|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Reconstruction of precipitation variation from tree rings in recent 1000 years in Delingha, Qinghai显示文摘Using seven well-replicated Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies developed at Zongwulong and Shalike Mts. in the northeastern part of the Qaidam Basin annual precipitation from previous July to current June in the recent 1000 years was re- constructed for Delingha. The reconstruction can capture 63.1% of precipitation variance and the equation was stable over time. For the reconstructed precipitation, wet periods occurred in AD1520—1633 and 1933—2001, whereas dry intervals in 1429—1519 and 1634—1741. In ad- dition, the magnitude in precipitation variation was lower before 1430 with about 15 mm, but it increased to 30 mm during the period of 1430 to 1850. After 1850, the precipitation variance de- creased again. In contrast to the increase in temperature, a decrease in annual precipitation was evident since the 1990s. The agreement in low-frequency variation between the reconstruction and the glacier accumulation and particulate content in Dunde ice cores during the recent several hundred years suggested that the precipitation reconstructed in this study was rather reliable, and represented a regional signal. This 1000-year reconstruction could benefit our understanding of climatic variation in decadal to century-scale in this region, and provide basic data to climate models and to prediction of future climate in the 21st century. | SHAO Xuemei1, HUANG Lei1, LIU Hongbin2, LIANG Eryuan1, FANG Xiuqi3 & WANG Lili1 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2. National Climate Center, Beijing 100081, China 3. Beijing Normal University, Beijing 100875, China | 2005 | Science China Earth Sciences2005,48,7: | 113 |
| 2 | 贺兰山孔兹岩系的变质时代及其对华北克拉通西部陆块演化的制约显示文摘贺兰山孔兹岩系作为华北克拉通西部孔兹岩带的重要组成部分,其变质时代问题一直悬而未决。利用SHRIMP锆石U-Pb定年技术,对贺兰山孔兹岩系中3个代表性富铝片麻岩(石榴堇青钾长片麻岩、石榴堇青二长片麻岩与石榴黑云斜长片麻岩)样品进行了精确定年。发现这3种岩石虽处不同层位,但其碎屑锆石年龄却非常集中,各测点^(207)Pb/^(206)Pb年龄总体变化在2.0~2.1Ga之间,加权平均年龄则在2017~2040Ma之间。这些碎屑锆石都具有岩浆结构特征,反映当时曾存在大规模花岗质岩浆活动,所成岩体为孔兹岩系沉积提供了充足物源。另有少量大于2.5Ga的碎屑锆石(2520~2949Ma),表明本区存在太古代岩浆活动记录。本区石榴堇青二长片麻岩中发育典型的变质增生锆石,其成因很可能与黑云母的脱水熔融反应有关。利用该锆石确定贺兰山孔兹岩系的变质时代为1950±8Ma。该时代与东部大青山、乌拉山孔兹岩系变质时代相同,表明华北克拉通西部的阴山地块与鄂尔多斯地块大体是以平行的方式正面拼贴到一起的。 | 周喜文 耿元生 | 2009 | 岩石学报2009,25,8: | 55 |
| 3 | Belowground carbon balance and carbon accumulation rate in the successional series of monsoon evergreen broad-leaved forest显示文摘The balance, accumulation rate and temporal dynamics of belowground carbon in the successional series of monsoon evergreen broadleaved forest are obtained in this paper, based on long-term observations to the soil organic matter, input and standing biomass of litter and coarse woody debris, and dissolved organic carbon carried in the hydrological process of subtropical climax forest ecosystem—monsoon evergreen broad-leaved forest, and its two successional forests of natural restoration—coniferous and broad-leaved mixed forest and Pinus massoniana forest, as well as data of root biomass obtained once every five years and respiration measurement of soil, litter and coarse woody debris respiration for 1 year. The major results include: the belowground carbon pools of monsoon evergreen broad-leaved forest, coniferous and broad-leaved mixed forest, and Pinus massoniana forest are 23191 ± 2538 g·m?2, 16889 ± 1936 g·m?2 and 12680 ± 1854 g·m?2, respec- tively, in 2002. Mean annual carbon accumulation rates of the three forest types during the 24a from 1978 to 2002 are 383 ± 97 g·m?2·a?1, 193 ± 85 g·m?2·a?1 and 213 ± 86 g·m?2·a?1, respectively. The belowground carbon pools in the three forest types keep increasing during the observation period, suggesting that belowground carbon pools are carbon sinks to the atmosphere. There are seasonal variations, namely, they are strong carbon sources from April to June, weak carbon sources from July to September; while they are strong carbon sinks from October to November, weak carbon sinks from December to March. | ZHOU Guoyi1, ZHOU Cunyu1, LIU Shuguang2, TANG Xuli1, OUYANG Xuejun1, ZHANG Deqiang1, LIU Shizhong1, LIU Juxiu1, YAN Junhua1, ZHOU Chuanyan1, LUO Yan1, GUAN Lili1 & LIU Yan1 1. Dinghushan Forest Ecosystem Research Station, Chinese Academy of Sciences, Guangzhou 510650, China 2. SAIC, EROS Data Center, U.S. Geological Survey, Sioux Falls, SD 57198, USA | 2006 | Science China Earth Sciences2006,49,3: | 36 |
