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91.
Enormous progress has been made in the past 100 years in improving diet and nutritional status. However, the job is not done. This paper summarizes some of the current challenges and proposes priorities for future research and policy development. The nutrition agenda is more complex than it was 100 years ago. The world now faces undernutrition side-by-side with dietary excess and related chronic diseases. The complexity of modern nutrition necessitates using a systems approach to identifying effective policies and programs. There is a renewed interest in addressing the new nutrition agenda.  相似文献   
92.
The functional properties of mixtures of maize, cassava and yam starches and their relationships with microstructural characteristics were investigated. Experiments were performed following the simplex‐centroid design with internal points and restrictions (upper limit) for yam starch proportion. The statistical model used (Scheffé canonical equation) was a powerful tool to predict the pastes behaviour within the limits of the experimental area. Polynomials with second level interactions were applied to obtain the surface response. Viscoelastic attributes of mixtures differed from those of individual starches. As shown by differential scanning calorimetry and microscopical observations, physical properties of the mixtures depended on the type of networks obtained. These networks varied upon yam, corn and cassava starch proportions as each one has a particular characteristic: gelatinisation temperature, granule size, swelling capacity and amylose/amylopectin ratio among others.  相似文献   
93.
94.
Wistar rats were fed with surimi gels containing either sunflower oil, fish oil (ω3), and the same formulation additionally supplemented with 1.05 g kg−1 quercetin (ω3‐Q). Antioxidant capacity was highest in gels with added quercetin when measured by the ferric‐reducing/antioxidant power (FRAP) method, but not by the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical assay. Lipid stability was not enhanced by quercetin since commercial fish oil already contains stabilizers. Quercetin modified neither rheological properties nor water‐holding capacity of the gels; however, it produced a large increase in yellowness (b*). Serum lipid profile of rats was not significantly different. Total serum antioxidant capacity by FRAP was significantly increased only in the ω3‐Q group. Plasma malondialdehyde was similar in the ω3 and ω3‐Q groups, indicating no prooxidative effect of quercetin in vivo. These results suggest that quercetin might be used as a food ingredient in fish gel to improve some nutritional properties of the gel. Copyright © 2005 Society of Chemical Industry  相似文献   
95.
96.
Constitutive Model for Municipal Solid Waste   总被引:5,自引:0,他引:5  
Municipal solid waste (MSW) is a refuse composed of various materials with different properties. Some of the components are stable while others degrade as a result of biological and chemical processes. These aspects impart to MSW a complex behavior that has been modeled, with many limitations, within the concepts of soil mechanics. In this paper, a framework to model the MSW mechanical behavior is proposed based on results from laboratory tests, such as triaxial compression and confined compression of large samples. It is suggested that two different effects command MSW mechanical behavior: (a) the reinforcement of MSW by synthetic fibers (composed by many types of polymers) and (b) the behavior of the MSW paste, without fibers. Accordingly, two distinct frameworks were used to represent the main MSW characteristics: (a) a critical state framework for MSW paste and (b) an elastic perfectly plastic framework for waste fibers, with a time lag for fiber loading (function fm). The proposed model is capable of reproducing quite well the results obtained from triaxial and confined compression tests performed in the laboratory as well as the settlement recorded in a sanitary landfill.  相似文献   
97.
The Use of Fractal Geometry in Pharmaceutical Systems   总被引:2,自引:0,他引:2  
The nature of surface irregularity affects many phenomena including adsorption/desorption, catalysis, crystal growth, drug dissolution and chromatography. Many excellent models have been developed with the oversimplified assumption that all particles are smooth spheres; fractal geometry allows these models to be expanded to irregular surfaces by providing a quantitative means of assessing surface roughness.

An overview of fractal analysis is presented in the following, and the state of the art, as far as pharmaceutical systems are concerned are outlined. Erroneous approaches, as well as the directions pharmaceutical research and technology might take in the area of fractal analysis are suggested.

From a historical perspective, micromeritics (the science of particle size, shape and surface area) were first developed with the assumptions that all particles were smooth spheres.

Much excellent work has been developed with such an oversimplified model. For example, numerous workers have shown that particle flow through an orifice is a function of “particle diameter”, and experiments have most often been carried out on particles as close to spherical as possible, and as monodisperse as possible.

The science of micromeritics, the science of small particles, is the making of Dalla Valle (1943) who coined the term in a book of the same name which describes methods of particle size measurement, mostly used by soil scientists.1  相似文献   
98.
A national survey of 749 practicing psychotherapists was conducted to examine their use of personal psychotherapy before and after entering professional practice. A usable return rate of 44% (N?=?318) was obtained. Variables related to the use of personal therapy are identified, and a discussion of the results is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
99.
In Aplysia fasciata, the sea hare, shock paired with moderate increases or decreases in the seawater concentration leads to pairing-specific increases in the respiratory pump rate in response to the same solutions an hour later. A common neural circuit underlies learned changes to increased and decreased seawater concentration, as shown by complete generalization of learning between these stimuli. Different neural circuitry controls learning after pairing a shock with pH 7 seawater, as shown by a lack of generalization of learning to this stimulus. Preexposure to strong changes in the seawater leads to sensitization of respiratory pumping. The hypothesis was tested that associative learning and sensitization arise from activation of common pathways. However, patterns of generalization of sensitization elicited by preexposure to altered seawaters differ from those produced by associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
100.
Agonist-stimulated phospholipases release arachidonate, but not 8,11,14-eicosatrienoate, from human endothelial cells. One source of the arachidonic acid is deacylation of 1-alkyl-2-arachidonoyl-glycerophosphocholine, with subsequent conversion of some of the resultant lysophospholipid to platelet-activating factor. This study has compared the distribution of incorporated 8,11,14-[14C]-eicosatrienoate in alkylacyl-GPC and diacyl-GPC with that of [14C]arachidonate synthesized endogenously by desaturation of the 8,11,14-[14C]eicosatrienoate. Cells were incubated for 24 or 48 hr with 8,11,14-[14C]eicosatrienoate, and the resultant mixture of14C-fatty acids in the cellular lipids was characterized by gas chromatography. The choline phospholipids were then separated, hydrolyzed with phospholipase C and derivatized to diradylbenzoates. Gas chromatographic analysis indicated extensive incorporation of [14C]eicosatrienoate, as well as [14C]arachidonate, into alkylacyl-GPC. Although the ratio of esterified [14C]arachidonate to [14C]eicosatrienoate was greater in alkylacyl-GPC than in diacyl-GPC, the enrichment with [14C]arachidonate was far less than the ratio of arachidonate/eicosatrienoate released from these cells. These results thus support the hypothesis that the acyl specificity of polyunsaturated fatty acid release is provided by the agonist-stimulated phospholipase A2 rather than the composition of the alkylacyl-GPC.  相似文献   
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