塔克拉玛干沙漠北缘夏季典型晴天近地层湍流能谱特征

利用塔克拉玛干沙漠北缘肖塘地区涡动相关系统三维方向风速（u,v,w）、气温、CO₂、H₂O等观测数据,分析了夏季典型晴天不同大气稳定度条件下湍流功率谱和协谱。结果表明：大部分情况下湍流速度谱分布满足-2/3幂指数率,垂直方向高频段惯性副区符合程度更高,水平方向次之;CO₂和H₂O浓度则符合程度较低;温度谱与无因次频率总体上都具有很好的相关性。垂直风速与径向风速u的协谱斜率拟合值大多数情况下更接近-1,而在近中性层结条件下更符合-4/5斜线。稳定层结条件下的协谱峰值比不稳定层结时更大,且约大一个量级;不稳定层结条件下高频段协谱近直线型下降。u谱对应的谱峰波长随稳定度增加而减小,v谱和T谱对应的谱峰波长随稳定度的增加没有规律性增减;u、v、w、T谱谱峰波长约67~827、69~2417、4~54、12~661 m。     

“绿政”视角：硅谷新一轮创新的思考与实践

绿政是在全球金融危机、气候危机和能源危机背景下,世界各国为契合可持续发展战略,借鉴历史危机应对经验的一种对全球未来发展模式的探索与尝试,硅谷作为世界科技创新中心,以其极强的创新能力和探索精神,持续主导全球经济发展方向。近10年来,硅谷创新的理论和实践重点正向以绿色科技和清洁能源开发为主的绿政之路布局,被美国各级政府2008年后针对金融危机所采取的一系列经济复苏刺激政策推波助澜,成为推动硅谷地区各企业、政府和学术界不断互动与创新的主导趋势,不断刷新硅谷的经济繁荣和科技进步,引领着全球创新的未来。本文详细分析硅谷该轮绿政探索的思考与实践及其对我国的启示,以期为我国经济的可持续发展提供借鉴。     

全球化下的“生产消费者”——分布式生产系统研究评述

经济全球化背景下,日益精细的劳动分工和跨地域生产协作带来生产片段化和地方专业化集聚。这种生产模式加剧了生产与消费的割裂,并将消费主义作为驱动生产不断扩大的途径。近年来,基于智能电网、可再生能源、3D打印等新兴技术的应用,生产与消费活动紧密联系的分布式生产模式受到可持续发展领域的关注,其中分布式可再生能源的利用和推广成为最主要的驱动力。论文以“生产消费者(Prosumer)”这一概念为切入点,从地理条件、技术基础、市场协作关系和可持续性表现4个方面,探讨分布式生产系统中生产与消费关系的重构。结论指出：以分布式生产为特征的“产消一体”生产模式并非是一种全球化脱钩策略,而是在开放条件下,生产与消费更紧密联系的地方化过程,这种生产模式转型有可能为更多样化的可持续发展实践开辟空间,值得进一步开展以行动为导向的扎根研究和区域比较分析。     

南、北松潘-甘孜块体及扬子板块壳幔过渡带结构研究

采用接收函数方法,研究南、北松潘-甘孜块体及扬子板块的壳幔过渡带结构,得到3个不同构造块体的壳幔过渡带厚度和速度结构。结果显示,南松潘-甘孜块体壳幔过渡带厚度为1.79~3.4 km,速度结构为高低速相间结构,该块体壳幔过渡带不断变厚,改变了原有的壳幔过渡带温压条件,且东南东北向都有剧烈的构造活动,产生高、低速相间的速度结构;巴颜喀拉松潘-甘孜块体壳幔过渡带厚度为2.22~3.72 km,该块体受到持续挤压,壳幔过渡带逐渐变厚,逐渐改变壳幔过渡带温压条件,形成速度渐变结构;扬子块体壳幔过渡带厚度为0.86~1.58 km,扬子块体四川盆地有坚硬的岩石圈,壳幔过渡带没有遭受破坏,为完好的一级间断面,过渡带厚度较薄,结构为速度突变结构。     

NUMERICAL STUDY OF THE EFFECTS OF PERSISTENT WARMER SEASURFACE TEMPERATURE IN TROPICAL INDIAN OCEAN ONATMOSPHERIC CIRCULATION IN THE EARLY SUMMERIN EAST ASIA IN 1991

By employing the CCM1（R15L12）long-range spectral model, study is undertaken of the effects of sea surface temperature anomaly(SSTA) for tropical Indian ocean on circulation transformation in the early summer in East Asia in 1991. The results indicate that warmer SSTA contributes to the increasing of the temperature over the Plateau in early summer, resulting in the intensification of tropical easterly jet on 100 hPa and northward shift of Northern Hemisphere subtropical westerly jet in May. It is obviously favorable for the subtropical high enhancement over western Pacific Ocean in May and subtropical westerly jet maintaining at 35～40 °N in June, making the Mei-Yu come earlier and stay over the Changjiang basin in 1991. Furthermore, warmer SSTA is also advantageous to averaged temperature rise in East Asia land region and Nanhai monsoon development. These roles are helpful in accelerating the seasonal transition for East Asia in early summer.     

