Studies on Alternating Pulse Current-Chronopotentiometric Stripping Analysis

Alternating pulses current - chronopotentiometric stripping analysis (APC-CPSA) is a new method as a variant of chronopotentiometric stripping analysis (CPSA). During the stripping step an alternating pulse current with a high frequency in a square wave mode is imposed on the electrode system. Thus, tau and sensitivity of APC-CPSA is increased a lot. The tau, E similar to t equation and its reciprocal derivative equation for APC-CPSA are derived and verified by the experimental results.

Fast Tensor Principal Component Analysis via Proximal Alternating Direction Method with Vectorized Technique

This paper studies the problem of tensor principal component analysis (PCA). Usually the tensor PCA is viewed as a low-rank matrix completion problem via matrix factorization technique, and nuclear norm is used as a convex approximation of the rank operator under mild condition. However, most nuclear norm minimization approaches are based on SVD operations. Given a matrix , the time complexity of SVD operation is O(mn2), which brings prohibitive computational complexity in large-scale problems. In this paper, an efficient and scalable algorithm for tensor principal component analysis is proposed which is called Linearized Alternating Direction Method with Vectorized technique for Tensor Principal Component Analysis (LADMVTPCA). Different from traditional matrix factorization methods, LADMVTPCA utilizes the vectorized technique to formulate the tensor as an outer product of vectors, which greatly improves the computational efficacy compared to matrix factorization method. In the experiment part, synthetic tensor data with different orders are used to empirically evaluate the proposed algorithm LADMVTPCA. Results have shown that LADMVTPCA outperforms matrix factorization based method.

Material Design and Experimental Analysis of a New Type of Semiconductor ER Fluids

To improve the electrorheological effect of electrorheological fluid (ERF), a new type of the electrosensitive particle material, polynaphthalene quinone was prepared, whose molecules contain blended atoms of nitrogen, oxygen, sulphur and big π bond conjugate system. In both DC and AC electric fields, the ERF material showed a distinct ER effect. Especially, in the alternating electric field, the shear stress of this material versus AC voltage has a better quadratic relation than that of the other materials. The experimental data showed that organic semiconductor polymers with big π bond conjugate system are a new type of electrosensitive particle materials which are worth well developing.

一种在紧框架下求解Analysis Dantzig-selector模型的快速算法

Analysis Dantzig-selector模型是基于经典Dantzig-selector的l_(∞)限制的l_(1)分析模型。本文使用了紧框架下求解此模型的线性化交替方向乘子法,使得每个子问题都有显式解析解,并通过数值实验证明了该方法的有效可行性。

Chebyshev Fitting Way and Error Analysis for Propeller Atlas across Four Quadrants

A Chebyshev fitting way for a propeller atlas across four quadrants is discussed. As an example, Chebyshev polynomial fitting results and its error analysis are given. Because it’s difficult generally to get a propeller atlas across four quadrants, a way is used to construct an alternative with higher accuracy based on the properties. As an application example, an alternative for the propeller property of a Deep Submergence Vehicle across four quadrants is given practically and a simulation model of the four quadrants propeller for dynamic condition is set up. The model lays a foundation for DSV full operating-condition movement simulation. A lot of simulation work shows that the results are very close to the practical data and, therefore, are effective.

Comparative analysis of volatile constituents between herbal pair flos lonicerae-caulis lonicerae and its single herbs

Gas chromatography-mass spectrometry(GC-MS) and the chemometric resolution method(alternative moving window factor analysis,AMWFA) were used for comparative analysis of volatile constituents in herbal pair(HP) flos lonicerae-caulis lonicerae(FL-CL) and its single herbs.The temperature-programmed retention index(PTRI) was also employed for the identification of compounds.In total,44,39,and 50 volatile chemical components in volatile oil of FL,CL and HP FL-CL were separately determined qualitatively and quantitatively,accounting for 87.22%,94.54% and 90.08% total contents of volatile oil of FL,CL and HP FL-CL,respectively.The results show that there are 32 common volatile constituents between HP FL-CL and single herb FL,33 common volatile constituents between HP FL-CL and single herb CL,and 10 new constituents in the volatile oil of HP FL-CL.

