We investigate the sensitivity and figure of merit （FOM） of a localized surface plasmon （LSP） sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon senso...We investigate the sensitivity and figure of merit （FOM） of a localized surface plasmon （LSP） sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon sensor is 317 nm/RIU, and the FOM is predicted to be above 8, which is very high for a localized surface plasmon sensor. By employing the rigorous coupled-wave analysis （RCWA） method, we analyze the distribution of the magnetic field and find that the sensing property of our proposed system is attributed to the interactions between the localized surface plasmon around the gold nanostrips and the surface plasmon polarition on the surface of the gold planar metallic film. These findings are important for developing high FOM localized surface plasmon sensors.展开更多
Figure of merit analysis is a general methodology used to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants. In this paper, the assessment methodology using figure of mer...Figure of merit analysis is a general methodology used to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants. In this paper, the assessment methodology using figure of merit analysis was re-examined for a hybrid solar-geothermal power plant. A new definition of the figure of merit was introduced specifically for a solar boosted geothermal plant to include both the technical and economic factors. The new definition was then applied in a case study of a hypothetical demonstration hybrid solar-geothermal power plant in Australia. The power plant was considered to have a typical net power output of 2.2 MW with a solar energy fraction of 27%. The analysis was performed to compare the power output and capital cost of the hybrid plant with the state-of-the-art (SoA) and existing stand-alone solar and geothermal plants. Based on the new definition, the hybrid plant was found to generally outperform the two existing stand-alone plants. Moreover, at an ambient temperature of 5 °C, the hybrid plant was found to outperform the SoA stand-alone plants when the geothermal temperature was greater than 150 °C. For geothermal temperature of 180 °C on the other hand, the hybrid plant outperformed the SoA stand-alone plants at ambient temperatures lower than 33 °C.展开更多
A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition techniq...A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.展开更多
The purpose of this paper is to present the results of investigations on quasi-one-dimensional organic crystals of tetrathiotetracene-tetracyanoquinodi- methane (TTT(TCNQ)<sub>2</sub>) from the prospective...The purpose of this paper is to present the results of investigations on quasi-one-dimensional organic crystals of tetrathiotetracene-tetracyanoquinodi- methane (TTT(TCNQ)<sub>2</sub>) from the prospective of thermoelectric applications. The calculations were performed after analytical expressions, obtained in the frame of a physical model, more detailed than the model presented earlier by authors. The main Hamiltonian of the model includes the electronic and phonon part, electron-phonon interactions and the impurity scattering term. In order to estimate the electric charge transport between the molecular chains, the physical model was upgraded to the so-called three-dimen- sional (3D) physical model. Numeric computations were performed to determine the electrical conductivity, Seebeck coefficient, thermal conductivity, thermoelectric power factor and thermoelectric figure-of-merit as a function on charge carrier concentrations, temperatures and impurity concentrations. A detailed analysis of charge-lattice interaction, consisting of the exploration of the Peierls structural transition in TCNQ molecular chains of TTT(TCNQ)<sub>2</sub> was performed. As result, the critical transition temperature was determined. The dispersion of renormalized phonons was examined in detail.展开更多
In the present study,we have synthesized Ag2Te nanoparticles using the hydrothermal method and showed significant improvement in the thermoelectric properties compared to the bulk Ag2Te sample.Ag2Te nanoparticles show...In the present study,we have synthesized Ag2Te nanoparticles using the hydrothermal method and showed significant improvement in the thermoelectric properties compared to the bulk Ag2Te sample.Ag2Te nanoparticles showed the highest figure of merit(zT)of 1.37 at 373 K,which is the highest zT reported for this undoped material.This high zT in Ag2Te nanoparticles is mainly due to about~2 times higher electrical conductivity(1967 S/cm)and subsequently~2 times lower thermal conductivity(0.53 W/(m$K))as compared to the bulk Ag2Te sample.The higher electrical conductivity in Ag2Te nanoparticles can be accredited for two reasons(i)better mobility of the charge carrier and(ii)increased carrier concentration.The low thermal conductivity is associated with the enhanced scattering of phonons at the interface of the Ag2Te nanoparticles.展开更多
