检索结果-南通市图书馆

Lower Bounds of Dirichlet Eigenvalues for General Grushin Type Bi-Subelliptic Operators

在线全文

学校读者我要写书评

暂无评论

Analysis in Theory and Applications 2019年第1期35卷 66-84页

作者： Hua Chen Hongge Chen junfang wang Nana Zhang School of Mathematics and Statistics Wuhan University

Let Q be a bounded open domain in R^n with smooth boundaryаΩ.Let X=(X1,X2…,Xm)be a system of general Grushin type vector fields defined onΩand the boundaryаΩis non-characteristic for ***△x=∑j=1^mXj^2,we denoteλk as the k-th eigenvalue for the bi-subelliptic operator△X2^2 onΩ.In this paper,by using the sharp sub-elliptic estimates and maximally hypoeliptic estimates,we give the optimal lower bound estimates ofλk for the operatork△X^2.

关键词： Eigenvalues degenerate elliptic operators sub-elliptic estimate maximally hypoelliptic estimate bi-subelliptic operator

High-pressure capacity expansion and water injection mechanism and indicator curve model for fractured-vuggy carbonate reservoirs

在线全文

学校读者我要写书评

暂无评论

Petroleum 2024年第3期10卷 511-519页

作者： Lixin Chen Chengzao Jia Rujie Zhang Ping Yue Xujian Jiang junfang wang Zhou Su Yun Xiao Yuan Lv Institute of Unconventional Oil and Gas Science and Technology China University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Reservoir Geology and Development Southwest Petroleum UniversityChengdu610500China Tarim Oilfield Company PetroChinaKorla841000China

Water injection for oil displacement is one of the most effective ways to develop fractured-vuggy carbonate *** the increase in the number of rounds of water injection,the development effect gradually *** emergence of high-pressure capacity expansion and water injection technology allows increased production from old *** high-pressure capacity expansion and water injection technology has been implemented in practice for nearly 10 years in fractured-vuggy reservoirs,its mechanism remains unclear,and the water injection curve is not *** the past,evaluating its effect could only be done by measuring the injection-production *** this study,we analyze the mechanism of high-pressure capacity expansion and water *** propose a fluid exchange index for high-pressure capacity expansion and water injection and establish a discrete model suitable for high-pressure capacity expansion and water injection curves in fractured-vuggy *** propose the following mechanisms:replenishing energy,increasing energy,replacing energy,and releasing *** above mechanisms can be identified by the high-pressure capacity expansion and water injection curve of the well HA6X in the Halahatang Oilfield in the Tarim *** solving the basic model,the relative errors of Reservoirs I and II are found to be 1.9%and 1.5%,respectively,and the application of field examples demonstrates that our proposed high-pressure capacity expansion and water injection indicator curve is reasonable and *** research can provide theoretical support for high-pressure capacity expansion and water injection technology in fracture-vuggy carbonate reservoirs.

关键词： Fractured-vuggy carbonate reservoirs High-pressure capacity expansion and water injection Mechanism Water injection indicator curve

The Mechanics of Tumor Cells Dictate Malignancy via Cytoskeleton-Mediated APC/Wnt/β-Catenin Signaling

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

Research 2024年第2期2023卷 659-673页

作者： Xi Chen Zichen Xu Kai Tang Guanshuo Hu Pengyu Du junfang wang Cunyu Zhang Ying Xin Keming Li Qiantang Zhang Jianjun Hu Zhuxue Zhang Mo Yang Guixue wang Youhua Tan The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen518057China Key Laboratory for Biorheological Science and Technology of Ministry of Education State and Local Joint Engineering Laboratory for Vascular ImplantsBioengineering College of Chongqing UniversityChongqing400030China Research Institute of Smart Ageing The Hong Kong Polytechnic UniversityHong KongChina Department of Biomedical Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Pathology Guizhou Provincial People's HospitalGuiyangGuizhou550002China

Tumor cells progressively remodel cytoskeletal structures and reduce cellular stiffness during tumor progression,implicating the correlation between cell mechanics and ***,the roles of tumor cell cytoskeleton and the mechanics in tumor progression remain incompletely *** report that softening/stiffening tumor cells by targeting actomyosin promotes/suppresses self-renewal in vitro and tumorigenic potential in ***/strengthening actin cytoskeleton impairs/reinforces the interaction between adenomatous polyposis coli(APC)andβ-catenin,which facilitatesβ-catenin nuclear/cytoplasmic ***β-catenin binds to the promoter of Oct4,which enhances its transcription that is crucial in sustaining self-renewal and *** results demonstrate that the mechanics of tumor cells dictate self-renewal through cytoskeleton-APC-Wnt/β-catenin-Oct4 signaling,which are correlated with tumor differentiation and patient *** study unveils an uncovered regulatory role of cell mechanics in self-renewal and malignancy,and identifies tumor cell mechanics as a hallmark not only for cancer diagnosis but also for mechanotargeting.

