期刊文献+
共找到141,522篇文章
< 1 2 250 >
每页显示 20 50 100
Synthesis of C_3S by Sol-Gel Technique and Its Features 被引量:3
1
作者 何真 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第1期138-141,共4页
Sol-gel method is a technique to synthesize inorganic materials based on wet-chemical reaction theory. The results have shown that reactants tetraethyl orthosilicate (TEOS) and Ca(NO3)2·4H2O can form sol and ... Sol-gel method is a technique to synthesize inorganic materials based on wet-chemical reaction theory. The results have shown that reactants tetraethyl orthosilicate (TEOS) and Ca(NO3)2·4H2O can form sol and gel in solution at 50-60 ℃, and the cosolvents are propyl alcohol (NPA) and H2O, the catalyst is HNO3. This sol-gel is burned for 12 hat 1 350-1 450 ℃ so that the organic matter, free water (moisture) in sol-gel system are removed and a solid reaction has taken place to form the resulting product. The product has been confirmed to be C3S by XRD, SEM and 29Si MAS NMR, as well as free lime content of the product which is less than 0.2% was determined by propanetriol-ethanol-method. The analysis determined by EDXA has indicated that the n(Ca)/n(Si) ratio in corresponding to micro-region is close to theoretical value of 3∶1. This resulting product is C3S with Si sites of Q0 polymerization, and has higher purity and hydraulic activities at earlier age of hydration. 展开更多
关键词 sol-gel technique synthesization PURITY tricalcium silicate MORPHOLOGY 29Si MAS NMR
下载PDF
Capillary Electrochromatography Using C_8 Open Tubular Column Prepared by Sol-Gel Technique 被引量:1
2
作者 李方 靳慧 +1 位作者 顾峻岭 傅若农 《Journal of Beijing Institute of Technology》 EI CAS 1996年第2期122-122,共1页
Open tubthar C8 columns were prepared by sol-gel technology and used in the electrochromatographic separations.
关键词 sol-gel technology OPEN TUBULAR CAPILLARY COLUMN CAPILLARY ELECTROCHROMATOGRAPHY
下载PDF
Fabrication of Chemically-Modified Electrode Containing 1:12 Phosphomolybdic Anions by Sol-Gel Technique and Its Electrocatalytic Reduction of BrO_3 ^-Anions
3
作者 Wen Bo SONG Chang Qing SUN(Department of Chemistry, Jinn University, Changchun 130023) 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第12期0-0,共4页
A novel chedrically-modified electrode containing 1:12 phosphomolybdic anions wasachieved on the surface of platinum electrode by the sol-gel technique. The electrode exhibits ahigh catalytic activity towards the elec... A novel chedrically-modified electrode containing 1:12 phosphomolybdic anions wasachieved on the surface of platinum electrode by the sol-gel technique. The electrode exhibits ahigh catalytic activity towards the electroreduction of BrO3- anions. 展开更多
关键词 Chemically-modified electrode ELECTROCATALYSIS POLYOXOMETALLATES sol-gel technique
下载PDF
Preparation of nanosized W/Cu composite powder by sol-gel technique 被引量:9
4
作者 LIBinghu KANGZhanying +1 位作者 CHENWenge DINGBingjun 《Rare Metals》 SCIE EI CAS CSCD 2005年第2期170-173,共4页
Cu(NO3)(2) and (NH4)(6)H(2)W(12)O(40)center dot 4H(2)O were used to prepare W/Cu nanosized composite powder by sol-gel technique. The influences of heat treatment process, pH value of the solution and the amount of an... Cu(NO3)(2) and (NH4)(6)H(2)W(12)O(40)center dot 4H(2)O were used to prepare W/Cu nanosized composite powder by sol-gel technique. The influences of heat treatment process, pH value of the solution and the amount of an addition agent on particle size were investigated by DSC, XRD and TEM. The results show that, at a certain heat treatment temperature, the W/Cu nanoparticle size increases with the pH value or the amount of the addition agent increasing. 展开更多
关键词 COMPOSITE nanosized composite powder sol-gel particle size W/Cu
下载PDF
Synthesis of Long Afterglow Phosphor CaAl_2Si_2O_8∶Eu~ (2+), Dy^(3+) via Sol-Gel Technique and Its Optical Properties 被引量:6
5
作者 王银海 王智宇 +3 位作者 张朋越 张福安 樊先平 钱国栋 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第5期625-628,共4页
