全文获取类型
收费全文 | 2007篇 |
免费 | 110篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 504篇 |
金属工艺 | 61篇 |
机械仪表 | 70篇 |
建筑科学 | 88篇 |
矿业工程 | 7篇 |
能源动力 | 178篇 |
轻工业 | 356篇 |
水利工程 | 7篇 |
石油天然气 | 16篇 |
无线电 | 71篇 |
一般工业技术 | 389篇 |
冶金工业 | 42篇 |
原子能技术 | 10篇 |
自动化技术 | 306篇 |
出版年
2024年 | 12篇 |
2023年 | 23篇 |
2022年 | 47篇 |
2021年 | 82篇 |
2020年 | 69篇 |
2019年 | 62篇 |
2018年 | 123篇 |
2017年 | 107篇 |
2016年 | 120篇 |
2015年 | 81篇 |
2014年 | 118篇 |
2013年 | 303篇 |
2012年 | 94篇 |
2011年 | 125篇 |
2010年 | 150篇 |
2009年 | 114篇 |
2008年 | 100篇 |
2007年 | 97篇 |
2006年 | 44篇 |
2005年 | 29篇 |
2004年 | 32篇 |
2003年 | 15篇 |
2002年 | 22篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 13篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 12篇 |
1980年 | 6篇 |
1978年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有2119条查询结果,搜索用时 0 毫秒
31.
Inhibition of the corrosion of mild steel in 1.0 M HCl solution by a Schiff base compound named 2-[(4-phenoxy-phenylimino)methyl]-phenol (APS) was investigated at different temperatures (25–55 °C) using electrochemical measurements. The inhibition efficiency increased as APS concentration and temperature increased. It was found that adsorption for APS on mild steel complies with the Langmuir adsorption isotherm in all studied temperature. Thermodynamic parameters (ΔGads, ΔHads and ΔSads) for APS adsorption on mild steel were found out and discussed at each temperature. Time dependency of mild steel in 1.0 M HCl solution in the absence and presence of APS was also studied. The surface morphology of mild steel was examined via SEM analysis. 相似文献
32.
In this study, a composite containing WC (Tungsten Carbide) and Ni was produced by two different processing routes. Electroless Ni coated WC powders were consolidated and sintered at 1200 °C. Diffusion bonding couples of WC(Ni)-electrolytic Cu, WC(Ni)-AISI 316 stainless steel and WC(Ni)-WC(Ni) were manufactured by using a preloaded compression system under Ar atmosphere. Diffusion bonding was carried out at varying bonding temperatures; 750 °C for (WC)Ni-Cu diffusion couple and 1200 °C for (WC)Ni-(WC)Ni and (WC)Ni-AISI 316 stainless steel diffusion couples. Standard metallographic techniques, Scanning Electron Microscopy and a shear test were employed to characterize the microstructure of bondline and mechanical properties of each diffusion couple, respectively. 相似文献
33.
O. Özşahin H.N. Özgüven E. Budak 《International Journal of Machine Tools and Manufacture》2010,50(6):585-589
Chatter is one of the major problems in machining resulting in poor surface quality and reduced productivity. Stability diagrams can be used to determine chatter-free process conditions yielding high productivity. For generation of stability diagrams, frequency response functions (FRF) at the tool tip are needed to be used in stability models. Impact tests involving accelerometers are commonly used in FRF measurements. Although mass of a typical accelerometer used in these measurements is extremely small compared with the cutting tool, it can have a significant effect on the FRF measurement. In this paper, the effect of accelerometer’s mass on tool point FRFs and stability diagrams is demonstrated for several cases with different tool-to-accelerometer mass ratios by using laser velocity sensor measurements. In addition, a structural modification method which can be used to compensate this effect is also presented on several cases. The structural modification method can be used to correct the FRFs measured with accelerometers, and thus the resulting stability diagrams. 相似文献
34.
A. Büyüksağiş 《Protection of Metals and Physical Chemistry of Surfaces》2010,46(1):134-138
In this study, the influence of different alcohol on the passivation of aluminium alloys have been investigated by using current-potential curves. Experimental results show that the addition of alcohol in H2SO4 solution have been changed passivation potential distance of the alloys. Elemental compositions of alloys have also directly affected passivation of alloys. This influence is more effective especially in alloys content higher Si also and less Cu. 相似文献
35.
