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11篇 您的检索式:作者名="Chengyi Yu"
    题名 作者 年代 出处 被引量
1Numerical simulations of land surface physical processes and land-atmosphere interactions over oasis-desert/Gobi region显示文摘A land-surface physical process model was coupled with a mesoscale atmospheric model. This cou- pled model was then used to simulate the interactions between land and the atmosphere, including surface temperature, net radiation, sensible heat flux and latent heat flux over a desert/Gobi with an oasis in northwestern semiarid regions in China. Comparisons between observations and simulations were made over the oasis and the desert/Gobi, respectively. Both cold island effect and wet island ef- fect, the so-called oasis effect, were observed and simulated. Lower temperature, higher specific hu- midity and weaker turbulent transfer were present over the oasis than the desert/Gobi. A subsidence occurred over the oasis, leading to a thermally-generated mesoscale circulation.LIU ShuHua LIU HePing HU Yu ZHANG ChengYi LIANG FuMing WANG JianHua 2007Science China Earth Sciences2007,50,2:9
2Isolation and identification of sinapine-degrading bacteria from the intestinal tract of laying hens显示文摘This study was aimed to isolate sinapine-degrading bacteria from the intestinal tract of laying hens and to identify the predominant bacteria. Thirty-week old healthy laying hens were killed, and the chyme in the digestive tract was inoculated into modified Czapek medium containing sinapin and cultivated at 37 ℃for 10 days. The optical density(OD) values of the bacterial solutions at different cultivating times were detected by a spectrophotometric method. The predominant strains were identified by 16 S rRNA gene analysis. We extracted the extracellular products of the predominant strains to determine the total protein using the Coomassie brilliant blue method, and to determine the activities of some extracellular enzymes using the agar plate diffusion method. Nine strains were isolated from the lower intestinal tract of laying hens. Among the 9 strains, 5 were from the ileum, 2 were from the ceca and 2 were from the jejunum. We could not isolate any strains from the upper intestinal tract, such as the stomach and duodenum. Eight of those 9 isolated strains were gram negative and one was gram positive. Strains YD-1 and YD-2 were better than other strains in their abilities to degrade sinapine. Strains YD-1 and YD-2 were identified as Escherichia coli and Klebsiella spp., respectively, by the 16 S rRNA sequence analysis.The total protein level of the extracellular products was 1.213 g/L for YD-1 and 1.990 g/L for YD-2. Both extracellular products of YD-1 and YD-2 had the activities of protease, amylase and urease. This study confirmed that the primary site of sinapine degradation is in the lower intestinal tract of laying hens. The sinapine-degrading strains are mainly gram negative. Strains YD-1 and YD-2 are predominant in degrading sinapine and they belong to E. coli and Klebsiella spp., respectively. Both extracellular products of YD-1 and YD-2 contain protease, amylase and urease. Strain YD-2 is better than strain YD-1 in its ability to degrade sinapine.Dan Yu Xiaoli Huang Chengyi Zou Bin Li Jing Duan Qin Yin 2016Animal Nutrition2016,,1:5
3Analysis of diffusion behavior of harmful emissions from trackless rubber-wheel diesel vehicles in underground coal mines显示文摘To define the diffusion behavior of harmful exhaust substances from diesel vehicles and support safety risk assessments of underground coal mines,we performed a multi-species coupling calculation of the emission and diffusion of harmful substances from a trackless rubber-wheel diesel vehicle.A computational fluid dynamics(CFD)model of the diffusion of harmful emissions was hence established and verified.From the perspective of risk analysis,the diffusion behavior and distribution of hazardous substances emitted by the diesel vehicle were studied under 4 different conditions;moreover,we identified areas characterized by hazardous levels of emissions.When the vehicle idled upwind in the roadway,high-risk areas formed behind and to the right of the vehicle:particularly high concentrations of pollutants were measured near the rear floor of the vehicle and within 5 m behind the vehicle.When the vehicle idled downwind,high-risk areas formed in front of it:particularly high concentrations of pollutants were measured near the floor and within 5 m from the front of the vehicle.In the above cases,the driver would not breathe highly polluted air and would be relatively safe.When the vehicle idled into the chamber,however,high-risk areas formed on both sides of the vehicle and near the upper roof.Forward entry of the vehicle caused a greater increase in the concentration of pollutants in the chamber and in the driver’s breathing zone compared with reverse entry.Yun Hua Wen Nie Qiang Liu Xiaofei Liu Chengyi Liu Weiwei Zhou Fengning Yu 2022International Journal of Mining Science and Technology2022,32,6:1
4GPER mediates enhanced cell viability and motility via non-genomic signaling induced by 17β-estradiol in triple-negative breast cancer cells显示文摘Tenghua Yu Manran Liu Haojun Luo Chengyi Wu Xi Tang Shifu Tang Ping Hu Yuzhao Yan Zhiliang Wang Gang Tu 2014Journal of Steroid Biochemistry and Molecular Biology2014,,:1
