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Non-coherent space-time code based on full diversity space-time block coding

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Science in China(Series F) 2008年第1期51卷 53-62页

作者： guo YongLiang zhu ShiHua Department of Information and Communications Engineering Xi'an Jiaotong University Xi'an 710049China

A non-unitary non-coherent space-time code which is capable of achieving full algebraic diversity is proposed based on full diversity space-time block coding, The error performance is optimized by transforming the non-unitary space-time code into unitary space-time code, By exploiting the desired structure of the proposed code, a grouped generalized likelihood ratio test decoding algorithm is presented to overcome the high complexity of the optimal algorithm, Simulation results show that the proposed code possesses high spectrum efficiency in contrast to the unitary space-time code despite slight loss in the SNR, and besides, the proposed grouped decoding algorithm provides good tradeoff between performance and complexity,

关键词： algebraic diversity gain non-unitary space-time code generalized likelihood ratio test pair-wise error probability,grouped GLRT decoding

Stable NiPt-Mo_(2)C active site pairs enable boosted water splitting and direct methanol fuel cell

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Green Energy & Environment 2023年第2期8卷 559-566页

作者： Jing Li zhu guo Wenjie Zhang Jing guo Konggang Qu Weiwei Cai Sustainable Energy Laboratory Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan430074China Shandong Provincial Key Laboratory/Collaborative Innovation Center of Chemical Energy Storage&Novel Cell Technology Liaocheng UniversityLiaocheng252059China

Sluggish kinetics of methanol oxidation reaction(MOR)and alkaline hydrogen evolution reaction(HER)even on precious Pt catalyst impede the large-scale commercialization of direct methanol fuel cell(DMFC)and water electrolysis *** both of MOR and alkaline HER are related to water dissociation reaction(WDR),it is reasonable to invite secondary active sites toward WDR to pair with Pt for boosted MOR and alkaline HER activity on ***_(2)C and Ni species are therefore employed to engineer NiPt-Mo_(2)C active site pairs,which can be encapsulated in carbon cages,via an in-situ self-confinement *** activity of Pt in NiPt-Mo_(2)C@C toward HER is boosted to11.3 A mg_(pt)^(-1),33 times higher than that of Pt/***,MOR catalytic activity of Pt in NiPt-Mo_(2)C@C is also improved by 10.5 times and the DMFC maximum power density is hence improved by *** considering the great stability,NiPt-Mo_(2)C@C exhibits great practical application potential in DMFCs and water electrolysers.

关键词： Hydrogen evolution reaction Methanol oxidation reaction Direct methanol fuel cell Active site pair Self-confinement

Characteristic Parameters for Dendritic Microstructure of Solidification During Slab Continuous Casting

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Journal of Iron and Steel Research International 2009年第1期16卷 17-21页

作者： guo Wei zhu Miao-yong School of Materials and Metallurgy Northeastern University Shenyang 110004 Liaoning China

The operating conditions during the continuous casting process have a great effect on the microstructure of slab solidification, including primary and secondary dendritic arm spacing. On the basis of the analysis of available work, a revised expression for describing secondary dendritic arm spacing during solidification of slab continuous casting was presented, and the relation between the ratio of primary dendritic arm spacing to secondary dendritic arm spacing and the cooling rate was obtained.

关键词： slab continuous casting dendritic solidification microstructure dendritic arm spacing

Comparison of Grain Size in Plain Carbon Hot-Rolled Sheets Manufactured by CSP and Conventional Rolling Processing

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Journal of Iron and Steel Research International 2012年第1期19卷 17-22页

作者： zhu Xue-song zhu guo-hui MAO Wei-min School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Anhui University of Technology Ma＇anshan 243002 Anhui China

