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Analysis of Perioperative Respiratory Care Methods and their Application Value in Children with Congenital Heart Disease
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作者 Liangyin Quan 《Journal of Clinical and Nursing Research》 2024年第2期22-27,共6页
Objective:To analyze the perioperative respiratory care methods and application value in children with congenital heart disease.Methods:60 children with congenital heart disease(treated from January 2021 to October 20... Objective:To analyze the perioperative respiratory care methods and application value in children with congenital heart disease.Methods:60 children with congenital heart disease(treated from January 2021 to October 2023)were screened and divided into two groups randomly.Each group consisted of 30 cases.The perioperative routine was used in the control group.The observation group underwent the perioperative routine along with better respiratory care.Oxygenation indicators,surgical complications,and family satisfaction levels of the groups were compared.Results:There was no significant difference in the oxygenation index between the two groups of children at admission(P>0.05).At discharge,the oxygenation indicators in the observation group were better than those of the control group,and the incidence of surgical complications was lower than that of the control group.The total satisfaction of family members in the observation group was higher than that of the control group(P<0.05).Conclusion:During the perioperative period for children with congenital heart disease,the implementation of respiratory care,which mainly involves symptomatic care,catheter care,sputum suction care,etc.,can actively improve the oxygenation indicators,reduce surgical complications,and promote faster and better recovery,of children with congenital heart disease. 展开更多
关键词 Congenital heart disease Perioperative respiratory care Nursing methods and value
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Application of geophysical methods in fine detection of urban concealed karst:A case study of Wuhan City,China
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作者 Dao-han Liu Lei Wang +3 位作者 Lei Liu Jun-jie Xu Jian-qiang Wu Pan Liu 《China Geology》 CAS CSCD 2024年第3期517-532,共16页
The construction of modern livable cities faces challenges in karst areas,including ground collapse and engineering problems.Wuhan,with a population of 13.74×10^(6) and approximately 1161 km^(2)of soluble rocks i... The construction of modern livable cities faces challenges in karst areas,including ground collapse and engineering problems.Wuhan,with a population of 13.74×10^(6) and approximately 1161 km^(2)of soluble rocks in the urban area of 8569.15 km^(2),predominantly consists of concealed karst areas where occasional ground collapse events occur,posing significant threats to underground engineering projects.To address these challenges,a comprehensive geological survey was conducted in Wuhan,focusing on major karstrelated issues.Geophysical methods offer advantages over drilling in detecting concealed karst areas due to their efficiency,non-destructiveness,and flexibility.This paper reviewed the karst geological characteristics in Wuhan and the geophysical exploration methods for karst,selected eight effective geophysical methods for field experimentation,evaluated their suitability,and proposed method combinations for different karst scenarios.The results show that different geophysical methods have varying applicability for karst detection in Wuhan,and combining multiple methods enhances detection effectiveness.The specific recommendations for method combinations provided in this study serve as a valuable reference for karst detection in Wuhan. 展开更多
关键词 Ground Penetrating Radar(GPR) Electric Resistivity Tomography(ERT) Opposing-coils Transient Electromagnetic Method(OCTEM) Microtremor Array Measurements(MAM) Multi-channel Analysis of surface wave(MASW) Multi-source surface wave exploration(MSSW) Electromagnetic wave CT(EM CT) Surface Nuclear Magnetic Resonance(SNMR) Concealed karst Urban geological survey engineering
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Advances in Research of Treatment of Angina Pectoris in Coronary Heart Disease from the Method of Dredging Collaterals with Pungent
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作者 Sihui WANG Yan SHEN 《Medicinal Plant》 CAS 2023年第2期84-89,共6页
