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61.
地震模拟振动台振动对建筑物中人体的舒适感的影响分析   总被引:1,自引:0,他引:1  
本文给出了一种地震模拟振劝台振运对建筑物中人体的舒适感影响的分析方法,并结合实例进行了具体分析。文中给出的分析方法和实例计算结果对于地震馆的设计有一定参考价值。  相似文献   
62.
本文以大量的实测资料为依据,总结了岩矿石电磁频散的规律性。结合电磁波勘探方法中的实际问题,讨论了频散对相位常数α和吸收系数β所产生的影响及误差。提出了在实际工作中对频散进行校正的必要性,并且给出了校正公式。  相似文献   
63.
本文对用负阻抗变换电路同小圆锥螺旋天线相结合,构成的有源接收天线进行了理论分析,并给出了该有源天线稳定工作的条件。结果表明,用该方法设计的有源接收天线具有较宽的频带、较高的灵敏度和较小的尺寸。是多频电磁波测井较理想的接收天线。  相似文献   
64.
九甸峡工程区断层测年结果研究与讨论   总被引:2,自引:0,他引:2  
断层的年代测定是研究断层活动性的重要内容之一。然而, 一个工程同一条断层会出现不同的测年结果, 从而引起争议和难予决断。近年来我们通过几个大型工程区域稳定性研究, 对此获得了一些认识。本文以洮河九甸峡地区几条主干断层为研究对象, 采用同位素年龄测定与野外地质调查和显微构造分析相结合的方法, 对断层测年问题作一分析和讨论, 也许对岩土工程断层活动性研究有一定参考价值。  相似文献   
65.
形成岩溶的高阻碳酸盐岩对电磁波的吸收较弱,而且成层沉积的特定环境使碳酸盐岩地区岩石的各向异性现象较明显,由于地空界面的存在及岩溶洞壁两侧介质电性差异明显,界面清晰,又使电磁波出现强烈的反射及散射现象,从理论上对碳酸盐岩地区电磁波传播的特有现象进行了研究和分析,并给出结论。  相似文献   
66.
W. Cai  P. C. Chu 《Annales Geophysicae》1997,15(8):1067-1075
The study demonstrates that an incompatibility between a surface temperature climatology and a given ocean model, into which the climatology is assimilated via Haney restoration, can cause model ocean climate drift and interdecadal oscillations when the ocean is switched to a weaker restoration. This is made using an idealized Atlantic Ocean model driven by thermal and wind forcing only. Initially, the temperature climatology is forcefully assimilated into the model, and an implied heat flux field is diagnosed. During this stage any incompatibility is suppressed. The restoring boundary condition is then switched to a new forcing consisting of a part of the diagnosed flux and a part of the restoring forcing in such a way that at the moment of the switching the heat flux is identical to that prior to the switching. Under this new forcing condition, the incompatibility becomes manifest, causing changes in convection patterns, and producing drift and interdecadal oscillations. The mechanisms are described.  相似文献   
67.
Three third-order sequences and about one hundred high-frequency cycles or Milankovitchcycles within the Late Permian Changxingian to Early Triassic Griesbachian are identified in theMeishan Section of Changxing, Zhejiang Province, southern China, the candidate stratotype sec-tion of the global Permo-Triassic boundary, based on a detailed study of the biological,ecological and high-resolution allochthonous cyclic events, microfacies and depositional systems.Furthermore, the stacking pattern of the depositional systems across various Changxingian andGriesbachian sedimentary facies of the Lower Yangtze and the sequence stratigraphic frameworkare outlined with the Meishan section as the principal section. In this paper the habitat types offossil biota are applied to semiquantitative palaeobathymetry and the study of relative sea levelchanges.  相似文献   
68.
地史转折期的生态系   总被引:7,自引:2,他引:7  
生态系的演变是地球各圈层系统耦合关系变化的直接标志。地史转折期的生态系具有复杂的生物内涵,在绝灭—残存—复苏过程中,各生物类别的演替遵循着一定的生存型式。大绝灭后生态系复苏的原动力是绝灭后迁入避难所的复活类型和大绝灭末期高压环境中产生的祖先类型的新生和辐射发展。全面了解绝灭后生态系的组成和结构,对于正确认识地史转折期,即圈层耦合结点处的地质作用型式和过程具有重要作用。  相似文献   
69.
The comprehensive observations on lightning discharges were conducted in Naqu area of Qinghai-Tibet Plateau in summer of 2002. The electric structures of thunderstorms and the characteristics of lightning discharges at initial stage were analyzed by using the observation data. The results show that most of intracloud (IC) lightning flashes were polarities inverted in thunderstorms with tripole electric charge structure and occurred between negative charge region located in the middle of the thunderstorm and positive charge region located at the bottom of the thunderstorm. The radiation characteristics of discharge processes in cloud with longer lasting time involved in Cloud-to-Ground (CG) lightning flashes were similar to that of IC discharges.A lot of radiation pulses were produced in these discharge processes. Because the IC discharges took place at the bottom of thundercloud and were near the ground, they may produce more serious damage to equipment on the ground therefore should not be neglected in lightning protection.  相似文献   
70.
The comprehensive observations on lightning discharges were conducted in Naqu area of Qinghai-Tibet Plateau in summer of 2002. The electric structures of thunderstorms and the characteristics of lightning discharges at initial stage were analyzed by using the observation data. The results show that most of intracloud (IC) lightning flashes were polarities inverted in thunderstorms with tripole electric charge structure and occurred between negative charge region located in the middle of the thunderstorm and positive charge region located at the bottom of the thunderstorm. The radiation characteristics of discharge processes in cloud with longer lasting time involved in Cloud-to-Ground (CG) lightning flashes were similar to that of IC discharges. A lot of radiation pulses were produced in these discharge processes. Because the IC discharges took place at the bottom of thundercloud and were near the ground, they may produce more serious damage to equipment on the ground therefore should not be neglected in lightning protection.  相似文献   
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