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势质量概念的提出及意义
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作者 孔宪毅 《电力学报》 1998年第3期216-218,228,共4页
提出了势质量这一新概念,推导出了势质量的表达式,并阐述了提出势质量概念的意义。
关键词 势质量 质量 质能关系式
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摄影镜头的光学成像质量控制——镜头关键指标对摄影创作的影响(上)
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作者 赵阳 周令非 《现代电影技术》 2018年第7期23-31,共9页
电影摄影镜头成像素质的水平优劣,会对素材画面产生决定性的影响。一颗镜头内部精密的光学及机械组件,经过长期的使用和颠簸,即使采取了严格的保护措施,也难免会出现成像质量下降的情况,有时即使从外观上看不出来,其实内部已经出现问题... 电影摄影镜头成像素质的水平优劣,会对素材画面产生决定性的影响。一颗镜头内部精密的光学及机械组件,经过长期的使用和颠簸,即使采取了严格的保护措施,也难免会出现成像质量下降的情况,有时即使从外观上看不出来,其实内部已经出现问题。主创人员在拍片之前,应提前检查镜头在成像分辨率、色相差、光圈位置和后焦距等方面的各种问题,才能避免由于素材采集设备的误差,降低自己的创作水准,同时缩小对后期创作的不良影响。 展开更多
关键词 电影镜头 成像素质 色相差 光圈 光学调制传递函数 质量检测
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Effects of Different Cultivation Methods on Growth, Yield and Quality of Cassava 被引量:1
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作者 蒋万 吴勇 +2 位作者 江定 杨金辉 宋勇 《Agricultural Science & Technology》 CAS 2015年第10期2086-2090,共5页
The research explored effects of cultivation methods on growth, yield and quality of cassava. The results showed that the mulching treatment by direct seed- ing, the mulching treatment by transplanting, and the expose... The research explored effects of cultivation methods on growth, yield and quality of cassava. The results showed that the mulching treatment by direct seed- ing, the mulching treatment by transplanting, and the exposed treatment by trans- planting performed excellently in bringing seedling stage forward, improving germina- tion rate, yield and quality. For example, seedling emergence stages were 36, 31 and 31 d earlier; germination rates improved by 19.24%, 14.29% and 14.29%; yields grew by 41.98%, 26.72% and 11.45%; starch contents increased by 3.50%, 2.10% and 1.40%, respectively. Therefore, cassava in the mulching treatment by direct seeding is characterized by earlier seedling emergence stage, high germination rate, high yield and quality. 展开更多
关键词 CASSAVA Cultivation methods Growth vigor YIELD QUALITY
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An Analytical Model of Drain Current for Ultra-Thin Body and Double-Gate Schottky Source/Drain MOSFETs Accounting for Quantum Effects 被引量:2
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作者 栾苏珍 刘红侠 +3 位作者 贾仁需 蔡乃琼 王瑾 匡潜玮 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第5期869-874,共6页
A compact drain current including the variation of barrier heights and carrier quantization in ultrathin-body and double-gate Schottky barrier MOSFETs (UTBDG SBFETs) is developed. In this model, Schrodinger's equat... A compact drain current including the variation of barrier heights and carrier quantization in ultrathin-body and double-gate Schottky barrier MOSFETs (UTBDG SBFETs) is developed. In this model, Schrodinger's equation is solved using the triangular potential well approximation. The carrier density thus obtained is included in the space charge density to obtain quantum carrier confinement effects in the modeling of thin-body devices. Due to the quantum effects, the first subband is higher than the conduction band edge, which is equivalent to the band gap widening. Thus, the barrier heights at the source and drain increase and the carrier concentration decreases as the drain current decreases. The drawback of the existing models,which cannot present an accurate prediction of the drain current because they mainly consider the effects of Schottky barrier lowering (SBL) due to image forces,is eliminated. Our research results suggest that for small nonnegative Schottky barrier (SB) heights,even for zero barrier height, the tunneling current also plays a role in the total on-state currents. Verification of the present model was carried out by the device numerical simulator-Silvaco and showed good agreement. 展开更多
关键词 Schottky barrier quantum effects the effective mass electron density
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Analysis of Heterosis, Combining Ability and Heritability of Cadmium Content in Brown Rice of Three-line Indica Hybrid Rice
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作者 游书梅 曹应江 +8 位作者 蒋开锋 郑家奎 吴先军 张涛 杨莉 杨乾华 万先齐 罗婧 李昭祥 《Agricultural Science & Technology》 CAS 2012年第11期2358-2362,共5页
