期刊文献+
共找到23,277篇文章
< 1 2 250 >
每页显示 20 50 100
Borate-Modified,Flame-Retardant Paper Packaging Materials for Archive Conservation 被引量:2
1
作者 Juanli Wang Ming Cao +5 位作者 Jiaxin Li Kaiyuan Li Xiaolian Chao Bingjie Mai Yuhu Li Jing Cao 《Journal of Renewable Materials》 SCIE EI 2022年第4期1125-1136,共12页
Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retar... Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role.Herein,boric acid,borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety.The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests,without much influence on mechanical properties such as tensile strength and elongation at break.Thermogravimetric analysis(TGA),scanning electron microscope(SEM),and X-ray photoelectron spectroscopy(XPS)reveal that porous glass structure is formed during the combustion,because thermal decomposition of boric acid,borax and disodium octaborate will produce porous glassy matter as B_(2)O_(3).The porous glass covers the paper surface as an insulating layer which retards the further pyrolysis and combustion,resulting in a denser carbon layer.Our study provides a robust way to reduce the fire hazard of the archive packaging material by applying environment-friendly boron-based fire retardants. 展开更多
关键词 Paper packaging materials archive conservation flame retardant
下载PDF
Recent Progress of Earth Observation Satellites in China
2
作者 HUANG Shusong QI Wenping +3 位作者 ZHANG Shuai XIA Tian WANG Jingqiao ZENG Yong 《空间科学学报》 CAS CSCD 北大核心 2024年第4期731-740,共10页
Currently,China has 32 Earth observation satellites in orbit.The satellites can provide various data such as optical,multispectral,infrared,and radar.The spatial resolution of China Earth observation satellites ranges... Currently,China has 32 Earth observation satellites in orbit.The satellites can provide various data such as optical,multispectral,infrared,and radar.The spatial resolution of China Earth observation satellites ranges from low to medium to high.The satellites possess the capability to observe across multiple spectral bands,under all weather conditions,and at all times.The data of China Earth observation satellites has been widely used in fields such as natural resource detection,environmental monitoring and protection,disaster prevention and reduction,urban planning and mapping,agricultural and forestry surveys,land survey and geological prospecting,and ocean forecasting,achieving huge social benefits.This article introduces the recent progress of Earth observation satellites in China since 2022,especially the satellite operation,data archiving,data distribution and data coverage. 展开更多
关键词 China Earth Observation Satellites Satellite operation Data archiving Data distribution Data coverage
下载PDF
Analysis of the Creation of Demonstration Digital Archives: Taking the Construction of Smart Archives in Dongcheng District, Beijing as an Example
3
作者 Huifang Wu 《Journal of Applied Mathematics and Physics》 2024年第10期3349-3357,共9页
The construction of demonstration digital archives is a key project for the innovative development of the archival industry vigorously promoted by the National Archives Administration. Taking the construction of the S... The construction of demonstration digital archives is a key project for the innovative development of the archival industry vigorously promoted by the National Archives Administration. Taking the construction of the Smart Archives in Dongcheng District, Beijing as an example, this paper deeply explores the work objectives, functional requirements, and technical means of creating a demonstration digital archive. One is scientific planning, which is building the basic framework of digital archives. Proposed the infrastructure of “three major supports, five major platforms, and three major guarantees”. The second is to highlight key points and improve the basic functions of digital archives. Including hardware construction, software configuration, digitization of library archives, electronic archive management, sharing and utilization of digital archive information, and formulation of management systems for digital archives. The third is to strive for practical results and deepen the construction of smart libraries. This includes vigorously promoting the construction of smart archive centers, establishing a comprehensive management platform for smart libraries, and introducing new-generation information technology to achieve the integration of smart libraries in order to explore some mature experiences and methods that can be referenced for the creation of demonstration digital archives. 展开更多
