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Axial-torsional nonlinear vibration of bottom hole assembly in the air drilling technology

Petroleum 2024年第3期10卷 446-461页

作者： Shujie Ding Pan Fang Gao Li Junan Lu yanmin wang Yang Li Yutian Han Dong Xiao School of Mechanical Engineering Southwest Petroleum UniversityChengdu610500China Petroleum Engineering School Southwest Petroleum UniversityChengdu610500China Petrochina Tarim Oilfield CNPCKorla841000China PetroChina Huabei Oilfield Co CNPC834000China

The safety and efficiency of drilling engineering are greatly impeded by destructive vibrations of drill string in air drilling,such as stick-slip,bit-bounce and their coupled *** avoid or suppress these vibrations improving the stability of drilling operations,revealing the occurrence mechanisms of abovementioned harmful vibrations are indispensable by investigating dynamics characteristics of drill string *** this paper,an axial-torsional coupled dynamics model that can capture the motion behaviors of bottom hole assembly(BHA)is established adopting the lumped parameter ***,a rate of penetration(ROP)model appropriating for air drilling is obtained firstly by linear fitting ***,a novel discontinuous support model is established to describe the bitformation ***,BHA dynamics are discussed using numerical simulations under different vibration scenarios:normal operation;stick-slip;bit-bounce;bit-bounce and stick-slip ***,in two drilling modes:the continuous and intermittent drilling,the vibration mitigation strategies and dynamics sensibility study of BHA are carried out based on the parametric *** results show that increasing torsional stiffness of drill-pipes,appropriately adjusting rotation speed of top driven system and dynamic weight on bit(WOB)are deemed as an effective strategy suppressing or eliminating stick-slip and bit-bounce vibrations of *** that the rotation speed of top driven system and dynamic WOB are 5 rad/s and 3.5 kN,***,the constructed probability maps allow to driller to choose reasonable mechanical parameters,thereby realizing smooth drilling operation in the air drilling.

关键词： Drill string BHA Contact model ROP Stick-slip Bit-bounce

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Mechanism of Guangdong Shenqu in regulating intestinal flora in mice with food stagnation and internal heat based on 16S rDNA sequencing Author links open overlay panel

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Journal of Traditional Chinese Medical Sciences 2024年第2期11卷 232-244页

作者： Yani Jiang Zhenhong Zhang Han Chen yanmin wang Yanrui Xu Zijie Chen Yan Xu Jingjuan wang School of Chinese Materia Medica Beijing University of Chinese MedicineBeijing102488China School of Chinese Traditional Medicine Beijing University of Chinese MedicineBeijing102488China Department of Chemistry Cleveland State UniversityCleveland44115USA

Objective To investigate the effect of Guangdong Shenqu(GSQ)on intestinal flora structure in mice with food stagnation through 16S rDNA *** Mice were randomly assigned to control,model,GSQ low-dose(GSQL),GSQ medium-dose(GSQM),GSQ high-dose(GSQH),and lacidophilin tablets(LAB)groups,with each group containing 10 mice.A food stagnation and internal heat mouse model was established through intragastric administration of a mixture of beeswax and olive oil(1:15).The control group was administered normal saline,and the model group was administered beeswax and olive oil to maintain a *** GSQL(2 g/kg),GSQM(4 g/kg),GSQH(8 g/kg),and LAB groups(0.625 g/kg)were administered corresponding drugs for 5 *** administration,16S rDNA sequencing was performed to assess gut microbiota in mouse fecal *** The model group exhibited significant intestinal flora *** GSQ administration,the abundance and diversity index of the intestinal flora increased significantly,the number of bacterial species was regulated,andαandβdiversity were *** administration increased the abundance of probiotics,including Clostridia,Lachnospirales,and Lactobacillus,whereas the abundance of conditional pathogenic bacteria,such as Allobaculum,Erysipelotrichaceae,and Bacteroides *** prediction analysis indicated that the pathogenesis of food stagnation and GSQ intervention were primarily associated with carbohydrate,lipid,and amino acid metabolism,among other metabolic *** The digestive mechanism of GSQ may be attributed to its role in restoring diversity and abundance within the intestinal flora,thereby improving the composition and structure of the intestinal flora in mice and subsequently influencing the regulation of metabolic pathways.

关键词： Guangdong Shenqu Food stagnation Gut microbiota High-throughput gene sequencing Species annotation Metabolic pathway

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Sensing-Communication-Computing-Control Closed Loop for NOMA-UAV Systems

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China Communications 2024年第8期21卷 89-103页

作者： Lei Chengleyang Feng Wei wang Jue wang yanmin Jin Shi Yin Liuguo Ge Ning Department of Electronic Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Space Network and Communications Tsinghua UniversityBeijing 100084China School of Information Science and Technology Nantong UniversityNantong 226019China School of Information Engineering Minzu University of ChinaBeijing 100041China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China

In the areas without terrestrial communication infrastructures,unmanned aerial vehicles(UAVs)can be utilized to serve field robots for mission-critical *** this purpose,UAVs can be equipped with sensing,communication,and computing modules to support various requirements of *** the task process,different modules assist the robots to perform tasks in a closed-loop way,which is referred to as a sensing-communication-computing-control(SC3)*** this work,we investigate a UAV-aided system containing multiple SC^(3)loops,which leverages non-orthogonal multiple access(NOMA)for efficient resource *** describe and compare three different modelling levels for the SC^(3)*** on the entropy SC^(3)loop model,a sum linear quadratic regulator(LQR)control cost minimization problem is formulated by optimizing the communication *** for the assure-to-be-stable case,we show that the original problem can be approximated by a modified user fairness problem,and accordingly gain more insights into the optimal *** results demonstrate the performance gain of using NOMA in such task-oriented systems,as well as the superiority of our proposed closed-loop-oriented design.

