During the incubation period of isothermal treatment（or aging） within the bainitic transformation temperature range in a salt bath （or quenching in water） immediately after solution treatment, not only are the def...During the incubation period of isothermal treatment（or aging） within the bainitic transformation temperature range in a salt bath （or quenching in water） immediately after solution treatment, not only are the defects formed at high temperatures maintained, but new defects can also be generated in alloys, iron alloys and steels. Due to the segregation of the solute atoms near defects through diffusion, this leads to non-uniform distributions of solute atoms in the parent phase with distinct regions of both solute enrichment and solute depletion. It is proposed that when the Ms temperature at the solute depleted regions is equal to or higher than the isothermal （or aged） temperature,nucleation of bainite occurs within these solute depleted regions in the manner of martensitic shear. Therefore it is considered that, at least in steel, iron and copper alloy systems, bainite is formed through a shear mechanism within solute depleted regions, which is controlled and formed by the solute atoms diffusion in the parent phase.展开更多
The NaCl-H_2O binary system is a major component of solutions coexisting with ores. Observation ofsaturated solutions of NaCl-H_2O by using the method of hydrothermal diamond anvil cell (HDAC) is a new approach tothe ...The NaCl-H_2O binary system is a major component of solutions coexisting with ores. Observation ofsaturated solutions of NaCl-H_2O by using the method of hydrothermal diamond anvil cell (HDAC) is a new approach tothe study of ore-forming fluids. The salinities of NaCl-H_2O solutions in experimental observation are in a range of 32-55%. The observed temperature range is 25℃-850℃, and the pressure range 1 atm-10 kb. In this temperature-pressure range, the supercritical single phase, two phases (L,V) close to the critical state and two-phased (L+V) immis-cible region were observed. And for the salinity of 35% the two phase L+V immiscible region of NaCl-H_2O solutionwas observed in a range of 253-720℃. Another temperature range, 400-817℃, was observed for the immiscible two-phased region of 50% salinity solution. In the high-temperature part of the two-phased immiscible region, the phase na-ture is very unstable. A "critical phenomenon" was observed when the heating path was very close to the critical state.It is possible to observe a 'critical phenomenon': an "explosion" occurred almost constantly at the interface between theliquid and vapour and the interface is rather obscure. A continuous transition between phases L and V could be foundin the immiscible L+V phase while heating continuously. Moreover, as the NaCl-H_2O solution was separated into liq-uid and vapour phases, static charges surrounding each vapour bubble could be seen, and these bubbles were attractedtogether by the static charges to form a special solution structure. Besides, critical states of different salinities of NaCl-H_2O were observed in order to study the properties of the fluids occurring in the rocks in the earth interior, the origin ofore-bearing fluids and the significance of supercritical fluid with respect to the ore formation. The comparison of the sa-linity data of the fluid inclusions in the minerals of ore deposits with observations of NaCl-H_2O under HDAC in theconditions of high temperatures and pressures, combined with further thermodynamic analysis of ore-formation condi-tions would explain in depth the factors determining the ore formation.展开更多
In this paper ,the bending problem of the non-homogeneous cylindrical orthotropiccircular plate is described.A general solution for the bending of circular plate underuniformly distributed transverse load is solved.an...In this paper ,the bending problem of the non-homogeneous cylindrical orthotropiccircular plate is described.A general solution for the bending of circular plate underuniformly distributed transverse load is solved.and the exact solution of such circularplate with clamped edges is obtained.展开更多
