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1988年3月18日,太原市地震局召开地震暨抗震工作会议.会上总结了经验,分析了震情,研究了防震抗震措施,表彰了先进.来自全市9个区(县)和14个大型厂矿的80余名代表参加了会议.市政府、省地震局的领导及有关部门的负责同志出席了会议并讲了话. 相似文献
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考虑刚度及边界条件的短索索力求解与试验研究 总被引:1,自引:1,他引:0
建立了一个非齐次边界拉索力学模型,基于拉索线性振动理论,推导了考虑拉索抗弯刚度及边界条件的拉索频率方程;根据双曲函数的数理特性对频率方程进行了合理简化,得到了实用的频率简化方程,提出了逆过程求解索力的方法和步骤,并探讨了不同支承刚度对索力的影响。设计了室内拉索试验模型并进行了27种工况索力试验,比较了不同工况下的计算索力与实际索力,验证了本文提出的频率简化方程和逆过程求解方法的实用可靠性。 相似文献
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综述了地震综合观测与综合分析预报的工作概况,首先对日、苏、美、中等四国的这方面状况进行了回顾,并列表作了比较,继而论述了地震预报的探索与实用化问题,文章最后作了某些分析并提出了今后的展望。 相似文献
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基于地震易损性的框架结构的优化方法 总被引:1,自引:0,他引:1
给出了一种框架结构地震易损性优化的准则算法.根据优化准则构造了一种修改设计变量的格式,提出了设计方案可行性调整的方法并推导了计算公式,给出了优化算法的计算步骤,并通过一个算例阐述了这种算法的应用。 相似文献
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生命线工程系统抗震可靠度算法复杂性及简化原则 总被引:4,自引:0,他引:4
研究了生命线工程系统抗震可靠度常规算法的适用性,定义了算法的时间复杂性和结构复杂性,分析了使可行算法失效的原因,给出了回路分解公式,提出了优先降低结构复杂性的简化原则。 相似文献
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包尚联 《CT理论与应用研究》1998,(3)
本文介绍了国际医用磁共振协会及其主办的国际会议情况,即InternationalSocietyforResonanceinMedicine-ISMRM。该协会代表了世界上医用磁共振成像方面的最高水平,从第4次年会开始,会议在每年的4月份进行。本文作者参加了1997年在加拿大温哥华召开和1998年在澳大利亚悉尼召开的年会。会议主要讨论的题目包括功能磁共成像(fMRI),结构磁共振成像(aMRI)波谱成像(MRI/S)和血管造影等方面的内容,以及磁共振成像技术协会方面关于诊断方法,显像增强剂技术,磁共振成像设备及其部件技术,以及数据处理方面的技术进步等课题。推动该领域发展的主要动力显然是对人类自身的研究和对疾病诊疗的需要,尤其对脑功能研究、功能性疾病的诊断和治疗的需要。但是磁共振成像目前在心脏、肺脏以至软骨方面的诊断已经有很大进步,在设备技术和数据处理方法方面的进步同样也是很快的。 相似文献
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Nineteen trace elements were determined in liver, muscle, kidney, gonads, and hair of 18 harp seals (Phoca groenlandica) from Pangnirtung in the Baffin Island, Canada. Concentrations of V, Mn, Fe, Cu, Mo, Ag, and Hg in the liver, Co, Cd, and Tl in the kidney, and Ba and Pb in the hair were significantly higher than those in other tissues. Significant positive correlations between Hg concentrations in the hair, and liver, kidney and testis imply usefulness of the hair sample for non-destructive monitoring of Hg in the harp seals. It is suggested that whereas Hg preferentially accumulates in the liver, the accumulation in other tissues is induced at higher hepatic Hg levels. In contrast, Se may not be accumulated in other tissues compared with the liver even at higher hepatic Hg levels because of the presence of excess Se for Hg detoxification in other tissues. 相似文献
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This study investigated the subcellular distribution of Cu, Zn, Cd and Ag in liver of mallard (Anas platyrhynchos), spot-billed duck (A. poecilorhyncha) and great cormorant (Phalacrocorax carbo) to better understand metal fractionation and dynamics in avian liver. Most of the total Cu, Zn, Cd and Ag were present in hepatocytosol, and their concentrations increased with total hepatic levels in all the three avian species. Copper, Zn and Cd in hepatocytosol were present mostly in metallothionein fractions (MTs), and Cu and Cd contents in this fraction were positively correlated with hepatocytosol levels in all the species. Silver was observed mostly in both high-molecular weight and MT fractions in hepatocytosol in mallard and great cormorant, whereas it was present in both low-molecular weight and MT fractions in spot-billed duck, suggesting that distribution of Ag in the hepatocytosol was species-specific. The elution profile of metals in MT fractions revealed six metallic peaks in mallard and spot-billed duck, and three peaks in great cormorant, implying the presence of multiple MT isoforms in the liver of these avian species. The present study demonstrated that MTs are closely associated with metal regulation, especially Cu and Cd, in these three aquatic birds. 相似文献
