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81.
Nikolov ID  Monovsky VK 《Applied optics》1994,33(17):3695-3701
We present results obtained in the implementation of adaptive methods and a system for image processing. The light-developing nonlinear elements are used in the filtering block of the mirror optical configuration. The processing of gray-scale and of binary images with the help of adaptive optical elements is fulfilled for realization of ground-suppressing, contouring, differentiating, and skeletonizing adaptive filters. A comparison is made between optical and digital methods applied in the pattern processing.  相似文献   
82.
用CMOS工艺实现VSR光电集成接收机的途径   总被引:1,自引:0,他引:1  
介绍了10Gbit/s速率的甚短距离光传输系统VSR(Very Short Reach)中的接收机。分析了几种有希望用于VSR系统的CMOS工艺兼容的光电探测器。提出用CMOS电路实现VSR光电集成(OEIC)接收机的可能性和实现方法。  相似文献   
83.
文章采用系统工程的观点和方法来讨论计算机这一现代化信息处理工具如何在市场营销管理中的应用问题。首先分析了市场营销管理系统的现状和存在的问题、系统的输入输出信息关系以及系统的数据流程图(即业务流程图)等,然后根据现代化市场营销管理的要求,构造出市场营销管理系统的功能结构图和系统的计算机处理模型图(即系统模型图)。  相似文献   
84.
Cyclodextrin glycosyltransferase (CGTase) is an industrially important enzyme that produces cyclodextrins (CD) from starch by intramolecular transglycosylation. CGTase consists of five globular domains labeled A through E. To better understand the role of domain E in CGTase catalysis, we have constructed several mutants of Bacillus macerans CGTase. Removing the entire E domain resulted in an inactive enzyme. Adding six amino acids between domains D and E caused a decrease in activity and thermostability. Replacing domain E with the similar starch-binding domain from Aspergillus awamori glucoamylase I caused a drastic decrease in activity, indicating the necessity of correct alignment of bound substrate. Substituting tyrosine residue 634 (Tyr634) with phenylalanine had very little effect on activity or thermostability. Substituting Tyr634 with glycine resulted in a 25% increase of specific cyclization and starch-hydrolyzing activities compared with that of the wild-type enzyme. The latter mutant was less thermostable. The results of this study indicate that domain E is important for the stability and integrity of B. macerans CGTase.  相似文献   
85.
A new technology for treating waste plastics (WP) by traditional coking process was introduced. With a thermo-balance and a 10 g atmospheric fixed bed reactor, the thermo-gravimetric behavior and product were studied during co-coking of WP with blended coal. And then, using a coke-oven with capacity of 200 kg, the characteristics of products were assessed. The results showed that there is an overlapping temperature range (200-550℃ ) of decomposition between WP and blended coal, and the pyrolysis synergism index η and synergism strength β proposed could evaluate the synergism between them. 1% of added WP results in the maximum synergism in all series experiments. The increase of added WP decreases the synergism. Tar yield in co-coking is increased with the decrease of water yield for synergism. Moreover, it was also found that the quality indexes of coke, such as M10, M40, CRI and CSR, are degraded with the increase of WP until 4%, though the quality of tar and gas is optimized for WP addition.  相似文献   
86.
Using CD spectroscopy, guanine tetraplex formation was studied with short DNA fragments in which cytosine residues were systematically added to runs of guanine either at the 5' or 3' ends. Potassium cations induced the G-tetraplex more easily with fragments having the guanine run at the 5' end, which is just an opposite tendency to what was reported for (G+T) oligonucleotides. However, the present (G+C) fragments simultaneously adopted other conformers that complicated the analysis. We demonstrate that repeated freezing/thawing, performed at low ionic strength, is a suitable method to exclusively stabilize the tetraplex in the (G+C) DNA fragments. In contrast to KCl, the repeated freeze/thaw cycles better stabilized the tetraplex with fragments having the guanine run on the 3' end. The tendency of guanine blocks to generate the tetraplex destabilized the d(G5).d(C5) duplex whose strands dissociated, giving rise to a stable tetraplex of (dG5) and single-stranded (dC5). In contrast to d(G3C3) and d(G5C5), repeated freezing/thawing induced the tetraplex even with the self-complementary d(C3G3) or d(C5G5); hence the latter oligonucleotides preferred the tetraplex to the apparently very stable duplex. The tetraplexes only included guanine blocks while the 5' end cytosines interfered neither with the tetraplex formation nor the tetraplex structure.  相似文献   
87.
对电沉积非晶态铬镀层的研究现状,非晶态铬镀层的组织与性能特点进行了全面的综述,指出了研究中尚未解决的问题,展望了非晶态铬镀层在工程中的应用前景.  相似文献   
88.
Single and bi-metallic silver modified ZSM-5 catalysts were synthesized using three methods of preparation, characterized by different techniques: X-ray powder diffraction (XRD), scanning electron microscopy (SEM), nitrogen physisorption, X-ray fluorescence (XRF), inductively coupled plasma atomic emission spectrometry (ICP-AES) and tested in heterogeneous catalytic decomposition of ozone at ambient temperature. The highest degree of ozone decomposition was observed over 5Ag(Imp)-H(IE)-ZSM-5 catalyst, which exhibit 97% conversion and does not show any deactivation with the time. The method of preparation, amount of supported silver and the presence of modifiers as Cu, Ce, and Zr were found to be important for the ozone decomposition reaction.  相似文献   
89.
This paper describes the application of 3-D synthetic aperture focusing (SAF) to a single-element trans-rectal ultrasound transducer. The transducer samples a 3-D volume by simultaneous rotation and translation, giving a helical motion. Two different 3-D SAF methods are investigated, a direct and a two-step approach. Both methods perform almost identically for simulated scatterers and give a significant improvement in azimuth resolution and a constant resolution in elevation. Side lobes below -60 dB are achievable for both methods. Validation of the method is achieved by scanning a simple wire phantom and a complex phantom containing wires in azimuth and elevation. The simple wire phantom shows the same results as that found through simulation. The complex phantom shows simultaneous focusing in azimuth and elevation for the wire scatterers. Consideration of the processing requirements for both 3-D SAF methods shows that the two-step approach can give equivalent performance using an order of magnitude fewer calculations. This reduction requires a temporary storage of 9.1 GB of data for the investigated setup.  相似文献   
90.
基于共振式水泥混凝土路面破碎车共振机构的载荷分析,给出了其共振频率和振幅的模型。针对共振机构电液比例控制系统的非线性和不确定性问题,建立了基于比例泵控马达的频率控制数学模型,设计了自适应反推滑模的频率控制算法,针对系统模型中的不确定项,给出了各参数项的自适应律,基于Lyapunov函数,证明了频率输出跟踪的渐近收敛。仿真和车载实验结果表明,该方法具有较好地频率跟踪性能,能满足共振式水泥混凝土路面破碎车的施工作业要求。  相似文献   
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