Material flow and phase transformation were studied at the interface of dissimilar joint between Al 6013 and Mg, produced by stir friction welding （FSW） experiments. Defect-free weld was obtained when aluminum and m...Material flow and phase transformation were studied at the interface of dissimilar joint between Al 6013 and Mg, produced by stir friction welding （FSW） experiments. Defect-free weld was obtained when aluminum and magnesium were placed in the advancing side and retreating side respectively and the tool was placed 1 mm off the weld centerline into the aluminum side. In order to understand the material flow during FSW, steel shots were implanted as indexes into the welding path. After welding, using X-ray images, secondary positions of the steel shots were evaluated. It was revealed that steel shots implanted in advancing side were penetrated from the advancing side into the retreating side, whereas the shots implanted in the retreating side remained in the retreating side, without penetrating into the advancing side. The welded specimens were also heat treated. The effects of heat treatment on the mechanical properties of the welds and the formation of new intermetallic layers were investigated. Two intermetallic compounds, Al3Mg2 and Al12Mg17, were formed sequentially at Al6013/Mg interface.展开更多
Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 stee...Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 steels are the state of the art process and grades, respectively; however novel processes and steel grades are under considerations. In the current research, behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized. During semi-hot stamping process, the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly, simultaneously. Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks. The hot stamped blanks attained the strength values as high as water quenched blanks. The highest ductility and consequently, the best formability were achieved for the blank which had been semi-hot stamped. It was concluded that for the mentioned steel, semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability, but also led to ultra high strength values.展开更多
Cancer is a frightful disease and represents one of the biggest health-care issues for the human race and demands a proactive strategy for cure. Plants are reservoirs for novel chemical entities and provide a promisin...Cancer is a frightful disease and represents one of the biggest health-care issues for the human race and demands a proactive strategy for cure. Plants are reservoirs for novel chemical entities and provide a promising line for research on cancer. Hitherto, being effective, chemotherapy is accompanied by certain unbearable side effects. Nevertheless,plants and plant derived products is a revolutionizing field as these are Simple, safer, ecofriendly, low-cost, fast, and less toxic as compared with conventional treatment methods.Phytochemicals are selective in their functions and acts specifically on tumor cells without affecting normal cells. Carcinogenesis is complex phenomena that involves many signaling cascades. Phytochemicals are considered suitable candidates for anticancer drug development due to their pleiotropic actions on target events with multiple manners. The research is in progress for developing potential candidates(those can block or slow down the growth of cancer cells without any side effects) from these phytochemicals. Many phytochemicals and their derived analogs have been identified as potential candidates for anticancer therapy. Effort has been made through this comprehensive review to highlight the recent developments and milestones achieved in cancer therapies using phytomolecules with their mechanism of action on nuclear and cellular factors. Furthermore, drugs for cancer treatment and their limitations have also been discussed.展开更多
Heat transport phenomenon of two-dimensional magnetohydrodynamie Casson fluid flow by employing Cattaneo-Christov heat diffusion theory is described in this work. The term of heat absorption/generation is incorporated...Heat transport phenomenon of two-dimensional magnetohydrodynamie Casson fluid flow by employing Cattaneo-Christov heat diffusion theory is described in this work. The term of heat absorption/generation is incorporated in the mathematical modeling of present flow problem. The governing mathematical expressions are solved for velocity and temperature profiles using RKF 45 method along with shooting technique. The importance of arising nonlinear quantities namely velocity, temperature, skin-friction and temperature gradient are elaborated via plots. It is explored that the Casson parameter retarded the liquid velocity while it enhances the fluid temperature. Fhrther, we noted that temperature and thickness of temperature boundary layer are weaker in case of Cattaneo-Christov heat diffusion model when matched with the profiles obtained for Fourier＇s theory of heat flux.展开更多
High temperature deformation characteristics of a semiaustenitic grade of precipitation-hardening stain- less steels were investigated by conducting hot compression tests at temperatures of 900--1 100 ℃ and strain ra...High temperature deformation characteristics of a semiaustenitic grade of precipitation-hardening stain- less steels were investigated by conducting hot compression tests at temperatures of 900--1 100 ℃ and strain rates of 0. 001--1 s^-1. Flow behavior of this alloy was investigated and it was realized that dynamic recrystallization （DRX） was responsible for flow softening. The correlation between critical strain for initiation of DRX and de- formation parameters including temperature and strain rate, and therefore, Zener-Hollomon parameter （Z） was studied. Metallographic observation was performed to determine the as-deformed microstructure. Microstructural observation shows that recrystallized grain size increases with increasing the temperature and decreasing the strain rate. The activation energy required for DRX of the investigated steel was determined using correlations of flow stress versus temperature and strain rate. The calculated value of activation energy, 460 kJ/mol, is in accordance with other studies on stainless steels. The relationship between peak strain and Z parameter is proposed.展开更多
