20世纪60年代初江苏省支援农业述论

20世纪60年代初,为了克服大跃进给农业生产和发展带来的困难,江苏省积极响应中共中央支援农业的号召,采取了一系列政策和措施支援农业:如降低农业税、提高农业品价格和增加农业投入,下放劳动力,调整工业服务方向,加强传统农具的生产和维修,以及加强支农新产品和代替品的研发和推广等,这些政策和措施的实施为江苏省农业的恢复和发展起到了非常重要的作用。     

故宫中和殿某中金檩断裂分析

勘查发现,故宫中和殿明间某中金檩在与上部爬梁相交位置出现局部断裂,造成下部中金枋产生较大挠度.为探明该中金檩产生断裂的原因,采取理论计算与数值模拟相结合的方法,对中金檩、中金枋体系进行了分析.基于榫卯连接边界条件的特征,分别考虑中金檩与中金枋叠合、中金檩与中金枋分离、中金檩完全断裂等三种工况,建立了中金檩-枋体系的受力模型,进行了静力分析,获得了中金檩、中金枋的变形及内力分布特征,讨论了中金檩断裂破坏的影响因素.结果表明:由于中金檩在爬梁作用位置截面削弱,造成中金檩自身拉、压、弯承载力不足,从而导致中金檩产生断裂;中金檩与中金枋分离条件下,中金檩断裂造成的中金枋内力增加,且比檩枋叠合条件更明显;中金檩完全断裂后,将造成中金枋内力及变形剧增,威胁中金枋安全.因此,对中金檩采取及时有效的加固措施极其重要.研究结果将为中金枋采取加固措施提供理论参考.     

Inelastic Displacement Ratios for Seismic Assessment of Structures Subjected to Forward-Directivity Near-Fault Ground Motions

This article presents results of a statistical study focused on evaluating inelastic displacement ratios (i.e., ratio of maximum inelastic displacement with respect to maximum elastic displacement demand) of degrading and non degrading single-degree-of-freedom (SDOF) systems subjected to forward-directivity near-fault ground motions. C_R spectra are computed for normalized periods of vibration with respect to the predominant period of the ground motion to provide a better ground motion characterization. This period normalization allows reducing the record-to-record variability in the estimation of C_R. An equation to obtain estimates of C_R for the seismic assessment of structures exposed to forward-directivity near-fault ground motions is proposed.     

Effects of Near-Fault Pulses on Nonlinear Soil-Structure Systems

ABSTRACT

This paper is focused on effects of near-fault pulse characteristics on seismic performance of soil-structure systems considering foundation uplifting and soil yielding. To this end, an extensive parametric study is conducted. Mid-to-high-rise buildings of different aspect ratios (SR) resting on shallow mat foundations are investigated. Different vertical load-bearing safety factors (F_S) of foundation as well as different soil types (i.e. soft to very dense) are considered in this study. Finite element method is used for numerical modeling. The underlying soil is simply modeled with a set of nonlinear springs and dashpots beneath the foundation. Mathematical near-fault pulse models of fling step and forward directivity are used as input ground motions. The results show that reduction in structural drift demands due to nonlinear soil-structure interaction (SSI) is more considerable in the case of short-period pulses compared to long-period ones. In more precise words, significant reduction occurs when pulse-to-fixed-base period ratio falls within 0.7–1.5 in the case of directivity pulses and 0.5–1.4 in the case of fling pulses. It is also demonstrated that the beneficial effects of nonlinear SSI reduce when the number of stories increases.     

苏联因素对毛泽东发动“大跃进”的影响

本文初步探讨了苏联因素对毛泽东发动"大跃进"的影响,认为苏联的建设成就使毛泽东坚信,只要真心实意学苏联,中国经济就能获得高速发展;通过借鉴苏联模式,毛泽东探索出了"大跃进"的发展方针;通过批判苏联领导人的"老子党"和大国沙文主义作风以及通过打破苏联模式在人们心目中的神圣地位,毛泽东使党和人民清除了民族自卑心理,振奋了民族精神,从而全面投身于"大跃进"运动.     

"大跃进"运动悲剧命运探源

"大跃进"运动因其主观动机与客观效果的巨大反差而成为一场深刻的历史悲剧.工作着重点的转移受到了"政治统帅经济"的干扰,"以苏为鉴"误入回归革命经验的歧途,解放思想、破除迷信为唯意志论所扭曲,赶超战略在积极平衡论的支配下走向极端,这些因素便是造成这场悲剧的根源.     

Archaeological Quantification of Pottery: The Rims Count Adjusted using the Modulus of Rupture (MR)

Archaeological quantification is a recurrent issue in research about pottery, its typologies and its distribution. We accept the validity of other methods of quantification—sherd count, minimum number of individuals (MNI) or sherd weight—but the methodology that we have proposed for quantification of assemblages of archaeological contexts is the rims count, which has to be transformed into coefficients of reference through a correction using the modulus of rupture (MR). Such correctors are obtained through measuring the percentage of preserved rim of a significant number of sherds of each type and establishing the average of that percentage. This quantification method is easily applicable to all pottery types and it is also statistically reliable. Besides, it can be used in any study in which the gross number of rims is published. Finally, in the case of ceramic transport containers, a second correction can be applied by multiplying the corrected coefficient (number of rims × MR) by its average capacity (AC), another corrector that will allow us to gather statistics according to the litres of transported product. We believe that the rims count (the easiest part to classify) is a fast, relatively easy and very reliable method that needs to be corrected using the MR.     

“大跃进”期间的深耕土地运动

1957～1958年,毛泽东对山东省厉家寨村和河南省长葛县深翻土地增产经验的总结报告充分肯定,号召全国学习,通过深翻土地达到增产目的。1958年8月,中共中央发出指示,要求全国在两三年内,将一切可能深耕的土地全部深耕一尺以上。全国掀起了轰轰烈烈的深耕土地热潮。在运动中,各地积极组织学习长葛县的深翻土地方法和经验,开展群众性深翻土地大会战。科研人员也积极研制和改造深翻农机具,总结和论证深翻措施及效果,开展深翻土地创高产试验。尽管通过深耕土地达到增产在一定的科学范围内是可行的,但1958年全国性的深耕土地运动,在翻土深度、进度和数量上层层加码,出现了许多盲目蛮干的事例,未能取得预期的增产效果。