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Routes to hydrate formation from water dissolved in gas and impact of mineral surfaces

Petroleum 2021年第4期7卷 385-401页

作者： Bjørn Kvamme Na Wei Jinzhou Zhao Shouwei Zhou Liehui Zhang wantong sun Navid Saeidi State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityXindu Road No.8Chengdu610500China State Key Laboratory of Natural Gas Hydrate Sun Palace South Street No.6Beijing10027China Hyzenenergy 26701 Quail CreekLaguna HillsCA92656USA Strategic Carbon LLC 20 Ladd St.Suite 200PortsmouthNH03801USA

Mineral surfaces adsorb water to extreme densities and corresponding low chemical *** results in a dual effect in terms of *** and slightly polar components adsorb directly on mineral surfaces and generate efficient conditions for hydrate *** due to the extremely low chemical potential of adsorbed water the hydrate nuclei formed towards mineral surfaces have to either detach from the vicinity of mineral surfaces,or be bridged by structured water in a dynamic attachment of hydrate cores some few nm outside mineral *** transport of gas(CH4,gas mixtures,CO2)the conventional water dew-point analysis will typically result in a substantially higher acceptable water concentration as compared to the concentration for adsorption of water from gas to rust *** formation of hydrate from water dissolved in gas is thermodynamically feasible,as discussed in open *** this work we demonstrate that it is also feasible in terms of mass transport.A new theory for enthalpy of hydrate dissociation has been extended to also direct hydrate formation from water dissolved in *** remaining question is whether direct hydrate formation from gas is also feasible in terms of transporting the hydrate formation heat away through a heat insulating *** propose further research strategies to enlighten this *** of glycols to critical points in processing of gas or transport is already in use by companies like for instance *** is,however,a need for more work on how efficient it is and if it can also be used for multiphase transport of hydrocarbons with significant water *** research activities are in progress and briefly outlined here.

关键词： Hydrate Thermodynamics Risk Inhibitors

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Alcohols for hydrate inhibition-Different alcohols and different mechanisms

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Petroleum 2022年第1期8卷 1-16页

作者： Bjorn Kvamme Na Wei Jinzhou Zhao Shouwei Zhou Liehui Zhang wantong sun Navid Saeidi State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China State Key Laboratory of Natural Gas Hydrate Beijing10027China Hyzenenergy Laguna Hills92656USA Strategic Carbon LLC Portsmouth03801USA

Methanol has been used to prevent hydrate formation in industrial handling of hydrate forming mixtures containing water for many *** is also used for the same purpose in countries that have easy access to low price ethanol,like for instance *** to these small alcohols is that they also have surfactant properties that will promote hydrate formation,but when added to water in sufficient amounts,the hydrate prevention characteristics will *** alcohols will primarily prevent heterogeneous hydrate formation on the interface between water and a separate hydrate *** effect of“alcohol”on both of these routes to hydrate formation are investigated and compared to experimental *** particular we also investigate the effects of these small alcohols on Gibbs free energy for the hydrate formed on the new,shifted,stability *** free energy is generally higher than hydrate formed from pure *** of hydrate formation are also higher for hydrate formed from water containing *** are negative numbers,so in absolute values released formation enthalpy is *** presence of these alcohols in water will also prevent homogeneous hydrate formation from dissolved hydrate formers in *** have more important roles in other routes to hydrate *** hydrate nucleation towards mineral surfaces is feasible in different *** hydrate formers like H2S and CO_(2)can adsorb directly on rust,and as discussed here,are able to form hydrate from adsorbed state on rust ***-polar hydrocarbons like,for instance methane might get trapped in structured water and then nucleate to *** research on this is published and further research is in *** have very strong attraction to rust and corresponding chemical potentials for adsorbed glycols on rust are favourable enough to facilitate phase transition from glycols dissolved in water over to *** of glycol in gas

关键词： Hydrate Non-equilibrium Thermodynamics Alcohols Nucleation

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Analysis of Pragmatic Functions of“Smile”Emoji in Chinese WeChat Communication Between People of Different Ages

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Sino-US English Teaching 2021年第8期18卷 207-215页

作者： sun wantong University of Shanghai for Science and Technology ShanghaiChina

With the rapid development of social media,emojis have gradually become an indispensable communication tool in computer-mediated communication(CMC).In recent years,researchers have found that emojis not only have semantic and syntax functions(e.g.,punctuation),but also perform pragmatic ***,this thesis is to investigate the differences in pragmatic functions of“smile”emoji between people of different *** this paper is a small-scale quantitative research based on the eight pragmatic functions of emoticons proposed by Yus(2014).To find out similarities and differences of“smile”emoji between people of different ages,this paper compared the use frequency and pragmatic functions of“smile”emoji in two WeChat groups which are from youth and middle-aged people and did statistical analysis by Statistic Package for Social Science(SPSS).According to similarities and differences in frequency and pragmatic functions,“smile”emoji can be divided into four categories,which are:(1)similar frequency but different functions;(2)different frequency but similar function,(3)emojis exist only in one group;and(4)similar in both use frequency and ***,the results suggest that there is a difference between people of different ages using“smile”emoji in WeChat ***,this study will provide insights into how to use emojis in WeChat when people at different ages communicate with each other can make a successful conversation.

