检索结果-南通市图书馆

Simulation study on cuttings transport of the backreaming operation for long horizontal section wells

Petroleum Science 2024年第2期21卷 1149-1170页

作者： yu-fei chen Hui Zhang Wen-Xin Wu Jun Li Yong Ouyang Zong-yu Lu De-Xin Ma Yong-Chuan Wu Jun-Bo Liu Ke-Rou Liu Zhuo-Xin Dong China University of Petroleum(Beijing) Beijing102249China Beijing Normal University at Zhuhai Experimental and Practical Education Innovation CenterZhuhai519087GuangdongChina Oil&Gas Technology Research Institute of PetroChina Changqing Oilfield Company Xi'an710016ShaanxiChina PetroChina Xinjiang Oilfield Company Karamay834002XinjiangChina China Oilfield Services Ltd. Tianjin300459China

The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than

关键词： Backreaming Stuck pipe Hole cleaning Transient solid transport Multiple flow patterns

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 robust technique to reconstruct sound field for all wave-numbers

引用

Science China(Technological Sciences) 2004年第5期47卷 505-517页

作者： yu fei chen Jian LI Weibing chen Xinzhao School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China School of Mechanical and Automotive Engineering Hefei University of Technology Hefei 230009 China

A robust technique has been proposed for reconstructing sound field for all wave-numbers, which is suitable for the radiation analysis on an arbitrarily-shaped body. According to the wave superposition formulation, the spatial sound field of an actual radiator can be represented equivalently by superposing the fields generated by some fictitious sources interior to the actual radiator. Meanwhile, the strength density on the fictitious sources can be obtained by matching the sound pressures of a finite number of field points. Once the strength density is calculated, the acoustic information at any field point can be obtained subsequently. Finally, some typical numerical examples are given to validate the theoretical analysis, and some investigations are made to analyze the influence of sound frequency and the fictitious source position on the reconstruction precision, which are helpful to the application of the proposed technique to real industrial measurements.

关键词： sound field reconstruction, wave superposition, hybrid layer potential theory, non-uniqueness,robustness.

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

Time-frequency analysis of internal waves generated by a towed and self-propelled submerged body model

引用

Journal of Hydrodynamics 2023年第6期35卷 1191-1207页

作者： yu-hang Li fei-yu chen Li-ping Qin Ke chen yun-xiang You Zhengzhou Electromechanical Engineering Research Institute Zhengzhou450015China Henan Key Laboratory of Underwater Intelligence Equipment Zhengzhou450015China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai200240China Yazhou Bay Institute of Deepsea Technology Shanghai Jiao Tong UniversityShanghai200240China

The spectrogram,based on a short-time Fourier transform,can visualize the time-dependent frequency spectrum of waves and is easy to *** time-frequency analysis method provides crucial information about waves generated by moving vessels and has been utilized to analyze Kelvin ship waves and internal *** further study the internal waves induced by a submerged body,an experiment is conducted for the towed and self-propelled SUBOFF model in a stratified *** internal wave elevation signals are captured using electronic conductivity *** with the calculation results of theoretical model,the high-frequency component of internal waves is *** high-frequency component has the exact same characteristics in both the towed and self-propelled model experiment and is consistent with the theoretical results for all Froude ***,this component is composed mainly of lee *** spectral characteristics identification,a low-frequency component is discovered in the spectrogram in addition to the lee wave *** intensity of the low-frequency component is tightly related to the vortex structure behind the submerged *** vortex structure depends on the net momentum imparted by the submerged ***,this component is composed mainly of wake waves induced by the vortex structure.

关键词： Stratified fluid internal waves submerged body experimental study time-frequency analysis

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

NEAR-FIELD ACOUSTIC HOLOGRAPHY FOR SEMI-FREE ACOUSTIC FIELD BASED ON WAVE SUPERPOSITION APPROACH

引用

Chinese Journal of Mechanical Engineering 2006年第3期19卷 455-459页

作者： LI Weibing chen Jian yu fei chen Xinzhao Institute of Sound and Vibration Research Hefei University of Technology Hefei 230009 China

In the semi-free acoustic field, the actual acoustic pressure at any point is composed of two parts： The direct acoustic pressure and the reflected acoustic pressure. The general acoustic holographic theories and algorithms request that there is only the direct acoustic pressure contained in the pressure at any point on the hologram surface, consequently, they cannot be used to reconstruct acoustic source and predict acoustic field directly. To take the reflected pressure into consideration, near-field acoustic holography for semi-free acoustic field based on wave superposition approach is proposed to realize the holographic reconstruction and prediction of the semi-free acoustic field, and the wave superposition approach is adopted as a holographic transform algorithm. The proposed theory and algorithm are realized and verified with a numerical example, and the drawbacks of the general theories and algorithms in the holographic reconstruction and prediction of the semi-free acoustic field are also demonstrated by this numerical example.

