Objective To investigate the effects of Total Saponins of Panax notoginseng(PNS) and Liguastrazine(LIT) on the proliferation of cultured cerebral microvascular endothelial cells. Methods The inverted microscope was us...Objective To investigate the effects of Total Saponins of Panax notoginseng(PNS) and Liguastrazine(LIT) on the proliferation of cultured cerebral microvascular endothelial cells. Methods The inverted microscope was used to observe endothelial cells and immunochemical methods was also used to detect FVIII-related antigens so as to observe endothelial cells. PNS or LIT in concentrations 0.5?g·L -1, 1.0?g·L -1 and 2.0?g·L -1 were used on the cultured cerebral endothelial cells of rats for 24 hours. MTT method was adopted to determine the outcome of endothelial proliferation. Results 1. Immunochemical methods was used to detect FVIII-related antigens. The brownish yellow showed positive, and the observation of the cultured endothelial cells under inverted microscope showed that the cells appeared to be in the morphological form of cobble-stones. 2. PNS in lower concentration (0.5?g·L -1) could facilitate the proliferation of the cells, while 1?g·L -1 and 2?g·L -1 of PNS could inhibit the proliferation of the cells. 0.5?g·L -1 of LIT could facilitate the proliferation of cellswhile LIT of 1?g·L -1 and 2?g·L -1 had no significant effect. Conclusion The two kind of TCM ingredients extracted in lower concentration could facilitate the proliferation of the cells. And, at the same concentration, the inhibition of PNS on the cells is stronger than that of LIT.展开更多
The travelling wave solutions (TWS) in a class of P. D. E. is studied. The travelling wave equation of this P. D. E. is a planar cubic polynomial system in three-parameter space. The study for M became the topological...The travelling wave solutions (TWS) in a class of P. D. E. is studied. The travelling wave equation of this P. D. E. is a planar cubic polynomial system in three-parameter space. The study for M became the topological classifications of bifurcations of phase portraits defined by the planar system. B using the theory of planar dynamical systems to do qualitative analysis, all topological classifications of the cubic polynomial system can be obtained. Returning the results of the phase plane analysis to TWS, u(xi), and considering discontinuity of the right side of the equation of TWS when xi = x - ct is varied along a phase orbit and passing through a singular curve, all conditions of existence of smooth and nonsmooth travelling waves are given.展开更多
Using the secondary spinel standard, the authors have precisely measured theFe^(3+)/SIGMA Fe values of spinels in mantle xenoliths from Cenozoic basalts in eastern China, andestimated the oxygen fugacities recorded by...Using the secondary spinel standard, the authors have precisely measured theFe^(3+)/SIGMA Fe values of spinels in mantle xenoliths from Cenozoic basalts in eastern China, andestimated the oxygen fugacities recorded by 63 mantle xenoliths through olivine-orthopyroxene-spineloxygen barometry. The results indicate that the oxygen fugacities of the lithospheric mantle ineastern China are higher in the south than in the north. Among them, the oxygen fugacity of theNorth China craton lithospheric mantle is the lowest, similar to that of the oceanic mantle, whilethat of Northeast and South China are the same as that of the global continental mantle. Thevariations of mantle redox state in eastern China are mainly controlled by the C-O-H fluids derivedfrom the asthenospheric mantle. According to the mantle oxidation state, it can be concluded thatthe C-O-H fluids in the lithospheric mantle of eastern China consist mainly of CO_2 and minor H_2O,but CH_4-rich fluids should come from the asthenosphere where the oxidation state is lower.展开更多
By using an LKB\|2277 bioactivity monitor and a mpoule method, the fundamental thermogenesis curves of the metabolic process of liver mitochondria from Carassius auratus hybrid carps and the toxic effect of Na ...By using an LKB\|2277 bioactivity monitor and a mpoule method, the fundamental thermogenesis curves of the metabolic process of liver mitochondria from Carassius auratus hybrid carps and the toxic effect of Na 2 SeO 3 on it were studied at 28 ℃.From the thermogenes is curves, the thermokinetic equations were established under different conditio n. The kinetics show that Na 2 SeO 3 has toxic action on the m etabolism process of Carassius auratus hybrid carps liver mitochondria.展开更多