The long afterglow phosphor CaAl2Si2O8:Eu^2+ , Dy^3+ was prepared by a sol-gel method. The sol-gel process and the structure of the phosphor were investigated by means of X-ray diffraction analysis (XRD). It is f... The long afterglow phosphor CaAl2Si2O8:Eu^2+ , Dy^3+ was prepared by a sol-gel method. The sol-gel process and the structure of the phosphor were investigated by means of X-ray diffraction analysis (XRD). It is found that the single anorthite phase formed at about 1000 %, which is 300 % lower than that required for the conventional solid state reaction. The obtained phosphor powders are easier to grind than those of solid state method and the partical size of phosphor has a relative narrow distribution of 200 to 500 nm. The photoluminescence and afterglow properties of the phosphor were also characterized. An obvious blue shift occurs in the excitation and emission spectra of phosphors obtained by sol-gel and solid state reaction methods. The change of the fluorescence spectra can be attributed to the sharp decrease of the crystalline grain size of the phosphor resulted from the sol-gel technique. 展开更多
关键词 long afterlow phosphor sol-gel method luminescent properties rare earths
下载PDF
Preparation and characterization of SnO_2-Li_4Ti_5O_(12) composite by sol-gel technique 被引量:1
6
作者 熊利芝 何则强 +1 位作者 尹周澜 陈启元 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第S1期267-270,共4页
SnO2-Li4Ti5O12 was prepared by sol-gel method using tin tetrachloride,lithium acetate,tetrabutylorthotitanate and aqueous ammonia as starting materials.The composite was characterized by thermogravimertric(TG)analysis... SnO2-Li4Ti5O12 was prepared by sol-gel method using tin tetrachloride,lithium acetate,tetrabutylorthotitanate and aqueous ammonia as starting materials.The composite was characterized by thermogravimertric(TG)analysis and differential thermal analysis(DTA),X-ray diffractometry(XRD)and transmission electron microscopy(TEM)combined with electrochemical tests.The results show that SnO2-Li4Ti5O12 composite derived by sol-gel technique is a nanocomposite with core-shell structure, and the amorphous Li4Ti5O12 layer with 20?40 nm in thickness is coated on the surface of SnO2 particles.Electrochemical tests show that SnO2-Li4Ti5O12 composite delivers a reversible capacity of 688.7 mA·h/g at 0.1C and 93.4%of that is retained after 60 cycles at 0.2C.The amorphous Li4Ti5O12 in composite can accommodate the volume change of SnO2 electrode and prevent the small and active Sn particles from aggregating into larger and inactive Sn clusters during the cycling effectively,and enhance the cycling stability of SnO2 electrode significantly. 展开更多
关键词 SNO2 LI4TI5O12 COMPOSITE sol-gel method lithium ion batteries
下载PDF
Synthesis of ZrO_2-HfO_2-Y_2O_3-Sc_2O_3 Nano-Particles by Sol-Gel Technique in Aqueous Solution of Alcohol 被引量:1
7
作者 甄强 陈瑞芳 +1 位作者 严凯 李榕 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第2期199-203,共5页
Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2... Agglomeration-free nanosized ZrO2-HfO2-Y2O3-Sc2O3 composite powders were successfully synthesized by Sol-Gel technique in heated aqueous solution of alcohol, using analytically pure ZrOCl2 · 8H2O, HfOCl2·8H2O, Y(NO3)3·6H2O, and Sc2O3 as raw materials. The effect of synthesis condition on the size and dispersity of the composite powders was investigated by means of XRD, TEM, and TG-DSC techniques. The results showed that well-dispersed predecessor of ZrO2-HfO2-Y2O3-Sc2O3 composite nanopowders could be obtained. The optional condition : PEG6000 as dispersant was 1%, alcohol/H2O ratio was 5/1, metallic ion concentration in whole solution was 0.5 mol·L^-1 and the pH value of the solution was 12. After calcined at 620 ℃, the powder obtained was in uniform cubic structure, and its average particle size was about 13 nm, which was good for producing nanocrystalline solid electrolyte. 展开更多
关键词 ZrO2-HfO2-Y2O3-Sc2O3 composite nanopowders sol-gel aqueous solution of alcohol DISPERSIBILITY rare earths
下载PDF
Determination of A.C. Conductivity of Nano-Composite Perovskite Ba<sub>(1- x - y)</sub>Sr<sub>(x)</sub>TiFe<sub>(y)</sub>O<sub>3</sub>Prepared by the Sol-Gel Technique 被引量:1
8
