检索结果-南通市图书馆

Heat Transfer and Performance Characteristics of Axial Cooling Fans with Downstream Guide Vanes

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2012年第2期21卷 162-171页

作者： Alexandros Terzis Ioannis Stylianou Anestis I. Kalfas peter ott Group of Thermal Turbomachinery (GTT) School of Engineering EPFL-SCI-STI-PO CH-1015 Lausanne Switzerland Laboratory of Fluid Mechanics and Turbomachinery Dept. of Mechanical Engineering School of Engineering Aristotle University of Thessaloniki (AUTH) GR-54124 Thessaloniki Greece

This study examines experimentally the effect of stators on the performance and heat transfer characteristics of small axial cooling fans. A single fan impeller, followed by nine stator blades in the case of a complete stage, was used for all the experimental configurations. Performance measurements were carried out in a constant speed stage performance test rig while the transient liquid crystal technique was used for the heat transfer measurements. Full surface heat transfer coefficient distributions were obtained by recording the temperature history of liquid crystals on a target plate. The experimental data indicated that the results are highly affected by the flow conditions at the fan outlet. Stators can be beneficial in terms of pressure drop and efficiency, and thus more economical operation, as well as, in the local heat transfer distribution at the wake of the stator blades if the fan is installed very close to the cooling object. However, as the separation distance increases, enhanced heat transfer rate in the order of 25% is observed in the case of the fan impeller.

关键词：表面传热系数性能特点冷却风扇轴流导叶风机叶轮液晶技术性能试验台

Eccentric error and compensation in rotationally symmetric laser triangulation

在线全文

学校读者我要写书评

暂无评论

仪器仪表学报 2007年第9期28卷 1548-1553页

作者： Wang Lei Gao Jun Wang Xiaojia Johannes Eckstein peter ott Lab of Image Information Processing School of Computer and Information Hefei University of Technology Hefei 230009 China Optical Engineering Lab. Heilbronn University Heilbronn D-74081 Germany Dep. of Mechanical and Electrical Engineering Xiamen University Xiamen 361005 China

Rotationally symmetric triangulation(RST)sensor has more flexibility and less uncertainty limits because of the abaxial rotationally symmetric optical *** if the incident laser is eccentric,the symmetry of the image will descend,and it will result in the eccentric error especially when some part of the imaged ring is *** model of rotationally symmetric triangulation that meets the Schimpflug condition is presented in this *** error from eccentric incident laser is *** is pointed out that the eccentric error is composed of two parts,one is a cosine in circumference and proportional to the eccentric departure factor,and the other is a much smaller quadric factor of the *** the ring is complete,the first error factor is zero because it is integrated in whole ring, but if some part of the ring is blocked,the first factor will be the main *** verifies the result of the a- *** last,a compensation method to the error when some part of the ring is lost is presented based on neural *** results of experiment show that the compensation will make the absolute maximum error descend to half,and the standard deviation of error descends to 1/3.

关键词：补偿作用旋转对称激光三角测量法偏心因子视力测量神经网络

Obeticholic acid for severe bile acid diarrhea with intestinal failure:A case report and review of the literature

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2018年第21期24卷 2320-2326页

作者： Christian Lodberg Hvas peter ott peter Paine Simon Lal Soren peter Jorgensen Jens Frederik Dahlerup Department of Hepatology and Gastroenterology Aarhus University HospitalAarhus C 8000Denmark Department of Gastroenterology Salford Royal NHS Foundation TrustSalfordManchester M6 8HDUnited Kingdom

Bile acid diarrhea results from excessive amounts of bile acids entering the colon due to hepatic overexcretion of bile acids or bile acid malabsorption in the terminal ileum. The main therapies include bile acid sequestrants, such as colestyramine and colesevelam, which may be given in combination with the opioid receptor agonist loperamide. Some patients are refractory to conventional treatments. We report the use of the farnesoid X receptor agonist obeticholic acid in a patient with refractory bile acid diarrhea and subsequent intestinal failure. A 32-year-old woman with quiescent colonic Crohn's disease and a normal terminal ileum had been diagnosed with severe bile acid malabsorption and complained of watery diarrhea and fatigue. The diarrhea resulted in hypokalemia and sodium depletion that made her dependent on twice weekly intravenous fluid and electrolyte infusions. Conventional therapies with colestyramine, colesevelam, and loperamide had no effect. Second-line antisecretory therapies with pantoprazole, liraglutide, and octreotide also failed. Third-line treatment with obeticholic acid reduced the number of stools from an average of 13 to an average of 7 per 24h and improved the patient's quality of life. The fluid and electrolyte balances normalized. The effect was sustained during follow-up for 6 mo with treatment at a daily dosage of 25 mg. The diarrhea worsened shortly after cessation of obeticholic acid. This case report supports the initial report that obeticholic acid may reduce bile acid production and improve symptoms in patients with bile acid diarrhea.

