检索结果-南通市图书馆

Micromechanism and mathematical model of stress sensitivity in tight reservoirs of binary granular medium

Petroleum Science 2024年第3期21卷 1780-1795页

作者： jian-Bang Wu Sheng-Lai yang Qiang Li Kun yang Can Huang Dao-ping Lv Wei Zhou State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China Laboratoire de G eologie Ecole Normale Sup erieure/CNRS UMR8538PSL Research UniversityParis75005France Research Institute of Exploration and Development Xinjiang Oilfield CompanyKaramay834000XinjiangChina

Research on reservoir rock stress sensitivity has traditionally focused on unary granular structures,neglecting the binary nature of real reservoirs,especially tight *** the stresssensitive behavior and mathematical characterization of binary granular media remains a challenging *** this study,we conducted online-NMR experiments to investigate the permeability and porosity evolution as well as stress-sensitive control mechanisms in tight sandy conglomerate *** results revealed stress sensitivity coefficients between 0.042 and 0.098 and permeability damage rates ranging from 65.6%to 90.9%,with an average pore compression coefficient of 0.0168—0.0208 MPa ***-scale compression occurred in three stages:filling,compression,and compaction,with matrix pores playing a dominant role in pore *** stress sensitivity of binary granular media was found to be influenced by the support structure and particle *** stress sensitivity was associated with small fine particle size,high fines content,high uniformity coefficient of particle size,high plastic deformation,and low Young's ***-supported samples exhibited a high irreversible permeability damage rate(average=74.2%)and stress sensitivity coefficients(average=0.089),with pore spaces more *** contrast,grain-supported samples showed low stress sensitivity coefficients(average=0.021)at high stress *** on the experiments,we developed a mathematical model for stress sensitivity in binary granular media,considering binary granular properties and nested interactions using Hertz contact deformation and Poiseuille *** describing the change in activity content of fines under stress,we characterized the non-stationary state of compressive deformation in the binary granular structure and classified the reservoir into three *** model was applied for production prediction using actual data from the Mahu reservoir in China,showing that the e

关键词： Stress sensitivity Binary granular medium Tight reservoir Online-NMR Reservoir energy retention rate

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

Bifurcations of Resonant Solutions and Chaos in Physical Pendulum Equation with Suspension Axis Vibrations

引用

Acta Mathematicae Applicatae Sinica 2010年第4期26卷 677-704页

作者： Xiang-ling Fu Jin Deng jian-ping yang School of Mathematics Hunan University of Science and TechnologyHunan 411201China College of Mathematics and Computer Sciences Hunan Normal UniversityHunan 410081China Department of Mathematics and Physics Hunan Institute of EngineeringHunan 411104China College of Science China Agricultural UniversityBeijing 100083China

This paper is a continuation of ＂Complex Dynamics in Physical Pendulum Equation with Suspension Axis Vibrations＂[1].In this paper,we investigate the existence and the bifurcations of resonant solution for ω0：ω：Ω ≈ 1：1：n,1：2：n,1：3：n,2：1：n and 3：1：n by using second-order averaging method,give a criterion for the existence of resonant solution for ω0：ω：Ω ≈ 1：m：n by using Melnikov＇s method and verify the theoretical analysis by numerical *** numerical simulation,we expose some other interesting dynamical behaviors including the entire invariant torus region,the cascade of invariant torus behaviors,the entire chaos region without periodic windows,chaotic region with complex periodic windows,the entire period-one orbits region;the jumping behaviors including invariant torus behaviors converting to period-one orbits,from chaos to invariant torus behaviors or from invariant torus behaviors to chaos,from period-one to chaos,from invariant torus behaviors to another invariant torus behaviors;the interior crisis;and the different nice invariant torus attractors and chaotic *** numerical results show the difference of dynamical behaviors for the physical pendulum equation with suspension axis vibrations between the cases under the three frequencies resonant condition and under the periodic/quasi-periodic *** exhibits many invariant torus behaviors under the resonant *** find a lot of chaotic behaviors which are different from those under the periodic/quasi-periodic ***,we did not find the cascades of period-doubling bifurcation.

