关于“正弦振动试验”现行国家标准与正在修订中的新版标准的解读

正弦振动试验是试验室经常采用的振动方式,对应正弦振动试验国家标准GB／T2423．10应用非常广泛。本文介绍了该标准的用途、制修订背景等,在此基础上分析了现行正弦振动试验国家标准GB／T2423．10—2008与正在修订的6B／T2423．10—201×之间的异同之处,并指明了此标准应用中的几点注意的问题。     

国家生态文明建设试点示范区指标合理性探讨

环保部于2013年5月23日颁布的《国家生态文明建设试点示范区指标（试行）》（以下简称《指标（试行）》）已实施有9个月。到目前为止,全国已有6批生态文明建设试点地区参照《指标》要求确定生态文明建设目标,编制生态文明规划。然而,实际工作中发现指标体系中部分指标的合理性有待商榷。本文通过对问题指标进行分类探讨,将指标存在的问题分为四大类：指标定义亟待完善、指标标准设定偏高、指标数据获取性差和参考标准有待更新。根据不同类型指标问题的特点,分别对指标进行分析并提出合理的改进和解决方案,为环保部对《指标（试行）》的进一步完善和改进提供了理论依据和思路,对我国生态文明建设工作持续健康发展起到了促进作用。     

湖北省珍稀濒危保护水禽物种多样性及种群数量

使用直接计数法和专项调查法于1996年5月～2003年7月对湖北省珍稀濒危保护水禽物种多样性和种群数量进行了研究。结果表明：湖北省珍稀濒危保护水禽有45种,隶属于6目9科24属;记录到34种,其中有黄嘴白鹭和小苇鳽2个新记录种。按区系型分,古北界种类占优势,有35种,东洋种8种,广布种2种;按季节型分,冬候鸟为主体,有30种,夏候鸟8种,旅鸟5种,留鸟2种;按生活型分,涉禽23种,游禽22种,种类几乎相等。种群数量为41.1796万只。在45种珍稀水禽中,IUC红皮书水禽23种,8 247只;中国红皮书水禽22种,3 615只;CITES濒危水禽23种,40.631 6万只;国家重点保护水禽24种,3 838只。角等11种水禽未发现,可能已绝迹或极度濒危。按水禽1 %地理种群数量的标准,洪湖、沉湖、龙感湖、梁子湖、网湖等湿地可以确定为国际重要湿地。     

Demonstrating a correlation between infrastructure and national development

This paper demonstrates a correlation between the extensiveness of infrastructure and national development. This was achieved by considering kilometres of paved roads, kilometres of rail, kilometres of paved runways, quality of shipping ports and quality of urban infrastructure. Data were collected from a variety of sources including the World Bank and the United Nations databases. Measures of the quantity or extensiveness of the infrastructures were normalized based on the populations of the various countries, transforming them into per capita measures, which were then logarithmically transformed to produce indices of the extensiveness of the infrastructures. These indices were then plotted against the national development indicator, the human development index (HDI). Of the infrastructures considered, paved roads per capita index showed the strongest correlation with HDI, while quality of port infrastructure index showed the weakest correlation. When the indices for the different infrastructures were combined into a single index the correlation with HDI appeared to be strongest, highlighting the synergistic effect of different infrastructures when working in tandem. Based on this, the findings of this study support the position of holistically managing a country's infrastructure assets.     

Mountains and Handrails: Risk,Meaning, and Responsibility in Three National Parks

Where we live, the relationships we maintain, or the experiences we have can tell us about the way we perceive risk and the responsibility for its management. Perceptions of risk and responsibility are particularly relevant in US national parks, where unintentional injury is prevalent, yet support exists for allowing risk exposure. If experiencing risk may be both desirable (e.g., self-affirming) and undesirable (e.g., injury-causing), what is its role in a national park? Moreover, what are the expectations for visitors to encounter or to avoid it? In-depth interviews with National Park Service employees suggest that desired risk is contingent upon the circumstances in which it is encountered, and the values and prior experience of individuals. Employees perceive visitors as responsible for avoiding undesirable risk through information seeking and awareness, but also recognize considerable barriers to doing so. Theoretical and practical implications and avenues for future research are presented.     

基于网络团购的民族地区旅行社电子商务发展研究

网络团购已经逐渐发展成为一种新兴的电子商务模式,团购产品的覆盖范围也已非常广泛.揭示了民族地区旅行社电子商务发展与网络团购的内在相关性和作用机理,并探讨了适合民族地区旅行社电子商务发展的网络团购模式,提出了发展民族地区旅行社电子商务的思路与对策.     

