全文获取类型
收费全文 | 2755篇 |
免费 | 162篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 119篇 |
综合类 | 30篇 |
化学工业 | 557篇 |
金属工艺 | 78篇 |
机械仪表 | 67篇 |
建筑科学 | 83篇 |
矿业工程 | 20篇 |
能源动力 | 97篇 |
轻工业 | 390篇 |
水利工程 | 29篇 |
石油天然气 | 21篇 |
武器工业 | 1篇 |
无线电 | 215篇 |
一般工业技术 | 498篇 |
冶金工业 | 181篇 |
原子能技术 | 50篇 |
自动化技术 | 493篇 |
出版年
2023年 | 22篇 |
2022年 | 32篇 |
2021年 | 60篇 |
2020年 | 54篇 |
2019年 | 53篇 |
2018年 | 94篇 |
2017年 | 93篇 |
2016年 | 82篇 |
2015年 | 82篇 |
2014年 | 125篇 |
2013年 | 227篇 |
2012年 | 206篇 |
2011年 | 276篇 |
2010年 | 148篇 |
2009年 | 161篇 |
2008年 | 90篇 |
2007年 | 103篇 |
2006年 | 59篇 |
2005年 | 124篇 |
2004年 | 67篇 |
2003年 | 67篇 |
2002年 | 92篇 |
2001年 | 65篇 |
2000年 | 32篇 |
1999年 | 33篇 |
1998年 | 69篇 |
1997年 | 54篇 |
1996年 | 35篇 |
1995年 | 25篇 |
1994年 | 24篇 |
1993年 | 19篇 |
1992年 | 14篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 19篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1979年 | 14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2929条查询结果,搜索用时 15 毫秒
101.
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
102.
103.
104.
105.
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
106.
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
107.
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
108.
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
109.
Arif Nesrullajev ?i?dem Y?rür-G?reci Belkis Bilgin-Eran 《International Journal of Thermophysics》2012,33(1):58-68
The synthesis and investigations of the mesomorphic, thermotropic, thermo-morphologic, and thermo-optical properties of two
new salicylaldimine compounds, synthesized by our group, are reported in this work. Temperature transformations of specific
textures of the smectic C mesophase, taking place in these compounds, and thermo-morphologic and thermotropic properties of
the biphasic regions for direct and reverse phase transitions have been investigated. Temperature hysteresis and enlargement
of the biphasic regions have been found. The character of texture transformations and temperature behavior of the optical
birefringence indicate to the first order a smectic C–isotropic liquid-phase transition in these salicylaldimine compounds. 相似文献
110.
Many Plans: Multidimensional Ensembles for Visual Decision Support in Flood Management 总被引:1,自引:0,他引:1
J. Waser A. Konev B. Sadransky Z. Horváth H. Ribičić R. Carnecky P. Kluding B. Schindler 《Computer Graphics Forum》2014,33(3):281-290
Uncertainties in flood predictions complicate the planning of mitigation measures. There is a consensus that many possible incident scenarios should be considered. For each scenario, a specific response plan should be prepared which is optimal with respect to criteria such as protection, costs, or realization time. None of the existing software tools is capable of creating large scenario pools, nor do they provide means for quick exploration and assessment of the associated plans. In this paper, we present an integrated solution that is based on multidimensional, time‐dependent ensemble simulations of incident scenarios and protective measures. We provide scalable interfaces which facilitate and accelerate setting up multiple time‐varying parameters for generating a pool of pre‐cooked scenarios. In case of an emergency, disaster managers can quickly extract relevant information from the pool to deal with the situation at hand. An interactive 3D‐view conveys details about how a response plan has to be executed. Linked information visualization and ranking views allow for a quick assessment of many plans. In collaboration with flood managers, we demonstrate the practical applicability of our solution. We tackle the challenges of planning mobile water barriers for protecting important infrastructure. We account for real‐world limitations of available resources and handle the involved logistics problems. 相似文献