压裂车车架动态特性分析与研究

通过对压裂车车架进行有限元模态分析,提取车架固有频率及振型,制定压裂车车架动态特性评价准则,获得车架动态特性以保证其安全性与稳定性,为车架优化设计及压裂车设计与开发提供理论基础。     

低位水喷射真空除氧器与节能

在工业上，锅炉采用的是地位水喷射真空除氧器技术，相比用大气热力除氧技术，采用低位真空除氧器不仅效果显著，而且此项技术的节能效果也是令人欢喜。因此。本文就针对当前工业锅炉采用的低住真空除氧器技术的工作原理、系统组成以及性能特点、节能等内容进行了探讨，希望此项技术能够被进一步推广与使用，节省工业能源。     

美国理想班组支援武器系统(OCSW)及其发展

概述 美国理想班组支援武器(OCSW)系统(图1)的研制,由美国三军轻武器规划办公室负责,普赖麦克斯技术公司(前奥林公司)主承包。该武器系统自1994年开始研制,预计2000年结束,2010年装备部队。它是集火控、材料及弹药领域内的最新技术于一体的下一代步兵班组支援武器系统,将为21世纪士兵提供精确、远射程、毁灭性火力。 目前,该项目已经进行到原理样机试验阶段。在第34届     

基于OAV和AEDA对工夫红茶的PLSR分析

采用顶空蒸汽蒸馏提取结合气相色谱-质谱联用技术及气相色谱-嗅闻技术,对4?种中国工夫红茶进行定性、定量分析。根据香气成分的香气活力值和芳香萃取物稀释分析分别筛选出30、36?种挥发性成分作为香气成分,结合2?种方法确定22?种香气成分为工夫红茶的香气关键成分,并将其与感官属性和红茶样品进行偏最小二乘法相关性分析。确定对工夫红茶香气起重要作用的22?种关键香气物质为：1-戊醇、叶醇、1-辛烯-3-醇、反式氧化芳樟醇、芳樟醇、顺-6-壬烯醇、香叶醇、苯甲醇、苯乙醇、橙花叔醇、戊醛、己醛、反-2-己烯醛、糠醛、（反,反）-2,4-庚二烯醛、苯乙醛、（反,反）-2,4-癸二烯醛、水杨酸甲酯、丙位-壬内酯、2,3-丁二酮、2-庚酮和香豆素。     

解析俄罗斯SV98狙击步枪

本刊在2007年1(下)期刊登了《各司其职:俄罗斯SVD与SV98狙击步枪》一文,介绍了这两支7.62mm狙击步枪不同的战术定位。本文更进一步挖掘俄罗斯新列装的SV98狙击步枪,对这一步枪再探究竟。     

浅谈无损检测诊断技术

无损检测技术是一门新兴的综合性技术,具有一定的适用性,在煤矿机械设备维修中使用该技术非常重要.     

Semantic Role Labeling of Chinese Nominal Predicates with Dependency-Driven Constituent Parse Tree Structure

This paper explores a tree kernel based method for semantic role labeling （SRL） of Chinese nominal predicates via a convolution tree kernel. In particular, a new parse tree representation structure, called dependency-driven constituent parse tree （D-CPT）, is proposed to combine the advantages of both constituent and dependence parse trees. This is achieved by directly representing various kinds of dependency relations in a CPT-style structure, which employs dependency relation types instead of phrase labels in CPT （Constituent Parse Tree）. In this way, D-CPT not only keeps the dependency relationship information in the dependency parse tree （DPT） structure but also retains the basic hierarchical structure of CPT style. Moreover, several schemes are designed to extract various kinds of necessary information, such as the shortest path between the nominal predicate and the argument candidate, the support verb of the nominal predicate and the head argument modified by the argument candidate, from D-CPT. This largely reduces the noisy information inherent in D-CPT. Finally, a convolution tree kernel is employed to compute the similarity between two parse trees. Besides, we also implement a feature-based method based on D-CPT. Evaluation on Chinese NomBank corpus shows that our tree kernel based method on D-CPT performs significantly better than other tree kernel-based ones and achieves comparable performance with the state-of-the-art feature-based ones. This indicates the effectiveness of the novel D-CPT structure in representing various kinds of dependency relations in a CPT-style structure and our tree kernel based method in exploring the novel D-CPT structure. This also illustrates that the kernel-based methods are competitive and they are complementary with the feature- based methods on SRL.     

数控加工过程的虚拟仿真系统

研究了对数控加工过程的虚拟仿真;阐述了系统的整体框架;着重讨论了本系统中机床、刀具和工件等模型的建立以及NC代码的读取与解析问题。系统仿真效果真实感强、实时性好。