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Revisiting East Asian monsoon change during the Last Glacial Maximum using PMIP4 simulations
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作者 Zhiping Tian 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第3期47-52,共6页
利用PMIP4多模式试验数据,本文重新检查了末次冰盛期(距今约21000年)东亚季风变化.结果表明:相对于工业革命前期,所有5个模式一致模拟显示末次冰盛期东亚季风减弱,冬季和夏季减幅分别为1%-18%和2-32%;不同模式中东亚季风环流变化的空间... 利用PMIP4多模式试验数据,本文重新检查了末次冰盛期(距今约21000年)东亚季风变化.结果表明:相对于工业革命前期,所有5个模式一致模拟显示末次冰盛期东亚季风减弱,冬季和夏季减幅分别为1%-18%和2-32%;不同模式中东亚季风环流变化的空间分布存在差异,这主要源于该时期大尺度变冷和海平面气压梯度变化的空间分布不同;由于模式之间的差异和重建记录之间的不确定性,未来有待开展更多模拟和重建工作以更好地理解冰期东亚季风变化. 展开更多
关键词 末次冰盛期 东亚冬季风 东亚夏季风 PMIP4试验
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Small Modular Solutions to Fermat’s Last Theorem
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作者 Thomas Beatty 《Advances in Pure Mathematics》 2024年第10期797-805,共9页
The proof by Andrew Wiles of Fermat’s Last Theorem in 1995 resolved the existence question for non-trivial solutions in integers x,y,zto the equation xn+yn=znfor n>2. There are none. Surprisingly, there are infini... The proof by Andrew Wiles of Fermat’s Last Theorem in 1995 resolved the existence question for non-trivial solutions in integers x,y,zto the equation xn+yn=znfor n>2. There are none. Surprisingly, there are infinitely many solutions if the problem is recast in terms of modular arithmetic. Over a hundred years ago Issai Schur was able to show that for any n there is always a sufficiently large prime p0such that for all primes p≥p0the congruence xn+yn≡zn(modp)has a non-trivial solution. Schur’s argument wasnon-constructive, and there is no systematic method available at present to construct specific examples for small primes. We offer a simple method for constructing all possible solutions to a large class of congruences of this type. 展开更多
关键词 Fermat’s last Theorem Modular Arithmetic CONGRUENCES Prime Numbers Primitive Roots Indices Ramsey Theory Schur’s Lemma in Ramsey Theory
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Whole Perfect Vectors and Fermat’s Last Theorem
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作者 Ramon Carbó-Dorca 《Journal of Applied Mathematics and Physics》 2024年第1期34-42,共9页
A naïve discussion of Fermat’s last theorem conundrum is described. The present theorem’s proof is grounded on the well-known properties of sums of powers of the sine and cosine functions, the Minkowski norm de... A naïve discussion of Fermat’s last theorem conundrum is described. The present theorem’s proof is grounded on the well-known properties of sums of powers of the sine and cosine functions, the Minkowski norm definition, and some vector-specific structures. 展开更多
关键词 Fermat’s last Theorem Whole Perfect Vectors Sine and Cosine Functions Natural and Rational Vectors Fermat Vectors
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ACE、CICARE及LAST护理服务理念在脑梗死患者康复护理中的应用效果 被引量:10
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作者 张燕琴 李晓萍 +1 位作者 孔维维 范东英 《西部中医药》 2019年第11期122-124,共3页
目的:观察ACE、CICARE及LAST护理服务在脑梗死患者康复护理中的应用效果。方法:将脑梗死恢复期患者60例随机分为观察组和对照组各30例。对照组行常规护理,观察组在对照组基础上行ACE、CICARE及LAST护理服务,比较2组患者护理满意度、Bart... 目的:观察ACE、CICARE及LAST护理服务在脑梗死患者康复护理中的应用效果。方法:将脑梗死恢复期患者60例随机分为观察组和对照组各30例。对照组行常规护理,观察组在对照组基础上行ACE、CICARE及LAST护理服务,比较2组患者护理满意度、Barthel指数、护理依从性、回归社会生活信心等心理状况。结果:观察组护理满意度、Barthel指数、护理治疗依从性、对回归社会生活的信心及心理状况优于对照组,差异具有统计学意义(P<0.05)。结论:ACE、CICARE及LAST护理服务有利于提高脑梗死患者临床康复护理满意度,提高患者慢病自我管理能力,增加护理治疗依从性及患者回归社会生活的信心,减少焦虑及抑郁情绪等心理状况的发生。 展开更多
关键词 脑梗死 ACE CICARE last 护理服务理念 临床护理
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Mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration
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作者 JoséM.Izquierdo 《Neural Regeneration Research》 SCIE CAS 2025年第3期805-807,共3页
The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of previously replication-competent cells. 展开更多
关键词 LATIN POTENTIAL lasting
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LAST理论与外语教学 被引量:4
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作者 刘振前 张秀丽 《西安外国语学院学报》 2003年第4期4-9,共6页
