In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use th...In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use the idea of changing variables to transform the model into a uniform dispersal one.Then the existence and uniqueness of positive stationary solution to the model can be verified by the squeezing argument,where the solution plays a crucial role in later analyses.Moreover,the asymptotic behavior of solutions to the model is obtained by the upper-lower solutions method.The result indicates that the solutions of the model converge to the corresponding positive stationary solution locally uniformly in one dimension as time goes to infinity.展开更多
Dongguashan deposit is a large porphyry-skarn copper(gold) deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magm...Dongguashan deposit is a large porphyry-skarn copper(gold) deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magma origin, rock-forming dynamic background and rock-forming process were studied, and the rock-forming mechanism of Qingshanjiao intrusion was discussed, based on geological characteristics, detailed observation of petrography and systematic investigation of petrochemistry, trace elements and REE geochemistry characteristics of Qingshanjiao intrusion. The results show that Qingshanjiao rock body belongs to high-K calc-alkaline series with higher LREE elements, Th, Rb and Sr abundance, but depleted in HREE elements, Ba, Nb and Ta. The primary magma originated from the mantle-crust mixtures which were caused by basaltic magma of mantle mixing with syenite magma of partial melting of the lower crust, and the formation environment of Qingshanjiao intrusion was emplaced in the transitional environment from compression to extension. The Harker diagram and hybrid structures of plagioclase and potassium feldspar indicate that the fractional crystallization occurred in the process of magmatic evolution. The petrochemistry, trace elements and REE geochemistry characteristics indicate that the magma was contaminated by crustal material during the rock-forming. These results suggested that the Qingshanjiao intrusion was formed by fractional crystallization and assimilation and hybridization of mantle-crust magma in the transitional environment from compression to extensional.展开更多
Root-knot nematodes (Meloidogvne spp.) constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the...Root-knot nematodes (Meloidogvne spp.) constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the use of synthetic nematicides, most of which have been banned due to their toxicity to humans and the environment. Farmer-participatory trials were established, for two consecutive growing seasons on farmers' fields infested with root-knot nematodes (A4eloidogvne javanica and Meloidogyne incognita), at two sites in central Kenya (Maragua and Kirinyaga districts), representing two contrasting group of farmers (low-input and high-input). The trials aimed at evaluating the potential of using biological control agents (BCAs), i.e. Poehonia ehlamydosporia and Pasteuria penetrans, antagonistic plants (Crotalaria grahamiana and Tagetes minuta), "'trash burning" and chemical control (dazomet 98% = Basamid~ Granular) in the management of root-knot nematodes in tomato nursery beds, and quantify the associated net benefits, compared to an untreated control. Crotalaria grahamiana, "trash burning" and dazomet, significantly (P 〈 0.05) reduced the number of second-stage juveniles (J2s) of the root-knot nematodes in the soil in nursery beds during the first season at Karigui-ini, but there was no significant (P 〉 0.05) increase in yield after transplanting tomato seedlings from the respective treatment. Similarly, one of the BCAs (P. ehlamydosporia), was effectively transferred to the field with seedlings from the BCA-treated nursery beds, but there was no significant (P 〉 0.05) increase in yield due to slow proliferation of the BCA, after transplanting. Participatory partial budgets were successfully developed with srnallholder farmers, and proved to be a vital tool in making informed decisions on management options for root-knot nematodes. In general, labour was considered by all farmers as the major input that contributed to the overall additional cost of the different treatments at both sites. This necessitates improvement in efficiency of labour resource use.展开更多
The possible place to search for exotic states in J/ψ hadronic decays is in J/ψ →ρρπ. Because of the symmetry of identical particle and the symmetry of isospin, the physical analysis on this channel is quite com...The possible place to search for exotic states in J/ψ hadronic decays is in J/ψ →ρρπ. Because of the symmetry of identical particle and the symmetry of isospin, the physical analysis on this channel is quite complicated. In this paper, the method to use the partial wave analysis based on covariant helicity amplitude analysis to study the invariant mass spectrum of ρρπ and to find the evidence of exotic states in ρρπ spectrum is discussed. The decay amplitude for the decay sequence J/ψ→ρX, X →ρπ is given first. Then we discuss how to realize the identical particle symmetry and the isospin symmetry in the decay amplitude, which is the key point in the analysis of this channel. Then the total decay amplitude of this channel including all decay components is given. After that, how to identify the exotic states in the ρρπ spectrum is discussed. What is discussed in this paper is the theoretical basis on experimentally searching for exotic states at BEPC/BES.展开更多
For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and...For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and constant boundary temperature,combustion in the furnace was investigated numerically using computational fluid dynamics(CFD).The predicted gas temperature shows good agreement with the measured results,and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment,which confirms the reliability of the numerical solution.The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K,the energy utilization of the furnace could increase from 34.55% to 37.14%.However,as the excess air coefficient increases from 1.0 to 1.4,energy utilization drops from 34.55% to 29.56%.Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace.High reactant temperature and medium excess air coefficient are recommended for high operation performance,and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized.展开更多
