检索结果-南通市图书馆

High-frequency lacustrine sequence stratigraphy of clastic lakes: lessons from ancient successions

Journal of Palaeogeography 2024年第4期13卷 621-645页

作者： Carlos Zavala Hua-Qing Liu Xiang-Bo Li Valentin Trobbiani Yang Li Mariano Arcuri Agustin Zorzano Departamento de Geología Universidad Nacional del Sur (UNS) GCS consulting services.Bahía Blanca Research Institute of Petroleum Exploration&Development-Northwest Consejo Nacional de Investigaciones Científicas y T ecnicas (CONICET) Shandong University of Science and Technology

Sequence stratigraphic concepts and methods provide novel tools for performing stratigraphic analysis, allowing us to improve our understanding of depositional models and basin evolution. Main controls and depositional elements(e.g., surfaces, systems tracts, parasequences, etc.) recognized in conventional sequence stratigraphy are designed for marine-related systems. In contrast, the sequence stratigraphy of lacustrine successions is much more complex and poorly understood, because it is not driven by sea-level changes, but by a complex interaction between tectonics and high-frequency climatic cycles. The comprehensive analysis of the water balance of lacustrine systems allows the recognition of three types of lake conditions: Underfilled, balanced-fill and overfilled lakes. Understanding the lake conditions in ancient successions is fundamental for unraveling lacustrine sequence stratigraphy, since these conditions effectively control water salinity, internal stacking pattern and the characteristics of systems tracts. Underfilled lakes are hydrologically closed lakes, and consequently, the lake-level can highly fluctuate, driven by high-frequency wet-dry climatic cycles. During wet periods, rivers supply water and sediments, resulting in fining-and thinning-upward elementary depositional sequences(EDS's) accumulated during the transgressive systems tract(TST). In contrast, dry periods are characterized by a relative lake-level fall with the subaerial exposure of lake margin areas during the regressive systems tract(RST). Lake water salinity can fluctuate from brackish to hypersaline. Balanced-fill lakes are partially closed lakes, and consequently, they have characteristics of both underfilled and overfilled lakes. During the TST, the lake is in underfilled condition, and consequently, the introduction of water and sediment will accumulate a fining-upward interval until reaching the spill point during the maximum flooding. The RST is accumulated under an overfille

关键词： Lacustrine sequence stratigraphy Underfilled lakes Balanced-fill lakes Overfilled lakes Forced transgression Forced regression

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Use of Geosynthetic Access Mats in Construction

引用

World Journal of Engineering and Technology 2024年第3期12卷 552-574页

作者： Waseem A. Khatri Abdullah Al Gazlan Nawaf Alubaidi Abiola Ojo Waleed Al Safarji consulting services Department Saudi Arabian Oil Company Dhahran Kingdom of Saudi Arabia Industrial Projects Department Saudi Arabian Oil Company Dhahran Kingdom of Saudi Arabia

A stable surface to move manpower and equipment is a key for the construction operations. To create a stable road surface, the road construction techniques are time-consuming and expensive for a traditional construction which requires compaction of soil, aggregate base, sub-base and asphaltic layers. A Geosynthetic Access Mat (GAM) system can serve as an alternative to other traditional construction techniques to accommodate temporary construction. Due to its rigidity, the mat system can provide substantial vertical resistance to the applied load under a large deflection subject to soil conditions. This paper provides details of GAM specifications, soil conditions, applications, installation procedure, comparison with other soil stabilization methods and Aramco experience for deployments of these mats.

关键词： Geosynthetic Access Mats (GAM) Bearing Capacity Ground Water Level (GWL) Soil Testing Construction Installation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Spatio-temporal evolution analysis of landscape pattern and habitat quality in the Qinghai Province section of the Yellow River Basin from 2000 to 2022 based on InVEST model

引用

Journal of Arid Land 2024年第9期16卷 1183-1196页

作者： ZHENG Guoqiang Li Cunxiu LI Runjie LUO Jing FAN Chunxia ZHU Hailing College of Geography Qinghai Normal UniversityXining 810008China Qinghai Engineering consulting Center Co. Ltd.Xining 810001China Qinghai University Xining 810016China

