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Inference for Gompertz distribution under records 被引量:6
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作者 Liang Wang Yimin Shi Weian Yan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第1期271-278,共8页
The parameter estimation is considered for the Gompertz distribution under frequensitst and Bayes approaches when records are available.Maximum likelihood estimators,exact and approximate confidence intervals are deve... The parameter estimation is considered for the Gompertz distribution under frequensitst and Bayes approaches when records are available.Maximum likelihood estimators,exact and approximate confidence intervals are developed for the model parameters,and Bayes estimators of reliability performances are obtained under different losses based on a mixture of continuous and discrete priors.To investigate the performance of the proposed estimators,a record simulation algorithm is provided and a numerical study is presented by using Monte-Carlo simulation. 展开更多
关键词 Gompertz model records confidence interval Bayes estimation Monte-Carlo simulation
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records相关术语比较研究(摘编)
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作者 吕文婷 《中国档案》 北大核心 2023年第3期70-70,共1页
文件生命周期(records lifecycle management)理论和文件连续体理论(records continuum theory)有一个共同的基础术语,即records,目前,我国的翻译中,较为普遍的观点是将documents、records译成“文件”,将archives译为“档案”。然而,... 文件生命周期(records lifecycle management)理论和文件连续体理论(records continuum theory)有一个共同的基础术语,即records,目前,我国的翻译中,较为普遍的观点是将documents、records译成“文件”,将archives译为“档案”。然而,随着理论研究与实践工作的不断发展与深化,将records翻译成“文件”的做法渐渐出现了分歧。虽然文件生命周期理论目前在不同场景的应用范畴不同. 展开更多
关键词 文件生命周期 文件生命周期理论 records
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Three new records of lycopsids and ferns from Vietnam
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作者 LU Yu WANG Bo +2 位作者 LIN Guoliang JIANG Rihong WANG Zhenxing 《广西植物》 CAS CSCD 北大核心 2024年第10期1943-1946,共4页
Three new records from Vietnam,Phlegmariurus guangdongensis Ching,Adiantum longzhouensis A.H.Wang,F.G.Wang&F.W.Xing,and Lepisorus bicolor Ching,are reported.The identification characteristics,information of specim... Three new records from Vietnam,Phlegmariurus guangdongensis Ching,Adiantum longzhouensis A.H.Wang,F.G.Wang&F.W.Xing,and Lepisorus bicolor Ching,are reported.The identification characteristics,information of specimen,and geographical distribution of the species are described.The discovery of new records not only enriches the study of plant diversity in Vietnam,but also provides important information for biodiversity conservation and botanical research in the region.The voucher specimens are kept in the Herbarium of Kunming Institute of Botany,Chinese Academy of Sciences(KUN),Herbarium of Institute of Botany,Chinese Academy of Sciences(PE)and Herbarium of Guangxi Forestry Research Institute(GXFI). 展开更多
关键词 Phlegmariurus guangdongensis Adiantum longzhouensis Lepisorus bicolor new record VIETNAM
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Asymptotic Probability of Record Numbers in Random Walks
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作者 PENG Wenjie LI Yuqiang 《应用概率统计》 北大核心 2025年第1期17-27,共11页
In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are dif... In this paper,large deviations principle(LDP)and moderate deviations principle(MDP)of record numbers in random walks are studied under certain conditions.The results show that the rate functions of LDP and MDP are different from those of weak record numbers,which are interesting complements of the conclusions by Li and Yao[1]. 展开更多
关键词 random walk record number large deviation moderate deviation
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北京木本植物新分布 被引量:1
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作者 路端正 贺文同 《北京农学院学报》 1991年第1期44-48,共5页
