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991.
Symmetric porous membranes were prepared from concentrated poly(ether-imide) (PEI) solutions using vapor-induced phase separation (VIPS) coupled with a drying pretreatment. Moderately concentrated solutions of PEI in N-methylpyrrolidinone (NMP) (14–16 wt%) were first cast on glass plates and the solvent was then allowed to evaporate under a dry air flow up to the desired concentration (16–38 wt%) before forming the membrane structure by VIPS. The polymer concentration profiles (confocal Raman microscopy) and model predictions were in good agreement to show that the evaporation stage did not induce a polymer gradient concentration with PEI/NMP systems. These results were confirmed by examination of the final membrane morphology (SEM). 相似文献
992.
0引言法国皮拉德EGCI股份公司(PILLARD EGCI)成立于1919年,是专业从事锅炉、回转窑及分解炉燃烧设备的专业公司。在世界范围内,皮拉德公司提供的水泥及其它矿物处理行业的回转窑及分解炉燃 相似文献
993.
Maham Yasmeen Syed Asif Ansar Amir Azam Khan Thierry Joyeux Jean Claude Labbe 《Journal of Materials Engineering and Performance》2001,10(5):542-547
Commercial zirconia was milled and sedimented to separate finer and coarser particles. Then additives such as CaO and Y2O3 were added in proportions of 7 and 13 mol.% each. Wet mixing of these powders was done in the ball mill. These mixtures were
then compacted through uniaxial compaction using 150 MPa of pressure to make pellets of 8 mm diameter and 3 mm height approximately.
The compacts were sintered at 1700 °C under argon atmosphere during 1 h. Densification calculations revealed densities of
more than 80% in all samples. Scanning electron microscopy (SEM) showed that closed porosity was present. X-ray diffraction
(XRD) results confirmed the presence of cubic phase with quantities higher in samples of finer powder and 13 mol.% additive. 相似文献
994.
Claude Thibeault 《Journal of Electronic Testing》2000,16(4):339-353
This paper presents a diagnostic method based on differential IDDQprobabilistic signatures, inspired by telecommunications systems. The method and its unique features are described. Then, results from an IC monitor containing controllable faults show the capability of the method to diagnose actual activated faults, despite a strong experimental current standard variation. These results validate previous simulation procedures, which are applied to quantify effects not covered by the monitor experiment, that is, the effect of the load of a bridged node and the effect of the bridge resistance value. These experimental and simulation results reveal the robustness of the proposed diagnosis method, that has identified and located every single fault considered so far. 相似文献
995.
一、中国的缺水问题在中国的很多地区,可用水量的日益减少是当前最大的社会、经济和政治问题。以人均可用量2500m3的标准相比较,中国大陆的淡水供应只达到2000m3,属于世界 相似文献
996.
Thomas Gaudron Claude Peters Elodie Boland André Steinmetz Gilbert Moris 《European Food Research and Technology》2009,229(2):295-305
With the ever increasing number of genetically modified plants authorized worldwide, including in the European Union, high
throughput detection methods need to be developed. In this paper, a quadruplex-real-time-PCR method is described which allows
rapid and simultaneous screening of food for the presence of target DNA sequences from the cauliflower mosaic virus 35S promoter,
the NOS terminator from Agrobacterium tumefaciens, the soya reference lectin gene and the maize reference alcool dehydrogenase gene (adh). Three of the four primers and probe
combinations have already been published elsewhere, whereas primers and probe for NOS terminator-PCR were developed in-house.
Validation data show sensitivities down to five copies for 35S promoter and NOS terminator PCR, even when target sequences
of the competing PCRs are in large excess. Thorough adjustment of primer and probe concentrations allowed high individual
PCR efficiencies with negligible physical cross-talk between the four detection channels. This method provides a basis for
a rapid screening of food for the most frequently used regulatory elements present in GM crops authorized for food in the
European Union. In addition it provides information about the presence of species which are possibly genetically modified. 相似文献
997.
