检索结果-南通市图书馆

Analysis of the displacements of pipeline overpasses based on geodetic monitoring results

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geodesy and Geodynamics 2022年第1期13卷 50-71页

作者： Roman Shults Andriy Annenkov Gulnur Seitkazina Saule Soltabayeva Zhenis Kozhayev Andrii Khailak Kira Nikitenko Bohdan Sossa Nataliia Kulichenko Department of Civil and Environmental Engineering Michigan Technological University Houghton49931 MIUSA Department of Applied Geodesy Kyiv National University of Construction and Architecture03037 KyivUkraine Department of Mining and Geodesy K.Turysov Institute of GeologyOil and MiningSatbayev UniversityAlmatyKazakhstan

There are many approaches to address geospatial monitoring of pipeline overpasses,among which the most widespread methods are terrestrial laser scanning and total station measurements.However,there is a problem in comparing the geospatial monitoring data collected by different methods in different epochs.The main task of this work is to find the correspondence between points in different epochs.The total station measurements are carried out in specific discrete points of the pipeline overpass.In contrast,terrestrial laser scanning allows the collection of the whole data set without fixing specific point co-ordinates.In order to compare different data in different epochs,it is necessary to select a relevant presentation of the monitoring results(reference model)and specify appropriate criteria for quality inspection.In general,a pipeline can be presented as a spatial curve.In this study,two types of reference models are considered:cubic splines and Bezier curves.These models are examined for the monitoring of two gas pipeline overpasses.The first measurement epoch is accomplished by the terrestrial laser scanning,and the second measurement epoch is completed by the total station.The reference models are simulated by Matlab coding.The preliminary accuracy of ground laser scanning and total station mea-surement is selected as the criterion of quality inspection.The simulation and comparison results provide the evidence that the correct selection of reference model is a crucial component of successful geospatial monitoring.The results show that the Hermite splines are effective in the comparison of different data sets.These splines present the interpolation accuracy compatible with measurement accuracy,i.e.,15-20 mm for spatial displacement determination.

关键词： Geospatial monitoring Terrestrial laser scanning Total station pipeline

维普期刊数据库

Design and Dynamic Analysis of pipeline Dredging Devices

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第6期19卷 1349-1367页

作者： Zhong Chen Yalin Wang Yue Li Jiangsu Key Laboratory of Advanced Manufacturing Technology Huaiyin Institute of TechnologyHuai’an223003China School of Mechanical and Material Engineering Huaiyin Institute of TechnologyHuai’an223003China

In order to improve the efficiency as well the adaptability and operability of traditional devices used to dredge drainage pipelines a new design is presented here,obtained by matching the structural specifications of a drainage pipeline with the working principle of a high-pressure water jet(HPWJ).To effectively improve the water jet nozzle performances,the nozzle’s structural parameters of the proposed device have been analyzed through Computational fluid dynamics(CFD)simulation.The corresponding behavior of the fluids inside and outside the selfrotational nozzle has been numerically simulated.The final design for the nozzle has been optimized taking into account such results.

关键词： pipeline nozzle head nozzle fluid simulation

Evaluation of the submarine debris-flow hazard risks to planned subsea pipeline systems: a case study in the Qiongdongnan Basin, South China Sea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2023年第5期42卷 139-153页

作者： Mingquan Huang Xuesheng Qian Jingping Xu Xuecheng Li School of Environment Harbin Institute of TechnologyHarbin 150001China Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China China Offshore Fugro Geosolutions(Shenzhen)Corporation Limited Shenzhen 518067China

The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a case study on evaluating the debris-flow hazard risks to the planned pipeline systems in this region.We used a numerical model to perform simulations to support this quantitative evaluation.First,one relict failure interpreted across the development site was simulated.The back-analysis modeling was used to validate the applicability of the rheological parameters.Then,this model was applied to forecast the runout behaviors of future debris flows originating from the unstable upslope regions considered to be the most critical to the pipeline systems surrounding the Manifolds A and B.The model results showed that the potential debris-flow hazard risks rely on the location of structures and the selection of rheological parameters.For the Manifold B and connected pipeline systems,because of their remote distances away from unstable canyon flanks,the potential debris flows impose few risks.However,the pipeline systems around the Manifold A are exposed to significant hazard risks from future debris flows with selected rheological parameters.These results are beneficial for the design of a more resilient pipeline route in consideration of future debris-flow hazard risks.

