LAND USE CHANGE AND ITS SOCIO-ECONOMIC DRIVING FORCES UNDER STRESS OF PROJECT IN OLD RESERVOIR AREA——Case Study of Linshui Reservoir Area of Dahonghe Reservoir in Sichuan Province

The old reservoir areas built in 1950s- 1970s left behind many socio-economic problems, because of the administrative backward migration and little migration fund, and all these problems would be tied to land. Based on interviewing with peasant households, combining land use survey and socio-economic statistical index, this paper analyzed land use change and its corresponding driving forces in Linshui reservoir area of Dahonghe Reservoir. Results showed that land use change in the reservoir area was mainly embodied on low-lying land submergence and migration requisition land. The former changed the land use patterns, and the latter mainly reconstructed original land property and made land over-fragmented. Cultivated land per capita was 0.041ha in this area, below the cordon of cultivated land per capita enacted by FAO. Currently, there were still 30.25% of peasant households being short of grain in trimester of one year, and there were 35.27% of people living under the poverty line. The conditions of eco-environmerit in Linshui Reservoir Area were worse, and healthy and sub-healthy eco-environment accounted for less proportion, composed of green belt around the reservoir area and paddy field ecosystem, and economic forest and orchard ecosystem, respectively. The stress of the reservoir project was macroscopic background to analyze the driving factors of land use change, and real underlying diving factor of the land use change in the area was the change of cultural landscape under the stress of reservoir project. The rapid increase of population was the key factor to induce the change of man-land relationship in the reservoir area, the low level of rural economy was the crucial factor to decide how migrants input for production, and the belief of migrants, influencing the land use patterns in a certain extent, was the inducing factor to keep land use stable. The low-lying submergence and infrastructure construction accompanied the reservoir project were leading factors driving land use change in the area, while changes in land use patterns, after the reservoir being built, were the responses of peasant households＇ behaviors to land use change.

Spatiotemporal characteristics and driving mechanisms of land use/land cover(LULC)changes in the Jinghe River Basin,China

Understanding the trajectories and driving mechanisms behind land use/land cover(LULC)changes is essential for effective watershed planning and management.This study quantified the net change,exchange,total change,and transfer rate of LULC in the Jinghe River Basin(JRB),China using LULC data from 2000 to 2020.Through trajectory analysis,knowledge maps,chord diagrams,and standard deviation ellipse method,we examined the spatiotemporal characteristics of LULC changes.We further established an index system encompassing natural factors(digital elevation model(DEM),slope,aspect,and curvature),socio-economic factors(gross domestic product(GDP)and population),and accessibility factors(distance from railways,distance from highways,distance from water,and distance from residents)to investigate the driving mechanisms of LULC changes using factor detector and interaction detector in the geographical detector(Geodetector).The key findings indicate that from 2000 to 2020,the JRB experienced significant LULC changes,particularly for farmland,forest,and grassland.During the study period,LULC change trajectories were categorized into stable,early-stage,late-stage,repeated,and continuous change types.Besides the stable change type,the late-stage change type predominated the LULC change trajectories,comprising 83.31% of the total change area.The period 2010-2020 witnessed more active LULC changes compared to the period 2000-2010.The LULC changes exhibited a discrete spatial expansion trend during 2000-2020,predominantly extending from southeast to northwest of the JRB.Influential driving factors on LULC changes included slope,GDP,and distance from highways.The interaction detection results imply either bilinear or nonlinear enhancement for any two driving factors impacting the LULC changes from 2000 to 2020.This comprehensive understanding of the spatiotemporal characteristics and driving mechanisms of LULC changes offers valuable insights for the planning and sustainable management of LULC in the JRB.

Quantifying impacts of climate and human activities on the grassland in the Three-River Headwater Region after two phases of Ecological Project

The Three-River Headwater Region(TRHR)of China is a typical representative of the alpine environment in the Central Asian plateau and the alpine grassland in the world.Grassland degradation is one of its serious eco-logical problems.The purpose of this study is to quantify the joint impacts of climate and human activities on grassland changes in TRHR after two phases of Ecological Conservation and Construction Project(Ecological Project).Grassland vegetation coverage is selected as an indicator for analyzing grassland changes.We adopt Sen+Mann-Kendall trend analysis,residual trend analysis and correlation analysis methods to analyze the trends in spatial-temporal changes and driving factors of grassland in TRHR from 2000 to 2019.The results show that:(1)The grassland has been mainly restored,and the degraded grassland area only accounts for 1.66%of TRHR.After the implementation of the first phase of the Ecological Project,the percentage of restored grassland area has significantly increased from 8.82%to 24.57%,and slightly decreased during the second phase.(2)The establish-ment of national nature reserves and the implementation of the Ecological Project have changed the situation that“the grassland inside the reserve is worse than that outside the reserve”.(3)Grassland restoration is mainly af-fected by the joint effects of climate and human activities.Nevertheless,grassland degradation is mainly affected by human activities such as overgrazing and grassland reclamation.All of these findings can enrich our under-standing of grassland restoration in TRHR.Artificial measures have certain limitations in promoting grassland restoration.Natural restoration should be considered when human beings strengthen ecological conservation and transform their production and life styles.