Five cytoplasmic male sterile (CMS) lines were used as parents in an incomplete diallet cross and six restorer lines of rice design (Nc II design). Thirty hybrid combinations with the same growth period were selec... Five cytoplasmic male sterile (CMS) lines were used as parents in an incomplete diallet cross and six restorer lines of rice design (Nc II design). Thirty hybrid combinations with the same growth period were selected as experimental ma- terials to investigate the heterosis, combined ability and heredity of Cd content in brown rice of indica hybrid rice. According to the results, Cd content in brown rice showed a significantly negative heterosis; the general combining ability and specific combination ability of Cd content in CMS and restorer lines both reached extremely significant level (P〈0.01), indicating that both genetic improvement of parents and e- valuation of combinations are important to the breeding of hybrid combinations with low accumulation of Cd; the broad-sense heritabitity and narrow-sense heritability of Cd content were both relatively high with slight differences, which respectively reached 97.73% and 80.10%, indicating that Cd content in brown rice mainly de- pends on the additive action of genes; in addition, parent improvement showed bet- ter effect on the selection of early generation. 展开更多
关键词 Indica hybrid rice Brown rice Cytoplasmic male sterile (CMS) line Re-storer line Cadmium HETEROSIS Combining ability HERITABILITY
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Role of original and modified Frey's procedures in chronic pancreatitis 被引量:1
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作者 Chun-Lu Tan Hao Zhang +3 位作者 Min Yang Shao-Jun Li Xu-Bao Liu Ke-Zhou Li 《World Journal of Gastroenterology》 SCIE CAS 2016年第47期10415-10423,共9页
AIM To retrospectively review patients with chronic pancreatitis(CP) treated with Frey's procedures between January 2009 and January 2014.METHODS A retrospective review was performed of patients with CP treated wi... AIM To retrospectively review patients with chronic pancreatitis(CP) treated with Frey's procedures between January 2009 and January 2014.METHODS A retrospective review was performed of patients with CP treated with Frey's procedures between January 2009 and January 2014 in the Department of Pancreatic Surgery. A cross-sectional study of postoperative pain relief, quality of life(Qo L), and alcohol and nicotine abuse was performed by clinical interview, letters and telephone interview in January 2016. Qo L of patients was evaluated with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire(EORTC QLQ-C30) version 3.0. The patients were requested to fill in the questionnaires by themselves via correspondence or clinical interview.RESULTS A total of 80 patients were enrolled for analysis, including 44 who underwent the original Frey's procedure and 36 who underwent a modified Frey's procedure. The mean age was 46 years in the original group and 48 years in the modified group. Thirtyfive male patients(80%) were in the original group and 33(92%) in the modified group. There were no differences in the operating time, blood loss, and postoperative morbidity and mortality between the two groups. The mean follow-up was 50.3 mo in the original group and 48.7 mo in the modified group. There were no differences in endocrine and exocrine function preservation between the two groups. The original Frey's procedure resulted in significantly betterpain relief, as shown by 5-year follow-up(P = 0.032), better emotional status(P = 0.047) and fewer fatigue symptoms(P = 0.028). When stratifying these patients by the M-ANNHEIM severity index, no impact was found on pain relief after the two types of surgery.CONCLUSION The original Frey's procedure is as safe as the modified procedure, but the former yields better pain relief. The severity of CP does not affect postoperative pain relief. 展开更多
关键词 Chronic pancreatitis Frey’s procedure M-ANNHEIM severity index Pain relief Quality of life
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The development and application of silicon Neutron Transmutation Doping (NTD) technology in China
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作者 Qiao Chenyang Sun Zhiyong Ke Guotu Lu Cungang Shen Feng Chen Huiqiang 《Engineering Sciences》 EI 2009年第4期95-100,共6页
The research and development history of silicon Neutron Transmutation Doping (NTD) technology and its applications at home and abroad are introduced in this paper.The advantages of NTD,compared with conventional techn... The research and development history of silicon Neutron Transmutation Doping (NTD) technology and its applications at home and abroad are introduced in this paper.The advantages of NTD,compared with conventional technology of doping,are narrated.The principle of NTD as well as the implementation of the main procedures related to Si NTD is explained.The market demand tendency is prospected,and the advanced measures on NTD quality control are described. 展开更多
关键词 monocrystal silicon Neutron Transmutation Doing (NTD) UNIFORMITY doping accuracy application design
