Inversion for multiple parameter classes

Many geophysical data, such as the frequencies of the free oscillations of the Earth, depend on more than one type of model parameter. For inverse problems depending on multiple parameter classes, an iterative solution procedure is introduced in which each parameter class can be treated in the same way. This approach has considerable advantages where a large number of parameters are employed, but can still be useful for smaller systems.
  The iteration by parameter class commences by solving for the direct dependence on a particular parameter class, and at subsequent iterations the cross-dependences between classes are introduced. The update affects only the right-hand side of the equations, and, because the same sets of equations have to be solved at each iteration, an efficient computational implementation can be made. The largest set of equations that has to be solved at a time corresponds to the number of variables in an individual parameter class rather than the full set of parameters, which confers substantial computational benefits for very large problems.     

Subgrade-reinforcement techniques for the dangerously deforming sections of railway lines in the north of the Russian Far East

This paper lists difficult railway construction conditions that are typical for the northern areas of the Russian Far East. Permafrost-bound issues of railway and highway construction and operation are described. Some of the authors'' developments for subgrade stabilization in the foregoing conditions are given as examples.     

On azimuthal eigenwavenumbers associated with Laplace's tidal equations

Laplace's tidal equations for the case of an ocean of constant depth bounded by meridians were considered by two authors at a specific frequency as an eigenvalue problem in the azimuthal wavenumber. A finite spectrum of eigenwavenumbers was found. That eigenvalue problem is re-examined by means of asymptotic techniques and numerical integration of the governing equation of the problem. At low frequencies a formula connecting the frequency and the number of eigensolutions is established. It is shown that at a given frequency the spectrum of eigenwavenumbers is wider than that reported, but (for this type of solution) the meridional boundary conditions are satisfied approximately only for the case of very low frequencies.     

Interfacing the DIGICO flux-gate spinner magnetometer to an APPLE IIe microcomputer

Summary. A hardware configuration and program are described for interfacing a DIGICO spinner rock magnetometer to an APPLE microcomputer. This configuration provides full control of measurements and permits storage of the results on floppy or hard discs. A similar configuration can be used to operate the anisotropy unit.     

湿地功能评价研究进展

湿地功能评价是湿地研究的核心内容之一，也是开展湿地管理工作的重要工具。美国湿地功能评价的代表性方法有生境评估规程、湿地评价技术和水文地貌评价法等。欧盟于1990年以来开发的湿地功能评价技术吸收了美国水文地貌评价法的部分做法，但更适应欧洲湿地的具体情况。有关国际机构主要从理论上对湿地功能评价方法进行了研究。我国湿地功能评价研究还很薄弱，不能适应快速发展的湿地管理需要，急需加强这方面工作。     

溴化锂的生产工艺综述

综述了国内外溴化锂生产方法,并指出了每种方法的优缺点,同时展望了今后溴化锂生产方法的发展方向。     

Assessment of biochemical concentrations of vegetation using remote sensing technology

The main biochemicals (such as lignin, protein, cellulose, sugar, starch, chlorophyll and water) of vegetation are directly or indirectly involved in major ecological processes, such as the functions of terrestrial ecosystems (i.e., nutrient-cycling processes, primary production, and decomposition). Remote sensing techniques provide a very convenient way of data acquisition capable of covering a large area several times during one season, so it can play a unique and essential role provided that we can relate remote sensing measurements to the biochemical characteristics of the Earth surface in a reliable and operational way. The application of remote sensing techniques for the estimation of canopy biochemicals was reviewed. Three methods of estimating biochemical concentrations of vegetation were included in this paper: index, stepwise multiple linear regression, and stepwise multiple linear regression based on a model of the forest crown. In addition, the vitality and potential applying value are stressed.     

Assessment of biochemical concentrations of vegetation using remote sensing technology

The main biochemicals (such as lignin, protein, cellulose, sugar, starch, chlorophyll and water) of vegetation are directly or indirectly involved in major ecological processes, such as the functions of terrestrial ecosystems (i.e., nutrient-cycling processes, primary production, and decomposition). Remote sensing techniques provide a very convenient way of data acquisition capable of covering a large area several times during one season, so it can play a unique and essential role provided that we can relate remote sensing measurements to the biochemical characteristics of the Earth surface in a reliable and operational way. The application of remote sensing techniques for the estimation of canopy biochemicals was reviewed. Three methods of estimating biochemical concentrations of vegetation were included in this paper: index, stepwise multiple linear regression, and stepwise multiple linear regression based on a model of the forest crown. In addition, the vitality and potential applying value are stressed.     

裸果木引种栽培试验研究

裸果木（Ｇｙｍｎｏｃａｒｐｏｓｐｒｚｅｗａｌｓｋｉｉ）为国家二级珍稀濒危保护植物。迄今，关于裸果木人工栽培特别是无性繁殖方面的研究，工作不多，成效甚微。笔者近三年调查了裸果木的生境，研究了其繁殖栽培技术，取得了一定成果。结果表明：裸果木的物候期比原产地稍早，生长发育较好，能正常开花结果；种子质地松软，无需特殊处理，在沙壤土播深２ｃｍ，１０天许发芽出土并且出苗较为整齐；插播育苗选１－２年生枝条，用１００、１５０ｍｇ／Ｌ　ＡＢＴ一号生根粉药液浓度处理其插条，均能达到４０－８０％的成活率。     

人文地理学研究方法述要

人文地理学是地理学的重要分支学科，20世纪60年代在人文地理学领域内进行的计量革命引发了人们对地理学的理论建设以及地理学方法论 思考，但是计量革命从一开始就经历着种种责难，文章从对计量革命这一运动的观察开始，对人文地理学方法论进行了反思，在此基础上对当前人文地理学采用的方法进行概括总结，并对一些研究方法应用前景予以展望。     

Frequency response modelling of seismic waves using finite difference time domain with phase sensitive detection (TD–PSD)

This paper describes an efficient approach for computing the frequency response of seismic waves propagating in 2- and 3-D earth models within which the magnitude and phase are required at many locations. The approach consists of running an explicit finite difference time domain (TD) code with a time harmonic source out to steady-state. The magnitudes and phases at locations in the model are computed using phase sensitive detection (PSD). PSD does not require storage of time-series (unlike a fast Fourier transform), reducing its memory requirements. Additionally, the response from multiple sources can be obtained from a single finite difference run by encoding each source with a different frequency. For 2-D models with many sources, this time domain phase sensitive detection (TD–PSD) approach has a higher arithmetic complexity than direct solution of the finite difference frequency domain (FD) equations using nested dissection re-ordering (FD–ND). The storage requirements for 2-D finite difference TD–PSD are lower than FD–ND. For 3-D finite difference models, TD–PSD has significantly lower arithmetic complexity and storage requirements than FD–ND, and therefore, may prove useful for computing the frequency response of large 3-D earth models.     

延津沙地葡萄优质栽培技术

对延津沙地引种筛选的葡萄品种及其重要栽培技术加以总结,以期对周边同类型沙地提供可行的配套技术,推动沙地农业产业结构的调整。     

河北省生态区划研究

该文根据河北省自然资源特征、生态环境现状和社会经济的发展,确立该区生态区划的原则、指标因子体系,利用3S技术,综合专家集成和定量分析方法,对地貌、气候、植被、土壤、经济结构、经济活动强度、土地利用类型、生态功能等主因子数据进行叠加与分析,将河北省分为8个生态环境区、15个生态环境亚区、24个生态环境小区。