Underwater vehicles have already adopted self-correcting directional guidance algorithms based on multi-beam self-guidance systems, not waiting for research to determine the most effective algorithms. The main challen...Underwater vehicles have already adopted self-correcting directional guidance algorithms based on multi-beam self-guidance systems, not waiting for research to determine the most effective algorithms. The main challenges facing research on these guidance systems have been effective modeling of the guidance algorithm and a means to analyze the simulation results. A simulation structure based on Simulink that dealt with both issues was proposed. Initially, a mathematical model of relative motion between the vehicle and the target was developed, which was then encapsulated as a subsystem. Next, steps for constructing a model of the self-correcting guidance algorithm based on the Stateflow module were examined in detail. Finally, a 3-D model of the vehicle and target was created in VRML, and by processing mathematical results, the model was shown moving in a visual environment. This process gives more intuitive results for analyzing the simulation. The results showed that the simulation structure performs well. The simulation program heavily used modularization and encapsulation, so has broad applicability to simulations of other dynamic systems.展开更多
A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visua...A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visual guiding mode, for the robot works in an open loop visual servo control mode, the manipulating burden of the operator is reduced largely. In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator. With the help of the operator, the diffieuh problems of finding and handling a target in a complicated environment by the robot can be solved easily.展开更多
Since the lower power requirement of code division multiple access(CDMA) than that of other multiple access, the CDMA technology is suitable to be used in low earth orbit(LEO) satellite communication system whose spac...Since the lower power requirement of code division multiple access(CDMA) than that of other multiple access, the CDMA technology is suitable to be used in low earth orbit(LEO) satellite communication system whose space power is limited due to the small size of satellite. The pilot channel of CDMA technology is very important for earth mobile station(EMS) in LEO system to recover carrier and code, but the power requirement of pilot channel is very higher than that of other channels. In this paper, a power reduction method for pilot channel is proposed. By the new method, the power of pilot channel transmitted from LEO satellite is reduced to a lower level. For improving the signal to noise ratio(SNR) of pilot channel with lower power, coherent integration is employed in EMS at the pre-processing stage. Considering the high dynamic situation of LEO satellite, the long period of time for integration will deteriorate the receiving performance of EMS, therefore, a dynamic compensation module is added to carrier tracking loop against the high dynamic. Meanwhile, the transfer function of the new tracking loop and the condition for steadystate zero error are deduced. Numerical examples are provided to demonstrate effectiveness of the proposed approach.展开更多
The plasma membrane calcium ATPases(PMCA) are a family of genes which extrude Ca2+from the cell and are involved in the maintenance of intracellular free calcium levels and/or with Ca2+signalling,depending on the cell...The plasma membrane calcium ATPases(PMCA) are a family of genes which extrude Ca2+from the cell and are involved in the maintenance of intracellular free calcium levels and/or with Ca2+signalling,depending on the cell type.In the cardiovascular system,Ca2+ is not only essential for contraction and relaxation but also has a vital role as a second messenger in signal transduction pathways.A complex array of mechanisms regulate intracellular free calcium levels in the heart and vasculature and a failure in these systems to maintain normal Ca2+homeostasis has been linked to both heart failure and hypertension.This article focuses on the functions of PMCA,in particular isoform 4(PMCA4) ,in the heart and vasculature and the reported links between PMCAs and contractile function,cardiac hypertrophy,cardiac rhythm and sudden cardiac death,and blood pressure control and hypertension.It is becoming clear that this family of calcium extrusion pumps have essential roles in both cardiovascular health and disease.展开更多
A global asymptotic analysis of orthogonal polynomials via the Riemann-Hilbert approach is presented,with respect to the polynomial degree.The domains of uniformity are described in certain phase variables.A resurgenc...A global asymptotic analysis of orthogonal polynomials via the Riemann-Hilbert approach is presented,with respect to the polynomial degree.The domains of uniformity are described in certain phase variables.A resurgence relation within the sequence of Riemann-Hilbert problems is observed in the procedure of derivation.Global asymptotic approximations are obtained in terms of the Airy function.The system of Hermite polynomials is used as an illustration.展开更多
