检索结果-南通市图书馆

Defence Technology（防务技术） 2018年第3期14卷 238-249页

作者： edison e.haro Jerzy A.Szpunar Akindele G.Odeshi Department of Mechanical engineering University of Saskatchewan

The mechanical behavior of chonta palm wood(Bactris gasipaes) microparticles reinforced high density polyethylene(HDPe) under high strain-rate compressive and ballistic impact loading were *** palm wood microparticles were introduced into the HDPe via an extrusion process using parallel twin screw extruder to produce biocomposite containing 10, 20, 25, and 30 wt % chonta wood microparticles. In addition to mechanical tests, fractographic analysis was done to understand the failure mechanism in the biocomposites under dynamic and ballistic impact loads. The results indicate that both quasi-static and dynamic mechanical properties of HDPe are enhanced by reinforcement with chonta palm wood particles. The biocomposites containing 25 wt % wood microparticles exhibited the highest strength, stiffness, ballistic impact resistance and impact energy absorption capability. Introduction of microparticles of chonta palm wood as reinforcement into a polymeric matrix such as HDPe is therefore a promising method to develop biocomposites with enhanced capacity to withstand dynamic impact loading and absorb impact energy.

关键词： HDPe 弹道行为盔甲机械测试吸收能力密度聚乙烯挤出过程

Accelerated Gradient Descent Methods for the Uniaxially Constrained Landau-de Gennes Model

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2022年第1期14卷 1-32页

作者： edison e.Chukwuemeka Shawn W.Walker Department of Mechanical engineering Louisiana State UniversityBaton RougeLA 70803USA Department of Mathematics and Center for Computation and Technology(CCT) Louisiana State UniversityBaton RougeLA 70803USA

This paper illustrates the efficacy of using accelerated gradient descent schemes for minimizing a uniaxially constrained Landau-de Gennes model for nematic liquid ***(alternating direction)minimization schemes are applied to a structure preserving finite element discretization of the uniaxial model:a standard gradient descent method,the“heavy-ball”method,and Nesterov’s *** performance of the schemes is measured in terms of the number of iterations required to obtain the equilibrium state,as well as the total computational time(wall time).The numerical experiments clearly show that the accelerated gradient descent schemes reduce the number of iterations and computational time significantly,despite the hard uniaxial constraint that is not“smooth”when defects are ***,our results show that accelerated schemes are not hindered when combined with an alternating direction minimization algorithm and are easy to implement.

关键词： Liquid crystals Landau-de Gennes uniaxial heavy-ball method Nesterov’s method

Comparative analysis of extreme ultraviolet solar radiation proxies during minimum activity levels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

earth and Planetary Physics 2023年第5期7卷 540-547页

作者： A.G.elias C.R.Martinis B.F.de.haro Barbas F.D.Medina B.S.Zossi M.Fagre T.Duran Laboratorio de Ionosfera Atmosfera Neutra y MagnetosferaFacultad de Ciencias Exactas y Tecnologia(FACET)Universidad Nacional de Tucuman(UNT)Tucuman 4000Argentina Instituto de Física del Noroeste Argentino Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET)-UNTTucuman 4000Argentina Center for Space Physics Astronomy DepartmentBoston UniversityMA 02215USA CONICeT Tucuman 4000Argentina Laboratorio de Telecomunicaciones Departamento de ElectricidadElectrónica y ComputaciónFACETUNTTucuman4000Argentina Departamento de Física Universidad Nacional del Sur(UNS)Bahia Blanca 8000Argentina Instituto de Física del Sur CONICET-UNSBahia Blanca 8000Argentina

Four extreme ultraviolet(eUV)solar radiation proxies(Magnesium II core-to-wing ratio(MgII),Lymanαflux(Fα),10.7-cm solar radio flux(F10.7),and sunspot number(Rz))were analyzed during the last four consecutive solar activity minima to investigate how they differ during minimum periods and how well they represent solar eUV *** variability within each minimum and between minima was compared by considering monthly means.A comparison was also made of their role in filtering the effect of solar activity from the critical frequency of the ionospheric F2 layer,foF2,which at mid to low latitudes depends mainly on eUV solar *** last two solar cycles showed unusually low eUV radiation levels according to the four *** the connection between the eUV“true”variation and that of solar proxies,according to the foF2 filtering analysis,MgII and Fαbehaved in a more stable and suitable way,whereas Rz and F10.7 could be overestimating eUV levels during the last two minima,implying they would both underestimate the inter-minima difference of eUV when compared with the first two minima.

