油气混输系统的实验研究与实验模拟准则   总被引：2，自引：0，他引：2  

吴应湘  郑之初  李东晖  劳力云  马艺馨 《海洋工程》1999,17(4)

描述了油气混输系统的实验研究,特别是多相流的流态、增压、计量系统的实验研究,并用动力相似理论分析了油气混输两相管流实验模拟所需满足的相似参数,提出了各种简化条件下的相似规律,讨论了用水和空气的两相流动来模拟原油和天然气的两相流动的可靠性和提高实验精度的手段和方法。  相似文献   

雅鲁藏布江断裂带的形成   总被引：4，自引：2，他引：2  

劳雄 《地质力学学报》1995,1(1):53-59

雅江断裂带①主要由4条断层组成3个向西南突出的巨大弧形断裂带。晚三叠世至第四纪,雅江断裂带都有沉积地层发育,从西北向东南,各弧形断裂带成为相继接受沉积的坳陷区,而同一时期,与之紧邻的南北两盘却为隆升区。雅江断裂带,正是在该区地壳多次层波运动中形成的。   相似文献   

海南岛土类的分布概况及物理力学特性     

劳国利 《岩土力学》1988,9(4):51-61

本文对以往三十来年的工作进行了总结,在统计和分析大量的土工试验资料的基础上,从区域土质学的观点出发,研究了海南岛土类的成因、成份及各种土类的分布规律,探索了各类土的物理力学特性。文中所列的海南岛各种土类的物理力学试验研究成果,对今后海南岛的进一步开发有一定的参考价值。  相似文献   

桂林岩溶峰丛区溶蚀速度计算及探讨   总被引：6，自引：0，他引：6  

周世英  朱德浩  劳文科 《中国岩溶》1988,7(1):73-80

研究区位于桂林地区典型峰丛洼地之中,选取的二个泉的流域面积分别为32.69和7.44平方公里,对Williams公式进行修正后建立了下列计算公式:其中△T=T-Ta,T为样品的总硬度,Ta为大气降水的硬度。m=Qs/Qp,Qs为泉流量,Qp为渗入碳酸盐岩之中的大气降水,由此得到桂林峰丛洼地的平均剥蚀速度为89.68毫米/千年。   相似文献   

基于多时相主被动遥感的漓江水面监测与水质参数反演(2016—2020年)   总被引：1，自引：0，他引：1  

刘曼  付波霖  何宏昌  解淑毓  仇继圣  孙习东  龚烨云  劳植楠  左萍萍 《湖泊科学》2021,33(3):687-705

以漓江流域为研究区域,以2016-2020年Landsat 8 OLI、GF-1、Sentinel-2A及Sentinel-1A逐月影像为数据源,选用归一化水指数(NDWI)、改进型归一化水指数(MNDWI)、增强型水体指数(EWI)、归一化差值池指数(NDPI)、后向散射系数(S)与主被动遥感加权指数(JQ)提取漓江水体信息,采用二类水体区域性近岸海域水色算法(C2RCC)、最大叶绿素指数(MCI)、双波段比值法(Double R)及叶绿素反射峰强度(ρchl)4种方式,反演漓江水体叶绿素a(Chl.a)与总悬浮物质(TSM)浓度.将漓江划分为278个基本评价单元,利用水面变化区域差异值(WDr)、河岸线发育系数(SDI)与水体信息变化动态度(K)等指标定量分析漓江上、中、下游枯水期和汛期的水文和水质信息的年内时空动态变化,得出以下结论:(1)主被动遥感加权指数JQ与NDPI指数的提取效果优于NDWI、MNDWI、EWI指数与后向散射系数,但与JQ指数相比,NDPI指数提取精度更高、可信度更强.(2)基于C2RCC算法反演的Chl.a浓度的均方根误差(RMSE)处于0.18~7.88 mg/m³之间,TSM浓度的RMSE为0.17~12.55 g/m³,可较好地反映漓江水质参数变化情况.(3)基本评价单元的划分可清楚地分析出上、中、下游地区水域水面宽度、水域面积、Chl.a与TSM浓度的连续变化情况,实测数据则依靠站点监测,所得结果较分散,无法进行连续性分析.(4)漓江5-10月降水较多、水体流动性强,大部分地区平均水面宽度在100~250 m范围内,水体富营养化程度低,水质较好,但2月水质最差,水体富营养化程度较高地区主要集中于上、中游的兴安县、灵川县等城镇居民区以及下游旅游开发区较多的兴坪镇.  相似文献   

