Institute Shenzhen 518057China Shenzhen Institute of Aggregate Science and Technology School of Science and EngineeringThe Chinese University of Hong KongShenzhen 518172China

The development of new polymerization routes to afford N-heterocyclic polymers is of vital importance and highly desired for various practical applications. herein, a facile and efficient polyannulation reaction of dual-activated alkyne and pyridines was developed to construct novel N-heterocyclic poly(quinolizine)s. This polymerization can proceed smoothly under catalystfree conditions with 100% atom utilization to furnish poly(quinolizine)s with high molecular weights(up to 34,100) and welldefined structures in acceptable yields. The resulting polymers show good solubility, high thermal stability and strong red emission. Moreover, the prepared poly(quinolizine)s exhibit low cytotoxicity and can selectively label lysosomes in live *** the remarkable advantages of readily available raw materials, mild polymerization conditions, atom economy, and excellent product performance, this new and efficient polymerization tool will open up enormous opportunities for preparing functional N-heterocyclic polymers.

关键词： polyannulation activated alkyne N-heterocyclic polymers poly(quinolizine)s bioimaging

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Effects of Y content and temperature on the damping capacity of extruded Mg-Y sheets

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Journal of Magnesium and Alloys 2019年第3期7卷 522-528页

作者： Y.T.tang C.Zhang L.B.Ren w.Yang D.D.Yin G.h.huang h.Zhou Y.B.Zhang Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuan 610031PR China Nano and heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094PR China

The damping behavior of extruded Mg-xY(x=0.5,1.0,3.0 wt.%)sheets were investigated in detail concerning the effects of Y addition and temperature,and the relationship between damping capacity and yield strength was *** room temperature(RT),with Y content increasing from 0.5%to 3.0%,the damping capacity(Q-1)significantly decreased from 0.037 to *** all the studied sheets,the relationship between strain amplitude and Q-1 fitted well with the Granato and Liicke(G-L)dislocation damping *** temperature increased,the G-L plots deviated from linearity indicating that the dislocation damping was not the only dominate mechanism,and the grain boundary sliding(GBS)could contribute to damping ***,the Q-1 increased remarkably above the critical temperature,and the critical temperature increased significantly from 50℃ to 290℃ with increasing Y contents from 0 to 3.0wt.%.This result implied that the segregation of Y solutes at grain boundary could depress the GBS,which was consistent with the recent finding of segregation tendency for rare-earth *** extruded Mg-IY sheet exhibited slightly higher yield strength(Rp0.2)and Q-1 comparing with high-damping Mg-0.6Zr at *** an elevated temperature of 325℃,the Mg-IY sheet had similar Q-1 but over 3 times larger Rp0.2 than that of the pure *** present study indicated that the extruded Mg-Y based alloys exhibited promising potential for developing high-performance damping alloys,especially for the elevated-temperature application.

关键词： Extruded sheets Mg-Y alloys Damping capacity Granato and Lücke model Elevated temperature

DEhP exposure destroys blood-testis barrier (BTB) integrity of immature testes through excessive ROS-mediated autophagy

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Genes & Diseases 2018年第3期5卷 263-274页

作者： w.E.I.Yi tang Xiang-Liang Zhou Yu Liu Bin Shen Lian-Ju Long Chun-lan L.I.N.Tao h.E.Da-wei w.U.Sheng-de w.E.I.Guang-hui Department of Urology Children’s Hospital of Chongqing Medical UniversityZhongshan 2RDYuzhong DistrictChongqing400014China Chongqing Key Laboratory of Children Urogenital Development and Tissue Engineering China Ministry of Education Key Laboratory of Child Development and Disorders China China International Science and Technology Cooperation Base of Child Development and Critical Disorders China Chongqing Key Laboratory of Pediatrics Chongqing China

