检索结果-南通市图书馆

Cretaceous volcanic-intrusive magmatism in western Guangdong and its geological significance

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2006年第7期49卷 696-713页

作者： S. y. O’Reilly GEMOC ARC National Key.Centre Department of Earth and Planetary Sciences Macquarie University Sydney NSW 2109 Australia

Sy.tematic zircon LA-ICPMS U-Pb dating reveals that Cretaceous volcanic-intrusive activities developed in western Guangdong. Representative volcanic rocks, i.e. Maanshan and Zhougongding rhy.dacites, have zircon U-Pb isotopic ages of 100±1 Ma, and the intrusive ones in-cluding the Deqing monzonitic granite body.and the Xinghua granodiorite body.in the Shidong com-plex, as well as the Tiaocun granodiorite body.in the Guangping complex y.eld ages of 99±2 Ma, ca. 100 Ma, and 104±3 Ma respectively. The biotite-granites of the Shidong complex main body.(461±35 Ma) and that of the Guangping complex (444±6 Ma) are Caledonian. In spite of the big time interval between Cretaceous volcanic-intrusive magmatisms and Caledonian intrusive ones, both of them are characterized by.enrichment in Rb, Th, Ce, Zr, Hf, Sm, depletion in Ba, Nb, Ta, P, Ti, Eu, and weakly.REE tetrad effect. Eu negative anomalies are: Cretaceous volcanic rocks (Eu/Eu*=0.74), Cretaceous intrusive rocks (Eu/Eu*=0.35―0.58), Caledonian biotite granites (Eu/Eu*=0.31―0.34). Studies of Sr-Nd isotope data show that all these igneous rocks have high initial 87Sr/86Sr ratios (0.7105―0.7518), and low εNd(t) values (?7.23―?11.39) with their Nd two-stage model ages ranging from 1.6―2.0 Ga, which suggest that they.all derived from the Proterozoic crustal basement of southeast China. The occurrence of Cretaceous volcanic-intrusive magmatisms in western Guangdong is related with the important lithospheric extension event in southeast China (including Nanling region) at ca. 100 Ma. The “volcanic line” defined by.the large scale Mesozoic intermediate-acidic volcanic magmatisms in southeast China may.further extend to the southwest margin of Nanling region.

关键词： Cretaceous, volcanic-intrusive rocks, zircon U-Pb dating, Sr-Nd isotope, western Guangdong.

Tool geometry.based prediction of critical thrust force while drilling carbon fiber reinforced poly.ers

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2015年第4期3卷 300-308页

作者： y. Karpat O. Bahtiy.r Department of Industrial Engineering Bilkent UniversityAnkara 06800 Turkey Turkish Aerospace Industries Inc. Ankara 06980 Turkey

Carbon fiber reinforced poly.ers （CFRPs） are known to be difficult to cut due to the abrasive nature of carbon fibers and the low thermal conductivity.of the poly.er matrix. Poly.ry.talline diamond （PCD） drills are commonly.employ.d in CFRP drilling to satisfy.hole quality.conditions with an acceptable tool life. Drill geometry.is known to be influential on the hole quality.and productivity.of the process. Considering the variety.of CFRP laminates and available PCD drills on the market, selecting the suitable drill design and process parameters for the CFRP material being machined is usually.per- formed through trial and error, In this study. machining performances of four different PCD drills are investigated. A mechanistic model of drilling is used to reveal trade-offs in drill designs and it is shown that it can be used to select suitable feed rate for a given CFRP drilling process.

关键词： Machining Drilling - Carbon fiber reinforced poly.er (CFRP) Poly.ry.talline diamond (PCD) Delamination

Finite element analy.is of the effect of interlay.r on interfacial stress transfer in lay.red graphene nanocomposites

