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Review of recent trends in friction stir welding process of aluminum alloys and aluminum metal matrix composites

Transactions of Nonferrous metals Society of China 2021年第11期31卷 3281-3309页

作者： John victor CHRISTY Abdel-Hamid ISmAIL mOURAD muhammad m.SHERIF B.SHIVAmURTHY mechanical Engineering Department College of EngineeringUnited Arab Emirates UniversityAl-AinP.O.Box.15551United Arab Emirates mechanical Design Department Faculty of EngineeringHelwan UniversityCairoEgypt National Water and Energy Center United Arab Emirates UniversityAl Ain 15551United Arab Emirates Civil Construction and Environmental Engineering DepartmentCollege of EngineeringUniversity of Alabama–BirminghamBirminghamALUSA Department of mechanical&manufacturing Engineering Manipal Institute of TechnologyManipal Academy of Higher EducationManipalKarnatakaIndia

Welding is a vital component of several industries such as automotive,aerospace,robotics,and *** welding,these industries utilize aluminum alloys for the manufacturing of many components or ***,fusion welding of aluminum alloys is challenging due to several factors,including the presence of non-heat-treatable alloys,porosity,solidification,and liquation of *** manufacturers adopt conventional in-air friction stir welding(FSW)to weld metallic alloys and dissimilar *** researchers reported the drawbacks of this traditional in-air FSW technique in welding metallic and polymeric materials in general and aluminum alloys and aluminum matrix composites in specific.A number of FSW techniques were developed recently,such as underwater friction stir welding(UFSW),vibrational friction-stir welding(VFSW),and others,for welding of aluminum alloy joints to overcome the issues of welding using conventional ***,the main objective of this review is to summarize the recent trends in FSW process of aluminum alloys and aluminum metal matrix composites(Al mmCs).Also,it discusses the effect of welding parameters of the traditional and state-of-the-art developed FSW techniques on the welding quality and strength of aluminum alloys and Al *** among the techniques and advantages and limitations of each are *** review suggests that VFSW is a viable option for welding aluminum joints due to its energy efficiency,economic cost,and versatile modifications that can be employed based on the *** review also illustrated that significantly less attention has been paid to FSW of Al-mmCs and considerable attention is demanded to produce qualified joint.

关键词： aluminum alloys aluminum matrix composites traditional FSW techniques state-of-the-art FSW techniques microstructure mechanical properties

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CHEmICAL SENSITIZATION OF TABULAR－GRAIN EmUL－SIONS IN THE PRESENCE OF SENSITIZING DYE

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影像科学与光化学 1995年第3期 277-285页

作者： WEIDE victor YANG(3m Printing & Publishing Systems Division,St.Paul,55144,USA)

ＣＨＥＭＩＣＡＬＳＥＮＳＩＴＩＺＡＴＩＯＮＯＦＴＡＢＵＬＡＲ－ＧＲＡＩＮＥＭＵＬ－ＳＩＯＮＳＩＮＴＨＥＰＲＥＳＥＮＣＥＯＦＳＥＮＳＩＴＩＺＩＮＧＤＹＥ￥ＣＨＥＭＩＣＡＬＳＥＮＳＩＴＩＺＡＴＩＯＮＯＦＴＡＢＵＬＡＲ－Ｇ... 详细信息

ＣＨＥＭＩＣＡＬＳＥＮＳＩＴＩＺＡＴＩＯＮＯＦＴＡＢＵＬＡＲ－ＧＲＡＩＮＥＭＵＬ－ＳＩＯＮＳＩＮＴＨＥＰＲＥＳＥＮＣＥＯＦＳＥＮＳＩＴＩＺＩＮＧＤＹＥ￥ＣＨＥＭＩＣＡＬＳＥＮＳＩＴＩＺＡＴＩＯＮＯＦＴＡＢＵＬＡＲ－ＧＲＡＩＮＥＭＵＬ－ＳＩＯＮＳＩＮＴ...