Severity models of cross-median and rollover crashes on rural divided highways in Pennsylvania

Introduction

Crossover and rollover crashes in earth-divided, traversable medians on rural divided highways can lead to severe injury outcomes. This study estimated severity models of these two crash types. Vehicle, driver, roadway, and median cross-section design data were factors considered in the models. A unique aspect of the data used to estimate the models were the availability of median cross-slope data, which are not commonly included in roadway inventory data files.

Methods

A binary logit model of cross-median crash severity and a multinomial logit model of rollover crash severity were estimated using five years of data from rural divided highways in Pennsylvania.

Results

The highest probability of a fatal or major injury in cross-median and rollover crashes was found to occur in cases when a driver was not wearing a seatbelt. While flatter cross-slopes and narrower medians were associated with more severe cross-median crash outcomes, steeper cross-slopes and narrower medians significantly increased rollover crash severity outcomes. The presence of horizontal curves was associated with increased probabilities of high-severity outcomes in a median rollover crash.

Impact on Industry

Modeling results in this study confirmed that cross-median and median rollover crash severity outcomes are associated with median cross-section design characteristics. Based on the estimated models, it appears that flatter and narrower medians lead to more severe injury outcomes in cross-median crashes. Steeper median cross-slopes and narrower medians were associated with higher probabilities of more severe outcomes in median rollover crashes. The results presented in this study suggest that there is a trade-off between median cross-section design and cross-median and rollover crashes in earth-divided, traversable medians on rural divided highways. While the severity models can be included in a framework to develop design guidance in relation to this trade-off, models of crash frequency should also be considered.     

基于地理探测器的中国国家级开发区时空演化过程及其驱动力研究

各种类型的开发区是我国改革开放的“试验田”和经济快速发展的重要空间载体,其空间分布格局一直是国内外关注的热点问题,但对其中长时间尺度的空间演化过程研究相对较少,而后者是理解中国经济空间演化的重要基础。运用最邻近指数、核密度指数和地理探测器等方法,总结了中国国家级开发区空间演化的过程及其驱动力因子。研究的主要结论是：各类国家级开发区的时空演化经历了三个阶段,即起步试点阶段、稳步推进阶段和快速推广阶段;政策上实现了从试点探索到面上推广;空间上呈现出从东部沿海向沿江、沿边以及内陆不断拓展,从东部向中西部推进,从省会城市向地级市递进的特征;开发区的时空演化格局是距离、城市等级、经济实力、开放程度等因素综合作用的结果,其中城市等级、开放程度和经济发展水平是核心影响因子,距离和经济密度是次级影响因子;不同类型的开发区核心驱动因子既存在共同性,同时因为定位、功能不同也具有差异性。     

红色旅游对游客国家认同的影响

红色旅游作为传承红色基因、加强爱国主义教育、增强国家认同的有效载体,具有鲜明的政治功能。以认知评价情绪评价理论和积极情绪拓展—建构理论为基础,构建红色旅游国家认同影响模型并提出相应假设,运用偏最小二乘法结构方程模型（PLS-SEM）进行了实证检验。结果显示：构建的红色旅游国家认同影响模型具有良好的解释力和预测力,模型具有交叉效度,整体模型的GOF值高于良好适配度的标准值;红色旅游通过红色旅游情感对游客国家认同有正向促进作用;历史认同对国家认同的影响不明显,其他假设均成立。该研究为相关模型构建提供了思路,成果可为强化红色旅游的国家认同研究、拓展红色旅游理论内涵与教育功能、促进红色旅游高质量发展提供理论依据。     

国外大尺度生态廊道保护进展与秦岭国家公园建设

大型山脉在其走向上往往是生物扩散和分布的天然廊道。然而,由于人类干扰引起的生境碎片化,山地廊道的连通性已大为降低。20世纪以来,人们普遍意识到当前或过去的自然保护措施往往规模太小,无法维持许多物种的长期生存及其所依赖的生态过程。因而,山地廊道的连通性保护日益受到关注,大尺度生态廊道被认为是长远意义上保护气候变化下生物多样性的最优策略。综述连通性保护和生态廊道的概念、发展历程及国外大尺度生态廊道建设实践的经验,并从连通性保护的角度对秦岭国家公园建设提出一些建议,强调大尺度的连通性保护和生态廊道建设对于国家公园自然生态系统的长远保护具有重要意义。