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Review on Zinc Oxide Nanoparticles: Antibacterial Activity and Toxicity Mechanism 被引量:88
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作者 Amna Sirelkhatim Shahrom Mahmud +5 位作者 Azman Seeni Noor Haida Mohamad Kaus Ling Chuo Ann Siti Khadijah Mohd Bakhori Habsah hasan Dasmawati Mohamad 《Nano-Micro Letters》 SCIE EI CAS 2015年第3期219-242,共24页
Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many micro... Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions.These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition. 展开更多
关键词 Antibacterial activity Zn O-NPs Toxicity mechanism Reactive oxygen species Zinc ions release Food antimicrobial
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番茄细菌性溃疡病研究进展 被引量:37
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作者 罗来鑫 赵廷昌 +3 位作者 李健强 张乐 李勇 hasan Bolkan 《中国农业科学》 CAS CSCD 北大核心 2004年第8期1144-1150,共7页
根据国内外近年来番茄溃疡病的研究概况,对番茄溃疡病的历史、主要症状、病原菌的分类地位及生物学特性、病原菌的分离、检测和鉴定技术、病害的田间发生、流行条件及防治方法进行了综述,分析了我国加入世界贸易组织后实施《卫生与植物... 根据国内外近年来番茄溃疡病的研究概况,对番茄溃疡病的历史、主要症状、病原菌的分类地位及生物学特性、病原菌的分离、检测和鉴定技术、病害的田间发生、流行条件及防治方法进行了综述,分析了我国加入世界贸易组织后实施《卫生与植物卫生措施协定》以及农产品安全条例等,认为做好番茄溃疡病风险性分析、监测国际种子贸易传入该病害的可能性非常重要,同时提出了今后加强番茄溃疡病研究的主要方向。 展开更多
关键词 番茄 细菌性溃疡病 症状 病原菌 生物学特性
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Fintech investments in European banks:a hybrid IT2 fuzzy multidimensional decision‑making approach 被引量:41
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作者 Gang Kou Ozlem Olgu Akdeniz +1 位作者 hasan Dincer Serhat Yuksel 《Financial Innovation》 2021年第1期826-853,共28页
Financial technology(Fintech)makes a significant contribution to the financial system by reducing costs,providing higher quality services and increasing customer satisfaction.Hence,new studies play an essential role t... Financial technology(Fintech)makes a significant contribution to the financial system by reducing costs,providing higher quality services and increasing customer satisfaction.Hence,new studies play an essential role to improve Fintech investments.This study evaluates Fintech-based investments of European banking services with an application of an original methodology that considers interval type-2(IT2)fuzzy decision-making trial and evaluation laboratory and IT2 fuzzy TOPSIS models.Empirical findings are controlled for consistency by applying the VIKOR method.Moreover,we conduct a sensitivity analysis by considering six distinct cases.This study contributes to the existing literature by identifying the most important Fintech-based investment alternatives to improve the financial performance of European banks.Our empirical findings illustrate that results are coherent,reliable,and identify“competitive advantage”as the most important factor among Fintech-based determinants.Moreover,“payment and money transferring systems”are the most important Fintech-based investment alternatives.It is recommended that,among Fintech-based investments,European banks should mainly focus on payment and money transferring alternatives to attract the attention of customers and satisfy their expectations.This is also believed to have a positive impact on the ease of bank’receivable collection.Another important point is that Fintech-based investments in money transferring systems could help to decrease costs. 展开更多
关键词 Financial technology European banking industry Interval type-2 fuzzy TOPSIS DEMATEL
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A review on machinability of carbon fiber reinforced polymer(CFRP)and glass fiber reinforced polymer(GFRP)composite materials 被引量:39
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作者 Meltem Altin Karatas hasan Gokkaya 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第4期318-326,共9页
