期刊文献+
共找到63篇文章
< 1 2 4 >
每页显示 20 50 100
英语短语动词的三要素——以away组成的含gradually之义的短语动词为例
1
作者 赵静云 《安徽农业大学学报(社会科学版)》 2003年第6期124-128,共5页
从语义的角度来对短语动词进行系统地认知是一种科学的新理念、新方法。以短语动词中的副词或介词为主线来进行纵向的组群亦是切实可行的一种好方法。然后在横向上辨析相关的同义的短语。以三者的有机结合所形成的复合思维来加以认知则... 从语义的角度来对短语动词进行系统地认知是一种科学的新理念、新方法。以短语动词中的副词或介词为主线来进行纵向的组群亦是切实可行的一种好方法。然后在横向上辨析相关的同义的短语。以三者的有机结合所形成的复合思维来加以认知则更具特色。由away组成的短语动词可表数个意义。含“gradually”之义时,所表意义为动状关系。 展开更多
关键词 英语 短语动词 三要素 away gradually 语义认知 纵向组群 动状关系
下载PDF
A gradually descent method for discrete global optimization 被引量:1
2
作者 杨永建 张连生 《Journal of Shanghai University(English Edition)》 CAS 2007年第1期39-44,共6页
In this paper, a new method named as the gradually descent method was proposed to solve the discrete global optimization problem. With the aid of an auxiliary function, this method enables to convert the problem of fi... In this paper, a new method named as the gradually descent method was proposed to solve the discrete global optimization problem. With the aid of an auxiliary function, this method enables to convert the problem of finding one discrete minimizer of the objective function f to that of finding another at each cycle. The auxiliary function can ensure that a point, except a prescribed point, is not its integer stationary point if the value of objective function at the point is greater than the scalar which is chosen properly. This property leads to a better minimizer of f found more easily by some classical local search methods. The computational results show that this algorithm is quite efficient and reliable for solving nonlinear integer programming problems. 展开更多
关键词 gradually descent method nonlinear integer programming integer programming ALGORITHM
下载PDF
China's Science Gradually Strengthened
3
作者 Shangguan Yun 《China's Foreign Trade》 1995年第11期9-9,共1页
In order to ensure the steady development of our science, the Chinese government has continuously increased input in the last ten years. Information from the State Statistics Bureau shows that by the end of 1994, the ... In order to ensure the steady development of our science, the Chinese government has continuously increased input in the last ten years. Information from the State Statistics Bureau shows that by the end of 1994, the national institutions and enterprises boasted 18.659 million technical experts, 4.3 times the number in 1978, or 1258 technical experts every ten thousand people, redoubling that of 1978. The whole country has 5860 independent scientific research and development (R & D) institutions, 展开更多
关键词 HIGH China’s Science gradually Strengthened
下载PDF
Improved Plasticity and Cold-rolling Workability of Fe–6.5wt%Si Alloy by Warm-rolling with Gradually Decreasing Temperature 被引量:3
4
作者 Yuanke Mo Zhihao Zhang +1 位作者 Hongjiang Pan Jianxin Xie 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2016年第5期477-484,共8页
The effects of warm-rolling process on the microstructure, ordering, mechanical properties and cold- rolling workability of Fe-6.Swt%Si alloy were investigated, where three processes of warm-rolling with the same tota... The effects of warm-rolling process on the microstructure, ordering, mechanical properties and cold- rolling workability of Fe-6.Swt%Si alloy were investigated, where three processes of warm-rolling with the same total reduction of 93% were used, including (1) 500 ℃/12 passes/total reduction of 93%, (2) 500 ℃13 passes/total reduction of 50% + 400 ℃19 passes/total reduction of 86%, and (3) 500 ℃13 passes/total reduction of 50% + 400 ℃15 passes/total reduction of 60% + 300 ℃14 passes/total reduction of 64%. The results show that compared with process (1) warm-rolling with constant temperature of 500 ℃, process (2) and process (3) warm-rolling with gradually decreasing temperature can significantly improve the room temperature plasticity and cold-rolling workability of the Fe-6.5wt%Si alloy. For example, the three point bending fracture deflections are increased by 54.5% and 81.8% for processes (2) and (3), respectively, and the maximum reductions of single pass cold-rolling without edge crack are increased from 50% of process (1) to 55% of process (2) and 62% of process (3), respectively. The plasticity improvement of the Fe- 6.5wt%Si alloy can be attributed to both reductions of surface oxidation degree and order degree of the alloy by warm-rolling with gradually decreasing temperature. 展开更多
关键词 Fe–6.5wt%Si alloy Warm-rolling gradually decreasing temperature Ordering Mechanical property
原文传递
RANDOM GRADUALLY VARIED SURFACES FITTING
5
