检索结果-南通市图书馆

Journal of.Environmental Sciences 2012年第7期24卷 1240-1250页

作者： I. Ameur-b.uddab.ous J. Kasperek A. b.rb.er f. Harel b. Hannoyer GPM-UMR 6634 CNRS. Uf. Science and Technology University of Rouen BP 12 76801 Saint Etienne du Rouvray Cedex France LCAE Chemistry Department Science Faculty of Tunis Campus Universitaire 2092 El Manar Tunis Tunisie DIRNO Rue de Verdun 76160 Darnetal France

With regard to automotive traf.ic, a tunnel-type semi enclosed atmosphere is characterized b. a higher concentration of.gaseous pollutants than on urb.n traf.ic roads and highlights the gaseous ef.luent species having an impact on material degradation. Theref.re, a transverse approach b.tween air quality and its consequences upon the longevity of.materials is necessary, implying b.tter knowledge of.tunnel atmosphere and a b.tter understanding of.material degradation inside a tunnel f.r operating administration. Gaseous pollutant measurements carried out in a road tunnel in Rouen （Normandy） give the real world traf.ic concentrations of.experimental exposure conditions. The sampling campaigns, achieved in summer and winter include SO2, NO2, b.EX and aldehyde analyses. Ef.luent prof.les in the upward and downward tub.s have b.en estab.ished. The current work shows that SO2, NO〉 f.rmaldehyde, acetaldehyde, propanal and b.tanal must b. considered in the degradation process of.materials in a stuf.y environment. As regards NO,, its concentration depends on the modif.cation of.the automotive f.eet. The total aldehyde concentrations indicate no particular trend b.tween the two b.res. f.rmaldehyde, acetaldehyde, propanal, b.tanal and acrolein species are the most ab.ndant species emitted b. vehicles and represent 90% to 95% of.the total aldehyde emissions.

关键词： SO2 tunnel study aldehydes NO2 b.EX atmospheric corrosion

Non-Intrusive Elastic Query Processing in the Cloud

在线全文

学校读者我要写书评

暂无评论

Journal of.Computer Science & Technology 2013年第6期28卷 932-947页

作者： Ticiana L. Coelho da silva Mario A. Nascimento Jose Antonio f. de Macedo f.avio R. C. Sousa Javam C. Machado Department of.Computing Federal University of Ceara Fortaleza Ceara Brazil Department of.Computing Science University of Alberta Edmonton Alberta T6G 2E8 Canada

Cloud computing is a very promising paradigm of.service-oriented computing. One major b.nef.t of.cloud computing is its elasticity, i.e., the system＇s capacity to provide and remove resources automatically at runtime. f.r that, it is essential to design and implement an ef.icient and ef.ective technique that takes f.ll advantage of.the system＇s potential f.exib.lity. This paper presents a non-intrusive approach that monitors the perf.rmance of.relational datab.se management systems in a cloud inf.astructure, and automatically makes decisions to maximize the ef.iciency of.the provider＇s environment while still satisf.ing agreed upon ＂service level agreements＂（SLAs）. Our experiments conducted on Amazon＇s cloud inf.astructure, conf.rm that our technique is capab.e of.automatically and dynamically adjusting the system＇s allocated resources ob.erving the SLA.

关键词： elasticity query processing non-intrusive service level agreement

Novel therapeutic strategies targeting mitochondria as a gateway in neurodegeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第5期18卷 991-995页

作者： Diogo Trigo Jose Joao Vitoria Odete A.b.da Cruz e silva Neuroscience and Signalling Lab.ratory Institute of Biomedicine(iBiMED)Department of Medical SciencesUniversity of AveiroAveiroPortugal

In recent years, multiple disciplines have f.cused on mitochondrial b.ology and contrib.ted to understanding its relevance towards adult-onset neurodegenerative disorders. These are complex dynamic organelles that have a variety of.f.nctions in ensuring cellular health and homeostasis. The plethora of.mitochondrial f.nctionalities conf.rs them an intrinsic susceptib.lity to internal and external stressors(such as mutation accumulation or environmental toxins), particularly so in long-lived postmitotic cells such as neurons. Thus, it is reasonab.e to postulate an involvement of.mitochondria in aging-associated neurological disorders, notab.y neurodegenerative pathologies including Alzheimer’s disease and Parkinson’s disease. On the other hand, b.ological ef.ects resulting f.om neurodegeneration can in turn af.ect mitochondrial health and f.nction, promoting a f.edb.ck loop f.rther contrib.ting to the progression of.neuronal dysf.nction and cellular death. This review examines state-of.the-art knowledge, f.cus on current research exploring mitochondrial health as a contrib.ting f.ctor to neuroregeneration, and the development of.therapeutic approaches aimed at restoring mitochondrial homeostasis in a pathological setting.