本文简要介绍了最新的语言加工模式后句法指派理论 ,并探讨了这一理论对外语教学的启示。L AST认为 ,语言理解是联想与符号计算两种过程的组合 ,人在理解过程中首先根据输入的表层线索形成意义 /形式假设 ,即假句法 ,然后根据句法规则... 本文简要介绍了最新的语言加工模式后句法指派理论 ,并探讨了这一理论对外语教学的启示。L AST认为 ,语言理解是联想与符号计算两种过程的组合 ,人在理解过程中首先根据输入的表层线索形成意义 /形式假设 ,即假句法 ,然后根据句法规则生成完整的结构 ,并与输入序列进行对比 ,如果相符 ,则将结果存储到概念记忆中 ,进入下一句的理解。反之 ,则重复上述过程。句子是理解过程中联想信息和符号信息融合的自然层次。大量的研究证据无疑都支持上述理论 ,而且用这种理论可以更好地解释以前难以解释的一些心理语言学现象。同时 ,该理论对我们重新审视语言习得理论有重要意义 :人不同于其他动物 ,具有语言学习的能力 ,但外部刺激对语言发展起重要的作用 ,出现频率高的SVO结构先得到发展。这就为外语教学中传统教学法的应用提供了理论依据。 展开更多
关键词 last理论 英语教学 语言习得 语言理解 后句法指派理论 语法翻译法
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基于Hadoop Streaming的Last比对软件并行化的研究与实现
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作者 董本志 李文浩 景维鹏 《计算机工程与应用》 CSCD 2014年第2期226-230,共5页
随着下一代测序技术的到来,单机版Last比对软件已经不能满足海量数据的处理需求。使用Hadoop Streaming技术将Last比对软件快速部署到云计算环境中,解决当前单机版Last比对软件处理大数据能力差的问题。通过自定义的基于NFS文件系统的... 随着下一代测序技术的到来,单机版Last比对软件已经不能满足海量数据的处理需求。使用Hadoop Streaming技术将Last比对软件快速部署到云计算环境中,解决当前单机版Last比对软件处理大数据能力差的问题。通过自定义的基于NFS文件系统的数据集切分方法和基于Partitioner的任务分配方式能够实现均衡高效的数据切分,并保证并行化粒度可控。实验结果表明,在保证与单机运行结果一致的情况下,这种方法能有效缩减软件运行时间,具有较高的加速比。 展开更多
关键词 HADOOP STREAMING 软件并行化 last比对软件
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书信中语篇人际意义的实现——从对“A Soldier’s Last Letter”语言的分析谈起 被引量:1
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作者 赵青 郭英杰 《陕西教育学院学报》 2008年第4期88-92,共5页
结合功能语言学理论,以"A Soldier’s Last Letter"中的部分段落为例进行分析,可以展示如何通过语气系统和情态系统来进行选择形成语篇,从而突显语言选择对语篇人际意义实现的重要性以及功能语言学在分析文学作品时的可行性。
关键词 A Soldier’s last LETTER 人际功能 语气 情态
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China's English Learners' Verbal Phrase Acquisition Research Based on the Corpus——“at last”and“in the end”as an Example
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作者 张俊梅 柴晶 《海外英语》 2013年第24期262-263,287,共3页
This study is a comparative research based on corpus. This article compares China's English learners with English na?tive speakers about the use of "at last" and "in the end" from three aspects... This study is a comparative research based on corpus. This article compares China's English learners with English na?tive speakers about the use of "at last" and "in the end" from three aspects: frequency of use, location, semantic prosody. The study shows that the use of the two words are greatly different between China's English learners and English native speakers. In addition, this study discusses about causes of obvious differences and teaching enlightenments. 展开更多
关键词 at last in the end" China’s English LEARNERS
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A Post-colonial Approach to The Last of the Mohicans
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作者 谭秀敏 《海外英语》 2013年第23期232-234,共3页
The Last of the Mohicans is one of the five frontier novels written by famous American novelist James Fenimore Cooper in the early 19thcentury.Although it has been criticized for its narrative flaws,its length and for... The Last of the Mohicans is one of the five frontier novels written by famous American novelist James Fenimore Cooper in the early 19thcentury.Although it has been criticized for its narrative flaws,its length and formal prose style,it was one of the most popular in its time and is of a high literary value nowadays.With the coming of the white European colonialists,the Indians underwent various changes.Some Indians submitted themselves to the white while some Indians rebelled against the invaders and sought their revenge.With a post-colonial approach,the changes of the Indians will be better understood,and people nowadays will also have a better understanding of the Indian history and culture in early American history. 展开更多
关键词 The last of Mohicans POST-COLONIAL THEORY COLONIAL
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Photoluminescence of Long Lasting Phosphors Ca_2MgSi_2O_7∶Eu^(2+),Dy^(3+) 被引量:1
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作者 张国斌 戚泽明 +4 位作者 周洪军 符义兵 霍同林 罗昔贤 施朝淑 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第S1期56-57,共2页
