宽带DDS跳频源设计

直接数字合成（DDS）简单可靠、控制方便，具有很高的频率分辨率，高速转换，非常适合快速跳频的要求。在对DDS基本原理进行了简要介绍和分析后，提出宽带跳频源设计方案。     

陶瓷企业实施MRPⅡ现状及问题分析

分析了我国陶瓷企业实施制造资源计划的现状，并提出了成功实施的方略，最后通过实例进行了分析。     

Mining predecessor–successor rules from DAG data

Data mining extracts implicit, previously unknown, and potentially useful information from databases. Many approaches have been proposed to extract information, and one of the most important ones is finding association rules. Although a large amount of research has been devoted to this subject, none of it finds association rules from directed acyclic graph (DAG) data. Without such a mining method, the hidden knowledge, if any, cannot be discovered from the databases storing DAG data such as family genealogy profiles, product structures, XML documents, task precedence relations, and course structures. In this article, we define a new kind of association rule in DAG databases called the predecessor–successor rule, where a node x is a predecessor of another node y if we can find a path in DAG where x appears before y. The predecessor–successor rules enable us to observe how the characteristics of the predecessors influence the successors. An approach containing four stages is proposed to discover the predecessor–successor rules. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 621–637, 2006.     

线性调频雷达最小作用距离范围内目标距离的测量

介绍了一种新的探测雷达最小作用距离的方法,打破了传统的最小跟踪距离受发射脉宽局限的限制,重点介绍对发射线性调频信号的雷达的近距离探测方法,并给出了仿真计算结果。     

电磁超声流量计的研制

基于电磁声换能器的原理，研制了一种新型的电磁超声流量计，并讨论提高测量精度的措施。     

Microscale Patterning of Mesoscopic PZN-PT Single Crystal Films by Crystal ion Slicing and Laser-Induced Etching

Advances in the fabrication of solid-solution single crystal relaxor ferroelectrics have made it possible to produce highly efficient piezoelectric crystals, and have attracted renewed interest in the use of these crystals for a new generation of piezoelectric transducers, actuators and sensors. Of particular interest is their incorporation into micro-electromechanical systems (MEMS). In this paper we report on the laser-induced wet chemical etching of lead zinc niobate-lead titanate (PZN-PT) in hydrochloric acid (HCl). Argon-ion laser radiation at power levels up to 4 W is focused to a spot diameter of about 15μm and results in the chemical etching of grooves at patterning speeds up to 5μm/sec. Crystal ion slicing, an ion-implant-based film separation technique, is used in combination with laser etching to form 5 to 10μm-thick patterned and freestanding films for incorporation into micro-electromechanical devices.     

An Analysis of Citation Counts of ETRI‐Invented US Patents

From its foundation until 2004, ETRI has registered over 1,000 US patents. This letter analyzes the characteristics of these patents and addresses the explanatory factors affecting their citation counts. For explanatory variables, research team related variables, invention specific variables, and geographical domain related variables are suggested. Zero‐altered count data models are used to test the impact of independent variables. A key finding is that technological cumulativeness, the scale of invention, outputs in the electronic field, and the degree of dependence on the US technology domain positively affect the citation counts of ETRI‐invented US patents. The magnitude of international presence appears to negatively affect the citation counts of ETRI‐invented US patents.     

一种改进的MC-CDMA系统结构

MC-CDMA在频域扩频时实际上是一种频率分集,对于频率分集重数的要求通常小于子载波的数目N,故扩频因子可以小于子载波数目。改进了这种MC-CDMA系统的结构,通过在频域引入交织器,使交织后频率分集各分量经历独立的哀落,从而提高了抗哀落能力。最后给出了用系统仿真软件SPW仿真的结果。     

低温脂肪酶产生菌的筛选、鉴定及其部分酶学性质

从南极乔治王岛冻土来源的76株低温细菌中筛选到13株低温脂肪酶产生菌，对其中的BTsl0022菌株进行鉴定。通过生理生化特征、16s rDNA基因序列的同源性和系统发育分析发现，菌株RTsl0022属于假单胞菌属(Pseudomonas)，但与已定名的假单胞菌有一定的差异，与未定名的Pseudomonas sp．PsB的亲缘关系最接近，故将其暂定名为Pseudomonas sp．BTsl0022。对该菌脂肪酶的酶学性质初步研究表明，酶的最适作用温度为24℃，对热敏感，60℃处理30min仅残留25％酶活性，酶的适宜作用pH范围在7．0～9．0，最适pH为8．0。     

向家坝水电站右岸隧道进出口边坡的处理研究

文章主要从实践方面介绍了向家坝水电站右岸地方还建公路北线段隧道洞口施工期边坡缺陷处理措施,并总结了几点经验,这对于以后公路隧道洞口的设计和施工,尤其是洞口边坡塌方的处理具有一定指导意义。