关键词： Alzheimer’s disease axon energy homeostasis glymphatic system mitochondria mitostasis neurodegeneration neuroregeneration Parkinson’s disease therapeutical strategies

f.ctors af.ecting somatic emb.yogenesis in conif.rs

在线全文

学校读者我要写书评

暂无评论

Journal of.f.restry Research 2012年第4期23卷 503-515页

作者： Jaime A.Teixeira da silva Ravindra b.Malab.di f.culty of.Agriculture and Graduate School of.Agriculture Kagawa UniversityMiki-choIkenobe 2393Kagawa-ken761-0795Japan Division of.Plant b.otechnology Department of BotanyKarnatak UniversityPavate NagarDharwad-580003Karnataka StateIndia

This review seeks to examine the extreme response of.isolated somatic plant cells of.apical meristematic tissues of.mature conif.r trees towards specif.c stress conditions in vitro resulting in somatic emb.yo- genesis. Signal molecules regulating emb.yo development have b.en describ.d in angiosperms, b.t very little is known ab.ut somatic rejuve- nation in conif.rs. Recent studies on cloning of.mature conif.rs provide new perspectives on signal molecules on cellular dedif.erentiation into the emb.yogenic pathway. Our recent studies show that signal molecules such as b.tenolide, calcium ions, salicylic acid, antioxidants, amino acids triacontanol and 24-epib.assinolide all play an important role in the con- version of.somatic cells into an emb.yogenic pathway in many recalcitrant pines. This constitutes a major b.eakthrough in f.rest b.otechnology with many practical applications in clonal f.restry.

关键词： cloning commercial f.restry in vitro micropropagation thin cell layers

Seasonal Ab.ndance and Diversity of.b.rds of.Prey and Owls in Al Wathb. Wetland Reserve in Ab. Dhab., UAE

在线全文

学校读者我要写书评

暂无评论

Open Journal of.Ecology 2024年第3期14卷 228-244页

作者： Shakeel Ahmed Salim Jáved Shahid b. Khan Eissa Al Hammadi Ab.ullah Al Hammadi Nouf.Sameer Alqadi Environment Agency-Ab. Dhab. Abu Dhabi United Arab Emirates

Inland wetlands in Ab. Dhab. Emirate are wintering and stopover sites f.r migratory b.rds of.prey. We conducted long-term regular monitoring surveys in Al Wathb. Wetland Reserve (AWWR) f.om January 1995 to Decemb.r 2022. b.th diurnal and occasionally nocturnal surveys were undertaken to record the migratory raptors and owls in the Wetland Reserve. During the study, a total of.1282 regular monitoring visits were undertaken and 27 species of.diurnal raptors and owls representing f.ve f.milies and three orders were detected. These represent 57% of.the total species of.b.rds of.prey recorded in the UAE. Overall, 63% of.all the species that we ob.erved were Accipitrif.rmes f.llowed b. 26% f.lconif.rmes and 11% Strigif.rmes. We f.und that changes in mean daily temperature have a positive ef.ect on raptor species diversity and ab.ndance in the Wetland Reserve. The species encounter rate was higher in low temperature as compared to high temperature and overall regression equation was statistically signif.cant f.(4, 1126) = 8.49), p = 0.00). However, the numb.rs of.raptors did not vary signif.cantly across the years (p = 0.51). Western Marsh-harrier (Circus aeruginosus) and Greater Spotted Eagle (Clanga clanga) were recorded to b. the most ab.ndant species in the wetland reserve f.llowed b. Common Kestrel (f.lco tinnunculus). However, the encounter rate of.glob.lly threatened Greater Spotted Eagle was detected to have signif.cantly decreased since 2016. Moreover, 63% of.the species detected were uncommon and rarely recorded such as 1) Saker f.lcon 2) Lanner f.lcon 3) Long-eared Owl & Merlin, which were the rare records f.om the wetland reserve. f.rthermore, 27 years of.regular monitoring in the wetland have yielded diverse diurnal raptors and owl f.una (H) = 0.83, (E) = 1.43 (Shannon Diversity Index). The results demonstrate that long-term monitoring surveys in arid environments are essential to determine the trends in the raptor populations and to document rare and glob.lly