关键词： Near-field acoustical holography Semi-free acoustic field Wave superposition approach

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

Spatial resolved temperature measurement based on absorption spectroscopy using a single tunable diode laser

引用

Acta Mechanica Sinica 2010年第1期26卷 147-149页

作者： Xilong yu fei Li Lihong chen Xinyu Zhang Key Laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences100190 Beijing China

A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS scheme is used to implement the wavelength-multi- plexed-profile fitting method. Second harmonic （2f） signal of eight H20 transitions features near 7,170 cm^-1 are measured in one period using a single tunable diode laser. Spatial resolved temperature distribution upon a CH4/air premixed flat flame burner is obtained. The result validates the feasibility of strategy for non-uniform flow field diagnostics by means of WMS-2f TDLAS.

关键词： WMS-2fTDLAS - Profile fitting Spatial resolved - Temperature measurement

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

Resistance to antibody-drug conjugates in breast cancer:mechanisms and solutions

引用

Cancer Communications 2023年第3期43卷 297-337页

作者： yu-fei chen Ying-ying Xu Zhi-Ming Shao Ke-Da yu Department of Breast Surgery Fudan University Shanghai Cancer CenterShanghai 200032P.R.China Shanghai Medical College Fudan UniversityShanghai 200032P.R.China Department of Breast Surgery First Affiliated Hospital of China Medical UniversityShenyangLiaoning 110001P.R.China

Antibody-drug conjugates(ADCs)are a rapidly developing therapeutic approach in cancer treatment that has shown remarkable activity in breast ***,there are two ADCs approved for the treatment of human epidermal growth factor receptor 2-positive breast cancer,one for triple-negative breast cancer,and multiple investigational ADCs in clinical ***,drug resistance has been noticed in clinical use,especially in trastuzumab ***,the mechanisms of ADC resistance are summarized into four categories:antibodymediated resistance,impaired drug trafficking,disrupted lysosomal function,and payload-related *** overcome or prevent resistance to ADCs,innovative development strategies and combination therapy options are being *** predictive biomarkers for optimal therapy selection may also help to prevent drug resistance.

关键词： Antibody-drug conjugate breast cancer drug resistance combination therapy predictive biomarker

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

Reduction of unactivated alkyl chlorides enabled by light-induced single electron transfer

引用

Science China Chemistry 2024年第2期67卷 471-481页

作者： Lei Dai Zhao-fei Zhang Xiang-yu chen School of Chemical Sciences University of the Chinese Academy of SciencesBeijing100049China Institute of Chemistry Chinese Academy of SciencesBeijing100190China Binzhou Institute of Technology Weiqiao-UCAS Science and Technology ParkBinzhou256606China

Alkyl chlorides are abundant and easily accessible starting ***,due to the high reduction potentials associated with unactivated alkyl chlorides,achieving their single electron reduction remains a persistent *** challenge has spurred the exploration of efficient activation methods to overcome this *** recent years,photocatalysis has emerged as a mild and potent tool for the single electron reduction of unactivated alkyl chlorides,opening up new possibilities in this *** the rapid advancements in this area,a comprehensive review that provides a conceptual understanding of this emerging field,with a specific focus on reaction design and catalytic mechanisms,would be timely and highly ***,we present an overview of various synthetic techniques for photoinduced single electron reduction of unactivated alkyl ***,we also discuss the limitations of the present methods and future directions that lie ahead in this field.

关键词： photocatalysis unactivated alkyl chlorides single electron transfer radical reactions

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

Effects of slag composition and additive type on desulfurization of rejected electrolytic manganese metal scrap by Na2O-containing electroslag

引用

Journal of Iron and Steel Research International 2021年第12期28卷 1515-1529页

作者： Ru Lu Guang-qiang Li Chang Liu yun-ming Gao yu-fei chen Qiang Wang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina Hubei Rising Technology Co. Ltd.Huangshi435000HubeiChina

