带TMD的结构基于动力可靠性约束的优化设计

本文在运用复模态法求得多自由度带TMD结构随机地震响应解析解的基础上．采用基于动力可靠性约束的优化设计方法对TMD装置参数的优化取值进行了系统研究,以结构最大位移响应的期望值为目标函数,以TMD装置响应的动力可靠性为约束条件,运用罚函数法获得到TMD装置的优化设计参数．并给出了算例,从而建立了带TMD结构基于动力可靠性约束的抗震优化设计的一整套方法,本文方法也可用于基础隔震结构、带TLD减震结构以及带TMD和TLD抗风结构的优化设计。     

Orogenic and Anorogenic Granitoids in the Altay Mountains of Xinjiang and Their Discrimination Criteria

On the basis of field geological studies of the granotoids in the region, mineralogical, petrological, geochemical(including stable isotope geochemical) and isotopic geochronological investigations were carried out on selected representative granitic bodies of various types. The authors have concluded that, apart from the bodies of the orogenic granitoid series, there also exist intrusions of the anorogenic granitoid series in the region. The intrusives of the two series were formed not only in different ages and tectonic environments, but also were derived from different sources of materials. Moreover, they are associated with different mineralizations, belonging to different minerologenetic series(Cheng et al., 1983). They show distinctly a series of discriminative criteria. The problems under discussion in the present paper are of important theoretical and practical significance in the studies of granites of the orogenic belt, particularly the studies of the genesis and related metallogeny of the granites of the region.     

Formulation of the thermodynamic functions for mantle minerals: MgO as an example

The formulas for thermodynamic functions for minerals are presented, couched in terms of the important thermodynamic variable K_T= (P/T)_v, where is the volume thermal expansivity and K_T is the isothermal bulk modulus. Presenting the formulas in this way leads to simplification since K_T as a product varies only slightly with volume, and is close to being independent of temperature at high temperature. Using our equations, we present as examples some computed data in the form of graphs on the entropy, internal energy, Helmholtz free energy, and Gibbs free energy in the high temperature regime (up to 2000 K) and for high compression (up to 0.7), for MgO. For entropy, knowledge of the V, T dependence of K_T is sufficient. For enthalpy and internal energy, the equation of state is needed in addition.     

城市人口的遥感估算方法

常规人口估算方法耗时、费力、财物消耗大且周期长,况且,仅靠少数年份的人口统计资料也是难以准确揭示人口状况的。尽管应用遥感方法估算人口的历史并不长,精度也还不高,但已显示了其优越性。遥感估算人口的主要原理如下。 (1)美国国防卫星及NOAA卫星的热红外通道图像说明,人口分布及其数量与城市耗能量(人工热源)相关,而耗能量又与图像灰度相关;(2)城市人口的膨胀与城市面积的扩展相关;(3)像片上进行住宅计数,用人口普查资料或抽样调查方法确定每户平均人数则可进行人口估算;4)人口密度大小也反映在人工结构物及自然物体的波谱反射率差异上,据此可建立人口数量与反射率的回归方程。     

中国与澳大利亚的气象合作

中国与澳大利亚的领土面积很接近,跨越经度大致相同,所处纬度数也差不多,但是人口、历史和社会结构则有极大差异。在过去的十五年间,两国合作迅速发展,作为人类活动中必然进行国际合作的领域之一——气象更是如此。本文简单地对比了两国气象发展的历史和目前状况,并概述了1985年两国开展双边气象合作以来所执行的项目的主要内容。     

Determination of atmospheric precipitable water and humidity profiles by a ground-based 1,35 cm radiometer

In four seasons of 1982 measurements of atmospheric water vapor profiles and total precipitable water were made by a ground-based microwave radiometer operating at 1.35 cm wavelength. All data were processed by using Monte Carlo method. The statistical results of more than seventy cases show that the relative error compared to the radiosonde observations is 5.3% for the total precipitable water vapor and less than 20% for humidity profiles in the lower atmosphere below 750 mb. In addition, the relationship between the weather background and both the humidity profiles and the total precipitable water vapor were analyzed.     

Distribution of water vapor content (WVC) and its seasonal variation over the mainland of China

Based on the meteorological data of 105 aerological stations during the period of 1960－1969, the monthly average water vapor content (WVC) in air column over the mainland of China is calculated. Charts showing the distribution of mean WVC for January and July and its seasonal variation associated with the atmos-pheric circulation in the lower troposphere over East Asia are also presented. Results obtained from this anal-ysis will contribute to the assessment of water resources, as well as the studies of the formation of rainfall and climate.     

THE EFFECT OF ASPECT RATIO ON THE BIFURCATION PROPERTIES OF A DOUBLE PARALLEL-CONNECTION LORENZ SYSTEM

A double parallel-connection (DPC) Lorenz system is developed by performing spectrum truncation of the Galerkin series expansion of the two-dimensional Rayleigh-Benard convection equation. Analyses of the equilibrium states indicate that a convective roll stems from a flow with a given wavenumber first losing its stability for a particular aspect ratio β after a stable laminar flow gets unstable; when β has the value βc able to deprive synchronously two flows with different wavenumbers of stability, occurrences of convective rolls with different wavenumbers depend entirely on the initial conditions, in good agreement with the relevant experimental results. The calculations of the unstablized rolls show that, with a smaller β (as compared with βc), the DPC Lorenz system has the same bifurcation properties as the ordinary Lorenz system; for a moderate β, the system has very complicated periodic, quasi-periodic and phase-locking motions; for a larger β, it results in intermittent chaos and causes mean flows with different numbers of vortices to occur alternately with time. All these indicate that β has substantial effect on the two Lorenz systems coupled through parallel connection in their interaction and the results.     

1987年1月8日甘肃迭部5.9级地震与地形变特征

根据１９８７年１月８日甘肃迭部５．９级地震前，该区域的地壳形变中长期背景和定点台站连续观测资料的震反应异常，分析研究了这此异常的变化特征。     

Characteristics and method of synthesis seismic wave based on wavelet reconstruction

A novel method of synthesizing seismic wave using wavelet reconstruction is proposed and compared with the traditional method of using theory of Fourier transform. By adjusting the frequency band energy and taking it as criterion, the formula of synthesizing seismic wave is deduced. Using the design parameters specified in Chinese Seismic Design Code for buildings, seismic waves are synthesized. Moreover, the method of selecting wavelet bases in synthesizing seismic wave and the influence of the damping ratio on synthesizing results are analyzed. The results show that the synthesis seismic waves using wavelet bases can represent the characteristics of the seismic wave as well as the ground characteristic period, and have good time-frequency non-stationary.