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11.
The analysis of five independent isolates of Kluyveromyces lactis shows that CBS 2359, CBS 683 and CBS 4574 could grow in the presence of mitochondrial inhibitors (antimycin A, oligomycin or erythromycin) and that CBS 2360 and CBS 141 were unable to grow in the presence of drugs. The resistant growth was observed only on glucose and not on other fermentable carbon sources (galactose, lactose). The phenotype 'growth on glucose in the presence of mitochondrial inhibitors' was called Rag+. This phenotype was found to be controlled by two unlinked nuclear genes: RAG1 and RAG2. Either of their recessive alleles, rag1 and rag2, led to the Rag- phenotype (i.e. the failure of growth on glucose in the presence of antimitochondrial drugs). Rag- strains represent the case in which fermentative growth becomes absolutely dependent on the functioning of the normal respiratory chain.  相似文献   
12.
The Remote Didactic Laboratory Laboratorio Didattico Remoto - LA.DI.RE. ldquoG. Savastanordquo is the e-learning measurement laboratory supported by the Italian Ministry of Education and University. It involves about 20 Italian universities and provides students of electric and electronic measurement courses with access to remote measurement laboratories delivering different didactic activities related to measurement experiments. In order to demonstrate the versatility for didactic use, the overview of some experiments is given. The didactic experiments summarized in this paper concern measurement characterization of instruments and communication systems, measurement devices for remote laboratories, basic electrical measurements, magnetic measurements, electromagnetic-interference measurements, and signal processing for measurement applications.  相似文献   
13.
A preliminary study of an adaptive unmanned aerial vehicle (UAV) wing actuated by shape memory alloy (SMA) devices is presented. The wing consists of a sandwich box substructure, flexible ribs, and a flexible laminated skin. The adaptation capability to the changing flight conditions is obtained via airfoil shape adjustments. Torsion SMA tubes are employed for wing camber control, while levers powered by SMA wires are employed for local shape control. A new architecture is proposed: the downward or upward actuation torque is provided by counterrotating concentric tubes connected through a clutch and a positioning piezoelectric motor to the flexible ribs. These actuator tubes are heated one at a time while the other is made free by the clutch in order to obtain any wanted shape without waiting for cooling. The capability of the wing to bear the aerodynamic loads, the power required by the actuators, and their force and torque are assessed by finite-element simulations. An improved version of a recently developed element is employed that accurately and efficiently captures stresses and deformations in the composite structure. The wing requires a peak power of 1,223 W that is compatible with the UAV considered here, i.e., with a maximum take-off weight of 1,000 kg and jet engine. It can smoothly deform with a camber mean rotation of 22° and rotation at the tip of 40° with a load factor of 5, a differential camber rotation of 10°, and a profile variation from 40 to 55% of the chord (4.5% increase and 3.9% decrease of thickness) at cruise speed.  相似文献   
14.
A multiobjective optimization problem involves multiple objectives, often conflicting, to be met or optimized. A Pareto front provides a set of best solutions to determine the trade-offs between the various objectives. New evolutionary approaches demonstrated its ability to build well-delineated Pareto fronts in diverse multiobjective optimization problems, including multicriteria optimization in job shop scheduling with regular and nonregular objective functions. Good parameter settings and appropriate representations can enhance the behavior of an evolutionary algorithm. The present article shows a study of the influence of distinct parameter combinations as well as different chromosome representations. Details of implementation and results are discussed.  相似文献   
15.
An in vitro synergism between different inducers of AML cell differentiation has been previously observed. Therefore, we treated 53 myelodysplastic (MDS) patients with a low dose combination of cis-retinoic acid (cRA, 20-40 mg/day) and 1,25 alpha (OH)2 cholecalciferol [(OH)2D3, 1-1.5 micrograms/day] +/- intermittent 6-thioguanine (30 mg/m2/day). The latter was reserved for patients with bone marrow (BM) blast excess (> or = 5%). The treatment was well tolerated, without major toxicity. Among 25 patients with BM blasts less than 5%, we observed one complete, eight partial and four minor responses (response rate 52%) with a median response duration of 8 months (2 +/- 24). Median survival, which did not correlate with response, is projected at 76 months. Thirty-one patients with BM blast excess (> or = 5%), including three of the previous group who progressed to refractory anemia with excess of blasts (RAEB), were treated with the three-drug protocol. One complete, 12 partial and six minor responses were obtained (response rate 61%) with a median response duration of 6 months (2-29+). A significant difference in survival (P < 0.005) was observed between the 19 responders (median 25 months) and the 12 non-responders (median 9 months). A reduction in the transfusion need was observed in 41% of the transfusion-dependent patients with blast excess and in 53% of those without blast excess. Therefore, combined differentiating therapy seems more effective than previously reported single agent treatments and should be considered for a larger randomized study to assess its actual impact on survival of MDS patients.  相似文献   
16.
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   
17.
In a trigeneration plant, the thermal energy recovered from the prime mover is exploited to produce a cooling effect. Although this possibility allows the working hours of the plant to be extended over the heating period, providing summer air conditioning through thermally activated technologies, it is rather difficult to find in the literature experimental data on trigeneration plants operation, and the availability of performance characteristics at off‐design conditions is anyway limited. The paper has the aim of showing the experimental data of a real trigeneration system installed at the Politecnico di Torino (Turin, Italy), composed of a natural gas 100 kWel microturbine coupled to a liquid desiccant system. The data are presented for both cogeneration and trigeneration configurations, and for full and partial load operations. An energetic and economic performance assessment at rated power operation is presented, and compared with the partial load operation strategy. The primary energy savings are calculated through a widely accepted methodology, proposed by the European Union, and through another methodology, reported in literature, which seems to the Authors more suitable to describe the energetic performances of trigeneration plants. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
18.
Laser writing attached many attentions for fabrication micro-channels in microfluidics devices and lab-on-chip devices for biomedical applications. In this study, micro-channels were fabricated on different materials as masters using nanosecond diode-pumped solid state (DPSS) laser writing for imprinting on glass and polymer microfluidics devices. Good quality microstructures were fabricated on silicon, nickel alloy, cooper/brass and alumina, respectively by laser writing which proved that the nanosecond DPSS laser is suitable for rapid prototyping and rapid manufacturing of surface microstructures on different substrates as mask-less exposure system of imprinting.  相似文献   
19.
A new error model for a special class of multiport vector network analyzers (VNAs) is presented in this paper. This model can be applied to multiport network analyzers with noncomplete reflectometers, i.e., when the measurement of the incident waves at each port is not always available. The method used to compute the error coefficients proposed here is based on a compact and easy formulation. This method is an extension of the already existing general theory for complete reflectometer multiport network analyzers. Furthermore, the new error model generalizes the theory for three-sampler two-port VNAs. The proposed model has been tested against the complete reflectometer one and exhibits the same accuracy level.  相似文献   
20.
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