全文获取类型
收费全文 | 1062篇 |
免费 | 62篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 5篇 |
综合类 | 2篇 |
化学工业 | 345篇 |
金属工艺 | 14篇 |
机械仪表 | 11篇 |
建筑科学 | 52篇 |
能源动力 | 15篇 |
轻工业 | 205篇 |
水利工程 | 6篇 |
石油天然气 | 2篇 |
无线电 | 69篇 |
一般工业技术 | 178篇 |
冶金工业 | 79篇 |
原子能技术 | 5篇 |
自动化技术 | 138篇 |
出版年
2024年 | 3篇 |
2023年 | 7篇 |
2022年 | 29篇 |
2021年 | 43篇 |
2020年 | 38篇 |
2019年 | 18篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 31篇 |
2015年 | 31篇 |
2014年 | 44篇 |
2013年 | 77篇 |
2012年 | 64篇 |
2011年 | 71篇 |
2010年 | 64篇 |
2009年 | 63篇 |
2008年 | 63篇 |
2007年 | 56篇 |
2006年 | 47篇 |
2005年 | 53篇 |
2004年 | 34篇 |
2003年 | 24篇 |
2002年 | 23篇 |
2001年 | 13篇 |
2000年 | 26篇 |
1999年 | 17篇 |
1998年 | 18篇 |
1997年 | 19篇 |
1996年 | 15篇 |
1995年 | 8篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 9篇 |
1989年 | 4篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1934年 | 3篇 |
排序方式: 共有1126条查询结果,搜索用时 328 毫秒
71.
72.
To get precise material data for advanced numerical modelling of tube hydroforming process, the tube bulging test is recommended. Stresses and strains in the tube cannot be evaluated easily and several approaches have been proposed. A review is proposed and points out their advantages and drawbacks. 相似文献
73.
Nathalie Meunier Myriam Chartier Guy Mercier Jean-Fran?ois Blais 《Canadian Metallurgical Quarterly》2009,135(9):869-875
Many problems are associated with pig manure production like high biochemical oxygen demand, chemical oxygen demand, nitrogen, and phosphorus contents. Manure produces may be used in land spreading for agricultural purposes. Over application of liquid manure or runoff caused by precipitation contribute notably to surface or overland flow of phosphorus. In this study, the LISOX process is proposed for use in medium size farms, namely a 2,000-head swine farm. The LISOX process uses biological passive flotation, without any gas addition, to enable the flocs to rise to the surface. Results show that this technology is able to considerably reduce the solids content in the final effluent to 1.1±0.3% and reached solids content of 17.9±2.6% in the combined solid manure obtained at the end of the LISOX process. Total phosphorus (Pt) concentrations have been reduced from 1,234±428?mg/L to 146±46?mg/L in the final effluent, while a value of Pt of 20.6±7.9?g/kg has been obtained in the final solid fraction of the treated manure. The initial ammonium ion/total phosphorus ratio of 2.3±1.0 has been increased to respectively 16.4±4.6 and 17.6±5.4 after the primary and the secondary flotation, which is clearly much higher than the target value (NH4/Pt>7). 相似文献
74.
Interactive information visualization systems rely on widgets to allow users to interact with the data and modify the representation. We define interactive legends as a class of controls combining the visual representation of static legends and interaction mechanisms of widgets. As interactive legends start to appear in popular websites, we categorize their designs for common data types and evaluate their effectiveness compare to standard widgets. Results suggest that 1) interactive legends can lead to faster perception of the mapping between data values and visual encodings and 2) interaction time is affected differently depending on the data type. Additionally, our study indicates superiority both in terms of perception and interaction of ordinal controls over numerical ones. Numerical techniques are mostly used in today's systems. By providing solutions to allowing users to modify ranges interactively, we believe that interactive legends make it possible to increase the use of ordinal techniques for visual exploration. 相似文献
75.
Miguel Mauricio-Iglesias Nathalie Gontard Emmanuelle Gastaldi 《Applied Clay Science》2011,51(1-2):174-176
The modification of sodium montmorillonite after a high pressure pasteurization treatment was followed by X-ray diffraction, FTIR spectroscopy and thermogravimetric analysis. Regardless of the treatment intensity (300 and 800 MPa), the structure of montmorillonite was clearly modified. Such changes should be taken into consideration when binging montmorillonite–polymer nanocomposites into contact with food. 相似文献
76.
