检索结果-南通市图书馆

Variable stiffness methods of flexible robots for minimally invasive surgery:A review

在线全文

学校读者我要写书评

暂无评论

Biomimetic Intelligence & Robotics 2024年第3期4卷 3-14页

作者： botao lin Shuang Song Jiaole Wang Harbin Institute of Technology(Shenzhen) Shenzhen 518055China

With high flexibility and slim body,flexible robots have been widely used in minimally invasive surgery because they can safely reach the lesion deep inside the human body through small incisions or natural ***,high stiffness of robot body is also required for transferring force and maintaining the motion *** meet these two contradictory requirements,various methods have been implemented to enable adjustable stiffness for flexible surgical *** this review,we first summarize the anatomic constraints of common natural tracts of human body to provide a guidance for the design of variable stiffness flexible *** then,the variable stiffness methods have been categorized based on their basic principles of varying the *** the end,two variable stiffness methods with great potential and the moving strategy of variable stiffness flexible robots are discussed.

关键词： Minimally invasive surgery Continuum robot Variable stiffness

Resistance to chemical attack of bittern-resisting cement in high-bittern environment

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

Journal of University of Science and Technology Beijing 2005年第5期12卷 469-475页

作者： Yunbing Hou Bingwen Wang Yu Chen botao Zhang lin Yu School of Resource ＆ Safety Engineering China University of Mining ＆ Technology （Beijing） Beijing 100083 China

A new kind of bittern-resisting cement （BRC） was introduced. This material is based on the ternary cementitious system of clinker containing C4A3 S phase, high-activity ground granulated blast-furnace slag （GGBFS） and fly ash （FA）. The hydration process and the hydrated products of BRC were studied by means of XRD, TG-DTA and SEM, and the resistance to chemical attack of BRC in high-bittern environment was also examined. The corrosion experiment in seven kinds of brines proved that BRC exhibits an excellent resistance to chemical attack of bittern. The corrosion resistance factors were calculated and all of them were greater than 0.96. It showed that BRC totally controls the cement-based material corrosion in brines from four aspects：（1） making full use of the dominant complementation effect of mineral materials; （2） diminishing the hydrated products easy to be attacked; （3） improving the microstructure of hardened cement mortar; （4） degrading the chemical attack of bittern.

关键词： bittern-resisting cement ternary cementitious system high-activity mineral materials resistance to chemical attack bittern corrosion resistance factor corrosion mechanism

Study on fracture propagation behavior in ultra-heavy oil reservoirs based on true triaxial experiments

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

Petroleum Exploration and Development 2020年第3期47卷 651-660页

作者： lin botao SHI Can ZHUANG Li YOU Hongjuan HUANG Yong State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing 102249China Korea Institute of Civil Engineering and Building Technology Goyang 10223Korea Research Institute of Engineering Technology PetroChina Xinjiang Oilfield CompanyKaramay 834000China

As the ultra-heavy oil reservoirs developed by steam assisted gravity drainage(SAGD)in the Fengcheng oilfield,Xinjiang have problems such as huge steam usage,long preheating period,low production,and inaccessible reserve in local *** on the rock mechanics and porosity/permeability characteristics of heavy oil reservoir and interlayer,a series of true triaxial experiments and CT tests considering the fracturing fluid injection rate,viscosity,perforation density and location of fracture initiation were conducted to disclose the propagation behavior of micro-and macro-fractures in the reservoirs and mudstone *** experiments show that fracturing in the heavy oil reservoirs only generates microfractures that cannot break the *** contrast,when fracturing in the interlayer,the higher the injection rate(greater than 0.6 m^3/min),the lower the viscosity,the easier it is to form macro-fractures in the interlayers,and the further the fractures will propagate into the ***,increasing perforation density tends to create complex macro-fracture network in the interbedded reservoirs and mudstone *** findings of this study can provide scientific guidance for the selection of fracturing layer and the optimization of parameters in the interlayer fracturing of heavy oil reservoirs.