Fiber reinforced polymer(FRP) composite materials are heterogeneous and anisotropic materials that do not exhibit plastic deformation. They have been used in a wide range of contemporary applications particularly in s... Fiber reinforced polymer(FRP) composite materials are heterogeneous and anisotropic materials that do not exhibit plastic deformation. They have been used in a wide range of contemporary applications particularly in space and aviation,automotive,maritime and manufacturing of sports equipment. Carbon fiber reinforced polymer(CFRP) and glass fiber reinforced polymer(GFRP) composite materials,among other fiber reinforced materials,have been increasingly replacing conventional materials with their excellent strength and low specific weight properties. Their manufacturability in varying combinations with customized strength properties,also their high fatigue,toughness and high temperature wear and oxidation resistance capabilities render these materials an excellent choice in engineering applications.In the present review study,a literature survey was conducted on the machinability properties and related approaches for CFRP and GFRP composite materials. As in the machining of all anisotropic and heterogeneous materials,failure mechanisms were also reported in the machining of CFRP and GFRP materials with both conventional and modern manufacturing methods and the results of these studies were obtained by use of variance analysis(ANOVA),artificial neural networks(ANN) model,fuzzy inference system(FIS),harmony search(HS) algorithm,genetic algorithm(GA),Taguchi's optimization technique,multi-criteria optimization,analytical modeling,stress analysis,finite elements method(FEM),data analysis,and linear regression technique. Failure mechanisms and surface quality is discussed with the help of optical and scanning electron microscopy,and profilometry. ANOVA,GA,FEM,etc. are used to analyze and generate predictive models. 展开更多
关键词 COMPOSITE MATERIALS Fiber reinforced polymer COMPOSITE MATERIALS CFRP GFRP Machining Wear Surface damage
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Recent improvements in oily wastewater treatment:Progress, challenges, and future opportunities 被引量:38
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作者 Sanaa Jamaly Adewale Giwa Shadi Wajih hasan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第11期15-30,共16页
Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently devel... Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently developed methods for oily wastewater treatment through which contaminants such as oil, fats, grease, and inorganics can be removed for safe applications.These include electrochemical treatment, membrane filtration, biological treatment,hybrid technologies, use of biosurfactants, treatment via vacuum ultraviolet radiation,and destabilization of emulsions through the use of zeolites and other natural minerals.This review encompasses innovative and novel approaches to oily wastewater treatment and provides scientific background for future work that will be aimed at reducing the adverse impact of the discharge of oily wastewater into the environment. The current challenges affecting the optimal performance of oily wastewater treatment methods and opportunities for future research development in this field are also discussed. 展开更多
关键词 Oily wastewater Electrochemical Biological Membrane Treatment
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The ReaxFF reactive force-field: development, applications and future directions 被引量:33
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作者 Thomas P Senftle Sungwook Hong +10 位作者 Md Mahbubul Islam Sudhir B Kylasa Yuanxia Zheng Yun Kyung Shin Chad Junkermeier Roman Engel-Herbert Michael J Janik hasan Metin Aktulga Toon Verstraelen Ananth Grama Adri CT van Duin 《npj Computational Materials》 SCIE EI 2016年第1期202-215,共14页
The reactive force-field(ReaxFF)interatomic potential is a powerful computational tool for exploring,developing and optimizing material properties.Methods based on the principles of quantum mechanics(QM),while offerin... The reactive force-field(ReaxFF)interatomic potential is a powerful computational tool for exploring,developing and optimizing material properties.Methods based on the principles of quantum mechanics(QM),while offering valuable theoretical guidance at the electronic level,are often too computationally intense for simulations that consider the full dynamic evolution of a system.Alternatively,empirical interatomic potentials that are based on classical principles require significantly fewer computational resources,which enables simulations to better describe dynamic processes over longer timeframes and on larger scales.Such methods,however,typically require a predefined connectivity between atoms,precluding simulations that involve reactive events.The ReaxFF method was developed to help bridge this gap.Approaching the gap from the classical side,ReaxFF casts the empirical interatomic potential within a bond-order formalism,thus implicitly describing chemical bonding without expensive QM calculations.This article provides an overview of the development,application,and future directions of the ReaxFF method. 展开更多
