Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious fo...Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious form, stress-strain curve, peak strength, peak strain and elastic modulus with temperature were analyzed and the essence of rock failure modes was explored. The results indicate that, compared with granite after the high temperature treatment, the brittle-ductile transition critical temperature is lower, the densification stage is longer, the elastic modulus is smaller and the damage is larger under high temperature. In addition, the peak stress is lower and the peak strain is greater, but both of them change more obviously with the increase of temperature compared with that of granite after the high temperature treatment. Furthermore, the failure modes of granite after the high temperature treatment and under high temperature show a remarkable difference. Below 100 ℃, the failure modes of granite under both conditions are the same, presenting splitting failure. However, after 100 ℃, the failure modes of granite after the high temperature treatment and under high temperature present splitting failure and shear failure, respectively.展开更多
A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machi...A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machine (HEDSM) motor and its three-phase full-bridge inverter, in the proposed analytical method, all possible working modes are generally listed. Then, with the H_PWM-L_ON control strategy, the working modes are detailed with eorresponding equivalent circuits. Experimental results verify the robustness of the analysis.展开更多
The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has ...The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by"forest-vil age-terrace-river", including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.展开更多
[Objective] This paper aims to confirm that Yunnan is one origin center of rice and human in the world.[Method] The complicated and unique ecological environment in Yunnan makes Yunnan Province the largest center of g...[Objective] This paper aims to confirm that Yunnan is one origin center of rice and human in the world.[Method] The complicated and unique ecological environment in Yunnan makes Yunnan Province the largest center of genetic diversity and cultural diversity of rice and human being as well as the cradle of human childhood.[Result] The genetic diversity and cultural diversity of rice and human being is closely related to the ecosystem diversity.Rice civilization in Yunnan can be divided into four types,including the diversity center region of rice civilization in southwestern Yunnan,diffusion region of rice civilization of Hani-Zhuang in southern Yunnan,rice civilization region of water-drought rotation in central Yunnan and poverty region of rice civilization in northern Yunnan.Southwestern Yunnan is not only the center of genetic ecological diversity and rice cultural diversity,but also the center of origin and diversity of crop genetic diversity.It is not only a transitional region among East Asia continent,South Asian sub-continent and Indo-China Peninsula,but also a core integration area of Chinese culture,Indian culture and Mid-south Peninsula culture which all merge with the local culture.[Conclusion] Yunnan is one common sphere where the origin of human evolution is closely related to the origin of rice evolution.展开更多
The electrochemical and corrosion?wear behaviors of TC4 alloy in artificial seawater were studied. And the influences of electrochemical state on passive behavior, failure mechanism of passive film and corrosion?wear ...The electrochemical and corrosion?wear behaviors of TC4 alloy in artificial seawater were studied. And the influences of electrochemical state on passive behavior, failure mechanism of passive film and corrosion?wear synergy were emphatically analyzed. The corrosion?wear analysis of the alloy was fulfilled by methods of mass loss, electrochemical testing and scanning electron microscope (SEM). It can be observed that the cathodic shift of open circuit potential and three order of magnitude increase of current density can be obtained during corrosion?wear process. Total corrosion?wear loss increases with increasing applied potential, confirming the synergy between wear and corrosion. High polarisation potential results in low coefficient of friction and high corrosion rate. The relative contribution of pure mechanical wear to total material loss deceases obviously with the increase of potential from open circuit potential to 0.9 V during corrosion?wear. Contributions of wear-induced-corrosion and corrosion-induced-wear are significant especially at higher potentials.展开更多
