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排序方式: 共有1421条查询结果,搜索用时 15 毫秒
91.
Shinsuke Hara Hiroyuki Yomo Petar Popovski Kazunori Hayashi 《Wireless Personal Communications》2006,37(3-4):233-241
This paper discusses what a new paradigm can be in wireless communication systems of the twenty-first century. First, it suggests two directions for the new paradigm; one is “micro- and nano-device communication system” which is the projected scenario considering that the entities in source and destination have been shrinking throughout the history of wireless communication systems. The second direction is “networked robot system”, which emerges as a natural extension of mobile ad hoc networking where the networking is closely related to motion control of robots. Secondly, it shows two interesting research topics, “the new communication protocol design” and “signal processing”, respectively, that arise in the wake of the fusion between the two directions in the novel communication paradigm. Finally, it considers a new science of wireless communications in the twenty-first century.
Shinsuke Hara received the B.Eng., M.Eng. and Ph.D. degrees in communications engineering from Osaka University, Osaka, Japan, in 1985, 1987 and 1990, respectively. From April 1990 to March 1997, he was an assistant professor in the Department of Communication Engineering, School of Engineering, Osaka University, and from October 1997 to September 2005, he was an associate professor in the Department of Electronic, Information and Energy Engineering, Graduate School of Engineering, Osaka University. Since October 2005, he has been a professor in the Department of Physical Electronics and Informatics, Graduate School of Engineering, Osaka City University. In addition, from April 1995 to March 1996, he was a visiting scientist at Telecommunications and Traffic Control Systems Group, Delft University of Technology, Delft, The Netherlands. His research interests include wireless communications systems and digital signal processing.
Hiroyuki Yomo received B.S. degree in communication engineering from Department of Communication Engineering, Osaka University, Osaka, Japan, in 1997, and M.S. and Ph.D. degrees in communication engineering from Department of Electronic, Information, and Energy Engineering, Graduate School of Engineering, Osaka University, Osaka Japan, in 1999 and 2002, respectively. From April 2002 to March 2004, he was a Post-doctoral Fellow in Department of Communication Technology, Aalborg University, Denmark. From April 2004 to September 2004, he was at Internet System Laboratory, NEC Corporation, Japan. Since October 2004, he has been an Assistant Research Professor in Center for TeleInfrastructure (CTIF), Aalborg University, Denmark. His main research interests are access technologies, radio resource management, and link-layer techniques in the area of short-range communication, cellular network, cognitive radio, and sensor network.
Petar Popovski received the Dipl.-Ing. in electrical engineering and M.Sc. in communication engineering from the Faculty of Electrical Engineering, Sts. Cyril and Methodius University, Skopje, Republic of Macedonia, in 1997 and 2000, respectively. He received a Ph.D. degree from Aalborg University, Denmark, in 2004. From 1998 to 2001 he was a teaching and research assistant at the Institute of Telecommunications, Faculty of Electrical Engineering in Skopje. He is currently Assistant Professor at the Department of Communication Technology at the Aalborg University. His research interests are related to the PHY-MAC aspects of wireless protocols, wireless sensor networks, random access protocols, and network coding.
Kazunori Hayashi received the B.E., M.E. and Ph.D. degrees in communication engineering from Osaka University, Osaka, Japan, in 1997, 1999 and 2002, respectively. He spent 3 months in 2000 at Aalborg University, Denmark, as a Visiting Scholar. Since 2002, he has been with the Department of Systems Science, Graduate School of Informatics, Kyoto University. He is currently an Assistant Professor there. His research interests include digital signal processing for communications systems. 相似文献
92.
Sinusoidal wavelength-scanning interferometric reflectometry 总被引:1,自引:0,他引:1
We propose interferometric reflectometry in which a sinusoidal wavelength-scanning tunable laser diode is used to detect positions and profiles of multiple reflecting surfaces. An objective signal extracted from an interference signal contains modulation amplitude Z and phase alpha, which are related to the positions and profiles, respectively, of multiple reflecting surfaces. By using values of the objective signal at special times, we can produce an image intensity that shows where the reflecting surfaces exist. To obtain exact values of Z or values of alpha, we estimated the objective signal by using a conjugate gradient method. Experimental results show that a resolution of two-optical-path difference (OPD) in the image intensity is ~60 mum, and the final OPD precisions are 2 and 8 mum for two and three reflecting surfaces, respectively, for a wavelength-scanning width of 7 nm. Profiles of the front and rear surfaces of a silica glass plate with a thickness of 20 mum have been measured with a precision of ~10 nm. 相似文献
93.
Micheletto R Denyer M Scholl M Nakajima K Offenhauser A Hara M Knoll W 《Applied optics》1999,38(31):6648-6652
We report the observation of live-cell dynamics by noncontact scanning near-field optical microscopy (SNOM) modified to work with living biological samples that are fully immersed in liquid. We did not use the SNOM setup in strictly near-field conditions (we used 1-mum constant-height mode); however, we could examine the dynamics of rhythmically beating cardiac myocytes in culture with extremely high vertical sensitivity below the nanometric range. We could halt scans at any point to record localized contraction profiles of the cell membrane. We show that the contractions of the organisms changed shape dramatically within adjacent areas. We believe that the spatial dependency of the contractions arises because of the measurement system's ability to resolve the behavior of individual submembrane actin bundles. Our results, combining imaging and real-time recording in localized areas, reveal a new, to our knowledge, noninvasive method for using SNOM setups for studying the dynamics of live biological samples. 相似文献
94.
