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Yan Taiming Hu Jiaxiang Cai Yueping Xiong Sen Yang Shiyong Wang Xiongyan He Zhi 《中国海洋湖沼学报》2017,35(5):1197-1204
Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was verifi ed by monitoring larvae and juveniles of knownage.The results revealed that lapilli and sagittae developed before hatching,and the first otolith increment was identified at 2 days post hatching in both.The shape of lapilli was relatively stable during development compared with that of sagittae;however,growth of four sagittae and lapilli areas was consistent,but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface.Similarly,the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length,respectively.Moreover,daily deposition rates were validated by monitoring knownage larvae and juveniles.The increase in lapilli width was 1.88±0.080 0μm at the ninth increment,which reached a maximum and the decreased gradually toward the otolith edge,whereas that of sagittae increased more slowly.These results illustrate the developmental biology of S.davidi,which will aid in population conservation and fish stock management. 相似文献
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碳酸盐岩储层孔隙结构的影响因素与储层参数的定量评价 总被引：1，自引：0，他引：1
近几年,在海外区块遇到了大量的孔隙型碳酸盐岩储层。由于岩性复杂,孔隙类型多样,致使其孔隙结构十分复杂,储层参数难以准确计算,油气储量难以客观评价。文中针对研究靶区这一类型的碳酸盐岩储层,首先从沉积作用和成岩作用两个方面分析了孔隙结构的影响因素,得出在不同岩性之间,孔隙类型之间的差异是造成孔隙结构存在较大差异的主要原因。而在同种岩性之间,泥质含量的增加会降低孔隙结构的品质。另外,成岩作用对颗粒粒径较大的岩石的影响更大一些。其次,讨论了储层参数的定量评价,由于不同类型孔隙的共存,导致孔隙度相似,而渗透率、饱和度等储层参数却存在较大差异。针对这一问题,指出了可以采用核磁和成像等特殊测井资料来表征不同类型孔隙的数值分布,利用三维数字化成像技术来展示不同类型孔隙的空间分布,为储层参数的准确计算和油气储量的客观评价奠定基础。 相似文献
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Based on the seismic response characteristics of space frame structures,a new type of seismic isolation bearing defined as a three-dimensional seismic isolation bearing(3DSIB) is developed in this paper.The bearing offers excellent properties such as multi-dimensional seismic isolation,reasonable rotation capability,good ability to resist lifting load,uncoupled stiffness in horizontal and vertical directions,etc.In the 3DSIB,the horizontal dimension is designed by combining the Teflon sliding device and helical spring,while the vertical dimension is developed by introducing disk springs or helical springs.The mathematical model of the 3DSIB was established and its performance with the critical parameters was tested on a shaking table.Furthermore,the 3DSIB was applied in a 120 m span hangar structure and simulated using SAP2000 software to evaluate its performance in practical structures.The performance of the structures with and without 3DSIB was compared.It is shown that the hangar structure with 3D bearings achieves a better performance.The axial force and acceleration response of the structures with 3DSIB are effectively reduced,while the displacement response of the bearing is within the predetermined range. 相似文献
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The Annular Crossed Cable-Truss Structure (ACCTS) is a new type of Tensile Spatial Structure with a configuration suitable to cover large-span stadiums. Its configuration has potential to perform well in resisting disproportionate collapse. However, its disproportionate collapse resistance hasn’t yet been analyzed in depth. In this study, numerical and experimental research was carried out to investigate the performance of ACCTS under cable rupture. The numerical analysis was done for ten cable-rupture plans using LS-DYNA (explicit method) and the experimental test on an ACCTS with a diameter of 17.15 m was performed for three cable-rupture plans. It is concluded that, while deflections increase with the number of removed cables, an ACCTS does not undergo a disproportionate collapse and it provides a promising structural concept for tensile spatial structures. 相似文献
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摩擦-碟簧三维复合隔震支座的性能试验研究 总被引：2，自引：0，他引：2
对适用于大跨结构的摩擦-碟簧三维复合隔震支座进行了振动台试验研究,该支座在水平向和竖向分别采用摩擦滑移装置和碟型弹簧隔震。在水平向,试验重点测试了简谐激励和地震动激励下支座的滞回性能,考察了竖向荷载变化及地震动强度对隔震性能的影响,以期为建立水平隔震理论模型提供依据;在竖向,对碟型弹簧的等效阻尼比和等效刚度进行了测试,研究了竖向预压荷载和动力荷载对竖向滞回性能的影响。结果表明,复合隔震支座在水平向和竖向均具有较好的滞回性能,竖向等效阻尼比在0.10～0.15间,且随着预压荷载的增加而增大。 相似文献
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Suduo Xue Mingyue Shan Xiongyan Li Shuanzhu Liang Fuyun Huang Yi Liu 《地震工程与工程振动(英文版)》2019,18(3):611-630
In order to study the influence of the ground motion spatial effect on the seismic response of large span spatial structures with isolation bearings, a single-layer cylindrical latticed shell scale model with a similarity ratio of 1/10 was constructed. An earthquake simulation shaking table test on the response under multiple-support excitations was performed with the high-position seismic isolation method using high damping rubber(HDR) bearings. Small-amplitude sinusoidal waves and seismic wave records with various spectral characteristics were applied to the model. The dynamic characteristics of the model and the seismic isolation effect on it were analyzed at varying apparent wave velocities, namely infinitely great, 1000 m/s, 500 m/s and 250 m/s. Besides, numerical simulations were carried out by Matlab software. According to the comparison results, the numerical results agreed well with the experimental data. Moreover, the results showed that the latticed shell roof exhibited a translational motion as a rigid body after the installation of the HDR bearings with a much lower natural frequency, higher damping ratio and only 1/2～1/8 of the acceleration response peak values. Meanwhile, the structural responses and the bearing deformations at the output end of the seismic waves were greatly increased under multiple-support excitations. 相似文献
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依据自回归(AR)法,确立了考虑风速时程空间相关性的模拟方法,并利用Matlab语言编制了相应的程序。基于上述方法,模拟了某体育场挑篷结构的风速时程,并对所得风速时程离散值进行数理统计分析,结果表明模拟谱与目标谱吻合较好。根据结构风振响应分析的需要,将模拟风速转变为风荷载对结构进行时程分析,获得了结构风振响应,为结构抗风设计提供依据。计算表明,基于风速时程的结构风振响应分析方法可有效分析体育场挑篷的风振响应。 相似文献
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Control devices incorporated with shape memory alloy 总被引：2，自引：1，他引：1
Shape Memory Alloy (SMA) is a type of material that offers some unique characteristics for use in devices for vibration control applications. Based on SMA's material properties, four types of control devices that incorporate NiTi SMA wires are introduced in this paper, which include three types of dampers (SMA damper, SMA-MR damper and SMA-friction damper) and one kind of isolation bearing (SMA-rubber bearing). Mechanical models of these devices and their experimental verifications are presented. To investigate the control performance of these devices, the SMA-MR damper and SMA-rubber bearing are applied to structures. The results show that the control devices could be effective in reducing the seismic response of structures. 相似文献
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