期刊文献+
共找到6,512篇文章
< 1 2 250 >
每页显示 20 50 100
Future Physics Programme of BESⅢ 被引量:538
1
作者 M.Ablikim M.N.Achasov +147 位作者 P.Adlarson S.ahmed M.Albrecht M.Alekseev A.Amoroso F.F.An Q.An Y.Bai O.Bakina R.Baldini Ferroli Y.Ban K.Begzsuren J.V.Bennett N.Berger M.Bertani D.Bettoni F.Bianchi J Biernat J.Bloms I.Boyko R.A.Briere L.Calibbi H.Cai X.Cai A.Calcaterra G.F.Cao N.Cao S.A.Cetin J.Chai J.F.Chang W.L.Chang J.Charles G.Chelkov Chen G.Chen H.S.Chen J.C.Chen M.L.Chen S.J.Chen Y.B.Chen H.Y.Cheng W.Cheng G.Cibinetto F.Cossio X.F.Cui H.L.Dai J.P.Dai X.C.Dai A.Dbeyssi D.Dedovich Z.Y.Deng A.Denig Denysenko M.Destefanis S.Descotes-Genon F.De Mori Y.Ding C.Dong J.Dong L.Y.Dong M.Y.Dong Z.L.Dou S.X.Du S.I.Eidelman J.Z.Fan J.Fang S.S.Fang Y.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.Q.Feng M.Fritsch C.D.Fu Y.Fu Q.Gao X.L.Gao Y.Gao Y.Gao Y.G.Gao Z.Gao B.Garillon I.Garzia E.M.Gersabeck A.Gilman K.Goetzen L.Gong W.X.Gong W.Gradl M.Greco L.M.Gu M.H.Gu Y.T.Gu A.Q.Guo F.K.Guo L.B.Guo R.P.Guo Y.P.Guo A.Guskov S.Han X.Q.Hao F.A.Harris K.L.He F.H.Heinsius T.Held Y.K.Heng Y.R.Hou Z.L.Hou H.M.Hu J.F.Hu T.Hu Y.Hu G.S.Huang J.S.Huang X.T.Huang X.Z.Huang Z.L.Huang N.Huesken T.Hussain W.Ikegami Andersson W.Imoehl M.Irshad Q.Ji Q.P.Ji X.B.Ji X.L.Ji H.L.Jiang X.S.Jiang X.Y.Jiang J.B.Jiao Z.Jiao D.P.Jin S.Jin Y.Jin T.Johansson N.Kalantar-Nayestanaki X.S.Kang R.Kappert M.Kavatsyuk B.C.Ke I.K.Keshk T.Khan A.Khoukaz P.Kiese R.Kiuchi R.Kliemt L. 《Chinese Physics C》 SCIE CAS CSCD 2020年第4期I0001-I0004,1-102,共106页
There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B fac... There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity. 展开更多
关键词 MESON HADRON optimization
原文传递
A review on the generation, determination and mitigation of Urban Heat Island 被引量:130
2
作者 RIZWAN ahmed Memon DENNIS Y.C. Leung LIU Chunho 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第1期120-128,共9页
Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generate... Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generated from urban structures, as they consume and re-radiate solar radiations, and from the anthropogenic heat sources are the main causes of UHI. The two heat sources increase the temperatures of an urban area as compared to its surroundings, which is known as Urban Heat Island Intensity (UHII). The problem is even worse in cities or metropolises with large population and extensive economic activities. The estimated three billion people living in the urban areas in the world are directly exposed to the problem, which will be increased significantly in the near future. Due to the severity of the problem, vast research effort has been dedicated and a wide range of literature is available for the subject. The literature available in this area includes the latest research approaches, concepts, methodologies, latest investigation tools and mitigation measures. This study was carded out to review and summarize this research area through an investigation of the most important feature of UHI. It was concluded that the heat re-radiated by the urban structures plays the most important role which should be investigated in details to study urban heating especially the UHI. It was also concluded that the future research should be focused on design and planning parameters for reducing the effects of urban heat island and ultimately living in a better environment. 展开更多
