Based on the heat flow data published in 1990 and 2001, a study of the factors influencing the terrestrial heat flow distribution in the China continent and its quantitative expression is carried out using the ＂Netli...Based on the heat flow data published in 1990 and 2001, a study of the factors influencing the terrestrial heat flow distribution in the China continent and its quantitative expression is carried out using the ＂Netlike Plastic-Flow＂ continental dynamics model and the methods of statistic analysis and optimum fitting. The result indicates that the factors influencing the heat flow distribution is classified into two groups, i.e. background and tectonic ones, in which the former mainly involves the non- uniform distribution of mantle heat flow, heat production of radioactive dements in the crust, heattransfer media and hydrothermal circulation, while the latter mainly involves plastic-flow networks and relatively-stable blocks. The plastic-flow network is a manifestation of shear localization in the netlike plastic-flow process in the lower lithosphere, which is composed of two sets of plastic-flow belts （PFBs） intersecting each other and, as one of the basic action regimes, controls the intraplate tectonic deformation. Relatively stable blocks （RSBs）, which are the tectonic units with relatively-high viscosities existing in the netlike plastic-flow field, as one of the principal origins, result in the development of large-seale compressional basins. PFB and RSB, as the active and quiet states of tectonic deformation, give rise to the higher and lower heat flow values, respectivdy. The provincial average heat flow in continent can be estimated using the expression qav = q0 ＋ a Pbt-c Pbk, where the three terms of the right side are background heat flow, PFB-positive contribution and RSB-negative contribution, Pbt and Pbk are the PFB- and RSB-coverage ratios, respectively, a is the coefficient of PFB- positive contribution depending mainly on the strain in the lower lithosphere, and c is the coefficient of RSB-negative contribution related mainly to the thickness of the lithosphere, the aseismic-area ratio and the tectonic age. For the major portion of the China continent excluding some of the southeastern region of China, the confidence interval of the provincial average background heat flow is qo=57.25±24.8 mW/m^2 and the PFB-positive- and RSB-negative-contribution coefficients are a=14.8-71.9 mW/m^2 and c=0-25.6 mW/m^2, respectively. The concepts of PFB and RSB effects and the heat flow expression suggested provide a new choice of the approach to the quantitative description of the characteristics of heat flow distribution in continent and their physical mechanisms.展开更多
Southern root-knot nematode （Meloidogyne incognita） is a major problem in vegetable production in China due to the expansion of plastic tunnel and solar greenhouse. Using resistant cultivars is an effective approach...Southern root-knot nematode （Meloidogyne incognita） is a major problem in vegetable production in China due to the expansion of plastic tunnel and solar greenhouse. Using resistant cultivars is an effective approach to control the disease. Nine genes, Mi-1 to Mi-9, have been reported and only Mi-1 has been successfully used in tomato breeding. However, Mi-1 is inactive at a temperature above 28~C. In order to identify sources for heat-stable resistance to southern root-knot nematode, 53 genotypes of tomato （Solarium spp.） were inoculated with an isolate of M. incognita in the growth chamber at 28 or 32℃ for initial screening. 28 lines had less than 25 galls and were considered as resistant candidates. The top 60% （16 in total） of resistant candidates obtained from each temperature were subject to re-evaluation at 32~C using the same nematode isolate. Three lines ZN17, ZN 48, and LA0385 showed heat-stable resistance with an average of 10 galls or less per plant. LA0385 is a wild species, while ZNI7 and ZN48 are elite breeding lines. These lines were grown in a greenhouse for two seasons, and also showed high resistance with less than 10 galls per plant. Thus they were considered as good sources for breeding resistance to southern root-knot nematode in tomato.展开更多
