全文获取类型
收费全文 | 1952篇 |
免费 | 98篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 18篇 |
综合类 | 3篇 |
化学工业 | 473篇 |
金属工艺 | 40篇 |
机械仪表 | 48篇 |
建筑科学 | 46篇 |
矿业工程 | 4篇 |
能源动力 | 58篇 |
轻工业 | 367篇 |
水利工程 | 12篇 |
石油天然气 | 4篇 |
无线电 | 198篇 |
一般工业技术 | 298篇 |
冶金工业 | 188篇 |
原子能技术 | 14篇 |
自动化技术 | 282篇 |
出版年
2023年 | 20篇 |
2022年 | 57篇 |
2021年 | 59篇 |
2020年 | 42篇 |
2019年 | 31篇 |
2018年 | 60篇 |
2017年 | 64篇 |
2016年 | 72篇 |
2015年 | 54篇 |
2014年 | 73篇 |
2013年 | 130篇 |
2012年 | 119篇 |
2011年 | 117篇 |
2010年 | 93篇 |
2009年 | 87篇 |
2008年 | 102篇 |
2007年 | 87篇 |
2006年 | 77篇 |
2005年 | 48篇 |
2004年 | 41篇 |
2003年 | 61篇 |
2002年 | 56篇 |
2001年 | 37篇 |
2000年 | 31篇 |
1999年 | 29篇 |
1998年 | 66篇 |
1997年 | 57篇 |
1996年 | 32篇 |
1995年 | 29篇 |
1994年 | 19篇 |
1993年 | 27篇 |
1992年 | 19篇 |
1991年 | 12篇 |
1990年 | 19篇 |
1989年 | 14篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1973年 | 5篇 |
1971年 | 3篇 |
1966年 | 4篇 |
排序方式: 共有2053条查询结果,搜索用时 15 毫秒
1.
O Bernard B Chachuat A Hélias B Le Dantec B Sialve J-P Steyer L Lardon P Neveu S Lambert J Gallop M Dixon P Ratini A Quintabà S Frattesi J M Lema E Roca G Ruiz J Rodriguez A Franco P Vanrolleghem U Zaher D J W De Pauw K De Neve K Lievens D Dochaine O Schoefs H Fibrianto R Farina V Alcaraz Gonzalez V Gonzalez Alvarez P Lemaire J A Martinez F Esandi O Duclaud J F Lavigne 《Water science and technology》2005,52(1-2):457-464
The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do not benefit from a local expert in wastewater treatment. The TELEMAC system takes advantage of new sensors to better monitor the process dynamics and to run automatic controllers that stabilise the treatment plant, meet the depollution requirements and provide a biogas quality suitable for cogeneration. If the automatic system detects a failure which cannot be solved automatically or locally by a technician, then an expert from the TELEMAC Control Centre is contacted via the internet and manages the problem. 相似文献
2.
A new loss allocation (LA) scheme based on the principle of equivalent bilateral exchanges (EBEs) is presented and compared with other available techniques. Formulation and results from extensive simulations including consistency tests show that the suggested methodology has several desirable properties: It is flow-based, requiring only a solved load flow for its implementation; it is not dependent on the choice of a slack bus; it is straightforward to apply; undesirable negative loss allocation is not produced; and low volatilities are shaped. An economic analysis with various LA methods is also carried out when these are integrated into a combined economic dispatch/load flow dispatch strategy, a likely scenario for LA in a real system. This combined dispatch strategy yields prices charged to the loads and rates received by the generators that account for loss allocation and loss supply. Results show that these economic indexes are very close to the marginal costs derived from an optimal power flow (OPF) approach with the advantage of reducing volatility. 相似文献
3.
4.
Brigati S. Francesconi F. Malcovati P. Maloberti F. 《IEEE transactions on instrumentation and measurement》2004,53(2):266-270
In this paper, we present a switched-capacitor sigma-delta (/spl Sigma/-/spl Delta/) modulator for high resolution applications. In particular, this /spl Sigma/-/spl Delta/ modulator is well suited for distributed sensor networks. The circuit, implemented in a double-poly, double-metal 0.6 /spl mu/m CMOS technology, is based on a fourth-order single-loop architecture with a sampling frequency of 256 kHz. The chip consumes 50 mW from a single 5-V supply and achieves a signal-to-noise ratio of 104.9 dB over a bandwidth of 400 Hz, corresponding to a resolution of 17.1 bits. 相似文献
5.