In the heterogeneous digital libraries, users are allowed to have access to data of different modalities, from different information sources, and ranked by different criteria. This paper,which assumes that each inform...In the heterogeneous digital libraries, users are allowed to have access to data of different modalities, from different information sources, and ranked by different criteria. This paper,which assumes that each information retrieval model is satisfactory in its own context, proposes two results processing methods: Ranking by Sources (RBS) and Simply Merging Results (SMR). It defines satisfied ranking, which satisfies most source rankings, and satisfied distance to indicate how a specific source ranking suits the satisfied ranking. RBS ranks sources by their satisfied distances and groups the results by sources. SMR, using source scoring function distributions, substitutes normalized scores for original scores from sources, and then merges the results using these normalized scores. The results show they are very feasible and efficient in the heterogeneous展开更多
Based on the Yamamoto's soil model by considering the Coulomb friction effects, the wave-induced seabed instability has been investigated. An analytical solution is derived for soil response of a finite depth seab...Based on the Yamamoto's soil model by considering the Coulomb friction effects, the wave-induced seabed instability has been investigated. An analytical solution is derived for soil response of a finite depth seabed tinder surface water wave. The effects of wave parameters and soil characteristics on the seabed instability are addressed for three types of soil. Finally, the roles of Coulomb friction stability are then analyzed as well.展开更多
In this paper, the buoyancy, kinetic properties and stability of air floated structures have been studied by theoretical and experimental methods. The equations for calculation of the buoyancy of the air floated buoy ...In this paper, the buoyancy, kinetic properties and stability of air floated structures have been studied by theoretical and experimental methods. The equations for calculation of the buoyancy of the air floated buoy are derived according to the Boyler law and the equilibrium equations of the air floated structure are established. Through simplification of the air floated structure as a single freedom rigid body and spring system, the natural period of heaving and some kinetic properties are discussed. In the stability analysis, the formulas for calculation of the meta centric height are presented. The theoretical results are in good agreement with the data observed from the model test and prototype test. The air buoyancy decrease coefficient presented in this paper has a large influence on the floating state, stability and dynamic properties of the air floated structure. The stability of the air floated structure can also be judged by the parameter of meta centric height, and calculations show that the air floated structure is less stable than the conventional float.展开更多
Adaptive space-time finite element method, continuous in space but discontinuous in time for semi-linear parabolic problems is discussed. The approach is based on a combination of finite element and finite difference ...Adaptive space-time finite element method, continuous in space but discontinuous in time for semi-linear parabolic problems is discussed. The approach is based on a combination of finite element and finite difference techniques. The existence and uniqueness of the weak solution are proved without any assumptions on choice of the spacetime meshes. Basic error estimates in L-infinity (L-2) norm, that is maximum-norm in time, L-2-norm in space are obtained. The numerical results are given in the last part and the analysis between theoretic and experimental results are obtained.展开更多
