期刊文献+
共找到216篇文章
< 1 2 11 >
每页显示 20 50 100
渤海湾盆地石臼坨凸起秦皇岛27-3大型油田发现与地质新认识 被引量:6
1
作者 周家雄 徐春强 +4 位作者 杨海风 张宏国 张震 柳永军 张德龙 《中国海上油气》 CAS CSCD 北大核心 2024年第1期14-25,共12页
渤海湾盆地石臼坨凸起历经50余年勘探,在凸起高部位背斜区发现了3个浅层亿吨级大油田,而低部位斜坡区浅层由于构造圈闭不发育,勘探程度较低,近10年无规模性发现。随着渤海海域勘探程度提高,现已全面进入岩性勘探阶段,针对石臼坨凸起东... 渤海湾盆地石臼坨凸起历经50余年勘探,在凸起高部位背斜区发现了3个浅层亿吨级大油田,而低部位斜坡区浅层由于构造圈闭不发育,勘探程度较低,近10年无规模性发现。随着渤海海域勘探程度提高,现已全面进入岩性勘探阶段,针对石臼坨凸起东段顺向断裂斜坡区浅层油气运移、岩性圈闭刻画和油气成藏规律等展开了深入系统研究。研究认为:(1)研究区南北两侧被富生烃凹陷夹持,凸起边界大断层晚期强烈活动和陡坡带近源扇体普遍发育使凸起区成为规模性油气运聚的最终指向区;(2)凸起边界大断层在馆陶组开启系数最小,馆陶组含砾砂岩输导层是石臼坨凸起之上主要的油气横向运移通道;(3)馆陶组输导脊坡度和切脊断层组合控制顺向斜坡区油气的垂向输导,当坡度小于1°且断层长度大于2.50 km、成藏期断距大于40 m时斜坡区可产生规模性的油气垂向运移,突破顺向断裂斜坡区“过路不留”的传统认识;(4)在凸起斜坡区,与构造脊方向斜交的砂体有利于油气保存,同时,提出井约束谱蓝化整形高分辨率处理技术,实现了对斜坡区岩性圈闭有效刻画,优选出保存条件较好的斜向砂体开展钻探部署。基于上述新认识、新技术,2023年在石臼坨凸起东段顺向斜坡区成功评价了秦皇岛27-3亿吨级油田,实现了勘探老区浅层挖潜的重大突破,为渤海湾盆地高成熟探区持续油气发现提供了借鉴。 展开更多
关键词 秦皇岛27-3 顺向斜坡区 油气运聚 岩性圈闭刻画 石臼坨凸起 渤海海域 浅层 油田发现
下载PDF
First assessment of Noise-Equivalent Sigma-Zero in GF3-02 TOPSAR mode with sea surface wind speed retrieval
2
作者 Junxin Yang Lihua Zhong +3 位作者 Xinzhe Yuan Xiaochen Wang Bing Han Yuxin Hu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第10期84-96,共13页
Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment mon... Gaofen-3-02(GF3-02)is the first C-band synthetic aperture radar(SAR)satellite with terrain observation with progressive scans of SAR(TOPSAR)imaging mode in China,which plays an essential role in marine environment monitoring.Given the weak scattering characteristics of the ocean,the system thermal noise superimposed on SAR images has significant interference,especially in cross-polarization channels.Noise-Equivalent Sigma-Zero(NESZ)is a measure of the sensitivity of the radar to areas of low backscatter.The NESZ is defined to be the scattering cross-section coefficient of an area which contributes a mean level in the image equal to the signal-independent additive noise level.For TOPSAR,NESZ exhibits the shape of the SAR scanning gain curve in the azimuth and the shape of the antenna pattern in the range.Therefore,the accurate measurement of NESZ plays a vital role in the application of spaceborne SAR sea surface cross-polarization data.This paper proposes a theoretical calculation method for the NESZ curve in GF3-02 TOPSAR mode based on SAR noise inner calibration data and the imaging algorithm.A method for correcting the error existing in the theoretical curve of NESZ is also proposed according to the relationship between sea surface backscattering and wind speed and the same characteristics of target scattering in the overlapping area of adjacent sub-swaths.According to assessment with wide-swath TOPSAR cross-polarization data,the GF3-02 TOPSAR mode has a very low thermal noise level,which is better than−33 dB at the edge of each beam,and controlled below−38 dB at the center of the beam.The two-dimensional reference curves of the NESZ of each beam are provided to the GF3-02 TOPSAR users.After discussing the relationship between normalized radar cross section(NRCS)and wind speed,we provide a formula for NRCS related to wind speed and radar incidence angle.Compared with the NRCS derived from this formula and the NESZ-subtracted NRCS of SAR images,the bias is−0.0048 dB,the Root Mean Square Error is 1.671 dB and the correlation coefficient is 0.939. 展开更多
