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Chinese Journal of Polymer Science 2007年第6期25卷 545-553页

作者： Li-ming tang Ji feng yu Wang Advanced Materials Laboratory Department of Chemical Engineering Tsinghua University Beijing 100084 China

Five secondary amine terminated poly（ester-amine）s （defined as PEA） with controlled molecular structures were synthesized through reacting excessive piperazine with phthalicdiglycol diacrylate （PDDA） and 1,1,1-trimethylolpropane triacrylate （TMPTA） at a constant secondary amine/acrylate group ratio of 1.5/1 and at different PDDA/TMPTA molar ratios. Both IR and ^1H-NMR spectra indicated that all acrylate groups were consumed in the reaction, based on which the structural parameters were calculated from the ^1H-NMR spectra. With decreasing PDDA/TMPTA ratio, the content of secondary amine, degree of branching, molecular weight, Tg and Td increased accordingly. These polymers were further used as both crosslinkers and flexibilizers for a linear epoxy resin E51 to form cured films under ambient condition. The gel content, relative hardness and Tg of the resulting films increased as PEA molecules changed from linear to highly branching structures. Due to the flexibility of PEA molecules, all the films possessed excellent mechanical performance.

关键词： Poly(ester-amine) Molecular structure Epoxy resin Cured film.

PIV EXPERIMENTAL RESEARCH OF FLOW STRUCTURE IN RECtangULAR CHANNEL WITH TRANSVERSELY PLACED SPIRAL COIL INSERT

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Journal of Hydrodynamics 2012年第4期24卷 518-525页

作者： tang yu-feng TIAN Mao-cheng ZHANG Guan-min School of Energy Source and Power Engineering Shandong UniversityJinan 250061China

The flow field in a rectangular channel with a transversely placed spiral coil insert is investigated by Particle Image Velocimetry （PIV） measurements in both transverse and longitudinal sections. The experimental results show that multi-longitudinal vortices are induced downstream of the spiral coil and are distributed as a symmetrical vortex array along the horizontal central line of the transverse section. Along the mainstream, due to the spiral motion of the longitudinal vortices, the velocity fluctuates in a manner of the damped sinusoidal curve and the velocity component in the wall normal direction is improved in the channel. Com- pared with the flow field in a smooth channel it is found that the movement of the longitudinal vortices can cause a continuous dis- turbance near the channel walls and thus enhances the fluid velocity in the near wall region, which consequently leads to the redu- ction of the velocity gradient and a more uniform velocity distribution. With the increase of the Reynolds number, the induced longitudinal vortices gain strength and become straighter and closer to the channel walls, thus the turbulence intensity is further enha- nced in this area.

关键词： Particle Image Velocimetry (PIV) spiral coil longitudinal vortices flow disturbance

NUMERICAL SIMULATION OF FLOW AND HEAT TRANSFER CHARA-CTERISTICS OUTSIDE A PERIODICALLY VIBRATING TUBE

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Journal of Hydrodynamics 2008年第5期20卷 629-636页

作者： JIANG Bo TIAN Mao-cheng LENG Xue-li tang yu-feng PAN Ji-hong School of Energy Source and Power Engineering Shandong University Jinan 250061 China

Fluid flow and heat transfer characteristics outside a vibrating tube were numerically simulated by the dynamic mesh method. The mechanism of heat transfer enhancement via periodic vibration of the tube was explored by using the field synergy principle. It is found that the field synergy angle between fluid velocity vector and temperature gradient vector for a periodically vibrating tube is significantly smaller than that for a stationary tube, and it changes approximately according to the sinusoidal law in a vibration period. The effect of time phase of the vibration on the field synergy angle and convective heat transfer coefficient were also discussed. Results indicate that the vibration can enhance heat transfer and this effect is more remarkable when time phase angle ranges between 50° and 1400 in a half period. Especially when the time phase angle is 90°, the average field synergy angle outside the tube reaches the minimum, which leads to the best heat transfer performance.

关键词： heat transfer enhancement dynamic mesh vibration field synergy Computational Fluid Dynamics (CFD)

Reducing Subspaces of Toeplitz Operators Induced by a Class of Non-analytic Monomials over the Unit Ball

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1767-1777页

作者： Yan yue SHI Bo ZHANG Xu tang yu feng LU School of Mathematical Sciences Ocean University of ChinaQingdao 266100P.R.China School of Mathematics and Information Sciences Yantai UniversityYantai 264005P.R.China School of Mathematical Sciences Space Engineering UniversityBeijing 101416P.R.China School of Mathematical Sciences Dalian University of TechnologyDalian 116024P.R.China

In this paper,we describe the minimal reducing subspaces of Toeplitz operators induced by non-analytic monomials on the weighted Bergman spaces and Dirichlet spaces over the unit ball B_(2).It is proved that each minimal reducing subspace M is finite dimensional,and if dim M≥3,then M is induced by a ***,the structure of commutant algebra v(T_(w)N_(z)N):={M^(*)_(w)NM_(z)N,M^(*)_(z)NM_(w)N}′is determined by N and the two dimensional minimal reducing subspaces of(T_(w)N_(z)*** also give some interesting examples.

