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A New Version of Unified Field Theory—Stochastic Quantum Space Theory on Particle Physics and Cosmology 被引量:3
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作者 Zhi-Yuan Shen 《Journal of Modern Physics》 2013年第10期1213-1380,共168页
Stochastic Quantum Space (SQS) theory is a new version of unified field theory based on three fundamental postulations: Gaussian Probability Postulation, Prime Numbers Postulation, Vacuon Postulation. It build a frame... Stochastic Quantum Space (SQS) theory is a new version of unified field theory based on three fundamental postulations: Gaussian Probability Postulation, Prime Numbers Postulation, Vacuon Postulation. It build a framework with theoretical results agree with many experimental data well. For more information, please refer to the PDF. 展开更多
关键词 Unified Field THEORY space Structure Elementary Particles Gaussian Probability Prime Numbers SPORADIC Groups GUT DARK Matter DARK Energy Cosmos INFLATON MULTIVERSE Anthropic Principle General Relativity Primary Basic Equations
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Einstein’s General Relativity and Pure Gravity in a Cosserat and De Sitter-Witten Spacetime Setting as the Explanation of Dark Energy and Cosmic Accelerated Expansion
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作者 Mohamed S. El Naschie 《International Journal of Astronomy and Astrophysics》 2014年第2期332-339,共8页
Ordinary energy and dark energy density are determined using a Cosserat-Cartan and killing-Yano reinterpretation of Einstein’s special and general relativity. Thus starting from a maximally symmetric space with 528 k... Ordinary energy and dark energy density are determined using a Cosserat-Cartan and killing-Yano reinterpretation of Einstein’s special and general relativity. Thus starting from a maximally symmetric space with 528 killing vector fields corresponding to Witten’s five Branes model in eleven dimensional M-theory we reason that 504 of the 528 are essentially the components of the relevant killing-Yano tensor. In turn this tensor is related to hidden symmetries and torsional coupled stresses of the Cosserat micro-polar space as well as the Einstein-Cartan connection. Proceeding in this way the dark energy density is found to be that of Einstein’s maximal energy mc2 where m is the mass and c is the speed of light multiplied with a Lorentz factor equal to the ratio of the 504 killing-Yano tensor and the 528 states maximally symmetric space. Thus we have E (dark) = mc2 (504/528) = mc2 (21/22) which is about 95.5% of the total maximal energy density in astounding agreement with COBE, WMAP and Planck cosmological measurements as well as the type 1a supernova analysis. Finally theory and results are validated via a related theory based on the degrees of freedom of pure gravity, the theory of nonlocal elasticity as well as ‘t Hooft-Veltman renormalization method. 展开更多
关键词 General RELATIVITY COSSERAT Micro-Polar space Dark Energy Teleparellelism Wittens M-THEORY De Sitter spaceTIME Killing-Yano Tensor Einstein-Cartan RELATIVITY PURE GRAVITY Kaluza-Klein Theory Nonlocal Elasticity 't Hooft-Veltman Renormalization
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Modeling and Simulation Study of Space Data Link Protocol
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作者 Ismail Hababeh Rizik M. H. Al-Sayyed +2 位作者 Ja’far Alqatawna Yousef Majdalawi Marwan Nabelsi 《International Journal of Communications, Network and System Sciences》 2014年第10期440-452,共13页
This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). ... This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). The primer focus is the telecommand (TC) part of the standard. The implementation of the standard was in the form of DLL functions using C++ programming language. The second objective of this paper was to use the DLL functions with OMNeT++ simulating environment to create a simulator in order to analyze the mean end-to-end Packet Delay, maximum achievable application layer throughput for a given fixed link capacity and normalized protocol overhead, defined as the total number of bytes transmitted on the link in a given period of time (e.g. per second) divided by the number of bytes of application data received at the application layer model data sink. In addition, the DLL was also integrated with Ground Support Equipment Operating System (GSEOS), a software system for space instruments and small spacecrafts especially suited for low budget missions. The SDLP is designed for rapid test system design and high flexibility for changing telemetry and command requirements. GSEOS can be seamlessly moved from EM/FM development (bench testing) to flight operations. It features the Python programming language as a configuration/scripting tool and can easily be extended to accommodate custom hardware interfaces. This paper also shows the results of the simulations and its analysis. 展开更多
