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Numerical solution of oscillatory flow of Maxwell fluid in a rectangular straight duct

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Applied Mathematics and Mechanics(English Edition) 2019年第11期40卷 1647-1656页

作者： Xuyang SUN Shaowei WANG Moli ZHAO Qiangyong ZHANG Department of Engineering Mechanics School of Civil Engineering Shandong University

A numerical analysis is presented for the oscillatory flow of Maxwell fluid in a rectangular straight duct subjected to a simple harmonic periodic pressure *** numerical solutions are obtained by a finite difference scheme *** stability of this finite difference scheme method is *** distributions of the velocity and phase difference are given numerically and *** effects of the Reynolds number,relaxation time,and aspect ratio of the cross section on the oscillatory flow are *** results show that when the relaxation time of the Maxwell model and the Reynolds number increase,the resonance phenomena for the distributions of the velocity and phase difference enhance.

关键词： Maxwell fluid oscillatory flow finite difference method rectangular duct

Experimental Study of Effect of Air duct Structures on Heat Dissipation of Heating-Only Fan Coil

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湖南大学学报（自然科学版） 2009年第S1期36卷 102-105页

作者： WU Xiao-zhou,ZHAO Jia-ning(School of Municipal and Environmental Engineering,Harbin Institute of Technology,Harbin,Heilongjiang 150090,China) School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly *** the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,distance between fan and coil,fan structure and air inlet *** natural air convection or forced,experimental studies were made on the effects of these factors upon the heat dissipation performance of *** results show that:1)After reducing the leakage through coil bypass,the heat dissipation of HFC increases 16.9% under natural convection,and increases 8.3% under forced convection.2)After the distance between fan and coil be raised from 23.2cm to 41.7cm,the heat dissipation of HFC decreases 21.3% under natural convection,but increases12.8% under forced convection.3)After changing the fan structure,the heat dissipation of HFC increases 41.8% under natural convection,and the heat dissipation per motor power increases 96.1% under forced convection.4)The heat dissipations of HFC with round pass,slit and strip type of air inlet are different,whose proportion is about 100%,110%,136% under natural convection,and 100%,105%,116% under forced convection.

关键词： heating-only fan coil heat dissipation performance air duct structure natural convection forced convection

Machine-learning based ocean atmospheric duct forecasting:a hybrid model-data-driven approach

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The Journal of China Universities of Posts and Telecommunications 2023年第4期30卷 1-9页

作者： Feng Yuting Gong Haobing Hao Xiaojing Gao Hui Guo Xiangming Key Laboratory of Trustworthy Distributed Computing and Service Beijing University of Posts and TelecommunicationsBeijing 100876China Key Laboratory of Radio Wave Propagation Characteristics and Modeling Technology 22nd Research Institute of China Electronics Technology CorporationQingdao 266107China

The atmospheric duct is a vital radio wave *** methods of forecasting the atmospheric duct mainly include statistical analysis based on sounding observation data and mesoscale numerical model-based *** former can provide accurate duct information but is highly dependent on the acquisition of data *** latter is more practical but still lacks *** paper introduces machine learning to establish a novel meteorological parameter correction model for atmospheric duct *** detail,using the weather research and forecasting(WRF)model data and spatiotemporal characteristics as input,sounding data as label and extreme gradient boosting(XGBoost)model for training,the meteorological parameter correction effect is the best,i.e.,the accuracy of forecast meteorological parameters is improved by about 65.4%.Combining the mapping relationship between meteorological parameters and corrected atmospheric refractive index(CARI),and the transition mechanism of CARI to duct parameters,a new duct forecasting mechanism is *** to the high efficiency of numerical model and the accuracy of sounding data,the new duct forecasting mechanism has excellent *** comparing the duct forecasting results,the forecasting accuracy of the new duct forecasting model is significantly higher than that of the mesoscale model.

关键词： marine atmospheric duct neural network fitting machine learning forecasting mechanism

Diagnosis of bile duct hepatocellular carcinoma thrombus without obvious intrahepatic mass

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World Journal of Gastroenterology 2010年第39期16卷 4998-5004页

作者： Long XY Li YX Wu W Li L Cao J. Department of General Surgery Xiangya Hospital Central South University Changsha 410008 Hunan Province China. liyixiong6@***