近年来,作者结合教学和科研,在北京地区进行了树种资源调查和标本采集.经整理鉴定,确定了北京市木本植物区系新记录计6种1变种,分别属于7科7属,其中1属为北京植物区系属的新记录.全部标本存于北京林业大学森林植物标本室.这一调查成果... 近年来,作者结合教学和科研,在北京地区进行了树种资源调查和标本采集.经整理鉴定,确定了北京市木本植物区系新记录计6种1变种,分别属于7科7属,其中1属为北京植物区系属的新记录.全部标本存于北京林业大学森林植物标本室.这一调查成果为研究北京植物区系和植物资源的地理分布提供了新的参考资料. 展开更多
关键词 BEIJING NEW records of WOODY PLANTS
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电子化测量健康相关生命质量的随机交叉对照试验SF-36电子版和纸质版的比较 被引量:8
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作者 陈天辉 杨春华 +1 位作者 杜亚平 李鲁 《中国全科医学》 CAS CSCD 2006年第15期1231-1234,共4页
目的评估被调查者对电子版问卷的反应性以及评价电子版问卷的等效性。方法面对面调查。由被调查者自填问卷;两样本的随机交叉对照试验:方便样本,包括高校普通人群(50例)和社区疾病人群(100例);主要工具是纸质版和基于QL—Recor... 目的评估被调查者对电子版问卷的反应性以及评价电子版问卷的等效性。方法面对面调查。由被调查者自填问卷;两样本的随机交叉对照试验:方便样本,包括高校普通人群(50例)和社区疾病人群(100例);主要工具是纸质版和基于QL—Recorder软件的电子版SF-36。结果基于QL-Recorder软件的中文SF-36电子版在一般人群中具有良好的接受性,在社区使用的接受性很好。在纬度水平,电子版和纸质版具有很高的分值等效性:除了GH纬度,其他7个纬度两版本分值间差异均无显著性意义(P〉0.05);GH纬度两版本的差异仅为2.33,〈5%的标准。在单个被调查者水平,电子版的等效性也比较理想:精确一致性为64%-99%;总体一致性为72%-99%;77%的Kappa系数属于“好一致性”及以上,23%的Kappa系数属于“中等一致性”。结论本研究验证了基于QL—Recorder软件的SF-36电子版问卷的接受性和等效性,能够代替纸质版。此外,也验证了SF-36电子版的优点:完成时间快,数据没有缺失值、质量高,数据的结果直观并且能够马上得到结果,数据的兼容性好,能直接输出到其他软件包。 展开更多
关键词 健康相关生命质量(HRQoL) SF-36 电子化 测量 QL—Recorder
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EPICS实现ECR离子源高压电源控制 被引量:2
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作者 顾可伟 张玮 +1 位作者 常建军 安石 《原子能科学技术》 EI CAS CSCD 北大核心 2015年第B10期595-596,共2页
本文在EPICS架构下设计了ECR离子源高压电源的控制逻辑结构,开发了支持其控制器的Record类型,完成了其IOC端的代码实现,实现了ECR离子源高压电源的控制并在现场运行。
关键词 EPICS ECR离子源 高压电源 RECORD
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电子化测量健康相关生命质量的软件QL-Recorder 被引量:2
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作者 陈天辉 杨春华 +1 位作者 杜亚平 李鲁 《中国全科医学》 CAS CSCD 2006年第23期1988-1989,共2页
本文综述了电子化测量健康相关生命质量的软件QL-Recorder的优点及其国内外研究现状,并在此基础上指出了其在中国研究的必要性及其应用前景。
关键词 健康相关生命质量 SF-36 电子化测量 QL—Recorder
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智能数据采集系统 被引量:2
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作者 张书奎 《计算机工程》 CAS CSCD 北大核心 2003年第12期133-134,共2页
对数据采集的智能化过程进行了研究,结合实际提出了一个整体解决方案,并在中国电信163/169计费系统中得到了实现。
关键词 远程采集器 INTERNET DATA RECORD RADIUS
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RECENT ADVANCES IN GEOLOGICAL RESEARCH IN PARTS OF LESSER AND TETHYS HIMALAYA OF INDIA, SOUTH OF TIBETAN PLATEAU (KUMAON, GARHWAL AND ARUNACHAL PRADESH)
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作者 Vinod C. Tewari(Wadia Institute of Himalayan Geology, Dehra Dun, 248001, India) 《地学前缘》 EI CAS CSCD 2000年第S1期66-66,共1页
Recent advances in geological, palaeobiological and stable isotopic research in Kumaon\|Garhwal Lesser and Tethys Himalaya suggest that India was part of a major single super continent Rodinia during Neoproterozoic—L... Recent advances in geological, palaeobiological and stable isotopic research in Kumaon\|Garhwal Lesser and Tethys Himalaya suggest that India was part of a major single super continent Rodinia during Neoproterozoic—Lower Palaeozoic times. The breakup of Rodinia and fragmentation of Gondwana land, existence of large Proto\|Tethys ocean, low latitude glaciation and global warming reflected by carbon isotopes and imprints of Pan African rifting events have been recently recorded in the Indian Himalaya, South of Tibetan Plateau (Tewari, 1998). A detailed correlation of these events in other parts of the NW and NE Himalaya and China further supports that these events are of global significance.The complete sequence of Lower Palaeozoic is missing in the Lesser Himalaya after regression of sea in the Lower Cambrian, however three major marine transgressions during Permian, Cretaceous and Eocene have been recorded over Terminal Proterozoic/Cambrian sequences. The discovery of microstromatolites and microbiota from the Menga (Buxa) dolomite of eastern Himalaya, Arunachal Pradesh (Tewari, 1999) also confirm Terminal Proterozoic age and sedimentation. The Permian marine transgression throughout the Himalaya suggest birth of Neotethys sea.Shallow marine reef builders, cyanobacteria\|bacteria and stromatolites of Early Carboniferous age were thriving in the Himalayan Tethys of India. 13 C records from Lesser and Tethys Himalaya reflect global isotopic variations in Neoproterozoic to Palaeozoic oceans of the world. 展开更多
