检索结果-南通市图书馆

Influence of bean rhizosphere on the biological properties and phosphorus fractionation in the calcareous soils amended with municipal sewage sludge

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2015年第5期7卷 644-652页

作者： Tahereh RAIESI alireza HOSSEINPUR Hamideh RAIESI Horticultural Science Research Institute Citrus and Subtropical Fruit Research Center Agricultural Research and Education Organization (AREO) Department of Soil Science College of Agriculture Shahrekord University Department of Plant Protection College of Agriculture Guilan University

The biological and chemical conditions of the rhizosphere are known to considerably differ from those of the bulk soil, as a consequence of a range of processes that are induced either directly by the activity of plant roots or indirectly by the stimulation of microbial population and activity in the rhizosphere. Information about phosphorus （P） fractionation in the rhizosphere soils amended with municipal sewage sludge （MSS） is limited, were We carried out greenhouse experiments using a rhizobox in order to evaluate the effects of bean rhizosphere on the various inorganic P （Pi） fractions, organic P （Po）, P in particulate fraction （PF-P）, Olsen-P, dissolved organic C （DOC）, microbial biomass P （MBP） and alkaline phosphatase （ALP） enzyme in 10 calcareous soils amended with MSS （10 g MSS was added to 1 kg soil）. Non-occluded P, occluded P, calcium phosphate and residual P were also quantitated. The results showed that DOC, MBP and ALP activity strongly increased and PF-P and Olsen-P de- creased in the rhizosphere soils compared with in the bulk soils （P〈0.05）. The contents of non-occluded P, oc- cluded P and residuaI-P fractions in the rhizosphere soils were lower than in the bulk soils, while the contents of calcium phosphate and organic P in the rhizosphere soils were higher than in the bulk soils. Simple correlation coefficients showed that P uptake had positive relationship with non-occluded P, occluded P, calcium phosphate fractions and PF-P in the rhizosphere soils. The results suggest that the short-term application of MSS to the cal- careous soils may increase Po and calcium phosphate fractions in the rhizosphere soils, and calcium phosphate fraction is potentially available to crops.

关键词： biological properties mineral phosphorus organic phosphorus semi-arid land

Rapid synthesis of MoSi_2-Si_3N_4 nanocomposite via reaction milling of Si and Mo powder mixture

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2013年第11期20卷 1107-1114页

作者： Majid Abdellahi alireza Amereh Hamed Bahmanpou Behzad Sharafati Department of Materials Engineering Islamic Azad UniversityNajafabad Branch Department of Materials Engineering Islamic Azad UniversitySaveh Branch Department of Chemical Engineering and Materials Science University of California

The nanocomposite of MoSi2-SiaN4 （molybdenum disilicide-silicon nitride） was synthesized by reaction milling of the Mo and Si powder mixture. Changing the processing parameters led to the formation of different products such as a- and B-MoSi2, SiaN4, Mo2N, and M05Si3 at various milling times. A thermodynamic appraisal showed that the milling of Moa2Siss powder mixture was associated with highly exothermic mechanically induced self-sustaining reaction （MSR） between Mo and Si. The MSR took place around 5 h of milling led to the formation of a-MoSi2 and the reaction between Si and N2 to produce Si3N4 under a nitrogen pressure of 1 MPa. By increasing the nitrogen pressure to 5 MPa, more heat is released, resulting in the dissociation of Si3N4 and the transformation of a-MoSi2 to β-MoSi2. Heat treatment was also performed on the milled samples and led to the formation of Mo2N and the transformation of a-MoSi2 to β-MoSi2 at the milling times of 10 and 40 h, respectively.

关键词： nanocomposites reaction milling molybdenum disilicide silicon nitride powders

Effect of natural and synthetic fibers reinforcement on California bearing ratio and tensile strength of clay

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2021年第3期13卷 626-642页

作者： Mahdi Ghasemi Nezhad alireza Tabarsa Nima Latifi Department of Civil Engineering Faculty of EngineeringGolestan UniversityGorganIran Terracon Consultants Inc.5217 Linbar Dr#309NashvilleTN37211USA

Use of environmentally friendly approaches with the purpose of strengthening soil layers along with finding correlations between the mechanical characteristics of fiber-reinforced soils such as indirect tensile strength(ITS)and California bearing ratio(CBR)and as well as the evaluation of shear strength parameters obtained from the triaxial test would be very effective at geotechnical construction *** research was aimed at investigating the influence of natural fibers as sustainable ones including basalt(BS)and bagasse(BG)as well as synthetic polyester(PET)fibers on the strength behavior of clayey *** this end,the effects of various fiber contents(0.5%,1%and 2%)and lengths(2.5 mm,5 mm and 7.5 mm)were experimentally *** conducting ITS and CBR tests,it was found that increasing fiber content and length had a significant influence on CBR and ITS ***,2%of 7.5 mm-long fibers led to the largest values of CBR and *** CBR values of soil reinforced with PET,BS,and BG fibers were determined as 19.17%,15.43%and 13.16%,*** ITS values of specimens reinforced with PET,BS,and BG fibers were reported as 48.57 kPa,60.7 kPa and 47.48 kPa,*** results of the triaxial compression test revealed that with the addition of BS fibers,the internal friction angle increased by about 100%,and with the addition of PET fibers,the cohesion increased by about 70%.Moreover,scanning electron microscope(SEM)analysis was employed to confirm the *** relationship between CBR and ITS values,obtained via statistical analysis and used for the optimum design of road pavement layers,demonstrated that these parameters had high correlation *** outcomes of multiple linear regression and sensitivity analysis also confirmed that the fiber content had a greater effect on CBR and ITS values than fiber length.

