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351.
Abstract

This paper examines implementation of the Kyoto Protocol without Russia. It concludes that implementation without Russia is possible, although it requires political will on the part of the countries that wish to proceed with the Protocol. It would lead to higher compliance costs for Annex B buyer regions, but other regions, except Russia, would benefit financially. Russia would forego revenue of at least $20 billion for the first commitment period. Implementation without Russia could improve the environmental performance of the Protocol. It would reduce reliance on Annex B sinks, use of surplus assigned amount units (AAUs) for compliance, and the quantity of Kyoto units banked for subsequent commitment periods. Actual emissions by Kyoto Protocol Parties would fall, but the reduction may be offset by leakage to the US and Russia.  相似文献   
352.
We estimated phosphate uptake in an eutrophic and macrophyte-rich Pampean stream, in a basin where dominant land use was agricultural activity. Our hypothesis was that phosphate retention may be linked to macrophyte abundance, especially that of submerged plants. Four short-term constant-rate phosphate addition experiments were carried out in late spring, summer, autumn and winter under different discharge, background phosphate concentration and macrophyte abundance. Changes in added soluble reactive phosphorus (SRP) concentration were monitored along the studied reach and corrected for dilution to estimate phosphate uptake length (Sw) and other spiraling metrics (Vf or mass transfer coefficient, and U or nutrient uptake rate). All spiraling metrics indicated a higher SRP retention in spring than in autumn, despite macrophyte cover was similar in both sampling dates (39% and 51%, respectively). Phosphate retention was not detected neither in summer (when macrophyte biomass and especially that of submerged plants was the highest one) nor in winter. Ambient SRP concentrations in the stream were an order of magnitude higher than concentrations observed in pristine streams; nevertheless, under the varying conditions of discharge and phosphate levels observed in our study, we found no retention in summer and winter, a phosphate uptake comparable with those measured in impaired streams in autumn, and with those measured in pristine streams in late spring.  相似文献   
353.
Study of an upper Santonian to upper Campanian hemipelagic succession from the southern part of the Romanian Eastern Carpathians enables us to establish an integrated biostratigraphy based on planktonic foraminifera and calcareous nannofossils and to compare this record with the agglutinated foraminiferal biozonation used for the Carpathians.Benthic foraminiferal assemblages were investigated using several methods, such as agglutinated and calcareous benthic foraminiferal morphogroups, and the benthic foraminiferal oxygen index in order to determine their response to environmental parameters in the basin (correlated with sea-level maxima documented by regional sea-level curves for the Tethys). A pattern of changes in benthic foraminiferal communities associated with increased organic carbon flux and rising sea-levels can be summarized as follows in the studied succession. As sea-level begins to rise there is an increase in the proportion of calcareous benthic foraminifera at the expense of agglutinated foraminifera within the benthic assemblages (earliest Campanian, mid-late Campanian). Once sea-level rises, an increase in the elongate keeled morphotype of agglutinated foraminifera (shallower water forms) can be observed, and if sea-level remains high for an extended period (as in the early Campanian) then an invasion of both agglutinated and benthic calcareous foraminifera characteristic of outer shelf-upper slope environments take place in the basin. The variations in tubular and deep infaunal morphotypes of agglutinated foraminifera are ascribed to varying levels of organic carbon flux.  相似文献   
354.
Sphalerite oxidation is a common process under acid-mine drainage (AMD) conditions and results in the release of , Zn and potentially toxic trace metals, which can pollute rivers and oceans. However, there are only a few studies on the mechanisms of aerobic sphalerite oxidation. Oxygen and S isotope investigations of the produced may contribute to the understanding of sphalerite oxidation mechanisms so helping to interpret field data from AMD sites. Therefore, batch oxidation experiments with an Fe-rich sphalerite were performed under aerobic abiotic conditions at different initial pH values (2 and 6) for different lengths of time (2–100 days). The O and S isotope composition of the produced indicated changing oxidation pathways during the experiments. During the first 20 days of the experiments at both initial pH values, molecular O2 was the exclusive O source of . Furthermore, the lack of S isotope enrichment processes between and sphalerite indicated that O2 was the electron acceptor from sphalerite S. As the oxidation proceeded, a sufficient amount of released Fe(II) was oxidized to Fe(III) by O2. Therefore, electrons could be transferred from sphalerite S sites to adsorbed hydrous Fe(III) and O from the hydration sphere of Fe was incorporated into the produced as indicated by decreasing δ18OSO4 values which became more similar to the δ18OH2O values. The enrichment of 32S in relative to the sphalerite may also result from sphalerite oxidation by Fe(III).The incorporation of O2 into during the oxidation of sphalerite was associated with an O isotope enrichment factor εSO4–O2 of ca. −22‰. The O isotope enrichment factor εSO4–H2O was determined to be ?4.1‰. A comparison with O and S studies of other sulfides suggests that there is no general oxidation mechanism for acid-soluble sulfides.  相似文献   
355.
During extended winter(November–April),43% of the intraseasonal rainfall variability in China is explained by three spatial patterns of temporally coherent rainfall.These patterns were identified with empirical orthogonal teleconnection(EOT) analysis of observed 1982–2007 pentad rainfall anomalies and connected to midlatitude disturbances.However,examination of individual strong EOT events shows that there is substantial inter-event variability in their dynamical evolution,which implies that precursor patterns found in regressions cannot serve as useful predictors.To understand the physical nature and origins of the extratropical precursors,the EOT technique is applied to six simulations of the Met Office Unified Model at horizontal resolutions of 200–40 km,with and without air–sea coupling.All simulations reproduce the observed precursor patterns in regressions,indicating robust underlying dynamical processes.Further investigation into the dynamics associated with observed patterns shows that Rossby wave dynamics can explain the large inter-event variability.The results suggest that the apparently slowly evolving or quasi-stationary waves in regression analysis are a statistical amalgamation of more rapidly propagating waves with a variety of origins and properties.  相似文献   
