Linear increase law of optimum age of scientific creativity

A linear increase law of optimum age of scientific creativity is proposed. The author has analysed the optimum age of major scientific discoveries (or inventions) by the least square method and an increase ratio has been obtained. The optimum age and the age of great fame in next half century are forcast also.     

阻燃水性聚氨酯研究进展

阻燃水性聚氨酯是水性聚氨酯功能化的重要方向之一,具有较高的实际应用价值。根据阻燃剂在水性聚氨酯中的存在方式,可以将阻燃水性聚氨酯分为共混复配型和反应型两大类。文中主要从聚氨酯硬段阻燃改性与软段阻燃改性两个方面综述了反应型阻燃水性聚氨酯的研究现状,并展望了阻燃水性聚氨酯的发展趋势。     

重型汽车车架结构的强度分析

本文以重型汽车车架结构为研究对象,首先,用实车实验的方法对车架进行典型工况下的强度分析,获得其敏感位置的强度分析结果：其次,通过建立车架的有限元模型,对典型工况的车架进行有限元分析,获得较为全面的车架强度分析结果：最后,通过与实车实验的对比,验证该有限元模型。经过计算分析表明,文中所涉及的建模和分析手段是行之有效的,有限元方法为车架的强度分析提供了很好的途径。     

Roget's engineering successor [Samuel Romilly Roget biography]

Samuel Romilly Roget, grandson of Peter Mark Roget of Thesaurus fame, was by profession an electrical engineer. A Cambridge graduate who had studied under James Alfred Ewing, he embarked upon an intensive career encompassing industrial employment, technical journalism and finally original work for the British Standards Institution on the definition of electrotechnical standards and vocabularies. In this last occupation, he may have inherited some of the methodical classification skills of his grandfather, This article traces his working life through a period of great scientific and technological change spanning two world wars     

超高速CT及其在心血管中的应用

本文阐述了超高速CT的基本概念、成像原理及其在心血管中的应用．超高速CT检出冠状动脉钙化简便易行，有较高的敏感性、特异性，可广泛用于临床预测及早期诊断冠心病．年轻组与老年组相比，冠状动脉钙化预测冠心病的敏感性较低而特异性较高．超高速CT可作为检测、分析心肌缺血早期形态学表现和定量分析其CT值变化的一种高敏感性的非创伤性方法．它是有发展前途的检查方法，被誉为金标准。     

鄂州花样剪纸“笔定双钱”纹样解读

鄂州花样剪纸"笔定双钱"纹样作为一种吉祥符号,从符号的能指分析,其语音与"必定双全"相似,其形象特点是由一支毛笔穿过2个并排的铜钱再加上奇特的图案组成;从符号的所指分析,其通过符号寓意与谐音寓意2种方式表达了民众对幸福美满生活的追求。该纹样的语意特征相当明显:以圆形的铜钱象征着完整和圆满(当然它还蕴含着财富之意),以毛笔象征了读书与学问,两者结合,表现中华民族"求全"与"求功名"等心理。     

James Bond and citations to his books

This paper investigates two bibliometric problems: the listing of books in a specialist area (ornithology) and the determination of the citation pattern to individual authors, who often re-issue their books in later editions. James Bond, a Philadelphia ornithologist, who specialised in the birds of the West Indies, is used as an example of a naturalist whose long career led to many journal articles and enduring scientific fame through a well-known book. He also attained some unexpected notoriety through the use of his name by a popular novelist. Methods for the evaluation of his book and associated bird checklists in comparison with other similar works are presented on the basis of their citations. This revised version was published online in June 2006 with corrections to the Cover Date.     

The Decisive Network: Producing Henri Cartier-Bresson at Mid-Century

Henri Cartier-Bresson’s photobook The Decisive Moment (1952) popularised the notion that the best photographs are made by the patient and gifted photographer who captures a fleeting moment with just one click of the shutter, creating an image with internal geometry and balance. The book solidified Cartier-Bresson’s reputation as an artist working with a camera and it encouraged scholars, curators, and hobbyists to understand photography as the product of trained individual vision and talent. Yet the book’s emphasis on personal vision also deflected attention away from the collective efforts and infrastructure necessary to promote Cartier-Bresson’s practice as art. By shifting our attention to the decisive network of magazine editors, book publishers, printers, and curators who helped Cartier-Bresson onto a highly orchestrated road to fame at mid-century, this article considers the ways in which collective work is central to the material and social history of photography, and how these realities challenge the decisive moment’s paradigm of individual and inspired creation.     

