It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their...It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their photosynthetic structures (leaves) and non-photosynthetic structures (branches and stem) is unknown. The purpose of this study is to test the hypotheses that: (1) the above-ground parts of plants have functional equilibriums between their photosynthetic structures and non-photosynthetic structures; (2) the maintenance of the equilibriums is guaranteed by the alteration of biomass partitioning to photosynthetic and non-photosynthetic structures. To test these hypotheses, a pruning experiment with four pruning intensities (0%, 20%, 50%, and 70%) were carried out with three subtropical Chinese tree species ( Ficus microcarpa, Ficus virens, Cinnamomum camphora). Pruning treatments were conducted in two successive years. The results were in conformity with the hypothesis, i.e. above-ground parts of trees had functional equilibriums between photosynthetic and non-photosynthetic structures. Pruning decreased instantaneously the mass ratios of photosynthetic structures to non-photosynthetic structures (P/NP) of all three tree species, the reduction in P/NP was strengthened with pruning intensity. However, one year after pruning, the P/NP of all pruned trees increased and were not smaller than those of unpruned trees. In agreement with the expectation, the biomass partitioning of pruned trees was altered, more newly produced above-ground biomass was partitioned to leaf growth and less to branch and stem growth, thus enabled the damaged trees to restore their functional equilibrium between photosynthetic and non-photosynthetic structures. It is clear that the maintenance of functional equilibrium between photosynthetic and non-photosynthetic structures guaranteed by the alteration of biomass partitioning provides plants a good strategy to resist external disturbance and damage.展开更多
Using CHIP (Chinese Household Income Project Survey) data and the sample selection bias corrected wage function model, this paper estimated changes in wage structure in China by ownership types (SOEs, COEs, FEs, an...Using CHIP (Chinese Household Income Project Survey) data and the sample selection bias corrected wage function model, this paper estimated changes in wage structure in China by ownership types (SOEs, COEs, FEs, and PEs) in 1995 and 2007. The major conclusions are as follows. First, effects of education on wage levels in SOEs and FEs become greater, while education effects decrease in SOEs and PEs under economic transition periods; firm-specific human capital becomes more important in the wage determination mechanism along with market-oriented reforms in SOEs, PEs, and FEs; age effect decreases in SOEs and COEs, but it becomes greater in PEs and FEs. Second, there exist wage structure differences between sectors by wage distributions. For example, in 2007, in SOEs, education return rates are higher for the low-wage and middle-wage groups, and the effect is the highest at the 40th percentile. However in COEs and FEs, education return rates are higher for the high-wage groups, and the effect is the highest at the 70th percentile in COEs and at the 70th percentile in FEs. Tenure effects are greater in the middle-wage groups (40th-80th) in SOEs, COEs, and FEs, and age effects are greater in the low-wage groups (5th-30th) in SOEs, FEs, and PEs.展开更多
The adsorption isotherms of four activated carbons (Norit Rill, Chemviron BPL, Monolit, and Ambersorb-572) have been examined by nitrogen adsorption at 77.5 K. A method for adsorption potential distribution calculat...The adsorption isotherms of four activated carbons (Norit Rill, Chemviron BPL, Monolit, and Ambersorb-572) have been examined by nitrogen adsorption at 77.5 K. A method for adsorption potential distribution calculation has been proposed based on the adsorption isotherms. This distribution provides information about possible changes in the Gibbs free energy caused by the energetic and geometrical heterogeneities of an activated carbon as well as by the adsorbate-related entropic effects. The general character of the adsorption potential distribution is clearly visible by its simple relation to the micropore and mesopore distribution,展开更多
An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraint...An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method.展开更多
This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption de...This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption demand.Then,the paper finds that the existing widening income distribution gap in China has a negative impact on consumption demand,but this is not the key factor for the insufficient consumption demand because of the low level of per capital income.At last,it suggests that governments should improve the income level of entire residents and adjust income distribution structure simultaneously.展开更多
