Fluidic Thrust Vectoring(FTV)is used for the yaw attitude control of tailless flying wing,which can significantly improve stealth performance,maneuverability and lateral/heading maneuverability.The FTV control scheme ...Fluidic Thrust Vectoring(FTV)is used for the yaw attitude control of tailless flying wing,which can significantly improve stealth performance,maneuverability and lateral/heading maneuverability.The FTV control scheme of co-directional secondary flow was designed based on a 30 kgf thrust turbojet engine,an equivalent rudder deflection control variable of Mass Flow Combination(MFC)was proposed,and a control model was established to form a FTV control system scheme,which was integrated with the flight control system of a 100 kg tailless flying wing with medium aspect ratio to achieve closed-loop control of the yaw attitude based on FTV.The heading stability augmentation and maneuvering control characteristics and time response characteristics of tailless flying wing by FTV were quantitatively studied through virtual flight test in a wind tunnel at a wind speed of 35 m/s.The results show that the control strategy based on MFC achieves bidirectional continuous and stable control of thrust vector angle in a range of±11°,and the thrust vector angle varies monotonically with MFC;the co-directional FTV realizes bidirectional continuous and stable control of the yaw attitude of tailless flying wing,without longitudinal/lateral coupling moment.The increment of the maximum yawing moment coefficient is 0.0029,the maximum yaw rate is 7.55(°)/s,and the response time of the yaw rate of the vectoring nozzle actuated by the secondary flow is about 0.06 s,which satisfies the heading stability augmentation and maneuvering control response requirements of the aircraft with statically unstable heading,and provides new control means for the heading rudderless attitude control of tailless flying wing.展开更多
The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus...The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.展开更多
As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and application.Aiming at the problem of nonl...As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and application.Aiming at the problem of nonlinear effectiveness evaluation under small sample conditions,we propose an evaluation method based on support vector regression(SVR)to effectively address the defects of traditional methods.Considering the performance of SVR is influenced by the penalty factor,kernel type,and other parameters deeply,the improved grey wolf optimizer(IGWO)is employed for parameter optimization.In the proposed IGWO algorithm,the opposition-based learning strategy is adopted to increase the probability of avoiding the local optima,the mutation operator is used to escape from premature convergence and differential convergence factors are applied to increase the rate of convergence.Numerical experiments of 14 test functions validate the applicability of IGWO algorithm dealing with global optimization.The index system and evaluation method are constructed based on the characteristics of RSS.To validate the proposed IGWO-SVR evaluation method,eight benchmark data sets and combat simulation are employed to estimate the evaluation accuracy,convergence performance and computational complexity.According to the experimental results,the proposed method outperforms several prediction based evaluation methods,verifies the superiority and effectiveness in RSS operational effectiveness evaluation.展开更多
Large-scale underground projects need accurate in-situ stress information,and the acoustic emission(AE)Kaiser effect method currently offers lower costs and streamlined procedures.In this method,the accuracy and speed...Large-scale underground projects need accurate in-situ stress information,and the acoustic emission(AE)Kaiser effect method currently offers lower costs and streamlined procedures.In this method,the accuracy and speed of Kaiser point identification are important.Thus,this study aims to integrate chaos theory and machine learning for accurately and quickly identifying Kaiser points.An intelligent model of the identification of AE partitioned areas was established by phase space reconstruction(PSR),genetic algorithm(GA),and support vector machine(SVM).Then,the plots of model classification results were made to identify Kaiser points.We refer to this method of identifying Kaiser points as the partitioning plot method based on PSR–GA–SVM(PPPGS).The PSR–GA–SVM model demonstrated outstanding performance,which achieved a 94.37%accuracy rate on the test set,with other evaluation metrics also indicating exceptional performance.The PPPGS identified Kaiser points similar to the tangent-intersection method with greater accuracy.Furthermore,in the feature importance score of the classification model,the fractal dimension extracted by PSR ranked second after accumulated AE count,which confirmed its importance and reliability as a classification feature.The PPPGS was applied to in-situ stress measurement at a phosphate mine in Guizhou Weng'an,China,to validate its practicability,where it demonstrated good performance.展开更多
