检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

氯化钠对马铃薯酪氨酸酶的抑制作用

食品科技 2010年第5期35卷 32-35页

作者：苟琳姚倩傅泱四川农业大学生命科学与理学学院雅安625014

马铃薯在加工过程中易受酪氨酸酶催化发生酶促褐变。实验研究了氯化钠对马铃薯酪氨酸酶的抑制作用。结果表明:NaCl对马铃薯酪氨酸酶有明显的抑制作用,其半抑制率(IC50)为0.2mol/L,抑制机理表现为可逆非竞争性抑制,抑制常数为4.68mmol/L... 详细信息

马铃薯在加工过程中易受酪氨酸酶催化发生酶促褐变。实验研究了氯化钠对马铃薯酪氨酸酶的抑制作用。结果表明:NaCl对马铃薯酪氨酸酶有明显的抑制作用,其半抑制率(IC50)为0.2mol/L,抑制机理表现为可逆非竞争性抑制,抑制常数为4.68mmol/L。氯化钠可作为抑制马铃薯酪氨酸酶褐变的添加剂。

关键词：马铃薯酪氨酸酶氯化钠抑制作用

Atomic-scale dissecting the formation mechanism of gradient nanostructured layer on Mg alloy processed by a novel high-speed machining technique

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第23期82卷 227-238页

作者： Hui fu Xiaoye Zhou Bo Wu Lei qian Xu-Sheng yang State Key Laboratory of Ultra-precision Machining Technology Advanced Manufacturing Technology Research CentreDepartment of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute ShenzhenChina Guangdong Province Key Laboratory of Durability for Marine Civil Engineering School of Civil EngineeringShenzhen UniversityShenzhen 518060China

Severe plastic deformation(SPD)-induced gradient nanostructured(GNS)metallic materials exhibit superior mechanical performance,especially the high strength and good *** this study,a novel high-speed machining SPD technique,namely single point diamond turning(SPDT),was developed to produce effectively the GNS layer on the hexagonal close-packed(HCP)structural Mg *** high-resolution transmission electron microscopy observations and atomistic molecular dynamics simulations were mainly performed to atomic-scale dissect the grain refinement process and corresponding plastic deformation mechanisms of the GNS *** was found that the grain refinement process for the formation of the GNS Mg alloy layer consists of elongated coarse grains,lamellar fine grains with deformation-induced-tension twins and contraction twins,ultrafine grains,and nanograins with the grain size of~70 nm along the direction from the inner matrix to ***,experiment results and atomistic simulations reveal that these deformation twins are formed by gliding twinning partial dislocations that are dissociated from the lattice dislocations piled up at grain *** corresponding deformation mechanisms were evidenced to transit from the deformation twinning to dislocation slip when the grain size was below 2.45μ***,the Hall-Petch relationship plot and the surface equivalent stress along the gradient direction estimated by finite element analysis for the SPDT process were incorporated to quantitatively elucidate the transition of defo rmation mechanisms during the grain refinement *** findings have implications for the development of the facile SPD technique to construct high strength-ductility heterogeneous GNS metals,especially for the HCP metals.

关键词： Gradient nanostructured Mg alloy High-speed machining Deformation twinning High-resolution transition electron microscopy Hall-Petch relationship

Asynchronism of the spreading dynamics underlying the bursty pattern

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第5期29卷 586-592页

作者： Tong Wang Ming-yang Zhou Zhong-qian fu Department of Electronic Science and Technology University of Science and Technology of ChinaHefei 230027China Guangdong Province Key Laboratory of Popular High Performance Computers College of Computer Science and Software EngineeringShenzhen UniversityShenzhen 518060China Department of Physics University of FribourgChemin du Mus´ee 3FribourgCH-1700Switzerland

The potential mechanisms of the spreading phenomena uncover the organizations and functions of various ***,due to the lack of valid data,most of early works are limited to the simulated process on model *** this paper,we track and analyze the propagation paths of real spreading events on two social networks:Twitter and *** empirical analysis reveals that the spreading probability and the spreading velocity present the explosive growth within a short period,where the spreading probability measures the transferring likelihood between two neighboring nodes,and the spreading velocity is the growth rate of the information in the whole ***,we observe the asynchronism between the spreading probability and the spreading *** explain the interesting and abnormal issue,we introduce the time-varying spreading probability into the susceptible-infected(SI)and linear threshold(LT)*** the analytic and experimental results reproduce the spreading phenomenon in real networks,which deepens our understandings of spreading problems.

