Euler’s First-Order Explicit Method–Peridynamic Differential Operator for Solving Population Balance Equations of the Crystallization Process

Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed.

The Development of Meta-functional Approaches in Translation Studies

Functional linguistics has exerted an increasing impact on modern linguistic studies.Functional approaches,especially metafunctions have undergone a process of development and improvement.The affirmation of the metafunctions of language has aroused more and more scholars'concern on the"functional"facet of language,especially in Translation studies.The formation and improvement of functional approaches are introduced separately.

An efficient method for train-track-substructure dynamic interaction analysis by implicit-explicit integration and multi-time-step solution

In this work,a method is put forward to obtain the dynamic solution efficiently and accurately for a large-scale train-track-substructure(TTS)system.It is called implicit-explicit integration and multi-time-step solution method(abbreviated as mI-nE-MTS method).The TTS system is divided into train-track subsystem and substruc-ture subsystem.Considering that the root cause of low effi-ciency of obtaining TTS solution lies in solving the alge-braic equation of the substructures,the high-efficient Zhai method,an explicit integration scheme,can be introduced to avoid matrix inversion process.The train-track system is solved by implicitly Park method.Moreover,it is known that the requirement of time step size differs for different sub-systems,integration methods and structural frequency response characteristics.A multi-time-step solution is pro-posed,in which time step size for the train-track subsystem and the substructure subsystem can be arbitrarily chosen once satisfying stability and precision demand,namely the time spent for m implicit integral steps is equal to n explicit integral steps,i.e.,mI=nE as mentioned above.The numeri-cal examples show the accuracy,efficiency,and engineering practicality of the proposed method.

The Explicitation and Implicitation of Connectives in E-C Literature Translation:A Corpus-based Case Study on Jane Eyre

This study is aimed to discover the explicitation and implicitation of connectives in literature translation. Based on parallel corpus, two Chinese versions of Jane Eyre are studied from three aspects, Intra-language comparison, inter-language comparison and case study. The findings in the study prove the reliability of Blum-Kulka's(1986) famous explicitation hypothesis, and its possible motivations are fully explored as well.

The Explicitation in English Translation of Chinese Ancient Books from the Perspective of H/L Context Culture

The Chinese culture is classified as high-context culture and the English culture low- context.In classical Chinese,most of the information is either in the physical context or internalized in the person.But mass of the information in English is vested in the explicit code.Chinese ancient books,which are usually filled with cultural factors,need to be explicit to foreign readers who are not familiar with Chinese culture.Besides,the two languages differ in many regards.Therefore,explicitation should be adopted in the translation process in order to meet the needs of the readers,the language and the function of the text.On the basis of analysis of two translation versions of Cai Gen Tan,it is found that three types of explicitation within the translation texts are commonly adopted,which are lexical explicitation,subjects explicitation and that of cohesion and coherence.

An Analysis of the Non-mandatory Explicitation in Two English Versions of Chuanxilu from the Perspective of Poetics

Chuanxilu is a collection of Wang Yangming’s questions&answers and letters on learning.It is a masterpiece of Neo Confucianism since the pre-Qin period.This paper,from the perspective of translation poetics,takes two English versions of Chuanxilu as the main research objects,makes quantitative statistics and qualitative analysis of the non-mandatory explicitation in the translation,aiming to explore the influence of poetics on the translator’s English translation of Chuanxilu,so as to provide some enlightenment for the external translation and interpretation of Wang Yangming’s theory of mind.

Explicit K-symplectic methods for nonseparable non-canonical Hamiltonian systems

We propose efficient numerical methods for nonseparable non-canonical Hamiltonian systems which are explicit,K-symplectic in the extended phase space with long time energy conservation properties. They are based on extending the original phase space to several copies of the phase space and imposing a mechanical restraint on the copies of the phase space. Explicit K-symplectic methods are constructed for two non-canonical Hamiltonian systems. Numerical tests show that the proposed methods exhibit good numerical performance in preserving the phase orbit and the energy of the system over long time, whereas higher order Runge–Kutta methods do not preserve these properties. Numerical tests also show that the K-symplectic methods exhibit better efficiency than that of the same order implicit symplectic, explicit and implicit symplectic methods for the original nonseparable non-canonical systems. On the other hand, the fourth order K-symplectic method is more efficient than the fourth order Yoshida’s method, the optimized partitioned Runge–Kutta and Runge–Kutta–Nystr ¨om explicit K-symplectic methods for the extended phase space Hamiltonians, but less efficient than the the optimized partitioned Runge–Kutta and Runge–Kutta–Nystr ¨om extended phase space symplectic-like methods with the midpoint permutation.

