全文获取类型
收费全文 | 266篇 |
免费 | 9篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 45篇 |
金属工艺 | 10篇 |
机械仪表 | 4篇 |
建筑科学 | 13篇 |
能源动力 | 2篇 |
轻工业 | 39篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 22篇 |
一般工业技术 | 41篇 |
冶金工业 | 69篇 |
原子能技术 | 1篇 |
自动化技术 | 19篇 |
出版年
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 15篇 |
2012年 | 11篇 |
2011年 | 16篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 20篇 |
1997年 | 14篇 |
1996年 | 10篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1981年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 5篇 |
1970年 | 3篇 |
1968年 | 1篇 |
1948年 | 1篇 |
1941年 | 1篇 |
1940年 | 1篇 |
1939年 | 1篇 |
1931年 | 1篇 |
1930年 | 1篇 |
1928年 | 1篇 |
1927年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 15 毫秒
21.
W. A. Koehler 《Journal of the American Ceramic Society》1928,11(2):107-109
The need for investigation of new uses for clays which may become necessary if brick are substituted for by new materials is stressed. The shortcomings of brick, and possible new methods of clay processing are enumerated. 相似文献
22.
T Temelkova-Kurktschiev C Koehler F Schaper E Henkel A Hahnefeld K Fuecker G Siegert M Hanefeld 《Canadian Metallurgical Quarterly》1998,41(6):706-712
We analysed the relationship between fasting plasma glucose, carotid intima media thickness and some atherosclerosis risk factors in 307 non-diabetic individuals. Male (n = 120) and female subjects (n = 187) with a familial history of Type II diabetes mellitus and/or obesity and hyperlipoproteinaemia were examined in the age group 40-70 years. Plasma triglycerides, total and high-density-lipoprotein cholesterol, plasminogen activator inhibitor were measured by conventional methods. Specific insulin, pro-insulin and C-peptide were measured by specific enzyme immunoassay. Intima media thickness increased in quintiles for fasting plasma glucose in men, but not in women. There was a rise of triglycerides, body mass index, waist to hip ratio, plasminogen activator inhibitor, true insulin, proinsulin, C-peptide and a decrease of high-density-lipoprotein cholesterol in quintiles for fasting plasma glucose. Fasting plasma glucose was found to be significantly positively correlated to intima media thickness, body mass index, waist to hip ratio, haemoglobin A1c, insulin, C-peptide, triglycerides, plasminogen activator inhibitor and significantly negatively correlated to high density lipoprotein cholesterol. However, the correlation of fasting plasma glucose to intima media thickness was no longer significant after adjustment for age and sex. After adjustment for age and sex intima media thickness was significantly correlated to body mass index, total cholesterol, triglycerides, albuminuria and inversely correlated to high-density-lipoprotein cholesterol. In multivariate analysis age, male sex, high-density-lipoprotein cholesterol and total cholesterol were significant determinants of intima media thickness. Our data suggest that a weak association exists between fasting plasma glucose and intima media thickness, which may be mediated by a clustering of risk factors in the upper range of non-diabetic fasting plasma glucose level with a central role for dyslipidaemia. 相似文献
23.
Paren Patel Sergey Osechinskiy Jeff Koehler Li Zhang Surekha Vajjhala Chris Philips Steve Hobbs 《Journal of The Association for Laboratory Automation》2004,9(3):185-191
The Nanostream (Pasadena, CA) Veloce system, together with 24-column Brio cartridges, offers a novel approach to micro parallel liquid chromatography (μPLC). This system allows users to achieve unprecedented throughput for standard assays while matching the performance of conventional LC instrumentation, thus enabling routine compound purity assessment and physiochemical property profiling early in the drug discovery and development process.The Veloce system—which includes instrumentation, software, and replaceable microfluidic cartridges—incorporates pressure-driven flow to achieve chromatograms comparable to conventional high performance liquid chromatography (HPLC) instrumentation for a broad class of analytical applications while offering a dramatic increase in sample analysis capacity. The system enables parallel chromatographic separations and simultaneous, real-time UV detection. Each Nanostream Brio cartridge, made of polymeric materials, incorporates 24 columns packed with standard (C-18) stationary phase material to achieve reverse phase separations. Mixing and distribution of the mobile phase to each of the 24 columns is precisely controlled in each cartridge. The system provides an ideal platform to accelerate assessment of compound purity and physicochemical properties (i.e., log P, CHI, etc.) for a large number of compounds. In addition, the 24-fold increase in sample analysis capacity allows standard curve generation and simultaneous analysis of multiple replicates of samples in a single run. 相似文献
24.
