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31.
Simulating Microstructural Evolution and Electrical Transport in Ceramic Gas Sensors 总被引:1,自引:0,他引:1
Yunzhi Wang Yuhui Liu Cristian Ciobanu Bruce R. Patton 《Journal of the American Ceramic Society》2000,83(9):2219-2226
An integrated computational approach to microstructural evolution and electrical transport in ceramic gas sensors has been proposed. First, the particle-flow model and the continuum-phase-field method are used to describe the microstructural development during the sintering of a prototype two-dimensional film. Then, the conductivity of the sintering samples is calculated concurrently as the microstructure evolves, using both resistor lattice models and effective medium theory for electrical transport in porous aggregates of lightly sintered particles. This approach, when combined with the modeling of resistivity at the grain–grain contacts as a function of neck geometry, ambient gas concentration and temperature, could facilitate the development and optimization of novel microstructures for advanced ceramic gas sensors. 相似文献
32.
We report the copolymerization of a flexible aliphatic-bridged bisphenol-based benzoxazine monomer comprising ten methylene units (BZ(10)BA) with two rigid benzoxazine monomers (commercially available Araldite 35600 and 35900) via a solvent-free cationic ring-opening polymerization process. The effects of monomer feed composition on polymerization behavior, thermomechanical transitions, and thermal degradation properties are reported. DSC of the ring-opening copolymerizations showed that the copolymerization behavior – in terms of polymerization onset temperature and total exothermic transition – depend greatly on the composition of the monomer feed. Samples containing larger concentrations of BZ(10)BA exhibited higher onset temperatures with lower polymerization enthalpies. The thermomechanical properties of the copolybenzoxazine networks, as evaluated by DMA, show a strong dependence on the monomer feed ratio, where higher Araldite content resulted in a higher Tg of the network. The most salient feature of benzoxazine copolymerization was revealed in the tailorability in thermomechanical properties, which were varied by 149 °C simply by changing the monomer feed ratio and the Tg was observed to be accurately predicted using the Fox equation. 相似文献
33.
Zaslow Martha J.; Weinfield Nancy S.; Gallagher Megan; Hair Elizabeth C.; Ogawa John R.; Egeland Byron; Tabors Patton O.; De Temple Jeanne M. 《Canadian Metallurgical Quarterly》2006,42(1):27
This study examined predictions from preschool parenting measures to middle childhood cognitive and socioemotional child outcomes to explore whether parenting assessment methodologies that require more time, training, and expense yield better predictions of child outcomes than less intensive methodologies. Mother-child dyads (N=278) in low-income African American families were assessed when the child was in preschool, using maternal report, the Home Observation for Measurement of the Environment-Short Form (P. Baker & F. Mott, 1989; R. Bradley & B. Caldwell, 1984), and structured observational measures of parenting. Child outcomes reported by children, mothers, teachers, and direct assessment were collected 4 years later. All parenting methodologies showed some predictive value; however, observational parenting measures showed the strongest and most consistent predictions of child outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
34.
Genetic polymorphism in a mucin of the human milk fat globule arises from variable numbers of a tandemly repeated amino acid sequence. As a consequence, the gene from each parent expresses a variable-sized protein. This is manifest on SDS gels in the form of either one or, more often, two protein bands, which differ among individuals in mobility. Evidence of such polymorphism in the bovine mucin, PAS-I, was first obtained from Holstein milk samples. The objective of this study was to evaluate the other major dairy breeds for polymorphism of their PAS-I. Milk samples from individual Jerseys, Guernseys, Ayrshires, and Brown Swiss were analyzed by SDS-PAGE. Bands of the mucin varying in number and mobility were seen in samples from all four breeds. In three of the breeds (Ayrshire, Brown Swiss, and Jersey), there was evidence that two alleles for PAS-I may have become predominant, possibly through degeneration in the structure of their tandem repeats, one that gives rise to a faster moving mucin (relative molecular weight 170,000) and the other to a slower form (relative molecular weight 200,000). In contrast, the PAS-I band patterns on SDS gels for both Guernseys and Holsteins were characterized in nearly 50% of samples by two close bands near the 205,000-molecular weight marker. This pattern was never seen in the other three breeds. The findings suggest a genetic kinship among the Ayrshire, Brown Swiss, and Jersey, on the one hand, and between the Holstein and Guernsey, on the other. 相似文献
35.