The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especi...The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especially the active component of the pressure and horizontal particle velocity cross-spectrum, also called ho- rizontal complex cross acoustic intensity, when only two normal modes are trapped in the waveguide. Both the approximate theo- retic analysis and the numerical results show that the sign of the horizontal complex cross acoustic intensity active component is independent of the range when vertically deployed receiving dual sensors are placed in appropriate depths, the sum of which is equal to the waveguide effective depth, so it can be used to tell whether the sound source is near the surface or underwater; while the range rate is expected to be measured by utilizing the sign distribution characteristic of the reactive component. The further robustness analysis of the depth classification algorithm shows that the existence of shear waves in semi infinite basement and the change of acoustic velocity profiles have few effects on the application of this method, and the seabed attenuation will limit the detection range, but the algorithm still has a good robustness in the valid detection range.展开更多
To overcome the disadvantage that the standard least squares support vector regression(LS-SVR) algorithm is not suitable to multiple-input multiple-output(MIMO) system modelling directly,an improved LS-SVR algorithm w...To overcome the disadvantage that the standard least squares support vector regression(LS-SVR) algorithm is not suitable to multiple-input multiple-output(MIMO) system modelling directly,an improved LS-SVR algorithm which was defined as multi-output least squares support vector regression(MLSSVR) was put forward by adding samples' absolute errors in objective function and applied to flatness intelligent control.To solve the poor-precision problem of the control scheme based on effective matrix in flatness control,the predictive control was introduced into the control system and the effective matrix-predictive flatness control method was proposed by combining the merits of the two methods.Simulation experiment was conducted on 900HC reversible cold roll.The performance of effective matrix method and the effective matrix-predictive control method were compared,and the results demonstrate the validity of the effective matrix-predictive control method.展开更多
The Bypass Dual Throat Nozzle(BDTN)is a novel fluidic Thrust Vectoring(TV)nozzle,it switches to TV state by opening the valve in the bypass.To greatly manipulate the BDTN,the dynamic characteristics in the TV starting...The Bypass Dual Throat Nozzle(BDTN)is a novel fluidic Thrust Vectoring(TV)nozzle,it switches to TV state by opening the valve in the bypass.To greatly manipulate the BDTN,the dynamic characteristics in the TV starting process should be analyzed.This paper conducts numerical simulations to grasp the variation processes of performances and the flow field evolution of BDTN and Dual Throat Nozzle(DTN).The dynamic responses of TV starting in typical DTN models are investigated at first.Then,the TV starting processes of BDTN in different Nozzle Pressure Ratio(NPR)conditions are simulated,and the valve opening durations(T)are also considered.Before the expected TV direction is achieved in the DTN,the jet is deflected to the opposite direction at the beginning of the dynamic process,which is called the reverse TV phenomenon.However,this phenomenon disappears in the BDTN.The larger injection width of DTN intensifies unsteady oscillations,and the reverse TV phenomenon is strengthened.In the BDTN,T determines the delay degree of performance variations compared to the static results,which is called hysteresis effect.At NPR=10,the hysteresis affects the final stable performance of BDTN.This study analyses the dynamic characteristics in DTN and BDTN,laying a foundation for further design of nozzles and control strategies.展开更多
Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainsta...Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainstay of effective control.But,indiscriminate and rampant use of the chemical insecticides in controlling mosquito vectors,in order to prevent diseases vectored by them,has resulted problems related to the adverse environmental effects for their(insecticides)potential toxicity,high operational cost,community acceptance,and the development of insecticide resistance among the vectors.The factors mentioned above prompted the search for new means of control strategies.Currently,the botanicals(viz.,plant extracts,essential oils and phytochemicals)with mosquitocidal potential展开更多