Entropy Analysis of Vapor-Compression Refrigeration System by Using the Second Law of Thermodynamics

By means of the Second Law of Thermodynamics,thispaper gives out the entropy analysis method for vapor-comperession refrigeration system.The thermal irrevers-ibility of the system charged with R12 and its hopeful al-ternative refrlgerant R134a have been studied respective-ly.On the basis of all the research results of this paper,the measure used to save energy for vapor-compressionrefrigeration system has been put out.

Implementing an Information System Strategy: A Cost, Benefit, and Risk Analysis Framework for Evaluating Viable IT Alternatives in the US Federal Government

In the US Federal government, an analysis of alternatives (AoA) is required for a significant investment of resources. The AoA yields the recommended alternative from a set of viable alternatives for the investment decision. This paper presents an integrated AoA and project management framework for analyzing new or emerging alternatives (e.g., Cloud computing), as may be driven by an information system strategy that incorporates a methodology for analyzing the costs, benefits, and risks of each viable alternative. The case study in this paper, about a business improvement project to provide public health and safety services to citizens in a US Federal agency, is a practical application of this integrated framework and reveals the benefits of this integrated approach for an investment decision. The decision making process in the framework—as an integrated, organized, and adaptable set of management and control practices—offers a defensible recommendation and provides accountability to stakeholders.

Alternative RNA splicing in stem cells and cancer stem cells:Importance of transcript-based expression analysis

Alternative ribonucleic acid(RNA)splicing can lead to the assembly of different protein isoforms with distinctive functions.The outcome of alternative splicing(AS)can result in a complete loss of function or the acquisition of new functions.There is a gap in knowledge of abnormal RNA splice variants promoting cancer stem cells(CSCs),and their prospective contribution in cancer progression.AS directly regulates the self-renewal features of stem cells(SCs)and stem-like cancer cells.Notably,octamer-binding transcription factor 4A spliced variant of octamerbinding transcription factor 4 contributes to maintaining stemness properties in both SCs and CSCs.The epithelial to mesenchymal transition pathway regulates the AS events in CSCs to maintain stemness.The alternative spliced variants of CSCs markers,including cluster of differentiation 44,aldehyde dehydrogenase,and doublecortin-like kinase,α6β1 integrin,have pivotal roles in increasing selfrenewal properties and maintaining the pluripotency of CSCs.Various splicing analysis tools are considered in this study.LeafCutter software can be considered as the best tool for differential splicing analysis and identification of the type of splicing events.Additionally,LeafCutter can be used for efficient mapping splicing quantitative trait loci.Altogether,the accumulating evidence re-enforces the fact that gene and protein expression need to be investigated in parallel with alternative splice variants.

Progressive Collapse Analysis of Concrete-Filled Steel Tubular Frames with Semi-rigid Connections

A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of simulation, which include substructure model, beam element model and solid element model. The comparison results show that the substructure model has a satisfying capability, calculation efficiency and accuracy to predict the concerned joints as well as the overall framework. Based on the substructure model and a kind of semi-rigid connection for concretefilled square hollow section steel column proposed in this paper, the nonlinear dynamic analyses are conducted by the alternate path method. It is found that the removal of the ground inner column brings high-level joint moments and comparatively low-level axial tension forces. The initial stiffness and transmitted ultimate moment of the semi-rigid connection are the main factors that influence the frame behavior, and their lower limit should be guaranteed to resist collapse. Reduced ultimate moment results in drastic displacement and axial force development, which may bring progressive collapse. The higher initial stiffness ensures that the structure has a stronger capacity to resist progressive collapse.