关键词 PROPERTIES DIRECTIONS BONDING
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Glycogen storage diseases: New perspectives 被引量:31
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作者 hasan zen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第18期2541-2553,共13页
Glycogen storage diseases (GSD) are inherited metabolic disorders of glycogen metabolism. Different hormones, including insulin, glucagon, and cortisol regulate the relationship of glycolysis, gluconeogenesis and gl... Glycogen storage diseases (GSD) are inherited metabolic disorders of glycogen metabolism. Different hormones, including insulin, glucagon, and cortisol regulate the relationship of glycolysis, gluconeogenesis and glycogen synthesis. The overall GSD incidence is estimated 1 case per 20000-43000 live births. There are over 12 types and they are classified based on the enzyme deficiency and the affected tissue. Disorders of glycogen degradation may affect primarily the liver, the muscle, or both. Type I a involves the liver, kidney and intestine (and I b also leukocytes), and the clinical manifestations are hepatomegaly, failure to thrive, hypoglycemia, hyperlactatemia, hyperuricemia and hyperlipidemia. Type Ilia involves both the liver and muscle, and lib solely the liver. The liver symptoms generally improve with age. Type IV usually presents in the first year of life, with hepatomegaly and growth retardation. The disease in general is progressive to cirrhosis. Type Ⅵ and Ⅳ are a heterogeneous group of diseases caused by a deficiency of the liver phosphorylase and phosphorylase kinase system. There is no hyperuricemia or hyperlactatemia. Type Ⅺ is characterized by hepatic glycogenosis and renal Fanconi syndrome. Type Ⅱ is a prototype of inborn lysosomal storage diseases and involves many organs but primarily the muscle. Types V and Ⅶ involve only the muscle. 展开更多
关键词 Glycogen storage disease LIVER MUSCLE
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Cataract in diabetes mellitus 被引量:27
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作者 hasan Kiziltoprak Kemal Tekin +1 位作者 Merve Inanc Yasin Sakir Goker 《World Journal of Diabetes》 SCIE CAS 2019年第3期140-153,共14页
Diabetes mellitus (DM) is a chronic systemic disease that has increases in prevalence over time. DM can affect all ocular structures, with cataract being the most common ocular complication. Cataract is the leading ca... Diabetes mellitus (DM) is a chronic systemic disease that has increases in prevalence over time. DM can affect all ocular structures, with cataract being the most common ocular complication. Cataract is the leading cause of blindness worldwide. Due to several mechanisms, there is an increased incidence of cataract formation in the diabetic population. Advancements in technology have now made cataract surgery a common and safe procedure. However, the diabetic population is still at risk of vision-threatening complications, such as diabetic macular edema (ME), postoperative ME, diabetic retinopathy progression, and posterior capsular opacification. 展开更多
关键词 DIABETES CATARACT COMPLICATIONS SURGERY
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A Stable, Wideband Tunable, Near Transform-Limited, Graphene- Mode-Locked, Ultrafast Laser 被引量:25
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作者 Zhipei Sun Daniel Popa +6 位作者 Tawfique hasan Felice Torrisi Fengqiu Wang Edmund J.R.Kelleher John C.Travers Valeria Nicolosi Andrea C.Ferrari 《Nano Research》 SCIE EI CSCD 2010年第9期653-660,共8页