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In order to understand the various processes responsible for siltation in the entrance channel and in the sand bar area near the old Mangalore port, variations in temperature, salinity, suspended sediment load, currents and extinction coefficient in the Netravathi-Gurpur Estuary and in the sea near the sand bar were studied in relation to tides during monsoon, post-monsoon and pre-monsoon seasons. The hydrographic characteristics in the estuary showed marked seasonal changes and were influenced by tides to a considerable extent. In the sea, seasonal variations of these parameters were less marked, and the effect of tides was not significant. Salinity and temperature values in the estuary and in the sea were maximum during the pre-monsoon season in general. The suspended sediment load values were always higher in the estuary than in the sea and they were found to be maximum in the monsoon season. Currents in the estuary were controlled by tides as well as by the river flow, particularly in the monsoon season, whereas currents in the sea mostly followed the general circulation pattern. Extinction coefficient values were higher in the monsoon season both in the estuary and in the sea due to increase in the particulate matter from inland drainage. 相似文献
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Structure and Significance of S-wave Velocity and Poisson’s Ratio in the Crust beneath the Eastern Side of the Qinghai-Tibet Plateau 总被引:2,自引:0,他引:2
The receiver functions of body waves of distant earthquakes obtained for the regions beneath 41 digital stations (Lhasa and
GANZ in Tibet, Mandalay and Rangoon in Myanmar, SHIO in India, CHTO in Thailand, and station network in Sichuan and Yunnan)
were used to invert for S-wave structure in the crust and upper mantle in Sichuan, Yunnan, and their surrounding areas. Meanwhile
the distribution characteristics of the Poisson’s ration and the crustal thickness in Sichuan and Yunnan areas were also obtained.
Results indicate that the depth of Moho beneath the eastern side of Qinghai-Tibetan plateau varies strikingly. It is obvious
that the greatest changes in crustal thickness occur in a north-south direction. The crustal thickness decreases from north
to south, being as thick as 70 km in eastern Tibet, the northern portion of our area of interest, and less than 30 km in Chaing
Mai and Rangoon, the southern portion of our area. There are, however, exceptions regarding the trend. The thickness exhibits
an east-west variation trend in the area from Ma’erkong-Kongding in Sichuan to Lijiang in Yunnan. In general the Jinpingshan-Longmenshan
fault and Anninghe fault can be taken as the boundaries of this exception area. The thickness in Kongding in the west is 68 km,
while it is only 39 km in Yongchuan in the east. Moreover the Poisson’s ratio values in the blocks of central Sichuan and
Sichuan-Yunnan Diamond are high, and a low velocity layer in the crust of this area can be obviously detected. The distribution
characteristics of the high Poisson’s ratio and the low velocity of the crust in this block correspond to the tectonic structure,
being in contrast with the surrounding areas. Combining with the distribution features of the modern tectonic stress field,
it is deduced that the Sichuan-Yunnan area is probably the channel through which the materials of the lithosphere flow eastward. 相似文献
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V. N. Mikhailov D. V. Magritsky V. I. Kravtsova M. V. Mikhailova M. V. Isupova 《Water Resources》2012,39(1):11-43
Regularities in the response of the mouths of major rivers, flowing into the Caspian Sea, to large-scale variations in its
level and river water runoff and sediment yield are considered. Changes in the morphological structure and hydrological regime
