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41.
全井眼微电阻率成像(Fullbore Formation Micro Imager,FMI)技术广泛应用于强非均质性的碳酸盐岩储层测并精细解释.然而,由于各极板间间隙的影响,FMI无法测量360°全井壁地层电阻率信息,这使得FMI图像出现空白条带,严重影响了图像视觉和测井解释进程.为获取全井壁的电阻率信息,必须有效的填充空白条带.本文在探讨现有的电成像图像空白条带填充方法基础上,提出了一种基于卷积神经网络的电成像图像空白条带填充方法.与常用的Criminisi插值法对比填充效果显示:该方法完全适用于各种特征的电成像图像空白条带填充,延续了所有待填充边缘的暗色条带和亮色背景,填充结果与原始图像的像素值频率占比相关性高达0.9581.Criminisi插值法在复杂区域电成像图像的填充结果连通性较差且存在干扰区域,填充结果与原始图像的像素值频率占比相关性仅为0.5924.本文提出的方法具有处理速度快、干扰区域少、连通性强、相关性高的特点,能够满足电成像空白条带成规模填充的实际应用需求,还可为测量极板间的测量缺失带信息处理提供参考手段.  相似文献   
42.
风沙活动威胁着龙羊峡水库的安全运营,查清沙害来源和入库量对于防治水患和沙害具有重要意义。基于1987、1995、2003、2013、2019年的Landsat卫星影像,利用COSI-Corr技术监测了龙羊峡库区不同时空的沙丘移动特征,并重新评估库区近32 a的潜在风沙入库量。结果显示:(1)1987—2019年龙羊峡库区沙丘平均移动速率为5.81 m·a-1,呈先加速(1987—2003年)后减速(2003—2013年)再加速(2013—2019年)趋势;沙丘移动方向在132.81°—165.82°范围内,与该区主风向一致。(2)近32 a向龙羊峡水库输送的潜在风沙量可达7.82×107 m3(1.20×108 t)。上风向塔拉滩潜在输送量为7.38×107 m3(1.14×108 t),下风向木格滩仅贡献了0.44×107 m3(0.68×107 t)。(3)库区内风沙输移受风况、气候、植被等多种因素的影响,在未来全球变暖条件下,青藏高原的风沙活动将会持续发展,风沙入库量的长期累计效应将对水库安全构成严重威胁,必须引起足够重视。  相似文献   
43.
This study investigated the difference of nutrient composition in Caulerpa lentillifera collected from different regions.The nutrient compositions of C.lentillifera from China's Hainan and Shandong provinces were determined and compared with those from Semporna(Malaysia),Sabah(Malaysia),Petchburi(Thailand),and two other species of seaweeds(Malaysia).The results showed that the polysaccharide and protein contents of C.lentillifera from Hainan(44.82%±0.98%and 12.5%±0.70%),Shandong(43.22%±1.42%and 14.7%±0.72%),Petchburi(59.27%±2.31%and 12.49%±0.30%),and Sabah(44.02%±2.01%and 19.38%±1.48%)were higher than those of Eucheuma cottonii(26.49%±3.01%and 9.76%±1.33%)and Sargassum polycystum(33.49%±1.70%and 5.40%±0.07%),respectively.The polyunsaturated fatty acid contents in C.lentillifera from Hainan(29.98%)and Shandong(22.11%)were higher than that in Semporna(16.76%±0.27%),Sabah(9.49%),and S.polycystum(20.34%±0.43%),but lower than that in E.cottonii(51.55%±0.57%).In Caulerpa lentillifera of Hainan and Shandong provinces,the essential amino acid(EAA)/total amino acid(TAA)ratios were 35.22%and 38.78%,respectively;and the EAA/ETAA ratios were 54.36%and 63.35%,respectively.The EAA composition of C.lentillifera was close to the ideal model of Food and Agriculture Organization/World Health Organization.C.lentillifera was rich in mineral elements,including calcium((3315.85±127.55)mg(100 g)^-1 and(3728.35±92.38)mg(100 g)^-1),magnesium((6715.74±82.58)mg(100 g)^-1 and(8128.59±242.72)mg(100 g)^-1),and trace elements,including iron((510.65±5.47)mg(100 g)^-1 and(1972.97±183.35)mg(100 g)^-1),selenium((1.04±0.08)mg(100 g)^-1 and(0.83±0.15)mg(100 g)^-1),and zinc((33.90±0.13)mg(100 g)^-1 and(11.75±2.05)mg(100 g)^-1).These results showed that C.lentillifera was more nutritious than S.polycystum or E.cottonii in terms of polysaccharide,protein,and fatty acid contents.Furthermore,both C.lentillifera species collected from Hainan and Shandong provinces show more basic nutrients.Therefore,C.lentillifera has important development and application prospects.  相似文献   
44.
