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Controllable thermal rectification design for buildings based on phase change composites
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作者 Hengbin Ding Xiaoshi Li +2 位作者 Tianhang Li Xiaoyong Zhao He Tian 《Journal of Semiconductors》 EI CAS CSCD 2024年第2期40-45,共6页
Phase-change material(PCM)is widely used in thermal management due to their unique thermal behavior.However,related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device... Phase-change material(PCM)is widely used in thermal management due to their unique thermal behavior.However,related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device level,which results in a gap to real applications.Here,we propose a controllable thermal rectification design towards building applications through the direct adhesion of composite thermal rectification material(TRM)based on PCM and reduced graphene oxide(rGO)aerogel to ordinary concrete walls(CWs).The design is evaluated in detail by combining experiments and finite element analysis.It is found that,TRM can regulate the temperature difference on both sides of the TRM/CWs system by thermal rectification.The difference in two directions reaches to 13.8 K at the heat flow of 80 W/m^(2).In addition,the larger the change of thermal conductivity before and after phase change of TRM is,the more effective it is for regulating temperature difference in two directions.The stated technology has a wide range of applications for the thermal energy control in buildings with specific temperature requirements. 展开更多
关键词 phase change composites controllable thermal rectification building applications
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Enhancement of thermal rectification by asymmetry engineering of thermal conductivity and geometric structure for multi-segment thermal rectifier 被引量:1
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作者 杜甫烨 张望 +1 位作者 王惠琼 郑金成 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期34-43,共10页
Thermal rectification is an exotic thermal transport phenomenon,an analog to electrical rectification,in which heat flux along one direction is larger than that in the other direction and is of significant interest in... Thermal rectification is an exotic thermal transport phenomenon,an analog to electrical rectification,in which heat flux along one direction is larger than that in the other direction and is of significant interest in electronic device applications.However,achieving high thermal rectification efficiency or rectification ratio is still a scientific challenge.In this work,we performed a systematic simulation of thermal rectification by considering both efforts of thermal conductivity asymmetry and geometrical asymmetry in a multi-segment thermal rectifier.It is found that the high asymmetry of thermal conductivity and the asymmetry of the geometric structure of multi-segment thermal rectifiers can significantly enhance the thermal rectification,and the combination of both thermal conductivity asymmetry and geometrical asymmetry can further improve thermal rectification efficiency.This work suggests a possible way for improving thermal rectification devices by asymmetry engineering. 展开更多
关键词 thermal conductivity SIMULATION thermal rectification multi-segment thermal rectifier
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Thermal rectification induced by Wenzel–Cassie wetting state transition on nano-structured solid–liquid interfaces
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作者 李海洋 王军 夏国栋 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期520-526,共7页
Thermal rectification refers to the phenomenon by which the magnitude of the heat flux in one direction is much larger than that in the opposite direction.In this study,we propose to implement the thermal rectificatio... Thermal rectification refers to the phenomenon by which the magnitude of the heat flux in one direction is much larger than that in the opposite direction.In this study,we propose to implement the thermal rectification phenomenon in an asymmetric solid–liquid–solid sandwiched system with a nano-structured interface.By using the non-equilibrium molecular dynamics simulations,the thermal transport through the solid–liquid–solid system is examined,and the thermal rectification phenomenon can be observed.It is revealed that the thermal rectification effect can be attributed to the significant difference in the interfacial thermal resistance between Cassie and Wenzel states when reversing the temperature bias.In addition,effects of the liquid density,solid–liquid bonding strength and nanostructure size on the thermal rectification are examined.The findings may provide a new way for designs of certain thermal devices. 展开更多
关键词 thermal rectification wetting transition interfacial thermal resistance solid–liquid interfaces
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Nonlinear optical rectification of GaAs/Ga_(1-x)Al_(x)As quantum dots with Hulthén plus Hellmann confining potential