关键词： AgX silver halide T-grain emulsion chemical sensitization

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Strong shape-dependence of morin transition in α-Fe2O3 single-crystalline nanostructures

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Nano Research 2015年第6期8卷 1906-1916页

作者： JunWang victor Aguilar Le Li Fa-gen Li Wen-zhong Wang Guo-meng Zhao Department of Physics Faculty of Science Ningbo University Ningbo China Department of Physics and Astronomy California State University Los Angeles CA 90032 USA School of Science Minzu University of China Beijing 100081 China

Single-crystalline hematite （α-Fe2O3） nanorings （short nanotubes） and nanotubes were synthesized by a hydrothermal method. High-resolution transmission electron microscopy and selected-area electron diffraction confirm that the axial directions of both the nanorings and nanotubes are parallel to the crystalline c-axis. Intriguingly, the morin transition occurs at about 210 K in the short nanotubes with a mean tube length of about 115 nm and a mean outer diameter of about 169 nm. However, it does not occur in the nanotubes with a mean tube length of about 317 nm and a mean outer diameter of about 148 nm. Detailed analysis of magnetization data, X-ray diffraction patterns, and room-temperature m6ssbauer spectra demonstrates that this very strong shape-dependence of morin transition is intrinsic to hematite. We explain this intriguing shape- dependence quantitatively, in terms of the opposite signs of the surface mag- netic anisotropy constants of the surface planes parallel and perpendicular to the c-axis.

关键词： hematite nanostructures morin transition shape-dependence surface magneticanisotropy

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Natural history of Valentin’s rock lizard(Darevskia valentini) in Armenia

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Zoological Research 2019年第4期40卷 277-292页

作者： Eduard Galoyan Alisa Bolshakova manush Abrahamyan Ruzanna Petrosyan Valeria Komarova victor Spangenberg marine Arakelyan Zoological museum of the Lomonosov moscow State University Moscow 125009Russia Department of Zoology Biological Faculty of Moscow State UniversityMoscow 119992Russia Department of Zoology Biological Faculty of Yerevan State UniversityYerevan 0025Armenia Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences Moscow 119071Russia Vavilov Institute of General Genetics Russian Academy of SciencesMoscow 119991Russia

Valentin's rock lizard (Darevskia valentini) is suggested to be the pare nt for several parthenoge netic species (e.g., D. armeniaca, D. bendimahiensis, D. sapphirina, and D. unisexualis) that evolved through hybridization. Complex evolutionary processes (ineluding reticulate evolution) are occurring within the areas where Valentin' s rock lizard coexists with these and other rock lizards. Hence, a detailed biological specification of this species is important for understanding how vertebrates evolve. Valentin's rock lizard is a longlived (up to 9 years), small diurnal lizard with larger females than males, which is unlike other species of the genus. Their relatively large eggs and early reproducti on period, which occurs just after emerge nee from winter shelters, are adaptatio ns for living in a high elevation climate (higher than 2 000 m a.s.l.). Their body temperatures (31 -32℃) are comparable to body temperatures of rock lizards living in milder climates, though female body temperature is more depe ndent on substrate temperature and basking due to their lower activity than that found in males. Population density fluctuates from several individuals to several hundred per hectare and is not affected by parthenogen coexistenee, although hybrids do occur in sexually biased populations where males are more common than females. The male home range is larger than that of females, though these home ranges broadly overlap. Prey is not limited in the mountain meadows and Valentin's rock lizards feed on a great variety of arthropods. Infan ticide occurs in high-de nsity populati ons.

关键词： Darevskia valentini Reproduction Population density Skeletochronology Home range Seasonal activity

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Ganglion cells apoptosis in diabetic rats as early prediction of glaucoma:a study of Brn3b gene expression and association with change of quantity of NO, caspase-3, NF-κB, and TNF-α

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International Journal of Ophthalmology(English edition) 2020年第12期13卷 1872-1879页