In this study, the soft magnetic properties and crystallization behavior of Fes3B10C6-xSixCul （x=0-4） nanocrystalline alloys prepared by annealing the melt-spun amorphous ribbons have been investigated. It is found ...In this study, the soft magnetic properties and crystallization behavior of Fes3B10C6-xSixCul （x=0-4） nanocrystalline alloys prepared by annealing the melt-spun amorphous ribbons have been investigated. It is found that in the Fe83B10C6-xSixCU1 alloy system, the coercivity （Hc） decreases slightly with increasing Si addition and exhibits a minimum value with composition of x = 2, while the effective permeability （Ue） shows an opposite variation trend. The saturation magnetic flux density （Bs） shows a slightly decreasing trend owing to the decreasing volume fraction of nanocrystalline phase. The Fe83B10CaSi2Cu1 nanocrystalline alloy exhibits excellent soft magnetic properties with a high Bs of 1.78 T, high ue of 13 600 and low Hc of 4 A/m.展开更多
p75NTR is a low-affinity nerve growth factor receptor, which promotes cell proliferation as a positive modulator of high-affinity receptor TrkA, as well as binds with cell ligands to induce apoptosis and mediate death...p75NTR is a low-affinity nerve growth factor receptor, which promotes cell proliferation as a positive modulator of high-affinity receptor TrkA, as well as binds with cell ligands to induce apoptosis and mediate death signals. To analyze the regulatory mechanisms of p75NTR, the present study utilized a new membrane yeast two-hybrid system to screen a human fe- tal brain cDNA library. Results identified BFAR, a novel protein that interacts with p75NTR. Interaction specificity was veri- fied by membrane yeast two-hybrid co-transformation assays, in vitro GST pull-down assays, and in vitro co-irnmunopreci- pitation assays. The fluorescent subcellular localization assay revealed that the two proteins co-localized within the cytoplasm. BFAR overexpression in PC-12 and HEK293T cells inhibited the NFnB and JNK signaling pathway, as determined with the luciferase test. Co-transfected p75NTR and BFAR in HEK293T or PC-12 cells, respectively, increased the percentage of cells in the G2/M phase, decreased the number of S-phase cells, and did not change the number of G0/Gl-phase cells.展开更多
文摘Underwater vehicles have already adopted self-correcting directional guidance algorithms based on multi-beam self-guidance systems, not waiting for research to determine the most effective algorithms. The main challenges facing research on these guidance systems have been effective modeling of the guidance algorithm and a means to analyze the simulation results. A simulation structure based on Simulink that dealt with both issues was proposed. Initially, a mathematical model of relative motion between the vehicle and the target was developed, which was then encapsulated as a subsystem. Next, steps for constructing a model of the self-correcting guidance algorithm based on the Stateflow module were examined in detail. Finally, a 3-D model of the vehicle and target was created in VRML, and by processing mathematical results, the model was shown moving in a visual environment. This process gives more intuitive results for analyzing the simulation. The results showed that the simulation structure performs well. The simulation program heavily used modularization and encapsulation, so has broad applicability to simulations of other dynamic systems.
基金Supported by the National High Technology Research and Development Program of China （No. 2003AA421030） and the National Science Foundation of China （No. 60375026）.
文摘A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visual guiding mode, for the robot works in an open loop visual servo control mode, the manipulating burden of the operator is reduced largely. In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator. With the help of the operator, the diffieuh problems of finding and handling a target in a complicated environment by the robot can be solved easily.
基金supported by the National High Technology Research and Development Program of China (863 Program) (No.2012AA01A502)the National Natural Science Foundation of China (No.61179006)the Science and Technology Support Program of Sichuan Province (No.2014GZX0004)
文摘Since the lower power requirement of code division multiple access(CDMA) than that of other multiple access, the CDMA technology is suitable to be used in low earth orbit(LEO) satellite communication system whose space power is limited due to the small size of satellite. The pilot channel of CDMA technology is very important for earth mobile station(EMS) in LEO system to recover carrier and code, but the power requirement of pilot channel is very higher than that of other channels. In this paper, a power reduction method for pilot channel is proposed. By the new method, the power of pilot channel transmitted from LEO satellite is reduced to a lower level. For improving the signal to noise ratio(SNR) of pilot channel with lower power, coherent integration is employed in EMS at the pre-processing stage. Considering the high dynamic situation of LEO satellite, the long period of time for integration will deteriorate the receiving performance of EMS, therefore, a dynamic compensation module is added to carrier tracking loop against the high dynamic. Meanwhile, the transfer function of the new tracking loop and the condition for steadystate zero error are deduced. Numerical examples are provided to demonstrate effectiveness of the proposed approach.
