This study evaluates the capability of the Simulating WAves Nearshore(SWAN)wave model(version 41.01)in predicting significant wave height and spectral peak energy content for swell waves in very shallow water of surf ...This study evaluates the capability of the Simulating WAves Nearshore(SWAN)wave model(version 41.01)in predicting significant wave height and spectral peak energy content for swell waves in very shallow water of surf zone during depth-induced wave breaking and dissipation.The model results were compared with field measurements at five nearshore stations.The results demonstrated that some breaker index formulations were successful for significant wave height prediction in surf zones.However,an incorrect shape of the energy spectrum and overestimated near spectral peak energy content at shallow water stations were obtained using all of the embedded depth-induced wave breaking formulations in SWAN.The dependent breaker index on relative depth(Kpd)formulation,which was successful in predicting near spectral peak energy content,resulted in an average error of 30%.Finally,this formulation was modified to enhance the model performance in reproducing the spectral peak energy content.展开更多
The relationships between crustal stretching and thinning,basin structure and petroleum geology in Baiyun deep-water area were analyzed using large area 3D seismic,gravity,magnetic,ocean bottom seismic(OBS),deep-water...The relationships between crustal stretching and thinning,basin structure and petroleum geology in Baiyun deep-water area were analyzed using large area 3D seismic,gravity,magnetic,ocean bottom seismic(OBS),deep-water exploration wells and integrated ocean drilling program(IODP).During the early syn-rifting period,deep-water area was a half-graben controlled by high angle faults influenced by the brittle extension of upper crust.In the mid syn-rifting period,this area was a broad-deep fault depression controlled by detachment faults undergone brittle-ductile deformation and differentiated extension in the crust.In the late syn-rifting period,this area experienced fault-sag transition due to saucer-shaped rheology change dominated by crustal ductile deformation.A broad-deep fault depression controlled by the large detachment faults penetrating through the crust is an important feature of deep-water basin.The study suggests that the broad-deep Baiyun sag provides great accommodation space for the development of massive deltaic-lacustrine deposition system and hydrocarbon source rocks.The differentiated lithospheric thinning also resulted in the different thermal subsidence during post-rifting period,and then controlled the development of continental shelf break and deep-water reservoir sedimentary environment.The high heat flow background caused by the strong thinning of lithosphere and the rise of mantle source resulted in particularities in the reservoir diagenesis,hydrocarbon generation process and accumulation of deep-water area in northern South China Sea.展开更多
For reasonable assessment and safe exploitation of marine gas hydrate resource, it is important to determine the stability conditions of gas hydrates in marine sediment. In this paper, the seafloor water sample and se...For reasonable assessment and safe exploitation of marine gas hydrate resource, it is important to determine the stability conditions of gas hydrates in marine sediment. In this paper, the seafloor water sample and sediment sample （saturated with pore water） from Shenhu Area of South China Sea were used to synthesize methane hydrates, and the stability conditions of methane hydrates were investigated by multi-step heating dissociation method. Preliminary experimental results show that the dissociation temperature of methane hydrate both in seafloor water and marine sediment, under any given pressure, is depressed by approximately -1.4 K relative to the pure water system. This phenomenon indicates that hydrate stability in marine sediment is mainly affected by pore water ions.展开更多
