首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   486篇
  免费   11篇
  国内免费   13篇
测绘学   16篇
大气科学   134篇
地球物理   29篇
地质学   127篇
海洋学   77篇
天文学   2篇
综合类   19篇
自然地理   106篇
  2023年   8篇
  2022年   9篇
  2021年   15篇
  2020年   10篇
  2019年   14篇
  2018年   14篇
  2017年   55篇
  2016年   35篇
  2015年   48篇
  2014年   30篇
  2013年   44篇
  2012年   12篇
  2011年   28篇
  2010年   17篇
  2009年   23篇
  2008年   23篇
  2007年   21篇
  2006年   17篇
  2005年   10篇
  2004年   5篇
  2003年   8篇
  2002年   14篇
  2001年   9篇
  2000年   4篇
  1999年   9篇
  1998年   7篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1994年   3篇
  1993年   1篇
  1992年   2篇
  1991年   3篇
  1989年   2篇
  1987年   1篇
  1985年   1篇
排序方式: 共有510条查询结果,搜索用时 578 毫秒
161.
Public support for stringent climate policies is currently weak. We develop a model to study the dynamics of public support for climate policies. It comprises three interconnected modules: one calculates policy impacts; a second translates these into policy support mediated by social influence; and a third represents the regulator adapting policy stringency depending on public support. The model combines general-equilibrium and agent-based elements and is empirically grounded in a household survey, which allows quantifying policy support as a function of effectiveness, personal wellbeing and distributional effects. We apply our approach to compare two policy instruments, namely carbon taxation and performance standards, and identify intertemporal trajectories that meet the climate target and count on sufficient public support. Our results highlight the importance of social influence, opinion stability and income inequality for public support of climate policies. Our model predicts that carbon taxation consistently generates more public support than standards. Finally, we show that under moderate social influence and income inequality, an increasing carbon tax trajectory combined with progressive revenue redistribution receives the highest average public support over time.  相似文献   
162.
Reducing emissions of greenhouse gases is facilitated by changes in several consumption activities, such as food choices. This paper examines factors explaining red meat consumption in Norway, especially the role of climate concerns. The paper adds to our knowledge as most existing analyses of (red) meat consumption focus on health and animal welfare issues. Moreover, it expands our understanding by drawing on perspectives from both institutional and social psychological theory, including variables emphasizing the social dynamics behind consumption decisions. The study is based on data from a survey of 2000 people aged 18 years or older conducted in 2018. The data are analyzed using structural equation modelling. We find that there is a strong pro-meat culture in Norway, currently rather weakly influenced by climate concerns – specifically, personal norms and social pressures focused on reducing climate impacts. Instead, habits, beliefs about the qualities of red meat (being tasteful, nutritious, healthy) and social norms supporting red meat consumption are the three most important factors explaining the variation observed. Gender and income also influence red meat consumption, but less than found in other studies. The paper discusses policy implications of these findings, including for taxation, point-of-sale information and communicative processes to support changes in the perceptions of what could be a new “normal” diet.  相似文献   
163.
Given the growing frequency, severity, and salience of social mobilization and community action on energy and climate issues, in this study we systematically explore the configurations of types of infrastructure, actors, tactics, and outcomes of recent opposition to energy transitions across seven carbon-intensive regions in Asia, Europe, and North America. Based on both a literature review and an original dataset of 130 case studies spanning the past decade, we track opposition to a wide range of energy infrastructure in these regions, including low-carbon options such as renewable energy and nuclear power; provide network analyses of the actors and coalitions involved in such events; and develop a typology and frequency analysis of tactics (such as litigation or protest), and outcomes (such as remuneration, policy change, concessions, or labor protections). We show that the politics of energy transitions in carbon-intensive regions varies significantly from country to country and across types of energy, and we discuss how the configurations of infrastructure, actors, tactics, and outcomes can be explained by differences in national institutions and their responses to global or supranational pressures. By bringing both a sociotechnical and comparative perspective to the global analysis of social movements and energy transitions, we suggest how goals of energy transition are refracted through national and subnational institutions and through local mobilizations both in support of and opposed to those transitions.  相似文献   
164.