关键词 GF3-02 TOPSAR Noise-Equivalent Sigma-Zero(NESZ) CROSS-POLARIZATION normalized radar cross section(NRCS) sea surface wind
下载PDF
Seismic description and fluid identification of thin reservoirs in Shengli Chengdao extra-shallow sea oilfield
3
作者 SHU Ningkai SU Chaoguang +5 位作者 SHI Xiaoguang LI Zhiping ZHANG Xuefang CHEN Xianhong ZHU Jianbing SONG Liang 《Petroleum Exploration and Development》 CSCD 2021年第4期889-899,共11页
The meandering channel deposit of the upper member of Neogene Guantao Formation in Shengli Chengdao extra-shallow sea oilfield is characterized by rapid change in sedimentary facies.In addition,affected by surface tid... The meandering channel deposit of the upper member of Neogene Guantao Formation in Shengli Chengdao extra-shallow sea oilfield is characterized by rapid change in sedimentary facies.In addition,affected by surface tides and sea water reverberation,the double sensor seismic data processed by conventional methods has low signal-to-noise ratio and low resolution,and thus cannot meet the needs of seismic description and oil-bearing fluid identification of thin reservoirs less than 10 meters thick in this area.The two-step high resolution frequency bandwidth expanding processing technology was used to improve the signal-to-noise ratio and resolution of the seismic data,as a result,the dominant frequency of the seismic data was enhanced from 30 Hz to 50 Hz,and the sand body thickness resolution was enhanced from 10 m to 6 m.On the basis of fine layer control by seismic data,three types of seismic facies models,floodplain,natural levee and point bar,were defined,and the intelligent horizon-facies controlled recognition technology was worked out,which had a prediction error of reservoir thickness of less than 1.5 m.Clearly,the description accuracy of meandering channel sand bodies has been improved.The probability semi-quantitative oiliness identification method of fluid by prestack multi-parameters has been worked out by integrating Poisson’s ratio,fluid factor,product of Lame parameter and density,and other prestack elastic parameters,and the method has a coincidence rate of fluid identification of more than 90%,providing solid technical support for the exploration and development of thin reservoirs in Shengli Chengdao extra-shallow sea oilfield,which is expected to provide reference for the exploration and development of similar oilfields in China. 展开更多
关键词 Jiyang Depression Chengdao oilfield extra-shallow sea NEOGENE sea and land dual-sensor prestack two-step high resolution frequency bandwidth expanding processing intelligent horizon-facies controlled recognition technology prestack seismic fluid identification
下载PDF
渤海海域渤中19-2大型岩性油田发现与成藏新认识
4
作者 王昕 杨海风 +4 位作者 许鹏 王德英 汤国民 刘庆顺 肖述光 《中国海上油气》 CAS CSCD 北大核心 2024年第4期12-22,共11页
随着渤海海域勘探程度的增加,寻找浅层规模岩性油气田难度日益加剧。2021年,在渤中凹陷西南部洼中隆,发现了渤中19-2大型河流相岩性油气田。利用地震、薄片、地化等资料,对渤中19-2油田关键成藏条件进行分析。结果表明:①明下段大型曲... 随着渤海海域勘探程度的增加,寻找浅层规模岩性油气田难度日益加剧。2021年,在渤中凹陷西南部洼中隆,发现了渤中19-2大型河流相岩性油气田。利用地震、薄片、地化等资料,对渤中19-2油田关键成藏条件进行分析。结果表明:①明下段大型曲流河频繁迁移,不同期次河道交切叠置,控制了规模性岩性圈闭的形成;②深浅汇油背景垂向叠置,为浅层油气富集提供有利构造背景;③渤中19-2构造明下段北西向河道砂体与关键断裂具有良好的“断-脊”配置关系,形成烃柱高度大的“一级充注”;④渤中19-4构造紧邻油源断裂形成“双脊继承-强活动断层-局部砂体”成藏模式,渤中19-2构造远离油源断裂形成“双脊接力-强活动断层-连片砂体”成藏模式。渤中19-2油田的发现,证实了渤海海域洼中隆起区浅层岩性油气藏勘探潜力,有助于类似地区大面积岩性勘探取得新突破。 展开更多
关键词 渤海海域 新近系 渤中19-2 渤中19-4 岩性油田 河流相 成藏模式
下载PDF
基于SEA分析验证的混响箱-消声室实验方法设计及隔声性能研究 被引量:2
