Objective To investigate the social mental state of drug addicts in a compulsive drug abuse treatment center; evaluate the effectiveness of integrated program for the prevention of abuse relapse and improvement of dru...Objective To investigate the social mental state of drug addicts in a compulsive drug abuse treatment center; evaluate the effectiveness of integrated program for the prevention of abuse relapse and improvement of drug addicts' psychological health. Methods The study subjects were addicts from the Wuhan Compulsive Drug Abuse Treatment Center between October 2003 and June 2004, who satisfied the inclusion criteria. A non-randomized control-intervention study design was adopted. Volunteers willing to take part in intervention were put into the intervention group with their full awareness and willingness to prevent drug abuse relapse. The control group was composed of the addicts who were willing to prevent relapse and to be followed up after their discharge. Results The effectiveness of the integrated intervention program in promoting addicts' psychological health: before the intervention, the scores of Self-Rating Anxiety Scale (SAS), the positive and negative dimensionalities of Simple Coping Style Questionnaire (SCSQ) and Chinese Perceived Stress Scales (CPSS) had no significant differences between the intervention group and the control group. After the intervention, except that the SCSQ's positive dimensionality in the intervention group was significantly higher than that in the control group, other indices in the intervention group were lower. Before and after the intervention, the psychological health level in both the groups was lower than that in the normal population; there were significant differences between addicts and normal subjects in regards with all of the indices above. Conclusion Drug abuse was associated closely with addicts' social mental factors. The integrated intervention program can alleviate anxiety and stress, reduce co-morbid mental disorders and effectively improve their coping style. In conclusion, the program can promote addicts' psychological health significantly.展开更多
Fusarium head blight(FHB)is a worldwide devastating disease of small grain cereals and Fusarium graminearum species complex(FGSC)is the major pathogen causing the disease.The epidemics of FHB lead to the reduction of ...Fusarium head blight(FHB)is a worldwide devastating disease of small grain cereals and Fusarium graminearum species complex(FGSC)is the major pathogen causing the disease.The epidemics of FHB lead to the reduction of grain yield and economic losses.Additionally,mycotoxins produced by the FHB pathogens are hazardous to the health of human and livestock.In this review,we summarize the epidemiology of FHB,and introduce effects of this disease on economy,environment and food safety.We focus on the integrated management approaches for controlling FHB including agronomic practices,resistant cultivars,chemical control,and biocontrol.In addition,we also discuss the potential novel management strategies against FHB and mycotoxin.展开更多
A novel simulation program with an integrated circuit emphasis(SPICE) model developed for trench-gate metal-oxide-semiconductor field-effect transistor(M OSFET)devices is proposed. The drift region resistance was ...A novel simulation program with an integrated circuit emphasis(SPICE) model developed for trench-gate metal-oxide-semiconductor field-effect transistor(M OSFET)devices is proposed. The drift region resistance was modeled according to the physical characteristics and the specific structure of the trench-gate MOSFET device. For the accurate simulation of dynamic characteristics, three important capacitances, gate-to-drain capacitance Cgd, gate-to-source capacitance Cgsand drain-to-source capacitance Cds, were modeled, respectively, in the proposed model. Furthermore,the self-heating effect, temperature effect and breakdown characteristic were taken into account; the self-heating model and breakdown model were built in the proposed model; and the temperature parameters of the model were revised. The proposed model is verified by experimental results, and the errors between measured data and simulation results of the novel model are less than 5%. Therefore, the model can give an accurate description for both the static and dynamic characteristics of the trench-gate MOSFET device.展开更多
为了满足功率电路及系统设计对p-GaN HEMT(High Electron Mobility Transistor)器件模型的需求,本文建立了一套基于表面势计算方法的增强型p-GaN HEMT器件SPICE(Simulation Program with Integrated Circuit Emphasis)模型.根据耗尽型Ga...为了满足功率电路及系统设计对p-GaN HEMT(High Electron Mobility Transistor)器件模型的需求,本文建立了一套基于表面势计算方法的增强型p-GaN HEMT器件SPICE(Simulation Program with Integrated Circuit Emphasis)模型.根据耗尽型GaN HEMT器件和增强型p-GaN HEMT器件结构的对比,推导出p-GaN栅结构电压解析公式.考虑到p-GaN栅掺杂效应和物理机理,推导出栅电容和栅电流解析公式.同时,与基于表面势的高电子迁移率晶体管高级SPICE模型内核相结合,建立完整的增强型p-GaN HEMT功率器件的SPICE模型.将所建立的SPICE模型与实测结果进行对比验证.结果表明,所建立的模型准确实现了包括转移特性、输出特性、栅电容以及栅电流在内的p-GaN HEMT器件的电学特性.模型仿真数据与实测数据拟合度误差均小于5%.本文所提出的增强型p-GaN HEMT器件模型在进行电路设计时具有重要的应用价值.展开更多
