In order to carry out tensor analysis in a neighborhood of a reference surface,the principal-direction orthogonal basis accompanying with Lame s coefficients or general curvilinear coordinate systems are widely used.A...In order to carry out tensor analysis in a neighborhood of a reference surface,the principal-direction orthogonal basis accompanying with Lame s coefficients or general curvilinear coordinate systems are widely used.A novel kind of field theory termed as the nonholonomic theory of the Principal-Direction Orthonormal Basis(PDOB)is presented systematically in the present paper,in which the formal Christoffel symbols are related directly to the principal and geodesic curvatures with respect to the principal directions of the surface.Furthermore,a systematic and simple way to determine the curvatures of the surface are presented with some examples.It provides a way to recognize qualitatively the bending property of a surface.展开更多
A critical problem in the cube attack is how to recover superpolies efficiently.As the targeting number of rounds of an iterative stream cipher increases,the scale of its superpolies becomes larger and larger.Recently...A critical problem in the cube attack is how to recover superpolies efficiently.As the targeting number of rounds of an iterative stream cipher increases,the scale of its superpolies becomes larger and larger.Recently,to recover massive superpolies,the nested monomial prediction technique,the algorithm based on the divide-and-conquer strategy,and stretching cube attacks were proposed,which have been used to recover a superpoly with over ten million monomials for the NFSR-based stream ciphers such as Trivium and Grain-128AEAD.Nevertheless,when these methods are used to recover superpolies,many invalid calculations are performed,which makes recovering superpolies more difficult.This study finds an interesting observation that can be used to improve the above methods.Based on the observation,a new method is proposed to avoid a part of invalid calculations during the process of recovering superpolies.Then,the new method is applied to the nested monomial prediction technique and an improved superpoly recovery framework is presented.To verify the effectiveness of the proposed scheme,the improved framework is applied to 844-and 846-round Trivium and the exact ANFs of the superpolies is obtained with over one hundred million monomials,showing the improved superpoly recovery technique is powerful.Besides,extensive experiments on other scaled-down variants of NFSR-based stream ciphers show that the proposed scheme indeed could be more efficient on the superpoly recovery against NFSR-based stream ciphers.展开更多
The theory of quadratic residues plays an important role in cryptography.In 2001,Cocks developed an identity-based encryption(IBE)scheme based on quadratic residues,resolving Shamir’s 17-year-old open problem.However...The theory of quadratic residues plays an important role in cryptography.In 2001,Cocks developed an identity-based encryption(IBE)scheme based on quadratic residues,resolving Shamir’s 17-year-old open problem.However,a notable drawback of Cocks’scheme is the significant expansion of the ciphertext,and some of its limitations have been addressed in subsequent research.Recently,Cotan and Teşeleanu highlighted that previous studies on Cocks’scheme relied on a trial-and-error method based on Jacobi symbols to generate the necessary parameters for the encryption process.They enhanced the encryption speed of Cocks’scheme by eliminating this trialand-error method.Based on security analysis,this study concludes that the security of Cotan-Teşeleanu’s proposal cannot be directly derived from the security of the original Cocks’scheme.Furthermore,by adopting the Cotan-Teşeleanu method and introducing an additional variable as a public element,this study develops a similar enhancement scheme that not only accelerates the encryption speed but also provides security equivalent to the original Cocks’scheme.展开更多
Gassmann＇s equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction r...Gassmann＇s equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction reliability.In this paper,combining the Russell fluid factor with the Gassman-Biot-Geertsma equation and introducing the dry-rock Poisson＇s ratio,we propose an effective matrix mineral bulk modulus extraction method.This method can adaptively invert the equivalent matrix mineral bulk modulus to apply the Gassmann equation to fluid substitution of complex carbonate reservoirs and increase the fluid prediction reliability.The verification of the actual material fluid substitution also shows that this method is reliable,efficient,and adaptable.展开更多