作者： Irwan Tjandra Purnomo Soeharso Widya Artini Nurjati Chairani Siregar Andi Arus victor Department of Biomedical Science Faculty of MedicineUniversitas IndonesiaJakarta 12930Indonesia Department of Biology Faculty of MedicineUniversitas IndonesiaJakarta 12930Indonesia Department of Ophthalmology Faculty of MedicineUniversitas IndonesiaJakarta 12930Indonesia Department of Anatomic Pathology Faculty of MedicineUniversitas IndonesiaJakarta 12930Indonesia

AIm:To find a new concept to show whether or not apoptosis of retinal ganglion cells(RGCs)canbe determined in the histology of acute hyperglycemia in the role of expressed Brn3b gene related to nitric oxide(NO),caspase-3,nuclear factor kappa-B(NF-κB),and tumor necrosis factor-α(TNF-α)as an early predictor of primary open angle glaucoma(POAG)eyes and their ***:Experimental in vivo study was carried out using adult male,white Sprague-Dawley rats aged≥2 mo,weighing 150-200 *** animals were divided into two groups,one group receiving intraperitoneal injection of streptozotociz 50 mg/kg in 0.01 mol/L citricbuffer and p H 4.5 and a comparison made with the control *** tissue was divided into two parts(both experimental and control groups respectively):a)right retina for immunohistochemistry(IHC;caspase-3 and TNF-α);b)left retina was divided into two parts for the purpose of real-time polymerase chain reaction(PCR)test(RNA extraction for Brn3b gene expression analysis)and ELISA test(NO and NF-κB).RESULTS:The experimental group showed a decrease in Brn3b gene expression compared to the control group(1.3-fold lower in 2nd month;1.1-fold lower in 4th month and 2.5-fold lower in 6th month).However,there was a decrease of NO,caspase-3,and an increase of NF-κB and TNF-α***:The expression of m RNA Brn3b gene is inversely proportional to apoptosis in *** quantity of NO,caspase-3,NF-κB and TNF-αis influential in expression of Brn3b in RGCs caused by hyperglycemia in diabetic rats.

关键词： retinal ganglion cells primary open angle glaucoma Brn3b apoptosis nitric oxide caspase-3 nuclear factor kappa-B tumor necrosis factor-α

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Effect of homogenization process on the hardness of Zn-Al-Cu alloys

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International Journal of minerals,metallurgy and materials 2015年第10期22卷 1076-1081页

作者： Jose D.Villegas-Cardenas maribel L.Saucedo-munoz victor m.Lopez-Hirata Antonio De Ita-De la Torre Erika O.Avila-Davila Jorge Luis Gonzalez-Velazquez Department of metallurgy and materials Instituto Politecnico Nacional(IPN-ESIQIE)Mexico City 07300Mexico Department of Industrial Engineering Universidad Politecnica del Valle de MexicoMexico CityMexico Department of materials Universidad Autonoma Metropolitana(UAM)Unidad AzcapotzalcoMexico

The effect of a homogenizing treatment on the hardness of as-cast Zn–Al–Cu alloys was investigated. Eight alloy compositions were prepared and homogenized at 350 °C for 180 h, and their Rockwell 'B' hardness was subsequently measured. All the specimens were analyzed by X-ray diffraction and metallographically prepared for observation by optical microscopy and scanning electron microscopy. The results of the present work indicated that the hardness of both alloys(as-cast and homogenized) increased with increasing Al and Cu contents; this increased hardness is likely related to the presence of the θ and τ′ phases. A regression equation was obtained to determine the hardness of the homogenized alloys as a function of their chemical composition and processing parameters, such as homogenization time and temperature, used in their preparation.

关键词： zinc–aluminum–copper alloys casting hardness homogenization phases microstructure

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On the mystery of the Interpulse Shift in the Crab Pulsar

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Journal of Physical Science and Application 2017年第4期7卷 11-27页

作者： victor m. Kontorovich Sergii V. Trofymenko Institute of Radio Astronomy of National Academy of Sciences of Ukraine Kharkov 61002 Ukraine Akhiezer Institute for Theoretical Physics of NSC "Kharkov Institute of Physics and Technology" Kharkov 61108 Ukraine Karazin Kharkov National University Kharkov 61022 Ukraine

A new mechanism of radiation emission in the polar gap of a pulsar is proposed. It is the curvature radiation emitted by positrons moving towards the surface of the neutron star along inclined magnetic field and reflected from the surface. Such radiation interferes with transition radiation emitted from the neutron star when positrons hit the surface. Proposed mechanism explains the mystery of the interpulse shift in the Crab pulsar at high frequencies discovered by moffett and Hankins twenty years ago. We have found also reflected energy flux and spectrum, discussed coherence and disappearance of interpulse shift with increase of frequency.