To meet the requirements of low damage and high seedling-standing of vegetable plug seedlings during mechanical transplanting,a new seedling planting mechanism combining non-circular gear system and multi-link was dev...To meet the requirements of low damage and high seedling-standing of vegetable plug seedlings during mechanical transplanting,a new seedling planting mechanism combining non-circular gear system and multi-link was developed,which consisted of a five-bar seedling pushing mechanism with the planetary gear train of non-circular gears and a cam linkage seedling supporting mechanism.Based on the agronomic requirements for transplanting vegetable plug seedlings,the design requirements and the poses of four key points of the seedling pushing mechanism were determined.The mechanism solution region synthesis method was applied to conduct precise four poses synthesis of the five-bar seedling pushing mechanism.Based on four key pose points and five additional positions of the seedling pushing trajectory,the angular variation curve of the connecting rod relative to the planetary carrier was derived through cubic B-spline curve fitting.Subsequently,the kinematics analysis of the seedling pushing mechanism was performed to complete continuous motion discrimination and determine the parameters of the five-bar seedling pushing mechanism.The kinematics model of the planetary gear train with non-circular gears was established,and the pitch curve design for each gear was undertaken to fulfill the design of the seedling pushing mechanism.According to the motion law of the seedling pushing mechanism and the seedling planting requirements,the kinematics model of the seedling supporting mechanism was established and its parameters were solved.The virtual simulation analysis and prototype experiment of the mechanism confirm that the simulation and test motion trajectory and key poses are basically consistent with the theoretical design results.Moreover,when the rotation speeds of the seedling planting mechanism are 60-80 r/min,the success rates of broccoli and pepper seedling planting all reach over 93%,indicating the correctness of the seedling planting mechanism design and its application feasibility and universality.展开更多
This article describes research needs for sustainable buildings as defi ned in a July 2009 National Science Foundationsponsored workshop.This workshop brought together building researchers with researchers in the area...This article describes research needs for sustainable buildings as defi ned in a July 2009 National Science Foundationsponsored workshop.This workshop brought together building researchers with researchers in the areas of distributed renewable energy and multifunctional materials to engage their expertise and identify overlapping research needs and opportunities.An overview of sustainable building design provided the broad context for discussion.This overview was followed by focused presentations in building control systems,advanced building envelopes,and systems and process integration.In addition,presentations on distributed renewable energy and multi-functional materials supported the participants in outlining and generating research needs that connect the topic areas.The primary outcome from this part of the workshop was the identifi cation of key sustainable building research needs in:transformative measurements;passive strategies;regional solutions and living labs;systems integration;storage and cascades;adoption of international advances;and implementation and market transformation.These needs,along with associated technical challenges and potential impacts,are described in this paper to guide sustainable building research.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.59171031)
文摘During the incubation period of isothermal treatment（or aging） within the bainitic transformation temperature range in a salt bath （or quenching in water） immediately after solution treatment, not only are the defects formed at high temperatures maintained, but new defects can also be generated in alloys, iron alloys and steels. Due to the segregation of the solute atoms near defects through diffusion, this leads to non-uniform distributions of solute atoms in the parent phase with distinct regions of both solute enrichment and solute depletion. It is proposed that when the Ms temperature at the solute depleted regions is equal to or higher than the isothermal （or aged） temperature,nucleation of bainite occurs within these solute depleted regions in the manner of martensitic shear. Therefore it is considered that, at least in steel, iron and copper alloy systems, bainite is formed through a shear mechanism within solute depleted regions, which is controlled and formed by the solute atoms diffusion in the parent phase.