采用合金设计、真空熔炼、快速凝固、球磨制粉、冷压成形和常压烧结工艺,制备了Cu、S掺杂的n型Bi_(2)Te_(2.7)Se_(0.3)热电材料,采用XRD、SEM和ZEM-3热电测试系统等表征热电材料晶体结构、微观形貌和热电性能,研究Cu、S掺杂的n型Bi_(2)T...采用合金设计、真空熔炼、快速凝固、球磨制粉、冷压成形和常压烧结工艺,制备了Cu、S掺杂的n型Bi_(2)Te_(2.7)Se_(0.3)热电材料,采用XRD、SEM和ZEM-3热电测试系统等表征热电材料晶体结构、微观形貌和热电性能,研究Cu、S掺杂的n型Bi_(2)Te_(2.7)Se_(0.3)热电材料热电性能机理。结果表明:Cu_(y)Bi_(2)Te_(2.62)S_(0.08)Se_(0.3)热电材料晶体结构为R-3m空间群斜方晶系的六面体层状结构;掺杂Cu的Cu_(y)Bi_(2)Te_(2.7)Se_(0.3)热电材料,形成Cui间隙缺陷和Bi′Te反位缺陷,随着载流子(电子)浓度增加,载流子迁移率降低,电导率显著增大;掺杂S的Bi_(2)Te_(2.62-z)SzSe_(0.3)热电材料,生成化学键健能较Bi-Te强的Bi-S,抑制反位缺陷Bi′Te形成,少数(空穴)载流子浓度减小,同时增强声子对声子散射和点缺陷对声子散射,从而使晶格热导率和双极扩散热导率降低,总热导率明显降低,抑制塞贝克系数的减少;Cu、S共掺杂的协同作用,n型Cu_(y)Bi_(2)Te_(2.62-z)SzSe_(0.3)热电材料电导率增大,而热导率基本不变,由此ZT值和功率因子显著提高;在300~400 K温度范围内,Cu_(0.03)Bi_(2)Te_(2.62)S_(0.08)Se_(0.3)的电导率约为7.0×10^(4)S/m,塞贝克系数约为220μV/K,功率因子约为2.4 m W/(m·K^(2)),热电优值(ZT值)约为1.0。Cu_(0.03)Bi_(2)Te_(2.62)S_(0.08)Se_(0.3)热电材料可广泛应用于低温尤其室温条件下的热电制冷器件和温差发电电池。展开更多
Memristor with memory properties can be applied to connection points(synapses)between cells in a cellular neural network(CNN).This paper highlights memristor crossbar-based multilayer CNN(MCM-CNN)and its application t...Memristor with memory properties can be applied to connection points(synapses)between cells in a cellular neural network(CNN).This paper highlights memristor crossbar-based multilayer CNN(MCM-CNN)and its application to edge detection.An MCM-CNN is designed by adopting a memristor crossbar composed of a pair of memristors.MCM-CNN based on the memristor crossbar with changeable weight is suitable for edge detection of a binary image and a color image considering its characteristics of programmablization and compactation.Figure of merit(FOM)is introduced to evaluate the proposed structure and several traditional edge detection operators for edge detection results.Experiment results show that the FOM of MCM-CNN is three times more than that of the traditional edge detection operators.展开更多
This paper investigates the effects of pH on stability and thermal properties of copper oxide(CuO),graphene oxide(GO),and their hybrid nanofluid(HNF)at different mixing ratios.Initially,sol-gel and Hummer’s method wa...This paper investigates the effects of pH on stability and thermal properties of copper oxide(CuO),graphene oxide(GO),and their hybrid nanofluid(HNF)at different mixing ratios.Initially,sol-gel and Hummer’s method was employed for the synthesis of CuO and GO nanoparticles(NPs),and they are characterized with various techniques.The effects of two different surfactants were analyzed on nanofluid’s(NF’s)stability at different pH values.The properties like thermal conductivity(TC)and viscosity(VST)of NFs were measured at different volume concentration(0.1 vol%to 1.0 vol%)and temperature range of 30-60℃,respectively.The TC and VST of GO/CuO(50:50)HNF are higher than that of GO/CuO(20:80).The figure of merit(FOM)is determined for the studied HNFs.The correlations were presented to calculate the TC as well as VST of HNFs.Two modern novel machine learning-based ensemble approaches were employed for predictive model development for TC and VST of considered HNFs.The comparison of prognostic models with Taylor’s diagram revealed that Bayesian optimized support vector machine(BoASVM)was superior to Bayesian optimized boosted regression trees(BoA-BRT)for both TC and VST models.展开更多
基金Project supported by the National Key Research Program of China(Grant No.2011ZX01015-001)
文摘We investigate the sensitivity and figure of merit （FOM） of a localized surface plasmon （LSP） sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon sensor is 317 nm/RIU, and the FOM is predicted to be above 8, which is very high for a localized surface plasmon sensor. By employing the rigorous coupled-wave analysis （RCWA） method, we analyze the distribution of the magnetic field and find that the sensing property of our proposed system is attributed to the interactions between the localized surface plasmon around the gold nanostrips and the surface plasmon polarition on the surface of the gold planar metallic film. These findings are important for developing high FOM localized surface plasmon sensors.