关键词： submarine debris flow pipeline manifold hazard evaluation route optimization Qiongdongnan Basin

维普期刊数据库

Dynamic Analysis of pipeline Lifting Operations for Different Current Velocities and Wave Heights

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第3期19卷 603-617页

作者： Dapeng Zhang Bowen Zhao Keqiang Zhu Ship and Maritime College Guangdong Ocean UniversityZhanjiang524088China Ocean College Zhejiang UniversityHangzhou316021China Faculty of Maritime and Transportation Ningbo UniversityNingbo315211China

pipelines are widely used for transporting oil resources in the context of offshore oil exploitation.The pipeline stress-strength analysis is an important stage in related design and ensuing construction techniques.In this study,assuming representative work environment parameters,pipeline lifting operations are investigated numerically.More specifically,a time-domain coupled dynamic analysis method is used to conduct a hydrodynamic analysis under different current velocities and wave heights.The results show that proper operation requires the lifting points are reasonably set in combination with the length of the pipeline and the position of the lifting device on the construction ship.The impact of waves on the pipeline is limited,however lifting operations under strong wind and waves should be avoided as far as possible.

关键词： pipeline OrcaFlex hydrodynamic analysis lifting operation

pipeline for previously stented basilar trunk aneurysm:a case focusing on how the pipeline should be deployed

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Neurosurgical Journal 2019年第1期5卷 56-59页

作者： Fei Liang Yupeng Zhang Yuntao Di Feng Guo Chuhan Jiang Department of Interventional Neuroradiology Beijing Neurosurgical Institute and Beijing Tiantan HospitalCapital Medical UniversityBeijing 100050China Department of Neurosurgery The People's Hospital of Tangxian CountyTangxianHebeiChina

Background:Recurrent,previously stented basilar trunk aneurysms pose significant challenges to either microsurgical clipping or traditional endovascular treatment.We here presented an intriguing case that was successfully treated by the pipeline embolization device(PED;ev3/Covidien Neurovascular,Irvine,California,USA).Case presentation:A 62-year-old male found a recurrent aneurysm,which had been treated with coiling and stentassisted coiling before.The patient came to our center seeking for a third treatment.In our center,a single PED and additional coils were used to treat this refractory aneurysm.The whole length of the PED was delicately implanted in the previous Enterprise stent(Cordis Corporation,Miami FL,USA),which resembled the double-layer flow diverter FRED(Microvention,Tustin,California,USA).The inflow zone of the aneurysmal sac was further coiled considering that this aneurysm had ruptured.No procedure-related complications occurred.Follow-up angiogram at 6 months indicated that the intractable aneurysm was completely occluded and the patient was free from any neurologic deficit.Conclusions:This is a case that adds knowledge to improve the poor performance of flow diverters in previously stented aneurysms.However,future studies with larger group of patients are needed to further test the safety and efficacy of this technique.

关键词： Previously stented aneurysm Basilar artery pipeline embolization device

维普期刊数据库

pipeline血流导向装置治疗颅内中小动脉瘤的临床研究

在线全文

学校读者我要写书评

暂无评论

Pipeline血流导向装置治疗颅内中小动脉瘤的临床研究

作者：陈宝桂林医学院

学位级别：硕士

目的:探索pipeline血流导向装置治疗广西壮族自治区少数民族颅内中小动脉瘤早期的临床疗效及安全性,以及探索影响中小动脉瘤血管内介入术后预后的相关因素。方法:根据拟定的纳入、排除标准,回顾性分析2018年7月至2021年7月在脑血管病科... 详细信息

目的:探索pipeline血流导向装置治疗广西壮族自治区少数民族颅内中小动脉瘤早期的临床疗效及安全性,以及探索影响中小动脉瘤血管内介入术后预后的相关因素。方法:根据拟定的纳入、排除标准,回顾性分析2018年7月至2021年7月在脑血管病科接受治疗的55名单发中小动脉瘤的少数民族患者(直径≤10mm)。收集其基线资料,观察其临床结局及随访情况,包括性别、年龄、高血压、糖尿病、高脂血症、动脉瘤破裂情况、入院的情况,动脉瘤尺寸、动脉瘤瘤颈直径、动脉瘤部位等。通过计算动脉瘤完全闭塞率及MRS评分评估手术疗效;根据患者术后死亡率、出血性卒中发生率、缺血性卒中发生率以及再治疗率评估手术的安全性;使用多因素逻辑回归分析明确中小动脉瘤血管内介入术后预后不良的危险因素。并发症定义为因手术及相关原因引起的缺血性卒中、出血性卒中等。其中缺血性卒中定义为头颅MRI检查发现被治疗血管供血区域的新发梗死灶。完全闭塞定义为Raymond-Roy I级;把传统治疗方法定义为单纯弹簧圈栓塞或支架辅助弹簧圈栓塞,纳入传统治疗组。结果:在55名患有单发中小动脉瘤少数民族患者中,有19名(34.5%)选择pipeline血流导向装置进行治疗,有36名(65.5%)选择传统治疗方法进行治疗,6个月后完全闭塞率分别为84.2%(16/19)、88.9%(32/36)。在PED治疗的患者中,有1(5.3%)名患者发生了缺血性脑卒中;在传统治疗方法治疗的患者中有4(11.1%)名发生了出血性卒中,3(8.3%)名发生了缺血性卒中,3(8.3%)名在6个月随访中出现死亡;但在6个月后的随访中,两种治疗方式在完全闭塞率、预后良好率(MRS评分≤2分)、并发症发生率、死亡率均未见明显统计学差异(P>0.05);在影响预后的单因素分析中显示年龄、吸烟、糖尿病、高脂血症以及术后并发症与临床预后相关(Ppipeline血流导向装置与传统治疗方法治疗广西壮族自治区少数民族颅内中小动脉瘤同样是安全有效的。在颅内中小动脉瘤血管内介入治疗中,吸烟、糖尿病及并发症的发生可能会导致患者更差的临床预后。