关键词 urban heat island (UHI) URBANIZATION temperature rise MITIGATION
下载PDF
线聚焦型太阳能二氧化碳发生器性能研究 被引量:128
3
作者 吴明清 李传峰 +42 位作者 罗华平 弋晓康 SHAKEEL ahmed Soomro 陈坤杰 胡云峰 魏增宇 李飞 陈君然 杜威 刘彩玲 魏丹 宋建农 黎艳妮 都鑫 张福印 赵倩 王利春 郭文忠 陈晓丽 聂铭君 贾冬冬 王利军 郭燕 贺佳 王利民 张喜旺 刘婷 赵引 毛晓敏 薄丽媛 谢斌 武仲斌 毛恩荣 郭枭 张远巍 冯志诚 王飞 田瑞 侯贤清 李荣 吴鹏年 李培富 王西娜 《农业机械学报》 EI CAS CSCD 北大核心 2018年第8期1-17,共17页
研究了一种线聚焦型太阳能二氧化碳发生器。分别在跟踪及非跟踪工况下,在呼和浩特地区测试并分析了系统的集热与产气性能。确定了系统的最佳运行方式,提出了气损率和产气能力2个系统性能评价指标。测试结果表明,跟踪较非跟踪工况,反应... 研究了一种线聚焦型太阳能二氧化碳发生器。分别在跟踪及非跟踪工况下,在呼和浩特地区测试并分析了系统的集热与产气性能。确定了系统的最佳运行方式,提出了气损率和产气能力2个系统性能评价指标。测试结果表明,跟踪较非跟踪工况,反应器内腔空晒最高温度、闷晒最高水温、最高集热效率分别提升16.30%、12.44%、94.50%;系统最佳运行工况确定为跟踪式。在产气原料分解温度范围内,系统集热效率为31.80%;测试阶段系统气损率为4.50%;当太阳直接辐照度在650~850W/m~2范围内变化时,系统产气能力随太阳直接辐照度呈正相关变化。基于系统产气能力的变化规律,可计算不同规模线聚焦型太阳能二氧化碳发生器的具体结构参数。 展开更多
关键词 线聚焦 太阳能 二氧化碳发生器 集热性能 产气能力
下载PDF
秸秆-土壤-旋耕刀系统中秸秆位移仿真分析 被引量:106
4
作者 方会敏 姬长英 +2 位作者 ahmed Ali Tagar 张庆怡 郭俊 《农业机械学报》 EI CAS CSCD 北大核心 2016年第1期60-67,共8页
秸秆-土壤-旋耕刀之间的相互作用机理对于分析耕作过程有着重要作用。为研究秸秆-土壤-旋耕刀的宏观及微观相互作用,对系统中的秸秆位移进行了仿真分析。首先建立了秸秆-土壤-旋耕刀相互作用的三维离散元模型;其次,对仿真结果与室内土... 秸秆-土壤-旋耕刀之间的相互作用机理对于分析耕作过程有着重要作用。为研究秸秆-土壤-旋耕刀的宏观及微观相互作用,对系统中的秸秆位移进行了仿真分析。首先建立了秸秆-土壤-旋耕刀相互作用的三维离散元模型;其次,对仿真结果与室内土槽实验结果进行对比分析,在土槽实验中采用示踪器方法测量秸秆位移;仿真中导出每个时刻的秸秆位置用来描述秸秆仿真位移;最后,利用仿真数据对秸秆位移进行三维分析。实验和仿真都在恒定前进速度0.222 m/s和耕深100 mm及4种转速(77、100、123、146 r/min)下进行。实验与仿真结果皆显示秸秆位移随着转速增加呈现增加的趋势;秸秆的水平运动位移总是大于同转速下的侧向位移;高转速下的实验与仿真位移误差约为40%,低转速下为70%。利用拟合的误差方程和仿真值可以估算秸秆的水平和侧向位移值,估算值与实验值误差为8.7%和9.3%。通过追踪不同位置的秸秆颗粒发现:初始位置不同的秸秆颗粒具有不同的运动:位于正切刃内侧的秸秆在刀刃切开土壤时,沿正切刃边缘滑出;而位于侧切刃下方的秸秆在开始时被侧切刃挤压随刀刃一起运动,而后随土壤一起被抛起;远离旋耕刀工作范围的秸秆,则因受土壤扰动影响而仅有微小的位移。紧靠侧切刃及过渡刃周围的秸秆颗粒在考察时间段内被直接旋耕入土。可以利用秸秆的垂直方向受力情况,优化旋耕刀刃口曲线提高秸秆在旋耕过程中直接入土的比例;还可以整合秸秆水平和侧向位移及分布,寻找最优工作参数使秸秆在3个方向都能均匀分散,从而提高秸秆分布均匀度。 展开更多
关键词 旋耕刀 秸秆运动 离散元仿真 微观分析
下载PDF
Clinical epidemiology and disease burden of nonalcoholic fatty liver disease 被引量:81
5
作者 Brandon J Perumpail Muhammad Ali Khan +3 位作者 Eric R Yoo George Cholankeril Donghee Kim Aijaz ahmed 《World Journal of Gastroenterology》 SCIE CAS 2017年第47期8263-8276,共14页
Nonalcoholic fatty liver disease(NAFLD) is defined as the presence of hepatic fat accumulation after the exclusion of other causes of hepatic steatosis, including other causes of liver disease, excessive alcohol consu... Nonalcoholic fatty liver disease(NAFLD) is defined as the presence of hepatic fat accumulation after the exclusion of other causes of hepatic steatosis, including other causes of liver disease, excessive alcohol consumption, and other conditions that may lead to hepatic steatosis. NAFLD encompasses a broad clinical spectrum ranging from nonalcoholic fatty liver to nonalcoholic steatohepatitis(NASH), advanced fibrosis, cirrhosis, and finally hepatocellular carcinoma(HCC). NAFLD is the most common liver disease in the world and NASH may soon become the most common indication for liver transplantation. Ongoing persistence of obesity with increasing rate of diabetes will increase the prevalence of NAFLD, and as this population ages, many will develop cirrhosis and end-stage liver disease. There has been a general increase in the prevalence of NAFLD, with Asia leading the rise, yet the United States is following closely behind with a rising prevalence from 15% in 2005 to 25% within 5 years. NAFLD is commonly associated with metabolic comorbidities, including