Seismic Performance of Precast Hybrid-Steel Concrete Connections

This article presents experimental and analytical investigations of hybrid-steel concrete connections. In the experimental study, four full-scale specimens including one cast-in-place and three precast specimens were tested under cyclic load reversals. The performance of the specimens in terms of energy dissipating capacity, cracking patterns, and variation of strains along the main reinforcement is described. However, due to the inherent complexity of beam-column joints and the unique features of the tested specimens, the experimental investigation was not sufficient enough to fully understand the influence of several parameters. Therefore, an analytical investigation based on the FE models using DIANA software is presented. Validation of the FE models against the experimental results has shown a good agreement. The critical parameters influencing the joint's behavior such as the continuation of beam bottom reinforcement, column axial load, the size and embedded length of the angle sections are varied, and their effects including possible implications on code specifications are discussed.     

被遗忘的曼陀罗：唐代初传的金刚界曼陀罗

本文探讨了金刚智、不空师徒初传于唐代的金刚界曼陀罗(即《金刚顶经》所述的金刚界大曼陀罗),作者一反过去成见,试图阐明以拟人化的形式表现的金刚界三十七尊的曼陀罗并非唐代初传期的金刚界曼陀罗,而最可能是由不空的弟子,即惠果等辈于8世纪末或9世纪初所完成的。证诸史料,金刚智、不空忠实于根本经典《金刚顶经》的指示,大日如来的四亲近,即四波罗蜜是以三昧耶形的形式出现。但此种金刚界曼陀罗,在9世纪初的中国似乎被以菩萨形表现的四波罗蜜完全取代,消失于历史洪流之中。反观藏传的金刚界曼陀罗,数百年来波罗蜜形与拟人化的四波罗蜜图像并行不悖,在一定程度上反映了汉藏传法演教历史的歧异。     

华盛顿会议与中国民众运动

第一次世界大战结束,美国由于未能在巴黎和会上满足其在远东地区扩张势力的目的而又积极倡议召开华盛顿会议来讨论远东和太平洋问题,以求拆散原有的英日同盟,打击日本在东方的优势,以建立自己在远东的霸权,而英国也深感日本发展趋势的威胁,迫切希望重新调整帝国主义在东方的势力均衡关系。因此经英、美共同发起、并由美国出面召开有英、美、法、意、日、中六国参加的华盛顿会议,后又增加荷兰、比利时及葡萄牙而成为九国会议。美国于１９２１年８月１３日向中、日、英、法、意等国发出正式邀请;１６日,北京政府表示与会,成立“太平…     

Investigations on the degree of bleaching of quartz OSL signals using modern aeolian dust from western Loess Plateau, China

Optically Stimulated Luminescence signal of quartz extracted from modern aeolian dust with known maximum age (about decades) was analyzed in terms of degree of bleaching. The results of dose recovery tests show that the modified double single-aliquot regenerative-dose protocol with the early background subtraction is robust for dating these modern dusts using small aliquots. Bleaching of these dusts is discussed based on the distribution of De values in histograms, scatter plots of D_e versus sensitivity corrected natural OSL signal and comparison between measured D_e and expected D_e. The results indicate that most dusts were completely bleached but some dusts were not completely bleached. For those incompletely bleached dusts in Lanzhou area, the maximum OSL age overestimation is up to ～1 ka, which might be caused by fast deposition accompanied by heavy sand/dust storms. The research suggests that cautions should be given to OSL ages younger than 1 ka in the western China close to deserts.     

地情资源开发利用的实践与探索——以洛阳市史志办地情资料开发利用为例

第二轮《洛阳市志》出版后,洛阳市志办把工作重心转移到地情资源开发利用的道路上。先后筹划实施了地情信息化建设、＂图说洛阳＂系列丛书编纂、＂千年帝都、牡丹花城＂系列丛书编纂、＂洛阳乡镇概览＂系列丛书编纂、历代旧志整理等项目。经过多年的实践的探索,作者提出应把握以下几点：党委、政府领导重视是做好地情资源开发的关键;人才队伍建设是做好地情资源开发的基础和前提;实施项目型、规模化、系列化开发是时代发展的新要求;以市场为导向,适应社会发展需要,是做好地情资源开发的必由之路;多渠道、多模式发展是地情资源开发的有效途径;统筹规划、突出重点是做好地情资源开发的重要方法;加强宣传、扩大影响是地情资源开发的必要手段。     

Examining quartz OSL age underestimation for loess samples from Luochuan in the Chinese Loess Plateau

When using quartz OSL to date loess samples from the Chinese Loess Plateau, it has been reported that the agreement between OSL ages and the independent ages is limited to the samples younger than ～70 ka with a corresponding D_e of ～230 Gy, and a sample with an expected age of 780 ka was dated to 107 ka, corresponding to 403 Gy. The growth curves of these samples do not saturate at doses of 700 Gy, and a linear growth part was observed for doses higher than 200 Gy. However, the maximum measured age of ～100 ka imply that the D_e determined using this linear part of a growth curve could be problematic, or that the quartz OSL signal is not as stable as previously thought and has a barrier age of ～100 ka. In the current study, we examine the reasons for the age underestimation. We examined the shape of growth curves, anomalous fading, thermal stability, etc. The results show that, for the loess samples examined, quartz OSL does not fade anomalously, and the barrier age of ～100 ka is due to the fact that the OSL signals are less thermally stable, the lifetime of 0.311 Ma at 20°C obtained is much smaller than those for quartz samples from other regions such as Australia (～100 Ma).     

用示踪气体法检测文物展柜换气率技术研究

摘要文物展柜为文物的展示和保存提供了一个相对独立的空间,展柜密封度的高低影响着展柜内微环境调控的效果。为评价文物展柜的密封度,用示踪气体法检测展柜换气率,从检测便捷、安全和实验数据可靠角度分析比较了二氧化碳和乙烯的实验结果。结果显示,两种示踪气体均可用于检测展柜的密封度。其中,二氧化碳气体检测法比较方便,但其密度较大,易于沉降,检测结果偏低。环境湿度对二氧化碳示踪气体法检测的结果有一定影响。应用二氧化碳示踪气体法测试了多种展柜的换气率表明,各展柜的密封度有较大差别,每天换气率从0.1次到37次不等。检测结果提示,二氧化碳示踪气体法为评价展柜的密封度提供了一个简便易行的方法。