We report an ultrafast laser mode-locked with a graphene saturable absorber.The linear dispersions of the Dirac electrons in graphene enable wideband tunability.We get-1 ps pulses,tunable between 1525 and 1559 nm,with... We report an ultrafast laser mode-locked with a graphene saturable absorber.The linear dispersions of the Dirac electrons in graphene enable wideband tunability.We get-1 ps pulses,tunable between 1525 and 1559 nm,with stable mode-locking,insensitive to environmental perturbations. 展开更多
关键词 GRAPHENE saturable absorber MODE-LOCKING fiber laser
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玉米螟赤眼蜂的产卵行为研究 被引量:19
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作者 王振营 周大荣 S.A.hasan 《中国生物防治》 CSCD 1996年第4期145-149,共5页
本文研究了玉米螟赤眼蜂在麦蛾卵及欧洲玉米螟卵上的产卵及辨别寄主行为,表明玉米螟赤眼蜂在不同寄主卵上产卵耗时不同,能根据寄主卵大小调节产卵数量;产卵时具有性别控制行为;该蜂可以通过“学习”提高辨别寄主卵已被寄生与否的能... 本文研究了玉米螟赤眼蜂在麦蛾卵及欧洲玉米螟卵上的产卵及辨别寄主行为,表明玉米螟赤眼蜂在不同寄主卵上产卵耗时不同,能根据寄主卵大小调节产卵数量;产卵时具有性别控制行为;该蜂可以通过“学习”提高辨别寄主卵已被寄生与否的能力,并对自身和同种个体间已寄生卵有很强的辨别力; 展开更多
关键词 玉米螟 赤眼蜂 产卵行为
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番茄细菌性溃疡病苗期接种新方法的研究 被引量:15
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作者 罗来鑫 李健强 hasan BOLKAN 《植物病理学报》 CAS CSCD 北大核心 2005年第2期123-128,共6页
在剪叶、浸根和针刺等细菌病害传统接种方法基础上设计了打顶接种新方法;以番茄细菌性溃疡病菌中国菌株和美国菌株借助打顶法接种佳粉10、合作908和华南红宝石3个国内主栽番茄品种2~3片真叶期幼苗,在昼夜最低、最高温度15~18℃、32~3... 在剪叶、浸根和针刺等细菌病害传统接种方法基础上设计了打顶接种新方法;以番茄细菌性溃疡病菌中国菌株和美国菌株借助打顶法接种佳粉10、合作908和华南红宝石3个国内主栽番茄品种2~3片真叶期幼苗,在昼夜最低、最高温度15~18℃、32~35℃和相对湿度为30%~60%的温室条件下,打顶法接种番茄幼苗后溃疡病发病率为87.5%~100.0%,病情指数随接种菌悬液浓度提高而增大,达到23.96~82.29,3个供试品种之间表现稳定一致;剪叶、浸根和针刺接种方法的发病率普遍在40%以下,病情指数在20以下,3个供试品种之间未表现明显差异;进一步研究显示,使用选择性培养基mSCM能够从打顶法接种后的发病植株上获得培养性状与原接种体一致的分离物,专化性免疫凝聚试剂盒检测到特定的测试线,PCR扩增到614 bp的特异性条带,证实该分离物为番茄细菌性溃疡病菌,发病植株为接种体侵染所致.该研究结果表明,打顶接种方法比剪叶法、针刺法和浸根法更适合用于番茄溃疡病菌的致病性测定和评价不同番茄品种苗期的抗病性,具有应用价值. 展开更多
关键词 番茄细菌性溃疡病 打顶法 接种 免疫凝聚检测 PCR检测
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2017年美国心脏病学会/美国心脏协会心脏瓣膜病患者管理指南更新:要点解读及前景展望 被引量:19
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作者 赵振刚 hasan Jilaihawi 《华西医学》 CAS 2018年第2期173-180,共8页
自2014版美国心脏病学会(American College of Cardiology,ACC)/美国心脏协会(American Heart Association,AHA)心脏瓣膜病患者管理指南发布以来,心脏瓣膜病的治疗领域又取得了一些重要进展。此次更新的内容主要涉及主动脉瓣狭窄治疗方... 自2014版美国心脏病学会(American College of Cardiology,ACC)/美国心脏协会(American Heart Association,AHA)心脏瓣膜病患者管理指南发布以来,心脏瓣膜病的治疗领域又取得了一些重要进展。此次更新的内容主要涉及主动脉瓣狭窄治疗方式的选择、二尖瓣反流的干预策略、人工瓣膜类型的选择以及生物瓣的抗栓治疗策略。该文对2017年ACC/AHA指南更新的主要内容进行了总结和解读,并在此基础上对心脏瓣膜病治疗领域的未来发展趋势进行了展望。 展开更多
关键词 心脏瓣膜病 经导管心脏瓣膜病治疗 抗栓治疗 指南更新
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Effect of Salicylic Acid on Salinity-induced Changes in Brassica juncea 被引量:16
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作者 Mohammad Yusuf Syed Aiman hasan +3 位作者 Barket Ali Shamsul Hayat Qazi Fariduddin Aqil Ahmad 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2008年第9期1096-1102,共7页
Seeds of Indian mustard (Brassicajuncea (L.) Czern. et Coss.) were exposed to 0, 50, 100 and 150 mmol/L NaCI for 8 h and seeds were sown in an earthen pot. These stressed seedlings were subsequently sprayed with 1... Seeds of Indian mustard (Brassicajuncea (L.) Czern. et Coss.) were exposed to 0, 50, 100 and 150 mmol/L NaCI for 8 h and seeds were sown in an earthen pot. These stressed seedlings were subsequently sprayed with 10μmol/L salicylic acid (SA) at 30 d and were sampled at 60 d to assess the changes in growth, photosynthesis and antioxidant enzymes. The seedlings raised from the seeds treated with NaCI had significantly reduced growth and the activities of carbonic anhydrase, nitrate reductase and photosynthesis, and the decrease was proportional to the increase in NaCI concentration. However, the antioxidant enzymes (catalase, peroxidase and superoxide dismutase) and proline content was enhanced in response to NaCI and/or SA treatment, where their interaction had an additive effect. Moreover, the toxic effects generated by the lower concentration of NaCI (50 mmol/L) were completely overcome by the application of SA. It was, therefore, concluded that SA ameliorated the stress generated by NaCl through the alleviated antioxidant system. 展开更多
关键词 carbonic anhydrase CATALASE MUSTARD net photosynthetic rate nitrate reductase PEROXIDASE salicylic acid SALINITY superoxidedismutase.