The Eu (2+) and Dy (3+) codoped silicates,Ca_2MgSi_2O_7∶Eu (2+),Dy (3+),was synthesized,and its photoluminescence properties were studied with synchrotron radiation. Under synchrotron radiation excitation at 305 nm,o... The Eu (2+) and Dy (3+) codoped silicates,Ca_2MgSi_2O_7∶Eu (2+),Dy (3+),was synthesized,and its photoluminescence properties were studied with synchrotron radiation. Under synchrotron radiation excitation at 305 nm,only the characteristic emission from Eu (2+) was excited. But the characteristic emission from Dy (3+) was also found under 175 nm excitation,besides the characteristic emission of Eu (2+). The characteristic emission from Dy (3+) was detected in the Eu (2+) and Dy (3+) codoped long lasting phosphorescence materials,which indicates that Dy (3+) is still existed in the phosphors under continue excitation at 175 nm. 展开更多
关键词 long lasting phosphor LUMINESCENCE synchrotron radiation rare earths
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Long Lasting Phosphorescence in Eu^(2+) and Ce^(3+) Co-Doped Strontium Borate Glasses 被引量:1
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作者 张岚 李成宇 苏锵 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期196-198,共3页
Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2 + and Ce3+ . The methods of photoluminescence, the... Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2 + and Ce3+ . The methods of photoluminescence, thermolu-minescence and phosphorescence were used to study the samples, and possible mechanism was suggested. The co-doping of Ce3 + ions poisoned the phosphorescence emission of Eu2 + because of the competition to obtain the trapped electron . The phosphorescence of Ce3 + in the sample decays more quickly than that of Eu2 + , which is suggested for the reason that the emission energy of Ce3 + is higher or the distance between Ce3 + and electron traps of the glasses is longer. 展开更多
关键词 long lasting phosphorescence strontium borate glasses Eu2+ Ce3+ rare earths
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Glacier Relics of the Last Glacial and Holocene Periods Discovered in the Middle-low Mountains of Eastern China: Sedimentary Sequences and Environmental Evolution of Mengshan Mountain in Shandong Province since 80 ka 被引量:9
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作者 WANG Zhaobo WANG Jiangyue +1 位作者 HE Lelong ZHANG Jian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第1期141-151,共11页
The goal of this research study is to describe academic issues which have been debated in the field of Chinese geosciences for a century. In 1922, Jonquei S. Lee(Li Siguang) discovered Quaternary glacial relics at Tai... The goal of this research study is to describe academic issues which have been debated in the field of Chinese geosciences for a century. In 1922, Jonquei S. Lee(Li Siguang) discovered Quaternary glacial relics at Taihang Mountainin eastern China. In 1947, he published his research findings in the magazine Mount Lushan in Glacial Age. The research results had established three Ice Ages: Poyang(Gonzi), Dagu(Minde), and Lushan(Lisi). However, at that time, no Wurm glacial relics of the last Ice Age had been found in Lushan Mountain. Since then, the research team represented by Shi Yafeng, who is considered to be "the father of glaciers in China", questioned Jonquei S. Lee’s research results and concluded that "Professor Jonquei S. Lee’s Quaternary glacier research in Lushan Mountain having misread the debris flow". In 2005, the "middle-low mountains" in eastern China were finally defined as follows: "We clearly and unambiguously believe that there were no glacial activities in the middle-low mountainous areas of eastern China(east of 102° to 104°E;below 3,000 and 2,500 m) during the Quaternary Period". Currently, the long-standing academic debate appears to have come to a conclusion. As of 2015, the author and others began to investigate and study the Quaternary glacial relics in Mengshan Mountain(1,156 m above sea level), Shandong Province, one of the "middle-low mountains" of eastern China. The relics have been observed to posses the systematic features of glacial erosion, trough and valley striations, and moraine deposits. The applied dating method shave confirmed that there were not only glacial relics of the last Ice Age(Wurm), but also Holocene glacial relics in the Mengshan Mountain area. Therefore, in order to further establish the corresponding relationship between the glacier, loess, stream sediment series, and MIS in the Mengshan Mountain