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作者 段一名 李学超 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期454-457,共4页
We investigate the nonlinear optical rectification(NOR) of spherical quantum dots(QDs) under Hulthén plus Hellmann confining potential with the external tuning elements. Energy and wavefunction are determined by ... We investigate the nonlinear optical rectification(NOR) of spherical quantum dots(QDs) under Hulthén plus Hellmann confining potential with the external tuning elements. Energy and wavefunction are determined by using the Nikiforov–Uvarov method. Expression for the NOR coefficient is derived by the density matrix theory. The results show that the applied external elements and internal parameters of this system have a strong influence on intraband nonlinear optical properties. It is hopeful that this tuning of the nonlinear optical properties of GaAs/Ga_(1-x)Al_(x)As QDs can make a greater contribution to preparation of new functional optical devices. 展开更多
关键词 nonlinear optical rectification quantum dots Hulthén plus Hellmann potential Nikiforov–Uvarov method
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Effect of flame rectification on corrosion property of Al-Zn-Mg alloy 被引量:1
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作者 李帅 郭丹 董红刚 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第2期250-257,共8页
The corrosion resistance of Al?Zn?Mg alloy subjected to different times in flame rectification was investigated based on the exfoliation corrosion test. The results indicate that the flame rectification deteriorate... The corrosion resistance of Al?Zn?Mg alloy subjected to different times in flame rectification was investigated based on the exfoliation corrosion test. The results indicate that the flame rectification deteriorates the exfoliation corrosion resistance of Al?Zn?Mg alloy. The corrosion resistance of Al-Zn-Mg alloy is ranked in the following order: base metal〉two times〉three times〉one time of flame rectification. The exfoliation corrosion behavior was discussed based on the transformation of precipitates at grain boundaries and matrix. With increasing the number of times in flame rectification, the precipitate-free zones disappeared and the precipitates experienced dissolution and re-precipitation. The sample was seriously corroded after one time of flame rectification, because the precipitates at grain boundaries are more continuous than those in other samples. 展开更多
关键词 Al-Zn-Mg alloy flame rectification exfoliation corrosion re-precipitation
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Flexible planar micro supercapacitor diode
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作者 Yihui Ma Pei Tang +7 位作者 Zhenyuan Miao Wuyang Tan Qijun Wang Yuecong Chen Guosheng Li Qingyun Dou Xingbin Yan Lingling Shui 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期429-435,I0011,共8页
Supercapacitor diode is a novel ion device that performs both supercapacitor energy storage and ion diode rectification functions.However,previously reported devices are limited by their large size and complex process... Supercapacitor diode is a novel ion device that performs both supercapacitor energy storage and ion diode rectification functions.However,previously reported devices are limited by their large size and complex processes.In this work,we demonstrate a screen-printed micro supercapacitor diode(MCAPode)that based on the insertion of a finger mode with spinel ZnCo_(2)O_(4) as cathode and activated carbon as anode for the first time,and featuring an excellent area specific capacitance(1.21 mF cm^(-2)at 10 mV s^(-1))and high rectification characteristics(rectification ratioⅠof 11.99 at 40 mV s^(-1)).Taking advantage of the ionic gel electrolyte,which provides excellent stability during repeated flexing and at high temperatures.In addition,MCAPode exhibits excellent electrochemical performance and rectification capability in"AND"and"OR"logic gates.These findings provide practical solutions for future expansion of micro supercapacitor diode applications. 展开更多
关键词 Micro devices Supercapacitor diodes Screen-printing rectification Logic gates
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Bidirectional rotating direct-current triboelectric nanogenerator with self-adaptive mechanical switching for harvesting reciprocating motion
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作者 Donghan Lee Joonmin Chae +6 位作者 Sumin Cho Jong Woo Kim Awais Ahmad Mohammad Rezaul Karim Moonwoo La Sung Jea Park Dongwhi Choi 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第4期324-335,共12页
Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic device... Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic devices.However,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a challenge.Accordingly,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating motions.The distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC output.Furthermore,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational direction.Owing to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC output.Applications of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this output.This study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices. 展开更多