关键词 Digital archive Smart Library Digitalization of archives Intelligent Management Infrastructure
下载PDF
解铃须从系铃处——Records与Archives概念正史(六)
4
作者 王岚 《档案管理》 北大核心 2024年第6期10-19,32,共11页
笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史... 笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史去寻找,才是解铃的关键:以英法八百年档案工作中重要人物和事件为主线,探求其档案的源流、本质、内含及演变,为档案概念正史。 展开更多
关键词 卷档 录卷归档 档案 皇家档案 馆藏档案 现行档案 概念 历史
下载PDF
解铃须从系铃处——Records与Archives概念正史(四)
5
作者 王岚 《档案管理》 北大核心 2024年第3期22-33,38,共13页
笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史... 笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史去寻找,才是解铃的关键:以英法八百年档案工作中重要人物和事件为主线,探求其档案的源流、本质、内含及演变,为档案概念正史。 展开更多
关键词 卷档 录卷归档 档案 皇家档案 馆藏档案 现行档案 概念 历史
下载PDF
解铃须从系铃处——Records与Archives概念正史(五)
6
作者 王岚 《档案管理》 北大核心 2024年第5期11-22,28,共13页
笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史... 笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史去寻找,才是解铃的关键:以英法八百年档案工作中重要人物和事件为主线,探求其档案的源流、本质、内含及演变,为档案概念正史。 展开更多
关键词 卷档 录卷归档 档案 皇家档案 馆藏档案 现行档案 概念 历史
下载PDF
解铃须从系铃处——Records与Archives概念正史(三)
7
作者 王岚 《档案管理》 北大核心 2024年第2期27-33,共7页
笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史... 笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史去寻找,才是解铃的关键:以英法八百年档案工作中重要人物和事件为主线,探求其档案的源流、本质、内含及演变,为档案概念正史。 展开更多
关键词 卷档 录卷归档 档案 皇家档案 馆藏档案 现行档案 概念 历史
下载PDF
解铃须从系铃处——Records与Archives概念正史(二)
8
作者 王岚 《档案管理》 北大核心 2024年第1期28-35,共8页
笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史... 笔者的“四正”,从名分、本义、学理、法律上已弄清Records的含义,但坚持“Records文件观”者依旧质疑:若Records是档案,那Archives是什么?两者并列时又怎么翻译?还有人说Records是记录。既然是英语和法语带来的问题,循着英法档案历史去寻找,才是解铃的关键:以英法八百年档案工作中重要人物和事件为主线,探求其档案的源流、本质、内含及演变,为档案概念正史。 展开更多
关键词 卷档 录卷归档 档案 皇家档案 馆藏档案 现行档案 概念 历史
下载PDF
Living Archives项目及其对数字档案资源整合与服务的启示 被引量:12
9
作者 刘磊 安小米 钟文睿 《浙江档案》 北大核心 2014年第8期5-8,共4页
瑞典Living Archives项目旨在将公共文化遗产档案转变为重要的社会资源,让公共文化遗产档案发挥其最大作用,从而提升公民文化意识、实现公众集体协作、共同应对档案数字转型带来的挑战。本文介绍了这一项目的研究背景,分析了其项目架构... 瑞典Living Archives项目旨在将公共文化遗产档案转变为重要的社会资源,让公共文化遗产档案发挥其最大作用,从而提升公民文化意识、实现公众集体协作、共同应对档案数字转型带来的挑战。本文介绍了这一项目的研究背景,分析了其项目架构、研究路线、先进理念和实现方法,剖析了它在记忆呈现、开放数据和公众参与设计方面对公共档案角色转变带来的影响和启示,对我国数字档案资源整合与服务提出了有益借鉴。 展开更多
关键词 LIVING archives 开放数据 记忆呈现 数字档案资源 瑞典
下载PDF
超媒体档案管理系统HyperArchives的分析与设计
10
作者 刘婷 金连甫 《计算机工程》 EI CAS CSCD 北大核心 1997年第2期41-44,共4页
分析了档案信息的特点。并在此基础上重点描述了超媒体档案管理系统HyperArchives的设计模型,还简要介绍了系统的总体结构及功能构成。
关键词 档案管理 超媒体 客户机/服务器 体系结构
下载PDF
Ontology-Based Semantic Annotation for Problem Set Archives in the Web 被引量:1
11
作者 SU Xiang ZHU Guo-jin WANG Zong- wei 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第1期63-67,共5页
Aimming at the difficulty in getting semantic informarton from each problem in problem set archives, We propose a new method of ontology based semantic annotation for problem set archives, which utilizes programming k... Aimming at the difficulty in getting semantic informarton from each problem in problem set archives, We propose a new method of ontology based semantic annotation for problem set archives, which utilizes programming knowledge domain ontology to add semantic annotations to problems in the Web. The system we developed adds semantic annotation for each problem in the form of Extensible Makeup Language. Our method overcomes the difficulty of extracting semantics from problem set archives and the efficiency of this method is demonstrated through a case study. Having semantic annotations of problems, a student can efficiently locate the problems that logically corre spond to his knowledge. 展开更多
关键词 ONTOLOGY semantic annotation problem set archive
下载PDF
Construction of Intelligent Recommendation Retrieval Model of FuJian Intangible Cultural Heritage Digital Archives Resources 被引量:2
12
作者 Xueqing Liao 《Intelligent Automation & Soft Computing》 SCIE 2023年第7期677-690,共14页