It is shown that such phenomena as quantum correlations (interaction of space-separated quantum entities), the action of magnetic vector potential on quantum entities in the absence of magnetic field, and near-field a...It is shown that such phenomena as quantum correlations (interaction of space-separated quantum entities), the action of magnetic vector potential on quantum entities in the absence of magnetic field, and near-field antenna effect (the existence of superluminally propagating electromagnetic fields) may be explained by action of spin supercurrents. In case of quantum correlations between quantum entities, spin supercurrent emerges between virtual particles pairs (virtual photons) created by those quantum entities. The explanation of magnetic vector potential and near-field antenna effect is based on contemporary principle of quantum mechanics: the physical vacuum is not an empty space but the ground state of the field consisting of quantum harmonic oscillators (QHOs) characterized by zero-point energy. Using the properties of the oscillators and spin supercurrent, it is proved that magnetic vector potential is proportional to the moment causing the orientation of spin of QHO along the direction of magnetic field. The near-field antenna effect is supposed to take place as a result of action of spin supercurrent causing secondary electromagnetic oscillations. In this way, the electromagnetic field may spread at the speed of spin supercurrent. As spin supercurrent is an inertia free process, its speed may be greater than that of light, which does not contradict postulates of special relativity that sets limits to the speed of inertial systems only.展开更多
Purpose of the present study: To explore the effect of electroacupuncture (EA) on canine pyloric pressure and its relation to somatostain (SS) of blood plasma and nitric oxide (NO).Methods: An intragastric pressure de...Purpose of the present study: To explore the effect of electroacupuncture (EA) on canine pyloric pressure and its relation to somatostain (SS) of blood plasma and nitric oxide (NO).Methods: An intragastric pressure detector and radioimmunoassay (RIA) and biochemical assay are used to determine changes of pyloric pressure and frequency, contents of SS and NO of blood plasma after EA stimulation of different acupoints. Results: Following EA of Zusanli (ST 36), the total pressure, basic pressure and systolic frequency of the sphincter muscle of pylorus lowered, plasma SS content decreased and NO content increased. After EA of Shangjuxu (ST 37), the total pressure, basic pressure and systolic frequency of the sphincter muscle of pylorus decreased, plasrna NO content increased but changes of these indexes are less obvious than those of EA of Zusanli (ST 36). These indexes in other groups had no any apparent changes. Conclusion: EA could lower pyloric pressure and systolic frequency of the pyloric sphincter muscle, whicb may be the important pathway of EA in regulating functional activities of the stomach and intestines. The effect of EA is associated with the contents of some plasma biological substances affecting pyloric pressure and the action of meridians and acupoints is of specificity to a certain degree.展开更多
Let （L, ,0, 1） be an effect algebra and let X be a Banach space. A function ： L→ X is called a vector measure if μ（a b） =μ（a） ＋ μ（b） whenever a⊥b in L. The function μ is said to be 8-bounded if limn...Let （L, ,0, 1） be an effect algebra and let X be a Banach space. A function ： L→ X is called a vector measure if μ（a b） =μ（a） ＋ μ（b） whenever a⊥b in L. The function μ is said to be 8-bounded if limn→∞μ（an） = 0 in X for any orthogonal sequence （an）n∈N in L. In this paper, we introduce two properties of sequence of s-bounded vector measures and give some results on these properties.展开更多
Effective Hamiltonians in periodically driven systems have received widespread attention for realization of novel quantum phases, non-equilibrium phase transition, and Majorana mode. Recently, the study of effective H...Effective Hamiltonians in periodically driven systems have received widespread attention for realization of novel quantum phases, non-equilibrium phase transition, and Majorana mode. Recently, the study of effective Hamiltonian using various methods has gained great interest. We consider a vector differential equation of motion to derive the effective Hamiltonian for any periodically driven two-level system, and the dynamics of the spin vector are an evolution under the Bloch sphere. Here, we investigate the properties of this equation and show that a sudden change of the effective Hamiltonian is expected. Furthermore, we present several exact relations, whose expressions are independent of the different starting points. Moreover, we deduce the effective Hamiltonian from the high-frequency limit, which approximately equals the results in previous studies. Our results show that the vector differential equation of motion is not affected by a convergence problem, and thus, can be used to numerically investigate the effective models in any periodic modulating system. Finally, we anticipate that the proposed method can be applied to experimental platforms that require time-periodic modulation, such as ultracold atoms and optical lattices.展开更多
