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51.
山西高河井田属海河水系长治盆地水文区,主要河流为纵贯全区的浊漳河,自西南流入区内。勘探区内地形地质条件复杂,河流及河漫滩面积大,为克服三维地震勘探存在的诸如检波线的铺设、检波器藕合、激发层位选择等难题,主要采取了陆上检波器挖坑埋置(黄土地段坑深20cm,沙滩地段坑深40cm)、水上检波器用木桩固定等措施,并采用陆上井中放炮、砾石层坑炮、河水中水下放炮相结合的激发方式。为防止井喷和声波产生的高频随机干扰,采取浅井井口压沙袋技术。通过处理解释,获得了较为精确的断层、陷落柱等地质信息,为矿方安全生产提供了可靠的地质保障。  相似文献   
52.
The Fast Imaging Solar Spectrograph (FISS) is being operated on the New Solar Telescope of the Big Bear Solar Observatory. It simultaneously records spectra of Hα and Ca ii 8542 Å lines, and this dual-spectra measurement provides an estimate of the temperature and nonthermal speed components. We observed a loop structure in AR 11305 using the FISS, SDO/AIA, and STEREO/EUVI in 304 Å, and found plasma material falling along the loop from a coronal height into the umbra of a sunspot, which accelerated up to 80 km?s?1. We also observed C2 and C7 flare events near the loop. The temperature of the downflows was in the range of 10?000?–?33?000 K, increasing toward the umbra. The temperature of the flow varied with time, and the temperature near the footpoint rose immediately after the C7 flare, but the temperature toward the umbra remained the same. There seemed to be a temporal correlation between the amount of downflow material and the observed C-class flares. The downflows decreased gradually soon after the flares and then increased after a few hours. These high-speed red-shift events occurred continuously during the observations. The flows observed on-disk in Hα and Ca ii 8542 Å appeared as fragmented, fuzzy condensed material falling from the coronal heights when seen off-limb with STEREO/EUVI at 304 Å. Based on these observations, we propose that these flows were an on-disk signature of coronal rain.  相似文献   
53.
The X-ray spectrum of an accretion disc around a black hole is obtained under the modified -viscosity law. Both electron scattering opacity and free-free absorption opacity are taken into account in our calculation. We also find that the requirement of a geometrically-thin disc forces a limit on the accretion rateM<0.25M cr (i.e.,L<0.25L edd). Several previous disc calculations violate this limit and their results are questionable.  相似文献   
54.
It is possible that the Finsler space-timeF( x, y ) may be endowed with a catastrophic nature. In particular, the horizon of the field of the general relativity is just a catastrophic set. If so, a particle with the super-luminal speeds could be projected near the horizon of these fields, and the particle will move on the space-like curves. It is very interesting that, in the Schwarzschild fields, the theoretical calculation as the space-like curves should be in agreement with the data of the superluminal expansion of extragalactic radio sources observed year after year.The project has been supported by the National Natural Science Foundation of China.  相似文献   
55.
首次对采自青岛即墨WN部两个深钻孔中新鲜玄武岩样品进行Rb-Sr同位素测年,测定年龄值为65.77±13.6Ma。认为该年龄值代表了胶莱盆地东南缘基性火山熔岩喷发的时代上限,对于整个胶莱盆地中基性火山岩的划分和对比具重要的年代学意义。  相似文献   
56.
坛紫菜中藻胆蛋白的性质与化学组成研究   总被引:10,自引:1,他引:10       下载免费PDF全文
坛紫菜(于1988年采自青岛太平角海区人工养殖筏上)的水溶性色素粗提物经过硫酸铵沉淀和羟基磷灰石(HA)柱层析后,分离出藻蓝蛋白(RPC)、藻红蛋白(RPE)和变藻蓝蛋白(APC)。在中性介质中,其吸收光谱和荧光发射光谱与文献报道基本一致;但在酸性(pH=3)或碱性(pH=12)介质中,吸收光谱较在中性介质中有明显改变,原有的荧光性质也消失。RPC和APC只分离到一种聚集体,但RPE有两种不同的聚集体。用SephadexG—100凝胶过滤方法测量藻胆蛋白的分子量分别为:RPC117000,APC112000,小分子RPE38000,大分子RPE232000。对三种藻胆蛋白的氨基酸分析的结果表明,三种藻胆蛋白中都是酸性氨基酸的含量大于碱性氨基酸的含量。  相似文献   
57.
本文是作者结合核电海域工程设计任务的体会,将ISO9000 系列标准与核安全法规(HAF0400)在工程中相结合,建立一个既符合ISO9000 标准又能满足法规要求的质量保证体系。  相似文献   
58.
本研究采取苗种强化培育、坑道培育大规格苗种、湖间带鲍参混养等相结合,并配套适当技术措施,促进鲍快速生长,缩短养殖周期一年左右,提高成活率15%以上,增加经济效益200%左右,形成鲍高效养殖的较理想模式。  相似文献   
59.
Although thin on the order of several to tens of millimeters, sheet flows normally comprise a lower pick-up sub-layer and an upper contact-load sub-layer, separated at the bed level (z = 0). The time-averaged concentration profile in the pick-up sub-layer shows a ‘convex upward’ curvature, but ‘concave upward’ shape characterizes the time-averaged concentration profile in the contact-load sub-layer. The time-dependent concentration in the contact-load sub-layer is approximately in-phase with the free stream flow velocity, whereas it is nearly in anti-phase with the free stream flow velocity in the pick-up sub-layer. Two distinct analytical expressions of the time-averaged concentration profiles for the respective sub-layers are proposed. The expressions are validated with detailed observation datasets collected in the Groβer Wellenkanal (GWK) prototype wave flume in Hannover, Germany. The agreement between the predicted and the measured values is excellent. Interparticle collisions in the pick-up sub-layer and convective lifting processes associated with vortex shedding in the contact-load sub-layer are considered responsible for the opposite curvatures and in-phase/anti-phase concentration variations. Both transitional boundary and reference concentration are also elaborated.  相似文献   
60.
Changes of subaqueous topography in shallow offshore water pose safety risks for embankments,navigation,and ports.This study conducted measurements of subaqueous topography between Datong and Xuliujing in the Yangtze River using a Sea Bat 7125 multi-beam echo sounder,and the channel change from 1998 to 2013 was calculated using historical bathymetry data.The study revealed several important results:(1)the overall pattern of changes through the studied stretch of the river was erosion–deposition–erosion.Erosion with a volume 700×10~6m~3occurred in the upper reach,deposition of about 204×10~6m~3occurred in the middle reach,and erosion of about 602×10~6m~3occurred in the lower reach.(2)Dunes are the most common microtopographic feature,accounting for 64.3%of the Datong to Xuliujing reach,followed by erosional topography and flat river topography,accounting for 27.6%and 6.6%,respectively.(3)Human activities have a direct impact on the development of the microtopography.For instance,the mining of sand formed holes on the surface of dunes with lengths of 20–35 m and depths of 3–5 m.We concluded that the overall trend of erosion(net erosion volume of 468×10~6m~3)occurred in the study area mainly because of the decreased sediment discharge following the closure of the Three Gorges Dam.However,other human activities were also impact factors of topographic change.Use of embankments and channel management reduced channel width,restricted river meandering,and exacerbated the erosion phenomenon.  相似文献   
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