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Acta Mechanica Sinica 2008年第2期24卷 223-228页

作者： Jun Zhang Yingxi Liu Xiuzhen sun Shen yu Chi yu State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China Department of Otorhinolaryngology the Second Affiliated Hospital of Dalian Medical University Dalian 116027 China

To study the airflow distribution in human nasal cavity during respiration and the characteristic parameters of nasal structure, three-dimensional, anatomically accurate representations of 30 adult nasal cavity models were recons- tructed based on processed tomography images collected from normal people. The airflow fields in nasal cavities were simulated by fluid dynamics with finite element software ANSYS. The results showed that the difference of human nasal cavity structure led to different airflow distribution in the nasal cavities and variation of the main airstream passing through the common nasal meatus. The nasal resistance in the regions of nasal valve and nasal vestibule accounted for more than half of the overall resistance. The characteristic model of nasal cavity was extracted on the basis of characteristic points and dimensions deduced from the original models. It showed that either the geometric structure or the airflow field of the two kinds of models was similar. The characteristic dimensions were the characteristic parameters of nasal cavity that could properly represent the original model in model studies on nasal cavity.

关键词： Nasal cavity Characteristic dimension Three-dimensional reconstruction Numerical simulation of flowfield Computational fluid dynamic Finite element method

Production and characterization of high porosity porous Fe?Cr?C alloys by the space holder leaching technique

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International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 793-798页

作者： Da-rong Tian yu-hua Pang Liang yu Li sun School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055China Research Center of Metallurgical Engineering and Technology of Shaanxi Province Xi'an 710055China AVIC Xi'an Aircraft Industry(Group)Company Ltd. Xi'an 710000China

Spherical carbamide particles were employed to produce porous Fe–Cr–C alloy with high porosity and large aperture via the space-holder leaching technique. A series of porous samples were prepared by regulating the processing parameters, which included the carbamide content and the compaction pressure. The pore characteristics and compression properties of the produced samples were investigated. The samples were characterized by scanning electron microscopy, image analysis, and compression tests. The results showed that the macro-porosity and the mean pore size were in the ranges 40.4%–82.4% and 0.6–1.5 mm, respectively. The compressive strength varied between 25.38 MPa and 127.9 MPa, and was observed to decrease with increasing total porosity.

关键词： porous metal powder metallurgy cellular manufacturing porosity compressive strength

Efficient video downscaling transcoder from MPEG-2 to H.264

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第4期9卷 457-463页

作者： Xiang-wen WANG Jun sun Rong XIE Song-yu yu Shanghai Key Lab. of Digital Media Processing ＆ Transmissions Institute of lmage Communication ＆ Information Processing Shanghai Jiao Tong University Shanghai 200240 China

The new H.264 video coding standard achieves significantly higher compression performance than MPEG-2. As the MPEG-2 is popular in digital TV, DVD, etc., bandwidth or memory space can be saved by transcoding those streams into H.264 in these applications. Unfortunately, the huge complexity keeps transcoding from being widely used in practical applications. This paper proposes an efficient transcoding architecture with a smart downscaling decoder and a fast mode decision algorithm. Using the proposed architecture, huge buffering memory space is saved and the transcoding complexity is reduced. Performance of the proposed fast mode decision algorithm is validated by experiments.

关键词： Video transcoding Mode decision Edge direction analysis

On the emergence of gravitational dynamics from tensor networks

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Communications in Theoretical Physics 2023年第8期75卷 134-138页

作者： Hua-yu Dai Jia-Rui sun yuan sun School of Physics and Astronomy Sun Yat-Sen UniversityGuangzhou 510275China

Tensor networks are used to describe the ground state wavefunction of the quantum many-body ***,it has been shown that a tensor network can generate the anti-de Sitter(AdS)geometry by using the entanglement renormalization approach,which provides a new way to realize bulk reconstruction in the AdS/conformal field theory ***,whether the dynamical connections can be found between the tensor network and gravity is an important unsolved *** this paper,we give a novel proposal to integrate ideas from tensor networks,entanglement entropy,canonical quantization of quantum gravity and the holographic principle and argue that the gravitational dynamics can be generated from a tensor network if the wave function of the latter satisfies the Wheeler–DeWitt equation.