关键词：颅内动脉瘤中小动脉瘤少数民族血流导向装置 pipeline

Correlation of microstructure with tensile behavior and properties of API X70 pipeline steels subjected to strain aging

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2020年第3期27卷 319-324页

作者： Sang-in Lee Byoungchul Hwang Department of Materials Science and Engineering Seoul National University of Science and TechnologySeoul 01811Republic of Korea

Variations in tensile behavior and properties after pre-strain and thermal aging were differently affected by strain aging phenomenon dependent on microstructure.With increasing polygonal ferrite fraction,decrement in uniform elongation is increased,and the increment in yield-to-tensile ratio is slightly decreased after pre-strain and thermal aging.Therefore,it can be concluded that the polygonal ferrite has contradictory effects on strain aging resistance although the polygonal ferrite still contributes to improvement of uniform elongation after strain aging.

关键词： Steel Microstructure Strain aging Deformability pipeline

A combined computational pipeline to detect circular RNAs in human cancer cells under hypoxic stress

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 Molecular Cell Biology 2019年第10期11卷 829-844页

作者： Antonella Di Liddo Camila de Oliveira Freitas Machado Sandra Fischer Stefanie Ebersberger Andreas WHeumliller Julia EWeigand Michaela Muller-McNicoll Kathi Zarnack Buchmann Institute for Molecular Life Sciences Goethe University FrankfurtFrankfurt am MainGermany Institute of Cell Biology and Neuroscience Goethe University FrankfurtFrankfurt am MainGermany Institute for Cardiovascular Regeneration Goethe University FrankfurtFrankfurt am MainGermany Department of Biology Technical University DarmstadtGermany Institute of Molecular Biology(IMB) MainzGermany

Hypoxia is associated with several diseases,including cancer.Cells that are deprived of adequate oxygen supply trigger tran-scriptional and post-transcriptional responses,which control cellular pathways such as angiogenesis,proliferation,and metabolic adaptation.Circular RNAs(circRNAs)are a novel class of mainly non-coding RNAs,which have been implicated in multiple cancers and attract increasing attention as potential biomarkers.Here,we characterize the circRNA signatures of three different cancer cell lines from cervical(HeLa),breast(MCF-7),and lung(A549)cancer under hypoxia.In order to reliably detect circRNAs,we integrate available tools with custom approaches for quantification and statistical analysis?Using this consolidated computational pipeline,we identify?12000 circRNAs in the three cancer celUines.Their molecular characteristics point to an involvement of complementary RNA sequences as well as trans-acting factors in circRNA biogenesis,such as the RNA-binding protein HNRNPC-Notably,we detect a number of circRNAs that are more abundant than their linear counterparts.In addition,64 circRNAs significantly change in abundance upon hypoxia,in most cases in a cell type-specific manner.In summary,we present a comparative circRNA profiling in human cancer cell lines,which promises novel insights into the biogenesis and function of circRNAs under hypoxic stress.

关键词： circular RNA computational pipeline differential expression cancer cells hypoxia RNA-Seq

An Parallel FPGA SAT Solver Based on Multi-Thread and pipeline

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2021年第6期30卷 1008-1016页

作者： LI Tiejun MA Kefan ZHANG Jianmin College of Computer National University of Defense Technology

The Boolean Satisfiability(SAT) problem is the key problem in computer theory and application. A parallel multi-thread SAT solver named pprob SAT+ on a configurable hardware is proposed. In the algorithm,multithreads are executed simultaneously to hide the circuit stagnate. In order to improve the working frequency and throughput of the SAT solver, the deep pipeline strategy is adopted. When all data stored in block random access memory of the field programmable gate array, the solver can achieve maximum performance. If partial data are stored in the external memory, the size of the problem instances the SAT solver can be greatly improved. The experimental results show that the speedup of three-thread SAT solver is approximately 2.4 times with single thread,and shows that the pprob SAT+ have achieved substantial improvement while a solution is found.

关键词： Logic circuits Memory circuits Logic and switching circuits Semiconductor storage FPGA Incomplete algorithm Multi-thread pipeline