压力注浆液地下作用机理   总被引：1，自引：0，他引：1  

杨世忠  屠厚泽 《煤田地质与勘探》1997,25(4):39-42

介绍了压力注浆液的性能和要求;根据不同地质条件下注浆工艺的不同,建立了各自的数学模型;并在实践中得到应用和验证。   相似文献   

中国西部铂矿床类型与找矿方向探讨     

涂怀奎 《化工矿产地质》2004,26(4):220-227

中国铂矿资源严重不足,主要分布在中国西部,根据原生矿床特征可划分为4类：①硫化物型;②铬铁矿型;③辉石岩型;④层控型。寻找铂矿新类型和富铂(岩石)资源,应成为解决中国铂矿资源紧缺的重要任务。铂矿找矿方向：地台与地槽接合部位,特别是围绕着基性、超基性岩内外接触带,铂的预富集岩带与层控型铂矿带,另外还有砂铂型铂矿发育区有望扩大找铂前景。  相似文献   

地基GNSS遥感探测气象应用     

梁宏  曹云昌  梁静舒  万晓敏  赵盼盼  涂满红  王海深  胡姮 《中国地震》2020,36(4):744-755

全球导航卫星系统（GNSS）给定位、导航和授时服务带来了革命性变化,同时其L波段（1160～1610MHz）微波信号可用于全球覆盖、高时间分辨率的大气、海洋和陆表参数遥感探测。基于信号类型,GNSS遥感可分为折射信号遥感和反射信号遥感两大类;基于探测平台,GNSS遥感可分为地基GNSS遥感、空基GNSS遥感和天基GNSS遥感三大类。随着我国自主建设的北斗卫星导航系统全面建成,GNSS遥感将迎来新的发展机遇和挑战。本文回顾近20年地基GNSS遥感探测在气象领域的应用进展,展望其在气象领域下一步可能的应用。  相似文献   

Application of the radial basis function neural network to the short term prediction of the Earth’s polar motion     

Guocheng Wang  Lintao Liu  Yi Tu  Xueqing Xu  Yunbin Yuan  Min Song  Wenping Li 《Studia Geophysica et Geodaetica》2018,62(2):243-254

By a number of test cases using different sample numbers and sample lengths, we obtain a Radial Basis Function Neural Network (RBFNN) model that is suitable for the short-term forecast of polar motion, especially for the ultra-short-term forecast. By using the same data sample of Earth’s polar motion, this RBFNN model can achieve better short-term prediction accuracy than the least-squares+autoregressive (LS+AR) method, and better ultra-short-term prediction accuracy than the LS+AR+Kalman method. Using this model to forecast the polar motion data from January 1, 2002 to December 30, 2007 and from January 1, 2010 to December 30, 2016, respectively, experimental results show that the ultra-short-term forecast accuracy of this RBFNN model is within a precision of 3.15 and 3.08 milliseconds of arc (mas) in polar motion x direction, 2.02 and 2.04 mas in polar motion y direction; the short-term forecast accuracy of RBFNN model is within a precision of 8.83 and 8.69 mas in polar motion x direction, and 5.59 and 5.85 mas in polar motion y direction. As is stated above, this RBFNN model is well capable of forecasting the short-term of polar motion, especially the ultra-short-term.  相似文献   

Total organic carbon fluxes of the Red River system (Vietnam)   总被引：1，自引：0，他引：1       下载免费PDF全文

Thi Phuong Quynh Le  Viet Nga Dao  Emma Rochelle‐Newall  Josette Garnier  XiXi Lu  Gilles Billen  Thi Thuy Duong  Cuong Tu Ho  Henri Etcheber  Thi Mai Huong Nguyen  Thi Bich Ngoc Nguyen  Bich Thuy Nguyen  Nhu Da Le  Quoc Long Pham 《地球表面变化过程与地形》2017,42(9):1329-1341

Riverine transport of organic carbon from terrestrial ecosystems to the oceans plays an important role in the global carbon cycle. The Red River is located in Southeast Asia where river discharge, sediment loads and fluxes of elements (carbon, nitrogen and phosphorus) associated with suspended solids have been dramatically altered over past decades as a result of reservoir impoundment and land use, population, and climate change. Dissolved organic carbon (DOC) and particulate organic carbon (POC) concentrations were measured monthly at four stations of the Red River system from January 2008 to December 2010. The results reveal that POC changed synchronically with total suspended solids (TSS) concentration and with the river discharge, whereas no clear trend was observed for DOC concentration. The mean value of total organic carbon (TOC = DOC + POC) flux in the delta of the Red River was 31.5 × 10¹³ ± 4.0 × 10¹³ MgC.yr^?1 (range 27.9–35.8 × 10¹³ MgC.yr^?1 which leads to a specific TOC flux of 2012 ± 255 kgC.km^?2.yr^?1 during this 2008–2010 period. About 80% of the TOC flux was transferred to the estuary during the rainy season as a consequence of the higher river water discharge. The high mean value of the POC:Chl‐a ratio (1585 ± 870 mgC.mgChl‐a^?1) and the moderate C:N ratio (7.3 ± 0.1) in the water column system suggest that organic carbon in the Red River system is mainly derived from erosion and soil leaching in the basin. The effect of two new dam impoundments in the Red River was also observable with lower TOC fluxes in 2010 compared with 2008. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