New evidence of sea‐level lowstands and paleoenvironment during MIS 6 and 4 in the Cantabrian coastal karst: the Cobiheru cave (North Iberia)          下载免费PDF全文

Daniel Ballesteros  Laura Rodríguez‐Rodríguez  Saúl González‐Lemos  Santiago Giralt  Diego Jaime Álvarez‐Lao  Luna Adrados  Montserrat Jiménez‐Sánchez 《地球表面变化过程与地形》2017,42(11):1704-1716

The geomorphological evolution of the Cobiheru Cave shows the influence of the non‐carbonate coastal mountain ranges on coastal karst evolution, as well as the temporal distribution of the cold‐adapted fauna sites in the Cantabrian Coast. Geomorphological observation and uranium/thorium (U/Th) dating lead to the construction of an evolution model. The model comprises two episodes of cave deposition occurring at c. 60–70 and 130–150 ka, linked to cold climate conditions, global sea‐level lowstands and the erosion of alluvial fans that covered the karst. Moreover, the comparison between the Cobiheru record and some raised beaches identified in previous studies sets the beginning of the sea‐level lowering in the Cantabrian Sea during the marine isotope stages (MIS) 5–4 transition. Two palaeoenvironments are inferred based on finding Equus ferus and Elona quimperiana. A wet deciduous forest would have developed on the emerged marine terrace of the Cobiheru Cave since at least the Middle Pleistocene, and an open landscape with scarce vegetation would have been present at c. 65 ka. The erosional event identified in the Cobiheru Cave helps to understand the temporal distribution of cold‐adapted mammals located in the Asturias region. The probable sites of cold‐adapted fauna developed in caves and alluvial fans would have disappeared after 65 ka. Therefore, palaeontological and palaeoclimate research based on cold‐adapted mammals suggests the occurrence of an hiatus in the palaeontological record prior to 50 ka. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Estimating submarine groundwater discharge at a subtropical river estuary along the Beibu Gulf,China     

Xilong Wang  Kaijun Su  Juan Du  Linwei Li  Yanling Lao  Guizhen Ning  Li Bin 《海洋学报(英文版)》2021,40(9):13-22

In certain regions,submarine groundwater discharge(SGD) into the ocean plays a significant role in coastal material fluxes and their biogeochemical cycle;therefore,the impact of SGD on the ecosystem cannot be ignored.In this study,SGD was estimated using naturally occurring radium isotopes(~(223)Ra and ~(224)Ra) in a subtropical estuary along the Beibu Gulf,China.The results showed that the Ra activities of submarine groundwater were approximately 10 times higher than those of surface water.By assuming a steady state and using an Ra mass balance model,the SGD flux in May 2018 was estimated to be 5.98×10~6 m~3/d and 3.60×10~6 m~3/d based on ~(224)Ra and ~(223)Ra,respectively.At the same time,the activities of Ra isotopes fluctuated within a tidal cycle;that is,a lower activity was observed at high tide and a higher activity was seen at low tide.Based on these variations,the average tidal pumping fluxes of SGD were 1.15×10~6 m~3/d and 2.44×10~6 m~3/d with ~(224)Ra and ~(223)Ra,respectively.Tidaldriven SGD accounts for 24%-51% of the total SGD.Therefore,tidal pumping is an important driving force of the SGD in the Dafengjiang River(DFJR) Estuary.Furthermore,the SGD of the DFJR Estuary in the coastal zone contributes significantly to the seawater composition of the Beibu Gulf and the material exchange between land and sea.  相似文献