obesity, type Ⅱ diabetes, dyslipidemia, and metabolic syndrome. Our understanding of the pathophysiology of NAFLD is constantly evolving. Based on NAFLD subtypes, it has the potential to progress into advanced fibrosis, end-stage liver disease and HCC. The increasing prevalence of NAFLD with advanced fibrosis, is concerning because patients appear toexperience higher liver-related and non-liver-related mortality than the general population. The increased morbidity and mortality, healthcare costs and declining health related quality of life associated with NAFLD makes it a formidable disease, and one that requires more in-depth analysis. 展开更多
关键词 Nonalcoholic fatty liver disease Hepatic steatosis Fatty liver PREVALENCE INCIDENCE FIBROSIS Risk factor EPIDEMIOLOGY OUTCOMES Nonalcoholic steatohepatitis
下载PDF
卫星导航几何因子的分析和仿真 被引量:67
6
作者 丛丽 ahmed I Abidat 谈展中 《电子学报》 EI CAS CSCD 北大核心 2006年第12期2204-2208,共5页
根据卫星导航几何因子GDOP在具体课题中的应用,从五个主要方面对其进行了研究,可知不同星座配置参数对不同纬度地区GDOP会产生影响;坐标转换时GDOP、PDOP和TDOP不变,HDOP、VDOP变化;GDOP随卫星数目增加单调递减,但递减幅度变小;卫星对G... 根据卫星导航几何因子GDOP在具体课题中的应用,从五个主要方面对其进行了研究,可知不同星座配置参数对不同纬度地区GDOP会产生影响;坐标转换时GDOP、PDOP和TDOP不变,HDOP、VDOP变化;GDOP随卫星数目增加单调递减,但递减幅度变小;卫星对GDOP贡献越大,其故障产生的定位误差越大;使用加权GDOP可有效的减小定位误差. 展开更多
关键词 卫星导航 DOP 星座配置参数 定位精度 加权GDOP
下载PDF
Expression of hepatitis B virus genes in early embryonic cells originated from hamster ova and human spermatozoa transfected with the complete viral genome 被引量:62
7
作者 Bahy ahmed Ali Tian-Hua Huang +1 位作者 Halima-Hassan Salem Qing-Dong Xie 《Asian Journal of Andrology》 SCIE CAS CSCD 2006年第3期273-279,共7页
Aim: To detect the expression of hepatitis B virus (HBV) genes (HB S and C genes) in early embryonic cells after introducing motile human sperm carrying HBV DNA into zona-free hamster oocytes via the in vitro fer... Aim: To detect the expression of hepatitis B virus (HBV) genes (HB S and C genes) in early embryonic cells after introducing motile human sperm carrying HBV DNA into zona-free hamster oocytes via the in vitro fertilization (IVF) technique. Methods: Human sperm-mediated HBV genes were delivered into zona-free hamster oocytes by the IVF method. Polymerase chain reaction (PCR) was used to detect HB S and pre-Core/Core (pre-C/C) coding genes both in one- and two-cell embryos. Reverse transcription-PCR (RT-PCR) analysis was used to study the expression of the two genes. Fluorescence in situ hybridization (FISH) analysis using the full-length HBV DNA as the hybridization probe was performed to confirm the integration of viral DNA in the host embryonic genome. Results: Both HB S and pre-C/C coding genes are present and transcribed in one- and two-cell embryos originated from hamster ova IVF with human spermatozoa carrying HBV DNA sequences. Conclusion: Sperm-mediated HBV genes are able to replicate and express themselves in early embryonic cells. These results provide direct evidence that HBV DNA could transmit vertically to the next generation via the male germ line. 展开更多
关键词 hepatitis B virus gene expression hamster ovary human spermatozoa in vitro fertilization
下载PDF
A new heterojunction in photocatalysis:S-scheme heterojunction 被引量:42
8
作者 S.Wageh ahmed A.Al-Ghamdi +2 位作者 Rashida Jafer Xin Li Peng Zhang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第5期667-669,共3页