关键词 Consultative COMMITTEE for space DATA Systems Standards space DATA Link PROTOCOL Mean END-TO-END Packet Delay Maximum Achievable Application Layer Throughput Normalized PROTOCOL OVERHEAD Telecommand spacecrafts space Instruments
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Deciphering of Space Images of the Inder Salt-Dome Upland in ENVI 4.7 Program
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作者 K. M. Akhmedenov A. G. Koshym R. Z. Zhumabekova 《International Journal of Geosciences》 2014年第3期286-295,共10页
Space images play an important role in the Earth study as they bring the main information received from the Space Flyer Units (SFU) to help researchers. Space images’ deciphering gives the opportunity to study the te... Space images play an important role in the Earth study as they bring the main information received from the Space Flyer Units (SFU) to help researchers. Space images’ deciphering gives the opportunity to study the territory and to plot different maps. On the basis of the space image obtained from Landsat 5TM (30 m resolution, 01.09.2012 year), we managed to get a picture of the modern relief of the northern part of Inder lake. When comparing the space image with topographic maps of 1985, we succeeded to identify the dynamics of landforms change on the studied area, what has been shown on the drawn map of the relief of the Inder salt dome uplift. 14 classes, corresponding to a particular type of terrain or to a landscape complex, have been distinguished on the studied area. Inder salt dome uplift is a paradynamic conjugation, consisting of highly karsted Inder Mountains corresponding to large diapir uplift, and of the Inder Lake having a large ellipsoidal shape. Geomorphologically, the investigated territory is located on the left bank of Zhaiyk River, and presents a salt dome uplift in the form of a plateau-like hill raised above the surrounding surface from 12 to 40 m. The maximum height reaches 42.5 m (g. Suatbaytau). The crest of the Inder salt dome is composed of Low Permian sediments (rock salt with anhydrite, potassiummagnesium salts), and has an area of about 210 km2. Inder lake’s basin is represented by a tectonic depression, which is the local basis of erosion and is a drainage place of the Inder uplift karstic water. The lake area is 150 km2. Depending on the climatic conditions, the water level can vary. 展开更多
关键词 space Image Inder Salt-Dome Uplift KARST RELIEF Exogenous PROCESSES KARST PROCESSES RELIEF Shapes Basis of Erosion Automated Deciphering Vector Layer Objects Classification Object Classes Landscapes Complex Mapping
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Pinched Material Einstein Space-Time Produces Accelerated Cosmic Expansion
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作者 M. S. El Naschie 《International Journal of Astronomy and Astrophysics》 2014年第1期80-90,共11页
An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a... An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a hyperbolic fractal Rindler space-time leading to the same robust results regarding real energy and dark energy being 4.5% and 95.5% respectively in full agreement with all recent cosmological measurements. 展开更多
关键词 Dark Energy Rindler space-TIME CARTAN Torsion Pinched Elastic Shells Negative Gravity COSMIC ACCELERATED EXPANSION Fractal space-TIME Topological Defects Hardys Quantum Entanglement Hawkings Radiation COSSERAT Elasticity
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A review and research on comprehensive characterization of microscopic shale gas reservoir space 被引量:5
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作者 Yu-ru Yang Xiao-chen Liu +12 位作者 Hui Zhang Gang-yi Zhai Jiao-dong Zhang Zhi-fang Hu Shu-jing Bao Cong Zhang Xiang-hua Wang Xiao Yang Zheng-zhuang Liu Ting Xie Juan Chen Liyu Fang Li-juan Qin 《China Geology》 2019年第4期541-556,共16页
In this paper,substantial domestic and foreign research results of microscopic shale reservoir space were systemically reviewed,the research history consisting of simple observation and qualitative classification,quan... In this paper,substantial domestic and foreign research results of microscopic shale reservoir space were systemically reviewed,the research history consisting of simple observation and qualitative classification,quantitative research,the combination of qualitative and quantitative research successively as well as the characteristics of each research stage were summarized.In addition,the current problems existing in the characterization methods of shale reservoir space were also analyzed.Furthermore,based on massive actual detection of typical core samples obtained from more than 50 global shale gas wells and relevant practical experience,a comprehensive characterization method of combining qualitative with the semiquantitative characterization was put forward.In detail,the indicators of the qualitative characterization include pore combination type and organic-matter microscopic morphology type,while the core elements of the semi-quantitative characterization include the percentage of the organic-matter