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101.
102.
石玉龙 《青岛科技大学学报(自然科学版)》1994,(1)
运用射频等离子体化学气相沉积在Si(100)P进行外延试验,并用四极质谱仪(QMS)进行监测,得出了SiH4浓度的变化规律。试验结果表明在600℃,压力为300mTorr时,外延生长率最高,为450/min,膜中H含量也较低,为1.5%[at]。在压力为30mTorr,700℃时,外延生长率为59.6/min,膜中H含量降至2.75%[at]。 相似文献
103.
104.
We present an overview of some recent developments in the area of mathematical modeling of maintenance decisions for multi-unit systems. The emphasis is on three main groups of multicomponent maintenance optimization models: the block replacement models, group maintenance models, and opportunistic maintenance models. Moreover, an example of a two-unit system maintenance process is provided in order to compare various maintenance policies. 相似文献
105.
Piotr Hońko 《国际智能系统杂志》2014,29(5):407-438
One of the popular methods to develop an algorithm for mining data stored in a relational structure is to upgrade an existing attribute‐value algorithm to a relational case. Current approaches to this problem have some shortcomings such as (1) a dependence on the upgrading process of the algorithm to be extended, (2) complicated redefinitions of crucial notions (e.g., pattern generality, pattern refinement), and (3) a tolerant limitation of the search space for pattern discovery. In this paper, we propose and evaluate a general methodology for upgrading a data mining framework to a relational case. This methodology is defined in a granular computing environment. Thanks to our relational extension of a granular computing based data mining framework, the three above problems can be overcome. 相似文献
106.
Yousef Erfanifard Krzysztof Stereńczak Bartłomiej Kraszewski Agnieszka Kamińska 《International journal of remote sensing》2013,34(23):9206-9227
ABSTRACTTree crown attributes are important parameters during the assessment and monitoring of forest ecosystems. Canopy height models (CHMs) derived from airborne laser scanning (ALS) data have proved to be a reliable source for extracting different biophysical characteristics of single trees and at stand level. However, ALS-derived tree measurements (e.g., mean crown diameter) can be negatively affected by pits that appear in the CHMs. Thus, we propose a novel method for generating pit-free CHMs from ALS point clouds for estimating crown attributes (i.e., area and mean diameter) at the species level. The method automatically calculates a threshold for a pixel based on the range of height values within neighbouring pixels; if the pixel falls below the threshold then it is recognized as a pitted pixel. The pit is then filled with the median of the values of the neighbouring pixels. Manually delineated individual tree crowns (ITC) of four deciduous and two coniferous species on Colour Infrared (CIR) stereo images were used as a reference in the analysis. In addition, a variety of different algorithms for constructing CHMs were compared to investigate the performance of different CHMs in similar forest conditions. Comparisons between the estimated and observed crown area (R2 = 0.95, RMSE% = 19.12% for all individuals) and mean diameter (R2 = 0.92, RMSE% = 12.16% for all individuals) revealed that ITC attributes were correctly estimated by segmentation of the pit-free CHM proposed in this study. The goodness of matching and geometry revealed that the delineated crowns correctly matched up to the reference data and had identical geometry in approximately 70% of cases. The results showed that the proposed method produced a CHM that estimates crown attributes more accurately than the other investigated CHMs. Furthermore, the findings suggest that the proposed algorithm used to fill pits with the median of height observed in surrounding pixels significantly improve the accuracy of the results the species level due to a higher correlation between the estimated and observed crown attributes. Based on these results, we concluded that the proposed pit filling method is capable of providing an automatic and objective solution for constructing pit-free CHMs for assessing individual crown attributes of mixed forest stands. 相似文献
107.
Fatemeh Noroozi Tomasz Sapiński Dorota Kamińska Gholamreza Anbarjafari 《International Journal of Speech Technology》2017,20(2):239-246
This paper proposes a new vocal-based emotion recognition method using random forests, where pairs of the features on the whole speech signal, namely, pitch, intensity, the first four formants, the first four formants bandwidths, mean autocorrelation, mean noise-to-harmonics ratio and standard deviation, are used in order to recognize the emotional state of a speaker. The proposed technique adopts random forests to represent the speech signals, along with the decision-trees approach, in order to classify them into different categories. The emotions are broadly categorised into the six groups, which are happiness, fear, sadness, neutral, surprise, and disgust. The Surrey Audio-Visual Expressed Emotion database is used. According to the experimental results using leave-one-out cross-validation, by means of combining the most significant prosodic features, the proposed method has an average recognition rate of \(66.28\%\), and at the highest level, the recognition rate of \(78\%\) has been obtained, which belongs to the happiness voice signals. The proposed method has \(13.78\%\) higher average recognition rate and \(28.1\%\) higher best recognition rate compared to the linear discriminant analysis as well as \(6.58\%\) higher average recognition rate than the deep neural networks results, both of which have been implemented on the same database. 相似文献
108.
Dziedzic Krzysztof Górecka Danuta Szwengiel Artur Michniewicz Jan Drożdżyńska Agnieszka Walkowiak Jarosław 《Food science and biotechnology》2019,28(3):649-655
Food Science and Biotechnology - The tomato pomace obtained during processing as a residue of tomato processing from large industry. The interactions between tomato pomace and fecal bacteria, bile... 相似文献
109.
The influence of the use of moulding sand with furan resin, prepared both with fresh sand and reclaimed matrix, on the formation of a flake graphite formation at the surface layer of ductile iron castings has been investigated. A series of experimental heats of ductile iron cast in moulds made of moulding sand characterised by different levels of surface active elements (sulphur, oxygen) were performed. The effect of the wall thickness and the initial temperature of the metal in the mould cavity on the formation of flake graphite in the surface layer of the casting is shown in the paper. Investigations carried out by means of scanning electron microscopy (energy dispersive X-ray spectroscopy and wavelength dispersive X-ray spectroscopy) showed concentration of gradient profiles of surface active elements in the castings surface layer, which are responsible for their quality. Finally, it has been shown that there exists a significant effect of the quality of the sand on the formation of the flake graphite layer and the surface characteristics of ductile iron castings. 相似文献
110.
Zofia Lisiewska Piotr Gębczyński Waldemar Kmiecik 《European Food Research and Technology》2007,226(1-2):25-31
The investigation included kale, New Zealand spinach and spinach. The evaluation covered the raw material; the raw material
after blanching; the raw material after cooking; and frozen products prepared for consumption after 0, 4, 8 and 12 months
of refrigerated storage. Both the traditional method of freezing (blanching before freezing) and the modified method of freezing
(cooked before freezing) were used in the experiment, as well as two storage temperatures, T = −20 °C and T = −30 °C. The content of chlorophylls in fresh kale was four times that in New Zealand spinach and 1.5 times that in spinach.
With the exception of New Zealand spinach, blanching and cooking significantly reduced the content of chlorophylls. In kale
products prepared for consumption, the content of chlorophylls decreased in each successive stage of the investigation. In
products of New Zealand spinach and spinach, the losses were usually not significant. After 12 months of refrigerated storage,
frozen kale products prepared for consumption retained 52–65% of total chlorophylls compared with the content in the raw material;
products of New Zealand spinach and spinach retained 66–71%. In kale and New Zealand spinach, the content of chlorophyll a
decreased more rapidly than that of chlorophyll b, while in spinach the converse was true. The kale products obtained using
the modified method contained more chlorophylls, while in the two spinach species their content was lower. The lower storage
temperature resulted in a higher retention of chlorophylls in vegetables. 相似文献