In order to reduce the disturbance on an authorizing user and lower the competition between cognitive users, assure the normal communication of a cognitive radio system, reliability theory is applied to describe if a ...In order to reduce the disturbance on an authorizing user and lower the competition between cognitive users, assure the normal communication of a cognitive radio system, reliability theory is applied to describe if a channel can be used by a cognitive user or not and the probability that the channel is continually used for a period. Three aspects including space, time domain and frequency domain are united for the research on the distribution of frequency spectrum. The simulation result shows that, in the space domain, time domain, frequency domain algorithm, the transmitted data volume and the total throughput of the system are superior to those in greedy algorithm and time domain—frequency domain algorithm, the novel algorithm is helpful to reduce the disturbance caused by a cognitive user to an authorizing user and lower the competition between cognitive users, this simulation result shows that the proposed algorithm is effective.展开更多
Two kinds of metal chelates of rare earth elements reacted with tribrimoarsenazo formed under the condition of critic acid were observed by simultaneous technique of capillary electrophoresisphotothermal interference ...Two kinds of metal chelates of rare earth elements reacted with tribrimoarsenazo formed under the condition of critic acid were observed by simultaneous technique of capillary electrophoresisphotothermal interference spectrometry. The tendency of the conversion between these chelates as functions of the mole ratio of the reagent and the metal, pH value and the elapsing time was investigated. Kinetic equation of competitive chelating reaction between the TBA-La (Ⅲ) and La (Ⅲ) -critic acid were established. It was found that the competitive chelating reaction follows secondorder kinetics, for this second-order reaction, k=5.55 L·mol-1·S-1.展开更多
The mobility of relay has great influence on the performance of a cooperative relay system.This paper proposes a dynamic selection scheme under the amplify-and-forward communication mode in high mobility environment,b...The mobility of relay has great influence on the performance of a cooperative relay system.This paper proposes a dynamic selection scheme under the amplify-and-forward communication mode in high mobility environment,based on the estimation of channels and the power allocation for each relay node by comparing it with the pre-set threshold.This scheme is used to choose the cooperative relay dynamically for a multiple relay scenario.Simulation results show that this proposed relay selection scheme decreases the outage probability effectively,maintains system capacity well,and improves the performance of the relay system.展开更多
Industrial wireless sensor networks adopt a hierarchical structure with large numbers of sensors and routers. Time Division Multiple Access (TDMA) is regarded as an efficient method to reduce the probability of confli...Industrial wireless sensor networks adopt a hierarchical structure with large numbers of sensors and routers. Time Division Multiple Access (TDMA) is regarded as an efficient method to reduce the probability of confliction. In the intra-cluster part, the random color selection method is effective in reducing the retry times in an application. In the inter-cluster part, a quick assign algorithm and a dynamic maximum link algorithm are proposed to meet the quick networking or minimum frame size requirements. In the simulation, the dynamic maximum link algorithm produces higher reductions in the frame length than the quick assign algorithm. When the number of routers is 140, the total number of time slots is reduced by 25%. However, the first algorithm needs more control messages, and the average difference in the number of control messages is 3 410. Consequently, the dynamic maximum link algorithm is utilized for adjusting the link schedule to the minimum delay with a relatively high throughput rate, and the quick assign algorithm is utilized for speeding up the networking process.展开更多
A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the rea...A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the reassembled nucleus had a double-layered nuclear membrane, nuclear pore complexes, and decondensed chromatin etc. Indirect immunofluorescence analysis demonstrated the presence of lamina in newly assembled nuclei. Western-blotting results showed that lamin LII was present in egg extracts and in lamina of the reassembled nuclei which were previously reported to contain only eggderived lamin LIII.展开更多
In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and reso...In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and resource allocation while establishing a realistic scenario of three-tier heterogeneous network architecture. The scheme consists of two stages: in stage I, a two-level sub-channel allocation algorithm and a power control method based on the logarithmic function are applied to allocate resource for Macrocell and Picocells, guaranteeing the minimum system capacity by considering the power limitation and interference coordination; in stage II, an interference management approach based on K-means clustering is introduced to divide Femtocells into different clusters. Then, a prior sub-channel allocation algorithm is employed for Femtocells in diverse clusters to mitigate the interference and promote system performance. Simulation results show that the proposed scheme contributes to the enhancement of system throughput and spectrum efficiency while ensuring the system energy efficiency.展开更多