Lewis Carroll

Abstract

There tend to be two classes of polymaths: those whose breadth of talent and contribution is uniformly recognized and acclaimed; and those for whom one achievement or area of achievement is of such fame that it overshadows or occludes all other, less celebrated, efforts. If the former category includes such individuals as Leonardo da Vinci and Thomas Jefferson, the latter certainly for tht' past century has encompassed the Reverend Charles Lutwidge Dodgson, better known under his literaly pseudonym Lewis Carroll. Carroll scholarship to date has been predominantly driven by the popularity of his Alice in Wonderland, Through the Looking Glass and other children's texts, to the extent that his accomplishments in other fields have been viewed as minor sidelines. This is particularly true in the case of photography, a pastime that occupied as much, if not more, of Dodgson's efforts as literature, and that resulted in an extensive and remarkable oeuvre on par with the greatest practitioners of his time.     

钢筋混凝土框架爆破拆除时后承重柱的应力分布

钢筋混凝土框架结构定向爆破拆除的力学过程,是一个复杂的结构动力学过程.后承重柱的应力分布,影响着整个框架倒塌定向的准确与施工安全.以某钢筋混凝土框架结构为建模实体,建立了有限元分析模型,并对其倒塌过程进行了定性分析.获得的后承重柱应力分布规律表明:后承重柱的应力值随爆破缺口的高度呈线性递增;梁的存在能有效地"拦截"后承重柱的应力;爆破缺口与梁间的距离越大,后承重柱的应力变化率也越大;含筋率的提高能有效地降低后承重的应力值,同样的含筋率有相同的应力降低幅度;应力突变与梁的状态和后承重柱的钢筋局部加密相关,其突变幅度随爆破缺口的高度的增加而增大,突变点的位置不受爆破缺口高度的影响,只受在倒塌过程发挥力学作用的梁的位置及其下方钢筋加密区长度的影响;后承重柱发生高位断裂的位置是在距爆破缺口最近的梁的下方钢筋加密区与非加密区的联接处附近,断裂口的形状呈"V"字形.     

中医的渊源和对中医学发展的思考

传统的中医学源远流长,博大精深,疗效显著,由于种种历史原因,加之自身流派众多,传承艰难,流传至今,已不能满足现代社会的发展与要求。中医要发展,须走“医学衷中纳西”的与时俱进之路。中医自身要统一理论认识,统一辩证纲领,统一到“五脏阴阳”之中,以“三维守恒”指导辩证,要明确医学的目的,认识生命的本质和生命运动的机制;要宏观与微观相结合,整体与局部相统一,以唯象涵盖唯物,以辩证指导分析,以调为本,以平为期;要司岁备药,先法制病,对中药剂型进行改进,以适应社会发展的需要。     

Nanodiamonds and Their Applications in Cells

Diamonds owe their fame to a unique set of outstanding properties. They combine a high refractive index, hardness, great stability and inertness, and low electrical but high thermal conductivity. Diamond defects have recently attracted a lot of attention. Given this unique list of properties, it is not surprising that diamond nanoparticles are utilized for numerous applications. Due to their hardness, they are routinely used as abrasives. Their small and uniform size qualifies them as attractive carriers for drug delivery. The stable fluorescence of diamond defects allows their use as stable single photon sources or biolabels. The magnetic properties of the defects make them stable spin qubits in quantum information. This property also allows their use as a sensor for temperature, magnetic fields, electric fields, or strain. This Review focuses on applications in cells. Different diamond materials and the special requirements for the respective applications are discussed. Methods to chemically modify the surface of diamonds and the different hurdles one has to overcome when working with cells, such as entering the cells and biocompatibility, are described. Finally, the recent developments and applications in labeling, sensing, drug delivery, theranostics, antibiotics, and tissue engineering are critically discussed.     

TiC-TiB2 复相陶瓷涂层的反应火焰喷涂制备

基于SHS 反应火焰喷涂技术, 采用Ti-B₄C-C 喷涂体系, 在钢基表面制备了TiC- TiB₂ 复相陶瓷涂层。通过对SHS 火焰喷涂陶瓷涂层的电子显微观察和X射线衍射及能谱分析, 探讨了SHS 反应火焰喷涂TiC- TiB₂复相陶瓷涂层的组织结构及成因。研究发现, 涂层是一种复相非均质、传统热喷涂层状涂层特征不明显的亚稳结构。涂层由占主体的TiC_0.7N_0.3 、TiC_0.2N_0.8 、TiB₂ 相和少量TiO₂ 、Ti₂O、Ti₃O₅ 相及气孔组成。涂层中有三类特征各异的组织, 即尺度在微2纳米级呈团簇状分布的组织, 尺寸在1～3μm 之间呈等轴状颗粒分布的组织和呈深黑色的不规则气孔。三类组织是由在喷涂粒子与基材接触之前, 喷涂团聚粉粒经飞行燃烧和反应合成形成的熔融陶瓷液滴(又分为实心和空心两类) 和不规则陶瓷颗粒(其形状与原喷涂团聚颗粒一样, 但组织结构已发生转变,基本成为陶瓷相) 与基材碰撞变形、冷却凝固、快速结晶形成的。      

