全文获取类型
收费全文 | 542篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 142篇 |
金属工艺 | 46篇 |
机械仪表 | 8篇 |
建筑科学 | 2篇 |
矿业工程 | 1篇 |
能源动力 | 13篇 |
轻工业 | 32篇 |
水利工程 | 5篇 |
无线电 | 43篇 |
一般工业技术 | 107篇 |
冶金工业 | 15篇 |
原子能技术 | 4篇 |
自动化技术 | 125篇 |
出版年
2023年 | 10篇 |
2022年 | 14篇 |
2021年 | 14篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 11篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 20篇 |
2013年 | 41篇 |
2012年 | 19篇 |
2011年 | 32篇 |
2010年 | 22篇 |
2009年 | 23篇 |
2008年 | 30篇 |
2007年 | 19篇 |
2006年 | 17篇 |
2005年 | 22篇 |
2004年 | 21篇 |
2003年 | 13篇 |
2002年 | 17篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 2篇 |
1997年 | 12篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有557条查询结果,搜索用时 15 毫秒
41.
The kinetics of cellulose and hemicellulose hydrolysis of wheat straw was studied using both isothermal and non-isothermal techniques in a batch reactor. Reactions were carried out between 100 and 210°C and product sugars were analyzed using a Bio-Rad HPX-87P liquid chromatographic column. A simple first order series reaction model was used for both cellulose and hemicellulose hydrolysis reactions and kinetic parameters were obtained for the Arrhenius rate equations for three different sulphuric acid concentrations (0.5, 1.O and 1.5%). Activation energies remained constant with acid concentration but the pre-exponential factors showed an increase with acid concentration. To minimize the amount of experimental data required and to achieve a unique solution to the kinetic parameters, the technique of combining isothermal and non-isothermal reaction data was studied. 相似文献
42.
Sandip P. Harimkar Narendra B. Dahotre 《Journal of Materials Processing Technology》2009,209(10):4744-4749
Laser surface microstructuring of porous alumina ceramic is investigated using a continuous wave Nd:YAG laser. The surface microstructure development is based on the rapid surface melting and subsequent solidification resulting in the evolution of crystallographic and morphological textures. The results indicated that surface microstructure is greatly influenced by the laser processing parameters. Detailed investigations of the influence of laser fluence on the thermal history and microstructural parameters are presented. Such investigations are intended to facilitate the tailoring of surface microstructures by controlling the laser processing parameters. 相似文献
43.
44.
Kumpati S. Narendra Manuel A. Duarte 《International Journal of Adaptive Control and Signal Processing》1989,3(2):131-142
A new approach, combining direct and indirect control methods, recently proposed by the authors is used to adaptively control plants with unknown parameters. The plant parameters are known to lie in a specified compact set in parameter space and the output of the plant has to follow a desired output in the presence of a piecewise-constant input disturbance. Simulation results indicate that the combined method performs better than either the direct or the indirect method. 相似文献
45.
46.
Dr. Anil Karbhari Shinde Dr. Rajesh Kumar Badange Veena Reballi Pramod Kumar Achanta Kumar Bojja Sravanthi Manchineella Nageswara Rao Muddana Ramkumar Subramanian Raghava Choudary Palacharla Vijay Benade Dr. Pradeep Jayarajan Jagadeesh Babu Thentu Bujji Babu Lingavarapu Sivasekhar Yarra Narendra Kagita Mallikarjuna Rao Doguparthi Dr. Abdul Rasheed Mohammed Dr. Ramakrishna Nirogi 《ChemMedChem》2022,17(3):e202100583
A series of chemical optimizations, which was guided by in vitro affinity at histamine H3 receptor (H3R), modulation of lipophilicity, ADME properties and preclinical efficacy resulted in the identification of 1-[2-(1-cyclobutylpiperidin-4-yloxy)-6,7-dihydro-4H-thiazolo[5,4-c]pyridin-5-yl]propan-1-one ( 45 e ) as a potent and selective (Ki=4.0 nM) H3R inverse agonist. Dipsogenia induced by (R)-α-methylhistamine was dose dependently antagonized by 45 e , confirming its functional antagonism at H3R. It is devoid of hERG and phospholipidosis issues. Compound 45 e has adequate oral exposures and favorable half-life in both rats and dogs. It has demonstrated high receptor occupancy (ED80=0.22 mg/kg) and robust efficacy in object recognition task and, dose dependently increased acetylcholine levels in brain. The sub-therapeutic doses of 45 e in combination with donepezil significantly increased acetylcholine levels. The potent affinity, selectivity, in vivo efficacy and drug like properties together with safety, warrant for further development of this molecule for potential treatment of cognitive disorders associated with Alzheimer's disease. 相似文献
47.