In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with ...In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.展开更多
Wafer-level mass production of photonic integrated circuits(PIC)has become a technological mainstay in the field of optics and photonics,enabling many novel and disrupting a wide range of existing applications.However...Wafer-level mass production of photonic integrated circuits(PIC)has become a technological mainstay in the field of optics and photonics,enabling many novel and disrupting a wide range of existing applications.However,scalable photonic packaging and system assembly still represents a major challenge that often hinders commercial adoption of PIC-based solutions.Specifically,chip-to-chip and fiber-to-chip connections often rely on so-called active alignment techniques,where the coupling efficiency is continuously measured and optimized during the assembly process.This unavoidably leads to technically complex assembly processes and high cost,thereby eliminating most of the inherent scalability advantages of PIC-based solutions.In this paper,we demonstrate that 3D-printed facet-attached microlenses(FaML)can overcome this problem by opening an attractive path towards highly scalable photonic system assembly,relying entirely on passive assembly techniques based on industry-standard machine vision and/or simple mechanical stops.FaML can be printed with high precision to the facets of optical components using multi-photon lithography,thereby offering the possibility to shape the emitted beams by freely designed refractive or reflective surfaces.Specifically,the emitted beams can be collimated to a comparatively large diameter that is independent of the device-specific mode fields,thereby relaxing both axial and lateral alignment tolerances.Moreover,the FaML concept allows to insert discrete optical elements such as optical isolators into the free-space beam paths between PIC facets.We show the viability and the versatility of the scheme in a series of selected experiments of high technical relevance,comprising pluggable fiber-chip interfaces,the combination of PIC with discrete micro-optical elements such as polarization beam splitters,as well as coupling with ultra-low back-reflection based on non-planar beam paths that only comprise tilted optical surfaces.Based on our results,we believe that the FaML concept opens an 展开更多
Aging is linked to the deterioration of many physical and cognitive abilities and is the leading risk factor for Alzheimer’s disease. The growing aging population is a significant healthcare problem globally that res...Aging is linked to the deterioration of many physical and cognitive abilities and is the leading risk factor for Alzheimer’s disease. The growing aging population is a significant healthcare problem globally that researchers must investigate to better understand the underlying aging processes. Advances in microarrays and sequencing techniques have resulted in deeper analyses of diverse essential genomes(e.g., mouse, human, and rat) and their corresponding cell types, their organ-specific transcriptomes, and the tissue involved in aging. Traditional gene controllers such as DNA-and RNA-binding proteins significantly influence such programs, causing the need to sort out long non-coding RNAs, a new class of powerful gene regulatory elements. However, their functional significance in the aging process and senescence has yet to be investigated and identified. Several recent researchers have associated the initiation and development of senescence and aging in mammals with several well-reported and novel long non-coding RNAs. In this review article, we identified and analyzed the evolving functions of long non-coding RNAs in cellular processes, including cellular senescence, aging, and age-related pathogenesis, which are the major hallmarks of long non-coding RNAs in aging.展开更多
The microstructural evolution and precipitation behaviour of Nb–V–Mo and single V containing transformation induced plasticity assisted steels were investigated during thermomechanical processing. A plane strain com...The microstructural evolution and precipitation behaviour of Nb–V–Mo and single V containing transformation induced plasticity assisted steels were investigated during thermomechanical processing. A plane strain compression testing machine was used to simulate the thermomechanical processing. Microstructures were characterised by optical microscopy, scanning-transmission electron microscopy and microanalysis, and X-ray diffraction analysis, and Vickers hardness was obtained from the deformed specimens. The resulting microstructure of both Nb–V–Mo and V steels at room temperature primarily consisted of an acicular/bainitic ferrite, retained austenite and martensite surrounded by allotriomorphic ferrite.The TEM analysis showed that a significant number of Nb（V,Mo）（C,N） precipitates were formed in the microstructure down to the finishing stage in Nb–V–Mo steel（i.e. 830℃）. It was also found that the V（C,N）precipitation primarily occurred in both ferrite and deformed austenite below the finishing stage. The results suggested that Nb–Mo additions considerably increased the temperature stability of microalloy precipitates and controlled the microstructural evolution of austenite. However, the microalloy precipitation did not cause a significant precipitation strengthening in both Nb–V–Mo and V steels at room temperature.展开更多
