检索结果-南通市图书馆

Influence of mechanical reduction amount on internal quality of continuous casting billets by thermal and numerical simulation

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第6期30卷 1234-1243页

作者： Dan-qing jiang Shu-jian Sun Han Wu yang-jian xu Fu-hai Zhu Zhen-qiang Zhang jiang Wang Zhong-ming Ren School of Materials Science and Engineering Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China

With establishment of thermal and numerical simulation models,the influence of reduction amount on solidification structure,segregation and shrinkage porosity of continuous casting(CC)billets was *** thermal–mechanical coupled simulation results indicated that with an increase in reduction amount,the temperature in the central area decreases,and the reduction efficiency firstly increases and then decreases,reaching the maximum value at reduction amount of 6 *** analysis showed that increasing the reduction amount is beneficial for the refinement of central solidification ***,the internal cracks are more likely to appear at higher reduction *** X-ray computerized tomography results revealed that a higher reduction amount can significantly reduce the volume fraction and equivalent diameter of the central shrinkage porosities of CC billets and increase the sphericity of ***,the macrosegregation of carbon along the central line is improved as the reduction amount increases;while the reduction amount exceeds 8 mm,the segregation degree will not change any more.

关键词： Mechanical reduction Solidification structure Porosity Thermal simulation Continuous casting billet

Melting and floating processes of inorganic materials in molten steel:Visualization physical simulation and mathematical modelling

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

China Foundry 2023年第2期20卷 89-98页

作者： Jin-hu Lai Sheng Yu yang-jian xu Dan-qing jiang San-san Shuai jiang Wang Zhong-ming Ren State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Shaoxing Institute of Technology Shanghai UniversityShaoxing 312000ZhejiangChina

It has been demonstrated that heat absorption method by using the inorganic material rod to cool the molten steel can significantly reduce the macrosegregation level of the large steel ***,owing to the opacity of the molten steel,the physical mechanism of the heat absorption method is not *** this work,a transparent hydraulic physical model with water and paraffin wax was built to simulate the melting and floating processes of inorganic materials in the molten steel.A mathematical simulation was also carried out to analyze the connection between the actual ingot and the physical *** show that it is feasible to simulate the molten steel and inorganic materials with water and paraffin *** the help of the physical model,the process of the melting of paraffin wax and its floating to the surface of water were clearly observed,during which the temperature of water at some characteristic positions in the mold was *** visualization findings demonstrate that the melting and floating processes of paraffin wax can help to bring the heat from the center of the mold to the top surface more quickly,which reduces the superheat and significantly accelerates the cooling rate of *** experimental results show that for the water with a certain superheat,the use of a larger mass of paraffin wax can accelerate the cooling of the water,but there is a risk of incomplete melting of the paraffin wax.A higher superheat of water will lead to a quicker melting rate for a given mass of paraffin wax,while a lower superheat leads to the incomplete melting of paraffin wax as well.

关键词： water and paraffin wax heat absorption method physical simulation superheat large steel ingot

Effects of curcumin on peroxisome proliferator-activated receptor γ expression and nuclear translocation/redistribution in culture-activated rat hepatic stellate cells

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2007年第9期120卷 794-801页

作者： CHENG yang PING jian xu Lie-ming Institute of Liver Diseases Shuguang Hospital Shanghai University of TCM Shanghai 201203 China

Background The function of peroxisome proliferator-activated receptor γ （PPARγ） in hepatic fibrogenesis remains largely unknown. Curcumin is a natural substance extracted form Curcuma Longa Linn and has a variety of pharmacological effects. In this study, the effects of curcumin on the proliferation, activation and apoptosis of rat hepatic stellate cells （HSCs） through PPARγ signaling were investigated. Methods HSCs were isolated from the normal Sprague Dawley rats through in situ peffusion of the liver with Pronase E and density-gradient centrifugation with Nycodenz. Cells were treated with curcumin, troglitazone, salvianolic acid B or GW9662. The effect on HSCs proliferation was determined by MTT colorimetry. Total RNA was extracted by TRizol reagent and gene levels were determined by semi-quantitative RT-PCR. Total cellular and nuclear protein were isolated and separated by 10% sodium dodecy Isulfate polyacrylamide gel electrophoresis. Protein levels were determined by Western blot. Cell apoptosis was detected by Hoechst 33258 staining. PPARγ subcellular distribution was detected by immunofluorescent staining. The activities of MMP-2 and 9 were measured by Gelatin zymograph assay. Results Curcumin suppressed HSCs proliferation in a dose-dependent manner. As HSCs underwent gradual activation with culture prolongation the PPARγ nuclear expression level decreased. Curcumin up-regulated PPARγ expression and significantly inhibited the production of a-SMA and collagen Ⅰ. PPARγ is expressed in the cytoplasm and nucleus and is evenly distributed in HSCs, but accumulated in the nucleus of HSCs and disappeared from cytoplasm after curcumin treatment. Hoechst 33258 staining showed that curcumin induced the apoptosis of culture-activated HSCs and significantly increased pro-apoptotic Bax expression and reduced anti-apoptotic Bcl-2 expression. Cyclin D1 gene, activated NFKB p65 protein and TGFβR-Ⅰ protein expression were down-regulated significantly by curcumin. The acti

