In order to effectively cope with exponent increase of the complexity faced to the rock mechanics analysis problems and the large incompatibility existing between the information level required to model the rock mass ...In order to effectively cope with exponent increase of the complexity faced to the rock mechanics analysis problems and the large incompatibility existing between the information level required to model the rock mass and engineering and our obtainable information level at hand,the integrated approaches with intelligent characters are proposed. Many previous standard methods,such as precedent type analysis,rock classification,analytic method stress-based,basic numerical methods (BEM,FEM,DEM,hybrid),and their extended numerical methods (fully coupled) to be developed,can be selected respectively or integrated accordingly. It is alternative to develop basic/fully integrated system,and internet-based approaches. These novel methods can also be selected or integrated each other or with the standard methods to perform rock mechanics analysis. Some key techniques to develop these alternative methods are discussed. It may focus in future on developing fully integrated systems and internet-based approaches. Developing an environmental,virtual facility/space shall be firstly done for this collaborative research on internet.展开更多
Three surface integral approaches of the acoustic analogies are studied to predict the noise from three concep- tual configurations of three-dimensional high-lift low-noise wings. The approaches refer to the Kirchhoff...Three surface integral approaches of the acoustic analogies are studied to predict the noise from three concep- tual configurations of three-dimensional high-lift low-noise wings. The approaches refer to the Kirchhoff method, the Ffowcs Williams and Hawkings (FW-H) method of the permeable integral surface and the Curle method that is known as a special case of the FW-H method. The first two approaches are used to compute the noise generated by the core flow region where the energetic structures exist. The last approach is adopted to predict the noise specially from the pressure perturbation on the wall. A new way to con- struct the integral surface that encloses the core region is proposed for the first two methods. Considering the local properties of the flow around the complex object-the actual wing with high-lift devices-the integral surface based on the vorticity is constructed to follow the flow structures. The surface location is discussed for the Kirchhoff method and the FW-H method because a common surface is used for them. The noise from the core flow region is studied on the basis of the dependent integral quantities, which are indicated by the Kirchhoff formulation and by the FW-H formulation. The role of each wall component on noise contribution is analyzed using the Curle formulation. Effects of the volume integral terms of Lighthill's stress tensors on the noise pre-diction are then evaluated by comparing the results of the Curle method with the other two methods.展开更多
The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in...The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in large spatial and temporal scales. The ~234Th/ ~238U disequilibrium is an effective method for the study of new production. Two sampling strategies, vertically integrated sampling ap proach based on trapezoidal integration principle and discrete layer sampling approach, were compared in the studies of the xiamen Bay and the northern South China Sea. The scavenging fluxes and removal fluxes of ~234Th and the residence times for dissolved and particulate ~234Th were calculated. The coinci dent results from two Sampling approach suggest that vertically integrated sampling approach is not only effective and reliable, but also significantly reduces the number and volume of samples. It allows us to study new production by ba ^(234)Th - ^(238)U disequilibria in large spatial scale.展开更多
Intense anthropogenic exploitation has altered distribution of forest resources. This change was analyzed using visual interpretation of satellite data of 1979, 1999 and 2009. Field and interactive social surveys were...Intense anthropogenic exploitation has altered distribution of forest resources. This change was analyzed using visual interpretation of satellite data of 1979, 1999 and 2009. Field and interactive social surveys were conducted to identify spatial trends in forest degradation and data were mapped on forest cover and land use maps. Perceptions of villagers were compiled in a pictorial representation to understand changes in forest resource distribution in central Himalaya from 1970 to 2010. For- ested areas were subject to degradation and isolation due to loss of con- necting forest stands. Species like Lantana camara and Eupatorium adenophorum invaded forest landscapes. Intensity of human pressure differed by forest type and elevation. An integrated approach is needed to monitor forest resource distribution and disturbance.展开更多
