仿生合成石质文物二氧化硅保护膜的研究

由于二氧化硅仿生材料具有优越的耐候性,与基底石材相容性好,合成条件的温和性及对环境无污染等优点,为此制备了二氧化硅防护膜。室温下利用CTAB自组装体为模板来调控Na2SiF6水解,在石材表面制备出具有优良性能的SiO2膜,并对膜进行了XRD、SEM分析表征。经过保护处理的石材表面清洁、透明,具有突出的抵抗酸碱性能。生成的保护膜具有良好的透气性,而吸水性有所下降。另外,该保护膜还显示出优良的抵抗高、低温,耐磨,及与基底结合紧密等性能。上述研究表明,仿生SiO2膜将会对石质文物起到更好的保护作用。     

The potential for abiotic organic synthesis and biosynthesis at seafloor hydrothermal systems

Calculations are presented of the extent to which chemical disequilibria are generated when submarine hydrothermal fluids mix with sea water. These calculations involve quantifying the chemical affinity for individual reactions by comparing equilibrium compositions with the compositions of mixtures in which oxidation–reduction reactions are inhibited. The oxidation–reduction reactions that depart from equilibrium in these systems provide energy for chemotrophic microbial metabolism. Methanogenesis is an example of this phenomenon, in which the combination of carbon dioxide, hydrogen and methane induced by fluid mixing is far from equilibrium, which can be approached if more methane is generated. Similarly, the production of other organic compounds is also favorable under the same conditions that permit methanogenesis. Alkanes, alkenes, alcohols, aldehydes, carboxylic acids and amino acids are among the compounds that, if formed, would lower the energetic state of the chemical composition generated in mixed fluids. The resulting positive values of chemical affinity correspond to the thermodynamic drive required for abiotic organic synthesis. It is also possible that energy release accompanies biosynthesis by chemotrophic organisms. In this way, hydrothermal ecosystems differ radically from familiar ecosystems at Earth's surface. If captured, the energy released may be sufficient to drive biosynthesis of carbohydrates, purines, pyrimidines and other compounds which require energy inputs.     

宋元墓葬中榜题、题记研究

宋元时期墓壁上的题刻文字,称之为榜题和题记。它们是研究当时丧葬观念和社会生活的重要文字资料,是现今所见到的最原始的宋元民间书写形式。榜题与图像相配,用于解释图像、指示图像内容;题记涉及纪年、地理、家族、历史史实等,富含大量的社会历史信息,堪补史籍之不足。     

Of Some Paradoxes in the Historiography of Molecular Biology**

Just when molecular biology is arguably delivering on some of its long-promised medical applications—think mRNA vaccines, monoclonal antibody drugs, PCR testing, and gene therapies—the history of molecular biology has lost much of its shine. What not too long ago seemed like a burgeoning field of research with endless possibilities, is now often reduced to the “central dogma” that saw its apotheosis in the effort to sequence the human genome but has since unraveled. The essay will discuss several possible answers to this apparent paradox.     

Culture and Politics,Behavior and Biology: Seeking Synthesis among Fragmentary Anthropological Perspectives on Hunter-Gatherers

Hunter-gatherers define humanity's Pleistocene evolutionary past. Yet, hunter-gatherer societies in the 20th–21st centuries are examples par excellence of cultural marginalization, domination, and resilience. This review of six recent works on hunter-gatherers—spanning Paleolithic archaeology, bioarchaeology, behavioral ecology, and cultural anthropology—underscores that human forager diversity can be explained neither by culturally embedded political processes nor by ecologically situated evolutionary factors alone. Yet, theoretical bridging frameworks remain elusive, with a narrowing but persistent culture-biology divide. Recent developments in evolutionary life-history theory provide a robust biocultural foundation for understanding human sociality and the symbolic constitution of embodied cultural practice.     