本研究对比分析了不同气候态下,华北冬、夏季降水及气温的差异,分析了气候平均值的改变对历史极端事件监测的可能影响。研究结果发现,1991~2020年(简称气候Ⅱ态)的冬季和夏季的平均降水量均略多于1981~2010年(简称气候Ⅰ态),但接近或略少于1961~2020年的平均降水量,平均降水量逐年变化幅度冬季Ⅱ态小于Ⅰ态,夏季反之。气候Ⅱ态冬季降水空间分布不均,夏季较Ⅰ态呈“中部减少,东西增加”的分布型。冬季和夏季极端降水阈值Ⅱ态(0.86 mm和22.0 mm)较Ⅰ态(0.83 mm和21.6 mm)均略有提高,造成近60年华北大部基于Ⅱ态阈值的冬、夏季极端降水日数较Ⅰ态略减少。此外,气候Ⅱ态的华北冬、夏季平均气温均明显高于Ⅰ态,也高于1961~2020年平均值。Ⅱ态气温较Ⅰ态基本呈全区增加特征,但空间分布不均匀。冬季极端低温和夏季极端高温阈值Ⅱ态(-9.8°C和27.9°C)较Ⅰ态(-10.2°C和27.5°C)均有所有所提高,造成华北大部分地区基于Ⅱ态阈值的近60年冬季极端低温日数较Ⅰ态有所增加,夏季极端高温日数较Ⅰ态存在不同程度的减少。因此,新气候态下华北气温和降水均值,华北大部极...  相似文献   
45.
Sun  Zhaoyan  Wang  Xinlong  Feng  Shaojun  Che  Huan  Zhang  Jinpeng 《GPS Solutions》2017,21(2):701-713
GPS Solutions - In vector tracking loop (VTL), the relativity among received signals is exploited to deeply integrate the entire information within signal processing channels. However, the tracking...  相似文献   
46.
车冰清  朱传耿  李敏 《地理科学》2017,37(12):1867-1874
以江苏省为研究对象,基于网络平台的银行网点地理数据,运用最近邻指数、Ripley’s K函数以及多元线性回归等分析方法,分别对五大商业银行、农业金融机构、中小商业银行、江苏地方银行以及外资银行的空间分布特征进行探讨,并揭示不同类型银行网点区位选择的影响因素。研究结果:整体上,江苏省银行网点空间偏向分布差异明显“南多北少”,空间集聚特征显著“城区密集分布和外围分散分布”;不同类型银行由于功能和市场定位的不同,除在城区密集分布的共性外,在城市外围区域的分布密度和服务范围存在较大差异。城市建成区面积、人口规模、人均地区生产总值、规模以上工业企业数量、城镇化率、二三产业产值比重是影响银行网点区位选择的主要因素,但对不同类型银行网点分布的影响程度不同。五大商业银行网点分布倾向于人口规模大、城镇化率高的城市,农业金融机构网点更依赖于农业人口因素,中小商业银行网点偏爱二三产业发达的区域,规模以上工业企业数量对江苏地方银行网点的布局具有显著影响,外资银行主要分布在对外开放程度高和国外资本输入较多的城市。城市行政级别和城市性质等制度因素对农业金融机构、外资银行网点区位选择的影响作用较强。  相似文献   
47.
Unimpeded trade is one of the cooperation priorities in the Belt and Road Initiative proposed by China. On 15 May 2017, the Joint Communique of the Leaders Roundtable of the Belt and Road Forum for International Cooperation reaffirmed the participants’ shared commitment to build an open economy and ensure free and inclusive trade. The Belt and Road Initiative (BRI) is not only China's new action to drive its open and global development, but also a platform for an increasing number of countries to explore free and inclusive trade and promote a universal, rule-based, open, non-discriminatory, and equitable multilateral trade system. It is therefore important to examine the topological relationship between the BRI and global trade networks. More specifically, this article first analyzes the community structure of trade networks using a community detection algorithm, and then estimates the topological relationship between different trade communities. The findings of this article are as follows. First, this research identified three trade communities and two sub-communities in the BRI trade network, in which China is the core, Russia is the sub-core of the biggest trade community, and India, United Arab Emirates, and Saudi Arabia are cores of the second trade community (South Asia-West Asia). Second, it identified five trade communities in the global trade network, centred on China, USA, Russia, India-United Arab Emirates, and Germany- Netherlands-France-Britain and other European developed countries. Third, the topological analysis indicated that in the global trade network, most BRI countries are attracted by the core nodes of the BRI regions, such as the China, Russia and India-United Arab Emirates core nodes, and have strong trade contacts with BRI countries. Most Central-East European countries are mainly attracted by Germany-Netherlands-France-Britain and other developed European countries with a low penetration of BRI trade. Although some Southeast Asian countries are incorporated into the Asia-Australia-South Africa community with China as the core, they still need to strengthen trade linkages with BRI countries.  相似文献   
48.
