One of the most effective methods for sand control is the chemical consolidation of sandstone structures.In this paper,the impacts of crude oil and brine in the static state and the impact of the flow rates of the flu...One of the most effective methods for sand control is the chemical consolidation of sandstone structures.In this paper,the impacts of crude oil and brine in the static state and the impact of the flow rates of the fluids in the dynamic state have been assessed at the reservoir conditions.The analyses in this research were Young’s modulus,compressive strength,porosity,and permeability which were done on core samples after and before fluid contact.Samples made with two different resins showed good resistance to crude oil in both states.No considerable change was seen in the analyses even at high crude oil injection rates in the dynamic state.Conversely,brine caused a noticeable change in the analyses in both states.In the presence of brine at the static state,Young’s modulus and compressive strength respectively decreased by 37.5%and 34.5%for epoxy cores,whereas these parameters respectively reduced by 30%and 41%for furan cores.In brine presence at the dynamic state,compressive strength reduction was 10.28 MPa for furan and 6.28 MPa for epoxy samples and their compressive strength reached 16.75 MPa and 26.54 MPa respectively which are higher than the critical point to be known as weak sandstone core.Moreover,Young’s modulus decrease values for furan and epoxy samples were respectively 0.37 GPa and 0.44 GPa.Therefore,brine had a more destructive effect on the mechanical characteristics of samples in the static state than the dynamic one for two resins.In addition,brine injection increased permeability by about 13.6%for furan and 34.8%for epoxy.Also,porosity raised by about 21.8%for furan,and 19%for epoxy by brine injection.The results showed that the chemical sand consolidation weakens in the face of brine production along with crude oil which can lead to increasing cost of oil production and treating wellbore again.展开更多
This paper introduces a hybrid approach combining Green’s function Monte Carlo(GFMC)method with projected entangled pair state(PEPS)ansatz.This hybrid method regards PEPS as a trial state and a guiding wave function ...This paper introduces a hybrid approach combining Green’s function Monte Carlo(GFMC)method with projected entangled pair state(PEPS)ansatz.This hybrid method regards PEPS as a trial state and a guiding wave function in GFMC.By leveraging PEPS’s proficiency in capturing quantum state entanglement and GFMC’s efficient parallel architecture,the hybrid method is well-suited for the accurate and efficient treatment of frustrated quantum spin systems.As a benchmark,we applied this approach to study the frustrated J_(1)–J_(2) Heisenberg model on a square lattice with periodic boundary conditions(PBCs).Compared with other numerical methods,our approach integrating PEPS and GFMC shows competitive accuracy in the performance of ground-state energy.This paper provides systematic and comprehensive discussion of the approach of our previous work[Phys.Rev.B 109235133(2024)].展开更多
The charterparty is a legal contract of employing a vessel. In shipping matters, it is a highly important document since it allocates obligations, rights, duties, liabilities, risks, earnings, costs and profits betwee...The charterparty is a legal contract of employing a vessel. In shipping matters, it is a highly important document since it allocates obligations, rights, duties, liabilities, risks, earnings, costs and profits between the contracted parties, namely, the shipowner and the charterer. The interpretation of the above mentioned matters, as well as the understanding of charterparty terms, is considered of critical importance in chartering practice. Therefore, this paper constitutes a review of the most important aspects arising from charterparties in the main types of charter. The present study is based on shipping practices followed in accordance with the English Common Law throughout the chartering process （pre-fixture, fixture, execution of the charter, post fixture）. This is a synopsis about the distribution of the liabilities and expenses between the shipowner and the charterer in the most representative types of charter. The analysis is seen from a commercial stand point. Therefore, it is mostly addressed to the shipping practitioners, maritime economists, academics, students and researchers who seek to form a comprehensive view on the subject. It may also form a basis for further study on chartering aspects （legal, economic, managerial and practical）.展开更多
We study a system consisting of two identical non-interacting single-mode cavity fields coupled to a common vacuum environment and provide general, explicit, and exact solutions to its master equation by means of the ...We study a system consisting of two identical non-interacting single-mode cavity fields coupled to a common vacuum environment and provide general, explicit, and exact solutions to its master equation by means of the characteristic function method. We analyze the entanglement dynamics of two-mode squeezed thermal state in this model and show that its entanglement dynamics is strongly determined by the two-mode squeezing parameter and the purity. In particular, we find that two-mode squeezed thermal state with the squeezing parameter r ≤ -（1/2） In √u is extremely fragile and almost does not survive in a common vacuum environment. We investigate the time evolution of nonlocality for two-mode squeezed thermal state in such an environment. It is found that the evolved state loses its nonlocality in the beginning of the evolution, but after a time, the revival of nonlocality can occur.展开更多