| 4 | Convolutional neural networks for time series classification显示文摘Time series classification is an important task in time series data mining, and has attracted great interests and tremendous efforts during last decades. However, it remains a challenging problem due to the nature of time series data: high dimensionality,large in data size and updating continuously. The deep learning techniques are explored to improve the performance of traditional feature-based approaches. Specifically, a novel convolutional neural network(CNN) framework is proposed for time series classification. Different from other feature-based classification approaches,CNN can discover and extract the suitable internal structure to generate deep features of the input time series automatically by using convolution and pooling operations. Two groups of experiments are conducted on simulated data sets and eight groups of experiments are conducted on real-world data sets from different application domains. The final experimental results show that the proposed method outperforms state-of-the-art methods for time series classification in terms of the classification accuracy and noise tolerance. | Bendong Zhao Huanzhang Lu Shangfeng Chen Junliang Liu Dongya Wu | 2017 | Journal of Systems Engineering and Electronics2017,28,1: | 33 |
| 5 | The age and tectonic environment of the rhyolitic rocks on the western side of Wuyi Mountain,South China显示文摘During the geological survey of the metamorphic rocks in Xingning-Wuhua region on the western side of Wuyi Mountain, South China, we discovered the Neoproterozoic rhyolite and rhyolitic greywacke for the first time that outcrop in the Proterozoic metamorphic rocks near Jingnan Town of Xingning County, eastern Guangdong Province. A systematic research on petrology, geochemistry and geochronology of rhyolitic rocks was conducted to understand their tectonic setting and formation age. The Jingnan rhyolite is interbedded with a coeval greywacke, with a total thickness of 60 m; both rhyolite and greywacke display a similar folding and metamorphic pattern. Meta-rhyolite consists of groundmass and phenocrystals including sanidine, orthoclase, and quartz with distinct undulose extinction; the groundmass has been recrystallized into fine-grain feldspar, quartz and sericite aggregation. Meta-greywacke is composed of crystallinoclastic grains (sanidine, orthoclase, quartz and oligoclase) and clay groundmass. Zircon grains used for the SHRIMP U-Pb analysis are light brown-colored and euhedral or subeuhedral. Dating data suggest two age groups; eight grains of magmatype zircon with an idiomorphic form yield an age of 972±8 Ma, and the other seven weakly corroded grains of zircon with euhedral to subeuhedral shape construct an average age of 1097±11 Ma, which were captured from older rocks by an uplifting magma, implying that a late Mesoproterozoic basement exists in the Nanling region. In addition, one Paleoproterozoic age, 2035±11 Ma, is obtained from a rounded detrital zircon, indicating that a Paleoproterozoic thermal event took place in the South China. Geochemically, the Jingnan rhyolitic rocks are characterized by high K2O content, intermediate Al2O3 content, with the ACNK value 0.98―1.11, and belonging to high-K alkaline series. They are rich in ΣREE, Rb, Th and Ce, depleted in Ba, Sr, Eu, Ti, P and Nb-Ta, and with moderate negative Eu and Sr anomalies. These features indicate that the Jingnan volcanic rocks have an affinity of continental arc that is similar to those of acid volcanic rocks in the SE-China Coastal Region, in other words, a Neoproterozoic tectonomagma event might have taken place in the western Wuyi region, leading to an eruption of high-K calc-alkaline granitic magma. | SHU LiangShu DENG Ping YU JinHai WANG YanBin JIANG ShaoYong | 2008 | Science China Earth Sciences2008,51,8: | 27 |