作者 M. Willander O. Nur +4 位作者 M. Q. Israr A. B. Abou Hamad F. G. El Desouky M. A. Salem I. K. Battisha 《Journal of Crystallization Process and Technology》 2012年第1期1-11,共11页
Nano-composite, perovskite Ba(1- x - y)Sr(x)TiFe(y)O3, denoted as (BSTFe) in powder form was derived via sol-gel (SG) method followed by sintering at fixed temperature 750℃ for one hour. The chemical composition, mor... Nano-composite, perovskite Ba(1- x - y)Sr(x)TiFe(y)O3, denoted as (BSTFe) in powder form was derived via sol-gel (SG) method followed by sintering at fixed temperature 750℃ for one hour. The chemical composition, morphology and structure of the powder samples were investigated by using X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM). The XRD characterization indicates formation of a cubic crystalline phase in the pure BST. A well defined perovskite phase with nano-crystallite sizes equal to about 34 nm was achieved from XRD for B10ST3F sample, while TEM study confirmed the obtained XRD results giving the following crystallite size value about 33.75 nm for the same sample. The dielectric A.C. conductivity was evaluated as a function of temperature and frequency ranging from 42 Hz up to 1 MHz. 展开更多
关键词 sol-gel Dielectric Permittivity A.C. CONDUCTIVITY NANO-COMPOSITE BaSrTiO3 (BST) TEM XRD and SEM
下载PDF
Optimization of Preparation Conditions of ZnO-TiO2 Nanoparticles by Sol-Gel Technique for Photodegradation Indigo Carmine
9
作者 I.A. Mkhalid 《Journal of Environmental Science and Engineering》 2011年第6期720-727,共8页
The results of a laboratory-scale study of an environmentally friendly water treatment method are presented, where the dyes in the industrial textile wastewater were removed by photocatalytic process. ZnO-TiO2 nanopar... The results of a laboratory-scale study of an environmentally friendly water treatment method are presented, where the dyes in the industrial textile wastewater were removed by photocatalytic process. ZnO-TiO2 nanoparticles as photocatalyst has been prepared via sol-gel technique. Several factors were studied in order to find the conditions that could be used to synthesize this photocatalyst for optimum degradation of Indigo Carmine dye in aqueous solutions. The optimum condition for preparation of ZnO-TiO2 mixed oxide are 1.5 TiO2/ZnO, 4 C2HsOH/TIP, 4 H20/TIP, 0.3 HNO3/TIP molar ratios, without aging, 550 ℃ calcination temperature for 5 hrs at which the surface area and the photocatalytic activity are 186.1 m^2/g and 96.1, respectively. Generally, the photocatalytic activity of the samples prepared by sol-gel technique is the highest activity. Details of the synthesis procedure and results of the characterization studies of the produced xerogel are presented in this paper. 展开更多
关键词 sol-gel NANOPARTICLES wastewater treatment PHOTOCATALYSIS indigo carmine dye
下载PDF
Fluorine-Doped Tin Oxide Thin Films Deposition by Sol-Gel Technique
10
作者 Amel Adjimi Meryem Lamri Zeggar +1 位作者 Nadhir Attaf Mohammed Salah Aida 《Journal of Crystallization Process and Technology》 2018年第4期89-106,共18页
In the present work, undoped (SnO2) and fluorine-doped tin oxide (FTO) thin films were prepared by sol-gel process using a solution composed of (SnCl2, H2O), (NH4F), and ethanol mixture. The fluorine concentration eff... In the present work, undoped (SnO2) and fluorine-doped tin oxide (FTO) thin films were prepared by sol-gel process using a solution composed of (SnCl2, H2O), (NH4F), and ethanol mixture. The fluorine concentration effect on structural, optical and electrical properties of SnO2 films is investigated. The electrical properties of FTO films prepared by sol gel remain relatively lower than the ones deposited by other techniques. In present paper, we try to elucidate this difference. Films composition and the FTIR analysis, of films and formed precipitate during film growth, indicate that few amounts of fluorine are incorporated in SnO2 network, most of fluorine atoms remain in the solution. The films resistivity is reduced from 1.1 Ω·cm for undoped films to 3 × 10-2 Ω·cm for 50 wt.% doped FTO, but remains higher than the reported ones in the literature. This high resistivity is explained in terms of fluorine bonding affinity in the solution. 展开更多