关键词： ultra-heavy oil SAGD mudstone interlayer muddy interlayer fracture propagation true triaxial test

同方期刊数据库

Intelligent production optimization method for a low pressure and low productivity shale gas well

在线全文

学校读者我要写书评

暂无评论

Petroleum Exploration and Development 2022年第4期49卷 886-894页

作者： ZHU Qikang lin botao YANG Guang WANG Lijia CHEN Man College of Artificial Intelligence China University of PetroleumBeijing 102249China College of Safety and Ocean Engineering China University of PetroleumBeijing 102249China College of Information Science and Engineering China University of PetroleumBeijing 102249China Sichuan Shale Gas Exploration and Development Co.LTD Neijiang 641100China China National Petroleum Corporation Southwest Oil and Gas Field Company Sichuan Changning Natural Gas Development Co.Ltd Changning 644000China

Shale gas wells frequently suffer from liquid loading and insufficient formation pressure in the late stage of *** address this issue,an intelligent production optimization method for low pressure and low productivity shale gas well is *** on the artificial intelligence algorithms,this method realizes automatic production and monitoring of gas *** method can forecast the production performance of a single well by using the long short-term memory neural network and then guide gas well production accordingly,to fulfill liquid loading warning and automatic intermittent *** with adjustable nozzle,the method can keep production and pressure of gas wells stable automatically,extend normal production time of shale gas wells,enhance automatic level of well sites,and reach the goal of refined production management by making production regime for each *** tests show that wells with production regime optimized by this method increased 15%in estimated ultimate reserve(EUR).Compared with the development mode of drainage after depletion recovery,this method is more economical and can increase and stabilize production effectively,so it has a bright application prospect.

关键词： shale gas low pressure and low productivity gas well production optimization artificial intelligence long short-term memory neural network adjustable nozzle

在线全文

学校读者我要写书评

暂无评论

疏松砂岩储层微压裂机理与应用技术研究

石油科学通报 2021年第2期6卷 209-227页

作者：林伯韬中国石油大学(北京)油气资源与探测国家重点实验室北京102249 中国石油大学(北京)石油工程学院北京102249 中国石油大学(北京)人工智能学院北京102249

疏松砂岩储层在改造及注水施工中表现出与致密储层压裂迥异的力学变形特征,亟需特定的力学机理解释其宏微观变形行为,从而为现场施工提供理论指导。针对疏松砂岩质地松软、塑性强、渗透率高的岩土力学性质,本文引入土力学的理念,介绍微... 详细信息

疏松砂岩储层在改造及注水施工中表现出与致密储层压裂迥异的力学变形特征,亟需特定的力学机理解释其宏微观变形行为,从而为现场施工提供理论指导。针对疏松砂岩质地松软、塑性强、渗透率高的岩土力学性质,本文引入土力学的理念,介绍微压裂这一储层改造与增注技术,深入分析该类储层在微压裂过程中的扩容及微裂缝起裂机理。在理清微压裂力学机理的基础上,总结归纳已有的储层微压裂效果评价方法,包括室内实验、解析分析和数值计算方法,阐明各类方法的必要性和优缺点。基于力学机理和计算方法,讨论了微压裂技术在超稠油储层改造、井筒解堵和人工干预地应力场中的应用方法和工程案例。最后,以超稠油储层改造为例,提出微压裂效果自动化评价技术。研究发现微压裂为综合孔隙弹性、塑性和断裂多种力学变形的复杂力学机制,在不同的应用场合实现的功能各异,但普遍体现为扩容至微裂缝起裂这一过程的局部至全部特征;分析微压裂作用效果应当考虑多尺度效应,结合多类数值计算方法开展实际工程案例评价。超稠油储层微压裂改造以井周产生微裂缝、井间储层发生孔隙扩容为主,加强井间热对流效应,加速井间连通。微压裂应用于井筒解堵时提供了反洗冲砂、井周扩容与造微裂缝恢复流体通道的作用,从而延长解堵效果。此外,微压裂亦可应用于致密储层,通过人工干预井周、井间、段簇间有效地应力场,使其利于预期造缝目标。未来的技术攻关应集中在完善自动化、进而发展智能化的微压裂技术,逐步取代人工决策及控制。

关键词：疏松砂岩微压裂扩容裂缝解堵地应力智能

基于八叉树的储层改造体积计算方法及工程应用

在线全文

学校读者我要写书评

暂无评论

岩石力学与工程学报 2019年第5期38卷 948-955页

作者：刘星金衍林伯韬林长庆谢琳中国石油大学(北京)石油工程学院北京102249 中国石油大学(北京)油气资源与探测国家重点实验室北京102249 中国石油青海油田勘探开发研究院甘肃酒泉736200

传统的采用规则几何体计算储层改造体积(SRV)往往具有较大误差。为此,提出一种基于八叉树的SRV计算方法,该方法可根据事件点密度生成不规则树状网格化结构,通过提取网格结构中的非空节点的体积来计算压裂改造的SRV。通过蒙特卡罗模拟计... 详细信息