The angina pectoris in coronary heart disease belongs to the category of"chest impediment"in traditional Chinese medicine,and belongs to the syndrome of root deficiency with tip excess.Its main pathogenesis ... The angina pectoris in coronary heart disease belongs to the category of"chest impediment"in traditional Chinese medicine,and belongs to the syndrome of root deficiency with tip excess.Its main pathogenesis is obstruction of the heart collaterals,and treatment mainly adopts dredging collaterals and relieving pain.Based on the treatment principles of dredging collaterals with pungent,aiming at the etiology,pathogenesis and disease characteristics of angina pectoris in coronary heart disease,this article systematically analyzes the Method of Dredging Collaterals with Pungent including the methods of dredging collaterals with pungent moisture,dredging collaterals with pungent warm,dredging collaterals with pungent aroma,and dredging collaterals with insect type drugs,to provide ideas for the treatment of angina pectoris in coronary heart disease. 展开更多
关键词 Coronary heart disease Angina pectoris Chest impediment Collateral diseases Impediment of heart collaterals Method of Dredging Collaterals with Pungent
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Geological reservoir and resource potential(10^(13)m^(3))of gas hydrates in the South China Sea
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作者 Pi-bo Su Wei Wei +5 位作者 Yun-bao Sun Yao-yao Lü Huai Cheng Wei-feng Han Wei Zhang Jin-qiang Liang 《China Geology》 CAS CSCD 2024年第3期422-444,共23页
A detailed understanding of the distribution and potential of natural gas hydrate(NGHs)resources is crucial to fostering the industrialization of those resources in the South China Sea,where NGHs are abundant.In this ... A detailed understanding of the distribution and potential of natural gas hydrate(NGHs)resources is crucial to fostering the industrialization of those resources in the South China Sea,where NGHs are abundant.In this study,this study analyzed the applicability of resource evaluation methods,including the volumetric,genesis,and analogy methods,and estimated NGHs resource potential in the South China Sea by using scientific resource evaluation methods based on the factors controlling the geological accumulation and the reservoir characteristics of NGHs.Furthermore,this study compared the evaluation results of NGHs resource evaluations in representative worldwise sea areas via rational analysis.The results of this study are as follows:(1)The gas hydrate accumulation in the South China Sea is characterized by multiple sources of gas supply,multi-channel migration,and extensive accumulation,which are significantly different from those of oil and gas and other unconventional resources.(2)The evaluation of gas hydrate resources in the South China Sea is a highly targeted,stratified,and multidisciplinary evaluation of geological resources under the framework of a multi-type gas hydrate resource evaluation system and focuses on the comprehensive utilization of multi-source heterogeneous data.(3)Global NGHs resources is n×10^(15)m^(3),while the NGHs resources in the South China Sea are estimated to be 10^(13)m^(3),which is comparable to the abundance of typical marine NGHs deposits in other parts of the world.In the South China Sea,the NGHs resources have a broad prospect and provide a substantial resource base for production tests and industrialization of NGHs. 展开更多
关键词 Reservoir characteristics Natural gas hydrates Gas migration Resource potential Resource evaluation methods Hierarchical evaluation system Volumetric method South China Sea Clean energy exploration engineering
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Research and Application of Advanced Detection of Water Hazards in Coal Mine Bore-Hole
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作者 Libo Deng 《Engineering(科研)》 2024年第7期181-187,共7页
For many years, the “short excavation and short exploration” excavation mode has been mainly used in the underground tunnel excavation of coal mines, which is difficult to meet the needs of rapid tunnel excavation. ... For many years, the “short excavation and short exploration” excavation mode has been mainly used in the underground tunnel excavation of coal mines, which is difficult to meet the needs of rapid tunnel excavation. For this reason, CCTEG Xi’an Research Institute has innovatively proposed a new working mode of “long excavation and long exploration” using directional long drilling and borehole geophysical exploration. This method utilizes directional long boreholes that have already been constructed, and uses transient electromagnetic technology in the borehole to detect the radial range of 30 meters and the depth exceeding 1000 meters of the borehole, ultimately forming a three-dimensional imaging of the entire spatial geological anomaly body, providing reliable technical support for the safety and long-term excavation of the tunnel. This paper introduces the application which is a long-distance advanced detection of 1026 m. . 展开更多
关键词 Transient Electromagnetic Method Bore-Hole Transient Electromagnetic TEM Geophysical Exploration