关键词 TRANSPARENT CONDUCTING OXIDE THIN Films sol-gel
下载PDF
Prepared of Olive Oil Doped SiO<sub>2</sub>via Sol-Gel Technique
11
作者 Fawaz Nasro Saiof Mohammed Alwan Hamza 《Advances in Materials Physics and Chemistry》 2013年第5期239-243,共5页
Olive oil doped Nanosilica is successfully prepared by wet chemical synthesis method. Samples were analyzed by a variety of techniques, including X-ray diffraction, FTIR, absorption and emission spectrometers to repor... Olive oil doped Nanosilica is successfully prepared by wet chemical synthesis method. Samples were analyzed by a variety of techniques, including X-ray diffraction, FTIR, absorption and emission spectrometers to report the capability of Sol-Gel technology on preparing of silica monolith as a host material for Olive oil, and investigate the effect of converting Olive oil to a solid state on its optical properties. Some absorption bands of Olive oil are disappearing from absorption spectrum of doped silica. Only single strong fluorescence peak was appearing in fluorescence spectrum of pure Olive oil at wavelength around 678 nm which attributed to chlorophylls, while fluorescence spectrum to doped sample shows two strong fluorescence peaks at the wavelength 681 nm and 585 nm which attributed to chlorophylls and Vitamin E respectively. The doping process enhances fluorescence activity of Olive oil through enhancing intensity of the fluorescence peak corresponding to Vitamin E. Absorption and fluorescence spectrums to doped silica sample give a good indication in direction of using Sol-Gel technique to prepare?for Olive oil doped SiO2 as an optical active material. 展开更多
关键词 sol-gel SIO2 OLIVE Oil
下载PDF
Influence of Heat Treatment Temperature and of Sb2O3 addition on Photoluminescence Properties of ZnO Ceramics Prepared by Sol-Gel Technique Preparation
12
作者 Hiroyuki Nasu Tomoyuki Yamauchi +3 位作者 Sachio Ninagawa Daisuke Hirota Tadanori Hashimoto Atsushi Ishihara 《Engineering(科研)》 2010年第12期969-972,共4页
To explore thin transparent electroluminescence and electric conductive films by sol-gel technique, Sb2O3 doped n-type ZnO ceramics powders were prepared by sol-gel technique and photoluminescence properties were meas... To explore thin transparent electroluminescence and electric conductive films by sol-gel technique, Sb2O3 doped n-type ZnO ceramics powders were prepared by sol-gel technique and photoluminescence properties were measured. Then, the influences of composition and heat treatment temperature on photoluminescence properties were investigated in detail. With respect to the dopant concentration, about 1mol% addition of Sb2O3 was effective to increase photoluminescence intensity. With respect to heat treatment temperature, 800℃ was appropriate, and rather higher heat treatment temperature resulted in the formation of Zn7Sb2O12 and decrease the intensity. The excited ultraviolet wavelength of 200nm was proper to intense photoluminescence. 展开更多
关键词 ZNO CERAMICS SB2O3 DOPING PHOTOLUMINESCENCE Heat Treatment Temperature sol-gel
下载PDF
Preparation and dielectric properties of compositionally graded (Ba,Sr)TiO_3 thin film by sol-gel technique 被引量:1
13
作者 章天金 王军 +3 位作者 张柏顺 王今朝 万能 胡兰 《中国有色金属学会会刊:英文版》 CSCD 2006年第B01期119-122,共4页
Compositional graded BaxSr1-xTiO3 (x=0.6, 0.7, 0.8, 0.9, 1.0) (BST) thin films (less than 400 nm) were fabricated on Si and Pt/Ti/SiO2/Si substrates by sol-gel technique. A special heating treatment was employed to fo... Compositional graded BaxSr1-xTiO3 (x=0.6, 0.7, 0.8, 0.9, 1.0) (BST) thin films (less than 400 nm) were fabricated on Si and Pt/Ti/SiO2/Si substrates by sol-gel technique. A special heating treatment was employed to form the uniform composition gradients at 700 ℃. The microstructures of the films were studied by means of X-ray diffraction, atomic force microscope and field emission scanning electron microscopy. The results show that the films have uniform and crack-free surface morphology with perovskite structure phase. The small signal dielectric constant (εr) and dielectric loss (tan δ) are found to be 335 and 0.045 at room temperature and 200 kHz. The dielectric properties change significantly with applied dc bias, and the graded thin film show high tunability of 42.3% at an applied field of 250 kV/cm. All the results indicate that the graded BST thin films prepared by sol-gel technique have a promising candidate for microelectronic device. 展开更多
