从造纸术摇篮到造纸工业现代化

众所周知，我国是造纸术的摇篮。造纸术的外传曾经一度起到促进世界文化发展的作用。然而，我国却经历了数百年的历程，机制纸才开始取代手工造纸，事实上，我国造纸工业是在中华人民共和国成立后，才开始阔步前进，并在1993年其纸和纸板总产量跃居世界主要产纸国家第三位。然而，人均消费量依然仅有36公斤，远远落后于世界平均水平的50公斤。为了促进我国造纸工业的现代化和健康发展，今后务必着眼于可持续纤维原料的开发和利用，认真执行清洁生产和质量第一的技术路线。这就意味着有必要在纤维原料中增加木材的份额。与此同时，又必须妥善处理工厂排污（特别是蒸煮废渣的处理），务使取得更好的环境保护效果。不言而喻，也就更有必要加强科研与开发工作，针对我国纤维原料的特点有所创新，并做到在实际生产中得到兑现。     

J. L. Lagrange's changing approach to the foundations of the calculus of variations

Archive for History of Exact Sciences -     

From endoderm to pancreas: a multistep journey

The formation of the vertebrate pancreas is a complex process that typifies the basic steps of embryonic development. It involves the establishment of competence, specification, signaling from neighboring tissues, morphogenesis, and the elaboration of tissue-specific genetic networks. A full analysis of this multistep process will help us to understand classic principles of embryonic development. Furthermore, this will provide the blueprint for experimental programming of pancreas formation from embryonic stem cells in the context of diabetes cell-therapy. Although in the past decade many studies have contributed to a solid foundation for understanding pancreatogenesis, important gaps persist in our knowledge of early pancreas formation. This review will summarize the current understanding of the early mechanisms coming into play to pattern the "pre-pancreatic" region within the endoderm and, gradually, specify the pancreatic tissue.     

From proportion to balance: the background to symmetry in science

We call attention to the historical fact that the meaning of symmetry in antiquity—as it appears in Vitruvius’s De architectura—is entirely different from the modern concept. This leads us to the question, what is the evidence for the changes in the meaning of the term symmetry, and what were the different meanings attached to it? We show that the meaning of the term in an aesthetic sense gradually shifted in the context of architecture before the image of the balance was attached to the term in the middle of the 18th century and well before the first modern scientific usage by Legendre in 1794.     

From successful measurement to the birth of a law: Disentangling coordination in Ohm's scientific practice

In this paper, I argue for a distinction between two scales of coordination in scientific inquiry, through which I reassess Georg Simon Ohm's work on conductivity and resistance. Firstly, I propose to distinguish between measurement coordination, which refers to the specific problem of how to justify the attribution of values to a quantity by using a certain measurement procedure, and general coordination, which refers to the broader issue of justifying the representation of an empirical regularity by means of abstract mathematical tools. Secondly, I argue that the development of Ohm's measurement practice between the first and the second experimental phase of his work involved the change of the measurement coordination on which he relied to express his empirical results. By showing how Ohm relied on different calibration assumptions and practices across the two phases, I demonstrate that the concurrent change of both Ohm's experimental apparatus and the variable that Ohm measured should be viewed based on the different form of measurement coordination. Finally, I argue that Ohm's assumption that tension is equally distributed in the circuit is best understood as part of the general coordination between Ohm's law and the empirical regularity that it expresses, rather than measurement coordination.     

How to put a black box in a showcase: History of science museums and recent heritage

Coping with recent heritage is troublesome for history of science museums, since modern scientific artefacts often suffer from a lack of esthetic and artistic qualities and expressiveness. The traditional object-oriented approach, in which museums collect and present objects as individual showpieces is inadequate to bring recent heritage to life. This paper argues that recent artefacts should be regarded as “key pieces.” In this approach the object derives its meaning not from its intrinsic qualities but from its place in an important historical event or development. The “key pieces” approach involves a more organic way of collecting and displaying, focussing less on the individual object and more on the context in which it functioned and its place in the storyline. Finally, I argue that the “key pieces” approach should not be limited to recent heritage. Using this method as a general guiding principle could be a way for history of science museums to appeal to today’s audiences.     

Monetary Aggregates to Improve Early Output Gap Estimates in the Euro Area: An Empirical Assessment

Output gap estimates at the current edge are subject to severe revisions. This study analyzes whether monetary aggregates can be used to improve the reliability of early output gap estimates as proposed by several theoretical models. A real‐time experiment shows that real M1 can improve output gap estimates for euro area data. For many periods the cyclical component of real M1 shows good results, while a forecasting strategy based on projecting GDP series seems to be more robust and provides superior results during the Great Recession. Broader monetary aggregates provide no superior information for output gap estimates. Copyright © 2015 John Wiley & Sons, Ltd.     

Introduction to values and pluralism in the environmental sciences: From inferences to institutions

Philosophers of science continue to elaborate our understanding of the roles that values play in scientific reasoning, practice, and institutions. This special issue focuses on the environmental sciences, a mosaic of fields ranging from restoration ecology to forestry to climatology, unified by its attention to the relationships between humans and their habitats. It is a field that revolves around ameliorating environmental problems, aiming to support the provision of social goods and provide guidance to policymakers about how to regulate individuals and industries. Values abound in such judgments as setting the boundaries of an ecosystem, integrating the human dimensions of social-ecological systems, and collaborating with stakeholders. Since few in the field are likely to insist that these judgments can be made without reference to social values, environmental science can serve as fertile ground for exploring the ethical, social, and political terrain at the frontier of the science and values discourse.     