A layered network model for optical transport networks is proposed in this paper,which involves IP,SDH and WDM layers.The strategy of Dynamic Joint Routing and Resource Allocation (DJRRA) and its algorithm description...A layered network model for optical transport networks is proposed in this paper,which involves IP,SDH and WDM layers.The strategy of Dynamic Joint Routing and Resource Allocation (DJRRA) and its algorithm description are also presented for the proposed layered network model.DJRRA optimizes the bandwidth usage of interface links between different layers and the logic links inside all layers.The simulation results show that in contrast to the classical separate sequential routing and resource allocation solutions,DJRRA can reduce the blocking probability and increase network throughput effectively.展开更多
We investigate cooperative behaviors of lattice-embedded scale-free networking agents in the prisoner'sdilemma game model by employing two initial strategy distribution mechanisms,which are specific distribution t...We investigate cooperative behaviors of lattice-embedded scale-free networking agents in the prisoner'sdilemma game model by employing two initial strategy distribution mechanisms,which are specific distribution to themost connected sites (hubs) and random distribution.Our study indicates that the game dynamics crucially dependson the underlying spatial network structure with different strategy distribution mechanism.The cooperators' specificdistribution contributes to an enhanced level of cooperation in the system compared with random one,and cooperationis robust to cooperators' specific distribution but fragile to defectors' specific distribution.Especially,unlike the specificcase,increasing heterogeneity of network does not always favor the emergence of cooperation under random mechanism.Furthermore,we study the geographical effects and find that the graphically constrained network structure tends toimprove the evolution of cooperation in random case and in specific one for a large temptation to defect.展开更多
At room temperature, dibenzoyl peroxide and pyridine N-oxide reacted with metallic copper powder in a mixed solvent(dichloromethane, trichloromethane and tetrahydrofuran), resulting in a binuclear copper(Ⅱ) complex. ...At room temperature, dibenzoyl peroxide and pyridine N-oxide reacted with metallic copper powder in a mixed solvent(dichloromethane, trichloromethane and tetrahydrofuran), resulting in a binuclear copper(Ⅱ) complex. [Cu (C_5H_5NO)-(C_6H_5COO)_2]_2. The structure of the complex was characterized by elemental analyses.IR spectra and X-ray single crystal analysis. The crystal is triclinic, space group P1,with cell parameters . a= 9. 262(4) ,b= 10. 697(2) , c=10. 881 (3 )A , a=59. 60( 2 ),β= 74. 83 ( 3 ) .Y = 72. 80 ( 2 )°. V= 880. 0 A ̄3 . D_c = 1 . 5 20 g/cm ̄3 . Z = 1 . μ= 1 2. 7 cm-1, R=0. 044 ,R_w=0. 048 for 3477 reflections with I>3σ(I), M_r=805. 78. Each copper(Ⅱ) atom is coordinated by four bridging bidentate benzoate ligands and one pyridine M-oxide.展开更多
In actual implementation of spectrum sharing systems, due to the selfishness of primary users, primary users often refuse the access of secondary users to their licensed spectrum bands even if the access of secondary ...In actual implementation of spectrum sharing systems, due to the selfishness of primary users, primary users often refuse the access of secondary users to their licensed spectrum bands even if the access of secondary users doesn't affect their transmission. Aimed at the selfishness problem of primary users, a seller's market trading mechanism is introduced which can not only stimulate primary users to tolerate larger interference power but also give the primary users an appropriate compensation at the same time, and which has very important practical significance. Based on the mechanism, the achievable maximal gross profit of secondary users and their optimal power allocation scheme in the Rayleigh fading environment are derived, and the interference price of primary users and the average revenue of secondary users' impact on them are also studied. Numerical calculation results are conducted to verify our theoretical results.展开更多
The molar mass distribution of SSO in the first generation derived from the hydrolytic condensation oftwo trialkoxysilanes, [ 3- ( Methacryloxy ) propyl ] trimethoxysilane ( MPMS ) and vinyltrimethoxysilane ( VMS ) ,a...The molar mass distribution of SSO in the first generation derived from the hydrolytic condensation oftwo trialkoxysilanes, [ 3- ( Methacryloxy ) propyl ] trimethoxysilane ( MPMS ) and vinyltrimethoxysilane ( VMS ) ,are determined by UV-MALDI-TOF MS. The comparisons of theoretical masses with experimental masses arecalculated using the proposed compounds, which are assigned to formulas Tn (OH)m, Tn (OMe)y orTn(OH)x(OMe)y[T=RSiO1.5 (x+y)/2n, R=--(CH2)3OOCCH(CH3)CH2 and--CHCH2]. Both theproposed cage and ladder structures of SSO derived from similar sol-gel process of monomers are illustrated. Thecauses for the difference in structures between SSO M and SSO V is discussed as well.展开更多
