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991.
Methods for measuring surface roughness based on light reflectivity have advantages over methods based on light interference
or diffraction, especially in in-situ, on-the-machine and inprocess applications. However, measurement inconsistencies caused
by changes in the specimen are still a drawback for field applications. In this study, we propose a new feedback-based algorithm
to enhance the consistency against changes in the specimen. The algorithm is deduced from simulations based on light reflectance
theory with typical modeled surfaces. The proposed method is similar to a digital controller and regulates the power of reflected
light. Experiments varying heights and materials, verified the improvements in robustness of the method against measurement
disturbances caused by specimen changes. 相似文献
992.
Kwang-wook Seo Byeong-ro Min Hyun-tae Kim So-yeon Lee Dae-weon Lee 《Journal of Mechanical Science and Technology》2008,22(12):2475-2480
Esophagitis is divided into four grades according to the progress degree of disease by the LA classification method. This
research was carried out on image processing with endoscope images for quantifying the four grades under the LA Classification.
In a previous paper, which presented our work, the algorithm for detecting abnormal parts from one image was developed. This
paper was conducted to classify esophagitis grade of one image itself. Whole 30 images were used in an experiment and included
normal images and abnormal images with four grades. GLCM (gray level co-occurrence matrices) factors were extracted. The distributions
of the texture image histogram were analyzed from each image for texture images. The algorithm to determine esophagitis grade
used BPN (Back propagation network) that was composed of the texture histogram distribution for input data. It learned 20
images and verified with 10 images to diagnose under the LA classification system. Recognition ratio of learning result was
93.0% and verification result 77.0%. With features of the neural network, the success rate could be improved with this result
by learning the data which were errors. Consequently, the recognition success rate appeared at 96% by total re-learned 30
images in addition to 10 images.
This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim 相似文献
993.
Jeongil Seo Han‐gil Moon Seungkwon Beack Kyeongok Kang Jae‐Keun Hong 《ETRI Journal》2005,27(5):635-638
Spatial audio coding (SAC) is an extremely high compact representation of encoded multi‐channel audio material. This paper suggests a multi‐channel audio service in the terrestrial digital multimedia broadcasting (T‐DMB) system using a novel SAC tool, which is called a virtual source location information (VSLI)‐based SAC tool. Intensive experiments are presented to evaluate the validity of the proposed VSLI‐based SAC tool, and prototypical systems are also presented to demonstrate the reliability of the proposed multi‐channel T‐DMB system in real applications. 相似文献
994.
Characterization of an ASE reflector-based gain-clamped erbium-doped fiber amplifier 总被引:1,自引:0,他引:1
Joon Tae Ahn Hong-Seok Seo Woon Jin Chung Bong Je Park Kyong Hon Kim 《Photonics Technology Letters, IEEE》2005,17(3):555-557
We develop a simulation tool for an all-optical gain-clamped erbium-doped fiber amplifier (GC-EDFA) based on an amplified spontaneous emission (ASE) reflector and thoroughly verify its validity by comparing simulation data with experimental ones. We carry out simulation work as changing conditions like reflection ratio and bandwidth of the ASE reflector, EDF length, and pump power. From this work, we have an exact understanding about the gain clamping principle that a reflected ASE acts like an intensity reservoir against input signal intensity variation. In general, as a reflected ASE power becomes higher, both a dynamic range and a noise figure (NF) increase; on the other hand, a clamped gain value decreases. The ASE reflector-based gain clamping scheme can be used for EDFAs with low NF characteristics at small input signal range in case a reflected ASE power is set at a level much lower than powers required for normal gain clamping function. 相似文献
995.
Joongwon Lee Seik Park Haikyung Seo Miyeong Kim Simoon Kim Junhwa Chi Kitae Kim 《Korean Journal of Chemical Engineering》2012,29(5):574-582
The integrated gasification combined cycle (IGCC) system is well known for its high efficiency compared with that of other
coal fueled power generating systems. In this study, gasification using different types of burners with different oxygen supply
angles in a bench-scale entrained flow gasifier was investigated. The effects of the oxygen gas supply angle of the coal burner
and resulting oxygen supply location in the gasifier on the syngas composition and temperature of the gasifier were experimentally
examined. These changes had a significant influence on the syngas composition of the final stream, carbon conversion, and
efficiencies. According to the experimental results, the models using the Aspen Plus process simulator were positioned to
define the effects of the experimental parameters and to find the optimum operating conditions in the bench gasifier facility. 相似文献
996.
997.
In the area of radar signature modelling, subspace-based methods have recently become very popular. To model radar signals using subspace-based methods, spatial-smoothing preprocessing (SSP) is essential to estimate the covariance matrix of the received signals. Here, the performances of two typical SSP techniques are compared in the context of radar signature modelling 相似文献
998.
Kaniz Fatima Sultana So Young Lee Ji-Eun Lee Joobeom Seo Shim Sung Lee 《Inorganic chemistry communications》2007,10(12):1496-1500
Two 20-membered penta- and hexadentate macrocycles containing one or two pyridine subunits, namely [20]aneNO2S2 (L1) and [20]aneN2O2S2 (L2), have been synthesized. Reaction of L1 with silver(I) nitrate afforded a unique 2:2 (M:L) disilver(I) complex [μ2-Ag2(L1)2](NO3)2 (1) in which two four-coordinate Ag atoms bridge two ligands to form a cyclic dimer. In contrast, an endo-dentate 1:1 monosilver(I) complexes [AgL2]X; [X = ClO4 (2) or PF6 (3)] which show isomorphous structures were obtained from the reactions of L2 with silver(I) salts. 相似文献
999.
D C Seo H J Lee H N Hwang M R Park N W Kwak I J Cho J S Cho J Y Seo W H Joo K H Park J S Heo 《Water science and technology》2007,55(1-2):251-259
To treat cutting oil wastewater produced in metal surface treatment industry, Ultrasonication (US)-Fenton process, which is one of the advanced oxidation processes, was used. The optimum conditions to treat non-biodegradable pollutants using the US-Fenton process were that the application rates of H2O2 and FeSO4 were 10% and 3 g/L, respectively, the value of pH was 3, and the ultrasonication time was 30 min. It identified non-degradable pollutants such as ethylene diamine tetraacetic acid (EDTA) and Triethanolamine (TEA) in the cutting oil wastewater. TLC analysis of two compounds of treated water by the coagulation process was similar to that of raw water. However, TLC analysis of two compounds of US-Fenton process was different from that of raw water, meaning that US-Fenton process decomposed the EDTA and TEA. To study the possibility of application with the US-Fenton process to pilot plant, the pollutants treatment efficiency of three different methods, such as US-Fenton process, activated sludge process and coagulation process, in continuous experiments were compared. The removal rate of pollutants by the US-Fenton process according to the effluent time was higher than any other processes. The removal rates of COD, SS, T-N and T-P by US-Fenton process were 98, 93, 75 and 95%, respectively. 相似文献
1000.