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《Marine Policy》2005,29(2):139-146
Regarding the regime of military and intelligence gathering activities in the EEZ, China argues that the freedoms of navigation and overflight in the EEZ have certain restrictions including that the activity must be peaceful and not threaten to use force against the coastal State. This includes military surveys, military maneuvers, and military reconnaissance which are a form of battlefield preparation. These activities are also subject to due regard for the rights of the coastal State. China also argues that there are serious shortcomings regarding the regime of marine scientific research (MSR) in the EEZ and that marine surveys or military surveys carried out by MSR platforms require the consent of the coastal State. 相似文献
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无锡梅雨期湿沉降综合分析 总被引：2，自引：0，他引：2
利用2008—2014年梅雨期间酸雨观测资料及2014年6月16—27日降水个例加密采样资料,结合大气污染物资料分析了近7 a无锡梅雨期酸雨特征,研究降水过程中空气污染物、p H值、电导率的变化及降水对污染物的清除作用。结果表明:无锡市梅雨期酸雨年平均p H值呈现逐年递增趋势。降水过程中,颗粒物质量浓度显著降低;气体浓度变化受其自身日变化及排放源影响大于雨水的清除作用;样品的p H值、K值每个过程变化并不一致,K值变化与颗粒物质量浓度变化大致保持一致。降水、风对颗粒物质量浓度影响大于对气体浓度的影响。长时间连续降水时,降水对颗粒污染物的清除存在极限。小时雨量在0~0.5 mm时,降水对颗粒物浓度做负清除,其值反而略有增加;小时雨量在0.6~5.0 mm时,降水对颗粒物质量浓度做正清除;小时雨量达到5.1 mm及以上时,对PM_(2.5)和PM_(2.5-10)做正清除,对PM_(10)做负清除。降水对SO_2有稀释清除作用;对NO_2的稀释作用取决于其开始浓度值;对CO、O_3的清除作用不显著。 相似文献
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近年来我国大部分地区在冬、春两季多遭受冻雨灾害,自动气象站的风向风速传感器容易因冻结而无法正常工作。针对冻结故障的实时检测问题,本文设计了一种基于ZQZ-TF型风传感器的故障自动检测装置。该装置通过检测风传感器的工作电压和工作电流,实现对传感器实时状态的监控。同时,结合具体的故障诊断算法,能够快速判断风传感器是否被冻结。系统的核心硬件电路、软件算法可分别集成在自动气象站风向风速数据采集电路和嵌入式软件中,具有结构紧凑、操作简单的特点。经验证,该装置能够实时检测风传感器冻结故障,且工作稳定,检测精度高。 相似文献
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利用1979—2018年ERA Interim地面10 m风场、位势高度场、温度场和风场,Hadley中心HadISST再分析海温资料,采用SVD分析、合成分析等方法,研究了夏季（6—8月）西太平洋暖池关键海域海表面温度（Sea Surface Temperature,简称SST）对华东海域夏季10 m日最大风速变化的影响关系。SVD分析结果表明,夏季华东近海风速变化与菲律宾以东海域SST有明显负相关,第一模态左、右空间向量的时间系数相关达0.58,通过了置信度为95%的显著性检验。当西太平洋暖池SST正异常时,暖池海域SST增高,西北太平洋副热带高压（以下简称副高）加强,副高脊线北进（西北太平洋副高脊线纬度位置与暖池SST相关系数达到0.46,通过置信度为95%显著性检验）。此时华东近海正处于副高控制,近海下沉运动增强,大气温度垂直剖面有普遍增温现象,10 m风场有偏北风异常,海面风速减小约占40 a平均风速的约30%;当暖池SST负异常时,副高东撤南退,华东近海冷空气活动加强,温度垂直剖面存在显著降温现象,华东近海风速增加占40 a平均风速的20%以上。本研究进一步说明了暖池SST异常是一个有效的预报因子,可用于华东近海海面风速预测预报。 相似文献
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蒸发波导模型常用来计算海上蒸发波导高度。为了认识当前不同蒸发波导模型之间的差异和方法,本文选取了目前使用广泛的4种蒸发波导模型(即P-J模型、Babin模型、NPS模型和伪折射率模型)进行对比和分析。本文首先探讨了在理想情况下它们对气象要素的敏感性,随后并利用我国南海近海大气层观测试验数据对比了这4种模型的蒸发波导高度计算结果。分析表明:相对湿度、风速和气—海温差的变化对4种模型的计算都有着较大的影响,特别是在不稳定层结状况下,4种模型计算得到的蒸发波导高度都随着相对湿度的增大而降低、随着风速的增大而增高。Babin模型和NPS模型计算的波导高度较为一致,伪折射率模型与前两种模型的计算结果存在差异,而P-J模型与其他3种模型存在较明显的偏差。基于南海气象数据的计算结果表明,不同蒸发波导模型在该海域蒸发波导的模拟结果略有不同,但4种模型计算得到的波导高度日变化变化趋势较为一致,波导高度极低值常出现在早晨,而极高值常出现在傍晚。 相似文献
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A suite of reservoir cores (oil sands) from a single well in Bohai Bay Basin, East China, displayed a progressive increase in petroleum biodegradation extent on the basis of bulk composition and 25-norhopane content. This fits with the proposal that subsurface petroleum biodegradation is dominantly an anaerobic process and usually occurs at the oil–water contact. It is likely that sequential microbial degradation of hydrocarbons under anoxic conditions does not occur in a true stepwise fashion, but is controlled by various factors such as concentration and solubility of hydrocarbons and their diffusion rate to the oil/water contact. In fact, 25-norhopanes were formed prior to the complete elimination of the acyclic, and mono- and bicyclic alkanes. An inverse response of