Gd2O3 thin films as high-κ gate dielectrics were deposited directly on Si(001) substrates by magnetron sputtering at a pressure of 1.3 Pa and different temperatures. X-ray diffraction results revealed that all the ...Gd2O3 thin films as high-κ gate dielectrics were deposited directly on Si(001) substrates by magnetron sputtering at a pressure of 1.3 Pa and different temperatures. X-ray diffraction results revealed that all the films grown from 450 to 570 ℃ were crystalline, and the Gd2O3 thin films consisted of a mixture of cubic and monoclinic phases. The growth temperature was a critical parameter for the phase constituents and their relative amount. Low temperature was favorable for the formation of cubic phase while higher temperature gave rise to more monoclinic phase. All the Gd2O3 thin films grown from different temperatures exhibited acceptable electrical properties, such as low leakage current density (JL) of 10-5 A/cm^2 at zero bias with capacitance equivalent SiO2 thickness in the range of 6-13 nm. Through the comparison between films grown at 450 and 570 ℃, the existence of monoclinic phase caused an increase in JL by nearly one order of magnitude and a reduction of effective dielectric constant from 17 to 9.展开更多
Given the demand for constantly scaling microelectronic devices to ever smaller dimensions, a SiO_2 gate dielectric was substituted with a higher dielectric-constant material, Hf(Zr)O_2, in order to minimize current l...Given the demand for constantly scaling microelectronic devices to ever smaller dimensions, a SiO_2 gate dielectric was substituted with a higher dielectric-constant material, Hf(Zr)O_2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant(high-κ) dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remotephonon scattering, and dielectric-charge trapping. III-V and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf(Zr)O_2/III-V(Ge) has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding conflgurations at Hf(Zr)O_2/III-V(Ge) interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize firstprinciple calculations to investigate the interface between HfO_2 and Ga As. Our study shows that As—As dimer bonding, Ga partial oxidation(between 3+ and 1+) and Ga— dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation.展开更多
A series of high dielectric material Er2O3 thin films with different thicknesses were deposited on p-type Si(100)substrate by pulse laser deposition at different temperatures.Phase structures of the films were deter...A series of high dielectric material Er2O3 thin films with different thicknesses were deposited on p-type Si(100)substrate by pulse laser deposition at different temperatures.Phase structures of the films were determined by means of X-ray diffraction(XRD)and high resolution transmission electron microscopy(HRTEM).Leakage current density was measured with an HP4142B semiconductor parameter analyzer.The XRD and HRTEM results reveal that Er2O3 thin films deposited below 400°C are amorphous,while films deposited from 400 to 840°C are well crystallized with(111)-preferential crystallographic orientation.I-V curves show that,for ultrathin crystalline Er2O3 films,the leakage current density increases by almost one order of magnitude from 6.20×10^-5 to 6.56×10^-4 A/cm^2,when the film thickness decreases by only 1.9 nm from 5.7 to 3.8 nm.However the leakage current density of ultrathin amorphous Er2O3 films with a thickness of 3.8 nm is only 1.73×10^-5 A/cm^2.Finally,analysis of leakage current density showed that leakage of ultrathin Er2O3 films at high field is mainly caused by Fowler-Nordheim tunneling,and the large leakage of ultrathin crystalline Er2O3 films could arise from impurity defects at the grain boundary.展开更多