An analysis method of injection and production dynamic transient flow in a gas field storage facility

A dynamic transient flow analysis method considering complex factors such as the cyclic injection and production history in a gas field storage facility was established in view of the limitations of the existing methods for transient flow analysis and the characteristics of the injection-production operation of strongly heterogeneous gas reservoirs, and the corresponding theoretical charts were drawn. In addition, an injection-production dynamic transient flow analysis model named "three points and two stages" suitable for an underground gas storage(UGS) well with alternate working conditions was proposed. The "three points" refer to three time points during cyclic injection and production, namely, the starting point of gas injection for UGS construction, the beginning and ending points of the injection-production analysis stage;and the "two stages" refer to historical flow stage and injection-production analysis stage. The study shows that the dimensionless pseudo-pressure and dimensionless pseudo-pressure integral curves of UGS well flex downward in the early stage of the injection and production process, and the dimensionless pseudo-pressure integral derivative curve is convex during the gas production period and concave during the gas injection period, and the curves under different flow histories have atypical features. The new method present in this paper can analyze transient flow of UGS accurately. The application of this method to typical wells in Hutubi gas storage shows that the new method can fit the pressure history accurately, and obtain reliable parameters and results.

Studying History Education of High School in Taiwan by Causal Layered Analysis

After the 21st century,high school history learning will focus on teachers promoting the twelve-year state education.In recent years,in line with the changes in the new 108-year social curriculum,supporting strategies have been proposed:such as literacy orientation,inquiry and practice,learning process archives,and the structural direction of the controversial Chinese history into East Asian history.Historical learning has indeed had a great impact on the people’s national spiritual education and the development of historical consciousness in Taiwan’s education policy.This is the reason Taiwan’s Ministry of Education strives to improve students’historical literacy and connotation application abilities.When developing a learning policy,both external and internal learning factors need to be considered.The external aspect deals with the reasons for learning:Is learning for the purpose of using or accumulating historical wisdom in daily life to learn from the past and the present,on the other hand,to test the content of the course and the degree of absorption;or is it specifically for exams or other enlightenment purposes.The internal aspect involves those most affected by the policy:students and teachers.After studying and observing high school history learning policies for decades,some alternative future visions for history learning were found in the method of reflection on future research-the conclusion is that history is interestingly revitalized,and the preferred future is thematic history.According to the famous futurology scholar Sohail Inayatuallah’s proposal:the causal layering model.It helps understand how Taiwan’s historical policies operate.And how teachers and students on the front line respond to changes and take future actions.The key is to change the future:in the process of building an alternative future,whether the internal and external mix has changed or whether you want to try new things and expand your horizons.In fact,the difficulty of teaching lies in students’cooperation and conscious learning.Therefore,in the analysis of learning through alternative futures,is it possible to distinguish between internal and external situations and methods such as:1.Internal:Is education centered on teachers?Or is it student-centered?2.External:Does the Ministry of Education prioritize testing,or encourage teachers to adopt interactive communication and integrate education into the curriculum?Therefore,what is the function and inspiration of studying high school history and life?If thematic history teaching is used:teachers can use thematic learning methods to help students focus on causal relationships,the causes of turning points,or the evolution process of the beginning and end of events.This is more advantageous for testing based on the application topic,and it is easy to test how much understanding and understanding of history?Has an activating effect.By studying history in high school,using the“CLA(Causal layered analysis)”method of future studies,you can enter the stage of worldview exploration with the goal of improving professional depth and emotional level,and use it in your own understanding and utilization of history.Based on research,some insights into the prospects and thinking of learning history in high schools are provided:1.Facing the impact of declining birthrate,Taiwan needs a macro perspective to improve its future competitiveness and look forward to a new perspective on world history,using futuristic cause-and-effect level analysis to combine world changes with daily life applications.2.The study of history in high schools should go into a systematic construction:understand its cause-and-effect relationships and global trends,so teachers play a professional and future role in controlling the use of new information and technology.3.In the future,humans may develop more“intelligent”needs.As a reference from history or to explore the preferred path for the future,there will also be a greater need to innovate and meet challenges.4.Studying high school history has entered the professional field.Through self-exploration,it can be transformed into life affairs and establish the concept and value of lifelong learning.5.In studying the“history of high school learning”,have new prospects for the future of education.Through professional knowledge such as“trend theory and causal hierarchy analysis”of futurology,pursue new horizons and visions,making future education full of hope and possibility.

