海底地震仪的信号传递效果和噪声水平          下载免费PDF全文

王笋  丘学林  赵明辉  李普春  刘丽华  张艺峰  谢志招 《地球物理学报》2019,62(8):3199-3207

单球式海底地震仪（以下简称OBS）由于其成本低、操作简便的优点在天然地震研究、人工地震探测中获得了广泛应用.本文首先分析多型进口和国产OBS在台湾海峡西部采集的地震数据,发现同一台OBS上的垂直向速度检波器（Z分量）的信噪比常显著低于压力检波器（H分量）,由于这两种检波器记录的都是海底的垂向振动信号,推测速度检波器的低信噪比更多的与仪器特性有关.然后从信号传递和噪声水平两方面分析影响速度检波器信噪比的因素：为检测速度检波器与OBS壳体的耦合效果,对某型宽频带OBS和陆上地震仪进行了同址同步观测试验,发现OBS的整机灵敏度有较大的差异;为分析速度检波器的水底噪声特征,以H分量记录作为基准,对比分析了同一台仪器不同站位的Z分量噪声水平,发现速度检波器在浅海区受到较大的次生干扰.本文指出OBS的内部耦合和水流次生干扰是至今尚未引起大家重视而又严重影响资料品质和多波探测成效的两个关键问题,这一研究结果对于改进OBS结构设计和制造工艺,以及OBS数据多分量处理方法研究有重要的参考意义.  相似文献   

Response of needle dark respiration of Pinus koraiensis and Pinus sylvestriformis to elevated CO_2 concentra-tions for four growing seasons’ exposure     

ZHOU YuMei  HAN ShiJie  ZHANG HaiSen  XIN LiHua & ZHENG JunQiang Institute of Applied Ecology  Chinese Academy of Sciences  Shenyang  China  Shenyang Agricultural University  Shenyang  China 《中国科学D辑(英文版)》2007,(4)

The long-term effect of elevated CO2 concentrations on needle dark respiration of two coniferous spe- cies—Pinus koraiensis and Pinus sylvestriformis on the Changbai Mountain was investigated using open-top chambers. P. koraiensis and P. sylvestriformis were exposed to 700, 500 μmol·mol-1 CO2 and ambient CO2 (approx. 350 μmol·mol-1) for four growing seasons. Needle dark respiration was meas- ured during the second, third and fourth growing seasons’ exposure to elevated CO2. The results showed that needle dark respiration rate increased for P. koraiensis and P. sylvestriformis grown at elevated CO2 concentrations during the second growing season, could be attributed to the change of carbohydrate and/or nitrogen content of needles. Needle dark respiration of P. koraiensis was stimu- lated and that of P. sylvestriformis was inhibited by elevated CO2 concentrations during the third growing season. Different response of the two tree species to elevated CO2 mainly resulted from the difference in the growth rate. Elevated CO2 concentrations inhibited needle dark respiration of both P. koraiensis and P. sylvestriformis during the fourth growing season. There was consistent trend be- tween the short-term effect and the long-term effect of elevated CO2 on needle dark respiration in P. sylvestriformis during the third growing season by changing measurement CO2 concentrations. How- ever, the short-term effect was different from the long-term effect for P. koraiensis. Response of dark respiration of P. koraiensis and P. sylvestriformis to elevated CO2 concentrations was related to the treatment time of CO2 and the stage of growth and development of plant. The change of dark respiration for the two tree species was determined by the direct effect of CO2 and long-term acclimation. The prediction of the long-term response of needle dark respiration to elevated CO2 concentration based on the short-term response is in dispute.  相似文献   

Response of needle dark respiration of Pinus koraiensis and Pinus sylvestriformis to elevated CO₂ concentrations for four growing seasons’ exposure     

Zhou YuMei  Han ShiJie  Zhang HaiSen  Xin LiHua  Zheng JunQiang 《中国科学D辑(英文版)》2007,50(4):613-619

The long-term effect of elevated CO2 concentrations on needle dark respiration of two coniferous species-Pinus koraiensis and Pinus sylvestriformis on the Changbai Mountain was investigated using open-top chambers. P. Koraiensis and P. Sylvestriformis were exposed to 700,500μmol·mol-1 CO2 and ambient CO2(approx.350 μmol·mol-1)for four growing seasons. Needle dark respiration was measurd during the second, third and fourth growing seasons' exposure to elevated CO2.The results showed that needle dark respiration rate increased for P. Koraiensis and P. Sylvestriformis grown at elevated CO2 concentrations during the second growing season, could be attributed to the change of carbohydrate and/or nitrogen content of needles. Needle dark respiration of P. Koraiensis was stimulated and that of P. Sylvestriformis was inhibited by elevated CO2 concentrations during the third growing season. Different response of the two tree species to elevated CO2 mainly resulted from the difference in the growth rate. Elevated CO2 concentrations inhibited needle dark respiration of both P. Koraiensis and P. Sylvestriformis during the fourth growing season. There was consistent trend between the short-term effect and the long-term effect of elevated CO2 on needle dark respiration in P. Sylvestriformis during the third growing season by changing measurement CO2 concentrations. However, the short-term effect was different from the long-term effect for P. Koraiensis. Response of dark respiration of P. Koraiensis and P. Sylvestriformis to elevated CO2 concentrations was related to the treatment time of CO2 and the stage of growth and development of plant. The change of dark respiration for the two tree species was determined by the direct effect of CO2 and long-term acclimation. The prediction of the long-term response of needle dark respiration to elevated CO2 concentration based on the short-term response is in dispute.  相似文献   

Estimation of reservoir and remaining oil prediction based on flow unit analysis     

Yin  TaiJu  Zhang  ChangMin  Zhang  ShangFeng  Wang  ShouPing  Mao  LiHua 《中国科学:地球科学(英文版)》2010,52(1):120-127

Through natural partition and clustering analysis, four kinds of flow units were distinguished in Pu53 block, Pucheng Oilfield. Taking the short-term cycle as studying unit, the two-dimensional distribution of each type of flow units was forecasted and the short-term cycle was classified into four types based on the two-dimensional characteristics of the flow units. The remaining oil was predicted by conceptual simulation, qualitative analysis and quantitative modeling. The results showed obvious control of the characteristics of reservoir flow units to the remaining oil. E and G units in type I and type II short-term cycles which are distributed continuously in large areas are mostly flooded, while the uncontrolled small isolated G flow unit in type III short-term cycles which were mainly made of F flow unit and F flow unit with continuous distribution become the accumulating place for remaining oil. Thus the development adjustment strategy should optimize the development of small-scale E and G units, strengthen the development of type III short-term cycles, and block out type I short-term cycles. This strategy improves the development of Pu53 block obviously.

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