中小功率农用柴油机的排放特性分析

为探讨并解决中小功率农用柴油机实际排放特性与台架试验结果差异大的问题,通过便携式排放测试系统(PEMS)检测分析其实际作业的排放特性。结果表明:在拖拉机旋耕作业过程中,柴油机处于重载状态,转速在额定点附近小范围内波动,作业平均功率相比非道路瞬态循环(NRTC)高约30.0%;氮氧化物(NO_(x))排放质量流量随着负荷剧烈变化,CO排放质量流量相对比较稳定;整个试验的NO_(x)和CO的比排放量分别为0.414 g(/kW·h)和0.454 g(/kW·h),分别比90%有效功工况下的基准比排放量低11.3%和10.6%。

基于微压印技术的柔性传感器的设计及制备

柔性传感器由于具有柔性、轻薄、力学性能优良且能与弹性被检测保持同步形变等优点,被广泛应用。由于聚二甲基硅氧烷(PDMS)聚合物具有高弹性、疏水性、防水性、加工性能较好,且易与多种材质在室温下结合等特点,提出了基于微压印技术及空间限域强制组装原理(SCFNA),以PDMS为基底,碳纤维(SCF)/碳纳米管(CNT)为导电填充填料,分别制成V槽微结构和平面2种结构的导电薄膜,以面对面的接触形式,采用PDMS薄膜将其封装成聚合物基柔性传感器。研究结果表明,在0~50 N范围内,聚合物基柔性传感器输出电阻与压力具有良好的线性响应特性,灵敏度能达到-27. 2Ω/N,重复性误差小于5. 5%,对传感器施压200次后,进行测试,稳定性误差小于6%。

基于PDMS基柔性传感器的智能感知系统

柔性传感器与受力被测体可以产生一致的形变,基于空间限域强制组装原理,以PDMS为基体,通过控制变量法分别分析微结构、膜片厚度、填料含量对感应膜片压阻特性的影响,选取三角微结构、厚度为0.3 mm、石墨烯含量为0.5%的导电薄膜作为敏感元件,使用PDMS薄膜将其封装为压阻式柔性传感器,传感器测量范围和对应输出阻值范围分别为0~10 N和83.542~352.113Ω。结合云计算和人工智能技术,将其应用于汽车座椅中,作为感知驾驶员人体特征的力学传感器,在实验中获取训练和测试数据的同时,通过机器学习,获取驾驶员的眼位等位姿信息,作为调节与驾驶员位姿信息匹配的后视镜角度的依据。通过分布座椅的多个测力传感器感知驾驶员身体不同位置受力,基于K-NN算法,辨识出最接近测试驾驶员的眼位,其误差精度可达3.5%,为后续汽车座椅的智能控制提供相关依据。

浙江省土地利用碳排放效应研究

为了优化浙江省土地利用结构,在经济发展的同时应做好减排工作。以浙江省为研究区域,利用碳足迹计算模型核算2007-2016年该地区碳足迹水平,利用脱钩分析和标准椭圆差探究浙江省土地利用碳排放效应。研究表明:2007-2016年浙江省年均净碳排放量增长率为4.06%,建设用地是浙江省主要碳源,碳源碳汇总量差距扩大,低碳发展难度加大;宁波市净碳排放量位居浙江省首位,丽水市净碳排放量最低,且是唯一碳汇作用大于碳源的地区,浙东北与浙西南碳排放差距扩大;浙江省人均GDP与人均碳足迹呈现弱脱钩状态,浙江省经济发展快于碳排放量增加速度,丽水市脱钩程度最优,舟山市脱钩程度较差;浙江省净碳排放量与建设用地碳排放量空间分布集聚于东北部,耕地碳排放量空间分布较为分散,较前两者中心偏西南方。

An Empirical Study on the Development of Regional Circular Economy Based on Ecological Efficiency： A Case Study of Jiangsu Province

Based on the theory of ecological efficiency,an empirical study on ecological efficiency and its changing path in Jiangsu Province during2005-2014 was conducted,and then the relationship between economic development and environmental pressure in the province was discussed by decoupling analysis. Finally,the main influencing factors of changes in ecological efficiency were analyzed by grey relational analysis method. The results showed that from 2005 to 2014,the resource efficiency of each indicator in Jiangsu Province fluctuated,while the environmental efficiency of most indicators increased slightly. The comprehensive resource efficiency and environmental efficiency also fluctuated,and the fluctuation range of the comprehensive environmental efficiency was larger than that of the comprehensive resource efficiency. Seen from the temporal evolution of ecological efficiency and circulation economy development pattern in Jiangsu Province,the leaping development mode was adopted in the province.The decoupling state of economic development and environmental pressure in Jiangsu Province was unstable,and they were in a state of strong decoupling,weak decoupling and expensive recoupling in most years. According to the results of grey relational analysis,comprehensive utilization of solid waste,industrial electricity consumption,electricity consumption of the whole society,domestic energy consumption,discharge of urban domestic sewage,and production of common industrial solid waste were the main influencing factors of changes in ecological efficiency in Jiangsu Province.