Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat tr...Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25 V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that： 1） For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18 μm; 2） The yield strength, tensile strength and-30℃ charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3） Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.展开更多
Hopf bifurcation inducing lasing without inversion has been analyzed by taking into account the effect of phase fluctuation in the driving field based on a closed three level ladder-type atomic model. It is shown that...Hopf bifurcation inducing lasing without inversion has been analyzed by taking into account the effect of phase fluctuation in the driving field based on a closed three level ladder-type atomic model. It is shown that due to the phase fluctuation of the driving field, the necessary threshold increases significantly. Furthermore the area domain to get lasing without inversion decreases as the driving field's linewidth increases.展开更多
This paper investigates the effects of spontaneously induced coherence on absorption properties in a nearly equispaced three-level ladder-type system driven by two coherent fields. It find that the absorption properti...This paper investigates the effects of spontaneously induced coherence on absorption properties in a nearly equispaced three-level ladder-type system driven by two coherent fields. It find that the absorption properties of this system with the probe field applied on the lower transition can be significantly modified if this coherence is optimized. In the case of small spontaneous decay rate in the upper excited state, it finds that such coherence does not destroy the electromagnetically induced transparency （EIT）. Nevertheless, the absorption peak on both sides of zero detuning and the linewidth of absorption line become larger and narrower than those in the case corresponding to the effects of spontaneously induced coherence; while in the case of large decay rate, it finds that, instead of EIT with low resonant absorption, a sharp absorption peak at resonance appears. That is, electromagnetically induced absorption in the nearly equispaced ladder-type system can occur due to such coherent effects.展开更多
A theoretical model is developed for calculating the eigenmodes of the multi-gap resonant cavity. The structure of concern is a kind of ladder-type circuit, offering the advantages of easy fabrication, high characteri...A theoretical model is developed for calculating the eigenmodes of the multi-gap resonant cavity. The structure of concern is a kind of ladder-type circuit, offering the advantages of easy fabrication, high characteristic impedance （R/Q）, and thermal capacity in the millimeter wave to THz regime. The eigenfunction expansion method is used to establish the field expressions for the gaps and the coupling region. Then, the match conditions at the interface are employed, which leads to a group of complicate boundary equations in the form of an infinite series. To facilitate the mathematical treatments and perform a highly efficient calculation, these boundary equations are transformed into the algebraic forms through the matrix representations. Finally, the concise dispersion equation is obtained. The roots of the dispersion equation include both the axial modes in the gaps, which include the fundamental and the high-order modes, and the cavity modes in the coupling region. Extensive numerical results are presented and the behaviors of the multi-gap resonant cavity are examined.展开更多
The population transfer in a ladder-type atomic system driven by linearly polarized sech-shape femtosecond laser pulses is investigated by numerically solving Schr6dinger equation without including the rotating wave a...The population transfer in a ladder-type atomic system driven by linearly polarized sech-shape femtosecond laser pulses is investigated by numerically solving Schr6dinger equation without including the rotating wave approximation （RWA）. It is shown that population transfer is mainly determined by the Rabi frequency （strength） of the driving laser field and the chirp rate, and that the ratio of the dipole moments and the pulse width also have a prominent effect on the population transfer. By choosing appropriate values of the above parameters, complete population transfer can be realized.展开更多
