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991.
In this paper, the concept of intension is used to introduce two types of ordering relations based on information that generates a cover for the universal set. These types of ordering relations are distinct from the well-known ordering relation based on set inclusion. For these ordering relations, we consider the algebraic structures that arise in various types of covers. We show that in the case of a representative cover, the algebraic structure resulting from the lower intension inclusion is a double Stone algebra, while in the case of a reduced cover, it is a Boolean algebra. In addition, the algebraic structure resulting from the upper intension inclusion in the case of a representative cover is a Boolean algebra, and in the case of a reduced cover, the two Boolean algebraic structures from lower and upper intension inclusions are isomorphic. 相似文献
992.
Regression testing is important activity during the software maintenance to deal with adverse effects of changes. Our approach is important for safety critical system as usually formal methods are preferred and highly recommended for the safety critical systems but they are also applied for the systems development of other than critical system. Our approach is based on Regression testing using VDM++ which takes two VDM++ specifications, one baseline and other delta (Changed) along with test suite for the baseline version. It compares both versions by using comparator module, identifies the change. By analyzing the change we classify the test cases from original test suite into obsolete, re-testable, and reusable test cases. Our scope is at unit level i.e. at class level. Our approach gets two versions of VDM++ specification and returns regression test suite for the delta version. Our approach distinguishes test cases which are still effective for the delta version of VDM++ specification and it differs from re-test all strategy as it can distinguish the test cases and identifies test cases which are useful for delta version. Test cases reusability and test case reduction is the main objective of our approach. Our approach presents how to perform regression testing using VDM++ specification during the maintenance of systems. 相似文献
993.
Domino Tiling: A New Method of Real-Time Conforming Mesh Construction for Rendering Changeable Height Fields 下载免费PDF全文
In this paper we present a novel GPU-oriented method of creating an inherently continuous triangular mesh for tile-based rendering
of regular height fields. The method is based on tiling data-independent semi-regular meshes of non-uniform structure, a technique
that is quite different from other mesh tiling approaches. A complete, memory efficient set of mesh patterns is created by
an off-line procedure and stored into the graphics adapter's memory at runtime. At rendering time, for each tile, one of the
precomputed mesh patterns is selected for rendering. The selected mesh pattern fits the required level of details of the tile
and ensures seamless connection with other adjacent mesh patterns, like in a game of dominoes. The scalability potential of
the proposed method is demonstrated through quadtree hierarchical grouping of tiles. The efficiency is verified by experimental
results on height fields for terrain representation, where the method achieves high frame rates and sustained triangle throughput
on high resolution viewports with sub-pixel error tolerance. Frame rate sensitivity to real-time modifications of the height
field is measured, and it is shown that the method is very tolerant and consequently well tailored for applications dealing
with rapidly changeable phenomena represented by height fields. 相似文献
994.
This paper presents a scheme for the design of a robust fixed‐lag smoother for a class of nonlinear uncertain systems. The proposed approach combines a nonlinear robust estimator with a stable fixed‐lag smoother, to improve the estimation error covariance. The robust fixed‐lag smoother is based on the use of integral quadratic constraints and minimax linear quadratic regulator estimation and control theory. The state estimator uses a copy of the system nonlinearity in the estimator and combines an approximate model of the delayed states to produce a smoother signal. Also in this work, a characterization of the delay approximation error is presented, and the corresponding integral quadratic constraint is included in the design, which gives a guaranteed bound on the performance cost function. In order to see the effectiveness of the method, it is applied to a quantum optical phase estimation problem. Results show a significant improvement in the error covariance of the estimator when compared with a robust nonlinear filter. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
995.