In this paper,we proposal stream surface and stream layer.By using classical tensor calculus,we derive 3-D Navier-Stokes Equations(NSE)in the stream layer under semigeodesic coordinate system,Navier-Stokes equation on...In this paper,we proposal stream surface and stream layer.By using classical tensor calculus,we derive 3-D Navier-Stokes Equations(NSE)in the stream layer under semigeodesic coordinate system,Navier-Stokes equation on the stream surface and 2-D Navier-Stokes equations on a two dimensional manifold. After introducing stream function on the stream surface,a nonlinear initial-boundary value problem satisfies by stream function is obtained,existence and uniqueness of its solution are proven.Based this theory we proposal a new method called"dimension split method"to solve 3D NSE.展开更多
A new shell finite element method (FEM) model with an equivalent boundary is presented for estimating the re- sponse of a buried pipeline under large fault movement. The length of affected pipeline under fault movemen...A new shell finite element method (FEM) model with an equivalent boundary is presented for estimating the re- sponse of a buried pipeline under large fault movement. The length of affected pipeline under fault movement is usually too long for a shell-mode calculation because of the limitation of memory and time of computers. In this study, only the pipeline segment near fault is modeled with plastic shell elements to study the local buckling and the large section deformation in pipe. The material property of pipe segment far away from the fault is considered as elastic, and nonlinear spring elements at equivalent boundaries are obtained and applied to two ends of shell model. Compared with the fixed-boundary shell model, the shell model with an equivalent boundary proposed by the study can remarkably reduce the needed memory and calculating time.展开更多
The fundamental principle and method of the determining of structure parameters for the hydraulic elastic bulging roller were discussed. The relationship among crown of roller, hydraulic pressure and thickness of roll...The fundamental principle and method of the determining of structure parameters for the hydraulic elastic bulging roller were discussed. The relationship among crown of roller, hydraulic pressure and thickness of roller sleeve was studied. Aluminum was chosen as experimental material to accomplish the dynamic load experiment. The hydraulic elastic bulging roller exerts good effect on shape control and therefore has a broad application prospect in engineering. [展开更多
The structural analysis based on the explanation of seismic profiles indicates that a lot of thrust faults and strike-slip faults of Late Cenozoic occur in western Hexi Corridor and its nearby regions. They can be di...The structural analysis based on the explanation of seismic profiles indicates that a lot of thrust faults and strike-slip faults of Late Cenozoic occur in western Hexi Corridor and its nearby regions. They can be divided into two types. One is thrust faults dipping southwards and extending NWwards, which was mainly correlated with the thrusting of northern Qilianshan and located at the NE margin of Qilianshan and the southwestern Hexi Corridor, the other is thrust faults and strike-slip faults that were related to the strike-slipping of Altun fault and located mainly at the regions of Hongliuxia, Kuantaishan, and Helishan that are close to the Altun fault. All these faults, which were related to the remote effects of collision between the two continents of India and Tibet during the Late Eocene and later, started to develop since the Late Tertiary and presented the features of violent thrust or strike-slip movement in Quaternary. Many of them are still active up to now and thus belong to the active faults that are the potential inducement of earthquakes in the Hexi Corridor. Moreover, a lot of intense structural deformation and many morphology phenomena such as tectonic terrace and river offset were formed under the control of these faults in Quaternary.展开更多
In this paper, we first provide a generalized difference method for the 2-dimensional Navier-Stokes equations by combing the ideas of staggered scheme m and generalized upwind scheme in space, and by backward Euler ti...In this paper, we first provide a generalized difference method for the 2-dimensional Navier-Stokes equations by combing the ideas of staggered scheme m and generalized upwind scheme in space, and by backward Euler time-stepping. Then we apply the abstract framework of to prove its long-time convergence. Finally, a numerical example for solving driven cavity flows is given.展开更多
