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Microscopy Observations of Habitable Space in Biochar for Colonization by Fungal Hyphae From Soil 被引量:11
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作者 Noraini M Jaafar Peta L Clode Lynette K Abbott 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第3期483-490,共8页
Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in ... Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in a biochar made from a woody feedstock. In addition to characterization of the biochar, it was necessary to optimize preparation and observation methodologies for examining fungal colonization of the biochar. Biochar surfaces and pores were investigated using several microscopy techniques. Biochar particles were compared in soilless media and after deposition in soil. Scanning electron microscopy (SEM) observations and characterization of the biochar demonstrated structural heterogeneity within and among biochar particles. Fungal colonization in and on biochar particles was observed using light, fluorescence and electron microscopy. Fluorescent brightener RR 2200 was more effective than Calcofluor White as a hyphal stain. Biochar retrieved from soil and observed using fluorescence microscopy exhibited distinct hyphal networks on external biochar surfaces. The extent of hyphal colonization of biochar incubated in soil was much less than for biochar artificially inoculated with fungi in a soilless medium. The location of fungal hyphae was more clearly visible using SEM than with fluorescence microscopy. Observations of biochar particles colonized by hyphae from soil posed a range of difficulties including obstruction by the presence of soil particles on biochar surfaces and inside pores. Extensive hyphal colonization of the surface of the biochar in the soilless medium contrasted with limited hyphal colonization of pores within the biochar. Both visualization and quantification of hyphal colonization of surfaces and pores of biochar were restricted by two-dimensional imaging associated with uneven biochar surfaces and variable biochar pore structure. There was very little colonization ofbiochar from hyphae in the agricultural soil used in this study. 展开更多
关键词 BIOCHAR agriculture FUNGI SOIL habitable pore space MICROSCOPY
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Activation of Transition Metal(Fe,Co and Ni)-Oxide Nanoclusters by Nitrogen Defects in Carbon Nanotube for Selective CO_(2) Reduction Reaction 被引量:1
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作者 Yi Cheng Jinfan Chen +7 位作者 Chujie Yang Huiping Wang Bernt Johannessen Lars Thomsen Martin Saunders Jianping Xiao Shize Yang San Ping Jiang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第1期253-263,共11页
The electrochemical carbon dioxide reduction reaction(CO_(2)RR),which can produce value-added chemical feedstocks,is a proton-coupled-electron process with sluggish kinetics.Thus,highly efficient,cheap catalysts are u... The electrochemical carbon dioxide reduction reaction(CO_(2)RR),which can produce value-added chemical feedstocks,is a proton-coupled-electron process with sluggish kinetics.Thus,highly efficient,cheap catalysts are urgently required.Transition metal oxides such as CoO_(x),FeO_(x),and NiO_(x)are