Summary： The purpose of the present study was to observe the structure and functional change of the bone-coating-prosthesis interface in vivo and to evaluate the histocompatibility of self-made prosthetic femoral com...Summary： The purpose of the present study was to observe the structure and functional change of the bone-coating-prosthesis interface in vivo and to evaluate the histocompatibility of self-made prosthetic femoral components in the body and the degree of their bonding with the surrounding bone tissues as well as their stability. Six mature beagle dogs underwent bilateral hip replacement with prosthetic femur components. Three groups were established in terms of different coating of prothesis （four joints in each group）： atmosphere （A） plasma-sprayed pure titanium （Ti） prosthetic joint with hydroxyapatite （HA） coating （HA＋Ti＋A group）; vacuum （V） plasma-sprayed pure Ti prosthetic joint with HA coating （HA＋Ti＋V group）; vacuum plasma-sprayed pure Ti prosthetic joint with Ti-HA stepped coating （Ti＋HAG＋Ti＋V group）. The hip joints were functionally evaluated, and subjected to X-ray examination, biomechanics inspection, and histological examination. As a result, X-ray imaging revealed all prosthetic joints were in a good location and no dislocation of joint was found. Shear strength of interface was significantly higher in Ti＋HAG＋Ti＋V group than in HA＋Ti＋V group （P〈0.05） and HA＋Ti＋A group （P〈0.05） at 28th week. Histological examination showed the amount of newborn bone in Ti＋HAG＋Ti＋V group was more than in HA＋Ti＋V group and HA＋Ti＋A group after 28 weeks. It was suggested that vacuum plasma-sprayed pure Ti prosthetic joint with TI-HA stepped coating could improve the bonding capacity of bone-prosthesis, enhance the stability of prosthesis, and increase the fixion of prosthetic femoral components because of better bone growth. This new type of biological material in prosthetic femoral components holds promises for application in clinical practice.展开更多
为降低区域综合能源系统(regional integrated energy system, RIES)的碳排放、促进可再生能源消纳、优化系统运行成本,提出了碳交易机制下计及电转气(power to gas, P2G)及负荷柔性特征的RIES低碳经济调度策略。建立了阶梯式碳交易机制...为降低区域综合能源系统(regional integrated energy system, RIES)的碳排放、促进可再生能源消纳、优化系统运行成本,提出了碳交易机制下计及电转气(power to gas, P2G)及负荷柔性特征的RIES低碳经济调度策略。建立了阶梯式碳交易机制,两阶段、多模块P2G及柔性电、热、冷负荷的数学模型,并将其纳入RIES优化调度的框架;综合考虑碳交易成本、运行成本、负荷响应成本及弃风/弃光惩罚成本,建立了RIES的多能量耦合、多目标协同的优化调度模型;编制了RIES能量优化调度程序,开展了多种运行方式下的算例研究。结果表明:阶梯式碳交易机制能有效地降低碳排放,碳减排成本增量及微增率可作为配置碳交易机制参数的重要依据;“EL+MR+HFC+储氢罐”的4模块、两阶段精细化模型更准确地反映了P2G的运行特性;负荷侧全要素的柔性调度能够缓解用能高峰时段的供能压力,提升系统的综合运行效益。展开更多
基金Project(51305388)supported by the National Natural Science Foundation of ChinaProject(BJ2014055)supported by the Youth Talent Projects of Colleges in Hebei Province,ChinaProject(2016M590211)supported by China Postdoctoral Science Foundation
文摘Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25 V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that： 1） For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18 μm; 2） The yield strength, tensile strength and-30℃ charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3） Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.
文摘Hopf bifurcation inducing lasing without inversion has been analyzed by taking into account the effect of phase fluctuation in the driving field based on a closed three level ladder-type atomic model. It is shown that due to the phase fluctuation of the driving field, the necessary threshold increases significantly. Furthermore the area domain to get lasing without inversion decreases as the driving field's linewidth increases.
基金Project supported by the National Science Foundation of China （Grant No 10234030） and the Natural Science Foundation of Shanghai, China （Grant No 03ZR14102）.
文摘This paper investigates the effects of spontaneously induced coherence on absorption properties in a nearly equispaced three-level ladder-type system driven by two coherent fields. It find that the absorption properties of this system with the probe field applied on the lower transition can be significantly modified if this coherence is optimized. In the case of small spontaneous decay rate in the upper excited state, it finds that such coherence does not destroy the electromagnetically induced transparency （EIT）. Nevertheless, the absorption peak on both sides of zero detuning and the linewidth of absorption line become larger and narrower than those in the case corresponding to the effects of spontaneously induced coherence; while in the case of large decay rate, it finds that, instead of EIT with low resonant absorption, a sharp absorption peak at resonance appears. That is, electromagnetically induced absorption in the nearly equispaced ladder-type system can occur due to such coherent effects.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61222110 and 60971073)
文摘A theoretical model is developed for calculating the eigenmodes of the multi-gap resonant cavity. The structure of concern is a kind of ladder-type circuit, offering the advantages of easy fabrication, high characteristic impedance （R/Q）, and thermal capacity in the millimeter wave to THz regime. The eigenfunction expansion method is used to establish the field expressions for the gaps and the coupling region. Then, the match conditions at the interface are employed, which leads to a group of complicate boundary equations in the form of an infinite series. To facilitate the mathematical treatments and perform a highly efficient calculation, these boundary equations are transformed into the algebraic forms through the matrix representations. Finally, the concise dispersion equation is obtained. The roots of the dispersion equation include both the axial modes in the gaps, which include the fundamental and the high-order modes, and the cavity modes in the coupling region. Extensive numerical results are presented and the behaviors of the multi-gap resonant cavity are examined.
