Multiphase flow simulation through porous media with explicitly resolved fractures

Accurate simulation of multiphase flow in fractured porous media remains a challenge. An important problem is the representation of the discontinuous or near discontinuous behaviour of saturation in real geological formations. In the classical continuum approach, a refined mesh is required at the interface between fracture and porous media to capture the steep gradients in saturation and saturation‐dependent transport properties. This dramatically increases the computational load when large numbers of fractures are present in the numerical model. A discontinuous finite element method is reported here to model flow in fractured porous media. The governing multiphase porous media flow equations are solved in the adaptive mesh computational fluid dynamics code IC‐FERST on unstructured meshes. The method is based on a mixed control volume – discontinuous finite element formulation. This is combined with the P_N+1DG‐P_NDG element pair, which has discontinuous (order N+1) representation for velocity and discontinuous (order N) representation for pressure. A number of test cases are used to evaluate the method's ability to model fracture flow. The first is used to verify the performance of the element pair on structured and unstructured meshes of different resolution. Multiphase flow is then modelled in a range of idealised and simple fracture patterns. Solutions with sharp saturation fronts and computational economy in terms of mesh size are illustrated.     

Chemical and Microscopic Study of Masonry Mortar in Ancient Pagodas in East China

Ancient mortars played a crucial role in the construction of historical architectures due to their physical and chemical compatibility with traditional building materials such as stones and bricks. Therefore, the analysis and optimization of the ancient mortar formula are significant in the restoration and preservation of historical sites. In this work, 20 mortar samples selected from five ancient stone pagodas in Zhejiang Province, China, were analyzed. The results showed that mud, lime-soil mortar, lime-sand mortar, and lime-gypsum mortar were used as binders in these pagodas. The Ca(OH)₂/aggregate ratio ranging from 0.3 to 2.7 was usually used to prepare lime mortar. Protein and polysaccharide were also found in some samples.     

从《牡丹亭》看女性教育

《牡丹亭》是汤显祖"至情论"在"临川四梦"中最集中的体现,其中女主角杜丽娘堪称"至情论"最佳诠释者。一部经典剧作的内涵往往不是单一的,作者在《牡丹亭》中除了建构"情教论",反科举外,还有对女性教育的思考。《闺塾》一出极为精彩,其中塾师陈最良、女学生杜丽娘及其伴读春香一同演绎了明末私塾教育的一个场景。通过《闺塾》以及相关剧情的解读,可以反观晚明社会女性教育的林林总总。如:教材的选用,教学内容的拟定,教育方法的采用,教育环节的把握等,这些均直接影响教学效果的实现,教学目标的达成,这有助于我们了解那个时代女性教育的情状,对当下的女性教育亦不无启迪意义。     

“罗马和平”时期石碑的保护修复

罗马帝国初期的200年(公元前27年~公元2世纪)是罗马的鼎盛时期,开创了经济、文化、军事、艺术前所未有的高峰,被称为"罗马和平"时期。本文保护修复的几件"罗马和平"时期的石碑原本收藏在意大利罗维纳市的Lapidario博物馆,后委托意大利博洛尼亚KRITERION文物修复公司进行保护修复,进行了清洗、补全、封护等保护修复工作。     

抗战中的知识分子

作者通过对甲午战争至全面抗战爆发历史的回顾,分析期间中国知识分子的思想变化.并分析抗战爆发后知识分子通过不同的方式积极投入救亡运动,重新认识抗战期间的知识分子的真实处境和历史,提出应更理性、客观的去看待抗战时期的知识分子的选择,无论是自由主义知识分子、马克思主义知识分子还是新儒家知识分子,对近代中国文化的追求,根本上都是“三民主义”.     

广西革新桥遗址出土的石拍研究

革新桥遗址是一处新石器时代石器制造场遗址。2002年10月至2003年1月发掘,出土数以万计的石制品,还发现两座墓葬。年代为距今6000-5500年前。本文对该遗址中出土的一件石拍进行观察,并就其制作工艺及功能和用途进行探讨。     

《坚持四项基本原则》的形成与历史地位

在全面拨乱反正的背景下,理论工作务虚会第一阶段对新中国成立以来的若干重大理论与历史问题进行了热烈讨论,但是会议期间出现了一些不协调的声音,引起中共中央的注意,加之社会上出现的错误思潮,影响了安定团结的局面。在这种情况下,邓小平代表中共中央在全国理论工作务虚会上作了《坚持四项基本原则》的报告,明确提出了"四个坚持"。这个报告在全国理论工作务虚会和随后召开的中央工作会议上引起热烈讨论,各地也很快掀起了一场贯彻学习四项基本原则、进行真理标准讨论"补课"的热潮。随着改革开放事业的发展,四项基本原则作为立国之本的地位被确立起来,并不断被赋予新的时代内涵。     

明初大运河南旺分水枢纽水工技术考

明朝初年,国脉皆仰东南,为解决南方粮财物的北运问题,宋礼和白英受命组织修建了大运河山东段南旺分水枢纽。该枢纽主要包括引汶济运、导泉补源、设立水柜和置闸节流四个组成部分。其中,引汶济运是工程之重点,包括戴村坝、小汶河、南旺分水以及配套工程等四个子系统。这些水利设施组成一个和谐的系统工程,保证了该段运河的水量稳定充足,从而实现了大运河500余年的正常通行。南旺分水枢纽代表了我国古代运河水工的最高科学技术成就,堪称世界水利史上的一大经典范例。     

A MOUNTAIN WEASEL SPOTTED IN LHASA

<正>Four of us went to a suburb in Lhasa for an autumn outing one day in the middle of October.We drove out of the downtown area heading east and reached our destination,Caigongtang Temple.Interestingly enough,it was a result of random selection based on Google maps that led us here since we neither knew     

洛林吉亚国王罗退尔二世离婚风波迭起的历史动因

基督教会提倡"婚姻不可分解"的理念,这种理念随着基督教会势力的壮大和宗教思想的深入人心,对中世纪西欧封建帝王的婚姻构成了一种道德约束作用。而罗马教延等现实政治生活中的各方势力也常常以此为由,向那些有违婚姻道德的世俗帝王问责发难。洛林吉亚王国的国王罗退尔二世的离婚案即是一起因此而发的政治风波。由于基督教婚姻理念的约束作用,加洛林帝国的分裂瓦解、同宗诸王的纷争内斗、教皇权威开始抬头等众多历史因素的叠加、交织,使得罗退尔二世不仅无法像他的先祖查理曼那样可以自由地离异,反而成了众矢之的,最后以"身死国灭"的历史悲剧黯然收场。