检索结果-南通市图书馆

Study of the pressure transient behavior of directional wells considering the effect of non-uniform flux distribution

引用

Petroleum Science 2024年第3期21卷 1765-1779页

作者： yan-zhong liang Bai-Lu Teng Wan-Jing Luo School of Energy Resources China University of Geosciences(Beijing)Beijing100083China

During the production,the fluid in the vicinity of the directional well enters the wellbore with different rates,leading to non-uniform flux distribution along the directional ***,in all existing studies,it is oversimplified to a uniform flux distribution,which can result in inaccurate results for field ***,this paper proposes a semi-analytical model of a directional well based on the assumption of non-uniform flux ***,the direction well is discretized into a carefully chosen series of linear sources,such that the complex well trajectory can be captured and the nonuniform flux distribution along the wellbore can be considered to model the three-dimensional flow *** using the finite difference method,we can obtain the numerical solutions of the transient flow within the *** the aid of Green's function method,we can obtain the analytical solutions of the transient flow from the matrix to the *** complete flow behavior of a directional well is perfectly represented by coupling the above two types of transient ***,on the basis of the proposed model,we conduct a comprehensive analysis of the pressure transient behavior of a directional *** computation results show that the flux variation along the direction well has a significant effect on pressure *** addition,the directional well in an infinite reservoir may exhibit the following flow regimes:wellbore afterflow,transition flow,inclined radial flow,elliptical flow,horizontal linear flow,and horizontal radial *** horizontal linear flow can be observed only if the formation thickness is much smaller than the well ***,a dip region that appears on the pressure derivative curve indicates the three-dimensional flow behavior near the wellbore.

关键词： Directional well Pressure transient behavior Semi-analytical model Non-uniform flux

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

Detection of engineering vehicles in high-resolution monitoring images

引用

Frontiers of Information Technology & Electronic Engineering 2015年第5期16卷 346-357页

作者： Xun LIU Yin ZHANG San-yuan ZHANG Ying WANG zhong-yan liang Xiu-zi YE College of Computer Science and Technology Zhejiang University College of Mathematics and Information Science Wenzhou University

This paper presents a novel formulation for detecting objects with articulated rigid bodies from highresolution monitoring images, particularly engineering vehicles. There are many pixels in high-resolution monitoring images, and most of them represent the background. Our method first detects ob ject patches from monitoring images using a coarse detection process. In this phase, we build a descriptor based on histograms of oriented gradient, which contain color frequency information. Then we use a linear support vector machine to rapidly detect many image patches that may contain ob ject parts, with a low false negative rate and a high false positive rate. In the second phase, we apply a refinement classification to determine the patches that actually contain ob jects. In this stage, we increase the size of the image patches so that they include the complete ob ject using models of the ob ject *** an accelerated and improved salient mask is used to improve the performance of the dense scale-invariant feature transform descriptor. The detection process returns the absolute position of positive ob jects in the original images. We have applied our methods to three datasets to demonstrate their effectiveness.

关键词： Object detection Histogram of oriented gradient (HOG) Dense scale-invariant feature transform(dense SIFT) Saliency Part models Engineering vehicles

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

Case Report:Surgical intervention of severe post-ERCP-pancreatitis accompanied with duodenum perforation

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第1期11卷 17-21页

作者： Zuo-bing CHEN zhong-yan liang Yun ZHANG Shao-yang ZHANG Shu-sen ZHENG Department of Emergency Surgery the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China Department of Hepatopancreatobiliary Surgery the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure widely used to diagnose and treat conditions of biliary or pancreatic ductal system. The post-ERCP severe acute pancreatitis (SAP) accompanied with duodenum perforation is rare but serious, remaining a challenge in clinic. In this study we report two such cases. Two Chinese women were treated for clinical suspicion of bile duct obstruction and underwent ERCP after admission. Both developed duodenum perforation and SAP after ERCP, and were managed in the intensive care unit (ICU) and required an organ-failure support. The surgical intervention of the peri-pancreatic debridement with lumber-abdominal compound incisions and postoperative washing and drainage was performed, and the two patients recovered well. The therapeutic effect of the peri-pancreatic debridement with lumber-abdominal compound incisions combined with postoperative washing and drainage in the patients of severe post-ERCP-pancreatitis (PEP) and duodenum perforation is satisfactory.

关键词： Endoscopic retrograde cholangiopancreatography (ERCP) Post-ERCP-pancreatitis (PEP) Duodenum perforation Debridement Drainage

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

Albumin resuscitation protects against traumatic/hemorrhagic shock-induced lung apoptosis in rats

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第11期9卷 871-878页

作者： Yun ZHANG zhong-yan liang Shao-yang ZHANG Fang-fang HUANG Wei WU Yuan GAO Zuo-bing CHEN Department of Emergency Surgery the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China Department of Intensive Care Unit the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China Institute of lnfectious Diseases the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

