国内外旅游业危机管理研究综述

本文强调了旅游业危机管理研究的必要性,对近年来国内外相关文献进行系统回顾,分析了旅游业危机管理的概念、理论基础、发展历程和研究内容等,并总结了国内外的差距,对新的研究趋势提出见解。     

Geographically Weighted Extreme Learning Machine: A Method for Space–Time Prediction

Spatial heterogeneity has been regarded as an important issue in space–time prediction. Although some statistical methods of space–time predictions have been proposed to address spatial heterogeneity, the linear assumption makes it difficult for these methods to predict geographical processes accurately because geographical processes always involve complicated nonlinear characteristics. An extreme learning machine (ELM) has the advantage of approximating nonlinear relationships with a rapid learning speed and excellent generalization performance. However, determining how to incorporate spatial heterogeneity into an ELM to predict space–time data is an urgent problem. For this purpose, a new method called geographically weighted ELM (GWELM) is proposed to address spatial heterogeneity based on an ELM in this article. GWELM is essentially a locally varying ELM in which the parameters are regarded as functions of spatial locations, and geographically weighted least squares is applied to estimate the parameters in a local model. The proposed method is used to analyze two groups of different data sets, and the results demonstrate that the GWELM method is superior to the comparative method, which is also developed to address spatial heterogeneity.     

清乾隆朝第二次廓尔喀侵藏战争(1791－1792)史上的几个问题(英文)

<正>From 1791 to 1792 (the 56th to 57th year of the Qianlong Emperor's reign) during the Qing Dynasty, the Gurkhas invaded Tibet for the second time. The first invasion had been in 1788-1789. This time the Qing court sent troops to Tibet and repelled the invaders going     

艰难的博弈:美国、中国与朝鲜战争的结束

艾森豪威尔当选美国总统后,急于结束朝鲜战争,为此目的而计划采取军事上的硬手段,发动强大的地面进攻,甚至企图诉诸核武器扩大战争的范围。与此形成鲜明对照的是,中国政府一直致力于打破停战谈判的僵局,早在斯大林去世前就在调整谈判政策,从而在推动战争结束的过程中发挥了决定性的作用。在此期间,华盛顿决策层一直考虑使用何种军事手段结束战争,最终明确制定了以核攻击为核心的政策。但无论何时,中国政府都不惧怕任何核威胁。通过与美国方面进行艰难的博弈,中国政府最终推动战争的结束,从而使朝鲜半岛恢复了和平。     

明清以来唐寅文集误收及著作权有争议者考论

唐寅文集自问世以来,不断有学者对其进行增补。人们在对唐寅文字作品有了比较全面认识的同时,错收、误收也时有发生。这些情况的出现,一方面是限于之前文献搜集比勘相对困难,另一方面也与艺术市场长期充斥唐寅的书画伪作有关。唐寅文集目前存在如下问题:他人作品误作唐寅者、原诗略经改动并易题后署名唐寅者、作者有不同说法者、改易数字另成一作等。另外,署名唐寅所作的散曲中,亦因各种晚明曲选的题署不一而存在争议。利用故宫博物院藏唐寅行书自书曲,可以部分地解开其散曲著作权之谜。唐寅文集出现的种种问题,不仅需要引起唐寅研究者的注意,也值得今人编辑艺术家文集时重视。     

Cities in a pandemic: Evidence from China

This paper studies the impact of urban density, city government efficiency, and medical resources on COVID-19 infection and death outcomes in China. We adopt a simultaneous spatial dynamic panel data model to account for (i) the simultaneity of infection and death outcomes, (ii) the spatial pattern of the transmission, (iii) the intertemporal dynamics of the disease, and (iv) the unobserved city-specific and time-specific effects. We find that, while population density increases the level of infections, government efficiency significantly mitigates the negative impact of urban density. We also find that the availability of medical resources improves public health outcomes conditional on lagged infections. Moreover, there exists significant heterogeneity at different phases of the epidemiological cycle.     

广东六朝墓葬出土瓷器研究

一、绪论 广东六朝墓葬分布广泛,数量较多,见诸报道的有广州①、曲江②、高要③、梅县④、韶关⑤、揭阳⑥、始兴⑦、英德⑧、博罗⑨等地,近年在鹤山、四会、肇庆等地又有发现⑩.这些墓葬以长方形券顶砖室墓最为常见,部分出有纪年砖.有确切纪年者,……     

读江泽民同志关于学习历史的论述

江泽民同志认为学习历史具有重要的意义和作用。他关于学习历史重要性的论述既具有历史传承性 ,又具有现实性 ,同时还极富针对性。他指出了学习历史的主要内容和所要达到的目的 ,提出了观察和认识历史的视角 ,这些对学习历史和研究历史具有十分重要的意义。他还提出了学习历史所应坚持的原则和方法 ,为我们学习和研究历史指明了方向。     

可持续旅游下旅游环境容量的量测问题探讨

本文在旅游可持续发展的前提下 ,运用环境科学的理论和方法对旅游区的旅游环境容量的量测问题做了理论上的探讨 ,并在对其进行量化确定上做了初步的研究。认为在对其量化过程中要进行环境背景值、基线值的现状评价分析 ,各环境因子之间的联系与制约关系分析 ,累积效应分析 ,风险评价分析和旅游资源利用的帕累托最适度分析 ,通过各阶段对旅游环境容量的校正 ,最后认为旅游规划的环境容量应是帕累托最适环境容量 ,这才是保证旅游区最佳持续发展的依据 ,其表示为Cg=(1-L)RkAuRA 5i=1 Ci i。