The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the...The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200 靘olm-2s-1 photosynthetic photon flux density (PPFD) and 500 靘olm-2s-1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at 500 靘olm-2s-1 PPFD were slower than those at 200 靘olm-2s-1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times of Korean pine seedlings grown in the understory depended on the sunfleck intensity.展开更多
Till now, most part of the biodiesel is produced from the refined vegetable oils using methanol as feedstock in the presence of an alkali catalyst. However, large amount of waste edible oils and grease are available. ...Till now, most part of the biodiesel is produced from the refined vegetable oils using methanol as feedstock in the presence of an alkali catalyst. However, large amount of waste edible oils and grease are available. The difficulty with alkali-catalyzed esterification of these oils is that they often contain large amount of free fatty acids (FFA), polymers and decomposition products. These free fatty acids can quickly react with the alkali catalyst to produce soaps that inhibit the separation of the ester and glycerine. An esterification and transesterification process is developed to convert the high FFA oil to its monoesters, The first step, the acidcatalyzed esterification with glycerine and these FFA reduces the FFA content of the oil and grease to less than 3%, and then an azeotropic distillation solvent is used to remove the water. The major factors affecting the conversion efficiency of the process such as glycerol to free fatty acid molar ratio, catalyst amount, reaction temperature and reaction duration are analyzed, The second step, alkali-catalyzed transesterificatiou process converts the products of the first step to its monoesters and glycerol, and then the glycerol is recycled for utilization in the first step. Technical indicators of the biodiesel product can meet the ASTM 6751 standard.展开更多
Spin parity effect on magnetic relaxation by quantum tunneling in the biaxial spin model is studied by taking into account the transverse local stray field. It is shown that the square root time dependence in the even...Spin parity effect on magnetic relaxation by quantum tunneling in the biaxial spin model is studied by taking into account the transverse local stray field. It is shown that the square root time dependence in the even resonance occurs in the presence of a distribution of transverse anisotropic parameters, while the odd resonance always shows exponential relaxation. Magnetic relaxation under a sweeping field is also studied. The variation of the relaxation curve with the increasing distribution width of the local stray field for even resonance is qualitatively different from that of the odd resonance. The theoretical result on even resonance is in agreement with experimental results on Fe8 system, while the prediction for odd resonance awaits the experimental verification.展开更多
The effect of DziaJoshinski-Moriya (DM) interaction on thermal entanglement of a two-qubit XXZ spin chain in a homogenous magnetic field is investigated. It is found that the DM interaction can enhance thermal entan...The effect of DziaJoshinski-Moriya (DM) interaction on thermal entanglement of a two-qubit XXZ spin chain in a homogenous magnetic field is investigated. It is found that the DM interaction can enhance thermal entanglement. When D is large enough, the entanglement can exist for larger temperatures and strong magnetic field.展开更多
Through the Jordan Wigner transformation, the entanglement entropy and ground state phase diagrams of exactly solvable spin model with alternating and multiple spin exchange interactions are investigated by means of G...Through the Jordan Wigner transformation, the entanglement entropy and ground state phase diagrams of exactly solvable spin model with alternating and multiple spin exchange interactions are investigated by means of Green's function theory. In the absence of four-spin interactions, the ground state presents plentiful quantum phases due to the multiple spin interactions and magnetic fields. It is shown that the two-site entanglement entropy is a good indicator of quantum phase transition (QPT). In addition, the alternating interactions can destroy the magnetization plateau and wash out the spin-gap of low-lying excitations. However, in the presence of four-spin interactions, apart from the second order QPTs, the system manifests the first order OPT at the tricritical point and an additional new phase called "spin waves", which is due to the collapse of the continuous tower-like low-lying excitations modulated by the four-spin interactions for large three-spin couplings.展开更多
During the recent past the rainfall pattern in Sri Lanka has shown a noticeable change. This paper describes the effect of this change on the occurrence of landslides and their impacts to eco systems. This study shows...During the recent past the rainfall pattern in Sri Lanka has shown a noticeable change. This paper describes the effect of this change on the occurrence of landslides and their impacts to eco systems. This study shows that most of the landslides occurring in Sri Lanka during northeast monsoons, southwest monsoons and second inter-monsoon were located in three distinctively separated areas. Analysis of rainfall time series shows a trend of increased lengths of dry periods along with an increasing trend of rainfall intensity, especially after the late seventies. A strong relation is obtained between the location of landslides and the spatial distribution of areas where rainfall intensity is increased.展开更多