文摘The plasma membrane calcium ATPases(PMCA) are a family of genes which extrude Ca2+from the cell and are involved in the maintenance of intracellular free calcium levels and/or with Ca2+signalling,depending on the cell type.In the cardiovascular system,Ca2+ is not only essential for contraction and relaxation but also has a vital role as a second messenger in signal transduction pathways.A complex array of mechanisms regulate intracellular free calcium levels in the heart and vasculature and a failure in these systems to maintain normal Ca2+homeostasis has been linked to both heart failure and hypertension.This article focuses on the functions of PMCA,in particular isoform 4(PMCA4) ,in the heart and vasculature and the reported links between PMCAs and contractile function,cardiac hypertrophy,cardiac rhythm and sudden cardiac death,and blood pressure control and hypertension.It is becoming clear that this family of calcium extrusion pumps have essential roles in both cardiovascular health and disease.
基金supported in part by National Natural Science Foundation of China(Grant Nos. 10471154,10871212)
文摘A global asymptotic analysis of orthogonal polynomials via the Riemann-Hilbert approach is presented,with respect to the polynomial degree.The domains of uniformity are described in certain phase variables.A resurgence relation within the sequence of Riemann-Hilbert problems is observed in the procedure of derivation.Global asymptotic approximations are obtained in terms of the Airy function.The system of Hermite polynomials is used as an illustration.
基金supported by the National High Technology Research and Development Program of China (863 Program) (Grant No.2009AA03Z214)the National Science Fund of China for Distinguished Young Scholars (Grant No. 50825103)+2 种基金the National Natural Science Foundation of China (Grant No. 51001112)the "Hundred of Talents Program" (Grant No. KGCX-2-YW-803) by Chinese Academy of Sciencesthe Fundamental Research Funds for the Central Universities (Grant No. 2010B15414)
文摘In this study, the soft magnetic properties and crystallization behavior of Fes3B10C6-xSixCul （x=0-4） nanocrystalline alloys prepared by annealing the melt-spun amorphous ribbons have been investigated. It is found that in the Fe83B10C6-xSixCU1 alloy system, the coercivity （Hc） decreases slightly with increasing Si addition and exhibits a minimum value with composition of x = 2, while the effective permeability （Ue） shows an opposite variation trend. The saturation magnetic flux density （Bs） shows a slightly decreasing trend owing to the decreasing volume fraction of nanocrystalline phase. The Fe83B10CaSi2Cu1 nanocrystalline alloy exhibits excellent soft magnetic properties with a high Bs of 1.78 T, high ue of 13 600 and low Hc of 4 A/m.
基金supported by the National High Technology Research and Development Program of China (Grant No. 2006AA02A310)National Science and Technology Key Program of China (Grant Nos. 2008ZX10003-006 and 2009ZX09301011)National Basic Research Program of China (Grant No. 2010CB912609) which were awarded to Huo KeKe
文摘p75NTR is a low-affinity nerve growth factor receptor, which promotes cell proliferation as a positive modulator of high-affinity receptor TrkA, as well as binds with cell ligands to induce apoptosis and mediate death signals. To analyze the regulatory mechanisms of p75NTR, the present study utilized a new membrane yeast two-hybrid system to screen a human fe- tal brain cDNA library. Results identified BFAR, a novel protein that interacts with p75NTR. Interaction specificity was veri- fied by membrane yeast two-hybrid co-transformation assays, in vitro GST pull-down assays, and in vitro co-irnmunopreci- pitation assays. The fluorescent subcellular localization assay revealed that the two proteins co-localized within the cytoplasm. BFAR overexpression in PC-12 and HEK293T cells inhibited the NFnB and JNK signaling pathway, as determined with the luciferase test. Co-transfected p75NTR and BFAR in HEK293T or PC-12 cells, respectively, increased the percentage of cells in the G2/M phase, decreased the number of S-phase cells, and did not change the number of G0/Gl-phase cells.