The effects of sea surface temperature（SST）,cloud radiative and microphysical processes,and diurnal variations on rainfall statistics are documented with grid data from the two-dimensional equilibrium cloud-resolvin...The effects of sea surface temperature（SST）,cloud radiative and microphysical processes,and diurnal variations on rainfall statistics are documented with grid data from the two-dimensional equilibrium cloud-resolving model simulations.For a rain rate of higher than 3 mm.h 1,water vapor convergence prevails.The rainfall amount decreases with the decrease of SST from 29℃ to 27℃,the inclusion of diurnal variation of SST,or the exclusion of microphysical effects of ice clouds and radiative effects of water clouds,which are primarily associated with the decreases in water vapor convergence.However,the amount of rainfall increases with the increase of SST from 29℃ to 31℃,the exclusion of diurnal variation of solar zenith angle,and the exclusion of the radiative effects of ice clouds,which are primarily related to increases in water vapor convergence.For a rain rate of less than 3 mm.h 1,water vapor divergence prevails.Unlike rainfall statistics for rain rates of higher than 3 mm.h 1,the decrease of SST from 29℃ to 27℃ and the exclusion of radiative effects of water clouds in the presence of radiative effects of ice clouds increase the rainfall amount,which corresponds to the suppression in water vapor divergence.The exclusion of microphysical effects of ice clouds decreases the amount of rainfall,which corresponds to the enhancement in water vapor divergence.The amount of rainfall is less sensitive to the increase of SST from 29℃ to 31℃ and to the radiative effects of water clouds in the absence of the radiative effects of ice clouds.展开更多
目的选择以海砂和珊瑚作为骨料,海水作为拌合水,采用先预湿珊瑚,再与水泥砂浆拌合的方法,制备一种新型活性矿物海水海砂珊瑚混凝土(Mineral Sea Rock Concrete,MSRC),解决建筑工程中砂石短缺等问题。方法通过坍落度和抗压强度试验,分别...目的选择以海砂和珊瑚作为骨料,海水作为拌合水,采用先预湿珊瑚,再与水泥砂浆拌合的方法,制备一种新型活性矿物海水海砂珊瑚混凝土(Mineral Sea Rock Concrete,MSRC),解决建筑工程中砂石短缺等问题。方法通过坍落度和抗压强度试验,分别分析净水灰比、骨料含水率和砂率对MSRC的和易性与抗压强度的影响。结果砂率在45%~58%内,坍落度随着砂率的增大而增大;砂率在58%~60%内,坍落度随着砂率的增大而减小;骨料含水率为12%时,混凝土拌合物和易性最优,立方体抗压强度最高;净水灰比为0.43、砂率为47%,骨料含水率12%的立方体抗压强度比骨料含水率9%和15%分别高3.9%和10.6%;强度等级相同时,随着砂率的增大,立方体抗压强度先增大后减小;对于强度等级为MSRC20、MSRC25和MSRC30的混凝土配合比,净水灰比分别为0.43、0.41和0.30时,立方体抗压强度取得最大值;MSRC前期抗压强度发展较快,超过15d时,抗压强度增长速度逐渐缓慢;基于试验结果,提出了立方体抗压强度计算公式,通过试验结果及公式计算结果对比可得,提出的计算公式与试验结果吻合良好。结论笔者制备的MSRC具有良好的和易性与力学性能,研究成果可以为MSRC的配合比设计和工程应用提供重要依据。展开更多
基金supported by Iranian National Institute for Oceanography and Atmospheric Science
文摘This study evaluates the capability of the Simulating WAves Nearshore(SWAN)wave model(version 41.01)in predicting significant wave height and spectral peak energy content for swell waves in very shallow water of surf zone during depth-induced wave breaking and dissipation.The model results were compared with field measurements at five nearshore stations.The results demonstrated that some breaker index formulations were successful for significant wave height prediction in surf zones.However,an incorrect shape of the energy spectrum and overestimated near spectral peak energy content at shallow water stations were obtained using all of the embedded depth-induced wave breaking formulations in SWAN.The dependent breaker index on relative depth(Kpd)formulation,which was successful in predicting near spectral peak energy content,resulted in an average error of 30%.Finally,this formulation was modified to enhance the model performance in reproducing the spectral peak energy content.
基金Supported by the Science and Technology Project of CNOOC Ltd.(YXKY-2012-SHENHAI-01)China National Science and Technology Major Project(2011ZX05025-003+1 种基金 2016ZX05026-003)the National Natural Science Foundation of China(91128207)
文摘The relationships between crustal stretching and thinning,basin structure and petroleum geology in Baiyun deep-water area were analyzed using large area 3D seismic,gravity,magnetic,ocean bottom seismic(OBS),deep-water exploration wells and integrated ocean drilling program(IODP).During the early syn-rifting period,deep-water area was a half-graben controlled by high angle faults influenced by the brittle extension of upper crust.In the mid syn-rifting period,this area was a broad-deep fault depression controlled by detachment faults undergone brittle-ductile deformation and differentiated extension in the crust.In the late syn-rifting period,this area experienced fault-sag transition due to saucer-shaped rheology change dominated by crustal ductile deformation.A broad-deep fault depression controlled by the large detachment faults penetrating through the crust is an important feature of deep-water basin.The study suggests that the broad-deep Baiyun sag provides great accommodation space for the development of massive deltaic-lacustrine deposition system and hydrocarbon source rocks.The differentiated lithospheric thinning also resulted in the different thermal subsidence during post-rifting period,and then controlled the development of continental shelf break and deep-water reservoir sedimentary environment.The high heat flow background caused by the strong thinning of lithosphere and the rise of mantle source resulted in particularities in the reservoir diagenesis,hydrocarbon generation process and accumulation of deep-water area in northern South China Sea.
