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Effects of Multiple strengthening Treatments on Mechanical Properties and stability of Nanoscale Precipitated Phases in an Aluminum-Copper-Lithium Alloy

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Journal of Materials science & Technology 2010年第12期26卷 1078-1082页

作者： s.ahmadi H.Arabi A.shokuhfar Department of Material science Faculty of EngineeringTarbiat Modares UniversityTehranIran Center of Excellence of Advanced Materials and Processing(CEAMP) Department of Metallurgy and Materials Science and EngineeringIran University of Science & Technology(IUST)NarmakTehranIran Department of Material science Faculty of Mechanical EngineeringK.N.Toosi University of TechnologyTehranIran

Effects of multiple strengthening treatments （i.e. ag mechanical properties and stability of nanoscale prec in this research. Various tests such as hardness, tensi ng either at three or four consecutive temperatures） on pitated phases in an AA2090 alloy have been evaluated e, electrical resistance, differential scanning calorimetric （DsC）, and transmission electron microscopy （TEM） have been performed. The results show that the ultimate tensile strength （UTs） and the yield strength of the samples aged at four consecutive temperatures （i.e. natural aging＋190℃＋150℃＋100℃） can be increased approximately to 660 and 610 MPa, respectively. It is also found that precipitation of T1 phase occurs during multiple aging process of the alloy and the higher amounts of enthalpies shown in DsC charts are linked to higher volume fraction of this precipitate. Furthermore, TEM observations reveal that T1 phase has plate shape morphology and its crystal structure is in the form of hcp with lattice parameters of a=0.467 nm and c=0.878 nm.

关键词： Multiple strengthening Thermo mechanical treatment (TMT) selected area electron diffraction (sAED) pattern Inter planar spacing (d)

Evaluation of the Electroslag Remelting Process in Medical Grade of 316LC stainless steel

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Journal of Materials science & Technology 2009年第5期25卷 592-596页

作者： s.ahmadi H.Arabi A.shokuhfar A.Rezaei Institute of Advanced Technologies for Metallic Materials Tarbiat Modares University Center of Excellence of Advanced Materials and Processing(CEAMP) Department of Metallurgy and Materials Science and EngineeringIran University of Science&Technology(IUST) Department of Material science Faculty of Mechanical EngineeringK.N.Toosi University of Technology

This study is focused on the effects of electroslag remelting by prefused slag （CaO, Al2O3, and CaF2） on macrostructure and reduction of inclusions in the medical grade of 316LC （316LVM） stainless steel. Analysis of the obtained results indicated that for production of a uniform ingot structure during electroslag remelting, shape and depth of the molten pool should be carefully controlled. High melting rates led to deeper pool depth and interior radial solidification characteristics, while decrease in the melting rates caused more reduction of nonmetallic inclusions. Large shrinkage cavities formed during the conventional casting process in the primary ingots were found to be the cause of the fluctuation in the melting rate, pool depth and extension of equiaxed crystals zone.

关键词： Ultra clean steel Electroslag Radial solidification remelting Prefused slag Vertical solidification

L^q Inequalities and Operator Preserving Inequalities

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Analysis in Theory and Applications 2014年第4期30卷 377-386页

作者： M.Bidkham s.ahmadi Department of Mathematics Semnan University

Let Pn be the class of polynomials of degree at most n. Rather and shah [15] proved that if P∈Pn and P（z） 6=0 in｜z｜〈1, then for every R〉0 and 0≤q〈∞,｜B[P（Rz）]｜q≤｜RnB[zn]＋λ0｜q｜1＋zn｜q ｜P（z）｜q, where B is a Bn-operator. In this paper, we prove some generalization of this result which in particular yield-s some known polynomial inequalities as special. We also consider an operator Dαwhich maps a polynomial P（z） into DαP（z）：=nP（z）＋（α-z）P′（z） and obtain exten-sions and generalizations of a number of well-known Lq inequalities.

关键词： Complex polynomial polar derivative B-operator.

用声学技术进行发电机线棒电老化过程中的局部放电检测

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国外大电机 2015年第2期 38-40页

作者： s.ahmadi 冯超

局部放电是检测发电机线棒绝缘状况的有效工具。可以使用多种方法检测发电机线棒的局部放电活动。声学检测局部放电已经得到广泛的应用。与电气检测方法相比，声学检测具有一些优势，例如对电磁场的抗干扰能力。本文中将对空冷发电机线... 详细信息