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Oil/Gas Accumulation Characteristics and Exploration Methods of the Deltaic Lithologic Reservoirs in Northern Shaanxi Area 被引量:4
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作者 YangHua FuJinhua YuJian DuJinliang MuJingkui 《Petroleum Science》 SCIE CAS CSCD 2004年第2期69-78,共10页
There are large deltaic systems in the Triassic Yanchang Formation in the northern Shaanxi area of the Ordos Basin, and developed two sets of good source-reservoir-caprock assemblages and many sets of oil-bearing beds... There are large deltaic systems in the Triassic Yanchang Formation in the northern Shaanxi area of the Ordos Basin, and developed two sets of good source-reservoir-caprock assemblages and many sets of oil-bearing beds. Exploration experience demonstrates that the formation and distribution of the reservoir were controlled by the generative depression of the Yanchang Formation, and deltaic reservoir sand body is the material basis for large-scale oilfields. In addition, secondary laumontite in a low permeable area was dissolved and then a high permeable area was formed. The updip lithologic variety of reservoir sand bodies is favorable to the formation of subtle lithologic traps, and the deltaic reservoirs are characterized by large multi-beds of oil-generation and abundant hydrocarbon resources. In this paper, the petroleum geologic settings of the studied area are analyzed, and the accumulation characteristics and exploration methods of lithologic reservoirs are summarized. It is of theoretical significance for the study of the exploration theories of lithologic reservoirs, and also expedites the exploration steps of deltaic reservoirs in the northern Shaanxi area. 展开更多
关键词 Northern Shaanxi area sedimentary cycle deltaic sand body laumontite solution pore subtle reservoir exploration method
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Construction of Parsimonious Event Risk Scores by an Ensemble Method. An Illustration for Short-Term Predictions in Chronic Heart Failure Patients from the GISSI-HF Trial 被引量:1
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作者 Benoî t Lalloué +2 位作者 Jean-Marie Monnez Donata Lucci Eliane Albuisson 《Applied Mathematics》 2021年第7期627-653,共27页
Selecting which explanatory variables to include in a given score is a common difficulty, as a balance must be found between statistical fit and practical application. This article presents a methodology for construct... Selecting which explanatory variables to include in a given score is a common difficulty, as a balance must be found between statistical fit and practical application. This article presents a methodology for constructing parsimonious event risk scores combining a stepwise selection of variables with ensemble scores obtained by aggregation of several scores, using several classifiers, bootstrap samples and various modalities of random selection of variables. Selection methods based on a probabilistic model can be used to achieve a stepwise selection for a given classifier such as logistic regression, but not directly for an ensemble classifier constructed by aggregation of several classifiers. Three selection methods are proposed in this framework, two involving a backward selection of the variables based on their coefficients in an ensemble score and the third involving a forward selection of the variables maximizing the AUC. The stepwise selection allows constructing a succession of scores, with the practitioner able to choose which score best fits his needs. These three methods are compared in an application to construct parsimonious short-term event risk scores in chronic HF patients, using as event the composite endpoint of death or hospitalization for worsening HF within 180 days of a visit. Focusing on the fastest method, four scores are constructed, yielding out-of-bag AUCs ranging from 0.81 (26 variables) to 0.76 (2 variables). 展开更多
关键词 Ensemble Score Ensemble methods SCORING Variable Selection heart Failure
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An index for evaluating distance of a healthy heart from Sino-Atrial blocking arrhythmia
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作者 Hossein Gholizade-Narm Morteza Khademi +1 位作者 Asad Azemi Masoud Karimi-Ghartemani 《Journal of Biomedical Science and Engineering》 2010年第3期308-316,共9页
In this paper, an index for evaluating Distance of a healthy heart from Sino-Atrial Blocking Arrhythmia (SABA) is presented. After definition of the main pacemakers' model of heart, Sino-Atrial (SA) and Atrio-Vent... In this paper, an index for evaluating Distance of a healthy heart from Sino-Atrial Blocking Arrhythmia (SABA) is presented. After definition of the main pacemakers' model of heart, Sino-Atrial (SA) and Atrio-Ventricular nodes (AV), the boundary of synchronization, which demonstrates the boundary of blocking arrhythmia, is obtained using perturbation method. In order to estimate of healthy heart characteristics, a parameter estimator is introduced. The distance from SABA is calculated using Lagrange method and Kohn-Tucker conditions. In addition, the maximum admissible decrease in the coupling intensity and the maximum admissible increase in the discrepancy between the natural frequencies of two pacemakers are determined in order to maintain the synchronization between the two pacemakers. 展开更多