Object tracking is an important task in computer vision that is essential for higher level vision applications such as surveillance systems, human-computer interaction, industrial control, smart compression of video, and robotics. Tracking, however, cannot be easily accomplished due to challenges such as real-time processing, occlusions, changes in intensity, abrupt motions, variety of objects, and mobile platforms. In this paper, we propose a new method to estimate and eliminate the camera motion in mobile platforms, and accordingly, we propose a set of optimal feature points for accurate tracking. Experimental results on different videos show that the proposed method estimates camera motion very well and eliminate its effect on tracking moving objects. And the use of optimal feature points results in a promising tracking. The proposed method in terms of accuracy and processing time has desirable results compared to the state-of-the-art methods. 相似文献
996.
Adel K. Madbouly Mohamed S. AbdelAziz Mosaad A. AbdelWahhab 《IET nanobiotechnology / IET》2017,11(6):702
Fusarium wilt of tomato (Lycopersicon esculentum) caused by Fusarium oxysporum f. sp. lycopersici is one of the most important diseases that affect this crop worldwide. This study aimed to biosynthesise nanosilver (AgNPs) using Chaetomium globosum, to evaluate its in vitro antifungal activity against pathogenic F. oxysporum and in vivo control of tomato seedlings wilt in the greenhouse. AgNPs was tested for its in vitro antifungal potential against F. oxysporum using poisoned food technique on three different growth media, agar well diffusion assay, inhibition of colony formation (CFU), and tested for its potency to control seedlings wilt upon its use at different concentrations (50, 100 and 500 mg/l) and for different incubation periods (0, 1, 2 and 4 h). Results indicated that C. globosum succeeded to biosynthesise AgNPs with maximum UV/vis absorbance around 420–450 nm, spherical in shape with particle size of 11–14 nm according to Transmittance electron microscope and displayed high purity recorded through X‐ray diffraction (XRD). In vitro studies revealed high antifungal activity of AgNPs against F. oxysporum noticed especially at a concentration of 500 mg/l and after incubation period for 4 h. The CFU of F. oxysporum on potato dextrose agar (PDA) medium decreased significantly on increasing the concentration and time of incubation with AgNPs. In the greenhouse, AgNPs caused appreciable enhancement in the growth parameters of tomato seedlings such as; root, shoot fresh weight, and height of seedlings in soil infested with F. oxysporum compared with the control. In addition, AgNPs reduced the severity of wilt disease by 90% observed through decreasing the number of wilted seedlings especially after placing their roots in 500 mg/l of AgNPs suspension for 4 h prior to soil infestation with the pathogen. This study recorded for the first time that C. globosum has the ability to synthesise AgNPs which showed significant in vivo antifungal potential observed through control of Fusarium wilt of tomato seedlings, in addition to enhancing their growth parameters in the greenhouse.Inspec keywords: crops, silver, nanoparticles, nanofabrication, antibacterial activity, diseases, botany, ultraviolet spectra, visible spectra, transmission electron microscopy, X‐ray diffraction, nanobiotechnologyOther keywords: biosynthesis, silver nanoparticles, Chaetomium globosum, Fusarium wilt, tomato, greenhouse, Lycopersicon esculentum, diseases, Fusarium oxysporum f. sp. lycopersici, Ag, seedling height, shoot fresh weight, root, growth parameters, potato dextrose agar, XRD, X‐ray diffraction, transmittance electron microscopy, particle size, UV/vis absorbance, incubation periods, seedling control, colony formation inhibition, agar well diffusion assay, poisoned food technique, antifungal activity 相似文献
997.
Amjid Ali Tahir Mahmood Hafiz Zafar Nazir Iram Sana Noureen Akhtar Sadia Qamar Muhammad Iqbal 《Quality and Reliability Engineering International》2016,32(7):2481-2490
Control charts are important statistical tool used to monitor fluctuations in the process location and dispersion parameters. The issues relating to the appropriate choice of control charts for the effective detection of process variability are addressed, and different control chart structures, such as Shewhart‐type, exponentially weighted moving average and cumulative sum are explored under ideal assumption of normality and contaminated normal environments, and hence, those control charts structures are identified which are more capable to detect aberrant changes in the process dispersion. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
998.