A new algorithm combining nonlinear Galerkin method and coupling method of finite element and boundary element is introduced to solve the exterior nonstationary Navier-Stokes equations. The regularity of the coupling ...A new algorithm combining nonlinear Galerkin method and coupling method of finite element and boundary element is introduced to solve the exterior nonstationary Navier-Stokes equations. The regularity of the coupling variational formulation and the convergence of the approximate solution corresponding to the algorithm are proved. If the fine mesh h is chosen as coarse mesh H-square, the nonlinear Galerkin method, nonlinearity is only treated on the coarse grid and linearity is treated on the fine grid. Hence, the new algorithm can save a large amount of computational time.展开更多
Summary: The effects of angiotensin Ⅱ receptor antagonist losartan on elastic properties of aorta in patients with mild to moderate essential hypertension were assessed. The ascending aortic distensibility in 26 pat...Summary: The effects of angiotensin Ⅱ receptor antagonist losartan on elastic properties of aorta in patients with mild to moderate essential hypertension were assessed. The ascending aortic distensibility in 26 patients (48±3 years) with mild to moderate essential hypertension before and after 12 weeks of treatment with losartan (50 mg/day) was evaluated by using two-dimensional echocardiography. M-mode measurements of aortic systolic (D s) and diastolic diameter (D d) were taken at a level approximately 3 cm above the aortic valve. Simultaneously, cuff brachial artery systolic (SBP) and diastolic(DBP) pressures were measured. Aortic pressure-strain elastic modulus (E p) was calculated as D d×(SBP-DBP)/(D s-D d)×1333 and stiffness index beta (β) was defined as D d×Ln (SBP/DBP)/(D s-D d). Blood pressure significantly decreased from 148±13/95±9 mmHg to 138±12/88±8 mmHg (systolic blood pressure, P=0.001; diastolic blood pressure, P=0.003). There was no significant difference in pulse pressure before and after treatment with losartan (53±10 mmHg vs 50±7 mmHg). The distensibility of ascending aorta increased significantly as showed by the significant decrease in pressure-strain elastic modulus from 4.42±5.79×10 6 dynes/cm 2 to 1.99±1.49×10 6 dynes/cm 2 (P=0.02) and stiffness index beta from 27.4±32.9 to 13.3±9.9 (P=0.02). Although there was a weak correlation between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in diastolic blood pressure after losartan treatment(r=0.40, P=0.04 and r=0.55, P=0.004, respectively), no correlation was found between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in systolic blood pressure (r=0.04, P=0.8 and r=0.24, P=0.2, respectively). Our study demonstrated that angiotensin Ⅱ receptor antagonist losartan has a beneficial effect on aortic distensibility in patients with mild to moderate essential hypertension and this effect is partly independent of blood pressure reduction.展开更多
Simulating annealing algorithm was used in docking computation to predict a selected peptide VYMSPF(P2) binding site on the ectodomain of FGFR1. The peptide is located on the hydrophobic surface of the receptor, which...Simulating annealing algorithm was used in docking computation to predict a selected peptide VYMSPF(P2) binding site on the ectodomain of FGFR1. The peptide is located on the hydrophobic surface of the receptor, which is critical for FGF binding. The synthesized peptide can effectively inhibit the mitogenic activity of aFGF, and has a potential to become a therapeutic agent as an aFGF antagonist.展开更多
Macroporous poly (vinyl acetate-co-triallyl isocyanurate) beads were prepared with suspension polymerization method. The copolymer beads were then transformed into poly (vinyl alcohol-co-triallyl isocyanurate) by est...Macroporous poly (vinyl acetate-co-triallyl isocyanurate) beads were prepared with suspension polymerization method. The copolymer beads were then transformed into poly (vinyl alcohol-co-triallyl isocyanurate) by ester exchange reaction. Aminocarboxylic acids were immobilized on the copolymer beads by the esterification of hydroxyl groups with diethyl-lenetriaminepentaacetic bisanhydride. The weak acid exchange capacities, specific surface areas and mean pore diameters of the resultant resin beads were measured.展开更多
