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1.
Performance of simple response method for the establishment and adjustment of calibration intervals 总被引:1,自引:0,他引:1
Managing calibration intervals in order to fulfill requirements of quality-oriented organizations is discussed in this paper. In particular, the simple response method is considered. According to this technique, the interval between successive calibrations is adjusted adaptively on the basis of the outcome of the last calibration process. An original analysis is presented about the properties of such calibration interval handling methods. Finally, directions are given on how to tune its parameters optimally, in order to meet desired levels of long-term measurement reliability. 相似文献
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Carbone P. Narduzzi C. Petri D. 《IEEE transactions on instrumentation and measurement》1994,43(2):139-145
The consequences of dithering on nonlinear quantizers are analyzed. A model of the nonlinear quantizer is considered, and a model of the same quantizer with dither is proposed. By means of this approach, relationships are given for the total quantization error in the case of discrete binary, uniform, and Gaussian dither signals 相似文献
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Ca2+ channels diversity of cultured rat embryo motoneurons was investigated with whole-cell current recordings. In 5-20 mM Ba2+, the whole-cell currents were separated in low- (LVA) and high-voltage-activated (HVA) current. The LVA current was evident since the first day in culture, while the HVA component was small and increased with time. Recordings after 4 days revealed approximately 20% L-, approximately 45% N- and approximately 35% P- and R-type currents. P-type currents were revealed only in 40% of motoneurons, in which 20-200 nM omega-Aga-IVA caused 20% irreversible block of total current. The remaining 60% of cells were insensitive even to higher doses of the toxin (500 nM in 5 mM Ba2+), suggesting weak expression and heterogeneous distribution of P-type channels compensated by high densities of HVA Ca2+ channels resistant to all the antagonists (R-type). A significant residual current could also be resolved after prolonged applications of 5 microM omega-CTx-MVIIC, which allowed separation of N- and P-type currents by the distinct onset of toxin block. The antagonists-resistant current reveals biophysical characteristics typical of HVA channels, but distinct from the alphaE channel. The current activates around -20 mV in 20 mM Ba2+; inactivates slowly and independently of Ca2+; is blocked by low [Cd2+] and high [Ni2+]; and is larger with Ba2+ than Ca2+. The uncovered R-type calcium current can account for part of the presynaptic Ca2+ current controlling neurotransmitter release at the mammalian neuromuscular junction whose activity is resistant to DHP-and omega-CTx-GVIA, and displays anomalous sensitivity to omega-Aga-IVA and omega-CTx-MVIIC. 相似文献
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Alysson Leandro Ribeiro Rattes 《Powder Technology》2007,171(1):7-14
This paper reports the preparation and characterization of sustained release sodium diclofenac microparticles by spray drying. Aqueous dispersions of ethyl cellulose (Surelease®) and Eudragit RS 30 D® were evaluated as controlled release polymers. The product properties (product moisture, size distribution, particle morphology, flow properties, total drug load, in-vitro dissolution studies, and encapsulating efficiency) were determined as a function of inlet temperature of the spray drying, the feed flow rate and composition of the microencapsulating formulation. In general, lower values of the product moisture content were observed at higher drying temperatures. The spray-dried product was composed mainly by rounded-shape and multi-size particles. The mean particle diameters of the Eudragit based microparticles tended to be slight bigger than the Surelease based microparticles. The spray dried microparticles showed delayed drug dissolution rates, sustaining the drug release for several hours. These findings confirm the feasibility of the spray drying for preparation of microparticles with sustained release properties. The physical and chemical properties of the microparticles can be changed by varying the spray drying parameters as well as the microencapsulating formulation. 相似文献
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André J. Torii Rafael H. Lopez Leandro F. F. Miguel 《Structural and Multidisciplinary Optimization》2016,54(2):289-299
Truss optimization based on the ground structure approach often leads to designs that are too complex for practical purposes. In this paper we present an approach for design complexity control in truss optimization. The approach is based on design complexity measures related to the number of bars (similar to Asadpoure et al. Struct Multidisc Optim 51(2):385–396 2015) and a novel complexity measure related to the number of nodes of the structure. Both complexity measures are continuously differentiable and thus can be used together with gradient based optimization algorithms. The numerical examples show that the proposed approach is able to reduce design complexity, leading to solutions that are more fit for engineering practice. Besides, the examples also indicate that in some cases it is possible to significantly reduce design complexity with little impact on structural performance. Since the complexity measures are non convex, a global gradient based optimization algorithm is employed. Finally, a detailed comparison to a classical approach is presented. 相似文献
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Leandro Madrazo 《Digital Creativity》2013,24(2):73-90
Abstract The course SDR: Sistemas de Representación(Systems of Representation), is the last stage of a line of work which has the objective of integrating information technologies in the education of architecture in a meaningful way. A distinctive mark of this pedagogic approach has been to look upon computer technology as an opportunity to rethink the methods, contents and goals of architecturaleducation,in thelight of contemporary culture. The course is structured in six themes, each one standing for a ‘system of representation’: ‘text’, ‘figure’, ‘object’, ‘image’, ‘space’ and ‘light’. Within every system, a variety of issues dealing with the concept of ‘representation’ are addressed in an interdisciplinary manner. It is a compulsory course lasting three semesters, in the second and third year of a five-year architectural program. It has been offered since the academic year 1999/2000. 相似文献
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