车云飞  房文  李宏宇  李德泉 《气象科技》2018,46(5):1044-1049
本研究以物联网技术为基础,利用条码、二维码和射频电子标签标识、射频扫码技术、声光电自动感应技术、GPS/GIS技术进行信息采集,建立人工影响天气装备弹药物联网管理系统,实现人工影响天气装备弹药从生产、验收、转运、仓储到发射作业的全程监控。在北京、陕西、贵州、河南4个地区进行试点开发研究,根据有源/无源射频识别(RFID)、二维码/条形码、火箭弹/高炮炮弹以及信息采集技术分别开展不同技术模式的应用试验,将弹药信息按照统一格式汇集至国家级物联网系统,有效提高了全国人工影响天气装备弹药信息采集的准确性和时效性,并结合有效传感器、无线通信技术,解决了大范围内的作业数据自动化采集及地面作业信息实时监控,提高人工影响天气作业安全管理的科技水平和业务信息化现代化程度,对全国开展人工影响天气装备物联网建设工作具有较强的参考价值。  相似文献   
49.
Concentration of 7 heavy metals, Zn, Fe, Cu, Cr, Cd, Pb and Ni in mudflat sediments, mangrove root sediments and root tissues of Acanthus ilicifolius, Aegicerus corniculatum and Kandelia candel from the Mai Po Nature Reserve, Northwest Hong Kong, were measured. Metal concentrations in the upper 0–10 cm of the sediment cores from the mudflat were 4–25% higher than those found in the bottom 21–30 cm. Relative Topsoil Enrichment Index approximated 1.0 for all the metals. Mudflat sediment concentrations of Fe, Ni, Cr, Cd and Cu were greater than those found in the mangrove sediments. Except for Fe, concentrations of the other 6 heavy metals were more elevated in the mangrove root sediments than in the corresponding root samples. Higher concentration factors for Zn, Fe and Cu may indicate bioaccumulation. Mean metal concentrations in both mudflat and mangrove sediments decreased in the order Fe > Zn > Pb > Ni > Cu > Cr > Cd. Mangrove root tissues also showed the same pattern except that Pb > Cu > Ni  相似文献   
50.
The Dansgaard-Oeschger event 4(DO4 event) is a significant warming event that occurred in the late Marine Isotope Stage 3. At present,there are different understandings about the detailed characteristics and internal structures of the DO4 event. Based on 6 precisely-dated 230Th ages and 188 oxygen isotope data of a stalagmite(No.XYⅢ-28)from the Xianyun Cave,Fujian Province,we present δ18O time series with an average resolution of 7 yr from 29.13 to 27.94 kyr B.P. Our new stalagmites δ18O records uncover the detailed processes of the DO4 event. The onset and end time of the DO4 event recorded by the stalagmite δ18O is 28.83±0.06 and 28.46±0.06 kyr B.P.,respectively, and the duration is 0.37±0.06 kyr. Differential with abrupt change of NGRIP ice core δ18O record at the onset of DO4 based on the GICC05 layer count time scale,the Xianyun Cave δ18O shows a relatively slow change. The Xianyun stalagmite δ18O values negatively shift by 0.4‰ within 145±60 yr,which indicates that the Xianyun Cave was likely affected by the ocean-atmosphere coupling of the tropical. In addition,the Xianyun stalagmite δ18O reveals a series of sub-million-scale summer monsoon enhancement events in and around the DO4 event,corresponding to the NGRIP ice core δ18O record and the Arabian Sea basin record. Our results suggest that the East Asian summer monsoon is related to the north-high latitude temperature and the ITCZ position changes on the sub-millennium-scale event.  相似文献   
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