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1.
A novel technique for both online and offline computation is presented. With this technique, a reconstruction analysis in elementary particle physics, otherwise prohibitively long, has been accomplished. It will be used online in an upcoming Fermilab experiment to reconstruct more than 100000 events per second and to trigger on the basis of that information. The technique delivers 40 gigaoperations per second, has a bandwidth on the order of gigabytes per second, and has a modest cost. An overview of the program, details of the system, and performance measurements are presented  相似文献   
2.
Efficiency is a term generally used to determine how well a system performs. However, efficiency can have different meanings and, unaccompanied by a formal definition or taken out of context, can lead to serious misconceptions. In many official publications, efficiency is calculated as the ratio of useful output to energy input. This measure reflects the first law of thermodynamics (conservation of energy) but does not reflect the potential for improvement. A better measure, that also reflects the second law of thermodynamics, is the ratio of the potential useful (exergy) output to the potential useful (exergy) input. We estimate second law efficiencies for the inorganic and organic chemical industries to be 29% and 35% respectively. We also estimate the efficiency of the U.S. industry sector as a whole to be 37.6%, as compared to only 7.7% for the overall U.S. economy. These figures are far lower than the "first law" figures published by the U.S. Department of Energy (80% for industry and 42.5% overall) and they imply a significant potential for improvement.  相似文献   
3.
Dynamic core–shell nanoparticles have received increasing attention in recent years. This paper presents a detailed study of Au–Hg nanoalloys, whose composing elements show a large difference in cohesive energy. A simple method to prepare Au@Hg particles with precise control over the composition up to 15 atom% mercury is introduced, based on reacting a citrate stabilized gold sol with elemental mercury. Transmission electron microscopy shows an increase of particle size with increasing mercury content and, together with X‐ray powder diffraction, points towards the presence of a core–shell structure with a gold core surrounded by an Au–Hg solid solution layer. The amalgamation process is described by pseudo‐zero‐order reaction kinetics, which indicates slow dissolution of mercury in water as the rate determining step, followed by fast scavenging by nanoparticles in solution. Once adsorbed at the surface, slow diffusion of Hg into the particle lattice occurs, to a depth of ca. 3 nm, independent of Hg concentration. Discrete dipole approximation calculations relate the UV–vis spectra to the microscopic details of the nanoalloy structure. Segregation energies and metal distribution in the nanoalloys were modeled by density functional theory calculations. The results indicate slow metal interdiffusion at the nanoscale, which has important implications for synthetic methods aimed at core–shell particles.  相似文献   
4.
This paper describes three novel displacement‐based formulations for the analysis of composite beams with a flexible connection which is capable of deforming along the longitudinal axis of the member as well as vertically, i.e. transverse to the interface connection. For completeness, the analytical model which forms the basis of the proposed modelling technique is presented in both its weak and strong forms. The three novel finite element formulations are derived and tested using different structural systems; their nodal freedoms include the vertical and axial displacements as well as the rotations at each element end of both layers. Curvature locking problems are observed to occur for one of these elements and the origin of this behaviour is demonstrated analytically. Two applications are then proposed adopting a bi‐linear constitutive relationship for the vertical interface connection to reflect the more realistic case in which, already in the linear‐elastic range of the materials forming the cross‐section and of the longitudinal interface connection, two vertical connection stiffnesses are required, i.e. one to model the event of separation between the layers and one when one bears against the other one. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
5.
Conducted an empirically based study in which the judgments of experts were used to identify the theoretical/methodological structure of the field of personality and social psychology, as well as the core "interest communities" extant in these disciplines. The similarities of figures prominent in the history of the field were judged by 16 of the American Psychological Association's Division 8 (Society of Personality and Social Psychology) Fellows. Multidimensional scaling of these similarity judgments revealed 3 general dimensions along which the figures varied: synthetic vs analytic, internal vs external determinants of behavior, and prominence. An alternate view of the field was provided by a taxonomic scheme in which the figures were grouped along major ideological, substantive, and methodological lines. The following 5 contemporary interest communities were identified from the self-characterizations of the Fellows: (a) psychoanalysis and psychiatry, (b) modern personality theory, (c) measurement and individual differences, (d) sociology, and (e) social psychology. Statements of implications for future directions in the field were also obtained from Ss. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
In a digital toll switching office a digital multifrequency (MF) receiver may be more economical than the present analog MF receiver. This paper suggests an algorithm that could be used for digital implementation of such a receiver. The algorithm employs discrete Fourier transform and leads to more efficient design than a system using second-order digital bandpass filters. The presented results of computer simulation of the digital MF receiver employing this method indicate satisfactory performance and good immunity to random noise interference.  相似文献   
7.
