全文获取类型
收费全文 | 1525篇 |
免费 | 57篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 11篇 |
综合类 | 1篇 |
化学工业 | 369篇 |
金属工艺 | 29篇 |
机械仪表 | 70篇 |
建筑科学 | 36篇 |
矿业工程 | 2篇 |
能源动力 | 66篇 |
轻工业 | 63篇 |
水利工程 | 78篇 |
无线电 | 186篇 |
一般工业技术 | 289篇 |
冶金工业 | 164篇 |
原子能技术 | 8篇 |
自动化技术 | 212篇 |
出版年
2023年 | 19篇 |
2022年 | 37篇 |
2021年 | 48篇 |
2020年 | 42篇 |
2019年 | 53篇 |
2018年 | 50篇 |
2017年 | 53篇 |
2016年 | 43篇 |
2015年 | 33篇 |
2014年 | 48篇 |
2013年 | 154篇 |
2012年 | 66篇 |
2011年 | 75篇 |
2010年 | 74篇 |
2009年 | 54篇 |
2008年 | 54篇 |
2007年 | 50篇 |
2006年 | 44篇 |
2005年 | 31篇 |
2004年 | 21篇 |
2003年 | 21篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 20篇 |
1999年 | 27篇 |
1998年 | 29篇 |
1997年 | 36篇 |
1996年 | 25篇 |
1995年 | 24篇 |
1994年 | 28篇 |
1993年 | 27篇 |
1992年 | 22篇 |
1991年 | 26篇 |
1990年 | 14篇 |
1989年 | 21篇 |
1988年 | 16篇 |
1987年 | 19篇 |
1986年 | 14篇 |
1985年 | 23篇 |
1984年 | 22篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1973年 | 5篇 |
排序方式: 共有1584条查询结果,搜索用时 15 毫秒
81.
Sumit Kumar Jana Asit Baran Biswas Sudip Kumar Das 《Korean Journal of Chemical Engineering》2014,31(4):574-581
Experimental studies on the gas holdup in two tapered bubble columns using non-Newtonian pseudoplastic liquid have been reported. The effects of different variables such as gas flow rate, liquid viscosity, bed height, and orifice diameter of sieve plate on gas holdup have been investigated. An empirical correlation has been developed for the prediction of the gas holdup as a function of various measurable parameters of the system. The correlation is statistically acceptable. 相似文献
82.
83.
The study deals with the vulcanization of carboxylated nitrile butadiene rubber (XNBR) having synergistic combinations of accelerators comprising thiophosphoryl disulfide as one of the components. Other constituent accelerators employed in the present investigation are 2-mercaptobenzothiazole (MBT), 2-mercaptobenzothiazyl disulfide (MBTS), bis(N-oxydiethylene)disulfide (ODDS), N-oxydiethylene 2-benzothiazole sulfenamide (OBTS), etc. The binary combinations of thiophosphoryl disulfides with OBTS exhibited the highest mutual activity in the respective areas, so far as the physical properties are concerned. Structural characterization of different thiophosphoryl disulfide-accelerated XNBR vulcanizates, including those formed from the synergistic combinations with OBTS, were studied using a methyl iodide probe. It was found that the amount of sulfidic crosslinks arising from the reaction between COOH groups of XNBR and thiophosphoryl disulfides, actually controls the network structure as wellas the physical properties of the vulcanizates. © 1996 John Wiley & Sons, Inc. 相似文献
84.
Kunal Biswas Awdhesh Kumar Mishra Pradipta Ranjan Rauta Abdullah G. Al-Sehemi Mehboobali Pannipara Avik Sett Amra Bratovcic Satya Kumar Avula Tapan Kumar Mohanta Muthupandian Saravanan Yugal Kishore Mohanta 《International journal of molecular sciences》2022,23(2)
At present, the potential role of the AgNPs/endo-fullerene molecule metal nano-composite has been evaluated over the biosystems in-vitro. The intra-atomic configuration of the fullerene molecule (C60) has been studied in-vitro for the anti-proliferative activity of human breast adenocarcinoma (MDA-MB-231) cell lines and antimicrobial activity against a few human pathogens that have been augmented with the pristine surface plasmonic electrons and antibiotic activity of AgNPs. Furthermore, FTIR revealed the basic vibrational signatures at ~3300 cm−1, 1023 cm−1, 1400 cm−1 for O-H, C-O, and C-H groups, respectively, for the carbon and oxygen atoms of the C60 molecule. NMR studies exhibited the different footprints and magnetic moments at ~7.285 ppm, explaining the unique underlying electrochemical attributes of the fullerene molecule. Such unique electronic and physico-chemical properties of the caged carbon structure raise hope for applications into the drug delivery domain. The in-vitro dose-dependent application of C60 elicits a toxic response against both the breast adenocarcinoma cell lines and pathogenic microbes. That enables the use of AgNPs decorated C60 endo fullerene molecules to design an effective anti-cancerous drug delivery and antimicrobial agent in the future, bringing a revolutionary change in the perspective of a treatment regime. 相似文献
85.