In the gneisses from the drillhole ZK2304 of the Donghai area, there have been preserved high- and ultrahigh-pressure metamorphic mineral assemblages, a series of complicated retrogressive textures and relevant metamo...In the gneisses from the drillhole ZK2304 of the Donghai area, there have been preserved high- and ultrahigh-pressure metamorphic mineral assemblages, a series of complicated retrogressive textures and relevant metamorphic reactions. In addition to garnet, jadeititic-clinopyroxene and rutile, other peak stage (M2) minerals in some gneisses include phengite, aragonite and coesite or quartz pseudomorphs after coesite. The typical peak-stage mineral assemblages in gneisses are characterized by garnet + jadeitic-clinopyroxene + rutile + coesite, garnet + jadeitic-clinopyroxene + phengite + rutile ± coesite and garnet + jadeitic-clinopyroxene + aragonite + rutile ± coesite. The grossular content (Gro) in garnet is high and may reach 50. 1 mol%. The SiO2 content of phengite ranges from 54.37% to 54.84% with 3.54-3.57 p.f.u. Quartz pseudomorphs after coesite occur as inclusions in garnet.The gneisses of the Donghai area have been subjected to multistage recrystallization and exhibit a closewise P-T evolutional path characterized by the near-isothermal decompression. The inclusion assemblage (Hb+Ep+Bi+Pl+Qz) within garnet and other minerals has recorded a pre-peak stage (Mi) epidote amphibole fades metamorphic event. High- and ultrahigh-pressure peak metamorphism (M2) took place at T=750-860℃ and P>2.7 GPa. The symplectitic assemblages after garnet, jadeitic-clinopyroxene and rutile imply a near-isothermal decompression metamorphism (M3, M4) during the rapid exhumation. Several lines of evidence of petrography and metamorphic reactions indicate that both gneisses and eclogites have experienced ultrahigh-pressure metamorphism in the Donghai area. This research may be of great significance for an in-depth study of the metamorphism and tectonic evolution in the Su-Lu ultrahigh-pressure metamorphic belt.展开更多
Comparison of regular(diurnal,seasonal and solar cycle)variations of high-latitude,mid-latitude and low-latitude ionospheric characteristics has been provided on basis of local empirical models of the peak electron de...Comparison of regular(diurnal,seasonal and solar cycle)variations of high-latitude,mid-latitude and low-latitude ionospheric characteristics has been provided on basis of local empirical models of the peak electron density and the peak height.The local empirical models were derived from the hand-scaled ionogram data recorded by DPS-4 digisondes located at Norilsk(69°N,88°E),Irkutsk(52°N,104°E)and Hainan(19°N,109°E)for a 6-year period from December,2002 to December,2008.The technique used to build the local empirical model is described.The primary focus is diurnal-seasonal behavior under low solar activity and its change with increasing solar activity.Both common and specific features of the high-latitude(Norilsk),mid-latitude(Irkutsk)and low-latitude(Hainan)regular variations were revealed using their local empirical models.展开更多
Objective: To investigate the effectiveness of a high-fidelity teaching simulation based on an NLN/Jeffries simulation in the nursing education theoretical framework and its influencing factors. Methods: A high-fide...Objective: To investigate the effectiveness of a high-fidelity teaching simulation based on an NLN/Jeffries simulation in the nursing education theoretical framework and its influencing factors. Methods: A high-fidelity teaching simulation on clinical nursing practices using intelligent human analogues was conducted with 200 students, and The Simulation Design Scale, and the Student Satisfaction and Self-Confidence in Learning Scale developed by the National League for Nursing were used to evaluate the training effectiveness and its influencing factors. Results: For the high-fidelity teaching simulation, students gave scores of 4.36± 0.54 points for satisfaction and 4.33 ± 0.46 points for Self-Confidence. The students highly rated the five dimensions of teaching design, i.e., teaching objectives/information, assistance/support for students, problem solving, guided feedback, and fidelity. The teaching design was closely correlated with the satisfaction of the high-fidelity teaching simulation and self-efficacy, and the dimensions of teaching objectives/informa- tion and assistance/support for students were particularly strong predictors of teaching effectiveness. Conclusions: A high-fidelity teaching simulation based on Jeffries' theoretical framework improved student satisfaction with the simulation and their Self-Confidence. In planning simulations, teachers should take into account five characteristics, i.e., teaching objectives/information on simulation education, assistance/support for students, problem solving, guided reflection, and fidelity, to achieve better teaching effectiveness.展开更多