作者 陈溧 《Chinese Science Bulletin》 SCIE EI CAS 1992年第16期1325-1329,共5页
Let D be a digital manifold, J the subset of non-empty of D; and let A<sub>1</sub>, A<sub>2</sub>, …, A<sub>m</sub> be m real numbers with A<sub>1</sub>【A<sub>2&... Let D be a digital manifold, J the subset of non-empty of D; and let A<sub>1</sub>, A<sub>2</sub>, …, A<sub>m</sub> be m real numbers with A<sub>1</sub>【A<sub>2</sub>【…【A<sub>m</sub>. Supposing function f<sub>J</sub>: J → A<sub>1</sub>,…, A<sub>m</sub>, we want to find a function f<sub>D</sub>: D→{A<sub>1</sub>…, A<sub>m</sub>}, such that f<sub>D</sub> is gradual variation on D, having f<sub>D</sub>(x)=f<sub>J</sub>(x), x∈J. Such f<sub>D</sub> is called the gradually varied extension or interpolation of f<sub>J</sub>. 展开更多
关键词 gradually varied SURFACE RANDOM algorithm PROBABILITY distribution.
原文传递
THE NECESSARY AND SUFFICIENT CONDITION AND THE EFFICIENT ALGORITHMS FOR GRADUALLY VARIED FILL
6
作者 陈溧 《Chinese Science Bulletin》 SCIE EI CAS 1990年第10期870-873,共4页
Filling is an important part in pattern recognition and computer vision. In the discrete plane (grid of plane)∑<sub>2</sub>, fill means 'determination of the region D enclosed by the simple closed c... Filling is an important part in pattern recognition and computer vision. In the discrete plane (grid of plane)∑<sub>2</sub>, fill means 'determination of the region D enclosed by the simple closed curve J which is given beforehand'. In other words, if the valuation of the point on the contour J is 1, we want to do a valuation for ∑<sub>2</sub> to make the valuation of the point p be 1 iff point p belongs to D. 展开更多
关键词 gradually varied FILL DIGITAL MANIFOLD algorithm.
原文传递
Slowly and Gradually
7
作者 YU SHUJUN 《Beijing Review》 2010年第31期2-2,共1页
In the wake of the financial crisis, any signs of a slowdown will trigger fears. China, although its economy has resumed double-digit growth, is no exception. China’s first-half economicfigures released in mid-July s... In the wake of the financial crisis, any signs of a slowdown will trigger fears. China, although its economy has resumed double-digit growth, is no exception. China’s first-half economicfigures released in mid-July show its GDP grew 10.3 展开更多
关键词 GDP Slowly and gradually
原文传递
2016 Tungsten Concentrate: Stable But Slightly Tight Supply, Demand Gradually Recovers, Price Bottoms Up
8
《China Nonferrous Metals Monthly》 2017年第4期1-4,共4页
In 2016,China’s tungsten concentrate output declined,domestic and foreign downstream enterprises’tungsten raw material stocks were at a historical low,and the current market supply is stable but slightly tight;outpu... In 2016,China’s tungsten concentrate output declined,domestic and foreign downstream enterprises’tungsten raw material stocks were at a historical low,and the current market supply is stable but slightly tight;output of carbide alloy and other downstream products increased,while that of some elementary 展开更多
关键词 DOWN Demand gradually Recovers Price Bottoms Up Stable But Slightly Tight Supply Tungsten Concentrate high than
原文传递
Experimental study of the flow structure of decelerating and accelerating flows under a gradually varying flume 被引量:3
9
作者 王协康 易子靖 +2 位作者 闫旭峰 黄尔 刘兴年 《Journal of Hydrodynamics》 SCIE EI CSCD 2015年第3期340-349,共10页
The turbulence characteristics of both decelerating and accelerating flows under a gradually varying flume are investigated by using a three-dimensional down-looking acoustic Doppler velocimeter (ADV). The time-aver... The turbulence characteristics of both decelerating and accelerating flows under a gradually varying flume are investigated by using a three-dimensional down-looking acoustic Doppler velocimeter (ADV). The time-averaged velocity profiles are flatened except for the central parts, and fairly fit into logarithmic laws and those in the plane circulation under the gradual expansion are more likely to be negative. The complex secondary currents are identified under the present gradual transition attributed to the combination of driving forces induced by both the boundary configuration variation and the tmbalanced turbulence: a circulation on each side of the expansion and a pair of circulations on each side of the contraction. One sees an anisotropy in the turbulence intensities, the turbulence intensities increase or level out with the flow depth except those under expansion, and the V component of the turbulence intensity typically outweighs that in the streamwise direction. Apart from the above results, the respective particular distributions of the primary Reynolds shear stresses ( rxy and rxz ) under the gradual expansion and contraction can account for the patterns of the secondary currents in this investigation. 展开更多
