检索结果-南通市图书馆

Machinery co.dition Prediction Based on Support Vector Machine Model with Wavelet Transform

在线全文

学校读者我要写书评

暂无评论

Journal of Donghua University(English Edition) 2014年第6期31卷 831-834页

作者：刘淑杰陆惠天李超胡娅维张洪潮 School of Mechanical engineering Dalian University of Technology Department of co.struction & Operations Management South Dakota State University offshore oil engineering co.. Ltd. Department of Industrial engineering Texas Tech University

Soft failure of mechanical equipment makes its performance drop gradually,which occupies a large proportion and has certain regularity. The performance can be evaluated and predicted through early state monitoring and data analysis. The vibration signal was modeled from the double row bearing,and wavelet transform and support vector machine model( WT-SVM model) was co.structed and trained for bearing degradation process prediction. Besides Hazen plotting position relationships was applied to describing the degradation trend distribution and a 95%co.fidence level based on t-distribution was given. The single SVM model and neural network( NN) approach were also investigated as a co.parison. Results indicate that the WT-SVM model outperforms the NN and single SVM models,and is feasible and effective in machinery co.dition prediction.

关键词： support vector machine(SVM) wavelet transform(WT) vibration intensity probabilistic forecasting

Fatigue Crack Propagation in Steel A131 Under Ice Loading of Crushing,Bending and Buckling

在线全文

学校读者我要写书评

暂无评论

China Ocean engineering 2001年第3期16卷 315-328页

作者：段梦兰樊晓东宋立崧方华灿 James C. M. LI R. & D. Center China Classification Society Shanghai offshore Petroleum Bureau China National offshore oil co. University of Petroleum University of Rochester Rochester

Three types of ice loading, which are most co.monly present when ice acts on structures, are chosen and simulated for use of fatigue crack propagation tests on offshore structural steel A131. The three types of ice categorized in acco.dance with the failure modes when acting on structures called Crushing ice, bending ice, and buckling ice, respectively. This paper presents an experimental investigation on the fatigue crack propagation behavior of widely used high strength steel A131 for offshore jackets in the loading environment of ice crushing, bending, and buckling. The test results of fatigue crack propagation in steel A131 tinder these simulated ice loading at temperature 292K are presented and analyzed in detail in this paper, The amplitude root mean square stress intensity factor is optimized to be the fundamental parameter of fatigue crack propagation for all types of ice loading histories. The results are also co.pared with co.stant amplitude fatigue crack propagation co.clusions as in wave load mode, and a joint investigation on the results from ice forces, ice-induced vibrations, and ice-induced fatigue crack propagation is co.ducted. co.clusions are drawn for reference in structural design and material selection for offshore structures in ice environments.

关键词： fatigue crack crack growth rate stress intensity factor ice loading temperature steel A131 test

Influence of Adding co.patibilizer to SBS Polymer-Modified Asphalt on co.patibility and Rheological Behavior

在线全文

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2021年第4期23卷 37-46页

作者： Dong Fuqiang Hao Yunzhe Yu Xin Shi Jingtao Chen Bei Qin Chenglin co.lege of Civil and Transportation engineering Hohai UniversityNanjing 210098 PetroChina Fuel oil co. Ltd.Research InstituteBeijing 100195

Adding co.patibilizer to polymer-modified asphalt(PMA)is an effective method to improve co.patibility and ***,only few studies have systematically focused on how co.patibilizer can affect the performance of styrene-butadiene-styrene(SBS)polymer-modified asphalt(PMA).In this study,six co.patibilizers with different co.positions were used to prepare SBS PMA *** performance,visco.ity-temperature characteristics,visco.lastic behavior,creep properties,and morphology were *** results show that adding co.patibilizer to SBS PMA has a great effect on its *** aromatics co.tent in co.patibilizers can improve the high-temperature performance of SBS PMA,while a high saturates co.tent can enhance the low-temperature ***,high aromatics co.tent in co.patibilizer can increase the temperature *** the aromatics co.tent does improve the co.patibility of SBS PMA to some extent,adding co.patibilizer to SBS PMA has few effects on the *** from our test results,we can co.clude that the optimum aromatics co.tent for adding co.patibilizer to SBS PMA ranges from 33.21%to 54.22%.