This paper introduces and analyzes a detection scheme for adaptive suppression of Multiuser Access Interference (MAI) and MultiPath Distortion (MPD) for mobile station of DS/CDMA system. The proposed detection scheme ...This paper introduces and analyzes a detection scheme for adaptive suppression of Multiuser Access Interference (MAI) and MultiPath Distortion (MPD) for mobile station of DS/CDMA system. The proposed detection scheme may amount to a RAKE receiver structure,wherein each branch is considered as a linear multiuser filter designed under a Linear Constrained Minimum Variance (LCMV) optimization strategy to suppress MAI, followed by a proper combining rule to suppress MPD. The adaptive blind multiuser detecting and optimum combining of the proposed receiver are realized, based on the Least-Mean-Square (LMS) algorithm and an adaptive vector tracking algorithm respectively. Finally, the feasibility of the above two algorithms is proved by the numerical results provided by computer simulation.展开更多
The compound {[Cu(Hpht)(N_3)]·H_2O}_n (Hpht = hydrogen phthalate) is formedby chains of copper atoms bridged simultaneously by syn-syn carboxylato and end-on azido bridges.Taking into account the large Cu-O(1)-C(...The compound {[Cu(Hpht)(N_3)]·H_2O}_n (Hpht = hydrogen phthalate) is formedby chains of copper atoms bridged simultaneously by syn-syn carboxylato and end-on azido bridges.Taking into account the large Cu-O(1)-C(7) bond angle of the single carboxylato bridge (131°), orthe large Cu-N(11)-Cu bond angle of the azido bridge (111.9°), a moderately intrachainantiferromagnetic behavior should be expected for the compound. This paper is devoted to examiningthe apparently anomalous intrachain ferromagnetic behavior of {[Cu(Hpht)(N_3)]·H_2O}_n, using firstprinciples within the full potential linearized augmented plane wave (FP-LAPW) method. The totalenergy, the density of states (DOS), and the spin distributions are obtained. The atomic spindistribution has been analyzed as resulting from the interplay of electron delocalization and spinpolarization. The DOS reveals a surprisingly strong exchange interaction between the d type orbitalsof the copper and the π molecular orbitals of the two ligands.展开更多
Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In mos...Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In most cases, these measurements are not suitable for detecting defects that appear as a result of failures of certain elements of the assembly lines. These so called self-recovering failures very often remain unnoticed, because they do not cause a suspension of the assembly process and if not taken into consideration, they can seriously menace the final product quality. In this paper, the authors use PFMEA to identify and evaluate the risk of the self-recovering failures. They also propose a simple Simulink model, which could be useful when trying to estimate the effect of installing new control devices at an existing assembly line upon its overall reliability and productivity.展开更多
A generalized finite element formulation is proposed for the study of the spin-dependent ballistic transport of electron through the two-dimensional quantum structures with Rashba spin-orbit interactions (SOI). The ...A generalized finite element formulation is proposed for the study of the spin-dependent ballistic transport of electron through the two-dimensional quantum structures with Rashba spin-orbit interactions (SOI). The transmission coefficient, conductance, the total and local polarization are numerically calculated and discussed as the Rashba eoefficient, the geometric sizes, and incident energy are changed in the T-shaped devices. Some interesting features are found in the proper parameter regime. The polarization has an enhancement as the Rashba coefficient becomes stronger. The polarization valley is rigid in the regime of the conductance plateaus since the local interference among the polarized multi-wave modes. The Rashba interactions coupling to geometry in sizes could form the structure-induced Fano-Rashba resonance. In the wider stub, the localized spin lattice of electron could be produced. The conductance plateaus correspond to weak polarizations. Strong polarizations appear when the stub sizes, incident energy, and the Rashba coupling coefficient are matched. The resonances are formed in a wide Fermi energy segment easily.展开更多
In this work, a new mathematical modelling of drying kinetics is described. At first, the modelling of the transfer speed (St) of water was performed. Then St was used as basis to state the drying rate model. The dr...In this work, a new mathematical modelling of drying kinetics is described. At first, the modelling of the transfer speed (St) of water was performed. Then St was used as basis to state the drying rate model. The drying rate depends not only on drying time, but also on some modelling parameters which are themselves time-dependent. All the modelling parameters are calculated directly from the experimental drying data. Then the theoretical model of the moisture content was stated. Subsequently, the drying kinetics of natural solar drying of plantain banana was studied as illustration. The drying rate was investigated. The comparison with other models encountered in literatures proved that the current theoretical model was decidedly more accurate. Then the modelling of moisture content of banana was performed and the results were compared with the Henderson and Pabis model. The current theoretical modelling provided by far the best fit.展开更多