关键词： Natural fibers Synthetic fibers Indirect tensile strength(ITS) California bearing ratio(CBR) Reinforced soil

Stability analysis of the Euler-Bernoulli beam with multi-delay controller

在线全文

学校读者我要写书评

暂无评论

Control Theory and Technology 2022年第3期20卷 338-348页

作者： alireza Jalili Rahmtati Genqi Xu Sohrab Effati Department of Mathematical Sciences Sharif University of TechnologyAzadi Ave.TehranIran Department of Mathematics Tianjin UniversityNankai DistrictTianjin300072China Department of Applied Mathematics Ferdowsi University of MashhadAzadi SquareMashhadIran

In this paper,we investigate the stabilization of an Euler-Bernoulli beam with time delays in the boundary *** boundary velocity feedback law is applied to obtain the closed-loop *** is shown that this system generates a C_(0-)semigroup of linear ***,the stability of the closed-loop system is discussed for different values of the controller constants and time delays via using spectral analysis and a suitable Lyapunov function.

关键词： Euler-Bernoulli beam Time delay Lyapunov method Spectral analysis

Enhanced viability and improved in situ antibacterial activity of the probiotic LAB microencapsulated layer-by-layer in alginate beads coated with nisin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

FOOD BIOSCIENCE 2023年第3期53卷 1025-1033页

作者： Zarali, Maryam Sadeghi, alireza Jafari, Seid Mahdi Ebrahimi, Maryam Mahoonak, alireza Sadeghi Gorgan Univ Agr Sci & Nat Resources Dept Food Sci & Technol Gorgan Iran Gorgan Univ Agr Sci & Nat Resources Dept Food Mat & Proc Design Engn Gorgan Iran Golestan Univ Med Sci Food Drug & Nat Prod Hlth Res Ctr Gorgan Iran

In the present study, a layer-by-layer technique was used to prepare alginate-nisin (Alg-N) as coating layer to encapsulate a potential probiotic-protective lactic acid bacteria (LAB) isolate in order to improve its both survival and antibacterial activities in situ. The isolate was identified as Pediococcus acidilactici according to the sequencing results of the PCR products. The mean size of Alg and Alg-N microcapsules was also equal to 762.63 and 501.77 mu m, respectively based on the results of field emission scanning electron microscopy. In accordance with the zeta potential data, the Alg-N surrounding layer was confirmed. Furthermore, the Fourier transform infrared findings revealed the adsorption of nisin on the Alg beads. The antibacterial activity of the produced microcapsule on Staphylococcus aureus (100% inhibition) was significantly (P < 0.05) higher than that of the other foodborne bacteria studied. In addition, enhanced viability of the microencapsulated LAB in simulated gastrointestinal conditions and flavored milk, as well as its improved in situ inhibitory effect on S. aureus were verified.

关键词： Layer-by-layer Alginate-nisin coating Enhanced survival In situ antibacterial

Plant-based synthesis of NiO nanoparticles using salvia macrosiphon Boiss extract and examination of their water treatment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2020年第10期39卷 1134-1144页

作者： Zahra Sabouri Narges Fereydouni alireza Akbari Hasan Ali Hosseini alireza Hashemzadeh Mohammad Sadegh Amiri Reza Kazemi Oskuee Majid Darroudi Department of Chemistry University of Payame NoorTehran 19395-4697Iran Neurogenic Inflammation Research Center University of Medical SciencesMashhad ***Iran NanoBioEletrochemistry Research Center University of Bam Medical SciencesBam ***Iran Department of Biology University of Payame NoorTehran 19395-4697Iran Targeted Drug Delivery Research Center Institute of Pharmaceutical TechnologyUniversity of Medical SciencesMashhad ***Iran Nuclear Medicine Research Center University of Medical SciencesMashhad ***Iran Department of Modern Sciences and Technologies School of MedicineUniversity of Medical SciencesMashhad ***Iran

The goal of this study was to synthesize nickel oxide nanoparticles(NiO-NPs)by the sol-gel method,which involved the use of salvia macrosiphon Boiss plant extract,Ni(NO3)2·6 H2 O as a capping agent,and a nickel precursor,*** synthesized NiO-NPs were characterized by Fourier transform infrared spectroscopy(FTIR),ultraviolet-visible(UV-Vis)spectrophotometer,X-ray diffraction(XRD),field electron scanning electron microscopy(FESEM)/energy-dispersive X-ray spectroscopy(EDX),thermo-gravimetric analysis/differential thermal analysis(TGA/DTA)and vibrating sample magnetometer(VSM)***,according to the results of UV-Vis,the gap band of nanoparticles was calculated to be in the range of about 2.9-3.9 *** photocatalytic activity of nanoparticles on methylene blue(MB)degradation was investigated and according to the results,about 80%MB was apparently degraded in the presence of NiO-NPs under UV-A light(11 W)after 5 h in pH^*** have evaluated the cytotoxicity of NiO-NPs on the multiple tumor cells by materials method,and all the utilized concentrations were observed to cause non-toxic effects;therefore,it can be suggested that these samples have the potential of being employed in different fields of medicine.