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Safety of tirofiban and dual antiplatelet therapy in treating intracranial aneurysms 被引量:17
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作者 Edgar A Samaniego Emilee Gibson +5 位作者 Daichi Nakagawa Santiago Ortega-Gutierrez Mario Zanaty Jorge A Roa Pascal Jabbour David M hasan 《Stroke & Vascular Neurology》 SCIE 2019年第1期36-42,共7页
Background Endovascular treatment of intracranial aneurysms usually involves stent-assisted coiling(SAC)and flow diverters.Glycoprotein IIb/IIIa inhibitors such as tirofiban and dual antiplatelet therapy(DAPT)are requ... Background Endovascular treatment of intracranial aneurysms usually involves stent-assisted coiling(SAC)and flow diverters.Glycoprotein IIb/IIIa inhibitors such as tirofiban and dual antiplatelet therapy(DAPT)are required to prevent thromboembolic complications afterwards.We sought to determine the safety of tirofiban and DAPT in these cases.Methods We conducted a retrospective analysis of our database for patients with intracranial aneurysms who underwent SAC or flow diversion.The tirofiban-DAPT protocol used is described.Data regarding duration of infusion,placement of external ventricular devices(EVDs),complications,haemoglobin levels and platelet count before and 24 hours after antiplatelet therapy were collected and analysed.results One-hundred and forty-one patients with 148 aneurysms/procedures were included.110 aneurysms were treated acutely and 38 electively.Minor and major haemorrhagic events were recognised in 20%(30/148)aneurysms.Only 5(3.4%)intracerebral haemorrhages were symptomatic:3 cortical/SAH and 2 EVD-related.The average blood volume in symptomatic haemorrhages was 24.8 cc versus 5.42 cc in asymptomatic haemorrhages(p=0.002).The rate of EVD-related haemorrhages was 15.7%(19/121)and only 2(1.7%)were symptomatic.Most haemorrhagic events occurred in ruptured aneurysms(90.1%,p=0.01).No significant change in platelet count or haemoglobin levels before and 24 hours after administration of tirofiban and DAPT was documented.Concomitant administration of heparin did not increase haemorrhagic events.Conclusion The use of the GP IIb/IIIa inhibitors tirofiban and DAPT in this series was safe.Tirofiban and DAPT did not affect platelet count or haemoglobin levels and did not increase rate of symptomatic haemorrhages or thromboembolic complications. 展开更多
关键词 ANEURYSM INTRACRANIAL INFUSION
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Rule of Structural Factors in Formation of Porphyry Copper Deposits in South Western Part of Kerman Area, Iran 被引量:17
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作者 hasan Alizadeh Mehran Arian 《Open Journal of Geology》 2015年第7期489-498,共10页
Kerman area is located in southern parts of central Iranian volcanic belt. The area under study is located in the southern part of this complex copper mineralization in the area, which is mainly porphyry type and is a... Kerman area is located in southern parts of central Iranian volcanic belt. The area under study is located in the southern part of this complex copper mineralization in the area, which is mainly porphyry type and is associated with extensive hydrothermal alteration. This area has a great potential as far as tertiary porphyry copper deposits are concerned. To the exploration of porphyry copper deposits in study area, we have analyzed the lineaments. The lineaments interpreted out from ETM + (band8) data is recognized as another method for locating porphyry type copper mineralization. There is a close correlation between photo lineament factor values and the known copper mineralization in the area. The relationship between 16 porphyry copper deposits with faults and fractures in the area is studied. Photo lineament factor assessments by using satellite photos indicate a strong relationship between a number of lineation intersection in each cell refer to an amount of average lineation in whole map (c/C ratio). In the study area, ratio of c/C even has more relationship refers to PF factor that has previously described in the papers. 展开更多
