首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
原子钟已经发展到很高的水平,它们在空间科学试验中起着非常重要的作用。本文介绍国外已经建议和正在开展的高精度空间钟计划,以及它们在国际空间站(ISS)微重力环境下所进行的某些基础物理方面的测试。  相似文献   

4.
北京稻香湖园林水系的浮游植物与水质变化   总被引:3,自引:0,他引:3  
2007年对以再生水为补给水源的北京稻香湖园林水系进行生态修复试验.该水系正常运行,按比例投加生态修复剂和滤食性鱼类,促进再生水中有机污染物的降解及其通过食物链的转化.试验区浮游植物群落由蓝藻、绿藻、硅藻、隐藻、裸藻和甲藻构成,平均密度为2959.95×104cells/L,其中蓝藻所占56.8%.透明度平均37.4cm,对TN、TP、CODcr的去除率分别为91.33%、94.07%、CODcr 81.96%.水质明显改善,夏秋季未发生蓝藻水华.  相似文献   

5.
现代企业的生产经营、内部公务、业务信息、商务信息、政信息都需要利用网快捷地实现。网络是信息交换的路径,信息是网络建设的基础和依据。只有建立完整,准确的数据才能使高速、快捷的网络发挥作用。  相似文献   

6.
Well-known in his day, but overlooked since, Erasmus King lectured in natural and experimental philosophy from the 1730s until 1756 at his Westminster home and twenty other venues, publicizing his frequent courses exclusively in the Daily Advertiser. In 1739 he escorted Desaguliers's youngest son to Russia, hoping to demonstrate experimental philosophy to the Russian empress. En route, he conducted trials with a sea-guage in the Baltic which were reported by Stephen Hales in his Statical Essays. Various sources testify to King's subsequent experimental research for Hales in the fields of anatomy, respiration and electricity. There is recorded evidence for the exceptional range and quality of King's scientific apparatus and models.  相似文献   

7.
Though Robert Boyle called final causes one of the most important subjects for a natural philosopher to study, his own treatise on the subject, the Disquisition about Final Causes, has received comparatively little scholarly attention. In this paper, I explicate Boyle's complex argument against the use of teleological explanations for inanimate bodies, such as metals. The central object of this argument is a mysterious allusion to a silver plant. I claim that the silver plant is best understood as a reference to alchemical product: the Arbor Dianae, an offshoot of George Starkey's recipe for the Philosophers' Stone. Then, I show how the context of alchemy not only clarifies Boyle's argument but also places it within a wider dialectic about matter and teleology. I then contrast the parallel arguments of Boyle and John Ray on the question of whether metals have divine purposes and show that the difference is explained by Boyle's belief in the transmutation of metals.  相似文献   

8.
SUMMARY

Eighteenth-century scientific translation was not just a linguistic or intellectual affair. It included numerous material aspects requiring a social organization to marshal the indispensable human and non-human actors. Paratexts and actors' correspondences provide a good observatory to get information about aspects such as shipments and routes, processes of translation and language acquisition (dictionaries, grammars and other helpful materials, such as translated works in both languages), texts acquisition and dissemination (including author's additions and corrections, oral presentations in academic meetings and announcements of forthcoming translations).

The nature of scientific translation changed in France during the second half of the eighteenth century. Beside solitary translators, it also happened to become a collective enterprise, dedicated to providing abridgements (Collection académique, 1755–79) or enriching the learned journals with full translations of the most recent foreign texts (Guyton de Morveau's ‘Bureau de traduction de Dijon’, devoted to chemistry and mineralogy, 1781–90). That new trend clearly had a decisive influence on the nature of the scientific press itself. A way to set up science as a social activity in the provincial capital of Dijon, translation required a local and international network for acquiring the linguistic and scientific expertise, along with the original texts, as quickly as possible. Laboratory results and mineralogical observations were used to compare material facts (colour, odour, shape of crystals, etc.) with those described in the original text. By providing a double kind of validation – with both the experiments and the translations – the laboratory thus happened to play a major role in translation.  相似文献   

9.
About a century ago, Ernst Mach argued that Archimedes’s deduction of the principle of the lever is invalid, since its premises contain the conclusion to be demonstrated. Subsequently, many scholars defended Archimedes, mostly on historical grounds, by raising objections to Mach’s reconstruction of Archimedes’s deduction. In the debate, the Italian philosopher and historian of science Giovanni Vailati stood out. Vailati responded to Mach with an analysis of Archimedes’s deduction which was later quoted and praised by Mach himself. In this paper, my objective is to show that the debate can be further advanced, as Mach indicated, by reframing it in terms of the empirical vs. the logical dimensions of mechanics. In this way, I will suggest, the debate about Archimedes’s deduction can be resolved in Mach’s favour.  相似文献   