5Ability of split urea applications to reduce nitrous oxide emis sions: A laboratory incubation experiment显示文摘Yu Yongxiang Zhao Chengyi Jia Hongtao 2016Applied Soil Ecology2016,100,4:1
6Hot-melt extrusion promotes dissolution,extends“spring-parachute”process and inhibits crystallization in supersaturating microparticle systems显示文摘Despite the potential advantages of amorphism-induced supersaturation,the merit of new amorphiza-tion formation methods on the properties of the amorphous drug including the stability of the amor-phous state,dissolution/solubility,supersaturation,and'spring-parachute'process is still poorly understood,particularly for certain amorphous supersaturating drug delivery systems(aSDDS).The present work aimed to explore the detailed merit of current attractive amorphization manufacturing methods(i.g.,hot-melt extrusion(HME)technique)on the property improvement of aSDDS in form of amorphous solid dispersion microparticles by employing a model Bcs II drug nitrendipine and a polyvinylpyrrolidone-based model polymer copovidone.Many asDDS systems were developed by various methods,and their physicochemical properties were characterized by SEM,PXRD and DSC.HME-triggered amorphization induced superior supersaturation by the observation of the highest dissolution and solubility.HME induced the optimal supersaturation duration by the observed greatest extension of'spring-parachute'process(e.g,maximum AUCspring-parachute).HME technique is comparable with other techniques for the stabilization of amorphous state during storage.All aSDDS systems by HME and other methods showed improved long-term stability of the amorphous state in comparison to the pure amorphous drug.Fourier transformation infrared spectroscopy,Noyes-Whitney equation,nucleation theory and Gibbs free energy of transfer(△G)were used to analyze the underlying mechanisms.Mo-lecular mechanism studies indicated that HME caused a stronger crystallization inhibition effect in the asDDS systems than other methods,but molecular interaction is not a dominant mechanism for property enhancement caused by HME.For the mechanism associated with the polymer itself(PVPVA64),it could inhibit the drug recrystallization,solubilize the drug spontaneously and cause the improved molecular interactions in all aSDDS systems.This study provided a deep insight into detailed advantage of HME-triggered supersaturation/amorphization and facilitated the applications of the technique both in the field of particuology and in pharmaceutical industry.Yanfei Zhang Huifeng Zhang Huan Yu Yinghui Ma Chengyi Hao Xiaoying Lin Yong Zhang Zhengqiang Li Xianrong Qi Jia Zeng Nianqiu Shi 2023Particuology2023,,7:0
7Finite element analysis on deformation of high embankment in heavy-haul railway subjected to freeze-thaw cycles显示文摘Finite element simulations are increasingly providing a versatile environment for this topic. In this study, a two-dimensional finite element analysis is conducted to predict the deformation of high embankment in Bazhun heavy-haul railway, China. A recently developed nonlinear softening-type constitutive model is utilized to model the behavior of subgrade filling materials subjected to freeze-thaw cycles. For the convenience of practical application, the dynamic loading induced by a vehicle is treated as a quasi-static axle load. The deformation of this embankment with different moisture content under freeze-thaw cycles is compared. The results show that when subjected to the first freeze-thaw cycle, the embankment experienced significant deformation variations. Maximum deformation was usually achieved after the embankment with optimum moisture content experienced six freeze-thaw cycles, however, the embankment with moisture content of 8.0% and 9.5% deforms continuously even after experiencing almost ten freeze-thaw cycles. Overall, this study provides a simple nonlinear finite element approach for calculating the deformation of the embankment in changing climate conditions.ChengYi Yu Shuang Tian Liang Tang XianZhang Ling GuoQing Zhou 2015Research in Cold and Arid Regions2015,7,4:0
8One-pot enantioselective construction of 3,4-dihydro-2H-1,4-oxazines over Ru/Au relay catalysis and its mechanistic serendipity显示文摘The preparation of enantiomerically pure 1,4-oxazines remains a continuous challenge in synthetic chemistry because of their potential application in the total synthesis of morpholines.Herein,a one-pot asymmetric transfer hydrogenation/cyclization enantio-relay process catalyzed by Ru and Au bimetallic catalysts was developed.This enantio-relay process firstly allows the asymmetric transfer hydrogenation of alkynones to form chiral alkynols in the presence of(S,S)-mesityleneRuClTsDPEN(TsDPEN=N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine)and then the chiral alkynols could be converted into 3,4-dihydro-2H-1,4-oxazines in moderate to good yields with excellent enantioselectivity retention accompanied by AuCl(PPh_(3))/AgNTf_(2) and HCOOH.A series of sulfonamide-tethered alkynones were well tolerated in this process.Mechanistic studies indicated that the alkynols formed in the first step were initially transformed into a methylenemorpholine intermediate when AuCl(PPh_(3))/AgNTf_(2) and HCOOH were added,which can be further isomerized into chiral 3,4-dihydro-2H-1,4-oxazines with the addition of a second HCOOH.This protocol offers not only a practical method to access 3,4-dihydro-2H-1,4-oxazines from alkynones in an enantioselective version,but also enriches the arsenal of gold chemistry from a mechanistic point of view.Dongfeng Yang Chengyi Wang Yu Wang Guohua Liu Tanyu Cheng Rui Liu 2022Organic Chemistry Frontiers2022,9,1:0