生态遥感新锐——轻小型无人机的应用     

张菁  孙千惠  叶震  杨默含  赵晓霞  巨袁臻  胡天宇  郭庆华 《热带地理》2019,39(4):604-615

基于研究对象视角梳理轻小型无人机遥感手段在生态学研究中的应用现状,重点分析了无人机在不同生态对象应用的优势和局限：优势主要在于其能够高灵活性、高分辨率地获取各生态对象的数据,为较大规模的生态研究提供了便利。在农田生态系统应用中主要关注农田信息检测、自动化农作等方面,但在这方面的应用还比较单一,缺乏更深层更全面的系统化应用;在森林草地中主要关注植被结构参数提取、生物量反演等,在数据采集过程中应注意设备的稳定性避免对数据准确性造成影响;城市生态系统主要集中在城市环境监测和测绘方面,同时城市方面飞控政策尚待完善;水生生态系统主要关注水生动植物监测和潮间带观测等,大规模监测也对设备续航和数据标准化处理提出了要求;动物研究应用中主要关注动物迁徙规律、物种分布等方面,在监测过程中需注意不要对动物栖息造成干扰。总的来说,无人机应用局限主要在于其获取的数据处理尚未标准化,飞控政策尚未成熟和硬件续航等方面。在此基础上探讨了未来无人机遥感在生态学研究的应用趋势：随着无人机智能化的软硬件发展和云端生态大数据的建立,无人机数据的获取和处理将更加智慧化,多源的无人机遥感数据将会更好地服务于生态学研究。  相似文献   

海洋测绘地理空间数据模型(S-100)综述     

洛佳男  万晓霞  孙东礼  邬金  徐卫国  刘莉雯  段晶 《测绘通报》2019,(3):91-97,112

为全面了解当前海洋测绘地理信息空间数据模型的发展现状、存在问题和下一步研究重点,对海洋测绘地理信息空间数据模型展开了研究。通过搜集、整理当前与海洋测绘地理信息空间数据模型相关的国内外研究文献和技术材料,按照时间序列将研究划分为3个阶段。对理论性研究阶段和应用性研究阶段的研究成果进行了阐述和分析,提出了创新性研究阶段的7个重点研究方向。  相似文献   

QTL Detection for Albinism-Related Loci in Chinese Tongue Sole (<Emphasis Type="Italic">Cynoglossus semilaevis</Emphasis>)     

Yang Liu  Wenteng Xu  Bo Zhang  Changwei Shao  Xiaoxia Wang  Hejun Sun  Na Wang  Songlin Chen 《中国海洋大学学报(英文版)》2018,17(6):1404-1410

The Chinese tongue sole (Cynoglossus semilaevis) is widely cultured in the coastal region of East Asia and has excellent economic value. However, the high albino rate of the breeding population has caused a significant loss to the aquaculture industry. To study the molecular mechanism of albinism, the present study used an albino Chinese tongue sole family to construct three simple sequence repeat (SSR) linkage groups, and draft a preliminary linkage map related to albinism. After albinism-related loci mapping, 18 albinism-related loci were detected under two models (containing 2407 genes) compared to the Chinese tongue sole genome. One of these loci, the tyrosinase related protein (tyrp2), which has been reported previously as an important gene regulating both eumelanin and phaeomelanin levels, was indicated to be the possible cause of albinism. Thirty-five Gene Ontology (GO) terms and 14 Kyoto Encyclopedia of Genes and Genome pathways were annotated via bioinformatic analyses. One GO term with protein tyrosine kinase activity, which contained 10 genes, was previously suggested to affect fish albinism. These results establish a foundation for further in-depth study of albinism in Chinese tongue sole.  相似文献   

Basin-scale seawater lead isotopic character and its geological evolution indicated by Fe-Mn deposits in the SCS     

Xiaoxia Tu  Chonghui Wang  Qunhui Yang  Benduo Zhu 《Marine Georesources & Geotechnology》2020,38(7):876-886

Abstract

The geochemical characteristics and Pb isotope variations in Fe-Mn deposits collected from the South China Sea (SCS) were studied in this paper. The mineralogical and chemical composition data indicate that the deposits are almost all hydrogenetic in origin. Compared with the Fe-Mn deposits in other oceans, the SCS Fe-Mn deposits have a significantly higher Pb content because of higher material supply in addition to a lower growth rate of the deposits. Pb isotope ratios in the surface of the SCS Fe-Mn deposits are relatively uniform, with a characteristic of relatively lower ²⁰⁶Pb/²⁰⁴Pb ratio. The Pb isotopic compositions of the SCS Fe-Mn deposits are controlled by the Pacific Deep Water and local inputs, which include eolian dust from the Asian continent and weathering products from Taiwan, Luzon and SCS submarine volcanic rocks. The continuously increasing ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb ratios along the transect of nodule D581 over the past 3.5?Ma are affected by the stepwise closure of the Luzon Strait that reduced volcanic material supply and the deep current strengthen at the same time.  相似文献   

A simple and direct method to analyse the influences of sampling fractions on modelling intra-city human mobility     

Jincheng Jiang  Qingquan Li  Wei Tu  Shih-Lung Shaw 《International journal of geographical information science》2019,33(3):618-644

Sampling fraction is crucial to sampling-related studies and applications, especially in the big data era when most data are neither originally designed nor controllable in the data collection process. A common concern among researchers is ‘what’s the modelling accuracy when using a sample?’. Taking intra-city human mobility as the study objective, this study utilizes a simple and direct method to analyse the influences of various sampling fractions on modelling accuracy. Five common intra-city human mobility indicators (travel distance, travel time, travel frequency, radius of gyration and movement entropy) are evaluated considering mean value, median and probability distribution. Experimental results demonstrate that the representativeness of each considered indicator converges to 1 in its own unique rate and variances. The minimum required sampling fractions to satisfy specific accuracies differ for various indicators and evaluation measures. To further investigate how related factors influence the modelling accuracy of sampling fractions, additional experiments are conducted considering multiple sampling methods, study scopes, and data sources. Several interesting general findings are observed. This study provides a reference for other sampling-based applications.  相似文献