关键词： co.patibilizer SBS polymer-modified asphalt rheological behavior co.patibility morphology

Stress Analysis of the Subsea Dynamic Riser BaseProcess Piping

在线全文

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2014年第3期13卷 327-332页

作者： Xuanzc Ju Wei Fang Hanjun Yin Ying Jiang offshore oil engineering co. Ltd. Tianjin 300451 China

Thesubsea dynamic riser base （SDRB） is an important piece of equipment for the floating production platform mooring *** end is co.nected to the rigid pipeline, carrying a rigid pipeline thermal expansion load and the other end is co.nected to a flexible riser, carrying the dynamic load of the flexible riser, so its function is a transition co.nection between the flexible riser and the rigid pipeline which fixes the flexible riser on the seabed. On the other hand. as a typical subsea product, the design will satisfythe requirements of the standards for subsea products. By studying the stress analysisphilosophy of the topside piping and subsea pipeline, a physical model and procedure for piping stress analysis of the SDRB have been *** co.ditions of the adverse design load have been co.sidered, and a co.bination of the static load from the rigid pipeline and the dynamic load flexibility has also been optimized. And a co.parative analysis between the AMSE, DNV and API standards for piping stress with the checking rules has been *** theSDRB belongs to the subsea pipeline terminal product, the use of DNV standards to check its process piping stress is reco.mended. Finally, the process piping stress of the SDRB has been calculated, and the results show that the jacket pipe and the carrier pipe stress of the SDRB process piping satisfy the DNV standards as a *** bulkhead cannot be accurately simulated by the AutoPIPE software which uses the FEA software ANSYS inthe detailed analysis, but the checking results will still meet the requirements of the DNV standards.

关键词： subsea product design subsea dynamic riserbase(SDRB) process piping stress analysis flexible riser rigidpipeline

Early Cenozoic paleontological assemblages and provenance evolution of the Lishui Sag,East China Sea

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2023年第3期42卷 113-122页

作者： Yingzhao Zhang Yiming Jiang Zhenghua Liu Shuai Li Ning Li Jinshui Liu Peijun Qiao Kai Zhong Shuhui Chen Thian Lai Goh Shanghai Branch of China National offshore oil co.poration(CNOOC)co. Ltd.Shanghai 200335China Shanghai Natural History Museum(Branch of Shanghai Science&Technology Museum) Shanghai 200041China State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Shenzhen Branch of China National offshore oil co.poration(CNOOC)co. Ltd.Shenzheng 518000China Department of Earth Sciences and Environment Faculty of Science and TechnologyUniversity Kebangsaan MalaysiaBangi 43600SelangorMalaysia

The East China Sea Shelf Basin generated a series of back-arc basins with thick successions of marine-and terrestrial-facies sediments during *** is enriched with abundant oil and gas resources and is of great significance to the petroleum exploration ***,the Lishui Sag formed fan delta,fluvial delta and littoral-to-neritic facies sediments during Paleocene–Eocene,and the research on its sedimentary environment and sediment source was *** study analyzed the paleontological co.bination characteristics,and co.ducted a source-to-sink co.parative analysis to restore the sedimentary environment and provenance evolution of the Lishui Sag during Paleocene–Eocene based on the integration of detrital zirco. U-Pb age spectra patterns with paleontological *** results indicated that Lishui Sag was dominated by littoral and neritic-facies environment during time co.roborated by large abundance of foraminifera,calcareous nannofossils and *** analysis of detrital zirco. U-Pb revealed that there were significant differences in sediment sources between the east and west area of the Lishui *** western area was featured by deeper water depths in the Paleocene–Eocene,and the sediment was characterized by a single Yanshanian peak of zirco. U-Pb age spectra,and mainly influenced from Yanshanian magmatic rocks of South China co.st and the surrounding ***,its eastern area partly showed Indosinian *** particular,the upper Eocene Wenzhou sediments were featured by increasingly plentiful Precambrian zirco.s in addition to the large Indosinian-Yanshanian peaks,indicating a possible impact from the Yushan Low Uplift to the ***,it is likely that the eastern Lishui Sag generated large river systems as well as deltas during *** to the Yuquan Movement,the Lishui Sag experienced uplifting and exhumation in the late stage of the late Eocene and was not deposited with sediment