关键词： Reducing subspace operator-weighted shifts Toeplitz operator von Neumann algebra

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Concerted Steric and Electronic Strategy in Thermostable Salicylaldiminato Nickel Catalysts for Ethylene(Co)polymerization

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Chinese Journal of Polymer Science 2024年第8期42卷 1085-1092页

作者： Hong-yu Ji Hong-Liang Mu Chun-feng tang yu-Xing Zhang yue Chi Zhong-Bao Jian Key Laboratory of Advanced Structural Materials Ministry of EducationSchool of Materials Science and EngineeringChangchun University of TechnologyChangchun 130012China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Olefin polymerization is one of the most im portant chemical reactions in *** work presents a strategy that emphasizes the synergistic meta/poro-steric hindrance of N-aryl groups and electronic effects in newly synthesized neutral salicylaldiminato nickel *** nickel(Ⅱ)catalysts exhibit exceptional thermostability,ranging from 30℃to 130℃,demonstrating enhanced catalytic activities and broadly regulated polyethylene molecular weights(3-341 kg·mol^(-1))and controlled polymer branch density(2-102 brs/1000C).The preferred catalyst Ni3 with concerted steric and electronic effects enables the production of solid-state semi-crystalline polyethylene materials at temperatures below 90℃.Notably,Ni3 exhibits an impressive tolerance of 110℃and can withstand even the challenging polymerization temperature of 130℃,leading to the production of polyethylene wax and ***,functionalized polyethylene is produced.

关键词： Polyolefin Salicylaldiminato ligand Nickel catalyst Oil Wax

Metabolites isolated from Penicillium HDS-Z-1E, an endophytic fungal strain isolated from Taxus cuspidata and their activation effect of catalase

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Chinese Herbal Medicines 2024年第2期16卷 227-230页

作者： Chuan tang Rui Gao Xiaoyuan tang yu Zhang Weixing feng Baomin feng Xuan Lu College of Life and Health Dalian UniversityDalian 116622China

Objective:To study the compounds isolated from Penicillium HDS-Z-1E,an endophytic fungal strain isolated from Taxus cuspidata and their activation effect of catalase(CAT).Methods:The chemical constituents were isolated from Penicillium HDS-Z-1E,by using silica gel,Sephadex LH-20 and *** structural elucidations of five metabolites were elucidated on the basis of spectroscopic including 1 H-NMR,13C-NMR,HMBC and *** activation sites of catalase have been investigated by molecular ***:Five metabolites,compounds(1–5)were isolated from Penicillium HDS-Z-1E and identified as 4-hydroxy-4-methyltetrahydro-2H-pyran-2-one(1),4-hydroxymethyl-5,6-dihydro-pyran-2-one(2),5,6-dihydro-2-oxo-2H-pyran-4-carboxylic(3),N-acetyl-hydrazinobenzoic acid(4),and methyl 2-(2,5-dihydroxyphenyl)acetate(5).Conclusion:Compound 3 is a new *** 3 and 4 may have potential activators of catalase,providing a theoretical basis for the development of CAT activators.

关键词： catalase activators 5,6-dihydro-2-oxo-2H-pyran-4-carboxylic molecular simulation penicillium Taxus cuspidata Sieb.et Zucc

Development of a scintillating-fiber-based beam monitor for the coherent muon-to-electron transition experiment

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Nuclear Science and Techniques 2024年第4期35卷 156-164页

作者： yu Xu yun-Song Ning Zhi-Zhen Qin Yao Teng Chang-Qing feng Jian tang yu Chen Yoshinori Fukao Satoshi Mihara Kou Oishi School of Physics Sun Yat-sen UniversityGuangzhou 510275China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China High Energy Accelerator Research Organization(KEK) Ibaraki 305‑0801Japan Department of Physics Imperial College LondonLondon SW72AZUK

The coherent muon-to-electron transition(COMET)experiment is a leading experiment for the coherent conversion of μ^(-)N→e^(-)N using a high-intensity pulsed muon beamline,produced using innovative slow-extraction ***,it is critical to measure the muon beam *** set up a muon beam monitor(MBM),where scintillating fibers woven in a cross shape were coupled to silicon photomultipliers to measure the spatial profile and timing structure of the extracted muon beam for the *** MBM detector was tested successfully with a proton beamline at the China Spallation Neutron Source and took data with good performance in the commissioning *** development of the MBM,including its mechanical structure,electronic readout,and beam measurement results,are discussed.

