检索结果-南通市图书馆

Optoelectronics Letters 2024年第3期20卷 163-170页

作者： Mohammad reza alizadeh Mahmood Seifouri Saeed Olyaee Faculty of Electrical Engineering Shahid Rajaee Teacher Training UniversityTehranIran Nano-photonics and Optoelectronics Research Laboratory(NORLab) Shahid Rajaee Teacher Training UniversityTehranIran

In this paper, a photonic crystal fiber(PCF) with a dispersion-engineered and high nonlinear coefficient has been designed for supercontinuum generation(SCG) and frequency comb generation(FCG). The proposed PCF has a Si_(3)N_(4) rod in the core. This rod provides more optical confinement in the core by increasing the refractive index of the core. This high confinement reduces the effective mode area of PCF and thus increases the nonlinear coefficient.

关键词： optical fiber nonlinear

Thermodynamic study and methanothermal temperature-programmed reaction synthesis of molybdenum carbide

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 339-347页

作者： Parham Roohi reza alizadeh Esmaeil Fatehifar Chemical Engineering Faculty Sahand University of Technology

Nanostructured molybdenum carbide （Mo2C） was successfully prepared from molybdenum trioxide （MoO3） using methanothermal temperature-programmed reaction. Thermodynamic analysis indicated that in presence of methane, the formation of Mo2C from MoO3 occurs through the path of MoO3 → MoO2→ Mo2C. The carburized MoO3 was characterized using X-ray diffraction （XRD）, CHNS/O analysis, Brunauer-Emmett-Teller （BET） analysis, and field-emission scanning electron microscopy （FESEM）. At final carburization temperatures of 700 and 800℃ and at methane contents ranging from 5vol% to 20vol%, Mo2C was the only solid product observed in the XRD patterns. The re- suits indicated that the effect of methane content on the formation of the carbide phase is substantial compared with the effect of carburization time. Elemental analysis showed that at a final temperature of 700℃, the carbon content of carburized MoO3 is very close to the theoretical carbon mass percentage in Mo2C. At higher carburization temperatures, excess carbon was deposited onto the surface of Mo2C. High-surface-area Mo2C was obtained at extremely low heating rates; this high-surface-area material is a potential electrocatalyst.

关键词： molybdenum carbide thermodynamic analysis temperature programmed reaction methane

Transformation of methane to synthesis gas over metal oxides without using catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2009年第2期18卷 124-130页

作者： reza alizadeh Esmail Jamshidi Guangqing Zhang Department of Chemical Engineering Sahand University of Technology Tabriz 51335-1996 lran Department of Chemical Engineering Amirkabir University of Technology （Tehran Polytechnic） Tehran 15875-4413 lran School of Material Science and Engineering The University of New South Wales UNSW Sydney NSW 2052 Australia

This article reviews a new developing method in the field of metal oxide reduction in chemical and metallurgical processes, which uses methane as a reducing agent. Commonly, coal is used as the reducing agent in the reduction of metal oxide and other inorganic materials; Metal producing factories are among the most intensive and concentrated source of greenhouse gases and other pollutants such as heavy metals, sulfur dioxide and fly ash. Thermodynamically, methane has a great reducing capability and can be activated to produce synthesis gas over a metal oxide as an oxygen donor. Metal oxide reduction and methane activation, two concurrent thermochemical processes, can be combined as an efficient and energy-saving process; nowadays this kind of technologies is of great importance. This new reduction process could improve energy efficiencies and significantly decrease greenhouse gas emission compared to the conventional process; furthermore, the produced gases are synthesis gas that is more valuable than methane. In this paper, thermodynamic studies and advantages of this promising method were discussed. The major aim of this article is to introduce methane as a best and environmentally friendly reducing agent at low temperature.

