Thioacetamide Additive Homogenizing Zn Deposition Revealed by In Situ Digital Holography for Advanced Zn Ion Batteries

Zinc ion batteries are considered as potential energy storage devices due to their advantages of low-cost,high-safety,and high theoretical capacity.However,dendrite growth and chemical corrosion occurring on Zn anode limit their commercialization.These problems can be tackled through the optimization of the electrolyte.However,the screening of electrolyte additives using normal electrochemical methods is time-consuming and labor-intensive.Herein,a fast and simple method based on the digital holography is developed.It can realize the in situ monitoring of electrode/electrolyte interface and provide direct information concerning ion concentration evolution of the diffusion layer.It is effective and time-saving in estimating the homogeneity of the deposition layer and predicting the tendency of dendrite growth,thus able to value the applicability of electrolyte additives.The feasibility of this method is further validated by the forecast and evaluation of thioacetamide additive.Based on systematic characterization,it is proved that the introduction of thioacetamide can not only regulate the interficial ion flux to induce dendrite-free Zn deposition,but also construct adsorption molecule layers to inhibit side reactions of Zn anode.Being easy to operate,capable of in situ observation,and able to endure harsh conditions,digital holography method will be a promising approach for the interfacial investigation of other battery systems.

The Beijing network of digital geomagnetic pulsation observatories

We present herein an introduction to the Beijing network of digital geomagnetic pulsation observatories, and describe its essential features, and important roles in earthquake prediction studies and other geomagnetic investigations. The network provides digitalized data of geomagnetic events, such as magnetic storms, magnetic disturbances, geomagnetic daily variations, and geomagnetic pulsations. The digitalized data, convenient for processing and analysis, contain very rich information because of high accuracy and wide dynamic range of the instruments.

Digital Ocean Information Framework of China and its application in the international marine cooperation

Digital Ocean Information Framework （DOIF） has been proposed by China in 2011 based on the achievements of the comprehensive offshore oceanic surveys supported by Chinese Offshore Investigation and Assessment Program, whose code name is 908. All observations from the surveys have been integrated and managed by DOIF. DOIF is capable of supporting the decision of making process for the sustainable use of marine resources in coastal regions of China, providing useful information and added value products as well as services for the improved management of the coastal areas in China with high business impact on the targeted groups as public authorities and commercial operators （e.g. managers, fishermen, shipping companies）. The future vision of DOIF in the international marine data and information exchange and service at Western Pacific region is presented in this paper.

Deformation Field around the Stress Induced Crack Area in Sandstone by the Digital Speckle Correlation Method

The deformation field around sub-cracks was calculated using the digital speckle correlation method. First, the uni-axial compression tests on sandstone samples containing a pre- fabricated fracture were made. Photomicrographs showing the characteristics of the sub-crack development were taken using a scanning electron microscope （SEM）. From these photomicrographs, the real-time images showing the initiation, growth and coalescence of sub-cracks and micro-cracks in the sandstone specimens were obtained and the effects of loading level as well as grain boundaries on the development of cracks were analyzed. Second, the intensity images of the sandstone specimen surface were captured from the observations of the SEM corresponding to different loading levels. Then correlation computation was carried out for the sequential pairs of intensity images to evaluate the displacement components, as well as the strain field. The results show that the deformation varies in different areas separated by sub-cracks during rock damage processes.

Dynamic experimental study on rock meso-cracks growth by digital image processing technique

A new meso-mechanical testing scheme based on SEM was developed to carry out the experiment of microfracturing process of rocks. The microfracturing process of the pre-crack marble sample on surrounding rock in the immerged Long-big tunnel in Jinping Cascade II Hydropower Station under uniaxial compression was recorded by using the testing scheme. According to the stereology theory, the propagation and coalescent of cracks at meso-scale were quantitatively investigated with digital technology. Therefore, the basic geometric information of rock microcracks such as area, angle, length, width, perimeter, was obtained from binary images after segmentation. The failure mechanism of specimen under uniaxial compression with the quantitative information was studied from macro and microscopic point of view. The results show that the image of microfracturing process of the specimen can be observed and recorded digitally. During the damage of the specimen, the distribution of microcracks in the specimen is still subjected to exponential distribution with some microcracks concentrated in certain regions. Finally, the change law of the fractal dimension of the local element in marble sample under different external load conditions is obtained by means of the statistical calculation of the fractal dimension.