Average grain size and grain size distribution in as hot-rolled SPHC, SPHD, and SPHE sheets manufac- tured by compact strip production （CSP） processing and traditional continuous casting and rolling （CCR） processing respectively were investigated by quantitative metallographic method. The results show that the average grain size and distribution width of grain size in sheets manufactured by CSP processing was obviously larger than that by CCR processing. It was analyzed that multi-phase transformation and high reduction ratio in CCR processing resulted in refining grain size, which would be dominant reason for controlling grain size. In plain carbon steels such as SPHC, SPHD and SPHE, the effect of fine precipitation in CSP on behavior of deformation and recrystallization of austenite during roiling, and consequent refinement of grain size seem not to be as important as the effect of reheating and roughing in CCR processing. Homogenizing in reheating and refining grain size in roughing in CCR processing would refine final grain size and also make grain size homogenized, Very coarse grain size would result in mixed grain size, large distribution width of grain size due to interaction of static and dynamic recrystallization in CSP processing

关键词： CSP CCR hot-rolled plate grain size

Recrystallization Behavior Design for Controlling Grain Size in Strip Rolling Process

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Journal of Iron and Steel Research International 2008年第1期15卷 39-44页

作者： zhu guo-hui S V Subramanian School of Materials Science and Engineering Anhui University of Technology Ma＇anshan 243002 Anhui China Department of Materials Science and Engineering McMaster University Hamilton LSS 4A7 Ontario Canada

To promote effectively dynamic recrystallization and obtain a homogeneous distribution of ultrafine grain size in strip finish rolling process,the behavior of static and dynamic recrystallization must be appropriately designed to provide an ultrafine austenite microstructure without mixed grain *** design of rolling schedule was analyzed based on the control of the recrystallization behavior to achieve ultrafine grain size in the strip rolling process of niobium microalloyed *** experimental simulations were presented to validate the twice dynamic recrystallization design to achieve ultrafine grain size control.

关键词： twice dynamic recrystallization critical strain dynamic recrystallization ultrafine grain size

EXPERIMENTAL INVESTIGATION OF TIP CLEARANCE FLOW FOR AN AXIAL FLOW FAN ROTOR

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Chinese Journal of Mechanical Engineering 2006年第3期19卷 376-382页

作者： guo Qiang zhu Xiaocheng DU Zhaohui School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China

The flow field in the tip region of an axial ventilation fan is investigated with a particle image velocimeter （PIV） system at the design condition. Flow fields with three different tip clearances are surveyed on three different circumferential planes, respectively. The phase-locked average method is used to investigate the generation and the development of a tip leakage vortex. The result from PIV system is compared with that from a particle dynamics anemometer（PDA） system. Both data are in good agreement and the structure of the tip leakage vortex for the rotor is illustrated. The characteristic of a leakage vortex is described in both velocity vectors and vortical contours. The unsteadiness of the leakage vortex and the position of the vortex are surveyed in detail, which interprets the discrepancy between the numerical simulation and PDA experimental results to a certain extent. The center loci of tip leakage vortex at different times and the mean center loci of the leakage vortex are displayed particularly. Finally, the trajectories of the tip leakage vortex by the experimental measurement are compared with predictions from the existing models for high speed and high-pressure compressors and turbines when appropriately interpreted. A good agreement is obtained.

关键词： Axial ventilation fan Tip leakage vortex Particle image velocimetry (PIV) Vortex center trajectory

Electromigration in eutectic SnAg solder reaction couples with various ambient temperatures and current densities

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International Journal of Minerals,Metallurgy and Materials 2009年第6期16卷 685-690页

作者： Guang-chen Xu Fu guo Wan-rong zhu College of Materials Science and Engineering Beijing University of Technology Beijing 100124 China

The electromigration behavior of eutectic SnAg solder reaction couples was studied at various temperature （25 and 120℃ when the current density was held constant at 104 A/cm^2 or 5×10^3 A/cm^2. Under the current density of 104 A/cm^2, scallop type Cu6Sn5 spalls and migrates towards the direction of electron flow at room ambient temperature （25℃）, but transforms to layer type Cu3Sn and leaves Kirkendall voids in it at high ambient temperature （120℃）. Under the current density of 5×10^3 A/cm^2 plus room ambient temperature, no obvious directional migration of metal atoms/ions is found. Instead, the thermal stress induced by mismatch of dissimilar materials causes the formation of superficial valley at both interfaces. However, when the ambient temperature increases to 120℃, the mobility of metal atoms/ions is enhanced, and then the grains rotate due to the anisotropic property of β-Sn.