Anoop K. Mukhopadhyay Keshaw D. Joshi Arjun Dey Riya Chakraborty Ashok K. Mandal Amit Rav Jiten Ghosh Sandip Bysakh Sampad K. Biswas Satish C. Gupta 《Ceramics International》2011,37(7):2365-2376
Shock recovered samples of a coarse grain (10 μm), high density (>99.9% theoretical) alumina from asymmetric impact tests conducted at 6.5 GPa (e.g. 3.2 times its Hugoniot Elastic Limit) in a single stage gas gun and characterized by X-ray diffractometry, scanning and field emission scanning electron microscopy, and transmission electron microscopy showed prolific presence of reduced crystallite size, higher average microstrain, grain localized micro/nano-scale deformations, micro-cleavages, grain-boundary microcracks, micro-wing crack formation, extensive shear induced deformations and fractures localized at grains, grain boundaries and triple grain junctions, grain localized entanglement of dislocations and their pile up impeded at grain boundaries. A new qualitative model based on micro-shear and micro-twist induced deformation and fracture in single and/or multiple planes in suitably oriented grain and/or grain assembly was developed to explain the experimentally observed damage evolution process. 相似文献
86.
Cocoa Butter Substitute (CBS) Produced from Palm Mid-fraction/Palm Kernel Oil/Palm Stearin for Confectionery Fillings 下载免费PDF全文
Nirupam Biswas Yuen Lin Cheow Chin Ping Tan Sivaruby Kanagaratnam Lee Fong Siow 《Journal of the American Oil Chemists' Society》2017,94(2):235-245
This study investigated the physicochemical properties of ternary mixtures of palm mid-fraction (PMF):refined bleached deodorized palm kernel oil (RBDPKO):refined bleached deodorized palm stearin (RBDPS) for cocoa butter substitute (CBS). Fatty acid constituents, triacylglycerol constituents, solid fat contents (SFCs), melting behavior, polymorphism and crystal morphology were determined using gas chromatography (GC), high-performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), pulsed nuclear magnetic resonance (p-NMR), X-ray diffraction (XRD) and polarized light microscopy (PLM), respectively. Eight blends of various ratios of ternary mixtures were investigated based on the previously studied binary fat mixtures. The composition of palmitic (P) and oleic (O), POP, and crystal morphology (size and shape) of the PMF/RBDPKO/RBDPS [14.9/59.6/25.5 (%w/w)] mixture were comparable to cocoa butter (CB), while its melting profile (18.5 and 37 °C), SFC at 20 °C and polymorphism were different from CB. The iso-solid diagrams of the mixture displayed a monotectic effect at 20–25 °C. Therefore, the 14.9/59.6/25.5 PMF/RBDPKO/RBDPS mixture could be used as a CBS in confectionery fillings because of the crystal morphology and monotectic behaviors comparable to those of CB. 相似文献
87.
Poly(N-vinyl carbazole) was sulfonated with different sulfonating agents and ion exchange capacities of the resins produced were evaluated. A maximum capacity of 4.5 meq · g?1 of dry resin was realized when sulfonation was done with 98.8% H2SO4 at 30°C for 10 h. The pH titration curves reveal the nature of a strong monofunctional cation exchanger with a pK value of 2.2. The resin exhibits a moderate rate of exchange with NaCl and is thermally stable up to ca. 250°C. 相似文献
88.
Polycrystalline diamond coatings have been grown on unpolished side of Si(100) wafers by hot filament chemical vapour deposition process. The morphology of the grown coatings has been varied from cauliflower morphology to faceted morphology by manipulation of the growth temperature from 700°C to 900°C and methane gas concentration from 3% to 1·5%. It is found that the coefficient of friction of the coatings under high vacuum of 133·32×10?7 Pa (10?7 torr) with nanocrystalline grains can be manipulated to 0·35 to enhance tribological behaviour of bare Si substrates. 相似文献
89.
Ananya Ghosh Suvanka Dutta Indrani Mukherjee Sourav Biswas Sriparna Chatterjee Rajnarayan Saha 《Advanced Powder Technology》2017,28(9):2256-2264
Well-dispersed single phasic flower-like zero valent iron nanoparticles have been synthesized under aerobic conditions using a facile approach without the addition of any additives or templates. The role of hydroxyl groups of polyhydroxy alcohols in controlling surface morphology of nanoparticles has been thoroughly investigated. The obtained nanoparticles have been characterized by TEM, FE-SEM, XRD and BET surface area analyzer. Electron microscopy analyses reveal that the solvent plays a pivotal role in determining the morphology of the particles. With increase in viscosity of the solvent, formations of ‘petal-like’ structures, which are joined at the center are formed. The nitrate removal efficiency of the iron nanoparticles synthesized in different solvents has been studied and it is seen that the “flower-like” iron nanoparticles were most active in the removal of nitrate. Experiments have been done by varying (i) nitrate concentrations, (ii) nanoparticle dose, and (iii) type of nanoparticles. The results conclude that highest removal efficiency (~100%) was achieved when the nanoparticle dose was 2.88 g/L, even for high nitrate concentrations up to 400 mg/L. The major highlight of this work is the fact that even though the nanoparticles synthesized in glycerol-water mixture have larger size in comparison to the other nanoparticles, still they remove the nitrates with highest efficiency.” 相似文献
90.
Asit K. Biswas 《国际水》2013,38(4):201-209
ABSTRACT For many arid and semiarid countries, international water bodies are the only new additional sources of water that could be economically developed to meet their ever increasing water requirements. Agreements between cobasin countries are necessary if such sources are to be developed promptly and properly. While some attempt is now being made to develop laws of nonnavigable uses of international watercourses, regrettably not enough attention has been paid thus far to review the negotiating processes that have led to successful water treaties. The present paper is an analysis of the negotiating process that resulted in the Indus River Treaty between India and Pakistan. 相似文献