黔北正安地区五峰组—龙马溪组页岩气地质特征及有利区预测     

贺永忠  向坤鹏  安亚运  易成兴  杨忠琴  于宁 《中国地质调查》2020,7(3):21-29

为明确黔北正安地区上奥陶统五峰组至下志留统龙马溪组的页岩气地质特征,充分应用页岩气地质调查、重磁电、二维地震、地质调查井及测试分析等工作方法,开展黔北正安地区1:5万页岩气基础地质调查,对五峰组至龙马溪组富有机质页岩的分布、沉积环境、有机地球化学、岩石矿物、储集性能及含气性等特征进行分析研究,结果表明: 研究区五峰组—龙马溪组富有机质页岩为深水陆棚相沉积,主要分布有安场向斜、斑竹向斜和泥高向斜,厚度14.5~55 m,埋深0~3 200 m; 有机碳(TOC)含量1.0%~4.0%,有机质镜质体反射率(R_o)为1.82%~2.23%,有机质类型以Ⅰ型干酪根为主; 岩石主要由石英、长石和黏土矿物组成,脆性矿物含量高,一般大于50%; 孔隙度为2.03%~3.89%,渗透率为0.35×10^-5~1.86×10^-5μm²,表现为低孔、特低渗的特征; 最高含气量为2.88 m³/t,显示出较好的含气性特征。综合分析和评价圈出3个页岩气聚集有利区,分别为安场区块、斑竹区块和泥高区块,这为研究区页岩气进一步勘探开发指明了方向。  相似文献   

福建省复杂地形下旬平均气温分布式模拟     

李威鹏  邱新法  曾燕  施国萍  徐金勤  王丹丹 《热带地理》2019,39(2):229-236

为建立高时空分辨率的福建省复杂地形下气温栅格数据集，利用福建省及其周边33个常规气象站观测资料，基于数字高程模型（DEM）数据，综合考虑海拔、太阳总辐射、地表长波有效辐射对旬平均气温的影响，模拟了福建省复杂地形下旬均温的空间分布。结果表明：1）常规站验证结果显示：各旬气温绝对误差平均值（MAE）最小为0.46℃，最大为2.3℃，全年平均为0.87℃；加密站验证结果显示，MAE最大为2.3℃，最小0.5℃，全年平均为0.96℃。2）模拟结果能反映旬均温的宏观分布规律与局地细节特征。宏观范围内，旬均温受纬度影响较大，由北至南气温逐渐升高，沿海地区旬均温整体高于内陆，山区旬均温明显较低；局地范围内，各坡向上气温差异显著，海拔越高、坡度越大，差异越明显；地形因子对旬平均温的影响具有季节差异，具体表现为冬季时地形因子对旬均温的影响最大，秋季次之，春夏季节中地形因子对旬均温的影响最弱。  相似文献   

Pricing Weather Derivatives Index based on Temperature: The Case of Bahir Dar,Ethiopia     

Tesfahun BERHANE  Aemiro SHIBABAW  Gurju AWGICHEW 《资源与生态学报(英文版)》2019,10(4):415-423

In this paper we present a stochastic model for daily average temperature to calculate the temperature indices upon which temperature-based derivatives are written. We propose a seasonal mean and volatility model that describes the daily average temperature behavior using the mean-reverting Ornstein-Uhlenbeck process. We also use higher order continuous-time autoregressive process with lag 3 for modeling the time evolution of the temperatures after removing trend and seasonality. Our model is fitted to 11 years of data recorded, in the period 1 January 2005 to 31 December 2015, Bahir Dar, Ethiopia, obtained from Ethiopia National Meteorological Services Agency. The analytical approximation formulas are used to price heating degree days (HDD) and cooling degree days (CDD) futures. The suggested model is analytically tractable for derivation of explicit prices for CDD and HDD futures and option. The price of the CDD future is calculated, using analytical approximation formulas. Numerical examples are presented to indicate the accuracy of the method. The results show that our model performs better to predict CDD indices.  相似文献   

