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Numerical Method for Singularly Perturbed Third Order Ordinary Differential Equations of Convection-Diffusion Type

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Numerical Mathematics(Theory,Methods and Applications) 2014年第3期7卷 265-287页

作者： j.christy Roja A.Tamilselvan Department of Mathematics Bharathidasan UniversityTiruchirappalli–620024TamilnaduIndia

In this paper,we have proposed a numerical method for Singularly Perturbed Boundary Value Problems(SPBVPs)of convection-diffusion type of third order Ordinary Differential Equations(ODEs)in which the SPBVP is reduced into a weakly coupled system of two ODEs subject to suitable initial and boundary *** numerical method combines boundary value technique,asymptotic expansion approximation,shooting method and finite difference *** order to get a numerical solution for the derivative of the solution,the domain is divided into two regions namely inner region and outer *** shooting method is applied to the inner region while standard finite difference scheme(FD)is applied for the outer *** error estimates are derived for the *** efficiency and accuracy are verified through numerical *** method is easy to implement and suitable for parallel computing.

关键词： Singularly perturbed problems third order ordinary differential equations boundary value technique asymptotic expansion approximation shooting method finite difference scheme parallel computation

Nanostructured grinding wheels for ultra-precision engineering applications

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Nanotechnology and Precision Engineering 2021年第3期4卷 63-75页

作者： M.j.jackson Integrated Studies College of Technology and AviationKansas State UniversitySalinaKansas 67401USA

Manufacturers face challenges when dealing with abrasives that lose roundness,wear excessively,and suffer from pitting of the surface of the grinding wheel that needs rectification using dressing *** abrasive grits manufactured by hybrid fusion processes and by sintering/extrusion/printing processes are found to reduce pitting quite *** phenomenon of wheel collapse is increasing and cycle times developed during the grinding of aerospace alloys are much smaller compared to using conventional *** paper reviews the phenomenon of wheel collapse induced by pitting and takes a critical look at the production and analysis of hybrid fused and printed/sintered abrasives.A mathematical analysis is carried out of the diffusion of primary and secondary phases due to mechanical and ultrasonic agitation with the aim of producing abrasive grits with improved strength and *** developments in extruded,printed,and sintered grits for use in precision grinding applications are critically *** paper concludes by explaining how such abrasives are used in practice by industrial manufacturers of high-precision products.

关键词： Nanotechnology Abrasives Alloys Finishing Grinding Machining

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How spiders practice aggressive and Batesian mimicry

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Current Zoology 2012年第4期58卷 620-629页

作者： Ximena j. NELSON Robert R. jackson School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch New Zealand International Centre of Insect Physiology and Ecology Thomas Odhiambo Campus EO. Box 30 Mbita Point Kenya

To understand communication, the interests of the sender and the receiver/s of signals should be considered sepa-rately. When our goal is to understand the adaptive significance of specific responses to specific signals by the receiver, questions about signal information are useful. However, when our goal is to understand the adaptive significance to the sender of generating a signal, it may be better to envisage the receiver＇s response to signals as part of the sender＇s extended phenotype. By making signals, a sender interfaces with the receiver＇s model of the world and indirectly manipulates its behaviour. This is especially clear in cases of mimicry, where animals use deceptive signals that indirectly manipulate the behaviour of receivers. Many animals adopt Batesian mimicry to deceive their predators, or aggressive mimicry to deceive their prey. We review examples from the lite-rature on spiders to illustrate how these phenomena, traditionally thought of as distinct, can become entangled in a web of lies .

