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排序方式: 共有804条查询结果,搜索用时 109 毫秒
61.
Highly reflective coatings for interior and exterior steel cladding and the energy efficiency of buildings 总被引:1,自引:0,他引:1
The effect of surface heat-radiation properties of coil-coated steel cladding material on the energy efficiency of buildings in Nordic climate is addressed by parallel temperature and energy usage measurements in a series of test cabins with different exterior solar reflectivity and interior thermal reflectivity. During one year, a number of one- or two-week experiments with air conditioner cooling and electrical floor heating were made while logging air-, radiation- and surface temperatures, energy consumption and weather conditions. Measurements show significant energy savings in the test cabins by the use of high thermal reflectivity interior surfaces both during heating and cooling and a strongly reduced cooling demand by the use of high solar reflectivity exterior surfaces. Results are interpreted within the context of a steady-state energy flux model, to illuminate the importance of surface resistance properties (radiation and convective heat dissipation). 相似文献
62.
Rönnholm Mats R. Hernández Carucci José R. Arve Kalle Eränen Kari Salmi Tapio 《Topics in Catalysis》2007,42(1-4):195-198
A silver/alumina catalyst was tested for its NO
x
reduction activity during oxygen-rich conditions and during variation in the input parameters (nitric oxide, octane and oxygen).
The experimental data using the microreactor was investigated by means of artificial neural networks (ANN). 相似文献
63.
64.
An evaluation of the CaO-SiO2 system has been made using a newly developed model, a two-sublattice model for ionic solutions. Two alternatives were tested.
In the first one, three anions were assumed, O−2, SiO4
−4, and SiO3
−2. In the second one, SiO3
−2 was omitted. A set of parameter values describing the Gibbs energy of the liquid phase and solid phases was fixed for each
alternative by a computer-operated optimization procedure called PARROT. Satisfactory assessments were achieved over the whole
phase diagram range with both alternatives. The main difference between them occurs at the monotectic point. A comparison
between calculated properties and experimental data is given.
Formerly Research Associate, Royal Institute of Technoloy 相似文献
65.
Garpenstrand H?kan; Annas Peter; Ekblom Jonas; Oreland Lars; Fredrikson Mats 《Canadian Metallurgical Quarterly》2001,115(2):358
Biological markers for acquisition and extinction of fear conditioning were studied in 40 individuals selected for displaying either good or poor acquisiton of fear conditioning, as estimated by the skin conductance response. Participants with a short serotonin transporter (5-HTT) promoter allele or low monoamine oxidase activity in platelets (trbc-MAO) displayed better acquisition than those with only long alleles or high trbc-MAO, whereas participants with a long dopamine D4 receptor (D4DR) exon III allele showed delayed extinction compared with those with only short alleles. The findings, that D4DR exon III and 5-HTT promotor genotypes and trbc-MAO activity are related to human fear conditioning, a basic form of associative learning, are consistent with animal studies suggesting a genetic contribution to fear conditioning. The authors suggest that in humans these genetic mechanisms are partly dopaminergic and serotonergic in origin. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
Niall W. G. Young Paul Wassell Johan Wiklund Mats Stading 《International Journal of Food Science & Technology》2008,43(11):2083-2089
Ultrasonic velocity profiling with pressure difference (UVP‐PD) was demonstrated to be a successful, non‐invasive, in‐line measurement system for instantaneous velocity and rheological flow profiling of complex, opaque fat blends. Model systems of 25% Akomic, 75% rapeseed oil; and 25% Akomic, 74% rapeseed oil and 1% Grindsted® Crystalliser 110 were compared under real process conditions with UVP‐PD. Results indicated that the sample containing the crystalliser had twice the viscosity of the control. These in‐line results are in agreement with previous off‐line results, and offer the chance to probe the mechanics of fat blend physics under real, dynamic conditions. 相似文献
67.
We give a careful, fixed-size parameter analysis of a standard (Blum and Micali in SIAM J. Comput. 13(4):850–864, 1984; Goldreich and Levin in Proceedings of 21st ACM Symposium on Theory of Computing, pp. 25–32, 1989) way to form a pseudo-random generator from a one-way function and then pseudo-random functions from said generator (Goldreich
et al. in J. Assoc. Comput. Mach. 33(4):792–807, 1986) While the analysis is done in the model of exact security, we improve known bounds also asymptotically when many bits are
output each round and we find all auxiliary parameters efficiently, giving a uniform result. These optimizations makes the
analysis effective even for security parameters/key-sizes supported by typical block ciphers and hash functions. This enables
us to construct very practical pseudo-random generators with strong properties based on plausible assumptions. 相似文献
68.
Ce0.9Gd0.1O1.95 powders were synthesized by spray drying and successive calcinations. The phase purity, BET surface area, and particle morphology of as-sprayed and calcined powders were characterized. After calcination above 300 °C, the powders were single phase and showed a BET surface area of 68 m2/g when calcined at 300 °C. The conductivity, in air, of sintered pellets was measured by electrochemical impedance spectroscopy (EIS) and it was found to be comparable with literature values. The activation energy for the total conductivity was around 0.83 eV. The powder calcined at lower temperature showed better sinterability and higher total conductivity due to an increased bulk conductivity. 相似文献
69.
70.
Marianne Wittrup Larsen Dr. Dorota F. Zielinska Mats Martinelle Dr. Aurelio Hidalgo Dr. Lars Juhl Jensen Prof. Uwe T. Bornscheuer Prof. Karl Hult Prof. 《Chembiochem : a European journal of chemical biology》2010,11(6):796-801
A water tunnel in Candida antarctica lipase B that provides the active site with substrate water is hypothesized. A small, focused library created in order to prevent water from entering the active site through the tunnel was screened for increased transacylation over hydrolysis activity. A single mutant, S47L, in which the inner part of the tunnel was blocked, catalysed the transacylation of vinyl butyrate to 20 mM butanol 14 times faster than hydrolysis. The single mutant Q46A, which has a more open outer end of the tunnel, showed an increased hydrolysis rate and a decreased hydrolysis to transacylation ratio compared to the wild‐type lipase. Mutants with a blocked tunnel could be very useful in applications in which hydrolysis is unwanted, such as the acylation of highly hydrophilic compounds in the presence of water. 相似文献