关键词： closed loop linear quadratic regulator(LQR) non-orthogonal multiple access(NOMA) power allocation unmanned aerial vehicle(UAV)

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A model with multiple intracranial aneurysms: possible hemodynamic mechanisms of aneurysmal initiation, rupture and recurrence

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中华神经外科杂志(英文) 2024年第2期10卷 1-8页

作者： Li Wenqiang wang Chao wang yanmin Zhao Yapeng Yang Xinjian Liu Xianzhi Liu Jian Department of Interventional Neuroradiology and Neurosurgery Beijing Neurosurgical Institute and Beijing Tiantan Hospital Beijing China Department of Neurosurgery The First Affiliated Hospital of Zhengzhou University Zhengzhou China

Background Hemodynamic factors play an important role in aneurysm initiation, growth, rupture, and recurrence, while the mechanism of the hemodynamic characteristics is still controversial. A unique model of multiple aneurysms (initiation, growth, rupture, and recurrence) is helpful to avoids the confounders and further explore the possible hemodynamic mechanisms of aneurysm in different *** We present a model with multiple aneurysms, and including the states of initiation, growth, rupture, and recurrence, discuss the proposed mechanisms, and describe computational fluid dynamic model that was used to evaluate the likely hemodynamic effect of different states of the *** The hemodynamic analysis suggests that high flow impingement and high WSS distribution at normal parent artery was found before aneurysmal initiation. The WSS distribution and flow velocity were decreased in the new sac after aneurysmal growth. Low WSS was the risk hemodynamic factor for aneurysmal rupture. High flow concentration region on the neck plane after coil embolization still marked in recanalized *** Associations have been identified between high flow impingement and aneurysm recanalization, while low WSS is linked to the rupture of aneurysms. High flow concentration and high WSS distribution at normal artery associated with aneurysm initiation and growth, while after growth, the high-risk hemodynamics of aneurysm rupture was occurred, which is low WSS at aneurysm dome.

关键词： Multiple intracranial aneurysms Hemodynamic Aneurysm initiation and growth Rupture Recurrence

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Strong Feller Property for SDEs with Super-linear Drift and Hölder Diffusion Coefficients

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应用数学 2024年第4期37卷 1066-1073页

作者： wang yanmin SHA Xiang GUO Zhongkai School of Mathematics and Statistics South-Central MinZu UniversityWuhan 430074China

In this paper,we investigate the strong Feller property of stochastic differential equations(SDEs)with super-linear drift and Hölder diffusion *** utilizing the Girsanov theorem,coupling method,truncation method and t... 详细信息

关键词： Super-linear drift Hölder continuous diffusion SDEs Strong Feller

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无人机数据采集系统中基于动态干扰的轨迹优化方案

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数据采集与处理 2024年第5期39卷 1271-1286页

作者：朱江王彦敏重庆邮电大学通信与信息工程学院重庆400065

针对无人机数据采集中的动态干扰问题,提出一种无人机飞行轨迹实时优化方案。在采集距离有限的情况下,通过优化无人机飞行轨迹,使无人机在有限任务时间内的能耗最小。为了规避干扰,该方案分为初始轨迹规划和在线轨迹优化2个阶段。初始... 详细信息

针对无人机数据采集中的动态干扰问题,提出一种无人机飞行轨迹实时优化方案。在采集距离有限的情况下,通过优化无人机飞行轨迹,使无人机在有限任务时间内的能耗最小。为了规避干扰,该方案分为初始轨迹规划和在线轨迹优化2个阶段。初始轨迹规划阶段,不考虑干扰,根据轨迹成本和转角能耗进行离线规划;在线轨迹优化阶段,在初始轨迹基础上,考虑动态干扰,设计出基于马尔可夫预测模型的干扰定位算法,同时还提出干扰势场,对初始轨迹进行优化。仿真分析表明,所提方案可以有效改善无人机通信的抗干扰性能,提高无人机数据采集能力。

关键词：无人机通信动态干扰轨迹优化数据采集马尔可夫预测模型

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基于UDF的煤层注水渗流演化规律的数值模拟研究

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煤矿安全 2024年第1期55卷 78-85页

作者：葛俊岭王彦敏刘涛济宁矿业集团有限公司霄云煤矿山东济宁272213 中煤科工集团重庆研究院有限公司重庆400037

为了更好地揭示煤体高压注水渗流演化规律,提高煤层注水抑尘效果;基于三轴压缩和煤矿生产实际,通过煤岩渗透性试验得到煤岩变形与孔隙水压匹配关系;利用用户自定义函数UDF模块将其编译到Fluent中对钻孔注水过程中的流体压力场、速度场... 详细信息