关键词： Mimicry Communication Spider Deception Signal Search image

Simulated perturbation in the sea-to-air flux of dimethylsulfi de and the impact on polar climate

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journal of Oceanology and Limnology 2021年第1期39卷 110-121页

作者： Bo QU Albert jGABRIC Rebecca jackson School of Science Nantong UniversityNantong 226219China School of Environment and Science Griffi th UniversityBrisbane 4111QLDAustralia

Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar *** used a global climate model(GCM)to investigate the impact on atmospheric chemistry from a change to the contemporary DMS fl ux to that which has been projected for the late 21 st *** perturbed simulation corresponded to conditions that pertained to a tripling of equivalent CO 2,which was estimated to occur by year 2090 based on current worst-case greenhouse gas emission *** changes in zonal mean DMS fl ux were applied to 50°S–70°S Antarctic(ANT)and 65°N–80°N Arctic(ARC)*** results indicate that there are clearly diff erent impacts after perturbation in the southern and northern polar *** quantities related to the sulfur cycle show a higher increase in ***,most sulfur compounds have higher peaks in *** perturbation in DMS fl ux leads to an increase of atmospheric DMS of about 45%in ANT and 33.6%in *** sulfur dioxide(SO 2)vertical integral increases around 43%in ANT and 7.5%in ***(SO 4)vertical integral increases by 17%in ANT and increases around 6%in *** emissions increases by 21%in ANT and increases by 9.7%in ***,oxidation of DMS by OH increases by 38.2%in ARC and by 15.17%in *** optical depth(AOD)increases by 4%in the ARC and by 17.5%in the ANT,and increases by 22.8%in austral *** importance of the perturbation of the biogenic source to future aerosol burden in polar regions leads to a cooling in surface temperature of 1 K in the ANT and 0.8 K in the ***,polar regions in the Antarctic Ocean will have a higher off setting eff ect on warming after DMS fl ux perturbation.

关键词： dimethylsulfi de(DMS) sulfur dioxide DMS sea-to-air fl ux perturbation global climate model(GCM) polar region

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DNA media storage

Progress in Natural Science:Materials International 2008年第5期18卷 603-609页

作者： christy M. Bogard Eric C. Rouchka Benjamin Arazi Computer Engineering and Computer Science Department University of Louisville

In 1994, University of Southern California computer scientist, Dr. Leonard Adleman solved the Hamiltonian path problem using DNA as a computational mechanism. He proved the principle that DNA computing could be used to solve computationally complex problems. Because of the limitations in discovery time, resource requirements, and sequence mismatches, DNA computing has not yet become a commonly accepted practice. However, advancements are continually being discovered that are evolving the eld of DNA computing. Practical applications of DNA are not restricted to computation alone. This research presents a novel approach in which DNA could be used as a means of storing les. Through the use of multiple sequence alignment combined with intelligent heu- ristics, the most probabilistic le contents can be determined with minimal errors.

关键词： DNA computing Error reduction Multiple sequence alignment

Friends! Let's Talk ...

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新东方英语（中英文版） 2006年第Z1期 127-133页

作者： christy j. Chan

Leading Approaches to Vascularize Kidney Constructs in Tissue Engineering

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Engineering 2022年第12期19卷 117-127页

作者： Diana S.Lim john D.jackson Anthony Atala james j.Yoo Wake Forest Institute for Regenerative Medicine Wake Forest University School of MedicineMedical Center BoulevardNC 27157USA

There is an unprecedented need for new treatments for renal failure,as the incidence of this disease is increasing disproportionately to advancements in *** treatments are limited by the availability of viable organs,for which there is a worldwide *** treatment modalities also require a substantial amount of infrastructure,significantly limiting the access to care in most *** tissue engineering approaches promise to develop alternative solutions that address many of the inadequacies in current *** many advancements have been made—primarily in the past decade—in biofabrication and whole-organ tissue engineering,many challenges *** major hindrance to the progress of current tissue engineering approaches is establishing successful vascularization of developed engineered tissue *** review focuses on the recent advancements that address the vascular challenge,including the biofabrication of vasculature,whole-organ engineering through decellularization and recellularization approaches,microscale organogenesis,and vascularization using organoids in the context of kidney tissue *** also highlight the specific challenges that remain in developing successful strategies capable of clinical translation.

