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硅负载离子液体的合成、表征以及其催化甲酸和三乙基胺作为氢源的环己酮还原胺化反应（英文）

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催化学报 2015年第8期36卷 1365-1371页

作者： Ashif h.Tamboli Avinash A.Chaugule Faheem A.Sheikh Wook-Jin chung hern Kim Department of Energy Science and Technology Energy and Environment Fusion Technology CenterMyongji University

A silica supported ionic liquid was synthesized and characterized by scanning electron microscopy(SEM), Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption-desorption, and thermogravimetric analysis. All these techniques, especially SEM results indicated the presence of well-defined spherical particles having diameters larger than the pristine silica particles, confirming the successful immobilization of the ionic liquid. The prepared silica supported ionic liquid was used in the reductive amination of cyclohexanone under different conditions with different azeotropic mixtures of formic acid and triethyl amine as a hydrogen source. The catalyst showed efficient catalytic performance and excellent yields of N-cyclohexyl amine derivatives in the range of 58% to 84% at 30 °C. After completion of the reaction, the catalyst was easily recovered by simple filtration and reused for another five cycles without any significant impact on product yields. The obtained catalytic performance indicates that the present catalyst is green, very active, and reusable for the reductive amination of cyclohexanone.

关键词：离子液体催化剂还原胺化硅胶负载环己酮三乙胺合成氢源甲酸

A three-level authenticated conference key establishment protocol for UMTS networks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第5期12卷 371-378页

作者： chung-Fu LU Tzong-Chen WU Chien-Lung hSU Department of Information Management National Taiwan University of Science and Technology Department of Computer and Communication Engineering Taipei College of Maritime Technology Department of Information Management Chang Gung University

A conference key establishment protocol allows a group of conferees to agree on a secret key shared among them for secure group *** paper proposes a three-level conference key establishment protocol based on the Universal Mobile Telecommunications System (UMTS) framework to establish a group-level key,home location register (hLR) level keys,and visitor location register (VLR) level keys simultaneously for a group of *** group-level key is used to secure the communications for all conferees,the hLR-level key is for those within the same hLR domain,and the VLR-level key is for those within the same VLR *** group-level key can be used for securing inter-domain group-oriented applications such as commercial remote conferencing *** hLRand VLR-level keys can be used for securing intra-domain subgroup applications (e.g.,location-based or context-aware services) and dynamic key *** our proposed protocol exploits existing UMTS security functions and the exclusive-or operation,it is compatible with UMTS *** means that it is fast and easy to implement on the existing UMTS ***,the proposed protocol has low computational complexities and can provide cost effectiveness,load-amortization,scalability,user authentication,key establishment,key confirmation,key updating,and lawful interception.

关键词： Universal Mobile Telecommunications System (UMTS) Three-level Conference key establishment Secure group communication Authentication

Video quality based link adaptation for low latency video transmission over WLANs

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 847-856页

作者： FERR Pierre DOUFEXI Angela chung-hOW James NIX Andrew BULL David University of Bristol Department of Electrical and Electronic Engineering Centre for Communications Research Bristol BS8 1UB UK ProVision Communication Technologies Bristol BS4 4EU UK

Wireless Local Area Networks (WLANs) such as IEEE 802.11a/g and hiperlan/2 utilise numerous transmission modes, each providing different throughputs and reliability levels. Many link adaptation algorithms proposed in the literature either maximise the error-free data throughput based on channel conditions or are based on the number of failed transmissions. however, these algo- rithms do not take into account the content of the data stream and strongly rely on the use of Automatic Repeat Requests (ARQs). Low latency video applications such as real-time video transmission may require no retransmission, or only a limited number of retrans- missions. Moreover, completely error-free communication is not essential, especially if robust video compression techniques are applied. In such scenarios, improved decoded video quality can be obtained with a video stream transmitted at a higher bit rate using a higher link speed but with some degree of transmission error, rather than an error-free video stream at a lower bit rate using a lower link speed. In this work, we investigate a link adaptation scheme that improves the Quality of Service (QoS) for video transmission, based on the overall received video quality (Peak Signal to Noise Ratio, PSNR), rather than by maximising the error-free throughput. We also study a practical link adaptation approach that uses PER thresholds at the PhY layer. An empirical study showed that thresholds for switching from one mode to another are much lower (almost error free) than those currently used by throughput based schemes. We show that traditional link adaptation strategies are not appropriate for real-time video transmission with no retransmis- sion. Simulation results using the h.264 video compression standard over IEEE 802.11a are presented.

