全文获取类型
收费全文 | 907篇 |
免费 | 20篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 85篇 |
综合类 | 1篇 |
化学工业 | 329篇 |
金属工艺 | 15篇 |
机械仪表 | 22篇 |
建筑科学 | 20篇 |
能源动力 | 59篇 |
轻工业 | 76篇 |
无线电 | 63篇 |
一般工业技术 | 157篇 |
冶金工业 | 21篇 |
原子能技术 | 35篇 |
自动化技术 | 47篇 |
出版年
2023年 | 4篇 |
2022年 | 9篇 |
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 16篇 |
2016年 | 12篇 |
2015年 | 6篇 |
2014年 | 18篇 |
2013年 | 40篇 |
2012年 | 38篇 |
2011年 | 57篇 |
2010年 | 48篇 |
2009年 | 33篇 |
2008年 | 37篇 |
2007年 | 41篇 |
2006年 | 38篇 |
2005年 | 32篇 |
2004年 | 35篇 |
2003年 | 26篇 |
2002年 | 29篇 |
2001年 | 14篇 |
2000年 | 21篇 |
1999年 | 20篇 |
1998年 | 29篇 |
1997年 | 14篇 |
1996年 | 23篇 |
1995年 | 15篇 |
1994年 | 13篇 |
1993年 | 16篇 |
1992年 | 17篇 |
1991年 | 16篇 |
1990年 | 4篇 |
1989年 | 9篇 |
1988年 | 14篇 |
1987年 | 16篇 |
1986年 | 14篇 |
1985年 | 20篇 |
1984年 | 10篇 |
1983年 | 15篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 12篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1976年 | 11篇 |
1975年 | 4篇 |
1974年 | 6篇 |
排序方式: 共有930条查询结果,搜索用时 15 毫秒
11.
Zilong Zhang Wen Zhao Guo Chen Masaya Toda Satoshi Koizumi Yasuo Koide Meiyong Liao 《Advanced functional materials》2023,33(27):2300805
Electrically integrable, high-sensitivity, and high-reliability magnetic sensors are not yet realized at high temperatures (500 °C). In this study, an integrated on-chip single-crystal diamond (SCD) micro-electromechanical system (MEMS) magnetic transducer is demonstrated by coupling SCD with a large magnetostrictive FeGa film. The FeGa film is multifunctionalized to actuate the resonator, self-sense the external magnetic field, and electrically readout the resonance signal. The on-chip SCD MEMS transducer shows a high sensitivity of 3.2 Hz mT−1 from room temperature to 500 °C and a low noise level of 9.45 nT Hz−1/2 up to 300 °C. The minimum fluctuation of the resonance frequency is 1.9 × 10−6 at room temperature and 2.3 × 10−6 at 300 °C. An SCD MEMS resonator array with parallel electric readout is subsequently achieved, thus providing a basis for the development of magnetic image sensors. The present study facilitates the development of highly integrated on-chip MEMS resonator transducers with high performance and high thermal stability. 相似文献
12.
Kikuta K Tochigi N Saito S Shimoda T Morioka H Toyama Y Hosono A Suehara Y Beppu Y Kawai A Hirohashi S Kondo T 《Proteomics. Clinical applications》2010,4(5):560-567
Purpose : We aimed to identify novel chemotherapy responsiveness biomarkers for osteosarcoma (OS) by investigating the global protein expression profile of 12 biopsy samples from OS patients. Experimental design : Six patients were classified as good responders and six as poor responders, according to the Huvos grading system. The protein expression profiles obtained by 2‐D DIGE consisted of 2250 protein spots. Results : Among them, we identified 55 protein spots whose intensity was significantly different (Bonferroni adjusted p‐value<0.01) between the two patient groups. Mass spectrometric protein identification demonstrated that the 55 spots corresponded to 38 distinct gene products including peroxiredoxin 2 (PRDX 2). Use of a specific antibody against PRDX 2 confirmed the differential expression of PRDX 2 between good and poor responders, while PRDX 2 levels as measured by Western blotting correlated highly with their corresponding 2‐D DIGE values. The predictive value of PRDX 2 expression was further confirmed by examining an additional four OS cases using Western blotting. Conclusions and clinical relevance : These results establish PRDX 2 as a candidate for chemotherapy responsiveness marker in OS. Measuring PRDX 2 in biopsy samples before treatment may contribute to more effective management of OS. 相似文献
13.
Yasuo Ariki 《New Generation Computing》2000,18(4):341-357
Because of the media digitization, a large amount of information such as speech, audio and video data is produced everyday.
In order to retrieve data from these databases quickly and precisely, multimedia technologies for structuring and retrieving
of speech, audio and video data are strongly required. In this paper, we overview the multimedia technologies such as structuring
and retrieval of speech, audio and video data, speaker indexing, audio summarization and cross media retrieval existing today
for TV news detabase. The main purpose of structuring is to produce tables of contents and indices from audio and video data
automatically. In order to make these technologies feasible, first, processing units such as words on audio data and shots
on video data are extracted. On a second step, they are meaningfully integrated into topics. Furthermore, the units extracted
from different types of media are integrated for higher functions.
Yasuo Ariki, Ph.D.: He is a Professor in the Department of Electronics and Informatics at the Ryukoku University. He received his B.E., M.E.
and Ph.D. in information science from Kyoto University in 1974, 1976 and 1979, respectively. He had been an Assistant in Kyoto
University from 1980 to 1990, and stayed at Edinburgh University as visiting academic from 1987 to 1990. His research interests
are in speech and image recognition and in information retrieval and database. He is a member of IPSJ, IEICE, ASJ, Soc. Artif.