关键词 turbulence characteristics secondary currents gradual transition non-uniform flows open channel
原文传递
Improvement of blue InGaN light-emitting diodes with gradually increased barrier heights from n- to p-layers 被引量:1
10
作者 Wu TIAN Xiong HUI Yang LI Jiangnan DAI Yanyan FANG Zhihao WU Changqing CHEN 《Frontiers of Optoelectronics》 EI CSCD 2013年第4期429-434,共6页
The advantages of blue InGaN light-emitting diodes (LED) with the active region of gradually increased barrier heights from n- to p-layers are studied. The energy band diagram, hole concentration, electrostatic fiel... The advantages of blue InGaN light-emitting diodes (LED) with the active region of gradually increased barrier heights from n- to p-layers are studied. The energy band diagram, hole concentration, electrostatic field near the electron blocking layer (EBL), and the internal quantum efficiency (IQE) are investigated by Crosslight simulation program. The simulation results show that the structure with gradually increased barrier heights has better performance over the equal one, which can be attributed to the mitigated polarization effect near the interface of the last barrier/EBL due to less interface polarization charges. Moreover, reduced barrier height toward the n-layers is beneficial for holes injection and transportation in the active region. As a result, holes are injected into the active region more efficiently and distributed uniformly in the quantum wells, with which both the IQE and the total lighting power are increased. Although it can lead to the broadening of the spontaneous emission spectrum, the increase is slight such that it has little effect on the application in solid-state lighting. 展开更多
关键词 INGAN light-emitting diodes (LED) polariza-tion effect gradual barrier height
原文传递
The gradual subduction-collision evolution model of Proto-South China Sea and its control on oil and gas 被引量:1
11
作者 Xiaojun Xie Wu Tang +5 位作者 Gongcheng Zhang Zhigang Zhao Shuang Song Shixiang Liu Yibo Wang Jia Guo 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第3期123-137,共15页
This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The re... This study involved outcrop,drilling,seismic,gravity,and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea(PSCS)and establish its evolution model.The results indicate that a series of arc-shaped ophiolite belts and calcalkaline magmatic rocks are developed in northern Borneo,both of which have the characteristics of gradually changing younger from west to east,and are direct signs of subduction and collision of PSCS.At the same time,the subduction of PSCS led to the formation of three accretion zones from the south to the north in Borneo,the Kuching belt,Sibu belt,and Miri belt.The sedimentary formation of northern Borneo is characterized by a three-layer structure,with the oceanic basement at the bottom,overlying the deep-sea flysch deposits of the Rajang–Crocker group,and the molasse sedimentary sequence that is dominated by river-delta and shallow marine facies at the top,recording the whole subduction–collision–orogeny process of PSCS.Further,seismic reflection and tomography also confirmed the subduction and collision of PSCS.Based on the geological records of the subduction and collision of PSCS,combined with the comprehensive analysis of segmented expansion and key tectonic events in the South China Sea,we establish the“gradual”subduction-collision evolution model of PSCS.During the late Eocene to middle Miocene,the Zengmu,Nansha,and Liyue–Palawan blocks were separated by West Baram Line and Balabac Fault,which collided with the Borneo block and Kagayan Ridge successively from the west to the east,forming several foreland basin systems,and PSCS subducted and closed from the west to the east.The subduction and extinction of PSCS controlled the oil and gas distribution pattern of southern South China Sea(SSCS)mainly in three aspects.First,the“gradual”closure process of PSCS led to the continuous development of many large deltas in SSCS.Second,the deltas formed during the subduction–collision of PSCS controlled the development of source rocks in the basins of SSCS.Macroscopically,the distribution and scale of deltas controlled the distribution and scale of source rocks,forming two types of source rocks,namely,coal measures and terrestrial marine facies.Microscopically,the difference of terrestrial higher plants carried by the delta controlled the proportion of macerals of source rocks.Third,the difference of source rocks mainly controlled the distribution pattern of oil and gas in SSCS.Meanwhile,the difference in the scale of source rocks mainly controlled the difference in the amount of oil and gas discoveries,resulting in a huge amount of oil and gas discoveries in the basin of SSCS.Meanwhile,the difference of macerals of source rocks mainly controlled the difference of oil and gas generation,forming the oil and gas distribution pattern of“nearshore oil and far-shore gas”. 展开更多