关键词： Link adaptation Wireless LAN Video quality Peak Signal to Noise Ratio (PSNR) Packet Error Rate (PER)

Determination of the number ofψ(3686)events taken at BESⅢ

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Chinese Physics C 2024年第9期48卷 8-20页

作者： M.Ablikim M.N.Achasov P.Adlarson O.Afedulidis X.C.Ai R.Aliberti A.Amoroso Q.An Y.Bai O.Bakina I.Balossino Y.Ban h.-R.Bao V.Batozskaya K.Begzsuren N.Berger M.Berlowski M.Bertani D.Bettoni F.Bianchi E.Bianco A.Bortone I.Boyko R.A.Briere A.Brueggemann h.Cai X.Cai A.Calcaterra G.F.Cao N.Cao S.A.Cetin J.F.Chang G.R.Che G.Chelkov C.Chen C.h.Chen Chao Chen G.Chen h.S.Chen h.Y.Chen M.L.Chen S.J.Chen S.L.Chen S.M.Chen T.Chen X.R.Chen X.T.Chen Y.B.Chen Y.Q.Chen Z.J.Chen Z.Y.Chen S.K.Choi G.Cibinetto F.Cossio J.J.Cui h.L.Dai J.P.Dai A.Dbeyssi R.E.de Boer D.Dedovich C.Q.Deng Z.Y.Deng A.Denig I.Denysenko M.Destefanis F.De Mori B.Ding X.X.Ding Y.Ding Y.Ding J.Dong L.Y.Dong M.Y.Dong X.Dong M.C.Du S.X.Du Y.Y.Duan Z.h.Duan P.Egorov Y.h.Fan J.Fang J.Fang S.S.Fang W.X.Fang Y.Fang Y.Q.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.Q.Feng J.h.Feng Y.T.Feng M.Fritsch C.D.Fu J.L.Fu Y.W.Fu h.Gao X.B.Gao Y.N.Gao Yang Gao S.Garbolino I.Garzia L.Ge P.T.Ge Z.W.Ge C.Geng E.M.Gersabeck A.Gilman K.Goetzen L.Gong W.X.Gong W.Gradl S.Gramigna M.Greco M.h.Gu Y.T.Gu C.Y.Guan Z.L.Guan A.Q.Guo L.B.Guo M.J.Guo R.P.Guo Y.P.Guo A.Guskov J.Gutierrez K.L.han T.T.han F.hanisch X.Q.hao F.A.harris K.K.he K.L.he F.h.heinsius C.h.heinz Y.K.heng C.herold T.holtmann P.C.hong G.Y.hou X.T.hou Y.R.hou Z.L.hou B.Y.hu h.M.hu J.F.hu S.L.hu T.hu Y.hu G.S.huang K.X.huang L.Q.huang X.T.huang Y.P.huang T.hussain F.hölzken N.hüsken N.in der Wiesche J.Jackson S.Janchiv J.h.Jeong Q.Ji Q.P.Ji W.Ji X.B.Ji X.L.Ji Y.Y.Ji X.Q.Jia Z.K.Jia D.Jiang h.B.Jiang P.C.Jiang S.S.Jiang T.J.Jiang X.S.Jiang Y.Jiang J.B.Jiao J.K.Jiao Z.Jiao S.Jin Y.Jin M.Q.Jing X.M.Jing T.Johansson S.Kabana N.Kalantar-Nayestanaki X.L.Kang X.S.Kang M.Kavatsyuk B.C.Ke V.Khachatryan A.Khoukaz R.Kiuchi O.B.Kolcu B.Kopf M.Kuessner X.Kui N.Kumar A.Kupsc W.Kühn J.J.Lane P.Larin L.Lavezzi T.T.Lei Z.h.Lei M.Lellmann T.Lenz C.Li C.Li C.h.Li Cheng Li D.M.Li F.Li