The Effectiveness of Explicit Vocabulary Instruction on Productive Vocabulary Learning in Writing Among Intermediate School Learners in Saudi Arabia

This study aimed to identify the effectiveness of explicit vocabulary instruction on productive vocabulary learning in writing among intermediate school learners in Saudi Arabia,verify the existence of any statistically significant differences at the significance level of 0.01 between the mean scores of the post-test of the control group and the experimental group in the vocabulary test,and verify the existence of any statistically significant differences at the significance level of 0.01 between the mean scores of the pre-and post-test of the experimental group in the vocabulary test in favor of the post-test.The study community consisted of all intermediate school students in the Kingdom of Saudi Arabia,while the study sample included 30 students.The experimental method was adopted to identify the effectiveness of explicit vocabulary instruction on productive vocabulary learning in writing and the achievement test was used as the study tool.The study reached many results including there were no statistically significant differences at the significance level of 0.01 between the mean scores of the post-test of the control group and the experimental group in the vocabulary test and there were no statistically significant differences at the significance level of 0.01 between the mean scores of the pre-and post-test of the experimental group in the vocabulary test in favor of the post-test.According to these results,some recommendations and proposals were made including training English teachers at the intermediate school level in the Kingdom of Saudi Arabia,on explicit vocabulary instruction and conducting future researches on the trends of English teachers at the intermediate school level,in the Kingdom of Saudi Arabia,regarding the adoption of explicit vocabulary instruction while teaching the English language.

基于偏航机动的常推力定点着陆制导方法

实现定点着陆终端位置速度六分量控制通常需要发动机推力可调。提出了一种通过偏航机动实现固定推力下的定点着陆制导方法。该方法通过偏转航向角,调节发动机输出在下降轨迹平面内的分量,从而实现航程控制;为了消除推力方向偏转产生的横向位置、速度偏差,设计了偏转角符号调整策略,使得着陆器在水平面内呈“之”字形运动,以一定推进剂为代价,最终保证了下降着陆终端位置、速度的全部可控。仿真表明,所提方法简单有效,易于工程实施。

新一代Wi-Fi的新型感知信息压缩方法

通信设备由于和雷达设备的工作存在重叠,也可以实现目标检测。但是传统的通信协议采用显式反馈传输信息,导致采用通信设备检测无法保留感知信息,因此可以对显式反馈的分解流程进行改进,从而在通信的间隙实现对环境目标的感知。在MIMO系统中,波束成型是发射端利用MIMO信道状态信息生成导向矩阵,从而提升接收端接收性能的一种技术。目前显式反馈波束成型是通信中波束成型的主流方式,接收端会对接收到的信道矩阵进行奇异值分解后转换成一系列角度值传回发射端。虽然采用传统的矩阵分解流程获得反馈矩阵可以有效降低反馈的冗余信息量,但是通常会丢失掉通信设备在感知过程中获得的大部分重要信息,从而导致利用Wi-Fi信号进行目标探测的功能受到限制。研究发现对于接收到的信道矩阵利用传统的分解方式获得的反馈矩阵特征向量无法保留目标的距离,速度信息。本文提出了一种新型的分解方式,基于信道矩阵的协方差矩阵,先求解左奇异矩阵,再利用左右两个酉矩阵正交向量的对应关系,进一步求解从而获得改进的右奇异矩阵,所提改进方法保留了目标的距离、速度以及角度信息,极大地提升了有效反馈信息量。最后通过仿真实验验证了所提方法的有效性。