The production of MoO3 from Sarcheshmeh molybdenite concentrate via a pyro-hydrometallurgical process was studied.The molybdenite concentrate and sodium carbonate were premixed and fused under air atmosphere.Then the ...The production of MoO3 from Sarcheshmeh molybdenite concentrate via a pyro-hydrometallurgical process was studied.The molybdenite concentrate and sodium carbonate were premixed and fused under air atmosphere.Then the fused products were leached in water and the dissolved molybdenum was recovered as ammonium molybdate.The ammonium molybdate was then calcined to produce mo-lybdic oxide.At the fusion stage,the effect of the mass ratio of carbonate to sulfide on the reaction products and the solubility of the products was investigated.The results show that during the fusion,sodium molybdate and sodium sulfate are the final reaction products and sodium sulfide is detected as an intermediate reaction product.By melting at 850℃with 5wt%excess carbonate,the maximum solubility of the products is obtained.The molybdenum is recovered from the solutions as ammonium molybdate.展开更多
The effect of vanadium （V） addition on the mechanical properties of a Cr-Ni-Mo-Cu-Ti stainless steel was studied and its influence on microstructural changes was also investigated. Results indicate that the structur...The effect of vanadium （V） addition on the mechanical properties of a Cr-Ni-Mo-Cu-Ti stainless steel was studied and its influence on microstructural changes was also investigated. Results indicate that the structure of the solution-treated specimens mainly comprises of austenite-martensite, and adding V leads to the formation of a consid erable amount of ferrite. Under this condition, austenite phase is not mechanically stable, and transforms to martensite by plastic deformation. The addition of 0.5% - 1.0% （in mass percent） of V increases the hardness and the strength of the 80% cold rolled and aged steel, without any effect on ductility. Improvement in mechanical properties is presumably attributed to the formation of a small amount of ferrite in the primary structure, and the formation of certain precipitates is accelerated by the addition of V during aging. By contrast, excessive V decreases the strength and ductility simultaneously. This is due to the strong effect of ferrite formation compared to the beneficial effect of precipitation. The loss of ductility caused by adding higher amount of V is due to the formation of ferrite phases which in turn are suitable nucleation sites for crack propagation.展开更多
In this article, a new type of coagulant material has been investigated and the performance of the coagulation process using this type of coagulant was evaluated. This new type is a combination of zinc oxide nanoparti...In this article, a new type of coagulant material has been investigated and the performance of the coagulation process using this type of coagulant was evaluated. This new type is a combination of zinc oxide nanoparticles and polyferric sulfate (ZnOPFS). The structure of zinc oxide nanoparticles was determined by spectroscopic, X-ray and electron microscopy methods, and based on this, it was determined that ZnOPFS is a complex and mixed compound that is mainly composed of zinc oxide nanoparticles and ferric sulfate. The effects of Zn/Fe (Zn/Fe) molar ratio and aging (time) on acidity and zeta potential were also evaluated using a specific method. The obtained results showed that in the simultaneous deposition process, zinc ions can prevent the formation of polyferric acid coagulation and subsequently improve the stability of ZnOPFS.展开更多
Geo-engineering problems are known for their complexity and high uncertainty levels,requiring precise defini-tions,past experiences,logical reasoning,mathematical analysis,and practical insight to address them effecti...Geo-engineering problems are known for their complexity and high uncertainty levels,requiring precise defini-tions,past experiences,logical reasoning,mathematical analysis,and practical insight to address them effectively.Soft Computing(SC)methods have gained popularity in engineering disciplines such as mining and civil engineering due to computer hardware and machine learning advancements.Unlike traditional hard computing approaches,SC models use soft values and fuzzy sets to navigate uncertain environments.This study focuses on the application of SC methods to predict backbreak,a common issue in blasting operations within mining and civil projects.Backbreak,which refers to the unintended fracturing of rock beyond the desired blast perimeter,can significantly impact project timelines and costs.This study aims to explore how SC methods can be effectively employed to anticipate and mitigate the undesirable consequences of blasting operations,specifically focusing on backbreak prediction.The research explores the complexities of backbreak prediction and highlights the potential benefits of utilizing SC methods to address this challenging issue in geo-engineering projects.展开更多