文摘Figure of merit analysis is a general methodology used to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants. In this paper, the assessment methodology using figure of merit analysis was re-examined for a hybrid solar-geothermal power plant. A new definition of the figure of merit was introduced specifically for a solar boosted geothermal plant to include both the technical and economic factors. The new definition was then applied in a case study of a hypothetical demonstration hybrid solar-geothermal power plant in Australia. The power plant was considered to have a typical net power output of 2.2 MW with a solar energy fraction of 27%. The analysis was performed to compare the power output and capital cost of the hybrid plant with the state-of-the-art (SoA) and existing stand-alone solar and geothermal plants. Based on the new definition, the hybrid plant was found to generally outperform the two existing stand-alone plants. Moreover, at an ambient temperature of 5 °C, the hybrid plant was found to outperform the SoA stand-alone plants when the geothermal temperature was greater than 150 °C. For geothermal temperature of 180 °C on the other hand, the hybrid plant outperformed the SoA stand-alone plants at ambient temperatures lower than 33 °C.
基金Supported by the Scientific Research Deanship of University of Dammam under Grant No 2014264
文摘A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.
文摘The purpose of this paper is to present the results of investigations on quasi-one-dimensional organic crystals of tetrathiotetracene-tetracyanoquinodi- methane (TTT(TCNQ)<sub>2</sub>) from the prospective of thermoelectric applications. The calculations were performed after analytical expressions, obtained in the frame of a physical model, more detailed than the model presented earlier by authors. The main Hamiltonian of the model includes the electronic and phonon part, electron-phonon interactions and the impurity scattering term. In order to estimate the electric charge transport between the molecular chains, the physical model was upgraded to the so-called three-dimen- sional (3D) physical model. Numeric computations were performed to determine the electrical conductivity, Seebeck coefficient, thermal conductivity, thermoelectric power factor and thermoelectric figure-of-merit as a function on charge carrier concentrations, temperatures and impurity concentrations. A detailed analysis of charge-lattice interaction, consisting of the exploration of the Peierls structural transition in TCNQ molecular chains of TTT(TCNQ)<sub>2</sub> was performed. As result, the critical transition temperature was determined. The dispersion of renormalized phonons was examined in detail.
基金The Department of Science and Technology(DST)of the Government of India(project no.RP03530)and the Ministry of Electronics and Information Technology(MeitY)have both offered financial assistance.The authors also thank Nanoscale Research Facility(NRF)for using different characterization techniques.Author A.K.Gautam is also grateful to the Council of Scientific and Industrial Research(CSIR)for the senior research fellowship(SRF)Grant.
文摘In the present study,we have synthesized Ag2Te nanoparticles using the hydrothermal method and showed significant improvement in the thermoelectric properties compared to the bulk Ag2Te sample.Ag2Te nanoparticles showed the highest figure of merit(zT)of 1.37 at 373 K,which is the highest zT reported for this undoped material.This high zT in Ag2Te nanoparticles is mainly due to about~2 times higher electrical conductivity(1967 S/cm)and subsequently~2 times lower thermal conductivity(0.53 W/(m$K))as compared to the bulk Ag2Te sample.The higher electrical conductivity in Ag2Te nanoparticles can be accredited for two reasons(i)better mobility of the charge carrier and(ii)increased carrier concentration.The low thermal conductivity is associated with the enhanced scattering of phonons at the interface of the Ag2Te nanoparticles.
