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991.
Neil R. Wilson Alexander J. Marsden Mohammed Saghir Catherine J. Bromley Renald Schaub Giovanni Costantini Thomas W. White Cerianne Partridge Alexei Barinov Pavel Dudin Ana M. Sanchez James J. Mudd Marc Walker Gavin R. Bell 《Nano Research》2013,6(2):99-112
Graphene growth by low-pressure chemical vapor deposition on low cost copper foils shows great promise for large scale applications. It is known that the local crystallography of the foil influences the graphene growth rate. Here we find an epitaxial relationship between graphene and copper foil. Interfacial restructuring between graphene and copper drives the formation of (n10) facets on what is otherwise a mostly Cu(100) surface, and the facets in turn influence the graphene orientations from the onset of growth. Angle resolved photoemission shows that the electronic structure of the graphene is decoupled from the copper indicating a weak interaction between them. Despite this, two preferred orientations of graphene are found, ±8° from the Cu[010] direction, creating a non-uniform distribution of graphene grain boundary misorientation angles. Comparison with the model system of graphene growth on single crystal Cu(110) indicates that this orientational alignment is due to mismatch epitaxy. Despite the differences in symmetry the orientation of the graphene is defined by that of the copper. We expect these observations to not only have importance for controlling and understanding the growth process for graphene on copper, but also to have wider implications for the growth of two-dimensional materials on low cost metal substrates. 相似文献
992.
Analytical solutions have varied uses. One is to provide solutions that can be used in verification of numerical methods. Another is to provide relatively simple forms of exact solutions that can be used in estimating parameters, thus, it is possible to reduce computation time in comparison with numerical methods. In this paper, an alternative procedure is presented. Here is used a hybrid solution based on Green's function and real characteristics (discrete data) of the boundary conditions. 相似文献
993.
994.
Modeling of ancillary services market can be described as institutional arrangements for establishing ancillary services management in deregulated electricity market. Models of the national ancillary services markets are market models which offer transmission system operator efficient procurement of ancillary services, reducing the system management risk, more competitive electricity market, better utilization of production facilities and complete deregulation of electricity markets. This paper deals with current mode of ancillary services market and potential market development in Croatia. Described models are used for establishing market of ancillary services which should occur in parallel with the electricity market. 相似文献
995.
Peter M. Bach Ana Deletic Christian Urich Robert Sitzenfrei Manfred Kleidorfer Wolfgang Rauch David T. McCarthy 《Water Resources Management》2013,27(14):4845-4863
Modelling the design and implementation of urban water infrastructure (particularly decentralised systems) for strategic planning and policymaking requires detailed information of the spatial environment and quantitative knowledge of social preferences. Currently available models, however, mostly use land use, population and impervious cover data without much regard for detailed urban form or society. This study develops an algorithm for determining urban form from minimal spatial data input by incorporating local planning regulations. The interaction between urban form and implementation of lot-scale infiltration systems under different social, biophysical and climate constraints is then investigated, firstly by looking at how this varies in different residential land uses and subsequently in a case study of a typical Melbourne residential subdivision of mixed land uses. Feasibility of infiltration and its downstream impact (runoff volume, frequency and pollution) were assessed for a range of social preferences (quantified as allowable garden space) and climate scenarios (30 % increase/decrease in rainfall and evapotranspiration). Performance indicators were determined through long-term simulation with the MUSIC software. Results show how different biophysical, planning, social and climate conditions affect infiltration feasibility as well as system performance. High infiltrating soils, for example, allow smaller, well-performing and socially less-imposing systems. Low infiltrating soils lead to larger system sizes, occupy much of the allotment’s garden space, but nevertheless provide the benefit of runoff frequency reduction. Overall, climate impact was not significant except for areas with poorly infiltrating soils. Joint consideration of social, planning, climate and water management aspects potentially allows more efficient policymaking, as an array of system configurations can be tested against different multi-faceted scenarios. Such models can help facilitate better participatory planning and policymaking. 相似文献
996.