Liquid sloshing is a type of free surface flow inside a partially filled water tank.Sloshing exerts a significant effect on the safety of liquid transport systems;in particular,it may cause large hydrodynamic loads wh...Liquid sloshing is a type of free surface flow inside a partially filled water tank.Sloshing exerts a significant effect on the safety of liquid transport systems;in particular,it may cause large hydrodynamic loads when the frequency of the tank motion is close to the natural frequency of the tank.Perforated plates have recently been used to suppress the violent movement of liquids in a sloshing tank at resonant conditions.In this study,a numerical model based on OpenF OAM(Open Source Field Operation and Manipulation),an open source computed fluid dynamic code,is used to investigate resonant sloshing in a swaying tank with a submerged horizontal perforated plate.The numerical results of the free surface elevations are first verified using experimental data,and then the flow characteristics around the perforated plate and the fluid velocity distribution in the entire tank are examined using numerical examples.The results clearly show differences in sloshing motions under first-order and third-order resonant frequencies.This study provides a better understanding of the energy dissipation mechanism of a horizontal perforated plate in a swaying tank.展开更多
The gene iscS-3 from ,4cidithiobacillus ferrooxidans may play a central role in the delivery of sulfur to a variety of metabolic pathways in this organism. For insight into the sulfur metabolic mechanism of the bacter...The gene iscS-3 from ,4cidithiobacillus ferrooxidans may play a central role in the delivery of sulfur to a variety of metabolic pathways in this organism. For insight into the sulfur metabolic mechanism of the bacteria, an integral three-dimensional (3D) molecular structure of the protein encoded by this gene was built by homology modeling techniques, refined by molecular dynamics simulations, assessed by PROFILE-3D and PROSTAT programs and further used to search bind sites, carry out flexible docking with cofactor pyridoxal 5'-phosphate(PLP) and substrate cysteine and hereby detect its key residues. Through these procedures, the detail conformations of PLP-IscS(P-I) and cysteine-PLP-IscS(C-P-I) complexes were obtained. In P-I complex, the residues of Lys208, His106, Thr78, Ser205, His207, Asp182 and Gln185 have large interaction energies and/or hydrogen bonds fixation with PLP. In C-P-I complex, the amino group in cysteine is very near His106, Lys208 and PLP, the interaction energies for cysteine with them are very high. The above results are well consistent with those experimental facts of the homologues from other sources. Interestingly, the four residues of Glul05, Glu79, Ser203 and Hisl80 in P-I docking and the residue of Lys213 in C-P-I docking also have great interaction energies, which are fitly conservation in IscSs from all kinds of sources but have not been identified before. From these results, this gene can be confirmed at 3D level to encode the iron-sulfur cluster assembly protein IscS and subsequently play a sulfur traffic role. Furthermore, the substrate cysteine can be presumed to be effectively recruited into the active site. Finally, the above detected key residues can be conjectured to be directly responsible for the bind and/or catalysis of PLP and cysteine.展开更多
The production of runoff in the source area of a debris flow is the consequence of a reduction in soil strength. Gravel soil is widely distributed in the source region, and the influence of its clay content on soil st...The production of runoff in the source area of a debris flow is the consequence of a reduction in soil strength. Gravel soil is widely distributed in the source region, and the influence of its clay content on soil strength is one of the important questions regarding the formation mechanism of debris flows. In this paper, the clay content in gravel soil is divided into groups of low clay content(1%, 2, 5%), moderate clay content(3.75%, 5.00%, 6.25%, 7.5%) and high clay content(10.0%, 12.5%, 15%). Tests of the unconsolidated undrained shear strength and consolidated drained shear strength were performed. The unconsolidated undrained shearing(UU) experiment simulates the rapid shear failure of loose gravel soil under the conditions of brief heavy rainfall. The consolidated drained shearing(CD) experiment simulates creep failure of consolidated sediment during extended rainfall. The pore water pressure first increased and then decreased as the clay content increased, and the increase in pore pressure was relatively high in the gravel soil sample when the clay content is in the range of 3.25-7.50%, and stress in the gravel soil is relatively low for a moderate clay content. Gravelly soils with a moderate clay content are moreprone to debris-flow initiation. This paper presents a mathematical formula for the maximum shear stress and clay content of gravel soil under two conditions. The key processes whereby the soil fails and triggers a debris flow—volume contraction of soil, expansion of clay soil, and rise of pore pressure―cause reductions in the soil friction force and enhancement of the water content in the clay particles, and subsurface erosion of soil reduces the soil viscosity, which eventually reduces the soil strength so that the soil loses its stability, liquefies and generates a debris flow.展开更多
In recent years, computer simulation appears to be very advantageous technique for researching the resource-constrained manufacturing system. This paper presents an object-oriented simulation modeling method, which co...In recent years, computer simulation appears to be very advantageous technique for researching the resource-constrained manufacturing system. This paper presents an object-oriented simulation modeling method, which combines the merits of traditional methods such as IDEF0 and Petri Net. In this paper, a four-layer-one-angel hierarchical modeling framework based on OOP is defined. And the modeling description of these layers is expounded, such as: hybrid production control modeling and human resource dispatch modeling. To validate the modeling method, a case study of an auto-product line in a motor manufacturing company has been carried out.展开更多