In order to improve the consistency between the recommended retrieval results and user needs,improve the recommendation efficiency,and reduce the average absolute deviation of resource retrieval,a design method of int... In order to improve the consistency between the recommended retrieval results and user needs,improve the recommendation efficiency,and reduce the average absolute deviation of resource retrieval,a design method of intelligent recommendation retrieval model for Fujian intangible cultural heritage digital archive resources based on knowledge atlas is proposed.The TG-LDA(Tag-granularity LDA)model is proposed on the basis of the standard LDA(Linear Discriminant Analysis)model.The model is used to mine archive resource topics.The Pearson correlation coefficient is used to measure the relevance between topics.Based on the measurement results,the FastText deep learning model is used to achieve archive resource classification.According to the classification results,TF-IDF(term frequency–inverse document frequency)algorithm is used to calculate the weight of resource retrieval keywords to achieve resource retrieval,and a recommendation model of intangible cultural heritage digital archives resources is built through the knowledge map to achieve comprehensive and personalized recommendation of resources.The experimental results show that the recommendation and retrieval results of the proposed method are more in line with users’needs,can provide users with personalized digital archive resources,and the average absolute deviation of resource retrieval is low,the recommendation efficiency is high,and the utilization effect of archive resources is effectively improved. 展开更多
关键词 Knowledge map intangible cultural heritage digital archives intelligent recommendation SEARCH TG-LDA model fasttext model
下载PDF
Behavior of the Cultivable Airborne Mycobiota in air-conditioned environments of three Havanan archives, Cuba 被引量:1
13
作者 Sofía Borrego Alian Molina 《Journal of Atmospheric Science Research》 2020年第1期16-28,共13页
High concentrations of environmental fungi in the archives repositories are dangerous for the documents preserved in those places and for the workers'health.The aims of this work were to evaluate the behavior of t... High concentrations of environmental fungi in the archives repositories are dangerous for the documents preserved in those places and for the workers'health.The aims of this work were to evaluate the behavior of the fungal concentration and diversity in the indoor air of repositories of 3 archives located in Havana,Cuba,and to demonstrate the potential risk that these taxa represent for the documentary heritage preserved in these institutions.The indoor and outdoor environments were sampled with a biocollector.From the I/O ratios,it was evident that two of the studied archives were not contaminated,while one of them did show contamination despite having temperature and relative humidity values very similar to the other two.Aspergillus,Penicillium and Cladosporium were the predominant genera in the indoor environments.New finds for archival environments were the genera Harposporium and Scolecobasidium.The principal species classified ecologically as abundant were C.cladosporioides and P.citrinum.They are known as opportunistic pathogenic fungi.All the analyzed taxa excreted acids,the most of them degraded cellulose,starch and gelatin while about 48%excreted different pigments.But 33%of them showed the highest biodeteriogenic potential,evidencing that they are the most dangerous for the documentary collections. 展开更多
关键词 archives Environmental fungi Indoor environments Microbial quality of archive environments Quality of indoor environments Documentary biodeterioration
下载PDF
Physical analysis on improving the recovery accuracy of the Earth's gravity field by a combination of satellite observations in along-track and cross-track directions 被引量:4
14
作者 郑伟 许厚泽 +1 位作者 钟敏 员美娟 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期633-640,共8页