Objective:To explore expression level of interferon-stimulated genes PKR,OAS1,MX1,and ISG15 in peripheral blood mononuclear cells of COVID-19 patients.Methods:In this study,changes in the expression of four interferon...Objective:To explore expression level of interferon-stimulated genes PKR,OAS1,MX1,and ISG15 in peripheral blood mononuclear cells of COVID-19 patients.Methods:In this study,changes in the expression of four interferon-stimulated genes(ISGs),including PKR,OAS1,MX1,and ISG15,in peripheral blood mononuclear cells of 45 COVID-19 patients with different severities were evaluated by real-time PCR method.Results:OAS1,MX1,PKR,and ISG15 were differently expressed in COVID-19 patients with different severity.The results showed that the expression of OAS1,MX1,PKR,and ISG15 genes was significantly(P=0.001)lower in severe patients.Conclusions:Weak and defective IFN response and subsequent disruption of ISGs may be associated with COVID-19 severity.展开更多
A two-dimensional cellular automaton(CA)model was utilized to analyze the effect of mechanical vibration on microstructure evolution of AZ91 alloy during friction stir welding(FSW).The simulated results,namely grain t...A two-dimensional cellular automaton(CA)model was utilized to analyze the effect of mechanical vibration on microstructure evolution of AZ91 alloy during friction stir welding(FSW).The simulated results,namely grain topology,grain size distribution,average grain size,and also the dynamic recrystallization(DRX)fraction were compared with measured data.The adequate comparability between FEM and experimental data shows that the CA method can be applied to the analysis of the microstructure progression during the friction stir welding of AZ91 alloy.It is concluded that the dislocation density during the friction stir vibration welding(FSVW)is higher than that in the FSW process and the process of nucleation and grain growth is faster for samples during FSVW compared to FSW.The grain size modification and DRX phenomenon with various vibration frequencies were also simulated in detail during FSVW.It is found that vibration makes nucleation start earlier and decreases the proportion of the incubation period and the percentage of recrystallization as vibration frequency improves.展开更多
An improved method of friction stir processing(FSP)was introduced for the processing of AZ91 magnesium alloy specimens.This novel process was called“friction stir vibration processing(FSVP)”.FSP and FSVP were utiliz...An improved method of friction stir processing(FSP)was introduced for the processing of AZ91 magnesium alloy specimens.This novel process was called“friction stir vibration processing(FSVP)”.FSP and FSVP were utilized to develop surface composites on the studied alloy while SiC nanoparticles were applied as second-phase particles.The effect of reinforcing SiC particles with different sizes(30 and 300 nm)on different characteristics of the composite surface was studied.The results indicated that the microstructure was refined and mechanical properties such as hardness,ductility,and strength were enhanced as FSVP was applied.Furthermore,it was concluded that the effect of reinforcing particles with a size of 30 nm on the microstructure and mechanical properties of the surface composite was more obvious than that of particles with a size of 300 nm.It was also found that mechanical properties and microstructure of FSV-processed specimens were improved as vibration frequency increased.The hardness value in the stir zone was about 157 MPa for the FSV-processed specimen at a vibration frequency of 50 Hz,while this value was around 116 MPa for the FSV-processed specimen at a vibration frequency of 25 Hz.展开更多
CRISPR/Cas9-mediated genome editing is a powerful tool for life science research. Recently, strawberry (Fragaria × ananassa), an important horticultural crop, has emerged as a model organism for investigating the...CRISPR/Cas9-mediated genome editing is a powerful tool for life science research. Recently, strawberry (Fragaria × ananassa), an important horticultural crop, has emerged as a model organism for investigating the regulatory mechanisms of fruit development and ripening (Shulaev et al., 2011; Jia et al., 2013, 2017; Kang et al., 2013; Han et al., 2015). While most cultivated strawberries展开更多
Objective:To determine the global level of knowledge,attitudes,and practices towards dengue fever among the general population.Methods:To complete this systematic review and meta-analysis,a thorough search for pertine...Objective:To determine the global level of knowledge,attitudes,and practices towards dengue fever among the general population.Methods:To complete this systematic review and meta-analysis,a thorough search for pertinent English-language literature was undertaken during the study's extension until October 2023.The search used Google Scholar,Scopus,PubMed/MEDLINE,Science Direct,Web of Science,EMBASE,Springer,and ProQuest.A quality assessment checklist developed using a modified Newcastle-Ottawa Scale for the cross-sectional study was used to evaluate the risk of bias in the included papers.Inverse variance and Cochran Q statistics were employed in the STATA software version 14 to assess study heterogeneity.When there was heterogeneity,the Dersimonian and Liard random-effects models were used.Results:59 Studies totaling 87353 participants were included in this meta-analysis.These investigations included 86278 participants in 55 studies on knowledge,20196 in 33 studies on attitudes,and 74881 in 29 studies on practices.The pooled estimates for sufficient knowledge,positive attitudes,and dengue fever preventive behaviors among the general population were determined as 40.1%(95%CI 33.8%-46.5%),46.8%(95%CI 35.8%-58.9%),and 38.3%(95%CI 28.4%-48.2%),respectively.Europe exhibits the highest knowledge level at 63.5%,and Africa shows the lowest at 20.3%.Positive attitudes are most prevalent in the Eastern Mediterranean(54.1%)and Southeast Asia(53.6%),contrasting sharply with the Americas,where attitudes are notably lower at 9.05%.Regarding preventive behaviors,the Americas demonstrate a prevalence of 12.1%,Southeast Asia at 28.1%,Western Pacific at 49.6%,Eastern Mediterranean at 44.8%,and Africa at 47.4%.Conclusions:Regional disparities about the knowledge,attitude and preventive bahaviors are evident with Europe exhibiting the highest knowledge level while Africa has the lowest.These findings emphasize the importance of targeted public health interventions tailored to regional contexts,highlighting the need for region-specif展开更多