Global change research and sustainable development need to be addressed at larger scales in the light of small scale process studies. Much remains to be done before the small scale, process level understanding of ecos...Global change research and sustainable development need to be addressed at larger scales in the light of small scale process studies. Much remains to be done before the small scale, process level understanding of ecosystem responses to global change can be reliably translated to larger scales. The paper reviews the status of scaling issues and tries to find how to extrapolate our observations and our findings at site scale up to regional scale and provide ecological information and interpretations at the regional scale. An integrated approach to scaling-up from site to region is proposed combining hierarchical theory, landscape ecology, remote sensing, geographical information system (GIS) with process/mechanistic modeling. Remote sensing and GIS will play key roles in spatial analysis, integration as well as cross scale modeling.展开更多
This paper investigates the stability of time-delay systems via a multiple integral approach. Based on the refined Jensen-based inequality, a novel multiple integral inequality is proposed. Applying the multiple integ...This paper investigates the stability of time-delay systems via a multiple integral approach. Based on the refined Jensen-based inequality, a novel multiple integral inequality is proposed. Applying the multiple integral inequality to estimate the derivative of Lyapunov-Krasovskii functional(LKF) with multiple integral terms, a novel stability condition is formulated for the linear time-delay systems. Two numerical examples are employed to demonstrate the improvements of our results.展开更多
In this paper, the output tracking control is investigated for a class of nonlinear systems when only output is available for feedback. Based on the multivariable analog of circle criterion, an observer is first intro...In this paper, the output tracking control is investigated for a class of nonlinear systems when only output is available for feedback. Based on the multivariable analog of circle criterion, an observer is first introduced. Then, the observer-based output tracking controller is constructively designed by using the integral backstepping approach together with completing square. It is shown that, under relatively mild conditions, all the closed-loop signals are uniformly bounded. Meanwhile the system output asymptotically tracks the desired output. A simulation example is given to illustrate the effectiveness of the theoretical results.展开更多
Based on the first-order shear deformation theory,a 3-node co-rotational triangular finite element formulation is developed for large deformation modeling of non-smooth,folded and multi-shell laminated composite struc...Based on the first-order shear deformation theory,a 3-node co-rotational triangular finite element formulation is developed for large deformation modeling of non-smooth,folded and multi-shell laminated composite structures.The two smaller components of the mid-surface normal vector of shell at a node are defined as nodal rotational variables in the co-rotational local coordinate system.In the global coordinate system,two smaller components of one vector,together with the smallest or second smallest component of another vector,of an orthogonal triad at a node on a non-smooth intersection of plates and/or shells are defined as rotational variables,whereas the two smaller components of the mid-surface normal vector at a node on the smooth part of the plate or shell(away from non-smooth intersections)are defined as rotational variables.All these vectorial rotational variables can be updated in an additive manner during an incremental solution procedure,and thus improve the computational efficiency in the nonlinear solution of these composite shell structures.Due to the commutativity of all nodal variables in calculating of the second derivatives of the local nodal variables with respect to global nodal variables,and the second derivatives of the strain energy functional with respect to local nodal variables,symmetric tangent stiffness matrices in local and global coordinate systems are obtained.To overcome shear locking,the assumed transverse shear strains obtained from the line-integration approach are employed.The reliability and computational accuracy of the present 3-node triangular shell finite element are verified through modeling two patch tests,several smooth and non-smooth laminated composite shells undergoing large displacements and large rotations.展开更多