基于BP神经网络的RC框架结构地震易损性曲面分析:考虑地震动强度和持时的影响

与短持时地震动相比,长持时地震动会加剧结构的损伤,增加结构的失效概率,因此有必要更充分地研究地震动持时特性对结构地震易损性分析结果的影响。该文提出了一种基于BP神经网络的地震易损性曲面分析方法,使用神经网络模型,综合考虑地震动强度和持时特性对结构地震需求的影响,并进行地震易损性分析,得到不同损伤水平下考虑地震动持时特性的结构易损性曲面。选用3个不同高度的钢筋混凝土框架结构为研究对象,分别选择具有长、短持时特性的2组地震动记录为输入,采用BP神经网络模型建立地震动强度指标与结构响应间的关系,在此基础上得到目标地震易损性曲面,并对该方法的有效性进行讨论。分析结果表明,研究建立的BP神经网络模型精度较高,依据该方法可得到可信的损伤概率分析结果。相比于传统方法,神经网络可以更为有效和准确地建立持时与结构损伤的相关关系,得到考虑持时特性的易损性分析结果。该文的方法亦可进一步拓展,将更多地震动特性纳入地震易损性分析过程,具有明确的应用前景。     

Introduction

Abstract

In this first issue we begin the serialization of twelve articles under the general heading of Early Photography in Eastern Europe. Together they will form a compendium of information and comment not now available from any other source. The fame of Nicefor N'eps and Luijs ?aks Dagers may have travelled to Latvia and beyond, but the West has remained largely uninformed of photographic achievements in the East. International gatherings of the kind that bring scientists and engineers into regular communion are still a great rarity among photographic historians who, more often than not, have tended to view their task in nationalistic terms. No doubt this outlook stems from the fact that photography itself did much to raise national consciousness in many lands. The East was not short of photographic heroes but, on the whole, they remained local heroes (pace Joseph Petzval; pace Count Esterházy}, not unsung, but rarely more than folksung. Language problems may have contributed to this state of affairs, as did the bitter wars and struggles against unacceptable regin1es, which run like a grinding refrain through all accounts of the past century. Again and again, the work of talented photographers was destroyed, sometimes accidentally, often with savage deliberation.     

The Reception of Albert Renger-Patzsch's Die Welt ist schön

Abstract

No history of photography or publication on the photography of the 1920s fails to mention the photo-book Die Welt ist schön. Regarded as a ‘manifesto of the revival of Realism,’¹ and hailed as the ‘bible’ of Neue Sachlichkeit photography,² ‘hardly any other book has influenced a generation of photographers to the same great extent and with such long-lasting effects as this volume‘.³ It was the book's tide in particular that was received like a catchword and influenced the reception of this photographic volume: ‘The tide became symbolic for an attitude of Neue Sachlichkeit to the world and the book was acknowledged as the ideal volume of Neue Sachlichkeit photography’.⁴ Hitherto in the history of the book's reception, this opinion has been restricted primarily to the reference to Walter Benjamin's well-known negative critique of 1931.⁵ Amongst the multitude of reviews of Die Welt ist schon, it is Benjamin's assessment which is most frequendy cited in the literature. That Benjamin was able to neglect explicidy mentioning Renger-Patzsch's name and to refer merely to the tide of the book can be interpreted as proof of the great fame of this photographic author. In fact, Die Welt ist schön had by this time been reviewed in nearly all leading cultural magazines and daily newspapers and evaluated as an exemplary volume of a modem, neusachliche photography. For critics such as Benjamin, however, the tide was synonymous with a new, sterile ‘l’art pour l'art' photography which manipulated reality and denied social contexts. But to confine negative criticism of Die Welt ist schön to the political left and its praise to a more conservative attitude is too simple a model as becomes apparent when all of the reviews are taken into consideration. Karl With's attempt to summarize the contradictions of this picture book may be cited here: ‘Ein seltsames Buch!} (A strange book!). Exciting in its busding abundance, as well as in its silence’.⁶     