Based on the elastic trap-assisted tunneling mechanism in high-κgate stacks,a quantum percolation tunneling current 1/fγ noise model is proposed by incorporating quantum tunneling theory into the quantum percolation...Based on the elastic trap-assisted tunneling mechanism in high-κgate stacks,a quantum percolation tunneling current 1/fγ noise model is proposed by incorporating quantum tunneling theory into the quantum percolation model.We conclude that the noise amplitude of the PSD(Power Spectral Density)for three stages,namely the fresh device,one-layer BD(breakdown),and two-layer BD,increases from 10-22→10-14→10-8 A2/Hz.Meanwhile,the noise exponent γ for the three stages,has the 1/f2type(γ→2),1/fγ type(γ→1~2),and 1/f type(γ→1),respectively.The simulation results are in good agreement with the experimental results.This model reasonably interprets the correlation between the bi-layer breakdown and the tunneling 1/fγ noise amplitude dependence and 1/fγ noise exponent dependence.These results provide a theoretical basis for the high-κ gate stacks bi-layer breakdown noise characterization methods.展开更多
The Roman high(RHA) and low-Avoidance (RLA) rats were selectively bred for rapid vs poor acquisition of two-way active avoidance behavior. These lines differ in numerous behavioral traits, with RLA rats being more fea...The Roman high(RHA) and low-Avoidance (RLA) rats were selectively bred for rapid vs poor acquisition of two-way active avoidance behavior. These lines differ in numerous behavioral traits, with RLA rats being more fearful/anxious than RHA rats, and the latter being novelty-seekers and showing larger intake of, and preference for, addictive substances including ethanol (ETH). Moreover, several differences in central dopaminergic, serotonergic, and GABAergic functions have been reported in these two lines. Since those neural systems are involved in the regulation of ETH consumption, it was considered of interest to investigate: 1) the differences in ETH intake and preference between RHA and RLA rats, 2) the effects of ETH on DA release in the shell of the nucleus accumbens (AcbSh) using brain microdialysis. ETH solutions of increasing concentrations (2% - 10%) were presented on alternate days in a free choice with water. To examine ETH intake and preference stability, animals were subsequently switched to daily presentations of 10% ETH for 10 consecutive days. RHA rats consumed significantly larger amounts of ETH and displayed higher ETH preference than did RLA rats throughout the acquisition and maintenance phases. Following chronic exposure to ETH the animals were habituated to a restricted access to ETH schedule (2% ETH, 2 h per day × 4 days) before surgical implantation of a dialysis probe in the AcbSh. Under these experimental conditions, voluntary ETH intake (2%, 1 h, p.o.) produced a significant increase in accumbal DA output in RHA rats but not in their RLA counterparts. Finally, the i.p. administration of ETH (0.25 g/kg) to na?ve Roman rats produced a significant increment in accumbal DA output only in RHA rats. These results indicate that the mesolimbic dopaminergic system of RHA rats is more responsive to the effects of ETH than that of RLA rats.展开更多