Objective: To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1, and the mech...Objective: To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1, and the mechanisms involved in this effect. Methods: TRAIL gene was transfected into pancreatic cancer cell line Panc-1 by an adenovirus vector (Ad-TRAIL). Level of TRAIL mRNA expression was determined using RT-PCR, and TRAIL protein synthesis was evaluated with Western blot. Cell-growth activities were determined by MTT assay. The bystander effect was observed by co-culturing the Panc-1 cells with the transfected TRAIL gene at different ratios. Apoptosis in pancreatic cancer cells was detected by flow cytometry. Procaspase-8 and procaspase-3 were determined by Western blot. Results: The stable overexpression of TRAIL was de-tected in Panc-1 cells transfected by Ad-TRAIL. Ad-TRAIL significantly inhibited of cell viability of Panc-1 cells. Furthermore, co-culture of cancer cells transfected with TRAIL with that nontransfected resulted in the cell death of both cells by bystander effect. Moreover, the percentage of apoptotic cells was significantly higher in the Ad-TRAIL-treatment group compared to the control groups (P < 0.01). And there was a diminished amount of procaspase-8 and procaspase-3 after infection with Ad-TRAIL. Conclusion: The overexpression of TRAIL gene in Panc-1 cells by Ad-TRAIL exerts its antitumor effects, and the mechanisms involved in this effect may be proapoptosis and bystander effect.展开更多
We study the quantum theory of the mass-less vector fields on the Rindler space. We evaluate the Bogoliubov coefficients by means of a new technique based upon the use of light-front coordinates and Mellin transform. ...We study the quantum theory of the mass-less vector fields on the Rindler space. We evaluate the Bogoliubov coefficients by means of a new technique based upon the use of light-front coordinates and Mellin transform. We briefly comment about the ensuing Unruh effect and its consequences.展开更多
Numerous considerations deal with specialties of bioelectromagnetic effects, including the force-free and field-free interactions. The fact that bioelectromagnetic phenomena consist of effects without mechanical force...Numerous considerations deal with specialties of bioelectromagnetic effects, including the force-free and field-free interactions. The fact that bioelectromagnetic phenomena consist of effects without mechanical forces and even without measurable fields looks impossible in the simple considerations. However, the stochastic fluctuations cause surprising results, with scientifically proven bioelectromagnetism in field-free conditions. In the first steps, we show the scalar and vector potentials’ specialties instead of electric and magnetic fields defined by the well-known Maxwellian equations. The vanishing of the fields is connected to the potentials’ stochastic fluctuations, the noises control the “zero-ground”. The result shows a possibility of a wave that has no attenuation during its transmission through the material. In this meaning, the result is similar to the consequences of the scalar-wave (SW) considerations. The structural changes follow a particular noise spectrum (called pink-noise or 1/f noise), which keeps the entropy constant in a broad range of scaling magnification.展开更多
Objective To construct Cox7a2 fluorescent vector and study its effect on cytochrome C oxidase ( COX) activity in mouse Sertoli cell line TM4. Methods The coding region of CoxTa2 was amplified from mouse Sertoli cell l...Objective To construct Cox7a2 fluorescent vector and study its effect on cytochrome C oxidase ( COX) activity in mouse Sertoli cell line TM4. Methods The coding region of CoxTa2 was amplified from mouse Sertoli cell line TM4 by RT-PCR. PCR product was展开更多
