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排序方式: 共有2223条查询结果,搜索用时 15 毫秒
1.
This study investigates Chinese tourists’ views of nature, interest in animal experiences and their preferred natural landscape interpretation content from a generational perspective. Eight hundred and eight self-administered questionnaires were collected at Wulingyuan, a UNESCO World Natural Heritage Site, in China. It suggests that overall Chinese traditional cultural values and beliefs, notably the thinking of tian ren he yi (oneness of nature with humans), still have considerable impacts on Chinese tourists. They were found to have a strong sense of connection with nature and a preference for cultural interpretations of natural landscapes. Meanwhile, Chinese might be reaching a point of convergence in terms of attitude towards nature and animals with their Western counterparts, as reflected by their weak anthropocentric view, and strong ethical and aesthetic appreciation of animals, regardless of generation cohorts. Yet, the study shows significant generational gaps: older generations have a stronger connection with nature, are more concerned about environmental issues and show more support for the Western approach towards nature protection; the younger generations hold weaker anthropocentrism, and are more interested in animals, yet are less likely to learn about nature through tourism interpretation.  相似文献   
2.
Poor bank governance has disastrous consequences for economies as the 2007–2009 financial crisis has shown. In the aftermath, board diversity is identified as an effective mechanism to enhance bank governance. Diversity, creating cognitive conflict between board members, is expected to enhance board's independence of thought to better perform monitoring and advising functions. Age is a key demographic measure and age dissimilarity between the chair and the CEO in non-financial firms leads to better economic outcomes (Goergen, Limbach, & Scholz, 2015). In this paper, we examine whether chair-CEO age dissimilarity can mitigate banks' excessive risk-taking behaviour. Using a unique sample of 100 listed banks in Europe between 2005 and 2014, we find that age difference between the chair and the CEO reduces bank risk-taking. A chair-CEO generational gap –defined as a minimum of 20 years' age difference– has a larger impact in reducing risk-taking.  相似文献   
3.
[目的]分析评价江苏省现有农田保护经济补偿政策绩效与空间差异对建立完善长效的农业生态补偿机制和推动我国农业生态环境的可持续发展具有重要意义。[方法]以江苏省为研究区域,运用熵权-TOPSIS法,选取2010—2017年全省及苏北、苏中、苏南三个区域内11个指标,计算江苏省及三大区域农田保护经济补偿政策综合绩效值与经济、生态和社会效益单项绩效值,进行比较分析。[结果](1)江苏省农田保护经济补偿政策在2010—2017年8年综合绩效值由0189波动增长到0841,效果初现且具有较强推广价值。(2)经济效益绩效值以年均257%的增长率由0增长到1,效果最为显著,社会效益次之,生态效益自2013年后为绩效值中最低值,与前两项最大差距在05左右,反映出环境改善、农田质量提高效应远低于农户创收、社会公平效应,政策拟合度不高。(3)江苏省农田保护经济补偿政策效果存在空间差异,综合来看政策效果表现为苏南>苏中>苏北,苏南凭借经济优势在2016年和2017年的综合绩效值上比苏中苏北高出01、在经济与社会绩效值以002的差距领先且生态绩效值没有下降拐点,具有长效可持续性。[结论]现阶段农田保护经济补偿政策效果依赖地方政府经济实力,尚未形成良性长效机制,需从制度体系、环境经济手段、差别化补偿措施、农业补贴结构和宣传等5方面着手,推进农田保护经济补偿政策更好地服务生态环境。  相似文献   
4.
沈阳城市周边耕地多功能评价   总被引:4,自引:0,他引:4  
[目的]为探索城市化影响下城市周边耕地多功能的现状,分析其空间差异,为耕地保护及城市周边耕地发展提供参考。[方法]从耕地的生产、生态、社会和景观4个功能出发构建评价指标体系,利用熵权法确定指标权重,加权求和法计算单一功能和多功能值,并用ArcGIS进行空间分析,对沈阳城市周边50个乡镇(街道)的耕地多功能性进行综合评价。[结果](1)沈阳城市周边耕地的多功能性空间差异较为明显。生产功能远郊平原区最强,远郊山区和近郊区较弱;生态功能总体偏弱,个别乡镇较好;距离城市越远,社会功能越强;景观功能近郊区较强,远郊区较弱。(2)耕地的生态、社会和景观功能主要受距市中心距离的影响,生产功能受地形和距市中心距离的双重影响,而多功能则受地形、距市中心距离及各乡镇(街道)耕地主导功能等的综合影响。(3)沈阳城市周边的大多数耕地以农业生产为主导,景观文化功能整体相对较弱。近郊区耕地生态功能所占比重较大,但社会功能比重较小,远郊区则与之相反。[结论]沈阳城市周边耕地多功能性空间差异较为明显且不均衡,应科学规划城市周边耕地功能,优化空间布局,协调耕地各功能的关系,促进耕地多功能综合发展。  相似文献   
5.