A class of fully third-order accurate projection methods for solving the incompressible Navier-Stokes equations

In this paper, a fully third-order accurate projection method for solving the incompressible Navier-Stokes equations is proposed. To construct the scheme, a continuous projection procedure is firstly presented. We then derive a sufficient condition for the continuous projection equations to be temporally third-order accurate approximations of the original Navier-Stokes equations by means of the localtruncation-error-analysis technique. The continuous projection equations are discretized temporally and spatially to third-order accuracy on the staggered grids, resulting in a fully third-order discrete projection scheme. The possibility to design higher-order projection methods is thus demonstrated in the present paper. A heuristic stability analysis is performed on this projection method showing the probability of its being stable. The stability of the present scheme is further verified through numerical tests. The third-order accuracy of the present projection method is validated by several numerical test cases.

Research on the New Mode of Computer Education based on Project Driving Methodology and Teaching Practice

In this paper, we conduct research on the new mode of computer education based on project driving methodology and teaching practice. Computer education is an important part in college education, application of computer technology can effectively cultivate students＇ ability and quality of information. Collaborative project teaching method of the implementation of the method can make students accept knowledge by only listen into doing which will not only enhance the students＇ ability but help teachers obtain better feedback as well which is meaningful and necessary. The proposed methodology and education pattern is proven to be effective and feasible.

Comment on the Recent Start of a New “IUPAC-Project”

The opening of a new IUPAC-project is highly appreciated. In the year 2009, the IUPAC had published an article “Discovery of the element with atomic number 112 (IUPAC Technical Report)” [1]* which contains a section on the work of the Marinov collaboration. It appears that this section is not always in agreement with conventional standards for scientific publications. This present comment focuses on these formal questions.

Analysis and Comparison of Electric Drive System Projects of Military Tracked Vehicles

The electric drive system characteristics of different projects for tracked vehicles are analyzed.For the two most typical projects,the parameters of power,torque and rotating speed and others of drive motor are figured out under the condition of satisfying adequate steering performance of the tracked vehicles.General opinions on the two projects are brought forward and conclusions are drawn.

Projective synchronisation with non-delayed and delayed coupling in complex networks consisting of identical nodes and different nodes

This paper first investigates the projective synchronisation problem with non-delayed and delayed coupling between drive-response dynamical networks consisting of identical nodes and different nodes. Based on Lyapunov stability theory, several nonlinear controllers are applied to achieve the projective synchronisation between the drive-response dynamical networks; simultaneously the topological structure of the drive dynamical complex networks can be exactly identified. Moreover, numerical examples are presented to verify the feasibility and effectiveness of the theorems.

关联用户的电驱动总成效率评价方法研究

为实现电驱动总成效率评价与用户端的关联,提出了基于用户实际行驶工况的效率评价方法。以采集的某型纯电动汽车用户工况数据为基础,基于核密度估计和马尔科夫链蒙特卡洛采样方法,预测了用户目标里程下的转矩-转速工况点分布。提出了以台架效率数据为驱动建立效率预测模型的方法,基于遗传算法优化的BP神经网络(GA-BP)建立了效率预测模型。结合用户目标里程下的转矩-转速工况点分布和效率预测模型,提出并建立了关联用户的电驱动总成效率评价方法。本研究为更加全面了解电驱动产品用户端使用特征、合理评价电驱动总成效率和电驱动总成效率匹配优化提供了参考依据。

促进幼儿深度学习的项目式活动中驱动性问题链的设计

驱动性问题是项目式学习的核心与灵魂,是项目式活动的抓手,能够促进幼儿的深度学习,是培养幼儿核心素养的重要途径。探讨驱动性问题的内涵及设计,从教与学角度及项目学习的基本要素角度着手,分析驱动性问题在项目式活动中的引领作用,形成驱动性问题解决模式,用驱动性问题链引领项目活动的开展,促进幼儿的学习及深层次发展。