In this paper a stochastic series expansion quantum Monte Carlo algorithm is used to study a frustratedspin chain with diagonal next-nearest-neighbor interactions.The detailed balance conditions are carefully analyzed...In this paper a stochastic series expansion quantum Monte Carlo algorithm is used to study a frustratedspin chain with diagonal next-nearest-neighbor interactions.The detailed balance conditions are carefully analyzed toimprove the efficiency of simulation process.As an application of this algothrim,the total magnetization,the staticstructure factor and spin-stiffness are calculated for a certain set of system parameters as a function of external fieldstrength.展开更多
The core of the presentation that I propose treats about the application of principal component analysis for the estimation of the future earnings of the Segregated Funds. The Segregated Funds are the pools of assets ...The core of the presentation that I propose treats about the application of principal component analysis for the estimation of the future earnings of the Segregated Funds. The Segregated Funds are the pools of assets which have been using in the Italian Insurance Market since mid 80's for managing the "with profit" business, also known as business with "discretionary participation feature" according to IFRS4 since the income attributable to the policyholders is composed by the net realised gains less a fee and by a minimum guarantee, if any. The discretion of the Management of the Entity lays on the decision on whether and when to realise both the financial gains and the financial losses of the underlying investments. This strategy is tied by the need to manage an appropriate ALM, from the rules included in the local legislation as well as by the policy about the solvency margin (for example a minimum solvency ratio to fulfil that is conditional upon the value of income attributed that year). The fee can not be changed, i.e., is not discretionary, the minimum granted could be fixed on annual basis-sometimes paid on cash recurrently-or could be promised only at expiration or sometimes promised at expiration or in advance only for death and disability. In case of years so adverse that the Entity is not able to avoid earnings too low, sometimes the entity delivers an additional bonus, in order to compensate their policyholders, which is based above a full discretion. Principal components are used in finance as well as in other fields such as genetic. You can see some of these applications in two of the references advised below. The purposes of the technique of principal components are (1) to increase objectivity of results and their verifiability by third parties such as auditors, (2) make speeder the time spent for the analytical calculations (i.e., runs of the actuarial models) and (3) to render the relationship between the asset composition and the their earnings effectively used for the best estimate liabilities through their contribution in forecasting future cash flows.展开更多
The choice of meter data acquisition methods has important significance for the electric energy management. Based on the comprehensive analysis of several meter data acquisition methods, this paper assess the performa...The choice of meter data acquisition methods has important significance for the electric energy management. Based on the comprehensive analysis of several meter data acquisition methods, this paper assess the performance of each one by analytic hierarchy process. We can draw a conclusion by calculating" The local automatic meter reading, the prepaid electric energy metering and the remote automatic meter reading have almost the same performance. They are better than the manual meter reading and the vehicle mounted mobile automatic meter reading. So we can choose any one of the three. Among them, the prepaid electric energy metering performs best. This can be a reference for grid company' s decision.展开更多
By lifelogging, we understand a specific, very recent phenomenon of digital technology, which falls within the range of practices of the quantified self. It is a complex form of self-management through self-monitoring...By lifelogging, we understand a specific, very recent phenomenon of digital technology, which falls within the range of practices of the quantified self. It is a complex form of self-management through self-monitoring and self-tracking practices, which combines the use of wearable computers for measuring psycho-physical performances through specific apps for the processing, selecting and describing of the data collected, possibly in combination with video recordings. Given that lifelogging is becoming increasingly widespread in technologically advanced societies and that practices related to it are becoming part of most people's everyday lives, it is more important than ever to gain an understanding of the phenomenon. In this paper, I am interested in particular in exploring the issue of the transformations in the perception, comprehension, and construction of self, and hence in subjectification practices, deriving from the new digital technologies, and especially lifelogging.展开更多