关键词： Neutron stars pulsar PSR B0531+21 non-thermal radiation mechanisms shift of interpulse coherem emission radiation energy spectrum.

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A Dynamic Forecasting System with Applications in Production Logistics

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厦门大学学报（自然科学版） 2002年第S1期41卷 133-134页

作者： CHEUNG Chi-fai LEE Wing-bun LO victor Department of Industrial and Systems Engineering The Hong Kong Polytechnic University Hung HomDepartment of Industrial and Systems EngineeringThe Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong ChinaKowloonHong Kong China Kaz (Fast East) Ltd Room 1705-07Kodak House II39 Healthy Street EastNorth Point Hong Kong China

Production logistics involve the co-ordination of ac tivities such as production and materials control (PmC), inventory management, p roduct life cycle management, etc. Those activities demand for an accurate forec asting model. However, the conventional methods of making sell and buy decision based on human forecast or conventional moving average and exponential smoothing methods is no longer be sufficient to meet the future need. Furthermore, the un derlying statistics of the market information change from time to time due to a number of reasons such as change of global economic environment, government poli cies and business risks. This demands for highly adaptive forecasting model which is robust enough to response and adapt well to the fast changes in the dat a characteristics, in other words, the trajectory of the "dynamic characteristic s" of the data. In this paper, an adaptive time-series modelling method was proposed for short -term dynamic forecasting. The method employs an autoregressive (AR) time-seri es model to carry out the forecasting process. A modified least mean square (mLm S) adaptive filter algorithm was established for adjusting the AR model coeffici ents so as to minimise the sum of squared of forecasting errors. A prototype dyn amic forecasting system was built based on the adaptive time-series modelling m ethod. Basically, the dynamic forecasting system can be divided into two phases, i.e. the Learning Phase and the Application Phase. The learning procedures star t with the determination of upper limit of the adaptation gain based on the conv ergence in the mean square criterion. Hence, the optimum ELmS filter parameters are determined using an iteration algorithm which changes each filter parameter i.e. the order, the adaptation gain andthe values initial coefficient vector on e by one inside a predetermined iteration range. The set of parameters which giv es the minimum value for sum of squared errors within the iteration range is sel ecte

关键词： adaptive time-series model dynamic forecasting production logistics modified least mean square algorithm

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Confirmatory factor analysis of VISA-P scale and measurement invariance across sexes in athletes with patellar tendinopathy

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Journal of Sport and Health Science 2017年第3期6卷 365-371页

作者： Sergio Hernandez-Sanchez Ferran Abat maría D.Hidalgo Antonio I.Cuesta-Vargas victor Segarra Jose m.Sanchez-Ibanez Antonia Gomez-Conesa Department of Pathology and Surgery Physiotherapy AreaMiguel Hernandez UniversityValencia 03550Spain Sports Orthopaedic Surgeon ReSport ClinicBarcelona 08017Spain Department of Basic Psychology and methodology University of MurciaMurcia 30100Spain Department of Physiotherapy Faculty of Health SciencesUniversity of MalagaMalaga 29009Spain

