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501.
21世纪海上丝绸之路建设在海洋经济活动、海上综合保障等方面对海洋科技领域提出了新命题。在分析我国海洋技术优势领域的基础上,围绕科技创新政策伙伴关系、培育创新品牌、推进海洋经济和产业发展等方面,深入阐述了海洋科技领域在21世纪海上丝绸之路建设中的支撑作用,同时提出具体工作思路。 相似文献
502.
利用溶胶凝胶法自制了碳纳米管和纳米二氧化钛的复合光催化剂,采用投射电子显微镜和X光衍射仪对粉体的粒径、物象、形貌和热稳定性等进行表征。通过研究光照条件、催化剂的投加量、油的初始浓度、催化剂制备的煅烧条件等因素,考察了自制碳纳米管和纳米二氧化钛的复合催化剂对降解模拟海洋柴油污染的海水去除率的影响。研究发现,在可见光照条件下,400℃煅烧2 h的复合催化剂,投加量为0.4 g/L、柴油的初始浓度为0.6 g/L、反应的光照时间为4 h时效果最好,去除率可达到67.65%。 相似文献
503.
海洋地震拖缆是海洋油气资源勘探中的关键设备,为研究海洋地震拖缆的动力特性及其在不同频率正弦激励干扰下的动力响应,建立了零浮力拖缆的数学模型,设计了一套完整的实验方案,通过弹性测力机构放大张力信号以排除环境干扰,测量了不同拖曳速度与激振频率条件下拖缆首部的张力变化及缆上位移响应情况,初步分析了正弦激励作用下零浮力拖缆的动力学响应。弹性测力机构具有良好的线性度与可重复性,拖缆受到的水阻力与拖曳速度的平方成正比,数值计算与实验结果对比验证了数学模型的正确性,初步分析了正弦激励作用下零浮力拖缆的动力学响应。 相似文献
504.
505.
海洋重力测量动态环境效应分析与补偿 总被引:1,自引:0,他引:1
针对使用小型测量船搭载摆杆型海洋重力仪获取数据质量不高的问题,在深入分析海洋环境动态效应误差特性基础上,提出了一种基于互相关分析的交叉耦合效应修正法,对高动态海洋重力测量数据实施综合误差补偿和精细处理。使用典型恶劣海况条件下的观测数据对该方法的有效性进行了验证,结果显示,重力测线成果内符合精度从原先的±9.35×10-5m/s2大幅提升到±1.43×10-5m/s2,同时使用卫星测高反演重力对精细处理结果的可靠性进行了外部检核,外符合精度也从原先的±7.73×10-5m/s2提高到±5.63×10-5m/s2。 相似文献
506.
507.
Based on combined Cloud Sat/CALIPSO detections, the seasonal occurrence of deep convective clouds(DCCs) over the midlatitude North Pacific(NP) and cyclonic activity in winter were compared. In winter, DCCs are more frequent over the central NP, from approximately 30°N to 45°N, than over other regions. The high frequencies are roughly equal to those occurring in this region in summer. Most of these DCCs have cloud tops above a 12 km altitude, and the highest top is approximately 15 km. These wintertime marine DCCs commonly occur during surface circulation conditions of low pressure, high temperature, strong meridional wind, and high relative humidity. Further, the maximum probability of DCCs,according to the high correlation coefficient, was found in the region 10°–20° east and 5°–10° south of the center of the cyclones. The potential relationship between DCCs and cyclones regarding their relative locations and circulation conditions was also identified by a case study. Deep clouds were generated in the warm conveyor belt by strong updrafts from baroclinic flows. The updrafts intensified when latent heat was released during the adjustment of the cyclone circulation current. This indicates that the dynamics of cyclones are the primary energy source for DCCs over the NP in winter. 相似文献
508.
An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main structures and characteristics are the same as during strong wind episodes with cold air outbreaks on land. The high frequency turbulent fluctuations(period<1 min) are nearly random and isotropic with weak coherency, but the gusty wind disturbances(1 min相似文献
509.
Based on the reanalysis data of monthly mean global SST and wind from the NCEP/NCAR and the observation data of rain seasons in 124 stations of Yunnan province from 1961 to 2006, we applied the analytical methods of correlation analysis and composite analysis and a significance testing method to two sets of samples of average differences. The goal is to investigate into the influence of the Southern Hemispheric (SH) SST on the summer precipitation in Yunnan from January to May so as to identify the key time and marine regions. Physical mechanisms are obtained by analyzing the influence of sea level wind and the key marine regions on the precipitation during Yunnan’s rain season. Results show that there is indeed significant relationship between the SST in SH and summer precipitation in Yunnan. The key areas for influencing the summer precipitation are mainly distributed in a region called “West Wind Drift” in the SH, including the Southeast Indian, southern Australia, west coast of eastern Pacific off Chile, Peru and the southwest Atlantic Magellan. Besides, the most significant marine region is the west coast of Chile and Peru (cold-current areas of the eastern Pacific). Diagnostic analysis results also showed that monsoons in the Bay of Bengal, a cross-equatorial flow in the Indian Ocean near the equator and southwest monsoon in India weaken during the warm phase of the Peruvian cold current in the eastern Pacific. Otherwise, they strengthen. 相似文献
510.
Fishing activities have the potential to alter the behaviour of cetaceans and pose a threat through bycatch. We present observations concerning the influence of inshore trawling on group size and behaviour of Hector's dolphins (Cephalorhynchus hectori) at Banks Peninsula, New Zealand, made during photo‐ID surveys from 2003 to 2007. Aggregations of dolphins, typically involved in what we assumed to be foraging behaviour, were observed following small inshore trawlers year‐round. Group size was larger for aggregations of dolphins following trawlers (mean ± SE = 22.9 ± 1.3, n = 83) than for non‐trawler groups (3.7 ± 0.2, n = 439), and dolphins were typically in a more “excited” state, frequently exhibiting aerial and sexual behaviours. We suggest that trawlers increase the availability of prey for Hector's dolphins and hence foraging behind trawlers is an energetically favourable activity. However, following trawlers probably also increases the risk of being caught in trawl nets, compounding the threats faced by this endangered species. 相似文献