全文获取类型
收费全文 | 496篇 |
免费 | 29篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 125篇 |
金属工艺 | 7篇 |
机械仪表 | 10篇 |
建筑科学 | 27篇 |
矿业工程 | 3篇 |
能源动力 | 29篇 |
轻工业 | 133篇 |
石油天然气 | 3篇 |
无线电 | 15篇 |
一般工业技术 | 62篇 |
冶金工业 | 42篇 |
原子能技术 | 3篇 |
自动化技术 | 63篇 |
出版年
2024年 | 4篇 |
2023年 | 11篇 |
2022年 | 18篇 |
2021年 | 31篇 |
2020年 | 23篇 |
2019年 | 26篇 |
2018年 | 31篇 |
2017年 | 25篇 |
2016年 | 28篇 |
2015年 | 19篇 |
2014年 | 27篇 |
2013年 | 48篇 |
2012年 | 31篇 |
2011年 | 32篇 |
2010年 | 36篇 |
2009年 | 27篇 |
2008年 | 18篇 |
2007年 | 27篇 |
2006年 | 13篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 3篇 |
1999年 | 3篇 |
1998年 | 17篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 1篇 |
排序方式: 共有525条查询结果,搜索用时 15 毫秒
101.
Filiz Cinar Sahin Halide Esra KanburBurcu Apak 《Journal of the European Ceramic Society》2012,32(4):925-929
Al2O3 and AlN powder mixtures were used to synthesise AlON ceramics using the reactive spark plasma sintering (SPS) method at temperatures between 1400 and 1650 °C for 15-45 min at 40 MPa under N2 gas flow. AlON phase formation was initiated in the samples sintered above 1430 °C, according to the X-ray analysis. The complete transformation of the initial phases (Al2O3 and AlN) into AlON was observed in the samples that were spark plasma sintered at 1650 °C for 30 min at 40 MPa. A high spark plasma sintering temperature together with a low heating rate produced a greater amount of AlON formation at a constant process time. The densification, microstructure and mechanical properties of the produced ceramics were analysed. The highest hardness value was recorded to be 16.7 GPa, and the fracture toughness of the sample with the highest AlON ratio was measured to be 3.95 MPa m1/2. 相似文献
102.
Esra Capanoglu 《International Journal of Food Properties》2013,16(3):690-702
In this study, bio-active molecules of ten different dried fruits, which are widely consumed in Turkey, were investigated in terms of their flavonoid profile, antioxidant capacities, total phenolic, and total flavonoid contents. According to the results, all dried fruits possess an antioxidant activity at a certain level and have a different flavonoid profile with compounds belonging to the groups of flavonols, flavan-3-ols, anthocyanins, as well as chlorogenic acid. Dried cranberries and black raisins were observed to have the highest levels of total phenolics, flavonoids, and total antioxidant capacity. Especially black raisin samples were featured with their high amounts of catechin and epicatechin. 相似文献
103.
Physical properties of sweet corn kernels have been evaluated as a function of kernel moisture content, varying from 9.12 to 17.06% (db). In the moisture range, kernel length, width, thickness, and geometric mean diameter increased linearly from 9.87 to11.09 mm, 7.41 to 9.25 mm, 3.25 to 4.37 mm, and 6.18 to 7.62 mm, respectively, with increase in moisture content from 9.12–17.06%. The sphericity index, kernel volume, kernel surface area, and thousand seed weight increased linearly from 62.6 to 68.8, 93.8 to 194.3 mm3, 120.1 to 182.9 mm2, and 220 to 268 gr, respectively. Apparent density and bulk density decreased linearly from 1.315 to 1.232 g/cm3 and 0.765 to 0.698 g/cm3, respectively, while bulk porosity increased from 41.8 to 43.3%. The highest static coefficient of friction was found on the plywood surface. The static coefficient of friction increased from 0.680 to 0.891, 0.605 to 0.741, and 0.530 to 0.644 for plywood, galvanized iron, and aluminum surfaces, respectively. The angle of repose increased linearly from 30.2 to 35.2° with the increase of moisture content. 相似文献
104.
The aim of this study was to investigate the effective parameters for subcritical water extraction of secoisolariciresinol diglucoside (SDG) lignan from flaxseed using accelerated solvent extractor. For this aim, the influence of extraction parameters such as material shape (flaxseed, ground flaxseed meal and flaxseed meal sticks), temperature (120, 140, 160 and 180 °C), extraction time (15, 30, 60 and 90 min), pressure (1.500 and 2.000 psi), fresh water (5, 40 and 100 %) and sample amount (5 and 10 g) was studied. SDG lignan analysis has been carried out by LC–MS/MS. It was shown that material shape, temperature, extraction time and sample amount had significant effect on SDG lignan content in water extracts (p < 0.05). The highest amount (12.94 mg/g) and extraction yield (72.57 %) were obtained at 180 °C for 15 min, 1.500 psi and 40 % fresh water using 5 g of flaxseed meal sticks. 相似文献
105.
