Hydrodynamics of gas-solid flow around immersed tubes in bubbling fluidized beds

A numerical study was conducted based on the gas-solid two-fluid model using the body-fitted coordinate system to analyze the behavior of particles and bubbles flow in bubbling fluidized beds without and with immersed tubes. The kinetic theory of granular flow was implemented in the model. The images of simulated instantaneous particle concentration and velocity gave the process of the formation, coalescence and eruption of bubbles. The effects of the tube pitch and superficial gas velocity on the fluidization in a bubbling fluidized bed were investigated. Calculated bubble frequencies without and with immersed tubes were in agreement with previous experimental and simulation findings. The wavelet multi-resolution analysis was used to analyze the simulated data of instantaneous particle concentration. From the random-like particle concentration fluctuations, the fluctuating components due to particle flow and bubble motion can be extracted based on the wavelet multi-resolution analysis over a time-frequency plane.     

乙醛法合成乙醛酸

研究了以硝酸、乙醛为原料合成乙醛酸的方法，考察了引发剂用量、乙醛与硝酸物质的量比、硝酸浓度、反应温度、反应时间等因素的影响，获得的最佳反应条件为：n(乙醛)：n(硝酸)=0．6：1，亚硝酸钠用量为乙醛质量的1．0％，硝酸浓度30％(质量分数)，反应温度55℃，时间6h，乙醛酸收率可达45．7％(以乙醛计)。     

烧结法微晶玻璃装饰板材的力学性能研究

本文研究了烧结法微晶玻璃装饰板材的密度、抗折强度等力学性能,讨论了成分、结构对密度、抗折强度的影响.     

Recent Progress in Software Testing, Debugging and Analysis: A Survey

This article is a survey on the recent progress of some hot topics of software engineering. The survey is based on the review on the papers of three premier conferences on software engineering from 2012 to 2013. Through the quantitative analysis on these papers, there are three hot topics identified, software testing, debugging, and analysis. Focusing on these three topics, this article summarizes some new achievements in these fields, analyzes the characteristics of these works, and points out some directions for future research.     

An algorithm and observability research of autonomous navigation and joint attitude determination in asteroid exploration descent stage

In this paper, an autonomous relative navigation and joint attitude determination algorithm in asteroid exploration descent stage is researched based on feature point information of perpendicular asteroid surface image observed by optical navigation camera, distance vectors from spacecraft to asteroid measured by three angled installed lidars and relative velocity increment measured by accelerometer when the relative distance vector to the centroid of asteroid can not be obtained. The inertial attitude of spacecraft is determined by sun vector, star vectors and inertial angular velocity respectively measured by sun sensor, star trackers and inertial reference unit. Also, in order to obtain measurement error model transferred from sensor noise, a covariance matrix solver considering error correlation is presented via the error model of normalized vector to first order. Numerical simulation and improved observability evaluation of filtering are undertaken to discuss the results of complete sensor observation and weak observation of lidars, and verify the effectiveness of the presented relative navigation and attitude determination algorithm.     

医院信息系统项目管理的现状与突破

自20世纪90年代以来,我国医院信息系统发展迅速。到目前为止,全国绝大部分医院实现了信息化管理,并且逐步向区域医疗信息资源共享模式迈进。在医院信息化建设进程中,随着信息系统规模日益庞大,信息管理部门对它的驾驭能力捉襟见肘,原有粗放式的管理模式已远不能适应工作需要。有必要重新审视医院信息系统项目管理模式,实现新的突破。本文以医院信息科为视角,探讨将项目管理九大手段运用到医院信息系统项目建设过程中的作用及效果。     

工控设备的安全保密风险评估实践

近期披露的信息安全事件表明,工控系统已经成为国外信息安全攻击的主要目标,必须加强工控系统的信息安全防护。工控系统与办公系统不同,系统中使用智能设备、嵌入式操作系统和各种专用协议,尤其是智能设备具有集成度高、行业性强、内核不对外开放、数据交互接口无法进行技术管控等特点,工控系统的安全风险评估方法、标准还在不断探索中。本文介绍工控设备安全保密风险评估模型和评估流程,以数控设备840D为例,进行工控设备的安全保密风险评估,围绕工控设备全生命周期给出了安全保密防护和检测的建议。     

高纯度甲基磺酸亚锡生产新工艺

研究了用锡和甲基磺酸反应直接生产电镀用的纯甲基磺酸亚锡的新工艺，其产品纯度达到99．5％以上，并研究了提高设备利用率和生产效率的措施，设备利用率可提高2．28倍，建成的150t/a甲基磺酸亚锡生产装置，其产品产量、质量均达到了预期效果。该工艺无毒无害无三废排放。     

Highly stable novel inorganic hydrides from aqueous electrolysis and plasma electrolysis

After 10⁴ h of continuous aqueous electrolysis with K₂CO₃ as the electrolyte, highly stable novel inorganic hydride compounds such as KH KHCO₃ and KH were isolated and identified by time of flight secondary ion mass spectroscopy (ToF-SIMS). The existence of novel hydride ions was determined using X-ray photoelectron spectroscopy (XPS) and solid state magic-angle spinning proton nuclear magnetic resonance spectroscopy (¹H MAS NMR). A novel hydride ion formed by plasma electrolysis of a K₂CO₃, Rb₂CO₃, or Cs₂CO₃ electrolyte was also observed by high resolution visible spectroscopy at 407.0 nm corresponding to its predicted binding energy of 3.05 eV.     

纳米碳酸钙对CPE／PVC体系脆韧转变的影响

纳米碳酸钙的加入可以使CPE／PVC用较少的CPE使制备的复合材料达到超韧，而轻质活性碳酸钙的加入却使其脆一韧转变大大延迟。加入了碳酸钙的体系的拉伸强度比不加的约低1MPa左右，但弯曲模量得到了提高，纳米碳酸钙和普通碳酸钙对拉伸强度和弯曲模量影响的区别不大。通过分析认为：银纹的引发与有效的终止是决定纳米碳酸钙刚性体分散相增韧合金材料，促进其脆-韧转变提前的一个重要因素。