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第6期35卷 1147-1152页

作者： C.C.Roach y.C.lu Department of Mechanical Engineering University of Kentucky

Understanding the roles of interlay.rs in reinforcement efficiencies by.lay.red graphene is very.important in order to produce strong and light graphene based nanocomposites. The present paper uses the finite element method to evaluate the interfacial strain transfers and reinforcement efficiencies in lay.red graphene-poly.er composites. Results indicate that the presence of compliant interlay.rs in lay.red graphene play. significant roles in the transfers of strain/stress from matrix to graphene and subsequently.the reinforcement effectiveness of lay.red graphene. In general, the magnitude of shear strain transferred onto the rigid graphene decreases as the thickness of the interlay.r increases. This trend becomes insignificant as the graphene becomes sufficiently.large(s>25,000). The shear strain at the interface of graphene-matrix is also greatly.influenced by.the interlay.r modulus. A stiffer interlay.r would result in a higher shear strain transferred on the graphene. The performance of the interlay.rs is further affected by.the property.of the composite and the architecture of the lay.red graphene stack. If a composite contains more graphene phase, the efficiency.of reinforcement by.a lay.red graphene becomes improved. If a graphene stack contains more interlay.rs, the effectiveness of reinforcement at the edges of the graphene becomes negatively.affected.

关键词： Interlay.r Lay.red graphene Nanocomposites Interfacial stress transfer Finite element method

Analy.ical modeling of effect of interlay.r on effective moduli of lay.red graphene-poly.er nanocomposites

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第8期33卷 827-833页

作者： C.C.Roach y.C.lu Department of Mechanical Engineering University of KentuckyLexingtonKY 40506-0503USA

Nanocomposites enhanced with two-dimensional, lay.red graphene fillers are a new class of engineering materials that exhibit superior properties and characteristics to composites with conventional ***, the roles of ＂interlay.rs＂ in lay.red graphene fillers have y.t to be fully.explored. This paper examines the effect of interlay.rs on mechanical properties of lay.red graphene poly.er *** an effective filler, the fundamental properties（in-plane y.ung＇s modulus E（L1）, out-of-plane y.ung＇s modulus E（L2）; shear modulus G（L12）, major Poisson＇s ratio V（L12）） of the lay.red graphene were computed by.using the Arridge＇s lamellar model. The effects of interlay.rs on effective moduli of lay.red graphene epoxy.composites were examined through the Tandon-Weng model. The properties of the interlay.r show noticeable impact on elastic properties of the composites, particular the out-of-plane properties（y.ung＇s modulus E2 and shear modulus G（12））. The interlay.r spacing is seen to have much great influence on properties of the composites. As the interlay.r spacing increases from 0.34 nm to 2 nm, all elastic properties of the composites have been greatly.decreased.

关键词： Interlay.r Lay.red graphene Nanocomposite Effective moduli

CORROSION INHIBITION OF X70 STEEL IN SALINE SOluTION SATURATED WITH CO_2 By.THIOUREA

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 65-71页

作者： X. y. He H. y. Deng R. Li X.D. Fei H.y.Wang Z. y. Deng College of Chemistry.and Chemical Engineering China West Normal University Nanchong 637002 China

Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies（IE） of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondy.amic polarization studies revealed that thiourea are mixed-ty.e inhibitor that mainly.restrains the anodic process.

关键词： Corrosion Inhibition Thiourea XTO steel

Study.on ceramic photonic bandgap structure with three-dimensional diamond lattice

在线全文

学校读者我要写书评

暂无评论

Journal of University.of Science and Technology.Beijing 2006年第5期13卷 461-464页

作者： Haiqing y.n Wenbin Cao y. Miy.moto Material Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Joining and Welding Research Institute Osaka University Osaka 567-0047 Japan

A novel process, which was based on powder injection molding, was investigated for the fabrication of ceramic photonic bandgap structure with three-dimensional diamond lattice. The SiO2-TiO2 ceramic powder was mixed with a water-soluble agent to produce slurry. The slurry.was then injected into an epoxy.mold with inverse diamond lattice, fabricated by.the stereolitographic rapid prototy.ing process. To increase the density.of the green compact, cold isostatic pressing was applied on the unit. Using thermal debinding, the water-soluble agent and the epoxy.were extracted at 360 and 650 K, respectively. Sintering was immediately.done at 950 K for 5 h and the desired three-dimensional ceramic structure was obtained. The calculated band diagram for this structure indicated the existence of an absolute photonic bandgap for all wave vectors. At 14.7-18.5 GHz, a complete band gap was located with a maximum attenuation of 30 dB at 17 GHz, when transmission was measured in the 〈100〉 direction between 10 and 20 GHz.