Aiming at the complexity of seismic gestation mechanism and spatial distribution, we hypothesize that the seismic data are composed of background earthquakes and anomaly earthquakes in a certain temporal-spatial scope...Aiming at the complexity of seismic gestation mechanism and spatial distribution, we hypothesize that the seismic data are composed of background earthquakes and anomaly earthquakes in a certain temporal-spatial scope. Also the background earthquakes and anomaly earthquakes both satisfy the 2-D Poisson process of different parameters respectively. In the paper, the concept of N-th order distance is introduced in order to transform 2-D superimposed Poisson process into 1-D mixture density function. On the basis of choosing the distance, mixture density function is decomposed to recognize the anomaly earthquakes through genetic algorithm. Combined with the temporal scanning of C value, the algorithm is applied to the recognition on spatial pattern of foreshock anomalies by exam-ples of Songpan and Longling sequences in the southwest of China.展开更多
A novel b-cyclodextrin dimer bearing 2, 9-diformyl-1, 10-phenanthroline tether 4 has been synthesized and its inclusion complexation behavior with two triangular model substrates (RhB and BG) has been investigated thr...A novel b-cyclodextrin dimer bearing 2, 9-diformyl-1, 10-phenanthroline tether 4 has been synthesized and its inclusion complexation behavior with two triangular model substrates (RhB and BG) has been investigated through fluorescence and ultraviolet spectrometry. The result obtained indicated that novel bridged bis(b-cyclodextrin)s could significantly enhance the original molecular binding ability of native b-cyclodextrin by cooperative binding of two hydrophobic cavities.展开更多
In the present paper, the authors summarize their results of 30 cases of external humeral epicondylitis treated with thermal acupuncture of Chongyang (ST 42) and Ashi points. After 3-15 sessions of treatment, of the 3...In the present paper, the authors summarize their results of 30 cases of external humeral epicondylitis treated with thermal acupuncture of Chongyang (ST 42) and Ashi points. After 3-15 sessions of treatment, of the 30 cases, 24 (80%) were cured, and the rest 6 (20%) responded with apparent improvement in their symptoms.展开更多
文摘Objective To investigate the effects of Total Saponins of Panax notoginseng(PNS) and Liguastrazine(LIT) on the proliferation of cultured cerebral microvascular endothelial cells. Methods The inverted microscope was used to observe endothelial cells and immunochemical methods was also used to detect FVIII-related antigens so as to observe endothelial cells. PNS or LIT in concentrations 0.5?g·L -1, 1.0?g·L -1 and 2.0?g·L -1 were used on the cultured cerebral endothelial cells of rats for 24 hours. MTT method was adopted to determine the outcome of endothelial proliferation. Results 1. Immunochemical methods was used to detect FVIII-related antigens. The brownish yellow showed positive, and the observation of the cultured endothelial cells under inverted microscope showed that the cells appeared to be in the morphological form of cobble-stones. 2. PNS in lower concentration (0.5?g·L -1) could facilitate the proliferation of the cells, while 1?g·L -1 and 2?g·L -1 of PNS could inhibit the proliferation of the cells. 0.5?g·L -1 of LIT could facilitate the proliferation of cellswhile LIT of 1?g·L -1 and 2?g·L -1 had no significant effect. Conclusion The two kind of TCM ingredients extracted in lower concentration could facilitate the proliferation of the cells. And, at the same concentration, the inhibition of PNS on the cells is stronger than that of LIT.
文摘The travelling wave solutions (TWS) in a class of P. D. E. is studied. The travelling wave equation of this P. D. E. is a planar cubic polynomial system in three-parameter space. The study for M became the topological classifications of bifurcations of phase portraits defined by the planar system. B using the theory of planar dynamical systems to do qualitative analysis, all topological classifications of the cubic polynomial system can be obtained. Returning the results of the phase plane analysis to TWS, u(xi), and considering discontinuity of the right side of the equation of TWS when xi = x - ct is varied along a phase orbit and passing through a singular curve, all conditions of existence of smooth and nonsmooth travelling waves are given.
基金the Nationa1 Natural Science Foundation(Grant No.49673185)the Ministry of Science and Technology of China(Grant No.95-Pre-39).