Location-based social media provide an enormous stream of data about humans' life and behavior. With geospatial methods, those data can offer rich insights into public health. In this research, we study the effect of climate and seasonality on the prevalence of depression in Twitter users in the U.S. Text mining and geospatial methods are used to detect tweets related to depression and their spatiotemporal patterns at the scale of Metropolitan Statistical Area. We find the relationship between depression rates, climate risk factors and seasonality are varied and geographically localized. The same climate measure may have opposite association with depression rates at different places. Relative humidity, temperature, sea level pressure, precipitation, snowfall, weed speed, globe solar radiation, and length of day all contribute to the geographic variations of depression rates. A conceptual compact map is designed to visualize scattered geographic phenomena in a large area. We also propose a three-stage framework that semi-automatically detects and analyzes geographically distributed health issues using location-based social media data.  相似文献   
165.
Nowadays, geographers show growing interest in providing location-based services for urban residents. It is of great practical significance to screen and recommend the most popular restaurants to consumers, as dining is important to every urban dweller. Consumer review website (CRW) has emerged as an active social media platform in catering industry. This paper demonstrated how to quantify the popularity of urban restaurants (PUR) by using CRW, namely, Dianping.com. An applied popularity index (PI) was developed to quantify PUR, based on the consumer review scores (food, service, and decoration) and physical data (evaluation frequency and restaurant grade) for 8259 restaurants within the Hangzhou city, China. All the information, together with the geographic location data, was harvested from the corresponding Application Programming Interface (API) platform. PUR was then mapped by using a geographic information system (GIS). Results showed that restaurants of high popularity were generally concentrated in old urban districts, whereas those in new urban districts presented low popularity. The kernel density distribution of PI also highlighted the geography that the PI values declined from the central city toward the outskirts. Locational associations between PUR and urban functional units (bank, shopping mall, school, cinema, hotel, bar, and scenic spot) generally presented a similar tendency. Restaurants with high PI values were in high proximity to urban functional units, whereas those with low PI values were located far away from other functional units. It implied that restaurants with high popularity tended to be located in high mixture with urban functional units. Although we used Dianping.com to perform the analysis, the presented methodology can be extended to other types of CRWs. Our study is believed to provide new insights into applied geographic sciences.  相似文献   
166.
This study investigated how the meaning of ‘home’ influences the social construction of bushfire in two Australian communities at high risk. An increasing number of Australians are living in proximity to areas of high bushfire risk due to climate, vegetation and demographic changes. Land and Fire Management Agencies recognise an urgent need to understand what motivates residents to take action to mitigate bushfire risk, and individual decisions whether or not to evacuate when bushfire is imminent. In bushfire policy and management, the home is considered to be synonymous with the house and associated built structures. Using a combination of visual and ethnographic research methods, we ‘mapped’ residents’ understanding of ‘home’. The findings suggest that the concept of ‘home’ embraces more than the private spaces of house and garden. Landscape practices such as gardening with indigenous plant species, ecological restoration, and habitual walking extend the home territory beyond the house and garden and into public landscapes. Physical elements of the landscape such as mountains and locally significant species of trees form part of the ‘imaginary’ of home. These findings are important to the on-going study of the meaning of home. The implications are also significant for land and bushfire managers as they suggest that community education programs that focus solely on the house may fail to connect with people’s wider sense of home in the landscape.  相似文献   
167.
Social movement organizations (SMOs) play an important role in movement building, however, the particular context and structure of a SMO has a direct impact on its ability to foster and sustain collaboration. In this paper I investigate the unique positioning of provincial networking organizations (PNOs) in Canadian food movements and document their efforts to support alternative food initiatives (AFIs) to interact and act collaboratively for food system change. The research draws on a network survey, over 35 in-depth interviews, site visits, and background information collected in three Canadian provinces to explore the ongoing work necessary for linking together heterogeneous elements without central coordinating mechanisms. I describe the ways that PNOs have established a series of common networking strategies to bring AFIs together across sectors, scales and places: (1) the creation of physical spaces that involve direct contact in particular places; (2) the development of virtual spaces where connections are mediated through digital technologies; and (3) the use of scalar strategies that scale-up local projects to address provincial level policy. I conclude by identifying key areas of contention that arise within the networks, and show that the different structures of the PNOs impact their ability to establish and implement networking strategies. I argue that addressing these challenges must be a preemptive focus in order to sustain networking activity. My contention that contemporary structures of social mobilization require novel strategies and support from networking organizations provides insight for studies of SMOs and movement building more broadly.  相似文献   
168.
