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881.
882.
地电故障数据处理系统软件研制的目的在于当地电仪器出现故障,无法采集到仪器内存中原始数据时,能根据地电纸带上仅有的一些原始数据,利用该系统可以准确、快速、方面地转换成特定格式的数据文件,及时上报至中国地震局。该系统的开发,将会减轻台站工作人员的负担,杜绝了数据格式的不正解性,防止了数据迟报现象的发生。 相似文献
883.
Based on the atmospheric circulation data provided by ECMWF and the sea surface temperature data by NOAA, we studied the mechanism for the impact of sea surface temperature anomaly on the ridgeline surface of western Pacific using an improved high truncated spectral model. Our results show that the wave-wave interaction and the wave-mean flow interactions are weaker in the inner dynamic process of atmospheric circulation, when atmospheric circulation is forced by the sea surface temperature of El Niño pattern. With the external thermal forcing changed from winter to summer pattern, the range of ridgeline surface of western Pacific moving northward is smaller, which causes the ridgeline surface of western Pacific on south of normal. On the contrary, the wave-wave interaction and the wave-mean flow interaction are stronger, when atmospheric circulation is forced by the sea surface temperature of La Niña pattern. With the external thermal forcing turning from winter to summer pattern, the ridgeline surface of western Pacific shifts northward about 19 latitude degrees, which conduces the ridgeline surface of western Pacific on north of normal. After moving to certain latitude, the ridgeline surface of western Pacific oscillates with the most obvious 30–60 d period and the 4°–7° amplitude. It is one of the important reasons for the interannual variation of ridgeline surface of Western Pacific that the atmospheric inner dynamical process forced out by different sea surface temperature anomaly pattern is different. 相似文献
884.
Liquefaction macrophenomena in the great Wenchuan earthquake 总被引:3,自引:2,他引:1
Longwei Chen Xiaoming Yuan Zhenzhong Cao Longqing Hou Rui Sun Lin Dong Weiming Wang Fanchao Meng Hongjuan Chen 《地震工程与工程振动(英文版)》2009,8(2):219-229
On May 12, 2008 at 14:28, a catastrophic magnitude M 8.0 earthquake struck the Sichuan Province of China.The epicenter was located at Wenchuan (31.00°N, 103.40°E). Liquefaction macrophenomena and corresponding destruction was observed throughout a vast area of 500 km long and 200 km wide following the earthquake. This paper illustrates the geographic distribution of the liquefaction and the relationship between liquefaction behavior and seismic intensity, and summarizes the liquefaction macrophenomena, including sandboils and waterspouts, ground subsidence, ground fissures etc., and relevant liquefaction features. A brief summary of the structural damage caused by liquefaction is presented and discussed. Based on comparisons with liquefaction phenomena observed in the 1976 Tangshan and 1975 Haicheng earthquakes, preliminary analyses were performed, which revealed some new features of liquefaction behavior and associated issues arising from this event. The site investigation indicated that the spatial non-uniformity of liquefaction distribution was obvious and most of the liquefied sites were located in regions of seismic intensity Ⅷ. However, liquefaction phenomena at ten different sites in regions of seismic intensity Ⅵ were also observed for the first time in China mainland. Sandboils and waterspouts ranged from centimeters to tens of meters, with most between 1 m to 3 m. Dramatically high water/sand ejections,e.g., more than 10 m, were observed at four different sites. The sand ejections included silty sand, fine sand, medium sand,course sand and gravel, but the ejected sand amount was less than that in the 1976 Tangshan earthquake. Possible liquefaction of natural gravel soils was observed for the first time in China mainland. 相似文献
885.
The Pearl River Estuary (PRE) in South China's Guangdong Province is a subtropical estuary with highly irregular topography
and dynamically complicated circulations. A nested-grid coastal circulation modelling system is used in this study to examine
dynamic responses of the PRE to tides, meteorological forcing and buoyancy forcing. The nested-grid modelling system is based
on the Princeton Ocean Model and consists of three downscaling subcomponents: including an outer-most model with a coarse
horizontal resolution of ~7 km for simulating tidally forced and wind-driven surface elevations and depth-mean currents over
the China Seas from Bohai Sea to the northern South China Sea and an innermost model with a fine resolution of ~1.2 km for
simulating the 3D coastal circulation and hydrography over the PRE and adjacent coastal waters. Model results during the winter
northeast monsoon surge in January and super typhoon Koryn in June of 1993 are used to demonstrate that the 3D coastal circulation
and hydrographic distributions in the PRE are affected by tides, winds and buoyancy forcing associated with river discharge
from the Pearl River with significant seasonal and synoptic variabilities. 相似文献
886.
Structural vibration passive control and economic analysis of a high-rise building in Beijing 总被引:1,自引:0,他引:1
Performance analysis of the Pangu Plaza under earthquake and wind loads is described in this paper.The plaza is a 39-story steel high-rise building,191 m high,located in Beijing close to the 2008 Olympic main stadium.It has both fluid viscous dampers(FVDs) and buckling restrained braces or unbonded brace(BRB or UBB) installed.A repeated iteration procedure in its design and analysis was adopted for optimization.Results from the seismic response analysis in the horizontal and vertical directions show that th... 相似文献
887.