5
作者 张磊 郑旭 +1 位作者 陈军 郝志勇 《振动与冲击》 EI CSCD 北大核心 2020年第8期258-263,270,共7页
不同于以往的理论、经验设计,采用低频段的声固耦合法、中高频段的统计能量法(SEA)对设计的混响声场进行声学分析,提高混响水平。根据虚拟结果建立混响箱实物,置于半消声室内进行测试,混响箱结构本体的噪声衰减量超过50 dB,混响时间达... 不同于以往的理论、经验设计,采用低频段的声固耦合法、中高频段的统计能量法(SEA)对设计的混响声场进行声学分析,提高混响水平。根据虚拟结果建立混响箱实物,置于半消声室内进行测试,混响箱结构本体的噪声衰减量超过50 dB,混响时间达到混响要求,混响场内不同位置声压值差距均小于2 dB,该混响箱设计满足混响声场的要求;将SEA法隔声计算结果与应用混响箱-消声室法对板件的隔声测试结果进行对比,两者吻合良好;因此该实验方法能实现很好的隔声效果。通过该方法可快速对单层板及夹层板件进行隔声测试,发现吻合频率效应对隔声性能影响较大;以上研究对工程应用有较大的参考意义。 展开更多
关键词 统计能量法(sea) 声固耦合 混响声场 混响箱-消声室 隔声(STL) 夹层板
下载PDF
Deep-sea Pollen Record during 3.0-2.0 Ma B.P. from ODP Site 1143 and Its Response to Global Climate Changes 被引量:1
6
作者 袁金红 罗运利 +1 位作者 徐兆良 孙湘君 《Marine Science Bulletin》 CAS 2006年第1期1-10,共10页
In order to study vegetation evolution and environmental changes around 2.5 Ma B.P., a total of 146 pollen samples with an average time resolution of 7 000 years were analyzed in the deep-sea record at the depth of 13... In order to study vegetation evolution and environmental changes around 2.5 Ma B.P., a total of 146 pollen samples with an average time resolution of 7 000 years were analyzed in the deep-sea record at the depth of 135 - 95 m (in composition depth) from ODP Site 1143 (9° 22' N, 113° 17' E) in the southern South China Sea. The results show that the pollen influx has a distinct change. During 2.6 - 2.0 Ma B.P., the average value of pollen influx increased evidently compared with that of 3.0 - 2.6 Ma B.P. It shows that the sea level of SCS dropped dramatically around 2.6 Ma B.P., corresponding to the formation of the Northern Hemisphere ice-sheets and the enhancement of the East Asian Monsoon. The pollen influx variations reflect the glacial-interglacial cycles corresponding with the deep-sea oxygen isotope curve and indicate that the sea level of SCS rose and dropped many times after 2.6 Ma B.P. The spectrum analysis results of pollen influx show that there are cycles at 0.1Ma (eccentricity) and 46.9 ka (obliquity) during 3.0 - 2.0 Ma B.P. 展开更多
关键词 pollen influx 3.0 - 2.0 Ma B.P. ODP Site 1143 the South China sea
下载PDF
The 30–60-day Intraseasonal Variability of Sea Surface Temperature in the South China Sea during May–September 被引量:3
7
作者 Jiangyu MAO Ming WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第5期550-566,共17页
This study investigates the structure and propagation of intraseasonal sea surface temperature(SST) variability in the South China Sea(SCS) on the 30-60-day timescale during boreal summer(May-September). TRMM-ba... This study investigates the structure and propagation of intraseasonal sea surface temperature(SST) variability in the South China Sea(SCS) on the 30-60-day timescale during boreal summer(May-September). TRMM-based SST, GODAS oceanic reanalysis and ERA-Interim atmospheric reanalysis datasets from 1998 to 2013 are used to examine quantitatively the atmospheric thermodynamic and oceanic dynamic mechanisms responsible for its formation. Power spectra show that the 30-60-day SST variability is predominant, accounting for 60% of the variance of the 10-90-day variability over most of the SCS. Composite analyses demonstrate that the 30-60-day SST variability is characterized by the alternate occurrence of basin-wide positive and negative SST anomalies in the SCS, with positive(negative) SST anomalies accompanied by