扣件刚度非线性对波磨区轮轨瞬态滚动接触行为的影响

WJ-8型扣件橡胶垫板刚度在长期服役过程中表现出非线性特征,静刚度随荷载增加而降低,为提高三维瞬态滚动接触有限元模型计算精确性,本文以LMA踏面车轮及CHN60型钢轨为基础,基于显式积分算法,将以往研究中线弹性扣件转化为非线性扣件,建立考虑扣件刚度非线性特征的三维轮轨瞬态滚动接触有限元模型,研究刚度非线性对车轮与钢轨波磨间高频动态响应及瞬态接触行为的影响,并重点分析了波磨工况下时频域内轮轨接触力、轴箱加速度的变化信息.结果表明:扣件非线性对轮轨接触力变化影响明显,主要表现为车轮行驶至扣件前端时强振动导致橡胶垫板表现为柔软特性使轮轨接触力减小,车轮行驶至扣件上方时在轴重作用下振动减弱表现为刚硬特性使轮轨接触力增大,轮轨力变化差异最大达到13.1%.

物理师范生核心素养培养的研究与实践

核心素养培养是基础物理教育的热点问题。在物理师范专业开展核心素养培养有助于落实“以学生发展为中心”的教育教学理念,促进师范生对物理学科特点的理解和教学素养的感悟。为此,必须显性地开展核心素养培养,把核心素养既作为教学理念也作为教学内容;引导学生学会反思与讨论;把核心素养纳入考核内容。同时,要为核心素养培养提供保障。

单步无条件稳定显式结构动力学算法

在结构动力学分析中,数值积分方法通常被用来高效和准确地求解复杂结构系统在动态负载下的响应。基于量纲分析的原理,提出一种求解结构动力学问题的单步无条件稳定显式算法。首先对所构造的关于位移和速度的函数关系式进行无量纲化处理,然后通过算法精度要求、无条件稳定条件和数值阻尼可控条件确定了其最终递推格式,并根据算法最终递推格式分析得出算法耗散与弥散特性、超调和自启动特性和多自由度系统计算步骤,最后通过数值算例验证了算法的收敛精度、可控数值阻尼和计算效率优势。研究结果表明:对于线性和非线性系统,该算法都兼具显式算法的非迭代特性和隐式算法的无条件稳定特性;该算法能实现真正意义上的自启动并且在速度和位移上均无超调;该算法的数值阻尼由单自由参数控制,数值耗散和弥散对系统低模态响应的影响可以忽略不计,与具有代表性的非迭代显式算法KR-α法相比,该算法在引入数值阻尼滤除虚假高频模态的同时更真实地保留了低阶振型的贡献,从而表现出更好的计算精度;该算法在求解非线性结构动力学问题时相较于常用隐式算法有着显著的计算效率优势,并略优于两求解器非迭代显式算法KR-α法。研究结果很有希望成为求解非线性结构动力学问题的最新且更加有效的显式算法。

一种结构不确定分析的改进多维平行六面体模型

多维平行六面体模型是一种能够同时考虑相关变量和独立变量的非概率凸集模型,更适用于工程结构中常见的多源不确定性问题。为更加有效合理地度量结构不确定性,提出一种改进多维平行六面体模型。通过定义区间变量的相关角和边缘区间,给出模型不确定域的显式表达式,进而给出依据实验样本点构建多维平行六面体模型的方法。3个算例分析结果表明,改进多维平行六面体模型能够较好地反映区间变量之间的相关性,是一种比传统多维平行六面体模型更为紧凑合理的模型。

长持时爆炸冲击波作用下钢梁动力响应分析

大规模爆炸时引起的长持时平面爆炸波会造成结构的整体破坏,与接触爆炸或近场爆炸的破坏模式有显著差异,但相关研究不多。为研究长持时冲击波作用下钢梁的动力响应,首先基于耦合欧拉-拉格朗日方法建立了大型数值激波管模型,然后采用该数值激波管得到作用在钢梁上的反射超压时程,最后通过显式动力学方法研究了冲击波入射方向、持时、超压等参数对钢梁破坏模式的影响规律。结果表明:本文提出的数值激波管模型能较好地模拟长持时爆炸波的绕射现象,可得到可靠的反射超压和冲量时程;随着冲击波入射角度的增加,简支钢梁跨中位移增大;冲击波超压峰值相同时,随着持时的增加,简支梁跨中的最大位移有增大的趋势,最大位移的增长速率则会变缓;简支钢梁在长持时爆炸冲击波作用下容易发生受弯破坏,梁跨中翼缘板会出现局部屈曲现象。