关键词 RODINIA Lower PALAEOZOIC TRANSGRESSION microstromatolite MICROBIOTA 13 C records
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Pheochromocytoma and Acute Cardiac or Cerebral Vascular Death:Clinical Analysis of 6 Cases
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作者 齐今吾 《中国医科大学学报》 CAS CSCD 1989年第S2期49-50,共2页
The clinical and pathological records of eighty-one cases of pheochrcn ocytoma admitted to our hospital between 1960 and 1986, were reexamined. Six cases died of acute cardiac or cerebral vascular complications were a... The clinical and pathological records of eighty-one cases of pheochrcn ocytoma admitted to our hospital between 1960 and 1986, were reexamined. Six cases died of acute cardiac or cerebral vascular complications were analized and to be reported in this paper. 展开更多
关键词 DEATH admitted records ENDOGENOUS ordinary possibly RIGIDITY ARREST FAILED
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低压电器最新技术发展动态
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作者 陈德桂 《电气制造》 2005年第2期1-4,共4页
进入新世纪,国外著名低压电器公司纷纷推出新一代低压断路器产品,在框架断路器方面如法国施耐德公司的。MT系列,西门子公司的WL系列,ABB公司的E系列等;在塑壳断路器方面,如ABB的TMAX系列,美国GE公司的Record Plus系列,日本三菱... 进入新世纪,国外著名低压电器公司纷纷推出新一代低压断路器产品,在框架断路器方面如法国施耐德公司的。MT系列,西门子公司的WL系列,ABB公司的E系列等;在塑壳断路器方面,如ABB的TMAX系列,美国GE公司的Record Plus系列,日本三菱公司的WS系列等。这些产品在高性能、小型化和多功能方面较老产品有大幅度提高。 展开更多
关键词 低压电器 技术发展动态 RECORD 美国GE公司 日本三菱公司 低压断路器 施耐德公司 西门子公司 ABB公司 塑壳断路器 MAX系列 MT系列 WS系列 L系列 E系列 S系列 大幅度 老产品 多功能 小型化
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HOLOCENE SALINE SEDIMENTARY RECORD IN TIBETAN DONG CO(LAKE) AND ITS SIGNIFICANCE ON PALAEOCLIMATE 被引量:5
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作者 Wei Lejun 1,2 ,Zheng Mianping 2,3 2.Open Laboratory of Saline Lake Resources & Environment ,Chinese Academy of Geological Sciences,Beijing 100037,China 3.Institute of Min 《地学前缘》 EI CAS CSCD 2000年第S1期378-378,共1页
Based on the sedimentary characteristics study of Holocene borax\|bearing mirabilite beds of Dong Co(lake) two sections, DZ01 and DZ02, in the center of North\|Tibetan Plateau,combined with dating of 14 C, applied the... Based on the sedimentary characteristics study of Holocene borax\|bearing mirabilite beds of Dong Co(lake) two sections, DZ01 and DZ02, in the center of North\|Tibetan Plateau,combined with dating of 14 C, applied theory and method of comparative salinology, it is determined that the palaeoclimate framework of Dong Co during early\|middle Holocene, and reckoned the range of the temperature variation. Furthermore, after completing regional analogue, discovered that the palaeoclimate environment is fully comparative and consistent with the synchronous lake\|water retreating trace of Zhaduixiong spits in Zabuye Lake basin, with palaeoclimate changes recorded by pollen in adjacent Zabuye Lake, with Holocene plaeoclimate environment indicated by drilling\|hole in Bangong Co,with palaeoclimate significance traced by δ 18 O value in Qinghai Lake and Siling Co and with the palaeoclimate framework during the 5th Level Arid (Salinization) Extension Period of Quaternary arid center of Western China. 展开更多
关键词 Dong CO Tibet HOLOCENE SEDIMENTARY record PALAEOCLIMATE change s
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共溅射沉积的TbFeCo薄膜
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作者 王伟杰 余维嘉 +1 位作者 姚新华 肖宗耀 《真空科学与技术学报》 EI CAS CSCD 1991年第6期401-406,共6页