As the fourth passive circuit component, a memristor is a nonlinear resistor that can "remember" the amount of charge passing through it. The characteristic of "remembering" the charge and non-volatility makes mem...As the fourth passive circuit component, a memristor is a nonlinear resistor that can "remember" the amount of charge passing through it. The characteristic of "remembering" the charge and non-volatility makes memristors great potential candidates in many fields. Nowadays, only a few groups have the ability to fabricate memristors, and most researchers study them by theoretic analysis and simulation. In this paper, we first analyse the theoretical base and characteristics of memristors, then use a simulation program with integrated circuit emphasis as our tool to simulate the theoretical model of memristors and change the parameters in the model to see the influence of each parameter on the characteristics. Our work supplies researchers engaged in memristor-based circuits with advice on how to choose the proper parameters.展开更多
The recent published experimental data of titanium oxide memristor devices which are tested under the same experi- mental conditions exhibit the strange instability and complexity of these devices. Such undesired char...The recent published experimental data of titanium oxide memristor devices which are tested under the same experi- mental conditions exhibit the strange instability and complexity of these devices. Such undesired characteristics preclude the understanding of the device conductive processes and the memristor-based practical applications. The possibility of the coexistence of dopant drift and tunnel barrier conduction in a memristor provides preliminary explanations for the undesired characteristics. However, current research lacks detailed discussion about the coexistence case. In this paper, dopant drift and tunnel barrier-based theories are first analyzed for studying the relations between parameters and physical variables which affect characteristics of mernristors, and then the influences of each parameter change on the conductive behaviors in the single and coexistence cases of the two mechanisms are simulated and discussed respectively. The simulation results provide further explanations of the complex device conduction. Theoretical methods of eliminating or reducing the coex- istence of the two mechanisms are proposed, in order to increase the stability of the device conduction. This work also provides the support for optimizing the fabrications of memristor devices with excellent performance.展开更多
The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital de...The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital devices,which is why this design is so popular,and it also reduces chip area,both of which are examples of circuit overheads.The proposed module we have investigated is a triple-logic-based one,based on advanced technology CNTFETs and an emphasis on minimizing delay times at various values,as well as comparisons of the design working with various load capacitances.Comparing the proposed design with the existing design,the delay times was reduced from 66.32 to 16.41 ps,i.e.,a 75.26%reduction.However,the power dissipation was not optimized,and increased by 1.44%compared to the existing adder.The number of transistors was also reduced,and the product of power and delay(P∗D)achieved a value of 0.0498053 fJ.An improvement at 1 V was also achieved.A load capacitance(fF)was measured at different values,and the average delay measured for different values of capacitance had a maximum of 83.60 ps and a minimum of 22.54 ps,with a range of 61.06 ps.The power dissipations ranged from a minimum of 3.38μW to a maximum of 6.49μW.Based on these results,the use of this CNTFET half-adder design in multiple Boolean circuits will be a useful addition to circuit design.展开更多
CCD is an integrated software tool which is intended to support the coding and debugging for C language. It integrates a hybrid editor,an incremental semantic analyzer,a multi-entry parser,an incremental unpaser and a...CCD is an integrated software tool which is intended to support the coding and debugging for C language. It integrates a hybrid editor,an incremental semantic analyzer,a multi-entry parser,an incremental unpaser and a source-level debugger into a single tool.The integration is realized by sharing common knowledge,among all the components of the system and by task-oriented comhination of the components.Nonlocal attribute grammar is adopted for specifying the common knowledge about the syntax and semantics of C language.The incremental attri bute evaluation is used to implement the semantic analyzer and the unparser to increase system efficiency.CCD keeps the preprocessors and comments most regular to make it practical.展开更多
Seafloor hydrothermal systems play a significant role in the oceanic Mg cycle due to ubiquitous deposits of secondary Mg-rich clays during the strong fluid-rock reactions.However,the magnitude of net Mg enrichment and...Seafloor hydrothermal systems play a significant role in the oceanic Mg cycle due to ubiquitous deposits of secondary Mg-rich clays during the strong fluid-rock reactions.However,the magnitude of net Mg enrichment and Mg isotopic fractionation,particularly within the medium-high temperature hydrothermal systems in felsic-hosted settings,are not well studied yet.Here we report elemental and isotopic compositions of Mg in hydrothermal chlorite-rich sediments,volcanic materials,and terrigenous sediments collected during the IODP Expedition 331 drilled to the thick sediment-covered and felsic-hosted middle Okinawa Trough(Iheya North Knoll) in the West