anomalous northeasterlies(southwesterlies). The transition and expansion of SST anomalies are driven by the monsoonal trough-ridge seesaw pattern that migrates northward from the equator to the northern SCS. Quantitative diagnosis of the composite mixed-layer heat budgets shows that, within a strong 30-60-day cycle, the atmospheric thermal forcing is indeed a dominant factor, with the mixed-layer net heat flux(MNHF) contributing around 60% of the total SST tendency, while vertical entrainment contributes more than 30%. However, the entrainment-induced SST tendency is sometimes as large as the MNHF-induced component, implying that ocean processes are sometimes as important as surface fluxes in generating the30-60-day SST variability in the SCS. 展开更多
关键词 sea surface temperature 30-60-day intraseasonal variability South China sea vertical entrainment
下载PDF
Fine anatomy of reservoir architecture of point bar in meandering river: a case study of Minghuazhen Formation in northern block of Q oilfield,Bohai Sea 被引量:3
8
作者 MENG Peng HU Yong 《Global Geology》 2014年第4期218-224,共7页
In order to solve dynamic Problems caused by the internal structure of fluvial reservoir,it is necessa-ry to study the fine anatomy of Point bar. Taking Minghuazhen Formation in the northern block of Q oilfield, Bohai... In order to solve dynamic Problems caused by the internal structure of fluvial reservoir,it is necessa-ry to study the fine anatomy of Point bar. Taking Minghuazhen Formation in the northern block of Q oilfield, Bohai Sea as an examPle,the authors studied identification marks,distribution Pattern and scale of Point bar based on coring,logging and dynamic data. The results show that the length of Point bar and the width of lateral accretion body are 713-911 m and 71-111m,resPectively;the diP angle and the thickness of lateral accretion bedding are 3. 5o-5. 9o and 0. 1-0. 5 m. The lateral accretion beddings are the key factor affecting the seePage velocity of the tracer. 展开更多
关键词 reservoir architecture lateral accretion body point bar meandering river Q oilfield Bohai sea
下载PDF
Intact Polar and Core Tetraether Lipids in Sediments from the Haiyang 4 Cold-seep of the Northern South China Sea and their Implications 被引量:1
9
作者 LI Yuejiao SU Xin +2 位作者 JIAO Lu CHEN Fang CHENG Sihai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2022年第2期691-700,共10页
A number of cold seeps have been discovered in the northern South China Sea(SCS) including the Haiyang 4 cold-seep area where Core 973-5 was collected. Intact polar lipids(IPLs) and core lipids(CLs) were analyzed sepa... A number of cold seeps have been discovered in the northern South China Sea(SCS) including the Haiyang 4 cold-seep area where Core 973-5 was collected. Intact polar lipids(IPLs) and core lipids(CLs) were analyzed separately in sediments from Core 973-5. The most abundant lipid biomarkers were isoprenoidal GDGTs(iso GDGTs), with Crenarchaeol and GDGT-0 predominating. IPL-iso GDGTs and CL-iso GDGTs were mainly derived from Thaumarchaeota. IPL-iso GDGTs were mainly produced and retained in situ thus containing most of the in situ microbiological information. Branched GDGTs were predominantly derived from generated in marine production, and mixed with some terrestrial inputs. All IPLs groups presented a high value in the sulfate-methane transition zone(SMTZ). Furthermore, IPL and CL-MI, IPL-R;showed the highest values within the SMTZ, while IPL and CL-R;had the lowest values at the SMTZ, suggesting that the contribution of Methanophila and methanogenic to GDGTs increased, while the contribution of ammonia-oxidizing Archaea to GDGTs decreased at the SMTZ. 展开更多