Habitat quality is an important indicator for evaluating the quality of *** Qinghai Province section of the Yellow River Basin plays an important role in the ecological protection of the upper reaches of the Yellow River *** comprehensively analysis the alterations of habitat quality in the Qinghai Province section of the Yellow River Basin,this study utilized the Integrated Valuation of Ecosystem services and Tradeoffs(InVEST)model to calculate the habitat quality index and analyze the spatio-temporal variation characteristics of habitat quality in the study area from 2000 to 2022,and calculated seven landscape pattern indices(number of patches,patch density,largest patch index(LPI),landscape shape index(LSI),contagion index(CONTAG),Shannon diversity index,and Shannon evenness index)to research the variation of landscape pattern in the study *** results showed that the number of patches,patch density,LPI,LSI,Shannon diversity index,and Shannon evenness index increased from 2000 to 2022,while the CONTAG decreased,indicating that the landscape pattern in the Qinghai Province section of the Yellow River Basin changed in the direction of distribution fragmentation,shape complexity,and *** average value of the habitat quality index in the Qinghai Province section of the Yellow River Basin from 2000 to 2022 was *** on the value of habitat quality index,we divided the level of habitat quality into five categories:lower(0.00-0.20),low(0.20-0.40),moderate(0.40-0.60),high(0.60-0.80),and higher(0.80-1.00).Most areas were at the higher habitat quality *** lower habitat quality patches were mainly distributed in Longyang Gorge and Yellow River-Huangshui River *** 2000 to 2022,the habitat quality in most areas was stable;the increase areas were mainly distributed in Guinan County,while the decrease areas were mainly distributed in Xining City,Maqen County,Xinghai County,Qumarleb County,and Darlag *** show the extent of

关键词： InVEST model landscape pattern index habitat quality largest patch index landscape shape index Shannon evenness index

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Methane and Hydrogen Storage in Metal Organic Frameworks: A Mini Review

引用

Journal of Environmental & Earth Sciences 2020年第2期2卷 56-68页

作者： Oghenegare Emmanuel Eyankware Idaeresoari Harriet Ateke tegafej consulting services Port HarcourtRivers StateNigeria Department of Petroleum and Gas Engineering University of Port HarcourtRivers stateNigeria

The need for a net zero carbon emission future is imperative forenvironmental sustainability hence, intensive carbon fuels would need tobe replaced with less carbon emitting energy sources such as natural gastill clean energy source such as hydrogen becomes commercialized. Asa result, this mini review discusses the use of metal organic framework(MOF) for adsorption of methane and hydrogen in specially designed tanksfor improved performance so as to increase their applicability. Herein,adsorption (delivery) capacity of selected high performing MOFs formethane and hydrogen storage were highlighted in reference to the targetsset by United States Department of Energy’s Advanced Research ProjectsAgency-Energy (ARPA-E) and Fuel Cells Technology Office. In thisregard, specific design and chemistry of MOFs for improved methane andhydrogen adsorption were highlighted accordingly. In addition, an overviewof computational and molecular studies of hypothetical MOFs was done- the various approaches used and their proficiency for construction ofspecific of crystalline structures and topologies were herewith discussed.

关键词： Methane Hydrogen Metal organic framework Adsorption Storage Computational

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Development of a multivariate empirical model for predicting weak rock mass modulus

引用

International Journal of Mining Science and Technology 2015年第4期25卷 545-552页

作者： Kallu Raj R. Keffeler Evan R. Watters Robert J. Agharazi Alireza Department of Mining Engineering University of Nevada RESPEC consulting and services University of Nevada Itasca Houston Inc.

Estimating weak rock mass modulus has historically proven difficult although this mechanical property is an important input to many types of geotechnical analyses. An empirical database of weak rock mass modulus with associated detailed geotechnical parameters was assembled from plate loading tests per- formed at underground mines in Nevada, the Bakhtiary Dam project, and Portugues Dam project. The database was used to assess the accuracy of published single-variate models and to develop a multivari- ate model for predicting in-situ weak rock mass modulus when limited geoteehnical data are available. Only two of the published models were adequate for predicting modulus of weak rock masses over lim- ited ranges of alteration intensities, and none of the models provided good estimates of modulus over a range of geotechnical properties. In light of this shortcoming, a multivariate model was developed from the weak rock mass modulus dataset, and the new model is exponential in form and has the following independent variables：（1） average block size or joint spacing, （2） field estimated rock strength, （3） dis- continuity roughness, and （4） discontinuity infilling hardness. The multivariate model provided better estimates of modulus for both hard-blocky rock masses and intensely-altered rock masses.