Based on the linear theories of thin cylindrical shells and viscoelastic materials, a governing equation describing vibration of a sandwich circular cylindrical shell with a viscoelastic core under harmonic excitation...Based on the linear theories of thin cylindrical shells and viscoelastic materials, a governing equation describing vibration of a sandwich circular cylindrical shell with a viscoelastic core under harmonic excitation is derived. The equation can be written as a matrix differential equation of the first order, and is obtained by considering the energy dissipation due to the shear deformation of the viscoelastic core layer and the interaction between all layers. A new matrix method for solving the governing equation is then presented With an extended homogeneous capacity precision integration approach. Having obtained these, vibration characteristics and damping effect of the sandwich cylindrical shell can be studied. The method differs from a recently published work as the state vector in the governing equation is composed of displacements and internal forces of the sandwich shell rather than displacements and their derivatives. So the present method can be applied to solve dynamic problems of the kind of sandwich shells with various boundary conditions and partially constrained layer damping. Numerical examples show that the proposed approach is effective and reliable compared with the existing methods.展开更多
Chinese medicine (CM) has been an experience based practice over the past three thousand years. The safety and efficacy of CM has been practised through experience, rather than nowadays’ modern scientific measurement...Chinese medicine (CM) has been an experience based practice over the past three thousand years. The safety and efficacy of CM has been practised through experience, rather than nowadays’ modern scientific measurements. In this way, the development of CM has not been keeping pace with the advance in science and technology and the progress in orthodox medicine. In order to meet the requirements of modern science and technology, an evidence based approach must be adopted. Reassurance is needed to convince people for safety and efficacy of CM and give confidence to the evidence based demands ——“Tradition is confirmed by Modern Science” (1) .展开更多
A new temporal gravity field model called WHU-Grace01s solely recovered from Gravity Recovery and Climate Experiment (GRACE) K-Band Range Rate (KBRR) data based on dynamic integral approach is presented in this pa...A new temporal gravity field model called WHU-Grace01s solely recovered from Gravity Recovery and Climate Experiment (GRACE) K-Band Range Rate (KBRR) data based on dynamic integral approach is presented in this paper. After meticulously preprocessing of the GRACE KBRR data, the root mean square of its post residuals is about 0.2 micrometers per second, and seventy-two monthly temporal solutions truncated to degree and order 60 are computed for the period from January 2003 to December 2008. After applying the combi- nation filter in WHU-Grace01s, the global temporal signals show obvious periodical change rules in the large-scale fiver basins. In terms of the degree variance, our solution is smaller at high degrees, and shows a good consistency at the rest of degrees with the Release 05 models from Center for Space Research (CSR), GeoForschungsZentrum Potsdam (GFZ) and Jet Pro- pulsion Laboratory 0PL). Compared with other published models in terms of equivalent water height distribution, our solution is consistent with those published by CSR, GFZ, JPL, Delft institute of Earth Observation and Space system (DEOS), Tongji University (Tongji), Institute of Theoretical Geodesy (ITG), Astronomical Institute in University of Bern (AIUB) and Groupe de Recherche de Geodesie Spatiale (GRGS}, which indicates that the accuracy of WHU-Grace01s has a good consistency with the previously published GRACE solutions.展开更多
As is known to all, the electron scattering in classical electromagnetic potential is one of the most widespread applications of quantum theory. Nevertheless, many discussions about electron scattering are based upon ...As is known to all, the electron scattering in classical electromagnetic potential is one of the most widespread applications of quantum theory. Nevertheless, many discussions about electron scattering are based upon single-particle Schrodinger equation or Dirac equation in quantum mechanics rather than the method of quantum field theory. In this paper, by using the path integral approach of quantum field theory, we perturbatively evaluate the scattering amplitude up to the second order for the electron scattering by the classical electromagnetic potential. The results we derive are convenient to apply to all sorts of potential forms. Furthermore, by means of the obtained results, we give explicit calculations for the one-dimensional electric potential.展开更多
EDITORIAL Severe Acute Respiratory Syndrome(SARS)is a new intractable disease worldwide,itsonset is acute,its infectivity and mortality is high,the knowledge about its etiology and pathogenesis is in-sufficient,the ex...EDITORIAL Severe Acute Respiratory Syndrome(SARS)is a new intractable disease worldwide,itsonset is acute,its infectivity and mortality is high,the knowledge about its etiology and pathogenesis is in-sufficient,the experience on SARS treatment awaits accumulation.Following pilot experiences of applyingICWM in fighting SARS is most valuable with scientific significance.展开更多
