检索结果-南通市图书馆

sports medicine and Health science 2022年第1期4卷 1-7页

作者： Fernando A.m.s.Pompeu The Physical Education Graduate Program Rio de Janeiro Federal UniversityRio de JaneiroUFRJBrazil

An important epistemological problem has been faced by Exercise *** one hand,one theory explains the fatigue through a ceiling effect of oxygen *** the other hand,the new theory proposes that an encephalon mechanism would stop the effort before a catastrophic homeostasis *** physiologists have looked for evidence to support their favourite theory even though the induction logic problem does not allow to prove whether truth is discovered;however,it is possible to prove that it does not *** some researchers fail to test their hypotheses,they use relativism to bring up their theories *** and his colleagues have based their theory on relativism,because it is impossible to refute by empirical *** also doesn't explain all phenomena that the oldest Hill's theory is able to ***'s theory isn't more accurate in its *** did not check whether the oxygen uptake plateau occurs in suitable tests to measure on the mouth what happens in the ***,it doesn't propose new tests for the encephalon role during maximal effort,as that is expected in scientific *** all of these reasons,it is possible to conclude there are no advantages in switching to the“Central Governor”theory.

关键词： Epistemological problem VO_(2)plateau Positivism scientific revolutions and philosophy of science

Experimental and numerical analysis on suitability of s-Glass-Carbon fiber reinforced polymer composites for submarine hull

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

Defence Technology（防务技术） 2023年第1期19卷 1-11页

作者： Elango Natarajan Lídio Inacio Freitas m.s.santhosh Kalaimani markandan Ammar Abdulaziz majeed Al-Talib C.s.Hassan Faculty of Engineering Technology and Built EnvironmentUCSI UniversityKuala LumpurMalaysia Dili Institute of Technology DiliTimor-Leste selvam Composite materials Research Laboratory Department of Mechanical EngineeringSelvam College of TechnologyTamil NaduIndia

suitability of s-Glass/carbon fiber reinforced polymer composite for submarine hull subjected to hydrostatic pressure has been investigated in the present *** materials have raised concerns owing to their decomposition due to low resistance towards salinity and hence polymer composites have been explored to showcase their mechanical stability to withstand transverse and impact *** this end,the mechanical properties of s-Glass/carbon fiber reinforced polymer composite were experimentally investigated and higher specific strength and stiffness of the composite in comparison to many metallic materials used for submarine hull were *** obtained experimental values were used for the static and dynamic crash analysis of the bow,stern and foil through Finite Element Analysis(FEA);where depth of travel was varied from sea surface level of 0-7000 *** assembly was later developed with the optimum shape and thickness of each *** also report the nonlinear crash analysis upon impact at velocity ranging from 3 to 21 m/***,kinetic energy,acceleration peak and internal energy in struck submarine revealed that travel depth 1750 m and 3500 m is recommendable,more particularly,crash safety factor of the submarine is found to be within limit when submarine encounters crash at 1750 m.

关键词： Crash Impact Design submarine Hull Bow stern Foil

Daily variation of radon gas and its short-lived progeny concentration near ground level and estimation of aerosol residence time

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第5期25卷 111-118页

作者： m mohery A m Abdallah A Ali s s Baz Physics Department Faculty of Science University of Jeddah Physics Department Faculty of Science Sohag University Astronomy Department Faculty of Science King Abdulaziz University Astronomy Department Faculty of Science Cairo University Physics Department Girls Faculty of Science King Abdulaziz University

Atmospheric concentrations of radon（^（222）Rn） gas and its short-lived progenies^（218）Po,^（214）Pb, and^（214）Po were continuously monitored every four hours at the ground level in Jeddah city, Kingdom of saudi Arabia. The measurements were performed three times every week, starting from November 2014 to October 2015. A method of electrostatic precipitation of positively charged^（218）Po and ^（214）Po by a positive voltage was applied for determining^（222）Rn gas concentration. The short-lived^（222）Rn progeny concentration was determined by using a filter holder connected with the alpha-spectrometric technique. The meteorological parameters（relative air humidity, air temperature, and wind speed） were determined during the measurements of^（222）Rn and its progeny concentrations.^（222）Rn gas as well as its short-lived progeny concentration display a daily and seasonal variation with high values in the night and early morning hours as compared to low values at noon and in the afternoon. The observed monthly atmospheric concentrations showed a seasonal trend with the highest values in the autumn/winter season and the lowest values in the spring/summer season. moreover, and in parallel with alphaspectrometric measurements, a single filter-holder was used to collect air samples. The deposited activities of^（214）Pb and the long-lived^（222）Rn daughter ^（210）Pb on the filter were measured with the gamma spectrometric technique. The measured activity concentrations of^（214）Pb by both techniques were found to be relatively equal largely. The highest mean seasonally activity concentrations of ^（210）Pb were observed in the autumn/winter season while the lowest mean were observed in the spring/summer season. The mean residence time（mRT） of aerosol particles in the atmospheric air could be estimated from the activity ratios of ^（210）Pb/^（214）Pb.

