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Occurrence of“Hippotherium”in the Old World:a revision of two hipparion species in Eurasia
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作者 SUN Bo-Yang LIU Yan +1 位作者 WANG Shi-Qi DENG Tao 《古脊椎动物学报(中英文)》 北大核心 2025年第1期57-80,共24页
A controversial taxon,Hipparion plocodus,is reviewed in the present study.Hi.plocodus has been confirmed to be a valid species with definite diagnostic characteristics,represented by cranial specimens from Baode,Shanx... A controversial taxon,Hipparion plocodus,is reviewed in the present study.Hi.plocodus has been confirmed to be a valid species with definite diagnostic characteristics,represented by cranial specimens from Baode,Shanxi Province.The phylogenetic analysis performed in the present study,with a new matrix,shows that Hi.plocodus forms a monophyletic group with a European species,Hippotherium malpassii.Actually,no close relationship between so-called Hm.malpassii and the genus Hippotherium has been identified,and the record of stratigraphic range of this genus in late stage of Late Miocene is currently absent.Herein previously Hi.plocodus and Hm.malpassii have both attributed into“Hipparion”before the discovery of better material.Evolutionary stages and correlative absolute age showed that these two species should derive independently from some primitive clade.During the late stage of the Late Miocene,the development of the Asian summer monsoon enhanced the humidity of China,with forest and wood habitats expanding considerably under this setting.As the result,one Eurasian closed-habitat lineage thus extended its range into China,which had become very suited for it,give rise to“Hi.”plocodus. 展开更多
关键词 Eurasian hipparion systematic revision PHYLOGENY paleozoogeography
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r-IPT_(ra)与r-IPT_V在淡水沉积物脱氮速率研究中的对比分析
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作者 曾洪玉 阮晓红 +2 位作者 李荣富 万宇 张亚平 《地质论评》 CAS CSCD 北大核心 2018年第1期141-148,共8页
正确评估淡水环境中沉积物脱氮效应对理解淡水系统氮循环过程具有重要的科学意义,修正^(15)N同位素配对技术(revised ^(15)N isotope pairing techniques,r-IPT)可同时评估沉积物柱样中反硝化与厌氧氨氧化速率及其脱氮贡献。本文利用流... 正确评估淡水环境中沉积物脱氮效应对理解淡水系统氮循环过程具有重要的科学意义,修正^(15)N同位素配对技术(revised ^(15)N isotope pairing techniques,r-IPT)可同时评估沉积物柱样中反硝化与厌氧氨氧化速率及其脱氮贡献。本文利用流动柱样培养实验,首次在淡水系统中对比了利用泥浆实验提供参数的r-IPT_(ra)与由柱样培养实验本身提供参数的r-IPT_V计算沉积物脱氮速率的差异性,并评估了秋季太湖不同沉积环境脱氮速率。研究表明:(1)泥浆实验结果表明,太湖梅梁湾与胥湖沉积物中均存在反硝化与厌氧氨氧化作用。(2)r-IPT方法的基本假设在研究区域均成立。其中,r-IPT_V得到的两湖区沉积物原位脱氮速率均与添加15NO-3浓度无关,表明r-IPT_V对沉积物脱氮速率评估具有更好的计算精度。(3)r-IPT_V计算结果表明,梅梁湾与胥湖沉积物反硝化、厌氧氨氧化、脱氮速率分别为3.09、1.47、4.56μmol/(m2·h)与0.69、0.02、0.71μmol/(m^2·h),厌氧氨氧化对两湖区沉积物脱氮贡献率(ra)分别为32.2%与3.3%。(4)对比r-IPT_(ra)与r-IPT_V在两个湖区的计算结果,当ra较低时(3.3%),r-IPT_(ra)与r-IPT_V计算的沉积物脱氮速率及厌氧氨氧化速率接近;而当ra较高时(32.2%),r-IPT_(ra)显著高估沉积物脱氮速率,低估厌氧氨氧化贡献率。 展开更多
关键词 修正15N同位素配对技术(revised 15N ISOTOPE PAIRING techniques r-IPT) 淡水沉积物 脱氮速率 泥浆实验 柱样流动培养实验
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Waveforms analysis and optimization of new electro-hydraulic excitation technology 被引量:3
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作者 韩冬 龚国芳 +2 位作者 杨华勇 刘毅 廖湘平 《Journal of Central South University》 SCIE EI CAS 2014年第8期3098-3106,共9页