关键词： Nickel oxide nanoparticles Sol-gel Photocatalytic degradation Salvia macrosiphon Boiss plant extract Cytotoxicity

Investigation of the stability and hydrodynamics of Tetrosomus gibbosus carapace in different pitchangles

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2019年第2期31卷 368-378页

作者： Mahyar Malekidelarestaqi alireza Riasi Hadi Moradi Mohammad Samadpour School of Mechanical Engineering University of TehranTehranIran Intelligent Systems Research Institute Sungkyunkwan UniversitySeoulKorea School of Electrics and Computer Engineering University of TehranTehranIran School of Mechanical Engineering Amirkabir University of TechnologyTehranIran

In this paper,stability properties of Tetrosomus gibbosus have been experimentally and numerically studied in pitching *** fish lives in southern offshores of *** usually live in extremely turbulent parts of seas and oceans,with high stability and maneuverability that has caught the attention of *** body shape let them swim with a quite rapid *** on Boxfishes have had influences on automotive and marine *** CAD file of the boxfish was created using optical *** a model was built and tested in a subsonic wind tunnel and a numerical study was conducted in virtual wind *** experimental results are consistent with the numerical ones and also support the findings of other studies on similar *** results show that the flow around the fish,which is a consequence of its body shape,tries to maintain the stable position of the fish by resisting against the external force tilting the fish from its stable horizontal *** ventral and dorsal keels of the boxfish generate column-like vortices in horizontal direction which play an imperative role in maintaining the stability of the fish.

关键词： Boxfish Tetrosomus gibbosus humpback turretfish hydrodynamic stability experimental fluid mechanics bio-inspired engineering

Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2019年第2期13卷 429-455页

作者： Hassan YOUSEFI alireza TAGHAVI KANI Iradj MAHMOUDZADEH KANI School of Civil Engineering College of EngineeringUniversity of TehranTehran11155-4563Iran Department of Civil Engineering Arak University of TechnologyArak***Iran

In this study, average-interpolating radial basis functions (RBFs) are successfully integrated with central high-resolution schemes to achieve a higher-order central method. This proposed method is used for simulation of generalized coupled thermoelasticity problems including shock (singular) waves in their solutions. The thermoelasticity problems include the LS (systems with one relaxation parameter) and GN (systems without energy dissipation) theories with constant and variable coefficients. In the central high resolution formulation, RBFs lead to a reconstruction with the optimum recovery with minimized roughness on each cell: this is essential for oscillation-free reconstructions. To guarantee monotonic reconstructions at cell-edges, the nonlinear scaling limiters are used. Such reconstructions, finally, lead to the total variation bounded (TVB) feature. As RBFs work satisfactory on non-unifdrm cells/grids, the proposed central scheme can handle adapted cells/grids. To have cost effective and accurate simulations, the multiresolution-based grid adaptation approach is then integrated with the RBF-based central scheme. Effects of condition numbers of RBFs, computational complexity and cost of the proposed scheme are studied. Finally, different 1-D coupled thermoelasticity benchmarks are presented. There, perfonnance of the adaptive RBF-based formulation is compared with that of the adaptive Kurganov-Tadmor (KT) second-order central high-resolution scheme with the total variation diminishing (TVD) property.

关键词： central high resolution schemes RBFs higher order accuracy generalized thermoelasticity multiresolutionbased adaptation

Bedload resistance in supercritical flow

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2009年第4期24卷 400-409页

作者： alireza HABIBZADEH Mohammad Hossein OMID Dept.of Irrigation and Reclamation Eng. University of Tehran Dept. of Irrigation and Reclamation Eng. University of Tehran

The movement of bedload in subcritical flow produces additional roughness as compared to flow in a rigid bed. The magnitude of this bed load roughness is proportional to the thickness of the sediment layer moving along the bed, the particle size and the sediment concentration. In a supercritical flow, however, further resistance is expected due to the momentum absorption by the high flow velocity. In this study the effect of sediment movement on the flow resistance in supercritical flow was experimentally investigated. The experiments included flows over smooth and rough beds carrying sediment of mean diameters D 50 =2.80, 5.42 and 7.06 mm in a rigid rectangular channel. The results show that the sediment transport may increase the friction factor by up to 90% and 60% in smooth and rough beds, respectively. Bedload extracts its momentum from the flow, which causes a reduction of near bed flow velocity and steeper velocity gradient near the bed resulting in an increase in shear velocity as well as in roughness height. The increase in friction factor is directly related to bedload concentration and particle size.

关键词： Hydraulic resistance Friction factor Bedload transport Supercritical flow