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排序方式: 共有125条查询结果,搜索用时 15 毫秒
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All numerical weather prediction (NWP) models inherently have substantial biases, especially in the forecast of near-surface weather variables. Statistical methods can be used to remove the systematic error based on historical bias data at observation stations. However, many end users of weather forecasts need bias corrected forecasts at locations that scarcely have any historical bias data. To circumvent this limitation, the bias of surface temperature forecasts on a regular grid covering Iran is removed, by using the information available at observation stations in the vicinity of any given grid point. To this end, the running mean error method is first used to correct the forecasts at observation stations, then four interpolation methods including inverse distance squared weighting with constant lapse rate (IDSW-CLR), Kriging with constant lapse rate (Kriging-CLR), gradient inverse distance squared with linear lapse rate (GIDS-LR), and gradient inverse distance squared with lapse rate determined by classification and regression tree (GIDS-CART), are employed to interpolate the bias corrected forecasts at neighboring observation stations to any given location. The results show that all four interpolation methods used do reduce the model error significantly, but Kriging-CLR has better performance than the other methods. For Kriging-CLR, root mean square error (RMSE) and mean absolute error (MAE) were decreased by 26% and 29%, respectively, as compared to the raw forecasts. It is found also, that after applying any of the proposed methods, unlike the raw forecasts, the bias corrected forecasts do not show spatial or temporal dependency. 相似文献
84.
The prospects of the Clean Development Mechanism (CDM) and for carbon income, up to and beyond 2012, in the industrial sectors of Iran and five other Asian countries are investigated. The attractiveness and suitability of each host country, the status of their industrial sectors (based on four post-2012 scenarios), and the post-2012 potential of the CDM (or similar carbon projects) in these sectors are all examined. A multi-criteria analysis of Iran, Saudi Arabia, the UAE, Qatar, China, and India, based on seven sets of criteria (institutional, regulatory, economic, political, social, CDM experience, and energy production/consumption), is conducted, and the post-2012 potential carbon incomes of each country – based on CO2e emissions of industrial processes – are calculated. Finally, the Iranian industrial sector and the impact of deregulation of energy prices are examined. The post-2012 potential savings in the Iranian industrial sector are calculated based on energy savings, carbon income, and environmental savings. The results indicate that there is strong demand for investment and new technology in this sector to combat several-fold energy price increases. Moreover, high-priced carbon credits could play a meaningful role in post-2012 energy policies in this sector. Policy relevance This research is the first study to quantify the carbon market potentials in the industrial sectors of the selected Organization of the Petroleum Exporting Countries (OPEC) members. The Kyoto Protocol is considered by most OPEC countries to be a mixed bag of threats and opportunities and they have shown ambivalence towards it, mainly due to the threat a reduction of fossil fuel consumption poses to their economies. On the other hand, energy efficiency is a desirable goal for their industrial sectors. Iran, as an OPEC member country with vast energy resources, has mostly ignored the CDM during the first commitment period of the Kyoto Protocol and has performed poorly on CDM implementation. However, the current deregulation of energy prices in Iran, with profound cuts in energy subsidies, would definitely alter the perspective of its industrial decision makers on the post-2012 carbon potentials. 相似文献
85.
Fabrizio Cecca Kazem Seyed-EmamiJohann Schnyder Mohamed BenzaggaghMahmoud Reza Majidifard Mohammed Mohammadi Monfared 《Cretaceous Research》2012,33(1):106-115
An early Berriasian (Berriasella jacobi Zone) ammonite fauna is described for the first time from the Alborz Mountains in northwest Iran. It has been collected from a section located near the village of Shal (Talesh region); in addition to rare phylloceratids, lytoceratids and Neolissoceras, the majority of ammonites belong to the neocomitid subfamily Berriasellinae. With the exception of a new genus and species, Taleshites fuersichi, these taxa are common in European and North African Tethyan successions. Associated calpionellids confirm the early Berriasian age of the ammonite-bearing levels. 相似文献
86.
Fataneh Taghizadeh-Farahmand Forough Sodoudi Narges Afsari Najmieh Mohammadi 《Journal of Seismology》2013,17(4):1207-1221
The Kopeh-Dagh fold belts are among the most seismically active areas in Northeastern Iran, which build the northern part of the Alpine–Himalayan orogen in western Asia. They act as the abrupt northeastern limit to active deformation in Iran. We perform a combined P and S receiver function analysis to detect the major discontinuities within the lithosphere beneath Northeast Iran. Our results obtained from 12 short period and broadband seismological stations significantly map the lateral variations of the Moho boundary. Based on P receiver functions, we show that the Moho depth varies from ~43 km beneath the southern Kopeh-Dagh foreland basin to ~49 km below the northern part of the basin. S receiver functions reliably reveal an average Moho depth of ~50–55 km beneath the Kopeh-Dagh mountain range showing the regional shortening in response to the collision of Arabia with Eurasia. Furthermore, we observe clear conversions with negative polarity at ~8.5–9.5 s in S receiver functions, which could be related to the conversion at the lithosphere–asthenosphere boundary. This may show a relatively thin continental lithosphere of about 85–95 km beneath the Kopeh-Dagh implying that the lithosphere was influenced by geodynamical reworking processes in the past. 相似文献
87.