Di-(2-ethylhexyl)phthalate(DEhP),is known to impair testicular functions and ***,its effects on immature testis Blood-testis barrier(BTB)and the underlying mechanisms remain *** constructed a rat model to investigate the roles of autophagy in BTB toxicity induced by *** rats were developmentally exposed to 0,250 and 500 mg/kg DEhP via intragastric administration from postnatal day(PND)1 to PND *** morphology,expressions of BTB junction proteins and autophagy related proteins were *** addition,expressions of oxidative stress markers were also *** results demonstrated that developmental DEhP exposure induced decreasing organ coefficients of immature testes and severe testicular damage in *** expressions of junctional proteins were down-regulated significantly after DEhP ***,DEhP simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II and p62,suggesting that the accumulated autophagosomes resulted from impaired autophagy ***,the expressions of hO-1 and SOD levels remarkably decreased after DEhP *** E and C could alleviate the DEhP-induced oxidative stress,reverse the autophagy defect and restore the BTB *** together,DEhP exposure destroys immature testis blood-testis barrier(BTB)integrity through excessive ROSmediated autophagy.

关键词： Autophagy BTB DEhP Immature testis Oxidative stress

Do specific ultrasonography features identified at the time of early pregnancy loss predict fetal chromosomal abnormality? e A systematic review and meta-analysis

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Genes & Diseases 2019年第2期6卷 129-137页

作者： J.huang w.Zhu J.tang S.h.Saravelos L.C.Y.Poon T.C.Li Department of Obstetrics and Gynaecology The First Affiliated Hospital of Chongqing Medical UniversityChongqing400016China Department of Obstetrics and Gynaecology The Chinese University of Hong KongHong Kong SARChina IVF Unit Hammersmith HospitalImperial College Healthcare NHS TrustLondonUK

To investigate the association of specific ultrasonography features identified during the diagnosis of early pregnancy loss(EPL)and abnormal *** was a systematic review and meta-analysis conducted in accordance with PRISMA *** searched PubMed,Cochrane and Ovid MEDLINE from 1977 to Jan 2017 to identify the articles that described EPL with karyotype and ultrasonography *** differences were pooled to estimate the chromosomal abnormality rates in ultrasonography features,including pre-embryonic,enlarged yolk sac(YS),short crown rump length(CRL),small gestational sac(GS),symmetrical arrested growth embryo,or gestational sac with only a *** assessment of included studies was performed using Strengthening the Reporting of Observational Studies in Epidemiology(STROBE)checklists for Observational Studies(2007 version).Thirteen studies were included in the *** abnormality was more likely to occur in embryonic EPL and enlarged *** the other hand,short CRL,small GS,symmetrical arrested growth embryo,or gestational sac with only a YS,were not associated with an increased risk of fetal chromosomal *** features at the time of diagnosis of EPL have limited predictive value of fetal chromosomal abnormality.

关键词： Ultrasonography Early pregnancy loss Chromosomal abnormality Predictive value

On Boundary Factors and Traces of Subgroups of Finite Groups

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Communications in Mathematics and Statistics 2014年第3期2卷 349-361页

作者： w.Guo Alexander N.Skiba X.tang School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026People’s Republic of China Department of Mathematics Francisk Skorina Gomel State University246019 GomelBelarus

A subgroup E of a finite group G is called hypercyclically embedded in G if every chief factor of G below E is *** A be a subgroup of a group *** we call any chief factor h/AG of G a G-boundary factor of *** any G-boundary factor h/AG of A,we call the subgroup(A∩h)/AG of G/AG a G-trace of *** the basis of these notions,we give some new characterizations of hypercyclically embedded subgroups.

关键词： Finite group hypercyclically embedded subgroup G-boundary factor G-trace of subgroup Meet-irreducible subgroup

Anaerobic bacteria and intrahepatic stones: detections of Clostridium sp. and Bacteroides fragilis

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Chinese Medical Journal 2000年第9期113卷 90-93页

作者： LIU Yanlei Kan Lam Yajarayma J tang Paul h Gumerlock Dong Ki Lee Myung hwa Kim Sum P Lee Joseph SilvaJr Joseph w Leung Division of Gastroenterology and Mr & MrsCwLaw Biofilm Research Center University of CaliforniaDavis MedicalCenterSacramentoCA95817USA