The Lande g-factor of a free atom determines the effective magnetic moment of an electron or atom with both spin and orbital angular momentum,which can be calculated by Lande formula,for a transition metal ion in the ...The Lande g-factor of a free atom determines the effective magnetic moment of an electron or atom with both spin and orbital angular momentum,which can be calculated by Lande formula,for a transition metal ion in the crystal field,the spin-orbital interaction can mix the non-zero orbital angular momentum of excited states with the"pure spin"ground state,resulting in an effective g-factor.Thus,the ability to probe the fine structure of the g-factor allows us to understand the internal spin properties of a magnetic system,such as the spin-orbital interaction.However,for molecular systems,traditional experimental methods for g-factor measurement,like EPR.展开更多
We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots (CQDs) with spin-orbit interactions (SOI) by exact diagonalization method. Through the SOI...We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots (CQDs) with spin-orbit interactions (SOI) by exact diagonalization method. Through the SOI induced spin mixing of the singlet and the triplet states, we show the different spin properties for the weak and strong SOI. We investigate the coherent singlet-triplet spin oscillations of the two electrons under the SOI, and demonstrate the detailed behaviors of the spin oscillations depending on the SOI strengths, the inter-dot separations and the external magnetic fields. To better understand the underlying physics of the spin dynamics, we introduce a four-level model Hamiltonian for both weak and strong SOI, and find that the SOI induced in plane effective magnetic fields can be quantitatively extracted from the two-electron excitation energy spectra.展开更多
In this paper,we have investigated the effect of Calogero-Moser type interaction on the quantum discord of thermal states of a spin chain.Our results imply that the quantum discord depends on the relative distance bet...In this paper,we have investigated the effect of Calogero-Moser type interaction on the quantum discord of thermal states of a spin chain.Our results imply that the quantum discord depends on the relative distance between the spins,the external magnetic field,and the temperature.By a comparison between the quantum discord and the entanglement of formation,the quantum discord is more robust than the entanglement of formation in the sense that the latter takes a zero value in a large range of the parameters,while the former takes a nonzero value.展开更多
Quantum discord, as a kind of measurement of quantum correlation, has received much attention since it was introduced. This paper focuses on studying quantum discord in three-spin XXZ chain with three-spin interaction...Quantum discord, as a kind of measurement of quantum correlation, has received much attention since it was introduced. This paper focuses on studying quantum discord in three-spin XXZ chain with three-spin interaction. The effects of all kinds of pa- rameters on quantum discord in the ferromagnetic region J=-I are studied. The three-spin interaction may increase the value of quantum discord between two spins, while the anisotropy may decrease the value. In addition, the regrowth of quantum discord with temperature is found in the model. For zero temperature, quantum phase transition is existent.展开更多
文摘The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200 靘olm-2s-1 photosynthetic photon flux density (PPFD) and 500 靘olm-2s-1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at 500 靘olm-2s-1 PPFD were slower than those at 200 靘olm-2s-1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times of Korean pine seedlings grown in the understory depended on the sunfleck intensity.
文摘Till now, most part of the biodiesel is produced from the refined vegetable oils using methanol as feedstock in the presence of an alkali catalyst. However, large amount of waste edible oils and grease are available. The difficulty with alkali-catalyzed esterification of these oils is that they often contain large amount of free fatty acids (FFA), polymers and decomposition products. These free fatty acids can quickly react with the alkali catalyst to produce soaps that inhibit the separation of the ester and glycerine. An esterification and transesterification process is developed to convert the high FFA oil to its monoesters, The first step, the acidcatalyzed esterification with glycerine and these FFA reduces the FFA content of the oil and grease to less than 3%, and then an azeotropic distillation solvent is used to remove the water. The major factors affecting the conversion efficiency of the process such as glycerol to free fatty acid molar ratio, catalyst amount, reaction temperature and reaction duration are analyzed, The second step, alkali-catalyzed transesterificatiou process converts the products of the first step to its monoesters and glycerol, and then the glycerol is recycled for utilization in the first step. Technical indicators of the biodiesel product can meet the ASTM 6751 standard.