关键词 direct-current triboelectric nanogenerator mechanical rectification self-adaptive mechanical design harvesting reciprocation motion
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Bidirectional rectifier with gate voltage control based on Bi_(2)O_(2)Se/WSe_(2)heterojunction
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作者 Ruonan Li Fangchao Lu +3 位作者 Jiajun Deng Xingqiu Fu Wenjie Wang He Tian 《Journal of Semiconductors》 EI CAS CSCD 2024年第1期63-70,共8页
Two-dimensional(2D)WSe_(2)has received increasing attention due to its unique optical properties and bipolar behavior.Several WSe_(2)-based heterojunctions exhibit bidirectional rectification characteristics,but most ... Two-dimensional(2D)WSe_(2)has received increasing attention due to its unique optical properties and bipolar behavior.Several WSe_(2)-based heterojunctions exhibit bidirectional rectification characteristics,but most devices have a lower rectification ratio.In this work,the Bi_(2)O_(2)Se/WSe_(2)heterojunction prepared by us has a typeⅡband alignment,which can vastly suppress the channel current through the interface barrier so that the Bi_(2)O_(2)Se/WSe_(2)heterojunction device has a large rectification ratio of about 10^(5).Meanwhile,under different gate voltage modulation,the current on/off ratio of the device changes by nearly five orders of magnitude,and the maximum current on/off ratio is expected to be achieved 106.The photocurrent measurement reveals the behavior of recombination and space charge confinement,further verifying the bidirectional rectification behavior of heterojunctions,and it also exhibits excellent performance in light response.In the future,Bi_(2)O_(2)Se/WSe_(2)heterojunction field-effect transistors have great potential to reduce the volume of integrated circuits as a bidirectional controlled switching device. 展开更多
关键词 Bi_(2)O_(2)Se WSe_(2) HETEROJUNCTION bidirectional rectification optoelectronic devices
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Optical Rectification Induced by Al-Si Schottky Barrier Potential and Mechanism of Two-Photon Response
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作者 刘云龙 贾刚 +3 位作者 周志雄 陈占国 张晓婷 李海兰 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2002年第8期805-808,共4页
By observing two-photon response and anisotropy of the light-induced voltage in Al-Si Schottky barrier potential,it is certified from the experimental and theoretical analysis that the built-in electric field generate... By observing two-photon response and anisotropy of the light-induced voltage in Al-Si Schottky barrier potential,it is certified from the experimental and theoretical analysis that the built-in electric field generated by the Schottky barrier potential will induce the phenomena of optical rectification in Si photodiode.Thus,it is deduced that there must be double-frequency absorption caused by phase-mismatch in the mechanism of two-photon response of Si photodiode.If the intensity of the built-in electric field is strong enough,the double-frequency absorption will be the main factor of the two-photon response,which is different from the conventional opinion that the two-photon response is just the two-photon absorption. 展开更多
关键词 optical rectification double-frequency two-photon absorption
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Sliding mode robust controller for automatic rectification of shield machine 被引量:8
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作者 岳明 孙伟 魏建 《Journal of Central South University》 SCIE EI CAS 2011年第2期536-541,共6页
According to the actual engineering problem that the precise load model of shield machine is difficult to achieve,a design method of sliding mode robust controller oriented to the automatic rectification of shield mac... According to the actual engineering problem that the precise load model of shield machine is difficult to achieve,a design method of sliding mode robust controller oriented to the automatic rectification of shield machine was proposed. Firstly,the nominal load model of shield machine and the ranges of model parameters were obtained by the soil mechanics parameters of certain geological conditions and the messages of the self-learning of shield machine by tunneling for previous segments. Based on this rectification mechanism model with known ranges of parameters,a sliding mode robust controller was proposed. Finally,the simulation analysis was developed to verify the effectiveness of the proposed controller. The simulation results show that the sliding mode robust controller can be implemented in the attitude rectification process of the shield machine and it has stronger robustness to overcome the soil disturbance. 展开更多
关键词 shield machine rectification sliding mode ROBUST upper bound
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Relationship between rectification moment and angle of shield based on numerical simulation 被引量:8