关键词： AdS/CFT correspondence tensor network emergent gravity

Anticancer drug discovery by targeting cullin neddylation

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Acta Pharmaceutica Sinica B 2020年第5期10卷 746-765页

作者： Qing yu Yihan Jiang Yi sun Cancer Institute of the 2nd Affiliated Hospital Institute of Translational MedicineZhejiang University School of MedicineHangzhou 310029China Division of Radiation and Cancer Biology Department of Radiation OncologyUniversity of MichiganAnn ArborMI 48109.USA

Protein neddylation is a post-translational modification which transfers the ubiquitin-like protein NEDD8 to a lysine residue of the target substrate through a three-step enzymatic *** bestknown substrates of neddylation are cullin family proteins,which are the core component of Cullin-RING E3 ubiquitin ligases(CRLs).Given that cullin neddylation is required for CRL activity,and CRLs control the turn-over of a variety of key signal proteins and are often abnormally activated in cancers,targeting neddylation becomes a promising approach for discovery of novel anti-cancer *** the past decade,we have witnessed significant progress in the field of protein neddylation from preclinical target validation,to drug screening,then to the clinical trials of neddylation *** this review,we first briefly introduced the nature of protein neddylation and the regulation of neddylation cascade,followed by a summary of all reported chemical inhibitors of neddylation *** then discussed the structure-based targeting of protein-protein interaction in neddylation cascade,and finally the available approaches for the discovery of new neddylation *** review will provide a focused,up-to-date and yet comprehensive overview on the discovery effort of neddylation inhibitors.

关键词： Neddylation Anticancer Drug discovery Ubiquitin-proteasome system Small molecule inhibitors Virtual screen High-throughput screening

A Note on Gradient Estimates for Elliptic Equations with Discontinuous Coefficients

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 1-10页

作者： yu PENG Xiandong sun Huichun ZHANG Department of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China.

The authors will use a method in metric geometry to show an L^(P)-estimate for gradient of the weak solutions to elliptic equations with discontinuous coefficients,even the BMO semi-norms of the coefficients are not *... 详细信息

关键词： L^(p)-Estimate Elliptic equation Discontinuous coefficients

Molecular-Dynamics Simulations of Droplets on a Solid Surface

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Chinese Physics Letters 2010年第6期27卷 152-155页

作者： GAO yu-Feng sun De-Yan Department of Physics East China Normal University Shanghai 200062

By using a semi-empirical Lennard-Jones embedded-atom-method potential, we study the influence of many-body forces and atomic size mismatch on the wetting behavior of nano droplets on a solid surface. With molecular dynamics simulations, we find that the contact angle decreases with increasing many-body forces. The increase of atomic size mismatch between solid and liquid results in the decrease of contact angles. Our calculation also shows that the interface structure is strongly affected by the interaction between liquid and solid as well as the atomic size mismatch. For weak solid-liquid interaction, the interface layer of the droplet nearest to the solid exhibits a typical simple liquid structure regardless of the size mismatch. For strong solid-liquid interaction, evident ordering in the interface layer is observed for well matched cases.