基金National Natural Science Foundation of China under Grant No.10575045
文摘Spin parity effect on magnetic relaxation by quantum tunneling in the biaxial spin model is studied by taking into account the transverse local stray field. It is shown that the square root time dependence in the even resonance occurs in the presence of a distribution of transverse anisotropic parameters, while the odd resonance always shows exponential relaxation. Magnetic relaxation under a sweeping field is also studied. The variation of the relaxation curve with the increasing distribution width of the local stray field for even resonance is qualitatively different from that of the odd resonance. The theoretical result on even resonance is in agreement with experimental results on Fe8 system, while the prediction for odd resonance awaits the experimental verification.
基金Supported by the National Natural Science Foundation of China under Grant No.10774108the Special Research Foundation for the Doctoral Program of Higher Education under Grant No.20050285002
文摘The effect of DziaJoshinski-Moriya (DM) interaction on thermal entanglement of a two-qubit XXZ spin chain in a homogenous magnetic field is investigated. It is found that the DM interaction can enhance thermal entanglement. When D is large enough, the entanglement can exist for larger temperatures and strong magnetic field.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10774051 and 10804034the National 973 Project under Grant No.2006CB921605+1 种基金the Research Fund for the Doctoral Program of Higher Education under Grant No.20090142110063the National Science Foundation of Hubei Province of China under Grant No.2008CDB003
文摘Through the Jordan Wigner transformation, the entanglement entropy and ground state phase diagrams of exactly solvable spin model with alternating and multiple spin exchange interactions are investigated by means of Green's function theory. In the absence of four-spin interactions, the ground state presents plentiful quantum phases due to the multiple spin interactions and magnetic fields. It is shown that the two-site entanglement entropy is a good indicator of quantum phase transition (QPT). In addition, the alternating interactions can destroy the magnetization plateau and wash out the spin-gap of low-lying excitations. However, in the presence of four-spin interactions, apart from the second order QPTs, the system manifests the first order OPT at the tricritical point and an additional new phase called "spin waves", which is due to the collapse of the continuous tower-like low-lying excitations modulated by the four-spin interactions for large three-spin couplings.
文摘During the recent past the rainfall pattern in Sri Lanka has shown a noticeable change. This paper describes the effect of this change on the occurrence of landslides and their impacts to eco systems. This study shows that most of the landslides occurring in Sri Lanka during northeast monsoons, southwest monsoons and second inter-monsoon were located in three distinctively separated areas. Analysis of rainfall time series shows a trend of increased lengths of dry periods along with an increasing trend of rainfall intensity, especially after the late seventies. A strong relation is obtained between the location of landslides and the spatial distribution of areas where rainfall intensity is increased.
文摘This paper introduces and analyzes a detection scheme for adaptive suppression of Multiuser Access Interference (MAI) and MultiPath Distortion (MPD) for mobile station of DS/CDMA system. The proposed detection scheme may amount to a RAKE receiver structure,wherein each branch is considered as a linear multiuser filter designed under a Linear Constrained Minimum Variance (LCMV) optimization strategy to suppress MAI, followed by a proper combining rule to suppress MPD. The adaptive blind multiuser detecting and optimum combining of the proposed receiver are realized, based on the Least-Mean-Square (LMS) algorithm and an adaptive vector tracking algorithm respectively. Finally, the feasibility of the above two algorithms is proved by the numerical results provided by computer simulation.
文摘The compound {[Cu(Hpht)(N_3)]·H_2O}_n (Hpht = hydrogen phthalate) is formedby chains of copper atoms bridged simultaneously by syn-syn carboxylato and end-on azido bridges.Taking into account the large Cu-O(1)-C(7) bond angle of the single carboxylato bridge (131°), orthe large Cu-N(11)-Cu bond angle of the azido bridge (111.9°), a moderately intrachainantiferromagnetic behavior should be expected for the compound. This paper is devoted to examiningthe apparently anomalous intrachain ferromagnetic behavior of {[Cu(Hpht)(N_3)]·H_2O}_n, using firstprinciples within the full potential linearized augmented plane wave (FP-LAPW) method. The totalenergy, the density of states (DOS), and the spin distributions are obtained. The atomic spindistribution has been analyzed as resulting from the interplay of electron delocalization and spinpolarization. The DOS reveals a surprisingly strong exchange interaction between the d type orbitalsof the copper and the π molecular orbitals of the two ligands.