The transformation behavior of Ni Ti Nb based alloys was analysed.The absence of R phase transformation in these alloys is related to the stress field in the NiTi matrix.The thermal mismatch stress was calculated by...The transformation behavior of Ni Ti Nb based alloys was analysed.The absence of R phase transformation in these alloys is related to the stress field in the NiTi matrix.The thermal mismatch stress was calculated by the Eshelby method in Ni Ti Nb alloys.The results show that the mean matrix elastic stress field is isostatic tensile,there is no preferred stress in [111] B 2 direction.The mean matrix stress from the thermal misfit between NiTi matrix and β Nb particle is too small to induce dislocations.All the factors tend to inhibit R phase transformation.展开更多
The idea of the gradient method for integrating the dynamical equations of a nonconservative system presented by Vujanovic is transplanted to a Birkhoffian system, which is a new method for the integration of Birkhoff...The idea of the gradient method for integrating the dynamical equations of a nonconservative system presented by Vujanovic is transplanted to a Birkhoffian system, which is a new method for the integration of Birkhoff＇s equations. First, the differential equations of motion of the Birkhoffian system are written out. Secondly, 2n Birkhoff＇s variables are divided into two parts, and assume that a part of the variables is the functions of the remaining part of the variables and time. Thereby, the basic quasi-linear partial differential equations are established. If a complete solution of the basic partial differential equations is sought out, the solution of the problem is given by a set of algebraic equations. Since one can choose n arbitrary Birkhoff＇s variables as the functions of n remains of variables and time in a specific problem, the method has flexibility. The major difficulty of this method lies in finding a complete solution of the basic partial differential equation. Once one finds the complete solution, the motion of the systems can be obtained without doing further integration. Finally, two examples are given to illustrate the application of the results.展开更多
To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key w...To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key with the help of the server.In this protocol,the client stores a plaintext version of the password,while the server stores a verifier for the password.And the protocol uses verifiers to authenticate between clients and the server.The security analysis and performance comparison of the proposed protocol shows that the protocol can resist many familiar attacks including password guessing attacks,server compromise attacks,man-in-the-middle attacks and Denning-Sacco attacks,and it is more efficient.展开更多
[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []V...[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.展开更多
This paper first develops the approaches to determine the geopotential of the local mean sea level,and then investigates the offset of the 1985 vertical datum surface defined by the mean sea level of Yellow Sea at the...This paper first develops the approaches to determine the geopotential of the local mean sea level,and then investigates the offset of the 1985 vertical datum surface defined by the mean sea level of Yellow Sea at the Dagang Tide Gauge in Qingdao city using the developed approaches and GPS/leveling data.It shows that the geopotential of the local mean sea level at the tide gauge is equal to 62 636 853.5±0.2 m2·s -2 and that the 1985 vertical datum surface is 24.6±5.4 cm above the geoid realized by the geopotential W 0= 62 636 856.0±0.5 m2·s -2.展开更多
The rollup and the drilldown are quite frequent based on dimension hierarchies in on-line analytical processing （OLAP）, but prefixCube does not directly support dimension hierarchies. The PrefixCube is extended for ...The rollup and the drilldown are quite frequent based on dimension hierarchies in on-line analytical processing （OLAP）, but prefixCube does not directly support dimension hierarchies. The PrefixCube is extended for incorporating hierarchical data cubes, i.e. cubes with hierarchical dimensions ,thus obtaining HierPrefixCube. HierPrefixCube retains advantages on computation and organization of PrefixCube, and it can directly support aggregate queries on levels of the dimension hierarchy.展开更多
The calculation of earth pressure is a difficult problem in the pit foundation design. Aiming at the problem, the earth pressure calculation formulas considering the displacement are proposed. A method for determining...The calculation of earth pressure is a difficult problem in the pit foundation design. Aiming at the problem, the earth pressure calculation formulas considering the displacement are proposed. A method for determining the limit displacement is given and it is convenient for use. The result indicates that the earth pressure calculated by the formulas is between the earth pressure at rest and the Rankine earth pressure, the formulas can reflect the change rules of active and passive earth pressures along with the displacement. Moreover, the calculation result using the formulas is approximate to the monitoring result. It confirms the validity of the formula deduction and the rationality of the calculation results. As for the passive earth pressure, the calculation method is theoretically feasible.展开更多