文摘Material flow and phase transformation were studied at the interface of dissimilar joint between Al 6013 and Mg, produced by stir friction welding （FSW） experiments. Defect-free weld was obtained when aluminum and magnesium were placed in the advancing side and retreating side respectively and the tool was placed 1 mm off the weld centerline into the aluminum side. In order to understand the material flow during FSW, steel shots were implanted as indexes into the welding path. After welding, using X-ray images, secondary positions of the steel shots were evaluated. It was revealed that steel shots implanted in advancing side were penetrated from the advancing side into the retreating side, whereas the shots implanted in the retreating side remained in the retreating side, without penetrating into the advancing side. The welded specimens were also heat treated. The effects of heat treatment on the mechanical properties of the welds and the formation of new intermetallic layers were investigated. Two intermetallic compounds, Al3Mg2 and Al12Mg17, were formed sequentially at Al6013/Mg interface.
文摘Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 steels are the state of the art process and grades, respectively; however novel processes and steel grades are under considerations. In the current research, behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized. During semi-hot stamping process, the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly, simultaneously. Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks. The hot stamped blanks attained the strength values as high as water quenched blanks. The highest ductility and consequently, the best formability were achieved for the blank which had been semi-hot stamped. It was concluded that for the mentioned steel, semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability, but also led to ultra high strength values.
文摘Cancer is a frightful disease and represents one of the biggest health-care issues for the human race and demands a proactive strategy for cure. Plants are reservoirs for novel chemical entities and provide a promising line for research on cancer. Hitherto, being effective, chemotherapy is accompanied by certain unbearable side effects. Nevertheless,plants and plant derived products is a revolutionizing field as these are Simple, safer, ecofriendly, low-cost, fast, and less toxic as compared with conventional treatment methods.Phytochemicals are selective in their functions and acts specifically on tumor cells without affecting normal cells. Carcinogenesis is complex phenomena that involves many signaling cascades. Phytochemicals are considered suitable candidates for anticancer drug development due to their pleiotropic actions on target events with multiple manners. The research is in progress for developing potential candidates(those can block or slow down the growth of cancer cells without any side effects) from these phytochemicals. Many phytochemicals and their derived analogs have been identified as potential candidates for anticancer therapy. Effort has been made through this comprehensive review to highlight the recent developments and milestones achieved in cancer therapies using phytomolecules with their mechanism of action on nuclear and cellular factors. Furthermore, drugs for cancer treatment and their limitations have also been discussed.
文摘Heat transport phenomenon of two-dimensional magnetohydrodynamie Casson fluid flow by employing Cattaneo-Christov heat diffusion theory is described in this work. The term of heat absorption/generation is incorporated in the mathematical modeling of present flow problem. The governing mathematical expressions are solved for velocity and temperature profiles using RKF 45 method along with shooting technique. The importance of arising nonlinear quantities namely velocity, temperature, skin-friction and temperature gradient are elaborated via plots. It is explored that the Casson parameter retarded the liquid velocity while it enhances the fluid temperature. Fhrther, we noted that temperature and thickness of temperature boundary layer are weaker in case of Cattaneo-Christov heat diffusion model when matched with the profiles obtained for Fourier＇s theory of heat flux.
文摘High temperature deformation characteristics of a semiaustenitic grade of precipitation-hardening stain- less steels were investigated by conducting hot compression tests at temperatures of 900--1 100 ℃ and strain rates of 0. 001--1 s^-1. Flow behavior of this alloy was investigated and it was realized that dynamic recrystallization （DRX） was responsible for flow softening. The correlation between critical strain for initiation of DRX and de- formation parameters including temperature and strain rate, and therefore, Zener-Hollomon parameter （Z） was studied. Metallographic observation was performed to determine the as-deformed microstructure. Microstructural observation shows that recrystallized grain size increases with increasing the temperature and decreasing the strain rate. The activation energy required for DRX of the investigated steel was determined using correlations of flow stress versus temperature and strain rate. The calculated value of activation energy, 460 kJ/mol, is in accordance with other studies on stainless steels. The relationship between peak strain and Z parameter is proposed.
