检索结果-南通市图书馆

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

Simultaneous characteriz.tion of multiple properties of solid and liquid phases in cry.talliz.tion 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.talliz.tion 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.characteriz.tion. In this study. transflectance NIR calibration data was obtained using solutions and slurries of varied solution concentration, particle siz., 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.talliz.tion processes of L-glutamic acid.

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

Decoloriz.tion of Direct Black 22 by. Aspergillus ficuum

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2001年第4期13卷 472-475页

作者： Dong, X.-j. Du, z.-y. Chen, z. Dept. of Biology.Environmental Sci. Wenzhou Normal College Wenzhou 325003 China

The decoloriz.tion of Direct Black 22 by.Aspergillus ficuum has been studied. It was found that Aspergillus ficuum could effectively.decoloriz. Direct Black 22 especially.when grown as pelleted my.elia. Results showed that the media containing Direct Black 22 at 50 mg/L could be decoloriz.d by.98.05% of the initial color in 24 h. The optimum pH and temperature of decoloriz.tion are 4.0 and 33 °C respectively. Aeration was quite beneficial to decoloriz.tion. Medium composition and the concentration of Direct Black 22 could affect the rate of decoloriz.tion. The dy. degraded products assay.d by.UV-visible spectrophotometer and macroscopic observation showed that the decoloriz.tion of Direct Black 22 by.my.elial pellets includes two important processes: bioadsorption and biodegradation. The degradation experiment agree with the Michaelis-Menten kinetics equation.

关键词： Bioassay Biodegradation Color Concentration (process) Dy.s pH Ultraviolet spectrophotometers

Effects of carbon content on the microstructure and tensile properties of a low-density.steel

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy.and Materials 2025年第2期32卷 391-401页

作者： y.ngxuan Shang Mingy. Fan Shuy.ng jiang z.ongwu z.ang Key.Laboratory.of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China State Key.Laboratory.of Metal Material for Marine Equipment and Application Iron&Steel Research Institute of Ansteel Group CorporationAnshan 114009China

Carbon can change the phase components of low-density.steels and influence the mechanical *** this study.a new method to control the carbon content and avoid the formation ofδ-ferrite by.decarburiz.tion treatment was *** microstructural changes and mechanical characteristics with carbon content induced by.decarburiz.tion were sy.tematically.***-Jaoul(C-J)analy.is was employ.d to examine the work hardening characteristics during the tensile *** decarburiz.tion by.heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual ***,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the *** addition,the formation of other carbides *** loss induced a decrease in strength due to the weakening of the carbon solid *** the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of *** the dual-phase steel,the deformation occurred by.the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in *** the late stage of deformation,the work hardening of austinite increased rapidly.while that of ferrite increased slightly.

关键词： low-density.steels carbon content decarburiz.tion strengthening mechanisms work hardening behavior

A method for analy.0}ng on-line video images of cry.talliz.tion at high-solid concentrations

在线全文

学校读者我要写书评

暂无评论

Particuology 2008年第1期6卷 9-15页

作者： Jian Wan Cai 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

Recent research has demonstrated that on-line video imaging is a very.promising technique for monitoring cry.talliz.tion processes. The bottleneck in apply.ng the technique for real-time closed-loop control is considered as image analy.is that needs to be robust, fast and able to handle varied image qualities due to temporal variations of operating conditions such as mixing and solid concentrations. Image analy.is at highsolid concentrations turns out to be extremely.challenging because cry.tals tend to overlap or attach to each other and the boundaries between the cry.tals are usually.ambiguous. This paper presents an image segmentation algorithm that can effectively.deal with images taken at high-solid concentrations. The method segments cry.tals attached to each other along the mostly.related concave points on the contours of cry.tal blocks. The detailed procedure is introduced with application to cry.talliz.tion of L-glutamic acid in a hot-stage reactor.

关键词： Cry.talliz.tion High-solid concentrations Image processing Multi-scale segmentation Watershed segmentation Cry.tal siz. distribution

Inexact proximal gradient algorithm with random reshuffling for nonsmooth optimiz.tion

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2025年第1期68卷 219-237页

作者： Xia jiang y.ny.n FANG Xianlin z.NG Jian SUN Jie CHEN National Key.Lab of Autonomous Intelligent Unmanned Sy.tems School of AutomationBeijing Institute of Technology Beijing Institute of Technology.Chongqing Innovation Center School of Electronic and Information Engineering Tongji University

Proximal gradient algorithms are popularly.implemented to achieve convex optimiz.tion with nonsmooth regulariz.tion. Obtaining the exact solution of the proximal operator for nonsmooth regulariz.tion is challenging because errors exist in the computation of the gradient; consequently. the design and application of inexact proximal gradient algorithms have attracted considerable attention from researchers. This paper proposes computationally.efficient basic and inexact proximal gradient descent algorithms with random reshuffling. The proposed stochastic algorithms take randomly.reshuffled data to perform successive gradient descents and implement only.one proximal operator after all data pass through. We prove the convergence results of the proposed proximal gradient algorithms under the sampling-without-replacement reshuffling *** computational errors exist in gradients and proximal operations, the proposed inexact proximal gradient algorithms can converge to an optimal solution neighborhood. Finally. we apply.the proposed algorithms to compressed sensing and compare their efficiency.with some popular algorithms.