It is the purpose of the present paper to convert hydraulic energy to electric energy and saves both the pressure and electrical energy for re - use during the next system upstroke using two secondary units coupled to...It is the purpose of the present paper to convert hydraulic energy to electric energy and saves both the pressure and electrical energy for re - use during the next system upstroke using two secondary units coupled to induction motor to drive cylinder loads. During upstroke operation, the variable pump/motor (P/M) driven by both electric motor and the second (P/M) works as hydraulic pump and output flow to the cylinders which drive the load. During load deceleration, the cylinders work as pump while the operation of the two secondary units are reversed, the variable (P/M) works as a motor generating a torque with the electric motor to drive the other (P/M) which transforms mechanical energy to hydraulic energy that is saved in the accumulator. When the energy storage capacity of the accumulator is attained as the operation continues, energy storage to the accumulator is thermostatically stopped while the induction motor begins to work as a generator and generates electricity that is stored in the power distribution unit. Simulations were performed using a limited PT2 Block, i.e. 2nd-order transfer function with limitation of slope and signal output to determine suitable velocity of the cylinder which will match high performance and system stability. A mathematical model suited to the simulation of the hydraulic accumulator both in an open-or close-loop system is presented. The quest for improvement of lower energy capacity storage, saving and re-utilization of the conventional accumulator resulting in the short cycle time usage of hydraulic accumulators both in domestic and industrial purposes necessitates this research. The outcome of the research appears to be very efficient for generating fluctuation free electricity, power quality and reliability, energy saving/reutilization and system noise reduction.展开更多
One of the most striking phenomena in recent years has been the increasing proportion of women in the labour force, enabling women in many fields to use their potential and to achieve economic independence. So the gen...One of the most striking phenomena in recent years has been the increasing proportion of women in the labour force, enabling women in many fields to use their potential and to achieve economic independence. So the gender structure analysis becomes more and more important to society and economic development. Accounting research lacks the study of gender issues. This paper intends to summarize the gender structure of accounting profession in China, and aims to explore the critical factors such as economic system of government, traditional characteristics of women, glass ceiling and psychological factors which take a great influence on the gender structure of accounting profession. A conclusion can be made that the proportion of women participation in accounting profession is higher than men, but the majority of senior accounting professionals in China are still men.展开更多
Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sourcesin a cavity is investigated.The results show the phenomenon that the concurrence disappears abruptly in a finite time...Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sourcesin a cavity is investigated.The results show the phenomenon that the concurrence disappears abruptly in a finite time,which depends on the initial atomic states and the properties of squeezed states.We find that there are two decoherencefreestates in squeezed vacuum fields:one is the singlet state,and the other entangled state is the state that combinesboth excited states and ground states with a relative phase being equal to the phase of the squeezed state.展开更多
China Electricity Council organized competent authorities across the industry of electric power to work out the "Research Reports on the 12th Five-Year Plan for Electric Power Industry" in nearly one year,which prov...China Electricity Council organized competent authorities across the industry of electric power to work out the "Research Reports on the 12th Five-Year Plan for Electric Power Industry" in nearly one year,which provides a reference for governmental departments to formulate the 12th Five-Year Plan on energy and electric power industry.The magazine will publish the serial reports including power sources,power grids,equipment manufacture,energy and environment,and power economics.This paper presents the part of "power sources," in which the strategies of developing various kinds of power sources are put forward.展开更多
Although the upwind configuration is more popular in the field of wind energy, the downwind one is a promising type for the offshore wind energy due to its special advantages. Different configurations have different a...Although the upwind configuration is more popular in the field of wind energy, the downwind one is a promising type for the offshore wind energy due to its special advantages. Different configurations have different aerodynamic performance and it is important to predict the performance of both downwind and upwind configurations accurately for designing and developing more reliable wind turbines. In this paper, a numerical investigation on the aerodynamic performance of National Renewable Energy Laboratory (NREL) phase V1 wind turbine in downwind and upwind configurations is presented. The open source toolbox OpenFOAM coupled with arbitrary mesh interface (AMI) method is applied to tackle rotating problems of wind turbines. Two 3D numerical models of NREL phase VI wind turbine with downwind and upwind configurations under four typical working conditions of incoming wind velocities are set up for the study of different unsteady characteristics of the downwind and upwind configurations, respectively. Numerical results of wake vortex structure, time histories of thrust, pressure distribution on the blade and limiting streamlines which can be used to identify points of separation in a 3D flow are presented. It can be concluded that thrust reduction due to blade-tower interaction is small for upwind wind turbines but relatively large for downwind wind turbines and attention should be paid to the vibration at a certain frequency induced by the cyclic reduction for both configurations. The results and conclusions are helpful to analyze the different aerodynamic performance of wind turbines between downwind and upwind configurations, providing useful references for practical design of wind turbine.展开更多
