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901.
张萌萌  孟晓晨 《地理科学进展》2014,33(12):1650-1658
近10年来中国高速铁路快速发展,对城市发展的影响正逐步显现.本文从市场潜力角度研究这一影响,根据《全国铁路旅客列车时刻表2012.07》统计获得的城市之间平均旅行时间和发车频次数据重新定义市场潜力函数,对比中国地级及以上城市普通铁路和叠加高速铁路之后的市场潜力特征,探讨高铁对城市市场潜力的提升作用,并从中分离出时间压缩效应和频次效应.研究发现:①普通铁路市场潜力呈现“多中心—廊道”结构,市场潜力高的城市主要分布在长三角、珠三角、京津冀城镇群内,以及京广、京沪、京哈等重要铁路线沿线;②叠加高速铁路之后城市市场潜力整体上仍呈现“多中心—廊道”结构,且多中心结构更为突出;③京沪、沪杭铁路沿线城市和东南沿海宁波—厦门段客运专线沿线城市的高铁效应最大;④高铁连接的109个城市时间压缩效应的平均值为31.3%,频次效应的平均值为68.7%,频次效应是高铁效应的主要形式.  相似文献   
902.
发展广州市湿地经济对改善当地民生、推进生态文明建设具有重要作用。广州市具有丰富的湿地资源,包括湿地水资源、湿地动植物资源和湿地旅游资源。目前广州市湿地经济发展模式主要为水产养殖模式、农业耕种模式、供水蓄能模式和生态旅游模式,但在发展过程中存在过度围垦、河流破坏、过度捕捞和盲目养殖、生态旅游开发不成熟等问题。针对存在的问题,提出以生态优先为原则、以统一规划为前提、以复合农业为重点、以生态旅游为特色的湿地经济发展建议。  相似文献   
903.
In recent years, the Chinese government has been increasingly supportive of the development of the ocean economy, implementing several national ocean-related strategies. For the first time, China's 12th five-year Plan for National and Social Development (2011—2015) includes “developing the ocean economy” as a key national development strategy for the country. Because of this, the demand for ocean economic statistics and indicators is growing rapidly. The aim of this paper is to define and quantify the value of the major ocean industries in China and to examine the growth in the major Chinese ocean industries in the period 2001 to 2010. The paper also outlines a methodology that provides a robust quantification of the marine sector over time. It finds that in 2010 the major ocean industries in China contributed $239.09 billion to the national economy and employed over 9 million individuals.  相似文献   
904.
Economic damage from natural hazards can sometimes be prevented and always mitigated. However, private individuals tend to underinvest in such measures due to problems of collective action, information asymmetry and myopic behavior. Governments, which can in principle correct these market failures, themselves face incentives to underinvest in costly disaster prevention policies and damage mitigation regulations. Yet, disaster damage varies greatly across countries. We argue that rational actors will invest more in trying to prevent and mitigate damage the larger a country's propensity to experience frequent and strong natural hazards. Accordingly, economic loss from an actually occurring disaster will be smaller the larger a country's disaster propensity – holding everything else equal, such as hazard magnitude, the country's total wealth and per capita income. At the same time, damage is not entirely preventable and smaller losses tend to be random. Disaster propensity will therefore have a larger marginal effect on larger predicted damages than on smaller ones. We employ quantile regression analysis in a global sample to test these predictions, focusing on the three disaster types causing the vast majority of damage worldwide: earthquakes, floods and tropical cyclones.  相似文献   
905.
South Africa's organically emerged cultural business of traditional healing is almost exclusively reliant on wild-harvested resources extracted from wilderness areas or open-access commons. The wild medicine business has been described for much of South Africa, although is little understood in Cape Town, the urban centerpiece of the Cape Floristic Region (CFR). A census of different traditional healer typologies in five typical working-class residential areas (representing ~71,500 residents) was conducted to assess the nature and extent of traditional medicine harvesting and trade. Extrapolating these findings for the city reveals a local industry of more than 15,000 practitioners collectively conducting trade worth US $15.6 million per year. More than 40% of the volume of traditional medicines traded in the city is harvested from the CFR. Future conservation approaches must consider that the business of traditional healing and dispensing wild-harvested medicines is both economically important and culturally entrenched.  相似文献   
906.