针对双站定位涉及的跳频信号多普勒频差估计问题,提出了归一化的频差最大似然估计算法,利用两个定位站接收到的跳频脉冲串信号,构建一个关于基准跳频频率多普勒频差的似然函数,通过网格搜索得到使似然函数最大的多普勒频差估计,既解决了跳频信号在不同跳频频率上多普勒频差不一致的问题,又充分利用在不同频率的脉冲串信号提高了多普勒频差估计精度。通过仿真对算法的性能进行了评估,结果表明,与基于子空间的算法比较,在脉冲数达到240个时,所提算法执行效率提升30%以上。  相似文献   
6.
The relationship between wage difference and relative employment is a very important issue in the field of economic structural change. An M-sector economic growth model is constructed in this paper to investigate the relationship between wage difference, price difference, technology gap, relative employment and sectoral dynamic change from the perspective of technologies. Labor flow is regarded as a decision-making behavior to maximize the benefits of economic agents. The benefits of labor flow mainly come from sectoral wage difference, and the costs of labor flow mainly come from the social resource expenditure during labor flow process. Our model illustrates that: (i) the relative employment is positively correlated with the real wage difference and technology gap; (ii) the sectoral dynamic changes coexist with the aggregate economic growth; (iii) increases in technology gap, and price and wage differences will stimulate labor migration, exacerbate the unbalanced growth of sectoral economies, and lead to faster and more effective aggregate economic growth.  相似文献   
7.
Rural residential land transition (RRLT) dominates rural land use transition. Therefore, analysing the laws of transition and differentiation of land use is not only the basis for the differential management of rural residential areas but key to the sustainable use of rural land. This study constructs a conceptual model of RRLT using multi-period remote sensing monitoring data based on a comprehensive index method, ArcGIS, and FRAGSTATS landscape pattern analysis, among others. It also analyses the characteristics of the transition extent, transition trend, transition morphology, and transition intensity of rural residential land in the Beijing-Tianjin-Hebei (BTH) region from 1980 to 2018. The results show that, from a vertical comparison of long time series, the transition extent is characterised by a process of ‘slow growth—expanding start—fast expansion—slowing down’; the transition trend is characterised by an increase in the amount of cultivated land occupied by rural residential land, followed by a large number of rural residential land is reclaimed as cultivated land; the transition morphology is characterised by an increase in mean patch size and degree of irregularity, as well as aggregation; and the transition intensity is characterised by fluctuations in the process of ‘small-scale reduction—small-scale growth—substantial growth—small-scale growth and reduction’. A horizontal comparison of counties in the BTH region reveals a long-lasting and active growth trend in transition extent and transition intensity in the Beijing-Tianjin region, and a gradually slowing trend in the areas around the region. The transition morphology features of the northwest Hebei region are more prominent, and show that the scale of rural settlements is small, the plaques fragmented and irregular, and the layout more scattered. The BTH region should formulate a differentiated transition direction for rural residential areas based on the different functional areas, and play into the agglomeration, scale, and synergy effects of urban agglomerations. It should also coordinate and improve the human–land relationship in rural areas, and construct an orderly and densely distributed pattern of urban and rural spatial development with a reasonable layout and complementary functions.  相似文献   
8.
This study examines financial analyst coverage for U.S. firms following an increase in foreign product market competition. To capture exogenous shocks to domestic firms' competitive environments, we exploit a quasi‐natural experiment from large import tariff reductions over the 1984 to 2005 period in the manufacturing sector. Using data for the years before and after large tariff reductions, our difference‐in‐differences analysis shows evidence of a significant decrease in analyst coverage for incumbent U.S. firms when they face greater entry threat from foreign competitors. We also find that analysts with less firm‐specific experience and less accurate prior‐period forecasts are more likely to stop following the domestic firm when foreign competition intensifies. Overall, the findings suggest that foreign product market competition from global trade liberalization is an important determinant of financial analysts' coverage decisions.  相似文献   
9.
随着空中交通的信息传输与新应用拓展需求不断增加,1090ES信号容量有限问题日益显现,对1090ES信号进行容量扩充是一种有效解决途径。针对一种基于脉内调相的1090ES信号扩容技术,给出了叠加调制的信号模型,研究了1090ES信号的解调解码算法;在GNU Radio+ USRP软件无线电平台上,实现了1090ES扩容信号的产生和接收处理,包括脉冲位置调制(Pulse Position Modulation,PPM)与8PSK叠加调制、低通滤波、报头检测、载波同步、PPM解码和相位解调等,并利用Matlab对实验的解码错误率和信号的频谱特性做了统计分析与仿真,结果表明了该扩容技术的可行性。  相似文献   
10.
遥测测距技术采用再生伪码作为上行链路信号。针对飞行器现有码跟踪环结构复杂、低信噪比条件下环路跟踪性能差的问题,提出了一种新的基于锁相环的码跟踪环结构,推导了环路的信号处理流程。该结构降低了环路实现的复杂度,改善了低信噪比条件下的相位测量精度,仿真进一步验证了方法的有效性和稳定性,较现有方法在信噪比为-10 dB时能提高1.5×10-3个码片的精度,适合遥测测距技术。  相似文献   
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