关键词： East China Sea Lishui Sag paleontological assemblages sedimentary provenance hydrocarbon exploration

Self-Lubricating PEO co.ting on an Al Alloy Produced by Vacuum Impregnation Post-treatment

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2015年第8期28卷 965-974页

作者： Ling Hong Dong Wang Guang-Dong Bian Lin-Lin Wang Shu-Gen Hu co.lege of Mechanical engineering Zhejiang University Zhejiang Wanliyang Transmission co. Ltd. co.lege of engineering Zhejiang Normal University

The objective of this research was to develop a novel self-lubricating co.ting on an AA6061 aluminum *** co.tings were prepared by the plasma electrolytic oxidation（PEO） process using 50-, 500-, and 1000-Hz pulsed direct current, respectively. The as-deposited co.tings were then post-treated using two different methods, viz., ultrasonic vibration-aided vacuum oil impregnation（UVOI） and oil impregnation under ambient pressure（OIAP）. After posttreatment, an oil-co.taining, self-lubricating top layer was formed on the co.tings. The effects of the co.tings＇ surface morphologies and structures on their oil-holding capabilities were discussed. The results revealed that co.tings prepared with higher frequency had a greater oil-holding capacity using OIAP post-treatment, while those prepared with lower frequency had a greater oil-co.taining capability using UVOI post-treatment. These phenomena are related to the morphologies of the co.tings produced with various current modes. The tribological properties of the co.tings before and after post-treatments were investigated by pin-on-disc sliding wear tests. Due to the formation of a lubricant-co.taining top layer, the post-treatment co.tings had a lower friction co.fficient and improved wear resistance co.pared with the asdeposited co.tings. In addition, the co.tings after UVOI treatment had better wear performance than those post-treated using the OIAP process. Among all co.tings, the co.ting produced with a 50-Hz pulsed current followed by UVOI posttreatment achieved the lowest friction co.fficient（0.03） and best wear resistance when sliding against a Si3N4 ceramic co.nterface. This study indicates that a novel self-lubricating co.ting can be prepared by a PEO process co.bined with vacuum oil impregnation post-treatment.

关键词： Tribological properties Self-lubricating co.ting Plasma electrolytic oxidation process oil impregnation Vacuum

Mechanical Modeling and Analysis of Stability Deterioration of Production Well During Marine Hydrate Depressurization Production

在线全文

学校读者我要写书评

暂无评论

China Ocean engineering 2024年第2期38卷 338-351页

作者： SUN Huan-zhao CHANG Yuan-jiang SUN Bao-jiang WANG Kang CHEN Guo-ming LI Hao DAI Yong-guo Centre for offshore engineering and Safety Technology China University of Petroleum(East China)Qingdao 266580China School of Petroleum engineering China University of Petroleum(East China)Qingdao 266580China Jiangsu Shuguang oil Tools co. LtdTaizhou 225532China

Different from oil and gas production,hydrate reservoirs are shallow and unco.solidated,whose mechanical properties deteriorate with hydrate ***,the formations will undergo significant subsidence during depressurization,which will destroy the original force state of the production ***,existing research on the stability of oil and gas production wells assumes the formation to be stable,and lacks co.sideration of the force exerted on the hydrate production well by formation subsidence caused by hydrate deco.position during *** fill this gap,this paper proposes an analytical method for the dynamic evolution of the stability of hydrate production well co.sidering the effects of hydrate *** on the mechanical model of the production well,the basis for stability analysis has been proposed.A multi-field co.pling model of the force state of the production well co.sidering the effect of hydrate deco.position and formation subsidence is established,and a solver is *** analytical approach is verified by its good agreement with the results from the numerical method.A case study found that the deco.position of hydrate will increase the pulling-down force and reduce the supporting force,which is the main reason for the stability *** higher the initial hydrate saturation,the larger the reservoir thickness,and the lower the production pressure,the worse the stability or even *** work can provide a theoretical reference for the stability maintaining of the production well.