| 6 | The UCR Time Series Archive显示文摘The UCR time series archive–introduced in 2002,has become an important resource in the time series data mining community,with at least one thousand published papers making use of at least one data set from the archive.The original incarnation of the archive had sixteen data sets but since that time,it has gone through periodic expansions.The last expansion took place in the summer of 2015 when the archive grew from 45 to 85 data sets.This paper introduces and will focus on the new data expansion from 85 to 128 data sets.Beyond expanding this valuable resource,this paper offers pragmatic advice to anyone who may wish to evaluate a new algorithm on the archive.Finally,this paper makes a novel and yet actionable claim:of the hundreds of papers that show an improvement over the standard baseline(1-nearest neighbor classification),a fraction might be mis-attributing the reasons for their improvement.Moreover,the improvements claimed by these papers might have been achievable with a much simpler modification,requiring just a few lines of code. | Hoang Anh Dau Anthony Bagnall Kaveh Kamgar Chin-Chia Michael Yeh Yan Zhu Shaghayegh Gharghabi Chotirat Ann Ratanamahatana Eamonn Keogh | 2019 | IEEE/CAA Journal of Automatica Sinica2019,6,6: | 26 |
| 7 | Assessment and sequencing of air target threat based on intuitionistic fuzzy entropy and dynamic VIKOR显示文摘In view of the fact that traditional air target threat assessment methods are difficult to reflect the combat characteristics of uncertain, dynamic and hybrid formation, an algorithm is proposed to solve the multi-target threat assessment problems. The target attribute weight is calculated by the intuitionistic fuzzy entropy(IFE) algorithm and the time series weight is gained by the Poisson distribution method based on multi-times data. Finally,assessment and sequencing of the air multi-target threat model based on IFE and dynamic Vlse Kriterijumska Optimizacija I Kompromisno Resenje(VIKOR) is established with an example which indicates that the method is reasonable and effective. | ZHANG Kun KONG Weiren LIU Peipei SHI Jiao LEI Yu ZOU Jie | 2018 | Journal of Systems Engineering and Electronics2018,29,2: | 24 |
| 8 | Geochronology of middle Neoproterozoic volcanic deposits in Yangtze Craton interior of South China and its implications to tectonic settings显示文摘Here we report new SHRIMP dating results of the crystal tuff in Ejiaao Formation of middle Banxi Group in northern Guizhou. The results indicate that the volcanic deposition occurred at ~780 Ma. We also suggests that the igneous activities across Yangtze Craton with diabase dyke swarms and basal volcanic rocks during middle Banxi time are indicative of the episodic, extensive and vigorous great bimodal igneous events during middle Neoproterozoic (825-720 Ma) in South China. The characteristics of the igneous series are contrary to the model claiming they are of island-arc origin, but suggest that they are the records of rifting process and may be related to the episodic plume activities leading to the break-up of Rodinia. | WANG ZhengJiang1, WANG Jian1, DUAN TaiZhong2, XIE Yuan1, ZHUO JieWen1,3 & YANG Ping1 1 Chengdu Institute of Geology and Mineral Resources, Ministry of Land and Resources, Chengdu 610082, China 2 Marathon Oil UK Ltd., Aberdeen, Scotland, AB15 6FZ, UK 3 Graduate Department, Chinese Academy of Geological Sciences, Beijing 100037, China | 2010 | Science China Earth Sciences2010,53,9: | 20 |
