用于新生代定年的Ar-Ar法标准样品候选样品初测结果   总被引：5，自引：1，他引：5  

桑海清  丁林  戴檀谟 《矿物岩石地球化学通报》2004,23(1):24-27

Ar Ar法定年的特点是必须要有一套年龄从小到大的标准样。迄今用于新生代定年的国内标准样极少。为满足新生代矿物Ar Ar法定年的需要,初选了一个标准样候选者BT 1透长石。样品总重366g,粒级6080目,纯度100%,缩分为100瓶,每瓶3 66g。Ar Ar阶段加热法初测结果为:全部12个阶段给出的总气体年龄为30 8±0 9Ma,412阶段视年龄十分接近,年龄谱平坦,对应的39Ar析出量达96%,坪年龄为29 6±0 4Ma,等时年龄为29 6±0 6Ma,MSWD=1 01。40Ar/36Ar初始值为293 6±3 9,与尼尔值295 5相当。重复测定结果为:全部气体年龄为31 0±0 9Ma(全部9个阶段),坪年龄为29 5±0 4Ma,等时年龄为29 4±0 6Ma,MSWD=1 94,40Ar/36Ar初始值为282 2±6 3。这些结果表明,BT 1透长石不含过剩氩,作为新生代定年的Ar Ar法标准样品候选者是较为理想的。  相似文献   

Precise/ Small Sample Size Determinations of Lithium Isotopic Compositions of Geological Reference Materials and Modern Seawater by MC-ICP-MS   总被引：6，自引：1，他引：6  

Alistair B. Jeffcoate  Tim Elliott  Alex Thomas  Claudia Bouman 《Geostandards and Geoanalytical Research》2004,28(1):161-172

The Li isotope ratios of four international rock reference materials, USGS BHVO-2, GSJ JB-2, JG-2, JA-1 and modern seawater (Mediterranean, Pacific and North Atlantic) were determined using multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). These reference materials of natural samples were chosen to span a considerable range in Li isotope ratios and cover several different matrices in order to provide a useful benchmark for future studies. Our new analytical technique achieves significantly higher precision and reproducibility (< ± O.3%o 2s) than previous methods, with the additional advantage of requiring very low sample masses of ca . 2 ng of Li.  相似文献   

西南地区中药产业发展   总被引：1，自引：0，他引：1  

徐云  何景峰 《山地学报》2004,(Z1)

本文总结西南地区中药产业发展现状,分析西南地区中药产业中药材、生产加工和研发能力上的竞争优势,提出西南地区中药产业的发展对策。  相似文献   

用GPS秒信号锁定高频振荡器的方法研究   总被引：1，自引：0，他引：1  

郭芳 《时间频率学报》2004,27(2):94-102

对用远距离传输的GPS秒信号锁定本地高频晶体振荡器的方法进行了探讨。介绍了高精度的时间数字转换器TDC(Time to Digital Converter)和对滤波的方法进行了探讨。为了降低成本又能够满足设计要求的精度，还考虑了双D／A转换的方法。有关的硬件系统已经通过了调试和一系列的测试和实验，在测量和控制精度方面，能达到设计的要求。此外，提出了这个系统有待解决的问题，如双D／A转换的非线性问题，Kalman滤波抗野值及继续提高精度的问题。  相似文献   

海岸带临港工业、海运物流与全球化大生产的探讨   总被引：5，自引：0，他引：5  

田汝耕  张振克  朱大奎 《世界地理研究》2004,13(2):1-8

海岸带是世界人口密集、经济发达的地带，在全球经济一体化和全球化大生产中具有重要的地位。近半个世纪以来，海岸带临港工业迅速崛起并持续高速发展，依托海港建设、大型船舶运输发展起来的临港工业和海运物流，在跨国公司的运作下形成了现代意义上的全球化大生产。这种生产方式使资源贫乏的日本快速发展成发达国家；深圳赤湾临港工业区成为中国高效益工业的典范。本文着重讨论了海岸带经济建设中大力发展临港工业对地区、国家和全球经济的影响，指出中国21世纪应大力开发利用海岸带港湾资源、重点建设全球化大生产的大进大出的基地，建立若干个具有国际竞争力的海岸带产业中心，推动国民经济持续、快速发展。  相似文献   