文摘Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In most cases, these measurements are not suitable for detecting defects that appear as a result of failures of certain elements of the assembly lines. These so called self-recovering failures very often remain unnoticed, because they do not cause a suspension of the assembly process and if not taken into consideration, they can seriously menace the final product quality. In this paper, the authors use PFMEA to identify and evaluate the risk of the self-recovering failures. They also propose a simple Simulink model, which could be useful when trying to estimate the effect of installing new control devices at an existing assembly line upon its overall reliability and productivity.
基金Supported by the National Science Foundation of China under Grant No.2006CB921605
文摘A generalized finite element formulation is proposed for the study of the spin-dependent ballistic transport of electron through the two-dimensional quantum structures with Rashba spin-orbit interactions (SOI). The transmission coefficient, conductance, the total and local polarization are numerically calculated and discussed as the Rashba eoefficient, the geometric sizes, and incident energy are changed in the T-shaped devices. Some interesting features are found in the proper parameter regime. The polarization has an enhancement as the Rashba coefficient becomes stronger. The polarization valley is rigid in the regime of the conductance plateaus since the local interference among the polarized multi-wave modes. The Rashba interactions coupling to geometry in sizes could form the structure-induced Fano-Rashba resonance. In the wider stub, the localized spin lattice of electron could be produced. The conductance plateaus correspond to weak polarizations. Strong polarizations appear when the stub sizes, incident energy, and the Rashba coupling coefficient are matched. The resonances are formed in a wide Fermi energy segment easily.
文摘In this work, a new mathematical modelling of drying kinetics is described. At first, the modelling of the transfer speed (St) of water was performed. Then St was used as basis to state the drying rate model. The drying rate depends not only on drying time, but also on some modelling parameters which are themselves time-dependent. All the modelling parameters are calculated directly from the experimental drying data. Then the theoretical model of the moisture content was stated. Subsequently, the drying kinetics of natural solar drying of plantain banana was studied as illustration. The drying rate was investigated. The comparison with other models encountered in literatures proved that the current theoretical model was decidedly more accurate. Then the modelling of moisture content of banana was performed and the results were compared with the Henderson and Pabis model. The current theoretical modelling provided by far the best fit.
基金Supported by NSFC under Grants Nos.10874235,10934010,60978019NKBRSFC under Grants Nos.2006CB921400,2009CB930704,2010CB922904
文摘In this paper a stochastic series expansion quantum Monte Carlo algorithm is used to study a frustratedspin chain with diagonal next-nearest-neighbor interactions.The detailed balance conditions are carefully analyzed toimprove the efficiency of simulation process.As an application of this algothrim,the total magnetization,the staticstructure factor and spin-stiffness are calculated for a certain set of system parameters as a function of external fieldstrength.
文摘The core of the presentation that I propose treats about the application of principal component analysis for the estimation of the future earnings of the Segregated Funds. The Segregated Funds are the pools of assets which have been using in the Italian Insurance Market since mid 80's for managing the "with profit" business, also known as business with "discretionary participation feature" according to IFRS4 since the income attributable to the policyholders is composed by the net realised gains less a fee and by a minimum guarantee, if any. The discretion of the Management of the Entity lays on the decision on whether and when to realise both the financial gains and the financial losses of the underlying investments. This strategy is tied by the need to manage an appropriate ALM, from the rules included in the local legislation as well as by the policy about the solvency margin (for example a minimum solvency ratio to fulfil that is conditional upon the value of income attributed that year). The fee can not be changed, i.e., is not discretionary, the minimum granted could be fixed on annual basis-sometimes paid on cash recurrently-or could be promised only at expiration or sometimes promised at expiration or in advance only for death and disability. In case of years so adverse that the Entity is not able to avoid earnings too low, sometimes the entity delivers an additional bonus, in order to compensate their policyholders, which is based above a full discretion. Principal components are used in finance as well as in other fields such as genetic. You can see some of these applications in two of the references advised below. The purposes of the technique of principal components are (1) to increase objectivity of results and their verifiability by third parties such as auditors, (2) make speeder the time spent for the analytical calculations (i.e., runs of the actuarial models) and (3) to render the relationship between the asset composition and the their earnings effectively used for the best estimate liabilities through their contribution in forecasting future cash flows.