关键词： methane metal oxide reaction reduction greenhouse gases synthesis gas

Effect of crystallographic texture and twinning on the corrosion behavior of Mg alloys:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第2期10卷 332-345页

作者： Ehsan Gerashi reza alizadeh Terence G.Langdon Department of Materials Science and Engineering Sharif University of TechnologyTehranIran Materials Research Group Department of Mechanical EngineeringUniversity of SouthamptonSouthampton SO171BJUnited Kingdom

Magnesium and its alloys have gained significant popularity due to their light weight and their potential for use as bioresorbable ***,their application is limited in practice due to their relatively poor corrosion *** methods are available for improving the corrosion resistance of Mg alloys for bio-applications such as using different coatings,alloying,and modifying the microstructural parameters such as the grain size and the crystallographic *** review provides a comprehensive summary of the effects of crystallographic texture and twinning,as one of the most important deformation mechanisms of Mg and Mg alloys,on the corrosion *** the crystallographic texture,it is shown that theoretically the basal planes should exhibit a lower corrosion rate but in some cases,such as when there is a galvanic effect or when corrosion films control the overall corrosion behavior,different results may take ***,there are contradictory results concerning the effect of twinning on the corrosion ***,in some cases twinning may provide preferential sites for corrosion due to the higher energies of atoms located in the twin region by comparison with normal atomic positions in the crystalline lattice whereas there are also other examples where experiments show that twins produce more protective films than in the surrounding matrix.

关键词： Bio-materials Corrosion Magnesium Texture Twinning

Recent advances using equal-channel angular pressing to improve the properties of biodegradable Mg-Zn alloys

在线全文

学校读者我要写书评

暂无评论

镁合金学报(英文) 2023年第7期11卷 2260-2284页

作者： Mohammad Hashemi reza alizadeh Terence G.Langdon Department of Materials Science and Engineering Sharif University of TechnologyTehranIran Materials Research Group Department of Mechanical EngineeringUniversity of SouthamptonSouthampton SO171BJUnited Kingdom

Magnesium alloys are of considerable current interest for use as degradable implants due to their unique properties including biodegrad-ability,biocompatibility,low density and adequate mechanical ***,there is a need to further improve these properties either by alloying or through the use of appropriate *** the different biodegradable Mg alloys now in use,the Mg-Zn series are of special interest and have been the subject of many research *** is primarily because Zn is an essential element for the human body in addition to its positive effects in improving the mechanical strength and lowering the degradation rate of the *** properties of Mg-Zn alloys may be further improved both through the addition of third and fourth alloying elements such as Ca,Ag,Sn or Sr and/or by thermo-mechanical processing where the latter is more environmentally and economically *** practice,procedures based on the application of severe plastic deformation(SPD)are especially suited to produce fine-grained microstructures with improved mechanical,degradation and cell ***-channel angular pressing(ECAP)is a popular SPD technique that has the capability of pro-ducing bulk materials that are sufficiently large for use as typical ***,this review is designed to provide a comprehensive summary of the research that has been undertaken on ECAP-processed biodegradable Mg-Zn alloys.

关键词： Bio-degradation ECAP Fine-grained microstructure Mg–Zn alloys Severe plastic deformation

Effects of heat treatment on the corrosion behavior and mechanical properties of biodegradable Mg alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第7期10卷 1737-1785页

作者： Meysam Mohammadi Zerankeshi reza alizadeh Ehsan Gerashi Mohammad Asadollahi Terence G.Langdon Department of Materials Science and Engineering Sharif University of TechnologyTehranIran Materials Research Group Department of Mechanical EngineeringUniversity of SouthamptonSouthampton SO171BJUnited Kingdom