To harness abundant and clean solar energy along with relieving energy and environmental issues,photocatalysis holds great promise.Semiconductor-based photocatalysts are crucial to its successful application.However,t... To harness abundant and clean solar energy along with relieving energy and environmental issues,photocatalysis holds great promise.Semiconductor-based photocatalysts are crucial to its successful application.However,the photocatalytic efficiency based on a unitary semiconductor material falls short of expectations,mainly because of the rapid recombination of photogenerated electrons and holes.This originates in the extremely strong Columbic force between them.Moreover,it is impossible for a single photocatalyst to achieve wide light absorption and ample redox ability concurrently. 展开更多
关键词 S型异质结 异质结光催化剂 电荷分离机制 充电转移路线 Z型光催化剂
下载PDF
丁酸梭菌对肉鸡生长性能和血清生化指标的影响 被引量:41
9
作者 郑爱娟 吴正可 +5 位作者 PIRZADO Shoaib ahmed 蔡辉益 陈志敏 常文环 邓雪娟 刘国华 《动物营养学报》 CAS CSCD 北大核心 2019年第12期5519-5525,共7页
本试验通过在基础饲粮中添加丁酸梭菌,研究其对肉鸡生长性能和血清生化指标的影响。选择1日龄180只健康爱拔益加肉鸡,随机分为3个组,分别为无抗对照组、抗生素组和丁酸梭菌组,每组6个重复,每个重复10只鸡。无抗对照组饲喂基础饲粮,抗生... 本试验通过在基础饲粮中添加丁酸梭菌,研究其对肉鸡生长性能和血清生化指标的影响。选择1日龄180只健康爱拔益加肉鸡,随机分为3个组,分别为无抗对照组、抗生素组和丁酸梭菌组,每组6个重复,每个重复10只鸡。无抗对照组饲喂基础饲粮,抗生素组在基础饲粮中添加5 mg/kg黄霉素、75 mg/kg金霉素和20 mg/kg吉他霉素,丁酸梭菌组在基础饲粮中添加2.5×108CFU/kg丁酸梭菌,试验期42 d。结果表明:1)饲粮添加丁酸梭菌未显著影响肉鸡21日龄和42日龄体重、1~21日龄平均日增重和料重比(P>0.05);与无抗对照组相比,饲粮添加丁酸梭菌极显著降低了1~21日龄肉鸡平均日采食量(P<0.01)。2)与无抗对照组和抗生素组相比,饲粮添加丁酸梭菌显著提高了42日龄肉鸡血清甘油三酯、总胆固醇含量和碱性磷酸酶活性(P<0.05)。3)与无抗对照组或抗生素组相比,饲粮添加丁酸梭菌显著提高了42日龄肉鸡血清总蛋白、白蛋白和球蛋白含量(P<0.05);与无抗对照组相比,饲粮添加丁酸梭菌极显著降低了21日龄和42日龄肉鸡血清氨含量(P<0.01),显著降低了21日龄肉鸡血清尿酸含量(P<0.05)。综上,饲粮添加丁酸梭菌显著改变了肉鸡脂类代谢,提高了血清中蛋白质含量,降低了蛋白质代谢废物含量。 展开更多
关键词 丁酸梭菌 肉鸡 生长性能 血清生化指标
下载PDF
Non-alcoholic fatty liver disease in 2015 被引量:41
10
作者 Monjur ahmed 《World Journal of Hepatology》 CAS 2015年第11期1450-1459,共10页
There is worldwide epidemic of non-alcoholic fatty liver disease(NAFLD). NAFLD is a clinical entity related to metabolic syndrome. Majority of the patients are obese but the disease can affect non-obese individuals as... There is worldwide epidemic of non-alcoholic fatty liver disease(NAFLD). NAFLD is a clinical entity related to metabolic syndrome. Majority of the patients are obese but the disease can affect non-obese individuals as well. Metabolic factors and genetics play important roles in the pathogenesis of this disorder. The spectrum of disorders included in NAFLD are benign macrovesicular hepatic steatosis, non-alcoholic steatohepatitis, hepatic fibrosis, cirrhosis of liver and hepatocellular carcinoma. Although the disease remains asymptomatic most of the time, it can slowly progress to end stage liver disease. It will be the most common indication of liver transplantation in the future. It is diagnosed by abnormal liver chemistry, imaging studies and liver biopsy. As there are risks of potential complications during liver biopsy, many patients do not opt for liver biopsy. There are some noninvasive scoring systems to find out whether patients have advanced hepatic fibrosis. At the present time, there are limited treatment options which include lifestyle modification to loose weight, vitamin E and thioglitazones. Different therapeutic agents are being investigated for optimal management of this entity. There are some studies done on incretin based therapies in patients with NAFLD. Other potential agents will be silent information regulator protein Sirtuin and antifibrotic monoclonal antibody Simtuzumab against lysyl oxidase like molecule 2. But they are still in the investigational phase. 展开更多
