Fine Characterization and Analysis of Drying Strain of the ELM Board via DIC Technology

In this paper,the occurrence and development mechanism of strain on the cross-section during the wood drying is explored.Therefore,strain regularity on the cross-section of 50 mm thickness elm(Ulmus rubra)board at the temperature of 40℃and 80℃is detected via digital image correlation technology.Hence,the difference between tangential and radial strain at surface and core layers was denoted.The results showed that strain distribution in the width direction of the board is uneven.Moreover,a large drying shrinkage strain occurs at the near-core layer,while the maximum strain difference reaches 4.08%.Hence,the surface of the board is cracked along the thickness direction.The radial strain of the board is higher than the tangential strain in the early stage of drying,while these strains are reversed in the later stage of drying.The temperature is related to the difference between the tangential and radial strains of the elm board.These differences at the core layer are larger than those of the surface layer.The conducted research results provide a theoretical basis for process optimization.

Nondestructive Testing and Characterization of Residual Stress Field Using an Ultrasonic Method

To address the difficulty in testing and calibrating the stress gradient in the depth direction of mechanical components, a new technology of nondestructive testing and characterization of the residual stress gradient field by ultrasonic method is proposed based on acoustoelasticity theory. By carrying out theoretical analysis, the sensitivity coefficients of different types of ultrasonic are obtained by taking the low carbon steel（12%C） as a research object. By fixing the interval distance between sending and receiving transducers, the mathematical expressions of the change of stress and the variation of time are established. To design one sending-one receiving and oblique incidence ultrasonic detection probes, according to Snell law, the critically refracted longitudinal wave（LCR wave） is excited at a certain depth of the fixed distance of the tested components. Then, the relationship between the depth of LCR wave detection and the center frequency of the probe in Q235 steel is obtained through experimental study. To detect the stress gradient in the depth direction, a stress gradient LCR wave detection model is established, through which the stress gradient formula is derived by the relationship between center frequency and detecting depth. A C-shaped stress specimen of Q235 steel is designed to conduct stress loading tests, and the stress is measured with the five group probes at different center frequencies. The accuracy of ultrasonic testing is verified by X-ray stress analyzer. The stress value of each specific depth is calculated using the stress gradient formula. Accordingly, the ultrasonic characterization of residual stress field is realized. Characterization results show that the stress gradient distribution is consistent with the simulation in ANSYS. The new technology can be widely applied in the detection of the residual stress gradient field caused by mechanical processing, such as welding and shot peening.

Characterization and Potential Recovery of Household Solid Waste in the City of Ouagadougou (Burkina Faso)

This study on physical and physicochemical characteristics of household solid waste (HSW) in the city of Ouagadougou by using MODECOM, “Method of Characterization of Household waste” was done fifteen (15) years after the first study. Special attention has been paid to waste sampled and also to estimate energy content, namely the higher heating value (HHV) and the lower heating value (LHV). As a general tendency, the results showed a sensitive evolution in the physical parameters of waste (composition by size and composition by category) and also in the physicochemical parameters (moisture content and energy content). The results of HSW composition study showed that regardless the seasons, fermentable fraction is dominant (39% in the rainy season and 20% in the dry season) followed by plastics (18% in the rainy season and 20% in the dry season). The moisture content is measured to be 56.69% and 37.69% respectively in the rainy season and dry season. The results analysis of the potential of recovery showed that the organic recovery is more important (60% in the rainy season and 55% in the dry season) than the matter recovery (43% in the rainy season and 46% in the dry season). These results highlight the need for organic recovery and matter recovery of HSW in the city of Ouagadougou. The results from the analysis of the energy content showed that the HHV is estimated to be 17.94 MJ/kg in the rainy season and 17.96 MJ/kg in the dry season. The LHV is calculated to be 6.38 MJ/kg in the rainy season and 10.27 MJ/kg in the dry season. These results suggest that incineration as treatment of HSW in the city of Ouagadougou is not economically an appropriate option.

Sigma Terms and Strangeness Contents of Baryon Octet in Modified Chiral Perturbation Theory

In the frame work of chiral perturbation theory, a modified effective Lagrangian for meson-baryon system is constructed, where the SU（3） breaking effect for meson is considered. The difference between physical and chiral limlt decay constants is taken into account. Calculated to one 1ooi） at O（p^3）, the sigma terms and strangeness contents of baryon octet are obtained.

Droplet Characterization Based on the Simulated Secondary Rainbows

The droplet size, size distribution, refractive index, and temperature can be measured simultaneously by the rainbow technique. In the present work, the rainbow scattering diagram for a spherical droplet in the secondary rainbow region is simulated by the use of the generalized Lorenz-Mie theory. For achieving high spatial resolution in denser droplet sprays, a focused Gaussian beam is used. For droplet characterization, different inversion algorithms are investigated, which includes trough-trough (θmin1 and θmin2) method and inflection-inflection (θinf1 and θinf2) method. For the trough-trough algorithm, the absolute error of the refractive index is between −6.4 × 10−4 and 1.7 × 10−4, and the error of the droplet radius is only between −0.55% and 1.77%. For the inflection-inflection algorithm, the maximum absolute error of the inverted refractive index is less than −1.1 × 10−3. The error of the droplet radius is between −0.75% and 5.67%.

