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991.
Lee Casalena Ashley N. Bucsek Darren C. Pagan Garrison M. Hommer Glen S. Bigelow Mark Obstalecki Ronald D. Noebe Michael J. Mills Aaron P. Stebner 《Advanced Engineering Materials》2018,20(9)
992.
Mills K.L. Gomaa H. 《IEEE transactions on pattern analysis and machine intelligence》2002,28(3):228-255
This paper describes a knowledge-based approach to automate a software design method for concurrent systems. The approach uses multiple paradigms to represent knowledge embedded in the design method. Semantic data modeling provides the means to represent concepts from a behavioral modeling technique, called Concurrent Object-Based Real-time Analysis (COBRA), which defines system behavior using data/control flow diagrams. Entity-relationship modeling is used to represent a design metamodel based on a design method, called COncurrent Design Approach for Real-Time Systems (CODARTS), which represents concurrent designs as software architecture diagrams, task behavior specifications and module specifications. Production rules provide the mechanism for codifying a set of CODARTS heuristics that can generate concurrent designs based on semantic concepts included in COBRA behavioral models and on entities and relationships included in CODARTS design metamodels. Together, the semantic data model, the entity-relationship model, and the production rules, when encoded using an expert system shell, compose CODA, an automated designer's assistant. CODA is applied to generate 10 concurrent designs for four real-time problems. The paper reports the degree of automation achieved by CODA. The paper also evaluates the quality of generated designs by comparing the similarity between designs produced by CODA and human designs reported in the literature for the same problems. In addition, it compares CODA with four other approaches used to automate software design methods 相似文献
993.
This paper presents results obtained in determining the residence time distribution (RTD) characteristics of the solid and liquid phases in a laboratory column and two industrial columns using radioactively labelled solid and liquid tracers. The dispersion model is shown to be superior to other models in describing the RTD in columns with diameter between 10cm and 150cm. Smaller diameter columns can be modelled using either the dispersion model or the tanks-in-series model and larger columns can be modelled using the latter model. Feed and gangue material produce similar tailings age distribution curves. The solid dispersion coefficient is larger than the liquid dispersion coefficient. The solid dispersion coefficient increases with increasing particle size in the laboratory column but remains constant with increasing particle size in the large columns. A modified correlation is proposed to predict the solid dispersion coefficient in large columns. 相似文献
994.
Rapid development of wind capacity in the United States has been coupled with a concern that increasing wind capacity will require substantial transmission infrastructure. This report summarizes the implied transmission cost per kW of wind from a sample of 40 transmission studies. This sample of studies, completed from 2001 to 2008, covers a broad geographic area across the U.S. The primary goal in the review is to develop a better understanding of the transmission costs needed to access increasing quantities of wind generation. A secondary goal is to gain a better appreciation of the differences in transmission planning approaches, in order to identify those methodologies that seem most able to estimate the incremental transmission costs associated with wind development. The total range in transmission costs per kW of wind implicit in the study sample is vast - ranging from $0/kW to over $1500/kW. The median cost of transmission from all scenarios in the sample is $300/kW, roughly 15-20% of the cost of building a wind project. The median cost of transmission is near the upper end of the range implied by two higher-level assessments of transmission required to provide 20% wind electricity in the U.S. by 2030. 相似文献
995.
George A. Asare Genevieve O. Okyere Matilda Asante Charles A. Brown Sheila Santa Bernice Asiedu 《Journal of food science》2013,78(12):T1948-T1951
Red palm oil produced in Ghana largely by village folks has never been tested for its mutagenic potential. The study aimed at determining the mutagenicity of high‐energy heated red palm oil (RRPO) and refined, bleached imported palm oil (PO) on the Ghanaian market. Samples of RRPO and PO were 1× and 5× heated for 10 min at 180 °C with a cooling period of 5 h in‐between. Unheated, together with heated samples, were tested for mutagenicity using Salmonella typhimurium TA 98 and TA 100 tester stains. Unheated PO was negative for the Ames mutagenicity test with TA 98 strain. However, 1× and 5× heated PO were mutagenic (P = 0.05, each). Testing PO, using TA 100 strain was negative. RRPO was mutagenic with TA 98 strain for heated oils (P = 0.05, each). Assays with TA 100 strain showed highly significant mutations (P = 0.001, each) that increased with increasing heating frequency. PO 1× and 5× heated samples caused significant frameshift mutation in the S. typhimurium TA 98 strain. RRPO caused highly significant point and frameshift mutations in heated samples. Furthermore, unheated RRPO mutagenic potential has serious health implications. 相似文献
996.
Adaptations of in vitro incorporation of gluconeogenic substrates into glucose and adaptations of metabolite concentrations of liver to subcutaneous phlorizin and dietary 1,3-butanediol were examined for liver samples from dairy steers. Later, the same adaptations were examined after 6 days of feed restriction. Feeding 1,3-butanediol significantly decreased conversion of carbon-14 of lactate and propionate to glucose and to carbon dioxide. There were no changes of concentrations of hepatic glycogen or triglyceride, and increases were only minor for beta-hydroxybutyrate concentration. Both phlorizin, with or without 1,3-butanediol, and feed restriction significantly increased rates of carbon incorporation into glucose from aspartate, lactate, and propionate but did not change rates of oxidation to carbon dioxide. Phlorizin had no effect on hepatic glycogen or triglyceride concentrations, but feed restriction decreased liver glycogen and increased triglyceride concentrations. Changes associated with either phlorizin treatment or feed restriction are consistent with a decreased ratio of insulin to glucagon of blood plasma. When combined, phlorizin and 1,3-butanediol seem to have some utility for developing a ketosis model. 相似文献
997.
