Direction and polarization estimation for coherent sources using vector sensors

A two-dimensional direction-of-arrival (DOA) and polarization estimation algorithm for coherent sources using a linear vector-sensor array is presented. Two matrices are first constructed by the receiving data. The ranks of the two matrices are only related to the DOAs of the sources and independent of their coherency. Then the source’s elevation is resolved via the matrix pencil (MP) method, and the singular value decomposition (SVD) is used to reduce the noise effect. Finally, the source’s steering vector is estimated, and the analytics solutions of the source’s azimuth and polarization parameter can be directly computed by using a vector cross-product estimator. Moreover, the proposed algorithm can achieve the unambiguous direction estimates, even if the space between adjacent sensors is larger than a half-wavelength. Theoretical and numerical simulations show the effectiveness of the proposed algorithm.     

环保型涂装前处理技术开发方向

随着国家对环保的重视程度日益加深,污染防治已成为几乎所有行业,尤其是工业领域急需解决的课题。而作为前瞻技术,环保型涂装前处理技术的开发将对涂装行业甚至汽车工业产生深远的意义,尤其是纳米陶瓷锆盐处理和硅烷处理技术的成功应用必将成为涂装前处理技术上的飞跃。     

基于企业服务总线的物流园区信息管理平台模型构建

采用一种与平台/编程无关的消息传递架构企业服务总线(ESB)构建物流园区信息系统平台架构,从而使物流园区能快速搭建敏捷的、按需应变的商业动态信息环境,使企业在市场上占据领先的竞争优势。     

Acquiring synonymous attribute phrases for named entities via online encyclopedia

In this work,an approach is proposed to acquire synonymous attribute phrases of named entities （NEs） from an online encyclopedia.Synonymous attribute phrases are the phrases that express the same attribute with different surface forms for a class of NEs.Specifically,the proposed approach is composed of three stages.Firstly,the entries related to a given NE class are automatically selected from an online encyclopedia.Secondly,attribute phrases are extracted based on the statistics of phrase frequency.Thirdly,synonymous attributes are identified in a pairwise manner through a classification framework combining multiple features.The proposed approach is applied on Baidu Baike,a Chinese online encyclopedia,for four different NE classes.Experimental results show that the approach obtains an average precision of 74％ and an average F-value of 65％ for the four NE classes.In particular,thousands of synonymous attribute phrase pairs are acquired for each class,which demonstrates the effectiveness of the proposed approach.     

应用氢化——原子荧光法测定钢材中的砷

研究了低温氢化—原子荧光法测定钢材中的砷时，介质、酸度等条件对测定的影响及常见元素的干扰情况。建立了用低温氢化—原子荧光法测定钢材中砷的分析方法，该方法简便快捷，用于钢材中砷的测定结果令人满意。     

重型汽车多轴转向系统摇臂机构的优化设计

以ＱＹ８０汽车起重机四轴转向摇臂机构为例，利用多刚体系统运动学理论对机构作了空间运动分析，建立了转向摇臂机构优化设计的数学模型，并用改进了的约束随机方向搜索法编写了优化设计的微机软件，并已应用于生产实践。     

两曲面立体相贯线的计算机实现

本文采用解析法，建立了两曲面立体相贯线的数学模型．据此，编制的绘图程序通用性好，绘出的相贯线精度高、速度快、输入参数少．     

离子型和非离子型表面活性剂在活性炭上的混合吸附

研究了25℃时Triton X-100(TX100),溴化十四烷基三甲铵(TTAB)和十二烷基硫酸钠(SDS)自其单组份水溶液及自TX100-SDS和TX100-TTAB混合水溶液在活性炭上的吸附。结果表明,三种表面活性剂自其单组份水溶液在活性炭上的吸附等温线均为Langmuir型;吸附能力以mol·g~(-1)为单位时的顺序为SDS>TTAB>TX100;在混合体系中,由于吸附质对吸附剂的竞争以及溶液体相中形成临界胶团浓度较小的混合胶团,使得离子型和非离子型表面活性剂的吸附相互抑制;混合体系中相应吸附量的关系是线性的。     

硝酸镨水合物热分解机理的研究

本文采用TG-DTG法研究了Pr(NO_3)3·nH_2O(n=6,4,2)的热分解行为,并通过IR对反应物、中间产物和最终产物进行了鉴别.同时,借助不同升温速率下的TG-DTG曲线,用Kissinger法计算了它们脱水的表观活化能,并利用DSC法求得了Pr(NO_3)_3·6H_2O的脱水焓.     

RuO_2电极的SEM和AFS研究

通过对 RuO_2电极在不同烧结温度和电解时间条件下表面形貌的观察与 AES分析,推断出RuO_2 电极的活性中心是氧结构空位,在电极表面凸处氧结构空位较多;随着电解的进行,电极活性降低,氧结构空位减少,但在凸处的比在凹处的减少较多,故认为反应点较多地集中在表面凸处。