关键词： diagnosis skeleton APC

Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie wang Wei wang Xuheng Chen junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

在线全文

学校读者我要写书评

暂无评论

氮气式水击泄压阀试验平台设计和试验研究

流体机械 2021年第4期49卷 42-47页

作者：王军防国家管网集团东部原油储运有限公司科技研发中心江苏徐州221008

为实现对氮气式水击泄压阀的功能和关键性能进行充分研制试验,设计并搭建了一种能够满足工作压力高、流量大等试验条件的液流试验平台,并在试验过程中设计了包含设定压力、响应时间和设定压力误差试验在内的四项试验验证方法。根据所设... 详细信息

为实现对氮气式水击泄压阀的功能和关键性能进行充分研制试验,设计并搭建了一种能够满足工作压力高、流量大等试验条件的液流试验平台,并在试验过程中设计了包含设定压力、响应时间和设定压力误差试验在内的四项试验验证方法。根据所设计方法分别对型号为200YXY-100D的氮气式水击泄压阀主阀在氮气腔压力为1,2,3,4,5 MPa工况下试验平台进行验证试验。结果表明所设计液流试验平台和试验方法能够充分验证氮气式水击泄压阀和氮气供应系统结构强度、密封性能、动作可靠性和整阀系统的可靠性。

关键词：氮气式水击泄压阀液流试验平台设定压力回座压力响应时间

Highly detectivity Tin-Based Self-Powered Photodetector Enabled by Synergistic Engineering for photoplethysmography Signal Acquisition in weak light

在线全文

学校读者我要写书评

暂无评论

Highly detectivity Tin-Based Self-Powered Photodetector Enab...

水助甲酰胺-H_2O_2氧化乙烯制环氧乙烷反应机理的理论研究

第十届新型太阳能材料科学与技术学术研讨会

作者： Tianhua Liu junfang wang Xiangyue Meng College of Materials Science and Opto-Electronic Technology

Photoplethysmography(PPG) is a non-invasive technique for measuring blood volume changes in the *** signals can be used for health monitoring,such as heart rate and blood oxygen ***,conventional PPG sensors require external power sources and have low sensitivity and stability in weak light *** this work,we report a highly detectivity tin-based self-powered photodetector(PD) enabled by synergistic engineering for PPG signal acquisition in weak *** PD is based on tin perovskite film with functional passivating molecules,which can improve the crystallization,reduce the oxidation and defects of the perovskite,and enhance the photoelectric performance and stability of the *** PD exhibits a high external quantum efficiency(EQE) of 60.6% at 800 nm,a high responsivity of 0.39 AW at 800 nm,a high detectivity of 2.14×10 Jones at 800 nm,and an ultrafast response time of 2.5 μ*** PD can also work as a flexible ***,the PD can be used for wearable health monitoring applications,such as PPG signal acquisition under weak light *** work demonstrates the potential of tinbased self-powered PDs for PPG sensing and other optoelectronic applications.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

化学学报 2010年第8期68卷 727-732页

作者：王俊芳孙琪王长生辽宁师范大学化学化工学院大连116029

采用MP2方法研究了甲酰胺-H2O2氧化乙烯制取环氧乙烷的反应机理.优化得到了反应物、过渡态、中间体及产物的几何构型并计算了反应势垒.研究结果表明:没有水参与时,反应需要通过四元环过渡态完成,反应势垒很高,在常温下难以进行;有水参与... 详细信息

采用MP2方法研究了甲酰胺-H2O2氧化乙烯制取环氧乙烷的反应机理.优化得到了反应物、过渡态、中间体及产物的几何构型并计算了反应势垒.研究结果表明:没有水参与时,反应需要通过四元环过渡态完成,反应势垒很高,在常温下难以进行;有水参与时,在水分子的协助下,反应可以通过六元环过渡态完成,反应势垒较低,常温下反应容易进行.

关键词：环氧化四元环过渡态六元环过渡态水助

在线全文

学校读者我要写书评

暂无评论

“联邦”概念的起源和内涵的演变

历史教学 2004年第7期 66-69页

作者：王俊芳南京大学历史系南京210093

在英帝国发展史上,"联邦"一词的产生经过了较长的时间,它正式出现于1917年.自诞生以来,这一术语的内涵也发生了质的变化:从以英国为主的"集权联盟"发展到"各主权行为体的联合".这一概念的产生及内涵的演变,是由于当时英国国内外情势的... 详细信息

在英帝国发展史上,"联邦"一词的产生经过了较长的时间,它正式出现于1917年.自诞生以来,这一术语的内涵也发生了质的变化:从以英国为主的"集权联盟"发展到"各主权行为体的联合".这一概念的产生及内涵的演变,是由于当时英国国内外情势的共同作用.这一过程也是英帝国逐步解体、殖民主义走向崩溃的过程.

关键词：英国 “联邦”体制殖民主义自治领制度

Mechanism of Surface Modification for Sericite

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 Wuhan University of Technology(Materials Science) 2007年第3期22卷 470-472页

作者：高惠民 School of Resources and Environmental Engineering Wuhan University of Technology

Surface modification of sericite by wet method was conducted with the addition of 1.0 % （w/w） silane. The resulting wetting contact angle and activity ratio of sericite were 130° and 98% respectively. Good pre-evaluation indexes of oil value （40.8%） and dispersivity （14.0 mL） were obtained. When 30 % of sericite was filled into acrylonitrile butadiene styrene（ABS） plastic, the bending strength and tensile strength of the composite material were reduced by 7% and 14.3% in comparison to those of pure ABS plastic, while the rigidity was increased by 3 times, and the impact strength and breaking elongation were reduced significantly. The mechanism of surface modification was investigated and the configuration of silane coupling agent on the surface of sericite was given. Infrared （IR） spectroscopic analysis indicates that the adsorption of silane on the surface of sericite belongs to chemical adsorption.

关键词： sericite surface modification ABS plastic