Spatial-temporal changes of tidal flats in the Huanghe River Delta using Landsat TM/ETM+ images

Integrating remote sensing, geographic information system (GIS) and fractal theory, change characteristics of tidal flats and tidal creeks in the Huanghe (Yellow) River Delta over the period of 1986-2001 were discussed. The results show that evolutions of tidal flats throughout the Huanghe River Delta are influenced by various factors, and that progressive succession and regression of tidal flats concur in different coastal segments of the delta. Human activities have played an increasingly important role in the succession process of tidal flats. Due to land reclamation in coastal zones of the delta in the last 15 years, lots of tidal flats were occupied, the artificial coastline migrated seaward (the maximum change rate was 0.8 kmyr-1) and tidal creeks became sparser (the highest decreasing rate of length of tidal creeks was 14.9 kmyr-1). Except for two coastal segments from the Tiaohe Estuary to the 106 Station and from the south of the Huanghe River mouth to the north of the Xiaodao River Estuary, fractal dimension values of tidal creeks in the remaining coastal segments of the delta decreased. In addition, the time dimension, sediment fluxes into the sea, waves and tidal-currents have profound influences on the evolution process of tidal flats. Four types of tidal flats-river-dominated tidal flats, tide-dominated tidal flats, wave-dominated tidal flats and man-dominated tidal flats can be identified. Owing to the intensification of human activities in coastal zones of the delta, man-dominated tidal flats have become the main kind of tidal flats.

Primary Analysis of the Causes of Temperature Changes after Songjiang Observation Station Transferring

Temperatures of the old station and the new one in Songjiang were compared with each other,and data via automatic weather station instead of manual observation after transferring were also analyzed.The results showed that the average temperature,the minimum temperature,the maximum temperature and the extreme temperature in the new observation station were all higher than those in the old one.The average temperature difference of the new observation and the old one from 20:00 to 08:00 of the next day was bigger than that from 08:00 to 20:00.There were two causes of temperature changes after Songjiang station transferring:one was that two stations were affected by the surrounding environment and the nature of underlying surface,and the other was that theory of sensing part,observation time and process were different between the automatic weather station and the manual observation.

The Challenges of Global Climate Change to Green Development and its Legislative Response

Global climate change has swept across every nation,community,business,and individual on the planet. It is essential to find a fundamental solution to address climate change from a broader perspective. Climate change legislation should followthe principle of the sustainable development,polluter pays principle,the principle of the common but differentiated responsibilities as well as the principle of subsidiarity. Under the guidance of the four basic principles of legislation,the international field should build the legal system of the global climate governance,China should formulate special"the act of addressing climate change".

The Research of ECG Signal Automatic Segmentation Algorithm Based on Fractal Dimension Trajectory

In this paper a kind of ECG signal automatic segmentation algorithm based on ECG fractal dimension trajectory is put forward.First,the ECG signal will be analyzed,then constructing the fractal dimension trajectory of ECG signal according to the fractal dimension trajectory constructing algorithm,finally,obtaining ECG signal feature points and ECG automatic segmentation will be realized by the feature of ECG signal fractal dimension trajectory and the feature of ECG frequency domain characteristics.Through Matlab simulation of the algorithm,the results showed that by constructing the ECG fractal dimension trajectory enables ECG location of each component displayed clearly and obtains high success rate of sub-ECG,providing a basis to identify the various components of ECG signal accurately.

Principle for the Working of the Lithium-Ion Battery

The technological advances in Lithium-ion batteries have created many new applications, including electric vehicles. In this short note, we shall explain in simple terms the basic physics why and how it is possible to have high energy capacity in Lithium-ion batteries. However, heating has been a common problem and without appropriate design, they might give fire and explosion as reported.

