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低温多向锻造锆-4合金的力学性能和超细晶组织演化（英文）

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中国有色金属学报：英文版 2015年第7期25卷 2221-2229页

作者： d.FULORIA S.GOEL R.JAYAGANTHAN d.srivastava G.K.dEY N.SAIBABA department of Metallurgical and Materials Engineering Centre of Nanotechnology ⅡT Roorkee Materials Science division Bhabha Atomic Research Center Nuclear Fuel Complex Limited

研究低温（77K）多向锻造锆-4合金累积应变为1.48,2.96,4.44和5.91时的力学性能和组织演变。通过万能拉伸测试和维氏硬度实验测得多向锻造合金的力学性能。相对于原始合金,当锆-4合金变形的累积变形为5.91时,其极限抗拉强度从474MPa提高... 详细信息

研究低温（77K）多向锻造锆-4合金累积应变为1.48,2.96,4.44和5.91时的力学性能和组织演变。通过万能拉伸测试和维氏硬度实验测得多向锻造合金的力学性能。相对于原始合金,当锆-4合金变形的累积变形为5.91时,其极限抗拉强度从474MPa提高到717MPa,维氏硬度从HV 190提高到HV 238。然而,由于锆-4合金的低应变硬化,其延展性显著降低（18%-3.5%）。变形合金强度和硬度的提高是因为多向锻造引起的晶粒尺寸效应和高的位错密度。采用光学显微镜和透射电镜表征变形试样的显微组织演化。当累积应变为5.91时,经12次多向锻造后合金的微观组织演化主要是超细晶的形成,其平均晶粒尺寸为150-250nm。

关键词：锆-4合金多向锻造低温超细晶显微组织演变力学性能

两相区各相激活能对Zr-2.5Nb-0.5Cu合金本构方程的影响（英文）

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Transactions of Nonferrous Metals Society of China 2017年第1期27卷 172-183页

作者： K.K.SAXENA S.K.JHA V.PANCHOLI G.P.CHAUdHARI d.srivastava G.K.dEY N.SAIBABA department of Metallurgical and Materials Engineering Indian Institute of TechnologyRoorkee-247667UttarakhandIndia Nuclear Fuel Complex Limited Hyderabad-501301India Materials Science division Bhabha Atomic Research CenterMumbai-40085India department of Mechanical Engineering Insitute of Engineering and TechnologyGLA UinversityMathura-281406Uttar PradeshIndia

通过计算Zr-2.5Nb-0.5Cu合金两相区各相激活能,研究该合金在热变形过程中的主要存在相。在温度为700~925°C、应变速率为10^(-2)~10^(-3) s^(-1)的条件下对Zr-2.5Nb-0.5Cu合金进行热机械压缩实验。单相流动应力推广用于两相区各相流动... 详细信息

通过计算Zr-2.5Nb-0.5Cu合金两相区各相激活能,研究该合金在热变形过程中的主要存在相。在温度为700~925°C、应变速率为10^(-2)~10^(-3) s^(-1)的条件下对Zr-2.5Nb-0.5Cu合金进行热机械压缩实验。单相流动应力推广用于两相区各相流动应力的计算,然后利用所得两相区流动应力数据来计算各相的激活能。对计算所得激活能数据进行比较可知,α相为两相区的主要相(形变控制相)。根据形变温度范围或各相存在形式,采用正弦双曲线型本构方程建立了合金的本构方程。统计学分析结果表明,从相关系数(R)和平均相对误差(AARE)考虑,采用为某特定相建立的本构方程所得计算结果与实验结果相符。

关键词： Zr-2.5Nb-0.5Cu合金热变形激活能本构方程两相材料

Natural product-based treatment potential for type 2 diabetes mellitus and cardiovascular disease

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World Journal of diabetes 2024年第7期15卷 1603-1614页

作者： dharmsheel Shrivastav Satyam Kumar Kumbhakar Shivangi srivastava desh deepak Singh Amity Institute of Biotechnology Amity University RajasthanJaipur 303002RajasthanIndia department of Biotechnology Govt Veer Surendra Say P.G.CollegeGariaband 493889ChhattisgarhIndia department of Life Science Chhatrapati Shahu ji Maharaj UniversityKanpur 208024Uttar PradeshIndia