本文介绍了利用射频共溅射技术制备垂直膜面单轴各向异性TbFeCo磁光薄膜,并研究了该薄膜的磁、磁光和读写性能。测试结果表明,这种TbFeCo薄膜的磁光盘其载噪比和擦写循环分别达到48dB和1×10~6次以上。该磁光盘可适用于数据存储。
关键词 溅射沉积 TBFECO 磁光盘 共溅射 载噪比 单轴各向异性 数据存储 单轴磁各向异性 RECORDING 氮气流量
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基于IK-medoids算法的飞机油耗聚类方法 被引量:6
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作者 陈静杰 车洁 《计算机科学》 CSCD 北大核心 2018年第8期306-309,314,共5页
为了分析给定外界条件下的飞机燃油消耗,提出了一种基于距离最大法的邻域搜索K-medoids聚类算法(IK-medoids)。基于距离最大的样本不可能被分到同一类簇的思想,该算法首先采用距离最大法选取初始中心,并根据剩余样本与初始中心之间的标... 为了分析给定外界条件下的飞机燃油消耗,提出了一种基于距离最大法的邻域搜索K-medoids聚类算法(IK-medoids)。基于距离最大的样本不可能被分到同一类簇的思想,该算法首先采用距离最大法选取初始中心,并根据剩余样本与初始中心之间的标准欧氏距离计算初始中心邻域;然后利用提出的一种近邻搜索策略进行初始中心的迭代更新,直到中心点不再发生变化。在同一机型和航段、不同大小的数据集上进行对比实验,根据起飞重量、巡航高度、实飞距离以及飞行环境等特征对飞机油耗进行精准分类。实验结果表明:相对于传统的改进K-medoids算法,IKmedoids算法在有效缩短分类时间的同时保证了聚类准确率,为进一步分析飞行过程中的燃油消耗提供了新视角。 展开更多
关键词 K-medoids聚类算法 距离最大法 标准欧氏距离 近邻搜索 油耗分类 Quick Access Recorder(QAR)数据
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不平衡油耗数据的区间预测方法 被引量:4
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作者 陈静杰 王琨 《计算机科学》 CSCD 北大核心 2021年第7期178-183,共6页
对油耗数据进行区间预测时,数据的不平衡性会导致一般的区间预测方法得到的预测区间质量较低。针对上述问题,提出了基于SMOTE-XGBoost算法的区间预测模型。采用SMOTE算法增加训练集中少数类样本的数量,消除了训练集数据的不平衡性;对XGB... 对油耗数据进行区间预测时,数据的不平衡性会导致一般的区间预测方法得到的预测区间质量较低。针对上述问题,提出了基于SMOTE-XGBoost算法的区间预测模型。采用SMOTE算法增加训练集中少数类样本的数量,消除了训练集数据的不平衡性;对XGBoost算法的分位数损失函数进行改进,平滑其一阶导数原点周围的小区域,解决了分位数损失函数对树分裂的影响;通过训练区间预测模型,得到预测区间的上下界。最后基于QAR数据集进行对比实验,结果表明,该方法使预测区间具有较高的区间覆盖率和较窄的区间宽度,提高了预测区间的质量。 展开更多
关键词 不平衡数据 区间预测 SMOTE XGBoost 油耗 Quick Access Recorder(QAR)数据
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Chrysosplenium fallax Koldaeva(Chrysosplenium),a newly recorded species from China 被引量:1
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作者 Xiang Niyan Chen Xitang +2 位作者 Yang Tiange Liu Xihong Liu Hong 《植物科学学报》 CAS CSCD 北大核心 2024年第4期423-430,共8页
Chrysosplenium fallax Koldaeva,recently discovered and collected in Yanji,Jilin Province,repre-sents a newly recorded species of Saxifragaceae in China.This species,native to the Russian Far East,was first described a... Chrysosplenium fallax Koldaeva,recently discovered and collected in Yanji,Jilin Province,repre-sents a newly recorded species of Saxifragaceae in China.This species,native to the Russian Far East,was first described as a new species in 2021.Based on precise field investigations and specimen examination,we provide a comprehensive description of C.fallax and its seed micromorphology.Phylogenetic analysis based on chloroplast genomes of 45 Chrysosplenium species confirmed the systematic position of C.fallax in Chrysosplenium.Voucher specimens were deposited in the Herbarium of South-Central Minzu University(HSN). 展开更多
关键词 Chrysosplenium fallax Chrysosplenium Newly record PHYLOGENY China
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Microstructure and magnetic properties of granularFePt/(FePt)_(27)Ti_(73) films for ultrahigh-density recording media 被引量:2
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作者 于红云 孙会元 +4 位作者 封顺珍 高凤菊 周鸿娟 聂向富 孙玉平 《Journal of Central South University of Technology》 2005年第2期155-158,共4页
FePt granular films were prepared by direct current facing-target magnetron sputtering system onto glass substrates and subsequently in-situ annealed in vacuum. Vibrating sample magnetometer, X-ray diffraction and sca... FePt granular films were prepared by direct current facing-target magnetron sputtering system onto glass substrates and subsequently in-situ annealed in vacuum. Vibrating sample magnetometer, X-ray diffraction and scanning probe microscope were applied to study the magnetic properties, microstructures, morphologies and domain structures of the samples. (FePt)27Ti73 bilayer films were fabricated at various conditions to investigate the effect of Ti on FePt grains. The results show that without Ti matrix layer, FePt films deposited onto the glass substrates are fcc disordered; with addition of Ti matrix layer, FePt/Ti films form a ternary (FePt)27Ti73 alloy possessing fcc and L10 (111) mixed texture. FePt/(FePt)27Ti73 films with perfectly ordered L10(111) structure and unique magnetic properties can be obtained at Ti thickness of 35nm and substrate temperature of 250℃. The maximum coercivity is more than 240kA/m and the squareness ratio is more than 0.9. The obtained results suggest that the granular FePt/(FePt)27Ti73 films can be applicable to ultrahigh-density magnetic recording media. 展开更多
