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近46年临汾浅层地温气候特征分析 总被引:6,自引:0,他引:6
利用临汾1962年~2007年0cm~20em各层逐月平均地温,采用气候倾向率、滑动t检验等气候统计方法,研究了近46年临汾浅层平均地温的变化趋势、异常年份和气候突变等.结果表明:近46年来临汾各季节浅层平均地温均呈现为显著的变化趋势(-0.07 ℃/10a~0.53℃/10a),春季最大,夏季最小;各浅层年平均地温均呈明显的升高趋势,平均每1-年升高0.15℃-0.26℃,以表层地温增温率最大;春季、秋季和年浅层平均地温表现为“暖-冷-暖”的变化趋势;浅层地温春季、冬季多异常年份,年平均地温异常偏高发生在2000年后,异常偏低发生在1996年;用滑动t检验法和Yarnamoto法发现地温在1996年附近发生了突变,用M—k法发现地温在2002年附近发生了突变;气温升高是导致地温上升的主要原因. 相似文献
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阐述了苹果卸袋技术与气候影响的关系,通过对2006年和2007年苹果卸袋前后气候条件的分析研究,提出了苹果卸袋的最佳时机。 相似文献
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根据湛江市1961-2008年的日降水量、气温、相对湿度、蒸发量等气象资料,通过Mann-Kendall趋势分析、小波分析以及相关性检验等方法,分析了近50年来雷州半岛北部地区水热变化特征、趋势性和周期性等,并探讨了其与ENSO活动的可能关系.结果表明,(1)1961-2008年雷州半岛北部地区气候趋向暖干,总体呈偏干气候态.自20世纪90年代中后期以来,气候干旱化趋势愈加显著,尤其在2002年左右出现突变性转折.(2)近50年来该地区气候水热组合季节特征主要表现为暖湿凉干组合,然而在年际与年代际时间尺度上,水热状况则表现出暖湿凉干、暖干凉湿等多种不同组合特征,且在年际与年代际时间尺度上的水热组合状况也并不完全一致.(3)采用连续小波周期分析发现该地区的气候干湿变化存在显著的2~3年短周期变化,可能与同一时期ENSO活动具有一定关系. 相似文献
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利用1961~2005年南宁市最高、最低和平均温度资料,分析近50a来南宁市的气温变化特征,通过气候变暖前后灾害性天气气候事件的对比,分析南宁市灾害性天气气候事件的变化规律。结果表明,1961~2005年南宁市年平均气温增温趋势明显,温度变率为0.3C/10a,各季节平均气温均呈上升趋势,秋季增温最明显,冬季次之,夏季位居第三,春季增温最小。年平均最高气温呈较弱的增暖,变率为0.13C/10a,而年平均最低气温的增暖趋势比年平均最高气温明显,为0.36C/10a。年平均日校差的变化则呈递减的趋势,变率为-0.23C/10a。在全球气候增暖和城市化快速发展的过程中,南宁市的灾害性天气气候事件发生了明显的变化:极端强降水有增加趋势,高温天气明显增多,持续高温天气加剧,雷暴和大风日数明显减少,春季低温阴雨天气减少。南宁市灾害性天气气候事件变化的原因可能与全球气候变暖有关,城市化可能是造成南宁市灾害性天气气候事件变化的主要原因。 相似文献
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为了揭示阜新气候变暖的影响因素及变化规律,利用近50年北太平洋海温资料、历年阜新地区气温资料,在太阳黑子谷值年活动周期内,采用数理统计分析方法,对阜新年、季、月气温变化进行了深入的分析和研究,找出了阜新气候变暖与海温之间的一些重要规律.结果证明了阜新气候变暖与海温有着密切的关系及海温对气温影响的长期效应.通过海温与气温的研究,对气候变暖、冷暖冬、高温、低温冷害、干旱、洪涝等方面的气候预测有着重要的帮助作用. 相似文献
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气候变迁与中国战争史之间的关系综述 总被引:1,自引:0,他引:1
气候是政治命运的影响因素之一,在中国近5000a的历史中,气候共经历了4次寒冷期和数次暖期中的短暂冷期.气候的突变,特别是气候变冷给农业社会带来巨大的打击,从而成为战争爆发的导火索.通过对气候变迁以及中国战争史的叠加研究,发现战争的发生和气候变迁存在着很大的关联. 相似文献
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研究了计算大型稀疏对称矩阵的若干个最大或最小特征值的问题,首先引入了求解大型对称特征值问题的预处理子空间迭代法和Chebyshev迭代法,并对其作了理论分析.为了加速预处理子空间迭代法的收敛性,笔者采用组合Chebyshev迭代法和预处理子空间迭代法,提出了计算大型对称稀疏矩阵的几个最大或最小特征值的Chebyshev预处理子空间迭代法.数值结果表明,该方法比预处理子空间方法优越. 相似文献
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Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
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QING Hai-ruo 《成都理工大学学报(自然科学版)》2004,31(6)
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction. 相似文献
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Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
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YUJia-shun HEZhen-hua 《成都理工大学学报(自然科学版)》2004,31(6):694-698
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod… 相似文献
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理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
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As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化 总被引:9,自引:1,他引:9
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。 相似文献
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There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying. 相似文献
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Yuriko Aoki 《华南师范大学学报(自然科学版)》2014,46(6):135-135
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to 相似文献