The hydrodynamic transport equations for charges in a semiconductor have been solved for a periodic excitation by means of a harmonic approach, in order to model microwave and millimetre-wave active devices. The solution is based on the expansion of physical variables in a Fourier series in the time domain, and on discretisation in the space domain. A waveform-balance technique in the TD is used to solve the nonlinear equations system. This approach allows for a longer time step with respect to standard TD solutions for most cases of interest, greatly reducing simulation time by at least two orders of magnitude in typical cases. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14: 36–48, 2004. 相似文献
6.
Injectivity, and existence of a bounded inverse, of Riccati operators is investigated for various classes of systems. A unified approach to this problem, based on few general properties verified by several control systems, is proposed. The relation between the invertibility of Riccati operators and the controllability of certain related systems is pointed out. 相似文献
7.
Franco Cataldo Giuseppe A. Baratta Giovanni Strazzulla 《Fullerenes, Nanotubes and Carbon Nanostructures》2002,10(3):197-206
C60 fullerene films have been bombarded with He+ ions at 30 keV at room temperature in vacuum. The structural changes undergone by C60 have been followed by both FT-IR and Raman spectroscopy. Raman spectroscopy was the most useful tool for this scope. It has been clearly discovered that at low radiation dose C60 forms oligomers but at higher radiation doses it is converted into an amorphous carbonaceous matter. The implications of these results on the possible survival of C60 fullerene in the interstellar space have been discussed briefly in connection with the previous results on the effects of various types of electromagnetic radiation over C60. 相似文献
8.
Carlos Garcia-Padilla Estefanía Lozano-Velasco María del Mar Muoz-Gallardo Juan Manuel Castillo-Casas Sheila Cao-Carrillo Francisco Jos Martínez-Amaro Virginio García-Lpez Amelia Arnega Diego Franco Virginio García-Martínez Carmen Lpez-Snchez 《International journal of molecular sciences》2022,23(15)
Various treatments based on drug administration and radiotherapy have been devoted to preventing, palliating, and defeating cancer, showing high efficiency against the progression of this disease. Recently, in this process, malignant cells have been found which are capable of triggering specific molecular mechanisms against current treatments, with negative consequences in the prognosis of the disease. It is therefore fundamental to understand the underlying mechanisms, including the genes—and their signaling pathway regulators—involved in the process, in order to fight tumor cells. Long non-coding RNAs, H19 in particular, have been revealed as powerful protective factors in various types of cancer. However, they have also evidenced their oncogenic role in multiple carcinomas, enhancing tumor cell proliferation, migration, and invasion. In this review, we analyze the role of lncRNA H19 impairing chemo and radiotherapy in tumorigenesis, including breast cancer, lung adenocarcinoma, glioma, and colorectal carcinoma. 相似文献
9.
Franco Bisceglie Giorgio Pelosi Nicol Orsoni Marianna Pioli Mauro Carcelli Paolo Pelagatti Silvana Pinelli Peter J. Sadler 《International journal of molecular sciences》2022,23(14)
We report the synthesis and characterization of three half-sandwich Ru(II) arene complexes [(η6-arene)Ru(N,N′)L][PF6]2 containing arene = p-cymene, N,N′ = bipyridine, and L = pyridine meta- with methylenenaphthalimide (C1), methylene(nitro)naphthalimide (C2), or methylene(piperidinyl)naphthalimide (C3). The naphthalimide acts as an antenna for photoactivation. After 3 h of irradiation with blue light, the monodentate pyridyl ligand had almost completely dissociated from complex C3, which contains an electron donor on the naphthalimide ring, whereas only 50% dissociation was observed for C1 and C2. This correlates with the lower wavelength and strong absorption of C3 in this region of the spectrum (λmax = 418 nm) compared with C1 and C2 (λmax = 324 and 323 nm, respectively). All the complexes were relatively non-toxic towards A549 human lung cancer cells in the dark, but only complex C3 exhibited good photocytoxicity towards these cancer cells upon irradiation with blue light (IC50 = 10.55 ± 0.30 μM). Complex C3 has the potential for use in photoactivated chemotherapy (PACT). 相似文献
10.
J.J. Ipus J.S. BlázquezV. Franco C.F. CondeA. Conde 《Journal of Alloys and Compounds》2011,509(5):1407-1410
The milling time evolution of magnetic anisotropy of ball milled powders can be described considering two regimes. First, for short milling times, the main factor affecting the magnetic behavior of the alloy is the accumulation of internal stresses. Second, for long milling times, magnetic anisotropy can be explained using three contributions: long-range magnetoelastic, averaged short-range magnetoelastic and averaged magnetocrystalline anisotropies. 相似文献