Using Monte Carlo method with zero-temperature dynamics, we investigate energy evolution of Ising spin configuration on a square lattice. The energies of some configurations exhibit long duration before those configur...Using Monte Carlo method with zero-temperature dynamics, we investigate energy evolution of Ising spin configuration on a square lattice. The energies of some configurations exhibit long duration before those configurations reach the final state -- ground state or frozen stripe state. For ground-state dynamical realization, the duration occurs when the energy per spin is 4/L, where L is the lattice size. For stripe-state dynamical realization, the energy is slightly higher than 2/L when the duration appears in the last evolution stage. In addition, it is found that the average energy per spin in final state is approximately 2/3L.展开更多
This paper aims to investigate the effects of labor allocation distortions and various levels of distortion-free labor allocation on social output in China's primary,secondary and tertiary industries.Theoretical m...This paper aims to investigate the effects of labor allocation distortions and various levels of distortion-free labor allocation on social output in China's primary,secondary and tertiary industries.Theoretical model creation and empirical study have led us to the following findings:the quantity of workforce in China's primary industry exceeds the quantity of workforce under the scenario of distortion-free labor allocation and the same is generally true for China's tertiary industry.However,the quantity of labor allocation in secondary industry is significantly below the level of distortion-free allocation but the share of allocation distortion overall tends to decline.Labor allocation distortions for various sectors are mainly caused by intra-sectoral allocation distortions and sectoral wage differences,of which the effect of internal distortion factor is the most obvious.In terms of total output,the eliminations of total distortion,wage difference distortion and internal allocation distortion will all cause total social output to exceed original output,and labor reallocation accompanying capital change will not only bring about a further increase of output but may offset the defects of limited potentials of labor resources reallocation.Growth rates with the eliminations of wage difference distortion,internal allocation distortion and superimposed factor can basically explain for the growth rates with the elimination of all distortions.Given this background,it is necessary to take effective measures at an early date to reduce China s labor allocation distortions and improve overall economic efficiency.展开更多
This paper presents the results of our experiments to assess average labor quality and labor force utilization in different regions of China using slack-based inefficiency measurement (SBI). We found that there is a...This paper presents the results of our experiments to assess average labor quality and labor force utilization in different regions of China using slack-based inefficiency measurement (SBI). We found that there is a discrepancy between different regions' labor resources and their stages' of economic development. In central and western regions, the average quality of labor is significantly higher than in eastern regions, but labor force utilization is less efficient. Slow in economic growth and laggard in industrial upgrading, central and western regions have failed to provide their high-quality labor forces with adequate and suitable job opportunities, leading to the discrepancy between labor resource quality and economic development. Resolving this discrepancy might help coordinate economic development across different regions in China.展开更多
Ye Shu-xian's proposal of "Road of Jade" brings forward a new way to study the origin of civilization. Jade replaced bronze as one of the major criterions of the birth of civilizations. Ye explains jade as a mystic...Ye Shu-xian's proposal of "Road of Jade" brings forward a new way to study the origin of civilization. Jade replaced bronze as one of the major criterions of the birth of civilizations. Ye explains jade as a mystical witchcraft which has a sacred power for the ancient people. Because the jade is produced in the water, and has the similar color with the sky, both of which have significance for the origin of life, jade is thus considered to be the origin of power. The notion of jade-god gave birth to the civilization in ancient China and triggered competition among the settlements, which in turn, advanced the development of civilization.展开更多
The main objective of the present paper is to determine the potential impact the qualitative and quantitative tendencies in the labor market on the decisions which influence the design of monetary policy worldwide. Th...The main objective of the present paper is to determine the potential impact the qualitative and quantitative tendencies in the labor market on the decisions which influence the design of monetary policy worldwide. The analysis is focused on how human resources and phenomena associated with them could influence potential growth and, further on, how they can impact monetary policy decisions at national level for European countries outside the euro area and at ECB level for the euro zone countries. Moreover, the paper will envisage potential macroeconomic reactions (monetary decisions herewith included) to human resources dynamics. The economic variations are regarded through the perspective of growth potential shown by the Research & Development sector and also through the effects of labor force migration. The analysis of statistical data aims at pointing out the different economic perspectives in the European Union, the United States, and Japan, also considering the disparities between EU member states. The analysis is completed by the use of the ranking method, the conclusions stating once more the crucial importance of the human factor in drawing monetary policy decisions展开更多
基金supported by the National Natural Science Foundation of China (Nos.12301101,12101121)the Guangdong Basic and Applied Basic Research Foundation (Nos.2022A1515110019,2020A1515110585)。
文摘In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use the idea of changing variables to transform the model into a uniform dispersal one.Then the existence and uniqueness of positive stationary solution to the model can be verified by the squeezing argument,where the solution plays a crucial role in later analyses.Moreover,the asymptotic behavior of solutions to the model is obtained by the upper-lower solutions method.The result indicates that the solutions of the model converge to the corresponding positive stationary solution locally uniformly in one dimension as time goes to infinity.