Member of Political Bureau of Central Committee of CPC, Vice Premier of State Council concurrently Minister of Health, General Command of National Protecting and Treating Severe Acute Respiratory Syndrome ( SARS) Head...Member of Political Bureau of Central Committee of CPC, Vice Premier of State Council concurrently Minister of Health, General Command of National Protecting and Treating Severe Acute Respiratory Syndrome ( SARS) Headquarters Vice premier WU Yi cordially met the well-known TCM specialists, and held a symposium with them. Sixteen specialists including WANG Yong-yan, CHEN Ke-ji, LI Fu-ren, JIAO Shu-de, HE Pu-ren, LIU展开更多
The enhanced definition of Mechatronics involves the four underlying characteristics of integrated,unified,unique,and systematic approaches.In this realm,Mechatronics is not limited to electro-mechanical systems,in th...The enhanced definition of Mechatronics involves the four underlying characteristics of integrated,unified,unique,and systematic approaches.In this realm,Mechatronics is not limited to electro-mechanical systems,in the multi-physics sense,but involves other physical domains such as fluid and thermal.This paper summarizes the mechatronic approach to modeling.Linear graphs facilitate the development of state-space models of mechatronic systems,through this approach.The use of linear graphs in mechatronic modeling is outlined and an illustrative example of sound system modeling is given.Both time-domain and frequency-domain approaches are presented for the use of linear graphs.A mechatronic model of a multi-physics system may be simplified by converting all the physical domains into an equivalent single-domain system that is entirely in the output domain of the system.This approach of converting(transforming)physical domains is presented.An illustrative example of a pressure-controlled hydraulic actuator system that operates a mechanical load is given.展开更多
The cooperative output regulation problem has been studied by two approaches:the distributed observer(DO)approach and the distributed internal model(DIM)approach,respectively.Each of these two approaches has its own m...The cooperative output regulation problem has been studied by two approaches:the distributed observer(DO)approach and the distributed internal model(DIM)approach,respectively.Each of these two approaches has its own merits and weaknesses.Recently,we presented an overview on the cooperative output regulation problem by the DO approach.This paper further surveys the cooperative output regulation problem by the DIM approach.We first summarize the constructions and the roles of two different versions of the internal models:the distributed p-copy internal model and the distributed canonical internal model.Then,we describe an integrated framework that combines the DO approach and the DIM approach.Extensions and variants of the DIM and their applications will also be highlighted.展开更多
The need for high-performance and cost-effective gas sensors in industrial and domestic settings has led to ad-vancements in gas sensors based on metal-organic frameworks(MOFs).However,challenges remain in the design ...The need for high-performance and cost-effective gas sensors in industrial and domestic settings has led to ad-vancements in gas sensors based on metal-organic frameworks(MOFs).However,challenges remain in the design and synthesis of MOFs with customized structure and affinity toward targeted gases and their integration onto miniaturized electronic devices.The deliberate design of MOFs with desired characteristics is hindered by limited understanding of the interactions between MOFs and analytes.Furthermore,there is a lack of customization of relevant MOF-based sensors with salient sensing performance and their integration into sensor arrays to align with different application scenarios.The combination of machine learning or artificial intelligence(AI)with gas sensors also represents a promising avenue for future research.Herein,we provide a mini-review of recent ac-complishments in MOF-based gas sensors,covering materials design and device integration.The challenges of miniaturization and building smart sensing systems with anomaly detection,self-calibration,and lifetime pre-diction are also discussed.展开更多
As the name reflects, integrative plant biology is the core topic of JIPB. In the past few years JIPB has been pursuing the development of this area, to assist the scientific community to bring together all possible r...As the name reflects, integrative plant biology is the core topic of JIPB. In the past few years JIPB has been pursuing the development of this area, to assist the scientific community to bring together all possible research tools to understand plant growth, development and stress responses in micro- and macro-scales. As part of these efforts, JIPB and Yantai University organized the 1st International Symposium on Integrative Plant Biology in the seaside town of Yantai during August 10-12, 2009 (Figure 1) The symposium was co-sponsored by Botanical Society of China, Chinese Society for Cell Biology, Genetics Society of China, and Chinese Society for Plant Physiology.展开更多
基金Nature Science Foundation of China under Grant no.50179034.