AIM:To study the diagnosis of hepatocellular carcinoma(HCC)presenting as bile duct tumor thrombus with no detectable intrahepatic ***:Six patients with pathologically proven bile duct HCC thrombi but no intrahepatic mass demonstrated on the preoperative imaging or palpated intrahepatic mass during operative exploration,were *** clinical and imaging data were retrospectively *** major findings or signs on comprehensive imaging were correlated with the surgical and pathologic ***:Jaundice was the major clinical symptom of the *** elevated serum total bilirubin,direct bilirubin and alanine aminotransferase levels were in concordance with obstructive jaundice and the underlying liver *** the 6 patients showing evidence of viral hepatitis,5 were positive for serum alpha fetoprotein and carbohydrate antigen 19-9,and 1 was positive for serum carcinoembryonic *** patient was correctly diagnosed by *** main features of patients on comprehensive imaging were filling defects with cup-shaped ends of the bile duct,with large filling defects presenting as casting moulds in the expanded bile duct,hypervascular intraluminal nodules,debris or blood clots in the bile *** obvious circular thickening of the bile duct walls was ***:Even with no detectable intrahepatic tumor,bile duct HCC thrombus should be considered in patients predisposed to HCC,and some imaging signs are indicative of its diagnosis.

关键词： Hepatocellular carcinoma Obstructive jaundice Bile duct tumor thrombus Diagnosis Diagnostic imaging

Benefits and limitations of middle bile duct segmental resection for extrahepatic cholangiocarcinoma

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Hepatobiliary & Pancreatic Diseases International 2020年第2期19卷 147-152页

作者： Masayuki Akita Tetsuo Ajiki Kimihiko Ueno Daisuke Tsugawa Motofumi Tanaka Masahiro Kido Hirochika Toyama Takumi Fukumoto Department of Hepato-Biliary-Pancreatic Surgery Kobe University Graduate School of MedicineKobe650-0017Japan

Background:Pancreaticoduodenectomy(PD)is a standardized strategy for patients with middle and distal bile duct *** aim of this study was to compare clinicopathological features of bile duct segmen-tal resection(BDR)with PD in patients with extrahepatic ***:Consecutive cases with extrahepatic cholangiocarcinoma who underwent BDR(n=21)or PD(n=84)with achievement of R0 or R1 resection in Kobe University Hospital between January 2000 and December 2016 were enrolled in the present ***:Patients who underwent PD were significantly younger than those receiving *** frequency of preoperative jaundice,biliary drainage and cholangitis was not significantly different between the two *** duration of surgery was longer and there was more intraoperative bleeding in the PD than in the BDR group(553 vs.421 min,and 770 vs.402 mL;both PClavien-DindoⅢa)were observed in the PD group(46%vs.10%,Pduct *** invasiveness and lower morbidity of BDR justified this technique for selected patients in a poor general condition.

关键词： Cholangiocarcinoma Middle bile duct resection Pancreaticoduodenectomy

Accuracy analysis of predicted velocity profiles of laminar duct flow with entropy generation method

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Applied Mathematics and Mechanics(English Edition) 2013年第8期34卷 971-984页

作者： J.A.ESFAHANI M.MODIRKHAZENI S.MOHAMMADI Center of Excellence on Modeling and Control Systems (CEMCS) & Department of Mechanical Engineering Faculty of Engineering Ferdowsi University of Mashhad

The objective of this work is to estimate the accuracy of a predicted velocity profile which can be gained from experimental results, in comparison with the exact ones by the methodology of entropy generation. The analysis is concerned with the entropy generation rate in hydrodynamic, steady, laminar, and incompressible flow for Newtonian fluids in the insulated channels of arbitrary cross section. The entropy generation can be calculated from two local and overall techniques. Adaptation of the results of these techniques depends on the used velocity profile. Results express that in experimental works, whatever the values of local and overall entropy generation rates are close to each other, the results are more accuracy. In order to extent the subject, different geometries have been investigated. Also, the influence studied, and the distribution of volumetric geometries is drawn. of geometry on the entropy generation rate is local entropy generation rate for the selected geometries is drawn.

关键词： entropy generation velocity profile duct arbitrary cross section laminarinternal flow

Endoscopic mucosal resection of a bile duct polyp: A case report

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World Journal of Clinical Cases 2019年第18期7卷 2864-2870页

作者： Shu Yang Li Yang Xiang-Yang Wang Yu-Ming Yang Department of Orthopaedics The Second Xiangya HospitalCentral South UniversityChangsha 410011Hunan ProvinceChina Department of Gastroenterology Hunan Provincial People’s HospitalHunan Normal UniversityChangsha 410011Hunan ProvinceChina

