离子色谱法测定配煤、焦炭和焦油中的氯含量

研究了用带电导检测器的离子色谱对配煤、焦炭和焦油中的Cl- 进行测定的方法。在YSA型8126A-4# 阴离子分离柱上用3.5mmol/LNa2CO3、5.3mmol/LNaHCO3做淋洗液对Cl-进行测定,方法简便快速。Cl-的检出限为2×10-6。该法也适用于F-、NO2-、NO3-、SO42-等的测定。     

几种表面活性剂在香精产品中的应用

本文阐述了几种表面活性剂在香精中应用的调配研究过程以及期间出现的不同现象,并对其进行了对比、比较.细述了这几种表面活性剂在应用过程中所出现的不同特征.     

A Non-Line-of-Sight mitigation localization algorithm for sensor networks using clustering analysis

Non-Line-of-Sight propagation of wireless signal has an impact on measured distances in range-based localization and will bias the final localization results. A new localization algorithm is proposed in this paper to mitigate Non-Line-of-Sight errors when there are more than enough anchor nodes deployed around the node to be located. This algorithm utilizes multi-round clustering analysis to filter the pre-located estimators which derive from all possible subsets of measured distances. In each round, the method density-based spatial clustering of applications with noise is adopted. Simulations show that the proposed algorithm can effectively improve localization accuracy not only when the measured distances with Non-Line-of-Sight error are minor but also under the condition that all of them suffer random Non-Line-of-Sight error.     

Acidic and catalytic properties of niobic acid crystallized at low temperature

Niobic acid was crystallized at 120 °C for 48 h, which showed the largest acid amounts at higher acid strengths. The crystallized niobic acid calcined at 300 °C was found to show higher activity than uncrystallized niobic acid and niobic acid washed with water or treated with sulfuric acid or phosphoric acid for the dehydration of isopropanol and the esterification of ethanol with acetic acid.     

基于SOAP的企业异构信息系统集成

阐述了SOAP通信协议的构成和实现机制以及与相似协议的比较。基于它的跨平台的能力,将其运用于企业的分布式环境中,实现了异构信息系统间的互操作和跨部门的数据处理,提高企业数据处理的效能,同时为企业异构信息系统集成提供了新的方法。     

Dynamics modeling and analysis of a flexible-base space robot for capturing large flexible spacecraft

Space robots are in huge demand due to the rapid growth of their service targets, i.e., spacecraft. There are generally large flexible components on spacecraft, such as antenna reflectors and solar paddles. Due to the vibratility of their structure, it is challenging for a space robot with flexible appendages (the base is then called flexible-base) to capture and repair the large flexible spacecraft. After capturing, the two spacecraft with flexible appendages are connected by a space manipulator, and a compounded system is formed. In this paper, we developed a dynamic model and a closed-loop simulation system, to provide a means to verify path planning and control algorithms. Initially, the dynamic characteristics of different capturing stages (preimpact and post-impact) were analyzed. The topologies of a flexible-base space robot and the compounded system were described based on incidence and channel matrices. Secondly, the recursive dynamics was formulated and resolved by an effective numerical method. The modeling was verified by Adams’ model. Thirdly, we implemented a dynamics calculation block in Matlab/Simulink environment using the S-function package for the C program, and developed a closed-loop simulation system, which was composed of the Planning and Controller, the Multibody Dynamic, and the 3D Display modules. Finally, based on the simulation system, two typical missions—target berthing and on-orbital manipulation of the target along a circle, were simulated and evaluated. Dynamics analysis results presented some useful rules for the path planning and control to suppress the vibration of the flexible structure.     

Users’ interest grouping from online reviews based on topic frequency and order

Large volume of online review data can reveal consumers’ major interests on domain product, which attracts great research interests from the academic community. Most of the existing works focus on the problems of review summarization, aspect identification or opinion mining from an item’s point of view such as the quality or popularity of products. Considering the fact that users who generate those review texts draw different attentions to product aspects with respect to their own interests, in this article, we aim to learn K users’ interest groups indicated by their review writings. Such K interest groups’ identification can facilitate better understanding of major and potential consumers’ concerns which are crucial for applications like product improvement on customer-oriented design or diverse marketing strategies. Instead of using a traditional text clustering approach, we treat the groupId/clusterId as a hidden variable and use a permutation-based structural topic model called KMM. Through this model, we infer K interest groups’ distribution by discovering not only the frequency of product aspects (Topic Frequency), but also the occurrence priority of respective aspects (Topic Order). They jointly present an informative summarization on the raw review corpus. Our experiment on several real-world review datasets demonstrates a competitive solution.     

基于EFPN的模糊离散事件系统可诊断性分析

针对模糊有限自动机及模糊Petri网在模糊离散事件系统(Fuzzy Discrete Event System,FDES)行为建模中的不足,提出一种扩展模糊Petri网(Extended Fuzzy Petri Net,EFPN),并基于EFPN构造了FDES行为模型及系统故障诊断器。EFPN以一种新的事件模型为基础对FDES的系统行为进行建模,并根据事件触发矩阵计算下一系统状态中各分量的可能性分布。与模糊有限自动机及模糊Petri网的对比分析表明,在描述FDES模糊事件时,对于同步距离为0的一组事件所造成的影响,EFPN的表达能力强于经典模糊Petri网;在对含有多个状态分量的FDES建模时,EFPN模型的规模远小于模糊有限自动机。在基于EFPN构造的系统行为模型中,运用可达状态标识图分析系统状态集,可有效地构造FDES的故障诊断器,并可据此进行系统可诊断性分析。