“三全育人”理念下大学生职业素养指标体系的构建

基于“三全育人”理念,以大学生隐性职业素养开发来补充和完善传统的显性职业素养开发的理念,衡量分析目前高校的职业素养开发状况,以全员、全过程、全方位的理念探讨大学生职业素养指标体系的构建,根据目前高校的职业素养教育以及企业管理实践,明确大学生显性职业素养指标和隐性职业素养指标,并突出职业政治素质教育,把思想价值引领贯穿大学生就业教育全过程和各环节,争取能够实现就业思政,培养综合性人才的教育目标。

招商宣传语篇隐性衔接的汉英翻译显化

汉语招商宣传语篇行文简约凝练,其语篇衔接表现出明显的“隐性”特征。由于招商宣传语篇隐性衔接主要筑基于汉文化认知模式,涉及的社会文化知识元素不多,汉英翻译时建议采用显化策略,以便兼顾劝说功能和原文信息的完整再现。在具体操作层面,可以采用补全事理逻辑关系、揭示图式意义关系、明确深层意义关系、完善段落主题框架和突显段落逻辑主线等方法。

《文心雕龙》英译的外显化策略分析

本文基于自建汉英平行语料库,对《文心雕龙》宇文所安译本和施友忠译本的外显化特征进行定量和定性相结合的研究。通过提取威氏拼音和词汇、句法层面的参数发现:两个英译本总体呈现外显化特征,主要体现在译文的语言及诗学形式、词句意义和文化语境等方面,背后的非文本原因可归于翻译意图、文化立场和意识形态等因素。两位译者的外显化翻译使译文指涉更加明确,语境更加清晰,意义更易理解,原著的文论思想、美学精神和文化内涵得到充分阐释。外显化翻译在信息补偿、话语建构和文论互动方面具有一定价值,表明其作为中国古代文论的指导性翻译策略具有可能性和可行性。

新时代青年大学生爱国主义的变迁与启示

新时代青年大学生爱国主义的积极变化主要表现在:展现空间上,新时代青年大学生更加注重在合作开放的全球化中谋取正当的民族权益,网络爱国行动更加积极主动;表现形式上,新时代青年大学生的理性爱国成分占比逐步增加,爱国行为更为匹配爱国认知;心理状态上,新时代青年大学生正在从外显自尊向真实自豪转变,反向表达多是为了抒发正向情感。这些变迁启示我们:新时代青年大学生的爱国主义教育未来应以复杂的全球化和加速的网络化为主要场域,应以言行理性化和实践指向性为主要方向,应以国家现代化和民众获得感为主要基础。

智能汽车轨迹跟踪多目标显式模型预测控制

针对现有智能汽车轨迹跟踪控制算法难以同时保证跟踪精确性、横向稳定性、舒适性以及控制实时性的问题,提出了一种基于多目标优化和显式模型预测控制理论的轨迹跟踪控制策略(MO-EMPC)。首先,建立考虑跟踪精确性、横向稳定性、舒适性的多目标函数及约束。然后,针对传统MPC控制实时性低的问题,设计基于EMPC的多目标优化轨迹跟踪控制器,通过引入多参数二次规划(MPQP)理论,将反复在线优化求解过程转化为等价的分段仿射系统(PPWA),离线计算得到最优显式控制律以供实时控制调用,减少在线运算时间。最后,基于CarSim/Simlink联合仿真方法,将所设计控制器的轨迹跟踪多目标优化效果与MPC控制效果进行对比验证。研究结果表明,所提出的轨迹跟踪策略在保证良好的跟踪精度前提下,横向稳定性、舒适性方面的表现更优于MPC控制器,且算法在线运行速度提高56.63%。