关键词： Wetland Reserve Raptors Ab.ndance Diversity Ab. Dhab. Inland Wetland AWWR Greater Spotted Eagle

Evaluation of.stress intensity f.ctors f.r b.-material interf.ce cracks using displacement jump methods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2017年第6期33卷 1051-1064页

作者： K. C. Nehar b. E. Hachi f. Cazes M. Hab.ussi Lab.ratoire de développement en mécanique et matériaux (LDMM) Université de Djelfa PB 3117 Djelfa Algeria Lab.ratoire des Sciences des Procédés et des Matériaux (LSPM) UPR 3407 CNRS Université Paris 13 Paris France

The aim of.the present work is to investigate the numerical modeling of.interf.cial cracks that may appear at the interf.ce b.tween two isotropic elastic materials. The extended f.nite element method is employed to analyze b.ittle and b.-material interf.cial f.tigue crack growth b. computing the mixed mode stress intensity f.ctors(SIf.. Three dif.erent approaches are introduced to compute the SIf.. In the f.rst one, mixed mode SIf.is deduced f.om the computation of.the contour integral as per the classical J-integral method,whereas a displacement method is used to evaluate the SIf.b. using either one or two displacement jumps located along the crack path in the second and third approaches. The displacement jump method is rather classical f.r mono-materials,b.t has to our knowledge not b.en used up to now f.r a b.material. Hence, use of.displacement jump f.r characterizing b.-material cracks constitutes the main contrib.tion of.the present study. Several b.nchmark tests including parametric studies are perf.rmed to show the ef.ectiveness of.these computational methodologies f.r SIf.considering static and f.tigue prob.ems of.b.-material structures. It is f.und that results b.sed on the displacement jump methods are in a very good agreement with those of.exact solutions, such as f.r the J-integral method, b.t with a larger domain of.applicab.lity and a b.tter numerical ef.iciency(less time consuming and less spurious b.undary ef.ect).

关键词： b.-material interf.ce crack Mixed mode stress intensity f.ctor Displacement jump X-f.M f.tigue crack growth

Can Quick Release Experiments Reveal the Muscle Structure？ A b.onic Approach

在线全文

学校读者我要写书评

暂无评论

Journal of.b.onic Engineering 2012年第2期9卷 211-223页

作者： D. f. b. Haeuf.e M. Gunther R. b.ickhan S. Schmitt Institute of.Sports and Exercise-Science University of Stuttgart Allmandring 28 D-70569 Stuttgart Germany Stuttgart Research Centre f.r Simulation Technology （SRC SimTech） University of Stuttgart Pfaffenwaldring 7a D-70569 Stuttgart Germany Institute of.Motion Science Friedrich-Schiller-University Seidelstraβe 20 D-07749 Jena Germany

The goal of.this study was to understand the macroscopic mechanical structure and f.nction of.b.ological muscle with respect to its dynamic role in the contraction. A recently pub.ished muscle model, deriving the hyperb.lic f.rce-velocity relation f.om f.rst-order mechanical principles, predicts dif.erent f.rce-velocity operating points f.r dif.erent load situations. With a new approach, this model could b. simplif.ed and thus, transf.rred into a numerical simulation and a hardware experiment. Two types of.quick release experiments were perf.rmed in simulation and with the hardware setup, which represent two extreme cases of.the contraction dynamics： against a constant f.rce （isotonic） and against an inertial mass. b.th experiments revealed hyperb.lic or hyperb.lic-like f.rce-velocity relations. Interestingly, the analytical model not only predicts these extreme cases, b.t also additionally all contraction states in b.tween. It was possib.e to validate these predictions with the numerical model and the hardware experiment. These results prove that the origin of.the hyperb.lic f.rce-velocity relation can b. mechanically explained on a macroscopic level b. the dynamical interaction of.three mechanical elements. The implications f.r the interpretation of.b.ological muscle experiments and the realization of.muscle-like b.onic actuators are discussed.