基金the council of Iran National Science Foundation and University of Kashan for supporting this work by Grant No (159271/999)
文摘In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.
基金the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy via the Excellence Cluster 3D Matter Made to Order(EXC-2082/1-390761711)the Collaborative Research Center WavePhenomena(CRC 1173)+4 种基金by the Bundesministerium für Bildung und Forschung(BMBF)via the projects PRIMA(#13N14630),DiFeMiS(#16ES0948)which is part of the programme“Forschungslabore Mikroelektronik Deutschland(ForLab),and Open6GHub(#16KISK010)by the European Research Council(ERC Consolidator Grant‘TeraSHAPE’#773248),by the H2020 Photonic Packaging Pilot Line PIXAPP(#731954)by the Alfried Krupp von Bohlen und Halbach Foundation,and by the Karlsruhe School of Optics and Photonics(KSOP).
文摘Wafer-level mass production of photonic integrated circuits(PIC)has become a technological mainstay in the field of optics and photonics,enabling many novel and disrupting a wide range of existing applications.However,scalable photonic packaging and system assembly still represents a major challenge that often hinders commercial adoption of PIC-based solutions.Specifically,chip-to-chip and fiber-to-chip connections often rely on so-called active alignment techniques,where the coupling efficiency is continuously measured and optimized during the assembly process.This unavoidably leads to technically complex assembly processes and high cost,thereby eliminating most of the inherent scalability advantages of PIC-based solutions.In this paper,we demonstrate that 3D-printed facet-attached microlenses(FaML)can overcome this problem by opening an attractive path towards highly scalable photonic system assembly,relying entirely on passive assembly techniques based on industry-standard machine vision and/or simple mechanical stops.FaML can be printed with high precision to the facets of optical components using multi-photon lithography,thereby offering the possibility to shape the emitted beams by freely designed refractive or reflective surfaces.Specifically,the emitted beams can be collimated to a comparatively large diameter that is independent of the device-specific mode fields,thereby relaxing both axial and lateral alignment tolerances.Moreover,the FaML concept allows to insert discrete optical elements such as optical isolators into the free-space beam paths between PIC facets.We show the viability and the versatility of the scheme in a series of selected experiments of high technical relevance,comprising pluggable fiber-chip interfaces,the combination of PIC with discrete micro-optical elements such as polarization beam splitters,as well as coupling with ultra-low back-reflection based on non-planar beam paths that only comprise tilted optical surfaces.Based on our results,we believe that the FaML concept opens an
文摘Aging is linked to the deterioration of many physical and cognitive abilities and is the leading risk factor for Alzheimer’s disease. The growing aging population is a significant healthcare problem globally that researchers must investigate to better understand the underlying aging processes. Advances in microarrays and sequencing techniques have resulted in deeper analyses of diverse essential genomes(e.g., mouse, human, and rat) and their corresponding cell types, their organ-specific transcriptomes, and the tissue involved in aging. Traditional gene controllers such as DNA-and RNA-binding proteins significantly influence such programs, causing the need to sort out long non-coding RNAs, a new class of powerful gene regulatory elements. However, their functional significance in the aging process and senescence has yet to be investigated and identified. Several recent researchers have associated the initiation and development of senescence and aging in mammals with several well-reported and novel long non-coding RNAs. In this review article, we identified and analyzed the evolving functions of long non-coding RNAs in cellular processes, including cellular senescence, aging, and age-related pathogenesis, which are the major hallmarks of long non-coding RNAs in aging.
文摘The microstructural evolution and precipitation behaviour of Nb–V–Mo and single V containing transformation induced plasticity assisted steels were investigated during thermomechanical processing. A plane strain compression testing machine was used to simulate the thermomechanical processing. Microstructures were characterised by optical microscopy, scanning-transmission electron microscopy and microanalysis, and X-ray diffraction analysis, and Vickers hardness was obtained from the deformed specimens. The resulting microstructure of both Nb–V–Mo and V steels at room temperature primarily consisted of an acicular/bainitic ferrite, retained austenite and martensite surrounded by allotriomorphic ferrite.The TEM analysis showed that a significant number of Nb（V,Mo）（C,N） precipitates were formed in the microstructure down to the finishing stage in Nb–V–Mo steel（i.e. 830℃）. It was also found that the V（C,N）precipitation primarily occurred in both ferrite and deformed austenite below the finishing stage. The results suggested that Nb–Mo additions considerably increased the temperature stability of microalloy precipitates and controlled the microstructural evolution of austenite. However, the microalloy precipitation did not cause a significant precipitation strengthening in both Nb–V–Mo and V steels at room temperature.