文摘It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their photosynthetic structures (leaves) and non-photosynthetic structures (branches and stem) is unknown. The purpose of this study is to test the hypotheses that: (1) the above-ground parts of plants have functional equilibriums between their photosynthetic structures and non-photosynthetic structures; (2) the maintenance of the equilibriums is guaranteed by the alteration of biomass partitioning to photosynthetic and non-photosynthetic structures. To test these hypotheses, a pruning experiment with four pruning intensities (0%, 20%, 50%, and 70%) were carried out with three subtropical Chinese tree species ( Ficus microcarpa, Ficus virens, Cinnamomum camphora). Pruning treatments were conducted in two successive years. The results were in conformity with the hypothesis, i.e. above-ground parts of trees had functional equilibriums between photosynthetic and non-photosynthetic structures. Pruning decreased instantaneously the mass ratios of photosynthetic structures to non-photosynthetic structures (P/NP) of all three tree species, the reduction in P/NP was strengthened with pruning intensity. However, one year after pruning, the P/NP of all pruned trees increased and were not smaller than those of unpruned trees. In agreement with the expectation, the biomass partitioning of pruned trees was altered, more newly produced above-ground biomass was partitioned to leaf growth and less to branch and stem growth, thus enabled the damaged trees to restore their functional equilibrium between photosynthetic and non-photosynthetic structures. It is clear that the maintenance of functional equilibrium between photosynthetic and non-photosynthetic structures guaranteed by the alteration of biomass partitioning provides plants a good strategy to resist external disturbance and damage.
文摘Using CHIP (Chinese Household Income Project Survey) data and the sample selection bias corrected wage function model, this paper estimated changes in wage structure in China by ownership types (SOEs, COEs, FEs, and PEs) in 1995 and 2007. The major conclusions are as follows. First, effects of education on wage levels in SOEs and FEs become greater, while education effects decrease in SOEs and PEs under economic transition periods; firm-specific human capital becomes more important in the wage determination mechanism along with market-oriented reforms in SOEs, PEs, and FEs; age effect decreases in SOEs and COEs, but it becomes greater in PEs and FEs. Second, there exist wage structure differences between sectors by wage distributions. For example, in 2007, in SOEs, education return rates are higher for the low-wage and middle-wage groups, and the effect is the highest at the 40th percentile. However in COEs and FEs, education return rates are higher for the high-wage groups, and the effect is the highest at the 70th percentile in COEs and at the 70th percentile in FEs. Tenure effects are greater in the middle-wage groups (40th-80th) in SOEs, COEs, and FEs, and age effects are greater in the low-wage groups (5th-30th) in SOEs, FEs, and PEs.
基金Natural Science Foundation of Guangdong Province (No. 36566)
文摘The adsorption isotherms of four activated carbons (Norit Rill, Chemviron BPL, Monolit, and Ambersorb-572) have been examined by nitrogen adsorption at 77.5 K. A method for adsorption potential distribution calculation has been proposed based on the adsorption isotherms. This distribution provides information about possible changes in the Gibbs free energy caused by the energetic and geometrical heterogeneities of an activated carbon as well as by the adsorbate-related entropic effects. The general character of the adsorption potential distribution is clearly visible by its simple relation to the micropore and mesopore distribution,
文摘An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method.
文摘This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption demand.Then,the paper finds that the existing widening income distribution gap in China has a negative impact on consumption demand,but this is not the key factor for the insufficient consumption demand because of the low level of per capital income.At last,it suggests that governments should improve the income level of entire residents and adjust income distribution structure simultaneously.
基金supported by Natural Science Foundation of Heilongjiang Province of China(No.F2015017)
文摘In order to reduce the disturbance on an authorizing user and lower the competition between cognitive users, assure the normal communication of a cognitive radio system, reliability theory is applied to describe if a channel can be used by a cognitive user or not and the probability that the channel is continually used for a period. Three aspects including space, time domain and frequency domain are united for the research on the distribution of frequency spectrum. The simulation result shows that, in the space domain, time domain, frequency domain algorithm, the transmitted data volume and the total throughput of the system are superior to those in greedy algorithm and time domain—frequency domain algorithm, the novel algorithm is helpful to reduce the disturbance caused by a cognitive user to an authorizing user and lower the competition between cognitive users, this simulation result shows that the proposed algorithm is effective.
