Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised...Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4–8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.展开更多
Natural gas hydrates are considered as strategic resources with commercial potential in the 21st century. Obvious BSR characteristics will be shown on seismic profiles, if there exist natural gas hydrates. The AVO met...Natural gas hydrates are considered as strategic resources with commercial potential in the 21st century. Obvious BSR characteristics will be shown on seismic profiles, if there exist natural gas hydrates. The AVO method is one of the methods which can be used to identify and forecast lithologic characteristics and fluid properties by using the relationship between Amplitude and Offset. AVO anomaly is one of the significant signs to check out whether or not there is free gas below the BSR, so it can be used to detect natural gas hydrates from the seismic profile. Considering the geological and geophysical characteristics of the Okinawa Trough and making use of the techniques mentioned above, we can conclude that the conditions there are favorable for the formation and concentration of natural gas hydrates. By analyzing the data collected from the study area, one can discover many different anomalous phenomena on the seismic profile which are related to the existence of natural gas hydrates. Preliminary estimation of the natural gas hydrates in the Okinawa Trough shows that the trough is rich in natural gas hydrates and may become a potential important resources exploration area.展开更多
Background and aim: Several systematic reviews and meta-analyses published within the past years have examined the associations of Mediterranean-style diets (MedSDs) on cognitive. However, these reviews have not be...Background and aim: Several systematic reviews and meta-analyses published within the past years have examined the associations of Mediterranean-style diets (MedSDs) on cognitive. However, these reviews have not been evaluated for satisfying Contemporary methodologies quality standards. At the same time, due to the high demand for related care during the aging process in China, it is necessary to summarize the ex-isting system evaluation and evaluate the quality of it, so as to provide strong evidence for the development of relevant work and to standardize the research process and methods in this field. This study evaluated the quality of recent systematic reviews and meta-analyses on MedSD and cognitive outcomes by using an established methodology quality scale, and to provide some valuable references for future research and Chinese systematic review and meta-analysis developing. Methods: We used the AMSTAR Methodology Quality Assessment Scale to evaluate the quality of methodology of the existing meta-analyses and systematic review. Meta analysis and systematic review that meets our criteria must contain the following characteristics: 1) used systematic or meta-analytic procedures to review the lit-erature, and 2) had MedSD interventions independently. Results: Reviews satisfied with 5 to 9 of the AMSTAR MedSD items (mean 7.35, standard deviation: 1.27), quality is above average with those published in higher-impact journals having a greater quality score. Conclusion: These data suggest that current meta-analyses/systematic reviews evaluating the effect of MedSD on cognitive do not fully meet contemporary methodology quality standards. The methodological quality of the literature needs to be im- proved. As a result, there are more research questions to answer to enhance our understanding of how MedSD affects cognitive. To clarify associations between MedSD and cognitive, future meta-analyses and systematic reviews should not only follow methodology quality standards but also include more statistical modeling results when data allow. And in order to make the conclusions more reliable, we expect higher quality RCTs in the future.展开更多
基金Supported by the National High Technology Research and Development Program of China (863 Program, 2006AA09Z349)the National Basic Research Program of China (2007CB411703)
文摘Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4–8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.
基金supported by the National High Technology Research and Development (863) Program (Grant No.2006AA09Z339)the Natural Science Foundation of Shandong, China (Grant No. Y2006E09)
文摘Natural gas hydrates are considered as strategic resources with commercial potential in the 21st century. Obvious BSR characteristics will be shown on seismic profiles, if there exist natural gas hydrates. The AVO method is one of the methods which can be used to identify and forecast lithologic characteristics and fluid properties by using the relationship between Amplitude and Offset. AVO anomaly is one of the significant signs to check out whether or not there is free gas below the BSR, so it can be used to detect natural gas hydrates from the seismic profile. Considering the geological and geophysical characteristics of the Okinawa Trough and making use of the techniques mentioned above, we can conclude that the conditions there are favorable for the formation and concentration of natural gas hydrates. By analyzing the data collected from the study area, one can discover many different anomalous phenomena on the seismic profile which are related to the existence of natural gas hydrates. Preliminary estimation of the natural gas hydrates in the Okinawa Trough shows that the trough is rich in natural gas hydrates and may become a potential important resources exploration area.
文摘Background and aim: Several systematic reviews and meta-analyses published within the past years have examined the associations of Mediterranean-style diets (MedSDs) on cognitive. However, these reviews have not been evaluated for satisfying Contemporary methodologies quality standards. At the same time, due to the high demand for related care during the aging process in China, it is necessary to summarize the ex-isting system evaluation and evaluate the quality of it, so as to provide strong evidence for the development of relevant work and to standardize the research process and methods in this field. This study evaluated the quality of recent systematic reviews and meta-analyses on MedSD and cognitive outcomes by using an established methodology quality scale, and to provide some valuable references for future research and Chinese systematic review and meta-analysis developing. Methods: We used the AMSTAR Methodology Quality Assessment Scale to evaluate the quality of methodology of the existing meta-analyses and systematic review. Meta analysis and systematic review that meets our criteria must contain the following characteristics: 1) used systematic or meta-analytic procedures to review the lit-erature, and 2) had MedSD interventions independently. Results: Reviews satisfied with 5 to 9 of the AMSTAR MedSD items (mean 7.35, standard deviation: 1.27), quality is above average with those published in higher-impact journals having a greater quality score. Conclusion: These data suggest that current meta-analyses/systematic reviews evaluating the effect of MedSD on cognitive do not fully meet contemporary methodology quality standards. The methodological quality of the literature needs to be im- proved. As a result, there are more research questions to answer to enhance our understanding of how MedSD affects cognitive. To clarify associations between MedSD and cognitive, future meta-analyses and systematic reviews should not only follow methodology quality standards but also include more statistical modeling results when data allow. And in order to make the conclusions more reliable, we expect higher quality RCTs in the future.