In fundamental theories of physics, the dynamical equations all have time inversion invariance. Except for the evolution of some simple system which has realistic inverse processes, but for a slightly more complicated...In fundamental theories of physics, the dynamical equations all have time inversion invariance. Except for the evolution of some simple system which has realistic inverse processes, but for a slightly more complicated system, the evolution processes are irreversible. This is the problem of arrow of time, which is always warmly debated. In different point of view, we find there may have some conceptual misunderstanding in the controversy: 1) The realization of an inverse process does not mean the time of the system goes backward. 2) The principles of relativity and covariance are the constraints to physical laws, but not constraints to specific solutions. The equations must be covariant, but the solutions are not definitely symmetric. 3) Time is a global property of the universe, which is a measurement of the evolution process of the universe. The internal time of a matter system reflecting its internal evolution speed also takes this cosmic time as a unified background and standard of measurement. 4) The universe has a unified cosmic time T and a cosmic space related to this cosmic time. They are objective and absolute. 5) The eigensolution of a spinor is a critical state losing time concept, which responses the interaction of environment with some uncertainty, then the evolution process of the world is not uniquely determined. 6) The non-uniqueness of the evolution process means that the inverse process is absent. So for a world including spinors, the evolution is essentially irreversible. In this paper, according to the widely accepted principles and direct calculations of transformation, we reveal the misunderstandings in the usual controversy, and then give more natural and reasonable explanations for structure of space-time and arrow of time.展开更多
When we study Lorentz transformation in the framework of quantum gauge theory of gravity, we will find that the vacuum gravitational gauge field will be changed under gravitational gauge transformation, which will cha...When we study Lorentz transformation in the framework of quantum gauge theory of gravity, we will find that the vacuum gravitational gauge field will be changed under gravitational gauge transformation, which will change the structure of the physical space-time and cause clock dilation effect. The study in this paper provides us with new insights to understand the essential and intrinsic relation between special relativity and general relativity. It provides us with a new way to unify special relativity and general relativity.展开更多
Qamdo block in the east Tibet lay in front of southwestern margin of the Yangtze landmass and was one of many micro\|blocks between the Gondwana and the Eurasia continents .It played an important role in the developme...Qamdo block in the east Tibet lay in front of southwestern margin of the Yangtze landmass and was one of many micro\|blocks between the Gondwana and the Eurasia continents .It played an important role in the development of the multi\|arc\|basin system of the north sector of the Jinsha\|lancang\|nujiang rivers . Space\|time texture of the block reflected the tectonic evolution of the east Tibet and neighbouring areas directly, providing important information for evolutionary history of the east Tethys.1\ Crustal structure of the Qamdo block\;Crustal structure of the Qamdo block is characterized by “double basement and double cover”.By double basement is meant the Middle—Upper Proterozoic crystalline basement and the Lower Paleozoic folded basement. The Middle—Upper Proterozoic crystalline basement is composed of medium\|high\|grade metamorphic biotite\|plagiogneiss, plagioclase\|amphibole schist, nacritid intercalated with (intermediate\|) basic metavolcanite. These rocks are characteristic of strong ductile deformed metamorphic core complex. The zircon of gneiss yields an U\|Pb age of 1680～2200Ma while the basic metavolcanite give a Sm\|Nd age of 1594Ma.The Lower Paleozoic folded basement consists of the Lower Ordovician and Silurian. Basement of the Qamdo block is similar to that of the Yangtze landmass. By double cover we mean two covers consisting of the Upper Paleozoic and Mesozoic, respectively. The Upper Paleozoic is composed of carbonate and clastic rock which were formed from epicontinental to back\|arc basins. The Mesozoic consists of the Upper Triassic—Cretaceous concordant formations which were formed in a back\|arc foreland basin.Sequences of the formations are molasse, neritic carbonate, paralic coal\|bearing rock and terrigenous red clastic rock from the bottom to the top.展开更多
