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161.
Ribot C Lalanne P Lee MS Loiseaux B Huignard JP 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(12):3819-3826
A new hybrid method for the analysis of diffractive optical elements, which combines fully vectorial and scalar theories, is presented. It is suitable for use with elements of arbitrary large zone, even when the local feature size is of the order of the wavelength. To assess its applicability, we have performed cross-checking tests. The model is shown to accurately predict many optical properties of diffractive optical elements based on two-dimensional artificial dielectrics, like the useful energy diffracted into the order of interest or the deterministic loss into high diffraction orders for an illumination with a wavelength different from the design wavelength or for highly oblique incidence. 相似文献
162.
We show that a semiconductor membrane made of two thin layers of opposite (n- and p-) doping can perform electrically tunable ion current rectification and filtering in a nanopore. Our model is based on the solution of the 3D Poisson equation for the electrostatic potential in a double-cone nanopore combined with a transport model. It predicts that, for appropriate biasing of the membrane-electrolyte system, transitions from ohmic behavior to sharp rectification with vanishing leakage current are achievable. Furthermore, ion current rectifying and filtering regimes of the nanopore correspond to different charge states in the p-n membrane, which can be tuned with appropriate biasing of the n- and p- layers. 相似文献
163.
三维分子结构检索系统的结构索引与匹配 总被引:3,自引:3,他引:0
介绍了三维分子结构检索系统的结构索引与匹配,应用位筛成功地实现了三维结构数据的索引,可以快速得到候选结构,然后使用原子-原子匹配算法获得精确的命中结构。 相似文献
164.
We address the problem of time-base synchronization for MPEG services in the presence of network jitter. The conventional methods to obtain a stable clock indication are based on Phase Locked Loops (PLLs). They have the disadvantage of a long startup phase and thus are unsuitable for services that require simultaneous accuracy and rapidity. We develop a new time-base synchronization technique based on a Least-square Linear Regression algorithm (LLR). We show that LLR is able to perform time-base synchronization with the same accuracy as of a PLL and with a substantial gain of rapidity. Finally, we discuss the implementation of the LLR technique as an intermediate time-base synchronization level between the network and a generic multimedia application. 相似文献
165.
Carole Mign Grard Prensier Jean-Pierre Utille Pierre Angibeaud Agns Cornu Elisabeth Grenet 《Journal of the science of food and agriculture》1998,78(3):373-381
Two phenolic compounds, p-coumaric acid and feruloyl-arabinose, were localised by immunocytochemistry in the cell walls of the apical internode of two lines of maize (Co125 and W401) of different digestibility. The compounds were detected at two stages of cell maturity in the lignified tissues (sclerenchyma, fibres and xylem) and in the medullary parenchyma, which, in the samples studied, was not lignified. p-Coumaric acid is a phenolic acid associated with lignins, which confer resistance on plant cell walls to microbial degradation in the rumen. Feruloyl-arabinose is a compound associated with xylans, the principal hemicelluloses in Gramineae, which are potentially degradable. Labelling of p-coumaric acid decreased in both maize lines with cell age and as the cell walls became lignified. The mass of lignin deposited in the cell walls masked p-coumaric acid, thereby making it less accessible to the antibodies. There was an inverse relationship in the labelling of p-coumaric acid and feruloyl-arabinose. Feruloyl-arabinose was more heavily labelled as the plant cell walls matured in all the lignified tissues of both maize lines and in the parenchyma of the less digestible line. All tissues except the parenchyma were more heavily labelled with both sera in Co125, the more digestible line. © 1998 Society of Chemical Industry. 相似文献
166.
Floriane Pailleux Pauline Maes Michel Jaquinod Justine Barthelon Marion Darnaud Claire Lacoste Yves Vandenbrouck Benoît Gilquin Mathilde Louwagie Anne-Marie Hesse Alexandra Kraut Jrme Garin Vincent Leroy Jean-Pierre Zarski Christophe Bruley Yohann Cout Didier Samuel Philippe Ichai Jamila Faivre Virginie Brun 《International journal of molecular sciences》2021,22(20)
Acute liver injury (ALI) is a severe disorder resulting from excessive hepatocyte cell death, and frequently caused by acetaminophen intoxication. Clinical management of ALI progression is hampered by the dearth of blood biomarkers available. In this study, a bioinformatics workflow was developed to screen omics databases and identify potential biomarkers for hepatocyte cell death. Then, discovery proteomics was harnessed to select from among these candidates those that were specifically detected in the blood of acetaminophen-induced ALI patients. Among these candidates, the isoenzyme alcohol dehydrogenase 1B (ADH1B) was massively leaked into the blood. To evaluate ADH1B, we developed a targeted proteomics assay and quantified ADH1B in serum samples collected at different times from 17 patients admitted for acetaminophen-induced ALI. Serum ADH1B concentrations increased markedly during the acute phase of the disease, and dropped to undetectable levels during recovery. In contrast to alanine aminotransferase activity, the rapid drop in circulating ADH1B concentrations was followed by an improvement in the international normalized ratio (INR) within 10–48 h, and was associated with favorable outcomes. In conclusion, the combination of omics data exploration and proteomics revealed ADH1B as a new blood biomarker candidate that could be useful for the monitoring of acetaminophen-induced ALI. 相似文献
167.