356.
Geo-information solutions can achieve a higher level of quality if they are developed in accordance with a user-centred design that requires definition of the user requirements in the first step of solution construction. We treat a geo-information solution as a system designed to support human-based activities in a specific context through which solutions to contextual problems can be achieved via geographic knowledge. Geographic knowledge is a result of geo-data exploration, analysis, interpretation and dissemination with a given geo-information system. Taking the characteristics of geo-information systems into account, existing methods and techniques of requirements engineering may be applied for the design and implementation of geo-information solutions. Based on these considerations, here we present a generic framework that can aid geo-information experts, geo-informaticians and cartographers in the design and construction of more efficient, effective and satisfactory solutions.  相似文献   
357.
358.
Complexities associated with dissolved organic matter (DOM) isolation from seawater have hampered compositional characterization of this key component of global carbon and nutrient cycles. DOM isolation efficiency by electrodialysis (ED) from salt-containing waters was optimized and evaluated on samples including coastal ocean seawater, open ocean seawater, artificial seawater from axenic cultures of marine phytoplankton, and artificial seawater samples containing standard compounds of different molecular sizes and charge. ED was performed with a system optimized for processing 2–10 L sample volumes. Additionally, the combination of ED and solid-phase extraction, using Bond Elut PPL exchange resin, was evaluated. Using only ED, the following DOC recoveries were achieved: coastal seawater, 71.3 ± 6.5 %; open ocean, 50.5 ± 3.1 %; phytoplankton cultures, 70.3 ± 12.5 %; glucose, 90.2 ± 2.1 %; EDTA, 67.5 ± 9.9 %; and vitamin B12, 98.3 ± 1.6 %. With the combination of PPL and ED techniques, an average DOC recovery of 76.7 ± 2.6 % was obtained for coastal seawater, but this recovery was not statistically different from seawater recoveries using only ED. Comparison of C/N ratios and fluorescence excitation emission matrices taken at the beginning and end of the recovery process for coastal samples processed using only ED indicated that the final recovered material was representative of the DOM present in the original samples. Typical recoveries using combined PPL and ED exceed those of previous isolation methods.  相似文献   
359.
Estimates of future flood hazards made under the assumption of stationary mean sea level are biased low due to sea-level rise (SLR). However, adjustments to flood return levels made assuming fixed increases of sea level are also inadequate when applied to sea level that is rising over time at an uncertain rate. SLR allowances—the height adjustment from historic flood levels that maintain under uncertainty the annual expected probability of flooding—are typically estimated independently of individual decision-makers’ preferences, such as time horizon, risk tolerance, and confidence in SLR projections. We provide a framework of SLR allowances that employs complete probability distributions of local SLR and a range of user-defined flood risk management preferences. Given non-stationary and uncertain sea-level rise, these metrics provide estimates of flood protection heights and offsets for different planning horizons in coastal areas. We illustrate the calculation of various allowance types for a set of long-duration tide gauges along U.S. coastlines.  相似文献   
360.
The role of agriculture in the context of climate change is a complex issue. On the one hand, concerns about food security highlight the need to prioritize adaptation; on the other hand, the target of the Paris Agreement (keeping global temperature rise well below 2°C) cannot be achieved without a significant decrease in agricultural emissions. Various analyses of nationally determined contributions (NDCs) submitted under the Paris Agreement show how countries intend to prioritize the needs for adaptation and mitigation in the agricultural sector. This paper focuses on 46 countries that contribute 90% of global agricultural emissions and asks how they are addressing the agricultural sector in their climate mitigation policies. It takes into account that conditions and circumstances in countries vary significantly but might also indicate similar patterns. The analysis is based on information provided by countries in their NDCs, as well as their Biennial Reports (BRs) or Biennial Update Reports (BURs) under the UN Framework Convention on Climate Change (UNFCCC). It further includes data on national agricultural emissions. By applying a mixed methods approach, which combines qualitative content analysis and comparative cluster analysis, we find that countries vary in their progress on agriculture and climate mitigation for many different reasons. These reasons include the national perception of the problem, divergent starting points for climate policy, particularities of the agricultural sector and, correspondingly, the availability of cost-effective mitigation technologies.

Key policy insights

  • While for many countries the NDCs signify the beginning of their climate policy, UNFCCC biennial reports can be used to learn more about the policies that countries have already implemented.

  • Mitigation action in the agricultural sector is emphasized most prominently in cases where co-benefits are possible and production is not impacted negatively.

  • Policies and measures in the agricultural sector often do not align with the UNFCCC system of monitoring, reporting and verification (MRV). In addition to improving MRV-systems, it seems equally important to exchange national experiences with implemented measures and policies.

  • The Koronivia Joint Work on Agriculture could take into account the problem of different definitions of sector boundaries and thus the importance of different mitigation measures.

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