文摘Fluidic Thrust Vectoring(FTV)is used for the yaw attitude control of tailless flying wing,which can significantly improve stealth performance,maneuverability and lateral/heading maneuverability.The FTV control scheme of co-directional secondary flow was designed based on a 30 kgf thrust turbojet engine,an equivalent rudder deflection control variable of Mass Flow Combination(MFC)was proposed,and a control model was established to form a FTV control system scheme,which was integrated with the flight control system of a 100 kg tailless flying wing with medium aspect ratio to achieve closed-loop control of the yaw attitude based on FTV.The heading stability augmentation and maneuvering control characteristics and time response characteristics of tailless flying wing by FTV were quantitatively studied through virtual flight test in a wind tunnel at a wind speed of 35 m/s.The results show that the control strategy based on MFC achieves bidirectional continuous and stable control of thrust vector angle in a range of±11°,and the thrust vector angle varies monotonically with MFC;the co-directional FTV realizes bidirectional continuous and stable control of the yaw attitude of tailless flying wing,without longitudinal/lateral coupling moment.The increment of the maximum yawing moment coefficient is 0.0029,the maximum yaw rate is 7.55(°)/s,and the response time of the yaw rate of the vectoring nozzle actuated by the secondary flow is about 0.06 s,which satisfies the heading stability augmentation and maneuvering control response requirements of the aircraft with statically unstable heading,and provides new control means for the heading rudderless attitude control of tailless flying wing.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12033007,61801458,12103058,12203058,12074309,and 61875205)the Key Project of Frontier Science Research of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH007)+2 种基金the Strategic Priority Research Program of CAS(Grant No.XDC07020200)the Youth Innovation Promotion Association,CAS(Grant Nos.2021408,2022413,and 2023425)the Research on Highly Sensitive Long-Wave Receiver Based on Rydberg Atoms(Grant No.1P2024000059)。
文摘The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.
基金the National Defense Science and Technology Key Laboratory Fund of China(XM2020XT1023).
文摘As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and application.Aiming at the problem of nonlinear effectiveness evaluation under small sample conditions,we propose an evaluation method based on support vector regression(SVR)to effectively address the defects of traditional methods.Considering the performance of SVR is influenced by the penalty factor,kernel type,and other parameters deeply,the improved grey wolf optimizer(IGWO)is employed for parameter optimization.In the proposed IGWO algorithm,the opposition-based learning strategy is adopted to increase the probability of avoiding the local optima,the mutation operator is used to escape from premature convergence and differential convergence factors are applied to increase the rate of convergence.Numerical experiments of 14 test functions validate the applicability of IGWO algorithm dealing with global optimization.The index system and evaluation method are constructed based on the characteristics of RSS.To validate the proposed IGWO-SVR evaluation method,eight benchmark data sets and combat simulation are employed to estimate the evaluation accuracy,convergence performance and computational complexity.According to the experimental results,the proposed method outperforms several prediction based evaluation methods,verifies the superiority and effectiveness in RSS operational effectiveness evaluation.
基金financially supported by the National Natural Science Foundation of China(Nos.52374107 and 52304165)。
文摘Large-scale underground projects need accurate in-situ stress information,and the acoustic emission(AE)Kaiser effect method currently offers lower costs and streamlined procedures.In this method,the accuracy and speed of Kaiser point identification are important.Thus,this study aims to integrate chaos theory and machine learning for accurately and quickly identifying Kaiser points.An intelligent model of the identification of AE partitioned areas was established by phase space reconstruction(PSR),genetic algorithm(GA),and support vector machine(SVM).Then,the plots of model classification results were made to identify Kaiser points.We refer to this method of identifying Kaiser points as the partitioning plot method based on PSR–GA–SVM(PPPGS).The PSR–GA–SVM model demonstrated outstanding performance,which achieved a 94.37%accuracy rate on the test set,with other evaluation metrics also indicating exceptional performance.The PPPGS identified Kaiser points similar to the tangent-intersection method with greater accuracy.Furthermore,in the feature importance score of the classification model,the fractal dimension extracted by PSR ranked second after accumulated AE count,which confirmed its importance and reliability as a classification feature.The PPPGS was applied to in-situ stress measurement at a phosphate mine in Guizhou Weng'an,China,to validate its practicability,where it demonstrated good performance.