The effects of different maize sowing dates and densities on stem and leaf morphological characters and yield of soybean in wheat/maize/soybean relaycropping system were studied. The results showed that with early sow...The effects of different maize sowing dates and densities on stem and leaf morphological characters and yield of soybean in wheat/maize/soybean relaycropping system were studied. The results showed that with early sowing of maize, the maize yield was promoted, and maize was harvested in advance, which reduced the intergrowth period with soybean and guaranteed soybean's proper plant height, larger stem diameter and optimal values of LAI and SLW, so that soybean yield was also increased. The effects of different maize densities on the stem and leaf of soybean mainly were significant before the maize harvest, but soybean yield under high maize density was significantly lower than that under middle and low maize density, and the highest maize yield was under middle density. Based on soybean and maize comprehensive values, the optimum combination of this experiment was sowed on March 21 and planting density was 5.25×10^4 plant/hm^2.展开更多
This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological L...This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites, a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect, vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems. The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.展开更多
Pure tungsten, oxide dispersion strengthened tungsten and carbide dispersion strengthened tungsten were fabricated by high-energy ball milling and spark plasma sintering process. In order to evaluate the properties of...Pure tungsten, oxide dispersion strengthened tungsten and carbide dispersion strengthened tungsten were fabricated by high-energy ball milling and spark plasma sintering process. In order to evaluate the properties of the tungsten alloys under transient high heat flues, four tungsten samples with different grain sizes were tested by high-intensity pulsed ion beam with a heat flux as high as 160 MW/(m^2·s^-1/2). Compared with the commercial tungsten, the surface modification of the oxide dispersion strengthened tungsten by high-intensity pulsed ion beam is completely different. The oxide dispersion strengthened tungsten shows inferior thermal shock response due to the low melting point second phase of Ti and Y2O3, which results in the surface melting, boiling bubbles and cracking. While the carbide dispersion strengthened tungsten shows better thermal shock response than the commercial tungsten.展开更多
On the basis of extensive literature search, the species, ingredients, pharmacology, clinical applications, ecological value and cultivation techniques of Scirpus tabemaemontani Gmel have been reviewed, to provide sci...On the basis of extensive literature search, the species, ingredients, pharmacology, clinical applications, ecological value and cultivation techniques of Scirpus tabemaemontani Gmel have been reviewed, to provide scientific data for further research & development.展开更多
[Objective] This study aimed to investigate the pollen morphology of nine major crops in Bashang Plateau of Hebei Province. [Method] By using an optical microscope, pollen morphology of nine major crops in Bashang Pla...[Objective] This study aimed to investigate the pollen morphology of nine major crops in Bashang Plateau of Hebei Province. [Method] By using an optical microscope, pollen morphology of nine major crops in Bashang Plateau of Hebei Province was observed and compared. [Result] Pollen grains were spherical, nearly spherical or prolate; pollen grains of Cucurbita pepo were the largest, and those of Brassica campestris were the smallest; P/E value of Vicia faba was the maximum of 1.77, and that of Avena chinsis was the minimum of 1.00; there were six types of germinal apertures, including single-aperture, scattered-aperture, 3-aperture, 3-groove, 3-colporate and 3-4-colporate; there were four types of exine ornamentation, including reticulate ornamentation, warty ornamentation, spinulose ornamentation and granular ornamentation. [Conclusion] This study not only provided standard maps and related information for the identification of crop pollens in different strata, but also provided modern palynological evidence for extracting information of synarthropic plants (cultivated crops mostly) in different strata, deducing the natural environment ancient human lived in, and understanding the relationship between human and environmental changes.展开更多
Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, ...Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, if a distributed parameter system is described by ordinary differential equations (ODE) during the analysis and the design of distributed parameter system, the reliability of the system description will be reduced, and the systemic errors will be introduced. Studies on working condition real-time monitoring can improve the security because the rechargeable LIBs are widely used in many electronic systems and electromechanical equipment. Single particle model (SPM) is the simplification of LIB under some approximations, and can estimate the working parameters of a LIB at the faster simulation speed. A LIB modelling algorithm based on PDEs and SPM is proposed to monitor the working condition of LIBs in real time. Although the lithium ion concentration is an unmeasurable distributed parameter in the anode of LIB, the working condition monitoring model can track the real time lithium ion concentration in the anode of LIB, and calculate the residual which is the difference between the ideal data and the measured data. A fault alarm can be triggered when the residual is beyond the preset threshold. A simulation example verifies that the effectiveness and the accuracy of the working condition real-time monitoring model of LIB based on PDEs and SPM.展开更多