关键词： social network information diffusion spreading probability asynchronism

Pore-scale lattice Boltzmann simulation of flow and mass transfer in bioreactor with an immobilized granule for biohydrogen production

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2017年第1期62卷 22-30页

作者： qiang Liao Yan-Xia yang Xun Zhu Rong Chen qian fu Key Laboratory of Low-grade Energy Utilization Technologies and Systems Chongqing University Ministry of Education Chongqing 400030 China Institute of Engineering Thermophysics Chongqing University Chongqing 400030 China

The photo bioreaction combined with flow and mass transfer is simulated with pore-scale lattice Boltzmann （LB） method, which is the scenario of a bioreactor filled with a porous granule immobilized photosynthetic bacteria cells for hydrogen production. The quartet structure generation set （QSGS） is used to generate porous structure of the immobilized granule. The effects of porosity of the immobilized granule on flow and concentration fields as well as the hydrogen production performance are investi- gated. Higher porosity facilitates the substrate solution smoothly flowing through the porous granule with increasing velocity, and thus results in higher product concentration inside the immobilized gran- ule. Additionally, the substrate consumption efficiency increases, while hydrogen yield slightly decreases with increasing porosity, and they tend to stable for the porosity larger than 0.5. furthermore, the LB numerical results have a good agreement with the experimental results. It is demonstrated that the pore-scale LB simulation method coupling with QSGS is available to simulate the photo hydrogen produc- tion in the hioreactor with porous immobilized granules.

关键词： Lattice Boltzmann method Pore scale Immobilized granule Photo biohydrogen production

Heat Transfer Characteristics outside the Condenser of a Rotating Heat Pipe Grinding Wheel with a Lateral Air Impinging Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2021年第2期30卷 493-503页

作者： CHEN Jiajia ZHANG Liyong fu Yucan qian Ning JIANG Huafei yang Lin College of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing 210037China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Jiangsu Wind Power Generation Engineering&Technology Center Nanjing 210023China

This study numerically analyzed the heat transfer characteristics outside the condenser of a rotating heat pipe grinding wheel(RHP-GW).The goal of this investigation is to determine the optimal structure and parameters for the condenser section of *** fin height(f=0-7 mm),rotational Reynolds number(Rer=1602-6408)and jet Reynolds number(Rej=42379-108302)were analyzed under input heat flux of 4000 W/m2.A fully developed flow was imposed at the outlet of the *** showed that the optimal heat transfer rate was obtained for fin height of 5 mm,which improved the average Nusselt number by 84%compared to the structure without fins.A critical Rej for each Rer that the impinging jet can reach the condenser section was *** critical Rej value increases with Rer,which is in the range from 42379 to 61215 and 61215 to 80050 for Rer=6408 and Rer=9610,respectively.

关键词： rotating heat pipe grinding wheel impinging jet heat transfer numerical analysis

Significant annealing-induced hardening effect in nanolaminate d-nanotwinne d(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)me dium-entropy alloy by severe cold rolling

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第3期170卷 156-166页

作者： Shuqing Yuan Hui fu Lei qian Chi Fai Cheung Xu-Sheng yang State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518060China

Due to the easy coarsening caused by poor thermal stability,the verified annealing-induced hardening in nanograined metals can only maintain at a relatively low-temperature *** this study,a nanolam-inated(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)medium-entropy alloy with an average lamellae thickness of∼20 nm embedded by thinner nanotwins was fabricated by severe cold rolling to achieve superior thermal *** with the conventional nanotwinned CrCoNi with nanotwins inside ultra-fined grains,the hier-archical nanolaminated-nanotwinned(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8) exhibits a significant annealing-induced hard-ening effect,i.e.,hardness increasing from∼250 HV in the original specimen to∼500 HV in the cold-rolled status and finally∼630 HV after annealing at 600℃for 1 *** microstructure characterizations reveal that the reduced dislocation density and formation of L1_(2)ordered domain are mainly responsible for such hardening effect,which is facilitated by the effectively suppressed coarsening with annealing temperature,i.e.,slow detwinning process and well-retained low-angle nanolamellar *** coarsening mechanisms from the cold-rolled nanolamellae to the fully recrystallized micro-equiaxed structures under the annealing temperatures ranging from 400 to 800℃ were also elucidated by atomic observations.