The physical investigations on the accuracy improvement to the measurement of the Earth's gravity field recovery are carried out based on the next-generation Pendulum-A/B out-of-plane twin-satellite formation in this... The physical investigations on the accuracy improvement to the measurement of the Earth's gravity field recovery are carried out based on the next-generation Pendulum-A/B out-of-plane twin-satellite formation in this paper. Firstly, the Earth's gravity field complete up to degree and order 100 is, respectively, recovered by the collinear and pendulum satellite formations using the orbital parameters of the satellite and the matching accuracies of key payloads from the twin GRACE satellites. The research results show that the accuracy of the Earth's gravity field model from the Pendulum-A/B satellite formation is about two times higher than from the collinear satellite formation, and the further improvement of the determination accuracy of the Earth's gravity field model is feasible by the next-generation Pendulum-A/B out-of-plane twin-satellite formation. Secondly, the Earth's gravity field from Pendulum-A/B complete up to degree and order 100 is accurately recovered based on the orbital parameters of the satellite (e.g., an orbital altitude of 400 km, an intersatellite range of 100 km, an orbital inclination of 89° and an orbital eccentricity of 0.001), the matching accuracies of space- borne instruments (e.g. 10-6 m in the intersatellite range, 10-3 m in the orbital position, 10-6 m/s in orbital velocity, and 10-11 m/s2 in non-conservative force), an observation time of 30 days and a sampling interval of 10 s. The measurement accuracy of the Earth's gravity field from the next-generation Pendulum-A/B out-of-plane twin-satellite formation is full of promise for being improved by about l0 times compared with that from the current GRACE satellite formation. Finally, the physical requirements for the next-generation Pendulum-A/B out-of-plane twin-satellite formation are analyzed, and it is proposed that the satellite orbital altitude be preferably designed to be close to 400±50 km and the matching precision of key sensors from the Pendulum-A/B mission be about one order of magnitude higher than from the GRACE program. 展开更多
关键词 twin pendulum-MB satellites collinear and pendulum satellite formations along-cross-track ob-servations physical analysis satellite gravity recovery
下载PDF
FOR CONSERVATION-THE CONSERVATION ATLAS OF CHINA
15
作者 范正一 《Chinese Geographical Science》 SCIE CSCD 1991年第4期91-98,共8页
I. THE IMPORTANCE AND URGENCY OF NATURAL CONSERVATION Mankind is seeking economic development and utilizing natural resources, which must agree, with limited resources and support of ecosystem while give full consider... I. THE IMPORTANCE AND URGENCY OF NATURAL CONSERVATION Mankind is seeking economic development and utilizing natural resources, which must agree, with limited resources and support of ecosystem while give full consideration for later generations. This is the meaning of conservation. With development of society and technology, the increasing ability of creation and construction of mankind directs the same force of destruction and ravage. In recent decades, as a result of the expanding scale 展开更多
关键词 ATLAS utilizing ATLAS servation mankind DESTRUCTION EXPANDING SEEKING creation RATIONAL
下载PDF
Library Archives Management Based on Electronic Technology 被引量:1
16
作者 Weiguo Xie Song Shan 《Journal of Electronic Research and Application》 2022年第2期38-43,共6页
In order to better promote the digital and electronic development of libraries,this paper first analyzes the management requirements of library archives,constructs a management mode based on electronic technology,and ... In order to better promote the digital and electronic development of libraries,this paper first analyzes the management requirements of library archives,constructs a management mode based on electronic technology,and analyzes the management measures of electronic library archives for reference. 展开更多
关键词 archives management LIBRARY Electronic technology
下载PDF
The Dexterity Management for Medical Spare Parts Archives
17
作者 Xin Mai Zhifeng Ye +3 位作者 Zhe Wei Changhua Chen Haili Ding Ran Wang 《Intelligent Information Management》 2019年第2期33-37,共5页