Middle-sized chambers (40cmx40cmx20 cm) and an infrared gas analyzer (IRGA) were used for the measurement of net photosynthesis of the grass layer and soil CO2 evolution, in Quercus liaotungensis Koidz. forest, which ...Middle-sized chambers (40cmx40cmx20 cm) and an infrared gas analyzer (IRGA) were used for the measurement of net photosynthesis of the grass layer and soil CO2 evolution, in Quercus liaotungensis Koidz. forest, which is a typical temperate forest ecosystem in the mountainous areas of Beijing. Changes of CO2 concentrations in both the atmosphere (2m above canopy) and the forest canopy (2m below the top of the canopy) together with those of net photosynthesis and soil CO2 evolution were also examined, in order to find the characteristics of CO2 exchange between the different components of the temperate forest ecosystem and the atmosphere. Atmospheric CO2 averaged (323+10) and (330+1) mol mol-1 respectively in summer and autumn. During the 24-hour measurements, large differences as much as -46 and -61 mol mol-1 respectively in the atmosphere and forest were found. Net photosynthesis of the grass layer in summer was (2. 59 9+ 1.05) mol CO2 m-2 S-1, two times of that in autumn, (1.31+0.39) mol CO2 s-1 In summer, there was much more CO2 evolved from soil than in autumn, averaging (5.18+0.75) mol CO2 m-2 s-1 and (1.96 + 0.57) (mol CO2 m-2 s-1, respectively. A significant correlation was found between soil CO2 evolution and ground temperature, with F =-0.864 2+0.310 1X,r=0.7164, P<0.001 (n=117). Both the minimal atmospheric CO2 level and the maximum net photosynthesis occurred around 14:00; and an increase in atmospheric CO2 and of soil CO2 evolution during night times were also found to be remarkable.展开更多
The properties of a bound polaron in a parabolic quantum dot with weak electron-LO-phonon coupling under a Coulomb field are studied. The ground state energy of the bound polaron is derived by using a linear combinati...The properties of a bound polaron in a parabolic quantum dot with weak electron-LO-phonon coupling under a Coulomb field are studied. The ground state energy of the bound polaron is derived by using a linear combination operator and the perturbation method. The influence of the interaction between phonons with different wave vectors in the recoil process on the ground state energy of the bound polaron is discussed. Numerical calculations are performed,and the results show that the ground state energy increases significantly as the effective confinement length of the quantum dot decreases,considering of the interaction between phonons. When l0〉1.0, the influence of the interaction between phonons on the ground state energy cannot be ignored.展开更多
A dynamic hierarchical description method for workflow is presented. The method provides a dynamic hierarchical way to define a workflow with non-determinate or dynamic factors. With this method, the main process defi...A dynamic hierarchical description method for workflow is presented. The method provides a dynamic hierarchical way to define a workflow with non-determinate or dynamic factors. With this method, the main process defined at build-time can be reified and extended by the principle of the sub-organizations at either the build-time or the run-time. To ensure the consistency and integrity of the description, a series of constraint rules are also discussed to realize seamless integration between a decomposed process and its original one. This approach supports the description of unpredictable uncertainties, the dynamic hierarchy of business process, and the dynamic modification of enterprise organizations, and all of these improve the flexibility and extendability of workflow management systems dramatically.展开更多