Ziqi Guan Jing Bai Jianglong Gu Xinzeng Liang Die Liu Xinjun Jiang Runkai Huang Yudong Zhang Claude Esling Xiang Zhao Liang Zuo 《材料科学技术学报》2021,68(9):103-111
In this work,the B2 partial disordered structure of the austenitic parent phase,martensitic transformation,elastic and magnetic properties of the Ni8 Mn4+xTi4-x(x=0,1 and 2) Heusler alloys have been systematically investigated by the first-principles calculations.The preferential atomic occupation of B2 structure is one Ti atom exchange with the nearest neighboring Mn atom from the view of lowest energy principle.This disordered exchange sites(Mn-Ti) and the excess Mn atoms occupying the Ti sites(MnTi)could reduce the nearest Mn-Mn distance,resulting in the anti ferromagnetic state in the austenitic and martensitic phases of the alloys.The total magnetic moment of the alloy decreases with the increasing Mn content;it is ascribed to the antiferromagnetic magnetic moments of the excess Mn atoms.When x=0,the alloy does not undergo martensitic transformation since the austenite has absolute phase stability.The martensitic transformation will occur during cooling process for x=1 or 2,owing to the energy difference between the austenite and the martensite could provide the driving force for the phase transformation.The elastic properties of the cubic austenitic phase for the Ni2 MnTi alloy is calculated,and the results reveal the reason why Ni-Mn-Ti alloy has excellent mechanical properties.The origin of martensitic transformation and magnetic properties was discussed based on the electronic density of states. 相似文献
998.
For systems that are not feedback linearizable, a natural question is: how to find the largest feedback linearizable subsystem and, if the partial linearization is not unique, what are the control‐theoretic properties of various partial linearizations. In this paper, we will consider the problem of how to choose a partially linearizing output that renders the zero dynamics asymptotically stable and when such an output exists. We will state general results solving completely the problem for systems whose linearizability defect is one by identifying and describing two classes of systems. For the first class, all maximal partial linearizations lead to the same zero dynamics. For the second class, any asymptotic behavior of the zero dynamics can be achieved by a suitable choice of a partially linearizing output. In the second part, we apply our results to mechanical systems with two‐degrees‐of‐freedom and provide a detailed study of their partial linearizations. We illustrate the obtained results by examples of Acrobot (which belongs to the second class) and Pendubot (which belongs to the first class). 相似文献
999.
Pu Bowen Mesguich David Estournès Claude Zhang Xiang Chevallier Geoffroy Zhao Naiqin Laurent Christophe 《Journal of Materials Science》2022,57(11):6266-6281
Journal of Materials Science - Tremendous impacts are usually made by the synthesis method and consolidation technique on microstructure and interface of graphene/Al composites. In the present... 相似文献
1000.
Adaptation of the Romanomermis culicivorax CCA-Adding Enzyme to Miniaturized Armless tRNA Substrates
Oliver Hennig Susanne Philipp Sonja Bonin Kvin Rollet Tim Kolberg Tina Jühling Heike Betat Claude Sauter Mario Mrl 《International journal of molecular sciences》2020,21(23)
The mitochondrial genome of the nematode Romanomermis culicivorax encodes for miniaturized hairpin-like tRNA molecules that lack D- as well as T-arms, strongly deviating from the consensus cloverleaf. The single tRNA nucleotidyltransferase of this organism is fully active on armless tRNAs, while the human counterpart is not able to add a complete CCA-end. Transplanting single regions of the Romanomermis enzyme into the human counterpart, we identified a beta-turn element of the catalytic core that—when inserted into the human enzyme—confers full CCA-adding activity on armless tRNAs. This region, originally identified to position the 3′-end of the tRNA primer in the catalytic core, dramatically increases the enzyme’s substrate affinity. While conventional tRNA substrates bind to the enzyme by interactions with the T-arm, this is not possible in the case of armless tRNAs, and the strong contribution of the beta-turn compensates for an otherwise too weak interaction required for the addition of a complete CCA-terminus. This compensation demonstrates the remarkable evolutionary plasticity of the catalytic core elements of this enzyme to adapt to unconventional tRNA substrates. 相似文献