关键词： Bile acid malabsorption Diarrhea Farnesoid X-activated receptor Crohn’s disease

Vitamin D deficiency in cirrhosis relates to liver dysfunction rather than aetiology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2011年第7期17卷 922-925页

作者： Mikkel Malham SΦren peter JΦrgensen peter ott JΦrgen Agnholt Hendrik Vilstrup Mette Borre Jens F Dahlerup Department of Medicine V (Hepatology and Gastroenterology) Aarhus University Hospital

AIM: To examine the vitamin D status in patients with alcoholic cirrhosis compared to those with primary biliary cirrhosis. METHODS: Our retrospective case series comprised 89 patients with alcoholic cirrhosis and 34 patients with primary biliary cirrhosis who visited our outpatient clinic in 2005 and underwent a serum vitamin D status assessment. RESULTS: Among the patients with alcoholic cirrhosis, 85% had serum vitamin D levels below 50 nmol/L and 55% had levels below 25 nmol/L, as compared to 60% and 16% of the patients with primary biliary cirrhosis, respectively (P < 0.001). In both groups, serum vitamin D levels decreased with increasing liver disease severity, as determined by the Child-Pugh score. CONCLUSION: Vitamin D deficiency in cirrhosis relates to liver dysfunction rather than aetiology, with lower levels of vitamin D in alcoholic cirrhosis than in primary biliary cirrhosis.

关键词：维生素D缺乏肝硬化肝功能病因酒精性原发性严重程度肝脏疾病

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于单幅灰度图像的快速三维重建方法研究

机械工程学报 2014年第2期50卷 42-47页

作者：高欣健张旭东高亚捷 ott peter 合肥工业大学计算机与信息学院合肥230009 德国海尔布隆大学光学实验室

对含有阴影的物体表面快速三维重建问题,提出一种融合阴影恢复形状(Shape from shading,SFS)数据与旋转对称激光三角传感器数据的基于单幅灰度图像的快速智能测量方法。针对SFS方法重建过程中出现的二义性问题,利用旋转对称激光三角传... 详细信息

对含有阴影的物体表面快速三维重建问题,提出一种融合阴影恢复形状(Shape from shading,SFS)数据与旋转对称激光三角传感器数据的基于单幅灰度图像的快速智能测量方法。针对SFS方法重建过程中出现的二义性问题,利用旋转对称激光三角传感器的关键数据对其进行修正。同时针对旋转对称激光三角传感器对未知物体表面需要逐点测量,测量速度慢的问题,利用修正后的SFS重建结果对旋转对称激光三角传感器进行智能视觉引导,对含有阴影的物体表面梯度变化较大的点及特征点进行精确测量。在此基础上搭建集成SFS方法的激光三角传感器高精度移动测量平台系统。该系统根据物体表面梯度变化的特点自动选取阈值调节测量精度,从而快速、精确地完成对未知物体表面的三维重建。并通过试验验证了方法的可行性和有效性。

关键词：三维重建数据融合激光三角

New tight junction protein 2 variant causing progressive familial intrahepatic cholestasis type 4 in adults: A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2020年第5期26卷 550-561页

作者： Chun-Shan Wei Naja Becher Jenny Blechingberg Friis peter ott Ida Vogel Henning Grønbæk Department of Clinical Medicine-Department of Hepatology and Gastroenterology Aarhus University HospitalAarhus N DK-8200Denmark Department of Hepatology Shenzhen Traditional Chinese Medicine HospitalThe Fourth Clinical Medical College of Guangzhou University of Chinese MedicineShenzhen 518033Guangdong ProvinceChina Department of Clinical Genetics Aarhus University HospitalAarhus N DK-8200Denmark

BACKGROUND Progressive familial intrahepatic cholestasis(PFIC)encompasses a group of autosomal recessive disorders with high morbidity and *** in the gene encoding tight junction protein-2(TJP2)have been linked to PFIC type 4(PFIC4),which predominantly presents in ***,there are only limited data from adults with TJP2-related *** report a family with an autosomal recessive disorder with a novel variant in the TJP2 gene in adults with very variable expression of *** SUMMARY The index patient presented at 19 years old with liver cirrhosis and variceal bleeding and was treated with endoscopic banding and *** 2018,he developed primary liver cancer that was treated with radiofrequency ablation followed by liver transplantation in *** testing revealed a novel homozygous TJP2 variant causing PFIC4(TJP2([NM_004817.3]:c.[3334C>T];[3334C>T])).The consanguineous family consists of the father and mother(both heterozygous)and their 12 children,of which five carry the variant in a homozygous state;however,these five siblings have highly variable expression of *** homozygous brothers had cirrhosis and portal hypertension at diagnosis at the ages of 19 and *** other homozygous brothers,age 23 and 19,and the homozygous sister,age 21,have elevated liver enzymes but presently no cirrhosis,which may suggest an age-dependent *** addition,five sisters had severe and mild intrahepatic cholestasis of pregnancy and carry the TJP2 variant in a homozygous and heterozygous state,*** This novel TJP2 variant is associated with PFIC4 causing severe liver disease with cirrhosis and primary liver cancer in adolescents/adults.