To develop modal macro-strain ( MMS ) identification techniques and improve their applicability in a continuous health monitoring system for civil infrastructures, the concept of operational macro-strain shape (OMS...To develop modal macro-strain ( MMS ) identification techniques and improve their applicability in a continuous health monitoring system for civil infrastructures, the concept of operational macro-strain shape (OMSS) and the corresponding identification method are proposed under unknown ever-changing loading conditions, and the MMS is then obtained. The core of the proposed technique is mainly based on the specific property that the macro-strain transmissibility tends to be independent of external excitations at the poles of the system and converges to a unique value. The proposed method is verified using the experimental data from a three-span continuous beam excited by an impact hammer at different locations. The identified results are also compared with the commonly used methods, such as the peak- picking (PP) method, the stochastic subspace identification (SSI) method, and numerical results, in the case of unknown input forces. Results show that the proposed technique has unique merits in accuracy and robustness due to its combining multiple tests under changing loading conditions, which also reveal the promising application of the distributed strain sensing system in identifying MMS of operational structures, as well as in the structural health monitoring (SHM) field.展开更多
A global three dimensional potential energy surface for the F+H2→HF+H reaction has been developed by spline interpolation of about 15,000 symmetry-unique ab initio points, obtained from the multi-reference configur...A global three dimensional potential energy surface for the F+H2→HF+H reaction has been developed by spline interpolation of about 15,000 symmetry-unique ab initio points, obtained from the multi-reference configuration interaction level with Davidson correction using the aug-cc-pV5Z basis set. In the entrance channel the spin-orbit coupling energy is also included.展开更多
Intertidal macroalgae experience continual alternation of photosynthesis between aquatic state at high tide and aerial state at low tide. The comparative photosynthetic responses to inorganic carbon were investigated...Intertidal macroalgae experience continual alternation of photosynthesis between aquatic state at high tide and aerial state at low tide. The comparative photosynthetic responses to inorganic carbon were investigated in the common intertidal macroalga Ulva lactuca L. along the coast of Shantou between aquatic and aerial state. The inorganic carbon dissolved in seawater at present could fully (at 10 ℃ or 20 ℃) or nearly (at 30 ℃) saturate the aquatic photosynthesis of U. lactuca . However, the aerial photosynthesis was limited by current ambient atmospheric CO 2 level, and such a limitation was more severe at higher temperature (20-30 ℃) than at lower temperature (10 ℃). The carbon_saturated maximal photosynthesis of U. lactuca under aerial state was much greater than that under aquatic state at 10 ℃ and 20 ℃, while the maximal photosynthesis under both states was similar at 30 ℃. The aerial values of K m (CO 2) for photosynthesis were higher than the aquatic values. On the contrary, the values of apparent photosynthetic CO 2 conductance under aerial state were considerably lower than that under aquatic state. It was concluded that the increase of atmospheric CO 2 would enhance the primary productivity of U. lactuca through stimulating the photosynthesis under aerial state during low tide.展开更多
基金Projects(51304241,11472311,51322403)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by Innovation Driven Plan of Central South University,China+1 种基金Project(2016zzts456)supported by Independent Exploration and Innovation Foundation of Central South University,ChinaProject(2015CB060200)supported by the National Basic Research Program of China
文摘Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious form, stress-strain curve, peak strength, peak strain and elastic modulus with temperature were analyzed and the essence of rock failure modes was explored. The results indicate that, compared with granite after the high temperature treatment, the brittle-ductile transition critical temperature is lower, the densification stage is longer, the elastic modulus is smaller and the damage is larger under high temperature. In addition, the peak stress is lower and the peak strain is greater, but both of them change more obviously with the increase of temperature compared with that of granite after the high temperature treatment. Furthermore, the failure modes of granite after the high temperature treatment and under high temperature show a remarkable difference. Below 100 ℃, the failure modes of granite under both conditions are the same, presenting splitting failure. However, after 100 ℃, the failure modes of granite after the high temperature treatment and under high temperature present splitting failure and shear failure, respectively.
文摘A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machine (HEDSM) motor and its three-phase full-bridge inverter, in the proposed analytical method, all possible working modes are generally listed. Then, with the H_PWM-L_ON control strategy, the working modes are detailed with eorresponding equivalent circuits. Experimental results verify the robustness of the analysis.
基金Supported by Project of Ministry of Human Resources and Social Security~~
文摘The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by"forest-vil age-terrace-river", including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.
