结合糙率校正的河网水情数据同化     

陈一帆  程海洋  万晓丽  方华建 《水科学进展》2015,26(5):731-738

为解决河网水动力模型重要参数糙率与水力状态量水位、流量的同步校正问题,以糙率和水力状态量作为河网非线性动态系统变量,采用扩展卡尔曼滤波,构建结合糙率动态校正的河网水情数据同化模型.通过算例计算,系统分析了水位动态噪声水平、糙率动态噪声水平、糙率初始值及测站个数对模型校正的影响.结果表明:模型能够有效用于水位状态量的实时校正;靠近测站的糙率校正值趋于真值,远离测站的糙率校正值趋于初始值;通过调整糙率动态噪声水平,可以有效控制糙率的修正量,防止糙率修正过大而引起计算失效问题.  相似文献   

Geochemistry of subducted metabasites exhumed from the Mariana forearc: Implications for Pacific seamount subduction     

Jianghong Deng  Lipeng Zhang  He Liu  Haiyang Liu  Renqiang Liao  Abdul Shakoor Mastoi  Xiaoyong Yang  Weidong Sun 《地学前缘(英文版)》2021,12(3):101117

Seamounts on the drifting oceanic crust are inevitably carried by plate motions and eventually accreted or subducted. However, the geochemical signatures of the subducted seamounts and the significance of seamount subduction are not well constrained. Hundreds of seamounts have subducted beneath the Philippine Sea Plate following the westward subduction of the Pacific Plate since the Eocene (~52 Ma). The subducted oceanic crust and seamount materials can be exhumed from the mantle depth to the seafloor in the Mariana forearc region by serpentinite mud volcanoes, providing exceptional opportunities to directly study the subducted oceanic crust and seamounts. The International Ocean Discovery Program (IODP) expedition 366 has recovered a few metamorphosed mafic clasts exhumed from the Mariana forearc serpentinite mud volcanoes, e.g., the Fantangisña and Asùt Tesoru seamounts. These mafic clasts have tholeiitic to alkaline affinities with distinct trace elements and Nd-Hf isotopes characteristics, suggesting different provenances and mantle sources. The tholeiites from the Fantangisña Seamount have trace element characteristics typical of mid-ocean ridge basalt. The Pacific-type Hf-Nd isotopic compositions, combined with the greenschist metamorphism of these tholeiites further suggest that they came from the subducted Pacific oceanic crust. The alkali basalts-dolerites from the Fantangisña and Asùt Tesoru seamounts show ocean island basalt (OIB)-like geochemical characteristics. The OIB-like geochemical signatures and the low-grade metamorphism of these alkali basalts-dolerites suggest they came from subducted seamounts that originally formed in an intraplate setting on the Pacific Plate. The Pacific Plate origin of these metabasites suggests they were formed in the Early Cretaceous or earlier.Two types of OIBs have been recognized from alkali metabasites, one of which is geochemically similar to the HIMU-EMI-type OIBs from the West Pacific Seamount Province, and another is similar to the EMII-type OIBs from the Samoa Island in southern Pacific, with negative Nb-Ta-Ti anomalies and enriched Nd-Hf isotopes. Generally, these alkali metabasites are sourced from the heterogeneous mantle sources that are similar to the present South Pacific Isotopic and Thermal Anomaly. This study provides direct evidence for seamount subduction in the Mariana convergent margins. We suggest seamount subduction is significant to element cycling, mantle heterogeneity, and mantle oxidation in subduction zones.  相似文献   

The spatial configuration of innovation networks in China     

Guoqing Lyu  Ingo Liefner 《GeoJournal》2018,83(6):1393-1410

China is rising and gradually developing into an innovation-oriented economy. This transition is fueled by public and private investment in education and by increasing inputs into science and technology. Little attention, however, has been paid to the great differences in China-specific context peculiarity. Hence, the paper assesses Chinese innovation networks using a comprehensive analytical model that includes network configuration, regional environment, government interference and firm attributes. The empirical analysis examines China’s machinery manufacturing industry to test the determinants of the spatial character of Chinese innovation networks based on questionnaire surveys and illustrative cases. Our study finds that Chinese innovation networks are affected not only by innovation resource endowments and firm attributes, but also by government interference and regional culture. Regarding the influence of regional culture, the typical Northern culture with the importance of guanxi plays an important role in the process of searching for partners and makes the innovation network and interpersonal network interwoven. Firms’ ownership and innovation ability are the two essential variables to determine whether any of the regional elements are of significance.  相似文献   