Methods for Setting up a Three-Dimensional Industrial Surveying System of “Building Blocks Type”     

FENG Wenhao 《地球空间信息科学学报》2004,(3)

1　Methodsfororientatinginitialdirec tioninindustrialsurveyDifferentfromconventionalengineeringsurvey,thedistancebetweenthetwoangle measurementdevicesinindustrialsurveyisnomorethantenmeters.Theaccu racyforthemeasurementofobjectpointsisrequiredtobebetween± ( 0 .0 2～ 0 .0 5～ 0 .2 0 )mm ,sotheaccu racyfortheorientationoftheinitialdirectionoughttobehigh .Theexistingmethodsfororientatingtheinitialdirectionbetweenthetwoangle measurementdevicesincludemethodofusinginnertarget,collimatormethod,metho…  相似文献   

Place‐based action in Wollongong: the role of union–community alliances in constructing labour geographies of steel     

Liza Tonkin 《The Australian geographer》2004,35(1):59-75

Place‐based action (PBA) features prominently in labour geographies, particularly in restructuring politics, and is consistently employed as an enduring union tactic, yet it remains relatively undervalued in steel restructuring accounts, with common approaches emphasising the class instability and limitations of such action. In contrast, and to redress the apparent imbalance, this paper argues the merit of recognising PBA as a distinct movement‐based politic with specific forms of representation and empowerment. Such an approach should lead to greater recognition and appreciation of the impact that PBA has had historically. To illustrate this, a case study is presented of how local groups used place‐based action in Wollongong to shape steel restructuring politics and industry policy during the 1980s. Although powerful, the influence of PBA diminished at the policy writing stage. Rather than devaluing all benefits from PBA due to such limitations, it is suggested that the constraints on PBA at this point suggests the need for other forms of intervention. It is concluded that the approach suggested here highlights when other tactics are required, strengthening real‐world tactical analysis.  相似文献   

吉林省发展矿泉水产业的战略思考   总被引：1，自引：0，他引：1  

于明宽 《吉林地质》2005,24(1):54-57,88

本文在分析吉林省矿泉水资源特征和矿泉水事业发展现状的基础上，结合国内外矿泉水产业的发展趋势，指出了当前吉林省矿泉水产业发展中存在的问题，提出了快速发展矿泉水产业的对策和建议。  相似文献   

Geochemistry of Late Cretaceous （ 60 - 67 Ma） igneous activities in the Hebrides Terrace seamount （guyot） area, Scotland     

M.El-Tokhi M.Omran A.E-Muslem 《中国地球化学学报》2005,24(1):9-17

Tholeiitic basalts in various stages of alteration were dredged from Late Cretaceous volcanic rocks (60 -67 Ma) in the Hebrides Terrace seamount area in the Atlantic Ocean. These rocks are extrusive olivine basalts, including high- and low-Al basalts. High-Al basalts are depleted in MgO, CaO, Cr,Sc, V, St, Zr and enriched in TiO2, Na2O, Nb, Rb as compared with low-A1 basalts. Petrography and bulk-rock composition (major, trace and rare-earth elements) data defined clear tholeiitic suites displaying possible liquid lines of descent related to different degrees of crystal fractionation and partial melting.Isotopic dating of dredged samples gave the guyot an age of 60 - 67 Ma, in support of the assumption that it was formed during the Late Cretaceous.  相似文献   

湖泊湿地生态地球化学评价的标准体系     

申锐莉  鲍征宇 《地质通报》2005,(Z1)

湖泊湿地生态地球化学评价的研究重点为湖泊湿地生态系统中的重金属、植物营养元素及一些有机污染物,评价标准体系相应地包括水质基准、营养物基准、水体沉积物质量基准、饮用水卫生标准、土壤环境质量标准、食品卫生标准、湖泊水库富营养化标准等。  相似文献