检索结果-南通市图书馆

Syntheses and properties of associative acrylamide copolymers containing short hydrophobic chains used in a friction reducer for slick-water fracturing

引用

Petroleum Science 2024年第3期21卷 1889-1901页

作者： Ya-Xing Dai xian-Li zhang Si-Yuan Liu Feng-Run-Ze zhang Yi-Xi zhang Yu-Tong Sang Jing-Xi Zheng Zhao-Sheng Liu Peng zhang College of Chemistry and Chemical Engineering Chongqing University of Science and TechnologyChongqing401331China College of Ecology and Environment Chongqing Resources and Environmental Protection of UniversityChongqing401331China China china Property Project Department of Dezhou Mining Property Service CenterShengli Oilfield Company of SinopecDezhou253000ShandongChina

Two allyldimethylalkyl quaternary ammonium salt(AQAS)monomers,N,N-dimethylallylphenylpropylammonium bromide(AQAS1)and N,N-dimethylallylnonylammonium bromide(AQAS2),were synthesized and used to prepare modified polyacrylamide *** new drag reducers were synthesized from acrylamide(AM),sodium acrylate(Na AA)and a cationic modified monomer(AQAS1 or AQAS2)via aqueous solution polymerization,and the copolymers were named P(AM/Na AA/AQAS1)and P(AM/Na AA/AQAS2),*** structures of the drag reduction agents were confirmed by IR and1H NMR *** molecular weight(Mw)of P(AM/Na AA/AQAS1)was 1.79×10^(6)g/*** the copolymer concentration was 1000 mg/L and the flow rate was 45 L/min,in fresh water the highest drag reduction rate was 75.8%,in 10,000 mg/L Na Cl solution the drag reduction rate decreased to 72.9%.The molecular weight of P(AM/Na AA/AQAS2)was 3.17×10^(6)g/*** the copolymer concentration was500 mg/L and the flow rate was 45 L/min,the drag reduction rate reached 75.2%,and in 10,000 mg/L Na Cl solution the drag reduction rate was 73.3%,decreased by approximately 1.9%.The drag reduction rate for partially hydrolyzed polyacrylamide(HPAM)was also investigated,and the results showed that the drag reduction rates for 500 and 1000 mg/L HPAM solutions were merely 43.2%and 49.0%in brine,*** with HPAM,both of the above copolymers presented better drag reduction capacities.

关键词： Shale gas Slick water Drag reducer Modified monomer Copolymerization

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

Sidewall rockburst of highly stressed D-shape hole tunnel triggered by impact load: An experimental investigation

Rock Mechanics Bulletin

引用

Rock Mechanics Bulletin 2024年第1期3卷 64-80页

作者： Wuxing Wu Fengqiang Gong Zong-xian zhang School of Civil Engineering Southeast UniversityNanjing211189China Oulu Mining School University of OuluOulu90570Finland

This study aims to clarity the failure mechanism of sidewall rockburst of highly stressed D-shape tunnel triggered by impact *** the biaxial Hopkinson pressure bar(BHPB)system,we have developed experimental capabilities to study the sidewall rockburst of D-shape tunnel by applying various prestresses,including horizontal and vertical static stresses,to sand prefabricated D-shape hole specimen,followed by impact ***-speed(HS)camera and digital image correlation(DIC)were used to tracked the process and strain field of the sidewall *** test results reveal that the process of sidewall rockburst can be summarized as:calm stage,crack initiation,propagation,and coalesce stage,spalling stage and rock fragments ejection *** the rockburst process,the surrounding rock experienced spalling and violent ejection,involving both tensile and tensile-shear *** mechanism of sidewall rockburst under the coupled of static stress and impact loads has been elucidated,i.e.,the static prestress determines the initial stress and strain distribution,and the horizontal prestress influences the affected range and strain values of strain concentration zone;the impact load disrupts the original static stress equilibrium,inducing alterations in the stress and strain of the surrounding rock and triggering sidewall rockburst.

