污染大气中浑仪,简仪的带锈防护

浑仪、简仪（以下简称两仪）在高PH、大气污染和日晒雨淋环境中的腐蚀是一种动态加速腐蚀过程。采用合成的双唑胺铜缓蚀剂和有机硅改性的甲基丙烯酸树脂,并分别复配成协同缓蚀剂群和含有增效稳定剂的封护剂。采用这两种材料和脱水后再防护的工艺,使带锈防护后的浑仪、简仪的腐蚀低于无污染大气中的速率。用电化学方法评价了防护技术的可行性,根据腐蚀与人工老化试验结果讨论了防护材料性能与腐蚀环境和带锈防护的关系,采用XPS分析方法探索了双唑胺比BTA更适用于两仪防护的原因。     

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.     

卢梭回归自然的美学之境

卢梭的“自然美”思想丰赡深邃,精远宏阔.从美育目标、理念、重点三个层面梳理了卢梭自然主义美育思想的核心内容,将其教育特点归纳为整体性、平民性、情感性和自然性,并着重阐述了这一思想对新时期我国美育工作的四个重要启示:即注重美育工作的辩证性;尊重美育实践的主体性;激励美育过程的情感性;倡导美育内容的生态性.     

新中国土地改革后新富农产生的规模与分布研究

从土地改革结束到农业集体化高潮前夕,新富农的出现从全国范围来看是稀少而缓慢的。在各省之间,农民的富裕程度与新富农比重大小关系不明显,但在同一地区内来看,两者呈现正相关关系。同时,在农业合作化程度较高亦即是较早对新富农采取限制政策的地区,新富农的比重并不一定低于甚至高于其他地区。这说明多种因素对新富农的产生、发展发生作用,单因素的分析不能解释清楚新富农这个复杂的社会经济问题。     

国民经济恢复时期北京的失业知识分子救济政策及其成效

国民经济恢复时期,面对失业和人才需求关系的矛盾,城市失业知识分子受到党和政府的高度关注。北京市的失业知识分子虽人数不多,但呈现出一定程度的复杂性。为此,北京市根据党和国家的政策,从首都社会秩序的稳定和首都建设的人才需求出发,在较短的时间内,有计划有步骤地对失业知识分子进行了必要的社会救济,达到了预期的目标。同时,实际操作中也遇到了一些不容回避的问题。     

Chemical and mineralogical characterization of Aguada Portezuelo pottery from Catamarca,north-western Argentina: PIXE,XRD and SEM-EDS studies applied to surface pre- and post-firing paints,slips and pastes

Particle-induced X-ray emission (PIXE), X-ray diffraction (XRD), electron microprobe analysis (EDS) and scanning electron microscopy (SEM) analytical techniques were used to characterize surface paints in pre- and post-fired Aguada Portezuelo decorated pottery. Surface paintings in black, white, red, brown, burgundy and ochre were analysed. Major, minor and trace elements were detected by PIXE, whereas XRD and SEM-EDS gave information on the main mineral phases and the characteristic morphology for each analysed pigment. The results obtained indicate that the main colour groups can be easily discriminated by PIXE, and they are characterized by only one pigment for each colour: hematite (red) and manganese mineral oxides (black), respectively, whereas white pigments are characterized by calcite, ghelenite and gypsum.     

First Evidence Of The Use Of Freshwater Pearls As A Cosmetic In Ancient China: Analysis Of White Makeup Powder From A Northern Song Dynasty Lv Tomb (Lantian,Shaanxi Province,China)

The Lv family tombs in Lantian, Shaanxi Province are one of the most important archaeological sites of China in recent years, providing numerous objects and a wealth of information for the study of the history of the Northern Song dynasty. There were a large number of exquisite cultural relics unearthed from the tombs, including one porcelain box containing white powder, which was identified as women's makeup. The phase composition, microstructure, thermal properties and characteristics of the trace elements in the unearthed white cosmetic powder were comprehensively analysed by X‐ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry – thermogravimetry (DSC–TG), Fourier transform infrared (FT–IR) microscopy and inductively coupled plasma atomic emission spectroscopy (ICP–AES). The white makeup powder was determined to be a product made from high‐quality freshwater pearls. These results, for the first time, showed evidence that freshwater pearl powder was used as a cosmetic in ancient China using archaeological objects, providing scientific evidence and new clues to enrich and expand research into the ancient Chinese cosmetic materials.     

Isotopic Composition of Lead in Copper Ores and a Copper Artefact from the La Profunda Mine (León,Spain)

This paper continues the characterization of the lead isotopic fingerprint of ancient copper mines in the north‐west of Spain. In this work, the lead isotopic compositions found in copper ores from the La Profunda mine are presented. Azurites and malachites sampled from this deposit were subjected to lead isotope analysis by multicollector ICP–MS. The results showed a clear radiogenic lead signature compatible with the presence of uranium‐rich minerals (such as zeunerite) in the same mining complex. Moreover, a rare copper artefact, found in the galleries of the mine during its modern exploitation, was also analysed and showed that local mineral was used for its manufacturing.     

柳诒徵的“史德”论及其史学批评

“史德”论是史学理论中的重要范畴之一。这一概念最早由清代史学家章学诚提出,后经梁启超等人进一步阐发。柳诒徵在对章学诚、梁启超等人“史德”论批评与继承的基础上,提出了自己的独到见解。他论述了“有史而德”及“从德而史”的辨证关系,并强调“治史以畜德”的重要性。柳诒徵的“史德”是对前人的补充和发展。     

日本侵华对中国现代化建设的破坏——以上海闸北为例

在一二八、八一三事变中,上海两次惨遭日军炮火蹂躏,尤其是闸北的繁华地带东北、西南两处,先后因日军轰炸使三十年的建设成就荡然无存。日本的侵华战争不但中断了闸北的现代化建设,还直接导致了该地区的长期沉沦。