期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
多壁碳纳米管改进QuEChERS-液相色谱-串联质谱法测定豆类中12种酰胺类杀菌剂残留量 被引量:1
1
作者 李巧莲 罗景阳 +3 位作者 张宏宏 王岩松 宣彤 蒋笑妍 《粮食与油脂》 北大核心 2023年第1期157-162,共6页
建立基于多壁碳纳米管改进分散固相萃取净化技术(QuEChERS),结合液相色谱-串联质谱法(LC-MS/MS),测定豆类中12种酰胺类杀菌剂残留量。结果表明:改进的QuEChERS最佳条件为无水MgSO4添加量800 mg、PSA添加量200 mg、HC-C18添加量100 mg、M... 建立基于多壁碳纳米管改进分散固相萃取净化技术(QuEChERS),结合液相色谱-串联质谱法(LC-MS/MS),测定豆类中12种酰胺类杀菌剂残留量。结果表明:改进的QuEChERS最佳条件为无水MgSO4添加量800 mg、PSA添加量200 mg、HC-C18添加量100 mg、MWCNTs添加量25 mg;在此条件下测得的12种酰胺类杀菌剂在0.1~2.5μg/L范围内均具有良好的线性关系,相关系数均大于0.99;方法检出限为0.05~2.00μg/kg,定量限为0.2~5.0μg/kg;加标实验平均回收率为70.7%~115.0%,相对标准偏差为0.4%~7.4%。该方法操作快捷,净化效果好,灵敏度高,适用于豆类中酰胺类杀菌剂残留量的分析。 展开更多
关键词 多壁碳纳米管 分散固相萃取净化技术 液相色谱-串联质谱法 酰胺类杀菌剂
下载PDF
Caudate lobe-sparing subtotal hepatectomy as treatment for extensive intrahepatic arterioportal fistula
2
作者 Rui Tang Guang-Dong Wu +4 位作者 Ang Li Li-Han Yu xuan tong Jun Yan Qian Lu 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2023年第4期409-411,共3页
Intrahepatic arterioportal fistulas(APFs)are abnormal hepatic artery and portal vein(PV)communications that develop as a result of congenital malformation,trauma,ruptured hepatic aneurysm,cirrhosis,tumor-related chang... Intrahepatic arterioportal fistulas(APFs)are abnormal hepatic artery and portal vein(PV)communications that develop as a result of congenital malformation,trauma,ruptured hepatic aneurysm,cirrhosis,tumor-related changes,biopsy,chemotherapy or iatrogenic causes[1,2].The most common symptoms are gastrointestinal bleeding and ascites secondary to portal hypertension;other symptoms include abdominal pain,pyrexia,edema,back pain and jaundice[3].The main goal of therapy is to decrease the portal pressure with variceal bleeding being the absolute indi-cation for surgical management.Transarterial embolization(TAE)should be the first choice to treat APFs,while resection,portocaval shunt and even transplantation may cure APFs in the case of TAE failure[4].In previous reports,caudate lobe-sparing subtotal hep-atectomy(CLSSH)has been applied for the treatment of primary hepatolithiasis and hepatocellular carcinoma[5,6].As far as we know,this is the first report describing CLSSH as treatment for an extensive intrahepatic APF,which involved segments 2 to 8,with corresponding hypertrophy of the caudate lobe. 展开更多
关键词 TREATMENT chemotherapy ARTERIAL
下载PDF
浮动环密封自锁位置的试验研究
3
作者 夏鹏 宣统 +1 位作者 周泽新 刘占生 《推进技术》 EI CAS CSCD 北大核心 2019年第4期884-891,共8页
浮动环密封被应用于液体火箭涡轮泵中,阻隔高压工质的泄漏。为了研究浮动环密封的运动特性和自锁位置的分布规律,开展试验研究,详细地展示了试验装置的原理和试验步骤。试验结果表明,间隙流体激励推动浮动环密封向转子靠近,转子的涡动... 浮动环密封被应用于液体火箭涡轮泵中,阻隔高压工质的泄漏。为了研究浮动环密封的运动特性和自锁位置的分布规律,开展试验研究,详细地展示了试验装置的原理和试验步骤。试验结果表明,间隙流体激励推动浮动环密封向转子靠近,转子的涡动运动使浮动环密封更加靠近转子涡动中心。压差恒定时,转子振动幅度决定浮动环密封能否自锁,自锁位置依赖于压差、转子振动的变化过程。试验中,自锁位置距离转子涡动中心的最小距离小于10μm。 展开更多
关键词 浮动环密封 锁死位置 振动 转子
下载PDF
Meshless Surface Wind Speed Field Reconstruction Based on Machine Learning
4
作者 Nian LIU Zhongwei YAN +6 位作者 xuan tong Jiang JIANG Haochen LI Jiangjiang XIA Xiao LOU Rui REN Yi FANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第10期1721-1733,共13页
We propose a novel machine learning approach to reconstruct meshless surface wind speed fields,i.e.,to reconstruct the surface wind speed at any location,based on meteorological background fields and geographical info... We propose a novel machine learning approach to reconstruct meshless surface wind speed fields,i.e.,to reconstruct the surface wind speed at any location,based on meteorological background fields and geographical information.The random forest method is selected to develop the machine learning data reconstruction model(MLDRM-RF)for wind speeds over Beijing from 2015-19.We use temporal,geospatial attribute and meteorological background field features as inputs.The wind speed field can be reconstructed