检索结果-南通市图书馆

First Record of Sexual Dimorphism in Toxasterid Echinoid Heteraster from the Early Cretaceous Deposits of the Kopet-Dagh Basin,NE Iran

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

Acta Geologica Sinica(English Edition) 2023年第5期97卷 1318-1334页

作者： Hossein KAMYABI SHADAN morteza TAHERPOUR KHALIL-ABAD Exploration Directorate of the National Iranian Oil Company TehranIran Young Researchers and Elite Club Mashhad BranchIslamic Azad UniversityMashhadIran

Spatangoid echinoids belonging to Heteraster found in the Lower Cretaceous limestones and calcareous deposits of the Tirgan and Sarcheshmeh formations(Barremian-Aptian)in the Bahman jan-Bala stratigraphic section on the northern flank of the Borouj syncline,situated in the eastern Kopet-Dagh Basin,northeastern Iran are assessed as a sexually dimorphic *** dimorphism is a common feature in echinoids and,in this study of Heteraster renngarteni Poretzkaja,1961,sexual dimorphism has been detected for the first time in the family Toxasteridae.

关键词： invertebrate paleontology echinodermata Heteraster sexual dimorphism Barremian–Aptian Kopet-Dagh Iran

Large-scale seismic isolation through regulated liquefaction： a feasibility study

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2016年第4期15卷 579-595页

作者： Seyed Amin Mousavi morteza Bastami Seyed Mehdi Zahrai School of Civil Engineering College of Engineering University of Tehran Tehran Iran International Institute of Earthquake Engineering and Seismology TehranIran Center of Excellence for Engineering and Management of Civil Infrastructures School of Civil Engineering Faculty of EngineeringUniversity of Tehran Tehran Ivan

Using controlled liquefaction, a seismic isolation technique is introduced by which a large area with dozens of structures can be seismically isolated. The proposed Large Scale Seismic Isolation （LSSI） is in many ways similar to conventional base isolations. The required bearing is provided by a fully undrained pre-saturated liquefiable layer which has substantial vertical stiffness/capacity and minimal lateral stiffness. Moreover, required energy dissipation would be provided through material damping and Biot flow-induced damping within the liquefied layer. LSSI consists of a thick non- liquefiable crust layer and an underlying engineered pre-saturated liquefiable layer bounded by two impermeable thin clay layers. The liquefiable layer should be designed to trigger liquefaction as soon as possible within the early seconds of a design level seismic event. Adopting the energy-based GMP liquefaction theory, optimum gradation of the liquefiable layer is also investigated. It tumed out that LSSI would effectively reduce acceleration response spectrum within short to medium periods. Contribution of the proposed LSSI is more pronounced in the case of stronger ground motions such as near field events as well as ground motions with longer return periods.

关键词： liquefaction seismic isolation effective stress analysis ground response analysis passive control

CELL ADHESION AND SURFACE PROPERTIES OF POLYSTYRENE SURFACES GRAFTED WITH POLY(N-ISOPROPYLACRYLAMIDE)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2013年第11期31卷 1509-1518页

作者： Esmaeil Biazar Mohammad Taghi Khorasani morteza Daliri Joupari Department of Biomedical Engineering Science and Research BranchIslamic Azad University Biomaterial Department of Iran Polymer and Petrochemical Institute National Research Center for Genetic Engineering and Biotechnology

Cell adhesion plays a key role in various aspects of biological and medical sciences. In this study, poly（N- isopropylacrylamide）（PNIPAM） was grafted on polystyrene surfaces using different solvents under UV radiation. Moreover, the relation between surface roughness and cell adhesion were evaluated by gravimetric, SEM, AFM, contact angle measurement and cellular analyses. The gravimetric analysis clearly indicated an increase in the grafting by adding 10% methanol to water. The study of surface topography by AFM images showed an increase in the surface roughness and as a result of which, a decrease in wettablity was observed. At 37 ~C, epithelial ceils were well attached and proliferated on the grafted surfaces, while these cells were spontaneously detached below 32 ℃ in the absence of any enzymes. Moreover, MTT assay and SEM images indicated good cell viability and an increase in cell adhesion caused by the roughness increase. The results of this study reveal the great potential of PNIPAM-grafted polystyrene for being used in the biomedical fields such as drug delivery systems, tissue engineering and cell separation.