low-cost,low toxicity,and abundant materials for a wide range of electrochemical reactions,but are almost inert for CO_(2)RR.Here,we report for the first time that nitrogen doped carbon nanotubes(N-CNT)have a surprising activation effect on the activity and selectivity of transition metal-oxide(MO_(x)where M=Fe,Ni,and Co)nanoclusters for CO_(2)RR.MO_(x)supported on N-CNT,MO_(x)/N-CNT,achieves a CO yield of 2.6–2.8 mmol cm−2 min−1 at an overpotential of−0.55 V,which is two orders of magnitude higher than MO_(x)supported on acid treated CNTs(MO_(x)/O-CNT)and four times higher than pristine N-CNT.The faraday efficiency for electrochemical CO_(2)-to-CO conversion is as high as 90.3%at overpotential of 0.44 V.Both in-situ XAS measurements and DFT calculations disclose that MO_(x)nanoclusters can be hydrated in CO_(2)saturated KHCO_(3),and the N defects of N-CNT effectively stabilize these metal hydroxyl species under carbon dioxide reduction reaction conditions,which can split the water molecules and provide local protons to inhibit the poisoning of active sites under carbon dioxide reduction reaction conditions. 展开更多
关键词 activation effect electrochemical CO_(2)reduction reaction N defect proton-coupled electron transfer process transition metal oxide nanocluster
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Spatial analysis of the osteoarthritis microenvironment: techniques, insights, and applications 被引量:1
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作者 Xiwei Fan Antonia Rujia Sun +5 位作者 Reuben S.E.Young Isaac O.Afara Brett R.Hamilton Louis Jun Ye Ong Ross Crawford Indira Prasadam 《Bone Research》 SCIE CAS CSCD 2024年第1期1-19,共19页
Osteoarthritis(OA)is a debilitating degenerative disease affecting multiple joint tissues,including cartilage,bone,synovium,and adipose tissues.OA presents diverse clinical phenotypes and distinct molecular endotypes,... Osteoarthritis(OA)is a debilitating degenerative disease affecting multiple joint tissues,including cartilage,bone,synovium,and adipose tissues.OA presents diverse clinical phenotypes and distinct molecular endotypes,including inflammatory,metabolic,mechanical,genetic,and synovial variants.Consequently,innovative technologies are needed to support the development of effective diagnostic and precision therapeutic approaches.Traditional analysis of bulk OA tissue extracts has limitations due to technical constraints,causing challenges in the differentiation between various physiological and pathological phenotypes in joint tissues.This issue has led to standardization difficulties and hindered the success of clinical trials.Gaining insights into the spatial variations of the cellular and molecular structures in OA tissues,encompassing DNA,RNA,metabolites,and proteins,as well as their chemical properties,elemental composition,and mechanical attributes,can contribute to a more comprehensive understanding of the disease subtypes.Spatially resolved biology enables biologists to investigate cells within the context of their tissue microenvironment,providing a more holistic view of cellular function.Recent advances in innovative spatial biology techniques now allow intact tissue sections to be examined using various-omics lenses,such as genomics,transcriptomics,proteomics,and metabolomics,with