G.Li h.B.Li h.J.Li h.N.Li hui Li J.R.Li J.S.Li Ke Li L.J.Li L.K.Li Lei Li M.h.Li P.R.Li Q.M.Li Q.X.Li R.Li S.X.Li T.Li W.D.Li W.G.Li X.Li X.h.Li X.L.Li X.Z.Li Xi Institute of high Energy Physics Beijing 100049China Beihang University Beijing 100191China Bochum Ruhr-University D-44780BochumGermany Budker Institute of Nuclear Physics SB RAS(BINP) Novosibirsk 630090Russia Carnegie Mellon University PittsburghPennsylvania 15213USA Central China Normal University Wuhan 430079China Central South University Changsha 410083China China Center of Advanced Science and Technology Beijing 100190China China University of Geosciences Wuhan 430074China chung-Ang University Seoul06974Republic of Korea COMSATS University Islamabad Lahore CampusDefence RoadOff Raiwind Road54000LahorePakistan Fudan University Shanghai 200433China GSI helmholtzcentre for heavy Ion Research Gmbh D-64291DarmstadtGermany Guangxi Normal University Guilin 541004China Guangxi University Nanning 530004China hangzhou Normal University Hangzhou 310036China hebei University Baoding 071002China helmholtz Institute Mainz Staudinger Weg 18D-55099MainzGermany henan Normal University Xinxiang 453007China henan University Kaifeng 475004China henan University of Science and Technology Luoyang 471003China henan University of Technology Zhengzhou 450001China huangshan College Huangshan 245000China hunan Normal University Changsha 410081China hunan University Changsha 410082China Indian Institute of Technology Madras Chennai 600036India Indiana University BloomingtonIndiana 47405USA INFN Laboratori Nazionali di Frascati (A)INFN Laboratori Nazionali di FrascatiI-00044FrascatiItaly(B)INFN Sezione di PerugiaI-06100PerugiaItaly(C)University of PerugiaI-06100PerugiaItaly INFN Sezione di Ferrara (A)INFN Sezione di FerraraI-44122FerraraItaly(B)University of FerraraI-44122FerraraItaly Inner Mongolia University Hohhot 010021China Institute of Modern Physics Lanzhou 730000China Institute of Physics and Technology Peace Avenue 54BUlaanbaatar 13330Mongolia Instituto de Alta Investigación Universidad de TarapacáCasilla 7DArica 1000000Chile Jilin University Changchun 130012China Joha