南水北调西线工程上线水源区大型底栖动物群落结构及环境驱动因子

为评估南水北调西线工程上线水源区大型底栖动物群落结构及环境驱动因子,于2022年7月(汛期)和11月(非汛期)开展监测采样工作。采用生物多样性指数和丰度-生物量比较曲线(ABC曲线)作为大型底栖动物群落特征参数,分析大型底栖动物群落在水源区的结构,并对其进行多元排序和Pearson相关性分析。结果表明:共采集45种大型底栖动物,隶属于4门5纲10目32科44属,其中优势种8种,所有优势物种出现频率均大于50%,水源区大型底栖动物群落结构一致性较高;水源区Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均值分别为4.01、1.68、0.61;多数采样区域大型底栖动物的ABC曲线呈纠缠态势,其丰度和生物量累积百分比的差值面积在0附近波动,群落以小个头物种为主;优势种以耐污值低的敏感种类为主,说明河流几乎不受污染,水体清洁;pH值是影响水源区大型底栖动物群落结构的主要环境驱动因子。

浙江省种植业碳排放时空演变规律及驱动因素分析

【目的】探讨浙江省种植业碳排放时空演变规律及影响因素,以期制定种植业固碳减排方案,促进浙江省种植业低碳绿色转型。【方法】基于浙江省种植业的能源投入数据,使用碳排放系数法评估2006—2021年浙江省种植业碳排放的时空演变规律,结合对数平均权重迪氏指数模型(LMDI)对种植业碳排放变化进行驱动因素分析,并采用灰色预测模型预测2022—2040年的种植业碳排放量。【结果】①2006—2021年,浙江省种植业碳排放量总体呈现先上升后下降的趋势,年际变化率为-1.80%,累计碳排放总量为1.29亿t;2006—2012年,碳排放量缓慢上升,2012年达到峰值后急剧下降,平均每年下降2.94%。②浙江省种植业的碳排放量呈现中部高南北两侧低的分布格局,中部地区的杭州、金华与台州是浙江省的主要碳排放地区,碳排放量占全省的39.86%。③种植业生产效率提高与地区产业结构优化对碳减排起到促进作用;经济发展水平提高、人口数量增加及农业生产结构上升是引起碳排放量增加的驱动因素,其中经济发展水平是影响碳排放量变化的主要驱动因素,引起的碳排放变化量占比为41.58%。④灰色预测模型预测结果表明:2022—2040年浙江省种植业碳排放量呈持续下降趋势,2040年的碳排放量下降至2021年的37.20%,其中杭州、嘉兴、绍兴及金华下降幅度最大。【结论】浙江省种植业已实现碳达峰。为保证未来碳排放持续下降,应重点关注农业生产技术的优化和产业结构的调整,种植过程中合理施用化肥,提高种植效率,减少能源消耗,加快推进农业绿色化现代化,加速实现碳中和目标。图4表2参37.

高职机械工程创新创业人才培养模式探索与实践--以福州职业技术学院为例

在创新创业人才培养过程中,福州职业技术学院机械工程专业探索采用"项目导入+专利驱动+专创融合+实习实践"培养模式,即以第一、第二课堂培养创新创业素质,以专利发明驱动创新实践,以创新创业大赛检验创新创业能力,以毕业实习平台对接产业创新创业人才需求,构建起"全闭环四步法"创新创业型人才培养体系。该模式极大地激发了学生的学习主观能动性,培育出具备技术创新、产品研发、团队管理、运营服务等综合能力的机械复合型人才。

基于ARM Cortex-M0+ KL系列MCU的汇编构件设计

汇编编程的复杂性及有关32位ARM Cortex-M0+等内核汇编开发资料和样例程序的短缺,使编程者学习、研究和开发微处理器汇编程序难度很大。针对这一现状,在对ARM Cortex-M0+内部寄存器、汇编指令系统等进行深入分析的基础上,以NXP半导体公司KL系列MCU为蓝本,提出一种规范、易用、实用的汇编构件设计编程方法。该方法根据软件工程构件设计思想,基于构件封装要点分析和汇编工程框架,设计并实现汇编构件,并给出了典型UART模块的汇编底层驱动构件的样例程序。通过对汇编构件设计编程方法的使用和样例程序的学习与理解,降低嵌入式汇编学习和编程难度,并进而轻松设计其他类似的规范化的汇编构件和程序。