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作者 孙伟 岳明 魏建 《Journal of Central South University》 SCIE EI CAS 2012年第2期517-521,共5页
The finite element method is used to simulate the rectification process of shield machine, to study the relationship between rectification moment and angle and to explore the influence laws of different soil parameter... The finite element method is used to simulate the rectification process of shield machine, to study the relationship between rectification moment and angle and to explore the influence laws of different soil parameters and buried depth on rectification moment. It is hoped that the reference value of rectification moment can be offered to operator, and theoretical foundation can be laid for future automatic rectification technology. The results show that the rectification moment and angle generally exhibit good linear behavior in clay layers with different soil parameters or buried depths, and then the concept of rectification coefficient, that is, the ratio of rectification angle to rectification moment, is proposed; different soil parameters and buried depths have different influences on rectification coefficient, in which elastic modulus has great influence but others have little influences; the simulations of rectification process are preformed in clay layers with different elastic modulus, and fitting results show that elastic modulus and rectification coefficient present the quadratic function relation. 展开更多
关键词 finite element method rectification moment rectification angle elastic modulus
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Polaron effect on the optical rectification in spherical quantum dots with electric field 被引量:5
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作者 冯振宇 闫祖威 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第10期446-451,共6页
The polaron effect on the optical rectification in spherical quantum dots with a shallow hydrogenic impurity in the presence of electric field is theoretically investigated by taking into account the interactions of t... The polaron effect on the optical rectification in spherical quantum dots with a shallow hydrogenic impurity in the presence of electric field is theoretically investigated by taking into account the interactions of the electrons with both confined and surface optical phonons. Besides, the interaction between impurity and phonons is also considered. Numerical calculations are presented for typical Zn1-xCdxSe/ZnSe material. It is found that the polaronic effect or electric field leads to the redshifted resonant peaks of the optical rectification coefficients. It is also found that the peak values of the optical rectification coefficients with the polaronic effect are larger than without the polaronic effect, especially for smaller Cd concentrations or stronger electric field. 展开更多
关键词 polaron effect optical rectification spherical quantum dot
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Impact of GCP distribution on the rectification accuracy of Landsat TM imagery in a coastal zone 被引量:2
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作者 ZHANG Ying ZHANG Dong +1 位作者 GU Yan TAO Fei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第4期14-22,共9页
The purpose is to explore the effect of the spatial distribution of ground control points (GCPs) on the accuracy of imagery rectification. Both area-distributed and linearly distributed GCPs were used to rectify a L... The purpose is to explore the effect of the spatial distribution of ground control points (GCPs) on the accuracy of imagery rectification. Both area-distributed and linearly distributed GCPs were used to rectify a Landsat TM image of a coastal zone. Rectification accuracy was checked against 99 independent points over the intertidal mudflats with no ground control. Results indicate that the root-mean-square error of residuals over these areas is several times larger than its GCPs-measured counterpart. If the GCPs are spatially dispersed over an area, residuals fluctuate but increase steadily with distance to the source of control in easting (R^2= 0. 827). in northing they fluctuate around 150 m until 15 km, beyond which they rise steadily at a small range of fluctuation. These residuals are less predictable from distance to the source of control than in easting (R^2= 0.517 ). If the GCPs are distributed along a control line, residuals rise with distance to it linearly and predictably (R^2 = 0. 877) in the direction perpendicular to it. In a direction parallel to it, the distance has little impact on rectification residuals. 展开更多
关键词 image rectification ground control point rectification residuals coastal zone
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NEW VERSATILE CAMERA CALIBRATION TECHNIQUE BASED ON LINEAR RECTIFICATION 被引量:2
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作者 PanFeng WangXuanyin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第4期507-510,共4页