Pacific.We investigate the sources of Mg in chlorite and Mg isotopic behavior at medium-high temperature hydrothermal alteration.After 1 mol/L HCl leaching,Mg isotopic compositions of chlorite-rich sediments present overall similar values in the residual fractions and bulk samples albeit with slightly higher values in the leachates.Mineralogical differentiation primarily determines the Mg isotopic compositions,showing that siliciclastic residues have slightly higher δ^(26) Mg values than the leachates dominated by carbonates and oxides/hydroxides.Significant Mg isotopic fractionation happened in the medium-high temperature(~150°C to 260°C) felsic-hosted hydrothermal system,with Δ^(26)MgChl-SW ranging from 0.15‰ to 0.71‰ and yielding a negative correlation with temperature.This observation suggests the preferential incorporation of heavy Mg isotopes by the secondary chlorite precipitation.We infer that the medium-high temperature hydrothermal systems can take up about 8–14% of riverine input of Mg in the arc and back-arc regions.Incomplete removal of aqueous Mg in porewater and vent fluids by the medium-high temperature hydrothermal alterations in the arc and back-arc basins provides constraints on the Mg budget and isotopic composition of seawater.展开更多
Sustainable food production in the changing climate and dwindling water resources in the Global Dry Land Alliance(GDLA)member countries is a real challenge,especially when considering marginal lands in dryland systems...Sustainable food production in the changing climate and dwindling water resources in the Global Dry Land Alliance(GDLA)member countries is a real challenge,especially when considering marginal lands in dryland systems.The definition of marginal land is very vague and defined from different perspectives(pragmatism about marginal lands).Dryland itself indicates"marginality"due to water stress.In general,the abandoned agriculture land where food production is not economical,and has low inherent productivity potential is considered marginal;however,a land may be marginal for agriculture but vital for grazing.In this paper attempts have been made to give review of literature(water stress,extent of marginal saline lands,marginality).Policy matters(development of soil,water and agriculture strategies)that GDLA and member countries should consider for future sustainable food production in their countries,including but not limited to,assessment of land resources for agriculture potential,defining,mapping and characterizing marginal lands,and use of innovative technologies(conservation agriculture,climate smart agriculture,integrated soil reclamation program and capacity building)for food production,are discussed.The international perception(FAO,UNEP,CGIAR)on marginal lands is also described.An innovative approach of using national biocapacity and ecological footprint is used to assess marginality of GDLA member countries.Ecological overshoot(using 1.5 earth planets)and biocapacity debtor and creditor countries are highlighted.Challenges and best management practices for food production in marginal lands are included.Other important issues,like leasing land abroad,GDLA strategic food reserves and best management practices,innovative ideas for food production are shared.Finally recommendations are drafted for actions by GDLA,its member countries and the partners.展开更多
基金a grant from the National Natural Science Foundation (No.30271140, 2002)
文摘Objective To investigate the social mental state of drug addicts in a compulsive drug abuse treatment center; evaluate the effectiveness of integrated program for the prevention of abuse relapse and improvement of drug addicts' psychological health. Methods The study subjects were addicts from the Wuhan Compulsive Drug Abuse Treatment Center between October 2003 and June 2004, who satisfied the inclusion criteria. A non-randomized control-intervention study design was adopted. Volunteers willing to take part in intervention were put into the intervention group with their full awareness and willingness to prevent drug abuse relapse. The control group was composed of the addicts who were willing to prevent relapse and to be followed up after their discharge. Results The effectiveness of the integrated intervention program in promoting addicts' psychological health: before the intervention, the scores of Self-Rating Anxiety Scale (SAS), the positive and negative dimensionalities of Simple Coping Style Questionnaire (SCSQ) and Chinese Perceived Stress Scales (CPSS) had no significant differences between the intervention group and the control group. After the intervention, except that the SCSQ's positive dimensionality in the intervention group was significantly higher than that in the control group, other indices in the intervention group were lower. Before and after the intervention, the psychological health level in both the groups was lower than that in the normal population; there were significant differences between addicts and normal subjects in regards with all of the indices above. Conclusion Drug abuse was associated closely with addicts' social mental factors. The integrated intervention program can alleviate anxiety and stress, reduce co-morbid mental disorders and effectively improve their coping style. In conclusion, the program can promote addicts' psychological health significantly.