关键词 PORPHYRY COPPER Deposit TECTONICS COPPER C/C Ratio FAULTS Iran
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Solution processed MoS2-PVA composite for subbandgap mode-locking of a wideband tunable ultrafast Er:fiber laser 被引量:15
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作者 Meng Zhang Richard C. T. Howe +6 位作者 Robert I. Woodward Edmund J. R. Kelleher Felice Torrisi Guohua Hu Sergei V. Popov J. Roy Taylor Tawfique hasan 《Nano Research》 SCIE EI CAS CSCD 2015年第5期1522-1534,共13页
We fabricate a free-standing few-layer molybdenum disulfide (MoS2)-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-lo... We fabricate a free-standing few-layer molybdenum disulfide (MoS2)-polymer composite by liquid phase exfoliation of chemically pristine MoS2 crystals and use this to demonstrate a wideband tunable, ultrafast mode-locked fiber laser. Stable, picosecond pulses, tunable from 1,535 nm to 1,565 nm, are generated, corresponding to photon energies below the MoS2 material bandgap. These results contribute to the growing body of work studying the nonlinear optical properties of transition metal dichalcogenides that present new opportunities for ultrafast photonic applications. 展开更多
关键词 molybdenum disulfide two-dimensional materials liquid phase exfoliation polymer composites saturable absorbers ultrafast lasers
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Ni/Pd core/shell nanoparticles supported on graphene as a highly active and reusable catalyst for Suzuki- Miyaura cross-coupling reaction 被引量:15
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作者 Onder Metin Sally Fae Ho +5 位作者 Cemalettin Alp hasan Can Max N. Mankin Mehmet Serdar Gueltekin Miaofang Chi Shouheng Sun 《Nano Research》 SCIE EI CAS CSCD 2013年第1期10-18,共9页
Monodisperse Ni/Pd core/shell nanoparticles (NPs) have been synthesized by sequential reduction of nickel(II) acetate and palladium(II) bromide in oleylamine (OAm) and trioctylphosphine (TOP). The Ni/Pd NPs ... Monodisperse Ni/Pd core/shell nanoparticles (NPs) have been synthesized by sequential reduction of nickel(II) acetate and palladium(II) bromide in oleylamine (OAm) and trioctylphosphine (TOP). The Ni/Pd NPs have a narrow size distribution with a mean particle size of 10 nm and a standard deviation of 5% with respect to the particle diameter. Mechanistic studies showed that the presence of TOP was essential to control the reductive decomposition of Ni-TOP and Pd-TOP, and the formation of Ni/Pd core/shell NPs. Using the current synthetic protocol, the composition of the Ni/Pd within the core/shell structure can be readily tuned by simply controlling the initial molar ratio of the Ni and Pd salts. The as-synthesized Ni/Pd core/shell NPs were supported on graphene (G) and used as catalyst in Suzuki-Miyaura cross-coupling reactions. Among three different kinds of Ni/Pd NPs tested, the Ni/Pd (Ni/Pd = 3/2) NPs were found to be the most active catalyst for the Suzuki-Miyaura cross-coupling of arylboronic acids with aryl iodides, bromides and even chlorides in a dimethylformamide/water mixture by using K2CO3 as a base at 110 ℃. The G-Ni/Pd was also stable and reusable, providing 98% conversion after the 5th catalytic run without showing any noticeable Ni/Pd composition change. The G-Ni/Pd structure reported in this paper combines both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst, and is promising catalyst candidate for various Pd-based catalytic applications. 展开更多
关键词 NICKEL PALLADIUM core/shell nanoparticles CATALYSIS Suzuki-Miyaura cross-coupling
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基于卷积神经网络的非侵入式负荷监测方法 被引量:11