关键词： Progressive familial intrahepatic cholestasis Tight junction protein 2 Genetic variants Liver cirrhosis Liver cancer Case report

用于旋转对称三角传感器的一种鲁棒的处理方法(英文)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

仪器仪表学报 2007年第2期28卷 203-211页

作者：王晓嘉高隽王磊张旭东 Eckstein Johannes ott peter 合肥工业大学计算机与信息学院海尔布隆大学光学工程实验室海尔布隆D-74081.德国海尔布隆大学光学工程实验室

旋转对称三角传感器由于其光学系统的旋转对称性而比其他的传统激光三角传感器具有更好的柔性,将旋转对称三角传感器应用于工业领域,相应的处理方法的性能是至关重要的。为了使传感器在复杂物体表面情况下仍具有较好的性能,我们设计了... 详细信息

旋转对称三角传感器由于其光学系统的旋转对称性而比其他的传统激光三角传感器具有更好的柔性,将旋转对称三角传感器应用于工业领域,相应的处理方法的性能是至关重要的。为了使传感器在复杂物体表面情况下仍具有较好的性能,我们设计了一种用于旋转对称三角传感器的鲁棒的处理方法。首先,分析旋转对称三角传感器图像的特性,这些特性取决于被测物体的表面特性,而这些图像特性将有助于传感器图像的处理方法的设计。其次,用一种由粗到精检测方法实现对传感器图像的处理。提出在精检测中,一种结合了自适应平滑和峰值法的方法,以实现检测的鲁棒性。在实际传感器图像上的实验结果证明,这种处理方法对于来自复杂表面的传感器图像具有很好的鲁棒性,从而提高了传感器的柔性。

关键词：旋转对称三角传感器由粗到精检测 Hough变换自适应平滑

旋转对称三角传感器激光散斑的仿真研究(英文)

在线全文

学校读者我要写书评

暂无评论

中国图象图形学报 2008年第12期13卷 2414-2419页

作者：王磊王晓嘉高隽 Johannes Eekstein peter ott 合肥工业大学计算机与信息学院图像信息处理研究室合肥230009 Optical Engineering Laboratory Heilbronn University Heilbronn 74081 Germany 厦门大学机电工程系厦门361005 中国科学院合肥智能机械研究所仿生感知与控制研究中心合肥230031

散斑是激光三角传感器测量不确定度极限的根本影响因素。提出了一种用于旋转对称激光三角传感器的激光散斑的仿真方法,获得了仿真散斑图像。在旋转对称的三角传感器中,投射的激光点在检测器上被成像为一个环,从而散斑也相应是圆弧形。... 详细信息

散斑是激光三角传感器测量不确定度极限的根本影响因素。提出了一种用于旋转对称激光三角传感器的激光散斑的仿真方法,获得了仿真散斑图像。在旋转对称的三角传感器中,投射的激光点在检测器上被成像为一个环,从而散斑也相应是圆弧形。研究了散斑的特性,该散斑在环的半径方向上服从主观散斑的特性,其尺寸由光学系统的数值孔径决定。而在环的切线方向上,其本质上是客观散斑,由于光学系统存在折返光路,其尺寸由物体到检测器的光程、投射的激光光斑尺寸和成像圆环的半径决定。实验结果表明,仿真结果与散斑理论一致。基于仿真给出了对旋转对称三角传感器位移测量不确定度极限的分析,结果表明,使用旋转对称形式的传感器光学布局,在相同的光学系统数值孔径和使用同样的灰度质心算法的情况下,可达到传统激光三角测量不确定度的1/5。

关键词：光学测量激光三角传感器散斑仿真旋转对称

Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2008年第40期14卷 6208-6212页

作者： Jens otto Clemmesen Annamaria Giraldi peter ott Kim Dalhoff Bent Adel Hansen Fin Stolze Larsen Department of Hepatology RigshospitaletUniversity Hospital of Copenhagen Clinical Pharmacology RigshospitaletUniversity Hospital of Copenhagen

AIM: To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with *** type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liver ***,the effect of phosphodiesterase type-5 inhibitors on splanchnic blood flow and portal hypertension remains essentially ***: Ten patients with biopsy proven cirrhosis (five females/five males,mean age 54 ± 8 years) and an HVPG above 12 mmHg were studied after informed *** of splanchnic blood flow and the HVPG during liver vein catheterization were done before and 80 min after oral administration of 50 mg *** flow was estimated by use of indocyanine green clearance technique and Fick's principle,with correction for non-steady ***: The plasma concentration of sildenafil was 222 ± 136 ng/mL 80 min after *** arterial blood pressure decreased from 77 ± 7 mmHg to 66 ± 12 mmHg,P = 0.003,while the splanchnic blood flow and oxygen consumption remained unchanged at 1.14 ± 0.71 L/min and 2.3 ± 0.6 mmol/ min,*** the HVPG remained unchanged (18 ± 2 mmHg vs 16 ± 2 mmHg) with individual changes ranging from -8 mmHg to +2 *** seven patients,HVPG decreased and in three it ***: In spite of arterial blood pressure decreases 80 min after administration of the phosphodiesterase type-5 inhibitor sildenafil,the present study could not demonstrate any clinical relevant influence on splanichnic blood flow,oxygen consumption or the HVPG.

关键词：肝硬化肝静脉压力高血压勃起功能障碍