检索结果-南通市图书馆

Pedosphere 2021年第2期31卷 342-352页

作者： Emma m.DOCHERTY andre. D.THOmAS Department of Geography and Earth Sciences Aberystwyth UniversityAberystwyth SY233DB(UK) School of Geography University of LeedsLeeds LS29JT(UK)

Seasonally flooded várzea forests of Western Amazonia are one of the most productive and biodiverse wetland forests in the ***,data on their soil CO_(2)emissions,soil organic matter decomposition rates,and soil C stocks are *** is a concern because hydrological changes are predicted to lead to increases in the height,extent,and duration of seasonal floods,which are likely to have a significant effect on soil C stocks and ***,with no empirical data,the impact of altered flood regimes on várzea soil C cycles remains *** study quantified the effects of maximum annual flood height and soil moisture on soil CO_(2)efflux rate(R_(s))and soil organic matter decomposition rate(k)in the várzea forests of Pacaya Samiria National Reserve,*** study was conducted between may and August *** results showed that R_(s)(10.6–182.7 mg C m^(-2)h^(-1))and k(0.016–0.078)varied between and within sites,and were considerably lower than the values reported for other tropical *** addition,R_(s)was negatively affected by flood height(Pmoisture(Pmentioned *** moisture was the dominant factor influencing R_(s),and it was significantly affected by maximum flood height,even after the floods had subsided(Pmain unchanged but with decomposition processes becoming more anaerobic.

关键词： C cycle climate change greenhouse gas soil CO_(2)emissions soil moisture soil organic matter decomposition rate tropical forest

modified approximation and error estimation for King’s type(p,q)-BBH operators

在线全文

学校读者我要写书评

暂无评论

Applied mathematics(A Journal of Chinese Universities) 2022年第2期37卷 199-212页

作者： m.mursaleen mohd.Ahasan Asif Khan Department of medical Research China Medical University HospitalChina Medical University(Taiwan)TaichungTaiwanChina Department of mathematics Aligarh Muslim UniversityAligarh 202002India Department of mathematics School of Basic and Applied SciencesGalgotias UniversityGreater Noida-203201India

In this paper,the King’s type modification of(p,q)-Bleimann-Butzer and Hahn operators is *** results based on Korovkin’s approximation theorem for these new operators are *** the help of modulus of continuity and the Lipschitz type maximal functions,the rate of convergence for these new operators are *** is shown that the King’s type modification have better rate of convergence,flexibility than classical(p,q)-BBH operators on some ***,for comparisons of the operators,we presented some graphical examples and the error estimation in the form of tables through mATLAB(R2015a)

关键词： (p,q)-integers (p,q)-Bleimann-Butzer and Hahn operators King's type modi cation modulus of continuity Holder inequality and Lipschitz functions

A Seismic Hazard map Based on Geology and Shear-wave Velocity in Rawalpindi–Islamabad,Pakistan

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2021年第2期95卷 659-673页

作者： Sarfraz KHAN muhammad WASEEm m.Asif KHAN National Centre of Excellence in Geology University of Peshawar 25130KPPakistan University of Peshawar 25120 KPPakistan

The‘twin cities’district of Rawalpindi–Islamabad is among the most endangered seismic regions in Pakistan,with the seismic hazard assessed(0.32 g)to intensity IX mmI for a 475-year return period.A seismic hazard map for Rawalpindi–Islamabad is presented herein,based on 85 shear-wave velocity(VS)profiles obtained through geophysical H/V measurements and from the geological map of the *** between the average top thirty-meter shear-wave velocities(VS30)and surficial geological units have been *** peak ground acceleration(PGA)maps for 150,475 and 2475-year return periods were converted into a seismic intensity *** increments for different soils were used to compute PGA values for 150,475 and 2475-year return *** located on softer ground experienced a higher degree of damage from moderate *** to the presence of soft clay or liquefiable soil and lateral spreading,a few locations may be classified as hybrid sites class C and *** map is a critical step in facilitating code-based site classification and seismic design throughout Rawalpindi–*** the seismic hazard map based on seismic intensities is no longer used in engineering geology,it is still important in seismological analysis and for civil protection purposes.

