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72.
Effects of carbon nanofibers on cell morphology, thermal conductivity and crush strength of carbon foam 总被引:1,自引:0,他引:1
The effects of low volume fractions of carbon nanofibers on the structure, thermal conductivity and crush strength of carbon foam were examined. Bulk density of the foam increased linearly with the fiber fraction reflecting the morphological changes in the cells. Thermal conductivity increased at low fiber fractions, but dropped at higher fiber fractions. Crush strength increased linearly with fiber fraction for short length fibers, but decreased for the longer length fibers. Scanning electron microscopy, petrography, and X-ray diffraction illustrated the complex effects of the carbon nanofibers on the foam. Available models for thermal conductivity and crush strength have been extended to accommodate these effects incorporating cell structure and morphology (macroeffect), presence of fibers (microeffect), and graphite crystal d-spacing (nanoeffect). This research has shown that the nanofibers have a complex role in the macro, micro, and nanoproperties of the composite foam. 相似文献
73.
Sobo EJ Billman G Lim L Murdock JW Romero E Donoghue D Roberts W Kurtin PS 《The Joint Commission journal on quality improvement》2002,28(9):498-509
BACKGROUND: The Institute of Medicine's 2001 report on quality delimits six dimensions of optimal care: safety, effectiveness, efficiency, timeliness, patient centeredness, and equity. In fall 2001 parents of pediatric cancer patients were interviewed to determine how well they thought these dimensions were addressed with respect to medication administration. Immediate goals were to identify system weaknesses and devise strategies to prevent future errors. A higher-order goal was to develop and demonstrate a model protocol for rapid-cycle interview assessments. METHODS: Hematology/oncology directors worked with a research expert to develop a semistructured interview protocol. After training, which included directed reading, oral instruction, and role-playing, a convenience sample of 20 English- and Spanish-speaking parents of inpatients was recruited. Parents were asked to characterize current medication administration practices and to describe problems that they had experienced or witnessed. Rapid content analysis techniques were used to identify issues of importance to the parents. FINDINGS: Parents' medication concerns centered on their children's comfort. Parents called for communication improvements, standardization of all nursing procedures and techniques, and a guide or an outline providing a clear understanding of what to expect when and from whom. Viewing these concerns in relation to the Institute of Medicine's quality domains allowed the department to frame an improvement action plan aligned with organizational and national priorities. IMPLICATIONS: With good supervision and limited focused training, inexperienced staff can successfully administer semistructured qualitative interviews and help analyze findings for rapid cycle improvement purposes. The protocol can be adapted for use in organizations interested in rapid qualitative assessments of patient and parent preferences. 相似文献
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Topics in Catalysis - Growth of ultrathin, single-crystalline, molybdenum-nitride films on Ru(0001) has been investigated by means of X-ray photoelectron spectroscopy (XPS), low energy electron... 相似文献
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Bor‐Sen Chiou George H. Robertson LuAnn E. Rooff Trung Cao Haani Jafri Kay S. Gregorski Syed H. Imam Greg M. Glenn William J. Orts 《应用聚合物科学杂志》2010,116(5):2638-2644
Wheat gluten films of various thicknesses formed at 30–70°C were treated with cold sulfuric acid to produce sulfated gluten films. Chemical, thermal, thermal stability, and water uptake properties were characterized for neat and sulfated films. The sulfated gluten films were able to absorb up to 30 times their weight in deionized water. However, this value dropped to 3.5 when the film was soaked in a 0.9% (w/w) NaCl solution. The films were also soaked 4 times in deionized water, and each soaking resulted in a reduced water uptake capacity. The temperature of film formation had no effect on the final water uptake properties. Also, thinner films had higher concentrations of sulfate groups than thicker films; this resulted in higher water uptake values. In addition, sulfated gluten films had comparable glass‐transition temperatures but lower thermal stabilities than the neat gluten films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
77.
Alkyd-, oil-modified-latex-, and latex-based finishes were applied to severely weathered western redcedar and redwood boards that did not have any surface treatment to ameliorate the weathered surface prior to painting. Six finishes were evaluated annually for 11 years for cracking, flaking, erosion, mildew growth, discoloration, and general appearance. Lowsolids-content latex finishes that contained about 10% raw linseed oil and 11% acrylic resin (i.e., the oil-modified latex finishes) performed better on badly weathered wood than did the alkyd and the other latex finish, even after 11 years. Latex finishes that contained raw linseed oil probably stabilized the weathered surface and plasticized the finish. The stabilization of the wood surface and the flexibility of the finish throughout its service life are the important factors in finish performance on these weathered substrates. Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53705-2398. The use of trade or firm names in this publication is for reader information and does not imply endorsement by the U.S. Department of Agriculture of any product or service. The Forest Products Laboratory is maintained in cooperation with the University of Wisconsin. This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright. 相似文献
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SiC-AIN alloys were prepared by the carbothermal reduction of silica and alumina, derived from an intimate mixture of silica, aluminium chloride and starch. The resulting single-phase SiC-AIN powder was hot-pressed without additives to a high density. The dense bodies had a fine-grained uniform microstructure. The Young's elastic modulus, microhardness, fracture toughness, thermal expansion and thermal conductivity were measured as functions of composition. The creep behaviour of the SiC-AIN alloy was compared with that of silicon carbide. 相似文献