关键词： natural gas hydrate production well depressurization production formation deformation stability deterioration

Approach to the Design Calculation of Sucker Rod Pumping Systems in co.lbed Methane Wells

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical engineering 2011年第6期24卷 983-991页

作者： WANG Fudong LIU Xinfu Guan Zhichuan LIU Chunhua School of Petroleum Electronic engineering China University of Petroleum Qingdao 266555 China Qingdao TSC offshore Equipment co Ltd. Qingdao 266108 China

The existing design of the pumping systems mainly focuses on the approximate co.putational formulae and procedures,which are developed based on the analytic approaches of co.ventional oil/gas *** calculation of polished rod loads usually just co.cerns about the static and inertial *** the co.putation of gearbox torque generally uses empirical formulae and co.rection *** above modeling procedures,if applied to the co.lbed methane（CBM） wells,can not give the desired accuracy of the system design and its pertinent *** this paper,based on the kinematic and dynamic analysis of the pumping system,the kinematic relation of polished rod is analyzed,and the variation of the total loads of polished rod is developed with the limits of CBM well co.ditions along the *** gearbox torque calculation model is established by co.bining the co.nterbalance effect with the calculated dynamometer cards and torque *** application characteristics of this model are demonstrated by the example of ZH002-4 well in Qinshui *** interpretations of results show that the cranks of beam units should rotate in a co.nter clockwise direction viewed with the wellhead to the *** with oil？gas fields,the dynamic and friction to polished rod load ratios are relatively high and the co.putation of polished rod loads should involve the static and inertial loads,as well as vibration and friction *** the dynamic load ratio decreases rapidly during the ***,the total deformation of the string is small in CBM *** for balanced operation,the gearbox torque load usually has two approximately equal peaks and the magnitudes of instantaneous torque are just within 50% of unbalanced gearbox *** proposed research improves efficiency of the pumping system,loads the pumping unit more uniformly,and provides the reasonable basis for selecting the units.

关键词： sucker rod pump kinematic analysis polished rod load dynamometer card gearbox torque

High thermally stable deep red-emitting Sb^(3+),Ho^(3+)-co.oped Cs_(2)NaScCl_(6) double perovskite for plant lighting

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第11期42卷 2043-2050,I0002页

作者： Houjiang You Gaoxuanyu Guan Tianchun Lang Mingsheng Cai Peng Su Huichao He Yang Zhong Tao Han School of Metallurgy and Materials engineering Chongqing University of Science and TechnologyChongqing401331China School of Material Science and engineering Chongqing University of TechnologyChongqing400054China Chongqing Key Laboratory of Materials Surface&Interface Science Chongqing University of Arts and SciencesChongqing402160China offshore oil engineering co. Ltd.Tianjin300461China

Lead-free halide double perovskite has received widespread attention due to its excellent optical ***,the lack of deep red light and poor heat quenching resistance severely limit its application in plant lighting *** this work,Ho^(3+) was introduced into the thermally stable Cs_(2)NaScCl_(6)host,exhibiting a deep red emission of 660 *** co.structing an energy transfer channel between Sb^(3+)and Ho^(3+),the photo luminescence quantum yield(PLQY) of Cs_(2)NaScCl_(6):1%Sb^(3+),40%Ho^(3+) rises up to53.8%,that is increased by 17 times,and its emission intensity can still be maintained by 80% at 423 K,exhibiting good heat quenching *** obtained Cs_(2)NaScCl_(6):1%Sb^(3+),40%Ho^(3+) and Cs_(2)NaScCl_(6):1%Sb^(3+) with blue light emission were employed for fabricating a light-emitting diode(LED) device with a340 nm UV chip,and its emission spectrum matches well the absorption spectra of chlorophyll A and chlorophyll B with the high resemblance of 70% and 75%,making it suitable for use as an artificial light source to co.trol the growth process of plants in the field of plant lighting.

关键词： Lead-free halide double perovskite Energy transfer Thermally stable Plant lighting Rare earths