关键词 Fatty LIVER Hepatic STEATOSIS Non-alcoholicfatty LIVER disease Non-alcoholic STEATOHEPATITIS
下载PDF
信贷需求:小额信贷覆盖率的决定因素之一——来自中国北方四县调查的证据 被引量:37
11
作者 程恩江 Abdullahi D. ahmed 《经济学(季刊)》 2008年第3期1391-1414,共24页
过去对小额信贷项目覆盖率的研究集中在供给方面,本文应用大规模农户调查的数据,从需求方面研究了中国三个小额信贷项目覆盖率低的问题。研究发现,在中国贫困地区试验的孟加拉乡村银行模式的小额信贷项目不能自动地瞄准贫困地区的贫... 过去对小额信贷项目覆盖率的研究集中在供给方面,本文应用大规模农户调查的数据,从需求方面研究了中国三个小额信贷项目覆盖率低的问题。研究发现,在中国贫困地区试验的孟加拉乡村银行模式的小额信贷项目不能自动地瞄准贫困地区的贫困人口,许多贫困农户将自身排除在小额信贷市场之外。本文的结论是,尽管中国的小额信贷试点项目没有能自动瞄准贫困地区的贫困户,它们仍然对中国的扶贫做出了积极贡献。为了提高小额信贷项目对贫困人群的覆盖率,需要通过减少对贫困人口的其他约束、依照贫困人群的需要定制小额贷款产品等方式来提高贫困农户对小额贷款的需求。 展开更多
关键词 小额信贷 信贷需求 覆盖率
原文传递
氮肥用量及其后效对棉花产量和生物质累积动态的影响 被引量:36
12
作者 宋兴虎 Tufail ahmed Wagan +4 位作者 Biangkham Souliyanonh Saif Ali 黄颖 袁源 杨国正 《棉花学报》 CSCD 北大核心 2018年第2期145-154,共10页
【目的】长江流域棉花适宜氮肥用量为300 kg·hm^(-2),在迟播高密度下可减少为225 kg·hm^(-2),而不影响产量。本研究旨在探讨迟播高密度下于见花期一次性施用氮肥,氮肥用量进一步减少的可行性、氮肥后效及其对棉花产量形成规... 【目的】长江流域棉花适宜氮肥用量为300 kg·hm^(-2),在迟播高密度下可减少为225 kg·hm^(-2),而不影响产量。本研究旨在探讨迟播高密度下于见花期一次性施用氮肥,氮肥用量进一步减少的可行性、氮肥后效及其对棉花产量形成规律的影响。【方法】采用盆栽试验,2014年设5个氮肥水平(120、150、180、210、240 kg·hm^(-2)),2015年设置相同氮肥用量(180 kg·hm^(-2)),研究棉花生育进程、产量及其构成以及生物质累积动态。【结果】氮肥用量显著影响棉花生物质累积和产量而不影响生育进程,氮肥后效不明显。施氮量为180 kg·hm^(-2)时籽棉产量(30.5 g·plant^(-1))和铃重(3.8 g)最高,生物质累积量较大,且生物质快速累积期生殖器官生物量所占比例最大,为64.4%。【结论】在中等肥力棉田氮肥用量减为180 kg·hm^(-2)是可行的,因为其快速累积期生殖器官生物质累积强度增加。 展开更多
关键词 棉花(Gossypium hirsutum L.) 氮肥 生物质累积 产量 快速累积期 最大累积速率
下载PDF
Study of BESIII trigger efficiencies with the 2018 J/ψ data 被引量:36
13
作者 M.Ablikim M.N.Achasov +150 位作者 P.Adlarson S.ahmed M.Albrecht R.Aliberti A.Amoroso M.R.An Q.An X.H.Bai Y.Bai O.Bakina R.Baldini Ferroli I.Balossino Y.Ban K.Begzsuren N.Berger M.Bertani D.Bettoni F.Bianchi J.Bloms A.Bortone I.Boyko R.A.Briere H.Cai X.Cai A.Calcaterra G.F.Cao N.Cao S.A.Cetin J.F.Chang W.L.Chang G.Chelkov D.Y.Chen G.Chen H.S.Chen M.L.Chen S.J.Chen X.R.Chen Y.B.Chen Z.J Chen W.S.Cheng G.Cibinetto F.Cossio X.F.Cui H.L.Dai X.C.Dai A.Dbeyssi R.E.de Boer D.Dedovich Z.Y.Deng A.Denig I.Denysenko M.Destefanis F.De Mori Y.Ding C.Dong J.Dong L.Y.Dong M.Y.Dong X.Dong S.X.Du Y.L.Fan J.Fang S.S.Fang Y.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.Q.Feng J.H.Feng M.Fritsch C.D.Fu Y.Gao Y.Gao Y.Gao Y.G.Gao I.Garzia P.T.Ge C.Geng E.M.Gersabeck A Gilman K.Goetzen L.Gong W.X.Gong W.Gradl M.Greco L.M.Gu M.H.Gu S.Gu Y.T.Gu C.Y Guan A.Q.Guo L.B.Guo R.P.Guo Y.P.Guo A.Guskov T.T.Han W.Y.Han X.Q.Hao F.A.Harris H Hüsken K.L.He F.H.Heinsius C.H.Heinz T.Held Y.K.Heng C.Herold M.Himmelreich T.Holtmann Y.R.Hou Z.L.Hou H.M.Hu J.F.Hu T.Hu Y.Hu G.S.Huang L.Q.Huang X.T.Huang Y.P.Huang Z.Huang T.Hussain W.Ikegami Andersson W.Imoehl M.Irshad S.Jaeger S.Janchiv Q.Ji Q.P.Ji X.B.Ji X.L.Ji H.B.Jiang X.S.Jiang J.B.Jiao Z.Jiao S.Jin Y.Jin T.Johansson N.Kalantar-Nayestanaki X.S.Kang R.Kappert M.Kavatsyuk B.C.Ke I.K.Keshk A.Khoukaz P.Kiese R.Kiuchi R.Kliemt L.Koch O.B.Kolcu B.Kopf M.Kuemmel 《Chinese Physics C》 SCIE CAS CSCD 2021年第2期48-55,共8页
Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,na... Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses. 展开更多
关键词 BESIII trigger efficiency Bhabha dimuon hadronic events
原文传递
绿色消费在推动高质量发展中的作用 被引量:33
14