基于交替注意力机制和图卷积网络的方面级情感分析模型

方面级情感分析旨在预测给定文本中特定目标的情感极性。针对忽略方面词和上下文之间的句法关系和平均池化带来的注意力差异性变小的问题,提出一种基于交替注意力(AA)机制和图卷积网络(GCN)的方面级情感分析模型(AA-GCN)。首先,利用双向长短期记忆(Bi-LSTM)网络对上下文和方面词进行语义建模;其次,通过基于句法依存树的GCN学习位置信息和依赖关系,再利用AA机制进行多层次交互学习,自适应地调整对目标词的关注度;最后,拼接修正后的方面特征和上下文特征,得到最终的分类依据。相较于基于目标依赖的图注意力网络(TDGAT),所提模型在4个公开数据集上准确率提升了1.13%~2.67%,在5个公开数据集上F1值提升了0.98%~4.89%,验证了利用句法关系和提升关键词关注度的有效性。

基于全息希尔伯特频谱分析的交流串联电弧故障电流特征研究

针对交流串联电弧故障信号特征提取和分析的难题,提出采用循环掩码经验模态分解(itEMD)进行信号分解以获取多层内涵模态分量(IMF),结合全息希尔伯特变换(HHT)展现高维幅度调制频率调制(AM-FM)谱图的分析方法,从而获取高区分度的电弧故障信号特征谱图。采用基于GB/T 31143—2014的电弧故障实验平台,采集7种屏蔽负载模式下电弧故障电流信号,分析研究不同环境下电弧故障特征。所提方法对于电弧故障检测技术的开发具有一定的理论指导意义。

星载分布式SAR双频乒乓模式测高精度分析

星载分布式合成孔径雷达(SAR)系统用于干涉测绘,凭借其基线灵活、时间去相关很小的特点得到了快速发展。与传统模式相比,双频乒乓模式能够同时得到两种频率的多幅SAR图像,可以实现更高精度的高程测量。本文首先简单介绍了双频乒乓模式的工作原理,然后深入研究了该模式下SAR干涉对的相位比例关系和相关性,理论上分析了其干涉相位估计精度和对应的测高精度,从而为系统设计和干涉处理方法研究提供理论依据。最后仿真分析结果直观展示了双频乒乓模式相较于传统模式的优越性,由于该模式增加了不同频率的干涉相位数据,干涉相位估计精度和测高精度均显著提升。

交流电场养护对水泥浆体性能的影响

交流电场养护是一种绿色、可智能调控水泥基材料温度的快速养护方式。为研究交流电场对水泥浆体性能的影响,测试了水泥净浆试件在养护电压、试件长度、截面面积和水灰比4个影响因素作用下的温度变化,并测试了不同峰值温度条件下试件的力学性能。通过MIP测试的试件微观孔隙结构分析了峰值温度对孔隙结构的影响,讨论了交流电场能耗和电功率对峰值温度的影响。结果表明:交流电场的施加提高了水泥浆体的峰值温度和升温速率。各因素对试件峰值温度的影响由大到小依次是电压、试件长度、试件截面面积、试件水灰比。试件的抗压强度随着峰值温度的增加先上升后下降。这可能是由于试件峰值温度的提升会加速水泥的水化和产物的形成,密实了样品的孔结构,进而提升试件早期力学性能。但过高的温度也会导致试件产生热伤损,不利于微结构与性能的发展。此外,发现单位体积能耗和电功率与试件峰值温度成线性关系。