面向资源约束的电动公交车充电调度策略

为减少公交运营成本、合理制定插入式充电模式下公交总站的电动公交车充电调度方案,本文基于帝国竞争算法提出了一种面向资源约束的公交车充电调度策略(RCO-CSS)。基于电动公交车运营的时空特点和充放电特性,应用多技能资源约束多项目调度问题(MSRC-MPSP)运筹规划思想对电动公交车充电问题进行抽象建模,以车队规模与充电桩数量为主要资源参数,以最小化充电成本和日均设备购置成本为目标,构建资源约束充电调度模型,进而设计一种二阶段演化帝国竞争算法(TSE-ICA)对模型进行求解,输出最佳的充电调度方案及匹配的行车运营计划。采用4个分别包含5、10、20和36条线路的公交运行实例对RCO-CSS进行了性能评估与有效性验证。在实例探讨中,首先运用Taguich法对资源参数进行了敏感性分析,发现资源越宽裕,模型输出的日充电费用越小,但车辆与充放电设备平摊至每日的购置成本越大;其次,将TSE-ICA与其他4种先进的元启发式算法进行实验数值对比,验证了所提算法的寻优性能;最后,通过与无序充电调度策略和常规有序充电调度策略进行比较,证明了RCO-CSS能够更好地降低用电成本、设备购置成本和电池充放电次数。基于MSRC-MPSP和TSE-ICA的RCO-CSS为公交运营商制定充电调度方案和行车运营计划提供了一种可行且敏捷高效的新思路。

基于驾驶模拟的高速公路施工区视错觉减速标线有效性研究

选择合适的视错觉减速标线进行设置,以高速公路改扩建施工区的行驶环境变化作为设置参数的设计依据,使其发挥良好的效果从而主动降低行车速度,保障施工路段交通安全。本文以典型改扩建的高速公路为研究对象,利用驾驶模拟技术,施工区设计3种视错觉减速标线(鱼刺型减速标线、纵向减速标线、立体减速标线),基于驾驶模拟试验测试,采集分析驾驶行为数据、心生理数据(包括眼动特性和生理信号等数据),参照数据变化规律及指标特性建立高速公路施工区视错觉减速标线有效性评价指标体系,构建基于熵权法与变异系数法的综合赋权模糊评价模型,提出高速公路施工区视错觉减速标线有效性模糊综合评价方法,对3种视错觉减速标线场景进行比较分析和安全评价。结果表明,不同的视错觉减速标线形式对行驶过程的驾驶员减速效果有一定影响,纵向减速标线的方案计算分值最高,综合响应表现最好。高速公路施工区设置纵向减速标线,能有效降低行车速度和保障施工路段交通安全,可为高速公路改扩建施工区交通的精细化设计提供决策参考。

时滞驱动-响应动力网络关于不同比例因子的投影同步

研究了一类时滞驱动-响应动力网络投影同步问题,其中网络节点不要求是部分线性的,且比例因子可以彼此不同.将比例因子分为有限定条件和无限定条件两种情形进行讨论,基于Lya-punov稳定性理论和脉冲控制方法,给出了驱动-响应动力网络关于不同比例因子的一些投影同步准则,其中有限定条件时,不需要增加额外的控制器;没有限定条件时,只要给每个节点增加简单的控制器即可实现同步.最后利用带有时滞的Hopfield神经网络作为节点动力学构成时滞驱动-响应动力网络进行数值仿真,理论分析和数值模拟结果均表明了这些同步准则的有效性.

中国体育旅游精品项目空间格局特征及其影响因素研究

中国体育旅游精品项目的培育是满足人民群众美好生活向往的重要途径。以近三年556个中国体育旅游精品项目为研究对象,综合运用GIS空间分析和地理探测器探究其空间分布格局及其影响因素。研究发现中国体育旅游精品项目的空间分布具有不均衡性特征,且倾向于随机分析,空间关联性较弱,聚集程度偏低;在各类影响因素中,高程、气候和水系等自然因素起着决定性作用,旅游发展水平和交通通达性是主要驱动因素,地域文化、政策保障、体育发展水平和区域接待水平是一般驱动因素,而区域经济发展水平的影响程度最低。

15-15Ti高温蠕变性能的研究

对20%冷加工的15-15T不锈钢分别在625℃和700℃、100~350 MPa条件下开展单轴蠕变实验。通过OSD参数法和θProjection方程对蠕变数据进行处理,并结合微观结构,分析其蠕变性能。结果表明:OSD参数法和θProjection方法预测的结果与实验结果具有较好的一致性;在625℃时,随着应力的降低,蠕变断口逐渐从穿晶韧性断裂向沿晶断裂转变;在晶界和晶粒内部均发现析出物,而晶粒内的析出物会阻碍位错运动。