In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strengt...In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strength growth characteristics of HFS-BFRS were analyzed.And thefitting equation of compressive strength growth characteristics of HFS-BFRS under the synergistic effect of multiple factors was given.And based on the orthogonal experimental method,the effects on the compressive strength,splitting tensile strength andflex-ural strength of HFS-BFRS under the action of different levels of influencing factors were investigated.The effect of three factors on the mechanical properties of HFS-BFRS,3,and 28 d,respectively,was revealed by choosing the colloidal sand ratio(C/H),basaltfiber volume fraction(BF Vol)and naphthalene high-efficiency water reducing agent(FDN)as the design variables,combined with indoor tests and theoretical analysis.The results show that the sensitivity of the three factors on compressive strength andflexural strength is C/H>FDN>BF Vol,and split-ting tensile strength is BF Vol>FDN>C/H.Finally,thefitting ratio of HFS-BFRS was optimized by the factor index method,and the rationality was verified by thefield test.For thefluidity of HFS-BFRS,the slump can be improved by 139%under the action of 1.2%FDN,which guarantees the pump-ability of HFS-BFRS.展开更多
A mathematical model and experimental analysis of the impact of oxide thickness on the ambipolar conduction in Schottky Barrier Carbon Nanotubes(CNTs)Field Effect Transistor(SB CNTFETs)is presented.Suppression of ambi...A mathematical model and experimental analysis of the impact of oxide thickness on the ambipolar conduction in Schottky Barrier Carbon Nanotubes(CNTs)Field Effect Transistor(SB CNTFETs)is presented.Suppression of ambipolar conduction in SB CNTFETs is imperative in order to establish them as the future of IC technology.The ambipolar nature of SB CNTFETs leads to a great amount of leakage current.Employing a gate oxide dielectric of thickness,tox^50 nm suppresses the ambipolar behavior.In an SB CNTFET,it is the electric field at the source/drain contacts that control the conductance and the band bending length at the contacts is defined by tox.Therefore,tox is the prime parameter that influences the width of the Schottky barrier and the current in the subthreshold region.Due to the wide SB,there is a loss in on-current due to tunneling,but the current due to thermionic emission is increased by employing a high-κdielectric such as Zirconium dioxide(ZrO2).This work proposes an approach to suppress ambipolar behavior in SB CNTFETs without decreasing the on current.The thickness and dielectric constant of the gate oxide are optimized using the particle swarm optimization(PSO)algorithm to achieve suppression of ambipolar conduction without any loss in on-current.The proposed SB CNTFET was modeled using Verilog-A.Experimental demonstration of the suppression of ambipolar property is also presented.Two SB CNTFETs are fabricated using high-κdielectric such as ZrO2 with different thickness.A device with thin(~5 nm)gate oxide and another device with thick(~50 nm)gate oxide were fabricated.From the experimental results,it is observed that the device with the thin gate oxide exhibited ambipolar characteristics and the device with the thick gate oxide did not exhibit ambipolar characteristics.The increase in thickness,tox,ensures suppression of ambipolar behavior.展开更多
基金General Research Institute for Nonferrous Metals Research Fund (82262)
文摘Gd2O3 thin films as high-κ gate dielectrics were deposited directly on Si(001) substrates by magnetron sputtering at a pressure of 1.3 Pa and different temperatures. X-ray diffraction results revealed that all the films grown from 450 to 570 ℃ were crystalline, and the Gd2O3 thin films consisted of a mixture of cubic and monoclinic phases. The growth temperature was a critical parameter for the phase constituents and their relative amount. Low temperature was favorable for the formation of cubic phase while higher temperature gave rise to more monoclinic phase. All the Gd2O3 thin films grown from different temperatures exhibited acceptable electrical properties, such as low leakage current density (JL) of 10-5 A/cm^2 at zero bias with capacitance equivalent SiO2 thickness in the range of 6-13 nm. Through the comparison between films grown at 450 and 570 ℃, the existence of monoclinic phase caused an increase in JL by nearly one order of magnitude and a reduction of effective dielectric constant from 17 to 9.
