2021年10月16日,美国国家航空航天局(NASA)利用宇宙神-5401(Atlas V 401)运载火箭从卡纳维纳尔角发射“露西”(Lucy)小行星探测器。“露西”将首次探测木星轨道上的特洛伊小行星,在12年的任务周期内先后飞越探测1颗主带小行星和7颗木星...2021年10月16日,美国国家航空航天局(NASA)利用宇宙神-5401(Atlas V 401)运载火箭从卡纳维纳尔角发射“露西”(Lucy)小行星探测器。“露西”将首次探测木星轨道上的特洛伊小行星,在12年的任务周期内先后飞越探测1颗主带小行星和7颗木星特洛伊小行星及其卫星。展开更多
Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed a...Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed as a fundamental equation of statistical physics. This equation reflects that the law of motion of particles obeying reversible, deterministic laws in dynamics becomes irreversible and stochastic in thermodynamics. From this the fundamental equations of nonequilibrium thermodynamics, the principle of entropy increase and the theorem of minimum entropy production have been derived. The hydrodynamic equations, such as the generalized Navier-Stokes equation and the mass drift-diffusion equation etc. have been derived rigorously from the kinetic kinetic equation which is reduced from the anomalous Langevin equation in Liouville space. All these are unified and self consistent. But it is difficult to prove that entropy production density σ can never be negative everywhere for all the isolated inhomogeneous systems far from equilibrium.展开更多
An adaptive method of residual life estimation for deteriorated products with two performance characteristics (PCs) was proposed, which was sharply different from existing work that only utilized one-dimensional degra...An adaptive method of residual life estimation for deteriorated products with two performance characteristics (PCs) was proposed, which was sharply different from existing work that only utilized one-dimensional degradation data. Once new degradation information was available, the residual life of the product being monitored could be estimated in an adaptive manner. Here, it was assumed that the degradation of each PC over time was governed by a Wiener degradation process and the dependency between them was characterized by the Frank copula function. A bivariate Wiener process model with measurement errors was used to model the degradation measurements. A two-stage method and the Markov chain Monte Carlo (MCMC) method were combined to estimate the unknown parameters in sequence. Results from a numerical example about fatigue cracks show that the proposed method is valid as the relative error is small.展开更多
We calculate Wigner function, tomogram of the pair coherent state by using its Sehmidt decomposition in the coherent state representation. It turns out that the Wigner function can be seen as the quantum entanglement ...We calculate Wigner function, tomogram of the pair coherent state by using its Sehmidt decomposition in the coherent state representation. It turns out that the Wigner function can be seen as the quantum entanglement （QE） between two two-variable Hermite polynomials （TVHP） and the tomogram is further simplified as QE of two single-variable Hermite polynomials. The Husimi function of pair coherent state is also calculated.展开更多
Nature's greatest splendors are often secreted in the remotest of spots. This is certainly true of Kanas Lake, deep in the Altay Mountains of northern Xinjiang Uygur Autonomous Region. This area of sublime, and as...Nature's greatest splendors are often secreted in the remotest of spots. This is certainly true of Kanas Lake, deep in the Altay Mountains of northern Xinjiang Uygur Autonomous Region. This area of sublime, and as yet unsullied, natural beauty is home to 2,000 people of the Tuwa ethnic minority. The ancestry of these herder-hunters is unclear. Certain anthropologists believe that they are descended from Genghis Khan's "Mongol hordes" that swept through on their 13th century rampage of Central Asia and Europe. Others argue that they are the posterity of Siberian migrants, and cousins to the Tuvan people of Russia.展开更多
Although we often see references to Carnap＇s inductive logic even in modern literatures, seemingly its confusing style has long obstructed its correct understanding. So instead of Carnap, in this paper, I devote myse...Although we often see references to Carnap＇s inductive logic even in modern literatures, seemingly its confusing style has long obstructed its correct understanding. So instead of Carnap, in this paper, I devote myself to its necessary and sufficient commentary. In the beginning part （Sections 2-5）, I explain why Carnap began the study of inductive logic and bow he related it with our thought on probability （Sections 2-4）. Therein, I trace Carnap＇s thought back to Wittgenstein＇s Tractatus as well （Section 5）. In the succeeding sections, I attempt the simplest exhibition of Carnap＇s earlier system, where his original thought was thoroughly provided. For this purpose, minor concepts to which researchers have not paid attention are highlighted, for example, m-function （Section 8）, in-correlation （Section 10）, C-correlate （Section 10）, statistical distribution （Section 12）, and fitting sequence （Section 17）. The climax of this paper is the proof of theorem （56）. Through this theorem, we will be able to overview Carnap＇s whole system.展开更多