Under the Kyoto Protocol, developing countries can voluntarily participate in climate change mitigation through the Clean Development Mechanism (CDM), in which industrialized countries, in order to meet their mitigation commitments, can buy emission reduction credits from projects in developing countries. Before its implementation, developing-country experts opposed the CDM, arguing that it would sell-off their countries’ cheapest emission reduction options and force them to invest in more expensive measures to meet their future reduction targets. This ‘low-hanging fruit’ argument is analysed empirically by comparing marginal abatement cost curves. Emissions abatement costs and potentials for CDM projects are estimated for different technologies in eight countries, using capital budgeting tools and information from project documentation. It is found that the CDM is not yet capturing a large portion of the identified abatement potential in most countries. Although the costs of most emissions reduction opportunities grasped are below the average credit price, there are still plenty of available low-cost opportunities. Mexico and Argentina appear to use the CDM predominantly for harvesting the low-hanging fruit, whereas in the other countries more expensive projects are accessing the CDM. This evidence at first sight challenges the low-hanging fruit claim, but needs to be understood in the light of the barriers for the adoption of low-cost abatement options.  相似文献   
169.
Abstract

The social cost of carbon (SCC) is the value of the climate change impacts from 1 tonne of carbon emitted today as CO2, aggregated over time and discounted back to the present day. We used PAGE2002, the same probabilistic integrated assessment model as used by the Stern Review (Stern et al., 2006), to calculate the SCC and to examine how it varies with discount rate; and find that it is not sensitive to the path of emissions on which the tonne of carbon is superimposed. The mean value of the SCC is $43 per tonne under both a business-as-usual scenario, and under a scenario aimed at stabilizing CO2 concentrations at 550 ppm. This counter-intuitive result is caused by the interplay between the logarithmic relationship between forcing and concentration, the nonlinear relationship of damage to temperature, and discounting. However, the SCC is sensitive to a number of scientific and economic inputs to the model. Two recent distributions for the sensitivity of climate to a doubling of atmospheric CO2 (Murphy et al., 2004; Stainforth et al., 2005) increase the mean value of the SCC from $43 to $68 and $90 per tonne. Using a pure rate of time preference of 0.1% per year, as in the Stern Review, gives a mean SCC of $365 per tonne.  相似文献   
170.
Transdisciplinary research is a promising approach to address sustainability challenges arising from global environmental change, as it is characterized by an iterative process that brings together actors from multiple academic fields and diverse sectors of society to engage in mutual learning with the intent to co-produce new knowledge. We present a conceptual model to guide the implementation of environmental transdisciplinary work, which we consider a “science with society” (SWS) approach, providing suggested activities to conduct throughout a seven-step process. We used a survey with 168 respondents involved in environmental transdisciplinary work worldwide to evaluate the relative importance of these activities and the skills and characteristics required to implement them successfully, with attention to how responses differed according to the gender, geographic location, and positionality of the respondents. Flexibility and collaborative spirit were the most frequently valued skills in SWS, though non-researchers tended to prioritize attributes like humility, trust, and patience over flexibility. We also explored the relative significance of barriers to successful SWS, finding insufficient time and unequal power dynamics were the two most significant barriers to successful SWS. Together with case studies of respondents’ most successful SWS projects, we create a toolbox of 20 best practices that can be used to overcome barriers and increase the societal and scientific impacts of SWS projects. Project success was perceived to be significantly higher where there was medium to high policy impact, and projects initiated by practitioners/other stakeholders had a larger proportion of high policy impact compared to projects initiated by researchers only. Communicating project results to academic audiences occurred more frequently than communicating results to practitioners or the public, despite this being ranked less important overall. We discuss how these results point to three recommendations for future SWS: 1) balancing diverse perspectives through careful partnership formation and design; 2) promoting communication, learning, and reflexivity (i.e., questioning assumptions, beliefs, and practices) to overcome conflict and power asymmetries; and 3) increasing policy impact for joint science and society benefits. Our study highlights the benefits of diversity in SWS - both in the types of people and knowledge included as well as the methods used - and the potential benefits of this approach for addressing the increasingly complex challenges arising from global environmental change.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号