全文获取类型
收费全文 | 1526篇 |
免费 | 61篇 |
国内免费 | 3篇 |
学科分类
工业技术 | 1590篇 |
出版年
2023年 | 11篇 |
2022年 | 26篇 |
2021年 | 56篇 |
2020年 | 15篇 |
2019年 | 30篇 |
2018年 | 30篇 |
2017年 | 24篇 |
2016年 | 42篇 |
2015年 | 36篇 |
2014年 | 49篇 |
2013年 | 95篇 |
2012年 | 80篇 |
2011年 | 103篇 |
2010年 | 77篇 |
2009年 | 83篇 |
2008年 | 91篇 |
2007年 | 68篇 |
2006年 | 73篇 |
2005年 | 53篇 |
2004年 | 48篇 |
2003年 | 55篇 |
2002年 | 55篇 |
2001年 | 31篇 |
2000年 | 27篇 |
1999年 | 27篇 |
1998年 | 50篇 |
1997年 | 38篇 |
1996年 | 32篇 |
1995年 | 24篇 |
1994年 | 17篇 |
1993年 | 19篇 |
1992年 | 13篇 |
1991年 | 15篇 |
1990年 | 6篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1970年 | 3篇 |
1969年 | 3篇 |
排序方式: 共有1590条查询结果,搜索用时 15 毫秒
91.
Kiyotaka Uyeda Kohsaku Shimizu Naoki Maki Akinori Ueda Kaoru Itoh 《Electrical Engineering in Japan》1993,113(4):11-24
The application of superconductivity technology to electric power apparatus is very important from the viewpoint of energy saving. Especially, the superconducting generators using superconductors as the field windings have many merits compared with conventional generators. Super-GM has been researching and developing 70-MW-class model machines since FY 1988 for a scheduled period of eight years, aiming at a 200-MW-class superconducting generator. This paper describes the basic specifications and designs of 70-MW-class superconducting generators by Super-GM and also describes the propriety of these basic specifications and designs. 相似文献
92.
N Yahata K Ohyashiki O Iwase Y Kimura A Kodama K Fukutake K Toyama 《Canadian Metallurgical Quarterly》1998,22(9):845-847
We report the second case of post-myelodysplasia acute myeloid leukemia (post-MDS AML) with a sole chromosome change del(15q). This anomaly is rarely seen. To our knowledge, only seven cases so far have been reported in human neoplasias, including one case each of acute myeloid leukemia (AML), acute lymphoid leukemia, post myelodysplasia AML, myelodysplastic syndrome, myelofibrosis, macroglobulinemia, Hodgkin's lymphoma and uterine leiomyoma. This case suggests that del(15q) is related to lympho-myeloproliferative disorders. Moreover, we speculate that certain oncogene(s) located on 15q might have some role in the progression of the disease, since the del(15q) anomaly appeared only in the AML phase in this case. 相似文献
93.
M Hisada T Fujita H Naoki Y Itagaki H Irie M Miyashita T Nakajima 《Canadian Metallurgical Quarterly》1998,36(8):1115-1125
Facile structure determination of acylpolyamines, glutamatergic nerve blocker obtained from the venom of the Joro spider (Nephila clavata) was carried out with the use of micro-column LC/MS and high energy collision induced dissociation (CID) mass spectrometry. 6-hydroxyindole-3-acetyl was proposed previously as a putative partial structure, for the acyl moiety of hydroxyindole-type polyamines (NPTX-1 to -6). The NMR data obtained for NPTX-6, NPTX-687 and hydroxyindole-3-acetic acid which was released by acid hydrolysis of Nephila clavata crude venom extracts proved that the lipophilic head is the 4-hydroxyindole-3-acetic acid. Various hydroxyindole-3-acetyl polyamines were found in N. Clavata venom and characterized by mass spectrometry. As a result, type-E, a new class of generalized acylpolyamine structure was proposed in addition to the previously reported polyamine backbones type-A to -D. 相似文献
94.
95.
Suga K Mochizuki N Yamashita H 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(5):255-258
A simple method for analysis of fumonisin B1 (FB1) and fumonisin B2 (FB2) in beer and raw materials of beer using liquid chromatography-electrospray ionization tandem mass spectrometry (LC/MS/MS) was developed. Samples were prepared and purified by using solid-phase extraction columns (SAX). The LC separation was performed with an octadecylated silica column at a flow-rate of 0.2 mL/min, using a mobile phase consisting of water and acetonitrile. MS/MS was used in multiple reaction monitoring, employing electrospray ionization (ESI-MRM). Recoveries of spiked FB1 and FB2 from beer were 64% and 52%, respectively, at the level of 5 microg/kg. Recoveries of spiked FB1 and FB2 from malt, cornstarch, and corn grit, at the level of 50 microg/kg, were 87.9% and 86.4%, 89.5% and 87.9%, 86.6% and 81.1%, respectively. This method may have applications in quality assurance. 相似文献
96.