作者 国合会“绿色转型与可持续社会治理专题政策研究”课题组 任勇 +17 位作者 罗姆松 范必 张建宇 祝宝良 周宏春 张建平 俞海 张小丹 李继峰 Dr.Lewis AKENJI Dr.Mark SANCTUAR Mrs.Carla MOONEN Dr.Miranda SCHREURS Dr.Mushtaq ahmed MEMON Dr.Vanessa Timmer 陈刚 Ms.Stefanie CHAN 孟令勃 《中国环境管理》 CSSCI 2020年第1期24-30,共7页
当前,中国经济正在从高速增长转向高质量发展,其中消费是拉动经济增长的主要动力,是推动高质量发展的重要动能。从中国整体绿色发展转型进程和状态看,不平衡不协调的问题比较突出,经济维度的绿色转型发展较快较好,社会维度相对滞后。因... 当前,中国经济正在从高速增长转向高质量发展,其中消费是拉动经济增长的主要动力,是推动高质量发展的重要动能。从中国整体绿色发展转型进程和状态看,不平衡不协调的问题比较突出,经济维度的绿色转型发展较快较好,社会维度相对滞后。因此,如何在社会生活和消费领域推动绿色转型是中国政府应关注和解决的重大关键问题。国合会2018年主题是“创新引领绿色新时代”,本项目作为“创新与可持续生产和消费”课题下的专题研究,将为国家生态文明建设战略部署下如何推动形成绿色生活方式和消费方式以及提升社会治理体系提供政策决策支持。 展开更多
关键词 绿色消费 高质量发展 绿色转型
下载PDF
Recent advances and perspectives of nucleic acid detection for coronavirus 被引量:31
15
作者 Minzhe Shen Ying Zhou +4 位作者 Jiawei Ye Abdu ahmed Abdullah AL-maskri Yu Kang Su Zeng Sheng Cai 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2020年第2期97-101,共5页
The recent pneumonia outbreak caused by a novel coronavirus(SARS-CoV-2)is posing a great threat to global public health.Therefore,rapid and accurate identification of pathogenic viruses plays a vital role in selecting... The recent pneumonia outbreak caused by a novel coronavirus(SARS-CoV-2)is posing a great threat to global public health.Therefore,rapid and accurate identification of pathogenic viruses plays a vital role in selecting appropriate treatments,saving people's lives and preventing epidemics.It is important to establish a quick standard diagnostic test for the detection of the infectious disease(COVID-19)to prevent subsequent secondary spread.Polymerase chain reaction(PCR)is regarded as a gold standard test for the molecular diagnosis of viral and bacterial infections with high sensitivity and specificity.Isothermal nucleic acid amplification is considered to be a highly promising candidate method due to its fundamental advantage in quick procedure time at constant temperature without thermocycler opera-tion.A variety of improved or new approaches also have been developed.This review summarizes the currently available detection methods for coronavirus nucleic acid.It is anticipated that this will assist researchers and clinicians in developing better techniques for timely and effective detection of coro-navirus infection. 展开更多
关键词 CORONAVIRUS Nucleic ACID detection PCR-Based METHODS Isothermal nucleic ACID amplification-based METHODS Microarray-based METHODS
下载PDF
Gastrointestinal neuroendocrine tumors in 2020 被引量:31
16
作者 Monjur ahmed 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2020年第8期791-807,共17页
Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological,biological,and clinical characteristics that have increased in incidence and prevalence within the last few decades.They c... Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological,biological,and clinical characteristics that have increased in incidence and prevalence within the last few decades.They contain chromogranin A,synaptophysin and neuron-specific enolase which are necessary for making a diagnosis of neuroendocrine tumor.Ki-67 index and mitotic index correlate with cellular proliferation.Serum chromogranin A is the most commonly used biomarker to assess the bulk of disease and monitor treatment and is raised in both functioning and non-functioning neuroendocrine tumors.Most of the gastrointestinal neuroendocrine tumors are non-functional.World Health