基金Supported by National Natural Science Foundation of China(31060186)Exploitue of Emphases New Production from Yunnan Provincial Scientific and Technology Department(2010BB001)Project for Innovative Pilot Enterprises from Science and Technology Bureau of Kunming City(Kunkejizi10N060204)~~
文摘[Objective] This paper aims to confirm that Yunnan is one origin center of rice and human in the world.[Method] The complicated and unique ecological environment in Yunnan makes Yunnan Province the largest center of genetic diversity and cultural diversity of rice and human being as well as the cradle of human childhood.[Result] The genetic diversity and cultural diversity of rice and human being is closely related to the ecosystem diversity.Rice civilization in Yunnan can be divided into four types,including the diversity center region of rice civilization in southwestern Yunnan,diffusion region of rice civilization of Hani-Zhuang in southern Yunnan,rice civilization region of water-drought rotation in central Yunnan and poverty region of rice civilization in northern Yunnan.Southwestern Yunnan is not only the center of genetic ecological diversity and rice cultural diversity,but also the center of origin and diversity of crop genetic diversity.It is not only a transitional region among East Asia continent,South Asian sub-continent and Indo-China Peninsula,but also a core integration area of Chinese culture,Indian culture and Mid-south Peninsula culture which all merge with the local culture.[Conclusion] Yunnan is one common sphere where the origin of human evolution is closely related to the origin of rice evolution.
基金Project(LSL-1310)supported by the Open Project of State Key Laboratory of Solid Lubrication,ChinaProjects(2014QN013,2015GJB004)supported by the Research Foundation of Henan University of Science and Technology,China
文摘The electrochemical and corrosion?wear behaviors of TC4 alloy in artificial seawater were studied. And the influences of electrochemical state on passive behavior, failure mechanism of passive film and corrosion?wear synergy were emphatically analyzed. The corrosion?wear analysis of the alloy was fulfilled by methods of mass loss, electrochemical testing and scanning electron microscope (SEM). It can be observed that the cathodic shift of open circuit potential and three order of magnitude increase of current density can be obtained during corrosion?wear process. Total corrosion?wear loss increases with increasing applied potential, confirming the synergy between wear and corrosion. High polarisation potential results in low coefficient of friction and high corrosion rate. The relative contribution of pure mechanical wear to total material loss deceases obviously with the increase of potential from open circuit potential to 0.9 V during corrosion?wear. Contributions of wear-induced-corrosion and corrosion-induced-wear are significant especially at higher potentials.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(nyhyzx07004-10)Major Science&Technology Program of Sichuan Province(01NG016-01)~~
文摘The effects of different maize sowing dates and densities on stem and leaf morphological characters and yield of soybean in wheat/maize/soybean relaycropping system were studied. The results showed that with early sowing of maize, the maize yield was promoted, and maize was harvested in advance, which reduced the intergrowth period with soybean and guaranteed soybean's proper plant height, larger stem diameter and optimal values of LAI and SLW, so that soybean yield was also increased. The effects of different maize densities on the stem and leaf of soybean mainly were significant before the maize harvest, but soybean yield under high maize density was significantly lower than that under middle and low maize density, and the highest maize yield was under middle density. Based on soybean and maize comprehensive values, the optimum combination of this experiment was sowed on March 21 and planting density was 5.25×10^4 plant/hm^2.
基金supported by Chinese Academy of Sciences"100 people’project and the Open Research Station of Changbai Mountain Forest Ecosystem
文摘This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites, a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect, vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems. The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.
基金roject (50634060) supported by the National Natural Science Foundation of ChinaProject (2010GB109000) supported by the National Basic Research Program of China
文摘Pure tungsten, oxide dispersion strengthened tungsten and carbide dispersion strengthened tungsten were fabricated by high-energy ball milling and spark plasma sintering process. In order to evaluate the properties of the tungsten alloys under transient high heat flues, four tungsten samples with different grain sizes were tested by high-intensity pulsed ion beam with a heat flux as high as 160 MW/(m^2·s^-1/2). Compared with the commercial tungsten, the surface modification of the oxide dispersion strengthened tungsten by high-intensity pulsed ion beam is completely different. The oxide dispersion strengthened tungsten shows inferior thermal shock response due to the low melting point second phase of Ti and Y2O3, which results in the surface melting, boiling bubbles and cracking. While the carbide dispersion strengthened tungsten shows better thermal shock response than the commercial tungsten.