BACKGROUND Bile duct polyps are difficult to diagnose and are usually excised by open abdominal surgery or snare polypectomy using choledochoscopy via the T-tube sinus tract. However, these two resection methods require the surgeon to open the abdomen and cut the bile duct to place the “T” tube. Moreover, simple snare polypectomy, without submucosal injection, can only remove pedunculated polyps and not flat polyps. Therefore, a new method is required for the excision of bile duct polyps, including flat polyps. CASE SUMMARY A 63-year-old woman was hospitalized following epigastric pain lasting a month. She had a 30-year history of cholelithiasis and had undergone cholecystectomy because of cholecystolithiasis, and had undergone cholangiolithotomy twice due to choledocholithiasis. Computed tomography (CT) and magnetic resonance imaging showed a communication between the bile duct and duodenal bulb. Inside the communication, CT showed a high-density shadow which was a hypointense lesion in T2 weighted image. The lesion showed no enhancement in T1 weighted image contrast enhanced. Gastroscopy revealed an incarcerated bile duct stone in the anterior wall of the duodenal bulb, which was removed with a basket under gastroscopy. Thereafter, a choledochoduodenal fistula was revealed. Finally, a flat polyp was detected in the lower part of the common bile duct and was removed by endoscopic mucosal resection (EMR) through the fistula. To our knowledge, this is the first reported case of the removal of a bile duct polyp using EMR. CONCLUSION EMR is a safe, effective, and low-cost method for the resection of all bile duct polyps.

关键词： Case report Cholangiolithiasis Bile duct polyp Endoscopic mucosal resection

Pediatric nasolacrimal duct obstruction-benefit of a combined therapeutic approach

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World Journal of Pediatrics 2017年第5期13卷 427-432页

作者： Milo(s)Fischer Iris-Susanne Horn Mathias Otto Mandy Pirlich Andreas Dietz Christian Mozet Clinic of Otolaryngology Head and Neck Surgery and Department of Head Medicine and Oral Health.University Hospital LeipzigGermany Depamnent ofENT Head&Neck SurgerySchwarzwald-Baar KIinikum Villingen—SchwenningenGermany Clinic of Ophthalmology and Department of Head Medicine and Oral Health University Hospital LeipzigGermany Deparmaent ofNeurology University Hospital LeipzigGermany.

Background:Pediatric nasolacrimal duct obstruction (PNDO) requires therapeutic intervention after conservative procedures *** resilient treatment guidelines for the treatment are missing,the aim of this study was to evaluate the advantages of two different intervention techniques in children with ***:Between January,2006 and June,2014,233 children (0-208 months) were treated either with conventional probing by ophthalmologists only (Group I) or with endonasal endoscopic interdisciplinary approach (Group Ⅱ).The clinical outcome was ***:The overall success rate of Group Ⅰ was 93.4% compared to 98.4% of Group Ⅱ (P24 ***:Endoscopic control in treatment of PNDO allows exact identification of the stenosis and appropriate surgical intervention with an improved clinical *** endoscopic surgical techniques should be the standard PNDO treatment.

关键词： dacryocystocele Hasner valve nasal endoscopy nasolacrimal duct probing pediatric nasolacrimal duct obstruction

Diagnostic-therapeutic management of bile duct cancer

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World Journal of Clinical Cases 2019年第14期7卷 1732-1752页

作者： José María Huguet Miriam Lobo José Mir Labrador Carlos Boix Cecilia Albert Luis Ferrer-Barceló Ana B Durá Patricia Suárez Isabel Iranzo Mireia Gil-Raga Celia Baez de Burgos Javier Sempere Digestive Disease Department General University Hospital of ValenciaValencia 46014Spain Medical Oncology Department General University Hospital of ValenciaValencia 46014Spain Unidad Hepática Avanzada Servicio de Cirugía General y DigestivaGeneral University Hospital of ValenciaValencia 46014Spain Medical Oncology Department Hospital de RequenaRequena 46340Spain

Biliary tract cancer, or cholangiocarcinoma, comprises a heterogeneous group of malignant tumors that can emerge at any part of the biliary tree. This group is the second most common type of primary liver cancer. Diagnosis is usually based on symptoms, which may be heterogeneous, and nonspecific biomarkers in serum and biopsy specimens, as well as on imaging techniques. Endoscopy-based diagnosis is essential, since it enables biopsy specimens to be taken. In addition, it can help with locoregional staging of distal tumors. Endoscopic retrograde cholangiopancreatography is a key technique for the evaluation and treatment of malignant biliary tumors. Correct staging of cholangiocarcinoma is essential in order to be able to determine the degree of resectability and assess the results of treatment. The tumor is staged based on the TNM classification of the American Joint Committee on Cancer. The approach will depend on the classification of the tumor. Thus, some patients with early-stage disease could benefit from surgery;complete surgical resection is the cornerstone of cure. However, only a minority of patients are diagnosed in the early stages and are suitable candidates for resection. In the subset of patients diagnosed with locally advanced or metastatic disease, chemotherapy has been used to improve outcome and to delay tumor progression. The approach to biliary tract tumors should be multidisciplinary, involving experienced endoscopists, oncologists, radiologists, and surgeons.

关键词： Bile duct cancer Cholangiocarcinoma Management Diagnosis Incidence Multidisciplinary treatment