关键词： impact rock load

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

Reaction mechanism between Al_(2)O_(3)–MgO refractory materials and rare earth high-carbon heavy rail steel

引用

Journal of Iron and Steel Research International 2024年第5期31卷 1153-1163页

作者： Yi Wang Guang-jie Song Ping Shen Jian-zhong He Da-xian zhang Jian-xun Fu Center for Advanced Solidification Technology(CAST) School of Materials Science and EngineeringState Key Laboratory of Advanced Special SteelShanghai UniversityShanghai200444China State Key Laboratory of Baiyunebo Rare Earth Resources Research and Comprehensive Utilization Baotou014030Inner MongoliaChina Inner Mongolia Baotou Steel Union Co. Ltd.Baotou014030Inner MongoliaChina

Submerged entry nozzle(SEN)clogging is a major problem affecting the production quality of rare earth steel,and finding a suitable refractory outlet can significantly reduce production *** explore the relationship between refractory composition and interface interaction,unprotected coated Al_(2)O_(3)–MgO refractories and SiO2-coated Al_(2)O_(3)–MgO refractories were added to rare earth high-carbon heavy rail steel under laboratory conditions,and the Al_(2)O_(3)–MgO refractory was found to be more *** results show that,from the epoxy resin side to the refractory side,the contour of the refractory interface reaction layer can be divided into two main layers:an iron-rich reaction layer and an iron-poor reaction *** based on the spherical model suggest that the adhesion force is proportional to the size of the refractory particles and inclusions,and the same result applies to the surface *** the inclusions at a smaller size has a specific effect on alleviating the erosion of *** with the erosion mechanism of Al_(2)O_(3)–MgO refractories,the interface reaction mechanism between Al_(2)O_(3)–MgO refractories and molten steel was proposed,which provides ideas for solving SEN clogging.

关键词： Rare earth high-carbon heavy rail steel Al_(2)O_(3)-MgO refractory Adhesion Surface tension Interface interaction

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

Rational design of ZnCdS/TpPa-1-COF heterostructure photocatalyst by strengthening the interface connection in solar hydrogen production reactions

引用

Nano Research 2024年第3期17卷 1027-1034页

作者： Di Yang Zhi-Gang Li Xinghao zhang Zenghuan Ren Weihan Lu Haining Liu Xiaomeng Guo Jijie zhang xian-He Bu Tianjin Key Laboratory of Metal and Molecule-Based Material Chemistry School of Materials Science and EngineeringNankai UniversityTianjin 300350China College of Chemistry and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018China State Key Laboratory of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China

ZnCdS quantum dots(QDs)are highly coveted in photocatalysis research for their exceptional visible-light responses and high light-absorption ***,their practical application is hindered by their tendency to aggregate,due to having high surface *** address this issue,herein,a heterostructure is synthesized by growing ZnCdS QDs with a size of approximately 5 nm onto the surface of a two-dimensional(2D)covalent organic framework(COF),*** approach suppresses the aggregation of the QDs and improves their *** ZnCdS/TpPa-1-COF composite exhibited a peak hydrogen evolution rate of 6244.16μmol·g^(-1)·h^(-1),which was 2.89 and 4.18 times greater than that of ZnCdS and TpPa-1-COF,*** zero-dimensional/two-dimensional(0D/2D)heterojunction formed by ZnCdS and TpPa-1-COF generates a strong interfacial force,which is attributed to the intimate contact between the *** connections accelerate charge separation,improve the utilisation of reduced electrons,and reduce the extent of agglomeration of the ZnCdS QDs,thereby resulting in high hydrogen production activity of the ***,the photocatalytic mechanism is studied using Kelvin probe force microscopy and theoretical *** study offers a novel approach for creating sulfide photocatalysts and is crucial for investigating the potential practical applications of the related photocatalysts.

关键词： covalent organic frameworks quantum dots photocatalysis hydrogen generation heterojunction

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

Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

引用

chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： Yi-Cong Wang Hui Zhat Pei-Yi Cheng Shu zhang xiang-Wei Liu Yi-xian Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

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 fluid therapy combined with a preoperative glucose load regimen on postoperative recovery in patients with rectal cancer

引用

World Journal of Gastrointestinal Surgery 2024年第8期16卷 2662-2670页

作者： Lv-chi Xia Ke zhang Chuan-Wen Wang Department of Emergency Medicine Jiujiang First People's HospitalJiujiang 332000Jiangxi ProvinceChina