基金Project(20091100704)supported by the Special Funds for Scientific Research of Land and Natural Resources,ChinaProject(2015CX008)supported by the Innovation Driven Plan of Central South University,China
文摘Dongguashan deposit is a large porphyry-skarn copper(gold) deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magma origin, rock-forming dynamic background and rock-forming process were studied, and the rock-forming mechanism of Qingshanjiao intrusion was discussed, based on geological characteristics, detailed observation of petrography and systematic investigation of petrochemistry, trace elements and REE geochemistry characteristics of Qingshanjiao intrusion. The results show that Qingshanjiao rock body belongs to high-K calc-alkaline series with higher LREE elements, Th, Rb and Sr abundance, but depleted in HREE elements, Ba, Nb and Ta. The primary magma originated from the mantle-crust mixtures which were caused by basaltic magma of mantle mixing with syenite magma of partial melting of the lower crust, and the formation environment of Qingshanjiao intrusion was emplaced in the transitional environment from compression to extension. The Harker diagram and hybrid structures of plagioclase and potassium feldspar indicate that the fractional crystallization occurred in the process of magmatic evolution. The petrochemistry, trace elements and REE geochemistry characteristics indicate that the magma was contaminated by crustal material during the rock-forming. These results suggested that the Qingshanjiao intrusion was formed by fractional crystallization and assimilation and hybridization of mantle-crust magma in the transitional environment from compression to extensional.
文摘Root-knot nematodes (Meloidogvne spp.) constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the use of synthetic nematicides, most of which have been banned due to their toxicity to humans and the environment. Farmer-participatory trials were established, for two consecutive growing seasons on farmers' fields infested with root-knot nematodes (A4eloidogvne javanica and Meloidogyne incognita), at two sites in central Kenya (Maragua and Kirinyaga districts), representing two contrasting group of farmers (low-input and high-input). The trials aimed at evaluating the potential of using biological control agents (BCAs), i.e. Poehonia ehlamydosporia and Pasteuria penetrans, antagonistic plants (Crotalaria grahamiana and Tagetes minuta), "'trash burning" and chemical control (dazomet 98% = Basamid~ Granular) in the management of root-knot nematodes in tomato nursery beds, and quantify the associated net benefits, compared to an untreated control. Crotalaria grahamiana, "trash burning" and dazomet, significantly (P 〈 0.05) reduced the number of second-stage juveniles (J2s) of the root-knot nematodes in the soil in nursery beds during the first season at Karigui-ini, but there was no significant (P 〉 0.05) increase in yield after transplanting tomato seedlings from the respective treatment. Similarly, one of the BCAs (P. ehlamydosporia), was effectively transferred to the field with seedlings from the BCA-treated nursery beds, but there was no significant (P 〉 0.05) increase in yield due to slow proliferation of the BCA, after transplanting. Participatory partial budgets were successfully developed with srnallholder farmers, and proved to be a vital tool in making informed decisions on management options for root-knot nematodes. In general, labour was considered by all farmers as the major input that contributed to the overall additional cost of the different treatments at both sites. This necessitates improvement in efficiency of labour resource use.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos, 10575002, 10421503, 10491306, and 10491300.Acknowledgments The authors acknowledge helpful discussions with H.Q Zheng and X.Y. Shen.
文摘The possible place to search for exotic states in J/ψ hadronic decays is in J/ψ →ρρπ. Because of the symmetry of identical particle and the symmetry of isospin, the physical analysis on this channel is quite complicated. In this paper, the method to use the partial wave analysis based on covariant helicity amplitude analysis to study the invariant mass spectrum of ρρπ and to find the evidence of exotic states in ρρπ spectrum is discussed. The decay amplitude for the decay sequence J/ψ→ρX, X →ρπ is given first. Then we discuss how to realize the identical particle symmetry and the isospin symmetry in the decay amplitude, which is the key point in the analysis of this channel. Then the total decay amplitude of this channel including all decay components is given. After that, how to identify the exotic states in the ρρπ spectrum is discussed. What is discussed in this paper is the theoretical basis on experimentally searching for exotic states at BEPC/BES.