关键词： Annealing-induced hardening Thermal stability Nanolaminated-nanotwinned structure CrCoNi Detwinning Grain boundary migration

Discovery of a new family member of arsenic–vanadium polyoxometalates with high catalytic performance for one-pot coupling of CO2, epoxides and amines

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tungsten 2025年第1期 80-87页

作者： Fang-qian Wang Yin Zhang Wei-Wei Wang Mei-qian fu Hong-Bing Mo Wei-Dong Yu Chao Liu Jun Yan College of Chemistry and Chemical Engineering Central South University Junior Education Department Changsha Normal University School of Science Hunan University of Technology and Business

Arsenic-vanadium polyoxometalates（POMs） represent a family of tremendous potential catalysts owing to their peculiar physical and chemical *** in CO2conversion,using POMs to catalyze the conversion of CO2and epoxide into chemical intermediates is the research ***,A new family number of arsenic-vanadium POMs,[N（CH3）4]4[As8V12O38（H2O）]·2H2O({As8V12O38}),was reported and characterized by single-crystal X-ray diffraction,fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,*** from other allotropicity,{As8V12O38}shows a different structure pattern with an I-43d *** obtained {As8V12O38} was employed as a catalyst for the *** initial catalytic reaction confirmed that {As8V12O38} can catalyze the formation of epoxy carbonate by using 1.01 kPa CO2and epoxide at 70℃.furtherly,when added amine in the catalytic system,oxazolidinone could be obtained by high yields,which provides an efficient way to convert CO2into profitable ***,a possible catalytic reaction mechanism was proposed by using different characterization analyses.{As8V12O38} first catalyzes the epoxide and CO2to form an epoxy carbonate and then catalyzes epoxy carbonate and benzylamine into oxazolidinone.

关键词：

Physical-based constitutive model considering the microstructure evolution during hot working of AZ80 magnesium alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2019年第1期7卷 30-41页

作者： Ze-Xing Su Chao-yang Sun Ming-Wang fu Ling-Yun qian School of Mechanical Engineering University of Science and Technology Beijing Beijing 100083 People's Republic of China Beijing Key Laboratory of Lightweight Metal Forming Beijing 100083 People's Republic of China Department of Mechanical Engineering The Hong Kong Polytechnic University Hung Hom Hong Kong People's Republic of China

A physical-based constitutive model was developed to model the viscoplastic flow behavior and microstructure evolution of AZ80 magnesium alloy during the hot working process. The competing deformation mechanisms, including work hardening, dynamic recovery, and dynamic recrystallization, in an isothermal compression environment were considered in the model. The internal state variables, including the normalized dislocation density and recrystallized volume fraction, were incorporated into the model to articulate the microstructure evolution during hot deformation. The kinetic condition critical for dynamic recrystallization, considering the effects of the deformation temperature and strain rate, was obtained by employing both the Poliak-Jonas criterion and Zener-Hollomon parameter. Microstructure observations indicate that the recrystallized volume fraction increases with decreasing Z parameter at constant strain, which is consistent with the predicted kinetics model. Based on the developed model, a good correlation was also obtained between the predicted and experimental flow stress. The results indicate a good predictability of the model in describing the hot deformation behavior and microstructure evolution of AZ80 magnesium alloy.

关键词： AZ80 magnesium alloy Hot deformation Constitutive model Microstructure evolution Dynamic recrystallization (DRX)

Isotope Effect in Collision Between Helium Atom and Hydrogen Molecule

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 1998年第1期15卷 19-20页

作者： yang Xiang-dong ZHANG Ji-yan JlNG fu-qian Laboratory for Shock Wave and Detonation Physics Research Southwest Institute of Fluid PhysicsP.O.Box 523Chengdu 610003 Institute of Atomic and Molecular Science under High Temperature and High Pressure Sichuan Union UniversityChengdu 610065

Rotationally inelastic He-H_(2),D_(2),T_(2) collision was studied *** cross sections were calculated by using the close coupling method for relative kinetic energies of 0.01 to 0.54 ***-Oppenheimer approximation was employed to determine the potential surface of He-D_(2),He-T_(2),and He-H_(2).Careful comparison between the cross sections of the isotopically substituted systems was carried out,and the regular changes of the total cross sections of the isotopically substituted He-H_(2) colliding systems were obtained.

关键词： substituted collision cross