The recycling rate of rejected electrolytic manganese metal(EMM)scrap can be increased by inhibiting the manganese metal(MM)vaporization during the remelting process with ***,if the latter is achieved by reducing the remelting temperature,the desulfurization behavior will ***,Na_(2)O-containing electroslag and metallic additive were used to increase the rejected EMM scrap recovery *** respective high-temperature experiment was conducted in a MoSi_(2) electrical resistance furnace filled with fluid argon at 1673 K using five different types of electroslag with the Na_(2)O content ranging from 5.81%to 15.71%.High-purity metallic magnesium and magnesium calcium alloy additives were used as *** addition of Na_(2)O and metallic additives effectively promoted the desulfurization and deoxidization of *** removal of sulfur and oxygen by the interaction between Na_(2)O-containing electroslag melt and molten MM with metallic additive was analyzed from the thermodynamic and kinetic *** effect of Na_(2)O-containing electroslag volatilization on desulfurization and deoxidization was *** an increase in Na_(2)O content in the slag,the mass loss rates of Na_(2)O and electroslag rose,as well as the final sulfur partition *** the Na_(2)O content volatilized in the slag melt did not exceed 10.44%,the sulfur removal ratio was increased by high sulfide capacity and CaO activity in all slags due to the addition of Na_(2)*** rejected EMM scrap deoxidization ratio grew with the increased activity of CaO and reduced activity of Al_(2)O_(3) in the molten slag,caused by the increased Na_(2)O content in the molten *** addition of metallic Mg and Mg-Ca alloy indirectly promoted desulfurization and deoxidization by reducing the MnO content in the rejected EMM scrap and growing slag *** Mg-Ca alloy could also react with dissolved sulfur and oxygen,directly promoting desulfurization and deoxidiza

关键词： Rejected electrolytic manganese metal Desulfurization Deoxidization Additive Na2O content Thermodynamic

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

Spatial and temporal variability of heat content above the thermocline in the tropical Pacific Ocean

引用

Acta Oceanologica Sinica 2003年第2期22卷 179-190页

作者： Pu Shuzhen, yu fei, Hu Xiaomin, chen Xingrong First Institute of Oceanography, State Oceanic Administration, Qingdao 266061,China, First Institute of Oceanography State Oceanic Administration Qingdao 266061 China

Heat content of the upper layer above the 20℃ isotherm in the tropical Pacific Ocean isestimated by using the sea temperature data set with a resolution 2°latitude×5°longitude (1980-1993) for the water depths (every 10 m) from 0 m to 400 m, and its temporal and spatial variabilities are analyzed. (1) The temporal variability indicates that the total heat in the upper layer of the equatorial Pacific Ocean is characterized by the interannual variability. The time series of the equatorial heat anomaly 5 months lead that of the El Nino index at the best positive lag correlation between the two, and the former 13 months lag behind the latter at their best negative lag correlation. Therefore the equatorial heat content can be used as a better predictor than the El Nino index for a warm or cold event. In addition, it is also found that less heat anomaly in the equator corresponds to the stronger warm events in the period (1980- 1993) and much more heat was accumulated in the 4 years including 1992/1993 ENSO (1989-1993) than the 4 years including 1982/1983 ENSO (1980-1983); (2) The spatial variability indicates that the area with the highest lag correlation among the grids moves in an anti-clockwise circle in the northern tropical Pacific Ocean within 4 years period and in a clockwise circle in the southern tropical Pacific Ocean. This result provides scientific evidence for the quasi - cycle theory of El Nino events.

关键词： Heat content ENSO tropical Pacific Ocean

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

Turnip mosaic virus pathogenesis and host resistance mechanisms in Brassica

引用

Horticultural Plant Journal 2024年第4期10卷 947-960页

作者： Guanwei Wu Xinxin Fang Tianqi yu Jianping chen fei Yan State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products Institute of Plant VirologyNingbo UniversityNingboZhejiang 315211China Key Laboratory of Biotechnology in Plant Protection of MARA and Zhejiang Province Institute of Plant VirologyNingbo UniversityNingboZhejiang 315211China

Turnip mosaic virus(TuMV)is a devastating potyvirus pathogen that infects a wide variety of both cultivated and wild Brassicaceae *** urgently need more information and understanding of TuMV pathogenesis and the host responses involved in disease development in cruciferous *** displays great versatility in viral pathogenesis,especially in its replication and intercellular ***,in the coevolutionary arms races between TuMV and its hosts,the virus has evolved to co-opt host factors to facilitate its infection and counter host defense *** review mainly focuses on recent advances in understanding the viral factors that contribute to the TuMV infection cycle and the host resistance mechanism in ***,we propose some future research directions on TuMV pathogenesis and control strategies to design durable TuMV-resistant Brassica crops.

关键词： Turnip mosaic virus Brassica Resistance genes Host factors Infection biology

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

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：