This paper gives several fundamental theorems for the stability, uniform stability, asymptotic stability and uniform asymptotic stability. Those theorems allow the derivative of Lyapunov functions to be positive on ce...This paper gives several fundamental theorems for the stability, uniform stability, asymptotic stability and uniform asymptotic stability. Those theorems allow the derivative of Lyapunov functions to be positive on certain sets,relax the restriction about the rate of change of state variable in a system to be bounded in Marachkov's theorem and extend the related results in [4—7].展开更多
[Objective] This study aimed to investigate the optimal component of culti- vation medium for container seedling raising of Camellia oleifera. [Method] In the application of container nursery technology of Camellia ol...[Objective] This study aimed to investigate the optimal component of culti- vation medium for container seedling raising of Camellia oleifera. [Method] In the application of container nursery technology of Camellia oleifera grafting in emergent stocks, yellow clay soil, surface soil of pine forest, decomposed edible fungus, peat soil, dung and dirt were mixed by different proportions into five formulae as nursery substrates, with garden soil as the control, in order to investigate the influences of various substrates on the growth of annual Camellia oleifera container seedlings by using randomized block design based on variance analysis and multiple comparisons, and to screen the optimal substrate formula for container nursery of Camellia oleifera. [Result] The influences of different substrates on the transplanting survival rate, seedling height, basal diameter, height-diameter ratio and lateral root length of Camellia oleifera container seedlings were significantly different. Various growth indi- cators of Camellia oleifera container seedlings cultivated in the substrate containing 40% of yellow clay soil ＋ 15% of surface soil of pine forest ＋ 20% of decomposed edible fungus ＋ 20% of peat soil ＋ 5% of dung and dirt exceeded that of the control and other substrate formulae, which could be used as the optimal substrate formula for the container nursery of Camellia oleifera. [Conclusion] This study screened the optimal substrate formula for the container nursery of Camellia oleifera, which provided technical reference for the cultivation of Camellia oleifera container seedlings.展开更多
基金Project supported by the National Natural Science Foundation of China(11972120,11472082,12032016)。
文摘In order to carry out tensor analysis in a neighborhood of a reference surface,the principal-direction orthogonal basis accompanying with Lame s coefficients or general curvilinear coordinate systems are widely used.A novel kind of field theory termed as the nonholonomic theory of the Principal-Direction Orthonormal Basis(PDOB)is presented systematically in the present paper,in which the formal Christoffel symbols are related directly to the principal and geodesic curvatures with respect to the principal directions of the surface.Furthermore,a systematic and simple way to determine the curvatures of the surface are presented with some examples.It provides a way to recognize qualitatively the bending property of a surface.
基金National Natural Science Foundation of China(62372464)。
文摘A critical problem in the cube attack is how to recover superpolies efficiently.As the targeting number of rounds of an iterative stream cipher increases,the scale of its superpolies becomes larger and larger.Recently,to recover massive superpolies,the nested monomial prediction technique,the algorithm based on the divide-and-conquer strategy,and stretching cube attacks were proposed,which have been used to recover a superpoly with over ten million monomials for the NFSR-based stream ciphers such as Trivium and Grain-128AEAD.Nevertheless,when these methods are used to recover superpolies,many invalid calculations are performed,which makes recovering superpolies more difficult.This study finds an interesting observation that can be used to improve the above methods.Based on the observation,a new method is proposed to avoid a part of invalid calculations during the process of recovering superpolies.Then,the new method is applied to the nested monomial prediction technique and an improved superpoly recovery framework is presented.To verify the effectiveness of the proposed scheme,the improved framework is applied to 844-and 846-round Trivium and the exact ANFs of the superpolies is obtained with over one hundred million monomials,showing the improved superpoly recovery technique is powerful.Besides,extensive experiments on other scaled-down variants of NFSR-based stream ciphers show that the proposed scheme indeed could be more efficient on the superpoly recovery against NFSR-based stream ciphers.