关键词 HEALTHY heart BLOCKING ARRHYTHMIA Perturbation method Synchronization Boundary Optimization Bifurcation
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Application Analysis of Various Geophysical Methods in Volume Calculation of Different Landfills
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作者 Jinsuo Liu Biao Jin 《Open Journal of Geology》 CAS 2022年第9期706-716,共11页
Garbage disposal has gradually become a key issue faced by environmental governance. What must be controlled in garbage disposal is the calculation of garbage volume. In this paper, according to the different landfill... Garbage disposal has gradually become a key issue faced by environmental governance. What must be controlled in garbage disposal is the calculation of garbage volume. In this paper, according to the different landfill conditions of a landfill in Anhui, including: covering soil, overlying HDPE membrane, overlying concrete, etc., combined with the physical differences between the rock mass and the garbage at the bottom of the landfill. The landfill covered with HDPE membrane adopts the transient electromagnetic method, the landfill covered with soil layer adopts the high-density electrical method, and the landfill covered with concrete adopts the combination of transient electromagnetic method and ground penetrating radar. At the same time, Combines the borehole data to determine that the resistivity value of the interface between the garbage and the soil was 29 Ω&sdot;m. Finally, the sections of multiple survey lines can accomplish three-dimensional stereoscopic that calculate the distribution and actual volume of the garbage. This method is used to determine the final investment cost. 展开更多
关键词 Garbage Volume Geophysical Exploration Transient Electromagnetic Method High-Density Electrical Method Ground Penetrating Radar
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Research and Application of New Methods to Oil-Gas Geochemical Exploration
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作者 CHEN Yuanrong JIA Guoxiang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第3期692-696,共5页
Based on the results of researches and applications for many years, it has been discovered that new methods and techniques for geochemical exploration of oil and gas such as δC, altered carbonate, Hg in absorption ph... Based on the results of researches and applications for many years, it has been discovered that new methods and techniques for geochemical exploration of oil and gas such as δC, altered carbonate, Hg in absorption phase, Ks, Fe2+, δ13C, fluorescence in two and three dimensions, and N2 and O2 in heat release can give full play in the following five fields: (1) optimization of the favourable target or hollow zones and structural zones in a region; (2) evaluation of oil traps and delineation of prospective oil and gas areas; (3) prediction of deep-seated oil-bearing horizons; (4) evaluation of the genesis of oil and gas geochemical anomalies and determination of the types of oil and gas accumulations; (5) forecast of the burial depths of oil and gas pools. 展开更多
关键词 geochemical exploration for oil and gas new method field of application
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Research progress on the application of traditional Chinese medicine in the draining water method of chronic heart failure
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作者 Rui Huang Jian-Qi Lu +3 位作者 Zhi-Liang Xu Jiong-Tong Li Pu-Wei Huang Jia-Hui Lu 《Journal of Hainan Medical University》 2021年第19期55-58,共4页
Chronic heart failure(CHF)is a public health problem that seriously affects the quality of life of patients with poor prognosis.Western medicine has been mature in the treatment of CHF,but it still has some limitation... Chronic heart failure(CHF)is a public health problem that seriously affects the quality of life of patients with poor prognosis.Western medicine has been mature in the treatment of CHF,but it still has some limitations and adverse reactions in improving the clinical symptoms of CHF.TCM has a long history of understanding of CHF,and in recent years,TCM has summarized and developed the experience of predecessors in the treatment of CHF,In particular,diuretic therapy,combined with Warming Yang,tonifying Qi,promoting blood circulation and removing blood stasis,has achieved good curative effect in treating CHF.When combined with basic treatment of Western medicine,it can reduce the adverse reactions of Western medicine.This review is to summarize. 展开更多