Organization updated the classification of neuroendocrine tumors in 2017 and renamed mixed adenoneuroendocrine carcinoma into mixed neuroendocrine neoplasm.Gastric neuroendocrine tumors arise from enterochromaffin like cells.They are classified into 4 types.Only type I and type II are gastrin dependent.Small intestinal neuroendocrine tumor is the most common small bowel malignancy.More than two-third of them occur in the terminal ileum within 60 cm of ileocecal valve.Patients with small intestinal neuroendrocrine tumors frequently show clinical symptoms and develop distant metastases more often than those with neuroendocrine tumors of other organs.Duodenal and jejunoileal neuroendocrine tumors are distinct biologically and clinically.Carcinoid syndrome generally occurs when jejuno-ileal neuroendocrine tumors metastasize to the liver.Appendiceal neuroendocrine tumors are generally detected after appendectomy.Colonic neuroendocrine tumors generally present as a large tumor with local or distant metastasis at the time of diagnosis.Rectal neuroendocrine tumors are increasingly being diagnosed since the implementation of screening colonoscopy in 2000.Gastrointestinal neuroendocrine tumors are diagnosed and staged by endoscopy with biopsy,endoscopic ultrasound,serology of biomarkers,imaging studies and functional somatostatin scans.Various treatmen 展开更多
关键词 Gastrointestinal neuroendocrine tumors Gastric neuroendocrine tumors Small intestinal neuroendocrine tumors Colonic neuroendocrine tumors Rectal neuroendocrine tumors Carcinoid syndrome
下载PDF
植物精油对大肠杆菌攻毒肉鸭生长性能、血清生化指标和免疫功能的影响 被引量:27
17
作者 刘娇 常文环 +5 位作者 PIRZADO Shoaib ahmed 李勇 郑爱娟 陈志敏 刘国华 蔡辉益 《动物营养学报》 CAS CSCD 北大核心 2020年第8期3670-3680,共11页
本试验旨在探究饲粮中添加植物精油对大肠杆菌攻毒肉鸭生长性能、血清生化指标和免疫功能的影响。选用1日龄健康雄性北京鸭公鸭144只,随机分为3组,每组6个重复,每个重复8只鸭。对照组饲喂基础饲粮,2个试验组分别在基础饲粮中添加30 mg/k... 本试验旨在探究饲粮中添加植物精油对大肠杆菌攻毒肉鸭生长性能、血清生化指标和免疫功能的影响。选用1日龄健康雄性北京鸭公鸭144只,随机分为3组,每组6个重复,每个重复8只鸭。对照组饲喂基础饲粮,2个试验组分别在基础饲粮中添加30 mg/kg维吉尼亚霉素(抗生素组)和200 mg/kg植物精油(植物精油组)。于试验的第7天分2次对所有鸭口腔灌服0.2 mL大肠杆菌O88(3×10~9CFU/mL),2次攻毒间隔8 h。试验期28 d。结果表明:1)与对照组相比,饲粮中添加抗生素和植物精油显著提高了9日龄体重及1~9日龄平均日增重(P <0.05),饲粮中添加植物精油显著或极显著降低了1~9日龄及1~28日龄料重比(P<0.05或P<0.01);抗生素组和植物精油组死淘率分别下降了6.25和4.17个百分点。2)与对照组相比,饲粮中添加植物精油极显著提高了14日龄的法氏囊指数(P<0.01),饲粮中添加抗生素显著提高了28日龄的脾脏和法氏囊指数(P<0.05)。3)与对照组相比,饲粮中添加植物精油显著或极显著降低了28日龄血清总蛋白和球蛋白含量(P<0.05或P<0.01)。4)与对照组相比,饲粮中添加植物精油显著或极显著提高了9日龄血清免疫球蛋白G(IgG)含量以及9、14、28日龄血清免疫球蛋白M(IgM)含量(P<0.05或P<0.01);饲粮中添加抗生素极显著提高了9日龄血清IgG含量以及14日龄血清IgM含量(P<0.05)。5)与对照组相比,饲粮中添加植物精油显著降低了9、28日龄空肠Toll样受体4(TLR4)含量,9、14、28日龄空肠肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)含量,以及14日龄空肠白细胞介素-6(IL-6)含量(P<0.05);饲粮中添加抗生素显著了降低9、14、28日龄空肠TLR4、IL-1β、IL-6含量以及9、28日龄空肠TNF-α含量(P<0.05)。综上,在大肠杆菌攻毒作用下,饲粮中添加植物精油能够替代抗生素用于缓解机体炎症反应,减少机体器官损伤以及空肠炎症细胞因子含量,提高机体免疫功能,� 展开更多
关键词 植物精油 肉鸭 大肠杆菌攻毒 生长性能 免疫功能 细胞因子
下载PDF
黄瓜游离小孢子培养诱导成胚和植株再生 被引量:28
18
作者 詹艳 陈劲枫 ahmed Abbas Malik 《园艺学报》 CAS CSCD 北大核心 2009年第2期221-226,共6页
以10个不同基因型黄瓜为试材进行游离小孢子培养,通过对成胚条件的系统研究,从‘7447’和‘Poinsett97’中获得了子叶形胚和再生植株。研究结果表明:基因型和小孢子发育时期是限制黄瓜游离小孢子成胚的关键因子。不同品种间胚状体产量... 以10个不同基因型黄瓜为试材进行游离小孢子培养,通过对成胚条件的系统研究,从‘7447’和‘Poinsett97’中获得了子叶形胚和再生植株。研究结果表明:基因型和小孢子发育时期是限制黄瓜游离小孢子成胚的关键因子。不同品种间胚状体产量差异显著,每皿产胚1.5~33.4个。单核靠边期是进行黄瓜游离小孢子培养的最佳时期。低温预处理有利于胚状体的诱导,4℃预处理2~4d为宜,以处理2d的胚状体产量最高。外源激素在诱导胚状体时并非必需,但低浓度外源激素(0.5mg.L-12,4-D、0.2mg.L-16-BA)能促进小孢子成胚。NLN和B5两种基础培养基在诱导胚状体上无显著差异。子叶形胚易分化成苗,而其它类型的胚状体未能获得再生植株。 展开更多