文摘The choice of meter data acquisition methods has important significance for the electric energy management. Based on the comprehensive analysis of several meter data acquisition methods, this paper assess the performance of each one by analytic hierarchy process. We can draw a conclusion by calculating" The local automatic meter reading, the prepaid electric energy metering and the remote automatic meter reading have almost the same performance. They are better than the manual meter reading and the vehicle mounted mobile automatic meter reading. So we can choose any one of the three. Among them, the prepaid electric energy metering performs best. This can be a reference for grid company' s decision.
文摘By lifelogging, we understand a specific, very recent phenomenon of digital technology, which falls within the range of practices of the quantified self. It is a complex form of self-management through self-monitoring and self-tracking practices, which combines the use of wearable computers for measuring psycho-physical performances through specific apps for the processing, selecting and describing of the data collected, possibly in combination with video recordings. Given that lifelogging is becoming increasingly widespread in technologically advanced societies and that practices related to it are becoming part of most people's everyday lives, it is more important than ever to gain an understanding of the phenomenon. In this paper, I am interested in particular in exploring the issue of the transformations in the perception, comprehension, and construction of self, and hence in subjectification practices, deriving from the new digital technologies, and especially lifelogging.
文摘The Lande g-factor of a free atom determines the effective magnetic moment of an electron or atom with both spin and orbital angular momentum,which can be calculated by Lande formula,for a transition metal ion in the crystal field,the spin-orbital interaction can mix the non-zero orbital angular momentum of excited states with the"pure spin"ground state,resulting in an effective g-factor.Thus,the ability to probe the fine structure of the g-factor allows us to understand the internal spin properties of a magnetic system,such as the spin-orbital interaction.However,for molecular systems,traditional experimental methods for g-factor measurement,like EPR.
基金Supported by Natural Science Foundation of China under Grant Nos. 10574077 and 10774085the "863" Programme of China under Grant No. 2006AA03Z0404MOST Programme of China under Grant Nos. 2006AA03Z0404 and 2006CBOL0601
文摘We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots (CQDs) with spin-orbit interactions (SOI) by exact diagonalization method. Through the SOI induced spin mixing of the singlet and the triplet states, we show the different spin properties for the weak and strong SOI. We investigate the coherent singlet-triplet spin oscillations of the two electrons under the SOI, and demonstrate the detailed behaviors of the spin oscillations depending on the SOI strengths, the inter-dot separations and the external magnetic fields. To better understand the underlying physics of the spin dynamics, we introduce a four-level model Hamiltonian for both weak and strong SOI, and find that the SOI induced in plane effective magnetic fields can be quantitatively extracted from the two-electron excitation energy spectra.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11105001,10975125 and 11004001)
文摘In this paper,we have investigated the effect of Calogero-Moser type interaction on the quantum discord of thermal states of a spin chain.Our results imply that the quantum discord depends on the relative distance between the spins,the external magnetic field,and the temperature.By a comparison between the quantum discord and the entanglement of formation,the quantum discord is more robust than the entanglement of formation in the sense that the latter takes a zero value in a large range of the parameters,while the former takes a nonzero value.
基金supported by the ‘211’ Innovative Talents Cultivation Project of Inner Mongolia Universitythe National Natural Science Foundation of China (Grant No. 10847005)the Inner Mongolia Talent Development Foundation and Chinese Universities Scientific Fund (Grant No.BUPT2011RC0706)
文摘Quantum discord, as a kind of measurement of quantum correlation, has received much attention since it was introduced. This paper focuses on studying quantum discord in three-spin XXZ chain with three-spin interaction. The effects of all kinds of pa- rameters on quantum discord in the ferromagnetic region J=-I are studied. The three-spin interaction may increase the value of quantum discord between two spins, while the anisotropy may decrease the value. In addition, the regrowth of quantum discord with temperature is found in the model. For zero temperature, quantum phase transition is existent.