基金the Science and Technology Project of Zhejiang Province,China(2018C02G2011110)the National Natural Science Foundation of China(31930088 and 32001855)the earmarked fund for China Agriculture Research System(CARS-3-1-29).
文摘Fusarium head blight(FHB)is a worldwide devastating disease of small grain cereals and Fusarium graminearum species complex(FGSC)is the major pathogen causing the disease.The epidemics of FHB lead to the reduction of grain yield and economic losses.Additionally,mycotoxins produced by the FHB pathogens are hazardous to the health of human and livestock.In this review,we summarize the epidemiology of FHB,and introduce effects of this disease on economy,environment and food safety.We focus on the integrated management approaches for controlling FHB including agronomic practices,resistant cultivars,chemical control,and biocontrol.In addition,we also discuss the potential novel management strategies against FHB and mycotoxin.
基金The National Natural Science Foundation of China(No.61604038)China Postdoctoral Science Foundation(No.2015M580376)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20160691)Jiangsu Postdoctoral Science Foundation(No.1501010A)
文摘A novel simulation program with an integrated circuit emphasis(SPICE) model developed for trench-gate metal-oxide-semiconductor field-effect transistor(M OSFET)devices is proposed. The drift region resistance was modeled according to the physical characteristics and the specific structure of the trench-gate MOSFET device. For the accurate simulation of dynamic characteristics, three important capacitances, gate-to-drain capacitance Cgd, gate-to-source capacitance Cgsand drain-to-source capacitance Cds, were modeled, respectively, in the proposed model. Furthermore,the self-heating effect, temperature effect and breakdown characteristic were taken into account; the self-heating model and breakdown model were built in the proposed model; and the temperature parameters of the model were revised. The proposed model is verified by experimental results, and the errors between measured data and simulation results of the novel model are less than 5%. Therefore, the model can give an accurate description for both the static and dynamic characteristics of the trench-gate MOSFET device.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 61003082) the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (Grant No. 60921062)
文摘As the fourth passive circuit component, a memristor is a nonlinear resistor that can "remember" the amount of charge passing through it. The characteristic of "remembering" the charge and non-volatility makes memristors great potential candidates in many fields. Nowadays, only a few groups have the ability to fabricate memristors, and most researchers study them by theoretic analysis and simulation. In this paper, we first analyse the theoretical base and characteristics of memristors, then use a simulation program with integrated circuit emphasis as our tool to simulate the theoretical model of memristors and change the parameters in the model to see the influence of each parameter on the characteristics. Our work supplies researchers engaged in memristor-based circuits with advice on how to choose the proper parameters.
基金supported by the National Natural Science Foundation of China(Grant No.61171017)
文摘The recent published experimental data of titanium oxide memristor devices which are tested under the same experi- mental conditions exhibit the strange instability and complexity of these devices. Such undesired characteristics preclude the understanding of the device conductive processes and the memristor-based practical applications. The possibility of the coexistence of dopant drift and tunnel barrier conduction in a memristor provides preliminary explanations for the undesired characteristics. However, current research lacks detailed discussion about the coexistence case. In this paper, dopant drift and tunnel barrier-based theories are first analyzed for studying the relations between parameters and physical variables which affect characteristics of mernristors, and then the influences of each parameter change on the conductive behaviors in the single and coexistence cases of the two mechanisms are simulated and discussed respectively. The simulation results provide further explanations of the complex device conduction. Theoretical methods of eliminating or reducing the coex- istence of the two mechanisms are proposed, in order to increase the stability of the device conduction. This work also provides the support for optimizing the fabrications of memristor devices with excellent performance.