Objective: To determine the effects of albumin administration on lung injury and apoptosis in traumatic/hemorrhagic shock (T/HS) rats. Methods: Studies were performed on an in vivo model of spontaneously breathing rats with induced T/HS; the rats were subjected to femur fracture, ischemia for 30 min, and reperfusion for 20 min with Ringer's lactate solution (RS) or 5% (w/v) albumin (ALB), and the left lower lobes of the lungs were resected. Results: Albumin administered during reperfusion markedly attenuated injury of the lung and decreased the concentration of lactic acid and the number of in situ TdT-mediated dUTP nick-end labelling (TUNEL)-positive cells. Moreover, immunohistochemistry performed 24 h after reperfusion revealed increases in the level of nuclear factor κB (NF-κB), and phosphorylated p38 mitogen-activated protein kinase (MAPK) in the albumin-untreated group was down-regulated by albumin treatment when compared with the sham rats. Conclusion: Resuscitation with albumin attenuates tissue injury and inhibits T/HS-induced apoptosis in the lung via the p38 MAPK signal transduction pathway that functions to stimulate the activation of NF-κB.

关键词： Traumatic/hemorrhagic shock (T/HS) Mitogen-activated protein kinase (MAPK) Nuclear factor κB (NF-κB) Albumin Apoptosis

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

Impact of misplaced subclavian vein catheter into jugular vein on transpulmonary thermodilution measurement variables

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2016年第1期17卷 60-66页

作者： Wen-qiao YU Yun ZHANG Shao-yang ZHANG zhong-yan liang Shui-qiao FU Jia XU Ting-bo liang Department of Hepatobiliary and Pancreatic Surgery and Intensive Care Unit the Second Affiliated HospitalSchool of MedicineZhejiang University Hangzhou 310021 China Women's Hospital School of MedicineZhejiang University Hangzhou 310006 China Department of Emergency the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

Objective： The subclavian vein （SCV） is usually used to inject the indicator of cold saline for a transpul- monary thermodilution （TPTD） measurement. The SCV catheter being misplaced into the internal jugular （IJV） vein is a common occurrence. The present study explores the influence of a misplaced SCV catheter on TPTD variables. Methods： Thirteen severe acute pancreatitis （SAP） patients with malposition of the SCV catheter were enrolled in this study. TPTD variables including cardiac index （CI）, global end-diastolic volume index （GEDVI）, intrathoracic blood volume index （ITBVI）, and extravascular lung water index （EVLWl） were obtained after injection of cold saline via the misplaced SCV catheter. Then, the misplaced SCV catheter was removed and IJV access was constructed for a further set of TPTD variables. Comparisons were made between the TPTD results measured through the IJV and mis- placed SCV accesses. Results： A total of 104 measurements were made from TPTD curves after injection of cold saline via the IJV and misplaced SCV accesses. Bland-Altman analysis demonstrated an overestimation of ＋111.40 ml/m2 （limits of agreement： 6.13 and 216.70 ml/m2） for GEDVI and ITBVI after a misplaced SCV injection. There were no significant influences on CI and EVLWI. The biases of ＋0.17 L/（min.m2） for CI and ＋0.17 ml/kg for EVLWI were re- vealed by Bland-Altman analysis. Conclusions： The malposition of an SCV catheter does influence the accuracy of TPTD variables, especially GEDVI and ITBVI. The position of the SCV catheter should be confirmed by chest X-ray in order to make good use of the TPTD measurements.

关键词： Transpulmonary thermodUution Jugular vein catheter Misplaced subclavian vein catheter Severe acutepancreatitis

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

恩施地区散佚旧志考述

引用

图书馆理论与实践 2017年第1期 62-66,78页

作者：严忠良武汉大学历史学院

恩施地区不晚于宋代之前即纂有方志,方志数量亦较为可观,但散佚严重,仅存25种。通过爬梳现存方志等资料,可知恩施地区散佚旧志至少有30种,其中,明代以前2种、明代9种、明清之际4种、清代14种,年代不明者1种。将恩施地区现存旧志和散佚... 详细信息

恩施地区不晚于宋代之前即纂有方志,方志数量亦较为可观,但散佚严重,仅存25种。通过爬梳现存方志等资料,可知恩施地区散佚旧志至少有30种,其中,明代以前2种、明代9种、明清之际4种、清代14种,年代不明者1种。将恩施地区现存旧志和散佚旧志结合考察,能够较好呈现恩施地区方志的编纂谱系,进一步推进恩施地区历史文献研究。

关键词：恩施地区散佚旧志明清

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

Dexamethasone protects the glycocalyx on the kidney microvascular endothelium during severe acute pancreatitis

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2019年第4期20卷 355-362页

作者： Wen-qiao YU Shao-yang ZHANG Shui-qiao FU Qing-hui FU Wei-na LU Jian ZHANG zhong-yan liang Yun ZHANG Ting-bo liang Department of Hepatobiliary and Pancreatic Surgery and Intensive Care Unit the First Affiliated Hospital School of Medicine Zhejiang University Department of Surgical Intensive Care Unit the Second Affiliated Hospital School of Medicine Zhejiang University Department of Reproductive Medicine Women's Hospital School of Medicine Zhejiang University