关键词 GDGTs IPLs SMTZ source Core 973-5 Haiyang 4 Cold-seep South China sea
下载PDF
Oxygen Isotope Records of Core 8KL of the South China Sea and Sea - level Change 被引量:1
10
作者 Qian JianxingThe Second Institute of Oceanography, SO A, Hangzhuu, Zhejiang Liu Linqun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1995年第2期209-219,共11页
Based on a comparison between the oxygen isotope records of benthic and plank tonic foraminifers from core 8KL of the South China Sea and sea-level change records derived from the Huon Peninsula, New Guinea, it is fou... Based on a comparison between the oxygen isotope records of benthic and plank tonic foraminifers from core 8KL of the South China Sea and sea-level change records derived from the Huon Peninsula, New Guinea, it is found that both records are very similar from 72 K a B.P. to the present, especially for the benthic oxygen isotope record. The linear regression shows that δ18O changes (0.9995‰ for benthic foraminifers and 1.022‰ for planktonic foraminifers) are equal to 100 m in sea-level fluctuation. After making temperature correction in the δ18O record of benthic foraminifers from 72 to 120 Ka B.P., the curve of sea-level oscillation of the South China Sea since 186 Ka B.P. has been reconstructed. The lowermost sea - level that occurred in the last glacial maximum and oxygen isotope stage 6 is approximately - 130 m. 展开更多
关键词 oxygen isotopic records of foraminifera sea - level change linear regression
下载PDF
Differential interformational velocity analysis as an effective direct hydrocarbon indicator under velocity reversal conditions,an example from the anomalously high temperature and over-pressured DF1-1 Gas Field in the Yinggehai Basin,South China Sea
11
作者 Zhu Hongtao Liu Keyu +2 位作者 Chen Kaiyuan Li Min Huang Shengbing 《Petroleum Science》 SCIE CAS CSCD 2009年第4期339-346,共8页
In the DF1-1 Gas Field in the Yinggehai Basin, South China Sea, the velocity-depth plot and velocity spectra show significant variations from a linear trend, exhibiting a distinct reversal phenomenon. Velocity paramet... In the DF1-1 Gas Field in the Yinggehai Basin, South China Sea, the velocity-depth plot and velocity spectra show significant variations from a linear trend, exhibiting a distinct reversal phenomenon. Velocity parameters derived from velocity spectral analysis of the seismic data and sonic logs indicate that the interval velocity reverses below 2,100 m (2.2 s two-way time (TWT)) in the DF1-1 Gas Field. Some direct hydrocarbon indicators (DHIs) models developed for the shallow strata cannot be simply applied to the moderately to deeply buried strata for direct exploration target recognition because the velocity reversal has caused the middle-deep gas reservoirs to exhibit a moderate or weak seismic amplitude. The hydrocarbon indicator method of “Differential Interformational Velocity Analysis (DIVA)” with the aid of other hydrocarbon indicating techniques was employed to effectively identify DHIs in the middle-deep strata under velocity inversion. The result has shown that the DIVA technique can be effectively used as a DHI in both the shallow and the middle-deep strata in the study area with the shallow strata characterized by Type I DIVA anomaly and the middle-deep strata characterized by the Type II DIVA anomaly. 展开更多