为了更好地揭示煤体高压注水渗流演化规律,提高煤层注水抑尘效果;基于三轴压缩和煤矿生产实际,通过煤岩渗透性试验得到煤岩变形与孔隙水压匹配关系;利用用户自定义函数UDF模块将其编译到Fluent中对钻孔注水过程中的流体压力场、速度场及水量分布情况进行模拟,分析不同注水压力下钻孔径向周围煤体内润湿范围以及渗流速度等因素。结果表明:渗流场压力随着孔隙水压的增大而增大,压力变化率随着时间段的增长逐渐降低并趋至稳定,渗流场速度变化展现出相似的变化规律;随着孔隙水压的不断增大,煤体孔隙率随之增大,煤体内部含水率逐渐升高,分布范围从钻孔周围逐渐向两侧扩大,煤层钻孔周围的润湿过程是一个快速增长后缓慢降低达到稳定的状态。

关键词：煤层注水数值模拟 UDF 孔隙率渗流润湿分布

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数字中国可以是什么样子?——中国发展数字经济的若干战略问题

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文化纵横 2024年第5期 112-122页

作者：孙喜王彦敏蔡锦江首都经济贸易大学工商管理学院新场智库深圳市智慧湾科技有限公司

中国到底应该如何发展数字经济?中国到底应该如何推进产业、政府与社会的数字化转型?尤其是如何确保中国庞大的工业体系与工业能力向数字时代平稳过渡,而不至于引发动荡甚至衰退?准确回答上述问题,找出一条发展数字经济的根本出路,于国... 详细信息

中国到底应该如何发展数字经济?中国到底应该如何推进产业、政府与社会的数字化转型?尤其是如何确保中国庞大的工业体系与工业能力向数字时代平稳过渡,而不至于引发动荡甚至衰退?准确回答上述问题,找出一条发展数字经济的根本出路,于国内外两方面都意义重大。从国内来看,这有助于破解当前大批企业对数字化转型“看不懂”“不想转”甚至“不敢转”的困境,有助于让那些在严峻形势下“躺平”的企业家重新站起来,杀回经济发展第一线。

关键词：数字经济产品数字化人工智能+

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全民阅读背景下高校图书馆中国传统文化文献阅读推广研究

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河南图书馆学刊 2024年第10期44卷 88-90页

作者：王艳敏开封大学图书馆河南开封475004

文章探讨了高校图书馆在传统文化阅读推广方面的意义和可行性,提出了全民阅读背景下高校图书馆开展中国传统文化文献阅读推广的具体方法,以期提升大学生的文化素养和阅读兴趣,挖掘传统文化文献的深层价值,推动传统文化的可持续发展。

关键词：高校图书馆中国传统文化阅读推广

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单宁酸沉淀分离-硫酸高铈滴定法测定钛铝铌合金中铌

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冶金分析 2024年第2期44卷 60-65页

作者：张霞谈笑王艳敏于雪陈静钢研纳克检测技术股份有限公司北京100094

钛铝铌合金因其密度小、抗氧化、耐高温等良好的性能在航空航天领域得到广泛应用,准确测定钛铝铌合金中铌具有重要意义。采用硫酸高铈标准溶液滴定铌元素时,大量存在的钛会对滴定结果产生影响。实验将钛铝铌合金经硫酸、氢氟酸、硝酸溶... 详细信息

钛铝铌合金因其密度小、抗氧化、耐高温等良好的性能在航空航天领域得到广泛应用,准确测定钛铝铌合金中铌具有重要意义。采用硫酸高铈标准溶液滴定铌元素时,大量存在的钛会对滴定结果产生影响。实验将钛铝铌合金经硫酸、氢氟酸、硝酸溶解后,用单宁酸沉淀铌与大部分钛分离;再将沉淀溶解之后,在硫酸介质中加入过氧化氢与铌元素形成稳定的1∶1过氧化氢铌络合物;通过定量加入过量的硫酸亚铁铵标准溶液将过氧化氢铌络合物破坏,剩余的硫酸亚铁铵标准溶液再用硫酸高铈标准溶液进行滴定,最终通过计算得到铌含量,从而建立了钛铝铌合金中铌元素的测定方法。试验考察了钛元素对铌的干扰,在含有4.00 mg铌的待滴定溶液中钛的最大允许量是1.60 mg,钛铝铌合金经单宁酸沉淀分离后待测液中钛含量远小于1.60 mg,因此不影响铌的滴定。按照实验方法测定钛铝铌合金样品中铌,结果的相对标准偏差(RSD,n=11)为0.21%~0.25%,极差为0.30%~0.33%;回收率为99%~101%。

关键词：钛铝铌合金铌钛单宁酸沉淀分离硫酸高铈滴定法过氧化氢硫酸亚铁铵

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