Matsui J Akamatsu K Nishiguchi S Miyoshi D Nawafune H Tamaki K Sugimoto N 《Analytical chemistry》2004,76(5):1310-1315
A molecularly imprinted polymer with immobilized Au nanoparticles (Au-MIP) is reported as a novel type of sensing material. The sensing mechanism is based upon the variable proximity of the Au nanoparticles immobilized in the imprinted polymer, which exhibits selective binding of a given analyte accompanied by swelling that causes a blue-shift in the plasmon absorption band of the immobilized Au nanoparticles. Using adrenaline as the model analyte, it was shown that molecular imprinting effectively enhanced the sensitivity and selectivity, and accordingly, Au-MIP selectively detects the analyte at 5 microM. The combination of molecular imprinting and the Au nanoparticle-based sensing system was shown to be a general strategy for constructing sensing materials in a tailor-made fashion due to wide applicability of the imprinting technique and the independence of the sensing mechanism from the analyte recognition system. 相似文献
97.
S Sugiyama M Wada JI Sugenoya H Toyoshima J Toyama K Yamada 《Canadian Metallurgical Quarterly》1977,94(4):445-453
This investigation was designed to diagnose right ventricular infarction, which is difficult to diagnose by the standard twelve-lead ECG, through the use of body surface isopotential maps which have significant diagnostic information. Right ventricular infarction was experimentally caused by ligation of the canine right coronary artery. Each dog had a series of maps recorded before and a week after experimentally-induced myocardial infarction. The common features of maps in right ventricular infarction are: 1. In the early stage of the ventricular depolarization the negative area occupies a comparatively large part of the right anterior chest surface, and in the middle stage, the larger part of the right anterior surface is also occupied by the negative area. 2. A minimum appears on the right anterior chest surface in the early stage. The delayed excitation resulting from intraventricular conduction disturbance caused by infarction, as verified by the epicardial isochronic map, is also well represented by the body surface isopotential map. In conclusion, through the use of body surface isopotential maps, it is much easier to diagnose right ventricular infarction and intraventricular conduction disturbance caused by infarction even in cases in which the standard twelve-lead ECG does not show the abnormalities clearly. 相似文献
98.
A novel optical sensor based on spectroscopic measurement of the plasmon absorption of a colloidal gold submonolayer immobilized upon a planar waveguide has been developed for label-free detection of biomolecular interactions at the sensor's surface. We fabricated the sensor by locally modifying a 50-microm-thick glass plate with hemoglobin (Hb) and then self-assembling gold colloids from the aqueous solution onto the Hb-modified area of the glass plate. Polychromatic light from a xenon-arc lamp was launched into the thin-film glass plate by use of a broadband fiber-coupling method. With the use of a CCD detector to monitor the light beam emitted from an end face of the glass plate, the plasmon absorption spectrum of the colloidal gold submonolayer was determined to depend on the polarization states of the guided light and to change with the refractive index of the medium in contact with the colloids. In addition to simplicity of fabrication and the ease of use, the sensor yields a larger absorbance sensitivity than the normal transmission measurement. 相似文献
99.
Useless-variable elimination is a transformation that eliminates variables whose values does not affect the result of a computation. We present a type-based method for useless-variable elimination and prove its correctness. The algorithm is a surprisingly simple extension of the usual type-reconstruction algorithm. Our method has several attractive features. First, it is simple, so that the proof of the correctness is clear and the method can be easily extended to deal with a polymorphic language. Second, it is efficient: for a simply-typed -calculus, it runs in time almost linear in the size of an input expression. Moreover, our transformation is optimal in a certain sense among those that preserve well-typedness, both for the simply-typed language and for an ML-style polymorphically-typed language. 相似文献
100.
Z. Li T. Schram L. Pantisano A. Stesmans T. Conard S. Shamuilia V.V. Afanasiev A. Akheyar S. Van Elshocht D.P. Brunco W. Deweerd Y. Naoki P. Lehnen S. De Gendt K. De Meyer 《Microelectronics Reliability》2007,47(4-5):518
A systematic study of the flat-band voltage (Vfb) shift of Ru gated metal-oxide-semiconductor (MOS) capacitors subjected to thermal treatment in O2 has been performed. The dependence of the Vfb shift on the thickness of Ru, anneal temperature and time is studied. The Vfb shift is ascribed to the shift of metal gates’ work function (WF), and is not significantly dependent on the type of dielectric (HfO2 or SiO2). From time-of-flight secondary ion mass spectrometry (TOF-SIMS) measurement, it was found that after thermal treatment in 18O2, 18O penetrated through Ru and was incorporated in the Ru/dielectric interface region. We believe that the formation of the thin interfacial RuOx layer is responsible for the Vfb shift. 相似文献