全文获取类型
收费全文 | 713篇 |
免费 | 14篇 |
学科分类
工业技术 | 727篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 10篇 |
2015年 | 11篇 |
2014年 | 12篇 |
2013年 | 33篇 |
2012年 | 23篇 |
2011年 | 20篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 28篇 |
2007年 | 38篇 |
2006年 | 20篇 |
2005年 | 27篇 |
2004年 | 28篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 15篇 |
2000年 | 26篇 |
1999年 | 17篇 |
1998年 | 22篇 |
1997年 | 33篇 |
1996年 | 29篇 |
1995年 | 20篇 |
1994年 | 22篇 |
1993年 | 13篇 |
1992年 | 18篇 |
1991年 | 16篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 2篇 |
排序方式: 共有727条查询结果,搜索用时 347 毫秒
31.
Simultaneous sequestration of nitrate and phosphate from wastewater using a tailor‐made bacterial consortium in biofilm bioreactor 下载免费PDF全文
Pallavi Mukherjee Chaitali Chanda Moumita Bhaumik Madhurima Ghosh Jaweria Sharmin Poulami Datta Srimoyee Banerjee Parthasarathi Barat Ashoke Ranjan Thakur Lalit Mohan Gantayet Indranil Mukherjee Shaon Ray Chaudhuri 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2018,93(5):1279-1289
32.
Shahabi C. Ghandeharizadeh S. Chaudhuri S. 《Knowledge and Data Engineering, IEEE Transactions on》2002,14(2):447-455
In multiuser multimedia information systems (e.g., movie-on-demand, digital-editing), scheduling the retrievals of continuous media objects becomes a challenging task. This is because of both intra and inter lobject time dependencies. Intraobject time dependency refers to the real-time display requirement of a continuous media object. Interobject time dependency is the temporal relationships defined among multiple continuous media objects. In order to compose tailored multimedia presentations, a user might define complex time dependencies among multiple continuous media objects with various lengths and display bandwidths. Scheduling the retrieval tasks corresponding to the components of such a presentation in order to respect both inter and intra task time dependencies is the focus of this study. To tackle this task scheduling problem (CRS), we start with a simpler scheduling problem (ARS) where there is no inter task time dependency (e.g., movie-on-demand). Next, we investigate an augmented version of ARS (termed ARS+) where requests reserve displays in advance (e.g., reservation-based movie-on-demand). Finally, we extend our techniques proposed for ARS and ARS+ to address the CRS problem. We also provide formal definition of these scheduling problems and proof of their NP-hardness 相似文献
33.
Sripati Ranjan Chaudhuri 《International Journal of Engineering Science》1979,17(12):1273-1281
Starting with a class of small deformations superposed on a finitely deformed state of a transversely isotropic elastic solid, we study a problem of small torsional vibration superposed on homogeneous finitely deformed state of a circular cylindrical rod made of transversely isotropic elastic material. It has been found that free vibration is possible and, due to anisotropy, the speed of propagation of waves of torsion along the cylinder is increased or decreased according as the initial stressed state is under tension or compression. 相似文献
34.
35.
The paper describes the implementation of a centralised control-design scheme in a real-time laboratory-based dynamic simulator. A centralised multivariable-control algorithm is designed employing remote feedback signals considering delay in signal transmission. The transmitted signals can be used for multiple-swing-mode damping using a single controller. Such an algorithm is numerically intensive owing to the high controller size and the predictor that takes care of the delay in signal transmission. The performance of the proposed controller is demonstrated by practical implementation using a rapid-prototyping controller mounted on a PC-ATX. Results of the experimental tests are shown for a detailed model of the power system implemented using Linux PC-based multiprocessor technology. 相似文献
36.
37.
Appreciable difference in the properties of undoped and oxide-doped mullite are observed. The oxidation state of cation, its concentration and the position of the mullite lattice occupied by it appear to be the responsible factors. Mullite has, therefore, been doped with four transition metal ions, Mn, Fe, Cr and Ti. With the help of EPR and Mössbauer spectroscopy (supplimented by X-ray diffractometry) the oxidation states of these ions and the mullite lattice sites where they enter has been investigated. It was observed that Mn ion was present in Mn2+ and Mn3+ states, the former remained as clusters and the latter occupied the octahedral sites in the mullite lattice. Only Fe3+ ion was detected and conclusive evidence was obtained for the entry of Fe3+ in the octahedral lattice position of mullite from the analysis of Mössbauer spectra with the help of a specially written computer programme. The Cr ion entered the mullite structure only in the Cr3+ state. The change in lattice parameters of Cr doped mullite were measured by the XRD technique. The results showed that the expansion of b-axis was more than that of the a-axis which supported the presence of Cr3+ ion in the octahedral site of mullite lattice. The absence of signal in the EPR spectra of Ti doped mullite suggested the presence of only Ti4+ (3d0) ion. Very low electrical resistivity of Ti doped mullite and close similarity between mullite and Al2TiO5 structures stood as evidence for incorporation of Ti4+ ion in the octahedral site of mullite lattice by replacing Al3+ ion. 相似文献
38.
The growth and microstructure of Cd1–x
Zn
x
S films were studied by depositing the films on to freshly cleaved NaCl, KCl, and LiF substrates at various x values (0相似文献
39.
Mahua Ghosh Chaudhuri Rajib Dey Manoj K Mitra Gopes C Das Siddhartha Mukherjee 《Science and Technology of Advanced Materials》2008,9(1)
Silicon nitride (Si3 N4) nanowires have been prepared by carbothermal reduction followed by the nitridation (CTRN) of silica gel containing ultrafine excess carbon obtained by the decomposition of dextrose over the temperature range of 1200–1350 °C. This innovative process involves repeated evacuation followed by purging of nitrogen gas so that the interconnected nanopores of the gel are filled with nitrogen gas prior to heat treatment. During heat treatment at higher temperatures, the presence of nitrogen gas in the nanopores of the gel starts the CTRN reaction simultaneously throughout the bulk of the gel, leading to the formation of Si3 N4 nanowires. The in situ generated ultrafine carbon obtained by the decomposition of dextrose decreases the partial pressure of oxygen in the system to stabilize the nanowires. The nanowires synthesized by this process are of ∼500 nm diameter and ∼0.2 mm length. The product was characterized by scanning electron microscope (SEM), energy dispersive x-ray analysis (EDX), x-ray diffraction (XRD) and infrared (IR) spectra. 相似文献
40.