关键词： solar eUV radiation solar minimum foF2 solar activity solar eUV proxy

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

废旧石墨回收及其储能应用的研究进展

新型炭材料(中英文) 2023年第5期38卷 787-803页

作者：王继锐杨大海徐义俭侯香龙 edison Huixiang Ang 王德钊张乐朱振东冯绪勇宋晓辉项宏发合肥工业大学材料科学与工程学院安徽合肥230009 Natural Sciences and Science education National Institute of EducationNanyang Technological University 637616Singapore 合肥国轩高科动力能源有限公司安徽合肥230012 合肥工业大学智能制造技术研究院安徽合肥230051

本文对从废旧锂离子电池中获得的电池级石墨的回收和再生进行了广泛的分析。其主要目的是应对供需挑战,最大限度地减少环境污染。该综述主要包括获得、分离、纯化和再生废石墨的方法,以确保其可适用于高质量的储能为目的。为了提高石墨... 详细信息

本文对从废旧锂离子电池中获得的电池级石墨的回收和再生进行了广泛的分析。其主要目的是应对供需挑战,最大限度地减少环境污染。该综述主要包括获得、分离、纯化和再生废石墨的方法,以确保其可适用于高质量的储能为目的。为了提高石墨回收效率和去除残留污染物,研究者们探索了热处理、溶剂溶解和超声波处理等技术。本综述进一步评估了湿法和火法冶金的净化和再生方法,考虑了它们对环境的影响和能源消耗等问题。为了可持续和成本效益的提高,可以采用无酸纯化和低温石墨化。讨论了锂离子电池和超级电容器中再生石墨的具体要求,强调了包括酸浸、高温处理和表面涂层在内的回收工艺。这篇综述为开发高效和可持续的储能系统、解决环境问题和满足日益增长的石墨需求提供了宝贵的信息。

关键词：废旧石墨锂离子电池再生负极再利用

Annulohypoxylon stygium,a Pandanus simplex-associated fungal endophyte withα-glucosidase inhibitory activity

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Studies in Fungi 2022年第1期7卷 38-43页

作者： Roberth Riggs L.Rondilla Thomas edison e.dela Cruz Fang-Rong Chang Maribel G.Nonato The Graduate School University of Santo TomasEspaña Blvd.1015 ManilaPhilippines Research Center for the Natural and Applied Sciences University of Santo TomasEspaña Blvd.1015 ManilaPhilippines Department of Biological Sciences College of ScienceUniversity of Santo TomasEspaña Blvd.1015 ManilaPhilippines Department of Chemistry College of ScienceUniversity of Santo TomasEspaña Blvd.1015 ManilaPhilippines Graduate Institute of Natural Products College of PharmacyKaohsiung Medical UniversityKaohsiungTaiwan Department of Mathematics and Natural Sciences College of Arts and SciencesSouthern Luzon State UniversityLucban 4328 QuezonPhilippines

Fungal endophytes offer structurally diverse and unique secondary metabolites with interesting biological *** reports have shown the potential of fungal endophytes as sources ofα-glucosidase inhibitors to alleviate *** this study,the fungal endophyte Annulohypoxylon stygium(Xylariales,Ascomycota)was identified for the first time from the leaves of the endemic tropical plant,Pandanus simplex *** extract was obtained by fermenting the fungal endophyte in Potato Dextrose Broth for 30 days at room *** *** crude extract exhibited good inhibition to theα-glucosidase enzyme with an IC_(50) of 31.88±2.86μg/*** of the crude extract afforded 8-methoxynaphthol with an IC_(50) value of 676.3±1.03μg/*** isolation of 8-methoxynaphthol from *** is reported herein for the first *** study highlights the ability of *** to produce metabolites that may be useful as antidiabetic drugs.