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作者 刘一铭 李惠民 +1 位作者 王乐挺 hasan RAFIQ 《电测与仪表》 北大核心 2022年第1期148-154,共7页
从深度学习与边缘计算的角度,对适用于电力物联网的非侵入式负荷监测方法展开了研究。针对NILM系统在物联网场景下的部署问题,提出了一种新的边缘计算架构,并讨论了各组成部分的任务分配。针对负荷激活在线提取问题,提出了基于离散度和... 从深度学习与边缘计算的角度,对适用于电力物联网的非侵入式负荷监测方法展开了研究。针对NILM系统在物联网场景下的部署问题,提出了一种新的边缘计算架构,并讨论了各组成部分的任务分配。针对负荷激活在线提取问题,提出了基于离散度和用电行为规律分析的激活判断策略;针对低频采样下的负荷特征问题,提出了一种可自动提取激活特征并识别类型的卷积神经网络架构,并通过分析负荷激活的背景功率、功率波动等特性,定义了三个一般性特征作为补充。最后,在民用数据集上进行了实验,证明了文中算法在泛化性能和计算效率方面的提升。 展开更多
关键词 非侵入式负荷监测 负荷分解 智能用电 深度学习 卷积神经网络 边缘计算
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白菜黑斑病菌三个种菌株基本培养条件比较 被引量:11
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作者 肖长坤 吴学宏 +3 位作者 李健强 郑建秋 hasan Bolkan 张文华 《菌物学报》 CAS CSCD 北大核心 2004年第4期573-579,共7页
选用来自国内外的白菜黑斑病菌三个种Alternaria brassicicola,A.brassicae和A.japonica为研究材料,以生长速率为评价指标,对其适宜生长温度、pH值、光照、培养基和菌落特征等基本培养条件和性状进行了对比研究.结果表明,三个种的病菌... 选用来自国内外的白菜黑斑病菌三个种Alternaria brassicicola,A.brassicae和A.japonica为研究材料,以生长速率为评价指标,对其适宜生长温度、pH值、光照、培养基和菌落特征等基本培养条件和性状进行了对比研究.结果表明,三个种的病菌最适生长温度均在20℃~25℃,变化幅度较小,但A.brassicicola和A.japonica菌丝体生长温度范围和已有文献报道相比提高了5℃;A.brassicae中国菌株菌丝体生长的pH值范围为4~8,其它所有供试菌株生长的pH值为3~11;24h光照、12h光暗交替和24h黑暗对国内外A.brassicicola菌株生长速率影响均不大,而A.brassicae在24h光照和12h光暗交替下的生长速率比24h黑暗处理的显著增大,24h光照和24h黑暗比12h光暗交替更适合A.japonica生长;PDA是白菜黑斑病菌营养生长的最适培养基,SNA除了适合其生长外,还对供试三个种的病菌生长有选择性;菌落直径及颜色可以作为区分三个种的参考指标.供试的白菜黑斑病菌三个种在基本培养条件方面存在种水平上的差异. 展开更多
关键词 白菜 病菌 光照 黑斑病 菌丝体生长 培养条件 生长速率 菌落 中国菌株 对比研究
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Stroke mechanisms and outcomes of isolated symptomatic basilar artery stenosis 被引量:13
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作者 Edgar A Samaniego Amir Shaban +6 位作者 Santiago Ortega-Gutierrez Jorge A Roa David M hasan Colin Derdeyn Biyue Dai Harold Adams Enrique Leira 《Stroke & Vascular Neurology》 SCIE 2019年第4期189-197,共9页
background While diffuse atherosclerotic disease affecting the posterior circulation has been described extensively,the prevalence,natural history and angiographic characteristics of isolated symptomatic basilar arter... background While diffuse atherosclerotic disease affecting the posterior circulation has been described extensively,the prevalence,natural history and angiographic characteristics of isolated symptomatic basilar artery stenosis(ISBAS)remain unknown.Methods We reviewed our prospective institutional database to identify patients with≥50% symptomatic basilar artery(BA)stenosis without significant atherosclerotic burden in the vertebral or posterior cerebral arteries.Stroke mechanism,collateral circulation,and degree and length of stenosis were analysed.The primary outcome was time from index event to new transient ischaemic attack(TIA),acute ischaemic stroke(AIS)or death.Other outcome variables included modified Rankin Scale(mRS)score on discharge and last follow-up.results Of 6369 patients with AIS/TIA,91(1.43%)had ISBAS.Seventy-three(80.2%)patients presented with AIS and 18(19.8%)with TIA.Twenty-nine(31.9%)were women and the median age was 66.8±13.6 years.The mean follow-up time was 2.7 years.The most common stroke mechanism was artery-to artery thromboembolism(45.2%),followed by perforator occlusion(28.7%)and flow-dependent/hypoperfusion(15.1%).The percentage of stenosis was lower in patients who had favourable outcome compared with those with mRS 3-6 on discharge(78.3±14.3 vs 86.9±14.5,p=0.007).Kaplan-Meier curves showed higher recurrence/death rates in patients with≥80% stenosis,mid-basilar location and poor collateral circulation.Approximately 13% of patients with ISBAS presented with complete BA occlusion.Conclusion ISBAS is an uncommon(1.43%)cause of TIA and AIS.Men in their 60s are mostly affected,and artery-to artery embolism is the most common stroke mechanism.Mid-basilar location,≥80% stenosis and poor collateral circulation are important factors associated with worse prognosis. 展开更多
关键词 STENOSIS BASILAR ARTERY
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