10.
11.
On an ordinary view of the relation of philosophy of science to science, science serves only as a topic for philosophical reflection, reflection that proceeds by its own methods and according to its own standards. This ordinary view suggests a way of writing a global history of philosophy of science that finds substantially the same philosophical projects being pursued across widely divergent scientific eras. While not denying that this view is of some use regarding certain themes of and particular time periods, this essay argues that much of the epistemology and philosophy of science in the early twentieth century in a variety of projects (neo-Kantianism, logical empiricism, pragmatism, phenomenology) looked to the then current context of the exact sciences, especially geometry and physics, not merely for its topics but also for its conceptual resources and technical tools. This suggests a more variable project of philosophy of science, a deeper connection between early twentieth-century philosophy of science and its contemporary science, and a more interesting and richer history of philosophy of science than is ordinarily offered.  相似文献   

12.
The precise position of a spectral line emitted by an atomic system depends on the mass of the atomic nucleus and is therefore different for isotopes belonging to the same element. The possible presence of an isotope effect followed from Bohr's atomic theory of 1913, but it took several years before it was confirmed experimentally. Its early history involves the childhood not only of the quantum atom, but also of the concept of isotopy. Bohr's prediction of the isotope effect was apparently at odds with early attempts to distinguish between isotopes by means of their optical spectra. However, in 1920 the effect was discovered in HCl molecules, which gave rise to a fruitful development in molecular spectroscopy. The first detection of an atomic isotope effect was no less important, as it was by this means that the heavy hydrogen isotope deuterium was discovered in 1932. The early development of isotope spectroscopy led to successes as well as problems. At the end of the paper I briefly comment on the relationship between theory, experiment and prediction in this area of spectral physics.  相似文献   

13.
14.
为了更好地将等斜率灰色聚类法应用于地表水质评价,提出了改进的等斜率灰色聚类法——灰色聚类样点排序法,并通过实例的计算比较,讨论灰色聚类样点排序法再权重处理过程的可行性。可以得出灰色聚类样点排序法能兼顾到:1)各测点地实测污染浓度都在级别标准范围内较有规律的变化,各污染物的标准之间差异不太大;2)污染物分布的离散度太大,各标准值之间差别也太大这两种情况。  相似文献   

15.
In this paper we compare two different contexts—the legal and the scientific—in which the concept of law is prominent. We argue that the acute philosophical awareness, in the early modern period, of the difficulties surrounding the law concept in the scientific context, and the various responses to these difficulties, are rooted in an earlier tradition of jurisprudential concerns over the concept of natural law in its legal sense. We seek to show, further, that each one of the various philosophical accounts of the concept of natural law (in both of its senses) is embedded in a metaphysical and theological context, so that different visions of God yield different accounts of the meaning of the natural law idiom in science as well as legal theory.  相似文献   

16.
17.
Co-integration analysis is used in a study of the advertising and sales relationship using the Lydia Pinkham data set. The series are shown to have a valid long-run relationship while Granger-causality runs in both directions. The latter is found by using a causality test involving the co-integration restrictions which seem to constitute a crucial part of such tests in the case of co-integrated variables. A comparison with previous models shows that forecasting co-integrated series is more accurate with error-correction systems, especially in the case of multi-step forecasting.  相似文献   

18.
This paper revisits the debate between Harry Collins and Allan Franklin, concerning the experimenters' regress. Focusing my attention on a case study from recent psychology (regarding experimental evidence for the existence of a Mozart Effect), I argue that Franklin is right to highlight the role of epistemological strategies in scientific practice, but that his account does not sufficiently appreciate Collins's point about the importance of tacit knowledge in experimental practice. In turn, Collins rightly highlights the epistemic uncertainty (and skepticism) surrounding much experimental research. However, I will argue that his analysis of tacit knowledge fails to elucidate the reasons why scientists often are (and should be) skeptical of other researchers' experimental results. I will present an analysis of tacit knowledge in experimental research that not only answers to this desideratum, but also shows how such skepticism can in fact be a vital enabling factor for the dynamic processes of experimental knowledge generation.  相似文献   

19.
This study deals with the relationship between Newton's gas model in the Principia (Book II, Proposition xxiii) and Dalton's theorizing. Dalton's first theory of mixed gases is an elegant extension of the Newtonian gas model which, in turn, led Dalton to a general model of chemical combination. The views on combination are contrasted with those of Arnold Thackray. Interestingly, the model of combination was knowingly based on a falsified theory.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号