地电化学法在豫西崤山黄土覆盖区找矿中的应用——以洛宁县石龙山预查区为例     

杨笑笑  罗先熔  文美兰  欧阳菲  吕星海  尹高科  郑广明 《物探与化探》2019,(2):244-256

豫西崤山北部沟壑纵横,第四系黄土广泛覆盖,地表植被发育。为探讨地电化学法在豫西崤山黄土覆盖区寻找金矿的有效性,选择了隐伏于黄土下的石寨沟金矿开展找矿可行性试验,并在其邻区石龙山金多金属矿预查区南部开展地电化学找矿研究。研究发现,石寨沟Au矿床上部发育地电化学综合异常,异常规律明显,元素相关性较好,具有很好的套合和分带关系。对石龙山预查区地电提取的微量元素含量特征(分形、变异系数、地电提取比)进行分析,发现其与石寨沟Au矿床具有相近的地电异常规律。进一步利用Surfer软件绘制等值线异常图,结合前人研究成果在异常套合较好的02号线45～47测点初步经过地表工程验证,确定了一条品位较好的工业金矿体,侧面证明实测、推测断层F1-1和F20确实存在。该成果为石龙山地区深部及石寨沟矿床外围找矿提供地电化学理论基础,也为崤山黄土覆盖区找矿提供了新的思路。  相似文献   

地勘时期煤层瓦斯与煤层气测试标准对比研究     

潘海洋  程爱国  赵欣  殷榕蔚  陈美英 《中国煤炭地质》2019,(4):30-34

基于现行的煤层瓦斯与煤层气测试标准,从适用范围、采样要求、仪器设备、解吸过程、残留气获取、损失气计算6个方面对比了煤层气、煤层瓦斯测试标准存在的差异,并从损失气、解吸气、残余气等三个方面分析了煤层气(煤层瓦斯)测试标准差异对测试结果的影响。分析结果表明损失气量是影响煤层气(煤层瓦斯)结果准确性的关键因素,但其受采样工艺影响较大,建议通过统一选择绳索取心工艺增加煤层瓦斯测试精度。  相似文献   

南京新近沉积土最大动剪切模量试验研究     

庄海洋  陈国兴  朱定华  胡庆兴 《世界地震工程》2010,(Z1)

使用自行研制的GZZ-1型共振柱试验机对南京及其邻近地区漫滩相成因的淤泥质粉质粘土、粉质粘土、粘土、粉土、互层土和粉细砂等新近沉积土进行了大量的共振柱试验研究。给出了各类土的最大剪切模量试验结果;采用经验公式对各类土的Gmax/Pa~σ0′/Pa关系曲线进行了拟合,给出了各类土的最大剪切模量经验计算公式中各个拟合参数的参考值。同时,总结了拟合参数的参考值随粘性土的液性状态或砂性土的密实度变化而变化的规律。  相似文献   

Effect of cyanobacteria extract on some associated enzymes in mouse liver <Emphasis Type="Italic">in vivo</Emphasis>     

陈建中  刘志礼  周国庆  韩志萍  张海洋  张易祥 《中国海洋湖沼学报》2010,28(6):1180-1186

Blooms of toxin-producing cyanobacteria have become increasingly common in the surface water of the world. In this study, we studied the dose- and time-dependent effects of a microcystin (MC) extract of cyanobacteria from Dianchi Lake in China on liver weight/body weight ratio and superoxide dismutase (SOD), lactate dehydrogenase (LDH) and glutathione peroxidase (GSH-Px) activities in mouse liver. We found that exposure to the cyanobacterial extract (CE) resulted in increase in liver weight/body weight ratio in a dose-dependent manner, and the mouse liver reached the maximum size at 1 h post-exposure (pe). SOD activity in mouse liver decreased in a dose-dependent manner, and time course study indicated that it decreased significantly at 1 and 2 h pe, and resumed at 3 h pe as compared to control. CE caused LDH activity in the livers of mice to decrease in a dose- and time-dependent manner except a small increase in 30 min pe mice. GSH-Px activity increased in a dose-dependent manner, and was higher than that in the control over the 3 h observation period. The present findings suggest that oxidative damage may be involved in the toxicity of microcystins on mouse.  相似文献   