area and the plane porosity of the pores of different types.Based on the reference of the naming and classification of rocks,the three-end-member diagram method was used to characterize microscopic shale reservoir space.This is achieved by plotting the three end-member diagram of 3 kinds of first-order critical reservoir spaces,i.e.,organic-matter pores,matrix pores,and micro-fractures,in order to intuitively present the features of the microscopic pore combination.Meanwhile,statistic histograms of organic-matter microscopic morphology type and the plane porosity of different types of pores were adopted to characterize the development degree of second-order pores quantitatively.By this comprehensive characterization method,the importance of both pore combination and the microscopic morphology of organic matter were emphasized,revealing the control of organic-matter microscopic morphology over the organic-matter pores.What is more,high-resolution FE-SEM was adopted to obtain semi-quantitative statistics results.In this way,the features of pore development and pore combination were quantified,not only reflecting the types and storage capacity of the microscopic shale reservoir space,but also presenting the hydrocarbongenerating potential of organic matter in shale.Therefore,the results of this research are capable of providing in-depth microscopic information for the assessment and exploration and development of shale gas resources. 展开更多
关键词 SHALE SHALE gas Reservoir space RESEARCH status Types of PORE COMBINATIONS Oil-gas exploration engineering Longmaxi FORMATION Niutitang FORMATION Shahejie FORMATION Yanchang FORMATION China USA
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基于Space P和K-means的货运航司航线网络特征分析研究
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作者 罗凤娥 卫昌波 +1 位作者 韩晓彤 郭玲玉 《现代电子技术》 北大核心 2026年第1期102-107,共6页
针对航空货运行业的迅速扩张,航空货运网络结构变得更加复杂,文中通过Space P建模方法构建了货运航空公司航线网络模型,并运用K-means聚类算法对网络进行了深入分析。选取度、平均路径长度、聚类系数和中间度等关键网络特性指标对航线... 针对航空货运行业的迅速扩张,航空货运网络结构变得更加复杂,文中通过Space P建模方法构建了货运航空公司航线网络模型,并运用K-means聚类算法对网络进行了深入分析。选取度、平均路径长度、聚类系数和中间度等关键网络特性指标对航线网络进行层次化分类,揭示了网络的复杂特征和层次结构。通过仿真实验评估了网络的小世界特性,并利用轮廓系数得到不同K值下的聚类结果,进而确定最优聚类结果。同时,模拟了航线网络在遭受攻击时的鲁棒性,实验结果表明:在航线网络较为脆弱的情况下,该方法为货运航司航线网络的优化和抗风险能力的提升提供了重要参考。 展开更多
关键词 space P 线
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Prescribed performance neural control to guarantee tracking quality for near space kinetic kill vehicle 被引量:5
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作者 ZHANG Tao LI Jiong +2 位作者 LI Weimin WANG Huaji LEI Humin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第3期573-586,共14页
A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the t... A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the traditional prescribed performance control in which the shape of the performance function is constant, this paper exploits new performance functions which can change the shape of their function according to different symbols of initial errors and can ensure the error convergence with a small overshoot. The neural backstepping control and the minimal learning parameters (MLP) technology are employed for exploring a prescribed performance controller (PPC) that provides robust tracking attitude reference trajectories. The highlight is that the transient performance of tracking errors is satisfactory and the computational load of neural approximation is low. The pseudo rate (PSR) modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation and high accuracy. 展开更多
关键词 PRESCRIBED PERFORMANCE control near space kinetic KILL vehicle (NSKKV) neural approximation minimal learning parameter (MLP) pseudo rate (PSR) MODULATOR
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A novel repetition space-time coding scheme for mobile FSO systems
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作者 黎明 曹阳 +1 位作者 李书明 杨绍文 《Optoelectronics Letters》 EI 2015年第2期125-129,共5页
Considering the influence of more random atmospheric turbulence, worse pointing errors and highly dynamic link on the transmission performance of mobile multiple-input multiple-output (MIMO) free space optics (FSO... Considering the influence of more random atmospheric turbulence, worse pointing errors and highly dynamic link on the transmission performance of mobile multiple-input multiple-output (MIMO) free space optics (FSO) communica- tion systems, this paper establishes a channel model for the mobile platform. Based on the combination of Alamouti space-time code and time hopping ultra-wide band (TH-UWB) communications, a novel repetition space-time coding (RSTC) method for mobile 2x2 free-space optical communications with pulse position modulation (PPM) is devel- oped. In particular, two decoding methods of equal gain combining (EGC) maximum likelihood detection (MLD) and correlation matrix detection (CMD) are derived. When a quasi-static fading and weak turbulence channel model are considered, simulation results show that whether the channel state information (CSI) is known or not, the coding sys- tem demonstrates more significant performance of the symbol error rate (SER) than the uncoding. In other words, transmitting diversity can be achieved while conveying the information only through the time delays of the modulated signals transmitted from different antennas. CMD has almost the same effect of signal combining with maximal ratio combining (MRC). However, when the channel correlation increases, SER performance of the coding 2×2 system de- grades significantly. 展开更多