关键词： temperature xylon Panda

Shea Tree State of Settlement According to the Cropping Systems in Burkina Faso [Rural Commune of Komki-Ipala (Tampoussoumdi)]

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2021年第4期12卷 635-644页

作者： Kadidia Semdé Hadou haro Souleymane Ganaba Irénée Somda Microbiology Laboratory Environment and Forests Department Environment and Agricultural Research Institute Ouagadougou Burkina Faso University of Nazi Boni Bobo-Dioulasso Burkina Faso environment and Forests Department Environment and Agricultural Research Institute Ouagadougou Burkina Faso

This study was to assess the effect of bush fires and human actions on the settlement status of the shea tree in cropping systems. It was carried out using three farming systems as treatments in which randomized plots were set. Thus, dendrometric data were collected from the shea trees. The sampling concerned twelve plots of 0.5 ha (100 m × 50 m) each and the number of adults of shea trees and that of the regeneration per plot was recorded. Forty-five (45) species divided into 20 families and 36 genera have been identified, with a decreasing number ranging from unburned fallow to fieldse="font-family:Verdana;"> through burnt fallow. From these results, it emerges that the young shea plants are predominant in the unburned fallow. The mapping using geographic coordinates showed that the shea tree gradually aggregated in the fallows with a higher density. Actions must then be taken to support farmers in the domestication and protection of the shea tree for its effective conservation in cropping systems.

关键词： Agrosystem Burkina Faso Dynamics Shea’s Tree

Cold adaptation does not alter ATP homeostasis during cold exposure in Drosophila melanogaster

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2018年第4期13卷 471-481页

作者： Caroline M.WILLIAMS James R.ROCCA Arthur S.edison David B.ALLISON Theodore J.MORGAN Daniel A.HAHN Department of Integrative Biology University of CaliforniaBerkeleyCaliforniaUSA Departments of entomology and Nematology University of FloridaGainesvilleFloridaUSA Biochemistry University of FloridaGainesvilleFloridaUSA Advanced Magnetic Resonance Imaging and Spectroscopy Facility McKnight Brain InstituteUniversity of FloridaGainesvilleFloridaUSA Departments of Genetics and Biochemistry Complex Carbohydrate Research CenterUniversity of GeorgiaAthensGeorgiaUSA Department of epidemiology and Biostatistics School of Public HealthIndiana University BloomingtonBloomingtonIndianaUSA Division of Biology Kansas State UniversityManhattanKansasUSA

In insects and other ectotherms,cold temperatures cause a coma resulting from loss of neuromuscular function,during which ionic and metabolic homeostasis are progressively *** adaptation improves homeostasis during cold exposure,but the ultimate targets of selection are still an open *** acclimation and adaptation remodels mitochondrial metabolism in insects,suggesting that aerobic energy production during cold exposure could be a target of ***,we test the hypothesis that cold adaptation improves the ability to maintain rates of aerobic energy production during cold exposure by using^(31)P NMR on live *** lines of Drosophila melanogaster artificially selected for fast and slow recovery from a cold coma,we show that cold exposure does not lower ATP levels and that cold adaptation does not alter aerobic ATP production during cold ***-hardy and cold-susceptible lines both experienced a brief transition to anaerobic metabolism during cooling,but this was rapidly reversed during cold exposure,suggesting that oxidative phosphorylation was sufficient to meet energy demands below the critical thermal minimum,even in cold-susceptible *** thus reject the hypothesis that performance under mild low temperatures is set by aerobic ATP supply limitations in ***,excluding oxygen and capacity limitation as a weak link in energy *** work suggests that the modulations to mitochondrial metabolism resulting from cold acclimation or adaptation may arise from selection on a biosynthetic product(s)of those pathways rather than selection on ATP supply during cold exposure.

关键词： chill coma energetics insect oxygen limitation thermal tolerance

Studying Tuff Rings and Volcanic Hazards in a Tropical Setting: The Case of the Batoke Tuff Ring, Limbe, SW Region Cameroon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Geology 2023年第8期13卷 883-899页

作者： George Teke Mafany edison Forbuck Njei Gerald G. J. ernst Wilson Yetoh Fantong Cheo emmanue Suh Samuel Ndonwi Ayonghe Robert Stephen John Sparks Koffi Teke Mafany Stephen Manga Njome Institute of Geological and Mining Research Yaoundé Cameroon Department of Geology University of Buea Buea Cameroon Department of Geology University of Bamenda Bamenda Cameroon Department of Geology and Soil Science University of Ghent Ghent Belgium Department of earth Sciences University of Bristol Bristol UK Department of earth & Space/Physics Cypress Springs High School Houston USA