关键词 DF1-1 Gas Field velocity reversal direct hydrocarbon indicator differential interformational velocity analysis South China sea
下载PDF
Study of the MSA,nssSO_(4)^(2-)concentration and MSA to nssSO_(4)^(2-)ratio in the snow/ice and atmospheric aerosols of the regions surrounding the Weddell Sea
12
作者 韩建康 《Chinese Journal of Polar Science》 1999年第1期12-20,共9页
The MSA and nssSO 2- 4 concentration data from the ice cores and from atmospheric aerosols of the regions surrounding Weddell Sea have been analyzed in the present paper. The results suggest that the high concen... The MSA and nssSO 2- 4 concentration data from the ice cores and from atmospheric aerosols of the regions surrounding Weddell Sea have been analyzed in the present paper. The results suggest that the high concentration of biogenic sulphur in the snow and ice as well as in the atmospheric aerosols reflects the proximity of the Weddell Sea even though a distinct strength discrepancy exists in the productivity among the areas. The snow/ice shows that the production seems to be higher in the middle of the Antarctic Peninsula than near the Filchner Ronne ice shelf. Despite the factors impacting on the transportation and deposition processes of biogenic surlphur, the concentration of MSA and nssSO 2- 4 in snow and ice shows a regular spatial distribution: decreasing with the distance from the open sea and the altitude above sea level. Nevertheless, below a certain height, the “altitude effect” is no longer significant. The “displacement” of seasonality for MSA concentration observed in ice cores of the regions has been discussed. The “out of phase” pattern in surface layer is attributed to the modification by prevailing meteorological condition to the transport and deposition process; while “relocation” in the deep layers may be caused by migration, a mechanism for which is to be further investigated.The comparative study of the atmospheric and snow/ice samples implies that at the high altitude like the Weddell Sea the atmospheric signal of SO 2- 4 and MSA could be somewhat muted in the snow samples. But the seasonal variations in the airborn sulphate and MSA are reasonably well reproduced in the surface snow, for temporal and spacial distribution. The very close ratio of MSA to nssSO 2- 4 (or to SO 2- 4) of atmospheric aerosol and snow/ice sample is indicative of weak, if any, fraction between the two species during the scavenging and deposition processes. This could serve as the internal cause to explain the relative stable MSA/nssSO 2- 4 ratio, both for atmosphere and snow, an important regional specificity for the study of marine biogenic sulphur. 展开更多
关键词 Weddell sea snow/ice AEROSOL MSA nssSO 2- 4.
下载PDF
渤海蓬莱19-3油田新近系明下段曲流河储层构型表征 被引量:3
13
作者 徐中波 汪利兵 +2 位作者 申春生 陈铭阳 甘立琴 《岩性油气藏》 CAS CSCD 北大核心 2023年第5期100-107,共8页
