大跨度钢桁架转换结构振动台试验研究

以某带高位大跨钢桁架转换结构高层建筑为工程背景,进行了1/25缩尺比例的模型振动台试验,通过粘贴在钢桁架杆件上的应变片,测试了输入不同加速度峰值地震波作用下钢桁架的地震响应。在加速度峰值0.9g地震波作用下,两端支承钢桁架筒体剪力墙才出现裂缝,表明连接部位剪力墙受力性能较好;人工波作用下结构的地震响应最大,层地震作用力在钢桁架转换结构层有突变;试验中随模型结构裂缝发展和抗侧刚度衰减,层地震作用力分布发生变化,其中钢桁架转换结构层承担地震力相对减小,钢桁架应变反应也相对趋缓;钢桁架两端杆件受力较大,表明支承剪力墙对钢桁架的约束作用较大。     

Characteristics of near-fault ground motion containing velocity pulses

There are many reports about the research on near-fault velocity pulses, which focus on the generation of velocity pulse and simplify the velocity pulse so as to be used in the seismic design of structure, However few researches have put emphasis on the characteristics of near-fault ground motions containing velocity pulses, especially the characteristics relevant with the design response spectrum prescribed by the code. Through collection of a large number of near-fault records containing velocity pulses, the response spectra and the characteristic periods of records containing no pulses are compared with those of records containing pulses. Response spectra of near-fault records are compared with standard spectra given by code; furthermore, the response spectra and the characteristic periods of each earthquake are compared with that given by code. The result shows that at long periods （longer than 1.5 s）, the response spectrum of pulse-containing records is bigger than the response spectrum of no-pulse-containing records; when the characteristic period of near-fault records is calculated, the method that does not fix frequency is more reasonable because the T1 and T2 have a lagging tendency; regardless of the site Ⅰ and site Ⅱ, the characteristic period of pulse-containing records is over twice bigger than the characteristic period given by the code,     

河南西峡地区二郎坪群火神庙组中发现泥盆纪孢子化石

在河南省西峡地区二郎坪群火神庙组粉砂质板岩中发现丰富的陆生植物孢子(Spores)、少数疑源类(Acritarchs)和极少数几丁虫(Chitinozoa)化石.该化石孢子组合可与中国华南、西南地区和西秦岭中泥盆世早期孢子组合比较,亦可与西欧和北美中泥盆世早期的孢子带比较,时代为中泥盆世,并有可能为中泥盆世早期,相当于西欧艾菲尔期(Eifelian).     

青藏铁路唐古拉山-拉萨段全新世控震断裂研究

地表调查表明,沿青藏铁路唐古拉山-拉萨段存在5条重要的全新世控震断裂带,从北到南分别是温泉盆地西缘断裂带、安多盆地北缘断裂带、崩错断裂带、谷露西缘断裂带和当雄-羊八井断裂带.构造-地貌和年代学分析结果表明,北部的温泉盆地西缘断裂和安多盆地北缘断裂带的活动强度相对比较小,平均垂直活动速率约为0.2～0.5mm/a.南侧的谷露西缘断裂带和当雄-羊八井断裂带的全新世垂直活动速率为约(15±0.5)mm/a.而中部的崩错走滑断裂带的活动强度最大,晚第四纪期间的走滑速率可达(11±4.5)mm/a.全新世断裂活动和古地震研究表明,其中温泉盆地西缘断裂带、安多盆地北缘断裂带、崩错断裂带的西北分支、当雄-羊八井断裂带的当雄段等区域未来发生强震的概率相对更大.     

云南金平白马寨含矿镁铁-超镁铁岩体岩石地球化学

云南金平白马寨铜镍硫化物矿床含矿岩体为侵位在奥陶系砂页岩的镁铁-超镁铁环状杂岩体。从岩体核心到边缘依次出现橄榄岩—橄榄辉石岩—辉石岩—辉长岩的岩相分带。该岩体的主量元素显示拉斑玄武岩岩浆分异演化的趋势。REE显示富集LREE的配分模式,具明显的Eu异常。微量元素蛛网图显示明显的Ta、Nb、Ti及P的负异常。具有高(⁸⁷Sr/⁸⁶Sr)_i(0.710974~0.722667)和低ε_Nd(t)(-13.17~-12.09)的特征。微量元素和同位素地球化学证据表明,岩浆源于俯冲地壳物质改造的富集地幔,岩浆上升过程中遭受了一定的地壳物质混染。岩体可能是在弧后拉张的构造环境中形成。     

Petroleum Systems of Chagan Depression,Yingen-Ejinaqi Basin, Northwest China

INTRODUCTIONYingen-Ejinaqi basinis locatedin the WulatehouBanner in the west of the Inner Mongolia Autono-mous Region of China ,and covers an area of approxi-mately 122 000 km2( Chen et al ., 2001) . As aMesozoic-Cenozoic depression in Yingen-Ejinaqi ba-sin,the Chagan depression lies in the northeast ofthis basin (Fig.1) .It is about 60 kmlong and 34 kmwide and covers an area of approxi mately 2 000 km2( Wang et al .,2002) .In terms of the basement ter-rain,forms of major structural…     

网络时代气象影视节目的创意与制作

对网络时代气象影视节目的发展方向、节目定位、主持风格等问题进行探讨，并以一档以网络信息为切入点的气象资讯节目为例，详细介绍了其在播报方式、场景设置、节目内容、表现手法等方面做的一些新创意和新尝试。     

The strength and fractal dimension characteristics of alum–kaolin flocs

Flocs generated by various shear forces exhibit different characteristics of size, strength and structure. These properties were investigated by employing a continuous optical monitoring and a microscope with CCD camera to directly monitor aggregation under six different shear intensities. The floc structure was characterized by the fractal dimension. The results showed that the flocculation index (FI) decreased from 1.16 at 20 rpm to 0.25 at 250 rpm and the floc size decreased from 550 μm to 150 μm, meantime, the FI value showed a good correlation with floc size. In order to determine the floc strength, two methods were used. One was the strength factor, ranging from 18.3% to 62.5%, calculated from FI curve, and the other was a theoretical value between 0.005 N/m² and 0.240 N/m², estimated by calculation. The floc strength increased with the G value in both cases. Furthermore, the fractal dimension increased with G and its value was between 1.30 and 1.63. The relation between fractal dimension and strength was also obtained.     

基于Flash的地质公园电子地图实现

用Flash制作地质公园电子地图,成本低廉、交互性强、美观生动,对于地质公园旅游开发与宣传具有重要作用。详细阐述了用这种方法制作地质公园电子地图的优势,并以湖南古丈红石林国家地质公园为例,从资料准备、地图显示与控制、地图查询、声音的插入等方面,说明了基于Flash的地质公园电子地图的实现过程。     

青藏高原狮泉河-康西瓦地区 1:100万区域重力调查成果

利用最新取得的区域重力资料,参考航磁、遥感、区域地质资料,对青藏高原狮泉河-康西瓦地区重力场分区、断裂构造体系、构造单元、局部异常、深部构造、成矿远景区(带)等进行了研究.对阿尔金走滑断裂西南端的走向和延伸提出了一些新的看法;讨论了2条重力低值带的成因;推断了班公湖-怒江结合带下部莫霍面隆起的高度,从重力角度提出了对班公湖-怒江结合带的认识;认为青藏块体在拼合后地壳有2个加厚中心;新圈定了一个中、新生代沉积盆地,并进行了初步研究;结合地质、矿产、航磁等资料,初步划分出4个成矿远景区(带).