spatial data.This fusion of approaches provides researchers with critical insights into the molecular composition and functions of the cells and tissues at precise spatial coordinates.Furthermore,advanced imaging techniques,including high-resolution microscopy,hyperspectral imaging,and mass spectrometry imaging,enable the visualization and analysis of the spatial distribution of biomolecules,cells,and tissues.Linking these molecular imaging outputs to conventional tissue histology can facilitate a more comprehensive characterization of disease phenotypes.This review summarizes the recent advancements in the molecular imaging modalities and methodologies for in-depth spatial analysis.It explores their applications,challenges,and potential opportunities in the field of OA.Additionally,this review provides a perspective on the potential research directions for these contemporary approaches that can meet the requirements of clinical diagnoses and the establishment of therapeutic targets for OA. 展开更多
关键词 INSIGHT SPATIAL enable
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Thermal stability of Mg_2 Si epitaxial film formed on Si(111) substrate by solid phase reaction 被引量:2
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作者 王喜娜 王勇 +8 位作者 邹进 张天冲 梅增霞 郭阳 薛其坤 杜小龙 张晓娜 韩晓东 张泽 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第7期3079-3083,共5页
A single crystalline Mg2Si film was formed by solid phase reaction (SPR) of a Si(111) substrate with an Mg overlayer capped with an oxide layer(s),which was enhanced by post annealing from room temperature to 10... A single crystalline Mg2Si film was formed by solid phase reaction (SPR) of a Si(111) substrate with an Mg overlayer capped with an oxide layer(s),which was enhanced by post annealing from room temperature to 100℃ in a molecular beam epitaxy (MBE) system.The thermal stability of the Mg2Si film was then systematically investigated by post annealing in an oxygen-radical ambient at 300℃,450℃ and 650℃,respectively.The Mg2Si film stayed stable until the annealing temperature reached 450℃ then it transformed into amorphous MgOx attributed to the decomposition of Mg2Si and the oxidization of dissociated Mg. 展开更多
关键词 MG2SI solid phase reaction thermal stability
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A Comparative Study of Automated Segmentation Methods for Use in a Microwave Tomography System for Imaging Intracerebral Hemorrhage in Stroke Patients 被引量:2
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作者 Qaiser Mahmood Shaochuan Li +4 位作者 Andreas Fhager Stefan Candefjord Artur Chodorowski Andrew Mehnert Mikael Persson 《Journal of Electromagnetic Analysis and Applications》 2015年第5期152-167,共16页
Microwave technology offers the possibility for pre-hospital stroke detection as we have previously demonstrated using non-imaging diagnostics. The focus in this paper is on image-based diagnostics wherein the technic... Microwave technology offers the possibility for pre-hospital stroke detection as we have previously demonstrated using non-imaging diagnostics. The focus in this paper is on image-based diagnostics wherein the technical and computational complexities of image reconstruction are a challenge for clinical realization. Herein we investigate whether information