Taking an extratropical cyclone that produced extreme precipitation as the research object,this paper calculates the contribution of condensation latent heat release(LHR)to relative vorticity tendency based on the com...Taking an extratropical cyclone that produced extreme precipitation as the research object,this paper calculates the contribution of condensation latent heat release(LHR)to relative vorticity tendency based on the complete-form vertical vorticity tendency equation.The results show that the heating rate of convectional condensation LHR can reach up to about 40 times that of stable condensation LHR.Both the stable and convectional heating centers are higher than 700 hPa,which would cause∂Q/∂z>0 and a positive vorticity source in the lower troposphere.The vertical gradient of stable condensation LHR contributes little to the growth of relative vorticity,while the relative vorticity tendency associated with the vertical gradient of convectional condensation LHR can be an order of magnitude higher than the former.The positive vorticity source is always located right below the latent heating center,and its maximum value can always be found in the lower troposphere.Convectional LHR is the primary factor for cyclone development from the perspective of diabatic heating.The horizontal gradient of total condensation LHR can contribute about 65%of the actual vorticity growth,but the effect of the vertical gradient of convectional condensation(LHR)can reach twice as much.The adiabatic heating from LHR can cause vorticity tendency directly.However,it can also change the vertical and horizontal gradient of potential temperature,which can further induce vorticity tendency.展开更多
A compact alternating direction implicit(ADI) method has been developed for solving multi-dimensional heat equations by introducing the differential operators and the truncation error is O(τ 2 + h 4 ). It is shown by...A compact alternating direction implicit(ADI) method has been developed for solving multi-dimensional heat equations by introducing the differential operators and the truncation error is O(τ 2 + h 4 ). It is shown by the discrete Fourier analysis that this new ADI scheme is unconditionally stable and the truncation error O(τ 3 + h 6 ) is gained with once Richardson's extrapolation. Some numerical examples are presented to demonstrate the efficiency and accuracy of the new scheme.展开更多
A mimetic finite difference scheme for the transient heat equation under Robin’s conditions is presented. The scheme uses second order gradient and divergence mimetic operators, on a staggered grid, to approximate th...A mimetic finite difference scheme for the transient heat equation under Robin’s conditions is presented. The scheme uses second order gradient and divergence mimetic operators, on a staggered grid, to approximate the space derivatives. The temporal derivative is replaced by a first order backward difference approximation to obtain an implicit formulation. The resulting scheme contains nonstandard finite difference stencils. An original convergence analysis by the matrix’s method shows that the proposed scheme is unconditionally stable. A comparative study against standard finite difference schemes, based on central difference or first order one side approximations, reveals the advantages of our scheme without being its implementation more expensive or difficult to achieve.展开更多
1 Introduction The technology of the laser-heated pedestal growth (LHPG) in making single crystalsand fibres is based on the Czochralski technique, which makes use of a laser as heaterto produce all kinds of high melt...1 Introduction The technology of the laser-heated pedestal growth (LHPG) in making single crystalsand fibres is based on the Czochralski technique, which makes use of a laser as heaterto produce all kinds of high melting temperature oxide single crystal materials. Inthe early 1980s, the Bell Laboratory in USA produeed some kinds of single cryatalsand fibres having special properties by using this technique. Since 1986, high-T_csuperconducing fibres have been produced in many laboratories of LHPG insome countries, and the Institute of Metal Research, Academia Sinica,also built an experimental apparatus financially supported by the NationalSuperconducting Centre specially to study the superconducor.展开更多