关键词 Proto-South China Sea gradual subduction-collision evolution model oil and gas distribution southern South China Sea BORNEO
下载PDF
Analysis of Key Physiological Characteristics of Portunus trituberculatus in Response to Short-Term Low Salinity Stress
12
作者 ZHANG Xinni LIU Qi +7 位作者 WANG Jiali GAO Gao NIU Mingming CHEN Lizhi WANG Huan WANG Fangfang WANG Chunlin MU Changkao 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第3期746-754,共9页
Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus i... Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus in response to short-term low salinity stress,the experiments of gradually decline and recovery as well as abrupt decline in salinity were carried out.The results showed that P.trituberculatus could survive in a certain low salinity range in the short term,and salinity 12 was the lowest tolerable salinity under the present experimental conditions.The change of the hemolymph osmotic pressure displayed significant positive correlations with water salinity,and the pressure was always higher than seawater osmotic pressure.Short-term low salinity stress changed the structure and morphology of gill tissue.The expansion of gill filament ends and epithelial cell shedding were conducive to osmotic adjustment.The activities of key ion transport enzymes such as Na^(+)-K^(+)-ATPase,carbonic anhydrase and V-ATPase also changed with the osmotic regulation,while Na^(+)-K^(+)-ATPase played a dominant role.In summary,as an osmotic adjustment species,P.trituberculatus rapidly adapt to the short-term low-salinity environment by osmotic adjustment in vivo,but salinity below salinity 12 is not conducive to its survival.Our result enriched the theoretical mechanism of osmotic regulation of P.trituberculatus,providing reference for the development of aquaculture technology of P.trituberculatus. 展开更多
关键词 Portunus trituberculatus gradual/abrupt decline in salinity GILL osmotic pressure ion transport enzymes
下载PDF
Material Removal Mechanism and Force Modeling in Ultrasonic Vibration-Assisted Micro-Grinding Biological Bone
13
作者 Jingang Sun Changhe Li +10 位作者 Zongming Zhou Bo Liu Yanbin Zhang Min Yang Teng Gao Mingzheng Liu Xin Cui Benkai Li Runze Li Yusuf Suleiman Dambatta Shubham Sharma 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第5期20-44,共25页
Micro-grinding with a spherical grinding head has been deemed an indispensable method in high-risk surgeries, such as neurosurgery and spine surgery, where bone grinding has long been plagued by the technical bottlene... Micro-grinding with a spherical grinding head has been deemed an indispensable method in high-risk surgeries, such as neurosurgery and spine surgery, where bone grinding has long been plagued by the technical bottleneck of mechanical stress-induced crack damage. In response to this challenge, the ultrasound-assisted biological bone micro-grinding novel process with a spherical grinding head has been proposed by researchers. Force modeling is a prerequisite for process parameter determination in orthopedic surgery, and the difculty in establishing and accurately predicting bone micro-grinding force prediction models is due to the geometric distribution of abrasive grains and the dynamic changes in geometry and kinematics during the cutting process. In addressing these critical needs and technical problems, the shape and protrusion heights of the wear particle of the spherical grinding head were frst studied, and the gradual rule of the contact arc length under the action of high-speed rotating ultrasonic vibration was proposed. Second, the mathematical model of the maximum thickness of undeformed chips under ultrasonic vibration of the spherical grinding head was established. Results showed that ultrasonic vibration can reduce the maximum thickness of undeformed chips and increase the range of