In this paper, a new observation equation of non-Gaussian frequency selective fading Bell Labs layered space time （BLAST） architecture system is proposed, which is used for frequency selective fading channels and no...In this paper, a new observation equation of non-Gaussian frequency selective fading Bell Labs layered space time （BLAST） architecture system is proposed, which is used for frequency selective fading channels and non-Gaussian noise in an application environment of BLAST system. With othogonal matrix triangularization （QR decomposition） of the channel matrix, the static observation equation of frequency selective fading BLAST system is transformed into a dynamic state space model, and then the particle filter is used for space-time layered detection. Making the full use of the finite alphabet of the digital modulation communication signal, the optimal proposal distribution can be chosen to produce particle and update the weight. Incorporated with current method of reducing error propagation, a new space-time layered detection algorithm is proposed. Simulation result shows the validity of the proposed algorithm.展开更多
高速移动环境会导致信道的双弥散效应,给无线通信系统带来巨大挑战。正交时频空间(orthogonal time frequency space,OTFS)调制通过将时-频域的双弥散信道转换为时延-多普勒域的平坦衰落信道,能够有效缓解双弥散信道带来的频率和时间选...高速移动环境会导致信道的双弥散效应,给无线通信系统带来巨大挑战。正交时频空间(orthogonal time frequency space,OTFS)调制通过将时-频域的双弥散信道转换为时延-多普勒域的平坦衰落信道,能够有效缓解双弥散信道带来的频率和时间选择性衰落的影响。针对多用户大规模多输入多输出(multiinput multi-output,MIMO)OTFS系统中的信道参数估计问题,通过对多天线信道结构特征进行深入分析,将用户与基站间的信道建模为稀疏结构模型。将大规模MIMO信道划分为多个群组,设计了适用于多用户大规模MIMO-OTFS系统的导频图案,提出了基于群组块共稀疏阈值结构化贝叶斯学习信道估计算法。利用估计得到的信道状态信息设计了分数多普勒频移、到达角度等信道参数估计方法,从而进一步感知用户状态。仿真结果表明,提出的信道参数估计算法具有更高的估计精度和系统频谱效率。展开更多
We examine the space-time structure of particle-emitting source and two-pion interferometry in a smoothed hydrodynamic model with fluctuating initial conditions. An equation of state with a crossover transition betwee...We examine the space-time structure of particle-emitting source and two-pion interferometry in a smoothed hydrodynamic model with fluctuating initial conditions. An equation of state with a crossover transition between quark-gluon plasma and hadronic gas is adopted in the description of the system evolution. We find that the fluctuating initial conditions lead to inhomogeneous particle-emitting sources. The interferometry results of Rs and Ro indicate that both the source size and the duration of pion emission decrease when the freeze-out temperature increases. The values of Ro/Rs obtained by our simulated two-pion interferometry are consistent with the previous results of smoothed particle hydrodynamics, and smaller than those calculated in usual hydrodynamic models.展开更多
文摘In fundamental theories of physics, the dynamical equations all have time inversion invariance. Except for the evolution of some simple system which has realistic inverse processes, but for a slightly more complicated system, the evolution processes are irreversible. This is the problem of arrow of time, which is always warmly debated. In different point of view, we find there may have some conceptual misunderstanding in the controversy: 1) The realization of an inverse process does not mean the time of the system goes backward. 2) The principles of relativity and covariance are the constraints to physical laws, but not constraints to specific solutions. The equations must be covariant, but the solutions are not definitely symmetric. 3) Time is a global property of the universe, which is a measurement of the evolution process of the universe. The internal time of a matter system reflecting its internal evolution speed also takes this cosmic time as a unified background and standard of measurement. 4) The universe has a unified cosmic time T and a cosmic space related to this cosmic time. They are objective and absolute. 5) The eigensolution of a spinor is a critical state losing time concept, which responses the interaction of environment with some uncertainty, then the evolution process of the world is not uniquely determined. 6) The non-uniqueness of the evolution process means that the inverse process is absent. So for a world including spinors, the evolution is essentially irreversible. In this paper, according to the widely accepted principles and direct calculations of transformation, we reveal the misunderstandings in the usual controversy, and then give more natural and reasonable explanations for structure of space-time and arrow of time.
文摘When we study Lorentz transformation in the framework of quantum gauge theory of gravity, we will find that the vacuum gravitational gauge field will be changed under gravitational gauge transformation, which will change the structure of the physical space-time and cause clock dilation effect. The study in this paper provides us with new insights to understand the essential and intrinsic relation between special relativity and general relativity. It provides us with a new way to unify special relativity and general relativity.