Objective: This study demonstrated that dexamethasone(DEX) protects the endothelial glycocalyx from damage induced by the inflammatory stimulus tumor necrosis factor-α(TNF-α) during severe acute pancreatitis(SAP), and improves the renal microcirculation. Methods: Ninety mice were evenly divided into 3 groups(Sham, SAP, and SAP+DEX). The SAP mice model was established by ligature of pancreatic duct and intraperitoneal injection of cerulein. Renal perfusion and function, and morphological changes of the glycocalyx were evaluated by laser Doppler velocimetry, electron microscopy, and histopathology(hematoxylin and eosin(H&E) staining), respectively. Serum levels of syndecan-1 and TNF-α were assessed by enzyme-linked immunosorbent assay(ELISA). The proàtectiveì effects of dexamethasone on the glycocalyx and renal microcirculation were evaluated. Results: Significantly high levels of serum TNF-α were detected 3 h after the onset of SAP. These levels might induce degradation of the glycocalyx and kidney hypoperfusion, resulting in kidney microcirculation dysfunction. The application of dexamethasone reduced the degradation of the glycocalyx and improved perfusion of kidney. Conclusions: Dexamethasone protects the endothelial glycocalyx from inflammatory degradation possibly initiated by TNF-α during SAP. This is might be a significant discovery that helps to prevent tissue edema and hypoperfusion in the future.

关键词： Severe acute pancreatitis(SAP) Acute kidney injury(AKI) Glycocalyx Dexamethasone Tumor necrosis factor-α(TNF-α)

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

基于综合截割性能优化的采煤机变速截割控制

引用

东北大学学报（自然科学版） 2018年第1期39卷 118-122,137页

作者：刘永刚侯立良秦大同闫忠良重庆大学机械传动国家重点实验室重庆400044 重庆大学汽车工程学院重庆400044

针对目前滚筒采煤机在生产过程中采用单一牵引调速影响截割性能的问题,对采煤机的变速截割进行了探索研究.考虑变速截割的可行性及可靠性,按截割阻抗的大小对煤层硬度进行了平均划分;综合考虑不同截割性能指标的要求,对其进行加权平均... 详细信息

针对目前滚筒采煤机在生产过程中采用单一牵引调速影响截割性能的问题,对采煤机的变速截割进行了探索研究.考虑变速截割的可行性及可靠性,按截割阻抗的大小对煤层硬度进行了平均划分;综合考虑不同截割性能指标的要求,对其进行加权平均作为优化目标,对截割运动参数进行了优化;在此基础上,对由截割阻抗变化引起的不同工况的调速策略进行了比较分析,得到了截割性能最优的变速截割调速控制策略.研究结果可为采煤机高效变速截割奠定理论基础.

关键词：采煤机参数优化截割性能变速截割调速控制

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

Morphology engineering of ZnO micro/nanostructures under mild conditions for optoelectronic application

引用

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 498-503页

作者： liang Chu Haoyu Shen Hudie Wei Hongyu Chen Guoqiang Ma Wensheng yan Institute of Carbon Neutrality and New Energy&School of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018China School of Applied Physics and Materials Wuyi UniversityJiangmen 529020China

Zinc oxide(ZnO)serves as a crucial functional semiconductor with a wide direct bandgap of approximately 3.37 *** reaction is commonly used in the synthesis of ZnO micro/nanostructures,given its low cost,simplicity,and easy ***,ZnO morphology engineering has become desirable through the alteration of minor conditions in the reaction process,particularly at room *** this work,ZnO micro/nanostructures were synthesized in a solution by varying the amounts of the ammonia added at low temperatures(including room temperature).The formation of Zn^(2+)complexes by ammonia in the precursor regulated the reaction rate of the morphology engineering of ZnO,which resulted in various structures,such as nanoparticles,nanosheets,microflowers,and single ***,the obtained ZnO was used in the optoelectronic application of ultraviolet detectors.

关键词： morphology engineering low temperature ZnO nanosheets microflowers ultraviolet detector

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

Clinical application of cross microsurgical vasovasostomy in scrotum for atypical obstructive azoospermia

引用

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2019年第3期20卷 282-286页

作者： zhong-yan liang Feng-bin ZHANG Le-jun LI Jing-ping LI Jing-gen WU Chong CHEN Yi-min ZHU Department of Reproductive Endocrinology Reproductive Medicine CenterWomen's HospitalSchool of MedicineZhejiang UniversityHangzhou 310006China Department of Ultrasonography Women's HospitalSchool of MedicineZhejiang UniversityHangzhou 310006China

Seminal duct obstruction may result in obstructive azoospermia(OA)and severe oligoasthenoteratozoospermia(OAT)(<0.5 million/mL)(Nordhoff et al.,2015).Cases of partial OA and OAT can be treated effectively by microsurgical anastomosis(Goldstein and Kim,2013)to obtain successful surgical ***,microsurgical vasovasostomy(VV)(Dickey et al.,2015)and vasoepididymostomy(VE)(Peng et al.,2017)are not suitable for patients with atypical OA and poor epididymis conditions or unpredictable obstruction of the distal vas *** those patients,cross anastomosis may be applied instead of routine VE or VV.

关键词：输精管吻合无精子症显微手术

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

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：