8.
Genetic parameters of milk, fat, and protein yields were estimated in the first 3 lactations for registered Tunisian Holsteins. Data included 140,187; 97,404; and 62,221 test-day production records collected on 22,538; 15,257; and 9,722 first-, second-, and third-parity cows, respectively. Records were of cows calving from 1992 to 2004 in 96 herds. (Co)variance components were estimated by Bayesian methods and a 3-trait-3-lactation random regression model. Gibbs sampling was used to obtain posterior distributions. The model included herd × test date, age × season of calving × stage of lactation [classes of 25 days in milk (DIM)], production sector × stage of lactation (classes of 5 DIM) as fixed effects, and random regression coefficients for additive genetic, permanent environmental, and herd-year of calving effects, which were defined as modified constant, linear, and quadratic Legendre coefficients. Heritability estimates for 305-d milk, fat and protein yields were moderate (0.12 to 0.18) and in the same range of parameters estimated in management systems with low to medium production levels. Heritabilities of test-day milk and protein yields for selected DIM were higher in the middle than at the beginning or the end of lactation. Inversely, heritabilities of fat yield were high at the peripheries of lactation. Genetic correlations among 305-d yield traits ranged from 0.50 to 0.86. The largest genetic correlation was observed between the first and second lactation, potentially due to the limited expression of genetic potential of superior cows in later lactations. Results suggested a lack of adaptation under the local management and climatic conditions. Results should be useful to implement a BLUP evaluation for the Tunisian cow population; however, results also indicated that further research focused on data quality might be needed.  相似文献   
9.
Used cooking oil (UCO) is a domestic waste generated daily by food industries, restaurants, and households. It is estimated that in Europe 5 kg of UCO are generated per inhabitant, totalling 2.5 million metric tons per year. Recovering UCO for the production of biodiesel offers a way of minimizing and avoiding this waste and related pollution. An exergy analysis of the integrated waste management (IWM) scheme for UCO is used to evaluate such a possibility by accounting for inputs and outputs in each stage, calculating the exergy loss and the resource input and quantifying the possible improvements. The IWM includes the collection, pretreatment, and delivery of UCO and the production of biodiesel. The results show that the greatest exergy loss occurs during the transport stages (57%). Such exergy loss can be minimized to 20% by exploiting the full capacity of collecting vans and using biodiesel in the transport stages. Further, the cumulative exergy consumption helps study how the exergy consumption of biodiesel can be further reduced by using methanol obtained from biogas in the transesterification stage. Finally, the paper discusses how increasing the collection of UCO helps minimize uncontrolled used oil disposal and consequently provides a sustainable process for biodiesel production.  相似文献   
10.
Caffeine is the most widely studied psychoactive molecule in history due to its many pharmacological activities and a high number of biological and physiological effects. In literature, there is a great number of applications that describe extraction, identification, and quantification of caffeine in foods and beverages. For this purpose, an extraction step is followed by an analytical technique for the identification and quantification of caffeine. This work proposes an innovative method in which sample preparation, separation, and detection steps are unified in a single step. To the best of our knowledge, this is the first report on the determination of caffeine in coffee, tea, and cocoa by means of an online extraction coupled to a liquid chromatographic system equipped with a photodiode array detector. The developed methodology was validated in terms of sensitivity, detection limits, accuracy, and precision. The advantages of this technique are (i) a significant reduction of analysis time (more than 70%) and of solvents used (the extraction step is integrated in the chromatographic analysis), (ii) the whole procedure is thus completely automated drastically reducing possible operator errors to occur, and (iii) easily realized by using a conventional monodimensional liquid chromatography system.  相似文献   
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