Biodegradable magnesium(Mg)alloys exhibit great potential for use as temporary structures in tissue engineering *** degradable implants require no secondary surgery for their *** addition,their comparable mechanical properties with the human bone,together with excellent biocompatibility,make them a suitable candidate for fracture ***,some challenges *** degradation of the Mg-based alloys in physiological environments leads to a loss of the mechanical support that is needed for complete tissue healing and also to the accumulation of hydrogen gas bubbles at the interface of the implant and *** different methods used to improve the performance of the biodegradable Mg alloys to address these challenges,it appears that heat treatment is the most effective way to modify the microstructure and thus the corrosion behavior and mechanical properties without changing the composition or shape of the alloys.A desirable combination of corrosion and mechanical properties can be obtained through a precise control of the heat treatment *** this report,the effects of different heat treatments(T4 and T6)on the microstructure,corrosion behavior,and mechanical properties of some of the most important heat-treatable biodegradable Mg alloys(Mg-Zn,Mg-Gd,Mg-Y,Mg-Nd,Mg-Al and Mg-Ag)are examined as well as new perspectives to enhance their clinical implementation.

关键词： Biodegradable implants Corrosion rate Heat treatment Mechanical properties Mg alloys

The Effect of Emotional Intelligence Training on the Quality of Working life in Nurses

在线全文

学校读者我要写书评

暂无评论

Journal of Health Science 2015年第5期3卷 241-247页

作者： Ravanbakhsh Esmaeili reza alizadeh Navaei Amir Hossein Goudarzian Maryam Yousefi Department of Nursing and Midwifery Mazandaran University of Medical Sciences Sari 48178-44718 Iran ran Nursing Student Research Committee Mazandaran University of Medical Sciences Sari 48177-35774 Iran Environmental Health Engineering student research committee Mazandaran University of Medical Science Sari 48177-45155 Iran

Emotional intelligence is a social skill and an important component of communication. It can be expressed as the ability to correctly identify emotions, to make proper decisions and to solve problems. Based on the conducted researchs, emotional intelligence is an important factor in achieving success in life including occupation and education. This study was designed and implemented to determine the effects of emotional intelligence on the quality of nurses＇ working life. This quasi-experimental study was conducted in 2015 on 70 of hospital nurses. Samples were randomly collected and divided into 2 groups （35 nurses in each group） and training sessions of emotional intelligence were conducted. Before the first session and after session 12, the quality of working life was measured by Walton＇s standard questionnaire of working life in both groups. The average age of the control and the experimental group was 30.83 ± 3.785 and 29.54 ± 3.407 respectively. Quality of working life in the experimental group had significant positive changes in comparison with the control group （P 〈 0.001） after the completion of training sessions. Based on the results, nurses＇ quality of working life improved after training. It seems that it is possible to improve university students and nurses＂ quality of working life by holding special workshops of emotional intelligence in training centers.

关键词： Emotional intelligence training quality of working life nurse.

Seasonal Variation in Volatile Oil, Polyphenol Content and Antioxidant Activity in Extract of Laurus nobilis Grown in 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

Journal of Pharmacy and Pharmacology 2015年第5期3卷 223-231页

作者： Atefeh Bahmanzadegan Vahid Rowshan Faraneh Zareian reza alizadeh Mohammad Bahmanzadegan Department of Natural Resources Fars Research Center for Agriculture and Natural Resources Shiraz PO Box 71555-617 Iran Department of Chemistry Faculty of science Qom University Qom PO Box *** Iran Department of Mechanical engineer Faculty of science Jahrom University Jahrom PO Box 7413 766171 Iran

The leaves ofLaurus nobilis were collected in the middle of four seasons （spring, summer, autumn, and winter） to determine the best harvesting time for obtaining the highest oil yield, 1,8-cineole and polyphenol content and antioxidant activity. After drying the plant materials in shade, their EOs （essential oils） were obtained by hydro-distillation method. Analysis of variance showed harvesting time had significant effect on the oil yields of L. nobilis. Seventy one components were identified in the oils of L. nobilis with 1, 8-cineole （5.7%-42.6%）, ot-terpinyl acetate （3.2%-13.1%）, sabinene （2.3%-12.0%）, beta-elemene （0.2%-17.7%） and （E）-caryophyllene （0.2%-16.9%） as the main constituents in different seasons. The predominant phenolic constituents in L. nobilis were cinnamic acid, carvacrol, quercetin and coumarin, respectively. Gallic acid, catechin, caffeic acid, chloregenic acid, p-Comaric acid and rutin were not detected in any seasons. The best antioxidant activity was in spring （268.6μg/mL） and the lowest one was in winter （702.1μg/mL）.