area, a large number of chronological studies have been carried out regarding the various types of sediments in the area, and 24 dating datahave been obtained using OSL, CRN, and 14 Cmethods.On this basis, the corresponding relationship between the sedimentary sequences and the MIS was established for the first time in eastern China, which in dicates the environmental changes which had occurred in eastern China since 80 ka. These discoveries s and chronological study results confirm the existence of the Last Ice Age, as well as Holocene glacial relics at Mengshan Mountain, there by confirming that Quaternary glaciation had occurred in the middle-low mountain areas of eastern China. 展开更多
关键词 OSL CRN MIS GLACIAL RELICS last Ice Age HOLOCENE Eastern China
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A white long-lasting phosphor Y_2O_2S:Tb^(3+), Sm^(3+): an improvement of Y_2O_2S:Tb^(3+) 被引量:3
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作者 林林 陈坤 +4 位作者 王志芳 游宝贵 陈永虎 张慰萍 施朝淑 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第5期648-651,共4页
As an improvement of reported Y2O2S:Tb^3+, a white-light long-lasting phosphor: Y2O2S:Tb^3+, Sm^3+ was prepared by the solid-state reaction. The photo-luminescence spectra showed that the position and shape of T... As an improvement of reported Y2O2S:Tb^3+, a white-light long-lasting phosphor: Y2O2S:Tb^3+, Sm^3+ was prepared by the solid-state reaction. The photo-luminescence spectra showed that the position and shape of Tb^3+ and Sm^3+ emissions under UV excitation were similar in this host, which ensured a stable white emission color (daylight standard of IEC) under different excitations. The decay curves of co-doped samples indicated that the decay times of emissions of the two ions were close. The thermo-luminescence measurement suggested that the traps created by the doped Sm^3+ ions were helpful to postpone the white afterglow of co-doped samples. Therefore, the function of co-doped Sm^3+ ions was confirmed as improving the white emission colors of samples and acting as new trap centers. 展开更多
关键词 TERBIUM SAMARIUM WHITE long-lasting phosphor rare earths
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A Multi-cycle Climatic Fluctuation Record of the Last Interglacial Period:Typical Stratigraphic Section in the Salawusu River Valley on the Ordos Plateau,China 被引量:23
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作者 LIBaosheng DavidDianZHANG +3 位作者 WENXiaohao DONGYuxiang ZHUYizhi JINHeling 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2005年第3期398-404,共7页
The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies... The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies and paleosols. Based on comprehensive analyses on the distribution of magnetic susceptibility and CaCO3 and paleo-ecology indicated by fossils in the region, it is considered that the sedimentation cycles resulted from dry-cold and warm-humid climate fluctuations. Magnetic susceptibility values and CaCO3 contents in stratigraphic sectors I, III, V and II, IV basically respectively present peaks and low vales, and the former three can in time correlate with MIS5a, MIS5c and MIS5e successively and the latter two with MIS5b and MIS5d. In addition, some horizons of eolian dune sands and the low vales of their magnetic susceptibility and CaCO3 are also correlated with 6 periods of cooling events indicated by the higher content of foraminifer Neogloboquadrina pachyderma (S.) documented in the V29—191 drill in the North Atlantic and the cold events recorded by δ 18O in the ice cores in GRIP, especially with 9 periods of dust events in Chinese Loess Plateau. 展开更多
关键词 last interglacial period dune events cold-warm climate cycles Salawusu River valley Inner Mongolia
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A Novel White Light Emitting Long-lasting Phosphor 被引量:3
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作者 BingFuLEI YingLiangLIU +1 位作者 ZeRenYE ChunShanSHI 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第3期335-338,共4页