the 22S/(22S + 22R) ratio between each extended 17α(H)-hopane and its corresponding 25-norhopane was observed as severe biodegradation occurred, supporting the proposal that the 25-norhopanes originate from demethylation of hopanes. Field observation revealed that biomarkers without extended alkyl side chains, such as oleanane, gammacerane and β-carotane, have significant resistance to biodegradation and can be used as naturally occurring “internal standards” to evaluate variations in other biomarkers. The results suggest that the quantity of 25-norhopanes showed a minor increase as the hopanes decreased significantly, i.e. only partial hopane conversion to the corresponding 25-norhopanes. Alternative degradation pathways for hopanes might occur in reservoirs, in addition to C-25 demethylation. 相似文献
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Secondary hydrocarbon generation potential from heavy oil, oil sand and solid bitumen during the artificial maturation 总被引：1，自引：0，他引：1
Secondary hydrocarbon generation potentials from natural bitumen, oil sand and heavy oil, representing different residual oil accumulations, were determined by artificial maturation in a closed pyrolysis system. Simulated results indicate that their thermal behavior and reactivity are similar to those of kerogen, and that they can generate hydrocarbons once subjected to suitable geological processes. Overall differences in oil and gas generation potentials among the samples result from differences in the chemical structure of precursor components, physical compaction status, and mineral matrices. Hydrogen rich precursors, such as oil sand and heavy oil, have greater potential to generate hydrocarbons than hydrogen poor ones. Naturally compacted oil sand has slightly higher conversion efficiency than artificially compacted heavy oil as indicated by lower residual bitumen content. However, total gas and liquid oil recovery from oil sand is lower than from heavy oil due to the poor release of pyrolytic products from well compacted and cemented networks in the experiments. Mineral matrices of previous oil deposits also affect further hydrocarbon generation potential. Carbonate matrices inhibit total oil and gas generation, which consequently retains high gas potential at the postmature stage. Traditional oil generation models mainly consider the thermal alteration of kerogen; this study provides supplemental information for superimposed basins where previous oil accumulations may have been destroyed and reburied to serve as secondary sources of oil and gas. Consideration of previous oil residues as potential source rock allows better estimates of available oil resources and the risks associated with their exploration. 相似文献
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Journal of Oceanology and Limnology - The Kuroshio Extension (KE) is one of the most eddy-energetic regions in the global ocean. However, most mesoscale eddy studies in the region are focused on... 相似文献
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一种由粗到精的机载激光测深信号检测方法 总被引：1，自引：1，他引：0
针对机载激光测深（airborne lidar bathymetry,ALB）中不同环境下波形的差异性较大,且信号检测精度受限于系统采样间隔等问题,提出一种由粗到精的机载激光测深信号检测方法。该方法首先利用接收波形的有效长度快速估计水深;粗检测依据水深近似值,分别采用理查德森-露西去卷积法（Richardson-Lucy deconvolution,RLD）和平均差方函数法（average square difference function,ASDF）对波形预处理,通过包含距离、导数和极值约束的逐级检测确定信号的初始位置;精检测以粗检测结果为初值,利用改进的二阶多项式指数函数模型,并在模型参数求解中引入信赖域优化算法以实现波形的精确拟合,进而获得信号的精确位置。实测数据和模拟数据的试验结果表明,粗检测能够根据波形的特点采取相应的处理方式为精检测提供可靠的初值;精检测可将检测结果精确至子采样间隔并在粗检测基础上进一步提高精度。与极大值检测、ASDF、RLD和四边形拟合法等传统方法相比,本文方法正确率平均提高10%左右,精度平均提高约30%。 相似文献