9Ultralow Interfacial Thermal Resistance of Graphene Thermal Interface Materials with Surface Metal Liquefaction显示文摘Developing advanced thermal interface materials(TIMs)to bridge heat-generating chip and heat sink for constructing an efficient heat transfer interface is the key technology to solve the thermal management issue of high-power semiconductor devices.Based on the ultra-high basal-plane thermal conductivity,graphene is an ideal candidate for preparing high-performance TIMs,preferably to form a vertically aligned structure so that the basal-plane of graphene is consistent with the heat transfer direction of TIM.However,the actual interfacial heat transfer efficiency of currently reported vertically aligned graphene TIMs is far from satisfactory.In addition to the fact that the thermal conductivity of the vertically aligned TIMs can be further improved,another critical factor is the limited actual contact area leading to relatively high contact thermal resistance(20-30 K mm^(2) W^(−1))of the“solid-solid”mating interface formed by the vertical graphene and the rough chip/heat sink.To solve this common problem faced by vertically aligned graphene,in this work,we combined mechanical orientation and surface modification strategy to construct a three-tiered TIM composed of mainly vertically aligned graphene in the middle and micrometer-thick liquid metal as a cap layer on upper and lower surfaces.Based on rational graphene orientation regulation in the middle tier,the resultant graphene-based TIM exhibited an ultra-high thermal conductivity of 176 W m^(−1) K^(−1).Additionally,we demonstrated that the liquid metal cap layer in contact with the chip/heat sink forms a“liquid-solid”mating interface,significantly increasing the effective heat transfer area and giving a low contact thermal con-ductivity of 4-6 K mm^(2) W^(−1) under packaging conditions.This finding provides valuable guidance for the design of high-performance TIMs based on two-dimensional materials and improves the possibility of their practical application in electronic thermal management.Wen Dai Xing-Jie Ren Qingwei Yan Shengding Wang Mingyang Yang Le Lv Junfeng Ying Lu Chen Peidi Tao Liwen Sun Chen Xue Jinhong Yu Chengyi Song Kazuhito Nishimura Nan Jiang Cheng-Te Lin 2023Nano-Micro Letters2023,15,1:0
10An Integrated-Plasmonic Chip of Bragg Reflection and Mach-Zehnder Interference Based on Metal-Insulator-Metal Waveguide显示文摘In this paper,a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal(MIM)waveguide.According to the effective refractive index modulation caused by different waveguide widths in a period,a reflection channel with a large bandwidth is firstly achieved.Besides,the Mach-Zehnder interference(MZI)effect arises by shifting the gratings away from the waveguide center.Owing to different optical paths with unequal indices on both sides of the grating,a narrow MZI band gap will be obtained.It is interesting to find out that the Bragg reflector and Mach-Zehnder interferometer are immune to each other,and their wavelengths can be manipulated by the period and the grating length,respectively.Additionally,we can obtain three MZI channels and one Bragg reflection channel by integrating three different gratings into a large period.The performances are investigated by finite-difference time-domain(FDTD)simulations.In the index range of 1.33–1.36,the maximum sensitivity for the structure is as high as 1500 nm/RIU,and it is believed that this proposed structure can find widely applications in the chip-scale optical communication and sensing areas.Liang ZENG Jiaqi LI Chengyi CAO Xudong LI Xinyuan ZENG Quanhao YU Kunhua WEN Jun YANG Yuwen QIN 2022Photonic Sensors2022,12,3:0
11Strong Coupling of Magnetism and Lattice Induces Near-Zero Thermal Expansion over Broad Temperature Windows in ErFe10V2−xMox Compounds显示文摘Alloys with low thermal expansion could overcome thermal stress issues under temperature-fluctuated conditions and possess important application prospects,while they are restricted to finite chemical components and temperature windows.In this study,we report a novel class of near-zero thermal expansion(near ZTE)alloys,ErFe_(10)V_(2−x)Mo_(x),over a wide temperature range(120–440 K).Neutron diffraction and magnetic measurements demonstrated that the ErFe_(10)V_(2−x)Mo_(x)compounds exhibited complex ferrimagnetic(FIM)structures below Curie temperature(TC).The near-ZTE behaviors were closely related to the itinerant Fe 3d moments in the collinear FIM states,as well as the geometric[−Fe−Fe−]linkages.Further,X-ray absorption near-edge structure(XANES)spectra revealed that the nonmagnetic substitution changed the electronic valence states of Fe atoms,which,in turn,changed Fe 3d moments and TC,hence,regulating the thermal expansion behaviors.Our work provides an insight into chemical modifications of thermal expansion in magnetic intermetallic compounds.Wenjie Li Kun Lin Yili Cao Chengyi Yu Chin-Wei Wang Xinzhi Liu Kenichi Kato Yilin Wang Jiaou Wang Qiang Li Jun Chen Jinxia Deng Hongjie Zhang Xianran Xing 2021CCS Chemistry2021,3,3:0
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