关键词： electromigration eutectic solder Joule heating intermetallic compound

Repairing whole facial nerve defects with xenogeneic acellular nerve grafts in rhesus monkeys

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Neural Regeneration Research 2022年第5期17卷 1131-1137页

作者： guo-Chen zhu Da-Jiang Xiao Bi-Wen zhu Yan Xiao Department of Otorhinolaryngology-Head and Neck Surgery Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical UniversityWuxiJiangsu ProvinceChina Department of Otorhinolaryngology-Head and Neck Surgery Affiliated Wuxi Clinical College of Nantong UniversityWuxiJiangsu ProvinceChina College of Animal Science&Technology Zhongkai University of Agriculture and EngineeringGuangzhouGuangdong ProvinceChina Department of Pathology Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical UniversityWuxiJiangsu ProvinceChina

Acellular nerve allografts conducted via chemical extraction have achieved satisfactory results in bridging whole facial nerve defects clinically,both in terms of branching a single trunk and in connecting multiple branches of an extratemporal ***,in the clinical treatment of facial nerve defects,allogeneic donors are *** this experiment,we exposed the left trunk and multiple branches of the extratemporal segment in six rhesus monkeys and dissected a gap of 25 mm to construct a monkey model of a whole left nerve *** monkeys were randomly assigned to an autograft group or a xenogeneic acellular nerve graft *** the autograft group,the 25-mm whole facial nerve defect was immediately bridged using an autogenous ipsilateral great auricular nerve,and in the xenogeneic acellular nerve graft group,this was done using a xenogeneic acellular nerve graft with *** of facial symmetry,nerve-muscle electrophysiology,retrograde transport of labeled neuronal tracers,and morphology of the regenerated nerve and target muscle at 8 months postoperatively showed that the faces of the monkey appeared to be symmetrical in the static state and slightly asymmetrical during facial movement,and that they could actively close their eyelids *** degree of recovery from facial paralysis reached House-Brackmann grade II in both *** muscle action potentials were recorded and orbicularis oris muscles responded to electro-stimuli on the surgical side in each *** Gold-labeled neurons could be detected in the facial nuclei on the injured *** staining showed abundant neurofilament-200-positive axons and soluble protein-100-positive Schwann cells in the regenerated nerves.A large number of mid-graft myelinated axons were observed via methylene blue staining and a transmission electron *** together,our data indicate that xenogeneic acellular nerve grafts from minipigs are safe and effec

关键词： acellular nerve compound muscle action potentials facial nerve defect facial symmetry monkey nerve graft nerve regeneration retrograde labeling test synaptophysin xenogeneic

Quantum Dynamics of Bound Entangled States

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Communications in Theoretical Physics 2008年第2期49卷 343-346页

作者： zhu guo-Qiang WANG Xiao-Guang Zhejiang Institute of Modern Physics Zhejiang University Hangzhou 310027 China Department of Physics and Institute of Theoretical Physics The Chinese University of Hong Kong Hong Kong China

By using the partial transpose and realignment method, we study the time evolution of the bound entanglement under the bilinear-biquadratie Hamiltonian. For the initial Horodecki＇s bound entangled state, it keeps bound entangled for some time, while for the initial bound entangled states constructed from the unextendable product basis, they become free once the time evolution begins. The time evolution provides a new way to construct bound entangled states, and also gives a method to free bound entanglement.

关键词： entanglement quantum dynamics