全文获取类型
收费全文 | 2826篇 |
免费 | 165篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 119篇 |
综合类 | 31篇 |
化学工业 | 583篇 |
金属工艺 | 82篇 |
机械仪表 | 71篇 |
建筑科学 | 88篇 |
矿业工程 | 20篇 |
能源动力 | 111篇 |
轻工业 | 414篇 |
水利工程 | 30篇 |
石油天然气 | 21篇 |
武器工业 | 1篇 |
无线电 | 202篇 |
一般工业技术 | 504篇 |
冶金工业 | 175篇 |
原子能技术 | 53篇 |
自动化技术 | 498篇 |
出版年
2023年 | 20篇 |
2022年 | 33篇 |
2021年 | 66篇 |
2020年 | 58篇 |
2019年 | 57篇 |
2018年 | 100篇 |
2017年 | 96篇 |
2016年 | 88篇 |
2015年 | 81篇 |
2014年 | 133篇 |
2013年 | 243篇 |
2012年 | 218篇 |
2011年 | 283篇 |
2010年 | 158篇 |
2009年 | 163篇 |
2008年 | 96篇 |
2007年 | 106篇 |
2006年 | 60篇 |
2005年 | 123篇 |
2004年 | 64篇 |
2003年 | 69篇 |
2002年 | 93篇 |
2001年 | 66篇 |
2000年 | 31篇 |
1999年 | 32篇 |
1998年 | 60篇 |
1997年 | 53篇 |
1996年 | 35篇 |
1995年 | 25篇 |
1994年 | 23篇 |
1993年 | 17篇 |
1992年 | 14篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 19篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 15篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1974年 | 8篇 |
1973年 | 11篇 |
排序方式: 共有3003条查询结果,搜索用时 187 毫秒
101.
D. Volochová P. Diko M. Radušovská S. Piovarči V. Antal K. Zmorayová M. Šefčiková 《Journal of Superconductivity and Novel Magnetism》2013,26(4):885-889
The TSMG process of YBCO bulk superconductors with Y1.5Ba2Cu3O x composition and 1 wt% CeO2 addition has been studied. It is shown that the window for isothermal growth of single-crystalline sample grown from Sm123 seed is between 988 °C and 1003 °C. At lower temperatures of this window, Y123 crystals grow with higher growth rate but the quality of crystals is worse due to the formation of steps at the growth front. During an isothermal dwell at the optimized temperature, the growth of Y123 single-crystal stops due to decreasing peritectic temperature with increasing CuO concentration in the melt. Additional slow cooling 1 °C/hour from the temperature of isothermal growth leads to epitaxial growth of Y123 crystal over the entire sample. Only very narrow part at the rim of the sample contains CuO phase and blocky Y123 crystals are formed there due to self-nucleation. 相似文献
102.
Spray drying is a very useful method for manufacturing of amorphous solid materials. This is mainly due to the possibility of fast solvent evaporation that leads to a rapid transformation of solution to a solid state. Besides evaporation kinetics, there are various process parameters that influence physical and chemical characteristics of such obtained material. The possibility of obtaining a stable amorphous structure of the active pharmaceutical ingredient in a spray dryer was examined. A solution of the hydrochloride crystalline structure of the active pharmaceutical ingredient in a mixture of water and acetonitrile was dried at different temperatures and flowrates of nitrogen used for atomization, as well as the flowrates of the solution. The influence of the process conditions on the properties of the product was analyzed. The final dried products were characterized and identified with a variety of analytical and physical methods. The results showed that a stable amorphous structure of the high purity active pharmaceutical ingredient is obtained, and that the optimal conditions of the process are defined. The amorphous structure is stable at temperatures below 200°C when it is transformed into a new crystal structure. Conditions of high relative air humidity lead to partial transformation. 相似文献
103.
104.
105.
106.
Machine Learning - Anomaly detection is a hard data analysis process that requires constant creation and improvement of data analysis algorithms. Using traditional clustering algorithms to analyse... 相似文献
107.
Korkanç Mustafa İnce İsmail Hatır M. Ergün Tosunlar M. Bahadır 《Bulletin of Engineering Geology and the Environment》2021,80(4):3053-3063
Bulletin of Engineering Geology and the Environment - The aim of this study is to determine the extent of deterioration of the limestone on which the İvriz rock monument is engraved. This... 相似文献
108.
Tijanić Ksenija Car-Pušić Diana Šperac Marija 《Neural computing & applications》2020,32(13):9343-9355
Neural Computing and Applications - Road construction projects on the territory of the Republic of Croatia are characterized by the overrun of planned costs. The experience of the contractor on... 相似文献
109.
Prof. Dr. Božidar Šarler Robert Vertnik Agnieszka Zuzanna Lorbiecka Igor Vušanović Bojan Senčič 《BHM Berg- und Hüttenm?nnische Monatshefte》2014,159(3):99-107
This paper represents the elements and the use of the upgraded simulation system, developed in the last half decade for ?tore Steel billet caster. The simulation system is used in the context of the state-of-the-art automation and information of the twenty-five year-old three-strand Concast billet continuous caster for dimensions square 140 and 180 mm with the capacity of 160,000 tons/year. The simulation system is used in the off-line and on-line modes. The off-line mode is used in order to set the proper process parameters and to calculate the temperature field, macrosegregation, and grain structure of the strand. It is also used to calculate the changes in the caster design such as the secondary cooling and the position of the SEN. The on-line model is used in automatic casting control system. The paper represents an update of our BHM publication of 2005 (Application of Continous Casting Simulation at ?tore Steel, BHM, Vol. 150, No. 9, 300–306). 相似文献
110.
The purpose of this research was to determine the effects of the packaging materials and size on the stability of monomeric anthocyanins, polyphenols, antioxidant activity, ascorbic acid, colour index and hydroxyl methyl furfural (HMF) during the 12‐month shelf life of sour cherry nectars at 4 °C and 20 °C. Sour cherry nectars were aseptically filled out into packaging of different sizes and materials. The packaging included cartons of two different sizes (200 and 1000 mL) and aluminium cans (330 mL). Results showed that the nectars were of better quality when stored at lower temperatures. HMF generally increased significantly for all nectars during storage. Conversely, the total polyphenol content and the antioxidant activity of the nectars stored in aluminium cans and the larger‐sized carton packaging decreased during storage. Lower anthocyanin loss and colour change were found in the nectars stored in aluminium cans. However, the better packaging material was found to be the large‐sized carton package when HMF was analysed. 相似文献