基金supported by the National Natural Science Foundation of China(1140440611374072)
文摘The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especially the active component of the pressure and horizontal particle velocity cross-spectrum, also called ho- rizontal complex cross acoustic intensity, when only two normal modes are trapped in the waveguide. Both the approximate theo- retic analysis and the numerical results show that the sign of the horizontal complex cross acoustic intensity active component is independent of the range when vertically deployed receiving dual sensors are placed in appropriate depths, the sum of which is equal to the waveguide effective depth, so it can be used to tell whether the sound source is near the surface or underwater; while the range rate is expected to be measured by utilizing the sign distribution characteristic of the reactive component. The further robustness analysis of the depth classification algorithm shows that the existence of shear waves in semi infinite basement and the change of acoustic velocity profiles have few effects on the application of this method, and the seabed attenuation will limit the detection range, but the algorithm still has a good robustness in the valid detection range.
基金Project(50675186) supported by the National Natural Science Foundation of China
文摘To overcome the disadvantage that the standard least squares support vector regression(LS-SVR) algorithm is not suitable to multiple-input multiple-output(MIMO) system modelling directly,an improved LS-SVR algorithm which was defined as multi-output least squares support vector regression(MLSSVR) was put forward by adding samples' absolute errors in objective function and applied to flatness intelligent control.To solve the poor-precision problem of the control scheme based on effective matrix in flatness control,the predictive control was introduced into the control system and the effective matrix-predictive flatness control method was proposed by combining the merits of the two methods.Simulation experiment was conducted on 900HC reversible cold roll.The performance of effective matrix method and the effective matrix-predictive control method were compared,and the results demonstrate the validity of the effective matrix-predictive control method.
基金the continued support of Key Laboratory of Inlet and Exhaust system Technology (Nanjing University of Aeronautics and Astronautics), ChinaMinistry of Education, National Science and Technology Major Project of China (Nos. 2017-V-0004-0054, 2019-II-0007-0027, Y2022II-0005-0008)+6 种基金Defense Industrial Technology Development Program of China (No. JCKY2019605D001)Advanced Jet Propulsion Creativity Center of AEAC of China (No. HKCX2020-02-011)China Postdoctoral Science Foundation (No. 2022M721598)Jiangsu Funding Program for Excellent Postdoctoral Talent of China (No. 2022ZB214)the Youth Fund Project of Natural Science Foundation of Jiangsu Province of China (No. BK20230891)the National Natural Science Foundation of China (No. 12332018)Science Center for Gas Turbine Project, China (P2022-B-I-006-001) and some other related foundations
文摘The Bypass Dual Throat Nozzle(BDTN)is a novel fluidic Thrust Vectoring(TV)nozzle,it switches to TV state by opening the valve in the bypass.To greatly manipulate the BDTN,the dynamic characteristics in the TV starting process should be analyzed.This paper conducts numerical simulations to grasp the variation processes of performances and the flow field evolution of BDTN and Dual Throat Nozzle(DTN).The dynamic responses of TV starting in typical DTN models are investigated at first.Then,the TV starting processes of BDTN in different Nozzle Pressure Ratio(NPR)conditions are simulated,and the valve opening durations(T)are also considered.Before the expected TV direction is achieved in the DTN,the jet is deflected to the opposite direction at the beginning of the dynamic process,which is called the reverse TV phenomenon.However,this phenomenon disappears in the BDTN.The larger injection width of DTN intensifies unsteady oscillations,and the reverse TV phenomenon is strengthened.In the BDTN,T determines the delay degree of performance variations compared to the static results,which is called hysteresis effect.At NPR=10,the hysteresis affects the final stable performance of BDTN.This study analyses the dynamic characteristics in DTN and BDTN,laying a foundation for further design of nozzles and control strategies.