文摘Using the secondary spinel standard, the authors have precisely measured theFe^(3+)/SIGMA Fe values of spinels in mantle xenoliths from Cenozoic basalts in eastern China, andestimated the oxygen fugacities recorded by 63 mantle xenoliths through olivine-orthopyroxene-spineloxygen barometry. The results indicate that the oxygen fugacities of the lithospheric mantle ineastern China are higher in the south than in the north. Among them, the oxygen fugacity of theNorth China craton lithospheric mantle is the lowest, similar to that of the oceanic mantle, whilethat of Northeast and South China are the same as that of the global continental mantle. Thevariations of mantle redox state in eastern China are mainly controlled by the C-O-H fluids derivedfrom the asthenospheric mantle. According to the mantle oxidation state, it can be concluded thatthe C-O-H fluids in the lithospheric mantle of eastern China consist mainly of CO_2 and minor H_2O,but CH_4-rich fluids should come from the asthenosphere where the oxidation state is lower.
文摘By using an LKB\|2277 bioactivity monitor and a mpoule method, the fundamental thermogenesis curves of the metabolic process of liver mitochondria from Carassius auratus hybrid carps and the toxic effect of Na 2 SeO 3 on it were studied at 28 ℃.From the thermogenes is curves, the thermokinetic equations were established under different conditio n. The kinetics show that Na 2 SeO 3 has toxic action on the m etabolism process of Carassius auratus hybrid carps liver mitochondria.
文摘In the heterogeneous digital libraries, users are allowed to have access to data of different modalities, from different information sources, and ranked by different criteria. This paper,which assumes that each information retrieval model is satisfactory in its own context, proposes two results processing methods: Ranking by Sources (RBS) and Simply Merging Results (SMR). It defines satisfied ranking, which satisfies most source rankings, and satisfied distance to indicate how a specific source ranking suits the satisfied ranking. RBS ranks sources by their satisfied distances and groups the results by sources. SMR, using source scoring function distributions, substitutes normalized scores for original scores from sources, and then merges the results using these normalized scores. The results show they are very feasible and efficient in the heterogeneous
文摘Based on the Yamamoto's soil model by considering the Coulomb friction effects, the wave-induced seabed instability has been investigated. An analytical solution is derived for soil response of a finite depth seabed tinder surface water wave. The effects of wave parameters and soil characteristics on the seabed instability are addressed for three types of soil. Finally, the roles of Coulomb friction stability are then analyzed as well.
文摘In this paper, the buoyancy, kinetic properties and stability of air floated structures have been studied by theoretical and experimental methods. The equations for calculation of the buoyancy of the air floated buoy are derived according to the Boyler law and the equilibrium equations of the air floated structure are established. Through simplification of the air floated structure as a single freedom rigid body and spring system, the natural period of heaving and some kinetic properties are discussed. In the stability analysis, the formulas for calculation of the meta centric height are presented. The theoretical results are in good agreement with the data observed from the model test and prototype test. The air buoyancy decrease coefficient presented in this paper has a large influence on the floating state, stability and dynamic properties of the air floated structure. The stability of the air floated structure can also be judged by the parameter of meta centric height, and calculations show that the air floated structure is less stable than the conventional float.
文摘Adaptive space-time finite element method, continuous in space but discontinuous in time for semi-linear parabolic problems is discussed. The approach is based on a combination of finite element and finite difference techniques. The existence and uniqueness of the weak solution are proved without any assumptions on choice of the spacetime meshes. Basic error estimates in L-infinity (L-2) norm, that is maximum-norm in time, L-2-norm in space are obtained. The numerical results are given in the last part and the analysis between theoretic and experimental results are obtained.
文摘In this paper,we proposal stream surface and stream layer.By using classical tensor calculus,we derive 3-D Navier-Stokes Equations(NSE)in the stream layer under semigeodesic coordinate system,Navier-Stokes equation on the stream surface and 2-D Navier-Stokes equations on a two dimensional manifold. After introducing stream function on the stream surface,a nonlinear initial-boundary value problem satisfies by stream function is obtained,existence and uniqueness of its solution are proven.Based this theory we proposal a new method called"dimension split method"to solve 3D NSE.