Research and Exploration of Automatic Welding Wire Technology for Horn

With the development of science and technology,the electronic component industry has become more and more extensive,covering circuits,electrical and electrical systems from small to large.Many of these parts have very high requirements for the production process,and the production process requires a certain amount of workshop space.In the traditional production process,soldering is mainly manual welding.With the development of intelligence,impersonality and automation,the design of electronic products will gradually move towards intelligence.In this process,the application and promotion of welding technology is essential.In order to ensure the production of automatic products,this paper studies and discusses the function control problems and solutions of the soldering machine.Loudspeaker(commonly known as loudspeaker)is one of the most widely used electronic devices.With the development of the electronic industry and the change of the market environment,major manufacturers are developing new products to meet the market demand and product performance.In order to meet the needs of a large number of high reliability electronic products with different structures now and in the future,automatic welding technology is required to ensure that the welding quality and reliability have certain advantages.

An Automatic Generation System of Reinforcement Detail Drawings for Hydraulic Structures

Reinforcement detail drawings are one important part of the design of hydraulic structures and the important basis of construction and management. However, the efficiency of the traditional creation of engineering drawings is very low and the workload is heavy. There is no satisfactory software for hydraulic engineering because of the irregularity and diversity of hydraulic structures' shape. An automatic generation system of reinforcement detail drawings for hydraulic structures is introduced. Its functions and modules are introduced first. The related technologies such as automatic driensioning are discussed in detail. At the end of the paper, an example is given.

Fast Fourier Transform of Multi-Assets Options under Economic Recession Induced Uncertainties

A Fast Fourier transform approach has been presented by Carr & Madan (2009) on a single underlying asset. In this current research paper, we present fast Fourier transform algorithm for the valuation of Multi-asset Options under Economic Recession Induced Uncertainties. The issue of multi-dimension in both finite and infinite case of Options is part of the focus of this research. The notion of economic recession was incorporated. An intuition behind the introduction of recession induced volatility uncertainty is revealed by huge volatility variation during the period of economic recession compared to the period of recession-free. Nigeria economic recession outbreak in 2016 and its effects on the uncertainty of the payoffs of Nigeria Stocks Exchange (NSE) among other investments was among the motivating factors for proposing economic recession induced volatility in options pricing. The application of the proposed Fast Fourier Transform algorithm in handling multi-assets options was shown. A new result on options pricing was achieved and capable of yielding efficient option prices during and out of recession. Numerical results were presented on assets in 3-dimensions as an illustration taking Black Scholes prices as a bench mark for method effectiveness comparison. The key findings of this research paper among other crucial contributions could be seen in computational procedure of options valuation in multi-dimensions and uncertainties in options payoffs under the exposure of economic recession.

The Characteristic in Infinite Dimension Space

In modern mathematics, geometric and algebraic properties of space can be applied by calculus in which the concept of gradually increasings of dimensions is existence (such as zero-dimension, one-dimension, two-dimension, and three-dimension, etc). However, this is not fact because some new concepts have been put forward in this paper where there is only a concept of infinitely great that is one quantitative continuum implied by the change of direction. The accurate description of this one quantitative continuum is that its parts are connected each other as a unity at the infinite distance (infinitely great) relative to any orientation (all orientations) of our existence. It is unity in which its random parts are these infinitely great quantities and thus we call this unity as infinite quantities of infinite dimensions.

BIM模型编码可变性检验与自动匹配方法研究

为解决BIM元素变更导致的Web-BIM系统数据库与BIM元素无法匹配的问题,本研究首先根据各类BIM文件的特点,选择Rvt文件作为编辑BIM文件,选择Gltf文件作为Web端加载文件。对BIM模型的编码可变性进行了验证,结果表明对BIM构件尺寸修改、属性修改、位置移动等操作均不会改变构件的编码;若对BIM构件进行删除,该构件会被赋予新的编码,但其他构件的编码均不会被影响。本研究提出一种BIM模型变更前后自动匹配方法,通过建立元素识别和跟踪数据库、元素匹配算法、用户交互及确认、更新质量信息、定期检查等步骤,可以实现BIM模型变更前后Web端与BIM元素的匹配,为建筑项目的管理提供了有力的工具。

