An extended state observer with adjustable bandwidth for measurement noise

In this paper,a bandwidth-adjustable extended state observer(ABESO)is proposed for the systems with measurement noise.It is known that increasing the bandwidth of the observer improves the tracking speed but tolerates noise,which conflicts with observation accuracy.Therefore,we introduce a bandwidth scaling factor such that ABESO is formulated to a 2-degree-of-freedom system.The observer gain is determined and the bandwidth scaling factor adjusts the bandwidth according to the tracking error.When the tracking error decreases,the bandwidth decreases to suppress the noise,otherwise the bandwidth does not change.It is proven that the error dynamics are bounded and converge in finite time.The relationship between the upper bound of the estimation error and the scaling factor is given.When the scaling factor is less than 1,the ABESO has higher estimation accuracy than the linear extended state observer(LESO).Simulations of an uncertain nonlinear system with compound disturbances show that the proposed ABESO can successfully estimate the total disturbance in noisy environments.The mean error of total disturbance of ABESO is 15.28% lower than that of LESO.

THE LEAST SQUARES COMPREHENSIVE ADJUSTMENT FOR MINE VENTILATION MEASUREMENTS

This paper systematically introduced the method of direct, indirect and free-network adjustments and their application in data process of minewide ventilation measurements. The direct adjustment is suitable for errors collating of the measurements of airflow rates. The indirect method is suitable for the adjustment of ventilation resistance. The free-net method is adapted to the combined adjustment of the measurements of both the ventilation in branches of the air network and the air pressure at nodes of the ventilation network, the partial adjustment is also introduced here to be used for saving the storage locations in computer required for the adjustment for large scale mine ventilation measurements.

Adjusting precipitation measurements from the TRwS204 automatic weighing gauge in the Qilian Mountains, China

With the popularity of the automatic precipitation gauges in national weather stations,testing their performance and adjusting their measurements are top priorities. Additionally,because different climatic conditions may have different effects on the performance of the precipitation gauges, it is also necessary to test the gauges in different areas. This study mainly analyzed precipitation measurements from the single-Altershielded TRwS204 automatic weighing gauge(TRwS_(SA)) relative to the adjusted manual measurements(reference precipitation) from the Chinese standard precipitation gauge in a doublefence wind shield(CSPG_(DF)) in the Hulu watershed in the Qilian Mountains, China. The measurements were compared over the period from August 2014 to July2017, and the transfer function derived from the work by Kochendorfer et al.(2017 a) for correcting windinduced losses was applied to the TRwS_(SA) measurements. The results show that the average loss of TRwS_(SA) measurements relative to the reference precipitation decreased from 0.55 mm(10.7%) to 0.51 mm(9.9%) for rainfall events, from 0.35 mm(8.5%)to 0.22 mm(5.3%) for sleet events, and from 0.49 mm(18.9%) to 0.33 mm(12.7%) for snowfall events after adjustment. The uncorrected large biases of TRwS_(SA) measurements are considered to be mainly caused by specific errors of TRwS_(SA), different gauge orifice area and random errors. These types of errors must be considered when comparing precipitation measurements for different gauge types, especially in the mountains.

Nonlinear least square estimation using difference quotient instead of derivative containing different classes of measurements

Using difference quotient instead of derivative, the paper presents the solution method and procedure of the nonlinear least square estimation containing different classes of measurements. In the meantime, the paper shows several practical cases, which indicate the method is very valid and reliable.

Question and Countermeasure Research of Human Living Environment Designs in New Countries

In the view of new rural living environment,problems existing in the construction of current new rural living environment were analyzed so as to propose some theoretical ideas and ways for resolving the problems existing in the design of new rural living environment.