基金Project(2009GK2009) supported by the Science and Technology Program of Hunan Province,China
文摘For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and constant boundary temperature,combustion in the furnace was investigated numerically using computational fluid dynamics(CFD).The predicted gas temperature shows good agreement with the measured results,and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment,which confirms the reliability of the numerical solution.The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K,the energy utilization of the furnace could increase from 34.55% to 37.14%.However,as the excess air coefficient increases from 1.0 to 1.4,energy utilization drops from 34.55% to 29.56%.Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace.High reactant temperature and medium excess air coefficient are recommended for high operation performance,and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized.
基金supported by the National Natural Science Foundation of China(Nos.51490675,51322903,and 51279224)
文摘Liquid sloshing is a type of free surface flow inside a partially filled water tank.Sloshing exerts a significant effect on the safety of liquid transport systems;in particular,it may cause large hydrodynamic loads when the frequency of the tank motion is close to the natural frequency of the tank.Perforated plates have recently been used to suppress the violent movement of liquids in a sloshing tank at resonant conditions.In this study,a numerical model based on OpenF OAM(Open Source Field Operation and Manipulation),an open source computed fluid dynamic code,is used to investigate resonant sloshing in a swaying tank with a submerged horizontal perforated plate.The numerical results of the free surface elevations are first verified using experimental data,and then the flow characteristics around the perforated plate and the fluid velocity distribution in the entire tank are examined using numerical examples.The results clearly show differences in sloshing motions under first-order and third-order resonant frequencies.This study provides a better understanding of the energy dissipation mechanism of a horizontal perforated plate in a swaying tank.
基金Project(2004CB619201) supported by the National Basic Research Program of China Project(50321402) supported by the National Natural Science Foundation of China
文摘The gene iscS-3 from ,4cidithiobacillus ferrooxidans may play a central role in the delivery of sulfur to a variety of metabolic pathways in this organism. For insight into the sulfur metabolic mechanism of the bacteria, an integral three-dimensional (3D) molecular structure of the protein encoded by this gene was built by homology modeling techniques, refined by molecular dynamics simulations, assessed by PROFILE-3D and PROSTAT programs and further used to search bind sites, carry out flexible docking with cofactor pyridoxal 5'-phosphate(PLP) and substrate cysteine and hereby detect its key residues. Through these procedures, the detail conformations of PLP-IscS(P-I) and cysteine-PLP-IscS(C-P-I) complexes were obtained. In P-I complex, the residues of Lys208, His106, Thr78, Ser205, His207, Asp182 and Gln185 have large interaction energies and/or hydrogen bonds fixation with PLP. In C-P-I complex, the amino group in cysteine is very near His106, Lys208 and PLP, the interaction energies for cysteine with them are very high. The above results are well consistent with those experimental facts of the homologues from other sources. Interestingly, the four residues of Glul05, Glu79, Ser203 and Hisl80 in P-I docking and the residue of Lys213 in C-P-I docking also have great interaction energies, which are fitly conservation in IscSs from all kinds of sources but have not been identified before. From these results, this gene can be confirmed at 3D level to encode the iron-sulfur cluster assembly protein IscS and subsequently play a sulfur traffic role. Furthermore, the substrate cysteine can be presumed to be effectively recruited into the active site. Finally, the above detected key residues can be conjectured to be directly responsible for the bind and/or catalysis of PLP and cysteine.
基金supported by the National Natural Science Foundation of China(Grant Nos.41501012 and 41502337)the China Geological Survey(Grant No.121201010000150003)
文摘The production of runoff in the source area of a debris flow is the consequence of a reduction in soil strength. Gravel soil is widely distributed in the source region, and the influence of its clay content on soil strength is one of the important questions regarding the formation mechanism of debris flows. In this paper, the clay content in gravel soil is divided into groups of low clay content(1%, 2, 5%), moderate clay content(3.75%, 5.00%, 6.25%, 7.5%) and high clay content(10.0%, 12.5%, 15%). Tests of the unconsolidated undrained shear strength and consolidated drained shear strength were performed. The unconsolidated undrained shearing(UU) experiment simulates the rapid shear failure of loose gravel soil under the conditions of brief heavy rainfall. The consolidated drained shearing(CD) experiment simulates creep failure of consolidated sediment during extended rainfall. The pore water pressure first increased and then decreased as the clay content increased, and the increase in pore pressure was relatively high in the gravel soil sample when the clay content is in the range of 3.25-7.50%, and stress in the gravel soil is relatively low for a moderate clay content. Gravelly soils with a moderate clay content are moreprone to debris-flow initiation. This paper presents a mathematical formula for the maximum shear stress and clay content of gravel soil under two conditions. The key processes whereby the soil fails and triggers a debris flow—volume contraction of soil, expansion of clay soil, and rise of pore pressure―cause reductions in the soil friction force and enhancement of the water content in the clay particles, and subsurface erosion of soil reduces the soil viscosity, which eventually reduces the soil strength so that the soil loses its stability, liquefies and generates a debris flow.