文摘In order to effectively cope with exponent increase of the complexity faced to the rock mechanics analysis problems and the large incompatibility existing between the information level required to model the rock mass and engineering and our obtainable information level at hand,the integrated approaches with intelligent characters are proposed. Many previous standard methods,such as precedent type analysis,rock classification,analytic method stress-based,basic numerical methods (BEM,FEM,DEM,hybrid),and their extended numerical methods (fully coupled) to be developed,can be selected respectively or integrated accordingly. It is alternative to develop basic/fully integrated system,and internet-based approaches. These novel methods can also be selected or integrated each other or with the standard methods to perform rock mechanics analysis. Some key techniques to develop these alternative methods are discussed. It may focus in future on developing fully integrated systems and internet-based approaches. Developing an environmental,virtual facility/space shall be firstly done for this collaborative research on internet.
基金supported by the Clean Sky Joint Undertaking(CSJU)(CS-GA-2009-255714)
文摘Three surface integral approaches of the acoustic analogies are studied to predict the noise from three concep- tual configurations of three-dimensional high-lift low-noise wings. The approaches refer to the Kirchhoff method, the Ffowcs Williams and Hawkings (FW-H) method of the permeable integral surface and the Curle method that is known as a special case of the FW-H method. The first two approaches are used to compute the noise generated by the core flow region where the energetic structures exist. The last approach is adopted to predict the noise specially from the pressure perturbation on the wall. A new way to con- struct the integral surface that encloses the core region is proposed for the first two methods. Considering the local properties of the flow around the complex object-the actual wing with high-lift devices-the integral surface based on the vorticity is constructed to follow the flow structures. The surface location is discussed for the Kirchhoff method and the FW-H method because a common surface is used for them. The noise from the core flow region is studied on the basis of the dependent integral quantities, which are indicated by the Kirchhoff formulation and by the FW-H formulation. The role of each wall component on noise contribution is analyzed using the Curle formulation. Effects of the volume integral terms of Lighthill's stress tensors on the noise pre-diction are then evaluated by comparing the results of the Curle method with the other two methods.
基金National Natural Science Foundation of China! 49676296National Scientific and Technical Project! 97-926-04-02.
文摘The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in large spatial and temporal scales. The ~234Th/ ~238U disequilibrium is an effective method for the study of new production. Two sampling strategies, vertically integrated sampling ap proach based on trapezoidal integration principle and discrete layer sampling approach, were compared in the studies of the xiamen Bay and the northern South China Sea. The scavenging fluxes and removal fluxes of ~234Th and the residence times for dissolved and particulate ~234Th were calculated. The coinci dent results from two Sampling approach suggest that vertically integrated sampling approach is not only effective and reliable, but also significantly reduces the number and volume of samples. It allows us to study new production by ba ^(234)Th - ^(238)U disequilibria in large spatial scale.
文摘Intense anthropogenic exploitation has altered distribution of forest resources. This change was analyzed using visual interpretation of satellite data of 1979, 1999 and 2009. Field and interactive social surveys were conducted to identify spatial trends in forest degradation and data were mapped on forest cover and land use maps. Perceptions of villagers were compiled in a pictorial representation to understand changes in forest resource distribution in central Himalaya from 1970 to 2010. For- ested areas were subject to degradation and isolation due to loss of con- necting forest stands. Species like Lantana camara and Eupatorium adenophorum invaded forest landscapes. Intensity of human pressure differed by forest type and elevation. An integrated approach is needed to monitor forest resource distribution and disturbance.