局部放电是检测发电机线棒绝缘状况的有效工具。可以使用多种方法检测发电机线棒的局部放电活动。声学检测局部放电已经得到广泛的应用。与电气检测方法相比，声学检测具有一些优势，例如对电磁场的抗干扰能力。本文中将对空冷发电机线棒（额定电压15．75kV）进行电应力老化试验。电老化试验参照IEEE1553．2002标准执行。每天记录发电机线棒在电老化过程中由局部放电产生的声学信号，电老化时长共计500h。在线棒上选取2点作为测试点。其中1点在线棒的一端，而另1点在线棒的中心。声学传感器的信号输出到80MHz的PC机A／D（模，数）卡中，并用传感器的最大频率带宽进行滤波。老化过程中检测声学信号的变化。（测得的）变化表明在初期（开始的几天）局部放电产生的声学信号幅值增加，随后减小，最后在老化过程中保持恒定。

关键词：发电机线棒老化局部放电声学

Efficient degradation of dye pollutant via Z-scheme ball milled ZnO-LaO-s powder photocatalyst

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Transactions of Nonferrous Metals society of China 2024年

作者： saeid ZAREI Hossein RAANAEI sara ahmadi saeed KAMALI Department of Physics， Faculty of Nano and Bio science and Technology， Persian Gulf University Chemistry Department， Faculty of science， University of Malaya Department of Physics and Astronomy， Middle Tennessee state University

This investigation aimed to analyze the degradation of Eriochrome Black T （EBT） dye using a semiconductor photocatalyst synthesized through mechanical alloying. Various characterization methods， including X-ray diffraction （XRD）， energy-dispersive X-ray spectroscopy （EDX）， and X-ray photoelectron spectroscopy （XPs）， were employed to study the properties of the photocatalysts. After 35 h of milling， a ball milled mixed metal oxides was formed as confirmed by XRD analysis. EDX and XPs analyses revealed significant differences in adsorption features with and without light exposure. The band gap of the 35 h ball milled sample was determined to be 4.08 eV. To optimize the EBT degradation， artificial neural network genetic algorithms were used to determine the optimal values for ZnO-La2O3dosage， lamp power， and pH， which were found to be 0.43， 52.06， and 3， respectively. The Z-scheme mechanism， supported by band gap， Fermi level， and work function analysis， was found to be responsible for the photocatalytic process. The photocatalysts demonstrated good reusability and high stability. Overall， the results suggest that the synthesized photocatalyst holds promising potential for the degradation of EBT dye in wastewater treatment.

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Advances in oral mesenchymal stem cell-derived extracellular vesicles in health and disease

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Genes & Diseases 2024年第1期11卷 346-357页

作者： Huanyu Luo Anahid ahmadi Birjandi Feilong Ren Tianmeng sun Paul T.sharpe Hongchen sun Zhengwen An Department of Oral Biology Jilin Provincial Key Laboratory of Tooth Development and Bone RemodelingSchool and Hospital of StomatologyJilin UniversityChangchunJilin 130021China Faculty of Dentistry Oral&Craniofacial SciencesCentre for Craniofacial and Regenerative BiologyKing's College LondonLondonSE19RTUK Department of Oral Pathology Jilin Provincial Key Laboratory of Tooth Development and Bone RemodelingSchool and Hospital of StomatologyJilin UniversityChangchunJilin 130021China

Extracellular vesicles(EVs)are nano-size vesicles secreted naturally by all cells into the extracellular space and have been recognized as important cell-cell mediators in multicel-lular *** contain nucleic acids,proteins,lipids,and other cellular components,regulating many basic biological processes and playing an important role in regenerative med-icine and *** can be traced to their cells of origin and exhibit a similar ***,EVs demonstrate low immunogenicity,good biocompatibility,and fewer side ef-fects,compared to their parent *** stem cells(MsCs)are one of the most important resource cells for EVs,with a great capacity for self-renewal and multipotent differ-entiation,and play an essential role in stem cell *** mechanism of MsC therapy was thought to be attributed to the differentiation of MsCs after targeted migration,as previously ***,emerging evidence shows the previously unknown role of MsC-derived para-crine factors in stem cell *** EVs derived from oral tissue MsCs(OMsC-EVs),show more advantages than those of all other MsCs in tissue repair and regeneration,due to their lower invasiveness and easier accessibility for sample ***,we systematically review the biogenesis and biological characteristics of OMsC-EVs,as well as the role of OMsC-EVs in intercellular ***,we discuss the potential therapeutic roles of OMsC-EVs in oral and systemic *** highlight the current challenges and future directions of OMsC-EVs to focus more attention on clinical *** aim to provide valuable insights for the explorative clinical application of OMsC-EVs.