36.
Fikret Kocabaş Özgür Kişi Mehmet Ardiçlioğlu 《Civil Engineering and Environmental Systems》2013,30(4):367-375
Density differences may occur because of temperature differentials, suspended sediments, dissolved salts or other chemicals. Most of the large surface reservoirs are stably stratified throughout most, or all, of the year. One of the means of assisting the management is to allow a selective withdrawal from the reservoir. And while an intake is used for withdrawal (from the lower layer), a maximum discharge is required not allowing the uptake of the upper layer fluids. The value of the intake's vertical distance from the upper layer elevation (submergence) when the upper layer fluids begin to be drawn into the intake is known as ‘critical submergence’. In this study, the critical submergence for a circular intake pipe in a stratified body (which has different layer thickness) is investigated. Experiments were conducted on a vertically flowing downward intake pipe in a still-water reservoir. Artificial neural network (ANN) models and formulas, which are found by the theoretical analysis of critical spherical sink surface (CSSS), are used for the analysis of experimental results. The CSSS has the same centre and discharge as the intake. The ANN model and CSSS results are compared with the experimental results. 相似文献
37.
In this study, bentonite originating from Turkey (Eski?ehir province) and activated carbon obtained from grapeseed were used as adsorbents for the removal of lead (Pb2+) and copper (Cu2+) ions from aqueous solutions. Experiments were performed in single- and binary-ion systems at constant temperature of 298 K and pH value of 5. In order to describe the adsorption mechanism Langmuir, Freundlich and Temkin isotherms were used. The total adsorption capacity values of adsorbents were compared. It was observed that the total adsorption capacity values were changed depending on the type of adsorbent used, type of metal ion and interaction between metal ions. 相似文献
38.
Yusuf Kayali Şükrü Talaş 《Protection of Metals and Physical Chemistry of Surfaces》2019,55(6):1148-1153
Protection of Metals and Physical Chemistry of Surfaces - AISI 316 L austenitic stainless steel is widely used in various sectors of the industry (chemical, petro-chemical industry, paper industry,... 相似文献
39.
Derviş A. Çelik Daniel F. Novoa-Díaz Juan A. Chávez Antoni Turó Miguel J. García-Hernández 《仪器科学与技术》2018,46(4):387-407
Ultrasound is an emerging technology that can be applied to monitor food processes. However, ultrasonic techniques are usually limited to research activities within a laboratory environment and they are not extensively used in industrial processes. The aim of this paper is to describe a novel ultrasonic sensor designed to monitor physical–chemical changes that occur in wines stored in industrial tanks. Essentially, the sensor consists of an ultrasonic transducer in contact with a buffer rod, mounted inside a stainless steel tube section. This structure allows the ultrasonic sensor to be directly installed in stainless steel tanks of an industrial plant. The operating principle of this design is based on the measurement of ultrasonic velocity of propagation. To test its proper operation, the sensor has been used to measure changes of concentration in aqueous samples and to monitor the progress of a malolactic fermentation of red wines in various commercial wineries. Results show the feasibility of using this sensor for monitoring malolactic fermentations in red wines placed in industrial tanks. 相似文献
40.
Fatma Tosun Çiğdem Akyüz Kızılay Kevser Erol Fatma Sultan Kılıç Mine Kürkçüoğlu Kemal Hüsnü Can Başer 《Food chemistry》2008
The anticonvulsant activity of furanocoumarins, coumarin mixture and the essential oil obtained from the fruits of Heracleum crenatifolium was examined against maximal electroshock (MES)-induced seizures in mice. Bergapten showed significant anticonvulsant activity. The furanocoumarins isolated from the fruits of the plant were identified using thin-layer chromatography, melting points and spectroscopic methods (IR, MS, 1H NMR) as isobergapten (1), pimpinellin (2), bergapten (3), isopimpinellin (4), sphondin (5) and byak-angelicol (6). The essential oil content of the fruits were found as 5.5%. Twenty-two compounds representing 99.3% of the essential oil obtained from the fruits of H. crenatifolium were determined and the major components were identified as octanol and octyl acetate (3.1% and 88.4% respectively) by GC and GC–MS. 相似文献