Progress of Earth Observation in China

China is expanding and sharing its capacity for Earth observation by developing sensors,platforms,and launch capabilities in tandem with growing lunar and deep space exploration.China is considering the Moon as a viable Earth observation platform to provide high-quality,planetary-scale data.The platform would produce consistent spatiotemporal data because of its long operational life and the geological stability of the Moon.China is also quickly improving its capabilities in processing and transforming Earth observation data into useful and practical information.Programs such as the Big Earth Data Science Engineering Program(CASEarth)provide opportunities to integrate data and develop“Big Earth Data”platforms to add value to data through analysis and integration.Such programs can offer products and services independently and in collaboration with international partners for data-driven decision support and policy development.With the rapid digital transformation of societies,and consequently increasing demand for big data and associated products,Digital Earth and the Digital Belt and Road Program(DBAR)allow Chinese experts to collaborate with international partners to integrate valuable Earth observation data in regional and global sustainable development.

Progress of Earth Observation in China

Sustainability is the current theme of global development, and for China, it is not only an opportunity but also a challenge. In 2016, the Paris Agreement on climate change was adopted, addressing the need to limit the rise of global temperatures. The United Nations(UN) has set Sustainable Development Goals(SDGs) to transform our world in terms of closely linking human well-being, economic prosperity, and healthy environments. Sustainable development requires the support of spatial information and objective evaluation,and the capability of macroscopic, rapid, accurate Earth observation techniques plays an important role in sustainable development. Recently, Earth observation technologies are developing rapidly in China, where scientists are building coordinated, comprehensive and sustainable Earth observation systems for global monitoring programs. Recent efforts include the Digital Belt and Road Program(DBAR) and comparative studies of the "three poles". This and other researches will provide powerful support for solving problems such as global change and environmental degradation.

Analyses on normal background characteristics about deformation observation data on the basis of wavelet transform method

Wavelet transform method is applied to measure time-frequency distribution characteristics of digital deformation data and noise. Based on the characteristics of primary modulus and stochastic white noise discrimination factor of wavelet decomposition, we analyze the variation rule of normal background and noise data from Shandong digital deformation observation data. The research results indicate that: a) 1/4 daily wave, semi-diurnal tide wave, daily wave and half lunar wave and so on quasi-periodic signal exist in the detail decomposing signal of wavelet when scale are equal to 2, 3 and 4; b) The amplitude of detail decomposing signal is the biggest when scale is equal to 3; c) The detail decomposing signal contains mainly noise corresponding to scale 1 and 5, respectively; d) We may trace the abnormal precursory which is related to earthquake by analyzing non-earthquake wavelet decomposing signal whose scale is specified from digital deformation observation data.

Position Sensorless Control for Permanent Magnet Synchronous Motor Using Sliding Mode Observer

An approach of position sensorless control for permanent magnet synchronous motor （ PMSM ） is put forward based on a sliding mode observer. The mathematical model of PMSM in a stationary αβ reference frame is adopted, and the system is controlled by the digital signal processor （ DSP; TMS320LF2407 according to the control achieve closed loop operation of the motor, the stator theory of sliding mode observer. In order to magnetic field should be vertical with the rotor magnetic field and be synchronous with rotor rotating, so the position and speed of PMSM is estimated in real time and the estimated position is modified continuously. The simulation results indicate that the proposed observer has high precision is more robust to the parametric variation and load in estimation of PMSM position and speed, and torque disturbance.

Think global,cube local:an Earth Observation Data Cube’s contribution to the Digital Earth vision

The technological landscape for managing big Earth observation(EO)data ranges from global solutions on large cloud infrastructures with web-based access to self-hosted implementations.EO data cubes are a leading technology for facilitating big EO data analysis and can be deployed on different spatial scales:local,national,regional,or global.Several EO data cubes with a geographic focus(“local EO data cubes”)have been implemented.However,their alignment with the Digital Earth(DE)vision and the benefits and trade-offs in creating and maintaining them ought to be further examined.We investigate local EO data cubes from five perspectives(science,business and industry,government and policy,education,communities and citizens)and illustrate four examples covering three continents at different geographic scales(Swiss Data Cube,semantic EO data cube for Austria,DE Africa,Virginia Data Cube).A local EO data cube can benefit many stakeholders and players but requires several technical developments.These developments include enabling local EO data cubes based on public,global,and cloud-native EO data streaming and interoperability between local EO data cubes.We argue that blurring the dichotomy between global and local aligns with the DE vision to access the world’s knowledge and explore information about the planet.