Satyendra K. Tripathi Khushboo Kesharwani Grace Kaul Abdul Akhir Deepanshi Saxena Dr. Ramesh Singh Dr. Narendra K. Mishra Prof. Archna Pandey Dr. Sidharth Chopra Dr. Khashti B. Joshi 《ChemMedChem》2022,17(15):e202200251
An amyloid-β inspired biocompatible short peptide amphiphile (sPA) molecule was used for controlled and targeted delivery of bioactive silver nanoparticles via transforming sPA nanostructures. Such sPA-AgNPs hybrid structures can be further used to develop antibacterial materials to combat emerging bacterial resistance. Due to the excellent antibacterial activity of silver, the growth of clinically relevant bacteria was inhibited in the presence of AgNPs-sPA hybrids. Bacterial tests demonstrated that the high biocompatibility and low cytotoxicity of the designed sPA allow it to work as a model drug delivery agent. It therefore shows great potential in locally addressing bacterial infections. The results of our study suggest that these nanodevices have the potential to trap and then engage in the facile delivery of their chemical payload at the target site, thereby working as potential delivery materials. This system has potential therapeutic value for the treatment of microbiota triggered progression of neurodegenerative diseases. 相似文献
48.
Zeraati Malihe Abbasi Hossein Safinejad Moosareza Kazemzadeh Parya Chauhan Narendra Pal Singh Sargazi Ghasem 《SILICON》2022,14(13):7633-7642
Silicon - Metal-assisted chemical etching (MACE) of silicon is used in this study to fabricate silicon nanowire arrays (SiNWs) of different length. This method was modeled using gene expression... 相似文献
49.
Chandel Narendra Singh Chakraborty Subir Kumar Rajwade Yogesh Anand Dubey Kumkum Tiwari Mukesh K. Jat Dilip 《Neural computing & applications》2021,33(10):5353-5367
Neural Computing and Applications - The identification of water stress is a major challenge for timely and effective irrigation to ensure global food security and sustainable agriculture. Several... 相似文献
50.
Yuqi Jin Teng Yang Narendra B. Dahotre Arup Neogi Tianhao Wang 《Advanced Engineering Materials》2023,25(19):2300206
Metals are excellent conductors for phonon transportation such as vibration, sound, and heat. Generally, metal sound insulators require multimaterial structure or defects and unimetal sound insulators are challenging. Therefore, a design of a defect-free sound insulator made by single alloys with multiple friction stir processes (FSPs) is proposed. Periodic friction stir processing can induce superlattice-like local mechanical properties’ modifications. By experimental acoustic characterization, it is observed that FSP can introduce clear acoustic–elastic property contrast on an aluminum plate by the presence of stir zone and heat-affected zones. In numerical simulations, the signature FSP-induced property profile is periodically and parallelly arranged on a long aluminum plate. The transmission gap frequencies are present on the frequency spectrum with the sound propagation direction perpendicular to the FSP paths. Disorder offsets on FSP periodicity are further introduced. Anderson localization is found on a resonance frequency, which provides −11 dB sound reduction by an exponential decay. Due to the finite design length, the slight disorder can also enhance sound insulation in the periodic transmission gap frequency. With analysis and comparison with different configurations, the best performance in the models can achieve −30 dB sound insulation in the 350 mm-long aluminum alloy plate with 14 parallel FSPs. 相似文献