关键词 Atmospheric turbulence Broadband networks Channel capacity Channel state information Codes (symbols) Communication channels (information theory) Fading channels Iterative decoding Maximum likelihood MIMO systems Optical communication Pulse position modulation Radio communication Random errors Signal detection Signal encoding space time adaptive processing Telecommunication networks Time delay Ultra wideband (UWB)
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E-Infinity Dualities, Discontinuous Spacetimes, Xonic Quantum Physics and the Decisive Experiment 被引量:2
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作者 Jean-Paul Auffray 《Journal of Modern Physics》 2014年第15期1427-1436,共10页
Using powerful concepts and tools borrowed from the seminal arsenal connecting physics fundamentals with esoteric set theoretical operations developed in recent years by Alexandria E-infinity theoretician M. S. El Nas... Using powerful concepts and tools borrowed from the seminal arsenal connecting physics fundamentals with esoteric set theoretical operations developed in recent years by Alexandria E-infinity theoretician M. S. El Naschie, this paper explores the deep implications of some of the dualities Dr El Naschie has identified and analyzed in his exposes, connecting them with our own Xonic Quantum Physics (XQP) which places dynamical action rather than spacetime and energy at the core of the System of the World. 展开更多
关键词 E-INFINITY El Naschie space Time spaceTIME Topology CANTOR Sets Energy Xon Xonic Quantum Physics PLANCK Scale Dirac Electron
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AN INTEGRATION METHOD WITH FITTING CUBIC SPLINE FUNCTIONS TO A NUMERICAL MODEL OF 2ND-ORDER SPACE-TIME DIFFERENTIAL REMAINDER——FOR AN IDEAL GLOBAL SIMULATION CASE WITH PRIMITIVE ATMOSPHERIC EQUATIONS
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作者 辜旭赞 张兵 王明欢 《Journal of Tropical Meteorology》 SCIE 2013年第4期388-396,共9页
In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubi... In this paper,the forecasting equations of a 2nd-order space-time differential remainder are deduced from the Navier-Stokes primitive equations and Eulerian operator by Taylor-series expansion.Here we introduce a cubic spline numerical model(Spline Model for short),which is with a quasi-Lagrangian time-split integration scheme of fitting cubic spline/bicubic surface to all physical variable fields in the atmospheric equations on spherical discrete latitude-longitude mesh.A new algorithm of"fitting cubic spline—time step integration—fitting cubic spline—……"is developed to determine their first-and2nd-order derivatives and their upstream points for time discrete integral to the governing equations in Spline Model.And the cubic spline function and its mathematical polarities are also discussed to understand the Spline Model’s mathematical foundation of numerical analysis.It is pointed out that the Spline Model has mathematical laws of"convergence"of the cubic spline functions contracting to the original functions as well as its 1st-order and 2nd-order derivatives.The"optimality"of the 2nd-order derivative of the cubic spline functions is optimal approximation to that of the original functions.In addition,a Hermite bicubic patch is equivalent to operate on a grid for a 2nd-order derivative variable field.Besides,the slopes and curvatures of a central difference are identified respectively,with a smoothing coefficient of 1/3,three-point smoothing of that of a cubic spline.Then the slopes and curvatures of a central difference are calculated from the smoothing coefficient 1/3 and three-point smoothing of that of a cubic spline,respectively.Furthermore,a global simulation case of adiabatic,non-frictional and"incompressible"model atmosphere is shown with the quasi-Lagrangian time integration by using a global Spline Model,whose initial condition comes from the NCEP reanalysis data,along with quasi-uniform latitude-longitude grids and the so-called"shallow atmosphere"Navier-Stokes primitive equations in the spherical coordinates.The Spline Model,which adopted the Navier-Stokes primitive equations and quasi-Lagrangian time-split integration scheme,provides an initial ideal case of global atmospheric circulation.In addition,considering the essentially non-linear atmospheric motions,the Spline Model could judge reasonably well simple points of any smoothed variable field according to its fitting spline curvatures that must conform to its physical interpretation. 展开更多