ductile and bone meal removals, revealing the mechanism of reducing grinding force. Further, the dynamic grinding behavior of diferent layers of abrasive particles under diferent instantaneous interaction states was studied. Finally, a prediction model of micro-grinding force was established in accordance with the relationship between grinding force and cutting depth, revealing the mechanism of micro-grinding force transfer under ultrasonic vibration. The theoretical model’s average deviations are 10.37% in x-axis direction, 6.85% in y-axis direction, and 7.81% in z-axis direction compared with the experimental results. This study provides theoretical guidance and technical support for clinical bone micro-grinding. 展开更多
关键词 Spherical grinding head Gradual contact arc length Maximum undeformed chip thickness Microgrinding force
下载PDF
Gradual Bedside Reduction of Gastroschisis in a Resource Constrained Setting: Preliminary Results from 32 Cases
14
作者 Nyanit Bob Dorcas Ntsobé Eric Tobie +9 位作者 Ndikontar Raymond Kouna Tsala Irène Nadine Ndongo René Bougoue Takou Horline Vougmo Clémence Kana Serges Paule Ngayap Guy Owono Etoundi Paul Essiene Agnès Steyaert Henri 《Open Journal of Pediatrics》 2023年第5期669-675,共7页
Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised ever... Introduction: Gastroschisis is one of the neonatal pathologies with bad prognosis in developing countries due to a lack of equipment. We aim to report one way of managing this malformation that could be practised everywhere, constituting an alternative approach to surgery in poor areas. Patients and Methods: This observational and descriptive study included newborn babies with gastroschisis who underwent gradual bedside reduction at the Paediatric Surgery Department of the Yaounde Central Hospital. Results: Our cohort was constituted by 32 newborn babies with a mean age of 18.12 hours on admission. The Lefort type 2 was the most frequent in 81.25% of cases. The mean time for oral feeding after complete reduction was 17.4 days and the duration of hospital stay was 24.91 days. Survival rates were at 40.63%, with a residual hernia after healing in 38.46% of cases. Conclusion: Despite the high rate of mortality, gradual reduction of gastroschisis at the bedside seems to be an opportunity for resource constrained areas and can be an alternative solution to surgery. 展开更多
关键词 GASTROSCHISIS Lefort Type 2 Gradual Reduction Limited Resources
下载PDF
Design of a Silicon-Based High-Speed Plasmonic Modulator
15
作者 Mu Xu, Jiayang Wu, Tao Wang, and Yikai Su (State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiaotong University, Shanghai 200240, P.R.China) 《ZTE Communications》 2012年第1期34-39,共6页
In this paper, we propose a siliconbased highspeed plasmonic modulator. The modulator has a double-layer structure with a 16 The long metaldielectricmetal plasmonic waveguide at the upper layer and two silicon singlem... In this paper, we propose a siliconbased highspeed plasmonic modulator. The modulator has a double-layer structure with a 16 The long metaldielectricmetal plasmonic waveguide at the upper layer and two silicon singlemode waveguides at the bottom layer. The upperlayer plasmonic waveguide acts as a phase shifter and has a dielectric slot that is 30 nm wide. Two taper structures that have gradually varied widths are introduced at the bottom layer to convert the photonic mode into plasmonicslot mode with improved coupling efficiency. For a modulator with two 1 mlong mode couplers, simulation shows that there is an insertion loss of less than 11 dB and a halfwave voltage of 3.65 V. The modulation bandwidth of the proposed modulator can be more than 100 GHz without the carrier effect being a limiting factor in silicon. The fabrication process is also discussed, and the proposed design is shown to be feasible with a hybrid of CMOS and polymer technology. 展开更多
关键词 plasmonic phase modulator gradually varied taper high speed
下载PDF
航务快讯
16
《中国远洋航务》 1995年第5期7-10,共4页
The China Classification Society has established its office at Perth in Australia with 1680 ships and total tonnages of 136 million. It plans to organize other offices in Spanish, west coast of United State and North ... The China Classification Society has established its office at Perth in Australia with 1680 ships and total tonnages of 136 million. It plans to organize other offices in Spanish, west coast of United State and North Europe. It had already created offlees in Hamburg, Stuttgrt Osaka, Tokyo, Hongkong, New York, Rotterdam, Port Said, London and Singapore on the other day. 展开更多