基金Rising-Star Program of Shanghai 2023 Science and Technology Innovation Action Plan(Yangfan Special Project),China(No.23YF1401000)Fundamental Research Funds for the Central Universities,China(No.2232022D-25)。
文摘The theory of quadratic residues plays an important role in cryptography.In 2001,Cocks developed an identity-based encryption(IBE)scheme based on quadratic residues,resolving Shamir’s 17-year-old open problem.However,a notable drawback of Cocks’scheme is the significant expansion of the ciphertext,and some of its limitations have been addressed in subsequent research.Recently,Cotan and Teşeleanu highlighted that previous studies on Cocks’scheme relied on a trial-and-error method based on Jacobi symbols to generate the necessary parameters for the encryption process.They enhanced the encryption speed of Cocks’scheme by eliminating this trialand-error method.Based on security analysis,this study concludes that the security of Cotan-Teşeleanu’s proposal cannot be directly derived from the security of the original Cocks’scheme.Furthermore,by adopting the Cotan-Teşeleanu method and introducing an additional variable as a public element,this study develops a similar enhancement scheme that not only accelerates the encryption speed but also provides security equivalent to the original Cocks’scheme.
基金sponsored by National Natural Science Foundation of China(Grant No.40904035)
文摘Gassmann＇s equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction reliability.In this paper,combining the Russell fluid factor with the Gassman-Biot-Geertsma equation and introducing the dry-rock Poisson＇s ratio,we propose an effective matrix mineral bulk modulus extraction method.This method can adaptively invert the equivalent matrix mineral bulk modulus to apply the Gassmann equation to fluid substitution of complex carbonate reservoirs and increase the fluid prediction reliability.The verification of the actual material fluid substitution also shows that this method is reliable,efficient,and adaptable.
文摘The transformation behavior of Ni Ti Nb based alloys was analysed.The absence of R phase transformation in these alloys is related to the stress field in the NiTi matrix.The thermal mismatch stress was calculated by the Eshelby method in Ni Ti Nb alloys.The results show that the mean matrix elastic stress field is isostatic tensile,there is no preferred stress in [111] B 2 direction.The mean matrix stress from the thermal misfit between NiTi matrix and β Nb particle is too small to induce dislocations.All the factors tend to inhibit R phase transformation.
基金The National Natural Science Foundation of China(No.10972151)
文摘The idea of the gradient method for integrating the dynamical equations of a nonconservative system presented by Vujanovic is transplanted to a Birkhoffian system, which is a new method for the integration of Birkhoff＇s equations. First, the differential equations of motion of the Birkhoffian system are written out. Secondly, 2n Birkhoff＇s variables are divided into two parts, and assume that a part of the variables is the functions of the remaining part of the variables and time. Thereby, the basic quasi-linear partial differential equations are established. If a complete solution of the basic partial differential equations is sought out, the solution of the problem is given by a set of algebraic equations. Since one can choose n arbitrary Birkhoff＇s variables as the functions of n remains of variables and time in a specific problem, the method has flexibility. The major difficulty of this method lies in finding a complete solution of the basic partial differential equation. Once one finds the complete solution, the motion of the systems can be obtained without doing further integration. Finally, two examples are given to illustrate the application of the results.
基金The National High Technology Research and Development Program of China(863Program)(No.2001AA115300)the Natural Science Foundation of Liaoning Province(No.20031018,20062023)
文摘To prevent server compromise attack and password guessing attacks,an improved and efficient verifier-based key exchange protocol for three-party is proposed,which enables two clients to agree on a common session key with the help of the server.In this protocol,the client stores a plaintext version of the password,while the server stores a verifier for the password.And the protocol uses verifiers to authenticate between clients and the server.The security analysis and performance comparison of the proposed protocol shows that the protocol can resist many familiar attacks including password guessing attacks,server compromise attacks,man-in-the-middle attacks and Denning-Sacco attacks,and it is more efficient.