基金supported by the National Basic Research Program of China(No.2009CB219503)the Special Fund for Ministry of Land and Resources research of China in the Public Interest(201111026)the Natural Science Foundation of Shandong Province of China(No.ZR2009FQ017)
文摘For reasonable assessment and safe exploitation of marine gas hydrate resource, it is important to determine the stability conditions of gas hydrates in marine sediment. In this paper, the seafloor water sample and sediment sample （saturated with pore water） from Shenhu Area of South China Sea were used to synthesize methane hydrates, and the stability conditions of methane hydrates were investigated by multi-step heating dissociation method. Preliminary experimental results show that the dissociation temperature of methane hydrate both in seafloor water and marine sediment, under any given pressure, is depressed by approximately -1.4 K relative to the pure water system. This phenomenon indicates that hydrate stability in marine sediment is mainly affected by pore water ions.
基金Project supported by the National Basic Research Program of China (Grant No. 2012CB417201)the National Natural Science Foundation of China (Grant Nos. 41075034,40930950,40975034,and 41075044)
文摘The effects of sea surface temperature（SST）,cloud radiative and microphysical processes,and diurnal variations on rainfall statistics are documented with grid data from the two-dimensional equilibrium cloud-resolving model simulations.For a rain rate of higher than 3 mm.h 1,water vapor convergence prevails.The rainfall amount decreases with the decrease of SST from 29℃ to 27℃,the inclusion of diurnal variation of SST,or the exclusion of microphysical effects of ice clouds and radiative effects of water clouds,which are primarily associated with the decreases in water vapor convergence.However,the amount of rainfall increases with the increase of SST from 29℃ to 31℃,the exclusion of diurnal variation of solar zenith angle,and the exclusion of the radiative effects of ice clouds,which are primarily related to increases in water vapor convergence.For a rain rate of less than 3 mm.h 1,water vapor divergence prevails.Unlike rainfall statistics for rain rates of higher than 3 mm.h 1,the decrease of SST from 29℃ to 27℃ and the exclusion of radiative effects of water clouds in the presence of radiative effects of ice clouds increase the rainfall amount,which corresponds to the suppression in water vapor divergence.The exclusion of microphysical effects of ice clouds decreases the amount of rainfall,which corresponds to the enhancement in water vapor divergence.The amount of rainfall is less sensitive to the increase of SST from 29℃ to 31℃ and to the radiative effects of water clouds in the absence of the radiative effects of ice clouds.
文摘目的选择以海砂和珊瑚作为骨料,海水作为拌合水,采用先预湿珊瑚,再与水泥砂浆拌合的方法,制备一种新型活性矿物海水海砂珊瑚混凝土(Mineral Sea Rock Concrete,MSRC),解决建筑工程中砂石短缺等问题。方法通过坍落度和抗压强度试验,分别分析净水灰比、骨料含水率和砂率对MSRC的和易性与抗压强度的影响。结果砂率在45%~58%内,坍落度随着砂率的增大而增大;砂率在58%~60%内,坍落度随着砂率的增大而减小;骨料含水率为12%时,混凝土拌合物和易性最优,立方体抗压强度最高;净水灰比为0.43、砂率为47%,骨料含水率12%的立方体抗压强度比骨料含水率9%和15%分别高3.9%和10.6%;强度等级相同时,随着砂率的增大,立方体抗压强度先增大后减小;对于强度等级为MSRC20、MSRC25和MSRC30的混凝土配合比,净水灰比分别为0.43、0.41和0.30时,立方体抗压强度取得最大值;MSRC前期抗压强度发展较快,超过15d时,抗压强度增长速度逐渐缓慢;基于试验结果,提出了立方体抗压强度计算公式,通过试验结果及公式计算结果对比可得,提出的计算公式与试验结果吻合良好。结论笔者制备的MSRC具有良好的和易性与力学性能,研究成果可以为MSRC的配合比设计和工程应用提供重要依据。