BACKGROUND Patients with rectal cancer undergoing radical resection often have poor post-operative recovery due to preoperative fasting and water deprivation and the removal of diseased tissue,and have a high risk of ***,it is of great significance to apply appropriate rehydration regimens to patients un-dergoing radical resection of rectal cancer during the perioperative period to improve the postoperative outcomes of *** To analyze the effects of goal-directed fluid therapy(GDFT)with a preoperative glucose load regimen on postoperative recovery and complications in patients undergoing radical resection for rectal *** Patients with rectal cancer who underwent radical resection(n=184)between January 2021 and December 2023 at our hospital were randomly divided into either a control group or an observation group(n=92 in each group).Both groups received a preoperative glucose load regimen,and routine fluid replacement and GDFT were additionally implements in the control and observation groups,*** operative conditions,blood levels of lactic acid and inflammatory markers,postoperative recovery,cognitive status,hemodynamic indicators,brain oxygen metabolism,and complication rates were compared between the *** The colloidal fluid dosage,total infusion,and urine volume,as well as time to first exhaust,time to food intake,and postoperative length of hospital stay,were lower in the observation group(P0.05).Compared with the control group,in the ob-servation group the lactic acid level was lower immediately after the surgery(P<0.05);the Mini-Mental State Examination score was higher on postoperative day 3(P<0.05);the pulse pressure variability(PPV)was lower at 30 min after pneumoperitone

关键词： Radical resection of rectal cancer Goal-directed fluid therapy Preoperative glucose load Cognitive condition Complication

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

A data-driven approach to RUL prediction of tools

引用

Advances in Manufacturing 2024年第1期12卷 6-18页

作者： Wei Li Liang-chi zhang Chu-Han Wu Yan Wang Zhen-xiang Cui Chao Niu Department of Mechanical Engineering University College LondonLondonWC1E 7JEUK Shenzhen Key Laboratory of Cross-Scale Manufacturing Mechanics Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China SUSTech Institute for Manufacturing Innovation Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China School of Mechanical and Manufacturing Engineering The University of New South WalesKensingtonNSW2052Australia Baoshan Iron&Steel Co. Ltd.Shanghai200941People’s Republic of China

An effective and reliable prediction of the remaining useful life(RUL)of a tool is important to a metal forming process because it can significantly reduce unexpected maintenance,avoid machine shutdowns and increase system *** study proposes a new data-driven approach to the RUL prediction for metal forming processes under multiple contact sliding *** data-driven approach took advantage of bidirectional long short-term memory(BLSTM)and convolutional neural networks(CNN).A pre-trained lightweight CNN-based network,WearNet,was re-trained to classify the wear states of workpiece surfaces with a high accuracy,then the classification results were passed into a BLSTM-based regression model as inputs for RUL *** experimental results demonstrated that this approach was able to predict the RUL values with a small error(below 5%)and a low root mean square error(RMSE)(around 1.5),which was more superior and robust than the other state-of-the-art methods.

关键词： Remaining useful life(RUL) Bidirectional long short-term memory(BLSTM) Data-driven approach Metal forming

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

Very Short-Term Forecasting of Distributed PV Power Using GSTANN

引用

CSEE Journal of Power and Energy Systems 2024年第4期10卷 1491-1501页

作者： Tiechui Yao Jue Wang Yangang Wang Pei zhang Haizhou Cao Xuebin chi Min Shi Computer Network Information Center of the chinese Academy of Sciences Beijing 100190China University of chinese Academy of Sciences Beijing 100190China School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China State Grid Hebei Electric Power Co. Ltd.Shijiazhuang 050000China

Photovoltaic(PV)power forecasting is essential for secure operation of a power *** prediction of PV power can improve new energy consumption capacity,help power system planning,promote development of smart grids,and ultimately support construction of smart energy ***,different from centralized PV power forecasts,three critical challenges are encountered in distributed PV power forecasting:1)lack of on-site meteorological observation,2)leveraging extraneous data to enhance forecasting performance,3)spatial-temporal modelling methods of meteorological information around the distributed PV *** address these issues,we propose a Graph Spatial-Temporal Attention Neural Network(GSTANN)to predict the very short-term power of distributed ***,we use satellite remote sensing data covering a specific geographical area to supplement meteorological information for all PV ***,we apply the graph convolution block to model the non-Euclidean local and global spatial dependence and design an attention mechanism to simultaneously derive temporal and spatial ***,we propose a data fusion module to solve the time misalignment between satellite remote sensing data and surrounding measured on-site data and design a power approximation block to map the conversion from solar irradiance to PV *** conducted with real-world case study datasets demonstrate that the prediction performance of GSTANN outperforms five state-of-the-art baselines.