关键词 NUMERICAL forecast and NUMERICAL SIMULATION 2nd-order space-TIME differential REMAINDER NUMERICAL model cubic spline functions Navier-Stokes PRIMITIVE EQUATIONS quasi-Lagrangian time-split integration scheme global SIMULATION case
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Lorentz Transform in Multi-Dimensional Space
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作者 I. A. Urusovskii 《Journal of Modern Physics》 2012年第11期1749-1756,共8页
It is shown that in Euclidean space with any number of spatial dimensions more than three, the Lorentz transform holds true if the proper time of each elementary particle is proportional to the length of its path in t... It is shown that in Euclidean space with any number of spatial dimensions more than three, the Lorentz transform holds true if the proper time of each elementary particle is proportional to the length of its path in the extra-dimensional subspace, and all elementary particles move at the speed of light in the complete space. The six-dimensional treatment of the Coulomb force of interaction between two charges is given. The electric force is due to the motion of charges in the extra-dimensional subspace and is equal to the corresponding Lorentz force. 展开更多
关键词 LORENTZ Transform Euclidean Multi-Dimensional space COMPTON Wave Length De BROGLIE Waves SPIN and Isotopic SPIN HEISENBERG Uncertainty CPT Symmetry COULOMB Force
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The Basics of Flat Space Cosmology
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作者 Eugene Terry Tatum U. V. S. Seshavatharam S. Lakshminarayana 《International Journal of Astronomy and Astrophysics》 2015年第2期116-124,共9页
We present a new model of cosmology which appears to show great promise. Our flat space cosmology model, using only four basic and reasonable assumptions, derives highly accurate Hubble parameter H0, Hubble radius R0 ... We present a new model of cosmology which appears to show great promise. Our flat space cosmology model, using only four basic and reasonable assumptions, derives highly accurate Hubble parameter H0, Hubble radius R0 and total mass M0 values for our observable universe. Our model derives a current Hubble parameter of , in excellent agreement with the newly reported (lower limit) results of the 2015 Planck Survey. Remarkably, all of these derivations can be made with only these basic assumptions and the current CMB radiation temperature . The thermodynamic equations we have generated follow Hawking’s black hole temperature formula. We have also derived a variety of other useful cosmological formulae. These include angular velocity and other rotational formulae. A particularly useful hyperbolic equation, , has been derived, which appears to be an excellent fit for the Planck scale as well as the current observable universe scale. Using the flat space Minkowski relativistic formula for Doppler effect, and a formula for staging our cosmological model according to its average mass-energy density at every Hubble time (universal age) in its expansion, a persuasive argument can be made that the observable phenomena attributed to dark energy are actually manifestations of Doppler and gravitational redshift. Finally, a theory of cosmic inflation becomes completely unnecessary because our flat space cosmology model is always at critical density. 展开更多
关键词 FLAT space COSMOLOGY Cosmic Inflation Dark Energy Hubble Parameter Critical Density Angular Velocity LIGHT SPEED Expansion LIGHT SPEED Rotation Redshift Universe CMBR
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Lion Eyes the Stars Senegal joins Chinese lunar station programme,a&rming its space ambitions
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作者 《ChinAfrica》 2025年第11期46-47,共2页
Space was once a distant dream for African nations like Senegal.But that is changing fast.Today,space is emerging as a strategic frontier for the continent,with 22 countries including Senegal now operating national sp... Space was once a distant dream for African nations like Senegal.But that is changing fast.Today,space is emerging as a strategic frontier for the continent,with 22 countries including Senegal now operating national space agencies.Senegal launched its own agency,the Senegalese Space Study Agency(ASES),in March 2023.The recent inauguration of the African Space Agency’s headquarters in Cairo,Egypt,marks a new chapter in Africa’s rising ambitions beyond Earth.Tasked with coordinating national programmes,the agency seeks to drive economic and social development through space technologies while promoting scientific cooperation both within Africa and internationally. 展开更多
关键词 coordinating national programmesthe space agenciessenegal space ambitions Senegal african space agency s senegalese space study agency ases space space agencies
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Levy Constrained Search in Fock Space:An Alternative Approach to Noninteger Electron Number 被引量:1
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作者 AYERS Paul W. LEVY Mel 《物理化学学报》 SCIE CAS CSCD 北大核心 2018年第6期625-630,共6页