文摘On the basis of extensive literature search, the species, ingredients, pharmacology, clinical applications, ecological value and cultivation techniques of Scirpus tabemaemontani Gmel have been reviewed, to provide scientific data for further research & development.
基金Supported by Natural Science Foundation of Hebei Province (D2012302007)Science and Technology Project of Hebei Academy of Sciences (2013055507)+1 种基金Personnel Training Project of Hebei Province (2012)Talent Project of Hebei Academy of Sciences (2013045333-4)~~
文摘[Objective] This study aimed to investigate the pollen morphology of nine major crops in Bashang Plateau of Hebei Province. [Method] By using an optical microscope, pollen morphology of nine major crops in Bashang Plateau of Hebei Province was observed and compared. [Result] Pollen grains were spherical, nearly spherical or prolate; pollen grains of Cucurbita pepo were the largest, and those of Brassica campestris were the smallest; P/E value of Vicia faba was the maximum of 1.77, and that of Avena chinsis was the minimum of 1.00; there were six types of germinal apertures, including single-aperture, scattered-aperture, 3-aperture, 3-groove, 3-colporate and 3-4-colporate; there were four types of exine ornamentation, including reticulate ornamentation, warty ornamentation, spinulose ornamentation and granular ornamentation. [Conclusion] This study not only provided standard maps and related information for the identification of crop pollens in different strata, but also provided modern palynological evidence for extracting information of synarthropic plants (cultivated crops mostly) in different strata, deducing the natural environment ancient human lived in, and understanding the relationship between human and environmental changes.
文摘Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, if a distributed parameter system is described by ordinary differential equations (ODE) during the analysis and the design of distributed parameter system, the reliability of the system description will be reduced, and the systemic errors will be introduced. Studies on working condition real-time monitoring can improve the security because the rechargeable LIBs are widely used in many electronic systems and electromechanical equipment. Single particle model (SPM) is the simplification of LIB under some approximations, and can estimate the working parameters of a LIB at the faster simulation speed. A LIB modelling algorithm based on PDEs and SPM is proposed to monitor the working condition of LIBs in real time. Although the lithium ion concentration is an unmeasurable distributed parameter in the anode of LIB, the working condition monitoring model can track the real time lithium ion concentration in the anode of LIB, and calculate the residual which is the difference between the ideal data and the measured data. A fault alarm can be triggered when the residual is beyond the preset threshold. A simulation example verifies that the effectiveness and the accuracy of the working condition real-time monitoring model of LIB based on PDEs and SPM.
基金This is a key project of National Natural Science Foundation of China.
文摘Middle-sized chambers (40cmx40cmx20 cm) and an infrared gas analyzer (IRGA) were used for the measurement of net photosynthesis of the grass layer and soil CO2 evolution, in Quercus liaotungensis Koidz. forest, which is a typical temperate forest ecosystem in the mountainous areas of Beijing. Changes of CO2 concentrations in both the atmosphere (2m above canopy) and the forest canopy (2m below the top of the canopy) together with those of net photosynthesis and soil CO2 evolution were also examined, in order to find the characteristics of CO2 exchange between the different components of the temperate forest ecosystem and the atmosphere. Atmospheric CO2 averaged (323+10) and (330+1) mol mol-1 respectively in summer and autumn. During the 24-hour measurements, large differences as much as -46 and -61 mol mol-1 respectively in the atmosphere and forest were found. Net photosynthesis of the grass layer in summer was (2. 59 9+ 1.05) mol CO2 m-2 S-1, two times of that in autumn, (1.31+0.39) mol CO2 s-1 In summer, there was much more CO2 evolved from soil than in autumn, averaging (5.18+0.75) mol CO2 m-2 s-1 and (1.96 + 0.57) (mol CO2 m-2 s-1, respectively. A significant correlation was found between soil CO2 evolution and ground temperature, with F =-0.864 2+0.310 1X,r=0.7164, P<0.001 (n=117). Both the minimal atmospheric CO2 level and the maximum net photosynthesis occurred around 14:00; and an increase in atmospheric CO2 and of soil CO2 evolution during night times were also found to be remarkable.