三个台风对我国东部沿海风电的联合影响     

吕海滨  刘昱君  顾鹏  赵星宇  陆银娟 《海洋科学》2019,43(9):72-77

基于CCMP(cross-calibrated multi-platform)再分析风场数据,研究了9907号, 9908号和9909号3个台风对中国沿海5个风电场的影响,分别从台风的形成以及路径,对沿海风电场风速的影响,台风期间的发电情况等详细地描述了台风对风电机组的影响。发现:台风对5个海上风电场的影响可以分为3个阶段,第一阶段是1999年8月1—4日,输出功率由南向北依次降低,此时主要受9907号台风的影响;第二阶段是8月6—9日,8月6日也呈现输出功率由南向北降低,主要是9909号台风由南海途径台湾海峡即将进入东海的影响;受9908号台风影响, 8月7日最大输出功率出现在S3风机。8月8日,受9908和9909号台风的叠加影响, S4风机的输出功率达到15天的最大值38.4 MW。第三个阶段是8月12—15日,受大气锋面的影响, S1—S5输出功率呈现波动。台风过境期间提高了各站点的运营能力和部分站点的额定容量,未对风电机组产生大的破坏。研究成果可为相关部门在台风期间海洋风力发电的决策提供参考。  相似文献   

近20年渤海叶绿素a浓度时空变化   总被引：3，自引：0，他引：3  

田洪阵  刘沁萍  Joaquim I. Goes  Helga do Rosario Gomes  杨萌萌 《海洋学报》2019,41(8):131-140

浮游植物作为食物链的基础，对海洋生态系统具有重要作用。渤海作为我国最大的内海和重要渔业生物的产卵场、育幼场和索饵场，该区浮游植物研究具有重要意义。叶绿素a浓度是反映浮游植物生物量的重要指标。利用Google Earth Engine平台，对1997–2010年的宽视场海洋观测传感器(SeaWiFS)叶绿素a浓度数据和2002–2018年的水色卫星中分辨率成像光谱仪传感器(MODIS Aqua)叶绿素a浓度数据进行合并，并研究其时空变化特征。研究表明，近20年来，渤海全年叶绿素a浓度增加了14.1%，且增加显著。叶绿素a浓度在所有季节都呈现增加趋势；除11月外，其他各月都呈现稳定或增加趋势。从滦河入河口沿岸至渤海海峡的渤海中部，叶绿素a浓度增加较明显。同时也分析了海洋表面温度、风速和降水量数据。夏季渤海周边区域降水量和风速增加以及秋季海表温度的降低都有助于同季叶绿素a浓度的升高。渤海浮游植物可能受陆源营养物质输入影响较大。  相似文献   

GNSS精密轨道产品不连续性分析及评估     

董志华  陈俊平  周旭华 《天文学报》2019,60(5):44-54

按照目前的国际规范, 高精度GNSS (Global Navigation Satellite System)轨道产品一般以天为周期进行发布, 提供给用户使用. 连续使用多天的产品存在不同天间的跳变问题. 利用德国地学研究中心(GFZ)、欧洲定轨中心(COD)、欧空局(ESA)、美国喷气试验室(JPL)以及上海天文台(SHA)共5个GNSS分析中心2013---2017年的轨道产品, 分析了轨道跳变的特性. 计算结果表明: GFZ、COD、ESA、SHA和JPL的3维轨道跳变平均分别为7.79cm、1.51cm、7.77cm、11.75cm和2.51cm. 轨道跳变序列的周期特性分析表明: 序列存在90d、120d、340d左右的显著周期项, 对应于海潮对地球自转的影响, 其振幅为数毫米至1cm左右. 表明精密轨道确定需要进一步精化该项模型; GPS的跳变序列还存在与卫星星座相关的175d和352d左右的交点年显著周期项. 此外, 针对COD产品外推轨道的分析, 验证了地球反照辐射压和太阳光压模型等动力学模型对轨道的差异.  相似文献   

Multi-band Solar Full-disk Extreme Ultraviolet Imager     

PENG Ji-long  FENG Tao-jun  SHI En-tao  LI Lin  YU Qian  ZHANG Kai  NIE Xiang-yu  MA Zi-liang 《Chinese Astronomy and Astrophysics》2019,43(3):444-456

Solar Extreme Ultraviolet (EUV) imaging observation is an important measure for the researches of solar activities and coronal plasma physics. But the traditional EUV imager and spectrograph can hardly achieve simultaneously the high spectral resolution and wide field-of-view of solar imaging. This paper has designed a new type of solar EUV multi-band imager, by adopting a kind of slitless grating and grazing incidence structure, it can realize the solar full-disk imaging of high spectral and spatial resolution. The field-of-view of the imager can be as broad as 47′. The spectral resolution is 2×10^?3nm per pixel, and the spatial resolution is 1.4′ per pixel. The temporal resolution of the solar full-disk is better than 60 s. The analysis of the solar full-disk spectral image and system response shows that the imager can observe the morphological evolutions of various solar activities, and can provide more comprehensive data for the researches of solar physics and space weather forecast.  相似文献   