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Research on Contract Management and Control in the Process of Project Cost
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作者 Lingtao BIAN 《International Journal of Technology Management》 2015年第5期44-46,共3页
In the current economic situation, strengthening the contract management of the construction cost has a beautifully role. At the same time, according to construction project cost management, the scientific management ... In the current economic situation, strengthening the contract management of the construction cost has a beautifully role. At the same time, according to construction project cost management, the scientific management of the contract, can promote the reasonable and balanced investment cost allocation in the quality and safety and other aspects of the project, so that the construction project can obtain higher added value, and to further promote China' s economic construction and accelerate the pace of the city. This paper first briefly elaborates our construction project cost of the contract management on the present situation, and some problems are analyzed and discussed, and then puts forward some suggestions on the measures and countermeasures for cost management of construction engineering contract. 展开更多
关键词 Construction project Cost management Contract management Problems and countermeasures
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Ranking Quality Management Indicators for Radio Programs
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作者 Chia-Kun Lee 《Journalism and Mass Communication》 2016年第7期389-396,共8页
Even though radio broadcasting is one of the most widespread electronic mass media, its management for survival is getting drastic. The competition among incumbent radio stations becomes challenging due to the market ... Even though radio broadcasting is one of the most widespread electronic mass media, its management for survival is getting drastic. The competition among incumbent radio stations becomes challenging due to the market change and environmental evolution. Managing program quality is a critical issue to a radio station to sharpen its competitive advantages. Quality management of radio programs is intertwined with complicated factors. In order to identify the primary factors affecting radio program quality as well as explore the impact level these factors bring, this study adopts modified Delphi method and analytic hierarchy process (AHP) to explore the issues. According to the outcomes modified Delphi method, the factors were categorized into four dimensions: operation, coordination, structure, and improvement. Ten sub-dimensions were followed. Each sub-dimension includes six to nineteen indicators for measuring radio program quality. In total, 72 indicators were identified. The AHP result revealed that the most important weight was given to the operation dimension. On the contrary, the least important weight was placed on the improvement dimension. Among the sub-dimensions, the standard procedure and organizational design were rated more important than the rest. The results could provide some facts to radio managers for future management. 展开更多
关键词 quality RADIO INDICATORS DELPHI AHP
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Asymptotic Iteration Method for Energies of Inversely Linear Potential with Spatially Dependent Mass
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作者 Eser Olgar Haydar Mutaf 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第6期1043-1045,共3页
The bound-state solution of the position dependent mass Klein-Gordon equation including inversely linear potential is obtained within the framework of the asymptotic iteration method. The relation between the scalar a... The bound-state solution of the position dependent mass Klein-Gordon equation including inversely linear potential is obtained within the framework of the asymptotic iteration method. The relation between the scalar and vector potentials is considered to S(x) = V(x)(β - 1). In particular, it is shown that the corresponding method exactly reproduces the spectrum of linearly inversely potentials with spatially dependent mass. 展开更多
关键词 Klein Gordon equation asymptotic iteration method position dependent mass
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Influence of Finite Chemical Potential on Critical Boson Mass in QED3
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作者 ZHANG Yun-Qiang LI Zhen FENG Hong-Tao 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3期525-528,共4页