The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic *** uncertainty is systematic and the statistical uncertainty is ***,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,*** numbers are consistent with the previous measurements within one standard *** total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.

关键词： ψ(3686) inclusive process hadronic events BESⅢdetector

Optimal concentration of mesenchymal stem cells for fracture healing in a rat model with long bone fracture

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World Journal of Stem Cells 2022年第12期14卷 839-850页

作者： Myung-Seo Kim hyun-Ju chung Kang-Il Kim Department of Orthopaedic Surgery School of MedicineKyung Hee University and Kyung Hee University Hospital at GangdongSeoul 05278South Korea Department of Core Research Laboratory Clinical Research InstituteKyung Hee University Hospital at GangdongSeoul 05278South Korea

BACKGROUND There is still no consensus on which concentration of mesenchymal stem cells(MSCs)to use for promoting fracture healing in a rat model of long bone *** To assess the optimal concentration of MSCs for promoting fracture healing in a rat *** Wistar rats were divided into four groups according to MSC concentrations:Normal saline(C),2.5×10^(6)(L),5.0×10^(6)(M),and 10.0×10^(6)(h)*** MSCs were injected directly into the fracture *** rats were sacrificed at 2 and 6 wk *** bone formation[bone volume(BV)and percentage BV(PBV)]was evaluated using micro-computed tomography(CT).histological analysis was performed to evaluate fracture healing *** protein expression of factors related to MSC migration[stromal cell-derived factor 1(SDF-1),transforming growth factor-beta 1(TGF-β1)]and angiogenesis[vascular endothelial growth factor(VEGF)]was evaluated using western blot *** expression of cytokines associated with osteogenesis[bone morphogenetic protein-2(BMP-2),TGF-β1 and VEGF]was evaluated using real-time polymerase chain *** Micro-CT showed that BV and PBV was significantly increased in groups M and h compared to that in group C at 6 wk post-fracture(P=0.040,P=0.009;P=0.004,P=0.001,respectively).Significantly more cartilaginous tissue and immature bone were formed in groups M and h than in group C at 2 and 6 wk post-fracture(P=0.018,P=0.010;P=0.032,P=0.050,respectively).At 2 wk post fracture,SDF-1,TGF-β1 and VEGF expression were significantly higher in groups M and h than in group L(P=0.031,P=0.014;Phigher in groups M and h than in group C at 6 wk postfracture(P=0.037,P=0.038;P=0.021,P=0.010).Compared to group L,TGF-β1 expression was significantly higher in groups h(P=0.016).There were no significant differences in expression levels of chemokines related to MSC migration,angiogenesis and cytokines associated

关键词： Rat model Femoral shaft fracture Mesenchymal stem cells Direct injection Optimal concentration Fracture healing

Thermoelectric transport across graphene/hexagonal boron nitride/graphene heterostructures

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Nano Research 2015年第2期8卷 666-672页

作者： Chun-chung Chen Zhen Li Li Shi Stephen B. Cronin Department of Electrical Engineering University of Southern California Los Angeles CA 90089 USA Department of Mechanical Engineering and Texas Materials Institute University of Texas at Austin Texas 78712 USA

We report thermoelectric transport measurements across a graphene/hexagonal boron nitride （h-BN）/graphene heterostructure device. Using an AC lock-in technique, we are able to separate the thermoelectric contribution to the I-V characteristics of these important device structures. The temperature gradient is measured optically using Raman spectroscopy, which enables us to explore thermoelectric transport produced at material interfaces, across length scales of just 1-2 nm. Based on the observed thermoelectric voltage （AV） and tem- perature gradient （AT）, a Seebeck coefficient of -99.3 μV/K is ascertained for the heterostructure device. The obtained Seebeck coefficient can be useful for understanding the thermoelectric component in the cross-plane I-V behaviors of emerging 2D heterostructure devices. These results provide an approach to probing thermoelectric energy conversion in two-dimensional layered heterostructures.

关键词： graphene boron nitride 2D materials heterostructure thermoelectric

Significant Lifetime Enhancement in QLEDs by Reducing Interfacial Charge Accumulation via Fluorine Incorporation in the ZnO Electron Transport Layer

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Nano-Micro Letters 2022年第12期14卷 432-446页

作者： Dong Seob chung Tyler Davidson-hall Giovanni Cotella Quan Lyu Peter Chun hany Aziz Department of Electrical and Computer Engineering Waterloo Institute for NanotechnologyUniversity of Waterloo200 University Avenue WestWaterlooON N2L 3G1Canada Ipswich Research Centre Huawei Technologies Research&Development(UK)Ltd.Phoenix House(B55)Adastral ParkIpswich IP53REUK Ottawa IC Laboratory Huawei Canada19 Allstate ParkwayMarkhamON L3R 5B4Canada

ZnO nanoparticles are widely used for the electron transport layers(ETLs)of quantum dots light emitting devices(QLEDs).In this work we show that incorporating fluorine(F)into the ZnO ETL results in significant enhancement in device electroluminescence stability,leading to LT50 at 100 cd m^(−2) of 2,370,000 h in red QLED,47X longer than the control devices.X-ray photo-electron spectroscopy,time-of-flight secondary ion mass spectroscopy,photoluminescence and electrical measurements show that the F passivates oxygen vacancies and reduces electron traps in *** photoluminescence versus bias measurements and capacitance-voltage-luminance measurements reveal that the CF4 plasma-treated ETLs lead to increased electron concentration in the QD and the QD/hole transport layer interface,subsequently decreasing hole accumulation,and hence the higher *** findings provide new insights into the critical roles that optimizing charge distribution across the layers play in influencing stability and present a novel and simple approach for extending QLED lifetimes.

