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71.
Various human factors classification frameworks have been used to identified causal factors for clinical adverse events. A systematic review was conducted to identify human factors classification frameworks that identified the causal factors (including human error) of adverse events in a hospital setting. Six electronic databases were searched, identifying 1997 articles and 38 of these met inclusion criteria. Most studies included causal contributing factors as well as error and error type, but the nature of coding varied considerably between studies. The ability of human factors classification frameworks to provide information on specific causal factors for an adverse event enables the focus of preventive attention on areas where improvements are most needed. This review highlighted some areas needing considerable improvement in order to meet this need, including better definition of terms, more emphasis on assessing reliability of coding and greater sophistication in analysis of results of the classification.
Practitioner Summary: Human factors classification frameworks can be used to identify causal factors of clinical adverse events. However, this review suggests that existing frameworks are diverse, limited in their identification of the context of human error and have poor reliability when used by different individuals. 相似文献
72.
Processing and Properties of Particulate Composites from Coated Powders 总被引:13,自引:0,他引:13
Tyrone D. Mitchell Jr. Lutgard C. De Jonghe 《Journal of the American Ceramic Society》1995,78(1):199-204
A method is described for sintering of highly loaded (≤20 vol%) alumina matrix/silicon carbide whisker or platelet composites to closed porosity. The method uses controlled heterogeneous precipitation in a suspension of whiskers or platelets. The suspension-coated particles are calcined to produce a free-flowing composite powder which can be hot-pressed or free-sintered to high density. The results of consolidation and mechanical property testing are reported. 相似文献
73.
Two of the majorNuphar alkaloids, nupharolutine and 6,6-dihydroxythiobinupharidine, were isolated from the aquatic perennial herbNuphar lutea (L.) Sibth. & Sm., yellow water lily. In a lettuce seedling bioassay of the two pure compounds, the former was inactive and the latter was highly inhibitory of radicle elongation at concentrations greater than 2 ppm. Structures and stereochemistry of the two compounds were confirmed by DEPT,1H-1H COSY,1H-13C COSY, and1H-1H NOESY experiments. 相似文献
74.
Helmut Alt Esther M. Arkin Alon Efrat George Hart Ferran Hurtado Irina Kostitsyna Alexander Kröller Joseph S. B. Mitchell Valentin Polishchuk 《Theory of Computing Systems》2014,54(4):689-714
We show how to compute the smallest rectangle that can enclose any polygon, from a given set of polygons, in nearly linear time; we also present a PTAS for the problem, as well as a linear-time algorithm for the case when the polygons are rectangles themselves. We prove that finding a smallest convex polygon that encloses any of the given polygons is NP-hard, and give a PTAS for minimizing the perimeter of the convex enclosure. We also give efficient algorithms to find the smallest rectangle simultaneously enclosing a given pair of convex polygons. 相似文献
75.
Sowdhamini R; Mitchell TJ; Andrew PW; Morgan PJ 《Protein engineering, design & selection : PEDS》1997,10(3):207-215
Pneumolysin and proaerolysin are bacterial toxins that form pores in host
cells by oligomerization. We propose that they may have similar structures
despite a poor sequence identity. The crystal structure of proaerolysin
reveals a protein composed of four domains, arranged in the shape of an
elongated comma. Electron microscopy of the pneumolysin monomer shows a
similar arrangement of domains. The sequence of pneumolysin recognizes the
template of proaerolysin from a library of protein folds. A
three-dimensional model of pneumolysin has been constructed by the
comparative approach using the structure of proaerolysin. This model,
together with results on the activity of site- specific mutants and the
positions of antigenic sites, has been used to propose functional roles of
individual domains.
相似文献
76.
Two-dimensional correlation relaxometry studies of cement pastes performed using a new one-sided NMR magnet 总被引:1,自引:0,他引:1
Peter J. McDonald Jonathan Mitchell Peter S. Aptaker Luc Monteilhet 《Cement and Concrete Research》2007,37(3):303-309
We present preliminary results of the first NMR T1-T2 two-dimensional relaxation correlation experiments performed using a one-sided NMR system in cement based materials. Two-dimensional correlation relaxometry has itself only recently been demonstrated in cement paste where it proved to be a particularly sensitive probe of pore-water dynamics providing direct information on exchange of water between the gel and capillary pore networks. Further to this we have observed differences in the structural development of a selection of cement pastes throughout the early stages of hydration and verified the theoretical frequency dependence of the ratio T1 / T2. When coupled with instrumentation developments in one-sided NMR magnets the way is opened to detailed, spatially resolved studies of the development of hydration and porosity in the surface layers (top 50 mm) of cementitious materials. A new magnet, suitable for such applications, is discussed. 相似文献
77.