at any station in the region not used in the training process to cross-validate model performance.The evaluation considers the spatial distribution of and seasonal variations in the root mean squared error(RMSE)of the reconstructed wind speed field across Beijing.The average RMSE is 1.09 m s^(−1),considerably smaller than the result(1.29 m s^(−1))obtained with inverse distance weighting(IDW)interpolation.Finally,we extract the important feature permutations by the method of mean decrease in impurity(MDI)and discuss the reasonableness of the model prediction results.MLDRM-RF is a reasonable approach with excellent potential for the improved reconstruction of historical surface wind speed fields with arbitrary grid resolutions.Such a model is needed in many wind applications,such as wind energy and aviation safety assessments. 展开更多
关键词 data reconstruction MESHLESS machine learning surface wind speed random forest
下载PDF
三重四极杆复合线性离子阱质谱联用技术在农兽药残留检测中的研究进展
5
作者 宣彤 祝军 +7 位作者 李巧莲 王岩松 袁帅 罗景阳 蒋笑妍 李娇 刘鑫 张承昕 《化学通报》 CAS CSCD 北大核心 2023年第4期451-457,共7页
三重四极杆复合线性离子阱质谱(QTRAP-MS/MS)联用技术可提供多种扫描模式,在保留良好选择性和灵敏度的同时提高仪器定性检测能力,在农兽药残留检测中具有独特优势。本文综合分析了近五年QTRAP-MS/MS在国内外农兽药残留检测中的应用现状,... 三重四极杆复合线性离子阱质谱(QTRAP-MS/MS)联用技术可提供多种扫描模式,在保留良好选择性和灵敏度的同时提高仪器定性检测能力,在农兽药残留检测中具有独特优势。本文综合分析了近五年QTRAP-MS/MS在国内外农兽药残留检测中的应用现状,从QTRAP-MS/MS的结构及原理和检测前处理等方面展开概述,并对其未来发展趋势从前处理技术、微型便携化仪器、与其他仪器联用等方面进行展望,以期为食品安全、农药兽药残留检测提供参考。 展开更多
关键词 三重四极杆线性离子阱质谱 农药残留 兽药残留
原文传递
多壁碳纳米管QuEChERS-液相色谱-串联质谱法测定粮谷中14种酰胺类杀菌剂残留量
6
作者 李巧莲 宣彤 +4 位作者 袁帅 王岩松 罗景阳 蒋笑妍 肖舒元 《食品科技》 CAS 北大核心 2023年第5期300-307,共8页
建立基于多壁碳纳米管改进的QuEChERS净化方法,结合液相色谱-串联质谱法测定粮谷中14种酰胺类杀菌剂。样品经乙腈提取,无水硫酸镁、N-丙基乙二胺、多壁碳纳米管和十八烷基硅烷键合硅胶净化,在多反应监测模式下用正离子扫描,使14种目标... 建立基于多壁碳纳米管改进的QuEChERS净化方法,结合液相色谱-串联质谱法测定粮谷中14种酰胺类杀菌剂。样品经乙腈提取,无水硫酸镁、N-丙基乙二胺、多壁碳纳米管和十八烷基硅烷键合硅胶净化,在多反应监测模式下用正离子扫描,使14种目标化合物在Symmetry C_(18)色谱柱上分离,外标法定量。在0.10~2.50μg/L范围内14种目标化合物具有良好的线性关系,相关系数(r)均大于0.99,方法检出限为0.02~0.10μg/kg,定量限为0.10~0.30μg/kg。在5种基质中进行低中高3水平加标试验,其平均回收率为70.70%~105.00%,相对标准偏差为0.2%~11.1%(n=6)。该方法操作快捷、净化效果好、灵敏度高,适用于粮谷中酰胺类杀菌剂残留的定性定量分析。 展开更多
关键词 多壁碳纳米管 Qu ECh ERS 液相色谱-串联质谱法 粮谷 酰胺类杀菌剂
原文传递
Safety analysis of COVID-19 vaccines in liver transplant recipients:a two-center study 被引量:1
7
作者 Rui Tang Chao Li +10 位作者 Guangdong Wu xuan tong Lihan Yu Huayuan Hao Rui Liao Yucheng Hou Jun Li Wenping Zhao Tieyan Fan Leida Zhang Qian Lu 《Hepatobiliary Surgery and Nutrition》 SCIE 2022年第1期166-168,共3页
Up to know,product information for COVID-19 mRNA vaccines do not include their use in patients receiving immunosuppressive medication,since they were not included in trials(1).For the BNT162b2 mRNA vaccine,one case of... Up to know,product information for COVID-19 mRNA vaccines do not include their use in patients receiving immunosuppressive medication,since they were not included in trials(1).For the BNT162b2 mRNA vaccine,one case of otherwise totally asymptomatic elevations of alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP)andγ-glutamyl transpeptidase(GGT)serum concentrations in a liver transplant recipient has been reported after the first injection(2).In the present retrospective study,we present safety outcomes of COVID-19 vaccinations in 56 liver transplant patients from two Chinese centers vaccinated with the domestic PiCoVacc,BBIBP-CorV and ZF2001 vaccines.Thirty vaccinated physicians from the Hepatopancreatobiliary Center of Beijing Tsinghua Changgung Hospital served as control,from which 1 participant received an Ad5-nCoV vaccine.The study deadline was 2021-10-31.The observation period for adverse reactions,such as muscle pain and fatigue was 1 week,while for laboratory examinations such as liver function the follow-up period was 1 month. 展开更多
关键词 vaccines VACCINE LIVER
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部