传统的采用规则几何体计算储层改造体积(SRV)往往具有较大误差。为此,提出一种基于八叉树的SRV计算方法,该方法可根据事件点密度生成不规则树状网格化结构,通过提取网格结构中的非空节点的体积来计算压裂改造的SRV。通过蒙特卡罗模拟计算和昆北油田的18口井的应用发现:该方法得到的不规则结构能够较好地包络事件点,有效去除未响应区域带来的计算误差;该方法根据事件点密度进行网格划分,充分考虑了事件点密度对SRV的影响,结果更符合工程认识。实例应用表明,对于较大规模的微地震数据,该方法具较高的计算效率,算得的SRV和油井改造后产液量变化趋势基本一致。相比较传统方法,该方法可为水力压裂施工提供更为可靠的评价指标。

关键词：石油工程八叉树储层改造体积微地震监测水力压裂

Sn掺杂TiO_2/ACF复合材料的制备、表征及光催化性能

在线全文

学校读者我要写书评

暂无评论

化工进展 2016年第2期35卷 549-554页

作者：蔺波涛施冬梅军械工程学院河北石家庄050003

以Ti(OC4H9)4为前体,SnCl_4为Sn源,采用胶溶-回流法制备了Sn掺杂的TiO_2,利用浸渍提拉法将其负载到活性炭纤维(ACF)表面,并运用SEM、XRD、XPS、DRS等手段对TiO_2/ACF复合材料进行表征,考察了复合材料光催化降解气相甲醛的性能。研究结... 详细信息

以Ti(OC4H9)4为前体,SnCl_4为Sn源,采用胶溶-回流法制备了Sn掺杂的TiO_2,利用浸渍提拉法将其负载到活性炭纤维(ACF)表面,并运用SEM、XRD、XPS、DRS等手段对TiO_2/ACF复合材料进行表征,考察了复合材料光催化降解气相甲醛的性能。研究结果表明,Sn元素掺入TiO_2晶格中,有利于抑制TiO_2晶粒的生长,促进TiO_2由锐钛矿型向金红石型的转化,光吸收范围发生一定程度红移;HNO_3的用量为0.015mol、掺锡量为6%、负载两层的TiO_2/ACF-50复合材料在紫外光照射下对甲醛的去除率复合材料可达85.2%,而在可见光下仅为65.3%。

关键词： TiO2/ACF复合材料吸附催化剂锡掺杂

NEW PERTURBATION TECHNIQUE FOR TRANSIENT ANALYSIS AND ITS APPLICATIONS IN DC-DC PWM SWITCHING POWER CONVERTERS

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics(China) 1997年第4期14卷 357-366页

作者： lin botao Qiu Shuisheng(Department of Electronic Engineering, South China University of Technology, Guang Zhou 510641) Department of Electronic Engineering South China University of Technology Guang Zhou

An improved perturbation technique proposed in a recent paper (Int. J. Electronics, vol. 63, pp.403-414) has been successfully applied to steady-state analysis of PWM switching converters. This paper extends the algorithm to transient analysis of a broader class of non-linear systems. As an example, the transient response of a Boost PWM switching converter is analyzed to demonstrate its simplicity and accuracy.

关键词： Asymptotic method Transient analysis Switching converters Nonlinear systems

Resistance to chemical attack of bittern-resisting cement in high-bittern environment

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2005年第5期 87-93页

作者： Yunbing Hou, Bingwen Wang, Yu Chen, botao Zhang, and lin Yu School of Resource & Safety Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China

A new kind of bittern-resisting cement (BRC) was introduced. This material is based on the ternary cementitious system of clinker containing C4A3 S phase, high-activity ground granulated blast-furnace slag (GGBFS) and fly ash (FA). The hydration proc- ess and the hydrated products of BRC were studied by means of XRD, TG-DTA and SEM, and the resistance to chemical attack of BRC in high-bittern environment was also examined. The corrosion experiment in seven kinds of brines proved that BRC exhibits an excellent resistance to chemical attack of bittern. The corrosion resistance factors were calculated and all of them were greater than 0.96. It showed that BRC totally controls the cement-based material corrosion in brines from four aspects: (1) making full use of the dominant complementation effect of mineral materials; (2) diminishing the hydrated products easy to be attacked; (3) improving the microstructure of hardened cement mortar; (4) degrading the chemical attack of bittern.

关键词： bittern-resisting cement ternary cementitious system high-activity mineral materials resistance to chemical attack bit- tern corrosion resistance factor corrosion mechanism