关键词 FePt magnetic layer ordered L1_0 structure facing-target magnetron sputtering system magnetic (recording) media
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Optimization of key technologies of penstock shaft construction for a pumped storage power station 被引量:2
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作者 ZHENG Jingxing CHEN Jianhua +4 位作者 HUANG Wenfeng YIN Jingke ZHANG Peng ZHANG Rui XIONG Fuyou 《水利水电技术(中英文)》 北大核心 2024年第S2期329-339,共11页
Completing the principal engineering components of a pumped storage power station spans between 50 and 60 months,from the inception of construction to the commencement of power generation by the first unit.The filling... Completing the principal engineering components of a pumped storage power station spans between 50 and 60 months,from the inception of construction to the commencement of power generation by the first unit.The filling of the penstock with water represents a critical phase preceding the production of electricity by the first unit.During this interval,the construction of the diversion shaft presents multiple challenges,including intricate construction procedures,considerable construction difficulty,elevated safety risks,and quality control issues.To address this issue,this study uses CFD software to analyze the flow field,pressure gradient,and head loss of shaft curved section with different curvature radius,and examines several key technologies by drawing on the practice of diversion shaft construction at the Meizhou pumped storage power station.These technologies include optimizing the curvature radius of the curved section of diversion shaft,reverse-well excavation for the shaft,and sliding-up for the lining concrete.It is found that as the curvature radius of shaft curved section reduces from 4 to 2 times the shaft diameter,the hydraulic characteristic index does not change much,and the increase of head loss accounts for about 0.18%of the total head loss of the water conveyance system.The result show that optimizing the curvature radius from 4 times to 2 times the shaft diameter is feasible and reasonable,and several improved technical measures have been proposed,such as stabilizing drill rods,mechanical scraper systems,and control technology of the relationship between concrete setting time and formwork sliding.Their implementation effectively mitigates difficulties and safety risks during shaft construction,expedites the project schedule,enhances engineering quality,and creates a 41-month timeline for the principal engineering schedule for the first power unit generation in China. 展开更多
关键词 hydroelectric engineering construction period record engineering technology optimization shaft construction curvature radius
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我国电力工业将推进四项跨世纪科研引导工程
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《现代电力》 1994年第3期69-69,共1页
我国电力工业将推进四项跨世纪科研引导工程在今年6月份召开的全国电力科技会议上,史大帧部长代表部党组提出我国电力工业将推进四项跨世纪科研引导工程。这四项工程是:一是跨大区联网工程。实现跨大区联网已日益迫切,要在统一规划... 我国电力工业将推进四项跨世纪科研引导工程在今年6月份召开的全国电力科技会议上,史大帧部长代表部党组提出我国电力工业将推进四项跨世纪科研引导工程。这四项工程是:一是跨大区联网工程。实现跨大区联网已日益迫切,要在统一规划的指导下,抓紧组织,适时推进;二是... 展开更多
关键词 power system FAILURE FAULT LOCATION RECORD FAILURE RECORDER WLB-144B type
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