Georg Schwamborn Lutz Schirrmeister Ali Mohammadi Hanno Meyer Andrei Kartoziia Flavio Maggioni Jens Strauss 《Sedimentology》2023,70(1):235-258
Arctic warming and permafrost thaw visibly expose changes in the landscape of the Lena River delta, the largest Arctic delta. Determining the past and modern river regime of thick deltaic deposits shaping the Lena River mouth in north-eastern Siberia is critical for understanding the history of delta formation and carbon sequestration. Using a 65 m long sediment core from the delta apex a set of sedimentological techniques is applied to aid in reconstructing the Lena River history. The analysis includes: (i) grain-size measurements and the determination of the bedload composition; (ii) X-ray fluorescence, X-ray diffractometry, and magnetic susceptibility measurements and heavy mineral analysis for tracking mineral change; (iii) pH, electrical conductivity, ionic concentrations, and the δ18O and δD stable isotope composition from ground ice for reconstructing permafrost formation. In addition; (iv) total and dissolved organic carbon is assessed. Chronology is based on; (vi) radiocarbon dating of organic material (accelerator mass spectrometry and conventional) and is complemented by two infrared – optically stimulated luminescence dates. The record stretches back approximately to Marine Isotope Stage 7. It holds periods from traction, over saltation, to suspension load sedimentation. Minerogenic signals do not indicate provenance change over time. They rather reflect the change from high energy to a lower energy regime after Last Glacial Maximum time parallel to the fining-up grain-size trend. A prominent minimum in the ground ice stable isotope record at early Holocene highlights that a river arm migration and an associated refreeze of the underlying river talik has altered the isotopic composition at that time. Fluvial re-routing might be explained by internal dynamics in the Lena River lowland or due to a tectonic movement, since the study area is placed in a zone of seismic activity. At the southern Laptev Sea margin, onshore continental compressional patterns are bordering offshore extensional normal faults. 相似文献
88.
M. Mohammadi Roozbahani M. M.Sc. P. Nassiri Ph.D. P. Jafari Shalkouhi M.Sc. 《International Journal of Environmental Science and Technology》2009,6(4):591-596
In order to assess the risks associated with worker’s hearing loss, due to exposure to noise pollution, at the Boroujerd Textile Factory a cross sectional study was conducted. 60 workers from the Spinning and Weaving workshops and official staff were randomly selected as case and control groups and their hearing were tested by audiometry. The audiometric results revealed that amongst workers being exposed to the noise pollution in the Spinning and Weaving Workshops there is a distinct increase in the number of cases of hearing loss at high frequencies. There also appears to be a slight bias towards hearing loss in the left ear, in preference to the right in addition, those who have worked for longer than 16 years are subjected to hearing loss even at low frequencies conversely, the office workers (the control group) seem to suffer little or no hearing loss at low frequencies at all, but after approximately 10 years of service there may be some hearing loss, but only at higher frequencies, which could be attributed to presbycusis. Also, the t-test (statistical hypothesis test) results verified the significant difference among both groups at high frequencies. The questionnaire results indicated that workers feel symptoms such as headache, no sense centralization, excitement, nervousness, vertigo. Hence, controlling procedures seem to be essential to protect workers from noise disorders. 相似文献
89.
K. Solaimani H. Mohammadi M. Z. Ahmadi M. Habibnejad 《International Journal of Environmental Science and Technology》2005,2(3):253-258
The application of Geographical Information system (GIS) in modeling flood and its prediction in catchments offers considerable potential. Several examples illustrate simple GIS techniques to produce flood hazard indices or its zonation using hydrologic-type models. Existing flood models can also be loosely coupled to a GIS, such as the HMS (Hydrological Modeling System) model. Forethermore, models can be fully integrated into a GIS by embedded coupling, such as the SCS (Soil Conservation Service) model. Installation of flood forecasting systems in watersheds with incomplete hydrometric data may reduce the flood-induced damages. In this study Geographical Information system used to up to date the watershed data and estimation of SCS model parameters which is sensible to considered the real time flood forecasting in Kasilian catchment of Mazandaran province. The main aim of this paper is to investigate the possibility of the linkage between GIS with a comprehensive hydrologic model, especially HMS. The use of GIS could produce a suitable agreement between observed results (extracted rainfall and runoff data of 1992, 1995 and 1996 from the related stations) with the calculated results of the hydrological model. The obtained results from rainfall-runoff process simulations of the model in this research showed that submergibility of the main watershed, Kasillian, does not depend on the outlet discharge rate of each one of its watershed independently. But it is related to how those two outlet hydrographs from main river watershed are combined. The model is capable of showing the flood characteristics temporally and spatially in each cross section of the channel network. 相似文献
90.
Cook Megan Bouchette Frédéric Mohammadi Bijan Sprunck Léa Fraysse Nicolas 《中国海洋工程》2021,35(6):802-813
China Ocean Engineering - Optimization theory is applied to a coastal engineering problem that is the design of a port. This approach was applied to the redesign of La Turballe Port in order to... 相似文献