关键词： Grafting Solvent effect PNIPAM Cell adhesion Surface roughness.

Optimal Predictive Impedance Control in the Presence of Uncertainty for a Lower Limb Rehabilitation Robot

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2020年第5期33卷 1310-1329页

作者： JALAEIAN-F.Mohsen FATEH Mohammad Mehdi RAHIMIYAN morteza Department of Electrical and Robotic Engineering Shahrood University of TechnologyShahroodIran

As an innovative concept,an optimal predictive impedance controlle is introduced here to control a lower limb rehabilitation robo in the presence of *** desired impedance law is considered to propose a conventional model-based impedance controller for the ***,external disturbances,model imperfection,and parameters uncertainties reduce the performance of the controller in *** order to cope with these uncertainties,an optimal predictive compensator is introduced as a solution for a proposed convex optimization problem,which is performed on a forward finite-length *** a result,the LLRR has the desired behavior even in an uncertain *** performance and efficiency of the proposed controller are verified by the simulation results.

关键词： Impedance control lower limb rehabilitation robots model predictive compensator optimal predictive impedance controller optimization in the presence of uncertainty

Effect of bank slope on the flow patterns in river intakes

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2014年第3期26卷 482-492页

作者： SEYEDIAN Seyed morteza BAJESTAN Mahmood Shafai FARASATI Masoomeh Department of Hydraulic Structure Ghonbad Kavoos UniversityGhonbad Kavoos Iran Department of Hydraulic Structure Shahid Chamran UniversityAhvaz Iran Department of Water Engineering Razi University Kermanshah Iran

In this work, we studied the dimensions of stream tube in the vertical as well as inclined bank conditions. Data were collected from both a physical model and a 3-D numerical model（SSIIM 2）. Equations for predicting stream tube dimensions were presented and compared with existing formulae. In comparison with vertical bank, it is found that inclining bank causes the bottom stream tube width to be greater than at the surface. The strength of secondary current formed at the entrance of branch channel is reduced. These changes in flow pattern can reduce the amount of sediment delivery into the intake.

关键词： lateral intakes flow pattern bank slope stream tube SSIIM 2 model

Improvement of the microstructural features and mechanical properties of advanced high-strength steel DP590 welds

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第6期28卷 1022-1029页

作者： Arian Ghandi morteza Shamanian Mohamad Reza Salmani Jalal Kangazian College of Pardis Materials Engineering SectionIsfahan University of TechnologyIsfahan 84156-83111Iran Department of Materials Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran Engineering&Quality of Auto Steel Division SAIPA GroupTehranIran

The effects of the welding current mode in resistance spot welding on the microstructure and mechanical properties of advanced high-strength steel dual-phase 590(DP590)sheets were *** showed that a rough martensitic structure was formed in the weld zone of the sample welded via the single-pulsed mode,whereas the microstructure in the heat-affected zone consisted of a very rough martensitic microstructure and rough ***,using the secondary pulse mode led to the formation of tempered martensite in the weld *** maximum load and the energy absorption to failure of the samples with the secondary pulsed cycle were higher than those of the samples with the single-pulsed *** shear results indicated that the secondary pulsed mode could significantly change the mode of failure upon shear tension ***,the obtained results suggest that the use of secondary pulsed mode can improve the microstructural feature and mechanical properties of advanced high-strength steel DP590 welds.

关键词： advanced high-strength steel resistance spot welding microstructure mechanical properties

Comparative study of heat transfer and pressure drop for curved-twisted tubes utilized in chemical engineering

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第12期34卷 53-64页

作者： morteza Khoshvaght-Aliabadi Saber Deldar Shafiqur Rehman Ashkan Alimoradi Department of Chemical Engineering Shahrood BranchIslamic Azad UniversityShahroodIran Department of Mechanical Engineering Tarbiat Modares UniversityTehranIran Center for Engineering Research The Research InstituteKing Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Department for Management of Science and Technology Development Ton Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Applied Sciences Ton Duc Thang UniversityHo Chi Minh CityViet Nam

Increasing importance of heat transfer in chemical engineering science causes that investigation in the field of enhancement techniques is always one of the up-to-date topics for *** the current comparative analysis,the thermal enhancement and friction penalty are explored numerically for curved tubes via twisted *** accomplish this,three common geometries namely helical,serpentine,and Archimedes spiral,are considered at different coil-pitches and twist-pitches as well as five Reynolds numbers in the laminar flow *** results exhibit noticeable enhancements(up to 60%)in the thermal performance of the twisted cases as compared to the smooth *** highest increases are recorded for the serpentine case,followed by the helical and spiral *** is found that these enhancements vary via coil-pitch and *** coil-pitch and twist-pitch augments both heat transfer coefficient and pressure drop in all curved-twisted tubes,however,the effects of twist-pitch are more *** predict Nusselt number and friction factor,new correlations are also *** maximum deviations of the predicted results compared to the simulated data are within±5%.