ABSTRACT In order to prevent the emission of SOx, with the flue gas, certain amount of the sulphur of the coal can be retained by adding an adequate amount of lime in the combustion chamber. In this study, two series of experiments were conducted by adding lime at the molar ratios of CaO/S = 0·5 to 2·0 using Ankara-Beypazan lignites, which have around 5 % sulphur content as received form. In one of the series lime was added directly in to the lump coal, and in the other, coal was briquetted together with lime using molasses as binder. It was observed from the experimental results that the increase in the lime ratio leads to an increase in the retained sulphur percentage while it leads to a considerable decrease in thermal efficiency. In order to retain 50 % of sulphur, it was necessary to add lime into lump coal at a CaO/S molar ratio of at least 1,1. This minimum ratio was 0·70 for briquetted coal. When lime was added at these ratios, the thermal efficiencies in the first case dropped to as low as 82 % and to 92 % in the second. 相似文献
106.
Esra Bozkır Nurşen Sarı Hatice Öğütcü 《Journal of Inorganic and Organometallic Polymers and Materials》2012,22(5):1146-1155
An investigation of antimicrobial properties of 12 novel modified polymer derived from the condensation reaction of (aminomethyl)polystyrene and four substitute salicylaldehyde (2-hydroxy benzaldehyde, 5-fluoro-2 hydroxy benzaldehyde, 5-fluoro-3-chloro-salicylaldehyde and 5-fluoro-3-methyl-salicylaldehyde) has been carried out and Cr(III) and Ni(II) complexes have been prepared. Modified polymers were characterized by magnetic susceptibility, elemental analyses, and spectral studies. The 1H NMR and 13C NMR spectra analysis of the polymeric carbinolamine/azomethine were determined. In addition, surface morphology and composition were determined by SEM/EDX. Thermo gravimetric analyses of polymers were carried out in nitrogen atmosphere. Antibacterial activities of the polymers attached carbinolamine/azomethine and their complexes were studied by the well-diffusion method against Listeria monocytogenes 4b, Staphylococcus aureus, Escherichia coli, Salmonella typhi H, Brucella abortus, Staphylococcus epidermis sp., Micrococcus luteus, Shigella dysenteria type 10, Bacillus cereus, Pseudomonas putida and antifungal activity against Candida albicans. 相似文献
107.
Nowadays outdoor location systems have been used extensively in all fields of human life from military applications to daily life. However, these systems cannot operate in indoor applications. Hence, this paper considers a novel indoor location system that aims to locate an object within an accuracy of about 2 cm using ordinary and inexpensive off-the-shelf devices and that was designed and tested in an office room to evaluate its performance.In order to compute the distance between the transducers (speakers) and object to be localized (microphone), time-of-arrival measurements of acoustic signals consisting of Binary Phase Shift Keying modulated Gold sequences are performed. This DS-CDMA scheme assures accurate distance measurements and provides immunity to noise and interference.Two methods have been proposed for location estimation. The first method takes the average of four location estimates obtained by trilateration technique. In the second method, only a single robust position estimate is obtained using three distances while the least reliable fourth distance measurement is not taken into account.The system?s performance is evaluated at positions from two height levels using system parameters determined by preliminary experiments. The precision distributions in the work area and the precision versus accuracy plots depict the system performance. The proposed system provides location estimates of better than 2 cm accuracy with 99% precision. 相似文献
108.
109.
Esra Maltas Mustafa Ozmen Hasibe Cingilli Vural Salih Yildiz Mustafa Ersoz 《Materials Letters》2011,65(23-24):3499-3501
The magnetite (Fe3O4) nanoparticles were prepared by the co-precipitation of ferrous and ferric salts with NH4OH, and then modified with 3-aminopropyltriethoxysilane (APTES) by silanization reaction and subsequent reaction with glutaraldehyde (GA) to obtain functional groups on their surface. The influence of different terminated groups on protein binding was studied with bare and modified magnetite nanoparticles. Amine terminated magnetite nanoparticles were shown the highest binding ability for immobilization process compared to Fe3O4 NPs and GA bonded NPs. This binding ability was shown by using sodium dodecyl polyacrylamide gel electrophoresis technique (SDS-PAGE). Albumin attached magnetite nanoparticles were also examined by Scanning Electron Microscopy (SEM). 相似文献
110.
Müfide Banar Yücel Güney Aysun Özkan Zerrin Günkaya Eren Bayrakcı Derya Ulutaş 《国际露天开采、回填与环境杂志》2019,33(3):206-222
The objective of this study was to investigate the potential utilisation of waste clay from boron production in sanitary landfills. The waste clay (CW) was mixed with bentonite (B) and waste tyre (TW) at different ratios. Results show that, any of the CW-TW mixtures were not acceptable to use in landfills because of insufficient bearing capacity values. On the other hand, CW and 2B/98CW mixtures have sufficient values from the point of experimental tests. As a conclusion, it has been concluded that CW can be used as a liner material for landfills without an addition. 相似文献