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1.
Visualizing multidimensional data such as the mel frequency cepstral coefficients (MFCCs) proves difficult, especially when the number of dimensions is greater than 3. As a result, it becomes extremely difficult to spot trends in high-dimensional signal interactions. Andrews curves seam to aid in the process of performing graphical analysis of high-dimensional data. This study examines the properties of the babble in the feature domain as well as the effect of the babble noise on the MFCCs of clean speech. Experiments have been conducted using two babble models: the overlapping conversation model and the overlapping speaker model. The purpose of this paper was to provide an insight into the effect of the babble noise on the first thirteen MFCCs of clean speech through the use of Andrews curves. The investigations of this paper give a visual comparison of the signals to expose trends, which the conventional visualization methods do not. The use of Andrews curves not only allows the signal to be observed, but also allows for a statistical comparisons between signals. With a better understanding of the difference between the models, it would be possible to develop systems, which are more robust in babble-corrupted environment.  相似文献   
2.
A systematic approach towards accident analysis and prevention has been developed. It relies on system theory as an incident causation model, and adopts a hybrid model for identifying elements of the safety management system. PDCA (Plan-Do-Check-Act) process, commonly practiced in business for quality control, has been applied to defining components of the system. Using the experts’ judgment, accident data and their reported causes are correlated to the defined components, with RBI (risk-based inspection) defined consequence scores as weighting factors. The application of this approach allows users such as governments and companies to identify and prioritize among causes of accidents and near-misses in the petrochemical industry. A case study using the accident data of Yeosu petrochemical complex from 1990 to 2004 has been applied to illustrate insights readily obtainable by using the developed analysis technique. The results suggest comprehensive identification and ranking of accident causes for effective prevention of accidents in the future.  相似文献   
3.
Previous studies have demonstrated that, when they are emotional, individuals are more likely to attend to emotional stimuli. However, such work has not established that individuals attend to the emotional dimensions of complex stimuli or that such changes in focus of attention affect judgments. In the present experiments a multidimensional scaling analysis was used to assess the weights that happy, sad, and neutral-emotion participants gave to emotional and nonemotional dimensions of face stimuli in judgments of similarity. Compared to neutral-emotion participants, those in emotional states gave more weight to the emotional dimension of the faces, less weight to other face dimensions, and rated pairs of faces that expressed the same emotion as more similar. Emotion-congruent dimension use was also observed in one experiment. Results are discussed with respect to emotional response categories (P. M. Niedenthal & J. B. Halberstadt, 1995), the tendency for stimuli to cohere as categories on the basis of the emotional response they elicit in the perceiver. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
4.
B cells expressing CD5 also carry its ligand, CD72. As an approach to understanding the role of CD5 and CD72 on B cells, we have examined the association of CD72 with CD5 and slgM by modulation/co-modulation and capping/co-capping following ligation of these surface molecules with specific antibodies. Modulation and co-modulation were measured after 24 h, whilst capping was measured after 1 h. CD5 and slgM co-modulated each other, CD72 co-modulated with slgM and CD5, but anti-CD72 did not affect either slgM or CD5. CD5 and slgM co-capped each other, whilst CD72 failed to co-cap with either slgM or CD5. The CD5-induced co-modulation of CD72 was partially blocked by specific protein tyrosine kinase inhibitor, but not the slgM-induced co-modulation, Protein kinase C (PKC) inhibitors abrogated the anti-mu- but not the anti-CD5-triggered modulation of CD72, whereas PKC activators prevented the CD5- but not the slgM-induced 24 h modulation of CD72. None of these drugs was able to modify the anti-CD72-induced modulation of CD72. Our data suggest that CD5 is physically associated with slgM in the B cell receptor complex but not with CD72. Furthermore, from the effect of drugs on modulation, there appears to be different associations of CD72 with slgM and CD5. These two pathways differed in some respects, consistent with a co-stimulatory function of CD72 and CD5 in B cell activation.  相似文献   
5.
This paper describes the synthesis of long‐chain fatty esters of corn starch (starch laurate and starch stearate) with a broad range in degree of substitution (DS = 0.24−2.96). The fatty esters were prepared by reacting the starch with vinyl laurate or vinyl stearate in the presence of basic catalysts (Na2HPO4, K2CO3, and Na acetate) in DMSO at 110°C. The yellowish products were characterized by 1H‐, 13C‐NMR and FT‐IR. The DS of the products is a function of the carbon number of the fatty acid chain, vinyl ester to starch ratio and the type of catalyst. When performing the reactions using Na2HPO4 as the catalyst, the DS for the starch laurate compounds is higher than for the corresponding starch stearates. For low vinyl ester to starch ratios, an increase in the vinyl ester concentration leads to higher product DS values. At higher ratios, the DS decreases, presumably due to a reduction of the polarity of the reaction medium. K2CO3 and Na acetate are superior catalysts with respect to activity compared to Na2HPO4 and products with DS values close to 3 were obtained.  相似文献   
6.
