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91.
Desertification and land degradation are worldwide problems affecting soil, vegetation and the livelihoods of rural populations. Bowal (plural bowé) is a particular form of degraded land that occurs in tropical regions and leads to the exposure of ferricretes, which are unsuitable for farming. Bowé are more common on farmland and degraded savanna. Changes in land use/land cover were used to map a region of 6.7 million ha in northern Benin, West Africa in 1975, 1990 and 2010. The changes observed during these periods (1975–1990, 1990–2010 and 1975–2010) were used to predict the occurrence of bowé in the period up to 2050 using Markovian chain analysis. The results showed a considerable change in land use/land cover during the three periods. The types of land on which bowé occur (farmland and degraded savanna) increased in northern Benin by 5.4% per year during the period 1975–1990 and 9.5% per year during the periods 1990–2010, while the natural vegetation (forest, woodland and tree savanna) decreased by the same amount. The future scenarios also predicted the same trend. In the period 1975–1990, 1.28 million ha (26%) of natural vegetation was converted to degraded savanna and farmland while 2.23 million ha (53%) of natural vegetation was converted to degraded savanna and farmland in the period 1990–2010. Based on the dynamics recorded during the period 1975–1990 and 1990–2010 respectively, a total of 1.28 million ha (26% of the natural vegetation that was present in 1975) and 1.29 million ha (31% of the natural vegetation that was present in 1990) will be converted to farmland and degraded savanna in the study area by 2050.Thus bowalization will persist and increase in the period up to 2050. The natural vegetation could disappear if protection and restoration measures are not taken. It is thus important to take measures to stop the degradation and to implement programs to restore soils on bowé based on the soil and water conservation techniques used on highly degraded West African soils, such as zaï pit and stone rows with grass strips. Some native plants species adapted to bowalization and resistant to climate change in northern Benin (e.g. Asparagus africanus, Andropogon pseudapricus and Combretum nigricans) should be used in association with soil and water conservation techniques on bowé.  相似文献   
92.
In the complex agro-ecological conditions of Vietnam's northern borderlands, attempts by ethnic minority farmers to create sustainable livelihoods, along with the impacts of state development policies, have direct consequences for land use and land cover (LULC) change. In this paper we analyse the degree to which LULC has changed and diversified from 1999 to 2009 in Lào Cai Province and the underlying relationships with ethnic minority livelihood diversification strategies. We examine the correlation between LULC diversity and various socioeconomic and biophysical proxies using a spatial autoregressive model. Our findings indicate two major changes in LULC: an increase in closed canopy forest and substantial urban growth. LULC diversity increased between 1999 and 2009, suggesting a transition between land uses and/or a diversification of livelihood strategies. Socioeconomic proxies are significant predictors of LULC diversity in both years, while biophysical proxies are only effective predictors in 2009. In-depth interviews regarding state-led policies and ethnic minority livelihoods reveal some of the underlying mechanisms of such LULC transitions and associations.  相似文献   
93.
3S技术是测量技术发展史的一次重大突破,给测量领域带来了新的生命力,并已推广应用在国家基础建设的各个方面。本文以京沪高铁天津段这样的国家重点建设工程项目为例,介绍了3S技术在该项目从土地规划到建设运营方面的应用。  相似文献   
94.
近年来,随着我国经济的快速增长和城市化进程的不断深入,我国出现了房价过快上涨的势头。高房价背后有着各种成因,抵押贷款证券化在解决高房价问题上具有合理性和可行性,保持审慎、稳健的监管,通过合理的金融市场建设和金融资源分配,房地产市场能够回归理性,房价回归正常合理的水平。  相似文献   
95.
96.
Over the past centuries, land systems in Italy experienced fundamental shifts, owing to the availability of new energy forms, population surges, and technological progress. The 20th century was characterized by massive productivity increases, accompanied by gradual land abandonment and the return of forest land. We here analyze 120 years of land system change in Italy, applying the human appropriation of net primary production (HANPP) framework, a metric for socio-economic pressures on terrestrial ecosystems. HANPP allows integrating ecological with societal perspectives, by systematically quantifying (a) biomass harvest and (b) the difference between potential productivity of ecosystems and current productivity induced by land use processes, such as land conversion, or land degradation. Besides assessing national trends we calculated HANPP separately for the Italian North and South between 1934 and 2007, in order to scrutinize if high regional discrepancies in terms of natural and socio-economic preconditions translate into diverging land system trajectories. Our results show that national HANPP has been declining from 78% of natural productivity before WWII to 56% in 2007, indicating a declining land -use induced pressure on biomass flows over time. Simultaneously, biomass harvest increased by around 26% due to agricultural intensification, despite shrinking croplands. Although we found a significant difference between the Northern and Southern region in the absolute levels of several land use indicators related to biomass appropriation, the overarching trends of land system change were remarkably similar in both regions. This suggests that underlying drivers of land system change, such as policies aimed at land-use intensification and structural change were equally dominating land system trajectories in the North and South of Italy, not withstanding their socio-ecological divergences.  相似文献   
97.
The accelerated rural hollowing driven by vast and increasing out-migration of rural labors under urban–rural dual-track system has imposed huge obstacles on improving land use efficiency and coordinating urban–rural development in China. Taking Dancheng County in Henan Province as an example, this paper analyzes the status quo of rural hollowing and discusses two typical rural residential land consolidation and allocation (RRLCA) practices in traditional agricultural areas (TAAs) of China. The results show that, Dancheng experienced rapid rural hollowing characterized as the hollowing of rural industries, infrastructure, and residential population and settlements. However, Dancheng has considerable potential and the necessity of RRLCA, for the model-based estimation shows that the potential of increasing farmland by carrying out RRLCA was about 5649 ha. The two community-based RRLCA practices show positive effects on the improvement of local living conditions, increment of farmland area and development of rural industries. Their experiences, including self-organized rural planning, democratic decision-making, and endogenous institutional innovation may benefit future RRLCA. Overall, it indicates that promoting community-based RRLCA scientifically according to local conditions could provide an integrated platform for increasing farmland area, developing modern agriculture, promoting new countryside construction, and thus revitalize hollowed villages. On considering the limitations and obstacles of current initiatives, suggestions for future RRLCA in rural China have been put forward.  相似文献   
98.
本分在充分调研9省(区、市)土地整治地方标准化建设工作的基础上,系统总结了现阶段土地整治地方标准化建设现状,并对存在的问题进行了深入分析,提出了新时期推进土地整治地方标准化建设的6点建议。  相似文献   
99.
100.
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   
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