文摘The production of MoO3 from Sarcheshmeh molybdenite concentrate via a pyro-hydrometallurgical process was studied.The molybdenite concentrate and sodium carbonate were premixed and fused under air atmosphere.Then the fused products were leached in water and the dissolved molybdenum was recovered as ammonium molybdate.The ammonium molybdate was then calcined to produce mo-lybdic oxide.At the fusion stage,the effect of the mass ratio of carbonate to sulfide on the reaction products and the solubility of the products was investigated.The results show that during the fusion,sodium molybdate and sodium sulfate are the final reaction products and sodium sulfide is detected as an intermediate reaction product.By melting at 850℃with 5wt%excess carbonate,the maximum solubility of the products is obtained.The molybdenum is recovered from the solutions as ammonium molybdate.
文摘The effect of vanadium （V） addition on the mechanical properties of a Cr-Ni-Mo-Cu-Ti stainless steel was studied and its influence on microstructural changes was also investigated. Results indicate that the structure of the solution-treated specimens mainly comprises of austenite-martensite, and adding V leads to the formation of a consid erable amount of ferrite. Under this condition, austenite phase is not mechanically stable, and transforms to martensite by plastic deformation. The addition of 0.5% - 1.0% （in mass percent） of V increases the hardness and the strength of the 80% cold rolled and aged steel, without any effect on ductility. Improvement in mechanical properties is presumably attributed to the formation of a small amount of ferrite in the primary structure, and the formation of certain precipitates is accelerated by the addition of V during aging. By contrast, excessive V decreases the strength and ductility simultaneously. This is due to the strong effect of ferrite formation compared to the beneficial effect of precipitation. The loss of ductility caused by adding higher amount of V is due to the formation of ferrite phases which in turn are suitable nucleation sites for crack propagation.
文摘In this article, a new type of coagulant material has been investigated and the performance of the coagulation process using this type of coagulant was evaluated. This new type is a combination of zinc oxide nanoparticles and polyferric sulfate (ZnOPFS). The structure of zinc oxide nanoparticles was determined by spectroscopic, X-ray and electron microscopy methods, and based on this, it was determined that ZnOPFS is a complex and mixed compound that is mainly composed of zinc oxide nanoparticles and ferric sulfate. The effects of Zn/Fe (Zn/Fe) molar ratio and aging (time) on acidity and zeta potential were also evaluated using a specific method. The obtained results showed that in the simultaneous deposition process, zinc ions can prevent the formation of polyferric acid coagulation and subsequently improve the stability of ZnOPFS.
文摘Geo-engineering problems are known for their complexity and high uncertainty levels,requiring precise defini-tions,past experiences,logical reasoning,mathematical analysis,and practical insight to address them effectively.Soft Computing(SC)methods have gained popularity in engineering disciplines such as mining and civil engineering due to computer hardware and machine learning advancements.Unlike traditional hard computing approaches,SC models use soft values and fuzzy sets to navigate uncertain environments.This study focuses on the application of SC methods to predict backbreak,a common issue in blasting operations within mining and civil projects.Backbreak,which refers to the unintended fracturing of rock beyond the desired blast perimeter,can significantly impact project timelines and costs.This study aims to explore how SC methods can be effectively employed to anticipate and mitigate the undesirable consequences of blasting operations,specifically focusing on backbreak prediction.The research explores the complexities of backbreak prediction and highlights the potential benefits of utilizing SC methods to address this challenging issue in geo-engineering projects.
基金the research council of Kerman University of Medical Sciences,Kerman,Iran(Grant Number:400000232).
文摘Objective:To explore expression level of interferon-stimulated genes PKR,OAS1,MX1,and ISG15 in peripheral blood mononuclear cells of COVID-19 patients.Methods:In this study,changes in the expression of four interferon-stimulated genes(ISGs),including PKR,OAS1,MX1,and ISG15,in peripheral blood mononuclear cells of 45 COVID-19 patients with different severities were evaluated by real-time PCR method.Results:OAS1,MX1,PKR,and ISG15 were differently expressed in COVID-19 patients with different severity.The results showed that the expression of OAS1,MX1,PKR,and ISG15 genes was significantly(P=0.001)lower in severe patients.Conclusions:Weak and defective IFN response and subsequent disruption of ISGs may be associated with COVID-19 severity.
