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71.
The discriminant validities of the original and the reconstructed Hamilton anxiety and depression scales (J. H. Riskind et al, 1987) were compared in patients who had principal Diagnostic and Statistical Manual of Mental Disorders-III—Revised (DSM-III—R) anxiety disorders with or without 1 or more comorbid mood disorders. The reconstructed anxiety and depression scales had better discriminant validity (scale intercorrelation?=?.61) than the original scales did (r?=?.78). However, the reconstructed scales shared considerable variance (about 37%), which was significantly higher than the shared variance (about 2%) reported by Riskind et al. Discriminant analyses showed that the reconstructed scales did not distinguish anxiety patients with comorbid mood disorders from those without comorbid mood disorders better than the original scales did. However, the reconstructed scales eliminate item overlap, an obvious source of artifactual correlations between scores on the Hamilton anxiety and depression scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
72.
We build an agent based computational framework to study large commodity markets. A detailed representation of the consumers, producers and the market is used to study the micro level behavior of the market and its participants. The user can control players’ preferences, their strategies, assumptions of the model, its initial conditions, market elements and trading mechanisms. The first part of the paper describes the computational framework and its three main modules. The later part describes a case study that examines the decentralized market in detail, specifically the computational options available for matching the buyers and suppliers in a synthetic market. The study illustrates the sensitivity of the outcome of various economic variables, such as clearing price, quantity, profits and social welfare, to different matching schemes in a bilateral computational setting. Based on seven different matching orders for the buyers and suppliers, our study shows that the results can vary dramatically for different pairing orders.  相似文献   
73.
Examined factors influencing sex-differentiated responses to selected interests and interpersonal traits by young people in 3 age groups: 516 in late childhood (Grades 4–6), 398 in early adolescence (Grades 7–9), and 337 in late adolescence (Grades 10–12). There was limited evidence for same-sex bias during late childhood, varying by sex and race in its pervasiveness or clarity. Interpersonal traits were not generally sex stereotyped. Several interests were sex stereotyped during adolescence, but not those most directly related to academic learning. In general, interests were more strongly sex stereotyped by boys than by girls. Greater cognitive maturity generally attenuated sex stereotyping of interests. Certain developmental trends differed by sex and/or by race, and socioeconomic background (parents" education) influenced developmental trends among Blacks but not among Whites. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
74.
Polyamidoamine (PAMAM) dendrimers were modified and tested for use as solution-phase diffusion probes in silica nanostructures. In order for the successful application of dendrimers as solution-phase probes, their interactions with silica surfaces must be understood and controlled, so that the motion of the probe is not influenced by adsorption. Adsorption/desorption kinetics of PAMAM dendrimers and their diffusion in solution near silica surfaces were investigated with total internal reflection fluorescence correlation spectroscopy (TIR-FCS). Dendrimers of generations 3, 5, and 7 were dye-labeled with carboxyrhodamine 6G. Because PAMAM dendrimers are positively charged in solution (having primary amines as end groups), significant adsorption of these molecules to the negatively charged silica surface was observed. Adsorption/desorption rates and the equilibrium constant for adsorption were determined by fitting the autocorrelation functions to a kinetic model. The desorption rate decreases and the absorption equilibrium constant increases with higher dendrimer generation. To reduce the adsorption of these probes to silica surfaces, the labeled dendrimers were reacted with succinic anhydride, converting the primary amine end groups to negatively charged carboxylic acid groups. These carboxylated dendrimers did not detectably adsorb to silica from aqueous solution. TIR-FCS was used to determine their free-solution diffusion constants near silica surfaces, and the corresponding hydrodynamic radii compare favorably with values reported from forced Rayleigh scattering measurements.  相似文献   
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Due to their widespread use in agriculture as well as in urban areas, agricultural chemicals are globally some of the most commonly encountered substances in waters. The objective of this study is to develop (including preparation and characterization) a new modified release system for the herbicide atrazine, employing poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) microspheres. The microspheres were prepared by the emulsification/solvent evaporation method, emulsifying an organic phase (atrazine and PHBV dissolved in chloroform) into an aqueous phase containing polyvinyl alcohol (PVA) as surfactant, under stirring, and then evaporating the solvent. A 24-1 fractional factorial design, investigating the influence of four variables at two levels, was performed to obtain formulations with optimized association efficiencies. There was a greater dependence of association efficiency on PVA concentration (negative) and the mass of polymer (positive) with lesser influence of both stirring speed and organic phase volume. The size of the particles was assessed using scanning electron microscopy, which showed that the particles were rough-surfaced spheres. The results obtained are promising, since the formulations presented encapsulation efficiency near 25% and the release kinetics profile of atrazine was altered when it was encapsulated in the microparticles, indicating that these systems may be efficient in reducing the environmental impact caused by the herbicide, hence making it safer to use.  相似文献   
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78.
The effects of red cactus pear encapsulation using spray drying with soluble fiber were evaluated. Cactus pear juice was mixed with 15, 22.5, or 30% soluble fiber and dried at 160, 180, or 200°C. Juice showed high levels of polyphenols, quercetin, kaempferol, isoharmetin, betacyanins, betaxanthins, and a high antioxidant activity. Increased soluble fiber amounts significantly (p<0.05) increased the pH, aw, water solubility index (WSI), L*, and b* values. Levels of polyphenols and betacyanins decreased significantly (p<0.05) as the soluble fiber content and the drying temperature increased, respectively. Encapsulation at 160°C and 22.5% of soluble fiber yielded good physical properties and high bioactive compounds. Microscopic analysis showed spherically shaped capsules, the shape was affected by the concentration of added soluble fiber. Low soluble fiber concentrations were associated with more collapsed capsules. Soluble fiber for encapsulating cactus pear resulted in a powder with good properties that can be used as a food ingredient.  相似文献   
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80.
This study describes the enrichment of wheat bread with hard-to-cook black bean (BBEF) and cowpea (CEF) extruded flours. Breads containing 10% BBEF and 10% CEF presented increase of, respectively, 9% and 10% in protein content. In addition the fiber content was 2.6 higher in 10% BBEF bread and 2.2 higher in 10% CEF bread in comparison with standard bread. Despite protein and fiber increasing, the energetic value of substituted breads remained unchanged. An increase in the substitution to 15% resulted in decrease of specific volume and density of the breads. Results of sensory analysis to 10% BBEF bread presented overall appearance scores higher than standard bread and overall flavor acceptance very similar to standard. A total of 10% CEF bread presented similar appearance to those standard bread and 73% overall flavor acceptance. It is interesting to point out that distribution of 10% CEF bread overall flavor scores showed 3 distinct levels of consumer's sensibility. Practical Application: Breads enriched with extruded bean flours presented fiber and protein content improved and a very good consumer's acceptance. These results indicate that extruded bean flours constitute ingredients nutritionally and economically viable for technological application in breads elaboration, conferring improvement of nutritional characteristics without changing sensory attributes.  相似文献   
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