Key global climate governance problems and Chinese countermeasures

Presently,the full implementation of the negotiations and collaborations under the Paris Agreement faces new key problems and severe challenges.These problems and challenges include the following:how to honor the principle of“common but differentiated responsibilities”to facilitate a comprehensive,balanced,and effective implementation of the key elements of the Paris Agreement,such as adaptation,mitigation,finance,technology,capacity building,and transparency;how to uphold and maintain the status of China and other emerging countries as developing countries in light of the requirements of the United Nations Framework Convention on Climate Change and the historical responsibilities of these countries;and how to assess the goal of limiting the global temperature increase to 1.5℃and what constitutes an equitable carbon mitigation pathway for different types of countries.Developed countries and developing countries have drastically diverging views on carbon border adjustment measures for trade with developing countries proposed by several developed countries such as the European Union.Developed countries have demonstrated obvious intentions and actions designed to weaken and neglect the principle of“common but differentiated responsibilities”,to impose mitigation pressure on developing countries,to shift the responsibilities for emissions onto others,and to pass on the costs of mitigation.The maneuvering among different types of countries and interest groups has become increasingly intense.In response,China must maintain its strategic focus,adhere to the goals and principles established by the Paris Agreement,stick to its strategic positioning as a developing country,solidify strategic support from the developing world,and safeguard the legitimate rights and interests of developing countries.China played a conducive role in facilitating the Paris Agreement and has become an active participant,contributor,and leader in global climate governance.China must continue to follow Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era and its conception of ecological civilization and the concept of building a community of common destiny,to actively lead the cooperation process in the construction of a global climate governance system characterized by equity,justice,and win-win collaborations,and to promote compliance with the Paris Agreement.At the same time,China should accelerate the green,low-carbon,circular transformation of its economy;accelerate the coordinated governance of the economy,environment,and climate change;and formulate and implement a long-term low-carbon development strategy.By the middle of the 21st century,while achieving the goal of building a great modern socialist country,China can also achieve a deep decarbonization development path that is in line with the goal of limiting the global temperature increase to well below 2°C and pursuing efforts to limit the increase to 1.5℃.

3-D Free-form Shape Measuring System Using Unconstrained Range Sensor

Three-dimensional（3-D） free-form shape measurement,a challenging task pursued by computer vision,is mainly characterized with single view acquisition and multiple view registration.Most of the conventional scanning systems are less flexibility and difficult to realize engineering applications for employing sequential registration tactic.To develop portable scanning system and engineering registration method overcoming problems of error accumulation and propagation is the research direction.In this paper,one 3-D free-form shape measuring system using unconstrained range sensor is designed.A quasi-active stereo binocular visual sensor embedded within a scanning mechanism is used as the range sensor.Error compensation is performed by residual amendment according to camera calibration lattice.Artificial control points are designed and adhered on object and one camera is introduced to shot these control points from different positions and orientations.Then ray bundle adjustment（BA） method is used to calculate the space coordinates of all the control points,so as to set up a global control net work.Registration can be completed by mapping at least 3 control points observed by range sensor in single view acquisition into the global control network.In this system,no calibration for laser plane is required and the motion of range sensor is completely free.The overlapping of neighboring region is unessential for registration.Therefore,the working range of the system can be easily extended.The measuring precision mainly depends on the quality of global control network.The sequential distances of coding control points are observed by electronic theodolites and then compared with those obtained according to BA result.Experimental results show that relative distance error of control points is no more than 0.2%.The proposed measuring system is portable,provides good capacity for global error control,and contributes to the engineering application of 3-D free-form shape measurement.

A New Approach for Measuring Shareholder Value Creation

This paper introduces a new approach for measuring shareholder value creation （called adjusted economic profit （EP）） which combines the advantages of both EP and APV （adjusted present value） methods. In particular, the shareholder value creation over a period is derived as the sum of two components： the EP relating purely to the operations of the company and the EP generated each period due to the tax benefit that arises from debt financing. We consider our results to be important for analysts and decision makers involved in appraising business performance or making investment decisions and HR professionals as well.

基于RTK测速的油菜直播机随速可控可调排种控制系统研究

针对油菜精量直播机连续作业过程中设定作业速度条件下,作业速度波动导致排种量与目标播量不一致的问题,设计了一种基于“RTK测速+落种检测+电机实时调控”的油菜精量直播机随速可控可调排种控制系统,确定了影响调速性能的关键参数,构建了步进电机调速模型;运用GNSSToolKitLite上位机开展ZED-F9P GNSS模块静态速度漂移试验,得到该模块静态速度漂移量服从均值为0.054 m/s、方差为0.029 m^(2)/s^(2)的正态分布。利用自动数粒仪与JPZS-16型排种性能试验台进行试验,得到正负气压组合式排种器转速为5~60 r/min时,落料计数器播种量检测值与实际值平均绝对误差小于10%;通过台架试验确定了不同排种器调速模型,得到不同排种器最佳工作转速、电机转速与目标播量的函数关系。不同排种器随速控制适应性台架试验结果表明:当作业速度为3~12 km/h时,系统搭载高速机械离心式与油麦兼用气送式排种器总排量稳定性变异系数小于1.21%。田间试验结果表明:当作业速度为5~12 km/h时,本系统搭载高速机械离心式与窝眼轮式排种器总排量稳定性变异系数小于9.7%,满足随速播种要求,可为油菜精量播种控制系统结构改进提供参考。