贵州草海生态监管平台研究与实现

立足贵州草海湿地生态系统的特点和治理管理需求,通过创建地理信息大数据条件下的环境监管技术框架,建立统一的环境监管数据库,构建基于全样本分析的生态异常自动变化监测技术体系、基于深度学习的自动或半自动要素提取技术体系以及大数据统计分析技术体系,研发“一张云图”共享平台及人类区域活动监测平台,为贵州草海的全数字化监管提供了坚强的科技支撑,助力草海实现“水清、山绿、景美、人和、鸟欢”目标。

刀库式加工中心自动换刀系统故障诊断与维修

我国是制造大国,数控机床作为工业生产的重要设备,能够有效提升工业生产自动化水平。主要探讨了刀库式加工中心自动换刀系统的故障诊断与维修策略,详细介绍了自动换刀系统的组成,包括自动换刀装置和自动换刀控制系统,并分析了刀库故障、换刀机械手故障以及主轴松刀故障等多种常见问题。在自动换刀控制系统故障方面,着重分析了换刀点漂移、刀库乱刀和换刀超时等问题,并提出了相应的诊断和维修策略。希望本文的研究能为相关技术人员提供参考和借鉴。

基于形变长短期记忆网络的换道意图预测

混行交通下的自动驾驶车辆需具备换道意图预测能力来保障行驶安全。为尽早预测车辆换道意图,提出一种基于形变长短期记忆(mogrifier long short-term memory,M-LSTM)网络的换道意图预测模型。首先采用S-G(Savitzky-Golay)滤波器对自然驾驶数据集NGSIM(next generation simulation)进行降噪筛选,按向左换道、向右换道、直线行驶对不同时间长度的轨迹序列标注,选取车辆运动信息与环境信息输入模型,最后采用softmax函数进行意图分类。试验结果表明,在不同预判时间下,模型准确率均高于支持向量机(support vector machine,SVM)、LSTM模型,且越接近换道点预测准确率越高,在1.0、2.5 s时预测准确率分别为93.83%与81.30%。提出的模型具有良好的准确性与预判性,能为自动驾驶车辆尽早识别换道意图提供技术支持。

轧机自动换辊装置研制

介绍了一种四辊可逆轧机的自动换辊装置。该设备安装于轧机操作侧,可实现自动更换成对工作辊或支承辊,且在其更换轧辊过程中,无需拆卸机旁盖板,便于留出物料通道。换辊过程操作稳定可靠,有效利用工厂空间,缩短了换辊时间,提高了轧线产能。

基于时间维度的城市公园人群活动研究——以深圳文心公园、四海公园、荔香公园为例

文章以时间、空间和人群活动为切入点,对深圳市南山区文心公园、四海公园、荔香公园的人群活动情况展开了调研,对时间维度下城市公园人群活动的人群构成特征、空间分布特征、活动变化特征进行了分析,解析了影响城市公园活动人群活动的因素。最后,基于调研和分析的结果,对城市公园的设计如何适应不同时段下不同人群的活动需要提出了建议。

多维度多角度探究自动控制原理实验课程思政元素

本文从实验内容、教学环节、评价体系等维度多角度深入挖掘自动控制原理实验课程中的思政元素,旨在实现实验教学与思政教育的有机融合,培养具有良好思想观念和价值观的高素质工程型人才。

