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231.
Perphosphorylated pentopyranoses and pentofuranoses were synthesized from parent carbohydrates as potential allosteric effectors of hemoglobin (Hb). The construction of seven- and eight-membered cyclic pyrophosphates was also carried out successfully on most of the pentoses. All final compounds were tested for their efficiency on oxygen release from human Hb. Most proved to be efficient allosteric effectors, some of them with an affinity toward Hb and an effect on oxygen release from Hb approaching that of myo-inositol hexakisphosphate, which is one of the most active allosteric effectors of Hb. The efficacy was higher for free phosphates than for pyrophosphates. 相似文献
232.
Alexandros Vavousis Andreas Apostolakis Mihalis Psarakis 《Journal of Electronic Testing》2013,29(6):805-823
The ever increasing adoption of field programmable devices in various application domains for building complex embedded systems based on FPGA processors along with the reliability issues having emerged for FPGA devices built with the latest nanometer technologies, have raised the need for new fault tolerant techniques in order to improve dependability and extend system lifetime. In addition, the runtime partial reconfiguration technology highly mature in the modern FPGA families along with the availability of unused programmable resources in most FPGA designs provide new and interesting opportunities to build advanced fault tolerance mechanisms. In this paper, we exploit the dynamic reconfiguration potential of today’s FPGA architectures and the advances in the related design support tools and we propose a fault-tolerant approach for FPGA embedded processors based on runtime partial reconfiguration. According to the proposed methodology, the processor core is partitioned into reconfigurable modules and each module is duplicated to implement a concurrent error detection mechanism. Precompiled configurations containing spare resources are generated for each duplicated module and are used to repair at runtime the defective modules. Also, a fault tolerance scheme for the proxy logic of the reconfigurable modules, which cannot move in the alternative configurations along with the rest logic, is proposed. Moreover, a compression method for the alternative partial bitstreams, which significantly reduces the high storage space requirements of the proposed approach, is presented. Two different hardware decompression schemes have been implemented in a Virtex-5 device and compared in terms of area overhead and decompression latency. Furthermore, a thorough examination has been performed, regarding how the percentage of the spare resources and their allocation in the reconfigurable regions affect the compression efficiency and the processor performance. Finally, the proposed approach has been demonstrated in three different components – ALU, multiplier-accumulator, and instruction-fetch unit – of an open-source embedded processor. 相似文献
233.
Alexandros Bartzas Author Vitae Christophe Poucet Author Vitae Christos Baloukas Author Vitae Dimitrios Soudris Author Vitae 《Journal of Systems and Software》2010,83(6):1051-1075
Development of new embedded systems requires tuning of the software applications to specific hardware blocks and platforms as well as to the relevant input data instances. The behaviour of these applications heavily relies on the nature of the input data samples, thus making them strongly data-dependent. For this reason, it is necessary to extensively profile them with representative samples of the actual input data. An important aspect of this profiling is done at the dynamic data type level, which actually steers the designers choice of implementation of these data types. The behaviour of the applications is then characterized, through an analysis phase, as a collection of software metadata that can be used to optimize the system as a whole. In this paper we propose to represent the behaviour of data-dependent applications to enable optimizations, rather than to analyze their structure or to define the engineering process behind them. Moreover, we specifically limit ourselves to the scope of applications dominated by dynamically allocated data types running on embedded systems. We characterize the software metadata that these optimizations require, and we present a methodology, as well as appropriate techniques, to obtain this information from the original application. The optimizations performed on a complete case study, utilizing the extracted software metadata, achieve overall improvements of up to 42% in the number of cycles spent accessing memory when compared to code optimized only with the static techniques applied by GNU G++. 相似文献
234.
Gate‐to‐gate life cycle assessment of biosurfactants and bioplasticizers production via biotechnological exploitation of fats and waste oils
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235.
Computational fluid dynamics modelling of different detention pond configurations in the interest of sustainable flow regimes and gravity sedimentation potential
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Alexandros Tsavdaris Steve Mitchell John B. Williams 《Water and Environment Journal》2015,29(1):129-139
This study presents the results of the flow regime evaluation, by means of computational fluid dynamics (CFD), of a vegetated detention pond located at Waterlooville, Hampshire, UK. Alternative pond layouts were assessed for the same flow conditions on the basis of recommendations made in the literature. The results were validated by comparing the maximum computational velocities for the same case using different numbers of mesh elements. It was found that the development of a CFD model of detention ponds is intricate but feasible. The main findings were: (i) The present design performed well in terms of flood risk management, but the flow patterns could result in questionable treatment efficiency; (ii) vegetation seems to promote horizontal recirculation and turbulence; (iii) triangular and elliptical pond designs showed very poor performance; (iv) the most appropriate design for the given location and hydrological regime is an elliptical pond with a central emergent/submerged island. 相似文献
236.
Dimitris Rafailidis Alexandros Nanopoulos Yannis Manolopoulos 《Multimedia Tools and Applications》2011,51(3):881-895
In this paper, we address the issue of nonlinear dimensionality reduction to efficiently index spectral audio similarity measures.
We propose the embedding of the spectral similarity space to a low-dimensional Euclidean space. This guarantees the triangular
inequality and allows the adoption of several indexing schemes. We enlighten the advantages of the proposed indexable method
against recently proposed spectral similarity measures that are also indexable. Moreover, our method compares favorably to
linear dimensionality reduction methods, like multidimensional scaling (MDS). The proposed method significantly reduces the
computation time during the construction process compared to any audio measure and, simultaneously, minimizes the searching
cost for similar songs. To the best of our knowledge, the important issue of audio similarity measures’ scalability is addressed
for the first time. 相似文献
237.
This study investigates the resource consumption of Japanese society since 1979 and its subsequent effects on the economic output of the nation and the environment. In order to quantify resource appropriation and trends in production and consumption, the concept of emergy synthesis is employed. Our results show a significant increase in the total amount of emergy consumed by 66.9% between 1979 and 2003 which comes hand in hand with an increase in the level of environmental stress by 93.7% (quantified as the environmental loading ratio). On the other hand the emergy required to produce 1 USD of economic output has been gradually decreasing which denotes an increase in the efficiency of the conversion of natural capital into economic output. What is most interesting though is the growing dependence of the Japanese economy on imported emergy, increasingly from developing nations, that severely affects the potential for unhindered economic growth. This can prove to be a big barrier that could affect the resource security of the Japanese economy and render it susceptible to risks associated with access to natural resources which in turn can jeopardise its long-term economic sustainability. 相似文献
238.
239.
Seventy-eight limbs of forty-eight patients undergoing total hip replacement were studied by roentgenographic phlebography, cuff-impedance phlebography, and 125I fibrinogen scanning. Compared with roentgenographic phlebography, cuff-impedance phlebography detected seven of ten thrombi in the thigh but none of nine thrombi in the calf and popliteal veins, giving an over-all accuracy of 80 per cent. The 125I fibrinogen scanning technique detected none of the ten thrombi in the thigh and seven of the nine in the calf and popliteal veins, giving an over-all accuracy of 78 per cent. Combining the results of the two techniques, fourteen of the nineteen thrombi were detected. Cuff-impedance phlebography appears to be a useful method for the diagnosis of thrombi in the thigh after hip surgery. 相似文献
240.