关键词 (Ba Sr)TiO3薄膜 基质 溶胶-凝胶法 制备 介电性质 成分梯度
下载PDF
Effects of heat treatment on morphological,optical and electrical properties of ITO films by sol-gel technique 被引量:2
14
作者 李芝华 柯于鹏 任冬燕 《中国有色金属学会会刊:英文版》 EI CSCD 2008年第2期366-371,共6页
Indium-tin-oxide(ITO)films were prepared on the quarts glass by sol-gel technique.Effects of different heat treatment temperatures and cooling methods on the morphological,optical and electrical properties of ITO film... Indium-tin-oxide(ITO)films were prepared on the quarts glass by sol-gel technique.Effects of different heat treatment temperatures and cooling methods on the morphological,optical and electrical properties of ITO films were measured by TG/DTA, IR,XRD,SEM,UV-VIS spectrometer and four-probe apparatus.It is found that the crystallized ITO films exhibit a polycrystalline cubic bixbyite structure.The heat treatment process has significant effects on the morphological,optical and electrical properties of ITO films.Elevating the heat treatment temperature can perfect the crystallization process of ITO films,therefore the optical and electrical properties of ITO films are improved.But the further increasing of heat treatment temperature results in the increment of ITO films’resistivity.Compared with ITO films elaborated by furnace cooling,those prepared through air cooling have following characteristics as obviously decreased crystalline size,deeply declined porosity,more compact micro-morphology,improved electrical property and slightly decreased optical transmission. 展开更多
关键词 热处理技术 光学特性 电学特性 溶胶-凝胶技术 薄膜
下载PDF
Masquelet technique using an allogeneic cortical bone graft for a large bone defect:A case report
15
作者 Hai-Yang Zong Yu Liu +2 位作者 Xing Yin Wei Zhou Nan Li 《World Journal of Clinical Cases》 SCIE 2025年第5期36-43,共8页
BACKGROUND The induced-membrane technique was initially described by Masquelet as an effective treatment for large bone defects,especially those caused by infection.Here,we report a case of chronic osteomyelitis of th... BACKGROUND The induced-membrane technique was initially described by Masquelet as an effective treatment for large bone defects,especially those caused by infection.Here,we report a case of chronic osteomyelitis of the radius associated with a 9 cm bone defect,which was filled with a large allogeneic cortical bone graft from a bone bank.Complete bony union was achieved after 14 months of follow-up.Previous studies have used autogenous bone as the primary bone source for the Masquelet technique;in our case,the exclusive use of allografts is as successful as the use of autologous bone grafts.With the advent of bone banks,it is possible to obtain an unlimited amount of allograft,and the Masquelet technique may be further improved based on this new way of bone grafting.CASE SUMMARY In this study,we reported a case of repair of a long bone defect in a 40-year-old male patient,which was characterized by the utilization of allograft cortical bone combined with the Masquelet technique for the treatment of the patient's long bone defect in the forearm.The patient's results of functional recovery of the forearm were surprising,which further deepens the scope of application of Masquelet technique and helps to strengthen the efficacy of Masquelet technique in the treatment of long bones indeed.CONCLUSION Allograft cortical bone combined with the Masquelet technique provides a new method of treatment to large bone defect. 展开更多
关键词 OSTEOMYELITIS Bone defect Allogeneic cortical bone Masquelet technique Membrane induction technique Case report
下载PDF
An Enhanced Lung Cancer Detection Approach Using Dual-Model Deep Learning Technique
16
作者 Sumaia Mohamed Elhassan Saad Mohamed Darwish Saleh Mesbah Elkaffas 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期835-867,共33页