基金supported by the National Natural Science Foundation of China (11304161, 11104148, and 51171082)the Tianjin Natural Science Foundation (13JCYBJC41100 and 14JCZDJC37700)+3 种基金the National Basic Research Program of China (973 Program) (2014CB931703)Specialized Research Fund for the Doctoral Program of Higher Education (20110031110034)the Fundamental Research Funds for the Central Universitiessupported by the Global Frontier Center for Multiscale Energy Systems at Seoul National University in Korea
文摘Given the demand for constantly scaling microelectronic devices to ever smaller dimensions, a SiO_2 gate dielectric was substituted with a higher dielectric-constant material, Hf(Zr)O_2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant(high-κ) dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remotephonon scattering, and dielectric-charge trapping. III-V and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf(Zr)O_2/III-V(Ge) has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding conflgurations at Hf(Zr)O_2/III-V(Ge) interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize firstprinciple calculations to investigate the interface between HfO_2 and Ga As. Our study shows that As—As dimer bonding, Ga partial oxidation(between 3+ and 1+) and Ga— dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No.072C201301)the Graduate Student Innovation Program of the Chinese Academy of Sciences
文摘A series of high dielectric material Er2O3 thin films with different thicknesses were deposited on p-type Si(100)substrate by pulse laser deposition at different temperatures.Phase structures of the films were determined by means of X-ray diffraction(XRD)and high resolution transmission electron microscopy(HRTEM).Leakage current density was measured with an HP4142B semiconductor parameter analyzer.The XRD and HRTEM results reveal that Er2O3 thin films deposited below 400°C are amorphous,while films deposited from 400 to 840°C are well crystallized with(111)-preferential crystallographic orientation.I-V curves show that,for ultrathin crystalline Er2O3 films,the leakage current density increases by almost one order of magnitude from 6.20×10^-5 to 6.56×10^-4 A/cm^2,when the film thickness decreases by only 1.9 nm from 5.7 to 3.8 nm.However the leakage current density of ultrathin amorphous Er2O3 films with a thickness of 3.8 nm is only 1.73×10^-5 A/cm^2.Finally,analysis of leakage current density showed that leakage of ultrathin Er2O3 films at high field is mainly caused by Fowler-Nordheim tunneling,and the large leakage of ultrathin crystalline Er2O3 films could arise from impurity defects at the grain boundary.
文摘In the gneisses from the drillhole ZK2304 of the Donghai area, there have been preserved high- and ultrahigh-pressure metamorphic mineral assemblages, a series of complicated retrogressive textures and relevant metamorphic reactions. In addition to garnet, jadeititic-clinopyroxene and rutile, other peak stage (M2) minerals in some gneisses include phengite, aragonite and coesite or quartz pseudomorphs after coesite. The typical peak-stage mineral assemblages in gneisses are characterized by garnet + jadeitic-clinopyroxene + rutile + coesite, garnet + jadeitic-clinopyroxene + phengite + rutile ± coesite and garnet + jadeitic-clinopyroxene + aragonite + rutile ± coesite. The grossular content (Gro) in garnet is high and may reach 50. 1 mol%. The SiO2 content of phengite ranges from 54.37% to 54.84% with 3.54-3.57 p.f.u. Quartz pseudomorphs after coesite occur as inclusions in garnet.The gneisses of the Donghai area have been subjected to multistage recrystallization and exhibit a closewise P-T evolutional path characterized by the near-isothermal decompression. The inclusion assemblage (Hb+Ep+Bi+Pl+Qz) within garnet and other minerals has recorded a pre-peak stage (Mi) epidote amphibole fades metamorphic event. High- and ultrahigh-pressure peak metamorphism (M2) took place at T=750-860℃ and P>2.7 GPa. The symplectitic assemblages after garnet, jadeitic-clinopyroxene and rutile imply a near-isothermal decompression metamorphism (M3, M4) during the rapid exhumation. Several lines of evidence of petrography and metamorphic reactions indicate that both gneisses and eclogites have experienced ultrahigh-pressure metamorphism in the Donghai area. This research may be of great significance for an in-depth study of the metamorphism and tectonic evolution in the Su-Lu ultrahigh-pressure metamorphic belt.
基金Supported by Russian Foundation for Basic Research(13-05-91159-GFEN_a)Project 14.518.11.7065 and agreement N8388 of the Ministry of Education and Science of the Russian Federation+1 种基金the National Natural Science Foundation(41274146)the Specialized Research Fund for State Key Laboratory in China
文摘Comparison of regular(diurnal,seasonal and solar cycle)variations of high-latitude,mid-latitude and low-latitude ionospheric characteristics has been provided on basis of local empirical models of the peak electron density and the peak height.The local empirical models were derived from the hand-scaled ionogram data recorded by DPS-4 digisondes located at Norilsk(69°N,88°E),Irkutsk(52°N,104°E)and Hainan(19°N,109°E)for a 6-year period from December,2002 to December,2008.The technique used to build the local empirical model is described.The primary focus is diurnal-seasonal behavior under low solar activity and its change with increasing solar activity.Both common and specific features of the high-latitude(Norilsk),mid-latitude(Irkutsk)and low-latitude(Hainan)regular variations were revealed using their local empirical models.