关键词 黄瓜 小孢子培养 胚状体 植株再生
原文传递
Nosocomial infections:Epidemiology,prevention,control and surveillance 被引量:27
19
作者 Hassan ahmed Khan Fatima Kanwal Baig Riffat Mehboob 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2017年第5期478-482,共5页
Nosocomial infections or healthcare associated infections occur in patients under medical care.These infections occur worldwide both in developed and developing countries.Nosocomial infections accounts for 7% in devel... Nosocomial infections or healthcare associated infections occur in patients under medical care.These infections occur worldwide both in developed and developing countries.Nosocomial infections accounts for 7% in developed and 10% in developing countries.As these infections occur during hospital stay,they cause prolonged stay,disability,and economic burden.Frequently prevalent infections include central line-associated bloodstream infections,catheter-associated urinary tract infections,surgical site infections and ventilator-associated pneumonia.Nosocomial pathogens include bacteria,viruses and fungal parasites.According to WHO estimates,approximately 15% of all hospitalized patients suffer from these infections.During hospitalization,patient is exposed to pathogens through different sources environment,healthcare staff,and other infected patients.Transmission of these infections should be restricted for prevention.Hospital waste serves as potential source of pathogens and about 20%–25% of hospital waste is termed as hazardous.Nosocomial infections can be controlled by practicing infection control programs,keep check on antimicrobial use and its resistance,adopting antibiotic control policy.Efficient surveillance system can play its part at national and international level.Efforts are required by all stakeholders to prevent and control nosocomial infections. 展开更多
关键词 Nosocomial infections Control strategies Hospital acquired infections PATHOGENS Healthcare
下载PDF
Recent advances in chemical modifications of graphene 被引量:27
20
作者 Sunil P. Lonkar Yogesh S. Deshmukh ahmed A. Abdala 《Nano Research》 SCIE EI CAS CSCD 2015年第4期1039-1074,共36页
Graphene has attracted the interest of chemists, physicists, and materials scientists due to its extraordinary structural, mechanical, and electronic properties. While pristine graphene is desirable for applications t... Graphene has attracted the interest of chemists, physicists, and materials scientists due to its extraordinary structural, mechanical, and electronic properties. While pristine graphene is desirable for applications that require a high electrical conductivity, many other applications require modified or functionalized forms of graphene, such as graphene oxide, reduced graphene, or other functionalized forms. Structurally modifying graphene through chemical functionalization reveals the numerous possibilities for tuning its structure; several chemical and physical functionalization methods have been explored to improve the stabilization and modification of graphene. In this review, we report recent progress towards the chemical modification of graphene, including both covalent and noncovalent methods, for use in various applications. 展开更多
关键词 GRAPHENE graphene oxide FUNCTIONALIZATION COVALENT NON-COVALENT APPLICATIONS
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部