车用天然气储气技术

天然气用作汽车的代用燃料,具有储量丰富、价格便宜;辛烷值高、燃烧充分;低硫、低氮、无灰、环境污染少等优点。但是,目前的压缩天然气储气技术存在储气压力高、储气量小、续驶里程短等缺点,严重制约着天然气汽车应用领域的扩展。对5种车用天然气储气技术进行了分析讨论后,指出了吸附储存和近临界流体储存天然气技术在天然气汽车领域将有着广阔的应用前景。     

扁平超宽连续箱梁桥空间受力性能分析与研究

扁平超宽箱梁桥由于具有较大的宽跨比，其受力性能呈现明显的空间效应，通常的单梁模型计算已不能满足设计的精度要求，主要体现在宽箱梁各腹板纵向受力的差异性以及明显的剪力滞效应，同时由于大宽跨比使得横向预应力的作用不仅增加了顶板的压应力，也使得整体箱梁截面下缘出现拉应力，造成边腹板底部纵向裂缝，这些都给宽箱梁的设计带来了不利。因此为研究宽箱梁的空间效应，本文运用ANSYS有限元软件建立了全桥实体模型，计算了各腹板纵向受力差异及剪力滞效应，以及横向预应力对箱梁横向受力的影响，得到了一些有益的结论，为设计人员提供一定的参考。     

千城一面——造城时代下的物竞天择

随着对城镇化质量的日益关注,媒体与学界对千城一面的批判愈演愈烈。然而,如果将城市看做是地球生态系统的一部分,遵循生物界优胜劣汰、适者生存的丛林法则,那么千城一面现象便是时代背景下环境选择的结果——特定的科技、经济、文化发展水平等客观属性,把在生存竞争中处于劣势的建筑形制与空间范式逐一淘汰,筛选出最符合时代需求与发展方向的特征传承下去。在理解千城一面的时代必然性的基础上,理性认识古典主义与现代主义、空间舒适性与独特性、空间使用者的主与客之间的辩证关系,才能走出"为批判而批判"的误区。     

Attenuating Initial Beliefs: Increasing the Acceptance of Anthropogenic Climate Change Information by Reflecting on Values

Anthropogenic climate change information tends to be interpreted against the backdrop of initial environmental beliefs, which can lead to some people being resistant toward the information. In this article (N = 88), we examined whether self‐affirmation via reflection on personally important values could attenuate the impact of initial beliefs on the acceptance of anthropogenic climate change evidence. Our findings showed that initial beliefs about the human impact on ecological stability influenced the acceptance of information only among nonaffirmed participants. Self‐affirmed participants who were initially resistant toward the information showed stronger beliefs in the existence of climate change risks and greater acknowledgment that individual efficacy has a role to play in reducing climate change risks than did their nonaffirmed counterparts.     

Why do participants in voluntary organizations leave? Exploring the relationship between value congruence and length of stay

Recognizing the importance of values and the specific characteristics of participants and situations in voluntary organizations, we examine how value congruence—the fit or compatibility of values between participants and the organization, or among participants—interacts with personal and situational factors to predict participants' length of stay in their organizations. Introducing the case of a voluntary organization that offers shared housing, we measure value congruence through textual similarity in the self‐introduction documents of 49 participants and the organization's mission statement. This approach differs from the self‐reported measures based on participants' perceptions or recalled interactions used in previous studies. In line with expectation‐disconfirmation theory, participants with the strongest beliefs in organizational values had shorter lengths of stay. The amount of intraorganizational communication also moderated the relationship between value congruence and length of stay. This study provides theoretical and methodological implications for nonprofit management by considering personal and situational factors and evaluating value congruence by textual similarity.     