蛋白质组学数据揭示可变剪接蛋白质变体

可变剪接使同一个基因产生多种不同的转录本和蛋白质,增加蛋白质多样性和功能复杂性。转录组学和蛋白质组学是鉴定可变剪接的两种主要途径,分别通过分析RNA测序数据和蛋白质测序数据来鉴定可变剪接事件和相应蛋白质产物。尽管RNA水平的可变剪接研究已经取得了一定的进展,但是对于剪接蛋白亚型的检测和区分仍然不足。本文综述了近年来对可变剪接及其生物功能,可变剪接在不同水平检测的研究进展,详细介绍利用“自下而上”的蛋白质组学数据鉴定可变剪接蛋白质变体的两种主要方法,序列数据库构建和蛋白质鉴定算法开发。鉴定不同的可变剪接蛋白质有利于认识更全面的蛋白质功能,对发现相关生物标志物和关键药物靶点具有重要意义。

交流罐式洁净空气绝缘开关设备中弹簧触指及三相母线的发热功率计算和分析

罐式洁净空气绝缘开关设备是理想的环保开关升级解决方案,相较于箱式结构产品,其绝缘性能更优,但是其大电流发热温升问题仍较为突出。文中结合一种40.5 kV罐式洁净空气绝缘充气柜产品,从降低发热功率角度对其弹簧触指电连接和三相母线进行了建模和比较计算。采用有限元法建立了一种V字形弹簧触指电连接模型,计算了交变电磁场对并联触指分流的影响,比较了双弹簧触指和单弹簧触指的通流和功耗差异,量化计算了触指材料对发热的影响,确认了一种优选的钴青铜双触指电连接方案。通过建立三相母线的三维电磁场模型,研究了集肤效应和邻近效应对三相导体发热功率的影响,比较了可选的铝合金材料,确认选用一种高导电铝合金空心导体作为优选的设计方案,并计算比较了母线导体的交流电阻和直流电阻差异。文中所得结论和建模仿真方法,对交流大电流环保电器产品的触指及导体设计具有指导意义。

可变剪切参与茶树对草甘膦胁迫的分子响应

【目的】在茶园生产中,喷施草甘膦等除草剂时会发生药液漂移,从而严重影响茶树生长并危害茶叶品质和产量,但茶树在草甘膦胁迫下基因转录水平的变化及响应机制还知之甚少。【方法】本研究以国家级茶树良种‘舒茶早’为试材,叶片喷施草甘膦(2.50 kg ai·hm-2)后在第1 d和第5 d进行转录组测序,并对差异基因的可变剪切(alternative splicing,AS)事件进行分析和验证。【结果】内含子保留的AS类型占比最多(16.51%),其次是3’端AS(13.58%)和5’端AS(8.43%),而外显子跳跃发生频率最低(6.75%),其余类型占比54.73%;两个时间点分别有1588条和1768条差异可变剪切基因(DAGs),其中788条为共有DAGs,DAGs主要富集在类黄酮生物合成、丙酮酸代谢等与草甘膦胁迫相关通路;进一步证实了CsSDH1、CsSDH2、CsPR、CsADH、CsHD-Zip和CsMYB等基因发生AS的真实性,并且qRT-PCR验证了CsSDH1、CsSDH2和CsMYB基因及其可变剪切体的表达水平与其转录组表达水平高度一致。【结论】本研究鉴定了大量的草甘膦胁迫条件下发生AS的差异基因,并证实了其AS事件的真实性,为进一步深入探究茶树对草甘膦胁迫响应的分子机制提供理论参考。

某混凝土联方网壳结构抗连续倒塌设计

进站的高速铁路列车如果发生脱轨事故,可撞击雨棚柱并导致雨棚结构连续倒塌。考虑该风险,进行郑州南站混凝土联方网壳雨棚结构抗连续倒塌设计。建立结构多尺度有限元模型,采用拆除构件法分析拆除柱后剩余结构动力行为。结果表明,原结构拆除边柱、次边柱和中柱三种工况下,结构发生局部破坏,破坏面积分别为775、2074、547m^(2);但破坏没有蔓延,结构没有发生连续倒塌。为提高结构抗倒塌性能,针对拆除柱后剩余结构受力特点,修改原结构设计,修改后拆除边柱、次边柱和中柱工况下,结构的破坏面积分别是775、0、0m^(2),即拆除次边柱和中柱工况下雨棚结构没有发生局部破坏。