渔山列岛潮间带底栖海藻生态的初步研究   总被引：7，自引：0，他引：7  

阮积惠 《海洋学研究》1994,12(4):48-57

本文根据１９８７年１１月至１９８９年５月渔山列岛（２８°５３′Ｎ，１２２°１６′Ｅ）潮间带底栖海藻调查资料，分析了该海区潮间带的海藻种类、垂直分布及生物量的季节变化规律，并将本区海藻生态特点与临近海区作了比较。  相似文献   

The Temporal Evolution of Shear wave Splitting and Geoelectrical Anisotropy During Yongdeng Earthquake     

Ruan Aiguo  Li Qinghe  Rong Dailu  Zhao Heyun 《中国地震研究》2001,15(2):134-145

Volume 15,Number 235INTRODUCTIONEddhquake PrePrecursors and study dthelr卜atures filedsignificance to eal’thqu让e prediction．heanlsotroPyPyfeature Is one dthe nPnPortant aspects dprecursors,while its study Isdbenefit totheunderstandingdthe evolutiondstressfield andtothe deterrmnatlonJthe selsmopnlc fanfaut．S、wavespitting based on the EDA model Is。e Of the most popular。thods to study the preen。cry vanatlonof stress ield before earthquake and has made gnat。hleve。ms(Crampin,e…  相似文献   

鸟类乐园——河南省罗山县董寨鸟类自然保护区     

阮祥峰 《湿地科学与管理》2000,(4):46-47

<正> 董寨鸟类自然保护区地处豫鄂两省交界的大别山北坡,罗山县最南部,总面积4.68万公顷。保护区内群山连绵起伏,地形复杂多变,地势南高北低,平均坡高15°,海拔从100米至840米,以主峰王坟顶(840米),灵山金顶(827米)为中心形成的两大山体群系构成了保护区的核心。 保护区在气候带上属暖温带向北亚热带过渡地带,具有典型的过渡性气候特征,其特点为:气候温和,雨量充沛,夏无酷署,冬无严寒。全年无霜期227天,年降水量1100—  相似文献   

Molecular cloning and characterization of a threonine/serine protein kinase lvakt from Litopenaeus vannamei     

阮灵伟  刘荣雕  徐洵  施泓 《中国海洋湖沼学报》2014,32(4):792-798

  相似文献   

基于自适应阈值的云团识别与追踪方法及个例试验   总被引：2，自引：0，他引：2  

蔡叔梅  阮征  陈钟荣 《气象科技》2011,39(3):332-338

利用FY-2系列静止气象卫星的IR1通道资料,开展对快速发展云团的识别与追踪研究.通过建立自适应亮温阈值的云团识别方法,获取云团的发生、发展、消亡的完整生命过程;基于两个连续红外图像的面积重叠法,处理云团追踪过程中的分裂和合并现象;提取有关云团的温度阈值、面积大小、移动速度、亮度温度、温度梯度等特征量,为开展云团演变的...  相似文献   

汶川8.0级地震前区域应力场动态研究   总被引：1，自引：0，他引：1  

程万正  张永久  阮祥  乔慧珍  张致伟 《中国地震》2011,27(3):215-225

利用成都、昆明遥测数字地震波形记录资料,研究大量小震震源机制解和视应力值,分析了区域应力场动态和视应力值的时-空分布.给出川青地块平均应力场方位的时间变化.川青地块平均主应力场的方位在汶川8.0级地震前出现明显扰动,同时,地块力轴张量的倾角变化也很明显.得出2006～2007年川青块体逆冲型地震比例偏高,汶川8.0级地震前区域中小地震震源错动类型发生变化的结果,与区域地形变的分析结果是一致的.根据地震波形全波段计算辐射能量,求得的视应力σapp值揭示区域视应力值的微动态起伏过程与区域主压应力场方位的转折类似,可用于地块蕴震物理过程的探索.从汶川8.0级地震前的中短期视应力σapp值的空间分布看,震中所在的龙门山断裂带是低应力分布区,而相对高视应力则分布在外围地区.这些图像可能揭示了汶川8.0级地震前中短期发震构造附近呈现的闭锁现象.  相似文献   

Selection of emergency shelter sites for seismic disasters in mountainous regions: Lessons from the 2008 Wenchuan Ms 8.0 Earthquake,China     

Qiang Liu  Xuejing Ruan  Pilong Shi 《Journal of Asian Earth Sciences》2011,40(4):926-934