A new electro-hydraulic exciter that consists of rotary valve and micro-displacement double-functioned hydraulic cylinder was proposed to realize different kinds of waveforms.Calculated fluid dynamics(CFD) simulation ... A new electro-hydraulic exciter that consists of rotary valve and micro-displacement double-functioned hydraulic cylinder was proposed to realize different kinds of waveforms.Calculated fluid dynamics(CFD) simulation of rotary valve orifice reveals that orifice exists the two-throttle phenomenon.According to the finding,the revised flow area model was established.Vibration waveforms analysis was carried out by means of mathematic model and the related experiments were validated.Furthermore,as a new analysis indicator,saturation percentage was introduced first.The experimental results indicate that the revised flow area model is more accurate compared to the original one,and vibration waveforms can be optimized through suitable spool parameters and the revised cylinder structure. 展开更多
关键词 rotary valve micro-displacement double-functioned hydraulic cylinder two-throttle phenomenon revised flow areamodel saturation drift motion
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基于RUSLE模型的河南省黄河流域土壤侵蚀研究 被引量:10
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作者 刘天可 袁彩凤 《华北水利水电大学学报(自然科学版)》 2020年第3期7-13,共7页
为了更好地研究黄河河南段的土壤侵蚀情况,以河南省黄河流域为研究区域,采用地理信息系统和遥感技术,融合遥感影像、DEM数据、降雨数据和土壤数据等,将RUSLE模型应用到该区域的土壤侵蚀研究中。结果表明:该区域的年均土壤侵蚀模数为861.... 为了更好地研究黄河河南段的土壤侵蚀情况,以河南省黄河流域为研究区域,采用地理信息系统和遥感技术,融合遥感影像、DEM数据、降雨数据和土壤数据等,将RUSLE模型应用到该区域的土壤侵蚀研究中。结果表明:该区域的年均土壤侵蚀模数为861.78 t/(km^2·a),年均土壤侵蚀总量为305.44×10^5 t/a,轻度以上的土壤侵蚀多发生在河南西部的一些省辖市内。其中,土壤侵蚀等级为轻度以下的区域,其面积占研究区总面积的88.39%,该区域主要分布在0°~10°坡度范围内,主要的土地利用类型为耕地和草地;中度侵蚀和强烈侵蚀的区域,二者的总面积占比为10.71%,主要分布在15°~25°坡度范围内,土地利用类型主要为林地;极强烈侵蚀和剧烈侵蚀的区域面积所占比例较小,占比共计0.9%,该区域零星分布在坡度范围大于25°的草地和林地区域。该研究成果揭示了河南省黄河流域的土壤侵蚀情况,可为区域水土流失治理提供科学依据。 展开更多
关键词 河南省黄河流域 RUSLE(Revised Universal Soil Loss Equation) 土壤侵蚀 水土流失
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《空气动力学学报》2012年第30卷第3期有6篇论文英文摘要用了Ei Thesaurus,Revised第6版主题词
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作者 胡沛泉 《西北工业大学学报》 EI CAS CSCD 北大核心 2012年第4期496-496,共1页
关键词 英文摘要 主题词 叙词 检索词 Ei Thesaurus Revised
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更正:对一个大单轴磁各向异性镍(Ⅱ)配合物中的磁跃迁的直接观察
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作者 Chelsea N.Widener Alexandria N.Bone +6 位作者 Mykhaylo Ozerov Rachael Richardson 路正光 Komalavalli Thirunavukkuarasu Dmitry Smirnov 陈学太 薛子陵 《无机化学学报》 SCIE CAS CSCD 北大核心 2021年第1期189-189,共1页
We have found following errors in the article“Direct Observation of Magnetic Transitions in a Nickel(Ⅱ)Complex with Large Anisotropy”(Chinese J.Inorg.Chem.2020,36(6):1149-1156):For Fig.3-Top,0 and 17 T spectra are ... We have found following errors in the article“Direct Observation of Magnetic Transitions in a Nickel(Ⅱ)Complex with Large Anisotropy”(Chinese J.Inorg.Chem.2020,36(6):1149-1156):For Fig.3-Top,0 and 17 T spectra are reversed and the wavenumber range should be adjusted.For Fig.3-Bottom,“B∥z”is shown twice.Fig.3 should be replaced by the following figure.Supporting information(Fig.S1 and S2)should be revised as well. 展开更多
关键词 单轴磁各向异性 reversed revised
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WORLD NEWS IN BRIEF
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《国际展望》 1987年第24期28-,共1页
The ruling Polish party saidon December I that the govern-ment’s economic and politicalreform packages, which failed towin approval in a nationalreferendum two days ago, need tobe revised, but stressed boldchanges wo... The ruling Polish party saidon December I that the govern-ment’s economic and politicalreform packages, which failed towin approval in a nationalreferendum two days ago, need tobe revised, but stressed boldchanges would continue. Fiji’s Army commander SitiveniRabuka Stepped down on December5 as head of government and saidthat fermer Governor-GeneralRatu Sir Penaia Ganilau hadaccepted the pesition as Fiji’sfirst president. 展开更多
关键词 approval PRESIDENT NEWS PARTY POLISH revised CONTINUE govern SIGNED stressed
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