关键词： Disease Extracellular vesicles Oral tissue MsC Therapeutic application Tissue regeneration

Robotic-assisted retroperitoneal lymph node dissection for stage II testicular cancer

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Asian Journal of Urology 2024年第1期11卷 121-127页

作者： George McClintock Ahmed s.Goolam Don Perera Ryan Downey scott Leslie Peter Grimison Henry Woo Peter Ferguson Nariman ahmadi Department of Urology Chris O'Brien LifehouseSydneyNSWAustralia Department of Anaesthesia Chris O'Brien LifehouseSydneyNSWAustralia The University of sydney SydneyNSW2006Australia Department of Medical Oncology Chris O'Brien LifehouseSydneyNSWAustralia

Objective:To evaluate the perioperative as well as early oncological outcomes of patients undergoing robotic retroperitoneal lymph node dissection for treatment of testicular ***:We conducted a prospective consecutive case series of patients undergoing robotic assisted retroperitoneal lymph node dissection for metastatic testicular cancer between May 2018 and July 2021 at our *** were collected on patient and tumour characteristics,intraoperative and postoperative parameters,and functional and oncological *** statistics are ***:Nineteen patients were identified;18(94.7%)completed the procedure robotically and one was converted to open surgery;78.9%of patients had stage≥IIB and 12(63.2%)patients had undergone prior *** median operative time was 300(interquartile range[IQR]240-315)*** blood loss was 100(IQR 50-175)*** length of stay was 2(range 1-11)*** robotically completed patients commenced diet and passed flatus on Day 1 and were discharged by Day *** median lymph node yield was 40.5(IQR 38-51)*** patients undergoing nerve-sparing procedures recovered antegrade ejaculatory *** patient had a Clavien-Dindo III complication(chylous ascites requiring drainage).At a median follow-up of 22.3(IQR 16.3-24.9)months,one patient developed retroperitoneal recurrence,which was successfully treated with second-line chemotherapy;no other patients have had ***:Robotic retroperitoneal lymph node dissection is a safe and feasible alternative to open surgery in appropriately selected patients,offering low *** oncological outcomes are *** cohorts and longer follow-ups are required to validate our institution's findings.

关键词： Retroperitoneal lymph node dissection Robotic surgery Testicular cancer Retroperitoneal node dissection

special Column on Recent Advances in PCMs as Thermal Energy storage in Energy systems

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Journal of Thermal science 2024年第2期33卷 395-395页

作者： Mohammad Hossein ahmadi Tingzhen MING Marc A.ROsEN s.A.sHERIF Mohammad Mehdi RAsHIDI shahrood University of Technology Iran Wuhan University of Technology China University of Ontario Institute of Technology Canada University of Florida USA University of Electronic science and Technology of China China

Thermal energy storage technology has the advantages of high energy storage density,small size,and high energy conversion *** is one of the key energy storage technologies and an important way to achieve carbon peaking and carbon neutrality *** change materials (PCMs) offer this opportunity to store high amount of energy and release it in the form of latent heat when needed,and therefore have the advantage of being capable to alleviate the intrinsic intermittency of renewable power production,especially in wind and solar farms.

关键词： efficiency store latent

surveying organic matter， thermal maturity level， and paleo-environmental conditions by considering biomarker and stable carbon isotopic analysis

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Journal of Earth science 2024年

作者： Meysam Hemmati Yaser ahmadi Behzad Vaferi Ali Hosin Alibak David A.Wood DWA Energy Limited school of Geology， College of science， University of Tehran Petroleum Engineering Department， Faculty of Engineering， soran University Department of Chemical Engineering， shiraz Branch， Islamic Azad University Chemical and Petroleum Engineering Department， Ilam University

Biomarker and stable carbon isotope analyses are presented for the Garau formation of the Cretaceous age， an important source rock in western Iran， to reveal its potential as an oil-prone source rock. The C28/C29sterane ratio value range (0.72 to 0.83) of bitumen samples from the formation suggests that they were likely formed during phytoplankton blooms. sterane， hopane， and isoprenoid/n-alkane ratios indicate that the formation’s organic matter predominantly consists of algae， and bacteria， accompanied by some reworked material derived from higher plants. Due to the predominance of anoxic conditions and the actions of sulfate-reducing bacteria， the bitumen present is enriched with sulfur compounds. The percentages of saturates， aromatics， and nitrogen-sulfur-oxygen (NsO) fractions in the bitumen samples classify them as naphthenic oils. Isotope analysis reveals that biodegradation and water-washing have reduced the concentrations of some volatile saturates and low molecular weight aromatics in the bitumen samples. These actions have resulted in distinctive δ13C values for the formation’s kerogen and bitumen fractions. The formation’s organic matter has been subjected to high-temperature thermal regimes and has entered the oil-generation window at the sampled localities， with vitrinite reflectance (%RC) varying between 0.7% and 0.75%.

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