关键词： In-situ modulus Weak rock mass Preliminary design Elastic deformation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A case study on the efficacy of different roof bolting schemes in Lhoist North America’s Crab Orchard Mine

引用

International Journal of Mining Science and Technology 2020年第1期30卷 99-104页

作者： Reece Kurre Gabriel Walton Stantec consulting services Inc. Walnut CreekCA 94597USA Department of Geology and Geological Engineering Colorado School of MinesGoldenCO 80401USA

Roof bolting has long been used in underground mines across the world to provide ground *** roof bolts are cheap and easy to install with the use of specialized machines as a part of the production cycle. Lhoist North America’s Crab Orchard Mine is an underground room and pillar limestone mine that uses mechanically anchored roof bolts for ground support. The mine currently employs two different roof bolting patterns: a standard 1.5 × 1.5 m pattern, and another 0.8 × 0.8 m pattern for use in areas with particularly hazardous roof conditions. The purpose of this study is to evaluate the relative effectiveness of each bolting pattern. A series of numerical models were created using Roc Science’s RS2. The models were based on a symmetrical section of the mine at its deepest point, and were modeled using generalized Hoek-Brown failure criterion along with a discrete fracture network. A series of sensitivity analyses were performed on the models by varying parameters such as joint friction angle, crack persistence, joint randomization, and tensile strength of the limestone. Based on the results of the original models and sensitivity analyses, it appeared that the standard bolting pattern provided sufficient roof support capacity under almost all the expected conditions at the mine, since safety factors below the design value of 1.5 were only found for individual bolts in a few of the worst test cases *** results can help improve the mine’s productivity and reduce operating costs without compromising safety.

关键词： Numerical modeling Mining Roof bolting Roof stability Analysis RocScience’s RS2 Underground stone

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An experimental and numerical study of chemically enhanced water alternating gas injection

引用

Petroleum Science 2015年第3期12卷 470-482页

作者： Saeed Majidaie Mustafa Onur Isa M.Tan Leap Energy-Subsurface consulting services Department of Petroleum and Natural Gas Engineering Istanbul Technical University Applied Science Department Universiti Teknologi Petronas

In this work, an experimental study combined with numerical simulation was conducted to investigate the potential of chemically enhanced water alternating gas （CWAG） injection as a new enhanced oil recovery method. The unique feature of this new method is that it uses alkaline, surfactant, and polymer additives as a chemical slug which is injected during the water alternating gas （WAG） process to reduce the interfacial tension （IFT） and simultaneously improve the mobility ratio. In essence, the proposed CWAG process involves a combination of chemical flooding and immiscible carbon dioxide （CO2） injection and helps in IFT reduction, water blocking reduction, mobility control, oil swelling, and oil viscosity reduction due to CO2 dissolution. Its performance was compared with the conventional immiscible water alter- nating gas （I-WAG） flooding. Oil recovery utilizing CWAG was better by 26 % of the remaining oil in place after waterflooding compared to the recovery using WAG conducted under similar conditions. The coreflood data （cumulative oil and water production） were history mat- ched via a commercial simulator by adjusting the relative permeability curves and assigning the values of the rock and fluid properties such as porosity, permeability, and the experimentally determined IFT data. History matching ofthe coreflood model helped us optimize the experiments and was useful in determining the importance of the parameters influencing sweep efficiency in the CWAG process. The effectiveness of the CWAG process in pro- viding enhancement of displacement efficiency is evident in the oil recovery and pressure response observed in the coreflood. The results of sensitivity analysis on CWAG slug patterns show that the alkaline-surfactant-polymer injection is more beneficial after CO2 slug injection due to oil swelling and viscosity reduction. The CO2 slug size analysis shows that there is an optimum CO2 slug size, around 25 % pore volume which leads to a maximum oil recover

关键词： Enhanced water alternating gas (CWAG) Enhanced oil recovery Interfacial tension Mobilitycontrol ~ Water blocking

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Flow correction control with electromagnetically induced preform resting process

引用

Advances in Manufacturing 2019年第2期7卷 199-208页

作者： Mohsen Poorzeinolabedin Kemal Levend Parnas Department of Mechanical Engineering Middle East Technical University Ankara Turkey Leopar Composite Engineering and consulting services Ltd. Ankara Turkey Department of Mechanical Engineering TED University Ankara Turkey