| 9 | 广义三角级数函数电离层延迟模型显示文摘研究一种参数可调的广义三角级数函数GTSF(generalized trignometric series function)电离层延迟模型.分析GTSF模型在电离层研究特别是为单频用户提供延迟改正应用方面的特点. 初步结果显示,较参数固定的三角级数函数TSF(trignometric series function)模型和目前广泛应用的多项式模型POLY(polynomial model)模型,GTSF模型能够更好的描述电离层TEC变化特性,可望进一步提高基于GPS的局部电离层延迟信息的确定精度. | 袁运斌 欧吉坤 | 2005 | 自然科学进展2005,15,8: | 18 |
| 10 | Geochemistry of khondalites from the central portion of North China craton (NCC):implications for the continental cratonization in the Neoarchean显示文摘Within the high-grade metamorphic basement, the central portion of North China Craton (NCC), a group of Neoarchean khondalites (KS) is identified. They are characterized by large ion lithophile elements (LILE) enrichment, lower abundances of Zr, Hf and Sr. Their rare earth element (REE) distribution has significant LREE enrichment and negative Eu anomalies. The protoliths of KS are interpreted as feldspathic quartzite, shale or petite and carbonite, deposited in a shallow sea upon cratonic shelf distant from the land. KS’s source region might be dominated by granitic rocks, with a minor amount of TTG, underwent comparatively severe chemical weathering. Considering relevent tectonic constraints, we suggest that khondalites from central portion of NCC, an important metamophosed sedimentary cover, are the most significant exogenetic marker of Neoarchean continental cratonization for NCC. | 李江海 钱祥麟 刘树文 | 2000 | Science China Earth Sciences2000,43,3: | 16 |
| 11 | 分布式系统中异地数据库的数据一致性维护显示文摘大型分布式系统通常需要在异地的数据库中存储同一数据的不同副本,不同副本之间需要维护数据的一致性。文章讨论了维护数据一致性的两种方法:消息队列法和复制控制法,并分别介绍了使用IBMMQSeries消息队列和MicrosoftSQLServer复制机制来维护数据一致的实现过程,对比分析了二者在实际应用中各自的特点,以及在理论上的技术差异。 | 张华伟 熊璋 欧阳元新 | 2004 | 计算机工程与应用2004,40,23: | 16 |
| 12 | Adaptive event-triggered control for a class of nonlinear systems with periodic disturbances显示文摘This paper investigates the adaptive event-triggered control problem for a class of nonlinear systems subject to periodic disturbances. To reduce the communication burden, a reliable relative threshold strategy is proposed. Fourier series expansion and radial basis function neural network are combined into a function approximator to model suitable time-varying disturbed function of known periods in strict-feedback systems. By combining the Lyapunov stability theory and the backstepping technique, the proposed adaptive control approach ensures that all the signals in the closed-loop system are bounded, and the tracking error can be regulated to a compact set around zero in finite time. Finally, simulation results are presented to verify the effectiveness of the theoretical results. | Hui MA Hongyi LI Renquan LU Tingwen HUANG | 2020 | Science China(Information Sciences)2020,63,5: | 14 |
| 13 | A series solution for surface motion amplification due to underground twin tunnels:incident SV waves显示文摘A series solution of displacement response of the ground surface in the presence of underground twin tunnels subjectcd to excitation of incident plane SV waves is derived by using Fourier-Bessel series expansion method. The numerical parametric study shows that underground twin tunnels significantly amplify the nearby surface ground motion. It is suggested that the effect of subways on ground motion should be considered when the subways are planned and designed. | 梁建文 张浩 Vincent W Lee | 2003 | Earthquake Engineering and Engineering Vibration2003,2,2: | 13 |
| 14 | 多机电力系统中多台TCSC控制器间的交互影响研究显示文摘建立了多机电力系统中装设多台可控串补装置(ThyristorControlledSeriesCompensation,TCSC)时的扩展Phillips-Heffron模型。基于该模型给出了4机11节点测试系统中联合运行2台TCSC控制器时TCSC间存在交互影响的实例,指出处于多机系统同一电力区域中的多个TCSC控制器之间存在负交互影响的可能,在设计TCSC时应予以考虑,以使电力系统中多个FACTS控制器能协调运行。 | 李亮 江全元 邹振宇 | 2005 | 电网技术2005,29,9: | 13 |
| 15 | TAYLOR SERIES AND ORTHOGONALITY OF THE OCTONION ANALYTIC FUNCTIONS显示文摘The Taylor series of the Octonion analytic function is given. And the orthog- onal formula for the Octonion analytic functions is also obtained. | 李兴民 彭立中 | 2001 | Acta Mathematica Scientia2001,21,3: | 12 |