基金National Natural Sciences Foundation of China (50078049)
文摘A new shell finite element method (FEM) model with an equivalent boundary is presented for estimating the re- sponse of a buried pipeline under large fault movement. The length of affected pipeline under fault movement is usually too long for a shell-mode calculation because of the limitation of memory and time of computers. In this study, only the pipeline segment near fault is modeled with plastic shell elements to study the local buckling and the large section deformation in pipe. The material property of pipe segment far away from the fault is considered as elastic, and nonlinear spring elements at equivalent boundaries are obtained and applied to two ends of shell model. Compared with the fixed-boundary shell model, the shell model with an equivalent boundary proposed by the study can remarkably reduce the needed memory and calculating time.
文摘The fundamental principle and method of the determining of structure parameters for the hydraulic elastic bulging roller were discussed. The relationship among crown of roller, hydraulic pressure and thickness of roller sleeve was studied. Aluminum was chosen as experimental material to accomplish the dynamic load experiment. The hydraulic elastic bulging roller exerts good effect on shape control and therefore has a broad application prospect in engineering. [
文摘The structural analysis based on the explanation of seismic profiles indicates that a lot of thrust faults and strike-slip faults of Late Cenozoic occur in western Hexi Corridor and its nearby regions. They can be divided into two types. One is thrust faults dipping southwards and extending NWwards, which was mainly correlated with the thrusting of northern Qilianshan and located at the NE margin of Qilianshan and the southwestern Hexi Corridor, the other is thrust faults and strike-slip faults that were related to the strike-slipping of Altun fault and located mainly at the regions of Hongliuxia, Kuantaishan, and Helishan that are close to the Altun fault. All these faults, which were related to the remote effects of collision between the two continents of India and Tibet during the Late Eocene and later, started to develop since the Late Tertiary and presented the features of violent thrust or strike-slip movement in Quaternary. Many of them are still active up to now and thus belong to the active faults that are the potential inducement of earthquakes in the Hexi Corridor. Moreover, a lot of intense structural deformation and many morphology phenomena such as tectonic terrace and river offset were formed under the control of these faults in Quaternary.
基金The project supported by Laboratory of Computational Physics,Institute of Applied Physics & Computational Mathematics,T.O.Box 80 0 9,Beijing 1 0 0 0 88
文摘In this paper, we first provide a generalized difference method for the 2-dimensional Navier-Stokes equations by combing the ideas of staggered scheme m and generalized upwind scheme in space, and by backward Euler time-stepping. Then we apply the abstract framework of to prove its long-time convergence. Finally, a numerical example for solving driven cavity flows is given.
文摘A new algorithm combining nonlinear Galerkin method and coupling method of finite element and boundary element is introduced to solve the exterior nonstationary Navier-Stokes equations. The regularity of the coupling variational formulation and the convergence of the approximate solution corresponding to the algorithm are proved. If the fine mesh h is chosen as coarse mesh H-square, the nonlinear Galerkin method, nonlinearity is only treated on the coarse grid and linearity is treated on the fine grid. Hence, the new algorithm can save a large amount of computational time.