关键词： Beam instrumentation Profile monitor Scintillating fiber Silicon photomultipliers

Data-driven modeling on anisotropic mechanical behavior of brain tissue with internal pressure

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Defence Technology（防务技术） 2024年第3期33卷 55-65页

作者： Zhiyuan tang yu Wang Khalil I.Elkhodary Zefeng yu Shan tang Dan Peng State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of Technology116023DalianPR China The Department of Mechanical Engineering The American University in CairoNew Cairo11835Egypt Department of Neurology The Second Hospital of Dalian Medical UniversityDalian116023PR China

Brain tissue is one of the softest parts of the human body,composed of white matter and grey *** mechanical behavior of the brain tissue plays an essential role in regulating brain morphology and brain ***,traumatic brain injury(TBI)and various brain diseases are also greatly influenced by the brain's mechanical *** white matter or grey matter,brain tissue contains multiscale structures composed of neurons,glial cells,fibers,blood vessels,etc.,each with different mechanical *** such,brain tissue exhibits complex mechanical behavior,usually with strong nonlinearity,heterogeneity,and directional *** a constitutive law for multiscale brain tissue using traditional function-based approaches can be very ***,this paper proposes a data-driven approach to establish the desired mechanical model of brain *** focus on blood vessels with internal pressure embedded in a white or grey matter matrix material to demonstrate our *** matrix is described by an isotropic or anisotropic nonlinear elastic model.A representative unit cell(RUC)with blood vessels is built,which is used to generate the stress-strain data under different internal blood pressure and various proportional displacement loading *** generated stress-strain data is then used to train a mechanical law using artificial neural networks to predict the macroscopic mechanical response of brain tissue under different internal ***,the trained material model is implemented into finite element software to predict the mechanical behavior of a whole brain under intracranial pressure and distributed body *** with a direct numerical simulation that employs a reference material model,our proposed approach greatly reduces the computational cost and improves modeling *** predictions made by our trained model demonstrate sufficient ***,we find that the level of internal blood pressur

关键词： Data driven Constitutive law Anisotropy Brain tissue Internal pressure

Efficacy and safety of Y- 2 sublingual tablet for patients with acute ischaemic stroke: protocol of a phase III randomised double- blind placebo- controlled multicentre trial

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Stroke & Vascular Neurology 2024年第1期9卷 90-95页

作者： yu Fu Renhong tang Rong Chen Anxin Wang Jinsheng Ren Shunwei Zhu Xiaofei feng Dongsheng Fan Deparment of Neurology Peking University Third HospitalBeijingChina State Key Laboratory of Neurology and Oncology Drug Development NanjingJiangsuChina Simcere Pharmaceutical Group Limited NanjingJiangsuChina Neurodawn Pharmaceutical Co. LtdNanjingJiangsuChina Department of Neurology Beijing Tiantan HospitalCapital Medical UniversityBeijingChina China National Clinical Research Center for Neurological Diseases Beijing Tiantan HospitalCapital Medical UniversityBeijingChina

Background and purpose Clinical studies have demonstrated that edaravone dexborneol can improve the functional outcomes in patients with acute ischaemic stroke(AIS).The present clinical trial aimed at testing the efficacy and safety of Y-2 sublingual tablet on 90-day functional outcome in patients with *** and design This is a randomised,double-blind,placebo-controlled,multicentre,parallel-group trial of Y-2 sublingual tablet on patients with *** estimated 914 patients at age of 18–80 years with AIS within 48 hours after symptom onset from 40 hospitals will be randomly assigned to receive Y-2 sublingual tablet or placebo for 14 *** are at score 6–20 points on National Institutes of Health Stroke Scale(NIHSS)and had a modified Rankin Scale(mRS)≤1 before this stroke,except mechanical thrombectomy and neuroprotective agents *** outcomes The primary outcome is the proportion of patients with mRS≤1 on day 90 after *** efficacy outcomes include mRS score on day 90,the proportion of patients with mRS≤2 on day 90;the change of NIHSS score from baseline to day 14 and the proportion of patients with NIHSS score≤1 at the days 14,30 and *** This trial will provide valuable evidence for the efficacy and safety of Y-2 sublingual table for improving 90 days the functional outcomes in patients with *** registration number NCT04950920.

关键词： patients protective centre

Cronkhite-Canada syndrome with esophagus involvement and sixyear follow-up:A case report

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World Journal of Gastroenterology 2024年第8期30卷 984-990页

作者： yu-Chen tang Department of Endocrinology The First Affiliated Hospital of Ningbo UniversityNingbo 315000Zhejiang ProvinceChina

BACKGROUND Cronkhite-Canada syndrome(CCS)is a rare,noninherited disease characterized by gastrointestinal polyposis with diarrhea and ectodermal *** polyps are distributed through the whole digestive tract,and they are common in the stomach and colon but very uncommon in the *** SUMMARY Here,we present a case of a 63-year-old man with skin hyperpigmentation accompanied by diarrhea,alopecia,and loss of his *** data indicated anemia,hypoalbuminemia,hypocalcemia,hypokalemia,and positive fecal occult *** showed numerous polyps scattered throughout the digestive tract,including the *** was treated with nutritional support and glucocorticoids with remission of his *** Comprehensive treatment led by hormonal therapy can result in partial or full remission of clinical *** should be individualized for each patient according to their therapy *** endoscopy is necessary for assessing mucosal disease activity and detecting malignant transformation.

关键词： Cronkhite-Canada syndrome Gastrointestinal polyposis Hormonal therapy Prognosis Case report