文摘Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed as a fundamental equation of statistical physics. This equation reflects that the law of motion of particles obeying reversible, deterministic laws in dynamics becomes irreversible and stochastic in thermodynamics. From this the fundamental equations of nonequilibrium thermodynamics, the principle of entropy increase and the theorem of minimum entropy production have been derived. The hydrodynamic equations, such as the generalized Navier-Stokes equation and the mass drift-diffusion equation etc. have been derived rigorously from the kinetic kinetic equation which is reduced from the anomalous Langevin equation in Liouville space. All these are unified and self consistent. But it is difficult to prove that entropy production density σ can never be negative everywhere for all the isolated inhomogeneous systems far from equilibrium.
基金Project(60904002)supported by the National Natural Science Foundation of China
文摘An adaptive method of residual life estimation for deteriorated products with two performance characteristics (PCs) was proposed, which was sharply different from existing work that only utilized one-dimensional degradation data. Once new degradation information was available, the residual life of the product being monitored could be estimated in an adaptive manner. Here, it was assumed that the degradation of each PC over time was governed by a Wiener degradation process and the dependency between them was characterized by the Frank copula function. A bivariate Wiener process model with measurement errors was used to model the degradation measurements. A two-stage method and the Markov chain Monte Carlo (MCMC) method were combined to estimate the unknown parameters in sequence. Results from a numerical example about fatigue cracks show that the proposed method is valid as the relative error is small.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10775097 and 10874174the Research Foundation of the Education Department of Jiangxi Province
文摘We calculate Wigner function, tomogram of the pair coherent state by using its Sehmidt decomposition in the coherent state representation. It turns out that the Wigner function can be seen as the quantum entanglement （QE） between two two-variable Hermite polynomials （TVHP） and the tomogram is further simplified as QE of two single-variable Hermite polynomials. The Husimi function of pair coherent state is also calculated.
文摘Nature's greatest splendors are often secreted in the remotest of spots. This is certainly true of Kanas Lake, deep in the Altay Mountains of northern Xinjiang Uygur Autonomous Region. This area of sublime, and as yet unsullied, natural beauty is home to 2,000 people of the Tuwa ethnic minority. The ancestry of these herder-hunters is unclear. Certain anthropologists believe that they are descended from Genghis Khan's "Mongol hordes" that swept through on their 13th century rampage of Central Asia and Europe. Others argue that they are the posterity of Siberian migrants, and cousins to the Tuvan people of Russia.
文摘Although we often see references to Carnap＇s inductive logic even in modern literatures, seemingly its confusing style has long obstructed its correct understanding. So instead of Carnap, in this paper, I devote myself to its necessary and sufficient commentary. In the beginning part （Sections 2-5）, I explain why Carnap began the study of inductive logic and bow he related it with our thought on probability （Sections 2-4）. Therein, I trace Carnap＇s thought back to Wittgenstein＇s Tractatus as well （Section 5）. In the succeeding sections, I attempt the simplest exhibition of Carnap＇s earlier system, where his original thought was thoroughly provided. For this purpose, minor concepts to which researchers have not paid attention are highlighted, for example, m-function （Section 8）, in-correlation （Section 10）, C-correlate （Section 10）, statistical distribution （Section 12）, and fitting sequence （Section 17）. The climax of this paper is the proof of theorem （56）. Through this theorem, we will be able to overview Carnap＇s whole system.