关键词： smile emoji pragmatic functions frequency WeChat communication

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Sensitivity analysis of reservoir risk in marine gas hydrate drilling

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Petroleum 2021年第4期7卷 427-438页

作者： wantong sun Jun Pei Na Wei Jinzhou Zhao Jin Xue Shouwei Zhou Liehui Zhang Bjørn Kvamme Qingping Li Haitao Li Lin Jiang Chao Zhang Cong Li State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China State Key Laboratory of Natural Gas Hydrate Beijing100027China CNOOC Research Institutes Limited Liability Company Beijing100027China Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang) Zhanjiang524013China

It is easy to change the original temperature state of marine gas hydrate reservoir by drilling,which leads to uncontrollable decomposition of gas hydrate and release of large amount of *** decomposition gas will further escape and expand,and the reservoir will break and collapse due to its weak cementation characteristic,which will easily lead to a series of other potential ***,in this study,based on the drilling process of marine gas hydrate,we establish the theoretical model and numerical calculation method of wellbore temperature field,analyze the influence on wellbore temperature of drilling fluid displacement,density,viscosity and injection temperature,and seawater *** the sensitivity laws of reservoir risk in marine gas hydrate drilling are *** results show that with the increase of drilling fluid displacement,density,viscosity and injection temperature,the temperature in lower well section and bottom hole will increase,making the increasing amplitude of temperature in hydrate reservoir larger and the scope of influence on hydrate reservoir stability ***,drilling is more likely to raise the temperature of reservoirs in shallow seawater depth,posing greater ***,engineering measures to avoid risks caused by rising reservoir temperature in marine gas hydrate reservoir drilling are *** study is of great significance to ensure the safety of marine gas hydrate reservoir drilling.

关键词： Marine gas hydrate Drilling Temperature rising Reservoir risk Sensitivity analysis

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Research on intelligent judgment method of natural gas hydrate drilling risk

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Petroleum 2021年第4期7卷 439-450页

作者： Haitao Li Zhaolong Ge Na Wei wantong sun Yao Zhang Jin Xue Lin Jiang Jun Pei Bing Liao Hongliang Cao Ruixu Zhang Shuangli Li Qixia Lu Jinyan Luo State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400030China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China State Key Laboratory of Natural Gas Hydrate Beijing100027China Drilling Department of CNPC Offshore Engineering Company Limited Tianjin300451China

There are many emergency risks in the process of natural gas hydrate(NGH)*** order to ensure the safe and efficient exploitation of NGH,it is urgent to establish an intelligent judgment method for the risks in the process of NGH *** this paper,the response relationship between monitoring parameters and risk categories of NGH while drilling is *** on fuzzy analytic hierarchy process(FAHP),the comprehensive weights of 10 risk monitoring parameters are obtained,including gas production,wellbore instability,hydrate ice barrier,drill string fracture,sticking,bit balling,drilling tool piercement,gas seepage,seabed subsidence and seabed ***,the comprehensive judgment weight matrix is constructed,and the reasonable fluctuation range of monitoring parameters is ***,the intelligent judgment method of NGH drilling risk is *** intelligent judgment and alarm of NGH drilling risks can be realized quickly and accurately by this method,namely,it can monitor the risks in the process of operation and guarantee the construction safety of NGH drilling.

关键词： Natural gas hydrate Monitoring parameter Risk Analytic hierarchy process Fuzzy judgement

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基于相关性分析的多标签特征选择方法

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重庆邮电大学学报（自然科学版） 2021年第6期33卷 1024-1037页

作者：王进孙万彤重庆邮电大学数据工程与可视计算重点实验室重庆400065

针对现有大多数多标签特征选择算法未能有效去除特征空间冗余特征,同时也忽略了标签差异性的现状,提出一种基于相关性分析的多标签特征选择方法,利用特征之间的相关度对特征进行分组,解决了特征之间的相关性问题。根据样本所对应的标签... 详细信息

针对现有大多数多标签特征选择算法未能有效去除特征空间冗余特征,同时也忽略了标签差异性的现状,提出一种基于相关性分析的多标签特征选择方法,利用特征之间的相关度对特征进行分组,解决了特征之间的相关性问题。根据样本所对应的标签属性对样本做一个正负类的聚类,对于正样本和负样本所构成的正类簇和负类簇单独确定其聚类个数,并计算原特征到正负类簇中各个类中心的距离,如此便产生了标签特定特征空间;将标签共享的特征空间和标签特定特征空间融合,考虑到多个标签之间的个性和关联性,解决了标签的差异性问题。实验测试表明,相较于现有的多标签特征选择算法,提出的基于相关性分析的多标签特征选择方法在各个分类指标上均有较优的表现,充分证明了该方法的有效性。

关键词：机器学习多标签学习特征选择关联性分析特征空间融合

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因地制宜的乡村建设评价指标体系构建研究--以长三角地区为例

