全文获取类型
收费全文 | 2268篇 |
免费 | 136篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 19篇 |
综合类 | 11篇 |
化学工业 | 553篇 |
金属工艺 | 63篇 |
机械仪表 | 47篇 |
建筑科学 | 140篇 |
矿业工程 | 24篇 |
能源动力 | 52篇 |
轻工业 | 128篇 |
水利工程 | 10篇 |
无线电 | 191篇 |
一般工业技术 | 472篇 |
冶金工业 | 124篇 |
原子能技术 | 21篇 |
自动化技术 | 555篇 |
出版年
2023年 | 30篇 |
2022年 | 43篇 |
2021年 | 68篇 |
2020年 | 65篇 |
2019年 | 54篇 |
2018年 | 68篇 |
2017年 | 54篇 |
2016年 | 82篇 |
2015年 | 83篇 |
2014年 | 83篇 |
2013年 | 197篇 |
2012年 | 162篇 |
2011年 | 177篇 |
2010年 | 146篇 |
2009年 | 147篇 |
2008年 | 149篇 |
2007年 | 133篇 |
2006年 | 113篇 |
2005年 | 86篇 |
2004年 | 64篇 |
2003年 | 65篇 |
2002年 | 51篇 |
2001年 | 29篇 |
2000年 | 24篇 |
1999年 | 35篇 |
1998年 | 24篇 |
1997年 | 17篇 |
1996年 | 19篇 |
1995年 | 16篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 17篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1960年 | 2篇 |
排序方式: 共有2410条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
Christina Dirk‐Faitakis D Grant Allen 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(7):737-745
This paper describes the development and simulation of an unsteady state biofilter model used to predict dynamic behaviour of cyclically‐operated biofilters and compares it with experimental results obtained from three, parallel, bench‐scale biofilters treating both periodically fluctuating concentrations and constant concentrations of an α‐pinene‐laden gas stream. The dynamic model, using kinetic parameters estimated from the constant concentration biofilter, was able to predict the performance of cyclic biofilters operating at short cycle periods (ie, in the order of minutes and hours). Steady state kinetic data from a constant concentration biofilter can be used to predict unsteady state biofilter operation. At a 24 h cycle period, the dynamic model compared well with experimental results. For long cycle periods (ie, hours and days), removal efficiency decreased after periods of non‐loading: the longer the period of non‐loading, the poorer the biofilter's performance at the re‐commencement of pollutant loading. At longer time scales the model did not effectively predict transient behaviour, as adsorption and changes in kinetic parameters were not accounted for. Modelling results showed that similar biofiltration performance for the cyclic and constant concentration biofiltration of α‐pinene is expected for biofilters operating solely in the first order kinetics regime. Poorer performance for cyclic biofilters following Monod kinetics spanning the entire kinetics range is expected as the cycle amplitude increases. The most important parameters affecting the performance of a cyclically‐operated biofilter with short cycle periods are: amplitude of cyclic fluctuations, Cg, max/Cg, relative value of the half‐saturation constant in the Monod expression, Ks, and effective diffusivity of α‐pinene in the biofilm, De. Copyright © 2005 Society of Chemical Industry 相似文献
6.
Sven Beyer Christian Jacobi Daniel Kröning Dirk Leinenbach Wolfgang J. Paul 《International Journal on Software Tools for Technology Transfer (STTT)》2006,8(4-5):411-430
In the verified architecture microprocessor (VAMP) project we have designed, functionally verified, and synthesized a processor
with full DLX instruction set, delayed branch, Tomasulo scheduler, maskable nested precise interrupts, pipelined fully IEEE
compatible dual precision floating point unit with variable latency, and separate instruction and data caches. The verification
has been carried out in the theorem proving system PVS. The processor has been implemented on a Xilinx FPGA.
A shorter version of this article with the title “Instantiating uninterpreted functional units and memory system: functional
verification of the VAMP” appeared in [8]. The work reported here was done while all the authors were with Saarland University. 相似文献
7.