文摘Summary: The effects of angiotensin Ⅱ receptor antagonist losartan on elastic properties of aorta in patients with mild to moderate essential hypertension were assessed. The ascending aortic distensibility in 26 patients (48±3 years) with mild to moderate essential hypertension before and after 12 weeks of treatment with losartan (50 mg/day) was evaluated by using two-dimensional echocardiography. M-mode measurements of aortic systolic (D s) and diastolic diameter (D d) were taken at a level approximately 3 cm above the aortic valve. Simultaneously, cuff brachial artery systolic (SBP) and diastolic(DBP) pressures were measured. Aortic pressure-strain elastic modulus (E p) was calculated as D d×(SBP-DBP)/(D s-D d)×1333 and stiffness index beta (β) was defined as D d×Ln (SBP/DBP)/(D s-D d). Blood pressure significantly decreased from 148±13/95±9 mmHg to 138±12/88±8 mmHg (systolic blood pressure, P=0.001; diastolic blood pressure, P=0.003). There was no significant difference in pulse pressure before and after treatment with losartan (53±10 mmHg vs 50±7 mmHg). The distensibility of ascending aorta increased significantly as showed by the significant decrease in pressure-strain elastic modulus from 4.42±5.79×10 6 dynes/cm 2 to 1.99±1.49×10 6 dynes/cm 2 (P=0.02) and stiffness index beta from 27.4±32.9 to 13.3±9.9 (P=0.02). Although there was a weak correlation between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in diastolic blood pressure after losartan treatment(r=0.40, P=0.04 and r=0.55, P=0.004, respectively), no correlation was found between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in systolic blood pressure (r=0.04, P=0.8 and r=0.24, P=0.2, respectively). Our study demonstrated that angiotensin Ⅱ receptor antagonist losartan has a beneficial effect on aortic distensibility in patients with mild to moderate essential hypertension and this effect is partly independent of blood pressure reduction.
基金Supported by a grant from the National Natural Science Foundation of China(No.30 0 70 892 )
文摘Simulating annealing algorithm was used in docking computation to predict a selected peptide VYMSPF(P2) binding site on the ectodomain of FGFR1. The peptide is located on the hydrophobic surface of the receptor, which is critical for FGF binding. The synthesized peptide can effectively inhibit the mitogenic activity of aFGF, and has a potential to become a therapeutic agent as an aFGF antagonist.
基金This work was supported by the National 973 project (G1999064707)
文摘Macroporous poly (vinyl acetate-co-triallyl isocyanurate) beads were prepared with suspension polymerization method. The copolymer beads were then transformed into poly (vinyl alcohol-co-triallyl isocyanurate) by ester exchange reaction. Aminocarboxylic acids were immobilized on the copolymer beads by the esterification of hydroxyl groups with diethyl-lenetriaminepentaacetic bisanhydride. The weak acid exchange capacities, specific surface areas and mean pore diameters of the resultant resin beads were measured.
文摘Aiming at the complexity of seismic gestation mechanism and spatial distribution, we hypothesize that the seismic data are composed of background earthquakes and anomaly earthquakes in a certain temporal-spatial scope. Also the background earthquakes and anomaly earthquakes both satisfy the 2-D Poisson process of different parameters respectively. In the paper, the concept of N-th order distance is introduced in order to transform 2-D superimposed Poisson process into 1-D mixture density function. On the basis of choosing the distance, mixture density function is decomposed to recognize the anomaly earthquakes through genetic algorithm. Combined with the temporal scanning of C value, the algorithm is applied to the recognition on spatial pattern of foreshock anomalies by exam-ples of Songpan and Longling sequences in the southwest of China.
基金This work was supported by the National Natural Science Foundation (No.299925908 and 29972029) of China Tianjin Natural Science Foundation (No.013613511) the Foundation of Ministry of Education, which are gratefully acknowledged.
文摘A novel b-cyclodextrin dimer bearing 2, 9-diformyl-1, 10-phenanthroline tether 4 has been synthesized and its inclusion complexation behavior with two triangular model substrates (RhB and BG) has been investigated through fluorescence and ultraviolet spectrometry. The result obtained indicated that novel bridged bis(b-cyclodextrin)s could significantly enhance the original molecular binding ability of native b-cyclodextrin by cooperative binding of two hydrophobic cavities.
文摘In the present paper, the authors summarize their results of 30 cases of external humeral epicondylitis treated with thermal acupuncture of Chongyang (ST 42) and Ashi points. After 3-15 sessions of treatment, of the 30 cases, 24 (80%) were cured, and the rest 6 (20%) responded with apparent improvement in their symptoms.