Using the coupled Dyson-Schwinger equation for the fermion propagator at finite chemical potential μ, we investigate the fermion chiral condensate when the gauge boson mass is nonzero in QED3. We show that the chiral... Using the coupled Dyson-Schwinger equation for the fermion propagator at finite chemical potential μ, we investigate the fermion chiral condensate when the gauge boson mass is nonzero in QED3. We show that the chiral symmetry restores when the boson mass is large enough, and the critical boson mass depends little on μ. 展开更多
关键词 DSE chemical potential critical boson mass
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Characteristics of water relations in seedling of Machilus yunnanensis and Cinnamomum camphora under soil drought condition 被引量:3
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作者 TANG Tian-tian ZHAO Lin-sen 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第4期281-284,共4页
The soil drought stress experiment in different durations (no watering within 3d, 6d, 9d, 11d individually) was conducted to study the drought-resistant capacity of one-year-old seedlings for the native tree species (... The soil drought stress experiment in different durations (no watering within 3d, 6d, 9d, 11d individually) was conducted to study the drought-resistant capacity of one-year-old seedlings for the native tree species (Machilus yunnanensis) in Yunnan Province and the introduced tree species (Cinnamomum camphora). The leaf water potential, chlorophyll content, proline content and plasma membrane permeability for two species seedlings were measured in different soil drought conditions. The results showed that, on the 9th day of drought stress, the leaf water potential of two species decreased obviously, whereas the free proline content and plasma membrane permeability increased sharply. On the 11th day, the leaf water potential of C. camphora seedlings was lower than that of M. yunnanensis seedlings; the plasma membrane permeability in C. camphora seedling leaves increased much more than that in M. yunnanensis seedling leaves, which showed that the injury to the former by soil drought stress was more severe than that to the latter. The free proline content in M. yunnanensis seedling leaves continued to increase on the 11th day, but that in the C. camphora seedling leaves started to drop obviously, indicating that the reduction of osmotic regulation substance in C. camphora seedling leaves after the 11th day was unable to maintain the osmotic balance between the plasma system and its surroundings and the water loss occurred inevitably. Comprehensively, M. yunnanensis seedlings enhanced the drought-resistance in the course of soil drought stress by maintaining higher leaf water potential and by increasing osmotic regulation substance to promote cell plasma concentration and maintain membrane structure integrity so as to reduce water loss. The subordination function index evaluated with fuzzy mathematic theory also showed that the drought-resistant capacity of M. yunnanensis seedlings was stronger than that of C. camphora seedlings. 展开更多
关键词 Soil drought Water potential Plasma membrane permeability Machilus yunnanensis Cinnamomum camphora
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Re-visit N/Z Ratio of Free Nucleons from Collisions of Neutron-Rich Nuclei as a Probe of EoS of Asymmetric Nuclear Matter
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作者 LIQing-Feng LIZhu-Xia +1 位作者 ZHAOEn-Guang H.Stoecker 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第3期435-440,共6页
The N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a function of their momentum is studied by means of isospin-dependent Quantum Molecular Dynamics. We find that this ratio is not only sensitive ... The N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a function of their momentum is studied by means of isospin-dependent Quantum Molecular Dynamics. We find that this ratio is not only sensitive to the form of the density dependence of the symmetry potential energy but also its strength determined by the symmetry energy coefficient. The uncertainties about the symmetry energy coefficient influence the accuracy of probing the density dependence of the symmetry energy by means of the N/Z ratio of free nucleons of neutron-rich nuclei. 展开更多
关键词 symmetry potential heavy ion collisions neutron and proton chemical potential
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Research on Pension Insurance System under the Background of Aging
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作者 WANG Chunqing 《International English Education Research》 2016年第5期40-42,共3页