It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we inves-tigated feature binding of col...It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we inves-tigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state.Z-values in the vision-related brain regions were calculated, conifrming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental ifndings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.展开更多
The nonclassicality of the two-variable Hermite polynomial state is investigated. It is found that the two-variable Hermite polynomial state can be considered as a two-mode photon subtracted squeezed vacuum state. A c...The nonclassicality of the two-variable Hermite polynomial state is investigated. It is found that the two-variable Hermite polynomial state can be considered as a two-mode photon subtracted squeezed vacuum state. A compact expression for the Wigner function is also derived analytically by using the Weyl-ordered operator invariance under similar transformations. Especially, the nonclassicality is discussed in terms of the negativity of the Wigner function. Then violations of Bell＇s inequality for the two-variable Hermite polynomial state are studied.展开更多
For the first time we construct the eigenstate ｜τ〉 of noncommutatlve coordinate. It turns out that｜τ〉 is an entangled state in the ordinary space. Remarkably, its Schmidt decomposition has definite expression in...For the first time we construct the eigenstate ｜τ〉 of noncommutatlve coordinate. It turns out that｜τ〉 is an entangled state in the ordinary space. Remarkably, its Schmidt decomposition has definite expression in the coordinate representation and the momentum representation. The 〈τ｜ representation can simplify some calculations for obtaining energy level of two-dimensional oscillator in noncommutative space.展开更多
Hardy＇s theorem on nonlocality has been verified by a series of experiments with two-qubit entangled pure states.However,in this paper we demonstrate the experimental test of the theorem by using the two-photon entan...Hardy＇s theorem on nonlocality has been verified by a series of experiments with two-qubit entangled pure states.However,in this paper we demonstrate the experimental test of the theorem by using the two-photon entangled mixed states.We first investigate the generic logic in Hardy＇s proof of nonlocality,which can be applied for arbitrary two-qubit mixed polarization entangled states and can be reduced naturally to the well-known logic tested successfully by the previous pure state experiments.Then,the optimized violations of locality for various experimental parameters are delivered by the numerical method.Finally,the logic argued above for testing Hardy＇s theorem on nonlocality is demonstrated experimentally by using the mixed entangled-photon pairs generated via pumping two type-I BBO crystals.Our experimental results shows that Hardy＇s proof of nonlocality can also be verified with two-qubit polarization entangled mixed states,with a violation of about 3.4 standard deviations.展开更多
Using the technique of integration within an ordered product of operators and the intermediate coordinatemomentum representation in quantum optics, as well as the excited squeezed state we derive a new form of Legendr...Using the technique of integration within an ordered product of operators and the intermediate coordinatemomentum representation in quantum optics, as well as the excited squeezed state we derive a new form of Legendre polynomials.展开更多
The equation of state(EOS)for square-well chain fluid with variable range(SWCF-VR) developed in our previous work based on statistical mechanical theory for chemical association is employed for the correlations of sur...The equation of state(EOS)for square-well chain fluid with variable range(SWCF-VR) developed in our previous work based on statistical mechanical theory for chemical association is employed for the correlations of surface tension and viscosity of common fluids and ionic liquids(ILs).A model of surface tension for multi-component mixtures is presented by combining the SWCF-VR EOS and the scaled particle theory and used to produce the surface tension of binary and ternary mixtures.The predicted surface tensions are in excellent agreement with the experimental data with an overall average absolute relative deviation(AAD)of 0.36%.A method for the calculation of dynamic viscosity of common fluids and ILs at high pressure is presented by combining Eyring’s rate theory of viscosity and the SWCF-VR EOS.The calculated viscosities are in good agreement with the experimental data with the overall AAD of 1.44% for 14 fluids in 84 cases.The salient feature is that the molecular parameters used in these models are self-consistent and can be applied to calculate different thermodynamic properties such as pVT,vapor-liquid equilibrium,caloric properties,surface tension,and viscosity.展开更多
During the Cold War,China’s diplomacy failed to treat the Arab states as a whole.It was not until the end of the Cold War that China established diplomatic relations with all 22 Arab states.Since then,a multilateral ...During the Cold War,China’s diplomacy failed to treat the Arab states as a whole.It was not until the end of the Cold War that China established diplomatic relations with all 22 Arab states.Since then,a multilateral cooperation mechanism between China and Arab states has come into existence and become steadily developed.In 2004,the China-Arab States Cooperation Forum was established.In 2010,China and the Arab states announced the establishment of a strategic cooperative relationship.After the Gulf War,the Arab world entered a period of fragmentation and division.The situation deteriorated after the drastic changes in the Middle East in 2011,to the point of entering an era of granulation.The ability of The League of Arab States to operate as a single international actor has been greatly impaired.In the era of the fragmentation of the Arab world,the mechanism of multilateral cooperation between China and the Arab States has developed in spite of these great difficulties.In future,the role and function of the multilateral mechanism of cooperation between China and the Arab states needs to be clarified,and efficiency needs to be improved based on the existing mechanisms.展开更多