In the field of medical equipment and equipment storage work, when we access accessories and equipment, due to the actual conditions, it causes low efficiency. It is often difficult to quickly and efficiently search b... In the field of medical equipment and equipment storage work, when we access accessories and equipment, due to the actual conditions, it causes low efficiency. It is often difficult to quickly and efficiently search by using simple data management software, such as excel. In order to solve the problem, our team used Python development tool to build high-performance retrieval software, which enabled the equipment custodian to maintain or redesign the database according to actual needs. Through actual verification, this system not only can greatly improve the accuracy of device access, but also has good expansion portability, which could manage various multimedia data systems. 展开更多
关键词 archives PYTHON DEXTERITY MANAGEMENT
下载PDF
Discussion on Collection of Precious Meteorological Archives under the Background of New Archives Law
18
作者 Xiaobei LIU Xiao LIU +1 位作者 Yun CAI Song YUAN 《Meteorological and Environmental Research》 CAS 2023年第3期45-47,53,共4页
On January 1,2021,the newly revised Archives Law of the People's Republic of China(hereinafter referred to as the new Archives Law)was officially implemented,providing legal protection for archive management,archi... On January 1,2021,the newly revised Archives Law of the People's Republic of China(hereinafter referred to as the new Archives Law)was officially implemented,providing legal protection for archive management,archive work and archive undertaking in the new era.Starting from the relevant provisions of the new Archives Law,the collection of precious meteorological archives was discussed,and it is believed that only on the basis of clarifying the definition,collection responsibility subject,collection scope,ways and methods of precious meteorological archives can the relevant units be convenient to practice and obtain substantive collection effect. 展开更多
关键词 archives Law Precious meteorological archives COLLECTION IDENTIFICATION
下载PDF
Research on Multi-Blockchain Electronic Archives Sharing Model
19
作者 Fang Yu Wenbin Bi +4 位作者 Ning Cao Jun Luo Diantang An Liqiang Ding Russell Higgs 《Computers, Materials & Continua》 SCIE EI 2023年第9期3921-3931,共11页
The purpose of introducing blockchain into electronic archives sharing and utilization is to break the information barrier between electronic archives sharing departments by relying on technologies such as smart contr... The purpose of introducing blockchain into electronic archives sharing and utilization is to break the information barrier between electronic archives sharing departments by relying on technologies such as smart contract and asymmetric encryption.Aiming at the problem of dynamic permission management in common access control methods,a new access control method based on smart contract under blockchain is proposed,which improves the intelligence level under blockchain technology.Firstly,the Internet attribute access control model based on smart contract is established.For the dynamic access of heterogeneous devices,the management contract,permission judgment contract and access control contract are designed;Secondly,the access object credit evaluation algorithm based on particle swarm optimization radial basis function(PSO-RBF)neural network is used to dynamically generate the access node credit threshold combined with the access policy,so as to realize the intelligent access right management method.Finally,combined with the abovemodels and algorithms,the workflow of electronic archives sharing and utilization model of multi blockchain is constructed.The experimental results show that the timeconsuming of the process increases linearly with the number of continuous access to electronic archives blocks,and the secure access control of sharing and utilization is feasible,secure and effective. 展开更多
关键词 Sharing and utilization of electronic archives dynamic permission management PSO-RBF neural network credit evaluation
下载PDF
Ophiolites as Archives of Recycled Crustal Material Residing in the Deep Mantle
20