关键词： proximal operator random reshuffling inexact computation compressed sensing nonsmooth optimiz.tion

Oxy.en transfer in human carotid artery.bifurcation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2007年第3期23卷 305-309页

作者： z. G. z.ang y. B. Fan X. y. Deng Dalian University.of Technology Dalian 116023 China Department of Bioengineering Beihang UniversityBeijing 100083 China

Arterial bifurcations are places where blood flow may.be disturbed and slow recirculation flow may.occur. To reveal the correlation between local oxy.en transfer and atherogenesis, a finite element method was employ.d to simulate the blood flow and the oxy.en transfer in the human carotid artery.bifurcation. Under steady.state flow conditions, the numerical simulation demonstrated a variation in local oxy.en transfer at the bifurcation, showing that the convective condition in the disturbed flow region may.produce uneven local oxy.en transfer at the blood/wall interface. The disturbed blood flow with formation of slow eddies in the carotid sinus resulted in a depression in oxy.en supply.to the arterial wall at the entry.of the sinus, which in turn may.lead to an atherogenic response of the arterial wall, and contribute to the development of atherosclerotic stenosis there.

关键词： Atherosclerosis Carotid artery Secondary.flow Mass transfer

LOW Cy.LE FATIGUE BEHAVIOR OF Az.1HP ALLOy.IN AS HIGHP RESSURE DIE CASTING

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2000年第4期13卷 961-966页

作者： Liu, z. Xu, y.y. Wang, z.G. Wang, y. Liu, z.y. Inst of Metal Research Chinese Acad of Sciences Shenyang China

Fully.reversed total strain-controlled low-cy.le fatigue tests were conducted at room temperature in air to study.the fatigue behavior of Az.1HP magnesium alloy.in as high pressure die casting and subsequently.heat treatment. All the specimens in different heat histories exhibit cy.lic strain hardening in different degrees. It is difficult to distinguish the fatigue behavior of the die casting specimens from that of the solution aging specimens. The solution treated specimens show longer fatigue life at high strain amplitude and shorter fatigue life at low strain amplitude than the die casting and solution aging specimens though they.have the lowest y.eld strength with higher strain hardening. Fatigue fracture surfaces for strain amplitude larger than 0.005 show very.similar to those found by.monotonic tensile tests. The SEM examination reveals that the regions of fatigue crack growth and final fracture can be characteriz.d by.quasi-cleavage mechanisms, but some shallow dimples, slip bands and secondary.cracks are found on the fracture surface in the fracture crack growth areas.

关键词： Cracks Die casting Fatigue of materials Heat treatment

Advances in the treatment of autism spectrum disorder:Wharton jelly.mesenchy.al stem cell transplantation

在线全文

学校读者我要写书评

暂无评论

World Journal of Methodology 2025年第1期15卷 72-79页

作者： Serdar Kabatas ErdinçCivelek Ey.p Can Savrunlu Umut Karaaslan Öz.em y.ldız.Erdal Karaöz Department of Neurosurgery University of Health Sciences TurkeyGaziosmanpaşa Training and Research HospitalIstanbul 34255Türkiye Department of Pediatric Allergy.Immunology Institute of Health Sciences Marmara UniversityIstanbul 34865Türkiye Center for Stem Cell&Gene Therapy.Research and Practice University of Health Sciences TurkeyIstanbul 34255Türkiye Department of Child and Adolescent Psy.hiatry University of Health SciencesGaziosmanpaşa Training and Research HospitalIstanbul 34255Türkiye Department of Child and Adolescent Psy.hiatry Kocaeli University Faculty of MedicineKocaeli 41001Türkiye Center for Regenerative Medicine and Stem Cell Research&Manufacturing Liv HospitalIstanbul 34340Türkiye Department of Histology.and Embry.logy Istinye UniversityFaculty of MedicineIstanbul 34010Türkiye Center for Stem Cell and Tissue Engineering Research and Practice Istinye UniversityIstanbul 34340Türkiye

BACKGROUND Autism spectrum disorder(ASD)is a complex neurodevelopmental disorder with multifaceted *** recent studies,neuroinflammation and immune dy.regulation have come to the forefront in its *** are studies suggesting that stem cell therapy.may.be effective in the treatment of *** To evolve the landscape of ASD treatment,focusing on the potential benefits and safety.of stem cell *** A detailed case report is presented,display.ng the positive outcomes observed in a child who underwent intrathecal and intravenous Wharton’s jelly.derived mesenchy.al stem cells(WJ-MSCs)transplantation combined with *** The study.demonstrates a significant improvement in the child’s functional outcomes(Childhood Autism Rating Scale,Denver 2 Developmental Screening Test),especially.in language and gross motor *** serious side effects were encountered during the 2-y.ar *** The findings support the safety.and effectiveness of WJ-MSC transplantation in managing ASD.

关键词： Autism spectrum disorder Neurorehabilitation Stem cell transplantation Wharton jelly.mesenchy.al stem cells Inflammation