To detect anaerobic bacteria Clostridium sp . and Bacteroides fragilis in intrahepatic stones by molecular genetic method Methods DNA was extracted from 59 stone samples and subjected to polymerase chain reaction (PCR) amplification targeting the 16S rRNA gene of Clostridium sp . and the glutamine synthetase gene of Bacteroides fragilis Single-strand conformational polymorphism (SSCP) analysis was performed to identify the Clostridium sp Results 16S rRNA gene sequences for Clostridium sp. were identified in 49 stones (83%, 49/59) The two most common groups were detected in 19 (41%) and 17 (37%) of the 46 samples using SSPC analysis, and 25/59 (42%) stones were tested positive for Bacteroides fragilis Conclusions Anaerobes such as Clostridium sp and Bacteroides fragilis present in intrahepatic stones and may play a role in stone formation PCR is a useful technique to detect fastidious pathogens, which are difficult to culture SSCP of PCR products is a rapid method in differentiating bacterial species

关键词： intrahepatic stone anaerobic bacteria PCR single-strand confromational polymorphism

The effect of downstream resistance on flow diverter treatment of a cerebral aneurysm at a bifurcation: A joint computational-experimental study

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Journal of hydrodynamics 2018年第5期30卷 803-814页

作者： ANDerson C.O.Tsang Billy Y.S.Yiu Abraham Y.S.tang w.C.Chung Gilberto K.K.Leung AlexANDer K.K.Poon Alfred C.h.Yu Simon S.M.Lai K.w.Chow Department of Surgery Li Ka Shing Faculty of Medicine University of Hong Kong Department of Electrical and Computer Engineering University of Waterloo Department of Mechanical Engineering University of Hong Kong Department of Electrical and Electronic Engineering University of Hong Kong

Intracranial aneurysm can lead to hemorrhagic stroke upon rupture. Deployment of flow diverters can restrict the blood flow into aneurysm and mitigate the rupture risk. Computational fluid dynamics（CFD） and ultrasonography with pulse-wave and color Doppler ultrasound measurements were employed jointly to investigate the complex flow pattern in cerebral aneurysms, both before and after the deployment of flow diverters. Patient-specific configurations of both bifurcation and side-wall aneurysms were selected. The effect of downstream flow resistance was investigated by adjusting the volume flow rate and pressure at the outlet vessels computationally and experimentally. Velocity profiles in the aneurysm measured from ultrasonography showed good agreement with those from computer simulations. The discrepancy in velocity between the computational and experimental sets of data is less than 10%. The downstream resistance can alter the volume flux into a bifurcation aneurysm with a flow diverter deployed by 236%, while the corresponding value of a side-wall aneurysm is negligible. The vorticity of the aneurysmal flow was reduced by more than 80% in both cases after stenting. This study demonstrated that careful investigation of downstream flow resistance of a bifurcation aneurysm is essential to provide an accurate assessment of the aneurysmal flow dynamics after flow diverter deployment.

关键词： Intracranial aneurysms computational fluid dynamics (CFD) doppler ultrasound

Computational aerodynamics of low Reynolds number plunging,pitching and flexible wings for MAV applications

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Acta Mechanica Sinica 2008年第4期24卷 351-373页

作者： w.Shyy Y.Lian J.tang h.Liu P.Trizila B.Stanford L.Bernal C.Cesnik P.Friedmann P.Ifju Department of Aerospace Engineering University of Michigan Ann Arbor MI 48109 USA Graduate School of Engineering Chiba University Chiba 263-8522. Japan Department of Mechanical and Aerospace Engineering University of Florida Gainesville FL 32611 USA

Micro air vehicles （MAV＇s） have the potential to revolutionize our sensing and information gathering capabilities in environmental monitoring and homeland security areas. Due to the MAV＇s＇ small size, flight regime, and modes of operation, significant scientific advancement will be needed to create this revolutionary capability. Aerodynamics, structural dynamics, and flight dynamics of natural flyers intersects with some of the richest problems in MAV＇s, inclu- ding massively unsteady three-dimensional separation, transition in boundary layers and shear layers, vortical flows and bluff body flows, unsteady flight environment, aeroelasticity, and nonlinear and adaptive control are just a few examples. A challenge is that the scaling of both fluid dynamics and structural dynamics between smaller natural flyer and practical flying hardware/lab experiment （larger dimension） is fundamentally difficult. In this paper, we offer an overview of the challenges and issues, along with sample results illustrating some of the efforts made from a computational modeling angle.

关键词： Micro air vehicles Aerodynamics Flexible wings Low Reynolds number