基金the Important Directional Project of Knowledge Innovation of the Chinese Academy of Sciences (No: KZCX2-308-4).
文摘Global change research and sustainable development need to be addressed at larger scales in the light of small scale process studies. Much remains to be done before the small scale, process level understanding of ecosystem responses to global change can be reliably translated to larger scales. The paper reviews the status of scaling issues and tries to find how to extrapolate our observations and our findings at site scale up to regional scale and provide ecological information and interpretations at the regional scale. An integrated approach to scaling-up from site to region is proposed combining hierarchical theory, landscape ecology, remote sensing, geographical information system (GIS) with process/mechanistic modeling. Remote sensing and GIS will play key roles in spatial analysis, integration as well as cross scale modeling.
基金supported by the National Natural Science Foundation of China(61473070,61433004,61627809)SAPI Fundamental Research Funds(2013ZCX01,2013ZCX14)
文摘This paper investigates the stability of time-delay systems via a multiple integral approach. Based on the refined Jensen-based inequality, a novel multiple integral inequality is proposed. Applying the multiple integral inequality to estimate the derivative of Lyapunov-Krasovskii functional(LKF) with multiple integral terms, a novel stability condition is formulated for the linear time-delay systems. Two numerical examples are employed to demonstrate the improvements of our results.
基金This work was supported by the National Natural Science Foundation of China(No.60304002), and the Science and Technical Development Plan ofShandong Province(No.2004GG4204014).
文摘In this paper, the output tracking control is investigated for a class of nonlinear systems when only output is available for feedback. Based on the multivariable analog of circle criterion, an observer is first introduced. Then, the observer-based output tracking controller is constructively designed by using the integral backstepping approach together with completing square. It is shown that, under relatively mild conditions, all the closed-loop signals are uniformly bounded. Meanwhile the system output asymptotically tracks the desired output. A simulation example is given to illustrate the effectiveness of the theoretical results.
基金This work was supported by National Natural Science Foundation of China under Grant 11672266.
文摘Based on the first-order shear deformation theory,a 3-node co-rotational triangular finite element formulation is developed for large deformation modeling of non-smooth,folded and multi-shell laminated composite structures.The two smaller components of the mid-surface normal vector of shell at a node are defined as nodal rotational variables in the co-rotational local coordinate system.In the global coordinate system,two smaller components of one vector,together with the smallest or second smallest component of another vector,of an orthogonal triad at a node on a non-smooth intersection of plates and/or shells are defined as rotational variables,whereas the two smaller components of the mid-surface normal vector at a node on the smooth part of the plate or shell(away from non-smooth intersections)are defined as rotational variables.All these vectorial rotational variables can be updated in an additive manner during an incremental solution procedure,and thus improve the computational efficiency in the nonlinear solution of these composite shell structures.Due to the commutativity of all nodal variables in calculating of the second derivatives of the local nodal variables with respect to global nodal variables,and the second derivatives of the strain energy functional with respect to local nodal variables,symmetric tangent stiffness matrices in local and global coordinate systems are obtained.To overcome shear locking,the assumed transverse shear strains obtained from the line-integration approach are employed.The reliability and computational accuracy of the present 3-node triangular shell finite element are verified through modeling two patch tests,several smooth and non-smooth laminated composite shells undergoing large displacements and large rotations.