关键词： curcumin hepatic stellate cell peroxisome proliferator-activated receptor γ

MATHEMATICAL MODELLING OF FLOW PHENOMENA IN METAL BATH COVERED WITH MOLTEN SLAG

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1990年第12期3卷 370-376页

作者： QU Ying yang jian xu Baomei University of Science and Technology Beijing,Beijing,China

By use of the two-component LDA and high speed camera,the water model of the flow field in metal bath under molten slag layer has been *** the basis of experimental results,the flow boundary conditions of liquid metal at the slag-metal interface of a gas injecting bath were *** flow field and the turbulent parameters of the metal bath covered with slag were solved by the vorticity-stream function *** results reveal that the flow velocity, turbulent energy and circulating rate of the melt under slag are lower than that of without *** one “dead zone” of the lowest turbulent energy is formed in the top layer under cover of slag near the ladle linning.

关键词： flow field metal bath injection metallurgy mathematical modelling

Routine use of a transanastomotic stent is unnecessary for hepatojejunostomy in liver transplantation

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2012年第14期125卷 2411-2416页

作者： WANG Gen-shu yang yang jianG Nan FU Bin-sheng LI Hua LI Shi-hui JIN Hai yang jian-xu ZHANG jian CHEN Gui-hua Liver Transplantation Center Department of Hepatic Surgery

Background The use of transanastomotic stents for Roux-en-Y hepatojejunostomy （RYHJ） in liver transplantation （LT） remains controversial. The aim of this retrospective study was to assess the role of transanastomotic stent for RYHJ in LT. Methods RYHJ for biliary reconstruction in LT was performed in 52 patients. Twenty-five patients had bile duct reconstruction by RYHJ with transanastomotic stents （S group）, while 27 patients underwent the same procedure without transanastomotic stents （non-S group）. The two groups were compared in terms of post-LT biliary complications and survival. Results The incidences of bile leakage, anastomotic stricture, non-anastomotic stricture, biliary sludge/lithiasis and biliary infection were 12% （3/25）, 9.5% （2/21）, 23.5% （4/17）, 11.8% （2/17）, and 24% （6/25）, respectively in the S group, and 0, 0, 20.0% （5/25）, 10.0% （2/20）, and 16.7% （4/24）, respectively in the non-S group. One and three year survival rates were 48.0% （12/25） and 34.0% （8/23）, respectively, in the S group and 57.7% （15/26） and 38.9% （7/18）, respectively, in the non-S group. There was no significant difference between the two groups in terms of the incidence of various biliary complications and survival （P 〉0.05）. Conclusion The routine use of transanastomotic stents is not necessary for RYHJ for biliary reconstruction in LT.

关键词： hepatojejunostomy liver transplantation, stent

Effects of ＂Phone Consultation＂ to Mental Status and Quality of Life of Patients with Cancer-related Pain and Physicians＇ Work and Life

在线全文

学校读者我要写书评

暂无评论

麻醉与监护论坛 2011年第2期18卷 119-121页

作者： Zhi-yang Chen jian-ming xu Yue-ling Chen Pain Clinic Anesthesia Department of Cancer Hospital Department of Oncology Fudan University Shanghai P.R.China 200032

Treatment and Outcome of Epileptogenic Temporal Cavernous Malformations

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

Chinese Medical Journal 2015年第7期128卷 909-913页

作者： Yong-Zhi Shan Xiao-Tong Fan Liang Meng yang An jian-Kun xu Guo-Guang Zhao Department of Neurosurgery Xuanwu Hospital Capital Medical University Beijing 100053 China

Background： The aim of this study is to explore the treatment and outcome ofepileptogenic temporal lobe cavernous malformations （CMs）. Methods： We analyzed retrospectively the profiles of 52 patients diagnosed as temporal lobe CMs associated with epilepsy. Among the 52 cases, 11 underwent a direct resection of CM along with the adjacent zone of hemosiderin rim without electrocorticogram （ECoG） monitoring while the other 41 cases had operations under the guidance of ECoG. Forty-six patients were treated by lesionectomy ＋ hemosiderin rim while the other six were treated by lesionectomy ＋ hemosiderin rim along with extended epileptogenic zone resection. The locations of lesions, the duration of illness, the manifestation, the excision ranges and the outcomes of postoperative follow-up were analyzed, respectively. Results： All of the 52 patients were treated by microsurgery. There was no neurological deficit through the long-term follow-up. Outcomes of seizure control are as follows： 42 patients （80.8%） belong to Engel Class I, 5 patients （9.6%） belong to Engel Class II, 3 patients （5.8%） belong to Engel Class Ill and 2 patients （3.8%） belong to Engel Class IV. Conclusion： Patients with epilepsy caused by temporal CMs should be treated as early as possible. Resection of the lesion and the surrounding hemosiderin zone is necessary. Moreover, an extended excision of epileptogenic cortex or cerebral lobes is needed to achieve a better prognosis if the ECoG indicates the existence of an extra epilepsy onset origin outside the lesion itself.