Baranyi P. Varkonyi-Koczy A.R. Yeung Yam Patton R.J. 《IEEE transactions on instrumentation and measurement》2005,54(1):52-60
One direction of measured data-set based modeling applies fuzzy logic identification tools and results in a fuzzy rule-base model. A typical problem of fuzzy identification methods is that the complexity of the resulting fuzzy rule-base, namely the number of rules in the rule-base, explodes with the modeling accuracy. As a result, the topic of fuzzy rule-base complexity reduction techniques emerged in the last decade. A common disadvantage of fuzzy rule-base complexity reduction methods is that the resulting complexity minimized fuzzy-rule bases cannot be simply adapted to new information. If we have new information that cannot be described by the fuzzy rules of the complexity minimized fuzzy rule-base, then we have two choices. The first choice is to add new fuzzy rules to the fuzzy rule-base until the new information can be described. The second choice is to modify the new information until it can be described by the fuzzy rule-base without using additional fuzzy rules. This second case has the prominent role if the number of fuzzy rules in the fuzzy rule-base is limited. This paper proposes a method for the second choice. The proposed method minimizes the necessary modification of the new information. This paper focuses attention on a recent complexity reduction method, termed Higher Order Singular Value Decomposition (HOSVD)-based complexity reduction, and Takagi-Sugeno (TS) inference operator-based fuzzy rule-bases. An example is used to provide the validation of the proposed method. In order to demonstrate the effectiveness of the proposed method, a control system of a differential-steered automatic guided vehicle is modeled in the paper. 相似文献
36.
A 1-year-old boy presented with pericardial effusion, pulmonary infiltrates, and disseminated intravascular coagulation; lung biopsy indicated pulmonary lymphangiomatosis. He did not respond to medical therapy and was a poor surgical candidate; therefore, he underwent partial splenic embolization. The procedure resulted in a complete disappearance of the DIC and marked improvement in his cardiorespiratory status. He continues to thrive and is transfusion-independent 2 years after the procedure. 相似文献
37.
This paper examines the robustness in modelling uncertainties of an observer-based fault-detection and isolation scheme applied to the industrial actuator benchmark problem. A linear dynamic model is used, and the observer is designed using eigenstructure assignment. Fault detection is achieved with a fixed threshold. The design and test example is an electromechanical system, subject to an actuator fault, a sensor fault and a load disturbance. The paper outlines the design, application, and an evaluation of the robustness of the method. 相似文献
38.
An observer design is proposed for linear systems with time delays. The key to the design is to find a generalized coordinate change such that, in the new coordinates, all the time-delay terms are injected by the system's output. The existence of such a coordinate change is guaranteed by a rank condition on the observability matrix. The novelty of the proposed design is clearly reflected in the multiple-output case, where a dimensional expansion in the coordinate change could become necessary, and hence is allowed 相似文献
39.
绿色高效活性染料酶型皂洗系统——节水、节能、省时 总被引:1,自引:0,他引:1
长期以来,直接、活性、酸性等水溶性染料的湿摩擦牢度因常常不能满足客户要求而一直被人们所关注. 相似文献
40.
JH Patton TC Fabian MA Croce G Minard FE Pritchard KA Kudsk 《Canadian Metallurgical Quarterly》1996,41(2):231-6; discussion 236-7
The efficacy of prophylactic vena caval filters (VCF) in reducing morbidity and mortality from pulmonary embolism (PE) in high-risk trauma patients has been shown, but minimal follow-up data is currently available. VCFs were prophylactically placed in 110 patients between August 1991 and June 1995. There was an early VCF complication rate of 7%. Twenty-two patients died; the remaining 88 patients formed the basis for the follow-up study. Forty-five patients were located and interviewed by phone, and 30 of these patients (34%) returned for evaluation. The mean follow-up time was 18 months (range, 4-42 months). There was no incidence of caval thrombosis on follow-up. Eleven patients had physical findings, and duplex evidence consistent with postphlebitic syndrome. An additional three patients had evidence of old deep venous thrombosis (DVT) by duplex, but no significant symptomatology. VCF are effective in preventing PE related deaths and have few major complications. The long-term morbidity associated with posttraumatic venous thrombosis is significant. This morbidity is related not to PE or VCF, but to the underlying DVT. Improved strategies against DVT are necessary. 相似文献