关键词： Colloidal quantum dots Quantum dots light emitting device Device stability Zinc oxide nanoparticles Fluorine

Differentiation of human mesenchymal stem cell spheroids under microgravity conditions

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Cell Regeneration 2012年第1期1卷 2-10页

作者： Wolfgang h Cerwinka Starlette M Sharp Barbara D Boyan haiyen E Zhau Leland W K chung Clayton Yates Children’s healthcare of Atlanta Emory University School of Medicine5445Meridian Mark RoadSuite 420AtlantaGA 30342USA Department of Biology and Center for Cancer Research Tuskegee UniversityCarver Research BuildingTuskegee InstituteAL 36088USA The Wallace h.Coulter Department of Biomedical Engineering Georgia Institute of Technology313 Ferst Drive AtlantaAtlantaGA 30332USA Samuel-Oschin Comprehensive Cancer Institute Cedars-Sinai Medical Center8750 Beverly Blvd.Atrium 103Los AngelesCA 90048USA Georgia Pediatric Urology 5445 Meridian Mark RdSuite 420AtlantaGA 30342USA Tuskegee University Carver Research Bld.Rm 22TuskegeeAL 36088USA.

To develop and characterize a novel cell culture method for the generation of undifferentiated and differentiated human mesenchymal stem cell 3D structures,we utilized the RWV system with a gelatin-based scaffold.3×10^(6) cells generated homogeneous spheroids and maximum spheroid loading was accomplished after 3 days of *** cultured in undifferentiated spheroids of 3 and 10 days retained expression of CD44,without expression of differentiation *** cultured in adipogenic and osteogenic differentiation media exhibited oil red O staining and von Kossa staining,*** characterization of osteogenic lineage,showed that 10 day spheroids exhibited stronger calcification than any other experimental group corresponding with significant expression of vitamin D receptor,alkaline phosphatase,and *** conclusion this study describes a novel RWV culture method that allowed efficacious engineering of undifferentiated human mesenchymal stem cell spheroids and rapid osteogenic *** use of gelatin scaffolds holds promise to design implantable stem cell tissue of various sizes and shapes for future regenerative treatment.

关键词： Mesenchymal stem cell RWV culture Tissue engineering Differentiation Osteogenesis

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油砂沥青改质产品中甲苯不溶物的表征

石油学报（石油加工） 2004年第1期20卷 68-74页

作者：许志明王宗贤 KOTLYAR L S chung K h 石油大学重质油加工国家重点实验室北京102200 加拿大国家研究院化工过程与环境技术研究所加拿大合成油公司埃德蒙顿研究中心

油砂沥青及其衍生产品中含有悬浮的甲苯不溶物如粘土和碳质固体颗粒,会导致后续加工过程中的结垢、催化剂失活和床层堵塞。笔者从油砂沥青衍生产品中分离出甲苯不溶物并进行了分析表征。研究发现,油砂沥青渣油中的甲苯不溶物主要是超细... 详细信息

油砂沥青及其衍生产品中含有悬浮的甲苯不溶物如粘土和碳质固体颗粒,会导致后续加工过程中的结垢、催化剂失活和床层堵塞。笔者从油砂沥青衍生产品中分离出甲苯不溶物并进行了分析表征。研究发现,油砂沥青渣油中的甲苯不溶物主要是超细的硅铝酸盐粘土颗粒,结合了部分干酪根成分;焦化渣油和焦化瓦斯油储罐中沉积的甲苯不溶物类似焦炭;焦化瓦斯油中的甲苯不溶物主要是碳质有机物颗粒,但氮、氧含量相对丰富,并含少量矿物质和粘土颗粒,含氮的杂环化合物如吡咯类物质的存在可能是导致焦化瓦斯油中甲苯不溶物生成的主要因素。

关键词：油砂沥青改质甲苯不溶物表征硅铝酸盐粘土颗粒焦炭碳质有机物颗粒微观结构红外光谱分析