of the Volga, Terek, Sulak, Ural, and Kura mouths have been analyzed in both geological past and separately for three modern
periods: a considerable drop in Caspian Sea level before 1978, its abrupt rise in 1978–1995, and a relative stabilization
in the subsequent years. Specific features were identified in the hydrological-morphological processes in different mouths,
caused by the differences in river sediment yields, and the slopes of delta surface and mouth nearshore beds. Some theoretical
and methodological approaches were verified in the analysis and evaluation of the processes under consideration. The obtained
results of studies of the mouths of rivers flowing into the Caspian Sea can be regarded as examples and analogues in the assessment
of processes, which take place at the mouths of other Russian and world rivers at present and can take place in the future
under anticipated natural and anthropogenic variations in sea level and river runoff. 相似文献
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云南地区处于印度板块与欧亚板块中国大陆碰撞带的东缘,地壳运动剧烈,活动块体特征明显,中强以上地震频发,是研究大震活动规律的理想场所。通过过去一个世纪的6.7级以上地震活动的时空分布以及地震动力分析认为,云南地区存在的4个具东西交替活动特征的地震活跃期,可能是东、西部各自地震活跃与平静过程叠加的结果,100a左右可能出现1次东、西部同时爆发大震的时段;云南地区地震活动与外围地区存在较好的呼应关系,安达曼-缅甸弧形带的巨震活动对云南地区地震活跃期的启动有一定的指示意义,而云南东部强震也与四川西部大震密切相关,四川大震活动往往滞后于云南地区;中强地震连发—平静—首发大震可能是云南以东部为活动主体的地震活跃期的启动模式。这些认识对云南地区大震预测、地震机理以及板缘动力学研究会有所帮助 相似文献
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《Marine pollution bulletin》2012,64(5-12):489-499
Nineteen trace elements were determined in liver, muscle, kidney, gonads, and hair of 18 harp seals (Phoca groenlandica) from Pangnirtung in the Baffin Island, Canada. Concentrations of V, Mn, Fe, Cu, Mo, Ag, and Hg in the liver, Co, Cd, and Tl in the kidney, and Ba and Pb in the hair were significantly higher than those in other tissues. Significant positive correlations between Hg concentrations in the hair, and liver, kidney and testis imply usefulness of the hair sample for non-destructive monitoring of Hg in the harp seals. It is suggested that whereas Hg preferentially accumulates in the liver, the accumulation in other tissues is induced at higher hepatic Hg levels. In contrast, Se may not be accumulated in other tissues compared with the liver even at higher hepatic Hg levels because of the presence of excess Se for Hg detoxification in other tissues 相似文献
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目的:探讨胸部CT及CT淋巴管成像(CTL)在原发性肺淋巴管扩张症(CPL)的诊断价值。材料及方法:回顾性分析2012年8月至2021年7月41例经临床及影像确诊为CPL患者的临床及影像学资料,所有患者均于直接淋巴管造影术(DLG)前行胸部CT检查,并于DLG后行CTL检查,分析胸部CT及CTL图像,所得结果采用分类变量资料中的构成比进行统计描述。结果:41例患者中胸部CT表现为支气管血管束增粗33例,小叶间隔增厚32例,小叶内间质增厚4例,磨玻璃密度影26例,肺实变5例,肺不张14例,胸腔积液24例。CTL碘油异常沉积于胸导管末端35例,支气管血管束31例,肺门32例,胸膜17例,纵膈36例,心包17例,横膈3例,腹腔内10例,腹膜后10例,盆腔及会阴20例。结论:CT和CTL可显示淋巴管异常的范围及分布,为CPL诊断和治疗提供影像学依据。 相似文献
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Agusa T Yasugi SY Iida A Ikemoto T Anan Y Kuiken T Osterhaus AD Tanabe S Iwata H 《Marine pollution bulletin》2011,62(5):963-975
Body distribution and growth- and nutritional status-dependent accumulation of 21 trace elements were investigated in harbor seals (Phoca vitulina) stranded in the North Sea coast in 2002. Higher concentrations and burdens of Mn, Se, Mo, Ag, Sn, Hg, and Bi in the liver, Cd in the kidney, As in the blubber, and Co, Sr, and Ba in the bone were observed. Significant positive correlations of hepatic Se, Mo, Ag, Cd, Sn, Hg, Tl, and Bi with standard body length were found, while significant negative relationships were detected for Mn, As, Rb, Sr, and Sb in the liver. Concentrations of Co, Se, Sr, Sn, Hg, and Bi in the liver, V, Sr, Ag, Sn, and Hg in the kidney, V, Mn, Co, Rb, Sr, Sn, Ba, and Pb in the blubber increased with decreasing blubber thickness of harbor seals, indicating enrichment of these elements in the target tissue by emaciation. 相似文献