作者 YANG Jingsui Paul T.ROBINSON Yildirim Dilek 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期49-,共1页
Deeply subducted lithospheric slabs may reach to the mantle transition zone(MTZ,410-660 km depth)or even to the core–mantle boundary(CMB)at depths of^2900km.Our knowledge of the fate of subducted surface material at ... Deeply subducted lithospheric slabs may reach to the mantle transition zone(MTZ,410-660 km depth)or even to the core–mantle boundary(CMB)at depths of^2900km.Our knowledge of the fate of subducted surface material at the MTZ or near the CMB is poor and based mainly on the tomography data and laboratory experiments through indirect methods.Limited data come from the samples of deep mantle diamonds and their mineral inclusions obtained from kimberlites and associated rock assemblages in old cratons.We report in this presentation new data and observations from diamonds and other UHP minerals recovered from ophiolites that we consider as a new window into the life cycle of deeply subducted oceanic and continental crust.Ophiolites are fragments of ancient oceanic lithosphere tectonically accreted into continental margins,and many contain significant podiform chromitites.Our research team has investigated over the last 10 years ultrahigh-pressure and super-reducing mineral groups discovered in peridotites and/or chromitites of ophiolites around the world,including the Luobusa(Tibet),Ray-Iz(Polar Urals-Russia),and 12 other ophiolites from 8orogenic belts in 5 different countries(Albania,China,Myanmar,Russia,and Turkey).High-pressure minerals include diamond,coesite,pseudomorphic stishovite,qingsongite(BN)and Ca-Si perovskite,and the most important native and highly reduced minerals recovered to date include moissanite(Si C),Ni-Mn-Co alloys,Fe-Si and Fe-C phases.These mineral groups collectively confirm extremely high?pressures(300 km to≥660 km)and super-reducing conditions in their environment of formation in the mantle.All of the analyzed diamonds have unusually light carbon isotope compositions(δ13C=-28.7 to-18.3‰)and variable trace element contents that*d i stinguish them from most kimberlitic and UHPmetamorphic varieties.The presence of exsolution lamellae of diopside and coesite in some chromite grains suggests chromite crystallization depths around>380 km,near the mantle transition zone.The carbon isotopes and other features of the high-pressure and super-reduced mineral groups point to previously subducted surface material as their source of origin.Recycling of subducted crust in the deep mantle may proceed in three stages:Stage 1–Carbon-bearing fluids and melts may have been formed in the MTZ,in the lower mantle or even near the CMB.Stage 2–Fluids or melts may rise along with deep plumes through the lower mantle and reach the MTZ.Some minerals,such as diamond,stishovite,qingsongite and Ca-silicate perovskite can precipitate from these fluids or melts in the lower mantle during their ascent.Material transported to the MTZ would be mixed with highly reduced and UHP phases,presumably derived from zones with extremely low f O2,as required for the formation of moissanite and other native elements.Stage 3–Continued ascent above the transition of peridotites containing chromite and ultrahigh-pressure minerals transports them to shallow mantle depths,where they participate in decompressional partial melting and oceanic lithosphere formation.The widespread occurrence of ophiolite-hosted diamonds and associated UHP mineral groups suggests that they may be a common feature of in-situ oceanic mantle.Because mid-ocean ridge spreading environments are plate boundaries widely distributed around the globe,and because the magmatic accretion of oceanic plates occurs mainly along these ridges,the on-land remnants of ancient oceanic lithosphere produced at former mid-ocean ridges provide an important window into the Earth’s recycling system and a great opportunity to probe the nature of deeply recycled crustal material residing in the deep mantle 展开更多
关键词 CMB MTZ Ophiolites as archives of Recycled Crustal Material Residing in the Deep Mantle
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部