Background:The victorian Institute of Sport Assessment–Patella(VISA-P) scale is the most condition-specific patient-reported outcome measure used to assess symptom severity in athletes with patellar *** exploratory factor analyses have been conducted to evaluate the scale's dimensionality,with inconsistent results,and the factor structure of the scale remains *** aims of the present study were to determine the factorial structure of the VISA-P scale using confirmatory factor analysis(CFA) and test measurement invariance across ***:The study included a convenience sample of 249 Spanish athletes with patellar *** was performed to assess factorial *** 1-and 2-factor models were *** invariance across sexes was evaluated via multi-group CFA with several fit indices using EQS 6.1 ***:The internal consistency coefficient was *** CFA models were examined and the 1-factor model in which errors for Items 7 and8 were correlated showed acceptable fit in terms of comparative fit index(CFI) and goodness-of-fit index(GFI) statistics(CFI = 0.93;GFI = 0.94;standardized root mean square residual = 0.06;root mean square error of approximation = 0.10;90% confidence interval:0.08–0.13).This model was invariant across ***:The 1-factor model of the Spanish version of the VISA-P scale(VISA-P-Sp) in which errors for Items 7 and 8 were correlated demonstrated relative fit in *** obtained via VISA-P-Sp can be compared between men and women without sexes *** studies should examine the VISA-P scale and other single-score patient-reported outcome measures concurrently.

关键词： Jumper's knee measurement invariance Patient-reported outcome measure Structural validity

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Primary parahiatal hernias:A case report and review of the literature

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World Journal of Clinical Cases 2019年第23期7卷 4020-4028页

作者： Silviu Daniel Preda Stefan Patrascu Bogdan Silviu Ungureanu Daniel Cristian Vasile Bintintan Cristian m Nica Valentin Calu victor Strambu Konstantinos Sapalidis Valeriu marin Surlin 1^(st) Clinic of Surgery Clinical Emergency Hospital of CraiovaUniversity of Medicine and Pharmacy of CraiovaCraiova 200642DoljRomania Gastroenterology Clinic Clinical Emergency Hospital of CraiovaUniversity of Medicine and Pharmacy of CraiovaCraiova 200642DoljRomania Departament of General Surgery “Coltea”Clinical HospitalCarol Davilla University of Medicine and PharmacyBucharest 030171Romania 1^(st) Clinic of Surgery of Cluj Napoca Iuliu Hatieganu University of Medicine and Pharmacy Cluj NapocaCluj Napoca 400006ClujRomania 3^(rd) Clinic of Surgery Timisoara Emergency Clinical County Hospital“Victor Babes”University of Medicine and Pharmacy of TimisoaraTimisoara 300723Romania Clinic of Surgery “Elias”Emergency University Hospital BucharestUniversity of Medicine and Pharmacy“Carol Davila”Bucharest 011461Romania Clinic of Surgery of“Dr.Carol Davila”Nephrology Clinical Hospital University of Medicine and Pharmacy“Carol Davila”Bucharest 010731Romania 3^(rd) Surgery Clinic University General Hospital of ThessalonikiAristotle University of ThessalonikiSalonic 54636Greece

BACKGROUND Parahiatal hernias(PHHs)are rare occurring disease,with a reported incidence of 0.2%-0.35%in patients undergoing surgery for hiatal *** found only a handful of cases of primary PHHs in the *** aim of this paper is to present a case of a primary PHH and perform a systematic review of the *** SUmmARY We report the case of a 60-year-old Caucasian woman with no history of thoracoabdominal surgery or trauma,which accused epigastric pain,starting 2 years prior,pseudo-angina and *** on imagistic findings the patient was diagnosed with a PHH and an associated type I hiatal *** underwent laparoscopic surgery and we found an opening in the diaphragm of 7 cm diameter,lateral to the left crus,through which 40%-50% of the stomach had herniated in the thorax,and a small sliding hiatal hernia with an anatomically intact hiatal orifice but slightly *** performed closure of the defect,suture hiatoplasty and a“floppy”Nissen *** outcome was uneventful,with the patient discharged on the fifth postoperative *** performed a review of the literature and identified eight articles regarding primary *** data was compiled into one tabled and *** Primary PHHs are rare entities,with similar clinical and imagistic findings with paraesophageal *** usually includes laparoscopic approach with closure of the defect and the esophageal hiatus should be dissected and *** outcome is favorable in all cases reviewed and no recurrence is cited in the literature.

关键词： Parahiatal Hernia Review Literature Case report

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