用Observer模式实现数字电路仿真系统

软件开发中如何应对变化,是近年来备受软件开发者关注的问题。文章采用Observer模式实现了一个简单的数字电路仿真系统,并对系统进行了验证。可以看出,应用设计模式的思想,可以设计出结构清晰而且容易扩展的软件架构。

The application of China’s land observation satellites within the framework of Digital Earth and its key technologies

Digital Earth is an interdisciplinary field involving space technology,information technology,and geoscience.This article introduces the land observation satellite system of China and discusses the requirements for satellite payloads in terms of spatial,temporal,and spectral resolution to establish a Digital Earth.The applications of land satellites under the framework of Digital Earth are introduced from the perspectives of data support,special subject services,and integrated information services.It is concluded that China’s land observation satellites and ground processing systems will be fundamental components of the Digital Earth system,in which satellite data and their derived information will serve as the principal information source and greatly promote applications of Digital Earth.

Hand-feel soil texture observations to evaluate the accuracy of digital soil maps for local prediction of soil particle size distribution:A case study in Central France

Digital maps of soil properties are now widely available.End-users now can access several digital soil mapping(DSM)products of soil properties,produced using different models,calibration/training data,and covariates at various spatial scales from global to local.Therefore,there is an urgent need to provide easy-to-understand tools to communicate map uncertainty and help end-users assess the reliability of DSM products for use at local scales.In this study,we used a large amount of hand-feel soil texture(HFST)data to assess the performance of various published DSM products on the prediction of soil particle size distribution in Central France.We tested four DSM products for soil texture prediction developed at various scales(global,continental,national,and regional)by comparing their predictions with approximately 3200 HFST observations realized on a 1:50000 soil survey conducted after release of these DSM products.We used both visual comparisons and quantitative indicators to match the DSM predictions and HFST observations.The comparison between the low-cost HFST observations and DSM predictions clearly showed the applicability of various DSM products,with the prediction accuracy increasing from global to regional predictions.This simple evaluation can determine which products can be used at the local scale and if more accurate DSM products are required.

数字化转型下AI课堂观察系统使用对师生课堂行为的影响——基于W中学412节课例的循证研究

当前,课堂教学的数字化转型实践和应用正如火如荼,但师生可能因习惯于传统教学环境而对新技术的引入产生抵触情绪,从而影响数字化转型的成效。对此,文章以武汉市W中学七年级四个班的412节课例为研究样本,通过前后测实验设计,对比了AI课堂观察系统投入使用前后师生的课堂行为变化情况、不同特征(包括科目、职称、性别)教师的课堂行为差异,结果发现:AI课堂观察系统对师生课堂行为有一定的影响,且这种影响会随着时间的推移而减弱;AI课堂观察系统对不同特征教师产生了不同程度的影响。文章的研究揭示了课堂教学数字化转型面临的实践挑战,可为课堂教学创新的科学管理提供理论支撑和实践参考。

基于DOPS数字教学平台对中西医临床综合技能实训穿刺模块课程教学模式的探索性研究

目的探讨操作技能直接观察评估(DOPS)数字教学平台在中西医临床综合技能实训穿刺模块课程中的应用方法及效果。方法选择北京中医药大学东直门医院120名2019级临床专业硕士研究生为研究对象,按照信封法将其分为对照组及试验组,每组60名。对照组实施中西医临床综合技能实训穿刺模块课程传统教学模式,试验组实施DOPS数字教学平台与传统教学模式相结合的教学方式。比较两组实际操作考试失分情况、测试成绩及满意度。结果试验组术者站位错误、操作车放置位置不规范、戴手套过程不规范、消毒器械使用不规范、操作时衣物污染洞巾、麻醉时注射器持针手法错误、麻醉手法不规范、穿刺针持针手法错误失分率均低于对照组(P<0.05)。试验组实际操作考试成绩、总满意度均高于对照组(P<0.05)。结论在中西医临床综合技能实训穿刺模块课程中,应用DOPS数字教学平台可提升中西医临床综合技能实训穿刺课程教学的有效性及学生的主观能动性,为中医院校临床技能课程设置和教学改革提供客观依据。