关键词： Pendulum equation suspension axis vibrations averaging method Melnikov's method bifurcations chaos three frequencies resonances resonant solution

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

Pre-operative enhanced magnetic resonance imaging combined with clinical features predict early recurrence of hepatocellular carcinoma after radical resection

引用

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1192-1203页

作者： jian-ping Chen Ri-Hui yang Tian-Hui Zhang Li-An Liao Yu-Ting Guan Hai-yang Dai Department of Intervention Meizhou People’s HospitalMeizhou 514031Guangdong ProvinceChina Department of Medical Imaging Meizhou People’s HospitalMeizhou 514031Guangdong ProvinceChina Department of Medical Imaging Huizhou Municipal Central HospitalHuizhou 516001Guangdong ProvinceChina

BACKGROUND Indentifying predictive factors for postoperative recurrence of hepatocellular carcinoma(HCC)has great significance for patient *** To explore the value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid(Gd-EOB-DTPA)enhanced magnetic resonance imaging(MRI)combined with clinical features in predicting early recurrence of HCC after *** A total of 161 patients with pathologically confirmed HCC were *** patients were divided into early recurrence and non-early recurrence group based on the follow-up *** clinical,laboratory,pathological results and Gd-EOB-DTPA enhanced MRI imaging features were *** Of 161 patients,73 had early recurrence and 88 were had non-early *** analysis showed that patient age,gender,serum alpha-fetoprotein level,the Barcelona Clinic Liver Cancer stage,China liver cancer(CNLC)stage,microvascular invasion(MVI),pathological satellite focus,tumor size,tumor number,tumor boundary,tumor capsule,intratumoral necrosis,portal vein tumor thrombus,large vessel invasion,nonperipheral washout,peritumoral enhancement,hepatobiliary phase(HBP)/tumor signal intensity(SI)/peritumoral SI,HBP peritumoral low signal and peritumoral delay enhancement were significantly associated with early recurrence of HCC after *** logistic regression analysis showed that patient age,MVI,CNLC stage,tumor boundary and large vessel invasion were independent predictive *** data validation indicated that the area under the curve of the combined predictors was 0.861,suggesting that multivariate logistic regression was a reasonable predictive model for early recurrence of *** Gd-EOB-DTPA enhanced MRI combined with clinical features would help predicting the early recurrence of HCC after operation.

关键词： Hepatocellular carcinoma Enhanced magnetic resonance imaging Microvascular invasion Hepatobiliary phase Recurrence

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

Bifurcations and Chaos in Duffng Equation with Damping and External Excitations

引用

Acta Mathematicae Applicatae Sinica 2014年第2期30卷 483-504页

作者： Mei-xiang CAI jian-ping yang Jin DENG Institute of Mathematics and Physics Central South University of Forestry and Technology College of Science China Agriculture University Department of Mathematics and Physics Hunan Institute of Engineering

Duffing equation with damping and external excitations is investigated. By using Melnikov method and bifurcation theory, the criterions of existence of chaos under periodic perturbations are obtained. By using second-order averaging method, the criterions of existence of chaos in averaged system under quasi-periodic perturbations for Ω = nω ＋ εσ, n = 2,4,6 （where σ is not rational to ω） are investigated. However, the criterions of existence of chaos for n = 1, 3, 5, 7 - 20 can not be given. The numerical simulations verify the theoretical analysis, show the occurrence of chaos in the averaged system and original system under quasi- periodic perturbation for n = 1, 2, 3, 5, and expose some new complex dynamical behaviors which can not be given by theoretical analysis. In particular, the dynamical behaviors under quasi-periodic perturbations are different from that under periodic perturbations, and the period-doubling bifurcations to chaos has not been found under quasi-periodic perturbations.