基金Nationd Natural Science Foundation of Chiina(No.59889505)
文摘In recent years, computer simulation appears to be very advantageous technique for researching the resource-constrained manufacturing system. This paper presents an object-oriented simulation modeling method, which combines the merits of traditional methods such as IDEF0 and Petri Net. In this paper, a four-layer-one-angel hierarchical modeling framework based on OOP is defined. And the modeling description of these layers is expounded, such as: hybrid production control modeling and human resource dispatch modeling. To validate the modeling method, a case study of an auto-product line in a motor manufacturing company has been carried out.
文摘It is the purpose of the present paper to convert hydraulic energy to electric energy and saves both the pressure and electrical energy for re - use during the next system upstroke using two secondary units coupled to induction motor to drive cylinder loads. During upstroke operation, the variable pump/motor (P/M) driven by both electric motor and the second (P/M) works as hydraulic pump and output flow to the cylinders which drive the load. During load deceleration, the cylinders work as pump while the operation of the two secondary units are reversed, the variable (P/M) works as a motor generating a torque with the electric motor to drive the other (P/M) which transforms mechanical energy to hydraulic energy that is saved in the accumulator. When the energy storage capacity of the accumulator is attained as the operation continues, energy storage to the accumulator is thermostatically stopped while the induction motor begins to work as a generator and generates electricity that is stored in the power distribution unit. Simulations were performed using a limited PT2 Block, i.e. 2nd-order transfer function with limitation of slope and signal output to determine suitable velocity of the cylinder which will match high performance and system stability. A mathematical model suited to the simulation of the hydraulic accumulator both in an open-or close-loop system is presented. The quest for improvement of lower energy capacity storage, saving and re-utilization of the conventional accumulator resulting in the short cycle time usage of hydraulic accumulators both in domestic and industrial purposes necessitates this research. The outcome of the research appears to be very efficient for generating fluctuation free electricity, power quality and reliability, energy saving/reutilization and system noise reduction.
文摘One of the most striking phenomena in recent years has been the increasing proportion of women in the labour force, enabling women in many fields to use their potential and to achieve economic independence. So the gender structure analysis becomes more and more important to society and economic development. Accounting research lacks the study of gender issues. This paper intends to summarize the gender structure of accounting profession in China, and aims to explore the critical factors such as economic system of government, traditional characteristics of women, glass ceiling and psychological factors which take a great influence on the gender structure of accounting profession. A conclusion can be made that the proportion of women participation in accounting profession is higher than men, but the majority of senior accounting professionals in China are still men.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10974125, 60978017, and 60821004in part by the Educational Committee of Fujian Province (JA09041)Fujian Normal University (2008100220)
文摘Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sourcesin a cavity is investigated.The results show the phenomenon that the concurrence disappears abruptly in a finite time,which depends on the initial atomic states and the properties of squeezed states.We find that there are two decoherencefreestates in squeezed vacuum fields:one is the singlet state,and the other entangled state is the state that combinesboth excited states and ground states with a relative phase being equal to the phase of the squeezed state.
文摘China Electricity Council organized competent authorities across the industry of electric power to work out the "Research Reports on the 12th Five-Year Plan for Electric Power Industry" in nearly one year,which provides a reference for governmental departments to formulate the 12th Five-Year Plan on energy and electric power industry.The magazine will publish the serial reports including power sources,power grids,equipment manufacture,energy and environment,and power economics.This paper presents the part of "power sources," in which the strategies of developing various kinds of power sources are put forward.
基金Foundation item: Supported by the National Natural Science Foundation of China (Grant Nos. 51379125, 51411130131, 11432009), the National Key Basic Research Development Plan (973 Plan) Project of China (Grant No. 2013CB036103), High Technology of Marine Research Project of the Ministry of Industry and Information Technology of China, ABS(China), and the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning (Grant No. 2013022).
