基于PGNAA技术在线分析系统的应用

近年来,随着核探测与分析技术的日趋成熟,使复杂γ谱的获取、解析达到了在线测量的要求,从而使在线PGNAA(中子活化瞬发γ射线分析)技术获得了飞速的发展。它可对一些工业生产过程中的全物料进行在线测量,其分析精度、可靠性等皆能满足在线元素含量分析的需要,因而显示出巨大的发展潜力和广阔的市场前景。这里介绍了基于PGNAA技术的在线分析系统的基本原理、组成和发展,并概述了它在水泥、煤炭等行业的应用情况。     

西藏俄卡地银多金属异常区地球化学

异常形态、分布严格受推覆断裂控制,范围大、浓集中心明显,浓度变化及因子载荷表明。区内找Ag、Pb有利,而Sb又为其最佳指示元素。     

明代军事地理研究概述

军事地理是谋兵布防的平台。明代被迫在南北两条战线作战：北部沿长城一线防御少数民族南下；东南沿海抗击倭寇入侵。因此，明代格外重视军事地理的研究，研究成果丰硕，著述很多。概述明代军事地理研究成果，不仅是回顾历史，而是借鉴经验。一些著作中提出的御敌方略至今有参考价值。     

基于广义Kопытов模型及乙型水驱曲线的综合预测法

将广义Kопытов预测模型和乙型水驱曲线方法有机的结合起来，得到了油田开发中后期——递减时期的一种预测水驱开发油田的含水率、产油量、产水量及其相应的累积产量随开发时间变化的方法，此方法克服了在水驱油田预测开发指标中二者所存在的局限性。     

人工值守台数字化地震仪标定原理

推导了人工台数字化地震仪的分段标定公式，提出数字化记录系统的微分近似标定和拾震器阻尼衰减法标定的方法，并提供了不同短周期地震仪与数字化地震仪并行的藕合方式和标定计算公式。     

隔震及超高层建筑的地震反应观测

2001年5月24日和6月20日分别发生了宜良4.2级和呈南3.6级两次地震，架设在云南省抗震培训中心隔震大楼和昆明佳华广场的结构强震观测台阵记录了这两栋建筑物对这两次地震反应。本介绍了获取的记录，并分析了两栋建筑物的地震反应情况。     

Production of selected cosmogenic radionuclides by muons: 2. Capture of negative muons

We have determined the production yields for radionuclides in Al₂O₃, SiO₂, S, Ar, K₂SO₄, CaCO₃, Fe, Ni and Cu targets, which were irradiated with slow negative muons at the Paul Scherrer Institute in Villigen (Switzerland). The fluences of the stopped negative muons were determined by measuring the muonic X-rays. The concentrations of the long-lived and short-lived radionuclides were measured with accelerator mass spectrometry (AMS) and γ-spectroscopy, respectively. Special emphasis was put on the radionuclides ¹⁰Be, ¹⁴C and ²⁶Al produced in quartz targets, ²⁶Al in Al₂O₃ and S targets, ³⁶Cl in K₂SO₄ and CaCO₃ targets, and ⁵³Mn in Fe₂O₃ targets. These targets were selected because they are also the naturally occurring target minerals for cosmic ray interactions in typical rocks. We also present results of calculations for depth-dependent production rates of radionuclides produced after cosmic ray μ⁻ capture, as well as cosmic ray-induced production rates of geologically relevant radionuclides produced by the nucleonic component, by μ⁻ capture, by fast muons and by neutron capture.     

Nonlinear earthquake response analysis and energy calculation for seismic slit shear wall structures

Based on the concept of structural passive control, a new type of slit shear wall, with improved seismic performance when compared to an ordinary solid shear wall, was proposed by the authors in 1996. The idea has been verified by a series of pseudo-static and dynamic tests. In this paper a macro numerical model is developed for the wall element and the energy dissipation device. Then, nonlinear time history analysis is carried out for a 10-story slit shear wall model tested on a shaking table. Furthermore, the seismic input energy and the individual energy dissipated by the components are calculated by a method based on Newmark-β assumptions for this shear wall model, and the advantages of this shear wall are further demonstrated by the calculation results from the viewpoint of energy. Finally, according to the seismic damage criterion on the basis of plastic accumulative energy and maximum response, the optimal analysis is carried out to select design parameters for the energy dissipation device.     

河北省粮食生产灰色关联动态分析

根据 194 9～ 1998年各县 (市 )的统计资料 ,分析了河北省近 5 0年粮食生产的变化历程和空间差异 ,运用灰色系统理论对影响河北省粮食生产的诸因素进行关联动态分析 ,量化了粮食总产量与诸因子的关联程度 ,指出粮食单产、有效灌溉面积和粮食播种面积是影响河北省粮食生产的最重要因素 ,并提出了实现河北省粮食生产可持续发展的基本途径 ,为今后河北省农业可持续发展提供了参考依据     

南宁市旅游商品开发研究

分析南宁市旅游商品资源优势及旅游商品开发中存在的问题。根据旅游商品资源优势及旅游商品开发设计的原则 ,设计旅游商品系列和旅游商品销售网点空间布局。提出旅游商品开发生产实施措施