文摘A two-dimensional cellular automaton(CA)model was utilized to analyze the effect of mechanical vibration on microstructure evolution of AZ91 alloy during friction stir welding(FSW).The simulated results,namely grain topology,grain size distribution,average grain size,and also the dynamic recrystallization(DRX)fraction were compared with measured data.The adequate comparability between FEM and experimental data shows that the CA method can be applied to the analysis of the microstructure progression during the friction stir welding of AZ91 alloy.It is concluded that the dislocation density during the friction stir vibration welding(FSVW)is higher than that in the FSW process and the process of nucleation and grain growth is faster for samples during FSVW compared to FSW.The grain size modification and DRX phenomenon with various vibration frequencies were also simulated in detail during FSVW.It is found that vibration makes nucleation start earlier and decreases the proportion of the incubation period and the percentage of recrystallization as vibration frequency improves.
基金Amirkabir University of Technology(AUT)Sharif University of TechnologyNational Elites Foundation of Iran for their support during this research.
文摘An improved method of friction stir processing(FSP)was introduced for the processing of AZ91 magnesium alloy specimens.This novel process was called“friction stir vibration processing(FSVP)”.FSP and FSVP were utilized to develop surface composites on the studied alloy while SiC nanoparticles were applied as second-phase particles.The effect of reinforcing SiC particles with different sizes(30 and 300 nm)on different characteristics of the composite surface was studied.The results indicated that the microstructure was refined and mechanical properties such as hardness,ductility,and strength were enhanced as FSVP was applied.Furthermore,it was concluded that the effect of reinforcing particles with a size of 30 nm on the microstructure and mechanical properties of the surface composite was more obvious than that of particles with a size of 300 nm.It was also found that mechanical properties and microstructure of FSV-processed specimens were improved as vibration frequency increased.The hardness value in the stir zone was about 157 MPa for the FSV-processed specimen at a vibration frequency of 50 Hz,while this value was around 116 MPa for the FSV-processed specimen at a vibration frequency of 25 Hz.
基金supported by the National Natural Science Foundation of China (Nos. 31572104, 31772284, 31471851 and 31672133)the Fok Ying-Tong Education Foundation of China (No. 151027)the Beijing Key Laboratory of New Technology in Agricultural Application (kf2016023)
文摘CRISPR/Cas9-mediated genome editing is a powerful tool for life science research. Recently, strawberry (Fragaria × ananassa), an important horticultural crop, has emerged as a model organism for investigating the regulatory mechanisms of fruit development and ripening (Shulaev et al., 2011; Jia et al., 2013, 2017; Kang et al., 2013; Han et al., 2015). While most cultivated strawberries
文摘Objective:To determine the global level of knowledge,attitudes,and practices towards dengue fever among the general population.Methods:To complete this systematic review and meta-analysis,a thorough search for pertinent English-language literature was undertaken during the study's extension until October 2023.The search used Google Scholar,Scopus,PubMed/MEDLINE,Science Direct,Web of Science,EMBASE,Springer,and ProQuest.A quality assessment checklist developed using a modified Newcastle-Ottawa Scale for the cross-sectional study was used to evaluate the risk of bias in the included papers.Inverse variance and Cochran Q statistics were employed in the STATA software version 14 to assess study heterogeneity.When there was heterogeneity,the Dersimonian and Liard random-effects models were used.Results:59 Studies totaling 87353 participants were included in this meta-analysis.These investigations included 86278 participants in 55 studies on knowledge,20196 in 33 studies on attitudes,and 74881 in 29 studies on practices.The pooled estimates for sufficient knowledge,positive attitudes,and dengue fever preventive behaviors among the general population were determined as 40.1%(95%CI 33.8%-46.5%),46.8%(95%CI 35.8%-58.9%),and 38.3%(95%CI 28.4%-48.2%),respectively.Europe exhibits the highest knowledge level at 63.5%,and Africa shows the lowest at 20.3%.Positive attitudes are most prevalent in the Eastern Mediterranean(54.1%)and Southeast Asia(53.6%),contrasting sharply with the Americas,where attitudes are notably lower at 9.05%.Regarding preventive behaviors,the Americas demonstrate a prevalence of 12.1%,Southeast Asia at 28.1%,Western Pacific at 49.6%,Eastern Mediterranean at 44.8%,and Africa at 47.4%.Conclusions:Regional disparities about the knowledge,attitude and preventive bahaviors are evident with Europe exhibiting the highest knowledge level while Africa has the lowest.These findings emphasize the importance of targeted public health interventions tailored to regional contexts,highlighting the need for region-specif