目的:观察小柴胡汤合葛根芩连汤加减治疗慢性阻塞性肺疾病(Chronic obstructive pulmonary disease,COPD)稳定期肺脾气虚兼湿热证的临床疗效。方法:对2021年7月~2022年3月的COPD稳定期肺脾气虚兼湿热证患者78例行回顾性分析,依据治疗差...目的:观察小柴胡汤合葛根芩连汤加减治疗慢性阻塞性肺疾病(Chronic obstructive pulmonary disease,COPD)稳定期肺脾气虚兼湿热证的临床疗效。方法:对2021年7月~2022年3月的COPD稳定期肺脾气虚兼湿热证患者78例行回顾性分析,依据治疗差异分为对照组39例(予常规西药治疗)和试验组39例(予常规西药+小柴胡汤合葛根芩连汤加减治疗)。对比两组临床疗效、证候积分、肺功能[第1秒用力呼气容积(Force the expiratory volume for the first second,FEV 1 )、第1秒用力呼气容积/用力肺活量(Force the expiratory volume for the first second/Forced Vital Capacity,FEV 1 /FVC)]、6min步行距离(6minute walking distance,6MWD)、慢阻肺生活质量量表(COPD Assessment Test,CAT)及安全性。结果:对照组、试验组总疗效率分别为74.36%、92.31%,试验组总疗效率更高( P <0.05)。两组治疗后,证候总积分均下降,但试验组证候总积分下降幅度更大( P <0.05)。两组治疗后FEV 1 、FEV 1 /FVC值均上升,且试验组比对照组高( P <0.05)。两组治疗后6MWD的距离均延长,且试验组明显长于对照组( P <0.05)。两组治疗后CAT评分(包括咳嗽、咳痰、胸闷、睡眠、情绪、精力评分)均降低,且试验组明显低于对照组( P <0.05)。治疗期间,对照组不良反应总发生率为2.56%(1/39),试验组不良反应总发生率为5.12%(2/39),两组不良反应总发生率相比较,差异无统计学意义( P >0.05)。结论:小柴胡汤合葛根芩连汤加减治疗可改善COPD稳定期肺脾气虚兼湿热证的患者生活质量、肺功能,提高临床疗效。展开更多
Effects of Al content and heat treatment on the structure,hardness and electrochemical properties of FeCoNiCrCu0.5Alx high-entropy alloys were investigated.The phase structure of as-cast alloys evolves from FCC phase ...Effects of Al content and heat treatment on the structure,hardness and electrochemical properties of FeCoNiCrCu0.5Alx high-entropy alloys were investigated.The phase structure of as-cast alloys evolves from FCC phase to BCC phase with the increase of Al content.The stable phase of FeCoNiCrCu0.5Alx high-entropy alloys will transform from FCC phase to FCC＋BCC duplex phases when x value increases from 0.5 to 1.5.The hardness of BCC phase is higher than that of FCC phase,and the corrosion resistance of BCC phase is better than FCC phase in chlorine ion and acid medium.High hardness and good corrosion resistance can be obtained in as-cast FeCoNiCrCu0.5Al1.0 alloy.展开更多
文摘Based on the heat flow data published in 1990 and 2001, a study of the factors influencing the terrestrial heat flow distribution in the China continent and its quantitative expression is carried out using the ＂Netlike Plastic-Flow＂ continental dynamics model and the methods of statistic analysis and optimum fitting. The result indicates that the factors influencing the heat flow distribution is classified into two groups, i.e. background and tectonic ones, in which the former mainly involves the non- uniform distribution of mantle heat flow, heat production of radioactive dements in the crust, heattransfer media and hydrothermal circulation, while the latter mainly involves plastic-flow networks and relatively-stable blocks. The plastic-flow network is a manifestation of shear localization in the netlike plastic-flow process in the lower lithosphere, which is composed of two sets of plastic-flow belts （PFBs） intersecting each other and, as one of the basic action regimes, controls the intraplate tectonic deformation. Relatively stable blocks （RSBs）, which are the tectonic units with relatively-high viscosities existing in the netlike plastic-flow field, as one of the principal origins, result in the development of large-seale compressional basins. PFB and RSB, as the active and quiet states of tectonic deformation, give rise to the higher and lower heat flow values, respectivdy. The provincial average heat flow in continent can be estimated using the expression qav = q0 ＋ a Pbt-c Pbk, where the three terms of the right side are background heat flow, PFB-positive contribution and RSB-negative contribution, Pbt and Pbk are the PFB- and RSB-coverage ratios, respectively, a is the coefficient of PFB- positive contribution depending mainly on the strain in the lower lithosphere, and c is the coefficient of RSB-negative contribution related mainly to the thickness of the lithosphere, the aseismic-area ratio and the tectonic age. For the major portion of the China continent excluding some of the southeastern region of China, the confidence interval of the provincial average background heat flow is qo=57.25±24.8 mW/m^2 and the PFB-positive- and RSB-negative-contribution coefficients are a=14.8-71.9 mW/m^2 and c=0-25.6 mW/m^2, respectively. The concepts of PFB and RSB effects and the heat flow expression suggested provide a new choice of the approach to the quantitative description of the characteristics of heat flow distribution in continent and their physical mechanisms.