A Companion to the History of Science

Snell's law of refraction did not affect the study of optics until twenty‐five years after its publication in 1637 and by then its universality threatened to break down already. Two optical phenomena—colour dispersion and strange refraction—were discovered that did not conform to the sine law. In the early 1670s, Isaac Newton and Christiaan Huygens respectively investigated these phenomena. They tried to describe the irregular behaviour of light rays mathematically and to reconcile it with ordinary refraction. This paper discusses their investigations and aims at throwing new light on the history of seventeenth‐century optics. Both initially approached the problem in a mathematical way in which they built on Descartes' analysis of refraction. This is surprising because it contradicts their earlier dismissal of Descartes' account and it does not fit our picture of them as mathematical physicists. By looking more closely at their early investigations it becomes clear that Newton and Huygens first had to develop the approach to optics of their later writings. After Descartes placed the issue of the physical nature of light rays on the scientific agenda in 1637, they recognized its purport in their struggles with colour dispersion and strange refraction. It was at this point that their physical optics evolved from the traditional geometrical optics with which they had started.     

The introduction of the differential notation to Great Britain

In the history of chemistry, the Danish chemist Julius Thomsen (1826–1909) is best known for his contributions to thermochemistry. Throughout his life, he was a pronounced atomist and a tireless advocate of neo-Proutian views as to the constitution of matter. On many occasions, especially in his later years, he engaged in speculations concerning the unity of matter and the complexity of atoms. In this engagement, Thomsen was alone in Danish chemistry, but his works were representative of a large number of 19th-century chemists, particularly in England and Germany. Thomsen's ideas as to the constitution of matter, the periodic system and the noble gases, may be seen as typical of this vigorous trend in fin de siècle chemistry.     

Relativity of motion: From Occam to Galileo

Early observations of the southern celestial sky were reported in many sixteenth-century books and compilations of voyages of discovery. Here we analyse these accounts in order to find out what was really seen and reported by the first navigators. Our analysis had resulted in new interpretations of the phenomena reported by Amerigo Vespucci and Andreas Corsali. Thus, a reassessment of the discovery of the Coalsack Nebula, the Magellanic Clouds, and the Southern Cross can be made. From a comparative review of the observations of the latter constellation as published between 1500 and 1600, we demonstrate that only questionable records found their way to contemporary compilations of voyages of discovery, and that as a result public knowledge about this constellation at the end of the sixteenth century was entirely unreliable. Another problem we discuss is that although the stars of the Southern Cross were the first to be discovered, and were observed again and again by many navigators, it was not until 1678 that their proper positions were found in stellar atlases and star catalogues accessible to astronomers. We explain how negligence of and subsequently confidence in Ptolemy's astronomy by, respectively, the early navigators and cartographers, were at the root of this amazingly long-lasting gap in the knowledge of the southern celestial sky.     

From immune response to cancer: a spot on the low molecular weight protein tyrosine phosphatase

Reversible tyrosine phosphorylation is a key posttranslational regulatory modification of proteins in all eukaryotic cells in normal and pathological processes. Recently a pivotal janus-faced biological role of the low molecular weight protein tyrosine phosphatase (LMWPTP) has become clear. On the one hand this enzyme is important in facilitating appropriate immune responses towards infectious agents, on the other hand it mediates exaggerated inflammatory responses toward innocuous stimuli. The evidence that LMWPTP plays a role in oncological processes has added a promising novel angle. In this review we shall focus on the regulation of LMWPTP enzymatic activity of signaling pathways of different immunological cells, the relation between genetic polymorphism of LMWPTP and predisposition to some type of inflammatory disorders and the contribution of this enzyme to cancer cell onset, growth and migration. Therefore, the LMWPTP is an interesting target for pharmacological intervention, thus modifying both inappropriate cellular immune responses and cancer cell aggressiveness. Received 15 August 2008; received after revision 06 October 2008; accepted 14 October 2008     

From sunspots to the Southern Oscillation: confirming models of large-scale phenomena in meteorology

The epistemic problem of assessing the support that some evidence confers on a hypothesis is considered using an extended example from the history of meteorology. In this case, and presumably in others, the problem is to develop techniques of data analysis that will link the sort of evidence that can be collected to hypotheses of interest. This problem is solved by applying mathematical tools to structure the data and connect them to the competing hypotheses. I conclude that mathematical innovations provide crucial epistemic links between evidence and theories precisely because the evidence and theories are mathematically described.     

From Helmholtz to Schlick: The evolution of the sign-theory of perception

Efforts to trace the influence of fin de siècle neo-Kantianism on early 20th Century philosophy of science have led scholars to recognize the powerful influence on Moritz Schlick of Hermann von Helmholtz, the doyen of 19th Century physics and a leader of the zur?ck zu Kant movement. But Michael Friedman thinks that Schlick misunderstood Helmholtz' signature philosophical doctrine, the sign-theory of perception. Indeed, Friedman has argued that Schlick transformed Helmholtz' Kantian view of spatial intuition into an empiricist version of the causal theory of perception. However, it will be argued that, despite the key role the sign-theory played in his epistemology, Schlick thought the Kantianism in Helmholtz' thought was deeply flawed, rendered obsolete by philosophical insights which emerged from recent scientific developments. So even though Schlick embraced the sign-theory, he rejected Helmholtz' ideas about spatial intuition. In fact, like his teacher, Max Planck, Schlick generalized the sign-theory into a form of structural realism. At the same time, Schlick borrowed the method of concept-formation developed by the formalist mathematicians, Moritz Pasch and David Hilbert, and combined it with the conventionalism of Henri Poincaré. Then, to link formally defined concepts with experience, Schlick's introduced his ‘method of coincidences’, similar to the ‘point-coincidences’ featured in Einstein's physics. The result was an original scientific philosophy, which owed much to contemporary scientific thinkers, but little to Kant or Kantianism.