| 16 | 基于SEA的机器人仿肌弹性驱动关节研究显示文摘为了实现机器人的拟人运动,提高其对外部环境的适应性,基于串联弹性驱动器(SEA)驱动形式提出一种仿肌弹性驱动的机器人转动关节,以实现机器人在受迫振动或受冲击下的柔顺自调整运动。该关节机构参考人体肌肉-肌腱组织的Hill-type模型,采用具有对抗形式的主动弹性驱动和被动弹性牵制的设计方案,模拟肌肉收缩运动和功能,产生牵拉力以驱动机器人的关节。通过对该弹性驱动关节进行建模分析,得到其动力学描述方程,结合多次仿真测试中获得的系统运动特性曲线,在掌握其运动规律的基础上完成了其动力学性能评估。此外,针对关节机构具有的强弹性、低刚度特点,提出一种基于虚拟刚度补偿的控制方法,并应用在具有仿肌弹性驱动关节的二自由度机器臂上,实验结果表明其可行、有效。 | 何福本 梁延德 孙捷夫 郭超 | 2014 | 中国机械工程2014,25,7: | 12 |
| 17 | Review of recent studies of the climatic effects of urbanization in China显示文摘This paper summarizes recent studies on the effects of urbanization on climate in China. The effects of urbanization on local climate trends have been re-estimated based on homogenized observations and using improved methods. In this respect, the effect of urbanization on the observed warming trend of local surface air temperatures during the last few decades is determined as being about 20% at urban stations such as the Beijing Observatory. The large-scale weakening trend of wind speed is also about 20% more prominent at the city center than its surroundings. The effect of urbanization on precipitation is not profound, but results of high-resolution regional climate modeling suggest that this effect may depend on the urban extent. Although the urban heat island(UHI) should favor local atmospheric convection and hence precipitation, the increasingly extending urban land-use may reduce precipitation over the urban cluster in North China. It is found that urbanization can play a more notable role in extreme events than usual weather. High-resolution simulations show a positive feedback between the UHI and the super-heat wave in Shanghai during Julye August 2013. Relevant studies dealing with urban climate adaptation are discussed in relation to recent ?ndings. | YAN Zhong-Wei WANG Jun XIA Jiang-Jiang FENG Jin-Ming | 2016 | Advances in Climate Change Research2016,7,3: | 11 |
| 18 | 美国全国教师资格考试制度探析——以NTE和Praxis Series为例显示文摘美国教师资格考试制度经历了从低标准到严要求、从分散独立到统一标准、从重视书本知识到关注教学实践能力的一个发展过程。以美国教育考试服务中心研发的两套全国统一的教师资格考试方案——'全国教师考试'(National Teacher Examinations)和'普瑞克西斯考试系列'(Praxis Series)为例,深入分析美国全国性教师资格考试制度发展过程及特点,对反思和推进当前我国教师资格考试制度改革具有重要的借鉴和参考意义。 | 黄建辉 洪明 | 2014 | 福建师范大学学报(哲学社会科学版)2014,,3: | 9 |
| 19 | Ultimate generalization to monotonicity for uniform convergence of trigonometric series显示文摘Chaundy and Jolliffe proved that if {a n } is a non-increasing (monotonic) real sequence with lim n →∞ a n = 0, then a necessary and sufficient condition for the uniform convergence of the series ∑∞ n=1 a n sin nx is lim n →∞ na n = 0. We generalize (or weaken) the monotonic condition on the coefficient sequence {a n } in this classical result to the so-called mean value bounded variation condition and prove that the generalized condition cannot be weakened further. We also establish an analogue to the generalized Chaundy-Jolliffe theorem in the complex space. | Zhou SongPing Zhou Ping Yu DanSheng | 2010 | Science China Mathematics2010,53,7: | 9 |
| 20 | Approximate homotopy symmetry method:Homotopy series solutions to the sixth-order Boussinesq equation显示文摘An approximate homotopy symmetry method for nonlinear problems is proposed and applied to the sixth-order Boussinesq equation,which arises from fluid dynamics.We summarize the general formulas for similarity reduction solutions and similarity reduction equations of different orders,educing the related homotopy series solutions.Zero-order similarity reduction equations are equivalent to the Painlevé IV type equation or Weierstrass elliptic equation.Higher order similarity solutions can be obtained by solving linear variable coefficients ordinary differential equations.The auxiliary parameter has an effect on the convergence of homotopy series solutions.Series solutions and similarity reduction equations from the approximate symmetry method can be retrieved from the approximate homotopy symmetry method. | JIAO XiaoYu1,GAO Yuan1 & LOU SenYue1,2,3 1 Department of Physics,Shanghai Jiao Tong University,Shanghai 200240,China 2 Department of Physics,Ningbo University,Ningbo 315211,China 3 School of Mathematics,Fudan University,Shanghai 200433,China | 2009 | Science China(Physics,Mechanics & Astronomy)2009,52,8: | 8 |