A Minimax Method for Finding the k Best “Differentiated” Paths

In real-world applications, the k-shortest-paths between a pair of nodes on a network will often be slight variations of one another. This could be a problem for many path-based models, particularly those on capacitated networks where different routing alternatives are needed that are less likely to encounter the same capacity constraints. This paper develops a method to solve for k differentiated paths that are relatively short and yet relatively different from one another, but not necessarily disjoint. Our method utilizes the sum of a path's distance plus some fraction of its shared distance with each other path. A minimax algorithm is used to select the path whose largest sum of length, plus shared length vis-à-vis each previously selected path, is as small as possible. We present computational results for the Chinese railway system, comparing the paths generated by a standard k-shortest-path algorithm with those from our new model.     

国外进口瓷器修复专用材料的应用研究

国内外瓷器修复的基本流程没有很大差异,但是西方国家生产的修复专用材料品种较丰富,值得国内修复界吸收与应用。为此,本研究着重对Hxtal NYL-1、Golden Porcelain Restoration Glaze、Golden Polymer Varnish with UVLS三款瓷器修复专用产品开展分析研究。测试结果显示,在国内外5类环氧树脂中,Hxtal NYL-1的拉伸强度最低,断裂伸长率最高。Hxtal NYL-1在波长365nm的紫外线照射78d后,其色差变化最平稳。紫外可见光谱数据显示Golden Glaze仅吸收一定的中波紫外线UVB,Golden Varnish对长波紫外线UVA和中波紫外线UVB都具有吸收能力。波长365nm紫外老化实验可证明Golden Glaze和Golden Varnish都具备较好的光稳定性。而在254nm紫外老化环境下,Golden Varnish表现出更佳的抗紫外性能。此外,围绕瓷器修复实例,对这些产品的在修复中的使用方法进行了简要梳理。     

Political Commitment,Policy Ambiguity,and Corporate Environmental Practices

A lack of clear political commitment together with confusing rules and enforcement often characterize the institutional context of policy implementation and regulatory compliance in developing countries. By connecting such contextual features to existing models of policy implementation and regulatory compliance, we examine how regulatory factors are related to basic and proactive corporate environmental management practices in the Pearl River Delta region in China. Drawing on data derived from both a survey and in‐depth interviews, we show that a perception of clear political commitment to environmental protection across multiple government levels and units is positively associated with business efforts in basic environmental practices, regardless of the specific enforcement intensity. Nevertheless, a perception of clear political commitment is not related to proactive environmental practices. Conversely, a perception of policy ambiguity, in the form of confusing regulatory standards and enforcement, is negatively associated with corporate efforts in both basic and proactive environmental practices; yet, intensive inspections mitigate these negative associations with policy ambiguity.     

基于GPS数据的北京郊区就业者工作与通勤行为特征研究——以上地信息产业园为例

城市空间快速扩张及郊区中心的崛起,带来多中心城市结构的演变及一系列城市问题。已有研究较少针对对郊区就业者的工作与通勤行为,未能全面地反映新职住“空间错位”。本文基于2012年对北京上地就业者的日常活动与出行调查数据得出以下结论：①主动郊区化的侧面通勤者体现出典型的郊区生活方式： “朝九晚六”、加班明显,生活活动空间更加广域化。②在郊区化过程中被动调整的逆通勤者职住距离最长、依赖公共交通通勤、“早出晚归”、错峰出行、生活活动空间呈现以家和工作地为主的“两极化”特征。③郊区中心内部相对职住接近的就地通勤者,在享受工作与通勤便利性（如职住接近、“晚出早归”）的同时活动空间高度隔离集中在郊区中心。     

Tracing the origin of Chinese early white porcelain in the late sixth century—evidence from Xing kiln

As the criterion used by archaeologists for determining early white porcelain is quite ambiguous, the origin of Chinese white porcelain remains a point of disagreement. In this study, we systematically investigate 61 typical Xing porcelains of the late Northern dynasties to the early Sui dynasty (550–600 CE) using spectrophotometer, X-ray fluorescence (XRF), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD), and analyze the differences between early white porcelain and celadon of Xing kiln in terms of their whiteness and raw materials characteristic. The results show that early white porcelain is a new type of ware that differs from celadon, which can be distinguished by whiteness, with a whiteness greater than 8% being early white porcelain and a whiteness less than 8% being celadon. It is assumed that the ancient potters created the whiter wares based on celadon by improving the glaze and selecting new raw materials for the body, but the production of this type of ware was short lived and subsequently refined in the Sui dynasty (581–618 CE) owing to the limited improvement in whiteness.     

国家权力、企业家精神与企业经营——以通用机器有限公司(1946~1949)为例

通用机器有限公司是国民政府资源委员会在抗战胜利后创办于上海的国有机械制造企业。资源委员会委派私营企业家马雄冠作为公司负责人,并肯定了马雄冠的"纯商业化"经营路线,使公司能边基建边投产运营,缓解了资金压力,在恶劣的局势下取得较好的成绩。尽管马雄冠为公司注入了企业家精神,但公司的销路问题有赖于资源委员会的重工业建设,其技术引进也由资源委员会负担了大笔先期资金,因此,该公司的成功是良好政企关系的产物。     

韩国迁都宜阳、阳翟考辨

从战国初年的历史形势和韩国的发展战略出发,考虑韩国灭郑的军事策略,结合考古材料,韩国迁都宜阳、阳翟的记载应是可信的。对文献记载的混乱现象应予以全新解读:韩国迁都宜阳、阳翟的时候,平阳作为政治中心在继续使用。换言之,韩国在保持平阳都城地位的同时,迁都宜阳、阳翟,以此来服务灭郑的军事战争。宜阳和阳翟是具有浓厚军事色彩的临时性都城,带有战时陪都的性质。     

伪色诺芬《雅典政制》史料价值初探

伪色诺芬《雅典政制》作为公元前5世纪后期雅典的历史文献,对于研究雅典政治状况、原提洛同盟"盟邦"与雅典的关系以及探析民主政治的实质具有重要的史料价值。作者主要从平民的权利、海上霸权两个方面论述雅典民主制保持完好的原因,评述"盟邦"主权遭到雅典侵夺的历史事实,从而证明雅典民主制乃是建立在全体雅典人对非雅典人剥削、奴役基础之上的。当政者所采取种种强化民主的措施,其目的都是为了维护雅典人的根本利益。     

从《牡丹亭》看女性教育

《牡丹亭》是汤显祖"至情论"在"临川四梦"中最集中的体现,其中女主角杜丽娘堪称"至情论"最佳诠释者。一部经典剧作的内涵往往不是单一的,作者在《牡丹亭》中除了建构"情教论",反科举外,还有对女性教育的思考。《闺塾》一出极为精彩,其中塾师陈最良、女学生杜丽娘及其伴读春香一同演绎了明末私塾教育的一个场景。通过《闺塾》以及相关剧情的解读,可以反观晚明社会女性教育的林林总总。如:教材的选用,教学内容的拟定,教育方法的采用,教育环节的把握等,这些均直接影响教学效果的实现,教学目标的达成,这有助于我们了解那个时代女性教育的情状,对当下的女性教育亦不无启迪意义。