about a patient’s brain anatomy obtained prior to a stroke event can be used to facilitate image-based stroke diagnostics. A priori information can be obtained by segmenting the patient’s head tissues from magnetic resonance images. Expert manual segmentation is presently the gold standard, but it is laborious and subjective. A fully automatic method is thus desirable. This paper presents an evaluation of several such methods using both synthetic magnetic resonance imaging (MRI) data and real data from four healthy subjects. The segmentation was performed on the full 3D MRI data, whereas the electromagnetic evaluation was performed using a 2D slice. The methods were evaluated in terms of: i) tissue classification accuracy over all tissues with respect to ground truth, ii) the accuracy of the simulated electromagnetic wave propagation through the head, and iii) the accuracy of the image reconstruction of the hemorrhage. The segmentation accuracy was measured in terms of the degree of overlap (Dice score) with the ground truth. The electromagnetic simulation accuracy was measured in terms of signal deviation relative to the simulation based on the ground truth. Finally, the image reconstruction accuracy was measured in terms of the Dice score, relative error of dielectric properties, and visual comparison between the true and reconstructed intracerebral hemorrhage. The results show that accurate segmentation of tissues (Dice score = 0.97) from the MRI data can lead to accurate image reconstruction (relative error = 0.24) for the intracerebral hemorrhage in the subject’s brain. They also suggest that accurate automated segmentation can be used as a surrogate for manual segmentation and can facilitate the rapid diagnosis of intracerebral hemorrhage in stroke patients using a microwave imaging system. 展开更多
关键词 Magnetic RESONANCE IMAGING Automatic Segmentation MICROWAVE DIELECTRIC Head Model INTRACEREBRAL HEMORRHAGE Reconstruction
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Cationic and Anionic Antimicrobial Agents Co‑Templated Mesostructured Silica Nanocomposites with a Spiky Nanotopology and Enhanced Biofilm Inhibition Performance 被引量:1
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作者 Yaping Song Qiang Sun +5 位作者 Jiangqi Luo Yueqi Kong Bolin Pan Jing Zhao Yue Wang Chengzhong Yu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第5期181-191,共11页
Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,... Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,their antibacterial efficacy is limited due to limited control in content and structure.Herein,we report a“dual active templating”strategy in the design of nanostructured silica composites with intrinsic antibacterial performance.This strategy uses cationic and anionic structural directing agents as dual templates,both with active antibacterial property.The cationic-anionic dual active templating strategy further contributes to antibacterial nanocomposites with a spiky surface.With controllable release of dual active antibacterial agents,the spiky nanocomposite displays enhanced anti-microbial and anti-biofilm properties toward Staphylococcus epidermidis.These findings pave a new avenue toward the designed synthesis of novel antibacterial nanocomposites with improved performance for diverse antibacterial applications. 展开更多