关键词： Duffing equation Melnikov method second-order averaging method chaos

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

Identification of differentially expressed mRNAs as novel predictive biomarkers for gastric cancer diagnosis and prognosis

引用

World Journal of Gastrointestinal Oncology 2024年第5期16卷 1947-1964页

作者： jian-Wei Zhou Yi-Bing Zhang Zhi-yang Huang Yu-ping Yuan Jie Jin Department of Gastroenterology Wenzhou Central HospitalDingli Clinical College of Wenzhou Medical UniversityThe Second Affiliated Hospital of Shanghai UniversityWenzhou 325000Zhejiang ProvinceChina

BACKGROUND Gastric cancer(GC)has a high mortality rate *** significant progress in GC diagnosis and treatment,the prognosis for affected patients still remains *** To identify important candidate genes related to the development of GC and iden-tify potential pathogenic mechanisms through comprehensive bioinformatics *** The Gene Expression Omnibus database was used to obtain the GSE183136 dataset,which includes a total of 135 GC *** limma package in R software was employed to identify differentially expressed genes(DEGs).Thereafter,enrichment analyses of Gene Ontology(GO)terms and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways were performed for the gene modules using the clusterProfile package in R *** protein-protein interaction(PPI)networks of target genes were constructed using STRING and visualized by Cytoscape *** common hub genes that emerged in the cohort of DEGs that was retrieved from the GEPIA database were then screened using a Venn *** expression levels of these overlapping genes in stomach adenocarcinoma samples and non-tumor samples and their association with prognosis in GC patients were also obtained from the GEPIA database and Kaplan-Meier ***,real-time quantitative polymerase chain reaction(RT-qPCR)and western blotting were performed to determine the mRNA and protein levels of glutamic-pyruvic transaminase(GPT)in GC and normal immortalized cell *** addition,cell viability,cell cycle distribution,migration and invasion were evaluated by cell counting kit-8,flow cytometry and transwell ***,we also conducted a retrospective analysis on 70 GC patients diagnosed and surgically treated in Wenzhou Central Hospital,Dingli Clinical College of Wenzhou Medical University,The Second Affiliated Hospital of Shanghai University between January 2017 to December *** tumor and adjacent normal samples were collected from the patients to determine the

关键词： Gastric cancer Differentially expressed genes Bioinformatics Hub genes Prognosis

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

Quantitative evaluation of multi-process collaborative operation in steelmaking–continuous casting sections

引用

International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1353-1366页

作者： jian-ping yang Qing Liu Wei-da Guo Jun-guo Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Engineering Research Center of MES Technology for Iron&Steel Production Ministry of EducationBeijing 100083China Laiwu iron and Steel Group Yinshan Section Steel Co. Ltd.Jinan 271104China Hesteel Group Tangsteel Company Tangshan 063000China

The quantitative evaluation of multi-process collaborative operation is of great significance for the improvement of production planning and scheduling in steelmaking–continuous casting sections(SCCSs). However, this evaluation is difficult since it relies on an in-depth understanding of the operating mechanism of SCCSs, and few existing methods can be used to conduct the evaluation, due to the lack of full-scale consideration of the multiple factors related to the production operation. In this study, three quantitative models were developed, and the multiprocess collaborative operation level was evaluated through the laminar-flow operation degree, the process matching degree, and the scheduling strategy availability degree. Based on the evaluation models for the laminar-flow operation and process matching levels, this study investigated the production status of two steelmaking plants, plants A and B, based on actual production data. The average laminar-flow operation(process matching) degrees of SCCSs were obtained as 0.638(0.610) and 1.000(0.759) for plants A and B, respectively, for the period of April to July 2019. Then, a scheduling strategy based on the optimization of the furnace-caster coordinating mode was suggested for plant A. Simulation experiments showed higher availability than the greedy-based and manual strategies. After the proposed scheduling strategy was applied,the average process matching degree of the SCCS of plant A increased by 4.6% for the period of September to November 2019. The multi-process collaborative operation level was improved with fewer adjustments and interruptions in casting.

