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91.
建筑结构响应是有效反映结构动力特性的最直接参数,开展结构动力响应实时监测可为结构抗震韧性评估提供准确的地震动输入。本文基于非结构构件损失构建结构抗震韧性评估方法,研究确定位移敏感型和加速度敏感型非结构构件的易损性模型。选择某六层钢筋混凝土框架结构进行实时监测系统建设,基于监测数据开展结构抗震韧性评估。通过构建建筑信息模型(BIM),并在有限元分析软件OpenSees中建立结构弹塑性分析模型,利用实时监测数据实现结构模型更新,直至监测数据与模型分析结果一致。由于实时监测数据峰值较低,结构不会发生塑性变形,因此选择10条双向非脉冲地震动模拟实时监测地震记录。根据层间位移角和楼面加速度分布,开展结构功能损失评估,得到该建筑结构的抗震韧性得分。分析表明,该结构抗震性能较好,在遭受地震破坏后,会发生非结构构件脱落,需要采取有效措施进一步提升建筑抗震韧性水平。  相似文献   
92.
树立良好的国土资源管理队伍形象,是当前国土资源管理体制改革的迫切需要,是充分发挥国土资源管理各项职能的客观要求。塑造新形势下的国土资源队伍形象是一项长期的、需要全体“国土卫士”持之以恒艰苦努力的工程。可总结为:塑“魂”、创“新”、建“制”、促“廉”、立“本”、树“形”6个方面。  相似文献   
93.
A planthopper originally assigned to the genus Boreocixius in Surijokocixiidae (Surijokocixioidea, Fulgoromorpha) from the Ladinian (Middle Triassic) of Tongchuan in Shaanxi, northwestern China is described as Boreocixius tongchuanensis Zhang et al. sp. nov. As the third species ascribed to the genus, it differs from its congeners in having the much larger tegmen with postnodal veinlets and pigmented bands, providing new morphological information for Boreocixius. The establishment of the new species further increases the diversity of Boreocixius and Surijokocixiidae as well.  相似文献   
94.
为了探讨车莫古隆起对内物源沉积体系及油气成藏的控制作用,从车莫古隆起形成与演化入手,利用岩心、地震、测井等资料,多种方法结合恢复其剥蚀量、古地貌,提出车莫古隆起从中侏罗世到早白垩世发育,侏罗世末是其鼎盛时期,并提供内物源,控制围绕车莫古隆起周缘沉积体系和砂体展布,从岩心、地震特征、重矿物稳定系数、古水流指向、砂岩厚度等方面给出存在依据,合理解释了古隆起控制范围内已发现油藏的砂体成因。车莫古隆起发育和潜伏埋藏期控制古油气藏的形成与分布,掀斜后内物源砂体展布、断裂体系和现今构造共同控制着油气调整、运移及次生油气藏的分布,围绕车莫古隆起发育的内物源砂体尖灭方向与现今构造高部位指向垂直和斜交区域是岩性地层油气藏有利区。围绕内物源勘探刚开始,在此认识指导下部署的沙门1、莫17、夏盐11、夏盐12等井已获得突破,腹部岩性地层油气藏勘探将进入一个油气发现新阶段。  相似文献   
95.
96.