基金Supported by National Natural Science Foundation of China(31072155)Natural Science Foundation of Jiangsu Province(BK2010068)+1 种基金Fund for Independent Innovation of Agricultural Science in Jiangsu Province[CX(11)2060]Special Fund for Agroscientific Research in the Public Interest(201303041)~~
文摘[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.
文摘This paper first develops the approaches to determine the geopotential of the local mean sea level,and then investigates the offset of the 1985 vertical datum surface defined by the mean sea level of Yellow Sea at the Dagang Tide Gauge in Qingdao city using the developed approaches and GPS/leveling data.It shows that the geopotential of the local mean sea level at the tide gauge is equal to 62 636 853.5±0.2 m2·s -2 and that the 1985 vertical datum surface is 24.6±5.4 cm above the geoid realized by the geopotential W 0= 62 636 856.0±0.5 m2·s -2.
文摘The rollup and the drilldown are quite frequent based on dimension hierarchies in on-line analytical processing （OLAP）, but prefixCube does not directly support dimension hierarchies. The PrefixCube is extended for incorporating hierarchical data cubes, i.e. cubes with hierarchical dimensions ,thus obtaining HierPrefixCube. HierPrefixCube retains advantages on computation and organization of PrefixCube, and it can directly support aggregate queries on levels of the dimension hierarchy.
基金Supported by the Natural Foundation of Jiangsu Province(BK2004427)~~
文摘The calculation of earth pressure is a difficult problem in the pit foundation design. Aiming at the problem, the earth pressure calculation formulas considering the displacement are proposed. A method for determining the limit displacement is given and it is convenient for use. The result indicates that the earth pressure calculated by the formulas is between the earth pressure at rest and the Rankine earth pressure, the formulas can reflect the change rules of active and passive earth pressures along with the displacement. Moreover, the calculation result using the formulas is approximate to the monitoring result. It confirms the validity of the formula deduction and the rationality of the calculation results. As for the passive earth pressure, the calculation method is theoretically feasible.
文摘This paper gives several fundamental theorems for the stability, uniform stability, asymptotic stability and uniform asymptotic stability. Those theorems allow the derivative of Lyapunov functions to be positive on certain sets,relax the restriction about the rate of change of state variable in a system to be bounded in Marachkov's theorem and extend the related results in [4—7].
基金Supported by Natural Science Foundation of Hubei Province(2012FFC03101)~~
文摘[Objective] This study aimed to investigate the optimal component of culti- vation medium for container seedling raising of Camellia oleifera. [Method] In the application of container nursery technology of Camellia oleifera grafting in emergent stocks, yellow clay soil, surface soil of pine forest, decomposed edible fungus, peat soil, dung and dirt were mixed by different proportions into five formulae as nursery substrates, with garden soil as the control, in order to investigate the influences of various substrates on the growth of annual Camellia oleifera container seedlings by using randomized block design based on variance analysis and multiple comparisons, and to screen the optimal substrate formula for container nursery of Camellia oleifera. [Result] The influences of different substrates on the transplanting survival rate, seedling height, basal diameter, height-diameter ratio and lateral root length of Camellia oleifera container seedlings were significantly different. Various growth indi- cators of Camellia oleifera container seedlings cultivated in the substrate containing 40% of yellow clay soil ＋ 15% of surface soil of pine forest ＋ 20% of decomposed edible fungus ＋ 20% of peat soil ＋ 5% of dung and dirt exceeded that of the control and other substrate formulae, which could be used as the optimal substrate formula for the container nursery of Camellia oleifera. [Conclusion] This study screened the optimal substrate formula for the container nursery of Camellia oleifera, which provided technical reference for the cultivation of Camellia oleifera container seedlings.