Schumpeter, Business Cycles and Co-evolution

In Business Cycles (1939 Schumpeter, J. A. 1939. Business Cycles, New York: McGraw‐Hill.  [Google Scholar]) Schumpeter took up empirical data which had been produced by Kondratieff, and made the “clustering” of innovations into the actual cause of long economic cycles. The book was a failure, largely due to negative reviews which stressed the poor quality of its statistical analysis. In fact, an even more serious fault in it is its reflection of a near‐total blind spot in Schumpeter's perspective about the part played by law in economic life. He thought that “It is entirely immaterial whether or not [changes in the institutional framework] are embodied in, or recognized by, legislation.” The reality is that the concept of co‐evolution of technology and ways of doing business, on the one hand, and legal changes which affect the conditions for investment in them, on the other, explain long cycles much more persuasively than Schumpeter's approach. It suggests that the first Kondratieff cycle was made possible by the availability of “full” property rights, the second by general limited liability law (which Schumpeter thought was “of comparatively small importance”) and the third by new patent legislation which made corporate investment in R&;D attractive. Schumpeter only discussed three cycles, but a co‐evolutionary perspective makes it possible to envisage a fourth cycle as dependent upon the trademark laws which sustain advertising and mass markets, and a fifth one, in which the entertainment and information industries have been similarly underwritten by copyright law. The most plausible reason why Schumpeter undervalued laws was his attraction to the economic interpretation of history. According to this, laws, like ideas, are no more than reflections on a psychic level of social and economic realities, and have little or no power to shape these. For Keynes, in contrast, “it is ideas, not vested interests, that are dangerous for good or ill”. There was consequently no place for co‐evolution in Schumpeter's thought. But what made him publish a book which he described as “a house which is not finished and furnished”, when he did? It could be that the stimulus was evidence of the huge fame which Keynes's General Theory was already winning.     

Radioactivity in building materials in Iraq

Activity concentrations of (226)Ra, (232)Th and (40)K in 45 samples of different building materials used in Iraq were measured using gamma-spectroscopy system based on high-purity germanium detector with an efficiency of 40 %. Radium equivalent activity, air-absorbed dose rate, annual effective dose, external and internal hazard indices and alpha index due to radon inhalation originating from building materials were measured to assess the potential radiological hazard associated with these building materials. The activity concentrations of the natural radionuclides (226)Ra, (232)Th and 40K were found to range from below detection limit (BDL) to 223.7 ± 9, BDL to 93.0 ± 3 and BDL to 343.1 ± 12, respectively. Values of average radium equivalent activity, air-absorbed dose rate, indoor and outdoor annual effective doses, external and internal hazard indices and alpha index ranged from 6.5 to 124.9, 16.2 to 89.5 (nGy h(-1)), 0.08 to 0.44 mSv, 0.02-0.11 mSv, 0.09 to 0.53, 0.13 to 0.69 and 0.03 to 0.62, respectively. These values indicate a low dose. Therefore, the building materials used in the current study are quite safe to be used as building materials.     

Quantity is only one of the qualities

As our fields have become more sophisticated, complex, and specialized, we deal with ever larger masses of data, and our quantitative results have become more detailed and esoteric, and difficult to interpret. Because our methods are predominantly quantitative, we tend to overlook or underemphasize the qualitative judgments that enter at every stage of our work, and to forget that quantity is only one of the qualities. As in our world today, where we face a flood of factoids and quantitative data stripped of context, and struggle to evaluate it, to give it meaning, and make it into information, so ought we qualitatively to acknowledge and contextualize our research results, not only to make them more relevant, meaningful, and useful to the larger world, but to give our work greater impact and value.     

Microstructural mechanics of granular media

A geometrically and physically linear micromechanical theory for elastic granular media is presented, based on the identification of the constituent grains with the nodes of a Bravais lattice. Adjacent particles are permitted to displace normally and transversely to each other, and to rotate with respect to the doublet axes. Thus, microstrains of the axial, torsional, and shear type are generated. The conjugate microstresses are then defined. Through a variational formulation, the microstress equations of motion are derived, together with natural boundary conditions and the transition from the microstresses to the macrostresses. The principles of thermodynamics are employed to derive the most general, invariant, and appropriately symmetric microconstitutive equations, and to close the system of field equations for the granular medium, subject to both adiabatic and non-adiabatic processes. The problem of a granular semispace loaded by compressive boundary force is solved as an application, and the existence of locally tensile microstresses is determined, while the associated macrostresses are computed to coincide with the well-known Flamant's solution and thus to be compressive everywhere.