A novel white light emitting long-lasting phosphor Cd1-xDyxSiO3 is reported in this letter. The Dy3+ doped CdSiO3 phosphor emits white light. The phosphorescence can be seen with the naked eye in the dark clearly ev... A novel white light emitting long-lasting phosphor Cd1-xDyxSiO3 is reported in this letter. The Dy3+ doped CdSiO3 phosphor emits white light. The phosphorescence can be seen with the naked eye in the dark clearly even after the 254 nm UV irradiation have been removed for about 30 min. In the emission spectrum of 5% Dy3+ doped CdSiO3 phosphor, there are two emission peaks of Dy3+, 580 nm (4F9/26H13/2) and 486 nm (4F9/26H15/2), as well as a broad band emission located at about 410 nm. All the three emissions form a white light with CIE chromaticity coordinates x=0.3874, y=0.3760 and the color temperature is 4000 K under 254 nm excitation. It indicated that this phosphor is a promising new luminescent material for practice application. 展开更多
关键词 Cadmium metasilicate white light long-lasting phosphor dysprosium ion.
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An Analysis of Subtitling through Andre Lefevere's Rewriting Theory:A Case Study on English and Two Chinese Translations of The Last Emperor 被引量:1
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作者 陈子婧 《疯狂英语(理论版)》 2016年第3期169-171,共3页
This paper will try to apply Andre Lefevere's rewriting theory to study subtitling.Through the analysis of The Last Emperor and its two Chinese translations,we will explore how ideology manipulates subtitle transl... This paper will try to apply Andre Lefevere's rewriting theory to study subtitling.Through the analysis of The Last Emperor and its two Chinese translations,we will explore how ideology manipulates subtitle translation. 展开更多
关键词 last Emperor Rewriting Theory SUBTITLING
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Variation of Surface Temperature during the Last Millennium in a Simulation with the FGOALS-gl Climate System Model 被引量:6
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作者 张洁 Laurent LI +1 位作者 周天军 辛晓歌 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第3期699-712,共14页
A reasonable past millennial climate simulation relies heavily on the specified external forcings, including both natural and anthropogenic forcing agents. In this paper, we examine the surface temperature responses t... A reasonable past millennial climate simulation relies heavily on the specified external forcings, including both natural and anthropogenic forcing agents. In this paper, we examine the surface temperature responses to specified external forcing agents in a millennium-scale transient climate simulation with the fast version of LASG IAP Flexible Global Ocean-Atmosphere-Land System model (FGOALS-gl) developed in the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics (LASG/IAP). The model presents a reasonable performance in comparison with reconstructions of surface temperature. Differentiated from significant changes in the 20th century at the global scale, changes during the natural-forcing-dominant period are mainly manifested in the Northern Hemisphere. Seasonally, modeled significant changes are more pronounced during the wintertime at higher latitudes. This may be a manifestation of polar amplification associated with sea-ice-temperature positive feedback. The climate responses to total external forcings can explain about half of the climate variance during the whole millennium period, especially at decadal timescales. Surface temperature in the Antarctic shows heterogeneous and insignificant changes during the preindustrial period and the climate response to external forcings is undetectable due to the strong internal variability. The model response to specified external forcings is modulated by cloud radiative forcing (CRF). The CRF acts against the fluctuations of external forcings. Effects of clouds are manifested in shortwave radiation by changes in cloud water during the natural-forcing-dominant period, but mainly in longwave radiation by a decrease in cloud amount in the ant hropogenic- forcing-dominant period. 展开更多
关键词 last millennium external forcing surface temperature cloud radiative forcing climate system model