基金supported by the National Natural Science Foundation of China (No. 10662003)the Doctoral Fund of Ministry of Education of China (No. 20040787013)
文摘Based on the linear theories of thin cylindrical shells and viscoelastic materials, a governing equation describing vibration of a sandwich circular cylindrical shell with a viscoelastic core under harmonic excitation is derived. The equation can be written as a matrix differential equation of the first order, and is obtained by considering the energy dissipation due to the shear deformation of the viscoelastic core layer and the interaction between all layers. A new matrix method for solving the governing equation is then presented With an extended homogeneous capacity precision integration approach. Having obtained these, vibration characteristics and damping effect of the sandwich cylindrical shell can be studied. The method differs from a recently published work as the state vector in the governing equation is composed of displacements and internal forces of the sandwich shell rather than displacements and their derivatives. So the present method can be applied to solve dynamic problems of the kind of sandwich shells with various boundary conditions and partially constrained layer damping. Numerical examples show that the proposed approach is effective and reliable compared with the existing methods.
文摘Chinese medicine (CM) has been an experience based practice over the past three thousand years. The safety and efficacy of CM has been practised through experience, rather than nowadays’ modern scientific measurements. In this way, the development of CM has not been keeping pace with the advance in science and technology and the progress in orthodox medicine. In order to meet the requirements of modern science and technology, an evidence based approach must be adopted. Reassurance is needed to convince people for safety and efficacy of CM and give confidence to the evidence based demands ——“Tradition is confirmed by Modern Science” (1) .
基金supported by the National 973Program of China(2013CB733302)the National Natural Science Foundation of China(41131067,41174020,41374023,41474019)+2 种基金the Open Research Fund Program of the State Key Laboratory of Geodesy and Earth's Dynamics(SKLGED2015-1-3-E)the open fund of State Key Laboratory of Geographic Information Engineering(SKLGIE2013-M-1-3)the open fund of Key Laboratory of Geospace Environment and Geodesy,Ministry of Education(13-02-05)
文摘A new temporal gravity field model called WHU-Grace01s solely recovered from Gravity Recovery and Climate Experiment (GRACE) K-Band Range Rate (KBRR) data based on dynamic integral approach is presented in this paper. After meticulously preprocessing of the GRACE KBRR data, the root mean square of its post residuals is about 0.2 micrometers per second, and seventy-two monthly temporal solutions truncated to degree and order 60 are computed for the period from January 2003 to December 2008. After applying the combi- nation filter in WHU-Grace01s, the global temporal signals show obvious periodical change rules in the large-scale fiver basins. In terms of the degree variance, our solution is smaller at high degrees, and shows a good consistency at the rest of degrees with the Release 05 models from Center for Space Research (CSR), GeoForschungsZentrum Potsdam (GFZ) and Jet Pro- pulsion Laboratory 0PL). Compared with other published models in terms of equivalent water height distribution, our solution is consistent with those published by CSR, GFZ, JPL, Delft institute of Earth Observation and Space system (DEOS), Tongji University (Tongji), Institute of Theoretical Geodesy (ITG), Astronomical Institute in University of Bern (AIUB) and Groupe de Recherche de Geodesie Spatiale (GRGS}, which indicates that the accuracy of WHU-Grace01s has a good consistency with the previously published GRACE solutions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374360,11405266,and 11505285)the National Basic Research Program of China(Grant No.2013CBA01504)
文摘As is known to all, the electron scattering in classical electromagnetic potential is one of the most widespread applications of quantum theory. Nevertheless, many discussions about electron scattering are based upon single-particle Schrodinger equation or Dirac equation in quantum mechanics rather than the method of quantum field theory. In this paper, by using the path integral approach of quantum field theory, we perturbatively evaluate the scattering amplitude up to the second order for the electron scattering by the classical electromagnetic potential. The results we derive are convenient to apply to all sorts of potential forms. Furthermore, by means of the obtained results, we give explicit calculations for the one-dimensional electric potential.
文摘EDITORIAL Severe Acute Respiratory Syndrome(SARS)is a new intractable disease worldwide,itsonset is acute,its infectivity and mortality is high,the knowledge about its etiology and pathogenesis is in-sufficient,the experience on SARS treatment awaits accumulation.Following pilot experiences of applyingICWM in fighting SARS is most valuable with scientific significance.