关键词： seismic hazard site classification intensity increment engineering geology Rawalpindi-Islamabad

Output digitization of simple measure-preserving linear systems

在线全文

学校读者我要写书评

暂无评论

Control Theory and Technology 2021年第4期19卷 430-443页

作者： A.DeStefano m.Thitsa C.martin Department of mathematics and Computer Science College of the Holy CrossWorcesterMA 01610USA Department of Electrical and Computer Engineering Mercer UniversityMaconGA 31207USA Department of mathematics and Statistics Texas Tech UniversityLubbockTX 79430USA

We examine three simple linear systems from the viewpoint of ergodic *** digitize the output and record only the sign of the output at integer *** show that even with this minimal output we can recover important information about the *** particular,for a two-dimensional system viewed as a fow on the circle,we can determine the rate of *** then use these results to determine the slope of the trajectories for constant irrational fow on the two-dimensional *** achieve this,we randomize the system by partitioning the state space and only recording which partition the state is in at each integer *** show directly that these systems have entropy ***,we examine two four-dimensional systems and reduce them to the study of linear fows on the two-dimensional torus.

关键词： Ergodic Linear system Observability Cantor set

Interaction of antipsychotic drug with novel surfactants: micellization and binding studies

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 Journal of Chemical Engineering 2018年第3期26卷 566-573页

作者： Naved Azum malik Abdul Rub Abdullah m.Asiri Center of Excellence for Advanced materials Research King Abdulaziz University Chemistry Department Faculty of Science King Abdulaziz University

The interaction of cationic gemini surfactants(alkanediyl-α,ω-bis(alkyl dimethylammonium bromide)) with an antipsychotic drug(chlorpromazine hydrochloride(CPZ)) has been investigated. Various micellar and interfacial parameters have been deliberated by surface tension measurement to report the nature of interactions between drug and novel surfactant mixtures. The behavior of mixed systems, their compositions and activities of components have been analyzed in the light of Rubingh's theory. The results indicate synergism in the binary *** binding study between CPZ and surfactants has been done by spectroscopic techniques such as UV–visible and fluorescence. The results are discussed in the light of the use of gemini surfactants as promising drug delivery agents for phenothiazine drugs, and hence, improve their bioavailability.

关键词： Gemini surfactants Antipsychotic drug Chlorpromazine hydrochloride mixed micellization

Solid fraction evolution characteristics of semi-solid A356 alloy and in-situ A356–TiB_2 composites investigated by differential thermal analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of minerals,metallurgy and materials 2015年第4期22卷 389-394页

作者： S.Deepak Kumar A.mandal m.Chakraborty School of mechanical Sciences Indian Institute of Technology Bhubaneswar School of minerals Metallurgical and Materials Engineering Indian Institute of Technology Bhubaneswar

The key factor in semi-solid metal processing is the solid fraction at the forming temperature because it affects the microstructure and mechanical properties of the thixoformed components. Though an enormous amount of data exists on the solid fraction-temperature re- lationship in A356 alloy, information regarding the solid fraction evolution characteristics of A356-TiB2 composites is scarce. The present article establishes the temperature-solid fraction correlation in A356 alloy and A356-xTiB2 （x = 2.5wt% and 5wt%） composites using dif- ferential thermal analysis （DTA）. The DTA results indicate that the solidification characteristics of the composites exhibited a variation of 2℃ and 3℃ in liquidus temperatures and a variation of 3℃ and 5℃ in solidus temperatures with respect to the base alloy. moreover, the eutectic growth temperature and the solid fraction（fs） vs. temperature characteristics of the composites were found to be higher than those of the base alloy. The investigation revealed that in-situ formed TiB2 particles in the molten metal introduced more nucleation sites and reduced undercooling.