Abstract By mineral and bulk compositions, the Lewis Cliff (LEW) 88516 meteorite is quite similar to the ALHA77005 martian meteorite. These two meteorites are not paired because their mineral compositions are distinct, they were found 500 km apart in ice fields with different sources for meteorites, and their terrestrial residence ages are different. Minerals in LEW88516 include: olivine, pyroxenes (low- and high-Ca), and maskelynite (after plagioclase); and the minor minerals chromite, whitlockite, ilmenite, and pyrrhotite. Mineral grains in LEW88516 range up to a few mm. Texturally, the meteorite is complex, with regions of olivine and chromite poikilitically enclosed in pyroxene, regions of interstitial basaltic texture, and glass-rich (shock) veinlets. Olivine compositions range from Fo64 to Fo70, (avg. Fo67), more ferroan and with more variation than in ALHA77005 (Fo69 to Fo73). Pyroxene compositions fall between En77Wo4 and En65Wo15 and in clusters near En63Wo9 and En53Wo33, on average more magnesian and with more variation than in ALHA77005. Shock features in LEW88516 range from weak deformation through complete melting. Bulk chemical analyses by modal recombination of electron microprobe analyses, instrumental neutron activation, and radiochemical neutron activation confirm that LEW88516 is more closely related to ALHA77005 than to other known martian meteorites. Key element abundance ratios are typical of martian meteorites, as is its non-chondritic rare earth pattern. Differences between the chemical compositions of LEW88516 and ALHA77005 are consistent with slight differences in the proportions of their constituent minerals and not from fundamental petrogenetic differences. Noble gas abundances in LEW88516, like those in ALHA77005, show modest excesses of 40Ar and 129Xe from trapped (shock-implanted) gas. As with other ALHA77005 and the shergottite martian meteorites (except EETA79001), noble gas isotope abundances in LEW88516 are consistent with exposure to cosmic rays for 2.5–3 Ma. The absence of substantial effects of shielding from cosmic rays suggest LEW88516 spent this time as an object no larger than a few cm in diameter.  相似文献   
97.
A new insect family Liaoximordellidae (fam. nov.) has been named for a well-preserved specimen which was collected from the Upper Jurassic outcropping west of Daxinfangzi Village, Lingyuan County, Liaoning Province. The specimen can not be put into Mordellidae or Praemordellidae because it possesses some original and intermediate characters in morphology. It serves the study of mordellid evolution. Besides, the fossil group associated with the insect is important for the stratigraphic division of the Mesozoic in western Liaoning.  相似文献   
98.
The most effective technique in long-range weather forecasting in China is teleconnection. Summer rainfall and temperatures are closely correlated to the preceding winter 500 mb heights over the Northern Hemisphere and sea surface temperatures over the North Pacific, so the former can be predicted from the latter. This kind of connection is called rhythm. In this paper, four examples of rhythm are outlined. The manifestation of rhythm and its universal significance is demonstrated. The mechanism of rhythm is discussed.  相似文献   
99.
Traditionally a streambed is treated as a layer of uniform thickness and low saturated hydraulic conductivity (K) in surface‐ and ground‐water studies. Recent findings have shown a high level of spatial heterogeneity within a streambed and such heterogeneity directly affects surface‐ and ground‐water exchange and can have ecological implications for biogeochemical transformations, nutrient cycling, organic matter decomposition, and reproduction of gravel spawning fish. In this study a detailed field investigation of K was conducted in two selected sites in Touchet River, a typical salmon spawning stream in arid south eastern Washington, USA. In‐stream slug tests were conducted to determine K following the Bouwer and Rice method. For the upper and lower sites, each 50 m long and 9 m wide and roughly 20 m apart, a sampling grid of 5 m longitudinally and 3 m transversely was used. The slug tests were performed for each horizontal coordinate at 0·3–0·45, 0·6–0·75, 0·9–1·05 and 1·2–1·35 m depth intervals unless a shallower impenetrable obstruction was encountered. Additionally, water levels were measured to obtain vertical hydraulic gradient (VHG) between each two adjacent depth intervals. Results indicated that K ranged over three orders of magnitude at both the upper and lower sites and differed between the two sites. At the upper site, K did not differ significantly among different depth intervals based on nonparametric statistical tests for mean, median, and empirical cumulative distribution, but the spatial pattern of K varied among different depth intervals. At the lower site, K for the 0·3–0·45 m depth interval differed statistically from those at other depth intervals, and no similar spatial pattern was found among different depth intervals. Zones of upward and downward water flow based on VHG also varied among different depth intervals, reflecting the complexities of the water flow regime. Detailed characterization of the streambed as attempted in this study should be helpful in providing information on spatial variations of streambed hydraulic properties as well as surface‐ and ground‐water interaction. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
100.
INTRODUCTIONAquiculturearearedtidesignalsoceanpollutionanddisaster.Althoughenvironmentscientistshaveconductedmanyin depthresearchesonthecauseandformationmechanismofredtide ,manyofitsaspectsarestillunknownbecauseredtideisacomplexphenomenonandtheecologic…  相似文献   
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