关键词： Cavernous Mallbrmation Electrocorticogram Epilepsy Surgery Temporal Lobe

Influence of granulocyte colony-stimulating factor on cardiac function in patients with acute myocardial infarction and leukopenia after revascularization

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2010年第14期123卷 1827-1832页

作者： GUO Shi-zun WANG Ning-fu ZHOU Liang YE Xian-hua PAN Hao TONG Guo-xin yang jian-min xu jian Department of Cardiology First Municipal Hospital of Hangzhou & Affiliated Hangzhou Hospital of Nanjing Medical University Hangzhou Zhejiang 310006 China

Background Granulocyte colony-stimulating factor （G-CSF） seems to improve cardiac function and perfusion when used systemically through mobilization of stem cells into peripheral blood, but results of previous clinical trials remain controversial. This study was designed to investigate safety and efficacy of subcutaneous injection of G-CSF on left ventricular function in patients with impaired left ventricular function after ST-segment elevation myocardial infarction （STEMI）. Methods Thirty-three patients （22 men; age, （68.5±6.1） years） with STEMI and with comorbidity of leukopenia were included after successful primary percutaneous coronary intervention within 12 hours after symptom onset. Patients were randomized into G-CSF group who received G-CSF （10 μg/kg of body weight, daily） for continuous 7 days and control group. Results of blood analyses, echocardiography and angiography were documented as well as possibly occurred adverse events. Results No severe adverse events occurred in both groups. Mean segmental wall thickening in infract segments increased significantly at 6-month follow up compared with baseline in both groups, but the longitudinal variation between two groups had no significant difference （P〉0.05）. The same change could also be found in longitudinal variation of wall motion score index of infarct segments （P 〉0.05）. At 6-month follow-up, left ventricular end-diastolic volume of both groups increased to a greater extent, but there were no significant differences between the two groups when comparing the longitudinal variations （P 〉0.05）. In both groups, left ventricular ejection fraction measured by echocardiography ameliorated significantly at 6-month follow-up （P 〈0.05）, but difference of the longitudinal variation between two groups was not significant （P 〉0.05）. When pay attention to left ventricular ejection fraction measured by angiocardiography, difference of the longitudinal variation between groups was significant （P=0.046）. Early diasto

关键词： myocardial infarction granulocyte colony-stimulating factor angiocardiography echocardiography stem cells

Influential and prognostic factors of small for gestational age infants

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2009年第4期122卷 386-389页

作者： ZHANG Yong-li LIU Jun-tao GAO Jin-song yang jian-qiu BIAN xu-ming Department of Obstetrics and Gynecology Peking Union MedicalCollege Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100730 China

Background Small for gestational age （SGA） infants are associated with a high rate of oligohydramnios, stillbirth and cesarean delivery. Among SGA patients there is a higher risk of neonatal complications, such as polycythemia, hyperbilirubinemia, and hypothermia. Additionally, the SGA infant is prone to suffer from major neurologic sequelae, as well as cardiovascular system disease, in later life. Proper monitoring and therapy during pregnancy are, therefore, of utmost importance. The present study aimed to investigate the influential and prognostic factors of SGA infants.Methods From January 2001 to June 2007, a total of 55 SGA neonatal infants were included in a study group. All were born at Peking Union Medical College Hospital, with regular formal antenatal examinations. In addition, a total of 122 cases of appropriate for gestational age （AGA） infants were born at the same time and were registered into a control group. All cases were singleton pregnancies with detailed information of the maternal age, gravidity, parity, maternal height and weight, complications, uterine height and abdominal circumference, results from transabdominal ultrasonography between 32-38 gestational weeks, pregnancy duration, delivery manner, placenta, umbilical cord, and neonatal *** Significant differences were observed in placenta weight and neonatal malformations between the study and control groups. Multivariate analysis revealed increased parity, maternal hyperthyroidism and hyperthyroidism history as risk factors. Fetal abdominal circumferences less than 30 and 32 cm at 32-38 gestational weeks respectively, as determined by ultrasonography, resulted in a Youden index of 0.62. Conclusions SGA infants were associated with a greater risk of smaller placentas and infant malformations. Increased parity, maternal hyperthyroidism, and a hyperthyroid history were risk factors for SGA infants. Fetal abdominal circumference less than 30 cm at 32 gestational weeks and

关键词： small for gestational age singleton pregnancy hyperthyroidism infant malformation