Analysis of new microsatellite markers developed from reported sequences of Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis>     

Haiyang Yu  Liming Jiang  Wei Chen  Xubo Wang  Zhigang Wang  Quanqi Zhang 《中国海洋大学学报(英文版)》2010,9(4):365-370

The expressed sequence tags (ESTs) of Japanese flounder, Paralichthys olivaceus, were selected from GenBank to identify simple sequence repeats (SSRs) or microsatellites. A bioinformatic analysis of 11111 ESTs identified 751 SSR-containing ESTs, including 440 dinucleotide, 254 trinucleotide, 53 tetranucleotide, 95 pentanucleotide and 40 hexanucleotide microsatellites respectively. The CA/TG and GA/TC repeats were the most abundant microsatellites. AT-rich types were predominant among trinucleotide and tetranucleotide microsatellites. PCR primers were designed to amplify 10 identified microsatellites loci. The PCR results from eight pairs of primers showed polymorphisms in wild populations. In 30 wild individuals, the mean observed and expected heterozygosities of these 8 polymorphic SSRs were 0.71 and 0.83 respectively and the average PIC value was 0.8. These microsatellite markers should prove to be a useful addition to the microsatellite markers that are now available for this species.  相似文献   

人工回灌过程中的水-岩相互作用模拟     

石旭飞  张文静  王寒梅  焦珣  何海洋 《吉林大学学报(地球科学版)》2013,43(1):220-227,234

人工回灌过程中所发生的水-岩相互作用是影响回灌层位地下水环境质量的重要因素。采用室内实验和水文地球化学模拟等技术对人工回灌过程中的水-岩相互作用机理进行了分析。研究结果表明：受混合作用影响,随着回灌水比例的增加,混合水中TDS质量浓度降低,水化学类型由Cl·HCO₃-Na型水逐渐转变为HCO₃·Cl-Na·Ca型水;受水-岩作用影响,在同一混合比例条件下,随着水-岩作用的进行,混合水中TDS质量浓度升高,各主要离子质量浓度呈现升高的趋势,但只有回灌水比例占10%时,混合水TDS质量浓度才大于原始地下水（涨幅约5%）。实验介质溶解于水的离子中,Ca²⁺、Mg²⁺和HCO^-₃主要来源于碳酸盐矿物的溶解, Na⁺主要来自岩盐的溶解。在人工回灌过程中,发生的水-岩相互作用主要包括方解石、白云石、钾长石、岩盐、CO₂的溶解和伊利石的沉淀。其中:钾长石溶解量与伊利石沉淀量、碳酸盐矿物溶解量与CO₂溶解量的相关性较强,其相关系数分别为1.00和0.78（显著性水平为0.05）;硅酸盐矿物反应量和回灌水比例之间的相关系数为0.97（显著性水平为0.01）,相关性极强;而碳酸盐矿物反应量和回灌水比例之间的相关系数为0.52（显著性水平为0.01）,相关性较弱。上述相关性分析为确定人工回灌过程中的水-岩相互作用机理、地下水中主要离子组分的来源途径以及定量分析人工回灌对含水层介质的影响提供了依据。  相似文献   

自适应的IDW插值方法及其在气温场中的应用   总被引：3，自引：0，他引：3  

段平  盛业华  李佳  吕海洋  张思阳 《地理研究》2014,33(8):1417-1426

反距离权重(Inverse Distance Weighting,IDW)插值通常采用距离搜索策略选择插值参考点,当采样点集分布不均匀时,距离搜索策略使得参考点聚集一侧影响插值精度。自然邻近关系具有良好的自适应分布特性,可有效地解决参考点分布不均匀问题。结合自然邻近关系,提出自适应的反距离权重(Adaptive-IDW,AIDW)插值方法。首先对采样数据构建初始Delaunay三角网,然后采用逐点插入法,将待插值点插入初始Delaunay三角网中,局部调整得到新的Delaunay三角网,以待插值点的一阶邻近点作为IDW插值的参考点,使参考点自适应均匀地分布在待插值点周围,再进行IDW插值计算。利用AIDW插值方法对Franke函数、全国气温观测数据进行插值实验,结果表明此方法具有较高的精度,且减少了“牛眼”现象。  相似文献