关键词 Chronic heart failure Draining water method INTERVENTION
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Nurses’ Experiences of Using the Liverpool Care Pathway Plan in Hospitalized Patients with Heart Failure in the End-of-Life Stage: A Qualitative Content Analysis
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作者 Randi Hove Nina Fålun Bengt Fridlund 《Open Journal of Nursing》 2016年第8期591-599,共9页
Background: The introduction of care pathway plans for end-of-life cares such as the Liverpool Care Pathway (LCP) reveals a unique possibility for inter professional collaboration. Knowledge of symptom relief and how ... Background: The introduction of care pathway plans for end-of-life cares such as the Liverpool Care Pathway (LCP) reveals a unique possibility for inter professional collaboration. Knowledge of symptom relief and how to meet the patients’ needs at the last stage of the palliative phase are essential for the nurses’ approach and care actions, but the documentation of such implementations is still rare and sometimes criticized. Aim: To explore and describe nurses’ experiences of using the LCP plan with patients hospitalized with heart failure at the end-of-life stage. An explorative design was applied, using qualitative content analysis of 20 interviews with nurses practicing the LCP plan in two district hospitals in Norway. Results: The nurses found the LCP plan as quality assurance for treatment and care in patients with heart failure in the last hours and days of life. The use of the LCP plan implied: 1) individualized adjustment, 2) symptom relief and 3) a holistic approach. Conclusion: Nurses experienced that using the LCP plan as a comprehensive action plan contributed in the decision making process and improved inter professional communication. Using the LCP plan should be seen as a tool to practice individualized and holistic nursing to patients at the end-of-life and their families, as well as a purposeful relief of symptoms associated with heart failure. 展开更多
关键词 End-of-Life Care heart Failure NURSING Palliative Care Qualitative Method
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The forward and inverse problem of cardiac magnetic fields based on concentric ellipsoid torso-heart model 被引量:1
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作者 王倩 华宁 +3 位作者 唐雪正 陆宏 马平 唐发宽 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第8期276-286,共11页
This paper constructs a concentric ellipsoid torso-heart model by boundary element method and investigates the impacts of model structures on the cardiac magnetic fields generated by both equivalent primary source--a ... This paper constructs a concentric ellipsoid torso-heart model by boundary element method and investigates the impacts of model structures on the cardiac magnetic fields generated by both equivalent primary source--a current dipole and volume currents. Then by using the simulated magnetic fields based on torso-heart model as input, the cardiac current sources--an array of current dipoles by optimal constrained linear inverse method are constructed. Next, the current dipole array reconstruction considering boundaries is compared with that in an unbounded homogeneous medium. Furthermore, the influence of random noise on reconstruction is also considered and the reconstructing effect is judged by several reconstructing parameters. 展开更多
关键词 concentric ellipsoid torso-heart model boundary element method current dipole array reconstruction optimal constrained linear inverse method
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一种基于TOF×E方法的空间中能离子探测器设计与仿真
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作者 张伟杰 沈国红 +2 位作者 张珅毅 张贤国 叶依众 《空间科学学报》 CAS CSCD 北大核心 2023年第2期340-351,共12页
对空间中几十keV到几MeV的中能离子进行成分、能谱和角分布进行测量,具有重要的科学价值和应用意义。中国在载人登月等深空探测计划中明确提出了对中能离子的探测需求,但当前尚未掌握中能离子测量技术。本文提出了一种基于SEE TOF×... 对空间中几十keV到几MeV的中能离子进行成分、能谱和角分布进行测量,具有重要的科学价值和应用意义。中国在载人登月等深空探测计划中明确提出了对中能离子的探测需求,但当前尚未掌握中能离子测量技术。本文提出了一种基于SEE TOF×E方法的中能离子探测器方案,方案包括复合材料二次电子薄膜、电极、位置灵敏MCP探测器和SSD等核心部件的设计,可同时实现对5个方向的中能离子和4个方向的中能电子的测量。结合目前空间粒子探测载荷可实现的硬件时间分辨率、能量分辨率和仿真计算结果,可以发现,该设计可以在40 keV~5 MeV能量范围实现中能离子能谱测量;并能够对40 keV~5 MeV的H离子,45 keV~5MeV的He离子,130 keV~5 MeV的O离子和240 keV~5 MeV的Fe离子进行离子成分分辨;同时可实现对20~500 keV的电子进行能谱测量。 展开更多
关键词 飞行时间法 质量分辨率 中能离子 中能电子 深空探测
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Highlights of the physical examination in heart failure 被引量:1
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作者 Sandesh Dev 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2006年第4期237-241,共5页