关键词： f.rce-velocity relation isotonic quick release proof.of.concept artif.cial muscle

The prostate of.weaned pups is altered b. maternal malnutrition during lactation in rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of.Andrology 2010年第2期12卷 180-185页

作者： Cristiane da f. Ramos Marcio A. b.b.nski Waldemar S. Costa f.ancisco J.b. Sampaio Urogenital Research Unit State University of Rio de Janeiro UERJ Rio de Janeiro 20551-030 Brazil

The aim of.this study was to evaluate the ef.ects of.maternal malnutrition during lactation on prostate growth and estradiol serum concentration in the prostate of.pups. At delivery,nine Wistar rats were separated into three groups：control group （C） with f.ee access to a standard lab.ratory diet containing 22% protein;protein-energyrestricted group （PER） with f.ee access to an isoenergy and protein-restricted diet containing 8% protein;and energyrestricted group （ER） receiving standard lab.ratory diet in restricted quantities,which were calculated according to the mean ingestion of.the PER group. All pups were killed at weaning. PER and ER groups presented a signif.cant reduction in estradiol serum concentration （C = 73.8±4.6,PER=48.7±3.2,ER = 59.7±5.5 pg mL^-1,P〈0.01）,total prostatic acini （C = 24 190.0±716.5,PER = 20 290.0±631.4,ER=19 550.0±759.1 μm^2;P〈0.01）,lumen of.the prostatic acini （C = 5 590.0±165.4,PER = 3 776.0±251.3,ER = 4 658.0±198.1 μm^2;P〈0.01） and epithelial area of.the prostate dorsal lob. （C=18 120.0±391.4,PER=16 520.0±799.2,ER = 14 890.0±589.8 μm^2;P〈0.01）.Testosterone concentration was signif.cantly increased only in the PER group when compared with the C group （C = 0.09±0.01,PER = 0.44±0.04,ER=0.15±0.03 ng mL^-1,P〈0.001）. An adequate nutritional state in early lif. is important f.r normal growth of.the prostate gland,which seem to b. related to serum levels of.estradiol.

关键词： estrogen receptors growth and development histology malnutrition prostate rats

Comb.ned Ef.ect of.Dissipation and Thermal Mixed State on Entanglement in the Dispersive Limit

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2008年第3期25卷 949-952页

作者： Ob.da A. -S. f. HESSIAN H. A. MOHAMED A. -b. A. f.culty of.Science Al-Azhar University Nasr City Cairo Egypt f.culty of.Science Assiut University Assiut Egypt

We investigate the entanglement in the interacting system of.a single mode thermal f.eld and a single qub.t with dissipation in the dispersive limit. The inf.uence of.initial temperature of.thermal f.eld and atoms on ... 详细信息

关键词： JAYNES-CUMMINGS MODEL QUANTUM-MECHANICS CURRENT SITUATION 2-LEVEL ATOM DECOHERENCE f.ELD GENERATION DYNAMICS ENTROPY APPROXIMATION

Modelling of.the elastoplastic b.haviour of.the b.o-cemented soils using an extended Modif.ed Cam Clay model

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.Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2184-2197页

作者： Xuerui Wang Christian b.Silb.rmann Thomas Nagel Udo Nackenhorst Institute of.Mechanics and Computational Mechanics Leibniz UniversitätHannoverAppelstr.9aHannover30167Germany Gesellschaf. f.r Anlagen-und Reaktorsicherheit(GRS)gGmb. Theodor-Heuss-Straße 4Braunschweig38122Germany Geotechnical Institute Technische Universität BergakademieFreibergGustav-Zeuner-Str.1Freiberg09599Germany

An elastoplastic constitutive model b.sed on the Modif.ed Cam Clay(MCC)model is developed to describ. the mechanical b.haviour of.soils cemented via microb.ally induced calcite precipitation(MICP).It considers the increase of.the elastic stif.ness,the change of.the yield surf.ce due to MICP cementation and the degradation of.calcium carb.nate b.nds during ***,to capture the typical contraction-dilation transition in MICP soils,the original volumetric hardening rule in the MCC model is modif.ed to a comb.ned deviatoric and volumetric hardening *** model could reproduce a series of.drained triaxial tests on MICP-treated soils with dif.erent calcium carb.nate ***,we carry out a parametric study and ob.erve numerical instab.lity in some *** comb.nation with an analytical analysis,our numerical modelling has identif.ed the b.nef.ts and limitations of.using MCCb.sed models in the simulation of.MICP-cemented soils,leading to suggestions f.r f.rther model development.

关键词： Microb.ally induced calcite precipitation(MICP) Elastoplasticity Modif.ed cam clay(MCC) OpenGeoSys Mf.ont Contraction-dilation transition