文摘The NaCl-H_2O binary system is a major component of solutions coexisting with ores. Observation ofsaturated solutions of NaCl-H_2O by using the method of hydrothermal diamond anvil cell (HDAC) is a new approach tothe study of ore-forming fluids. The salinities of NaCl-H_2O solutions in experimental observation are in a range of 32-55%. The observed temperature range is 25℃-850℃, and the pressure range 1 atm-10 kb. In this temperature-pressure range, the supercritical single phase, two phases (L,V) close to the critical state and two-phased (L+V) immis-cible region were observed. And for the salinity of 35% the two phase L+V immiscible region of NaCl-H_2O solutionwas observed in a range of 253-720℃. Another temperature range, 400-817℃, was observed for the immiscible two-phased region of 50% salinity solution. In the high-temperature part of the two-phased immiscible region, the phase na-ture is very unstable. A "critical phenomenon" was observed when the heating path was very close to the critical state.It is possible to observe a 'critical phenomenon': an "explosion" occurred almost constantly at the interface between theliquid and vapour and the interface is rather obscure. A continuous transition between phases L and V could be foundin the immiscible L+V phase while heating continuously. Moreover, as the NaCl-H_2O solution was separated into liq-uid and vapour phases, static charges surrounding each vapour bubble could be seen, and these bubbles were attractedtogether by the static charges to form a special solution structure. Besides, critical states of different salinities of NaCl-H_2O were observed in order to study the properties of the fluids occurring in the rocks in the earth interior, the origin ofore-bearing fluids and the significance of supercritical fluid with respect to the ore formation. The comparison of the sa-linity data of the fluid inclusions in the minerals of ore deposits with observations of NaCl-H_2O under HDAC in theconditions of high temperatures and pressures, combined with further thermodynamic analysis of ore-formation condi-tions would explain in depth the factors determining the ore formation.
文摘In this paper ,the bending problem of the non-homogeneous cylindrical orthotropiccircular plate is described.A general solution for the bending of circular plate underuniformly distributed transverse load is solved.and the exact solution of such circularplate with clamped edges is obtained.
基金supported by the National Natural Science Foundation of China(Grant No.32171899)Zhejiang Provincial Natural Science Foundation of China(Grant No.LD24E050007)。
文摘To meet the requirements of low damage and high seedling-standing of vegetable plug seedlings during mechanical transplanting,a new seedling planting mechanism combining non-circular gear system and multi-link was developed,which consisted of a five-bar seedling pushing mechanism with the planetary gear train of non-circular gears and a cam linkage seedling supporting mechanism.Based on the agronomic requirements for transplanting vegetable plug seedlings,the design requirements and the poses of four key points of the seedling pushing mechanism were determined.The mechanism solution region synthesis method was applied to conduct precise four poses synthesis of the five-bar seedling pushing mechanism.Based on four key pose points and five additional positions of the seedling pushing trajectory,the angular variation curve of the connecting rod relative to the planetary carrier was derived through cubic B-spline curve fitting.Subsequently,the kinematics analysis of the seedling pushing mechanism was performed to complete continuous motion discrimination and determine the parameters of the five-bar seedling pushing mechanism.The kinematics model of the planetary gear train with non-circular gears was established,and the pitch curve design for each gear was undertaken to fulfill the design of the seedling pushing mechanism.According to the motion law of the seedling pushing mechanism and the seedling planting requirements,the kinematics model of the seedling supporting mechanism was established and its parameters were solved.The virtual simulation analysis and prototype experiment of the mechanism confirm that the simulation and test motion trajectory and key poses are basically consistent with the theoretical design results.Moreover,when the rotation speeds of the seedling planting mechanism are 60-80 r/min,the success rates of broccoli and pepper seedling planting all reach over 93%,indicating the correctness of the seedling planting mechanism design and its application feasibility and universality.
文摘This article describes research needs for sustainable buildings as defi ned in a July 2009 National Science Foundationsponsored workshop.This workshop brought together building researchers with researchers in the areas of distributed renewable energy and multifunctional materials to engage their expertise and identify overlapping research needs and opportunities.An overview of sustainable building design provided the broad context for discussion.This overview was followed by focused presentations in building control systems,advanced building envelopes,and systems and process integration.In addition,presentations on distributed renewable energy and multi-functional materials supported the participants in outlining and generating research needs that connect the topic areas.The primary outcome from this part of the workshop was the identifi cation of key sustainable building research needs in:transformative measurements;passive strategies;regional solutions and living labs;systems integration;storage and cascades;adoption of international advances;and implementation and market transformation.These needs,along with associated technical challenges and potential impacts,are described in this paper to guide sustainable building research.