关键词： steelmaking–continuous casting multi-process collaborative operation quantitative evaluation model laminar-flow operation process matching scheduling strategy

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

Inverse Calculation and Regularization Process for the Solar Aspect System(SAS) of HXI Payload on ASO-S Spacecraft

引用

Research in Astronomy and Astrophysics 2024年第4期24卷 13-34页

作者： Ji-Rui Yu ping Ruan yang Su Ying-Hong He Jin-You Tao Zhe Zhang Song Guo Bin Xue jian-Feng yang Xi'an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences Xi'an 710119China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 20034China School ofAstronomy and Space Science Universityof Science and Technology of ChinaHefei 230026China

For the ASO-S/HXI payload, the accuracy of the flare reconstruction is reliant on important factors such as the alignment of the dual grating and the precise measurement of observation orientation. To guarantee optimal functionality of the instrument throughout its life cycle, the Solar Aspect System (SAS) is imperative to ensure that measurements are accurate and reliable. This is achieved by capturing the target motion and utilizing a physical model-based inversion algorithm. However, the SAS optical system’s inversion model is a typical ill-posed inverse problem due to its optical parameters, which results in small target sampling errors triggering unacceptable shifts in the solution. To enhance inversion accuracy and make it more robust against observation errors, we suggest dividing the inversion operation into two stages based on the SAS spot motion model. First, the as-rigid-aspossible (ARAP) transformation algorithm calculates the relative rotations and an intermediate variable between the substrates. Second, we solve an inversion linear equation for the relative translation of the substrates, the offset of the optical axes, and the observation orientation. To address the ill-posed challenge, the Tikhonov method grounded on the discrepancy criterion and the maximum a posteriori (MAP) method founded on the Bayesian framework are utilized. The simulation results exhibit that the ARAP method achieves a solution with a rotational error of roughly±3 5 (1/2-quantile);both regularization techniques are successful in enhancing the stability of the solution, the variance of error in the MAP method is even smaller—it achieves a translational error of approximately±18μm (1/2-quantile) in comparison to the Tikhonov method’s error of around±24μm (1/2-quantile). Furthermore, the SAS practical application data indicates the method’s usability in this study. Lastly, this paper discusses the intrinsic interconnections between the regularization methods.

关键词： methods:data analysis Sun:flares Sun:X-rays gamma rays

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

Multi-surrogate framework with an adaptive selection mechanism for production optimization

引用

Petroleum Science 2024年第1期21卷 366-383页

作者： Jia-Lin Wang Li-Ming Zhang Kai Zhang jian Wang jian-ping Zhou Wen-Feng Peng Fa-Liang Yin Chao Zhong Xia Yan Pi-yang Liu Hua-Qing Zhang Yong-Fei yang Hai Sun School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Qingdao University of Technology Qingdao266580ShandongChina College of Science China University of PetroleumQingdao266580ShandongChina Zepu Oil and Gas Development Department PetroChina Tarim Oilfield CompanyKorla841000XinjiangChina Hainan Branch of CNOOC Ltd Haikou70311HainanChina

Data-driven surrogate models that assist with efficient evolutionary algorithms to find the optimal development scheme have been widely used to solve reservoir production optimization ***,existing research suggests that the effectiveness of a surrogate model can vary depending on the complexity of the design problem.A surrogate model that has demonstrated success in one scenario may not perform as well in *** the absence of prior knowledge,finding a promising surrogate model that performs well for an unknown reservoir is ***,the optimization process often relies on a single evolutionary algorithm,which can yield varying results across different *** address these limitations,this paper introduces a novel approach called the multi-surrogate framework with an adaptive selection mechanism(MSFASM)to tackle production optimization *** consists of two *** the first stage,a reduced-dimensional broad learning system(BLS)is used to adaptively select the evolutionary algorithm with the best performance during the current optimization *** the second stage,the multi-objective algorithm,non-dominated sorting genetic algorithm II(NSGA-II),is used as an optimizer to find a set of Pareto solutions with good performance on multiple surrogate models.A novel optimal point criterion is utilized in this stage to select the Pareto solutions,thereby obtaining the desired development schemes without increasing the computational load of the numerical *** two stages are combined using sequential transfer *** the two most important perspectives of an evolutionary algorithm and a surrogate model,the proposed method improves adaptability to optimization problems of various reservoir *** verify the effectiveness of the proposed method,four 100-dimensional benchmark functions and two reservoir models are tested,and the results are compared with those obtained by six other surrogate-model-based *** res