关键词 航务 China CONTAINER gradually Chinese Ports Class APPEAR SPAN MATE
下载PDF
给失败者
17
作者 罗兰 刘荣跃 《大学英语》 2000年第11期53-54,共2页
关键词 gradually:4978 ridicule:3659 恢复神智:3621 过些时候:3060 祝你成功:3024 勇气和力量:3011 前途光明:2609 人的观念:2291 恢复体力:2167 nothing:2089
下载PDF
Gradual solution heat treatment of AlSiCuMg cast alloys 被引量:13
18
作者 WANG Guiqing , BIAN Xiufang ,and ZHANG Junyan1) The Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061, China2) Department of Material Science and Technology, Shandong Architectural Engineering Institute, Jinan 250014, China 《Rare Metals》 SCIE EI CAS CSCD 2003年第4期304-308,共5页
The microstructure characteristics of AlSiCuMg cast alloys were studied withdifferent Cu content and the gradual solution treatment by DSC, SEM, TEM and mechanical method. Themelting point of alpha (Al) + Si decreases... The microstructure characteristics of AlSiCuMg cast alloys were studied withdifferent Cu content and the gradual solution treatment by DSC, SEM, TEM and mechanical method. Themelting point of alpha (Al) + Si decreases and polynary eutectic phases with low melting point formwith increase of Cu content. Gradual solution treatment includes two steps: solution treating nearthe melting point of polynary eutectic phase to take it dissolve first, and then increasing solutiontemperature to take the remainder copper intermetallics dissolved into alpha (Al). Grain boundariesmelting can be avoided by gradual solution treatment, even the maximum solution temperature isabove final solidification point, and the age hardening response increases correspondingly 展开更多
关键词 aluminum alloy gradual solution heat treatment differential scanningcalorimetry (DSC) polynary eutectic phase
下载PDF
Transition from Metastablity to Instability in Dynamics for the Precipitation of δ'(Al_3Li) 被引量:7
19
作者 Xiaoling Li, Zheng Chen, Bing Liu, Yongxin Wang Department of Materials Science and Engineering, Northwestern Polytechnical University. Xi’an, 710072, China 《Rare Metals》 SCIE EI CAS CSCD 2001年第4期240-247,共8页
A computer simulation study on dynamics for the precipitation of δ'(Al_3Li) ordered particles from a disor- dered matrix (α) in binary Al-Li alloys is performed using the microscopic Langevin equation. A unique ... A computer simulation study on dynamics for the precipitation of δ'(Al_3Li) ordered particles from a disor- dered matrix (α) in binary Al-Li alloys is performed using the microscopic Langevin equation. A unique precipitation mechanism is found near the ordering spinodal line. Different from the classical nucleation mechanism in the me- tastable region and the congruent ordering followed by spinodal decomposition in the instable region, a nonstoichi- ometric single ordered phase with composition fluctuations is formed by non-classical nucleation, and this ordered phase decomposes spinodally. It can be concluded that the precipitation dynamics of δ' phase from metastability to instability is gradual, and no sharp transition occurs near the mean-field spinodal line as the mean-field theory pre- dicts. 展开更多
关键词 δ'(Al_3Li) precipitation dynamics non-classical nucleation gradual transition
下载PDF
A SIMPLE CONSTITUTIVE MODEL FOR FERROELECTRIC CERAMICS UNDER ELECTRICAL/MECHANICAL LOADING 被引量:5
20
作者 Yu Li Yu Shouwen Feng Xiqiao 《Acta Mechanica Solida Sinica》 SCIE EI 2007年第1期1-12,共12页
A simple phenomenological model is developed for describing the macroscopic constitutive response of ferroelectric materials based on consideration of the fact that domain switching is a progressive evolution process ... A simple phenomenological model is developed for describing the macroscopic constitutive response of ferroelectric materials based on consideration of the fact that domain switching is a progressive evolution process with loading. The volume fraction of domain switching is taken as an internal variable, which is derived from the domain nucleation theory. The proposed theory can simulate the dielectric hysteresis, reversed butterfly hysteresis, nonlinear strain-stress hysteresis, as well as electric displacement-stress relation of ferroelectric materials. Its compaxison with experimental results and two other theoretical models reveals that the model presented can well predict the nonlinear hysteresis of ferroelectrics under electrical or mechanical loading. 展开更多
关键词 FERROELECTRICS gradual domain switching constitutive laws electromechanical coupling
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部