文摘Member of Political Bureau of Central Committee of CPC, Vice Premier of State Council concurrently Minister of Health, General Command of National Protecting and Treating Severe Acute Respiratory Syndrome ( SARS) Headquarters Vice premier WU Yi cordially met the well-known TCM specialists, and held a symposium with them. Sixteen specialists including WANG Yong-yan, CHEN Ke-ji, LI Fu-ren, JIAO Shu-de, HE Pu-ren, LIU
基金supported by research grants from the Natural Sciences and Engineering Research Council(NSERC)of Canada
文摘The enhanced definition of Mechatronics involves the four underlying characteristics of integrated,unified,unique,and systematic approaches.In this realm,Mechatronics is not limited to electro-mechanical systems,in the multi-physics sense,but involves other physical domains such as fluid and thermal.This paper summarizes the mechatronic approach to modeling.Linear graphs facilitate the development of state-space models of mechatronic systems,through this approach.The use of linear graphs in mechatronic modeling is outlined and an illustrative example of sound system modeling is given.Both time-domain and frequency-domain approaches are presented for the use of linear graphs.A mechatronic model of a multi-physics system may be simplified by converting all the physical domains into an equivalent single-domain system that is entirely in the output domain of the system.This approach of converting(transforming)physical domains is presented.An illustrative example of a pressure-controlled hydraulic actuator system that operates a mechanical load is given.
基金supported by the National Natural Science Foundation of China(Nos.62173092,62173149)the Hong Kong Region Research Grants Council(No.14201621).
文摘The cooperative output regulation problem has been studied by two approaches:the distributed observer(DO)approach and the distributed internal model(DIM)approach,respectively.Each of these two approaches has its own merits and weaknesses.Recently,we presented an overview on the cooperative output regulation problem by the DO approach.This paper further surveys the cooperative output regulation problem by the DIM approach.We first summarize the constructions and the roles of two different versions of the internal models:the distributed p-copy internal model and the distributed canonical internal model.Then,we describe an integrated framework that combines the DO approach and the DIM approach.Extensions and variants of the DIM and their applications will also be highlighted.
基金supported by the National Natural Science Foundation of China(22201226)the Natural Science Foundation of Shannxi(2022JQ-469)+2 种基金the Special Fund for Basic Scientific Research of Central College of Chang an University(No.300102313110)support from"High-Level Overseas Talent Returming to China"projectthe support from Xi'an Jiaotong University within the framework of the"Young Talent Support Plan".
文摘The need for high-performance and cost-effective gas sensors in industrial and domestic settings has led to ad-vancements in gas sensors based on metal-organic frameworks(MOFs).However,challenges remain in the design and synthesis of MOFs with customized structure and affinity toward targeted gases and their integration onto miniaturized electronic devices.The deliberate design of MOFs with desired characteristics is hindered by limited understanding of the interactions between MOFs and analytes.Furthermore,there is a lack of customization of relevant MOF-based sensors with salient sensing performance and their integration into sensor arrays to align with different application scenarios.The combination of machine learning or artificial intelligence(AI)with gas sensors also represents a promising avenue for future research.Herein,we provide a mini-review of recent ac-complishments in MOF-based gas sensors,covering materials design and device integration.The challenges of miniaturization and building smart sensing systems with anomaly detection,self-calibration,and lifetime pre-diction are also discussed.
文摘As the name reflects, integrative plant biology is the core topic of JIPB. In the past few years JIPB has been pursuing the development of this area, to assist the scientific community to bring together all possible research tools to understand plant growth, development and stress responses in micro- and macro-scales. As part of these efforts, JIPB and Yantai University organized the 1st International Symposium on Integrative Plant Biology in the seaside town of Yantai during August 10-12, 2009 (Figure 1) The symposium was co-sponsored by Botanical Society of China, Chinese Society for Cell Biology, Genetics Society of China, and Chinese Society for Plant Physiology.