关键词 Antibacterial surfactants Spiky nanoparticles ANTIBACTERIAL Anti-biofilm Mesostructured nanocomposites
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High-entropy catalysts for electrochemical water-electrolysis of hydrogen evolution and oxygen evolution reactions 被引量:1
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作者 Simiao SHA Riyue GE +6 位作者 Ying LI Julie M.CAIRNEY Rongkun ZHENG Sean LI Bin LIU Jiujun ZHANG Wenxian LI 《Frontiers in Energy》 SCIE EI CSCD 2024年第3期265-290,共26页
High entropy materials (HEMs) have developed rapidly in the field of electrocatalytic water-electrolysis for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to their unique properties. In par... High entropy materials (HEMs) have developed rapidly in the field of electrocatalytic water-electrolysis for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to their unique properties. In particular, HEM catalysts are composed of many elements. Therefore, they have rich active sites and enhanced entropy stability relative to single atoms. In this paper, the preparation strategies and applications of HEM catalysts in electrochemical water-electrolysis are reviewed to explore the stabilization of HEMs and their catalytic mechanisms as well as their application in support green hydrogen production. First, the concept and four characteristics of HEMs are introduced based on entropy and composition. Then, synthetic strategies of HEM catalysts are systematically reviewed in terms of the categories of bottom-up and top-down. The application of HEMs as catalysts for electrochemical water-electrolysis in recent years is emphatically discussed, and the mechanisms of improving the performance of electrocatalysis is expounded by combining theoretical calculation technology and ex-situ/in situ characterization experiments. Finally, the application prospect of HEMs is proposed to conquer the challenges in HEM catalyst fabrications and applications. 展开更多
关键词 high-entropy ELECTROCATALYSIS synthetic methods water-electrolysis hydrogen and oxygen evolutions
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辽宁本溪庙后山遗址铀系测年初步结果 被引量:10
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作者 张丽 沈冠军 +1 位作者 傅仁义 赵建新 《东南文化》 北大核心 2007年第3期54-57,共4页
庙后山是位于我国东北的重要中更新世人类遗址。报道该地点出土人类化石的第5、6堆积层次生碳酸盐岩和骨化石样的铀系测年结果。夹生于第6堆积层3个钙板的年龄分别为276、>535、346ka,其下第5层中的钙板为526±31ka,据此第6层顶... 庙后山是位于我国东北的重要中更新世人类遗址。报道该地点出土人类化石的第5、6堆积层次生碳酸盐岩和骨化石样的铀系测年结果。夹生于第6堆积层3个钙板的年龄分别为276、>535、346ka,其下第5层中的钙板为526±31ka,据此第6层顶部应至少为200ka,第5层中部应大于500ka。结果远大于该地点原基于骨化石铀系测年的年代框架,支持中国直立人和早期智人交替比原认为约200ka早得多的观点。 展开更多
关键词 庙后山遗址 次生碳酸盐岩 铀系年代 直立人 早期智人
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陕西紫阳辉长岩锆石U-Pb年龄及微量元素地球化学特征 被引量:3
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作者 谢巧勤 赵月领 +4 位作者 张焕侠 陈天虎 徐晓春 薛怀民 赵建新 《地质科学》 CAS CSCD 北大核心 2014年第2期456-471,共16页
陕西安康的瓦房店、紫阳、岚皋、镇坪和湖北竹溪一带的早古生代地层中广泛出露具双峰式岩浆岩组合的岩墙群。本文通过紫阳高滩辉长岩锆石LA-ICP-MS U-Pb年代学研究,获得其侵位年龄为410±4.5Ma。高滩辉长岩具有类似OIB的稀土元素和... 陕西安康的瓦房店、紫阳、岚皋、镇坪和湖北竹溪一带的早古生代地层中广泛出露具双峰式岩浆岩组合的岩墙群。本文通过紫阳高滩辉长岩锆石LA-ICP-MS U-Pb年代学研究,获得其侵位年龄为410±4.5Ma。高滩辉长岩具有类似OIB的稀土元素和微量元素分配特征,Th/Nb比值小于0.11,Nb/Zr大于0.15,显示其形成于与地幔柱活动相关的富集地幔源区。Nb/U、Ce/Pb比值及U、Th、Pb和Ni含量特征显示岩浆演化早期经历橄榄石和辉石的弱分离结晶作用,岩浆上升过程中几乎未受到地壳物质混染作用。高滩辉长岩年代学、微量元素地球化学特征及区域地质特征表明,早古生代晚期扬子陆块北缘地幔柱作用使得该区软流圈地幔上涌,导致扬子板块北缘陆内裂解,引发紫阳、岚皋一带早古生代晚期的基性岩浆作用。由于地幔深部热动力条件制约,这次大陆裂解事件未能持续。高滩辉长岩锆石年龄是对扬子板块北缘陆内裂解事件的响应。 展开更多
