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我国文献计量学论文的主题分布研究 总被引:1,自引:0,他引:1
从主题分析和关键词分析的角度对我国献计量学论的主题内容进行了归纳和分类,以期深入认识该领域献的现状及其发展水平,明确该学科今后的发展重点和方向。 相似文献
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Comparison of oil and egg tempera paint systems using time-of-flight secondary ion mass spectrometry
Zachary E. Voras Kristin deGhetaldi Brian Baade Eric Gordon Glenn Gates Thomas P. Beebe 《文物保护研究》2016,61(4):222-235
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is quickly becoming a critical tool in the field of art conservation. This technique provides high-resolution spatial maps of both inorganic and organic components located within cross-sectional samples collected from works of art. With recent advances in surface analysis, ToF-SIMS can now be used to identify specific amino acids present in protein-containing materials as well as fatty acids in drying oils. For example, the detection of the ion fragment associated with the amino acid hydroxyproline can be used to confirm the use of animal glue in a paint sample. As an analytical technique, ToF-SIMS avoids the need for derivatization/silylation reagents, with no interference by the presence of pigments. Furthermore, the layered systems that are often encountered in historical paint samples remain intact throughout the analytical procedure. This allows for the co-localization of organic and inorganic species in specific layers (e.g. egg yolk paint atop a glue ground). Because of this ability to localize the analytical signal to approximately 6?µm or less, the mass spectral information can be used to produce mass-resolved and spatially-resolve images which can be correlated to previous studies of the same samples. In this study, ToF-SIMS was used to analyze a paint cross section obtained from a painting attributed to Raphael, and another from a painting by the Sienese artist Matteo di Giovanni. 相似文献
3.
知识的构成可从知识点、知识线、知识面、知识体和知识势几个方面来分析。教育手段在时间顺序上的一维性和教育内容在知识构成上的多维性之间的矛盾是知识传授的主要矛盾。由于高职课程体系组建尚不成熟,学科与学科之间、理论与实践之间、教学内容与行业发展之间都存在严重的维度缺失。当前的对策是:以教育大纲替代教学大纲,以知识线密度评价体系替代知识点评价体系,以改造各科教师的知识结构。 相似文献
4.
何俊梅 《安徽广播电视大学学报》2001,(3):67-70
语用学(pragmatics)是研究在特定情景中的特定话语,研究如何通过语境(context)来理解和使用语言。翻译是涉及两种语言、两种文化的信息传递,翻译的特殊困难也由此而产生。本文通过英汉互译实例分析来说明:翻译应以动态对等或功能对等为目标,挑选最接近效果的译法,语用等值得指译文与原文的交际价值的对等,而非表达形式及方式的同一,从语用学角度看,译文无论作怎样的处理,只要它能传达原文的用意,实现语言交际的目的,它就是一种可行的译法。 相似文献
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以苯酐和2-乙基己醇为原料,在自制的TiO_2/Al_2O_3复合型催化剂上合成邻苯二甲酸二异辛酯;确定了反应中催化剂的最佳配比及催化剂制备温度。考察了原料配比、催化剂用量、反应温度等工艺条件对酯化反应的影响。结果表明,该催化剂体系具有较好的催化活性,合成的DOP产品色相较好。 相似文献
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Hypocrellins,includinghypocrellinA (HA)andhypocrellinB (HB) (Fig .1) ,arenewtypesofphoto sensitivepigments growingabundantlyinChina[1,2 ] .Theyexhibitseveraladvantagesoverhaematoporphyrinderivatives (HPDs) presentlyusedinclinics[3] .Howev er,hypocrellinsarelipophilicagentsandexhibitweakab sorptioninthe phototherapeuticwindow (6 0 0— 90 0nm) ,whichpreventsfurtherinvestigationsontheirbio logicalconsequencesandlimitstheirPDTapplicationclinically .Fig .1 Chemicalstructuresofhypocrellinpare… 相似文献
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本文给出了200 A Ge V ~(16)O与核乳胶相互作用的靶核碎片多重数与角分布,讨论了靶核碎片多重数分布与射弹旁观者质子数之间的关联,靶核各类碎片多重数之间的关联,以及角分布与靶核大小之间的关联. 相似文献
9.
李成贵 《张家口职业技术学院学报》2002,15(3):1-3,31
教学过程中,实现教育思想转变的关键是抓住基本矛盾,即:学习课题乃至培养目标同学生知识能力现有发展水平之间的矛盾。核心是坚持以人为本,即:盯住个体,团材施教,差异发展,注重实效。指导教学过程,根本是确立全新教育观念,即:主体性教育观、差异性发展观、创新性质量观。 相似文献
10.
Alfredo Salerno Giampietro Lago Andrea Berti Francesco Calì Mario Mirisola Patrizia Carta Carmen Ferro Valentino Romano 《Journal of Cultural Heritage》2005,6(4):313-319
The sarcophagus containing the remains of Federico II, located in the Cathedral of Palermo (Sicily, Italy), was opened on 1998 to perform a multidisciplinary survey [1]. Next to the remains of Federico II and in close contact with them were laying two other skeletons belonging, according to historical records, to Pietro II di Aragona and to an anonymous person (“The Third Individual”), probably a woman. The bones appeared severely deteriorated. Chemical analysis performed on bone samples excluded that the bodies underwent some kind of embalming process. The analysis of mtDNA from bone samples taken from the three skeletons was successful in only one of the two labs involved. The HVR1-mtDNA sequence (region: from nt 16,035 to nt 16,395), obtained from the bone samples of Federico II and “The Third Individual” appear identical but bear double peaks at the same nucleotide positions, suggesting mixing (i.e. contamination) of different mtDNA types. The HVR1 sequence obtained from the bone sample of Pietro II di Aragona does not present double peaks and differ from the Cambridge Reference Sequence (CRS) at six nucleotide positions. Cloning experiment of the Federico II amplicon demonstrated that the mixed mtDNA types are only two: one identical to CRS, the other identical to the sequence of Pietro II di Aragona. A reconstruction of these data are proposed in the Discussion. Due to the problematic context in which this study was carried out (mixed and deteriorated biological material, failure to replicate results in two different labs), our results and reconstruction can only be offered on a tentative basis. It is hoped that the data presented in this study will reveal useful, for future comparison, if further molecular genetics research will be carried out on the royal dynasties that ruled Sicily in the early centuries of the past millennium. 相似文献