文摘Although the upwind configuration is more popular in the field of wind energy, the downwind one is a promising type for the offshore wind energy due to its special advantages. Different configurations have different aerodynamic performance and it is important to predict the performance of both downwind and upwind configurations accurately for designing and developing more reliable wind turbines. In this paper, a numerical investigation on the aerodynamic performance of National Renewable Energy Laboratory (NREL) phase V1 wind turbine in downwind and upwind configurations is presented. The open source toolbox OpenFOAM coupled with arbitrary mesh interface (AMI) method is applied to tackle rotating problems of wind turbines. Two 3D numerical models of NREL phase VI wind turbine with downwind and upwind configurations under four typical working conditions of incoming wind velocities are set up for the study of different unsteady characteristics of the downwind and upwind configurations, respectively. Numerical results of wake vortex structure, time histories of thrust, pressure distribution on the blade and limiting streamlines which can be used to identify points of separation in a 3D flow are presented. It can be concluded that thrust reduction due to blade-tower interaction is small for upwind wind turbines but relatively large for downwind wind turbines and attention should be paid to the vibration at a certain frequency induced by the cyclic reduction for both configurations. The results and conclusions are helpful to analyze the different aerodynamic performance of wind turbines between downwind and upwind configurations, providing useful references for practical design of wind turbine.
文摘Using Monte Carlo method with zero-temperature dynamics, we investigate energy evolution of Ising spin configuration on a square lattice. The energies of some configurations exhibit long duration before those configurations reach the final state -- ground state or frozen stripe state. For ground-state dynamical realization, the duration occurs when the energy per spin is 4/L, where L is the lattice size. For stripe-state dynamical realization, the energy is slightly higher than 2/L when the duration appears in the last evolution stage. In addition, it is found that the average energy per spin in final state is approximately 2/3L.
基金funded by National Social Sciences Foundation Program:Empirical Analysis and Countermeasures of Income Distribution Imbalances for Corporate Average Employees Based on Quality and Efficiency(Approval No.13BJY037)
文摘This paper aims to investigate the effects of labor allocation distortions and various levels of distortion-free labor allocation on social output in China's primary,secondary and tertiary industries.Theoretical model creation and empirical study have led us to the following findings:the quantity of workforce in China's primary industry exceeds the quantity of workforce under the scenario of distortion-free labor allocation and the same is generally true for China's tertiary industry.However,the quantity of labor allocation in secondary industry is significantly below the level of distortion-free allocation but the share of allocation distortion overall tends to decline.Labor allocation distortions for various sectors are mainly caused by intra-sectoral allocation distortions and sectoral wage differences,of which the effect of internal distortion factor is the most obvious.In terms of total output,the eliminations of total distortion,wage difference distortion and internal allocation distortion will all cause total social output to exceed original output,and labor reallocation accompanying capital change will not only bring about a further increase of output but may offset the defects of limited potentials of labor resources reallocation.Growth rates with the eliminations of wage difference distortion,internal allocation distortion and superimposed factor can basically explain for the growth rates with the elimination of all distortions.Given this background,it is necessary to take effective measures at an early date to reduce China s labor allocation distortions and improve overall economic efficiency.
文摘This paper presents the results of our experiments to assess average labor quality and labor force utilization in different regions of China using slack-based inefficiency measurement (SBI). We found that there is a discrepancy between different regions' labor resources and their stages' of economic development. In central and western regions, the average quality of labor is significantly higher than in eastern regions, but labor force utilization is less efficient. Slow in economic growth and laggard in industrial upgrading, central and western regions have failed to provide their high-quality labor forces with adequate and suitable job opportunities, leading to the discrepancy between labor resource quality and economic development. Resolving this discrepancy might help coordinate economic development across different regions in China.
基金This paper is supported by General Financial Grant from the China Postdoctoral Science Foundation (Grant No.: 2013M542363).
文摘Ye Shu-xian's proposal of "Road of Jade" brings forward a new way to study the origin of civilization. Jade replaced bronze as one of the major criterions of the birth of civilizations. Ye explains jade as a mystical witchcraft which has a sacred power for the ancient people. Because the jade is produced in the water, and has the similar color with the sky, both of which have significance for the origin of life, jade is thus considered to be the origin of power. The notion of jade-god gave birth to the civilization in ancient China and triggered competition among the settlements, which in turn, advanced the development of civilization.
文摘The main objective of the present paper is to determine the potential impact the qualitative and quantitative tendencies in the labor market on the decisions which influence the design of monetary policy worldwide. The analysis is focused on how human resources and phenomena associated with them could influence potential growth and, further on, how they can impact monetary policy decisions at national level for European countries outside the euro area and at ECB level for the euro zone countries. Moreover, the paper will envisage potential macroeconomic reactions (monetary decisions herewith included) to human resources dynamics. The economic variations are regarded through the perspective of growth potential shown by the Research & Development sector and also through the effects of labor force migration. The analysis of statistical data aims at pointing out the different economic perspectives in the European Union, the United States, and Japan, also considering the disparities between EU member states. The analysis is completed by the use of the ranking method, the conclusions stating once more the crucial importance of the human factor in drawing monetary policy decisions