A new versatile camera calibration technique for machine vision usingoff-the-shelf cameras is described. Aimed at the large distortion of the off-the-shelf cameras, anew camera distortion rectification technology base... A new versatile camera calibration technique for machine vision usingoff-the-shelf cameras is described. Aimed at the large distortion of the off-the-shelf cameras, anew camera distortion rectification technology based on line-rectification is proposed. Afull-camera-distortion model is introduced and a linear algorithm is provided to obtain thesolution. After the camera rectification intrinsic and extrinsic parameters are obtained based onthe relationship between the homograph and absolute conic. This technology needs neither ahigh-accuracy three-dimensional calibration block, nor a complicated translation or rotationplatform. Both simulations and experiments show that this method is effective and robust. 展开更多
关键词 Camera calibration Camera rectification Linear rectification
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Improved Mixed Integer Optimization Approach for Data Rectification with Gross Error Candidates 被引量:2
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作者 李笕列 荣冈 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第2期226-231,共6页
Mixed integer linear programming (MILP) approach for simultaneous gross error detection and data reconciliation has been proved as an efficient way to adjust process data with material, energy, and other balance con... Mixed integer linear programming (MILP) approach for simultaneous gross error detection and data reconciliation has been proved as an efficient way to adjust process data with material, energy, and other balance constrains. But the efficiency will decrease significantly when this method is applled in a large-scale problem because there are too many binary variables involved. In this article, an improved method is proposed in order to gen- erate gross error candidates with reliability factors before data rectification. Candidates are used in the MILP objec- tive function to improve the efficiency and accuracy by reducing the number of binary variables and giving accurate weights for suspected gross errors candidates. Performance of this improved method is compared and discussed by applying the algorithm in a widely used industrial example. 展开更多
关键词 data rectification gross error detection graphic theory Bayesian method
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Rectification of magnetic force tracker using neural network inaugmented reality system 被引量:2
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作者 丰艳 陈一民 《Journal of Shanghai University(English Edition)》 CAS 2006年第5期431-435,共5页
Nonlinear errors always exist in data obtained from tracker in augmented reality (AR), which badly influence the effect of AR. This paper proposes to rectify the errors using BP neural network. As BP neural network ... Nonlinear errors always exist in data obtained from tracker in augmented reality (AR), which badly influence the effect of AR. This paper proposes to rectify the errors using BP neural network. As BP neural network is prone to getting into local extrema and convergence is slow, genetic algorithm is employed to optimize the initial weights and threshold of neural network. This paper discusses how to set the crucial parameters in the algorithm. Experimental results show that the method ensures that the neural network achieves global convergence quickly and correctly. Tracking precision of AR system is improved after the tracker is rectified, and the third dimension of AR system is enhanced. 展开更多
关键词 BP neural network genetic algorithm augmented reality(AR) magnetic force tracker rectification.
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The First Principle Study on the Rectification of Molecular Junctions Based on the Alkyl-chain-modified Phenyl Benzothiophene Derivative 被引量:2
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作者 Fuzhou 350007 China) 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第7期1037-1044,共8页
Using density functional theory(DFT) combined with nonequilibrium Green's function investigates the electron-transport properties of several molecular junctions based on the PBTDT-CH=NH molecule, which is modified ... Using density functional theory(DFT) combined with nonequilibrium Green's function investigates the electron-transport properties of several molecular junctions based on the PBTDT-CH=NH molecule, which is modified by one to four alkyl groups forming PBTDT-(CH2)nCH=NH. The electronic structures of the isolated molecules(thiol-ended PBTDT-(CH2)nCH=N) have been investigated before the electron-transport calculations are performed. The asymmetric current-voltage characteristics have been obtained for the molecular junctions. Rectifying performance of Au/S-PBTDT-CH=N-S/Au molecular junction can be regulated by introducing alkyl chain. The N3 molecular junction exhibits the best rectifying effect. Its maximum rectifying ratio is 878, which is 80 times more than that of the molecular junction based on the original N molecular junction. The current-voltage(I-V) curves of all the sandwich systems in this work are illustrated by transmission spectra and molecular projection density analysis. 展开更多