师范生教学基本技能智能实训模型及应用研究

师范生作为教师队伍的储备力量,影响着教育未来的发展。依据《普通高等学校师范类专业认证标准》与教育部两批《人工智能助推教师队伍建设行动试点工作的通知》等政策文件要求,研究针对师范生教学基本技能培养难题与发展要求,结合人工智能技术潜能构建了面向师范生教学基本技能培养的“四维度18指标”微技能观测指标框架,设计了四层架构的师范生教学基本技能智能实训分析系统模型,提出了智能分析特点及教学基本技能“智学”实训方式,并于所在师范院校开展了试验应用。研究表明,以人工智能技术助推师范生高质量培养为导向,进行师范生教学基本技能智能实训框架模型构建、技术方法实现、实训场景设计和数字画像生成,能够提升师范生实训效果。

基于延迟校正扩张状态观测器的内置式永磁同步电机电流控制策略

高速电驱动场合会受到开关频率的限制,低载波比特性凸显,由此引起的控制延迟问题影响了内置式永磁同步电机(IPMSM)矢量控制系统性能。基于扩展电动势的建模方案能够获得IPMSM的对称化模型,有利于离散化分析和设计,以提升低载波比运行性能。扩张状态观测器(ESO)能够实现扩展电动势和扰动的集总观测,然而低载波比延迟问题影响了估算性能。该文在离散域中分析延迟影响,设计和对比研究了几种延迟影响抑制方案,即延迟校正扩张状态观测器,提升了估计精度。基于此,设计了IPMSM离散域电流控制方案,显著提升了电流响应特性。通过电动汽车驱动实验平台验证了该文的分析和设计。

面向高压设备数字孪生的虚拟传感器设计与应用技术

针对高压设备数字孪生的模型构建、信息交互、动态仿真等需求,对虚拟传感器的设计与应用技术进行了分析,虚拟传感器是具有传感器行为的计算机仿真系统,能够基于功能、结构和服务要求对复杂数字孪生系统进行解耦,降低工程应用的复杂性。文中提出虚拟传感器在高压设备数字孪生工程应用上的设计要求,给出了观测虚拟传感器、参量计算虚拟传感器和预测告警传感器的设计方法及其应用方式。研究结果表明:虚拟传感器具备组件化、服务化、易重构、可进化等优点,可作为数字孪生单元级功能组件的设计手段,解决目前工程应用中数据获取和融合困难、仿真预测算法耦合复杂等问题,支撑设备状态全面感知、趋势精准预测、风险提前预警和设备全寿命精益管理等应用。

数智技术赋能档案叙事:叙事结构与路径探析

大数据及人工智能等数智技术的广泛应用,深刻影响了档案的形态、存储方式、利用途径等。档案事业正面临着自身范式革命,这也要求其利用数智技术展开革命。以“跟着档案观上海”为例,系统分析了数智技术赋能档案叙事的必要性与可行性,将叙事结构划分为叙事时间结构、叙事空间结构、叙事主题结构,进而从数据赋能、知识赋能、情境赋能、传播赋能4个维度,构筑数智时代下档案叙事的推进路径,以期为社会记忆构建和文化传承提供参考。

数字化课堂观察与反馈:现状、评述与实现路径

随着人工智能技术的迅猛发展,数字化课堂观察与反馈成为研究热点。课堂观察技术的发展历经现场观察、录像观察和信息技术支持的观察三个阶段,观察工具分为要素构成类、信息交互类和行为交互类三类。课堂观察的数字化转变主要体现在课堂观察数据的自动化采集处理和智能化分析解释。本研究基于课堂观察常用的面部数据、言语信息、走动轨迹、身体姿态、日志五类数据系统梳理这两项技术,总结现阶段数字化课堂观察的一般流程。针对数字化课堂观察存在的观测点聚焦通用型课堂、数据利用侧重行为交互观察、可视化设计的可读性有待提高、教学解释难以对标实践需求等问题,本研究引入联合教师的新目标定位、学科课型的新观测视角、故事化叙事的可视化设计新形式以及大语言模型的教学解释新工具,构建了新思路下的实现路径,以期为课堂观察的数字化转型提供参考。