文摘One of the most effective methods for sand control is the chemical consolidation of sandstone structures.In this paper,the impacts of crude oil and brine in the static state and the impact of the flow rates of the fluids in the dynamic state have been assessed at the reservoir conditions.The analyses in this research were Young’s modulus,compressive strength,porosity,and permeability which were done on core samples after and before fluid contact.Samples made with two different resins showed good resistance to crude oil in both states.No considerable change was seen in the analyses even at high crude oil injection rates in the dynamic state.Conversely,brine caused a noticeable change in the analyses in both states.In the presence of brine at the static state,Young’s modulus and compressive strength respectively decreased by 37.5%and 34.5%for epoxy cores,whereas these parameters respectively reduced by 30%and 41%for furan cores.In brine presence at the dynamic state,compressive strength reduction was 10.28 MPa for furan and 6.28 MPa for epoxy samples and their compressive strength reached 16.75 MPa and 26.54 MPa respectively which are higher than the critical point to be known as weak sandstone core.Moreover,Young’s modulus decrease values for furan and epoxy samples were respectively 0.37 GPa and 0.44 GPa.Therefore,brine had a more destructive effect on the mechanical characteristics of samples in the static state than the dynamic one for two resins.In addition,brine injection increased permeability by about 13.6%for furan and 34.8%for epoxy.Also,porosity raised by about 21.8%for furan,and 19%for epoxy by brine injection.The results showed that the chemical sand consolidation weakens in the face of brine production along with crude oil which can lead to increasing cost of oil production and treating wellbore again.
基金Project supported by the National Natural Science Foundation of China(Grant No.11934020)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302402).
文摘This paper introduces a hybrid approach combining Green’s function Monte Carlo(GFMC)method with projected entangled pair state(PEPS)ansatz.This hybrid method regards PEPS as a trial state and a guiding wave function in GFMC.By leveraging PEPS’s proficiency in capturing quantum state entanglement and GFMC’s efficient parallel architecture,the hybrid method is well-suited for the accurate and efficient treatment of frustrated quantum spin systems.As a benchmark,we applied this approach to study the frustrated J_(1)–J_(2) Heisenberg model on a square lattice with periodic boundary conditions(PBCs).Compared with other numerical methods,our approach integrating PEPS and GFMC shows competitive accuracy in the performance of ground-state energy.This paper provides systematic and comprehensive discussion of the approach of our previous work[Phys.Rev.B 109235133(2024)].
文摘The charterparty is a legal contract of employing a vessel. In shipping matters, it is a highly important document since it allocates obligations, rights, duties, liabilities, risks, earnings, costs and profits between the contracted parties, namely, the shipowner and the charterer. The interpretation of the above mentioned matters, as well as the understanding of charterparty terms, is considered of critical importance in chartering practice. Therefore, this paper constitutes a review of the most important aspects arising from charterparties in the main types of charter. The present study is based on shipping practices followed in accordance with the English Common Law throughout the chartering process （pre-fixture, fixture, execution of the charter, post fixture）. This is a synopsis about the distribution of the liabilities and expenses between the shipowner and the charterer in the most representative types of charter. The analysis is seen from a commercial stand point. Therefore, it is mostly addressed to the shipping practitioners, maritime economists, academics, students and researchers who seek to form a comprehensive view on the subject. It may also form a basis for further study on chartering aspects （legal, economic, managerial and practical）.
基金Supported by Hunan Provincial Natural Science Foundation of China under Grant No.10JJ6010the Key Project Foundation of Hunan Provincial Education Department of China under Grant No.10A095
文摘We study a system consisting of two identical non-interacting single-mode cavity fields coupled to a common vacuum environment and provide general, explicit, and exact solutions to its master equation by means of the characteristic function method. We analyze the entanglement dynamics of two-mode squeezed thermal state in this model and show that its entanglement dynamics is strongly determined by the two-mode squeezing parameter and the purity. In particular, we find that two-mode squeezed thermal state with the squeezing parameter r ≤ -（1/2） In √u is extremely fragile and almost does not survive in a common vacuum environment. We investigate the time evolution of nonlocality for two-mode squeezed thermal state in such an environment. It is found that the evolved state loses its nonlocality in the beginning of the evolution, but after a time, the revival of nonlocality can occur.