基金supported by the National High Technology Research and Development Program of China (2006AA10Z1A6)
文摘Southern root-knot nematode （Meloidogyne incognita） is a major problem in vegetable production in China due to the expansion of plastic tunnel and solar greenhouse. Using resistant cultivars is an effective approach to control the disease. Nine genes, Mi-1 to Mi-9, have been reported and only Mi-1 has been successfully used in tomato breeding. However, Mi-1 is inactive at a temperature above 28~C. In order to identify sources for heat-stable resistance to southern root-knot nematode, 53 genotypes of tomato （Solarium spp.） were inoculated with an isolate of M. incognita in the growth chamber at 28 or 32℃ for initial screening. 28 lines had less than 25 galls and were considered as resistant candidates. The top 60% （16 in total） of resistant candidates obtained from each temperature were subject to re-evaluation at 32~C using the same nematode isolate. Three lines ZN17, ZN 48, and LA0385 showed heat-stable resistance with an average of 10 galls or less per plant. LA0385 is a wild species, while ZNI7 and ZN48 are elite breeding lines. These lines were grown in a greenhouse for two seasons, and also showed high resistance with less than 10 galls per plant. Thus they were considered as good sources for breeding resistance to southern root-knot nematode in tomato.
基金This study was supported by the Natural Science Foundation of Jiangsu Province[grant number BK20161603]the National Natural Science Foundation of China[grant numbers 41575010 and 41575070]the China Meteorological Administration[grant number CMAYBY2018-028].
文摘Taking an extratropical cyclone that produced extreme precipitation as the research object,this paper calculates the contribution of condensation latent heat release(LHR)to relative vorticity tendency based on the complete-form vertical vorticity tendency equation.The results show that the heating rate of convectional condensation LHR can reach up to about 40 times that of stable condensation LHR.Both the stable and convectional heating centers are higher than 700 hPa,which would cause∂Q/∂z>0 and a positive vorticity source in the lower troposphere.The vertical gradient of stable condensation LHR contributes little to the growth of relative vorticity,while the relative vorticity tendency associated with the vertical gradient of convectional condensation LHR can be an order of magnitude higher than the former.The positive vorticity source is always located right below the latent heating center,and its maximum value can always be found in the lower troposphere.Convectional LHR is the primary factor for cyclone development from the perspective of diabatic heating.The horizontal gradient of total condensation LHR can contribute about 65%of the actual vorticity growth,but the effect of the vertical gradient of convectional condensation(LHR)can reach twice as much.The adiabatic heating from LHR can cause vorticity tendency directly.However,it can also change the vertical and horizontal gradient of potential temperature,which can further induce vorticity tendency.
文摘A compact alternating direction implicit(ADI) method has been developed for solving multi-dimensional heat equations by introducing the differential operators and the truncation error is O(τ 2 + h 4 ). It is shown by the discrete Fourier analysis that this new ADI scheme is unconditionally stable and the truncation error O(τ 3 + h 6 ) is gained with once Richardson's extrapolation. Some numerical examples are presented to demonstrate the efficiency and accuracy of the new scheme.