基金Supported by the National Natural Science Foundation of China (No. 20005005) Chengguang Project of Wuhan, and Visiting Scholar Foundation of Key Lab in University.
文摘Two kinds of metal chelates of rare earth elements reacted with tribrimoarsenazo formed under the condition of critic acid were observed by simultaneous technique of capillary electrophoresisphotothermal interference spectrometry. The tendency of the conversion between these chelates as functions of the mole ratio of the reagent and the metal, pH value and the elapsing time was investigated. Kinetic equation of competitive chelating reaction between the TBA-La (Ⅲ) and La (Ⅲ) -critic acid were established. It was found that the competitive chelating reaction follows secondorder kinetics, for this second-order reaction, k=5.55 L·mol-1·S-1.
基金Supported by the National Natural Science Foundation of China(No.61172073)the State Key Laboratory of Rail Traffic Control and Safety,Beijing Jiaotong University(No.RCS2011ZT003)+2 种基金the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University(No.2012D19)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(No.2013JBZ001)the Program for New Century Excellent Talents in University of Ministry of Education of China(No.NCET-12-0766)
文摘The mobility of relay has great influence on the performance of a cooperative relay system.This paper proposes a dynamic selection scheme under the amplify-and-forward communication mode in high mobility environment,based on the estimation of channels and the power allocation for each relay node by comparing it with the pre-set threshold.This scheme is used to choose the cooperative relay dynamically for a multiple relay scenario.Simulation results show that this proposed relay selection scheme decreases the outage probability effectively,maintains system capacity well,and improves the performance of the relay system.
基金supported by Beijing Education and Scientific Research Programthe National High Technical Research and Development Program of China (863 Program) under Grant No. 2011AA040101+2 种基金the National Natural Science Foundation of China under Grants No. 61173150, No. 61003251Beijing Science and Technology Program under Grant No. Z111100054011078the State Scholarship Fund
文摘Industrial wireless sensor networks adopt a hierarchical structure with large numbers of sensors and routers. Time Division Multiple Access (TDMA) is regarded as an efficient method to reduce the probability of confliction. In the intra-cluster part, the random color selection method is effective in reducing the retry times in an application. In the inter-cluster part, a quick assign algorithm and a dynamic maximum link algorithm are proposed to meet the quick networking or minimum frame size requirements. In the simulation, the dynamic maximum link algorithm produces higher reductions in the frame length than the quick assign algorithm. When the number of routers is 140, the total number of time slots is reduced by 25%. However, the first algorithm needs more control messages, and the average difference in the number of control messages is 3 410. Consequently, the dynamic maximum link algorithm is utilized for adjusting the link schedule to the minimum delay with a relatively high throughput rate, and the quick assign algorithm is utilized for speeding up the networking process.
文摘A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the reassembled nucleus had a double-layered nuclear membrane, nuclear pore complexes, and decondensed chromatin etc. Indirect immunofluorescence analysis demonstrated the presence of lamina in newly assembled nuclei. Western-blotting results showed that lamin LII was present in egg extracts and in lamina of the reassembled nuclei which were previously reported to contain only eggderived lamin LIII.
基金partially supported by the Major Project of National Science and Technology of China under Grants No. 2016ZX03002010003 and No. 2015ZX03001033-002
文摘In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and resource allocation while establishing a realistic scenario of three-tier heterogeneous network architecture. The scheme consists of two stages: in stage I, a two-level sub-channel allocation algorithm and a power control method based on the logarithmic function are applied to allocate resource for Macrocell and Picocells, guaranteeing the minimum system capacity by considering the power limitation and interference coordination; in stage II, an interference management approach based on K-means clustering is introduced to divide Femtocells into different clusters. Then, a prior sub-channel allocation algorithm is employed for Femtocells in diverse clusters to mitigate the interference and promote system performance. Simulation results show that the proposed scheme contributes to the enhancement of system throughput and spectrum efficiency while ensuring the system energy efficiency.