To clarify whether motion information per se has a separable influence on action control, the authors investigated whether irrelevant direction of motion of stimuli whose overall position was constant over time would affect manual left-right responses (i.e., reveal a motion-based Simon effect). In Experiments 1 and 2, significant Simon effects were obtained for sine-wave gratings moving in a stationary Gaussian window. In Experiment 3, a direction-based Simon effect with random-dot patterns was replicated, except that the perceived direction of motion was based on the displacement of single elements. Experiments 4 and 5 studied motion-based Simon effects to point-light figures that walked in place--displays requiring high-level analysis of global shape and local motion. Motion-based Simon effects occurred when the displays could be interpreted as an upright human walker, showing that a high-level representation of motion direction mediated the effects. Thus, the present study establishes links between high-level motion perception and action. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
Ingo Alig Dirk Lellinger Harald Oehler Sergey A. Adamovsky Christoph Schick 《Progress in Organic Coatings》2008,61(2-4):166-175
A new microcalorimeter with eight parallel channels using robust, low cost sensors for characterization of coatings and adhesives is described and first experiments on coatings and adhesives are presented. The calorimetric sensors are based on thin glass plates (20 mm × 20 mm, thickness 150 μm) with heater and thermocouple sputtered on the surfaces (calorimetric active area of about 9 mm2). The setup allows heating and cooling experiments as well as isothermal measurements in the temperature-modulated mode with up to eight sensors in parallel. The measured quantities are the real (C′p) and imaginary part (C″p) of the complex heat capacity (), the related absolute value of the heat capacity () and the heat flow . An industrial computer (NI PXI system) with specific software for calibration and data recording controls the electronic components. Sensors can be embedded in a temperature controlled oven (heating and cooling by Peltier elements) or alternatively in a climatic cabinet with controlled temperature and humidity.
The method has been applied successfully to monitoring of film formation of aqueous polymer dispersions (styrene-acrylate copolymer) and curing of coatings. 相似文献
9.
Joseph Dunn Michael Neufeld Anmol Sheth Dirk Grunwald John Bennett 《Mobile Networks and Applications》2006,11(1):37-45
Many companies, organizations and communities are providing wireless hotspots that provide networking access using 802.11b wireless networks. Since wireless networks are more sensitive to variations
in bandwidth and environmental interference than wired networks, most networks support a number of transmission rates that
have different error and bandwidth properties. Access points can communicate with multiple clients running at different rates,
but this leads to unfair bandwidth allocation. If an access point communicates with a mix of clients using both 1 Mb/s and
11 Mb/s transmission rates, the faster clients are effectively throttled to 1 Mb/s as well. This happens because the 802.11
MAC protocol approximate “station fairness”, with each station given an equal chance to access the media. We provide a solution
to provide “rate proportional fairness”, where the 11 Mb/s stations receive more bandwidth than the 1 Mb/s stations. Unlike
previous solutions to this problem, our mechanism is easy to implement, works with common operating systems and requires no
change to the MAC protocol or the stations.
Joseph Dunn received an M.S. in computer science from the University of Colorado at Boulder in 2003, and B. S. in coputer science and
mathematics from the University of Arizona in 2001. His research interests are in the general area of computer systems, primarily
focusing on security and scalability in distributed systems. He is currently working on his Ph.D. in computer science from
the University of Colorado at Boulder.
Michael Neufeld received a Ph.D. in Computer Science from the University of Colorado at Boulder in December of 2004, having previously received
an M.S. in Computer Science from the University of Colorado at Boulder in 2000 and an A.B. in Computer Science from Princeton
University in 1993. His research interests are in the general area of computer system, specifically concentrating on wireless
networking, software defind/cognitive radio, and streerable antennas. He is currently a postdoc in the Computer Science department
at the University of Calorado at Boulder pursuing research related to software defined radio and new MAC protocols for steerable
phase array antennas.
Anmol Sheth is a Ph.D. student in Computer Science at the University of Colorado at Boulder. He received his B.S. in Computer Science
from the University of Pune, India in 2001. He has been co-leading the development of the MANTIS operating system. He has
co-authored three papers include MAC layer protocol design, energy-efficient wireless communication, and adapting communications
to mobility.
Dirk Grunwald received his Ph.D. from the University of Illinois in 1989 and joined the University of Colorado the same year. His work
addresses research and teaching in the broad area of “computer systems”, which includes computer architecture, operating systems,
networks, and storage systems. His interests also include issues in pervasive computing, novel computing models, and enjoying
the mountains. He is currently an Associate Professor in the Department of Computer Science and in Electrical and Computer
Engineering and is also the Director of the Colorado Center for Information Storage.
John Bennett is a Professor of Computer Science with a joint appointment in Electrical and Computer Engineering at the University of Colorado
at Boulder. He also serves as Associate Dean for Education in the College of Engineering and Applied Science. He joined the
CU-Boulder faculty in 2000, after serving on the faculty of Rice University for 11 years. While at Rice, Bennett pioneered
a course in engineering design for both engineering and non-engineering students that has been emulated at several universities
and high schools. In addition to other teaching awards, Bennett received the Keck Foundation National Award for Engineering
Teaching Excellence for his work on this course. Bennett received his Ph.D. in 1988 from the University of Washington. Prior
to completing his doctoral studies, he was a U.S. Naval Officer for several years and founded and served as President of Pacific
Mountain Research, Inc., where he supervised the design and development of a number of commercial computing systems. Bennett's
primary research interests are broadly focused in the area of distributed systems, and more narrowly in distributed information
management and distributed robotic macrosensors. 相似文献
10.