Characteristics of coastline changes in China's Mainland since the early 1940s

Based on multi-temporal topographic maps, remote sensing images and field surveys covering the entire coastal zone of China's Mainland, the coastlines of six periods since the early 1940s were extracted. Coastline changes over the last 70 years were then analyzed in terms of coastline structure, coastline fractals, coastline change rates, land-sea patterns, and bay areas. The results showed that mainland coastline structure changed dramatically, and due to the significant coastline artificialization mainly driven by sea reclamation and coastal engineering, the remaining natural coastline merely accounts for less than one third at present. Coastline fractal dimension represented an overall spatial pattern of ＂north 〈 entirety 〈 south＂; however, the discrepancy between the north and south coast was apparently narrowed due to dramatic coastline artificialization of northern China which in turn altered the whole pattern. Patterns and processes of land-sea interchange along the mainland coast were complex and varied spatially and temporally, with over 68% advancing toward sea and 22% retreating toward land. The net growth of land area was nearly 14.2 ×10^3 km2 with an average growth rate of 202.82 km2 al; and coast retreat was characterized by area decrease of 93 bays with a magnitude of 10.1 ×10^3 km2 and an average shrinking rate up to 18.19% or an average shrinking speed up to 144.20 km2 a-1, among which the total area of Bohai shrunk by 7.06%, with an average annual loss amounting to 82 km2. The dramatic coastline changes along China's Mainland have brought about kinds of challenges to the coastal environment, therefore the integrated management, effective environment protection and sustainable utilization of coastlines is urgent.

自动换卷机构的纸带拼接刚柔耦合分析与试验研究

针对卷烟纸带拼接中压模纹理与拼接力设计不当,易发生纸带拼接松脱、错位和穿透的问题,基于自动换卷机构的纸带拼接原理,建立自动换卷机构刚柔耦合模型,采用数值模拟与试验测试方法,研究对辊材料、拼接力和压模纹理对纸带拼接效果的影响规律。结果表明,4种对辊材料(橡胶、尼龙、铝、钢)的纸带拼接力仿真值分别为177.1,3.50×104,1.29×106,4.45×106 MPa,仿真结果与理论值相符。设计不同压模纹理的纸带拼接试验,测算出菱形压模拼接后的纸带断裂应力为1.040 MPa,弹性模量为17.816 MPa;矩形压模拼接后的纸带断裂应力为1.802 MPa,弹性模量为28.001 MPa,菱形压模拼接质量优于矩形压模。研究为自动换卷机构的对辊材料和压模纹理设计,以及纸带拼接效果评价提供技术支撑。

适应多类型纱筒的换筒末端执行器关键技术

为解决现有换筒夹持机构无法适用于不同规格纱筒抓取的问题,根据针织生产车间纱架结构特征和纱筒更换工艺流程,设计了由夹爪机构、刹车机构、离合机构、推纱机构、翻转机构等组成的换筒末端执行器,该末端执行器可通过外扩电动机和外张气缸分别调节夹爪收缩尺寸以及夹爪间角度,以适用于不同类型的纱筒抓取。在机构设计过程中,不仅对各组成部分及其运动原理进行分析,还通过ANSYS Workbench软件对不同直径和不同长度的夹爪进行了静力学仿真,得出夹爪的直径为18 mm、长度为58 mm时可满足设计要求。同时研制样机,并进行了不同规格圆柱筒和圆锥筒的抓取实验。实验结果表明:该换筒末端执行器能够稳定、快速抓取内径为20~65 mm、质量不大于6 kg的纱筒,可应用于圆型纬编针织生产线。

城市化进程下厦门市海岸线形态时空变化分析

中国海岸线绵长,海洋资源丰富。厦门作为沿海城市,近年来,港口建设、临海工业、滨海旅游开发等活动的增加导致海岸线出现较大变化。高效、精确地测量海岸线的时空动态变化极具研究价值和实际意义。该文基于2005年、2010年、2015年、2020年4期Landsat遥感影像数据,利用面向对象的方法对海岸线进行提取,然后从海岸线长度、形态和陆地面积变化等方面研究海岸线的时空演变。研究结果表明,15 a间,厦门市海岸线时空变化特征显著。海岸线长度整体持续增长,先加速后减速,2010—2015年间变化最快,平均速率高达4.1 km/a,变化主要集中在大嶝岛和海翔码头附近。海岸线形态逐年趋于平整,湖里区变化最为明显。2005—2020年间,厦门陆地面积增长约24.5 km 2,翔安区陆地面积增长最大。海岸线的变化受到多种因素的影响,其中人口增长、经济发展、政策的出台和改变等都对海岸线的变化产生巨大影响。