R Maire-Gauthier T Buronfosse J Magdalou R Herber S Besse P Delatour E Benoit 《Canadian Metallurgical Quarterly》1998,28(6):595-604
1. The stereoselective glucuronidation of carprofen, a non-steroidal anti-inflammatory drug, was investigated in vitro using microsomes prepared from liver of different species (rat, dog, horse, sheep and man) or UGT2B1 expressed in fibroblasts. 2. The Km towards the drug was very similar among these species and for the two enantiomers, whereas the Vmax varied substantially according to the animal used. The rat exhibited a high stereoselective glucuronidation whereas other species, including man, presented a low stereoselectivity. The R-enantiomer was glucuronidated at a more efficient rate than its enantiomorph, and was a better substrate (in terms of Vmax/Km). 3. To explain the enantioselective disposition of carprofen in man and in the different species, the ratio of the enzymatic efficacies (Vmax/Km) were compared with the ratio of the pharmacokinetic parameters AUCs. The basic hypothesis that the intrinsic clearance reflect the enantioselective behaviour of carprofen seemed substantiated when we focused on man and rat glucuronidation, but the in vivo-in-vitro correlation was not possible in other species. 4. In conclusion, the chiral pharmacokinetics of carprofen is less dependent on the stereoselective glucuronidation than other stereoselective processes such as protein binding of carprofen, enzymatic hydrolysis, or renal elimination of glucuronides. 相似文献
77.
Classement des porteurs de charge et conductivite du compose K8Na4Sb12O36 de structure KSbO3 cubique
H. Watelet J.-P. Picard G. Baud J.-P. Besse R. Chevalier 《Materials Research Bulletin》1981,16(7):877-882
Two structures have been reported for cubic KSbO3 type. One has space group Pn3, where K+ ions are in an ordered state. The other has Im3 with K+ ions in a disordered state. These ions are weakly bound in large tunnels along 〈111〉 and are mobile along them three-dimensionally.The presence of two alkaline cations in these tunnels is in favour of the ordered state. Single-crystals of K8Na4Sb12O36 are obtained and crystallize in the space group Pn3, . Using 563 independent reflections, the structure has been refined by full-matrix least squares, to factor R = 0,059.The comparison of the ionic conductivity of ordered (Pn3) and disordered (Im3) compounds is studied by the authors. 相似文献
78.
We measure with a gated intensified CCD camera the cross-polarized backscattered light from a linearly polarized laser beam penetrating a cloud made of spherical particles. In accordance with previously published results we observe a clear azimuthal pattern in the recorded images. We show that the pattern is symmetrical, that it originates from second-order scattering, and that higher-order scattering causes blurring that increases with optical depth. We also find that the contrast in the symmetrical features can be related to measurement of the optical depth. Moreover, when the blurring contributions are identified and subtracted, the resulting pattern provides a pure second-order scattering measurement that can be used for retrieval of droplet size. 相似文献
79.
Glidle A Yasukawa T Hadyoon CS Anicet N Matsue T Nomura M Cooper JM 《Analytical chemistry》2003,75(11):2559-2570
We describe a method, based on X-ray photoelectron spectroscopy (XPS) measurements, to assess the extent of protein adsorption or binding on a variety of different muTAS and biosensor interfaces. Underpinning this method is the labeling of protein molecules with either iodine- or bromine-containing motifs by using protocols previously developed for radiotracer studies. Using this method, we have examined the adsorption and binding properties of a variety of modified electrodeposited polymer interfaces as well as other materials used in muTAS device fabrication. Using polymer interfaces modified with poly(propylene glycol) (PPG) chains, our results indicate that a chain of at least approximately 30 monomer units is required to inhibit nonspecific adsorption from concentrated protein solutions. The XPS methodology was also used to probe specific binding of avidins and enzyme conjugates thereof to biotinylated and mixed biotin/PPG-modified polymer interfaces. In one example, using competitive binding, it was established that the mode of binding of a peroxidase-streptavidin conjugate to a biotinylated modified polymer interface was primarily via the streptavidin moiety (as opposed to nonspecific binding via the enzyme conjugate). XPS evaluation of nonspecific and specific peroxidase-streptavidin immobilization on various functionalized polymers has guided the design and fabrication of functionalized interdigitated electrodes in a biosensing muTAS device. Subsequent characterization of this device using scanning electrochemical microscopy (SECM) corroborated the adsorption and binding previously inferred from XPS measurements on macroscale electrodes. 相似文献
80.
Ravet N Abouimrane A Armand M 《Nature materials》2003,2(11):702; author reply 702-702; author reply 703