基金supported by National Basic Research Program of China (Grant No 2006CB806003)the Natural Science Foundation of Shandong Province,China (Grant No Y2006A21)+1 种基金the National Natural Science Foundation of China (Grant No 10675076)State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,China
文摘The population transfer in a ladder-type atomic system driven by linearly polarized sech-shape femtosecond laser pulses is investigated by numerically solving Schr6dinger equation without including the rotating wave approximation （RWA）. It is shown that population transfer is mainly determined by the Rabi frequency （strength） of the driving laser field and the chirp rate, and that the ratio of the dipole moments and the pulse width also have a prominent effect on the population transfer. By choosing appropriate values of the above parameters, complete population transfer can be realized.
基金supported by the Natural Science Foundation of Hubei Province of China(No.2012FFB02431)
文摘Summary： The purpose of the present study was to observe the structure and functional change of the bone-coating-prosthesis interface in vivo and to evaluate the histocompatibility of self-made prosthetic femoral components in the body and the degree of their bonding with the surrounding bone tissues as well as their stability. Six mature beagle dogs underwent bilateral hip replacement with prosthetic femur components. Three groups were established in terms of different coating of prothesis （four joints in each group）： atmosphere （A） plasma-sprayed pure titanium （Ti） prosthetic joint with hydroxyapatite （HA） coating （HA＋Ti＋A group）; vacuum （V） plasma-sprayed pure Ti prosthetic joint with HA coating （HA＋Ti＋V group）; vacuum plasma-sprayed pure Ti prosthetic joint with Ti-HA stepped coating （Ti＋HAG＋Ti＋V group）. The hip joints were functionally evaluated, and subjected to X-ray examination, biomechanics inspection, and histological examination. As a result, X-ray imaging revealed all prosthetic joints were in a good location and no dislocation of joint was found. Shear strength of interface was significantly higher in Ti＋HAG＋Ti＋V group than in HA＋Ti＋V group （P〈0.05） and HA＋Ti＋A group （P〈0.05） at 28th week. Histological examination showed the amount of newborn bone in Ti＋HAG＋Ti＋V group was more than in HA＋Ti＋V group and HA＋Ti＋A group after 28 weeks. It was suggested that vacuum plasma-sprayed pure Ti prosthetic joint with TI-HA stepped coating could improve the bonding capacity of bone-prosthesis, enhance the stability of prosthesis, and increase the fixion of prosthetic femoral components because of better bone growth. This new type of biological material in prosthetic femoral components holds promises for application in clinical practice.
文摘为降低区域综合能源系统(regional integrated energy system, RIES)的碳排放、促进可再生能源消纳、优化系统运行成本,提出了碳交易机制下计及电转气(power to gas, P2G)及负荷柔性特征的RIES低碳经济调度策略。建立了阶梯式碳交易机制,两阶段、多模块P2G及柔性电、热、冷负荷的数学模型,并将其纳入RIES优化调度的框架;综合考虑碳交易成本、运行成本、负荷响应成本及弃风/弃光惩罚成本,建立了RIES的多能量耦合、多目标协同的优化调度模型;编制了RIES能量优化调度程序,开展了多种运行方式下的算例研究。结果表明:阶梯式碳交易机制能有效地降低碳排放,碳减排成本增量及微增率可作为配置碳交易机制参数的重要依据;“EL+MR+HFC+储氢罐”的4模块、两阶段精细化模型更准确地反映了P2G的运行特性;负荷侧全要素的柔性调度能够缓解用能高峰时段的供能压力,提升系统的综合运行效益。