Because decompensated heart failure (HF) patients present primarily with symptoms of congestion, the assessment of volume status is of paramount importance. Despite the addition of new technologies that can predict in... Because decompensated heart failure (HF) patients present primarily with symptoms of congestion, the assessment of volume status is of paramount importance. Despite the addition of new technologies that can predict intracardiac filling pressures, the physical exam (PE) remains the most accessible and cost-effective tool available to clinicians. An elevated jugular venous pressure (JVP)useful cutoff is that if the JVP is greater than 3 cm in vertical distance above the sternal angle, the central venous pressure is elevated. In addition to assessment of volume status, the PE in HF can reveal adverse prognostic signs, namely: elevated JVP, presence of third heart sound, elevated heart rate, low systolic BP, and low proportional pulse pressure (< 25%). This article will review the evidence for the diagnostic and prognostic utility of common PE findings in HF. 展开更多
关键词 JUGULAR VENOUS PRESSURE central VENOUS PRESSURE heart failure physical EXAMINATION hepatojugular REFLEX ABDOMINAL
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Appraisal of Engineering Phases of a Mineral Asset: From Exploration to Mine Approval
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作者 Edmundo Tulcanaza 《Journal of Minerals and Materials Characterization and Engineering》 CAS 2023年第3期69-79,共11页
It is well known that the most common methodology for evaluating a mineral asset is the NPV. Most of the mining companies employ this technique for evaluating the expected economic benefits provided by the exploration... It is well known that the most common methodology for evaluating a mineral asset is the NPV. Most of the mining companies employ this technique for evaluating the expected economic benefits provided by the exploration and exploitation of a mineral deposit. However, companies also wish to know how their assets are creating value through the several exploration and development phases. The purpose being to assess the progressive value of the mineral asset in agreement with the information and data cumulated through the different steps from exploration to project approval. This paper establishes the value of a copper mineral deposit through their successive phases from exploration to feasibility and approval using the options’ binomial nodes framework. Results are applied to two copper negotiations for method validation. 展开更多
关键词 Mine Value Exploration Phases Binomial Nodes Copper Deposits Method Validation
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Comparative Analysis for Evaluating Wind Energy Resources Using Intelligent Optimization Algorithms and Numerical Methods
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作者 Musaed Alrashidi 《Computer Systems Science & Engineering》 SCIE EI 2023年第10期491-513,共23页
Statistical distributions are used to model wind speed,and the twoparameters Weibull distribution has proven its effectiveness at characterizing wind speed.Accurate estimation of Weibull parameters,the scale(c)and sha... Statistical distributions are used to model wind speed,and the twoparameters Weibull distribution has proven its effectiveness at characterizing wind speed.Accurate estimation of Weibull parameters,the scale(c)and shape(k),is crucial in describing the actual wind speed data and evaluating the wind energy potential.Therefore,this study compares the most common conventional numerical(CN)estimation methods and the recent intelligent optimization algorithms(IOA)to show how precise estimation of c and k affects the wind energy resource assessments.In addition,this study conducts technical and economic feasibility studies for five sites in the northern part of Saudi Arabia,namely Aljouf,Rafha,Tabuk,Turaif,and Yanbo.Results exhibit that IOAs have better performance in attaining optimal Weibull parameters and provided an adequate description of the observed wind speed data.Also,with six wind turbine technologies rating between 1 and 3MW,the technical and economic assessment results reveal that the CN methods tend to overestimate the energy output and underestimate the cost of energy($/kWh)compared to the assessments by IOAs.The energy cost analyses show that Turaif is the windiest site,with an electricity cost of$0.016906/kWh.The highest wind energy output is obtained with the wind turbine having a rated power of 2.5 MW at all considered sites with electricity costs not exceeding$0.02739/kWh.Finally,the outcomes of this study exhibit the potential of wind energy in Saudi Arabia,and its environmental goals can be acquired by harvesting wind energy. 展开更多
关键词 Weibull distribution conventional numerical methods intelligent optimization algorithms wind resource exploration and exploitation cost of energy($/kWh)
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Lateral bearing characteristics of subsea wellhead assembly in the hydrate trial production engineering