Intel. and IEEE. 相似文献
14.
Yasuo Kinouchi Shoji Inabayashi Akira Satou Fumitoshi Shouji S. Inabayashi 《Artificial Life and Robotics》2000,4(2):53-56
To construct a “thinking-like” processing system, a new architecture of an adaptive associative memory system is proposed.
This memory system treats “images” as basic units of information, and adapts to the environment of the external world by means
of autonomous reactions between the images. The images do not have to be clear, distinct symbols or patterns; they can be
ambiguous, indistinct symbols or patterns as well. This memory system is a kind of neural network made up of nodes and links
called a localist spreading activation network. Each node holds one image in a localist manner. Images in high-activity nodes
interact autonomously and generate new images and links. By this reaction between images, various forms of images are generated
automatically under constraints of links with adjacent nodes. In this system, three simple image reaction operations are defined.
Each operation generates a new image by combining pseudofigures or features and links of two images.
This work was presented, in part, at the Fourth International Symposium on Artificial Life and Robotics, Oita, Japan, January
19–22, 1999 相似文献
15.
Islam Z Capatina D Ruff JP Das RK Trakhtenberg E Nojiri H Narumi Y Welp U Canfield PC 《The Review of scientific instruments》2012,83(3):035101
We present a pulsed-magnet system that enables x-ray single-crystal diffraction in addition to powder and spectroscopic studies with the magnetic field applied on or close to the scattering plane. The apparatus consists of a single large-bore solenoid, cooled by liquid nitrogen. A second independent closed-cycle cryostat is used for cooling samples near liquid helium temperatures. Pulsed magnetic fields close to ~30 T with a zero-to-peak-field rise time of ~2.9 ms are generated by discharging a 40 kJ capacitor bank into the magnet coil. The unique characteristic of this instrument is the preservation of maximum scattering angle (~23.6°) on the entrance and exit sides of the magnet bore by virtue of a novel double-funnel insert. This instrument will facilitate x-ray diffraction and spectroscopic studies that are impractical, if not impossible, to perform using split-pair and narrow-opening solenoid magnets. Furthermore, it offers a practical solution for preserving optical access in future higher-field pulsed magnets. 相似文献
16.
Thin SiO2 layers were deposited by atomic layer deposition (ALD) using either Bis-dimethylamino-silane (BDMAS: SiH2(N(CH3)2)2) or Tris-dimethylamino-silane (TDMAS: SiH(N(CH3)2)3) precursors. The purpose of this study is to evaluate these precursors for their suitability for ALD of hafnium (Hf)-silicate gate dielectrics. The advantages of these precursors are that the melting points and vapor pressures are moderate. The thickness of SiO2 deposited using ALD process is controlled by the number of growth cycles and the growth rate was different for each precursor, that for BDMAS being 1.5 times that for TDMAS at the same reactor pressure. The carbon impurity in the SiO2 film deposited using BDMAS was about half an order of magnitude less than that using for TDMAS. Furthermore, the carbon impurity was reduced to about the detection limit of secondary ion mass spectrometry after high temperature annealing at 1000 °C during 5 s. 相似文献
17.
Suppose that some particular link in the Internet is currently
congested.
A natural solution is to try to make packets bypass that link.
This can be done by increasing the cost of that link intentionally,
say from a
1 to a
2, since the Internet uses shortest-path
routing. Unfortunately, however, this often causes temporary loops
for packet traveling, called routing loops. In this paper
we show that routing loops can be avoided by increasing the cost
of the link not directly from a
1 to a
2 but through an
intermediate value, a
3, i.e., from a
1 to a
3 and then
to a
2.
We may need several
intermediate values.
We show that in this case
the greedy strategy,
namely, raising the cost as much as possible in each step,
is optimal. 相似文献
18.
Takafumi Ishii Takuya Maie Naofumi Kimura Yuki Kobori Yasuo Imashiro Jun-ichi Ozaki 《International Journal of Hydrogen Energy》2017,42(23):15489-15496
The use of carbon cathode catalysts in polymer electrolyte fuel cells instead of the current platinum catalysts is attracting increasing attention. We claim that two factors are important for enhancing the activity of carbon cathode catalysts in the oxygen reduction reaction (ORR): the formation of a nanoshell structure and co-doping with boron and nitrogen. Herein, we investigate the preparation and characterization of active ORR carbon catalysts that combine the above factors. Boron and nitrogen (BN)-doped nanoshell-containing carbon (BN-NSCC) was prepared by carbonizing a mixture of poly(furfuryl alcohol), cobalt phthalocyanine, melamine, and a trifluoroborane–methanol complex at 1000 °C. Transmission electron microscopy and X-ray photoelectron spectroscopy revealed the formation of nanoshell structures with distorted graphitic layers and the introduction of boron and nitrogen atoms, respectively. The ORR activity was evaluated in oxygen-saturated 0.5 mol dm?3 H2SO4 using Koutecky–Levich analysis. The BN-NSCC showed an eight to ten times higher ORR activity than undoped NSCC, with an increased number of electrons participating in the reaction. Tafel analysis revealed a change in the rate-determining step caused by BN-doping. Thus, the combination of a nanoshell structure and co-doping with boron and nitrogen was found to improve the ORR activity of carbon catalysts. 相似文献
19.
20.
Inside Cover: Biosynthetic Gene Cluster for Surugamide A Encompasses an Unrelated Decapeptide,Surugamide F (ChemBioChem 18/2016) 下载免费PDF全文