文摘The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital devices,which is why this design is so popular,and it also reduces chip area,both of which are examples of circuit overheads.The proposed module we have investigated is a triple-logic-based one,based on advanced technology CNTFETs and an emphasis on minimizing delay times at various values,as well as comparisons of the design working with various load capacitances.Comparing the proposed design with the existing design,the delay times was reduced from 66.32 to 16.41 ps,i.e.,a 75.26%reduction.However,the power dissipation was not optimized,and increased by 1.44%compared to the existing adder.The number of transistors was also reduced,and the product of power and delay(P∗D)achieved a value of 0.0498053 fJ.An improvement at 1 V was also achieved.A load capacitance(fF)was measured at different values,and the average delay measured for different values of capacitance had a maximum of 83.60 ps and a minimum of 22.54 ps,with a range of 61.06 ps.The power dissipations ranged from a minimum of 3.38μW to a maximum of 6.49μW.Based on these results,the use of this CNTFET half-adder design in multiple Boolean circuits will be a useful addition to circuit design.
文摘CCD is an integrated software tool which is intended to support the coding and debugging for C language. It integrates a hybrid editor,an incremental semantic analyzer,a multi-entry parser,an incremental unpaser and a source-level debugger into a single tool.The integration is realized by sharing common knowledge,among all the components of the system and by task-oriented comhination of the components.Nonlocal attribute grammar is adopted for specifying the common knowledge about the syntax and semantics of C language.The incremental attri bute evaluation is used to implement the semantic analyzer and the unparser to increase system efficiency.CCD keeps the preprocessors and comments most regular to make it practical.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41806229, 41730531, and 41991324)。
文摘Seafloor hydrothermal systems play a significant role in the oceanic Mg cycle due to ubiquitous deposits of secondary Mg-rich clays during the strong fluid-rock reactions.However,the magnitude of net Mg enrichment and Mg isotopic fractionation,particularly within the medium-high temperature hydrothermal systems in felsic-hosted settings,are not well studied yet.Here we report elemental and isotopic compositions of Mg in hydrothermal chlorite-rich sediments,volcanic materials,and terrigenous sediments collected during the IODP Expedition 331 drilled to the thick sediment-covered and felsic-hosted middle Okinawa Trough(Iheya North Knoll) in the West Pacific.We investigate the sources of Mg in chlorite and Mg isotopic behavior at medium-high temperature hydrothermal alteration.After 1 mol/L HCl leaching,Mg isotopic compositions of chlorite-rich sediments present overall similar values in the residual fractions and bulk samples albeit with slightly higher values in the leachates.Mineralogical differentiation primarily determines the Mg isotopic compositions,showing that siliciclastic residues have slightly higher δ^(26) Mg values than the leachates dominated by carbonates and oxides/hydroxides.Significant Mg isotopic fractionation happened in the medium-high temperature(~150°C to 260°C) felsic-hosted hydrothermal system,with Δ^(26)MgChl-SW ranging from 0.15‰ to 0.71‰ and yielding a negative correlation with temperature.This observation suggests the preferential incorporation of heavy Mg isotopes by the secondary chlorite precipitation.We infer that the medium-high temperature hydrothermal systems can take up about 8–14% of riverine input of Mg in the arc and back-arc regions.Incomplete removal of aqueous Mg in porewater and vent fluids by the medium-high temperature hydrothermal alterations in the arc and back-arc basins provides constraints on the Mg budget and isotopic composition of seawater.
文摘Sustainable food production in the changing climate and dwindling water resources in the Global Dry Land Alliance(GDLA)member countries is a real challenge,especially when considering marginal lands in dryland systems.The definition of marginal land is very vague and defined from different perspectives(pragmatism about marginal lands).Dryland itself indicates"marginality"due to water stress.In general,the abandoned agriculture land where food production is not economical,and has low inherent productivity potential is considered marginal;however,a land may be marginal for agriculture but vital for grazing.In this paper attempts have been made to give review of literature(water stress,extent of marginal saline lands,marginality).Policy matters(development of soil,water and agriculture strategies)that GDLA and member countries should consider for future sustainable food production in their countries,including but not limited to,assessment of land resources for agriculture potential,defining,mapping and characterizing marginal lands,and use of innovative technologies(conservation agriculture,climate smart agriculture,integrated soil reclamation program and capacity building)for food production,are discussed.The international perception(FAO,UNEP,CGIAR)on marginal lands is also described.An innovative approach of using national biocapacity and ecological footprint is used to assess marginality of GDLA member countries.Ecological overshoot(using 1.5 earth planets)and biocapacity debtor and creditor countries are highlighted.Challenges and best management practices for food production in marginal lands are included.Other important issues,like leasing land abroad,GDLA strategic food reserves and best management practices,innovative ideas for food production are shared.Finally recommendations are drafted for actions by GDLA,its member countries and the partners.