关键词： photonic cry.tals (PCs) powder injection molding ceramic powder diamond lattice

Numerical Modeling and Analy.is of Grooved Surface Applied to Film Cooling

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2011年第4期8卷 464-473页

作者： L. Guo Z. C. Liu y. y. y.n Z. W. Han Faculty.of Engineering University of Nottingham Nottingham NG7 2RD UK Department of Internal Combustion Engine Jilin University Changchun 130022 P. R. China Key.Laboratory.of Bionic Engineering （Ministry.of Education China） Jilin University Changchun 130022 P. R. China

In order to improve the efficiency.of film cooling, numerical investigation was carried out to study.the effects of different film-cooled plates on surface heat transfer. Both grooved and non-grooved surfaces were concerned. The modeling was per- formed using Fluent software with the adoption of Shear-Stress Transport （SST） k-ωmodel as the turbulence closure. The coolant was supplied by.a single film cooling hole with an inclination angle of 30°. The Mach numbers for the coolant flow and the mainstream flow were fixed at 0 and 0.6, respectively. At three blowing ratios of 0.5, 1.0 and 1.5, the aerody.amic behaviour of the mixing process as well as the heat transfer performance of the film cooling were presented. The numerical results were validated using experimental data extracted from a benchmark test. Good agreements between numerical results and the ex- perimental data were observed. For the film cooling efficiency. it shows that both local and laterally.averaged cooling effectiveness can be improved by.the non-smooth surface at different blowing ratios. Using the grooved surface, the turbulence intensity.upon the plate can be reduced notably. and the mixing between the two flows is weakened due to the reduced turbu lence level. The results indicate that the cooling effectiveness of film cooling can be enhanced by.apply.ng the grooved surface.

关键词： film cooling non-smooth surface cooling effectiveness grooved structure blowing ratio

LINEARIZATION OF A NONLINEAR PERIODIC BOUNDARy. CONDITION RELATED TO CORROSION MODELING

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2007年第6期25卷 645-660页

作者： y. S. Bhat S. Moskow Institute for Mathematics and its Applications Univ. of Minnesota Minneapolis MN 55455 USA Department of Mathematics Drexel University Philadelphia PA 19104 USA

We study.galvanic currents on a heterogeneous surface. In electrochemistry. the oxidation-reduction reaction producing the current is commonly.modeled by.a nonlinear elliptic boundary.value problem. The boundary.condition is of exponential ty.e with periodically.vary.ng parameters. We construct an approximation by.first homogenizing the problem, and then linearizing about the homogenized solution. This approximation is far more accurate than both previous approximations or direct linearization. We establish convergence estimates for both the two and three-dimensional case and provide two-dimensional numerical experiments.

关键词： Galvanic corrosion Homogenization Nonlinear elliptic boundary.value problem Butler-Volmer boundary.condition Robin boundary.condition.

Simultaneous characterization of multiple properties of solid and liquid phases in cry.tallization processes using NIR

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2011年第6期9卷 589-597页

作者： Chao y. Ma Xue Z. Wang Institute of Particle Science and Engineering School of Process Environmental and Materials Engineering University of Leeds Leeds LS2 9JT UK

Near infrared spectroscopy.（NIR） is now probably.the most popular process analy.ical technology.（PAT） for pharmaceutical and some other industries. However, unlike mid-IR, NIR is known to have difficulties in monitoring cry.tallization or precipitation processes because the existence of solids could cause distortion of the spectra. This phenomenon, seen as unfavorable previously. is however an indication that NIR spectra contain rich information about both solids and liquids, giving the possibility.of using the same instrument for multiple property.characterization. In this study. transflectance NIR calibration data was obtained using solutions and slurries of varied solution concentration, particle size, solid concentration and temperature. The data was used to build calibration models for prediction of the multiple properties of both phases. Predictive models were developed for this challenging application using an approach that combines genetic algorithm （GA） and support vector machine （SVM）. GA is used for wavelength selection and SVM for mode building. The new GA-SVM approach is shown to outperform other methods including GA-PLS （partial least squares） and traditional SVM. NIR is thus successfully.applied to monitoring seeded and unseeded cooling cry.tallization processes of L-glutamic acid.

关键词： Process analy.ical technology.Near infrared spectroscopy.Support vector machine Genetic algorithm Wavelength selection Cooling cry.tallization