文摘Dear editor,Mosquito-borne diseases,viz.,malaria,filariasis,dengue hemorrhagic fever,chikungunya,Japanese encephalitis etc.,created huge impact on humans over the world,and the chemical insecticides remain the mainstay of effective control.But,indiscriminate and rampant use of the chemical insecticides in controlling mosquito vectors,in order to prevent diseases vectored by them,has resulted problems related to the adverse environmental effects for their(insecticides)potential toxicity,high operational cost,community acceptance,and the development of insecticide resistance among the vectors.The factors mentioned above prompted the search for new means of control strategies.Currently,the botanicals(viz.,plant extracts,essential oils and phytochemicals)with mosquitocidal potential
文摘It is shown that such phenomena as quantum correlations (interaction of space-separated quantum entities), the action of magnetic vector potential on quantum entities in the absence of magnetic field, and near-field antenna effect (the existence of superluminally propagating electromagnetic fields) may be explained by action of spin supercurrents. In case of quantum correlations between quantum entities, spin supercurrent emerges between virtual particles pairs (virtual photons) created by those quantum entities. The explanation of magnetic vector potential and near-field antenna effect is based on contemporary principle of quantum mechanics: the physical vacuum is not an empty space but the ground state of the field consisting of quantum harmonic oscillators (QHOs) characterized by zero-point energy. Using the properties of the oscillators and spin supercurrent, it is proved that magnetic vector potential is proportional to the moment causing the orientation of spin of QHO along the direction of magnetic field. The near-field antenna effect is supposed to take place as a result of action of spin supercurrent causing secondary electromagnetic oscillations. In this way, the electromagnetic field may spread at the speed of spin supercurrent. As spin supercurrent is an inertia free process, its speed may be greater than that of light, which does not contradict postulates of special relativity that sets limits to the speed of inertial systems only.
基金Supported by National Basic Research Program of China （973 Program） （2005CB321902） National Natural Science Foundation of China （90916024,60727002,60774003）+1 种基金 the Ph.D. Programs Foundation of Ministry of Education of China （20030006003） the Commission on Science,Technology,and Industry for National Defense （A2120061303）
文摘Purpose of the present study: To explore the effect of electroacupuncture (EA) on canine pyloric pressure and its relation to somatostain (SS) of blood plasma and nitric oxide (NO).Methods: An intragastric pressure detector and radioimmunoassay (RIA) and biochemical assay are used to determine changes of pyloric pressure and frequency, contents of SS and NO of blood plasma after EA stimulation of different acupoints. Results: Following EA of Zusanli (ST 36), the total pressure, basic pressure and systolic frequency of the sphincter muscle of pylorus lowered, plasma SS content decreased and NO content increased. After EA of Shangjuxu (ST 37), the total pressure, basic pressure and systolic frequency of the sphincter muscle of pylorus decreased, plasrna NO content increased but changes of these indexes are less obvious than those of EA of Zusanli (ST 36). These indexes in other groups had no any apparent changes. Conclusion: EA could lower pyloric pressure and systolic frequency of the pyloric sphincter muscle, whicb may be the important pathway of EA in regulating functional activities of the stomach and intestines. The effect of EA is associated with the contents of some plasma biological substances affecting pyloric pressure and the action of meridians and acupoints is of specificity to a certain degree.
文摘Let （L, ,0, 1） be an effect algebra and let X be a Banach space. A function ： L→ X is called a vector measure if μ（a b） =μ（a） ＋ μ（b） whenever a⊥b in L. The function μ is said to be 8-bounded if limn→∞μ（an） = 0 in X for any orthogonal sequence （an）n∈N in L. In this paper, we introduce two properties of sequence of s-bounded vector measures and give some results on these properties.