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Last Deglaciation Climatic Fluctuation Record by the Palaeo-Daocheng Ice Cap, Southeastern Qinghai-Tibetan Plateau 被引量:7
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作者 ZHANG Zhigang XU Xiaobin +3 位作者 WANG Jian ZHAO Zhijun BAI Shibiao CHANG Zhi Yang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第6期1863-1874,共12页
The last deglaciation, a key period for understanding present and future climate changes, has long been the hot topic for palaeoclimatological study. The Qinghai-Tibetan Plateau(QTP) is often a target study area for... The last deglaciation, a key period for understanding present and future climate changes, has long been the hot topic for palaeoclimatological study. The Qinghai-Tibetan Plateau(QTP) is often a target study area for understanding hemispheric, or even global environment changes. The glacial landforms on the QTP provide a unique perspective for its climate change. In order to investigate the onset of the last deglaciation at the QTP and its regional correlation, the terrestrial cosmogenic nuclides(TCN) 10 Be and 26 Al surface exposure dating was chosen to date the roche moutonnée, the polished surface and the moraine debris located at the palaeo-Daocheng Ice Cap(pDIC), southeastern QTP. Our results show that the onset of the last deglaciation is at about 19 ka, followed by another warming event occurring around 15 ka in the p-DIC area. These timings agree well with other records, e.g. equivalent with a rapid sea level rise at 19 ka and the onset of B?lling warming event at about 15 ka. Thus, our new data can provide good reveal constraint on the climate evolution at the QTP. 展开更多
关键词 Terrestrial Cosmogenic Nuclides last Deglaciation Palaeo-Daocheng Ice Cap Qinghai Tibetan Plateau
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Optimum Tilt Angle of Flow Guide in Steam Turbine Exhaust Hood Considering the Effect of Last Stage Flow Field 被引量:4
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作者 Lihua CAO Aqiang LIN +1 位作者 Yong LI Bin XIAO 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第4期866-875,共10页
Abstract Heat transfer and vacuum in condenser are influenced by the aerodynamic performance of steam tur- bine exhaust hood. The current research on exhaust hood is mainly focused on analyzing flow loss and optimal d... Abstract Heat transfer and vacuum in condenser are influenced by the aerodynamic performance of steam tur- bine exhaust hood. The current research on exhaust hood is mainly focused on analyzing flow loss and optimal design of its structure without consideration of the wet steam condensing flow and the exhaust hood coupled with the front and rear parts. To better understand the aerodynamic performance influenced by the tilt angle of flow guide inside a diffuser, taking a 600 MW steam turbine as an example, a numerical simulator CFX is adopted to solve compressible three-dimensional (3D) Reynolds time-aver- aged N-S equations and standard k-e turbulence model. And the exhaust hood flow field influenced by different tilt angles of flow guide is investigated with consideration of the wet steam condensing flow and the exhaust hood coupled with the last stage blades and the condenser throat. The result shows that the total pressure loss coefficient and the static pressure recovery coefficient of exhaust hood change regularly and monotonously with the gradual increase of tilt angle of flow guide. When the tilt angle of flow guide is within the range of 30~ to 40~, the static pressure recovery coefficient is in the range of 15.27% to 17.03% and the total pressure loss coefficient drops to approximately 51%, the aerodynamic performance of exhaust hood is significantly improved. And the effectiveenthalpy drop in steam turbine increases by 0.228% to 0.274%. It is feasible to obtain a reasonable title angle of flow guide by the method of coupling the last stage and the condenser throat to exhaust hood in combination of the wet steam model, which provides a practical guidance to flow guide transformation and optimal design in exhaust hood. 展开更多
关键词 Steam turbine Exhaust hood last stageblades Tilt angle of flow guide Aerodynamicperformance
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