关键词 扬子板块北缘 辉长岩 锆石U-PB定年 大陆裂解
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微量钪对Al-2.5Cu-1.5Mg合金时效特性与微观组织的影响 被引量:6
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作者 陈志国 郑子樵 Ringer S P 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2004年第8期811-814,共4页
研究了微量钪对Al-2.5Cu-1.5Mg合金微观组织与时效特性的影响。结果表明,微量钪的添加增强了Al-2.5Cu-1.5Mg合金的时效硬化效果,但并未改变该合金时效硬化的总体规律。透射电镜分析发现GPB在合金时效硬化第二阶段初期才开始析出,并且是... 研究了微量钪对Al-2.5Cu-1.5Mg合金微观组织与时效特性的影响。结果表明,微量钪的添加增强了Al-2.5Cu-1.5Mg合金的时效硬化效果,但并未改变该合金时效硬化的总体规律。透射电镜分析发现GPB在合金时效硬化第二阶段初期才开始析出,并且是该合金第二阶段硬化的主要原因,微量钪的添加促进了Al-2.5Cu-1.5Mg合金中GPB的弥散细小析出。 展开更多
关键词 铝合金 时效 显微组织
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Mg预处理蓝宝石衬底法制备的Zn极性ZnO外延薄膜的结构研究(英文) 被引量:2
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作者 王勇 袁洪涛 +6 位作者 杜小龙 梅增霞 曾兆权 邹进 贾金峰 薛其坤 张泽 《电子显微学报》 CAS CSCD 2007年第5期405-410,共6页
通过分子束外延法在经Mg预处理的蓝宝石衬底上制备了ZnO单晶薄膜,利用高分辨透射电镜、电子全息和X射线能谱对该薄膜的结构进行了细致的研究。结果表明,在蓝宝石衬底上预沉积一层很薄的Mg层,可以生长均匀Zn极性的ZnO外延薄膜。ZnO/MgO/... 通过分子束外延法在经Mg预处理的蓝宝石衬底上制备了ZnO单晶薄膜,利用高分辨透射电镜、电子全息和X射线能谱对该薄膜的结构进行了细致的研究。结果表明,在蓝宝石衬底上预沉积一层很薄的Mg层,可以生长均匀Zn极性的ZnO外延薄膜。ZnO/MgO/蓝宝石的界面非常清晰锐利,同时在界面处可以观察到大约3个原子层的MgO。预沉积的Mg薄层对随后ZnO的极性选择起了关键性作用。 展开更多
关键词 ZNO薄膜 透射电子显微术 电子全息术 极性 X射线能谱
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一维纳米结构的金属催化合成与生长机理 被引量:3
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作者 王世良 贺跃辉 +1 位作者 Zou Jin Huang Han 《材料科学与工程学报》 CAS CSCD 北大核心 2008年第5期802-809,共8页
金属催化合成法是合成一维无机纳米材料最重要、最成功的方法。本文以生长机理(包括气-液-固、气-固-固、溶液-液-固、超临界流体-液-固、超临界流体-固-固、固-液-固和广义气-液-固等)为线索,系统阐述了金属催化法在一维无机纳米结构... 金属催化合成法是合成一维无机纳米材料最重要、最成功的方法。本文以生长机理(包括气-液-固、气-固-固、溶液-液-固、超临界流体-液-固、超临界流体-固-固、固-液-固和广义气-液-固等)为线索,系统阐述了金属催化法在一维无机纳米结构的制备和生长机理研究方面的最新进展。最后,我们指出了金属催化法在制备技术和生长机理研究方面存在的一些问题并提出了一些可能的解决途径。 展开更多
关键词 一维纳米结构 金属催化 生长机理
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Mg/MmM5多层复合薄膜的储氢性能和显微结构研究
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作者 欧阳柳章 王辉 +1 位作者 邹进 朱敏 《武汉理工大学学报》 CAS CSCD 北大核心 2006年第E02期325-331,共7页
用X-ray衍射(XRD)方法研究了磁控溅射制备的MmNi35(CoAIMn)1.5/Mg(简写为Mg/MmM5)多层薄膜吸放氢前后的结构变化和储氢性能。XRD表明Mg/MmM5多层膜中Mg层的储氩性能有一定程度的改善,吸傲氢温度分别为473K和523K。用透射电镜... 用X-ray衍射(XRD)方法研究了磁控溅射制备的MmNi35(CoAIMn)1.5/Mg(简写为Mg/MmM5)多层薄膜吸放氢前后的结构变化和储氢性能。XRD表明Mg/MmM5多层膜中Mg层的储氩性能有一定程度的改善,吸傲氢温度分别为473K和523K。用透射电镜(TEM)分析方法研究了快速热退火(RTA)处理前后Mg/MmM5多层薄膜的微现结构的变化。Mg/MmM5多层膜中Mg层和MmM5层的结构与村底的温度和材料本身的性质有密切关系。Mg/MmM5多层膜在400℃经过3min RTA处理后,Mg层中的纳米晶和拄状晶都有所长大,长大后的纳米晶和拄状晶晶粒尺寸基本相当,约200nm,纳米晶和拄状晶区界限仍然明显,拄状晶依然保持着沿垂直于衬底表面的[001]方向生长;MmM5层中的非晶层消失,纳米晶得到长大,尺寸约20nm。 展开更多
关键词 镁基储氢材料 薄膜 磁控溅射 透射电镜(TEM)
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微量钪对Al-15Ag合金时效特性与微观组织的影响
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作者 陈志国 郑子樵 Simon P.Ringer 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2004年第9期928-932,共5页
通过时效硬化曲线测量及时效组织分析,研究了微量钪对Al-15Ag合金时效行为和显微组织的影响。在Al-15Ag合金中添加0.2%Sc(质量分数,下同),可以增强合金在190℃和350℃时效的时效硬化效果,延长峰时效的到达时间。微量钪的添加促使合金中... 通过时效硬化曲线测量及时效组织分析,研究了微量钪对Al-15Ag合金时效行为和显微组织的影响。在Al-15Ag合金中添加0.2%Sc(质量分数,下同),可以增强合金在190℃和350℃时效的时效硬化效果,延长峰时效的到达时间。微量钪的添加促使合金中γ′相细小密集地析出,同时钪的存在减少了γ′相宽面上的位错台阶数。含钪Al-15Ag合金中γ′相长大过程比较缓慢的微观机理是微量钪的添加影响了合金中γ′相宽面上的台阶分布。 展开更多
关键词 铝合金 时效 显微组织
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狮子洞铀系测年与百色盆地第Ⅲ级阶地的年代 被引量:5