In subtropical volcanic environments, there are often few accessible outcrops. These are often highly weathered and of very poor quality. Soil development is rapid (1 cm/y) and small eruptions are unlikely to be preserved in the geological record. Reconstructing past eruptions and assessing hazards is a challenge. Here, we studied a poorly outcropping tuff ring (very poor, incomplete sections) with the best outcrop observed at a beach cliff (up to ca. 5 - 10 m high) at Batoke, to the south of Mt Cameroon volcano. Mt Cameroon has a few tuff rings, currently of unknown ages, near the SW coast of Cameroon. In the Batoke case, the sequence is dominated by gently dipping tuff beds varying in the proportion of lithics, juvenile clasts, and accretionary lapilli (acc-laps). Several beds are close-packed with acc-laps of up to 10 - 15 mm diameter. Part of the section is gullied by mud flow deposits. The rocks are highly weathered but differential weathering enhances relationships. Quantitative data can be extracted from a detailed study of outcrops’ external surfaces. The preserved section is close to where the deposits were initially thickest and where acc-laps were most abundant and largest. There is an empirical correlation between maximum acc-lap size in the thickest outcrop and eruption column height. This and the deposit features suggest that the Batoke eruption was pulsating but dominated by fallout, with a water and ice-rich eruption column reaching 10 - 15 km high. Recycling of water drops and ice-coated fine ash accumulated during eruption. At switch off, wholesale gravitational collapse of this material produced the mud flows, which gullied the previously-laid down deposits. Such ash fall and mud flows can represent a substantial hazard, e.g. they can gully down through towns and roads and cut evacuation routes. This study illustrates how, at subtropical tuff rings, it is possible to extract key data needed for hazard assessment from only 1 - 2 poor outcrops.

关键词： Batoke Tuff Ring (BTR) Accretionary Lapilli

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

费德勒男人三十五依旧阳光下

网球大师 2017年第5期 28-31页

作者： edison

拿下澳网冠军后，费德勒并未打算就此“收手”。转眼间，“阳光双冠”又第三次被瑞士人收入囊中。35岁，对费德勒来说并不是终点，如今的他依旧在最美好的阳光下。

关键词：费德勒阳光男人瑞士人冠军澳网

Frequency and severity of OSAHS in Mexican adolescents. The role of BMI and neck circumference

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health 2013年第8期5卷 1-8页

作者： Armando Partida-Gaytán Arturo Berber Blanca estela del Río-Navarro Reyes haro-Valencia Chief of Sleep Breathing Disorders Clinic Universidad Nacional Autónoma de México Hospital General de México Secretaria de Salud Distrito Federal México Departamento de Alergia e Inmunología Clínica Pediátrica Hospital Infantil de México Federico Gómez Instituto Nacional de Salud Secretaria de Salud Distrito Federal México

Background: Overweight and obesity are major public-health issues in Mexico. Sleep breathing disorders directly impact the health of affected subjects. The aim of this study was to describe the frequency and severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) in Mexican adolescents grouped by weight status. Secondary objectives were to describe the influence of body mass index (BMI) and neck circumference (NC) as predictive factors of OSAH. Method: Somatometric, demographic data and full-night polysomnography were done. Linear and logistic regression models described the relationship between BMI and NC with OSAHS presence and severity. Receiver-Operating-Characteristics (ROC) curves showed different sensitivity and specificity performances of BMI and NC cutoff-values. Results: OSAHS frequency and severity were significantly greater in obese and extremely-obese adolescents (8% vs 22% vs 67%;p ear regression showed an AHI increase of 0.940 events/hour for every centimeter-increase in NC and 0.696 events/hour for every1 kg/m2-increase in BMI. Logistic-regression showed extreme-obesity as the main risk factor (OR 9.9) for diagnosis of OSAHS. ROC curves showed an area under the curve (AUC) of 0.83 for BMI defined cutoff-values, and of 0.80 for BMI percentile-for-age cutoff-values. The AUC of NC ROC curve was 0.8043. Conclusion: This is the largest study made on Latin-American population evaluating the frequency and severity of OSAHS with full-night polysomnography. We showed that obese and extremely-obese Mexican-adolescents are at highest risk for OSAHS. Increasing BMI and NC showed positive correlation with AHI. Different BMI cut-off values showed similar diagnostic performance. extreme-obesity increases 8 times the risk association for OSAHS.

关键词： Obesity Obstructive Sleep Apnea Hyopopnea Syndrome (OSAHS) Obstructive Sleep Apnea Sleep Apnea Syndromes Polysomnography Body Mass Index (BMI) Neck Circumference Adolescents