壳聚糖/二氧化硅复合仿生膜对 碳酸盐石材的保护作用

为探讨壳聚糖/二氧化硅复合仿生膜对碳酸盐石材的保护作用,采用仿生合成技术,以十六烷基三甲基溴化铵为有机模板,能过壳聚糖调控二氧化硅颗粒的生长,在碳酸盐石材表面仿生合成得到了一层壳聚糖/二氧化硅复合保护膜,对其基本性能进行了检测评价,并利用衰减全反射红外光谱和场发射环境扫描电子显微镜表征了膜的结构形貌。实验结果表明,该膜具有优良的耐酸、耐污性能,提高了膜层的抗冻融性和耐热老化性能,并保留了石材原有的吸水性和透气性。壳聚糖/二氧化硅复合膜改善了单一二氧化硅膜的开裂问题,且该保护膜与石材基体结合紧密、膜层薄,小影响石材外脱,是一种良好的碳酸盐石材保护材料。     

A Discussion on the Emergence and Development of Ancient Chinese Artificial Barium Copper Silicate Pigments from Simulation Experiments

The ancient Chinese barium copper silicate minerals mainly comprise Chinese purple (BaCuSi₂O₆) and Chinese blue (BaCuSi₄O₁₀), which were widely used from the late Warring States Period to the late Eastern Han Dynasty. In order to clarify the raw material of the pigment, a series of simulation experiments was conducted to produce Chinese purple pigment under varying mineral conditions. The minerals that we applied in the experiment were quartz as the source of silicon, malachite and copper oxide as the sources of copper, barite and witherite as the sources of barium and lead oxide as the source of lead. Simulation experiments showed that the barium copper silicate minerals and the purple pigment can be produced easily when witherite is used as the barium‐containing raw material. From the perspective of mineral resources, the birth of the ancient Chinese pigment associated with a unique barium mineral resource. The Chinese copper‐based pigments are assumed to have been developed independently and are presumably an outcome of historical developments in glazing techniques.     

Synthesis by microbes or chemists? Pharmaceutical research and manufacturing in the antibiotic era

This article presents a case study of the rise of Pfizer as a leading pharmaceutical company, with a focus on changing relationships between manufacturing technology and R&D between the mid 1940s and the mid 1960s. Pfizer first moved into pharmaceuticals through participation in the US government's penicillin effort during World War II. The company had expertise in deep tank, biological fermentation for the production of chemicals that it adapted to the manufacture of penicillin. Having greatly expanded its biological manufacturing capacity to meet state needs, Pfizer adopted an R&D program to find new microbial antibiotics suited to its manufacturing technology after the war ended. Pfizer's successes in this antibiotic era established the firm as a major pharmaceutical company. In looking to larger commercial markets for drugs, Pfizer, like its competitors, pursued medicines for chronic diseases rather than acute infections. For this pursuit, in the 1950s and 1960s, Pfizer transformed itself into a chemistry‐orientated pharmaceutical firm by reorienting its R&D toward chemistry. This led to a growing divergence between R&D and manufacturing and the eventual replacement of biological manufacturing with chemical manufacturing. The article explores the changing trajectories of R&D and manufacturing at Pfizer, their shifting positions within the firm, and the consequences of these changes and shifts for the firm's strategy and organization.     

近十年来大陆乾嘉考据学研究综述

近十年来,大陆学在继承前贤研究成果的基础上,对乾嘉考据学的成因、流派、史学成就以及与之相关的汉宋之争等问题进行了深入探讨。尤其值得注意的是,乾嘉经世之学和“乾嘉新义理学”的研究突破已有成说,开拓了新的研究路向,也扩展了乾嘉考据学的研究范围。     

明遗民与清初满汉文化的整合

在清初社会的重建过程中,满汉两种异质文化经历了从冲突到调融再到整合的演绎,与之相谐应,明遗民对清廷的态度也发生了从抗争到徘徊分化再到合流的转捩。满、汉文化与明遗民呈显一种双向互动关系,遗民现象因满、汉文化的紧张而凸显,亦因满、汉文化的调融而淡化。透过这种互动关系来探赜清初历史,将会得出合理的历史结论。