基于加速度响应控制时MTMD的地震特性

研究了由多个刚度和阻尼保持为常量且频率呈线性分布的TMD形成的MTMD的地震特性。基于虚拟激励法和Kanai Tajimi及Clough Penzien地震谱 ,建立了结构 MTMD系统的加速度传递函数 ,进而导出了设置MTMD时结构的加速度动力放大系数 (ADMF)明确表达式。于是MTMD的优化准则选择为 :结构最大加速度动力放大系数的最小值的最小化 [Min .Min .Max .ADMF]。通过最优搜寻得MTMD的最优频率间隔、平均阻尼比、调谐频率比和相应的控制有效性指标。选择结构受控频率与地震卓越频率比的不同取值 ,研究地震卓越频率对MTMD最优参数及有效性的影响     

地震作用下结构的AMTMD主动控制策略

提出了一种新的控制策略——主动多重调谐质量阻尼器(AMTMD)．AMTMD控制系统频率呈线性分布．AMTMD保持相同的刚度和阻尼但质量变化．AMTMD的主动控制力采用Roorda(1975)提出的生成模式．基于结构的广义振型模型，导出了设置AMTMD时结构的动力放大系数(DMF)．于是AMTMD优化准则选择为结构最大动力放大系数的最小值的最小化．分别使用位移、速度和加速度传感器，通过最优搜寻，研究了反映AMTMD有效性和鲁棒性的参数．这些参数包括：频率间隔、平均阻尼比、调谐频率比、Min．Min．Max．DMF、标准化反馈增益系数和环增益系数．为比较，同时考虑了多重调谐质量阻尼器和主动调谐质量阻尼器．而且，数值结果表明：AMTMD比MTMD具有更高的有效性和鲁棒性且ATMD也有更高的有效性．     

玻恩和沃尔夫合著的《光学原理》一书写作过程

《光学原理》(Principles of Optics)一书是玻恩与沃尔夫合著的、倍受好评的光学经典名著。回顾、梳理与品味这一名著的撰写过程，会得到诸多感悟。教书育人、著书立说的物理教育家以及物理学家，都可以从中得到一把尺子，用以衡量自己的工作。这有利于中国物理学的发展。     

Spectral properties of matrix polynomials in the max algebra

We consider the spectral properties of matrix polynomials over the max algebra. In particular, we show how the Perron-Frobenius theorem for the max algebra extends to such polynomials and illustrate the relevance of this for multistep difference equations in the max algebra. We also present a number of inequalities for the largest max eigenvalue of a matrix polynomial.     

Fritz Reiche and the Emergency Committee in Aid of Displaced Foreign Scholars

I discuss the family background and early life of the German theoretical physicist Fritz Reiche (1883–1969) in Berlin; his higher education at the University of Berlin under Max Planck (1858–1947); his subsequent work at the University of Breslau with Otto Lummer (1860–1925); his return to Berlin in 1911, where he completed his Habilitation thesis in 1913, married Bertha Ochs the following year, became a friend of Albert Einstein (1879–1955), and worked during and immediately after the Great War. In 1921 he was appointed as ordentlicher Professor of Theoretical Physics at the University of Breslau and worked there until he was dismissed in 1933. He spent the academic year 1934–1935 as a visiting professor at the German University in Prague and then returned to Berlin, where he remained until, with the crucial help of his friend Rudolf Ladenburg (1882–1952) and vital assistance of the Emergency Committee in Aid of Displaced Foreign Scholars, he, his wife Bertha, and their daughter Eve were able to emigrate to the United States in 1941 (their son Hans had already emigrated to England in 1939).From 1941–1946 he held appointments at the New School for Social Research in New York, the City College of New York, and Union College in Schenectady, New York, and then was appointed as an Adjunct Professor of Physics at New York University, where his contract was renewed year-by-year until his retirement in 1958.     

The Politics of Memory: Otto Hahn and the Third Reich

As President of the Kaiser Wilhelm Society and its successor, the Max Planck Society, from 1946 until 1960, Otto Hahn (1879–1968) sought to portray science under the Third Reich as a purely intellectual endeavor untainted by National Socialism. I outline Hahn’s activities from 1933 into the postwar years, focusing on the contrast between his personal stance during the National Socialist period, when he distinguished himself as an upright non-Nazi, and his postwar attitude, which was characterized by suppression and denial of Germany’s recent past. Particular examples include Hahn’s efforts to help Jewish friends; his testimony for colleagues involved in denazification and on trial in Nuremberg; his postwar relationships with émigré colleagues, including Lise Meitner; and his misrepresentation of his wartime work in the Kaiser Wilhelm Institute for Chemistry.     

图的最大二等分问题的非线性规划算法

基于图的最大二等分问题的半定规划松驰模型 ,本文提出一个非线性规划算法求解该模型 ,得到该半定规划松驰模型的一个次优解 ,并且给出算法的收敛性证明 .数值试验表明该方法可以有效地求解图的最大二等分问题的松驰模型     

最大乘积型Fuzzy文法与自动机

本文对提出的最大乘积型Ｆｕｚｚｙ文法与最大乘积型Ｆｕｚｚｙ自动机的关系作了详细讨论，得出了两个重要的结论。即：由给定的最大乘积型Ｆｕｚｚｙ正规文法可构造一个最大乘积型Ｆｕｚｚｙ自动机使得二者接受的语言集相同，反之亦然。从而达到自动识别语言的目的。     

On maximizing clique, clique-Helly and hereditary clique-Helly induced subgraphs

Clique-Helly and hereditary clique-Helly graphs are polynomial-time recognizable. Recently, we presented a proof that the clique graph recognition problem is NP-complete [L. Alcón, L. Faria, C.M.H. de Figueiredo, M. Gutierrez, Clique graph recognition is NP-complete, in: Proc. WG 2006, in: Lecture Notes in Comput. Sci., vol. 4271, Springer, 2006, pp. 269-277]. In this work, we consider the decision problems: given a graph G=(V,E) and an integer k≥0, we ask whether there exists a subset V^′⊆V with |V^′|≥k such that the induced subgraph G[V^′] of G is, variously, a clique, clique-Helly or hereditary clique-Helly graph. The first problem is clearly NP-complete, from the above reference; we prove that the other two decision problems mentioned are NP-complete, even for maximum degree 6 planar graphs. We consider the corresponding maximization problems of finding a maximum induced subgraph that is, respectively, clique, clique-Helly or hereditary clique-Helly. We show that these problems are Max SNP-hard, even for maximum degree 6 graphs. We show a general polynomial-time -approximation algorithm for these problems when restricted to graphs with fixed maximum degree Δ. We generalize these results to other graph classes. We exhibit a polynomial 6-approximation algorithm to minimize the number of vertices to be removed in order to obtain a hereditary clique-Helly subgraph.     

John Bell and the Identical Twins

I present a biographical profile of John S. Bell based upon extensive interviews I had with him. I present Bell‘s views on the quantum theory along with a simple explanation of his identity. Jeremy Bernstein is Professor Emeritus of Physics at the Stevens Institute of Technology and a former staff writer for The New Yorker.