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作者 孔丽娟 沈冠军 +2 位作者 王頠 李大伟 赵建新 《地球与环境》 CAS CSCD 北大核心 2012年第3期349-353,共5页
布兵盆地是广西百色盆地东南缘一小型附属盆地,狮子洞位于其南侧喀斯特峰林中,其内堆积由上部砂质粘土与下部砾石层构成,类似河流相二元结构。狮子洞与其周围分布广泛的河流第III阶地海拔高度相当,表明洞穴与阶地堆积时代的一致性。本... 布兵盆地是广西百色盆地东南缘一小型附属盆地,狮子洞位于其南侧喀斯特峰林中,其内堆积由上部砂质粘土与下部砾石层构成,类似河流相二元结构。狮子洞与其周围分布广泛的河流第III阶地海拔高度相当,表明洞穴与阶地堆积时代的一致性。本文报道狮子洞内夹生于砂质粘土层次生碳酸盐岩样的铀系测年结果。位于砂质粘土与砾石层界面处的钙板,高精度质谱铀系年代为366±19ka。其左上1.4m贴附于洞壁突岩的石幔,质谱年代为517±42ka。鉴于具明确层位意义、纯净致密次生碳酸盐岩质谱铀系年代高度可信,并基于狮子洞堆积与布兵盆地第Ⅲ级阶地同时、附属盆地与主盆地同步发育的认识,这二个盆地第Ⅲ级阶地应在366~517ka间形成。本文结果对系统研究百色盆地地貌和旧石器文化演化具重要性。 展开更多
关键词 狮子洞 铀系年代 布兵盆地 百色盆地 第Ⅲ级阶地
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5083铝合金组织中第二相的形态及微观结构 被引量:7
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作者 肖晓玲 刘宏伟 +1 位作者 詹浩 唐维学 《中国有色金属学报》 EI CAS CSCD 北大核心 2018年第12期2441-2449,共9页
应用透射电镜研究国内外5083铝合金H116态退火组织中第二相的形态和微观结构,观察到三类不同形态和晶体结构的第二相。第一类为具有单斜结构或伪四方结构的板条状η-Al_5(Mn,Cr)相,国产5083铝合金组织中该相含量较多;第二类为具有正交... 应用透射电镜研究国内外5083铝合金H116态退火组织中第二相的形态和微观结构,观察到三类不同形态和晶体结构的第二相。第一类为具有单斜结构或伪四方结构的板条状η-Al_5(Mn,Cr)相,国产5083铝合金组织中该相含量较多;第二类为具有正交结构的棒状Al_6(Mn,Fe)相,国产和国外的5083铝合金组织中该相均可见;第三类为具有单斜结构的球状或不规则形状θ-Al_(45)(Mn,Cr)_7相,国外5083铝合金组织中该相含量较多,此类单斜结构的θ-Al_(45)(Mn,Cr)7相易产生(111)或(111)孪晶和(110)共轭面。同时,利用Al-Cr二元相图和Al-Mn-Cr三元相图解释了5083铝合金H116态退火组织中第二相的生成机制以及它们的形态对加工性能的影响。 展开更多
关键词 5083铝合金 H116加工态 透射电镜 第二相 形态 结构
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CdS纳米锥的合成以及光致发光性能研究(英文)
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作者 陈志刚 邹进 +3 位作者 刘岗 李锋 逯高清 成会明 《电子显微学报》 CAS CSCD 2007年第5期423-427,共5页
将商用CdS粉在真空炉中通过简单的热蒸发获得了大量高纯的CdS锥状纳米结构。扫描电子显微镜(SEM)、透射电子显微镜(TEM)观察和X射线衍射谱(XRD)的分析表明:CdS纳米锥状晶体为六角硫镉矿晶体结构,其形状为典型的纳米锥,晶格常数为a=0.413... 将商用CdS粉在真空炉中通过简单的热蒸发获得了大量高纯的CdS锥状纳米结构。扫描电子显微镜(SEM)、透射电子显微镜(TEM)观察和X射线衍射谱(XRD)的分析表明:CdS纳米锥状晶体为六角硫镉矿晶体结构,其形状为典型的纳米锥,晶格常数为a=0.413nm,c=0.671nm,沿着[0001]方向生长。CdS纳米锥的长度是20μm到50μm,直径从~100nm减少到~20nm。本文还详细研究了CdS纳米锥晶体的拉曼特性及其在激光辐射下的室温光致发光行为,探讨了绿光(波长为~512nm)发射的机制。结果表明,这种CdS纳米锥可能用于新颖的光学器件。 展开更多
关键词 CDS 高纯度纳米锥 光致发光
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Fundamental and progress of Bi_2Te_3-based thermoelectric materials 被引量:8
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作者 Min Hong Zhi-Gang Chen Jin Zou 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期50-74,共25页
Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-co... Thermoelectric materials,enabling the directing conversion between heat and electricity,are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-consumption of fossil fuels.Bi2Te3-based alloys are the classical thermoelectric materials working near room temperature.Due to the intensive theoretical investigations and experimental demonstrations,significant progress has been achieved to enhance the thermoelectric performance of Bi2Te3-based thermoelectric materials.In this review,we first explored the fundamentals of thermoelectric effect and derived the equations for thermoelectric properties.On this basis,we studied the effect of material parameters on thermoelectric properties.Then,we analyzed the features of Bi2Te3-based thermoelectric materials,including the lattice defects,anisotropic behavior and the strong bipolar conduction at relatively high temperature.Then we accordingly summarized the strategies for enhancing the thermoelectric performance,including point defect engineering,texture alignment,and band gap enlargement.Moreover,we highlighted the progress in decreasing thermal conductivity using nanostructures fabricated by solution grown method,ball milling,and melt spinning.Lastly,we employed modeling analysis to uncover the principles of anisotropy behavior and the achieved enhancement in Bi2Te3,which will enlighten the enhancement of thermoelectric performance in broader materials 展开更多
