全文获取类型
收费全文 | 194篇 |
免费 | 5篇 |
专业分类
电工技术 | 3篇 |
综合类 | 1篇 |
化学工业 | 25篇 |
金属工艺 | 11篇 |
机械仪表 | 13篇 |
建筑科学 | 15篇 |
能源动力 | 1篇 |
轻工业 | 16篇 |
水利工程 | 4篇 |
无线电 | 8篇 |
一般工业技术 | 60篇 |
冶金工业 | 23篇 |
原子能技术 | 6篇 |
自动化技术 | 13篇 |
出版年
2021年 | 5篇 |
2019年 | 2篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 3篇 |
2012年 | 13篇 |
2011年 | 3篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1998年 | 11篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1993年 | 3篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1958年 | 1篇 |
1936年 | 1篇 |
1935年 | 1篇 |
1931年 | 3篇 |
1926年 | 2篇 |
1925年 | 2篇 |
1922年 | 1篇 |
排序方式: 共有199条查询结果,搜索用时 500 毫秒
51.
The status and prospects of new scintillation materials for calorimetry applications in high energy physics are reviewed. New readout methods are discussed with emphasis on the operation of high resolution scintillation calorimeters in magnetic fields. 相似文献
52.
53.
Gualtieri JG Lareau RT Eckart DW 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1990,37(5):393-403
Experimental observations are described in the air-sweeping of alpha-quartz that reveal the introduction of hydrogen. Porous electrodes facilitate the indiffusion of hydrogen. By contrast, the use of thick, nonporous, strongly adherent Au/Cr electrodes causes a color-center front to advance from anode to cathode. Evidence is presented that indicates that: (1) color centers form beneath nonporous portions of the anode that correlate with the formation of Cr(2)O(3) on the metal surface and Cr-silicides at the metal-quartz interface, and (2) large-diameter clear striae form along the c-axis that correlate with small openings in the anode. These observations suggest that: (1) openings in the anode metallization are required for hydrogen introduction; (2) the electrochemical charge-transfer reaction, leading to hydrogen introduction, occurs at the gas-electrode-quartz boundary and spreads laterally by interfacial diffusion of hydrogen species; and (3) color centers form through the suppression of interfacial H-diffusion. Additionally, electrode-surface damage and high electric fields can result in undesirable electrode-metal indiffusion. 相似文献
54.
RILEM Recommendations57-TSB RILEM/CIB Joint Technical Committee
Testing of timber structures and building boards 相似文献55.
Interface morphology, phase composition, and elemental diffusion of Pt/Ti/Ge/Pd ohmic contacts to both n and p+-GaAs have been investigated as a function of annealing temperature. Structural and chemical results were correlated with specific contact resistances (ρc) measured for each thermal treatment. Annealing at 450°C yielded the lowest ρc, ~6.4 × 10?7Ω-cm2. The interface was observed to be smooth and abrupt. Two interface phases were detected; a primary phase, PdGe, and a secondary, Ga-rich Pd-Ga-As ternary phase. The presence of this ternary phase was found to be critical to contact formation on n-GaAs. The Ti and Pt layers remained pristine. Annealing at 550°C resulted in a slightly higher ρc, ~2.1 × 10?6Ω-cm2. There was significant elemental diffusion within the contact metal and minor diffusion into the GaAs substrate. The interface possessed limited areas of spiking with uniform composition. Annealing at 600°C proved to have a detrimental effect on the ρc, ~10?4Ω-cm2. This electrical degradation was accompanied by strong chemical intermixing between the contact and substrate, resulting in a continuous nonplanar interface with deep multiphase protrusions. 相似文献
56.
This introduction sets the scene for the special issue compiled by Martin Keulertz, Eckart Woertz and Tony Allan. 相似文献
57.
Jan Rudolph Naceur Gaaloul Yeshpal Singh Holger Ahlers Waldemar Herr Torben A. Schulze Stephan Tobias Seidel Christina Rode Vladimir Schkolnik Wolfgang Ertmer Ernst Maria Rasel Hauke Müntinga Thorben Könemann Andreas Resch Sven Herrmann Claus Lämmerzahl Tim van Zoest Hansjörg Dittus Anika Vogel André Wenzlawski Klaus Sengstock Nadine Meyer Kai Bongs Markus Krutzik Wojciech Lewoczko-Adamczyk Max Schiemangk Achim Peters Michael Eckart Endre Kajari Stefan Arnold Gerrit Nandi Wolfgang P. Schleich Reinhold Walser Tilo Steinmetz Theodor W. Hänsch Jakob Reichel 《Microgravity science and technology》2011,23(3):287-292
Clouds of ultra-cold atoms and especially Bose–Einstein condensates (BEC) provide a source for coherent matter-waves in numerous earth bound experiments. Analogous to optical interferometry, matter-wave interferometers can be used for precision measurements allowing for a sensitivity orders of magnitude above their optical counterparts. However, in some respects the presence of gravitational forces in the lab limits experimental possibilities. In this article, we report about a compact and robust experiment generating Bose–Einstein condensates in the drop tower facility in Bremen, Germany. We also present the progress of building the succeeding experiment in which a two species atom interferometer will be implemented to test the weak equivalence principle with quantum matter. 相似文献
58.
59.
60.
Hanns Eckart 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1925,50(6):405-415
Ohne ZusammenfassungMitteilung aus dem Betriebslaboratorium der Firma Johs. Eckart, Konservenfabrik in München. 相似文献