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城市建筑 2023年第9期20卷 67-72页

作者：姚栋孙婉桐同济大学建筑与规划学院

为应对我国乡村发展的多样性,建立因地制宜、科学精准的评价体系成了实现乡村振兴的有力保障。然而,管理者在评价体系构建中缺乏明确的工作路径,难以充分获取并量化专家指导意见。因此,文章以长三角地区为例,基于移动端可视化SP法与KAN... 详细信息

为应对我国乡村发展的多样性,建立因地制宜、科学精准的评价体系成了实现乡村振兴的有力保障。然而,管理者在评价体系构建中缺乏明确的工作路径,难以充分获取并量化专家指导意见。因此,文章以长三角地区为例,基于移动端可视化SP法与KANO模型探索科学可复制的乡村建设评价指标体系建构路径:(1)指标筛选;(2)权重赋值;(3)属性判断;(4)调整优化;(5)评价建议。通过分析指标体系构建的专家集体智慧,可为长三角地区乡村发展提供科学建议。

关键词：乡村振兴乡村建设评价指标体系因地制宜长三角地区叙述性偏好法 KANO模型

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考虑负荷特性的光伏消纳能力的模拟与评估

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太阳能学报 2024年第4期45卷 475-481页

作者：孙万通陈众陈慧霞徐翼郎坤长沙理工大学电气与信息工程学院长沙410004 国网河北省电力有限公司馆陶分公司邯郸057750

针对目前在配电网光伏消纳能力评估过程中不能全面考虑电力系统中负荷特性多样化对光伏消纳能力影响的不足,提出一种考虑负荷运行中的实际情况,光伏消纳模拟与概率评估的方法。首先采用支持向量机-随机森林算法对负荷数据进行清洗,再采... 详细信息

针对目前在配电网光伏消纳能力评估过程中不能全面考虑电力系统中负荷特性多样化对光伏消纳能力影响的不足,提出一种考虑负荷运行中的实际情况,光伏消纳模拟与概率评估的方法。首先采用支持向量机-随机森林算法对负荷数据进行清洗,再采用改进谱聚类算法对不同类型的负荷特性进行聚类分析,然后基于场景分析法选取不同负荷的类型曲线作为节点处负荷数据,最后基于蒙特卡洛模拟法和均匀抽样法进行光伏消纳方案随机模拟与消纳能力近似评估。基于IEEE 33节点系统算例分析,对有无考虑负荷特性的抽样结果进行对比,有效验证了所述方法的适用性。

关键词：配电网光伏负荷改进谱聚类算法蒙特卡洛模拟法均匀抽样

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基于改进LSTM的光伏发电功率预测方法研究

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太阳能学报 2024年第11期45卷 296-302页

作者：彭曙蓉陈慧霞孙万通郭丽娟李彬长沙理工大学电气与信息工程学院长沙410004

针对光伏发电功率存在的较大随机性和不确定性问题,提出一种基于改进长短期记忆神经网络的光伏发电功率预测方法,以此提高光伏发电功率预测的准确性。首先,分析与光伏发电出力相关性较强的气象特征,并利用t分布近邻嵌入降维技术将被选... 详细信息

针对光伏发电功率存在的较大随机性和不确定性问题,提出一种基于改进长短期记忆神经网络的光伏发电功率预测方法,以此提高光伏发电功率预测的准确性。首先,分析与光伏发电出力相关性较强的气象特征,并利用t分布近邻嵌入降维技术将被选取的特征数据降至二维,以减小数据复杂度。然后,通过密度峰值聚类将降维后的数据自动聚成3类,帮助训练长短期记忆神经网络预测模型。与传统循环神经网络和长短期记忆神经网络模型相比,所提模型在光伏发电功率预测方面表现出较高的预测精度,MSE减少49.00%和31.77%,RMSE减少28.59%和17.41%,MAE减少62.35%和53.52%。研究结果表明,该模型在光伏发电功率预测方面具有较好的适用性。

关键词：光伏出力预测神经网络聚类分析 t分布近邻嵌入

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“厦两头”与“厦周匝”——从早期歇山建筑形象看歇山顶的起源与演化

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城市建筑 2023年第15期20卷 178-183页

作者：赵振宇孙婉桐同济大学建筑与城市规划学院

在歇山顶的众多祖型中,“悬山加披”的组合更为学界所公认,也更易于现有实物资料中得到证实。而悬山顶向歇山顶的演化,又存在“悬山两际加披厦”与“悬山四周加披厦”两种形式。现存早期歇山建筑形象中,可见两种与后世不同的歇山屋顶类... 详细信息

在歇山顶的众多祖型中,“悬山加披”的组合更为学界所公认,也更易于现有实物资料中得到证实。而悬山顶向歇山顶的演化,又存在“悬山两际加披厦”与“悬山四周加披厦”两种形式。现存早期歇山建筑形象中,可见两种与后世不同的歇山屋顶类型,很有可能分别对应了“厦两头”和“厦周匝”两种歇山顶生成逻辑。文章尝试通过对东汉至宋辽时期歇山建筑形象及建筑实例的分析,辨析早期歇山顶的起源、传播与演化过程。

关键词：歇山顶厦两头厦周匝井字式连架式

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