Polybrominated diphenyl ethers in the sediments of the Great Lakes. 1. Lake Superior 总被引:7,自引:0,他引:7
Song W Ford JC Li A Mills WJ Buckley DR Rockne KJ 《Environmental science & technology》2004,38(12):3286-3293
Sediment cores were taken in 2001 and 2002 in Lake Superior at six locations away from lakeshores and segmented at 0.5-5 cm intervals. The year of sediment deposition was estimated for each segment of four cores using the 210Pb dating technique. Samples were Soxhlet-extracted and cleaned up by silica gel fractionation, and the concentrations of 10 polybrominated diphenyl ethers (PBDEs) and 19 polychlorinated biphenyls (PCBs) were measured by GC-MS in SIM mode. In contrast to recent declining or level-off trends in PCB fluxes, the sedimentary records of PBDEs generally show a significant increase in recent years. The load of total PBDEs to Lake Superior was estimated to be 2-6 metric tons, and the current loading rate was about 80-160 kg yr(-1). With the exclusion of decabromodiphenyl ether (BDE209), the surficial concentration of sumPBDE (sum of 9 congeners) ranged from 0.5 to 3 ng g(-1), and the current sumPBDEs flux was 8-31 pg cm(-2) yr(-1). The concentrations of BDE209 were about an order of magnitude higher than the sum of other congeners, comprising 83-94% of the total PBDE inventory in the sediments. Among the other nine PBDEs detected, congeners 47 and 99 were the most abundant, and congeners 100, 153, 154, and 183 were also detected in all the cores. Congener analysis demonstrated that the pattern of PBDEs in Lake Superior sediments differs from those in air and fish. 相似文献
998.
Chopped barley forage was ensiled untreated or treated with several doses (1 x 10(5) to 1 x 10(6) cfu/g of fresh forage) of Lactobacillus buchneri 40788 in laboratory silos and untreated or treated (4 x 10(5) cfu/g) in a farm silo. Silage from the farm silos was fed to lactating cows. In the laboratory silo, the effects of inoculation on fermentation and aerobic stability were also compared to silage treated with a commercial inoculant and a buffered propionic acid additive. Inoculation with L. buchneri 40788 decreased the final concentrations of lactic acid but increased concentrations of acetic acid and ethanol in silage from laboratory and farm silos. Silages stored in laboratory silos did not heat after exposure to air for 7 d and were then mixed with alfalfa silage and a concentrate to form total mixed rations (TMR) that were further exposed to air. The TMR containing silages treated with L. buchneri 40788 or a buffered propionic-acid-based additive took longer to heat and spoil than the TMR containing untreated silage or silagetreated with the commercial inoculant. Silage stored in a farm silo and treated with L. buchneri 40788 had fewer yeasts and molds than did untreated silage. Aerobic stability was greater in treated silage alone and in a TMR containing treated silage. Dry matter intake (18.6 kg/d), milk production (25.7 kg/d), and milk composition did not differ between cows fed a TMR containinguntreated or treated silage. These findings show that L. buchneri can improve the aerobic stability of barley silage in laboratory and farm silos and that feeding treated silage had no negative effect on intake or performance. 相似文献
999.
A nonparametric method based on nonparametric impulse response (IR) models is applied to the control system design of a two-degree-of-freedom direct drive manipulator. Linearized models of the manipulator system are obtained by a direct test method and are in the form of nonparametric IRs. The controllers are also represented by nonparametric IR models, and are implemented as finite-impulse response (FIR) digital filters. Satisfactory control performance is achieved in the experimental verification of the non-parametric designs. 相似文献
1000.
J Koreska E P Schwentker A M Albisser D A Gibson R H Mills 《Medical instrumentation》1978,12(1):59-63
Present methods of obtaining spine radiographs for the clinical assessment of scoliosis are inadequate. Routine quantitative measurements made on anterior-posterior (A-P) and lateral radiographs describing the spinal deformities are grossly inaccurate since they are two-dimensional measurements of three-dimensional deformities. The approach described in this paper uses a simple device, the "Throne," which ensures reproducible positioning of patients for sitting spine radiographs as well as exact orthogonality of A-P and lateral film exposures. These two views of the spine form the data in digitized form for input into a computer program which generates the 3-D geometry of the line passing through the centers of each vertebral body from L5 to T1. Parameters describing the 3-D deformities of the spine are calculated automatically and converted to printed form for detailed examination and to plotted form for clinical use. Approximately 80 postambulatory Duchenne muscular dystrophy patients are being followed using this method. Of these, 20 have been followed for periods of 2 to 3 years. Costs of the method are minimal. The "Throne" can be built for approximately $50 of materials and 30 hours of labor. Each set of A-P and lateral radiographs can be processed in less than 5 minutes, including digitizing time at a computer cost of about 50 cents. The computer program may be handled by a minicomputer. 相似文献