提升金融服务实体经济效率是海南自贸港建设亟待研究和突破的“靶点”。论文通过测算2011—2020年海南自贸港18市县金融服务实体经济效率,利用Dagum基尼系数与Kernel密度估计方法刻画效率的时空异质性,并借助随机森林模型揭示其驱动机理,创新性地从时空视角挖掘海南自贸港金融服务实体经济效率分异机制。研究发现:(1)海南自贸港金融服务实体经济效率时空非平衡性明显,时序上阶段性显著,空间上呈西高东低、高值聚集、中部“洼地”的分布特征,西北部市县与中部市县各自逐步形成高值、低值聚集区;(2)总体及沿海市县梯度分化特征逐步加强,而非沿海市县内部差距则逐步缩小,沿海区域金融服务实体经济效率的空间分异是总体分异的主要来源;(3)政府干预是效率分化的主导因素,含金融集聚度在内的影响因素对效率均呈非线性影响且作用趋势与阈值各异,各因素的边际产出能力及各市县对要素的吸收与应用能力的动态差异是时空异质性的主要来源。研究结论可为优化海南自贸港金融资源的空间配置、提升金融服务实体经济效率提供科学依据。  相似文献   
907.
Landing a rescue helicopter in a wilderness environment, such as Yosemite National Park, requires suitable areas that are flat, devoid of tree canopy, and not within close proximity to other hazards. The objective of this study was to identify helicopter landing areas that are most likely to exist based on available geographic data using two GIScience methods. The first approach produced an expert model that was derived from predefined feature constraints based on existing knowledge of helicopter landing area requirements (weighted overlay algorithm). The second model is derived using a machine learning technique (maximum entropy algorithm, Maxent) that derives feature constraints from existing presence-only points; that is, geographic one-class data. Both models yielded similar output and successfully classified test coordinates, but Maxent was more efficient and required no user-defined weighting that is typically subject to human bias or disagreement. The pros and cons of each approach are discussed and the comparison reveals important considerations for a variety of future land suitability studies, including ecological niche modeling. The conclusion is that the two approaches complement each other. Overall, we produced an effective geographic information system product to support the identification of suitable landing areas in emergent rescue situations. To our knowledge, this is the first GIScience study focused on estimating the location of landing zones for a search-and-rescue application.  相似文献   
908.
Attempts to model the dynamic characteristics of a housing market include examining the spatial diffusion of price changes from an epicenter through a regional or national network of geographic units. Less common has been the study of a ripple effect of price changes within a single metropolitan area, with implications for the erosion of residential affordability. Such trends have particular salience within the Vancouver metropolitan area, the least affordable housing market in North America. Using quarterly price data from local real estate boards, we examine price changes through municipal regions from 2005–2017, a period including several externally-induced price shocks. Several techniques test for a ripple effect in price movements. A time lag of three months consistently exists in the communication of price shocks from an originating epicenter to other parts of the metropolitan region, with longer lags with several more distant municipalities, confirming the presence of an intra-metropolitan ripple effect.  相似文献   
909.
基于多年连续的、大量的统计数据,从三个不同维度对俄罗斯旅华客源市场进行研究:首先按照时间序列将俄罗斯旅华客源市场划分为缓慢增长、波动增长、持续增长和恢复增长四个阶段;其次根据空间分布对俄罗斯旅华目的地选择进行详细划分,表明俄罗斯游客更倾向于选择游览北方地区和滨海地区;最后根据2005—2010年俄罗斯入境旅游者和旅游外汇收入两组数据,建构 GM(1,1)模型并进行精度检验,预测俄罗斯旅华客源市场未来五年发展趋势。  相似文献   
910.
全球气候变化是当今人类面临的重大挑战之一,低碳经济在此背景下应运而生,成为世界各国政府和学术界关注的焦点。低碳经济背景下国际贸易结构变化和转型的研究也已开展起来,研究成果主要集中在低碳经济与能源消耗、碳排放的关系以及低碳经济背景下国际贸易结构转型路径等方面。尽管近年来研究取得很大进展,但由于各个学者选择的研究变量、研究地域和研究时段的不同,导致研究结果存在差异和分歧。各国学者出于代表本国或本区域利益的原因,对低碳贸易的研究侧重点不同,特别是与低碳贸易政策有关的研究存在利益分歧。而国内学者的研究大多是在借鉴国外研究成果的基础上展开,理论和方法上的创新不够。为此,迫切需要我国学者作进一步的研究,从中国的国情出发,研究如何解决低碳背景下我国外贸结构的优化、碳交易市场的拓展、碳关税的应对策略、碳金融的创新以及分行业、分地区的外贸转型发展等问题。  相似文献   
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