关键词 THERMOELECTRIC Bi2Te3-based alloys electron transports phonon scatterings
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Structural and functional aspects of the liver and liver sinusoidal cells in relation to colon carcinoma metastasis 被引量:4
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作者 Katrien Vekemans Filip Braet 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第33期5095-5102,共8页
Nowadays, liver metastasis remains difficult to cure. When tumor cells escape and arrive in the liver sinusoids, they encounter the local defense mechanism specific to the liver. The sinusoidal cells have been widely ... Nowadays, liver metastasis remains difficult to cure. When tumor cells escape and arrive in the liver sinusoids, they encounter the local defense mechanism specific to the liver. The sinusoidal cells have been widely described in physiologic conditions and in relation to metastasis during the past 30 years. This paper provides an “overview” of how these cells function in health and in diseases such as 展开更多
关键词 METASTASIS LIVER Colon carcinoma Sinusoidalcells Kupffer cells Liver sinusoidal endothelial cells Hepatic NK cells
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The hepatic sinusoidal endothelial lining and colorectal liver metastases 被引量:3
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作者 Filip Braet Keissuke Nagatsuma +3 位作者 Masaya Saito Lilian Soon Eddie Wisse Tomokazu Matsuura 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第6期821-825,共5页
Colorectal cancer (CRC) is a common malignant disease and the severe nature of cases in men and women who develop colorectal cancer makes this an important socio-economic health issue. Major challenges such as underst... Colorectal cancer (CRC) is a common malignant disease and the severe nature of cases in men and women who develop colorectal cancer makes this an important socio-economic health issue. Major challenges such as understanding and modeling colorectal cancer pathways rely on our understanding of simple models such as outlined in this paper. We discuss that the development of novel standardized approaches of multidimensional (correlative) biomolecular microscopy methods facilitates the collection of (sub) cellular tissue information in the early onset of colorectal liver metastasis and that this approach will be crucial in designing new effective strategies for CRC treatment. The application of X-ray micro-computed tomography and its potential in correlative imaging of the liver vasculature will be discussed. 展开更多
关键词 Apoptosis Australia Correlative microscopy Endothelial cells Hepatic metastasis Colorectal cancer CC531 GAPS Interferon gamma Kupffer cells Natural killer cells Nitric oxide MACROPHAGES Modeling PHAGOCYTOSIS Plugging Pit cells Stellate cells X-ray micro-computed tomography
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