文摘采用合金设计、真空熔炼、快速凝固、球磨制粉、冷压成形和常压烧结工艺,制备了Cu、S掺杂的n型Bi_(2)Te_(2.7)Se_(0.3)热电材料,采用XRD、SEM和ZEM-3热电测试系统等表征热电材料晶体结构、微观形貌和热电性能,研究Cu、S掺杂的n型Bi_(2)Te_(2.7)Se_(0.3)热电材料热电性能机理。结果表明:Cu_(y)Bi_(2)Te_(2.62)S_(0.08)Se_(0.3)热电材料晶体结构为R-3m空间群斜方晶系的六面体层状结构;掺杂Cu的Cu_(y)Bi_(2)Te_(2.7)Se_(0.3)热电材料,形成Cui间隙缺陷和Bi′Te反位缺陷,随着载流子(电子)浓度增加,载流子迁移率降低,电导率显著增大;掺杂S的Bi_(2)Te_(2.62-z)SzSe_(0.3)热电材料,生成化学键健能较Bi-Te强的Bi-S,抑制反位缺陷Bi′Te形成,少数(空穴)载流子浓度减小,同时增强声子对声子散射和点缺陷对声子散射,从而使晶格热导率和双极扩散热导率降低,总热导率明显降低,抑制塞贝克系数的减少;Cu、S共掺杂的协同作用,n型Cu_(y)Bi_(2)Te_(2.62-z)SzSe_(0.3)热电材料电导率增大,而热导率基本不变,由此ZT值和功率因子显著提高;在300~400 K温度范围内,Cu_(0.03)Bi_(2)Te_(2.62)S_(0.08)Se_(0.3)的电导率约为7.0×10^(4)S/m,塞贝克系数约为220μV/K,功率因子约为2.4 m W/(m·K^(2)),热电优值(ZT值)约为1.0。Cu_(0.03)Bi_(2)Te_(2.62)S_(0.08)Se_(0.3)热电材料可广泛应用于低温尤其室温条件下的热电制冷器件和温差发电电池。
基金supported by the Research Fund for International Young Scientists of the National Natural Science Foundation of China(61550110248)the Research on Fundamental Theory of Shared Intelligent Street Lamp for New Scene Service(H04W200495)+1 种基金Sichuan Science and Technology Program(2019YFG0190)the Research on Sino-Tibetan Multi-source Information Acquisition,Fusion,Data Mining and its Application(H04W170186).
文摘Memristor with memory properties can be applied to connection points(synapses)between cells in a cellular neural network(CNN).This paper highlights memristor crossbar-based multilayer CNN(MCM-CNN)and its application to edge detection.An MCM-CNN is designed by adopting a memristor crossbar composed of a pair of memristors.MCM-CNN based on the memristor crossbar with changeable weight is suitable for edge detection of a binary image and a color image considering its characteristics of programmablization and compactation.Figure of merit(FOM)is introduced to evaluate the proposed structure and several traditional edge detection operators for edge detection results.Experiment results show that the FOM of MCM-CNN is three times more than that of the traditional edge detection operators.
文摘This paper investigates the effects of pH on stability and thermal properties of copper oxide(CuO),graphene oxide(GO),and their hybrid nanofluid(HNF)at different mixing ratios.Initially,sol-gel and Hummer’s method was employed for the synthesis of CuO and GO nanoparticles(NPs),and they are characterized with various techniques.The effects of two different surfactants were analyzed on nanofluid’s(NF’s)stability at different pH values.The properties like thermal conductivity(TC)and viscosity(VST)of NFs were measured at different volume concentration(0.1 vol%to 1.0 vol%)and temperature range of 30-60℃,respectively.The TC and VST of GO/CuO(50:50)HNF are higher than that of GO/CuO(20:80).The figure of merit(FOM)is determined for the studied HNFs.The correlations were presented to calculate the TC as well as VST of HNFs.Two modern novel machine learning-based ensemble approaches were employed for predictive model development for TC and VST of considered HNFs.The comparison of prognostic models with Taylor’s diagram revealed that Bayesian optimized support vector machine(BoASVM)was superior to Bayesian optimized boosted regression trees(BoA-BRT)for both TC and VST models.