文摘The properties of a bound polaron in a parabolic quantum dot with weak electron-LO-phonon coupling under a Coulomb field are studied. The ground state energy of the bound polaron is derived by using a linear combination operator and the perturbation method. The influence of the interaction between phonons with different wave vectors in the recoil process on the ground state energy of the bound polaron is discussed. Numerical calculations are performed,and the results show that the ground state energy increases significantly as the effective confinement length of the quantum dot decreases,considering of the interaction between phonons. When l0〉1.0, the influence of the interaction between phonons on the ground state energy cannot be ignored.
文摘A dynamic hierarchical description method for workflow is presented. The method provides a dynamic hierarchical way to define a workflow with non-determinate or dynamic factors. With this method, the main process defined at build-time can be reified and extended by the principle of the sub-organizations at either the build-time or the run-time. To ensure the consistency and integrity of the description, a series of constraint rules are also discussed to realize seamless integration between a decomposed process and its original one. This approach supports the description of unpredictable uncertainties, the dynamic hierarchy of business process, and the dynamic modification of enterprise organizations, and all of these improve the flexibility and extendability of workflow management systems dramatically.
基金The National Natural Science Foudation of China(No.51578140)the Natural Science Foundation of Jiangsu Province(No.BK20151092)Scientific Innovation Research of College Graduates in Jiangsu Province(No.CXZZ12_0108)
文摘To develop modal macro-strain ( MMS ) identification techniques and improve their applicability in a continuous health monitoring system for civil infrastructures, the concept of operational macro-strain shape (OMSS) and the corresponding identification method are proposed under unknown ever-changing loading conditions, and the MMS is then obtained. The core of the proposed technique is mainly based on the specific property that the macro-strain transmissibility tends to be independent of external excitations at the poles of the system and converges to a unique value. The proposed method is verified using the experimental data from a three-span continuous beam excited by an impact hammer at different locations. The identified results are also compared with the commonly used methods, such as the peak- picking (PP) method, the stochastic subspace identification (SSI) method, and numerical results, in the case of unknown input forces. Results show that the proposed technique has unique merits in accuracy and robustness due to its combining multiple tests under changing loading conditions, which also reveal the promising application of the distributed strain sensing system in identifying MMS of operational structures, as well as in the structural health monitoring (SHM) field.
基金This work was supported by the National Natural Science Foundation of China (No.20328304 and 20533060).
文摘A global three dimensional potential energy surface for the F+H2→HF+H reaction has been developed by spline interpolation of about 15,000 symmetry-unique ab initio points, obtained from the multi-reference configuration interaction level with Davidson correction using the aug-cc-pV5Z basis set. In the entrance channel the spin-orbit coupling energy is also included.
文摘Intertidal macroalgae experience continual alternation of photosynthesis between aquatic state at high tide and aerial state at low tide. The comparative photosynthetic responses to inorganic carbon were investigated in the common intertidal macroalga Ulva lactuca L. along the coast of Shantou between aquatic and aerial state. The inorganic carbon dissolved in seawater at present could fully (at 10 ℃ or 20 ℃) or nearly (at 30 ℃) saturate the aquatic photosynthesis of U. lactuca . However, the aerial photosynthesis was limited by current ambient atmospheric CO 2 level, and such a limitation was more severe at higher temperature (20-30 ℃) than at lower temperature (10 ℃). The carbon_saturated maximal photosynthesis of U. lactuca under aerial state was much greater than that under aquatic state at 10 ℃ and 20 ℃, while the maximal photosynthesis under both states was similar at 30 ℃. The aerial values of K m (CO 2) for photosynthesis were higher than the aquatic values. On the contrary, the values of apparent photosynthetic CO 2 conductance under aerial state were considerably lower than that under aquatic state. It was concluded that the increase of atmospheric CO 2 would enhance the primary productivity of U. lactuca through stimulating the photosynthesis under aerial state during low tide.