一种机械加工参数速查卡的设计

本文通过对目前查询机械加工相关参数进行分析,设计了一种机械设计及加工参数速查卡,介绍了速查卡的组成结构、工作原理.解决了机械设计及加工参数复杂的查询及计算过程问题,确保了参数查询的准确性,有效的提高工作效率.     

Job accessibility and employment outcomes: which income groups benefit the most?

Improving job accessibility can increase the probability for individual persons to be employed and reduce their commutes. Empirical research suggests that the relationship between job accessibility and employment outcomes differ across income groups, but no research has investigated the difference or explored which income groups benefit the most from job accessibility improvements. This research fills the gap by examining six income groups in the Los Angeles metropolitan area. Results show that job accessibility affects the employment status of medium-to-low income groups (household income between US$25,000 and US$75,000). For the lowest-income group (household income lower than US$25,000), owning a car significantly improves their chances to be employed, but job accessibility has no effect. On the other hand, higher job accessibility is associated with shorter commuting distance for the other five income groups, but not for the lowest-income group. These results suggest that transportation and land use policies need to address the specific needs of distinct population groups and underscore the importance of spatial access for the middle-class, which tends to be overlooked in the literature on transportation equity.     

一种新型导静电拖地带的研究和应用

静电无处不在,若处置不当会引发车辆设备机械电子故障甚至安全事故,在易产生静电的交通运输车辆上都应按标准要求(GB 7258-2017)安装防静电装置(导静电拖地带).本文介绍一种新型导静电拖地带,具有环保、长寿命、可徒手随时随地快速(3-5s)调整维护等优点,克服了在用导静电拖地带由于整体暴露、雨水尘土污染和阳光直晒,易造成带体橡胶老化龟裂后导电体暴露氧化或带体断裂丢失,致使导静电性能降低或丧失、带体多道对折固定、维护调整费时费力等不足.本文观点供交流探讨.     

等截面送风管道静压分布和风口等量率计算

本文介绍了等截面多风口送风管道内静压分布基本式理论推导和风口等量率计算方法,着重对工程实践中应用较多的大阻力管道和小阻力管道压力分布特性进行分析比较,并根据实际地下工程测定数据验证其理论计算可靠性,可供道路隧道等量送风长管道和轨交地下车站站厅站台公共区、设备管理用房等量送风管道设计计算和工程调试作借鉴和参考。     

模块化电液转辙机的设计与实现

详细介绍了一种模块化设计的电液转辙机的工作原理及结构,主要包括一体式液压总成模块、传动锁闭模块和表示接点模块3部分,各模块间通过特定的机械接口联接完成转辙机转换、锁闭、表示等功能,具有结构紧凑、易于拆装维护、高稳定性等诸多优点。     

层次极限学习机用于高光谱图像预测绝缘子污秽度

高光谱图像具有图谱合一、光谱范围广及分辨率高等优势，能精细化地反映物质微观特性. 为此，引入高光谱成像技术以非接触式预测绝缘子污秽度. 考虑到极限学习机具有学习效率高和泛化能力强等优点，提出基于正则化约束极限学习机的绝缘子污秽度预测（extreme learning machine-insulator pollution degree prediction，ELM-IPDP）模型. 此外，为进一步提升预测性能，引入层次极限学习机从复杂的高光谱图像中学习出有效、抽象、判决性特征表示，继而建立基于层次极限学习机的绝缘子污秽度预测（hierarchical ELM-IPDP，HELM-IPDP）模型. 在不同的训练集与测试集比例和不同隐含层神经元个数的情况下分别进行实验，从实验结果可知:ELM-IPDP模型和HELM-IPDP模型的预测性能基本上随着隐含层神经元个数和训练样本的增加而不断提高；当训练集与测试集比例为9∶1时，ELM-IPDP模型的均方根误差和相关系数分别为0.040 3和0.944 7，而HELM-IPDP模型的均方根误差和相关系数分别提升到0.022 3和0.972 0.      

Optimization of traffic demand management policy in China: towards a sustainable mode split

The rapid increase in private car use in large metropolitan areas has led to irrational travel mode splits and severe traffic problems. Traffic demand management (TDM) is an effective policy to achieve a more sustainable development of traffic systems. This study analyzes the relationships between TDM policy, mode split, and travel mode choice using Stackelberg game theory. Then, using 0–1 programming, it establishes a combination of TDM policy instruments that can achieve a more sustainable mode split in a city and provides a case study in China. The method presented in this research has strong theoretical implications for TDM policymakers.     

液相法制备无机纳米一维材料进展

具有一维结构的无机纳米材料由于其量子限域效应在多个领域都展现出了广阔的应用前景,并且可以作为基本单元用于组装纳米器件。液相法是一种可控度高、成本低且易放大生产的用于制备一维纳米结构的通用方法,目前广泛应用于科学研究及生产中。本文对无机纳米一维材料的液相法制备进行了总结,主要包括有机金属胶体制备法、液相沉积法、水热/溶剂热法以及SLS法等。对纳米一维材料的形成机理如晶体各向异性生长等也进行了论述,并结合研究实例对不同液相法制备纳米一维材料的过程进行了分析。     

新形势下的海事公共关系建设——访上海海事局局长徐国毅

传播力决定影响力,话语权决定主导权,时效性决定有效性,透明度决定公信度。权威正面、真实及时的对外宣传,不仅为了将已有的工作成果锦上添花地报道出去,其意义更在于为将来的工作争取更好的公众配合以及谋求更大的发展空间。     

浅析“三点检查”在信号领域的运用

6502电气集中以及计算机联锁是保证站内运输作业安全,提高作业效率的安全设备,"三点检查"方法是进路内轨道电路区段正常解锁的依据条件之一。从信号安全角度对"三点检查"的应用进行了分析思考,重点阐述"三点检查"在既有信号领域的运用范围及其特点,进而在区间自动闭塞模式基础上引入区间进路的理念,从而把区间纳入联锁安全保障之中,并提出建议。