With the rapid development of economy in our country, the level of science and technology innovation, all of these prolong the life span of our life. Thus an aging population are increasingly highlight, which are deep... With the rapid development of economy in our country, the level of science and technology innovation, all of these prolong the life span of our life. Thus an aging population are increasingly highlight, which are deeply and widely influenced our society, economy, life and other aspects. As the basic insurance which maintain the elderly's life quality after they retired, Pension insurance will promove social stability and development. How to reform Pension insurance under the background of the aging of the population will get more and more attention from people. This article starts with the concept of the aging of the population and its development trend. Next, the article analyses the problems of Pension Insurance under the background of the aging of the population. Last, the article summarizes countermeasures according to solve these matters. 展开更多
关键词 the aging of population pension insurance
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Approximated Vector Potential of Intense Laser Pulses in a Pair Plasma
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作者 TIAN Duo-Xiang HE Guang-Jun HAN Jiu-Ning DUAN Wen-Shan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第3期529-532,共4页
A (3+1 )-dimensional Kadomtse-Petviashvili (KP) equation for nonlinearly interacting intense laser pulses with an electron-positron (e-p) plasma is derived. Taking into account the combined action of the relati... A (3+1 )-dimensional Kadomtse-Petviashvili (KP) equation for nonlinearly interacting intense laser pulses with an electron-positron (e-p) plasma is derived. Taking into account the combined action of the relativistic particle mass increase and the relativistic light ponderomotive force, using the perturbation method, and allowing different types solution, we discuss the analytical solution of (3+1)-dimensional KP-I equation, and give the approximate solutions of vector potential of the intense laser pulse in e-p plasma. Our results may be significantly useful in understanding the nonlinear wave propagation and interaction of intense laser beams in an e-p plasma. 展开更多
关键词 electron-positron plasma (3+1)-dimensional KP-I equation lump solution
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Characteristics of China's Automobile Recall Actions
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作者 Wang Yan Wang YunSong Sun Ning 《China Standardization》 2009年第5期22-30,共9页
For the purpose of enhancing automobile safety and the effectiveness of recalls,increasing manufacturers' quality control capabilities,and reducing defects,we investigated thestatus of recalls over the last five y... For the purpose of enhancing automobile safety and the effectiveness of recalls,increasing manufacturers' quality control capabilities,and reducing defects,we investigated thestatus of recalls over the last five years.We have examined patterns and trends in motor vehiclesafety recalls using databases from China,Europe and the United States.A recall rate parameterwas developed to evaluate the level of recall enforcement based on analyzing the reasonsfor recalls and manufactures' characteristics.Moreover,there were substantial differencesin the recall rates of China compared with those in other countries,indicating that Chinese manufacturersneed to take more active action in recall. 展开更多
关键词 AUTOMOBILE RECALL evaluate parameter
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Inter-comparison of seasonal variability and nonlinear trend between AERONET aerosol optical depth and PM10 mass concentrations in Hong Kong 被引量:1
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作者 HE JingJing ZHANG Min +1 位作者 CHEN XianYao WANG Meng 《Science China Earth Sciences》 SCIE EI CAS 2014年第11期2606-2615,共10页
Here we used Empirical Mode Decomposition (EMD) method to study seasonal variability and nonlinear trend of corrected AERONET Aerosol Optical Depth (AOD/Hi) and corrected PM10 mass concentrations (PMmxf(RH)) i... Here we used Empirical Mode Decomposition (EMD) method to study seasonal variability and nonlinear trend of corrected AERONET Aerosol Optical Depth (AOD/Hi) and corrected PM10 mass concentrations (PMmxf(RH)) in Hong Kong during 2005-2011. AODPrli is highly correlated with PMI0xf(RH) in semi-annual and annual time scales (with correlation coefficient 0.67 for semi-annual and 0.79 for annual components, 95% confidence interval). On the semi-annual scale, both AOD/Hi and PM10xf(RH) can capture the two maxima in March and October, respectively, with much stronger amplitude in March proba- bly due to the long-range transport of dust storm. On the annual cycle, the AOD/Hi and PMI0xf(RH), which are negatively correlated with the precipitation and solar radiation, vary coherently with the maxima in February. This annual peak