关键词： Production optimization Multi-surrogate models Multi-evolutionary algorithms Dimension reduction Broad learning system

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

Spherical Confinement Generates Entropic Force to Accelerate Polymer Chain Detachment

引用

Chinese Journal of Polymer Science 2024年第3期42卷 407-416,I0010页

作者： Yu-Shan Zheng jian-ping Zhou Yan Xu Kai Li Mechanical Engineering Xinjiang UniversityUrumqi 830002China

To understand the dynamic process of polymer detachment, it is necessary to determine the mean detachment time of a single breakable link, which is modeled as a spring. Normally, this time can be viewed as the escape of a Brownian particle from the potential well of the spring. However, as the free dangling length of the polymer chain increases, the conformational entropy of the chain is affected by geometric confinement. It means that the wall exerts a repulsive force on the chain, resulting in accelerated link detachment from a macroscopic perspective. In this work, we investigate the effect of entropy on the detachment rate in the case where the substrate is spherical. We demonstrate that spherical confinement accelerates chain detachment both inside and outside the sphere. An analytical expression for the mean detachment time of breakable links is given, which includes an additional pre-factor that is related to the partition function. Additionally, we analyze the expressions for entropic forces inside the sphere, outside the sphere, and on a flat wall, comparing their magnitudes to explain the difference in mean detachment time.

关键词： Polymer detachment Breakable link Entropic force Mean first passage time

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

Effect of screening colonoscopy frequency on colorectal cancer mortality in patients with a family history of colorectal cancer

引用

World Journal of Gastrointestinal Oncology 2024年第2期16卷 354-363页

作者： Li Zheng Bin Li Ling Lei Li-Jia Wang Zhi-ping Zeng jian-Dong yang Department of Gastroenterology The First Hospital of NanchangNanchang 330008Jiangxi ProvinceChina Department of General Surgery The First Hospital of NanchangNanchang 330008Jiangxi ProvinceChina

BACKGROUND Colorectal cancer is a common malignant tumor in China,and its incidence in the elderly is increasing *** bowel disease is a group of chronic non-specific intestinal inflammatory diseases,including ulcerative colitis and Crohn’s *** included the clinicopathological and follow-up data of patients with colorectal cancer who underwent laparoscopic colectomy or open colectomy at our Gastrointestinal Department between January 2019 and December *** indicators,oncological indicators,and survival rates were compared between the *** results of 104 patients who met the above criteria were extracted from the database(laparoscopic colectomy group=63,open colectomy group=41),and there were no statistically significant differences in the baseline data or follow-up time between the two *** Intraoperative blood loss,time to first ambulation,and time to first fluid intake were significantly lower in the laparoscopic colectomy group than in the open colectomy *** differences in overall mortality,tumor-related mortality,and recurrence rates between the two groups were not statistically significant,and survival analysis showed that the differences in the cumulative overall survival,tumor-related survival,and cumulative recurrence-free rates between the two groups were not statistically *** In elderly patients with colorectal cancer,laparoscopic colectomy has better short-term outcomes than open colectomy,and laparoscopic colectomy has superior long-term survival outcomes compared with open colectomy.

关键词： Colorectal cancer Laparoscopic surgery Open surgery Prognosis Laparoscopic colectomy Open colectomy

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：