Ten samples of mineral-matter residue were obtained by the radio-frequency low-temperature ashing of subbituminous and bituminous coals. The low-temperature ash samples were then heated progressively from 400 °C to 1400 °C at 100 °C intervals. Mineral phases present at each temperature interval were determined by X-ray diffraction analyses. The minerals originally present in the coals (quartz, kaolinite, illite, pyrite, calcite, gypsum, dolomite, and sphalerite) were all altered to higher temperature phases. Several of these phases, including kaolinite, metakaolinite, mullite, anhydrite, and anorthite, were found only in limited temperature ranges. Therefore the temperature of formation of the ashes in which they occur may be determined. Mineralogical differences were observed between coal samples from the Rocky Mountain Province, the Illinois Basin, and the Appalachians; and as a result of these mineralogical differences, different high-temperature phases resulted as the samples were heated. However, regional generalizations cannot be made until a greater number of samples have been studied. 相似文献
78.
We have synthesized a series of fully aliphatic polyimides (APIs) from bicyclo[2,2,2]oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride (BOCA) and various aliphatic diamines, including linear aliphatic, flexible alicyclic, and rigid adamantyl diamines. We performed the polymerization reactions using one‐step syntheses in m‐cresol at elevated temperatures without the isolation of poly(amic) acid. The chemical composition and structure of the polymers were characterized by nuclear magnetic resonance (NMR) and infrared (IR) spectrometry. The characterization data are reported from analyses using gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and wide‐angle X‐ray diffraction (WXAD) measurements. The polyimides are also subjected to solubility, solution viscosity, tensile strength, transparency, and dielectric constant measurements. The resultant polyimides possess well‐controlled molecular weight, reasonable intrinsic viscosity, good transparency, enhanced solubility, low dielectric constants, and high glass transition temperature, together with marginal thermal and mechanical stability. These properties were enhanced in copolyimides containing equimolar amounts of rigid and flexible moieties. These rigid‐rod APIs derived from the alicyclic dianhydride and aliphatic diamines are promising candidates as advanced materials for future applications in micro‐ and photoelectronic devices. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3316–3326, 2006 相似文献
79.
Sangram Ganguly Arindam Samanta Mitchell A. Schull Nikolay V. Shabanov Cristina Milesi Ramakrishna R. Nemani Yuri Knyazikhin Ranga B. Myneni 《Remote sensing of environment》2008,112(12):4318-4332
The evaluation of a new global monthly leaf area index (LAI) data set for the period July 1981 to December 2006 derived from AVHRR Normalized Difference Vegetation Index (NDVI) data is described. The physically based algorithm is detailed in the first of the two part series. Here, the implementation, production and evaluation of the data set are described. The data set is evaluated both by direct comparisons to ground data and indirectly through inter-comparisons with similar data sets. This indirect validation showed satisfactory agreement with existing LAI products, importantly MODIS, at a range of spatial scales, and significant correlations with key climate variables in areas where temperature and precipitation limit plant growth. The data set successfully reproduced well-documented spatio-temporal trends and inter-annual variations in vegetation activity in the northern latitudes and semi-arid tropics. Comparison with plot scale field measurements over homogeneous vegetation patches indicated a 7% underestimation when all major vegetation types are taken into account. The error in mean values obtained from distributions of AVHRR LAI and high-resolution field LAI maps for different biomes is within 0.5 LAI for six out of the ten selected sites. These validation exercises though limited by the amount of field data, and thus less than comprehensive, indicated satisfactory agreement between the LAI product and field measurements. Overall, the inter-comparison with short-term LAI data sets, evaluation of long term trends with known variations in climate variables, and validation with field measurements together build confidence in the utility of this new 26 year LAI record for long term vegetation monitoring and modeling studies. 相似文献
80.
Iris Reinbacher Marc Benkert Marc van Kreveld Joseph S. B. Mitchell Jack Snoeyink Alexander Wolff 《Algorithmica》2008,50(3):386-414
In geographic information retrieval, queries often name geographic regions that do not have a well-defined boundary, such
as “Southern France.” We provide two algorithmic approaches to the problem of computing reasonable boundaries of such regions
based on data points that have evidence indicating that they lie either inside or outside the region. Our problem formulation
leads to a number of subproblems related to red-blue point separation and minimum-perimeter polygons, many of which we solve
algorithmically. We give experimental results from our implementation and a comparison of the two approaches.
This research is supported by the EU-IST Project No. IST-2001-35047 (SPIRIT) and by grant WO 758/4-2 of the German Research
Foundation (DFG). 相似文献