关键词： Laurus nobilis EO seasonal variation polyphenol antioxidant.

Chronic effects of stretching on range of motion with consideration of potential moderating variables:A systematic review with meta-analysis

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

Journal of Sport and Health Science 2024年第2期13卷 186-194页

作者： Andreas Konrad Shahab alizadeh Abdolhamid Daneshjoo Saman Hadjizadeh Anvar Andrew Graham Ali Zahiri reza Goudini Chris Edwards Carina Scharf David George Behm Institute of Human Movement Science Sport and HealthGraz UniversityGraz A-8010Austria School of Human Kinetics and Recreation Memorial University of NewfoundlandSt.John’sNL A1C 5S7Canada Department of Sport Injuries and Corrective Exercises Faculty of Sport SciencesShahid Bahonar University of KermanKerman 76169-13439Iran

Background:It is well known that stretch training can induce prolonged increases in joint range of motion(ROM).However,to date more information is needed regarding which training variables might have greater influence on improvements in ***,the purpose of this metaanalysis was to investigate the effects of stretch training on ROM in healthy participants by considering potential moderating variables,such as stretching technique,intensity,duration,frequency,and muscles stretched,as well as sex-specific,age-specific,and/or trained state-specific adaptations to stretch ***:We searched through PubMed,Scopus,Web of Science,and SportDiscus to find eligible studies and,finally,assessed the results from 77 studies and 186 effect sizes by applying a random-effect ***,by applying a mixed-effect model,we performed the respective subgroup *** find potential relationships between stretch duration or age and effect sizes,we performed a ***:We found a significant overall effect,indicating that stretch training can increase ROM with a moderate effect compared to the controls(effect size=-1.002;Z=-12.074;95%confidence interval:-1.165 to-0.840;p<0.001;I^(2)=74.97).Subgroup analysis showed a significant difference between the stretching techniques(p=0.01)indicating that proprioceptive neuromuscular facilitation and static stretching produced greater ROM than did ballistic/dynamic ***,there was a significant effect between the sexes(p=0.04),indicating that females showed higher gains in ROM compared to ***,further moderating analysis showed no significant relation or ***:When the goal is to maximize ROM in the long term,proprioceptive neuromuscular facilitation or static stretching,rather than ballistic/dynamic stretching,should be *** to consider in future research as well as sports practice is that neither volume,intensity,nor frequency of stretching were

关键词： Flexibility Long-term stretching Stretch training

Environmentally Benign Oxidation of Some Organic Sulfides with 34% Hydrogen Peroxide Catalyzed by Simple Heteropolyoxometalates

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2007年第9期25卷 1340-1343页

作者： TAYEBEE, reza alizadeh, Mohammad Hassan Department of Chemistry Sabzevar University Sabzevar 397 lran Department of Chemistry Ferdowsi University Mashhad 91779 lran

An environmentally benign oxygenation protocol was developed for selective oxidation of some types of aromatic and aliphatic sulfides in good to excellent yields utilizing 34% hydrogen peroxide catalyzed by simple heteropolyoxometalates in normal drinking water at room temperature. The catalysts could be recovered and reused for at least seven reaction cycles under the described reaction conditions without considerable loss of reactivity. This procedure introduced a new insight into the use of simple heteropolyanions as recoverable catalysts for the oxidation of organic sulfides by an environmentally acceptable protocol. Keywords

关键词： oxidation heteropolyacid catalysis hydrogen peroxide organic sulfide