基金financially supported by grants from the National Natural Science Foundation of China,No.61170136,61373101,61472270,and 61402318Natural Science Foundation(Youth Science and Technology Research Foundation)of Shanxi Province,No.2014021022-5Shanxi Provincial Key Science and Technology Projects(Agriculture),No.20130311037-4
文摘It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we inves-tigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state.Z-values in the vision-related brain regions were calculated, conifrming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental ifndings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.
基金supported by the National Natural Science Foundation of China (Grant No. 11047133)the Natural Science Foundation of Jiangxi Province of China (Grant No. 2010GQW0027)the Research Foundation of the Education Department of Jiangxi Province of China (Grant No. GJJ11390)
文摘The nonclassicality of the two-variable Hermite polynomial state is investigated. It is found that the two-variable Hermite polynomial state can be considered as a two-mode photon subtracted squeezed vacuum state. A compact expression for the Wigner function is also derived analytically by using the Weyl-ordered operator invariance under similar transformations. Especially, the nonclassicality is discussed in terms of the negativity of the Wigner function. Then violations of Bell＇s inequality for the two-variable Hermite polynomial state are studied.
基金The project supported by Specialized Research Fund for the Doctorial Progress of Higher Education （SRFDP） under Grant No. 2004035819
文摘For the first time we construct the eigenstate ｜τ〉 of noncommutatlve coordinate. It turns out that｜τ〉 is an entangled state in the ordinary space. Remarkably, its Schmidt decomposition has definite expression in the coordinate representation and the momentum representation. The 〈τ｜ representation can simplify some calculations for obtaining energy level of two-dimensional oscillator in noncommutative space.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61308008 and U1330201)
文摘Hardy＇s theorem on nonlocality has been verified by a series of experiments with two-qubit entangled pure states.However,in this paper we demonstrate the experimental test of the theorem by using the two-photon entangled mixed states.We first investigate the generic logic in Hardy＇s proof of nonlocality,which can be applied for arbitrary two-qubit mixed polarization entangled states and can be reduced naturally to the well-known logic tested successfully by the previous pure state experiments.Then,the optimized violations of locality for various experimental parameters are delivered by the numerical method.Finally,the logic argued above for testing Hardy＇s theorem on nonlocality is demonstrated experimentally by using the mixed entangled-photon pairs generated via pumping two type-I BBO crystals.Our experimental results shows that Hardy＇s proof of nonlocality can also be verified with two-qubit polarization entangled mixed states,with a violation of about 3.4 standard deviations.
文摘Using the technique of integration within an ordered product of operators and the intermediate coordinatemomentum representation in quantum optics, as well as the excited squeezed state we derive a new form of Legendre polynomials.
基金Supported by the National Natural Science Foundation of China （20776040 20876041 20736002） the National Basic Research Program of China （2009CB219902）+1 种基金 the Program for Changjiang Scholars and Innovative Research Team in University of China （Grant IRT0721） the 111 Project （Grant B08021） of China
文摘The equation of state(EOS)for square-well chain fluid with variable range(SWCF-VR) developed in our previous work based on statistical mechanical theory for chemical association is employed for the correlations of surface tension and viscosity of common fluids and ionic liquids(ILs).A model of surface tension for multi-component mixtures is presented by combining the SWCF-VR EOS and the scaled particle theory and used to produce the surface tension of binary and ternary mixtures.The predicted surface tensions are in excellent agreement with the experimental data with an overall average absolute relative deviation(AAD)of 0.36%.A method for the calculation of dynamic viscosity of common fluids and ILs at high pressure is presented by combining Eyring’s rate theory of viscosity and the SWCF-VR EOS.The calculated viscosities are in good agreement with the experimental data with the overall AAD of 1.44% for 14 fluids in 84 cases.The salient feature is that the molecular parameters used in these models are self-consistent and can be applied to calculate different thermodynamic properties such as pVT,vapor-liquid equilibrium,caloric properties,surface tension,and viscosity.
文摘During the Cold War,China’s diplomacy failed to treat the Arab states as a whole.It was not until the end of the Cold War that China established diplomatic relations with all 22 Arab states.Since then,a multilateral cooperation mechanism between China and Arab states has come into existence and become steadily developed.In 2004,the China-Arab States Cooperation Forum was established.In 2010,China and the Arab states announced the establishment of a strategic cooperative relationship.After the Gulf War,the Arab world entered a period of fragmentation and division.The situation deteriorated after the drastic changes in the Middle East in 2011,to the point of entering an era of granulation.The ability of The League of Arab States to operate as a single international actor has been greatly impaired.In the era of the fragmentation of the Arab world,the mechanism of multilateral cooperation between China and the Arab States has developed in spite of these great difficulties.In future,the role and function of the multilateral mechanism of cooperation between China and the Arab states needs to be clarified,and efficiency needs to be improved based on the existing mechanisms.