我国东部海域不同类型的登陆再发展变性台风的统计分析

本文对1982年以来我国东部海域登陆再发展台风进行统计分析,选取其中15个个例进行对比分析,根据其移动路径和增强幅度分为3类,研究表明:台风如果移向东北方向则再发展较弱,而向北移动则发展较深,且向北越深发展越强,这与副热带高压(副高)的位置和强度以及上游高空槽存在一定的关系(整体偏向于正相关),在北上的过程中,如果与高空正位涡发生耦合,则增强越大,但非绝热加热所占的比重越小。同时动能收支分布显示,台风加强越深,动能转换越强,两者成正比,但在能量转化的方向和位置上,三者又存在差异。     

Research on percolation model and criticality of seismicity

IntroductionEarthquakepredictionisamainobjectiveintraditionalseismicitystUdy,whichistoattempttofindsomecriterionofprecursoryearthquakeactivitybycomparingdifferentpatternsofseismicityinhopesofpredictingoccurrenceofamajorshock.Theresultisoftendisappointing.Preearthquakeactivitiescandiffergreatlyforimpendingearthquake,althoughalltheruptureprocessesoflargeearthquakesareessentiallythesameasfarasweknowsofar.Asalreadydiscussedintheresultofresearchonseismicityevolution(Gu,Sun,1992),theself-enlargeme…     

基于重力数据特征的东北地区深部动力机制解析

中国东北地区处于古亚洲构造域、蒙古—鄂霍茨克构造域和环太平洋构造域叠加作用最为显著的地区,是地学研究的热点区域.为了探析欧亚大陆下西太平洋板片的俯冲形态以及揭示该区域深部地球动力学机制,利用卫星重力数据通过预处理共轭梯度快速密度反演算法获得了包含东北地区、华北部分地区及日本海海域在内的研究区域上地幔三维密度结构,结合天然地震三维层析成像结果共同揭示太平洋板片的俯冲形态和深部动力机制.俯冲的太平洋板片在日本海沟处呈高密度异常,向西横向持续扩张,深度方向上有逐渐增加趋势.不连续的高密度体俯冲至地幔转换带(410～660km)后继续水平西向俯冲,部分滞留板片可能进入下地幔;在大兴安岭断裂带下面转换带中同样发现水平分布的高密度体,推断是大兴安岭断裂带下方地幔岩石圈拆沉的结果,横向不均匀分布的俯冲板片边缘已抵至大兴安岭造山带附近,这对于研究东北地区深部动力学机制具有重要的意义.     

DEFORMATION OF THE BRITTLE-PLASTIC TRANSITION ZONE AT THE POST-SEISMIC RELAXATION PERIOD: A CASE STUDY OF THE RED RIVER FAULT

The transition from microscopic brittle deformation to microscopic plastic deformation is called brittle-plastic transition, which is considered as a key layer for determining the limit of lower continental crust seismicity. The depth and deformation mechanism of the brittle-plastic transition zone is controlled mainly by temperature. Besides, the strain rate and fluid pore pressure also affect the transition during the different deformation stages at the seismic cycle. In this paper, microstructure observation of catalcastic samples collected from the Red River Fault was carried out using optical polarized microscopy and scanning electron microscopy. The morphology, microstructures of deformation characteristics, mineral composition, water-rock reaction, pressure solution, exsolution, crack healing in the samples were systematically observed. The mineral components quantitative analyses were examined using the EDS. Water-rock reaction and pressure solution were systematically observed under SEM. The fabric of the main minerals in the samples was measured using electron backscattered diffraction(EBSD). Based on these analyses, the deformation mode was setup for the brittle-plastic transition zone of the fault during the post-seismic relaxation period. Both brittle deformation and plastic deformation were developed in the cataclastic samples. EBSD data shows that the c axial fabrics of quartz present low-temperature plastic deformation characteristics. The feldspar deformed as cataclastic rock, and the micro-fracture in feldspar was healed by static recrystallized quartz and calcite veins. The calcite vein underwent plastic deformation, which represents the post-seismic relaxation deformation. Based on the analysis of deformation mechanism of cataclastic samples in brittle-plastic transition zone of the Red River Fault, and combined with previous studies, we concluded that the brittle fracture and fracture healing is the main deformation mode at brittle-plastic transition zone in the post-seismic relaxation. High stress and high strain rate at post-seismic relaxation lead to brittle fracture of high-strength minerals such as feldspar in rocks. Plastic deformation occurs in low-strength minerals such as quartz and mica. Under the fluid condition, micro-fractures were healed by quartz and calcite. The minerals such as quartz and calcite in the fracture transformed from static recrystallization to dynamic recrystallization with stress gradually accumulating. With fracture healing and stress accumulation, the fault strength gradually increases which could accumulate energy for the next earthquake.