occurs about one month earlier than the first peak of the semi-annual variability in March, but with only half amplitude. During 2005-2011, both AOD/Hi and PM10xf(RH) exhibit the pronounced decreasing trend with the mean rate of 14 gg m-3 per year for PM10xf(RH), which reflects the significant effects of the air pollution control policy in Hong Kong during the past decade. The nonlinear trend analysis indicates that the decreasing of PM10xf(RH) is slower than that of AOD/Hi when the AOD/Hi is less than 0.44 but becomes faster when the AOD/Hi exceeds 0.44. These results illustrate that the AERONET AOD can be used quantitatively to estimate local air-quality variability on the semi-annual, annual, and long-term trend time scales. 展开更多
关键词 PM10 aerosol optical depth (AOD) empirical mode decomposition (EMD) seasonal variability nonlinear trend
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Large-area atomic-smooth polyvinylidene fluoride Langmuir-Blodgett film exhibiting significantly improved ferroelectric and piezoelectric responses 被引量:3
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作者 Shan He Mengfan Guo +8 位作者 Zhenkang Dan Shun Lan Weibin Ren Le Zhou Yue Wang Yuhan Liang Yunpeng Zheng Jiayu Pan Yang Shen 《Science Bulletin》 SCIE EI CSCD 2021年第11期1080-1090,M0003,共12页
Large roughness and structure disorder in ferroelectric ultrathin Langmuir-Blodgett(LB)film results in severe space scatter in electrical,ferroelectric and piezoelectric characteristics,thus limiting the nanoscale res... Large roughness and structure disorder in ferroelectric ultrathin Langmuir-Blodgett(LB)film results in severe space scatter in electrical,ferroelectric and piezoelectric characteristics,thus limiting the nanoscale research and reliability of nano-devices.However,no effective method aiming at large-area uniform organic ferroelectric LB film has ever been reported to date.Herein,we present a facile hot-pressing strategy to prepare relatively large-area poly(vinylidene fluoride)(PVDF)LB film with ultra-smooth surface root mean square(RMS)roughness is 0.3 nm in a 30μm×30μm area comparable to that of metal substrate,which maximized the potential of LB technique to control thickness distribution.More importantly,compared with traditionally annealed LB film,the hot-pressed LB film manifests significantly improved structure uniformity,less fluctuation in ferroelectric characteristics and higher dielectric and piezoelectric responses,owing to the uniform dipole orientation and higher crystalline quality.Besides,different surface charge relaxation behaviors are investigated and the underlying mechanisms are explained in the light of the interplay of surface charge and polarization charge in the case of nanoscale non-uniform switching.We believe that our work not only presents a novel strategy to endow PVDF LB film with unprecedented reliability and improved performance as a competitive candidate for future ferroelectric tunnel junctions(FTJs)and nano electro mechanical systems(NEMS),but also reveals an attracting coupling effect between the surface potential distribution and nanoscale non-uniform switching behavior,which is crucial for the understanding of local transport characterization modulated by band structure,bit signal stability for data-storage application and the related surface charge research,such as charge gradient microscopy(CGM)based on the collection of surface charge on the biased ferroelectric domains. 展开更多
关键词 Poly(vinylidene fluoride)(PVDF) Langmuir-Blodgett film Roughness FERROELECTRIC PIEZORESPONSE Charge relaxation
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Vector Meson Mass in Finite Density and Temperature Lattice QCD
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作者 王睿 陈莹 +6 位作者 宫明 刘川 刘玉斌 刘朝峰 马建平 孟祥飞 张剑波 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第5期559-564,共6页
Vector meson mass values are studied at finite chemical potential and temperature in lattice QCD with lattice size of 24 × 122× 6 using two flavors of staggered quarks. The investigation focuses on the chang... Vector meson mass values are studied at finite chemical potential and temperature in lattice QCD with lattice size of 24 × 122× 6 using two flavors of staggered quarks. The investigation focuses on the change of the vector meson mass in the critical region close to T c with two different types of chemical potentials switched on: the isoscalar chemical potential μS and its isovector counterpart μV. It is found that the vector meson mass increases in the QGP phase with both chemical potentials and decreases with μS in the confinement phase. 展开更多
关键词 lattice QCD numerical simulation vector meson
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