By extending the Levy wavefunction constrained search to Fock Space,one can define a wavefunction constrained search for electron densities in systems having noninteger number of electrons.For pure-state v-representab... By extending the Levy wavefunction constrained search to Fock Space,one can define a wavefunction constrained search for electron densities in systems having noninteger number of electrons.For pure-state v-representable densities,the results are equivalent to what one would obtain with the zero-temperature grand canonical ensemble.In other cases,the wavefunction constrained search in Fock space presents an upper bound to the grand canonical ensemble functional.One advantage of the Fock-space wavefunction constrained search functional over the zero-temperature grand-canonical ensemble constrained search functional is that certain specific excited states(i.e.,those that are not ground-statev-representable) are the stationary points of the Fock-space functional.However,a potential disadvantage of the Fock-space constrained search functional is that it is not convex. 展开更多
关键词 DENSITY FUNCTIONAL theory LEVY CONSTRAINED SEARCH FUNCTIONAL Fock space Fractional electron NUMBER Excited-state DENSITY FUNCTIONAL theory Universal DENSITY FUNCTIONAL Zero temperature grand canonicalensemble Convexity
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Triboelectric Nanogenerators for Future Space Missions
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作者 Rayyan Ali Shaukat Muhammad Muqeet Rehman +4 位作者 Maryam Khan Rui Chang Carlo Saverio Iorio Yarjan Abdul Samad Yijun Shi 《Nano-Micro Letters》 2026年第3期630-684,共55页
Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,whi... Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,which have to function under harsh space conditions such as extreme temperatures(−270 to 1650℃),microgravity(10^(-6)g),unhealthy humidity(<20%RH or>60%RH),high atmospheric pressure(~1450 psi),and radiation(4000–5000 mSv).Conventional energy-harvesting technologies(solar cells,fuel cells,and nuclear energy),that are normally used to power these space systems have certain limitations(e.g.,sunlight dependence,weight,degradation,big size,high cost,low capacity,radioactivity,complexity,and low efficiency).The constraints in conventional energy resources have made it imperative to look for non-conventional yet efficient alternatives.A great potential for enhancing efficiency,sustainability,and mission duration in space exploration can be offered by integrating triboelectric nanogenerators(TENGs)with existing energy sources.Recently,the potential of TENG including energy harvesting(from vibrations/movements in satellites and spacecraft),self-powered sensing,and microgravity,for multiple applications in different space missions has been discussed.This review comprehensively covers the use of TENGs for various space applications,such as planetary exploration missions(Mars environment monitoring),manned space equipment,In-orbit robotic operations/collision monitoring,spacecraft’s design and structural health monitoring,Aeronautical systems,and conventional energy harvesting(solar and nuclear).This review also discusses the use of self-powered TENG sensors for deep space object perception.At the same time,this review compares TENGs with conventional energy harvesting technologies for space systems.Lastly,this review talks about energy harvesting in satellites,TENG-based satellite communication systems,and future practical implementation challenges(with possible solutions). 展开更多
关键词 Triboelectric nanogenerators(TENGs) space missions Sustainable energy harvesting Harsh space conditions Selfpowered sensors Satellite missions
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A Design Method of Noncoherent Unitary Space-Time Codes
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作者 Li Peng Qiuping Peng Lingling Yang 《International Journal of Communications, Network and System Sciences》 2011年第7期430-435,共6页
We generalized an constructing method of noncoherent unitary space time codes (N-USTC) over Rayleigh flat fading channels. A family of N-USTCs with T symbol peroids, M transmit and N receive antennas was constructed b... We generalized an constructing method of noncoherent unitary space time codes (N-USTC) over Rayleigh flat fading channels. A family of N-USTCs with T symbol peroids, M transmit and N receive antennas was constructed by the exponential mapping method based on the tangent subspace of the Grassmann manifold. This exponential mapping method can transform the coherent space time codes (C-STC) into the N-USTC on the Grassmann manifold. We infered an universal framework of constructing a C-STC that is designed by using the algebraic number theory and has full rate and full diversity (FRFD) for t symbol periods and same antennas, where M, N, T, t are general positive integer. We discussed the constraint condition that the exponential mapping has only one solution, from which we presented a approach of searching the optimum adjustive factor αopt that can generate an optimum noncoherent codeword. For different code parameters M, N, T, t and the optimum adjustive factor αopt, we gave the simulation results of the several N-USTCs. 展开更多