关键词： particle reinforced composites aluminum alloys titanium boride casting solid fraction differential thermal analysis

Revisiting factors contributing to the strength of cemented backfill support system:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Rock mechanics and Geotechnical Engineering 2023年第6期15卷 1615-1624页

作者： N.m.Chiloane F.K.mulenga Department of mining Engineering University of South AfricaFlorida CampusPrivate Bag X6Johannesburg1710South Africa

This paper provides a review of the intrinsic and extrinsic factors affecting the uniaxial compressive strength(UCS)of cemented tailings backfill(CTB).The consideration is that once CTB is poured into underground stopes,its strength is heavily influenced by factors internal to the CTB as well as the surrounding mining ***-reviewed journal articles,books,and conference papers published between 2000 and 2022 were searched electronically from various databases and *** sources,such as doctoral theses,were obtained from academic *** important finding from the review is that the addition of fibers was reported to improve the UCS of CTB in some studies while decrease in *** discrepancy was accounted to the different properties of fibers *** research is therefore needed to determine the“preferred”fiber to be used in *** findings were also reported on the effects of stope size on the UCS of ***,the use of fly ash as an alternative binder may be threatened in the future when reliance on the coal power ***,an alternative cementitious by-product to be used together with furnace slag may be required in the ***,while most studies on backfill focused on single-layered structures,layered backfill design models should also be investigated.

关键词： Cemented tailings backfill(CTB) Uniaxial compressive strength(UCS) Extrinsic factors Intrinsic factors Underground support

Constraints on neutron skin thickness and symmetry energy of 208Pb through Skyrme forces and cluster model

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 C 2020年第5期44卷 92-99页

作者： m.moghaddari Amiri O.N.Ghodsi Department of Physics Faculty of ScienceUniversity of MazandaranP.O.Box 47415-416BabolsarIran

We used the cluster structure properties of the 212Po to estimate the neutron skin thickness of *** this purpose,we considered two important components:(a)alpha decay is a low energy phenomenon;therefore,one can expect that the mean-field,which can explain the ground state properties of 212Po,does not change during the alpha decay process.(b)212Po has a high alpha cluster-like structure,two protons and two neutrons outside its core nucleus with a double magic closed-shell,and the cluster model is a powerful formalism for the estimation of alpha decay preformation factor of such *** slope of the symmetry energy of 208Pb is estimated to be 75±25 meV within the selected same mean-fields and Skyrme forces,which can simultaneously satisfy the ground-state properties of parent and daughter nuclei,as their neutron skin thicknesses are consistent with experimental data.

关键词： α-decay isospin asymmetry neutron-skin thickness Hartree-Fock formalism

Effect of process parameters of pulsed current tungsten inert gas welding on weld pool geometry of titanium welds

在线全文

学校读者我要写书评

暂无评论

Acta metallurgica Sinica(English Letters) 2010年第4期23卷 312-320页

作者： m.Balasubramanian V.Jayabalan V.Balasubramanian Department of mechanical Engineering Velammal Engineering CollegeSurapetAnna University Department of manufacturing Engineering Anna University Centre for materials Joining & Research Department of Manufacturing EngineeringAnnamalai University

The effects of pulsing current parameters on weld pool geometry namely front height, back height, front width and back width of pulse current gas tungsten arc welded （GTAW） titanium alloy was analysed. Four factors, five levels, central composite design were used to develop empirical relationships, incorporating pulsed current parameters and weld pool geometry.

关键词： Gas tungsten arc welding Pulsed current Titanium alloy Design of experiments

Three-dimensional mixed convection flow with variable thermal conductivity and frictional heating

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2020年第3期72卷 14-20页

作者： m Qasim N Riaz Dianchen Lu S Shafie Department of mathematics Faculty of ScienceJiangsu UniversityZhenjiang 212013China Department of mathematics COMSATS University Islamabad(CUI)455000Park RoadTarlai KalanIslamabad.Pakistan Department of mathematical Sciences Faculty of ScienceUniversiti Teknologi Malaysia81310 UTM Johor BahruJohor 81310Malaysia

In this article,three-dimensional mixed convection flow over an exponentially stretching sheet is *** equation is modelled in the presence of viscous dissipation and variable thermal *** of the sheet is varying exponentially and is chosen in a form that facilitates the similarity transformations to obtain self-similar *** nonlinear ordinary differential equations are solved numerically employing the Runge-Kutta shooting *** order to check the accuracy of the method,these equations are also solved using bvp4c built-in routine in *** solutions are in excellent *** effects of physical parameters on the dimensionless velocity field and temperature are demonstrated through various *** novelty of this analysis is the self-similar solution of the threedimensional boundary layer flow in the presence of mixed convection,viscous dissipation and variable thermal conductivity.

关键词： self-similar equations viscous dissipation mixed convection variable thermal conductivity shooting technique bvp4c matlab