基金Supported by the Science & Technology Fund of Huawei Ltd(No.YJCB2005040SW) Postgraduate Creation Fund of Xid-ian University (No.05030) .
文摘A layered network model for optical transport networks is proposed in this paper,which involves IP,SDH and WDM layers.The strategy of Dynamic Joint Routing and Resource Allocation (DJRRA) and its algorithm description are also presented for the proposed layered network model.DJRRA optimizes the bandwidth usage of interface links between different layers and the logic links inside all layers.The simulation results show that in contrast to the classical separate sequential routing and resource allocation solutions,DJRRA can reduce the blocking probability and increase network throughput effectively.
文摘We investigate cooperative behaviors of lattice-embedded scale-free networking agents in the prisoner'sdilemma game model by employing two initial strategy distribution mechanisms,which are specific distribution to themost connected sites (hubs) and random distribution.Our study indicates that the game dynamics crucially dependson the underlying spatial network structure with different strategy distribution mechanism.The cooperators' specificdistribution contributes to an enhanced level of cooperation in the system compared with random one,and cooperationis robust to cooperators' specific distribution but fragile to defectors' specific distribution.Especially,unlike the specificcase,increasing heterogeneity of network does not always favor the emergence of cooperation under random mechanism.Furthermore,we study the geographical effects and find that the graphically constrained network structure tends toimprove the evolution of cooperation in random case and in specific one for a large temptation to defect.
文摘At room temperature, dibenzoyl peroxide and pyridine N-oxide reacted with metallic copper powder in a mixed solvent(dichloromethane, trichloromethane and tetrahydrofuran), resulting in a binuclear copper(Ⅱ) complex. [Cu (C_5H_5NO)-(C_6H_5COO)_2]_2. The structure of the complex was characterized by elemental analyses.IR spectra and X-ray single crystal analysis. The crystal is triclinic, space group P1,with cell parameters . a= 9. 262(4) ,b= 10. 697(2) , c=10. 881 (3 )A , a=59. 60( 2 ),β= 74. 83 ( 3 ) .Y = 72. 80 ( 2 )°. V= 880. 0 A ̄3 . D_c = 1 . 5 20 g/cm ̄3 . Z = 1 . μ= 1 2. 7 cm-1, R=0. 044 ,R_w=0. 048 for 3477 reflections with I>3σ(I), M_r=805. 78. Each copper(Ⅱ) atom is coordinated by four bridging bidentate benzoate ligands and one pyridine M-oxide.
基金Supported by the National Basic Research Program of China (2007CB307104), the National Natural Science Foundation of China (60973160), and the Intematiortal Scientific and Technological Cooperation Program (No. $2010GR0902).
文摘In actual implementation of spectrum sharing systems, due to the selfishness of primary users, primary users often refuse the access of secondary users to their licensed spectrum bands even if the access of secondary users doesn't affect their transmission. Aimed at the selfishness problem of primary users, a seller's market trading mechanism is introduced which can not only stimulate primary users to tolerate larger interference power but also give the primary users an appropriate compensation at the same time, and which has very important practical significance. Based on the mechanism, the achievable maximal gross profit of secondary users and their optimal power allocation scheme in the Rayleigh fading environment are derived, and the interference price of primary users and the average revenue of secondary users' impact on them are also studied. Numerical calculation results are conducted to verify our theoretical results.
基金Sponsored by the Foundation of Department of Science and Technology of Heilongjiang Province
文摘The molar mass distribution of SSO in the first generation derived from the hydrolytic condensation oftwo trialkoxysilanes, [ 3- ( Methacryloxy ) propyl ] trimethoxysilane ( MPMS ) and vinyltrimethoxysilane ( VMS ) ,are determined by UV-MALDI-TOF MS. The comparisons of theoretical masses with experimental masses arecalculated using the proposed compounds, which are assigned to formulas Tn (OH)m, Tn (OMe)y orTn(OH)x(OMe)y[T=RSiO1.5 (x+y)/2n, R=--(CH2)3OOCCH(CH3)CH2 and--CHCH2]. Both theproposed cage and ladder structures of SSO derived from similar sol-gel process of monomers are illustrated. Thecauses for the difference in structures between SSO M and SSO V is discussed as well.