基金supported by the National Natural Science Foundation of China (Grant No. 11774328)。
文摘Effective Hamiltonians in periodically driven systems have received widespread attention for realization of novel quantum phases, non-equilibrium phase transition, and Majorana mode. Recently, the study of effective Hamiltonian using various methods has gained great interest. We consider a vector differential equation of motion to derive the effective Hamiltonian for any periodically driven two-level system, and the dynamics of the spin vector are an evolution under the Bloch sphere. Here, we investigate the properties of this equation and show that a sudden change of the effective Hamiltonian is expected. Furthermore, we present several exact relations, whose expressions are independent of the different starting points. Moreover, we deduce the effective Hamiltonian from the high-frequency limit, which approximately equals the results in previous studies. Our results show that the vector differential equation of motion is not affected by a convergence problem, and thus, can be used to numerically investigate the effective models in any periodic modulating system. Finally, we anticipate that the proposed method can be applied to experimental platforms that require time-periodic modulation, such as ultracold atoms and optical lattices.
基金Supported by a grant from the National Natural Science Foundation of China (No. 30471693).
文摘Objective: To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1, and the mechanisms involved in this effect. Methods: TRAIL gene was transfected into pancreatic cancer cell line Panc-1 by an adenovirus vector (Ad-TRAIL). Level of TRAIL mRNA expression was determined using RT-PCR, and TRAIL protein synthesis was evaluated with Western blot. Cell-growth activities were determined by MTT assay. The bystander effect was observed by co-culturing the Panc-1 cells with the transfected TRAIL gene at different ratios. Apoptosis in pancreatic cancer cells was detected by flow cytometry. Procaspase-8 and procaspase-3 were determined by Western blot. Results: The stable overexpression of TRAIL was de-tected in Panc-1 cells transfected by Ad-TRAIL. Ad-TRAIL significantly inhibited of cell viability of Panc-1 cells. Furthermore, co-culture of cancer cells transfected with TRAIL with that nontransfected resulted in the cell death of both cells by bystander effect. Moreover, the percentage of apoptotic cells was significantly higher in the Ad-TRAIL-treatment group compared to the control groups (P < 0.01). And there was a diminished amount of procaspase-8 and procaspase-3 after infection with Ad-TRAIL. Conclusion: The overexpression of TRAIL gene in Panc-1 cells by Ad-TRAIL exerts its antitumor effects, and the mechanisms involved in this effect may be proapoptosis and bystander effect.
文摘We study the quantum theory of the mass-less vector fields on the Rindler space. We evaluate the Bogoliubov coefficients by means of a new technique based upon the use of light-front coordinates and Mellin transform. We briefly comment about the ensuing Unruh effect and its consequences.
文摘Numerous considerations deal with specialties of bioelectromagnetic effects, including the force-free and field-free interactions. The fact that bioelectromagnetic phenomena consist of effects without mechanical forces and even without measurable fields looks impossible in the simple considerations. However, the stochastic fluctuations cause surprising results, with scientifically proven bioelectromagnetism in field-free conditions. In the first steps, we show the scalar and vector potentials’ specialties instead of electric and magnetic fields defined by the well-known Maxwellian equations. The vanishing of the fields is connected to the potentials’ stochastic fluctuations, the noises control the “zero-ground”. The result shows a possibility of a wave that has no attenuation during its transmission through the material. In this meaning, the result is similar to the consequences of the scalar-wave (SW) considerations. The structural changes follow a particular noise spectrum (called pink-noise or 1/f noise), which keeps the entropy constant in a broad range of scaling magnification.
文摘Objective To construct Cox7a2 fluorescent vector and study its effect on cytochrome C oxidase ( COX) activity in mouse Sertoli cell line TM4. Methods The coding region of CoxTa2 was amplified from mouse Sertoli cell line TM4 by RT-PCR. PCR product was