基于旋量理论的镜像加工运动学建模及轨迹自动修调研究

针对镜像加工过程中结构变形致使加工精度难以控制的问题,建立了基于旋量理论的镜像加工剩余壁厚运动学模型,综合考虑零件加工要求及镜像约束关系,提出了镜像加工“支撑-铣削”轨迹生成方法,建立了针对工件变形补偿的镜像支撑轨迹修调模型,实现了镜像加工“支撑-铣削”轨迹自动修调。栅格壁板镜像加工验证试验结果表明,提出的镜像加工“支撑-铣削”轨迹生成和自动修调方法可以满足镜像加工剩余壁厚要求。

新型旋转激光扫描系统轴系调整与误差标定

旋转激光扫描系统是一种基于精密转台结合多路激光的空间多目标并行角度传感系统。为改善系统光源性能,设计了一种采用光纤从外部导入光源的新型轴系结构。但是当激光以一定角度穿过中空的转轴进入镜组后,若倾斜入射柱镜,将导致出射的扫描光面型发生变化。针对此问题,研究了一种基于平行线的传递性的激光光轴姿态的调整方法,并借助激光跟踪仪测量平台,分别对光轴与转轴轴系进行拟合,建立了对光轴倾斜误差的标定方法。实验结果表明,调整后光轴与转轴轴线的空间夹角优于0.15°,完全满足扫描光截面中心直线度对激光入射柱镜的角度要求。该调整方案可用于系统的装配环节,使扫描光更加接近理想平面,有助于系统测量精度的提升。

健全因地制宜发展新质生产力体制机制推动中国式现代化

党的二十届三中全会决议明确指出:“要健全因地制宜发展新质生产力体制机制”,这对于推动中国式现代化具有重大意义。习近平总书记创造性提出“因地制宜发展新质生产力”,这是一项重大理论和实践创新,将为我国高质量发展注入全新动力。为了深入学习贯彻党的二十届三中全会精神,加快形成同新质生产力更相适应的生产关系,健全因地制宜发展新质生产力体制机制,完善战略性产业发展政策和治理体系,建立未来产业投入增长机制,完善促进数字经济和智能经济发展政策体系,促进耐心资本和各类先进生产要素向发展新质生产力集聚,围绕“健全发展新质生产力体制机制推动中国式现代化”这个新时代经济发展的重要课题,本刊邀请国内著名专家、学者,撰写一组笔谈文章,以飨读者。

飞机复合材料机身壁板装配技术分析与展望

复合材料以其优异的综合性能在航空航天领域得到了大量应用,其应用范围逐渐从次承力结构向主承力结构扩展,包括在机身结构的组成方面,传统的金属组装壁板逐渐被复合材料整体壁板所取代。由于复合材料壁板具有不同于传统金属材料壁板的装配工艺特点,因此对其装配方法和装配工艺提出了新的要求。针对圆筒状机身复合材料机身壁板的装配过程,分别介绍了复合材料机身壁板大尺寸测量技术、复合材料机身壁板装配定位调姿技术和复合材料机身壁板的先进制孔连接技术,系统总结了近年来国内外相关研究进展和应用情况,指出了飞机大尺寸复合材料结构装配技术未来的研究与应用方向。

美联储调息与人民币汇率变化研究

为改善高通货膨胀的经济环境,2022年美联储宣布加息,不仅影响美国国内而且影响了包括中国在内的开放型经济国家。为提高实证分析结论的准确性,通过构建VAR模型,以此轮美联储加息为背景,选取2006年1月至2023年8月美元兑人民币汇率以及美国联邦基金利率等数据,逐步研究美联储调整利率后部分变量对人民币汇率的影响。研究结果表明,美联储调息的直接影响效果最为显著,且短期的影响效应大于长期。为此,在新发展阶段下,应建立强大的宏观审慎监管体系,适时干预外汇市场,以促进汇率改革与人民币汇率稳定。

实验室气候环境模拟应用进展

实验室气候环境模拟用来模拟气压、气温、湿度、风速、降水、日照和特定天气状况等气候气象以及太空行星大气等环境因素,试验、测试计量、考核评价特定对象(人和物)对气候环境等的适应性、耐久性,以及研究气候气象乃至太空环境影响的相关科学技术,从20世纪出现以来具有越来越重要的研究应用价值。本文回顾了国内外气候环境模拟在生物、农业、航空航天、汽车交通、建筑、兵器、太空探索等产业领域及科学工程等方面的试验、测试计量及应用等工程项目,介绍了相关温、压、湿、风、雨、雪、雾霾等相关模拟设备的技术及系统平台,展示了这一领域在国内外几十年来的应用研究进展,并对该领域在科学和产业应用、精密调控、仿真、虚拟现实和增强乃至太空环境模拟及生命支持研究等领域的发展进行了分析和展望。

