直角杠杆佯谬的能流解释和弹性定律协变性的统一

直角杠杆佯谬是指可绕角顶自由转动的直角杠杆在一个惯性系中已达力学平衡,但变换到另一惯性系中出现力矩,却仍处于平衡状态的似有矛盾的问题．本文介绍了劳厄的能流解释,并将其与弹性定律的协变性解释统一起来     

判断并解决线性规划“多反而少”悖论的逆最优值解法

现有研究通过调整线性规划模型的右端项来消除“多反而少”悖论,而该文提出并验证了悖论是由技术系数矩阵、目标函数系数以及右端项三者的不合理搭配造成的。首先,通过建立原-对偶模型来判断悖论现象存在与否;然后,将悖论问题转换成逆最优值问题进行解决,构建了通过调整目标函数系数以及技术系数矩阵来消除悖论的模型;最后,提出了判断并解决悖论的逆最优值解法,阐述了其优势与经济意义,并通过数值算例验证其有效性。     

The median-based resolution of the St. Petersburg paradox

The St. Petersburg Paradox contributed to establishing expected utility theory by demonstrating that decision making based on the expectation (expected value, or mean, average) leads to an unreasonable behavior. Although the expected value is commonly used as an optimization criterion in various fields of mathematical sciences, such paradoxical problems as arbitrariness and intransitivity have led many researchers to forsake expected utility theory in search of more useful alternatives. Here we show an analytical solution of the St. Petersburg Paradox based on the median of the probability distribution. The present method provides a reasonable solution to any related problem. The median payout of repeated games suggests a new scaling relation in the limit of a large number of repetitions, while the game has no characteristic scale in terms of expected value.     

The thermodynamics in a dynamical black hole

Considering the back-reaction of emitting particles to the black hole, a “new” horizon is suggested where thermodynamics can be built in the dynamical black hole. It, at least, means that the thermodynamics of a dynamical black hole should not be constructed at the original event horizon any more. The temperature, “new” horizon position and radiating particles’ energy will be consistent again under the theory of equilibrium thermodynamical system.      

Schrödinger’s Cat Meets Einstein’s Twins: A Superposition of Different Clock Times

The phenomenon of quantum superposition, which allows a physical system to exist in different states ‘simultaneously’, is one of the most bizarre notions in physics. Here we illustrate an even more bizarre example of it: a superposed state of a physical system consisting of both an ‘older’ version and a ‘younger’ version of that system. This can be accomplished by exploiting the special relativistic effect of time dilation featuring in Einstein’s famous twin paradox.     

零售商主导型供应链渠道管理与悖论机制分析

普遍认为零售企业压榨供应商、但实际上供应商利润率远高于零售商是业界关注的一个热点商业悖论问题。通过构建无退货、一般退货、全额退货、线性回扣等体现零售商不同强势地位的供应链渠道管理模型,研究并比较了退货和回扣等强势契约机制以及销售努力对零售供应链管理绩效的影响。分析表明供应商通过批发价定价可以有效转移强势契约带来的风险和成本支付,零售商不能通过强势契约显著提升零售供应链效益。零售商应该利用渠道优势首先强化对批发价定价权的影响,在此基础上合理采用强势契约机制。本文研究很好地解释了零供双方渠道地位与利润水平矛盾的商业悖论问题。     

狭义相对论百年风雨

介绍狭义相对论中某些争论并澄清一些看法．     

Entanglement generation in trapped atoms

The two atoms in the ion trap are entangled by the interaction with an external excited atom. The evolution of the entanglement is analytically derived without the decoherence. Considering the spontaneous decay from the environment, the evolution of the entanglement is similar to the damping Rabi oscillation. The generation of entanglement is induced by the dipole-dipole type interaction of atoms. It is found that the entanglement of two trapped atoms is robust with the uniform interaction with the external atom. The collective spontaneous emission from the coupling between the atoms may enhance the entanglement.     

Full separability criterion for tripartite quantum systems

In this paper, an intuitive approach is employed to generalize the full separability criterion of tripartite quantum states of qubits to the higher-dimensional systems [Phys. Rev. A 72, 022333 (2005)]. A distinct characteristic of the present generalization is that less restrictive conditions are needed to characterize the properties of full separability. Furthermore, the formulation for pure states can be conveniently extended to the case of mixed states by utilizing the Kronecker product approximate technique. As applications, we give the analytic approximation of the criterion for weakly mixed tripartite quantum states and investigate the full separability of some weakly mixed states.