开展复合砂体内部不同级次储层构型单元的精细表征对渤海蓬莱19-3油田明下段开发方案的优化至关重要。综合应用岩心、测井和三维地震资料,并进行多地震属性的智能融合,实现了对蓬莱19-3油田三区明下段Ⅳ油组2小层曲流河储层五—三级构... 开展复合砂体内部不同级次储层构型单元的精细表征对渤海蓬莱19-3油田明下段开发方案的优化至关重要。综合应用岩心、测井和三维地震资料,并进行多地震属性的智能融合,实现了对蓬莱19-3油田三区明下段Ⅳ油组2小层曲流河储层五—三级构型单元的精细刻画。研究结果表明:(1)蓬莱19-3油田目的层段可划分为单一曲流带、单一点坝砂体和单一侧积体不同级次储层构型单元。(2)地震属性中的最大振幅、反射强度和相对波阻抗对储层响应较为敏感,基于物性参数监督的神经网络多属性融合进一步提高了储层预测的精度和可信度。(3)研究区发育南北向展布、中间窄两端宽的单一曲流带五级构型单元;单一点坝四级构型单元呈串珠状分布且互相切割改造;单一点坝内部侧积体呈正韵律,侧积层倾角为2°~5°。(4)采用多属性智能融合技术对研究区曲流河多级次构型单元进行刻画的结果显示,不同成因类型构型单元的几何形态、规模及其结构存在相关性,对调整井位、完善注采井网、提高油田开发效率具有重要意义。 展开更多
关键词 多属性融合 曲流河 点坝 多级次 构型表征 明下段 新近系 蓬莱19-3油田 渤海
下载PDF
Off-Shore Sea Surface Electric Field Investigations around the Indian Sub-Continent during 9-20 May 1983
14
作者 G.K.Manohar S.M.Sholapurkar S.S.Kandalgaonkar 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1990年第4期453-462,共10页
Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-2... Sea surface electric field observations off the coast from Goa (15°25'N, 73°47'E) to Madras (13°04'N, 80°15'E) around Sri Lanka, in a distance range 25-135 km from coast, during 9-20 May 1983 were taken. In this paper we have examined the diurnal variation of electric field in the Arabian Sea, Indian Ocean and Bay of Bengal regions covered during the cruise of the research ship ORV Gaveshani. An aspect of electric field dependence on coastal distance and Aitken Nuclei concentration has also been studied. An attempt to examine the latitude dependence of field was also made. Results obtained in the above studies are presented and compared with those obtained elsewhere. 展开更多
关键词 Off-Shore sea Surface Electric Field Investigations around the Indian Sub-Continent during 9-20 May 1983 Bay
下载PDF
COMPARISON STUDY ON THE INTRASEASONAL VARIATIONS IN CIRCULATIONS AND PRECIPITATION MODULATED BY THE TROPICAL CYCLOGENESIS OVER SOUTH CHINA SEA-WESTERN PACIFIC DURING GUANGDONG FLOODING PERIOD
15
作者 李春晖 万齐林 +2 位作者 郑彬 谷德军 林爱兰 《Journal of Tropical Meteorology》 SCIE 2011年第4期363-374,共12页
Based on tropical cyclone datasets from Shanghai Typhoon Institute of China Meteorological Administration,the National Centers for Environmental Prediction (NCEP,USA) reanalysis data and the rainfall records from 743 ... Based on tropical cyclone datasets from Shanghai Typhoon Institute of China Meteorological Administration,the National Centers for Environmental Prediction (NCEP,USA) reanalysis data and the rainfall records from 743 stations in China,the impacts of cyclogenesis number over the South China Sea and the western Pacific are studied on the 30-60-day oscillations in the precipitation of Guangdong during the flooding period.The year with more-than-normal (less-than-normal) tropical cyclogenesis is defined as a 'high year' ('low year').In light of the irregular periodic oscillations,the method used to construct the composite life cycle is based on nine consecutive phases in each of the cycles.Phases 1,3,5,and 7 correspond to,respectively,the time when precipitation anomalies reach theminimum,a positive transition (negative-turning-to-positive) phase,the maximum,and a negative transition phase.The results showed that the precipitation of the 30-60-day oscillations is associated with the interaction between a well-organized eastward propagation system from the Arabian Sea/Bay of Bengal and a westward-propagating system (with cyclonic and anticyclonic anomalies in the northwest-southeast direction) from the South China Sea to western Pacific during the high years,whereas the precipitation is affected during a low year by the