Ling Gao Ying Wang Jia Hui Xu Yang Xu Yi Cao Zhi Yu Yun Chao Hong Jian Hua Zhu 《洁净——土壤、空气、水》2009,37(1):31-38
In order to protect the environment and public health, microwave irradiation was investigated as a means of reducing the nitrosamines level of tobacco smoke under mild conditions where the microwave energy was 1 kW and the irradiation time was shorter than 2 min. The microwave‐induced elimination of nitrosamines such as N‐nitrosopyrrolidine (NPYR) and N‐nitrosodiphenylamine (NDPA) was investigated and the impact of the presence of water and salt in the medium on the reduction was assessed in detail. The existence of water in the medium was crucial for the microwave‐induced reduction of NDPA, because the rapid movement of water molecules under the influence of microwaves strongly affects the adjacent nitrosamines leading to their decomposition. This was the first time that microwaves have been used to directly irradiate cigarettes sealed in their packaging, and the nitrosamines content of tobacco and smoke of these irradiated cigarettes were analyzed with care. Irradiation for 90 s with microwave energy of 1kW was seen to reduce 25 to 30% of the nitrosamines in tobacco and 50 to 60% of the levels present in the mainstream smoke of the cigarette. Moreover, lower mutagenic activity and higher CHO cell livability were found for the irradiated cigarettes in comparison with the control according to the results of in vitro tests. 相似文献
888.
贵州喀斯特农业生产中多种矿物元素液态肥的应用效果分析 总被引:1,自引:0,他引:1
为改变贵州喀斯特地区农产品产出率低、品质差的现状,从喀斯特生态地质环境脆弱、土壤缺少微量元素等特征入手,利用富含矿物元素的硅酸盐岩,开发生产多元素液态矿物肥料,补偿喀斯特地区农作物生长需要的矿物营养元素。2002年以来经100多个农户及贵州省各地土肥站、农业科研生产部门在贵州喀斯特地区十几个县市进行了700多亩种植试验,获得了农作物产量增加和农产品质量提高的效果。施用多元素液态矿物肥种植的水稻、玉米、辣椒、油菜、烤烟、水果及蔬菜等20多个农作物,其90%以上的作物增产超过5%,70%增产超过10%,农产品的蛋白质提高1~2个百分点,稻谷支链淀粉提高2.7%,果实的外观色、香、味、形得到明显改观。实践证明施用多元素液态矿物肥料是提高喀斯特地区农产品产出率的新途径。 相似文献
889.
近8ka东亚冬季风变化的东海内陆架泥质沉积记录 总被引:21,自引:2,他引:19
尝试从陆架上寻找全新世高分辨率的东亚季风替代性指标和记录.通过对位于东海内陆架闽浙沿岸泥中部的PC-6孔进行AMS14C年龄测试和粒度分析, 综合沉积构造、沉积层序与海平面变化讨论该孔的沉积环境, 其下、中、上段分别对应于前滨、近滨和与现今环境基本一致的浅海沉积环境.因上段的沉积作用主要受控于东海冬季沿岸流, 通过粒级-标准偏差分析, 提取了相对应的粒度组分或粒度子体, 该组分的平均粒径被用来作为研究东亚冬季风演化的替代性指标.分析表明, 由此方法建立的PC-6孔上段粒径时间序列, 较完整地反映了近8ka来东亚古季风的演化.东亚冬季风的变化呈现出3个各具特点的阶段7.6~5.1kaB.P.为中等强度的高频率波动; 5.1~1.7kaB.P.以多期、较频繁的强盛活动为特点; 1.7~0kaB.P.为稳定而较弱的时期.由PC-6孔指示的东亚冬季风活动的强盛期, 均在不同区域和材料的记录中找到了相对应降温的证据, 说明气候变化的区域性以至全球性联系. 相似文献
890.
垃圾土力学性质的室内试验研究 总被引:13,自引:0,他引:13
对室内配制的不同成份的垃圾土分别进行了固结不排水和固结排水三轴压缩试验。结果表明,垃圾土的本构关系基本符合邓肯-张双曲线模型。垃圾土中有机质及土粒的含量是影响垃圾土强度参数c,φ值的重要因素。对于有机质含量较高而土粒含量较低的垃圾土,c宜取低值,φ宜取高值。给出了c,φ值的取值范围及其变化规律。随着时间的变化,c值会有所增加,而φ值会有所降低。观察到垃圾土的轴向应变超过30 %而其主应力差仍然在增长。垃圾土在固结过程中,存在滞留孔隙水压力,其渗透系数k值的变化与应力、时间、垃圾土的成分等因素有关。在固结排水三轴压缩试验的剪切过程中,孔隙水压力会随轴向应力的增加而增加,试验所得到的总应力强度参数并不就是有效应力强度参数。 相似文献