基金supported by Jiangsu Province Health Vocational and Technical Education Research Grants Program(No.201402)Jiangsu Province College“Qing Lan Project”[Su Teacher No.2014(23)]The Science and Technology Innovation Team Project of Suzhou Health College(No.szwzytd 201304)
文摘Objective: To investigate the effectiveness of a high-fidelity teaching simulation based on an NLN/Jeffries simulation in the nursing education theoretical framework and its influencing factors. Methods: A high-fidelity teaching simulation on clinical nursing practices using intelligent human analogues was conducted with 200 students, and The Simulation Design Scale, and the Student Satisfaction and Self-Confidence in Learning Scale developed by the National League for Nursing were used to evaluate the training effectiveness and its influencing factors. Results: For the high-fidelity teaching simulation, students gave scores of 4.36± 0.54 points for satisfaction and 4.33 ± 0.46 points for Self-Confidence. The students highly rated the five dimensions of teaching design, i.e., teaching objectives/information, assistance/support for students, problem solving, guided feedback, and fidelity. The teaching design was closely correlated with the satisfaction of the high-fidelity teaching simulation and self-efficacy, and the dimensions of teaching objectives/informa- tion and assistance/support for students were particularly strong predictors of teaching effectiveness. Conclusions: A high-fidelity teaching simulation based on Jeffries' theoretical framework improved student satisfaction with the simulation and their Self-Confidence. In planning simulations, teachers should take into account five characteristics, i.e., teaching objectives/information on simulation education, assistance/support for students, problem solving, guided reflection, and fidelity, to achieve better teaching effectiveness.
基金supported by the National Natural Science Foundation of China(Grant Nos.61076101 and 61204092)
文摘Based on the elastic trap-assisted tunneling mechanism in high-κgate stacks,a quantum percolation tunneling current 1/fγ noise model is proposed by incorporating quantum tunneling theory into the quantum percolation model.We conclude that the noise amplitude of the PSD(Power Spectral Density)for three stages,namely the fresh device,one-layer BD(breakdown),and two-layer BD,increases from 10-22→10-14→10-8 A2/Hz.Meanwhile,the noise exponent γ for the three stages,has the 1/f2type(γ→2),1/fγ type(γ→1~2),and 1/f type(γ→1),respectively.The simulation results are in good agreement with the experimental results.This model reasonably interprets the correlation between the bi-layer breakdown and the tunneling 1/fγ noise amplitude dependence and 1/fγ noise exponent dependence.These results provide a theoretical basis for the high-κ gate stacks bi-layer breakdown noise characterization methods.
文摘The Roman high(RHA) and low-Avoidance (RLA) rats were selectively bred for rapid vs poor acquisition of two-way active avoidance behavior. These lines differ in numerous behavioral traits, with RLA rats being more fearful/anxious than RHA rats, and the latter being novelty-seekers and showing larger intake of, and preference for, addictive substances including ethanol (ETH). Moreover, several differences in central dopaminergic, serotonergic, and GABAergic functions have been reported in these two lines. Since those neural systems are involved in the regulation of ETH consumption, it was considered of interest to investigate: 1) the differences in ETH intake and preference between RHA and RLA rats, 2) the effects of ETH on DA release in the shell of the nucleus accumbens (AcbSh) using brain microdialysis. ETH solutions of increasing concentrations (2% - 10%) were presented on alternate days in a free choice with water. To examine ETH intake and preference stability, animals were subsequently switched to daily presentations of 10% ETH for 10 consecutive days. RHA rats consumed significantly larger amounts of ETH and displayed higher ETH preference than did RLA rats throughout the acquisition and maintenance phases. Following chronic exposure to ETH the animals were habituated to a restricted access to ETH schedule (2% ETH, 2 h per day × 4 days) before surgical implantation of a dialysis probe in the AcbSh. Under these experimental conditions, voluntary ETH intake (2%, 1 h, p.o.) produced a significant increase in accumbal DA output in RHA rats but not in their RLA counterparts. Finally, the i.p. administration of ETH (0.25 g/kg) to na?ve Roman rats produced a significant increment in accumbal DA output only in RHA rats. These results indicate that the mesolimbic dopaminergic system of RHA rats is more responsive to the effects of ETH than that of RLA rats.