Resin flow correction control with electromagnetic field source, a new variation of the vacuum-assisted resin transfer molding (VARTM) process called electromagnetically induced preform resting (EIPR) for dynamical resin flow controlling is introduced to manipulate the flow front and local permeability to prevent the formation of dry spots. This paper proposes an active and real-time flow control approach that is implemented during the composite laminate infusion. The EIPR process applies an electromagnetic field source to pinch (raise) and vibrate the upper flexible mold to rest the fiber preform and increase the local permeability. Vibration action delivers the fluid through the preform. The EIPR process includes a new and creative upper flexible vacuum bag with embedded elements to lift and create local vibrations via an automated gantry system. The control methodology is performed by tracking the flow front with a real-time correction. System capability is demonstrated with three configurations of preform of different preform permeabilities in each experiment. A low permeability preform is employed in these configurations to disturb the flow pattern and cause an artificial problem or pseudo problem during the filling process. The results indicate that this system fills the mold completely and reduces the filling time without any dry spots and therefore creates no waste material.

关键词： Resin flow Process monitoring On-line flow control Vacuum-assisted resin transfer molding

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Deep-Learning and Transfer-Learning Hybrid Aerosol Retrieval Algorithm for FY4-AGRI:Development and Verification over Asia

引用

Engineering 2024年第7期38卷 164-174页

作者： Disong Fu Hongrong Shi Christian AGueymard Dazhi Yang Yu Zheng Huizheng Che Xuehua Fan Xinlei Han Lin Gao Jianchun Bian Minzheng Duan Xiangao Xia Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 10029China Key Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Solar consulting services ColebrookNH 03576USA School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150006China State Key Laboratory of Severe Weather&Key Laboratory of Atmospheric Chemistry Institute of Atmospheric Composition and Environmental MeteorologyChinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing 100085China h National Satellite Meteorological Center China Meteorological AdministrationBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China

The Advanced Geosynchronous Radiation Imager(AGRI)is a mission-critical instrument for the Fengyun series of *** acquires full-disk images every 15 min and views East Asia every 5 min through 14 spectral bands,enabling the detection of highly variable aerosol optical depth(AOD).Quantitative retrieval of AOD has hitherto been challenging,especially over *** this study,an AOD retrieval algorithm is proposed that combines deep learning and transfer *** algorithm uses core concepts from both the Dark Target(DT)and Deep Blue(DB)algorithms to select features for the machinelearning(ML)algorithm,allowing for AOD retrieval at 550 nm over both dark and bright *** algorithm consists of two steps:①A baseline deep neural network(DNN)with skip connections is developed using 10 min Advanced Himawari Imager(AHI)AODs as the target variable,and②sunphotometer AODs from 89 ground-based stations are used to fine-tune the DNN ***-of-station validation shows that the retrieved AOD attains high accuracy,characterized by a coefficient of determination(R2)of 0.70,a mean bias error(MBE)of 0.03,and a percentage of data within the expected error(EE)of 70.7%.A sensitivity study reveals that the top-of-atmosphere reflectance at 650 and 470 nm,as well as the surface reflectance at 650 nm,are the two largest sources of uncertainty impacting the *** a case study of monitoring an extreme aerosol event,the AGRI AOD is found to be able to capture the detailed temporal evolution of the *** work demonstrates the superiority of the transfer-learning technique in satellite AOD retrievals and the applicability of the retrieved AGRI AOD in monitoring extreme pollution events.

关键词： Aerosol optical depth Retrieval algorithm Deep learning Transfer learning Advanced Geosynchronous Radiation Imager

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Educating children with autism in China-implementing Hong Kong Rainbow Model in Mainland

Educating children with autism in China-implementing Hong Ko...

引用

第十九届世界儿童及青少年精神卫生与相关学科学术会议

作者： Tad Zhengzhang Pu Geraldine Solis Rainbow consulting services Norway

＜正＞The Rainbow Model（TRM） is an education program for children with autism and other related developmental *** aims to provide a balance and sound approach in teaching children with *** believes in providing a learning environment that inspires children to be the best they can *** recognizes that children needs time to explore and enjoy their childhood,thus,providing them a learning opportunity that is not solely focus on the cognitive aspect of development but responds as well to their social,emotional,and physical ***

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：