Character Analysis for Love Is a Fallacy from the Perspectives of Speech Act Theory and Cooperative Principle

Love Is a Fallacy is a great work of Max Shulman, one of the America's most famous humorists. Literary pragmatics,an interdiscipline between literature and pragmatics, is concerned with the examples in which pragmatics is combined with linguistic and literary methods. Speech Act Theory, initiated by John Austin and developed by Paul Grice, has been employed in literary pragmatics. This paper aims to explore the characterization of the three roles in Love Is a Fallacy in the light of literary pragmatics. By delving into the realization of speech act and the flouting of the maxims of Cooperative Principle, the establishment process of characters can be better demonstrated.

Effect of content and spin state of iron on electronic properties and floatability of iron-bearing sphalerite:A DFT+U study

Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.

组态视角下AIGC应用平台用户中辍行为影响因素研究

[目的/意义]从组态视角对AIGC应用平台用户的中辍行为影响因素进行研究,明确人工智能技术服务的痛点与边界,更好地优化服务,以促进技术赋能。[方法/过程]使用问卷收集219份有效数据,采用扎根编码与定性比较分析相结合的方法,对影响AIGC应用平台用户中辍行为的因素进行识别,并构建相应的理论模型,揭示引致AIGC应用平台用户中辍行为发生的条件组合。[结果/结论]将AIGC应用平台用户中辍行为归纳为潜在威胁感知型和技术因素主导型两种模式,发现感知威胁、期望失验、系统质量、内容质量在AIGC应用平台用户中辍行为中发挥着重要作用。基于上述研究结论,对后续的研究视角提出了相关建议。

当代大学生消极苦乐观的表征解析、疗愈理论与教育对策——以“摆烂”现象为例

苦乐观是人生观的重要组成部分,体现了个体对自我生存意义的探寻,而当前部分大学生的“摆烂”现象反映了其苦乐观的消极倾向。通过对当代大学生的“摆烂”现象进行分析,可以发现部分大学生在苦乐观方面存在以下表征:片面理解苦乐内涵与关系的怀疑倾向,苦乐态度不端与情感消极为表征的颓废悲观倾向,苦乐信念缺乏与意志薄弱的精神虚无倾向以及苦乐动机功利与行为脱节的精致利己主义倾向。借助积极心理学相关理论探讨大学生苦乐观教育,有助于消解大学生“摆烂”症候,帮助大学生辩证对待人生苦乐矛盾,树立积极向上的苦乐观。

“植物生理学”理论结合实践的教学模式改革

“植物生理学”是高等农林院校植物生产类本科生的专业基础课,教学涉及的专业多,授课对象的知识结构和学习特点不断变化,且面临学时少、新知识和新技术层出不穷的窘境。因此,从甄选教学内容、丰富教学题材,改进教学方法,学以致用。建立“植物生理学”开放课堂,科研反哺教学、指导学生参加创新创业大赛、增强科研创新意识等方面对“植物生理学”进行了教学改革与实践。同时,“植物生理学”教学的研究对象选用本地的植物类型或地方品种并列举它们与当地生态环境之间的关系,使教学内容既贴近生活实际又符合学校的办学特色,既能提高学生的综合素质与实践能力,又可为培养创新型人才奠定基础。

基于制度文本分析的网络信息内容生态协同治理研究

[目的/意义]平台经济发展背景下,针对网络平台中的信息内容治理已成为国家战略的重要组成部分。构建网络信息内容生态协同治理的框架与模式,有助于健全网络综合治理体系,营造清朗的网络空间。[研究设计/方法]基于扎根理论方法中的三级编码工作开展研究,对77份来源于政府、行业组织和平台的三层级制度文本进行编码,得到160个初始概念、31个范畴、10个子范畴和3个主范畴;结合内容分析法,揭示网络信息内容生态结构组成要素并构建协同治理框架,同时进一步围绕主体协同关系探究协同治理模式。[结论/发现]网络信息内容生态包括治理对象、治理主体和治理活动三个组成要素;政府、行业组织、平台和用户四类治理主体按照制度规约、管理工作和处理方式三个方面的治理活动,并主要以“预防性治理-即时性治理-结果性治理”等治理环节开展协同治理工作。[创新/价值]基于三层级制度要求,结合信息生态学视角进行解构剖析,并构建网络信息内容生态协同治理框架与模式,重点揭示其中主体协同治理工作的运行机理与不足,可丰富网络信息内容治理的理论体系,所提出的优化策略可为有序实践具有中国特色的互联网信息内容治理提供指引。