欧盟碳边境调节机制对内蒙古的影响及应对措施

为实现应对气候变化国家自主贡献及碳中和目标,欧盟提出实施碳边境调节机制(CBAM)。欧盟是中国最重要的贸易伙伴国之一,实施该机制可能会对我国贸易产生一系列影响,中国对欧出口产品成本可能会有所增加。内蒙古是我国重要的能源和战略资源基地,也是重要的能源保供基地和制造业基地。虽然内蒙古出口欧盟金额在全国占比较小(约0.014%),但欧盟是内蒙古第二大出口目的地,提前研究欧盟碳边境调节机制对内蒙古的影响、机遇和挑战,具有重要意义。本文阐述了碳边境调节机制主要内容,并深入分析了该机制对内蒙古的影响、机遇和挑战,并从五个方面提出了应对措施和建议,以期为内蒙古提前布局、提早应对欧盟碳边境调节机制提供参考。

因地制宜发展新质生产力与高水平开放

推动高水平对外开放,是实现因地制宜发展新质生产力的重要方略。首先,以高水平开放倒逼深层次改革,通过深化经济体制、科技体制改革为新质生产力发展营造良好的制度环境,通过建立高标准市场体系完善新质生产力发展的激励约束机制,通过吸引全球先进优质生产要素优化生产要素配置。其次,以稳步扩大制度型开放培育新质生产力,通过深层次改革实现国内国际高标准经贸规则的双向互联,以构建高标准市场体系高效利用全球先进优质生产要素。再次,深化国际经贸合作为培育新质生产力提供发展基础,通过内外贸一体化拓展新质生产力的市场空间,以高质量共建“一带一路”延伸新质生产力的发展路径。

高精度管道漏风量测试仪的设计及实验研究

现有的国产漏风量测试仪普遍存在测量精度低、自动化水平低的问题,为此,基于漏风量测试仪的原理,开展了漏风量测试仪的结构设计、系统设计及整机实验研究。首先,对漏风量的测量过程、喷嘴流量测量原理进行了研究,推导了喷嘴流量测量公式,并根据相关标准设计了角接取压方式的喷嘴结构,基于仪器操作便捷性要求,对整机结构进行了设计;其次,采用空气密度补偿公式完成了高精度流量自适应测量,设计了基于自锁式电磁阀的换向调零电路,采用换向调零法对压差传感器零点漂移进行了补偿,使用小波阈值去噪算法消除了信号噪声,提高了流量的测量精度;采用抗积分饱和比例积分微分(PID)算法对流量进行了闭环控制;最后,研制了管道漏风量测试仪样机,开展了压差与流量测量精度与重复性实验。实验及研究结果表明:该高精度漏风量测试仪工作状态稳定,压差测量精度为±0.4%,流量测量精度为±2%;该漏风量测试仪的测量精度优于国内同类仪器,符合国家标准要求,具有良好的市场前景。

高速铁路精测精调人才职业特质培养探索与实践

高速铁路是国家经济社会发展的主动脉,是交通强国战略的重要支撑。轨道平顺性对高铁安全运行至关重要,精密测量和精准调整是保障轨道平顺的关键技术。随着高铁轨道平顺精度标准越来越高(亚毫米级),加之维修天窗时间短,就需要高铁施工、运营维护作业人员具备更高水平的精测精调能力。因此,怎样才能培养出适应高铁精测精调工作要求、具备更高水平职业技能素养的人才,成为轨道交通类高职院校面临的重要课题。

碳边境调节机制下近零碳制造体系建设研究

在国家“双碳”战略目标、欧盟碳排放交易体系改革的双重驱动下,我国制造业实施节能、减污、降碳协同增效,尽快实现低碳和零碳转型,成为关注焦点和发展亟需。本文重点探讨了欧盟碳边境调节机制(CBAM)对我国制造业的影响,基于此梳理了近零碳制造体系的概念特征,从关键技术、计量基础、市场驱动力等主要维度出发,详细阐述了近零碳制造体系的核心内容。分别从产品制造、电力供应两方面,提炼了近零碳制造体系的技术发展方向,建议形成“源网荷”碳计量系统以细化碳排放责任;借鉴国外碳市场发展经验并分析我国碳市场发展格局,在理论层面探讨了未来我国碳市场构建路径以促进近零碳制造体系发展。提出的近零碳制造体系实践方案,可为深化“双碳”背景下我国制造业高质量发展、开展CBAM背景下我国制造业低碳转型建设研究提供先导性和基础性参考。