Application of RFID technologies in the temperature mapping of the pineapple supply chain 总被引:2,自引:0,他引:2
Cecilia Amador Jean-Pierre Emond Maria Cecilia do Nascimento Nunes 《Sensing and Instrumentation for Food Quality and Safety》2009,3(1):26-33
Current temperature tracking systems lack the convenience and accuracy demanded by the real conditions of a fast-paced produce
supply chain. In recent years RFID technology has been suggested to be an enhanced method for temperature tracking because
of its many benefits, such as using little instrumentation, offering the quick readings necessary for real-time decision making,
and allowing the capture of long-duration temperature profiles. However its limitation lies in that probeless systems fail
to provide accurate temperature readings in some of the critical points of the pallet and the load. The objective of this
work was to study the use of RFID in temperature monitoring by comparing the performance of RFID temperature tags versus conventional
temperature tracking methods, as well as RFID temperature tags with probe versus RFID temperature tags without probes and
their utilization along the supply chain. Therefore, the temperature mapping of a shipping trial comprising pallets of crownless
pineapples instrumented using different RFID temperature dataloggers and traditional temperature dataloggers and packed in
two kinds of packages (corrugated boxes and reusable plastic containers) inside a container was performed. The results showed
that RFID temperature tags are analogous with regards to accuracy to the conventional methods, but have a superior performance
because they allow quick instrumentation and data recovery, and the possibility of accessing the sensor program and data at
any point of the supply chain without line of sight. In addition, the use of RFID tags with probe was justified by its role
in determining the efficiency of the pre-cooling operations and low temperature abuse tracking during transportation and refrigerated
storage; while the RFID tags without probe proved useful for high temperature abuse monitoring during transportation and refrigerated
storage. The creation of a RFID sensor with a probe, able to record both ambient and pulp temperatures simultaneously is suggested.
Presented at Food Processing Automation Conference, American Society of Agricultural and Biological Engineering (ASABE), Providence,
RI, USA, June 28–29 2008. 相似文献
168.
Serrano-Guisan S di Domenicantonio G Abid M Abid JP Hillenkamp M Gravier L Ansermet JP Félix C 《Nature materials》2006,5(9):730-734
The emerging field of spintronics explores the many possibilities offered by the prospect of using the spin of the electrons for fast, nanosized electronic devices. The effect of magnetization acting on a current is the essence of giant or tunnel magnetoresistance. Although such spintronics effects already find technological applications, much of the underlying physics remains to be explored. The aim of this article is to demonstrate the importance of spin mixing in metallic nanostructures. Here we show that magnetic clusters embedded in a metallic matrix exhibit a giant magnetic response of more than 500% at low temperature, using a recently developed thermoelectric measurement. This method eliminates the dominating resistivity component of the magnetic response and thus reveals an intrinsic spin-dependent process: the conduction-electron spin precession about the exchange field as the electron crosses the clusters, giving rise to a spin-mixing mechanism with strong field dependence. This effect appears sensibly only in the smallest clusters, that is, at the level of less than 100 atoms per cluster. 相似文献
169.
Markand Dipankumar Patel Nicolas Toussaint Geoffrey David Charles-Edwards Jean-Pierre Lin Philip G. Batchelor 《Magma (New York, N.Y.)》2010,23(5-6):399-408
Object
The anterior commissure is a critical interhemispheric pathway in animals, yet its connections in humans are not clearly understood. Its distribution has shown to vary greatly between species, and it is thought that in humans it may convey axons from a larger territory than previously thought. The aim was to use an anatomical mapping tool to look at the anterior commissure fibres and to compare the distribution findings with published anatomical understanding.Materials and methods
Two different diffusion-weighted imaging data sets were acquired from eight healthy subjects using a 3 Tesla MR scanner with 32 gradient directions. Diffusion tensor imaging tractography was performed, and the anterior commissure fibres were selected using three-dimensional regions of interest. Distribution of the fibres was observed by means of registration with T2-weighted images. The fibre field similarity maps were produced for five of the eight subjects by comparing each subject’s fibres to the combined map of the five data sets.Results
Fibres were shown to lead into the temporal lobe and towards the orbitofrontal cortex in the majority of subjects. Fibres were also distributed to the parietal or occipital lobes in all five subjects in whom the anterior commissure was large enough for interhemispheric fibres to be tracked through. The fibre field similarity maps highlighted areas where the local distances of fibre tracts were displayed for each subject compared to the combined bundle map.Conclusion
The anterior commissure may play a more important role in interhemispheric communication than currently presumed by conveying axons from a wider territory, and the fibre field similarity maps give a novel approach to quantifying and visualising characteristics of fibre tracts. 相似文献170.
Energy bandgaps are observed to increase with decreasing diameter due to quantum confinement in quasi-one-dimensional semiconductor nanostructures or nanowires. A similar effect is observed in semimetal nanowires for sufficiently small wire diameters: A bandgap is induced, and the semimetal nanowire becomes a semiconductor. We demonstrate that on the length scale on which the semimetal-semiconductor transition occurs, this enables the use of bandgap engineering to form a field-effect transistor near atomic dimensions and eliminates the need for doping in the transistor's source, channel, or drain. By removing the requirement to supply free carriers by introducing dopant impurities, quantum confinement allows for a materials engineering to overcome the primary obstacle to fabricating sub-5 nm transistors, enabling aggressive scaling to near atomic limits. 相似文献