Lung cancer continues to be a leading cause of cancer-related deaths worldwide,emphasizing the critical need for improved diagnostic techniques.Early detection of lung tumors significantly increases the chances of suc... Lung cancer continues to be a leading cause of cancer-related deaths worldwide,emphasizing the critical need for improved diagnostic techniques.Early detection of lung tumors significantly increases the chances of successful treatment and survival.However,current diagnostic methods often fail to detect tumors at an early stage or to accurately pinpoint their location within the lung tissue.Single-model deep learning technologies for lung cancer detection,while beneficial,cannot capture the full range of features present in medical imaging data,leading to incomplete or inaccurate detection.Furthermore,it may not be robust enough to handle the wide variability in medical images due to different imaging conditions,patient anatomy,and tumor characteristics.To overcome these disadvantages,dual-model or multi-model approaches can be employed.This research focuses on enhancing the detection of lung cancer by utilizing a combination of two learning models:a Convolutional Neural Network(CNN)for categorization and the You Only Look Once(YOLOv8)architecture for real-time identification and pinpointing of tumors.CNNs automatically learn to extract hierarchical features from raw image data,capturing patterns such as edges,textures,and complex structures that are crucial for identifying lung cancer.YOLOv8 incorporates multiscale feature extraction,enabling the detection of tumors of varying sizes and scales within a single image.This is particularly beneficial for identifying small or irregularly shaped tumors that may be challenging to detect.Furthermore,through the utilization of cutting-edge data augmentation methods,such as Deep Convolutional Generative Adversarial Networks(DCGAN),the suggested approach can handle the issue of limited data and boost the models’ability to learn from diverse and comprehensive datasets.The combined method not only improved accuracy and localization but also ensured efficient real-time processing,which is crucial for practical clinical applications.The CNN achieved an accuracy of 97.67%in classifying lung tissues into healthy and cancerous categories.The YOLOv8 model achieved an Intersection over Union(IoU)score of 0.85 for tumor localization,reflecting high precision in detecting and marking tumor boundaries within the images.Finally,the incorporation of synthetic images generated by DCGAN led to a 10%improvement in both the CNN classification accuracy and YOLOv8 detection performance. 展开更多
关键词 Lung cancer detection dual-model deep learning technique data augmentation CNN YOLOv8
下载PDF
Advancements and challenges in neuroimaging for the diagnosis of intracranial aneurysms:Addressing false positive diagnoses and emerging techniques
17
作者 Nanthida Arora Sombat Muengtaweepongsa 《World Journal of Clinical Cases》 SCIE 2025年第6期48-50,共3页
Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We dis... Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms. 展开更多
关键词 Intracranial aneurysms Neuroimaging techniques Computed tomographic angiography Magnetic resonance angiography Digital subtraction angiography False positive diagnoses
下载PDF
LATTICE DEFORMATION AND PHASE TRANSFORMATION FROM NANO-SCALE ANATASE TO NANO-SCALE RUTILE TiO_2 PREPARED BY A SOL-GEL TECHNIQUE 被引量:1
18
作者 YanqunShao DianTang +2 位作者 JinghuaSun YekunLee WeihaoXiong 《China Particuology》 SCIE EI CAS CSCD 2004年第3期119-123,共5页