Iemura Y Yamada T Takahashi T Furukawa K Hara S 《Journal of Bioscience and Bioengineering》1999,88(3):276-280
In the supernatant of sokujo-moto, a high level of acid carboxypeptidase (ACP) activity and a large amount of peptides were observed, however, the amount of free amino acids liberated was small. In order to determine why these peptides were not hydrolyzed to any significant degree by the ACP, the properties of the peptides in sokujo-moto were investigated in this study. Peptides were fractionated from sokujo-moto by ion exchange column chromatography. ACP purified from rice-koji (rice overgrown with Aspergillus oryzae) was allowed to react with the peptides, and it was found that they were not hydrolyzed to any significant degree by the enzyme. Gel filtration chromatography was performed to ascertain the molecular size distribution of the peptides in sokujo-moto, and it was revealed that they were of low molecular sizes; molecular size: mainly in the range of 200-400, and chain length: 2-3. ACP purified from rice-koji was also allowed to react with various synthetic peptides, and it was found that ACP of rice-koji could not rapidly hydrolyze low-molecular-size peptides, such as dipeptides or tripeptides. Acid protease (AP) purified from rice-koji released peptides of molecular sizes mainly in the range of 300-600 or above from rice protein under acidic conditions (pH 3.6; the pH of sokujomoto). When AP and ACP were allowed to act at the same time on rice protein, mainly low-molecular-size peptides (molecular sizes mainly in the range of 200-400) were produced. From these results, it was estimated that AP released peptides with molecular sizes mainly in the range of 300-600 or above from rice protein and ACP degraded the relatively higher molecular size peptides among them to lower molecular size peptides; consequently only low-molecular-size peptides with molecular sizes mainly in the range of 200-400 were released in the supernatant of sokujo-moto. 相似文献
95.
H Harada T Hirata J Utoh R Kunitomo M Hara N Kitamura 《Canadian Metallurgical Quarterly》1998,46(7):629-633
OBJECTIVE: The prevalence of obesity and thinness is unknown among Iranian high-school age girls. We determined the prevalence of overweight and underweight among Iranian high-school girls from Kerman (south-east province of Iran). DESIGN: A cross-sectional study of indicative cluster sample. MEASUREMENTS: Weight, height, body mass index (BMI), chest, waist, abdomen, hip and thigh circumference of 1000 Iranian high-school girls aged 14-21 y (mean (standard deviation, s.d.) 16.2 (1.3)) were measured. The criteria for very underweight, underweight, desirable weight, grade 1, 2 and 3 overweight used in the present study were: BMI in kg/m2 < 15, 15-19.9, 20-24.9, 25-29.9, 30-39.9 and > or = 40, respectively. RESULTS: 4.6% (95% confidence interval (CI): 3.4%-6.1%) were grade 1 overweight (BMI = 25.0-29.9), 0.7% (95% CI: 0.3%-1.4%) were grade 2 overweight (BMI = 30-39.9), and none were grade 3 overweight (BMI > or = 40), while 54.6% (95% CI: 51.5%-57.7%) were underweight (BMI = 15-19.9) and 1.6% (95% CI: 0.9%-2.6%) were very underweight (BMI < 15). The mean (s.d.) BMI was 19.8 (2.9) (95% CI: 19.6-20.0). The mean (s.d.) waist-to-hip ratio (WHR), abdomen-to-hip ratio and chest-to-hip ratio values were 0.8 (0.06) (95% CI: 0.8-0.81), 0.8 (0.07) (95% CI: 0.8-0.81) and 0.9 (0.07) (95% CI: 0.9-0.91), respectively, in this sample. CONCLUSION: The results suggest a low prevalence of overweight among Iranian young women. 相似文献
96.
97.
98.
99.
Kakimoto Y Naetoko Y Hara H Miyatake M Sato A Tatsuguchi H Takahata R Yamamoto R Joh T 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(3):165-174
A collaborative study involving 8 laboratories was conducted to evaluate a method for the simultaneous determination of pesticide residues in 6 types of fruits and vegetables (spinach, tomato, apple, radish, cabbage and carrot). The method of analysis was the same as reported by Kakimoto et al. in 2003. One hundred and thirty-nine pesticides were spiked by each of 8 laboratories at levels of 0.1 microg/g (pesticides analyzed by GC/MS) or 0.5 microg/g (pesticides analyzed by HPLC) into the 6 kinds of samples. Statistical analysis showed that 111 pesticides could be analyzed with practical precision by this method. For screening purposes, the method could analyze 118 pesticides. The median values of the limits of detection were 0.001-0.041 microg/g. The calibration curves were linear in the range of 0.5-5 microg/mL for most pesticides with median correlation coefficients of 0.983-1.000. 相似文献
100.
The influence of electrolytic variables on the content of Zn, Ni and Pb in copper deposited cathodically from ammine solution has been investigated. Solutions spiked with zinc or nickel sulphate were studied using a rotating cylindrical titanium cathode and a lead anode.The nickel and zinc contents in the cathodic deposit increase with increasing current density and their concentration in the electrolyte. A rise in the rotation speed of the cathode increases the lead and nickel contents but diminishes the zinc content in the deposit.To explain these results an attempt has been made to schematically reconstruct polarisation diagrams for each metal. Direct potential measurements are subject to considerable experimental error in the system studied. Polarisation measurements performed on a simplified system were in good agreement with the hypothetical diagram. 相似文献