In this paper, we use the 12 May 2008 Wenchuan Earthquake as a background event for analyzing and applying the principles of site selection of emergency shelters for a disastrous earthquake. Based on field investigations and analyses of remote sensing imagery, we identified the distribution of active faults and the locations of co-seismic surface rupture zones—areas in which buildings are at risk of intensive damage. It is important that emergency shelters are located outside of such vulnerable areas. One of the lessons learned from the Wenchuan Earthquake is that high fatality rates occur in areas without life-saving shelters. The principles that underlie the selection of emergency shelter sites are as follows: (1) keep far away from active fault zones, with the distance depending on the characteristics of the fault, including the nature of hangingwall and footwall structures; (2) disaster-mitigation strategies should be developed as a multi-dimensional system for the management of natural hazards, human activities, and urban expansion, involving keeping away from vulnerable slopes and establishing an early-warning system; (3) the accessibility of mountainous regions must be considered, including establishing small emergency shelters that house large numbers of people and covering regions with an uneven distribution of villages; and (4) government and law-making agencies in China must establish new earthquake design codes for buildings, emphasizing the importance of public facilities (including schools, collective welfare institutions, and medical facilities) as emergency shelters during disastrous earthquakes. The site-selection process requires an interdisciplinary approach involving seismologists, engineers, environmental and social scientists, emergency management personnel, and government officials. The parameters upon which the above principles are based can be qualitatively determined, thereby providing a valuable initial database for further quantitative analysis. The preliminary results and knowledge gained in the present paper can be used as a decision-making tool to support the government in earthquake-recovery and reconstruction programs. We also discuss practical examples of site evaluation in regions that suffered heavy damage during the Wenchuan Earthquake.  相似文献   

Biocarbonation of reactive magnesia for soil improvement     

Yang  Yang  Ruan  Shaoqin  Wu  Shifan  Chu  Jian  Unluer  Cise  Liu  Hanlong  Cheng  Liang 《Acta Geotechnica》2021,16(4):1113-1125

Acta Geotechnica - This paper presents a new microbial technique for soil improvement through microbially induced carbonate precipitation (MICP) incorporating with reactive magnesia cement (RMC)....  相似文献   

LA-ICP-MS U-Pb zircon geochronology and Hf isotope,geochemistry and kinetics of the Daxigou anorthosite from Kuruqtagh block,NW China     

Qian Yuan  Xiaofeng Cao  Xinbiao Lü  Xiangdong Wang  Enlin Yang  Yuegao Liu  Banxiao Ruan  Hong Liu  Mohammed Abdalla Adama Munir 《中国地球化学学报》2014,33(3):207-220

Kuruqtagh block is the best area for Precambrian geology in Xinjiang Autonomous Region, NW China, since it exposed complete Precambrian lithology units. The study of this ancient base will deepen the understanding of the Precambrian evolution of the Tarim Basin. In this paper, we studied the petrology, geochemistry, zircon LA-ICPMS U-Pb chronology and zircon Hf isotope of Daxigou anorthosite （DA） which is located at the northem margin of Tarim craton and discussed the rock formation, tectonic and geological significance. Zircons from the intrusions display oscillatory zoning and high Th/U ratios （0.39-1.35）, implying their magmatic origin. Zircon LA-ICP-MS U-Pb dating results indicate that they formed during the Paleoproterozoic age with the weighted 2~6pb/238U average age of 1818~9 Ma, which is significantly different from former＇s Neoproterozoic age, and is co- incidentally identical with its associated syenite granite age within the error range. Studies on petrogeochemistry suggest that DA belongs to medium-sodium peraluminous alkaline type, rich in Pb, La, Th and LILE, and poor in HFSE （Gd, Nd, and Ta）. The chondrite-normalized REE pattern is slightly to the right form. The average Y~REE is 317.2~ 10-6; HREE show moderate fractionation [average LREE/HREE is 14.71, average （La/Yb）N is 24.77; average （LaJSm）N is 3.85, and average （Gd/Yb）y is 3.46]; and the 6Eu and 8Ce are not obvious. Their initial Hf isotope ratios and Hf two-stage model ages range from -6.6 to -4.43 and 2.63 to 2.74 Ga, respectively. Taken together, it is sug- gested that Daxigou anorthosite is a typical volcanic anorthosite and its primary magma could be contaminated by the partial melt Neoarchaean crust and mainly formed in the arc environment, which recoded the tectonic-magma activities response of the Tarim refers to the amalgamation of the supercontinent Columbia.  相似文献   

Seismic stability for landfills with a triangular berm using pseudo-static limit equilibrium method     

S. L. Sun  X. B. Ruan 《Environmental Earth Sciences》2013,68(5):1465-1473

This paper extends a previously developed three-part wedge method for the seismic stability analysis of the landfill with a triangular berm using pseudo-static method, and moreover, the translation failure condition of the landfill along under bottom of the berm is only presented. In the seismic impact zone, it is necessary to consider the impact of the seismic force on the stability of the landfill. Generally, apart from the horizontal seismic force, the landfill is also subjected to both upward and downward vertical seismic forces. The downward vertical seismic force has a positive impact on the seismic stability of the landfill, while the upward vertical seismic force is just opposite. Therefore, simply ignoring vertical seismic force, the seismic stability of the landfill will be overestimated or underestimated in the seismic condition. Besides, the seismic yield coefficient is calculated by assuming FS_V = 2FS and the ratio of vertical seismic coefficient to horizontal seismic coefficient is equal to 2/3.  相似文献