circulation over the South China Sea and western Pacific (with cyclonic and anticyclonic anomalies in the northeast-southwest direction).During the high year,the warm and wet air mass from the ocean to the west and south are transported to Guangdong by westerly anomalies and an enclosed latitudinal cell,which ascends in the Northern Hemisphere low latitudes and descends in the Southern Hemisphere low latitudes.During the low year,the warm and wet air mass from the ocean to the south is transported to Guangdong by southwesterly wind anomalies and local ascending movements.Because the kinetic energy,westerly,easterly shift,vertical velocity and vapor transportation averaged over (109-119° E,10-20° N) is stronger in high years than those in low years,the precipitation of the 30-60-day oscillations in Guangdong is higher in high years than that in low years. 展开更多
关键词 cyclogenesis number over the South China sea and western Pacific precipitation in Guangdong province 30-60-day oscillation
下载PDF
New Oilfield Discovered in South China Sea
16
《China Oil & Gas》 CAS 1997年第1期36-36,共1页
关键词 New oilfield Discovered in South China sea
下载PDF
Environmental Protection Stressed in Weizhou Oilfield of South China Sea
17
《China Oil & Gas》 CAS 1997年第4期205-205,共1页
关键词 Environmental Protection Stressed in Weizhou oilfield of South China sea
下载PDF
Start of Production at the Ya 13-1 Gas Field in South China Sea
18
《China Oil & Gas》 CAS 1996年第1期62-62,共1页
StartofProductionattheYa13-1GasFieldinSouthChinaSeaTheceremonytocelebratethestartofproductionattheYa13-1gasF... StartofProductionattheYa13-1GasFieldinSouthChinaSeaTheceremonytocelebratethestartofproductionattheYa13-1gasFieldinSouthChinaS... 展开更多
关键词 Start of Production at the Ya 13-1 Gas Field in South China sea
下载PDF
渤海稠油油田热化学复合吞吐增效技术研究与应用 被引量:2
19
作者 姜维东 罗少锋 +2 位作者 张伟 孙玉豹 王少华 《中国海上油气》 CAS CSCD 北大核心 2024年第2期141-148,共8页
针对渤海稠油油田在生产稠油井存在的原油黏度大、胶质沥青质沉积造成储层有机堵塞严重、产量递减快、边底水突进、含水上升快等问题,通过室内实验研究分析、物理模拟与参数优化开展了海上热化学复合吞吐增效技术研究。结果表明:随温度... 针对渤海稠油油田在生产稠油井存在的原油黏度大、胶质沥青质沉积造成储层有机堵塞严重、产量递减快、边底水突进、含水上升快等问题,通过室内实验研究分析、物理模拟与参数优化开展了海上热化学复合吞吐增效技术研究。结果表明:随温度升高,胶质、沥青质扩散系数增大,石英石表面对重质组分的吸附能力减弱,有助于胶质沥青质解离;热气化学复合解堵后,岩心水测渗透率均可恢复到初始岩心水测渗透率的60%~70%;热(80℃)+气(溶解)作用下,与50℃脱气油相比可使原油黏度降低约80%;在热和化学剂作用下,原油形成低黏水包油乳状液,稠油黏度由2000 mPa·s降低至30 mPa·s,降黏率为98.5%;稠油相渗曲线测试实验(100℃)结果显示,化学剂注入后使稠油相渗曲线等渗点右移,两相共渗区域增大,油相渗透率变大,水相渗透率降低,残余油饱和度降低,开发效果改善;在热水驱过程中,注入泡沫堵调后,高渗填砂管和低渗填砂管采收率均有明显提高,低渗管采收率提高约11个百分点,高渗管采收率提高约8个百分点。模拟吞吐实验结果表明:在热+化学+气协同作用下,可至少降低含水20%~30%,采油指数由0.90 mL/(min·MPa)提高至1.95 mL/(min·MPa),可显著改善低产稠油井的开发效果。热化学复合吞吐增效技术已在渤海稠油油田现场取得成功试验,措施井含水最高降低73.4个百分点,有效期150天,平均日产油较措施前提高2.9倍,有效期内累增油4300 m^(3),为渤海稠油冷采井增储上产提供了新的技术思路和方向。 展开更多
关键词 渤海 稠油油田 热化学复合吞吐增效 采油指数 稠油冷采
下载PDF
基于SEA的机器人仿肌弹性驱动关节研究 被引量:12
20
作者 何福本 梁延德 +1 位作者 孙捷夫 郭超 《中国机械工程》 EI CAS CSCD 北大核心 2014年第7期900-905,共6页
为了实现机器人的拟人运动,提高其对外部环境的适应性,基于串联弹性驱动器(SEA)驱动形式提出一种仿肌弹性驱动的机器人转动关节,以实现机器人在受迫振动或受冲击下的柔顺自调整运动。该关节机构参考人体肌肉-肌腱组织的Hill-type模型,... 为了实现机器人的拟人运动,提高其对外部环境的适应性,基于串联弹性驱动器(SEA)驱动形式提出一种仿肌弹性驱动的机器人转动关节,以实现机器人在受迫振动或受冲击下的柔顺自调整运动。该关节机构参考人体肌肉-肌腱组织的Hill-type模型,采用具有对抗形式的主动弹性驱动和被动弹性牵制的设计方案,模拟肌肉收缩运动和功能,产生牵拉力以驱动机器人的关节。通过对该弹性驱动关节进行建模分析,得到其动力学描述方程,结合多次仿真测试中获得的系统运动特性曲线,在掌握其运动规律的基础上完成了其动力学性能评估。此外,针对关节机构具有的强弹性、低刚度特点,提出一种基于虚拟刚度补偿的控制方法,并应用在具有仿肌弹性驱动关节的二自由度机器臂上,实验结果表明其可行、有效。 展开更多
关键词 仿生机构 机器人 串联弹性驱动器 肌肉-肌腱 刚度控制 series elastic actuator(sea)
下载PDF
上一页 1 2 11 下一页 到第
使用帮助 返回顶部