关键词： Distributed photovoltaic power forecasting graph convolutional networks satellite images spatial-temporal attention

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

A near-zero quiescent power breeze wake-up anemometer based on a rolling-bearing triboelectric nanogenerator

引用

Microsystems & Nanoengineering 2024年第2期10卷 241-249页

作者： xianpeng Fu Zhichao Jiang Jie Cao Zefang Dong Guoxu Liu Meiling Zhu chi zhang CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing101400China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing100049China Center on Nanoenergy Research Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science&TechnologyGuangxi UniversityNanning530004China Institute of Intelligent Flexible Mechatronics Jiangsu UniversityZhenjiang212013China College of Engineering Mathematics and Physical ScienceUniversity of ExeterExeterEX44QFUK

Wind sensors have always played an irreplaceable role in environmental information monitoring and are expected to operate with lower power consumption to extend service ***,we propose a breeze wake-up anemometer(B-WA)based on a rolling-bearing triboelectric nanogenerator(RB-TENG)with extremely low static *** B-WA consists of two RB-TENGs,a self-waking-up module(SWM),a signal processing module(SPM),and a wireless transmission *** two RB-TENGs are employed for system activation and wind-speed *** the ambient wind-speed exceeds 2 m/s,the wake TENG(W-TENG)and the SWM can wake up the system within 0.96 *** the same time,the SPM starts to calculate the signal frequency from the measured TENG(M-TENG)to monitor the wind speed with a sensitivity of 9.45 Hz/(m/s).After the wind stops,the SWM can switch off the B-WA within 0.52 s to decrease the system energy *** quiescent on-duty mode,the operating power of the B-WA is less than 30 nW,which can greatly extend the service lifetime of the *** integrating triboelectric devices and rolling bearings,this work has realized an ultralow quiescent power and self-waked-up wireless wind-speed monitoring system,which has foreseeable applications in remote weather monitoring,IoT nodes,and so on.

关键词： generator power service

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

Flexible mica films coated by magnetron sputtered insulating layers for high-temperature capacitive energy storage

引用

SusMat 2024年第5期4卷 154-162页

作者： Chao Yin Tiandong zhang Changhai zhang Yue zhang Chang Kyu Jeong Geon-Tae Hwang Qingguo chi Key Laboratory of Engineering Dielectrics and its Application Ministry of EducationHarbin University of Science and TechnologyHarbinChina School of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbinChina Division of Advanced Materials Engineering Jeonbuk National UniversityJeonjuSouth Korea Department of Materials Science and Engineering Pukyong National UniversityBusanSouth Korea

High-temperature energy storage performance of dielectric capacitors is cru-cial for the next generation of power electronic ***,conduction losses rise sharply at elevated temperature,limiting the application of energy storage ***,the mica films magnetron sputtered by different insulating layers are specifically investigated,which exhibit the excellent high-temperature energy storage *** experimental results revealed that the PbZrO3/Al2O3/PbZrO3(PZO/AO/PZO)interface insulating layers can effec-tively reduce the high-temperature leakage current and conduction loss of the composite ***,the ultrahigh energy storage density(Wrec)and charge‒discharge efficiency(η)can be achieved simultaneously in the flexi-ble mica-based composite ***,PZO/AO/PZO/mica/PZO/AO/PZO(PAPMPAP)films possess excellent Wrec of 27.5 J/cm3 andηof 87.8%at 200◦C,which are significantly better than currently reported high-temperature capaci-tive energy storage dielectric *** with outstanding power density and electrical cycling stability,the flexible films in this work have great appli-cation potential in high-temperature energy storage ***,the magnetron sputtering technology can deposit large-area nanoscale insulating layers on the surface of capacitor films,which can provide technical support for the industrial production of capacitors.

关键词： energy storage high temperature insulating layer magnetron sputtering mica

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

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：