关键词： daily variation radon progeny concentration meteorological variables

Effect of Colouring Process on Pitting susceptibility of Austenitic stainless steel

在线全文

学校读者我要写书评

暂无评论

Journal of materials science & Technology 2008年第3期24卷 400-406页

作者： s.s.mahmoud m.m.Ahmed Chemistry Department University College of Girls for ArtsScience and EducationAin Shams University

Colouring of the austenitic stainless steel alloy （20.45% Cr, 8.57% Ni） was carried out in NaNO3-KNO3 eutectic melt without and with additions of Na2O2, NaCl and their mixtures at different temperatures ranging from 400-600℃, under open-circuit and galvanostatic anodic polarization conditions. The produced colours greatly depend on the thickness of oxide films, which in turn depends on the composition of the molten bath and its temperature. The more attractive, bright, adherent and uniform coloured oxide films can be obtained at 400, 450 and 500℃ in molten nitrate bath containing NaCl and Na2O2 mixtures. The pitting corrosion susceptibility of the coloured oxide films was tested in FeCl3 and NaCl as corrosive media. The obtained results indicate that the pitting corrosion susceptibility of the coloured oxide films greatly depends on the previous operating conditions of the colouring process of the stainless steel specimens such as the composition of molten bath, temperature and technique of colouring process.

关键词： stainless steel alloy Pitting corrosion Colouring processes

Vascular endothelial growth factor:a double-edged sword in the development of white matter lesions

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第1期20卷 191-192页

作者： Narek manukjan Daniel Fulton Zubair Ahmed Wmatthijs Blankesteijn sébastien Foulquier Department of Pharmacology and Toxicology Maastricht UniversityMaastrichtThe Netherlands CARIm-school for Cardiovascular Diseases Maastricht UniversityMaastrichtThe Netherlands Neuroscience and Ophthalmology Institute of Inflammation and AgeingUniversity of BirminghamEdgbastonBirminghamUK Centre for Trauma sciences Research University of BirminghamEdgbastonBirminghamUK mHeNs-school for mental Health and Neuroscience Maastricht UniversityMaastrichtThe Netherlands Department of Neurology Maastricht University Medical CenterMaastrichtThe Netherlands

As the population ages,the burden of age-related diseases becomes ***,over 55 million people suffer from dementia worldwide,with Alzheimer’s disease being the most common ***,it is becoming clearer that underlying vascular pathology such as cerebral small vessel disease(csVD)may be a more detrimental cause for dementia(Cuadrado-Godia et al.,2018).It is estimated that 10%-30%of the elderly population and 35%-90%of all dementia patients exhibit signs of *** term csVD refers to pathology affecting the small vessels of the brain,which can lead to lacunar cerebral infarcts,enlarged perivascular spaces,and cortical hemorrhages(Cuadrado-Godia et al.,2018).CsVD is often associated with cognitive decline,gait problems,and dementia(Cuadrado-Godia et al.,2018).

关键词： pathology becoming white

Cohomogeneity One de sitter space s1 n

在线全文

学校读者我要写书评

暂无评论

Acta mathematica sinica,English series 2010年第10期26卷 1915-1926页

作者： P.AHmADI s.m.B.KAsHANI H.ABEDI Department of Pure mathematics Faculty of Mathematical SciencesTarbiat Modares University Group of mathematics School of Sciences Bu-Ali Sina University

In this paper we study the cohomogeneity one de sitter space s1 n. We consider the actions in both proper and non-proper cases. In the first case we characterize the acting groups and orbits and we prove that the orbit space is homeomorphic to R. In the latter case we determine the groups and consequently the orbits in some different cases and prove that the orbit space is not Hausdorff.

关键词： Cohomogeneity one Lorentzian space de sitter space

Quantum pseudodots under the influence of external vector and scalar fields

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第8期27卷 109-117页

作者： m Eshghi s m Ikhdairt Department of Physics Imam Hossein Comprehensive UniversityTehranIran Department of Physics Faculty of ScienceAn-Najah National UniversityNablusPalestine Department of Electrical Engineering Near East UniversityNicosiaNorthern CyprusMersin 10Turkey

We study the spherical quantum pseudodots in the schr6dinger equation by using the pseudo-harmonic plus harmonic oscillator potentials considering the effect of the external electric and magnetic fields. The finite energy levels and the wave functions are calculated. Furthermore, the behavior of the essential thermodynamic quantities such as, the free energy, the mean energy, the entropy, the specific heat, the magnetization, the magnetic susceptibility, and the persistent currents are also studied by using the characteristic function. Our analytical results are found to be in good agreement with the other works. The numerical results on the energy levels as well as the thermodynamic quantities have also been given.