关键词： Forcing Dimensions Angling Wells Layering Liquids Liquid assets Solids

Determining the soil-water retention curve using mercury intrusion porosimetry test in consideration of soil volume change

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第5期12卷 1070-1079页

作者： Wen-Jing sun yu-Jun Cui State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Department of Civil Engineering School of Mechanics and Engineering ScienceShanghai UniversityShanghai200444China Ecole des Ponts ParisTech Laboratoire Navier/CERMES6e8 avenue Blaise PascalCitéDescartesChamps-sur-MarneMarne-la-Vallée cedex 277455France Institute for the Conservation of Cultural Heritage Shanghai200444China

It is well-known that a close link exists between soil-water retention curve(SWRC)and pore size distribution(PSD).Theoretically,mercury intrusion porosimetry(MIP)test simulates a soil drying path and the test results can be used to deduce the SWRC(termed SWRCMIP).However,SWRCMIP does not include the effect of volume change,compared with the conventional SWRC that is directly determined by suction measurement or suction control *** deformable soils,there is a significant difference between conventional SWRC and *** this study,drying test was carried out on a reconstituted silty soil,and the volume change,suction,and PSD were measured on samples with different water *** change in the deduced SWRCMIP and its relationship with the conventional SWRC were *** results showed that the volume change of soil is the main reason accounting for the difference between conventional SWRC and *** on the test results,a transformation model was then proposed for conventional SWRC and SWRCMIP,for which the soil state with no volume change is taken as a *** between the experimental and predicted SWRCs showed that the proposed model can well consider the influence of soil volume change on its water retention property.

关键词： Soil-water retention curve(SWRC) Mercury intrusion porosimetry(MIP) Pore size distribution(PSD) Deformable soils

Implications from protein uptake kinetics onto dextran-grafted Sepharose FF coupled with ion exchange and affinity ligands

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Chinese Journal of Chemical Engineering 2017年第7期25卷 906-910页

作者： Aiying Xue Linling yu Yan sun Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Our previous studies have reported the presence of "chain delivery" effects of protein adsorption onto ion exchangers with polymer-grafted ion-exchange groups, such as dextran-grafted and poly(ethylenimine)-modified Sepharose gels. However, it is unclear if the "chain delivery" occurs on affinity adsorption with specific interactions. This work is designed to address this issue. A dextran-grafted Sepharose gel was prepared, and then the matrix was modified using diethylaminoethyl, a typical ion-exchange group, or octapeptide(FYCHWQDE), an affinity ligand for human immunoglobulin G(h Ig G) to prepare ion-exchange or affinity adsorbents, *** of h Ig G adsorption showed that the uptake rate represented by the effective diffusivity of h Ig G onto the dextran-grafted ion exchangers was obviously enhanced by the dextran grafting, indicating the presence of"chain delivery" of the bound proteins on the charged groups on the dextran chains. By contrast, the effective diffusivity of h Ig G changed little as ligand density increased on the dextran-grafted FYCHWQDE *** adsorption capacities decreased and effective diffusivities were not accelerated by the dextran ***, this work clarified that grafted dextran could not accelerate h Ig G uptake rate on the affinity resins, or in other words, chain delivery did not occur on the specific interaction-based affinity adsorption.

关键词： Dextran-grafted adsorbent Ion exchange chromatography Affinity chromatography lmmunoglobulin G Kinetics

Synthesis of Stimuli-Responsive Block Copolymers and Block Copolymer Nano-assemblies

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Chinese Journal of Chemistry 2022年第8期40卷 965-972页

作者： yuan Liu yu sun Wangqing Zhang Key Laboratory of Functional Polymer Materials of the Ministry of Education Institute of Polymer ChemistryCollege of ChemistryNankai UniversityTianjin 300071China

Block copolymers have aroused much interest,and their application has been rapidly *** recent years,our group has committed to exploring synthesis and self-assembly of block *** have designed and synthesized several new thermo-responsive polymers and photo-responsive polymers by living/controlled radical polymerization(LCRP)and investigated their stimuli-responsive *** at convenient and efficient synthesis of block copolymer nano-assemblies,we have developed several methods based on polymerization-induced self-assembly(PISA).Herein,we give a short summary of our research in these *** aim of this account is to stimulate innovative synthesis strategies of block copolymer nano-assemblies,and promote more scientific research cooperation to face the exciting opportunities and challenges encountered in block copolymers.

关键词： Block copolymers Living/controlled radical polymerization(LCRP) Stimuli-responsive Self-assembly Nanostructures