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281.
Bart Grob 《History & Technology》2013,29(4):369-390
In 1901 the Dutch physiologist Willem Einthoven invented the string galvanometer. It was an instrument capable of recording weak electrical pulses in the human body. He used it to investigate the human heartbeat and in 1924 was awarded the Nobel Prize for medicine or physiology for the discovery of the mechanism of the electrocardiogram. Soon after his first publication he contacted a number of Dutch and international instrument makers with a view to persuading them to produce his apparatus. The correspondence between Einthoven and these instrument makers gives us an insight into the process from prototype through to sellable instrument. It also reveals that these instrument makers had an important part to play in the earliest development of the string galvanometer on its way to becoming an electrocardiograph. The first impression that the string galvanometer made on instrument makers appears to have been an important guiding factor in the direction taken by the technological development of the apparatus. Secondary considerations such as financial and legal matters were decisive in whether or not the instrument was actually made. 相似文献
282.
Joanna S. Ploeger 《History & Technology》2013,29(1):23-49
This paper examines how rhetoric shaped the early history of the National Accelerator Laboratory. In a situation defined by a contentious site search and shrinking budgets for research, Robert Wilson crafted an institutional identity for the NAL that emphasized both aesthetic and scientific experience. The paper addresses the circumstances of the laboratory's founding, the \"audiences\" important to its success, and the ways in which the physical environment and management structure--framed by Wilson's vision of a scientific utopia--reorganized existing perceptions of physics within a humanistic framework intended to distinguish the NAL from its predecessors in the National Laboratory system. 相似文献
283.
为了解贵州赫章可乐遗址出土的一件金饰汉代铜镜的制作工艺和腐蚀特性,运用金相显微镜观察、扫描电镜分析和ICP发射光谱分析等方法,对铜镜样品的相组织、微观形貌和化学元素组成进行了观察分析.结果表明,铜镜的相组织为铸态组织,中心部位有α+σ共析组织和共晶组织,边缘大部分为氧化物.铜镜正面锡含量高,铜和铅含量较低,有腐蚀坑,其元素成分有铜、锡、铅、铝、氧、硅和碳;镜背面三角凹陷区有碳酸盐物质.镜本体主要成分为氧、碳、锡、铜,凹陷区和凸楞边缘主要成分为金.镜断面处锈蚀产物为锡的氧化物及铜的氧化物或碳氧化物.铜在表面分布是中间部位高,两边低;锡相反;铅基本内外一致;硅是内部少,外部多.分析说明,仪器分析方法是了解出土铜镜制作工艺和腐蚀特性的一种有效方法. 相似文献
284.
近几十年来,我国考古工作曾先后在一些西汉遗址和墓葬中发现了若干纸状残片,于是引起国内外许多学和广大人民的关注和提出疑问。是否蔡伦前约二百年就有了纸?造纸术还是不是蔡伦发明的?新发掘的纸状物到底是个什么样?……经对历次的发掘作了详细的调查研究和分析化验,结论认为:20世纪有关纸的考古发现不能否定蔡伦发明造纸术。 相似文献
285.
286.
中国传统血料灰浆的应用历史和科学性 总被引:2,自引:1,他引:1
血料灰浆是中国古代建筑灰浆的重要代表作之一,体现出浓郁的中国传统工艺特色,反映了当时建筑技术的科技水平.本研究从血料灰浆的科技史入手,综述了传统血料灰浆的应用历史和制备方法,包括在油饰彩画地仗层、油漆地仗层、漆器和桥梁建筑等方面;结合各种现代科技文献评述了古代建筑灰浆中动物血蛋白的检测方法,包括各种物理化学方法和免疫法;阐述了灰浆中动物血的功能,如加气作用、减水作用、防水作用、平整和抗龟裂作用等,探讨了血料灰浆的作用机理.此外,还简述了血料、蛋清、糯米、红糖、桐油等有机添加剂的复配问题.本研究的总体目标是希望以此为基础,进一步加深对血料灰浆科学性和局限性的认识,并通过对血料灰浆的研究和传统工艺的科学化改进,更好地为当今古建筑修缮保护服务. 相似文献
287.
党中央提出的科学发展观,是青海实施全面、协调、可持续发展战略的行动指南。而依据青海可持续发展的总体能力,从实际出发,建立有效的宏观保障体系,则是其必要条件。 相似文献
288.
289.
“湘军,历史上一奇迹也。”太平天国起义后,曾国藩奉命在湖南原籍帮办团练,旋即组建并统帅湘军参与镇压太平军和捻军。当时的八旗军、绿营的战斗力相当弱,无力抵抗太平军的强大攻势,与之相比,由曾国藩组建的湘军却在镇压太平军的战斗中节节胜利,为巩固清王朝的统治起到了重大的作用。曾国藩实行的厚饷养军制度,使士兵安心服役;以“养将士之廉”为名,给予更优厚的待遇;同时不断保举有军功的将弁,广赐翎顶,以官禄为诱饵驱使官兵效命疆场,是鼓舞士气的有效措施。当时的湘军在军制等各方面都有值得我们借鉴和批判的地方。 相似文献
290.
Pollen analysis in relation to archaeological excavations has been carried out by the coast of central Norway to investigate for the first time long-term human impact on the vegetation in this region. A total of 297 samples from eleven archaeological sites and connected bogs/peat profiles reveal the vegetation development from the Mesolithic until today. Principal Component Analysis (PCA) is used to identify and elucidate the development through time and space, and the results of pollen diagrams from bogs are compared to the results of on-site pollen data. Human impact has transformed the vegetation to a varying degree in different time periods. A dense population connected to the shoreline is slightly visible as opening-up of the forest in the Mesolithic, whereas re-use of Mesolithic settlement sites for cultivation and grazing in the Late Neolithic and Early Bronze Age (from c. 2300 cal BC) is clearly documented by palaeobotany but weakly recorded in the archaeological record. Areas for settlement and cultivation are found from the Late Bronze and Iron Ages and pollen analysis contributes to a detailed picture of utilization of the landscape. The investigation shows the potential of combining archaeological and botanical data and analysing several small pollen sequences within an excavation area to reveal spatial patterns in vegetation development and human impact through time. 相似文献