关键词： Kidney Vascularization Tissue engineering Biofabrication Organoids

Household catastrophic payments for tuberculosis care in Nigeria: incidence, determinants, and policy implications for universal health coverage

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Infectious Diseases of Poverty 2013年第1期2卷 166-174页

作者： Kingsley Nnanna Ukwaja Isaac Alobu Seye Abimbola Philip christy Hopewell Department of Internal Medicine Federal Teaching HospitalAbakalikiEbonyi StateNigeria National Tuberculosis and Leprosy Control Programme Ministry of HealthAbakalikiEbonyi StateNigeria National Primary Health Care Development Agency AbujaNigeria Francis j Curry International Tuberculosis Center Division of Pulmonary and Critical Care MedicineSan Francisco General HospitalUniversity of CaliforniaSan FranciscoCAUSA

Background:Studies on costs incurred by patients for tuberculosis(TB)care are limited as these costs are reported as averages,and the economic impact of the costs is estimated based on average patient/household *** expenditures do not represent the poor because they spend less on treatment compared to other economic ***,the extent to which TB expenditures risk sending households into,or further into,poverty and its determinants,is *** assessed the incidence and determinants of household catastrophic payments for TB care in rural ***:Data used were obtained from a survey of 452 pulmonary TB patients sampled from three rural health facilities in Ebonyi State,*** household direct costs and income data,we analyzed the incidence of household catastrophic payments using,as thresholds,the traditional>10%of household income and the≥40%of non-food income,as recommended by the World Health *** used logistic regression analysis to identify the determinants of catastrophic ***:Average direct household costs for TB were US$157 or 14%of average annual *** incidence catastrophic payment was 44%;with 69%and 15%of the poorest and richest household income-quartiles experiencing catastrophic activity,*** determinants of catastrophic payments were:age>40 years(adjusted odds ratio[aOR]3.9;95%confidence interval[CI],2.0,7.8),male gender(aOR 3.0;CI 1.8,5.2),urban residence(aOR 3.8;CI 1.9,7.7),formal education(aOR 4.7;CI 2.5,8.9),care at a private facility(aOR 2.9;1.5,5.9),poor household(aOR 6.7;CI 3.7,12),household where the patient is the primary earner(aOR 3.8;CI 2.2,6.6]),and HIV co-infection(aOR 3.1;CI 1.7,5.6).Conclusions:Current cost-lowering strategies are not enough to prevent households from incurring catastrophic out-of-pocket payments for TB *** and social protection interventions are needed for identified at-risk groups,and community-level interventions may reduce

关键词： Cost analysis Health policy Tuberculosis Regression analysis Nigeria

Theoretical study and optimization of a high power mid-infrared erbium-doped ZBLAN fibre laser

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Chinese Physics B 2011年第3期20卷 239-246页

作者：李剑峰 Stuart D.jackson School of Optoelectronic Information University of Electronic Science and Technology of China Institute of Photonics and Optical Science School of PhysicsUniversity of Sydney

Based on the rate equations describing the erbium-doped fluoride glass （ZBLAN） fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the dynamic population density and the operation performance of a high power mid-infrared all-fibre erbium-doped ZBLAN fibre laser. It shows that the ground-state absorption, excited-state absorption and energy-transfer-upconversion processes co-exist and produce a population balance, causing the laser to operate stably at a continuous wave state. A good agreement between the theoretical results and recent experimental measurement is obtained. Furthermore, the laser structure parameters including fibre length, reflectance of output fibre Bragg grating and pumping configurations are quantitatively optimised to achieve the best performance. The results show, as expected, that the slope efficiency of the fibre laser can be improved significantly through optimisation, which then provides an important guide for the design of high-performance mid-infrared erbium-doped ZBLAN fibre lasers.

关键词： Lerbium-doped fibre laser mid-infrared fibre laser ZBLAN fibre rate equations

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