Nur Alia Sheh Omar Yap Wing Fen Khamirul Amin Matori Mohd Hafiz Mohd Zaid Mohd Rasdi Norhafizah Mohammad Nurzilla Mohd Ismail Maisarah Zamratul 《Journal of Materials Science: Materials in Electronics》2016,27(2):1092-1099
This paper presents a study on synthesis and optical properties of Zn2SiO4:1 wt% Eu3+ at different heat treatments. The objective of the research is to synthesize Zn2SiO4:1 wt% Eu3+ phosphor by using low cost solid state reaction method with recycled waste bottle glasses as the silicate source. The X-ray diffraction results showed that the prepared Zn2SiO4:1 wt% Eu3+ phosphors have a sharp diffraction peak as the heat treatment temperatures were increased from 600 to 1000 °C. Furthermore, the morphology from the Field emission scanning electron microscope analysis were shown the formation of well crystalline samples with dense packed grains due to the increment of heat treatment temperatures. Fourier transform infrared spectra has confirmed the present elements in Zn2SiO4:1 wt% Eu3+ phosphors while the narrow width of Raman line spectra were observed at temperatures ranging from 700 to 1000 °C indicates good homogeneity and crystallinity of synthesized powders. In addition, the energy band gap of europium doped zinc silicate increased dramatically up to 3.62 eV at temperature of 1000 °C. Photoluminescence measurements has also exhibited the red emission corresponding to the 5D0 → 7F2 (600 nm) when viewed under blue excitation. 相似文献
999.
Zameer Abbas Hafiz Zafar Nazir Noureen Akhtar Muhammad Riaz Muhammad Abid 《Quality and Reliability Engineering International》2020,36(5):1716-1730
Variation is an important phenomenon of the output of every manufacturing and production process. To deal with the natural and special cause variations in the process, quality practitioners mostly apply control charts. There have been regular advancements over time in the design structures of these charts such as runs rules, fast initial response, sampling mechanisms among many others. In this article, auxiliary-information-based progressive mean (AIB-PM) control chart has been proposed, in which study variable is found correlated with another auxiliary variable. The development of the proposed AIB-PM structure utilises both the study and auxiliary variables. It is based on the regression estimator to introduce an unbiased and efficient estimate of the location parameter of the study variable. The performance assessment is carried out using average run length as a metric under zero-state and steady-state modes. The proposed AIB-PM chart is compared with some existing competitors and found that it performs uniformly superior than the existing competitors at small and persistent shifts in the process mean. An illustrative example using a real data set is presented to show the implementation of the proposed method. 相似文献
1000.
Zameer Abbas Hafiz Zafar Nazir Noureen Akhtar Muhammad Riaz Muhammad Abid 《Quality and Reliability Engineering International》2020,36(7):2569-2591
The exponentially weighted moving average (EWMA) control chart is a memory chart that is widely used in process monitoring to spot small and persistent disturbances in the process parameter(s). This chart requires normality of the quality characteristic(s) of interest and a smaller choice of smoothing parameter. Any deviations from these conditions affect its performance in terms of efficiency and robustness. For the said two concerns, this study develops a new mixed EWMA chart under progressive setup (mixed EWMA–progressive mean [MEP] chart). The proposed MEP chart combines the advantages of robustness (under nonnormal scenarios) and high sensitivity to small and persistent shifts in the process mean. The performance of the proposed MEP control chart is evaluated in terms of average run length and some other characteristics of run length distribution. The assessment of the proposed chart is made under standard normal, student's t, gamma, Laplace, logistic, exponential, contaminated normal and lognormal distributions. The performance of the proposed MEP chart is also compared with some existing competitors including the classical EWMA, the classical cumulative sum (CUSUM), the homogenously weighted moving average, the mixed EWMA–CUSUM, the mixed CUSUM–EWMA and the double EWMA charts. The analysis reveals that the proposal of this study offers a superior design structure relative to its competing counterparts. An application from substrates manufacturing process (in which flow width of the resist is the key quality characteristic) is also provided in the study. 相似文献