7.
Yeom D  Kang J  Lee M  Jang J  Yun J  Jeong DY  Yoon C  Koo J  Kim S 《Nanotechnology》2008,19(39):395204
The memory characteristics of ZnO nanowire-based nano-floating gate memory (NFGM) with Pt nanocrystals acting as the floating gate nodes were investigated in this work. Pt nanocrystals were embedded between Al(2)O(3) tunneling and control oxide layers deposited on ZnO nanowire channels. For a representative ZnO nanowire-based NFGM with embedded Pt nanocrystals, a threshold voltage shift of 3.8?V was observed in its drain current versus gate voltage (I(DS)-V(GS)) measurements for a double sweep of the gate voltage, revealing that the deep effective potential wells built into the nanocrystals provide our NFGM with a large charge storage capacity. Details of the charge storage effect observed in this memory device are discussed in this paper.  相似文献   
8.
Development of a comprehensive, three-dimensional gas chromatograph (GC3) instrument is described. The instrument utilizes two six-port diaphragm valves as the interfaces between three, in-series capillary columns housed in a standard Agilent 6890 gas chromatograph fitted with a high data acquisition rate flame ionization detector. The modulation periods for sampling column one by column two and column two by column three are set so that a minimum of three slices (more commonly four or five) are acquired by the subsequent dimension resulting in both comprehensive and quantitative data. A 26-component test mixture and quantitative standards are analyzed using the GC3 instrument. A useful methodology for three-dimensional (3D) data analysis is evaluated, based on the chemometric technique parallel factor analysis (PARAFAC). Since the GC3 instrument produces trilinear data, we are able to use this powerful chemometric technique, which is better known for the analysis of two-dimensional (2D) separations with multichannel detection (e.g., GC x GC-TOFMS) or multiple samples (or replicates) of 2D data. Using PARAFAC, we mathematically separate (deconvolute) the 3D data "volume" for overlapped analytes (i.e., ellipsoids), provided there is sufficient chromatographic resolution in each of the three separation dimensions. Additionally, PARAFAC is applied to quantify analyte standards. For the quantitative analysis, it is demonstrated that PARAFAC may provide a 10-fold improvement in the signal-to-noise ratio relative to a traditional integration method applied to the raw, baseline-corrected data. The GC3 instrument obtains a 3D peak capacity of 3500 at a chromatographic resolution of one in each separation dimension. Furthermore, PARAFAC deconvolution provides a considerable enhancement in the effective 3D peak capacity.  相似文献   
9.
Despite the growing interest for LMDS systems there have been only a few commercial implementations until now especially outside of the U.S.A. The use of hierarchical structure through two‐layer networking has been even rarer. In many cases LMDS systems have strong advantages against their competitors to cover the last mile. In this article, we review and analyze the standards currently available and describe the European two‐layer trial system developed in 1996–2000. We show why further development towards IP based LMDS is useful in the future. Most of our recommendations are based on results derived from the European Union supported research project CABSINET. It had the aim of demonstrating the viability of a 40 GHz cellular digital television system with a return channel to offer interactive services. Two systems were tested: a line of sight link using QPSK, and a non‐line of sight with COFDM modulation scheme. In the RF‐subsystems, the greatest difficulty of any viable LMDS system is to obtain a moderately low price for the user receiver, while fulfilling the hard OFDM requirements in terms of phase noise, stability and spectrum restrictions. Several options have been studied in order to design the subsystems with the smallest cost. This paper will present the architectures of the transmitters, nomadic terminals, and the design of the IF/RF subsystems for both types of modulations. The discussion is focused on system engineering and selections required in order to build a full two‐layer LMDS system. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
10.
This paper describes a systematic study on the synthesis of higher fatty esters of corn starch (starch laurate and starch stearate) by using the corresponding vinyl esters. The reactions were carried out in DMSO using basic catalysts (Na2HPO4, K2CO3, and Na‐acetate). The effect of the process variables (vinyl ester to starch ratio, catalyst intake, reaction temperature and type of the catalyst) on the degree of substitution (DS) of the starch laurate and starch stearate esters was determined by performing a total of 54 experiments. The results were adequately modeled using a non‐linear multivariable regression model (R2≥0.96). The basicity of the catalyst and the reaction temperature have the highest impact on the product DS. The thermal and mechanical properties of some representative product samples were determined. High‐DS products (DS = 2.26‐2.39) are totally amorphous whereas the low‐DS ones (DS = 1.45‐1.75) are still partially crystalline. The thermal stability of the esterified products is higher than that of native starch. Mechanical tests show that the products have a tensile strength (stress at break) between 2.7–3.5 MPa, elongation at break of 3–26%, and modulus of elasticity of 46–113 MPa.  相似文献   
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