Modeling and Control of Hybrid-driven Gliding Motion for an Underwater Gliding Snake-like Robot

International Journal of Control, Automation and Systems - An underwater gliding snake-like robot (UGSR) combines the advantages of an underwater glider (UG) and an underwater snake-like robot...     

物流中心选址问题的二元语义决策方法

为了有效避免语言评价中信息的损失和扭曲,从而提高物流中心选址的准确性,在层次分析法中引入三角模糊数,将各评价指标量化,提出一种二元语义决策选址方法.给出二元语义评价的方法与步骤,并通过物流中心选址的算例分析说明该方法的合理性.     

Reaction mechanism and microstructure evolution of reaction sintered <Emphasis Type="Italic">h</Emphasis>-BN

Hexagonal boron nitride ceramic (h-BN) based on the nitridation of B powders was obtained by reaction sintering method. The effects of sintering temperature on the mechanical properties and microstructure of the resultant products were investigated and the reaction mechanism was discussed. Results showed that the reaction between B and N₂ occurred vigorously at temperatures ranging from 1 000 °C to 1 300 °C, which resulted in the generation of t-BN. When the temperature exceeded 1 450 °C, transformation from t-BN to h-BN began to occur. As the sintering temperature increased, the spherical particles of t-BN gradually transformed into fine sheet particles of h-BN. These particles subsequently displayed a compact arrangement to achieve a more uniform microstructure, thereby increasing the strength.     

针对网络不良信息的字词过滤系统设计

复杂网络环境中的不良信息处理技术需要不断更新改进。针对大量不良信息难以及时准确予以过滤净化的问题,重新设计一套字词过滤系统。详细介绍该系统中后台数据库维护、随机数据抽取、信息处理、模式匹配、审核过滤等模块的功能,并给出程序实现流程。     

如何将党建工作贯穿于企业的生产经营管理之中

党建和思想政治工作只有贯穿于企业的生产经营管理之中,实现两者的无缝对接,才能使党建工作充满活力,起到保驾护航的作用。本文围绕这一论题展开了阐述,提出了解决问题的办法,为提高企业生产经营管理水平进行了有益的尝试。     

Modal Identification of Linear Time-varying Systems Using Continuous Wavelet Transform

A wavelet based identification method for linear time-varying systems is presented,and the ridge and skeleton of the continuous wavelet transform of free response is used to extract time-varying parameters. The stiffness and damping coefficients of single-degree-of—freedom systems,frequencies and damping ratios of multi-degree-of-freedom systems are estimated without any prior information of systems. The proposed method is applied to linear time-varying systems with both abrupt and smooth variation parameters. Gaussian white noise is added to the response to test the anti-noise performance of the algorithm. The simulation results show that the proposed method is capable of accurately tracking the variation of the systems.     

THE IONIZATION THEORY OF DESULPHURIZATION WITH THE BLAST-FURNACE-TYPE SLAGS

根据新提出的碱度指标,对低碱度高炉型渣的离子结构作了假定。利用前文提出的、适用于各种碱性炼钢型渣的硫分配比公式: (％S)/[％S]=32L_Sf_S/γ_(Fe~(2+))γ_(S~(2-))·(∑n+∑n-)/n_(FeO)对Hatch和Chipman,Taylor和Stobo以及等的饱和碳铁液和高炉型渣平衡实验数据进行处理分析,得出: Igγ_(Fe~(2+))γ_(S~(2-))=-53.5 N_(O~(2-))+2.12。进一步计算证明了该硫分配比公式也适用于一般的低碱度渣。对碱性炼钢型渣适用的、关于FeO含量对脱硫作用的规律证明了也适用于低碱度渣。将f_S与(％S)/[％S]合并考虑,则(％S)/α_S基本上不受温度和铁液成分的影响。     

卧式加工中心试验模态分析

应用变时基采样的锤击法对卧式加工中心进行了试验模态分析，研究了该加工中心的动态特性，获得了感兴趣低频段的加工中心低阶固有频率。通过对整机各阶模态振型的分析，找到了加工中心结构的薄弱环节，为进行结构的优化设计指出了改进的方向。     

国内外不锈钢精炼剂研究发展现状

分析了精炼剂组元元素的作用能力，讨论并总结了精炼剂组元的复合作用，介绍了几种国内、国外精炼剂产品，提出发展高效复合精炼剂的想法。     

Preparation and characterization of GaN films grown on Ga-diffused Si （111） substrates

Hexagonal GaN films were prepared by nitriding Ga2O3 films with flowing ammonia. Ga2O3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. This paper have investigated the change of structural properties of GaN films nitrided in NH3 atmosphere at the temperatures of 850, 900, and 950℃ for 15 min and nitrided at the temperature of 900℃ for 10, 15, and 20 rain, respectively. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the structure, surface morphology and composition of synthesized samples. The results reveal that the as-grown films are polycrystalline GaN with hexagonal wurtzite structure and GaN films with the highest crystal quality can be obtained when nitrided at 900℃ for 15 min.