关键词： schr6dinger equation harmonic oscillator pseudo-harmonic potential thermodynamic quantities quantum pseudo-dots characteristic function

C-phycocyanin shows neuroprotective effect against rotenone-induced Parkinson’s disease in mice

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2024年第7期14卷 279-287页

作者： Hritik Rathod Ritu m.soni Jigna s.shah Department of Pharmacology Institute of Pharmacy Nirma UniversityAhmedabadGujaratIndia

Objective:To investigate the neuroprotective effect of C-phycocyanin in a mouse model of rotenone-induced Parkinson’s ***:C-phycocyanin(50 mg/kg,i.p.,daily)was administered to rotenone(30 mg/kg,p.o.,daily)treated mice for 28 *** studies(Y-maze,rotarod,round beam walk,and wire-hang tests)were carried out to assess neurobehavioral *** and malondialdehyde were determined in both serum and striatal *** proteins(AKT,AmPK,NF-κB,BDNF,and alpha-synuclein)in the striatum were estimated using *** analyses(hematoxylin and eosin stainning as well as Nissl staining)were carried out to assess structural abnormalities in the ***:C-phycocyanin significantly increased BDNF levels and decreased alpha-synuclein *** also slightly upregulated AmPK and AKT levels without significant difference compared with the rotenone ***,rotenone-induced elevated oxidative stress and structural abnormalities in the striatum were markedly mitigated by ***:C-phycocyanin might have potential neuroprotective effects against Parkinson’s *** studies are warranted to verify its efficacy and to understand the molecular mechanisms behind the neuroprotective effects of C-phycocyanin in Parkinson’s disease.

关键词： Parkinson’s disease C-phycocyanin Alphasynuclein BDNF Oxidative stress Rotenone

New ordered mAX phase mo_2 TiAlC_2: Elastic and electronic properties from first-principles

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

Chinese Physics B 2016年第10期25卷 323-329页

作者： m A Hadi m s Ali Department of Physics University of Rajshahi Department of Physics Pabna University of Science and Technology

First-principles computation on the basis of density functional theory(DFT) is executed with the CAsTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers’ hardness of newly discovered ordered mAX phase carbide mo2TiAlC2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson’s and Pugh’s ratios. The new mAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of mo2TiAlC2is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional mo–C–mo covalent bonding associated with a relatively weak Ti–C *** calculated Fermi surface is due to the low-dispersive mo 4d-like bands, which makes the compound a conductive *** hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding.

关键词： new ordered mAX phase density functional theory calculations Debye temperature Vickers hardness

Astrophysical s-factor and reaction rate for 15N(p,γ)16O within the modified potential cluster model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第4期48卷 130-145页

作者： s.B.Dubovichenko A.s.Tkachenko R.Ya.Kezerashvili N.A.Burkova B.m.Yeleusheva Fesenkov Astrophysical Institute 050020 AlmatyKazakhstan New York City College of Technology City University of New YorkBrooklyn11201 New YorkUSA Graduate school and University Center City University of New York10016 New YorkUSA al-Farabi Kazakh National University 050040 AlmatyKazakhstan

We study radiative p^(15)N capture on the ground state of ^(16)O at stellar energies within the framework of a modified potential cluster model(mPCm)with forbidden states,including low-lying *** investigation of the ^(15)N(p,γ0)^(16)O reaction includes the consideration of ^(3)s_(1) resonances due to E1 transitions and the contribution of the ^(3)P_(1) scattering wave in the p+^(15)N channel due to the ^(3)P_(1)→^(3)P_(0)m1 *** calculated the astrophysical low-energy s-factor,and the extrapolated s(0)turned out to be within 34.7−40.4 keV·*** important role of the asymptotic constant(AC)for the ^(15)N(p,γ0)16O process with interfering ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances is elucidated.A comparison of our calculation for the s-factor with existing experimental and theoretical data is addressed,and a reasonable agreement is *** reaction rate is calculated and compared with the existing *** has negligible dependence on the variation of AC but shows a strong impact of the interference of ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances in reference to the CNO Gamow windows,especially at low *** estimate the contribution of cascade transitions to the reaction rate based on the exclusive experimental data from ***.C.85,065810(2012).The reaction rate enhancement due to the cascade transitions is observed from T_(9)>0.3 and reaches the maximum factor~1.3 at T_(9)=*** present the Gamow energy window and a comparison of rates for radiative proton capture reactions ^(12)N(p,γ)^(13)O,^(13)N(p,γ)^(14)O,^(14)N(p,γ)^(15)O,and ^(15)N(p,γ)^(16)O obtained in the framework of the mPCm and provide the temperature windows,prevalence,and significance of each process.

关键词： low and astrophysical energies p^(15)N system thermonuclear reaction rate potential cluster model CNO-cycle