关键词： Computational fluid dynamics Heat transfer Laminar flow Curved-twisted tubes Comparative study

Comparison of Spatial Interpolation Methods for Gridded Bias Removal in Surface Temperature Forecasts

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2017年第4期31卷 791-799页

作者： Seyedeh Atefeh MOHAMMADI Majid AZADI morteza RAHMANI Technology Development Institute Tehran 13445-686 Iran Atmospheric Science and Meteorological Research Center Tehran 16385-14977 Iran Faculty of Basic and Advanced Technologies in Biology University of Science and Culture Tehran 14619-68151 Iran

All numerical weather prediction（NWP） models inherently have substantial biases, especially in the forecast of near-surface weather variables. Statistical methods can be used to remove the systematic error based on historical bias data at observation stations. However, many end users of weather forecasts need bias corrected forecasts at locations that scarcely have any historical bias data. To circumvent this limitation, the bias of surface temperature forecasts on a regular grid covering Iran is removed, by using the information available at observation stations in the vicinity of any given grid point. To this end, the running mean error method is first used to correct the forecasts at observation stations, then four interpolation methods including inverse distance squared weighting with constant lapse rate（IDSW-CLR）, Kriging with constant lapse rate（Kriging-CLR）, gradient inverse distance squared with linear lapse rate（GIDS-LR）, and gradient inverse distance squared with lapse rate determined by classification and regression tree（GIDS-CART）, are employed to interpolate the bias corrected forecasts at neighboring observation stations to any given location. The results show that all four interpolation methods used do reduce the model error significantly,but Kriging-CLR has better performance than the other methods. For Kriging-CLR, root mean square error（RMSE）and mean absolute error（MAE） were decreased by 26% and 29%, respectively, as compared to the raw forecasts. It is found also, that after applying any of the proposed methods, unlike the raw forecasts, the bias corrected forecasts do not show spatial or temporal dependency.

关键词： spatial interpolation bias correction lapse rate Kriging classification and regression tree

Effect of melt-to-solid volume ratio and preheating temperature on Mg/Al bimetals interface by centrifugal casting

在线全文

学校读者我要写书评

暂无评论

China Foundry 2023年第3期20卷 234-240页

作者： morteza Sarvari Mehdi Divandari Hassan Saghafan Sina Ghaemi Khiavi School of Metallurgy and Materials Engineering Iran University of Science and TechnologyNarmakTehran 16844Iran

Compound casting is an efficient method for bonding dissimilar metals,in which a dramatic reaction can occur between the melt and *** centrifugal casting process,a type of compound casting,was applied to cast Al/Mg dissimilar *** melt was poured at 700 °C,with melt-to-solid volume ratios(Vm/Vs) of 1.5 and 3,into a preheated hollow aluminum *** preheating temperatures of the solid part were 320,400,and 450 °C,and the constant rotational speed was 1,600 *** cast parts were kept inside the casting machine until reaching the cooling temperature of 150 °*** result showed that an increase in preheating temperature from 320 to 450 °C led to an enhanced reaction layer *** addition,an increase in the Vm/Vs from 1.5 to 3 resulted in raising the interface thickness from 1.2 to 1.8 ***,the interface was not continuously formed when a Vm/Vs of 3 was *** this case,the force of contraction overcame the resultant acting force on the *** interface formed at the volume ratio of 1.5 was examined using scanning electron microscopy(SEM) equipped with energy-dispersive X-ray spectroscopy(EDS),and the results demonstrated the formation of Al_(3)Mg_(2),Al_(12)Mg_(17) and(δ+Al_(12)Mg_(17)) eutectic structures in the interface.

关键词： compound casting centrifugal casting Mg/Al bimetal preheating temperature melt-to-solid volume ratio interface