Nano-scale rutile phase was transformed from nano-scale anatase upon heating, which was prepared by a sol-gel technique. The XRD data corresponding to the anatase and rutile phases were analyzed and the grain sizes of... Nano-scale rutile phase was transformed from nano-scale anatase upon heating, which was prepared by a sol-gel technique. The XRD data corresponding to the anatase and rutile phases were analyzed and the grain sizes of as-derived phases were calculated by Sherrer equation. The lattice parameters of the as-derived anatase and rutile unit cells were calculated and compared with those of standard lattice parameters on PDF cards. It was shown that the smaller the grain sizes, the larger the lattice deformation. The lattice parameter a has the negative deviation from the standard and the lattice parameter c has the positive deviation for both phases. The particles sizes had preferential in-fluence on the longer parameter between the lattice parameters of a and c. With increasing temperatures, the lattice parameters of a and c in both phases approached to the equilibrium state. The larger lattice deformation facilitated the nucleation process, which lowered the transformation temperature. During the transformation from nano-scale anatase to rutile, besides the mechanism involving retention of the {112} pseudo-close-packed planes of oxygen in anatase as the {100} pseudo-close-packed planes in rutile, the new phase occurred by relaxation of lattice deformation and adjustment of the atomic sites in parent phase. The orientation relationships were suggested to be anatase {101}//rutile {101} and anatase <201>//rutile<111>, and the habit plane was anatase (101). 展开更多
关键词 nano-scale materials ANATASE RUTILE phase transformation TIO2 sol-gel technique
原文传递
Fabrication of 2×2 Thermo-Optic Switches with Organic-Inorganic Hybrid Materials Prepared by Sol-Gel Technique
19
作者 Xianjiang Wang, Lei Xu, Dongxiao Li, Liying Liu, and Wencheng WangState Key Lab for Advanced Photonic Materials and Devices, Department of Optical Science and Engineering, Fudan University, Shanghai 200433, P. R. China 《光学学报》 EI CAS CSCD 北大核心 2003年第S1期265-266,共2页
2×2 Mach-Zehnder interferometric thermo-optic switch was fabricated with organic/inorganic hybrid materials by sol-gel technique and direct UV patterning. The switching time of device was measured to be 4.2 ms an... 2×2 Mach-Zehnder interferometric thermo-optic switch was fabricated with organic/inorganic hybrid materials by sol-gel technique and direct UV patterning. The switching time of device was measured to be 4.2 ms and switching power 9.3 mW. 展开更多
关键词 of on by with Thermo-Optic Switches with Organic-Inorganic Hybrid Materials Prepared by sol-gel technique Fabrication of 2
原文传递
Clinical diagnostic advances in intestinal anastomotic techniques:Hand suturing,stapling,and compression devices 被引量:1
20
作者 Ah Young Lee Joo Young Cho 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第5期1231-1234,共4页
The development of intestinal anastomosis techniques,including hand suturing,stapling,and compression anastomoses,has been a significant advancement in surgical practice.These methods aim to prevent leakage and minimi... The development of intestinal anastomosis techniques,including hand suturing,stapling,and compression anastomoses,has been a significant advancement in surgical practice.These methods aim to prevent leakage and minimize tissue fibrosis,which can lead to stricture formation.The healing process involves various phases:hemostasis and inflammation,proliferation,and remodeling.Mechanical staplers and sutures can cause inflammation and fibrosis due to the release of profibrotic chemokines.Compression anastomosis devices,including those made of nickel-titanium alloy,offer a minimally invasive option for various surgical challenges and have shown safety and efficacy.However,despite advancements,anastomotic techniques are evaluated based on leakage risk,with complications being a primary concern.Newer devices like Magnamosis use magnetic rings for compression anastomosis,demonstrating greater strength and patency compared to stapling.Magnetic technology is also being explored for other medical treatments.While there are promising results,particularly in animal models,the realworld application in humans is limited,and further research is needed to assess their safety and practicality. 展开更多
关键词 ANASTOMOSES Diagnostic advances Anastomotic techniques technique Intestine
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部