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作者 Jing Zeng Wen-wei Xie +8 位作者 Bei-bei Kou Jing-an Lu Xing-chen Li De-jun Cai Hao-xian Shi Ke-wei Zhang Hua-qing Liu Jin Li Bo Li 《China Geology》 CAS CSCD 2023年第3期455-465,共11页
Conductor and suction anchor are the key equipment providing bearing capacity in the field of deep-water drilling or offshore engineering,which have the advantages of high operation efficiency and short construction p... Conductor and suction anchor are the key equipment providing bearing capacity in the field of deep-water drilling or offshore engineering,which have the advantages of high operation efficiency and short construction period.In order to drill a horizontal well in the shallow hydrate reservoir in the deep water,the suction anchor wellhead assembly is employed to undertake the main vertical bearing capacity in the second round of hydrate trial production project,so as to reduce the conductor running depth and heighten the kick-off point position.However,the deformation law of the deep-water suction anchor wellhead assembly under the moving load of the riser is not clear,and it is necessary to understand the lateral bearing characteristics to guide the design of its structural scheme.Based on 3D solid finite element method,the solid finite element model of the suction anchor wellhead assembly is established.In the model,the seabed soil is divided into seven layers,the contact between the wellhead assembly and the soil is simulated,and the vertical load and bending moment are applied to the wellhead node to simulate the riser movement when working in the deep water.The lateral bearing stability of conventional wellhead assembly and suction anchor wellhead assembly under the influence of wellhead load is discussed.The analysis results show that the bending moment is the main factor affecting the lateral deformation of the wellhead string;the anti-bending performance from increasing the outer conductor diameter is better than that from increasing the conductor wall thickness;for the subsea wellhead,the suction anchor obviously improves the lateral bearing capacity and reduces the lateral deformation.The conduct of the suction anchor wellhead assembly still needs to be lowered to a certain depth that below the maximum disturbed depth to ensure the lateral bearing stability,Thus,a method for the minimum conductor running depth for the suction anchor wellhead assembly is developed.The field implementations show that compared with the first round of hydrate trial production project,the conductor running depth is increased by 9.42 m,and there is no risk of wellhead overturning during the trial production.The method for determining the minimum conductor running depth in this paper is feasible and will still play an important role in the subsequent hydrate exploration and development. 展开更多
关键词 Natural gas hydrate Deep-water Subsea wellhead Suction anchor Wellhead stability 3D solid finite element method Hydrate trial exploration engineering Natural gas hydrate trial production Shenhu area The South China Sea
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Visual-Graphical Methods for Exploring Psychological Longitudinal Data
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作者 Hsiang-wei Ker 《Psychology Research》 2012年第9期545-561,共17页
关键词 纵向数据 图形技术 视觉 心理 时间变化 异方差性 误差范围 截面数据
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Improving the accuracy of heart disease diagnosis with an augmented back propagation algorithm
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作者 颜红梅 《Journal of Chongqing University》 CAS 2003年第1期31-34,共4页
A multilayer perceptron neural network system is established to support the diagnosis for five most common heart diseases (coronary heart disease, rheumatic valvular heart disease, hypertension, chronic cor pulmonale ... A multilayer perceptron neural network system is established to support the diagnosis for five most common heart diseases (coronary heart disease, rheumatic valvular heart disease, hypertension, chronic cor pulmonale and congenital heart disease). Momentum term, adaptive learning rate, the forgetting mechanics, and conjugate gradients method are introduced to improve the basic BP algorithm aiming to speed up the convergence of the BP algorithm and enhance the accuracy for diagnosis. A heart disease database consisting of 352 samples is applied to the training and testing courses of the system. The performance of the system is assessed by cross-validation method. It is found that as the basic BP algorithm is improved step by step, the convergence speed and the classification accuracy of the network are enhanced, and the system has great application prospect in supporting heart diseases diagnosis. 展开更多
关键词 心脏病 反向繁衍算法 多层感知器神经网络 诊断方法 共轭梯度方法
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