Dynamic modeling and vibration suppression for an offshore wind turbine with a tuned mass damper in floating platform     

《Applied Ocean Research》2019

The worldwide demand for renewable energy is increasing rapidly. Wind energy appears as a good solution to copy with the energy shortage situation. In recent years, offshore wind energy has become an attractive option due to the increasing development of the multitudinous offshore wind turbines. Because of the unstable vibration for the barge-type offshore wind turbine in various maritime conditions, an ameliorative method incorporating a tuned mass damper (TMD) in offshore wind turbine platform is proposed to demonstrate the improvement of the structural dynamic performance in this investigation. The Lagrange's equations are applied to establish a limited degree-of-freedom (DOF) mathematical model for the barge-type offshore wind turbine. The objective function is defined as the suppression rate of the standard deviation for the tower top deflection due to the fact that the tower top deflection is essential to the tower bottom fatigue loads, then frequency tuning method and genetic algorithm (GA) are employed respectively to obtain the globally optimum TMD design parameters using this objective function. Numerical simulations based on FAST have been carried out in typical load cases in order to evaluate the effect of the passive control system. The need to prevent the platform mass increasing obviously has become apparent due to the installation of a heavy TMD in the barge-type platform. In this case, partial ballast is substituted for the equal mass of the tuned mass damper, and then the vibration mitigation is simulated in five typical load cases. The results show that the passive control can improve the dynamic responses of the barge-type wind turbine by placing a TMD in the floating platform. Through replacing partial ballast with a uniform mass of the tuned mass damper, a significant reduction of the dynamic response is also observed in simulation results for the barge-type floating structure.  相似文献   

Characterization of complex groundwater flows in the environment of singular buildings by combining hydrogeological and non-destructive geophysical (ground-penetrating radar) techniques: Punta Begoña Galleries (Getxo,Spain)     

Jesus A. Uriarte  Laura Damas Mollá  Maialen Sagarna  Arantza Aranburu  Francisco García  Iñaki Antigüedad  Tomás Morales 《水文研究》2020,34(4):1004-1015

Locating and quantifying groundwater flow in many built-up areas are a priority with regard to its complete restoration. In this work, a hydrogeological survey of the surroundings of the Punta Begoña Galleries (Getxo, Bizkaia), built on a coastal cliff, was completed by using ground penetrating radar (GPR) testing. Thus, the preliminary characterization of soils and rocks in accessible areas of the cliff was first improved by hydrogeological information gathered from a single survey borehole, including permeability measurements by low pressure injection tests (LPTs) and continuous water level monitoring. As a complementary method, the non-destructive GPR technique was performed during both dry and wet hydrological periods and in tandem with the injection tests, providing more complete spatial and temporal images of water flows. Specifically, GPR allows mapping of flow paths in soils and assessing the continuity of fractures in rock masses. Altogether, this complementary approach provides greater knowledge of complex underground flow dynamics in built environments, thus making it easier to make decisions for their management.  相似文献   

Snowpack disrupts relationship between young water fraction and isotope amplitude ratio; approximately one fifth of mountain streamflow less than one year old     

Éowyn M. S. Campbell  Igor Pavlovskii  M. Cathryn Ryan 《水文研究》2020,34(25):4762-4775

Previous “fraction of young water” (F_yw) estimates based on relative annual isotopic amplitudes in precipitation (A_p) and streamflow (A_s) produced low F_yw values in mountain catchments, which is contrary to extensive research that reports rapid water transmission in mountains. This study investigated this discrepancy by testing the effect of snow accumulation on the model that underpins the F_yw method. A Monte-Carlo analysis of simulations for 20,000 randomly-generated catchment model configurations used 10 years of precipitation inputs for the Upper Elbow River catchment in the Rocky Mountains (Alberta, Canada) to model discharge with and without snowpack storage of winter precipitation. Neither direct nor modified precipitation input produced a 1:1 relationship between A_s/A_p and F_yw, undermining the applicability of the original F_yw method in mountain watersheds with large seasonal snow accumulation. With snowpack-modified input a given A_s/A_p ratio corresponds to a range of F_yw values, which can still provide semi-quantitative information. In the small (435 km²) Elbow River catchment a F_yw range of 7–23% supports previous findings of rapid transmission in mountain catchments. Further analysis showed that the improved discharge prediction (Nash–Sutcliffe efficiency > 0.9) correlates with higher F_yw values and demonstrated that the interannual shifts in δ¹⁸O can be used to estimate of new water (<1 year) fraction in winter streamflow, and the estimate of 20% for the Elbow River further supports rapid transmission in mountain catchments.  相似文献