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。     

基于手机信令数据的长春市活动空间特征与社区分异研究

居民时空行为成为透视城市空间的重要视角,本文基于手机信令数据研究长春市活动空间及其社区分异,轮廓性的揭示居住空间、就业空间和消费休闲空间的分布规律,从人地互动的过程与格局的视角认识城市空间。研究发现,居住活动对中心城区依赖明显高于就业和消费休闲活动,就业活动呈现多中心连片发展格局,近郊的欧亚卖场和郊区的净月潭成为人们消费休闲活动的重要选择。就业-居住距离和消费休闲-居住距离的社区分异显著,折射出三类活动空间关系复杂,由此感知城市生活空间质量和社会空间结构。通过对社区分异的空间聚类分析明晰各地域自身问题,从而有针对性的对长春的空间调整优化和居民行为引导提出建议,构建和谐宜居的城市空间。     

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.     

Flexural Behavior of Typical Chinese Traditional Timber Stitching Beams

In Chinese traditional timber buildings, stitching is very common. When the bearing capacity or the rigidity is inadequate, a timber beam is often strengthened with another beam using the stitching method. The timber stitching beams are mainly of two types—the small-top/big-bottom type and the big-top/small-bottom type. To study the bending behavior of these two types of timber stitching beams, including the failure mode, the flexural capacity, the strain distribution at mid-span section, and the maximum deflection, bending tests are carried out on 14 timber stitching beams with Chinese traditional conformation for seven pine beams and seven fir beams. The results show that the failure modes of the small-top/big-bottom type of stitching beams all show brittle fractures at the bottoms of the bottom beams. The failure modes of the big-top/small-bottom type of stitching beams all show brittle fractures at the bottoms of the top beams. The distribution of section strain along the height of each part of the beam basically obeys plane hypothesis. Based on the theoretical and experimental analysis, the calculation formulas of flexural capacity and maximum deflection of these two types of timber stitching beams made of pine and fir are presented.     

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.     

南方地区古建筑木结构的整体性残损点指标研究

古建筑木结构的残损点指标是对古建筑木结构进行结构安全评估和加固修缮设计的重要指标,目前主要依据1992年制定的《古建筑木结构维护与加固技术规范》(GB 50165—92)中的规定,为了对该规范中的构架整体性残损点指标进行验证和补充,本研究通过对南方地区传统的穿斗木构体系和抬梁木构体系的典型榫卯节点和构架的试验研究,得出两种木构体系结构的整体性关键残损点指标,并与GB 50165—92规范进行比较分析。结果表明:规范规定的抬梁式木构架和穿斗式木构架的局部倾斜残损点比试验结果小,规范值偏于安全。规范中规定的抬梁式木构架梁柱榫卯连接残损点略小于试验结果,规范值偏于安全;而规范中规定的穿斗式木构架梁柱榫卯连接残损点对于燕尾榫穿斗木构而言是安全的,但对于透榫穿斗木构而言,则是不安全的。     

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.