Bluma G. Soares Ana C. F. Moreira Alex S. Sirqueira Ronilson V. Barbosa Renata A. Simão 《应用聚合物科学杂志》2008,107(2):930-938
Graft copolymers of poly(ethylene‐co‐vinyl acetate) (EVA) grafted with polystyrene (PS) with different molecular weight and different EVA/PS ratio were prepared by coupling reaction between acyl chloride functionalized PS (PS‐COCl) and hydrolyzed EVA. PS‐COCl with controlled molecular weight was prepared by anionic polymerization of styrene, followed by end capping with phosgene. The effect of the molecular architecture of the graft copolymer on the compatibilization of PS/EVA blends was investigated. Substantial improvement in the elongation at break and ductility was observed using the graft copolymer with PS segments with molecular weight as high as 66,000 g/mol and with a PS proportion equal or higher than EVA. The effect of the compatibilization on the morphology was also investigated by scanning electron microscopy and atomic force microscopy. The blend that presented the highest value of elongation at break also displayed dispersed phase constituted by inclusions of the PS phase inside the EVA particle forming a cocontinuous structure, as observed by AFM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 相似文献
997.
Alejandra P. Magnoli Luciana Tallone Carlos A.R. Rosa Ana M. Dalcero Stella M. Chiacchiera Rosa M. Torres Sanchez 《Applied Clay Science》2008,40(1-4):63-71
Some bentonites have been probed to be efficient as sequestering agents for aflatoxins; they decreased the bioavailability of the toxin in the gastrointestinal tracts of birds when they are incorporated in the diets. The binding capacity of these adsorbents varied with the rheological source and even among batches of a given source. Three bentonites from different sources in Argentina, which have very different aflatoxins (AFs) adsorption capacity, were studied. The characterization comprises chemical analysis, scanning electron microscopy (SEM), X-ray power diffraction (XRD), Hg intrusion porosimetry, swelling capacity, etc. The main factors affecting the adsorption of AFs seem to be related to the isomorphic substitution of the montmorillonite and to electrostatic interactions generated by the surface charge of the samples. Neither the mean pore size nor the percentage of quartz has any effect upon the AFs adsorption. 相似文献
998.
Leon Cohen Fernando Soto Ana Melgarejo David W. Roberts 《Journal of surfactants and detergents》2008,11(3):181-186
Sulfoxidation of fatty acid methyl esters with SO2, O2 and ultraviolet light of appropriate wavelength, has led to the synthesis of methyl esters sulfonates or sulfoxylates, known
as Φ-MES, because of the possible random position of SO3 group in the alkyl chain. Aqueous solutions based on the sulfoxylated methyl ester of palmitic acid (Φ-MES C16) have been
studied and compared to the leading types of surfactants used today: linear alkylbenzene sulfonate (LAS) secondary alkane
sulfonate (SAS) and α-sulfo fatty methyl ester sulfonate (α-MES) with regard to solubility, performance and skin compatibility.
The experimental results obtained indicate that Φ-MES C16 can be regarded as a potential component of detergent formulations
and most likely also of body care products.
