Third-order modified coefficient scheme based on essentially non-oscillatory scheme

A third-order numerical scheme is presented to give approximate solutions to multi-dimensional hyperbolic conservation laws only using modified coefficients of an essentially non-oscillatory （MCENO） scheme without increasing the base points during construction of the scheme. The construction process shows that the modified coefficient approach preserves favourable properties inherent in the original essentially nonoscillatory （ENO） scheme for its essential non-oscillation, total variation bounded （TVB）, etc. The new scheme improves accuracy by one order compared to the original one. The proposed MCENO scheme is applied to simulate two-dimensional Rayleigh-Taylor （RT） instability with densities 1：3 and 1：100, and solve the Lax shock-wave tube numerically. The ratio of CPU time used to implement MCENO, the .third-order ENO and fifth-order weighed ENO （WENO） schemes is 0.62：1：2.19. This indicates that MCENO improves accuracy in smooth regions and has higher accuracy and better efficiency compared to the original ENO scheme.     

Quantum Standard Teleportation Based on the Generic Measurement Bases

We study the quantum standard teleportation based on the generic measurement bases. It is shown that the quantum standard teleportation does not depend on the explicit expression of the measurement bases. We have given the correspondence relation between the measurement performed by Alice and the unitary transformation performed by Bob. We also prove that the single particle unknown states and the two-particle unknown cat-like states can be exactly transmitted by means of the generic measurement bases and the correspondence unitary transformations.     

害嗜鳞螨[Lepidoglyphus destructor (Schrank,1781)]形态的研究——(无气门目Astigmata甜食螨科Glycyphagidae)

<正> 一前言害嗜鳞螨[Lepidoglyphus destructor(Schrank)]属蜱螨亚纲(Acari)无气门目(Astig-mata)食甜螨科(Glycyphagidae)嗜鳞螨属(Lepidoglyphus),是一种常见为害贮藏食物的螨类之一,经常与粗脚粉螨(Acarus siro),普通肉食螨[Cheyletus eruditus(Schrank)]等混合发生,我们曾     

基于离散Bass模型的双十一销售预测

阿里巴巴双十一购物节的销售额走势,不仅是相关企业规划决策的依据,也是我国经济活动的重要方向性指标,运用Bass模型预测双十一销售额具有十分重要的意义.对普通正向的离散Bass模型采用普通最小二乘法得到的参数估计值偏离于原连续模型参数的真实值,因为存在着多重共线性和时间区间偏差.为克服这两个缺点,根据一类黎卡提方程构建精确的离散Bass模型.研究显示该模型及其解均收敛于原连续模型.给出基于非线性最小二乘法则的搜索算法,估计模型参数,拟合效果较好.最后将模型结果运用到阿里巴巴双十一的销售额预测,结果表明2018销售额将迎来拐点,增速将放缓.     

国内高等学校物理实验教学研讨会历史回顾——从“虞福春教授的一封贺信”谈起

基于对国内召开的高等学校物理实验教学研讨会的文献调研,本文将上述历次研讨会的发展历程及相关内容作概要介绍(包括时间、地点、承办单位、会议类型等),且就其中的两次会议给予进一步地详细叙述.     

新织物让你冬日暖洋洋

未来的冬装已经到来,保暖效果甚至超过你全身裹在电热毯里直到春天降临。研究者研制出一种织物,只需一点点电力就可比普通棉纤维更有效地保暖。科学家将普通棉服浸入银纳米线粒子溶液中,使衣物形成一个传导网络。通过改变溶液的浓度,研究者可以控制网络的粒子间隙,最终找到一个能够保存人体80%的热量同     

STUDY OF THE EQUIVALENT THEOREM OF GENERALIZED VARIATIONAL PRINCIPLES IN ELASTICITY

The relations of all generalized variational principles in elasticity are studied by employing the invariance theorem of field theory. The infinitesimal scale transformation in field theory was employed to investigate the equivalent theorem. Among the results found particularly interesting are those related to that all generalized variational principles in elasticity are equal to each other. Also studied result is that only two variables are independent in the functional and the stress-strain relation is the variational constraint condition for all generalized variational principles in elasticity. This work has proven again the conclusion of Prof. Chien Wei-zang.     

影响系统主因素综合筛选技术研究

系统影响因素过多不仅会增加系统建模难度,而且会增加系统模型的不确定性和数据收集工作量,因此提出一种影响系统的主因素综合筛选技术.技术将综合灰色关联度、普通相关技术、逐步回归方法、DEMATEL法以及系统动力学等方法的优点和缺点,通过彼此互补和相互融合技术,使得该技术能够有效地筛选出影响系统的主因素.通过在筛选影响船舶柴油机寿命周期费用主因素的应用,和其他方法的比较和分析,验证了本技术的可行性、有效性和先进性.     

对一道高考试题的讨论

文献[1]刊登了对2010年普通高等学校招生全国统一考试（上海卷）物理试题的评析，其中第24小题，给出了两种解法，这两种解法的确简单，但是读完之后，总觉得这样的解法没有考虑初始位置间的夹角，有些不妥．课堂上给学生讲完上述两种解法后，大部分学生同样不能理解：为什么不考虑初始位置间的夹角？     

一道考题的解法赏析与发散

2009年普通高等学校招生全国统一考试陕西卷（理）第6题如下：