基金This work was supported by the National Natural Science Foundation of China(51834001,52104129)a project supported by the China Postdoctoral Science Foundation(2020M672226,2022T150195)Key Laboratory of Mine Ecological Effects and Systematic Restoration,Ministry of Natural Resources,Open Fund(MEER-2022-09).
文摘In order to improve the comprehensive utilization rate of highfines sand(HFS)produced by the mine,full solid waste shotcrete(HFS-BFRS)was prepared with HFS asfine aggregate in cooperation with basaltfiber(BF).The strength growth characteristics of HFS-BFRS were analyzed.And thefitting equation of compressive strength growth characteristics of HFS-BFRS under the synergistic effect of multiple factors was given.And based on the orthogonal experimental method,the effects on the compressive strength,splitting tensile strength andflex-ural strength of HFS-BFRS under the action of different levels of influencing factors were investigated.The effect of three factors on the mechanical properties of HFS-BFRS,3,and 28 d,respectively,was revealed by choosing the colloidal sand ratio(C/H),basaltfiber volume fraction(BF Vol)and naphthalene high-efficiency water reducing agent(FDN)as the design variables,combined with indoor tests and theoretical analysis.The results show that the sensitivity of the three factors on compressive strength andflexural strength is C/H>FDN>BF Vol,and split-ting tensile strength is BF Vol>FDN>C/H.Finally,thefitting ratio of HFS-BFRS was optimized by the factor index method,and the rationality was verified by thefield test.For thefluidity of HFS-BFRS,the slump can be improved by 139%under the action of 1.2%FDN,which guarantees the pump-ability of HFS-BFRS.
文摘A mathematical model and experimental analysis of the impact of oxide thickness on the ambipolar conduction in Schottky Barrier Carbon Nanotubes(CNTs)Field Effect Transistor(SB CNTFETs)is presented.Suppression of ambipolar conduction in SB CNTFETs is imperative in order to establish them as the future of IC technology.The ambipolar nature of SB CNTFETs leads to a great amount of leakage current.Employing a gate oxide dielectric of thickness,tox^50 nm suppresses the ambipolar behavior.In an SB CNTFET,it is the electric field at the source/drain contacts that control the conductance and the band bending length at the contacts is defined by tox.Therefore,tox is the prime parameter that influences the width of the Schottky barrier and the current in the subthreshold region.Due to the wide SB,there is a loss in on-current due to tunneling,but the current due to thermionic emission is increased by employing a high-κdielectric such as Zirconium dioxide(ZrO2).This work proposes an approach to suppress ambipolar behavior in SB CNTFETs without decreasing the on current.The thickness and dielectric constant of the gate oxide are optimized using the particle swarm optimization(PSO)algorithm to achieve suppression of ambipolar conduction without any loss in on-current.The proposed SB CNTFET was modeled using Verilog-A.Experimental demonstration of the suppression of ambipolar property is also presented.Two SB CNTFETs are fabricated using high-κdielectric such as ZrO2 with different thickness.A device with thin(~5 nm)gate oxide and another device with thick(~50 nm)gate oxide were fabricated.From the experimental results,it is observed that the device with the thin gate oxide exhibited ambipolar characteristics and the device with the thick gate oxide did not exhibit ambipolar characteristics.The increase in thickness,tox,ensures suppression of ambipolar behavior.