Dr. Leon Cohen received his Ph.D. in chemistry at Sevilla University. In 1994, he earned the EURCHEM designation. He worked for PETRESA from 1970 to 1996. Since 1989 he has been a Professor of Chemical Engineering at the University of Cadiz, where he has led the research group on “Surface Activity and Detergency” since 1993. He is the author of more than 25 papers, more than 40 contributions to Congresses, and has four patents related to detergency. Dr. Fernando Soto received his M.Sc. in chemistry at the Sevilla University and his Ph.D. in Chemical Engineering in 2001 at Cadiz University. He has been a Professor of Chemical Engineering at the University of Cadiz, since 1979. He has been a member of the research group on “Surface Activity and Detergency” since 1994. Ana Melgarejo received her B.Sc. in Chemical Engineering at Cadiz University in 2007. Dr. David W Roberts received his Ph.D. in Chemistry from Manchester University, UK, in 1965. He is a Fellow of the Royal Society of Chemistry and has the EURCHEM designation. He worked for Unilever Research from 1967 to 2003. Since 2003 he has been a consultant in Manufacturing and Toxicological Chemistry and is an honorary researcher at John Moores University in Liverpool. He is the author of more than 100 papers in the fields of surfactant science and toxicology. 相似文献
Leon CohenEmail: |
Dr. Leon Cohen received his Ph.D. in chemistry at Sevilla University. In 1994, he earned the EURCHEM designation. He worked for PETRESA from 1970 to 1996. Since 1989 he has been a Professor of Chemical Engineering at the University of Cadiz, where he has led the research group on “Surface Activity and Detergency” since 1993. He is the author of more than 25 papers, more than 40 contributions to Congresses, and has four patents related to detergency. Dr. Fernando Soto received his M.Sc. in chemistry at the Sevilla University and his Ph.D. in Chemical Engineering in 2001 at Cadiz University. He has been a Professor of Chemical Engineering at the University of Cadiz, since 1979. He has been a member of the research group on “Surface Activity and Detergency” since 1994. Ana Melgarejo received her B.Sc. in Chemical Engineering at Cadiz University in 2007. Dr. David W Roberts received his Ph.D. in Chemistry from Manchester University, UK, in 1965. He is a Fellow of the Royal Society of Chemistry and has the EURCHEM designation. He worked for Unilever Research from 1967 to 2003. Since 2003 he has been a consultant in Manufacturing and Toxicological Chemistry and is an honorary researcher at John Moores University in Liverpool. He is the author of more than 100 papers in the fields of surfactant science and toxicology. 相似文献
999.
Beans consumption has been associated to reduction on chronic, non transmissible, diseases development. Generally, its consumption is less to the recommended and it is done principally as whole grain dishes. To increase the consumption, there is an especial interest in the use of new products. The main goal of this research was to design intermediate moisture bean purees (IMP) using soaked, cooked and grained Tortola bean, removing an important testa portion. In preparation of IMP two moisture levels, 25 and 30%, and two glycerol levels, 10 and 15%, were studied. Purees were preserved at ambient temperature (20 +/- 2 degrees C) for 30 days. Proximal analysis, phytate content and trypsin inhibitors were determined in the original non processed purees. IMPs were analyzed at preparation time and after 15 and 30 days of storage for moisture content, pH and water activity. Besides, microbiological analysis for total plate count on aerobic mesophile microorganisms, molds and yeast, total colifoms, fecal coliforms and Staphylococcus aureus, was carried out. Global quality and sensory acceptance was also determined. IMPs presented a(w) values between 0.800 and 0.844, a pH between 6.20 and 6.24 and the microbiological counting was negative or far below the accepted limits for more strict foods. IMPs presented good qualifications for global quality and were well accepted. Sensory parameters maintain their values during storage, except for color that in treatment with 30% moisture and 10% glycerol showed a light darkening. It is possible to elaborate intermediate moisture bean puree, with low level of antinutritional compounds, good quality and sensory acceptance and with adverse conditions for the development of food safety importance microorganisms. 相似文献
1000.
Ana Luísa Daniel‐da‐Silva João Carlos Moura Bordado José Miguel Martín‐Martínez 《应用聚合物科学杂志》2008,107(2):700-709
The study of the kinetics of the curing of isocyanate quasi‐prepolymers with water was performed by infrared spectroscopy and differential scanning calorimetry. The influence of the free isocyanate content, polyol functionality, and of the addition of an amine catalyst (2,2′‐dimorpholinediethylether) in the reaction kinetics and morphology of the final poly(urethane urea) was analyzed. A second‐order autocatalyzed model was successfully applied to reproduce the curing process under isothermal curing conditions, until gelation occurred. A kinetic model‐free approach was used to find the dependence of the effective activation energy (Ea) with the extent of cure, when the reaction was performed under nonisothermal conditions. The dependence of Ea with the reaction progress was different depending on the initial composition of the quasi‐prepolymer, which reveals the complexity of the curing process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 相似文献