Hybrid method for computing demagnetizing fields 总被引:1,自引:0,他引:1
A hybrid finite-element-boundary integral method is proposed for computing demagnetizing field. For a three-dimensional (3-D) mesh with N nodes in the magnetic region, the method requires storage O( N 4/3), and no nodes outside the magnetic region need to be considered. The method is suitable for nonlinear calculations, can be adapted to handle curved boundaries, and is especially convenient when the magnetic region consists of several parts whose relative positions are variable 相似文献
25.
The relationship between heart failure (HF), sleep-disordered breathing and cardiac arrhythmias is complex and poorly understood. Whereas the frequency of predominantly obstructive sleep apnea in HF patients is low and similar or moderately higher to that observed in the general population, central sleep apnea (CSA) has been observed in approximately 50% of HF patients, depending on the methods used to detect CSA and patient selection. Despite this high prevalence, it is still unclear whether CSA is merely a marker or an independent risk factor for an adverse prognosis in HF patients and whether CSA is associated with an increased risk for supraventricular as well as ventricular arrhythmias in HF patients. The current review focuses on the relationship between CSA and atrial fibrillation as the most common atrial arrhythmia in HF patients, and on the relationship between CSA and ventricular tachycardia and ventricular fibrillation as the most frequent cause of sudden cardiac death in HF patients. 相似文献
26.
J. Härkönen V. EreminP. Luukka T. MäenpääE. Tuovinen E. TuominenY. Gotra L. SpiegelL. Wiik M. Koehler 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,658(1):51-54
Two full size strip detectors were investigated in this study: one with p+ strips (p+/n−/n+) and another with n+ strips (n+/p−/p+). Both detectors, are made of magnetic Czochralski silicon (MCz-Si) and irradiated to S-LHC fluencies, were tested with 225 GeV muon beam in the CERN H2 area. The Current Injected Detector (CID) sensors were operated in a cooling box capable of providing a −53 °C temperature. Results indicate a relative charge collection efficiency (CCE) at 5×1015 neq/cm2 above 30% in irradiated p+/n−/n+ CID detector at 600 V bias voltage. The signal to noise ratio of this CID module was about eight and a forward current of 30 μA was needed for detector biasing. In standard reverse bias, the same detector could not provide a sufficiently large signal for particle tracking purposes. A p-type (n+/p−/p+) sensor was irradiated to a fluence of 2×1015 neq/cm2 and measured under the same test beam conditions. According to the theory of CIDs developed by the CERN RD39 Collaboration, this detector module could be biased up to only 230 V due to the low irradiation fluence. The CCE at 230 V was 35% in CID operation and 20% when reverse biased. 相似文献
27.
28.
29.
30.
Koehler S.D. Garmire E.M. Kost A.R. Yap D. Docter D.P. Hasenberg T.C. 《Quantum Electronics, IEEE Journal of》1996,32(6):1029-1037
A procedure for optimizing MQW hetero-nipi waveguide phase modulators is presented that includes both drive voltage and frequency response. Experimental phase change, absorption change, and frequency response measurements of a modulator designed using this algorithm are presented. In a 300-μm-long device consisting of 3 nipi periods, π phase shift is achieved with an applied voltage of 3.25 V with a frequency bandwidth on the order of 200 MHz 相似文献