中国天文学的回顾与展望

古代中国天文学纵观中国历史,古代中国天文学家取得过巨大的成就。传说在4000多年前的三皇五帝时期的尧时代,羲、和两兄弟接受尧帝的委托观测恒星并编制历法。这个远古传说可以说明中国天文学的久远和古代帝王对天文学的重视。那么为什么古代帝王如此重视天文学呢？主要有两方面的原因：其一,是皇帝统治国家的需要。拿日全食作为例子可以说明这一点。中国古人认为,日全食的发生是因为天狗吞食了太阳,这是一个重大的灾难,对国家稳定很不利。所以,皇帝迫切需要知道日全食何时发生、在何地发生以及是如何发生的？其二,皇帝需要建立完整的天文系统和精确的历法,指导国家臣民的生产和生活。     

第三届全国天文社团发展论坛附属项目 “星特朗杯”从零开始社团培训资料设计入赛及社团合作征文活动获奖名单公示

第三届全国天文社团发展论坛附属项目“星特朗杯”征文活动自开始以来即受到了全国天文社团人的踊跃支持,截止5月5日,共收到资料设计14份,社团合作征文7篇,其中不乏万余字的精心巨作。经论坛组委会评选获奖结果如下：     

第三届全国天文社团发展论坛附属项目“从零开始”社团培训资料设计大赛及“社团合作”征文启事

自2010年,“全国天文社团发展论坛”（以下简称“论坛”）在北京大学青年天文学会的主办下两度成功举行。2011年第二届论坛附属的征文大赛收到了来自北京、天津、甘肃、广西、河北、山东、湖南等地的众多投稿,为当年论坛成果的丰富性和实效性奠定了基础。在此成功经验下,于第三届论坛举办前夕,我们决定发起本次“从零开始”社团培训资料设计大赛暨有奖征文活动。一、主办单位简介2012年第三届全国天文社团发展论坛及其附属项目由中国科技大学学生天文爱好者协会主办。中国科大天协成立于2004年,致力于与各地天文社团的合作以期共同发展,近年来组织或参与协助了众多跨地区的天文交流活动,积极参加了过去两届论坛,在国内天文圈中颇受好评。     

助力长吉图“窗口”经济发展——吉林省珲春市国土资源局实施“双保工程”的做法

近年来,随着《中国图们江区域合作开发规划纲要——以长吉图为开发开放先导区》上升为国家战略,2012年4月,国务院正式批准设立"中国图们江区域(珲春)国际合作示范区",珲春市进入了一个新的发展时期。面对全市重大项目多、用地量大的实际,珲春市国土资源局坚持利用与保护并举,规范与发展并重,实现了土地资源利用效益和经济效益、社会效益的"多赢",促进了全市经济社会科学发展。保发展,当好地方经济发展的护航者     

中澳矿业投资合作的前景分析

中国和澳大利亚互为重要的贸易伙伴,中澳矿产资源合作已成为双边经贸合作的重点和亮点。面对当前脆弱的世界经济形势和澳大利亚矿业投资环境的变化,本文对中企在澳大利亚投资矿业的利弊进行了概要分析,仅供有意投资者参考。     

格陵兰矿业合作前景广阔

格陵兰地处北极,矿产资源丰富,特别是石油、天然气、铁、锌、钼、铜、稀土等矿产的勘查开发投资潜力巨大,是世界上最大的未开发地区之一。随着全球气候逐渐变暖,矿业开发的条件日益趋好,加之2009年格陵兰岛实行自治后,格陵兰政府采取积极吸引国际资本投资该岛矿业的政策,受到业内人士越来越多的关注。本文对格陵兰的矿产资源、矿产勘查开发现状及一些合作项目进行了概略的介绍,仅供参考。     

Co- and post-seismic surface deformation and gravity changes of Ms7.0 Lushan,earthquake

On April 20, 2013, an earthquake with mag- nitude 7.0 occurred in the southwest of the Longmenshan fault system in and around Lushan County, Sichuan Province, China. This devastating earthquake killed hun- dreds of people, injured 10 thousand others, and collapsed countless buildings. In order to analyze the potential risk of this big earthquake, we calculate the co- and post-seismic surface deformation and gravity changes of this event. In this work, a multilayered crustal model is designed, and the elastic dislocation theory is utilized to calculate the co- and post-seismic deformations and gravity changes. During the process, a rupture model obtained by seismic waveform inversion （Liu et al. Sci China Earth Sci 56（7）： 1187-1192, 2013） is applied. The time-dependent relaxation results show that the influences on Lushan and its surrounding areas caused by the Ms7.0 Lushan earthquake will last as long as 10 years. The maximum horizontal displacement, vertical uplift, and settlement are about 5 cm, 21.24 cm, and 0.16 m, respectively; the maximal positive and nega- tive values of gravity changes are 45 and -0.47 μGal, respectively. These results may be applied to evaluate the long-term potential risk caused by this earthquake and to provide necessary information for post-earthquake reconstruction.     

Bridge pier failure probabilities under combined hazard effects of scour, truck and earthquake. Part II: failure probabilities

In many regions of the world, a bridge will experience multiple extreme hazards during its expected service life. The current American Association of State Highway and Transportation Officials (AASHTO) load and resistance factor design (LRFD) specifications are formulated based on failure probabilities, which are fully calibrated for dead load and non-extreme live loads. Design against earthquake load effect is established separately. Design against scour effect is also formulated separately by using the concept of capacity reduction (or increased scour depth). Furthermore, scour effect cannot be linked directly to an LRFD limit state equation because the latter is formulated using force-based analysis. This paper (in two parts) presents a probability-based procedure to estimate the combined hazard effects on bridges due to truck, earthquake and scour, by treating the effect of scour as an equivalent load effect so that it can be included in reliability-based failure calculations. In Part I of this series, the general principle for treating the scour depth as an equivalent load effect is presented. In Part II, the corresponding bridge failure probability, the occurrence of scour as well as simultaneously having both truck load and equivalent scour load effect are quantitatively discussed. The key formulae of the conditional partial failure probabilities and the necessary conditions are established. In order to illustrate the methodology, an example of dead, truck, earthquake and scour effects on a simple bridge pile foundation is represented.     

“抛锚式教学”中的高效“抛锚”——“大规模的海水运动”课例研究

正抛锚式教学是以"创设情境-确定问题-自主(或协作)学习-效果评价"为流程,让学生在一个完整、真实的问题背景中,产生学习的需要,并通过镶嵌式教学以及学习共同体中成员间的互动交流(即合作学习),凭借自己的主动学习、生成学习,亲身体验从识别问题到分析问题、解决问题过程的一种教学模式。我们教研组决定围绕我校江苏省教育科学十二五规划重点课题《抛锚式教学的本土理解和校本实践创新研究》展开子课题"教师如何才能高效抛锚"的研究。抛锚式教学过程中的关键是"抛锚",即教师设定情     

红壤性质的验证与改良实验

正一、实验背景新课程基本理念倡导自主学习、合作学习和探究学习,开展地理观测、地理考察、地理实验、地理调查和地理专题研究等实践活动;强调学习过程与方法;注重情感、态度和价值观的养成。在新教材中,有许多地理素材、案例值得我们去实验、考察和探究,而其中的关键在于我们教师怎样去引导和挖掘?红壤性质的验证与改良就是一个非常直观和适合师生操作的实验。二、实验条件红壤是在湿热环境下形成的一种土壤,在我国南方低山丘陵区有广泛分布。红壤有机质少,酸性强,土