文摘A mimetic finite difference scheme for the transient heat equation under Robin’s conditions is presented. The scheme uses second order gradient and divergence mimetic operators, on a staggered grid, to approximate the space derivatives. The temporal derivative is replaced by a first order backward difference approximation to obtain an implicit formulation. The resulting scheme contains nonstandard finite difference stencils. An original convergence analysis by the matrix’s method shows that the proposed scheme is unconditionally stable. A comparative study against standard finite difference schemes, based on central difference or first order one side approximations, reveals the advantages of our scheme without being its implementation more expensive or difficult to achieve.
文摘1 Introduction The technology of the laser-heated pedestal growth (LHPG) in making single crystalsand fibres is based on the Czochralski technique, which makes use of a laser as heaterto produce all kinds of high melting temperature oxide single crystal materials. Inthe early 1980s, the Bell Laboratory in USA produeed some kinds of single cryatalsand fibres having special properties by using this technique. Since 1986, high-T_csuperconducing fibres have been produced in many laboratories of LHPG insome countries, and the Institute of Metal Research, Academia Sinica,also built an experimental apparatus financially supported by the NationalSuperconducting Centre specially to study the superconducor.
文摘目的:观察小柴胡汤合葛根芩连汤加减治疗慢性阻塞性肺疾病(Chronic obstructive pulmonary disease,COPD)稳定期肺脾气虚兼湿热证的临床疗效。方法:对2021年7月~2022年3月的COPD稳定期肺脾气虚兼湿热证患者78例行回顾性分析,依据治疗差异分为对照组39例(予常规西药治疗)和试验组39例(予常规西药+小柴胡汤合葛根芩连汤加减治疗)。对比两组临床疗效、证候积分、肺功能[第1秒用力呼气容积(Force the expiratory volume for the first second,FEV 1 )、第1秒用力呼气容积/用力肺活量(Force the expiratory volume for the first second/Forced Vital Capacity,FEV 1 /FVC)]、6min步行距离(6minute walking distance,6MWD)、慢阻肺生活质量量表(COPD Assessment Test,CAT)及安全性。结果:对照组、试验组总疗效率分别为74.36%、92.31%,试验组总疗效率更高( P <0.05)。两组治疗后,证候总积分均下降,但试验组证候总积分下降幅度更大( P <0.05)。两组治疗后FEV 1 、FEV 1 /FVC值均上升,且试验组比对照组高( P <0.05)。两组治疗后6MWD的距离均延长,且试验组明显长于对照组( P <0.05)。两组治疗后CAT评分(包括咳嗽、咳痰、胸闷、睡眠、情绪、精力评分)均降低,且试验组明显低于对照组( P <0.05)。治疗期间,对照组不良反应总发生率为2.56%(1/39),试验组不良反应总发生率为5.12%(2/39),两组不良反应总发生率相比较,差异无统计学意义( P >0.05)。结论:小柴胡汤合葛根芩连汤加减治疗可改善COPD稳定期肺脾气虚兼湿热证的患者生活质量、肺功能,提高临床疗效。
基金Project(NCET-11-0127) supported by the Program for New Century Excellent Talents in University,ChinaProject supported by the Fundamental Research Funds for the Central Universities,China
文摘Effects of Al content and heat treatment on the structure,hardness and electrochemical properties of FeCoNiCrCu0.5Alx high-entropy alloys were investigated.The phase structure of as-cast alloys evolves from FCC phase to BCC phase with the increase of Al content.The stable phase of FeCoNiCrCu0.5Alx high-entropy alloys will transform from FCC phase to FCC＋BCC duplex phases when x value increases from 0.5 to 1.5.The hardness of BCC phase is higher than that of FCC phase,and the corrosion resistance of BCC phase is better than FCC phase in chlorine ion and acid medium.High hardness and good corrosion resistance can be obtained in as-cast FeCoNiCrCu0.5Al1.0 alloy.
