一种分层A~*路径搜索算法及性能

基于层次道路网提出了一种分层A*路径搜索算法,其特点是在同一层路网中采用A*算法,而在层次切换时采用一种启发式定向搜索入口节点的方法。既顾及了道路等级性和朝着目标行进等驾驶员的心理因素,又可以获得比传统算法更快的求解速度。实验表明,该算法是可行的、高效的。     

传统社会主义道路的传延与变革

党的第一代领导集体开辟了社会主义道路,对中国社会主义现代化建设做出了重大贡献。在改革开放的新时期,我们党又开辟了中国特色社会主义道路;由于它对党的第一代领导集体开辟的社会主义道路的继承和发展,产生出了传统社会主义道路。传统社会主义道路的创造,表明了党的各代领导集体是社会主义传统的继承者和维护者,显示了中国社会主义理论和实践的历史连续性。     

广州亚运会对广州休闲经济的影响

广州亚运会后,广州休闲经济发展迅速,经济效益明显。广州亚运会在城市定位与发展规划,基础设施建设、环境改善、服务水平提高、整体应急系统建设等方面,给广州休闲经济的发展奠定了基础,使广州休闲经济在商业零售、文化产业、旅游业以及绿道休闲经济等方面获得丰硕的成果。     

浅析市政道路给水管道设计施工方式

当前随着经济的发展,城市吸引了越来越多的人进入,各类配套设施都在不断增加以满足人民的需求,给水管道作为民生必须品也在增加.给水管道的设计施工与民生息息相关,十分重要.本文首先对市政道路给水管道设计应遵循的原则进行阐述,其次对如何选择与确定给水管网管径进行分析,之后讨论道路管线位置的确定与施工,最后结合了市政道路给水管道...     

环境约束下中国省域旅游经济效率及其影响因素的空间计量分析

采用Super-SBM方法将环境因素作为非期望产出纳入旅游经济效率测算框架,结合空间计量经济方法分析2005—2016年我国省域旅游经济效率空间关联性及影响因素溢出效应,结果显示:环境约束下,我国省域旅游经济具有一定的空间集聚趋势,呈现出"东南热、西北冷"的分布特征,尚未实现网状结构均衡发展;我国省际旅游经济效率间存在显著的空间溢出作用。对于环境约束下旅游经济效率发展来说,人均GDP、技术创新、市场化、环境规制均有显著的正向作用,路网密度作用不显著,外国直接投资(FDI)有显著的负向作用。影响因素的溢出效应来看,市场化、经济增长、技术创新具有显著的积极间接溢出效应,但环境规制带来了显著的负向间接溢出效应,FDI与路网密度的间接溢出效应不显著。     

北京园林绿地6种树木的叶片和一年生枝中5种重金属含量比较

为了解不同园林树木对重金属的吸收情况,以北京市陶然亭公园、紫竹院公园、中科院植物园、马甸公园、皇城根遗址公园和营城建都滨水绿道不同环境绿地为样地,选择样地间共有的园林树木,采用ICP光谱仪测定了6种树木叶片和一年生枝条中重金属锌(Zn)、铬(Cr)、镍(Ni)、砷(As)和汞(Hg)的含量,以此为基础,采用隶属函数法将6种树木单位重量对5种重金属的综合富集能力进行排序,并对同树种叶片与当年生枝、5种重金属吸收量分别进行相关分析。结果表明：1)不同树种叶片和一年生生枝条单位重量中重金属含量有显著差异,且因重金属种类而异。Zn、As含量最高的为金银木,Cr、Ni、Hg含量最高的依次为圆柏、侧柏、丁香;丁香富集Zn、Cr、As的能力最低,白皮松富集Ni能力最低,侧柏富集Hg能力最低。2)树木叶片和当年生枝单位重量对5种重金属综合富集能力排序为：金银木＞侧柏＞圆柏＞油松＞丁香＞白皮松。其中,针叶树种中圆柏、侧柏、油松富集5种重金属的综合能力显著高于白皮松(P＜0.01),阔叶树种中金银木吸收重金属的能力显著高于丁香(P＜0.01)。3)树木不同器官中重金属含量也不同,不同树种间叶片与枝条中仅Cr含量具有显著相关性,相关系数为0.461(P＜0.01),其他4种元素均未达到显著水平。4)同树种叶片和当年生枝Cr和Ni吸收呈极显著相关性(P＜0.01),其他元素吸收之间未呈现相关性。本研究结果对北     

Chinese multinationals on the New Silk Route: Managing political risk by branding the nation

Though Chinese multinational enterprises (CMNEs) have brought investment and opportunities to countries along the Belt and Road Initiative, there has been scepticism regarding the content and context of their investment. On the one hand, infrastructural development contributes to GDP formation and enhances the efficiency of productive inputs where international trade enhances technology and export development, which jointly provides a path to economic growth. On the other hand, critical issues such as debt sustainability and national sovereignty among countries that have gone through the decolonization process mean that CMNEs need to grasp the implication of political risk when investing. This article focuses on South and Southeast Asia, where China has historical socio‐economic relationship, and proposes a nation branding model combining tradition and modernity which can be the way forward for CMNEs to mitigate political risk in relation to the Belt and Road Initiative (BRI) investment. Nation branding of BRI could be seen as a continuity of China's unfinished business in globalization that has preceded the modern polity; nevertheless, there is a need to communicate a coherent and authentic message that reflects the reality of business operations.     

略论中国银行业创新的路径选择

文章首先分析了中国金融业的结构性缺陷,其次分析了中国民营中小企业贷款难的形成和原因,最后提出了通过创办民营中小银行这一金融机构来解决以下三个问题:当前银行业的结构性缺陷、民营企业贷款难和民营经济在金融领域中的发展问题。     

Attitudes,norms and difficulties underlying road sharing intentions as drivers and cyclists: Evidence from the Czech Republic

Cycling-inclusive urban planning is attracting attention worldwide because of the environmental, health, economic, and transport benefits inherent to cycling from the individual and the societal perspectives. The Czech Republic is one of the emerging cycling countries that are trying to promote and support cycling, but cycling mode shares are low because of the poor quality of the scarce infrastructure and the psychological barrier of the perceived lack of safety when cycling in mixed traffic. This study takes a multimodal approach based on the Theory of Planned Behaviour and focuses on the factors underlying the willingness to share the road from the perspective of cyclists and drivers: positive attitudes toward cycling, positive attitudes toward cyclists’ behavior, social norms toward cycling and anxiety to share the road. A web-based questionnaire was tailor-designed and administered in the Czech Republic via social networks, web forums, and the Civinet network, and a hybrid bivariate-ordered model tested the behavioral framework. Results show that the willingness to share the road as a cyclist or as a driver relates positively to positive attitudes towards cycling and cyclists’ behavior, and negatively to the anxiety of sharing the road. Moreover, mediator effects are observed and a clear relation emerges between the experience on the road as both a cyclist and a driver on the willingness to share the road as a cyclist. Lastly, results show that the factors underlying road sharing intentions are related significantly to gender, travel habits, and perceived personal and infrastructure-related barriers to cycling.     

美丽的宿根花卉-鸢尾科植物

介绍了鸢尾科植物的种群分布,各个品种的生长特征,观赏特性以及它们在园林绿化、水土保持中的应用。