关键词 the first principle phenyl benzothiophene alkyl chain rectification
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Nonlinear Optical Rectification, Second and Third Harmonic Generations in Square-Step and Graded-Step Quantum Wells under Intense Laser Field 被引量:1
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作者 O.Ozturk E.Ozturk S.Elagoz 《Chinese Physics Letters》 SCIE CAS CSCD 2019年第6期93-97,共5页
For square-step quantum wells(SSQWs) and graded-step quantum wells(GSQWs), the nonlinear optical rectification(NOR), second harmonic generation(SHG) and third harmonic generation(THG) coefficients under an intense las... For square-step quantum wells(SSQWs) and graded-step quantum wells(GSQWs), the nonlinear optical rectification(NOR), second harmonic generation(SHG) and third harmonic generation(THG) coefficients under an intense laser field(ILF) are analyzed. The found results indicate that ILF can ensure a vital influence on the shape and height of the confined potential profile of both SSQWs and GSQWs, and alterations of the dipole moment matrix elements and the energy levels are adhered on the profile of the confined potential. According to the results, the potential profile and height of the GSQWs are affected more significantly by ILF intensity compared to SSQWs. These results indicate that NOR, SHG and THG coefficients of SSQWs and GSQWs may be calibrated in a preferred energy range and the magnitude of the resonance peak(RP) by tuning the ILF parameter. It is feasible to classify blue or red shifts in RP locations of NOR, SHG and THG coefficients by varying the ILF parameter. Our results can be useful in investigating new ways of manipulating the opto-electronic properties of semiconductor QW devices. 展开更多
关键词 square-step quantum wells(SSQWs) graded-step quantum wells(GSQWs) nonlinear optical rectification(NOR)
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Effect of proportion on rectification in organic co-oligomer spin rectifiers 被引量:1
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作者 胡贵超 王辉 任俊峰 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第7期410-415,共6页
The rectification behaviours in organic magnetic/nonmagnetic co-oligomer spin rectifiers are investigated theoretically. It is found that both the charge current and the spin current through the device are rectified a... The rectification behaviours in organic magnetic/nonmagnetic co-oligomer spin rectifiers are investigated theoretically. It is found that both the charge current and the spin current through the device are rectified at the same time. By adjusting the proportion between the magnetic and nonmagnetic components, the threshold voltage and the rectification ratio of the rectifier are modulated. A large rectification ratio is obtained when the two components are equal in length. The intrinsic mechanism is analysed in terms of the asymmetric localization of molecular orbitals under biases. The effect of molecular length on the rectification is also discussed. These results will be helpful in the future design of organic spin diodes. 展开更多
关键词 organic spintronics rectification co-oligomer PROPORTION
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Rectification and electroluminescence of nanostructured GaN/Si heterojunction based on silicon nanoporous pillar array 被引量:1
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作者 王小波 李勇 +1 位作者 闫玲玲 李新建 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第10期432-437,共6页
A GaN/Si nanoheterojunction is prepared through growing Ga N nanocrystallites(nc-GaN) on a silicon nanoporous pillar array(Si-NPA) by a chemical vapor deposition(CVD) technique at a relatively low temperature. T... A GaN/Si nanoheterojunction is prepared through growing Ga N nanocrystallites(nc-GaN) on a silicon nanoporous pillar array(Si-NPA) by a chemical vapor deposition(CVD) technique at a relatively low temperature. The average size of nc-Ga N is determined to be ~10 nm. The spectral measurements disclose that the photoluminescence(PL) from GaN/SiNPA is composed of an ultraviolet(UV) band and a broad band spanned from UV to red region, with the feature that the latter band is similar to that of electroluminescence(EL). The electron transition from the energy levels of conduction band and, or, shallow donors to that of deep acceptors of Ga N is indicated to be responsible for both the broad-band PL and the EL luminescence. A study of the I-V characteristic shows that at a low forward bias, the current across the heterojunction is contact-limited while at a high forward bias it is bulk-limited, which follows the thermionic emission model and space-charge-limited current(SCLC) model, respectively. The bandgap offset analysis indicates that the carrier transport is dominated by electron injection from n-GaN into the p-Si-NPA, and the EL starts to appear only when holes begin to be injected from Si-NPA into GaN with biases higher than a threshold voltage. 展开更多
关键词 GaN/Si-NPA HETEROJUNCTION rectification electroluminescence (EL)
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