排序方式: 共有24条查询结果,搜索用时 15 毫秒
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A. Rob MacKenzie Stefan Krause Kris M. Hart Richard M. Thomas Phillip J. Blaen R. Liz Hamilton Giulio Curioni Susan E. Quick Angeliki Kourmouli David M. Hannah Sophie A. Comer-Warner Nicolai Brekenfeld Sami Ullah Malcolm C. Press 《水文研究》2021,35(3):e14096
The ecosystem services provided by forests modulate runoff generation processes, nutrient cycling and water and energy exchange between soils, vegetation and atmosphere. Increasing atmospheric CO2 affects many linked aspects of forest and catchment function in ways we do not adequately understand. Global levels of atmospheric CO2 will be around 40% higher in 2050 than current levels, yet estimates of how water and solute fluxes in forested catchments will respond to increased CO2 are highly uncertain. The Free Air CO2 Enrichment (FACE) facility of the University of Birmingham's Institute of Forest Research (BIFoR) is the only FACE in mature deciduous forest. The site specializes in fundamental studies of the response of whole ecosystem patches of mature, deciduous, temperate woodland to elevated CO2 (eCO2). Here, we describe a dataset of hydrological parameters – seven weather parameters at each of three heights and four locations, shallow soil moisture and temperature, stream hydrology and CO2 enrichment – retrieved at high frequency from the BIFoR FACE catchment. 相似文献
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Aleksey Marchenko Nicolai Vasiliev Artem Nesterov Yuri Kondrashov Nikolay Belyaev 《寒旱区科学》2017,9(3):192-196
Measurements of the thermal deformations of frozen soil samples were performed in the cold laboratory in temperature range from 0°C to-12°C.Fiber Bragg Gratings strain and temperature sensors were used to measure the deformation and temperature inside the samples.A number of tests with the samples prepared from Kaolin and Cambrian clay saturated with fresh water,and prepared from fine and silt sand saturated with fresh or saline water,are performed.Thermal deformations of the samples are analyzed depending on the cyclic changes of their temperature. 相似文献
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Javier F. Pacheco Carlos A. Mortera-Gutirrez Hugo Delgado Shri K. Singh Raúl W. Valenzuela Nicolai M. Shapiro Miguel A. Santoyo Alejandro Hurtado Ricardo Barrn Esteban Gutirrez-Moguel 《Journal of South American Earth Sciences》1999,12(6):55
We studied a sequence of small earthquakes that occurred during the months of April and May of 1997, in Jalisco, southwestern Mexico. The earthquakes were located along a set of active faults that form the Zacoalco half-graben (La Lima fault system), west of Lake Chapala, within the rift–rift–rift triple junction. A total of 33 events were located, with magnitudes ranging from 1.5 to 3.5, recorded by a portable array of broadband seismographs. We identified two groups of events: one corresponding to a shallow normal fault, synthetic to La Lima fault system, and another group associated with a deeper fault. The events that occurred on the synthetic fault show normal faulting oriented on a NW–SE plane, dipping shallowly towards the SW. The other group of mechanisms showed either a normal fault oriented NW–SE and dipping steeply to the NE, or a very shallow-dipping normal fault, dipping to the SW. Earthquake distribution and fault plane solutions suggest that the Zacoalco half-graben developed from blocks that rotate as slip occurs on listric faults. These mechanisms could represent the type of motion expected for larger earthquakes in the area, like the one that occurred in 1568. 相似文献
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Abraha Gebrekidan Hannah Nicolai Liese Vincken Mekone Teferi Tsehaye Asmelash Tadesse Dejenie Samuel Zerabruk Kindeya Gebrehiwet Hans Bauer Josef Deckers Patricia Luis Luc De Meester Bart van der Bruggen 《洁净——土壤、空气、水》2013,41(3):235-243
This study aims to examine the efficiency of Opuntia ficus‐indica for removing organochlorine pesticides from surface waters. Adsorption properties such as size, dose, and time of O. ficus‐indica for aldrin, dieldrin, and dichlorodiphenyltrichloroethane (DDT) were studied through stirring and column methods. Because of their high affinity and swelling characteristics, dried O. ficus‐indica was studied in stirring while fresh unpeeled O. ficus‐indica was applied in both stirring and column experiments and proved to be well‐suited to column application. Before removing pesticides, the column was flashed with distilled water eliminate the turbidity and smell from fresh unpeeled cactus. The removal of pesticides increased with an increasing adsorbent dose and decreased with adsorbent particle sizes. The optimum adsorbent dose is 10 g for dried and 15 g for fresh unpeeled O. ficus‐indica. The experimental results show that O. ficus‐indica possesses strong adsorption ability for aldrin, dieldrin, and DDT, and the adsorption isotherm data obeyed the Freundlich model. The results of our small‐scale experiments suggest a strong potential to develop local small‐scale water treatment units that can be used at the level of individual households or local communities, using a widely available adsorbent. 相似文献
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Oksana A. Tarasova Nicolai F. Elansky Gennady I. Kuznetsov Irina N. Kuznetsova Irina A. Senik 《Journal of Atmospheric Chemistry》2003,45(3):245-259
The impact of air transport on the surface ozone variations is analyzed at Kislovodsk High Mountain Station for the period 1989–1996 on the basis of 2D back trajectories. It was shown that the contribution of photochemical and dynamical processes is different for the different seasons. In summer months the surface ozone concentration is governed by photochemical ozone production in semi polluted air from the regions of Northern Caspian, Southern Ural and Volga region. Time of the seasonal ozone maximum appearance is defined by joint influence of the processes of photochemical production and destruction in the eastern sectors and advection from Ukraine and Central Europe. The value of the seasonal minimum is determined by the processes of ozone destruction in the air coming from northeastern direction in the stable frontal zone. Distribution of sectors of the air transport changes from year to year and it can partly explain strong negative trend of the surface ozone concentration at the site. 相似文献
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Nicolai S. Panikov 《Polar research》1999,18(2):237-244
This review covers selected aspects of recent international efforts to measure and model greenhouse gas emission from northern wetlands, to identify the environmental factors that control gas emission, and to investigate wetlands'responses (particularly with respect to gas emission) to global change. Both bottom-up and top-to-bottom approaches, based respectively on local observations plus inventory of gas fluxes and inverse modelling of global circulation, agree on the size of the high latitude (>60° N) contribution to global methane, which should be about 13% or 70 Tg/year. It has been shown that winter and spring fluxes are an essential part in the annual budget of CH4 and especially CO2 exchange (varying from 5 to 50%). Soil micro-organisms were shown to be able to respire during winter even at-16° C. In comparison to aerobically respiring organisms, anaerobic methanogenic bacteria were less active in frozen soil, although they are subjected to significant stimulation by soil freeze-thaw cycles. The absence of immediate coupling of methanogenesis with plant photosynthesis implies that substrates for methane formation are derived from peat decomposition rather than from root exudation. 相似文献
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