关键词 NONCOHERENT Uintary space-TIME CODES (N-USTC) Coherent space-TIME CODES (C-STC) GRASSMANN Manifold Degree of Freedom Exponenatial Map Full Rate and Full Diversity (FRFD)
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Aiding Space Exploration
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作者 GE LIJUN 《ChinAfrica》 2025年第10期47-47,共1页
Deep space is incredibly quiet,but once astronauts leave the station,they must contend with extreme temperatures,fluctuating pressures,and high levels of radiation.Their spacesuits are equipped with life-support syste... Deep space is incredibly quiet,but once astronauts leave the station,they must contend with extreme temperatures,fluctuating pressures,and high levels of radiation.Their spacesuits are equipped with life-support systems,which are essential for a safe“walk in space.”On 15 August,the crew of Shenzhou-20 successfully completed their third spacewalk.For this mission,taikonaut Chen Dong wore the extravehicular spacesuit B,which has now been used in 20 spacewalks.With this achievement,the space station has reached the target of“four years and 20 spacewalks.” 展开更多
关键词 spaceSUIT RADIATION deep space space exploration extreme temperatures SHENZHOU spacewalk space station
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Simulation study of the void space gas effect on slope instability triggered by an earthquake
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作者 ZHOU Zhou WANG Xiao-qun +2 位作者 WEI Yu-feng SHEN Jun-hui SHEN Man 《Journal of Mountain Science》 SCIE CSCD 2019年第6期1300-1325,共26页
This study aims at exploring the void space gas effect of earthquake-triggered slope instability and providing a new method for studying the formation mechanism of earthquake-triggered landslides. We analysed the basi... This study aims at exploring the void space gas effect of earthquake-triggered slope instability and providing a new method for studying the formation mechanism of earthquake-triggered landslides. We analysed the basic characteristics, kinematic characteristics, initiation mechanisms and physical mechanical parameters of the Daguangbao landslide, generalized a landslide prototype, and established a geological model and performed simulation tests. Based on the seismic wave propagation theory of rock-soil mass, rock fracture mechanics and the effective stress principle, we found that the void space gas effect is due to the occurrence of excess void space gas pressure when the dynamic response of seismic loads impacts the void space gas in weak intercalated layers of the slope. The excess void space gas pressure generated by the vibration(earthquake) damages the rock mass around the void space with a certain regularity. The model test results show that the effective shear strength of the rock mass can be reduced by 4.4% to 21.6% due to the void space gas effect. 展开更多
关键词 EARTHQUAKE landslide Slope weak INTERCALATED layer VOID space GAS EFFECT Void-gas dynamic response Excess VOID space GAS pressure Gas-rock interaction mechanism
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PIC-MF-based Iterative Receiver for Multiuser Space Frequency Block Coding Systems
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作者 林文峰 何晨 熊勇 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第4期464-470,共7页
A novel low-complexity iterative receiver for multiuser space frequency block coding (SFBC) system was proposed in this paper. Unlike the conventional linear minimum mean square error (MMSE) detector, which requires m... A novel low-complexity iterative receiver for multiuser space frequency block coding (SFBC) system was proposed in this paper. Unlike the conventional linear minimum mean square error (MMSE) detector, which requires matrix inversion at each iteration, the soft-in soft-out (SISO) detector is simply a parallel interference cancellation (PIC)-matched filter (MF) operation. The probability density function (PDF) of PIC-MF detector output is approximated as Gaussian, whose variance is calculated with a priori information fed back from the channel decoder. With this approximation, the log likelihood ratios (LLRs) of transmitted bits are under-estimated. Then the LLRs are multiplied by a constant factor to achieve a performance gain. The constant factor is optimized according to extrinsic information transfer (EXIT) chart of the SISO detector. Simulation results show that the proposed iterative receiver can significantly improve the system performance and converge to the matched filter bound (MFB) with low computational complexity at high signal-to-noise ratios (SNRs). 展开更多
关键词 iterative MULTIUSER space FREQUENCY block coding (SFBC) parallel interference cancellation (PIC) matched filter (MF) EXTRINSIC information transfer (EXIT)
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