文摘Qamdo block in the east Tibet lay in front of southwestern margin of the Yangtze landmass and was one of many micro\|blocks between the Gondwana and the Eurasia continents .It played an important role in the development of the multi\|arc\|basin system of the north sector of the Jinsha\|lancang\|nujiang rivers . Space\|time texture of the block reflected the tectonic evolution of the east Tibet and neighbouring areas directly, providing important information for evolutionary history of the east Tethys.1\ Crustal structure of the Qamdo block\;Crustal structure of the Qamdo block is characterized by “double basement and double cover”.By double basement is meant the Middle—Upper Proterozoic crystalline basement and the Lower Paleozoic folded basement. The Middle—Upper Proterozoic crystalline basement is composed of medium\|high\|grade metamorphic biotite\|plagiogneiss, plagioclase\|amphibole schist, nacritid intercalated with (intermediate\|) basic metavolcanite. These rocks are characteristic of strong ductile deformed metamorphic core complex. The zircon of gneiss yields an U\|Pb age of 1680～2200Ma while the basic metavolcanite give a Sm\|Nd age of 1594Ma.The Lower Paleozoic folded basement consists of the Lower Ordovician and Silurian. Basement of the Qamdo block is similar to that of the Yangtze landmass. By double cover we mean two covers consisting of the Upper Paleozoic and Mesozoic, respectively. The Upper Paleozoic is composed of carbonate and clastic rock which were formed from epicontinental to back\|arc basins. The Mesozoic consists of the Upper Triassic—Cretaceous concordant formations which were formed in a back\|arc foreland basin.Sequences of the formations are molasse, neritic carbonate, paralic coal\|bearing rock and terrigenous red clastic rock from the bottom to the top.
文摘In this paper, a new observation equation of non-Gaussian frequency selective fading Bell Labs layered space time （BLAST） architecture system is proposed, which is used for frequency selective fading channels and non-Gaussian noise in an application environment of BLAST system. With othogonal matrix triangularization （QR decomposition） of the channel matrix, the static observation equation of frequency selective fading BLAST system is transformed into a dynamic state space model, and then the particle filter is used for space-time layered detection. Making the full use of the finite alphabet of the digital modulation communication signal, the optimal proposal distribution can be chosen to produce particle and update the weight. Incorporated with current method of reducing error propagation, a new space-time layered detection algorithm is proposed. Simulation result shows the validity of the proposed algorithm.
文摘高速移动环境会导致信道的双弥散效应,给无线通信系统带来巨大挑战。正交时频空间(orthogonal time frequency space,OTFS)调制通过将时-频域的双弥散信道转换为时延-多普勒域的平坦衰落信道,能够有效缓解双弥散信道带来的频率和时间选择性衰落的影响。针对多用户大规模多输入多输出(multiinput multi-output,MIMO)OTFS系统中的信道参数估计问题,通过对多天线信道结构特征进行深入分析,将用户与基站间的信道建模为稀疏结构模型。将大规模MIMO信道划分为多个群组,设计了适用于多用户大规模MIMO-OTFS系统的导频图案,提出了基于群组块共稀疏阈值结构化贝叶斯学习信道估计算法。利用估计得到的信道状态信息设计了分数多普勒频移、到达角度等信道参数估计方法,从而进一步感知用户状态。仿真结果表明,提出的信道参数估计算法具有更高的估计精度和系统频谱效率。
基金Supported by National Natural Science Foundation of China (10775024)Foundation of Theoretical Nuclear Physics Center of National Laboratory of Heavy Ion Accelerator of Lanzhou
文摘We examine the space-time structure of particle-emitting source and two-pion interferometry in a smoothed hydrodynamic model with fluctuating initial conditions. An equation of state with a crossover transition between quark-gluon plasma and hadronic gas is adopted in the description of the system evolution. We find that the fluctuating initial conditions lead to inhomogeneous particle-emitting sources. The interferometry results of Rs and Ro indicate that both the source size and the duration of pion emission decrease when the freeze-out temperature increases. The values of Ro/Rs obtained by our simulated two-pion interferometry are consistent with the previous results of smoothed particle hydrodynamics, and smaller than those calculated in usual hydrodynamic models.