Does media coverage influence public attitudes towards welfare recipients? The impact of the 2011 English riots

Following the shooting of Mark Duggan by police on 4 August 2011, there were riots in many large cities in the UK. As the rioting was widely perceived to be perpetrated by the urban poor, links were quickly made with Britain's welfare policies. In this paper, we examine whether the riots, and the subsequent media coverage, influenced attitudes toward welfare recipients. Using the British Social Attitudes survey, we use multivariate difference‐in‐differences regression models to compare attitudes toward welfare recipients among those interviewed before (pre‐intervention: i.e. prior to 6 August) and after (post‐intervention: 10 August–10 September) the riots occurred (N = 3,311). We use variation in exposure to the media coverage to test theories of media persuasion in the context of attitudes toward welfare recipients. Before the riots, there were no significant differences between newspaper readers and non‐readers in their attitudes towards welfare recipients. However, after the riots, attitudes diverged. Newspaper readers became more likely than non‐readers to believe that those on welfare did not really deserve help, that the unemployed could find a job if they wanted to and that those on the dole were being dishonest in claiming benefits. Although the divergence was clearest between right‐leaning newspaper and non‐newspaper readers, we do not a find statistically significant difference between right‐ and left‐leaning newspapers. These results suggest that media coverage of the riots influenced attitudes towards welfare recipients; specifically, newspaper coverage of the riots increased the likelihood that readers of the print media expressed negative attitudes towards welfare recipients when compared with the rest of the population.     

西部自然资源开发与西部可持续发展关系刍论

确保未开发之前就生活于自然资源所在地的居民和地方社区的社会和经济利益以及可持续发展事宜,是一个决策者需要关注的重要事项。确保国家对西部自然资源的政治意义上的所有权,全面而区分层次地理解西部的可持续发展内涵和程序要求,配置自然资源开发收益时考虑开发利用活动对资源所在地所造成的外部不经济性成本以及资源税费的收缴机制是科学治理西部自然资源开发同西部可持续发展之间关系的三个重要方面。     

Lung Cancer Risk from Radon in Marcellus Shale Gas in Northeast U.S. Homes

The amount of radon in natural gas varies with its source. Little has been published about the radon from shale gas to date, making estimates of its impact on radon‐induced lung cancer speculative. We measured radon in natural gas pipelines carrying gas from the Marcellus Shale in Pennsylvania and West Virginia. Radon concentrations ranged from 1,520 to 2,750 Bq/m³ (41–74 pCi/L), and the throughput‐weighted average was 1,983 Bq/m³ (54 pCi/L). Potential radon exposure due to the use of Marcellus Shale gas for cooking and space heating using vent‐free heaters or gas ranges in northeastern U.S. homes and apartments was assessed. Though the measured radon concentrations are higher than what has been previously reported, it is unlikely that exposure from natural gas cooking would exceed 1.2 Bq/m³ (<1% of the U.S. Environmental Protection Agency's action level). Using worst‐case assumptions, we estimate the excess lifetime (70 years) lung cancer risk associated with cooking to be 1.8×10^?4 (interval spanning 95% of simulation results: 8.5×10^?5, 3.4×10^?4). The risk profile for supplemental heating with unvented gas appliances is similar. Individuals using unvented gas appliances to provide primary heating may face lifetime risks as high as 3.9×10^?3. Under current housing stock and gas consumption assumptions, expected levels of residential radon exposure due to unvented combustion of Marcellus Shale natural gas in the Northeast United States do not result in a detectable change in the lung cancer death rates.     

西方平等理论从古典自然法学到新自然法学的嬗变

平等是一个非常复杂和抽象的范畴,西方法学对平等理论的热爱和追逐从未停止过,从古典自然法学追求的抽象的平等的政治理想,到新自然法学对平等的制度设计的现实关怀,平等理论随着自然法学的发展实现了其自身的嬗变,这种改变也是时代的要求、历史的必然。     

不齐之齐与无物之物——论《庄子》齐物思想的三个层次

庄子的齐物思想在整体上浑融一体,但其中又有层次可循。"万物本齐"是在肯定万物各自差异性的同时强调万物在本源上的一致,从而为"是非一齐"提供理论上的基础。"天人之齐",实质上是通过齐是非而对万物本然状态的复归。这三个层次共同包含了"不齐"与"齐","无物"与"物"的巧妙辩证,也生动地构成一种递进中的循环,超越中的复归。最后,齐物思想的最彻,是天人无分,"齐""物"同泯。