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排序方式: 共有814条查询结果,搜索用时 171 毫秒
751.
今日交通工具中广泛使用液晶显示萤幕,荧幕也随着各式各样的振动对人产生影响.尤其人们眼睛在阅读精确的文章时,振动所造成不适,影响就变得更剧烈,因此容易造成阅读绩效不佳与视觉不适.本研究想要探讨液晶萤幕在不同振动情形(振动频率、振动振幅与不同振动方向)对数字大小、数字多寡与数字排列之影响.阅读绩效与视觉疲劳的量测为反应时间、正确率、闪光融合阈值、视力变化与主观评量,由实验得到频率对反应时间、正确率与视觉疲劳有显著的影响.因此荧幕硬件与软件之设计必须考虑到振动的影响. 相似文献
752.
O.G. Chorayan 《Fuzzy Sets and Systems》1982,8(2):141-147
The paper presents the results of investigation of the neuron of the frog visual analyzer central part and the crayfish 6th abdominal ganglion on the basis of fuzzy sets theory and some set-theoretical operations to establish the neuron membership in a particular ensemble in accordance with their essential characteristics. 相似文献
753.
754.
An injector liner packed with a plug of glass wool is compared with a laminar and a mini laminar liner for large volume (20-50 microL) splitless injection with concurrent solvent recondensation (CSR-LV splitless injection). Videos from experiments with perylene solutions injected into imitation injectors show that glass wool perfectly arrested the sample liquid and kept it in place until the solvent had evaporated. The sample must be transferred from the needle to the glass wool as a band, avoiding 'thermospraying' by partial solvent evaporation inside the needle. The liquid contacted the liner wall when the band was directed towards it, but from there it was largely diverted to the glass wool. In the laminar liners, part of the liquid remained and evaporated at the entrance of the obstacle, while the other proceeded to the center cavity. Vapors formed in the center cavity drove liquid from the entrance of the obstacle upwards, but the importance of such problems could not be verified in the real injector. Some liquid split into small droplets broke through the obstacle and entered the column. Breakthrough through the laminar liners was confirmed by a chromatographic experiment. An improved design of a laminar liner for large volume injection is discussed as a promising alternative if glass wool causes problems originating from insufficient inertness. 相似文献
755.
A methodology for simultaneous preconcentration and determination of Cr(VI) from aqueous samples was developed using a membrane optode formed by physical inclusion of a Cr(VI) selective chromophore 1,5-diphenylcarbazide (DPC) into a plasticized cellulose triacetate matrix. The inclusion of an anion exchanger (Aliquat-336) was found to be effective for immobilization of both DPC and Cr(VI)-DPC complex in the optode matrix itself. The proportionality in intensity of the magenta color on the optodes loaded with varying amounts of Cr(VI) suggests its potential applications for screening of Cr(VI) in aqueous samples by visual colorimetry. On loading high amounts of Cr(VI) in the membrane optode, its color changes from magenta to yellow, which indicates the possibility of using it as a threshold detector for Cr(VI). The membrane optode was optimized in terms of obtaining maximum preconcentration efficiency for Cr(VI) and subsequent stable optical response proportional to the amount of Cr(VI) in the membrane optode sample. The membrane optodes were tested for Cr(VI) determination in tap water and seawater samples. Using this optode, Cr(VI) even at levels of 13.6 ppb could be quantitatively detected. The optodes developed in the present work were found to be stable, cost effective, easy to prepare and efficient for direct preconcentration and determination of Cr(VI) in a variety of aqueous samples using spectrophotometry. However, this membrane optode is for one time use only as the reaction of Cr(VI) with DPC is irreversible. 相似文献
756.
Two-dimensional difference gel electrophoresis (2-D DIGE), in combination with mass spectrometry, is a highly effective method for the rapid and reproducible detection of differentially expressed proteins. This approach, however, has the unfortunate drawback that it preferentially displays rather abundantly expressed proteins. Nevertheless, comparison of the protein expression levels of the striate cortex of adult cats and 30-day-old kittens, resulted in the identification of several proteins related to postnatal brain development and possibly age-dependent plasticity as well (Van den Bergh et al., J. Neurochem. 2003, in press). The goal of the present study was the selective enrichment and identification of less abundant proteins within the same paradigm. Hereto, we performed a reversed-phase chromatography prefractionation of our tissue lysate to separate the proteins in four fractions based on their hydrophobicity prior to 2-D DIGE analysis. This approach not only confirmed the differential expression levels of a number of proteins from the previous study, but also identified three additional proteins preferentially expressed in kitten visual cortex and five additional proteins with higher expression levels in adult cat visual cortex. These spots were not visible on the total tissue lysate protein maps, indicating that the high-performance liquid chromatography (HPLC) prefractionation enabled us to visualize additional, less abundant proteins. 相似文献
757.
758.
为了实现对现场生产过程进行监控,PLC串行通信技术在工业生产中正得到越来越广泛的应用,介绍了三菱FX2N系列PLC与上位机进行通信的主要原理,阐述在Visual Basic 6.0环境下上位机与三菱FX2N PLC串行通信的具体实现方法。具体介绍了与上位机通信的硬件连接,三菱FX2N PLC的通信协议及VB中的MSCOMM控件,对通信实现过程中的主要程序进行简单分析。 相似文献
759.
基于NVL75,FLIR92和CFLIR国内外3种不同的热成像系统静态性能模型,采用静态性能参量MRTD建立对面目标的视距估算方程,并通过CFLIR40软件计算,比较不同模型下视距估算结果,得出:凝视型热成像系统在CFLIR模型下计算得到的MRTD值比FLIR92模型计算得到的MRTD值更接近实际测量值;在基本参数相同的条件下,利用MRTD估算的凝视系统的视距远远优于扫描系统的视距;对凝视型系统,从视距估算的结果来看,CFLIR模型略优于FLIR92模型。 相似文献
760.
Unmanned aerial vehicle (UAV) based aerial visual tracking is one of the research hotspots in computer vision. However, the mainstream trackers for UAV still have two shortcomings: (1) the accuracy of correlation filter tracker is greatly improved with more complex model, it impedes accuracy-speed trade-off. (2) object occlusion and camera motion in the aerial tracking scene also seriously restrict the application of aerial tracking. To address these problems, and inspired by AutoTrack tracker, we propose an aerial correlation filtering tracker based on scene-perceptual memory, Fast-AutoTrack. Firstly, to perceive and judge tracking anomalies, such as object occlusion and camera motion, inspired by the peak sidelobe ratio and AutoTrack, a confidence score is designed by perceiving and remembering the changing trend of the confidence and the local historical confidence. Secondly, after tracking anomaly occurring, several search regions are predicted based on the local object motion trend and the Spatio-temporal context information for object re-detection. Finally, to accelerate the model updating, the perceptual hashing algorithm (PHA) is used to obtain the similarity of the search regions between two adjacent frames. On typical aerial tracking datasets UAVDT, UAV123@10fps, and DTB70, Fast-AutoTrack run 71.4% faster than AutoTrack with almost equal accuracy and show favorable accuracy-speed trade-off. 相似文献