全文获取类型
收费全文 | 155篇 |
免费 | 12篇 |
专业分类
化学工业 | 39篇 |
金属工艺 | 5篇 |
机械仪表 | 7篇 |
建筑科学 | 2篇 |
矿业工程 | 1篇 |
能源动力 | 12篇 |
轻工业 | 12篇 |
一般工业技术 | 62篇 |
冶金工业 | 3篇 |
自动化技术 | 24篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 9篇 |
2017年 | 14篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 10篇 |
2011年 | 12篇 |
2010年 | 6篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 8篇 |
2005年 | 16篇 |
2004年 | 16篇 |
2003年 | 10篇 |
1995年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有167条查询结果,搜索用时 15 毫秒
1.
In this paper, we bring into the scheduling field a new model of the learning effect, where in two ways the existing approach is generalized. First we relax one of the rigorous constraints, and thus in our model each job can provide different experience to the processor. Second we formulate the job processing time as a non-increasing k-stepwise function, that, in general, is not restricted to a certain learning curve, thereby it can accurately fit every possible shape of a learning function. Furthermore, we prove that the problem of makespan minimization with the considered model is polynomially solvable if every job provides the same experience to the processor, and it becomes NP-hard if the experiences are diversified. The most essential result is a pseudopolynomial time algorithm that solves optimally the makespan minimization problem with any function of an experience-based learning model reduced into the form of the k-stepwise function. 相似文献
2.
Agnieszka Łącz Łukasz Łańcucki Radosław Lach Bartosz Kamecki Ewa Drożdż 《International Journal of Hydrogen Energy》2018,43(18):8999-9005
Series of single-phase materials with assumed formula SrTi1?xCrxO3 (where x = 0, 1, 4, 6 mol.%) were obtained by sol-gel method. The structure and microstructure of materials were characterised by X-ray diffraction and scanning electron microscopy methods. Moreover, the study of electrical properties and evaluation of chemical stability in CO2/H2O atmosphere was performed by electrochemical impedance spectroscopy and thermogravimery methods, respectively. The possibility of participation of Cr-doped strontium titanate in oxidation–reduction processes was analysed by temperature-programed reduction (TPR) and temperature-programed oxidation (TPOx) measurements. The changes of lattice parameters together with XPS analysis, the Seebeck coefficient measurements results and TPR profiles obtained for SrTi1?xCrxO3 materials prove the presence of chromium on +3 and +6 oxidation stages. Thus, chromium can be treated as both acceptor- and donor-type dopant in the SrTiO3 structure. The Cr3+/Cr6+ ratio strongly affects the electrical properties, as the change of conduction mechanism was observed. The results of performed stability test clearly indicate that incorporation of chromium into SrTiO3 structure results with decrease of chemical stability in CO2 atmosphere. 相似文献
3.
4.
A comparative study on composition and antioxidant activities of supercritical carbon dioxide,hexane and ethanol extracts from blackberry (Rubus fruticosus) growing in Poland 下载免费PDF全文
5.
Free radical/cationic hybrid photopolymerization of acrylates and epoxides was induced using an initiator system comprised of the dye derivative 5,12-dihydroquinoxalino[2,3-b]quinoxaline or 5,12-dihydroquinoxalino[2,3-b]pyridopyrazine as the sensitizers and hexafluoroantimonate triarylsulfonium salt as the initiators. The curing experiments were carried out in the presence of air and the consumption of each monomer upon VIS-radiation was monitored in situ by real-time infrared spectroscopy. Hardness (H), elastic modulus (E) and the H/E ratio of the coatings obtained by visible-initiated acrylate/epoxide hybrid photopolymerization were determined using nanoindentation. DSC measurements show that the initiator system presented here may produce an interpenetrating polymer network. The pencil hardness of the obtained coatings indicates that the dye/hexafluoroantimonate triarylsulfonium salts systems studied here may have practical applications as visible-light hybrid initiators. 相似文献
6.
Actions and social interactions in multi-agent systems 总被引:3,自引:3,他引:0
7.
Rados C 《FDA consumer》2004,38(1):10-11
Keeping ready-to-eat foods cold is key to reducing listeriosis, a serious infection in humans. That's one of the conclusions of a recent Food and Drug Administration risk assessment on the relationships between foodborne listeriosis and human health. 相似文献
8.
Radosław Belka 《Journal of Materials Science》2007,42(24):10090-10097
In this article, results based on the research of optical properties of A2MX4 type crystals (A—organic cation, M—metal, X—halogen) composed of different chemical elements are presented. These crystals
were grown by the evaporation method from water solutions of AX and MX2 compounds in an appropriate molar ratio. The conducted X-ray investigations show a different crystal structures, ranging
from tetragonal to triclinic ones. Also, the structure of the ion complex for Cu2+ crystals varied. The investigation showed both CuCl42− tetrahedral and CuCl4 · 2H2O2− octahedral deformed complexes in investigated crystals. Additionally, the optical spectra of the samples were measured in
the range of 250–850 nm. Based on the crystal field theory, it was shown that the shape of absorption spectra and colour of
the crystals depend on the distortion of these complexes. 相似文献
9.
Rados?aw Bandomir Mariusz Krawczyk Jacek Namie?nik 《Journal of Automated Methods and Management in Chemistry》2005,2005(2):55-57
We present the results of a first stage of development work on a new type of analyzer for hydrogen and C1–C3 hydrocarbons concentration measurements in the lower explosive limit range, based on single pellistor sensor with artificial neural network data postprocessing. 相似文献
10.
Vibration analysis of machines operating under non-stationary operational conditions requires special attention. This refers to the necessity of use of order tracking algorithms together with additional advanced signal processing methods, especially when faults indicators of interest are located in resonance frequency ranges. 相似文献