BACKGROUNd Type 2 diabetes(T2d)is a metabolic disease of impaired glucose utilization and a major cause of cardiovascular disease(CVd).The pathogenesis of both diseases shares common risk factors and mechanisms,and both are significant contributors to global morbidity and *** of natural products for T2d mellitus(T2dM)and CVd can be seen as a potential preventive and effective therapeutic *** To critically evaluate the therapeutic potential of natural products in T2d and coronary artery disease(CAd).METHOdS By using specific keywords,we strategically searched the PubMed *** controlled trials(RCTs)were searched as the primary focus that examined the effect of natural products on glycemic control,oxidative stress,and antioxidant *** focused on outcomes such as low blood glucose levels,adjustment on markers of oxidative stress and *** screening fulllength papers,we included 9 RCTs in our review that met our inclusion *** In the literature search on the database,we found that various natural products like plant secondary metabolites play a diverse role in the management of *** ginseng,sesame oil and cocoa flavanols proved effective in lowering blood glucose levels and controlling blood pressure,which are key factors in managing T2dM and *** diabetic patients Melissa officinalis effectively reduce inflammation and shows diabetes *** fish oil and flaxseed oil reduced insulin levels and inflammatory markers,suggesting benefits for both *** lipid profile and endothelial function were enhanced by Nigella sativa oil and Terminalia chebula,which is significant for the management of cardiovascular risk factors in *** Bilberry extract also showed promise for improving glycemic control in patients with *** The high level of antioxidant,anti-inflammatory,and anti-angiogenic properties found in natural products makes them promising therapeutic opt

关键词： Type 2 diabetes mellitus Cardiovascular disease Natural products Antioxidants Oxidative stress Therapeutic impact Global burden

Flavonoid Myricetin as Potent Anticancer Agent: A Possibility towards development of Potential Anticancer Nutraceuticals

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Chinese Journal of Integrative Medicine 2024年第1期30卷 75-84页

作者： Anchal Trivedi Adria Hasan Rumana Ahmad Sahabjada Siddiqui Aditi srivastava Aparna Misra Snober S.Mir department of Biochemistry Era's Lucknow Medical College&HospitalEra UniversityLucknow(226003)India Molecular Cell Biology Laboratory Integral Information and Research Centre-4(IIRC-4)Department of BioengineeringFaculty of EngineeringIntegral UniversityLucknow(226026)India department of Biotechnology Era's Lucknow Medical College&HospitalEra UniversityLucknow(226003)India department of Biosciences Faculty of ScienceIntegral UniversityLucknow(226026)India

Good nutrition plays a crucial role in maintaining a balanced lifestyle. The beneficial effects of nutrition have been found to counteract nutritional disturbances with the expanded use of nutraceuticals to treat and manage cardiovascular diseases, cancer, and other developmental defects over the last decade. Flavonoids are found abundantly in plant-derived foods such as fruits, vegetables, tea, cocoa, and wine. Fruits and vegetables contain phytochemicals like flavonoids, phenolics, alkaloids, saponins, and terpenoids. Flavonoids can act as anti-inflammatory, anti-allergic, anti-microbial(antibacterial, antifungal, and antiviral) antioxidant, anti-cancer, and anti-diarrheal agents. Flavonoids are also reported to upregulate apoptotic activity in several cancers such as hepatic, pancreatic, breast, esophageal, and colon. Myricetin is a flavonol which is naturally present in fruits and vegetables and has shown possible nutraceutical value. Myricetin has been portrayed as a potent nutraceutical that may protect against cancer. The focus of the present review is to present an updated account of studies demonstrating the anticancer potential of myricetin and the molecular mechanisms involved therein. A better understanding of the molecular mechanism(s) underlying its anticancer activity would eventually help in its development as a novel anticancer nutraceutical having minimal side effects.

关键词： myricetin flavonoids anticancer nutraceuticals Chinese medicine Ayurveda complementary and alternative medicine

Synthesis and enhanced photoluminescence properties of red emitting divalent ion(Ca^(2+))doped Eu:Y_(2)O_(3)nanophosphors for optoelectronic applications

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Journal of Rare Earths 2022年第8期40卷 1187-1198页

作者： Arpita dwivedi Monika srivastava Ankur dwivedi Amit srivastava Anurag Mishra S.K.srivastava department of Physics Institute of ScienceBanaras Hindu University(BHU)Varanasi221005India School of Materials Science and Technology Indian Institute of Technology(BHU)Varanasi221005India department of Mining Engineering Indian Institute of Technology(BHU)Varanasi221005India department of Physics TdPG College VBS Purvanchal UniversityJaunpur222001India

This work presents the synthesis of Y_(2)O_(3):Eu^(3+),χCa^(2+)(χ=0 mol%,1 mol%,3 mol%,5 mol%,7 mol%,9 mol%,11 mol%)nanophosphors with enhanced photoluminescence properties through a facile solution combustion method for optoelectronic,display,and lighting *** X-ray diffraction(XRd)patterns of the proposed nanophosphor reveal its structural properties and crystalline *** transmission electron microscope(TEM)results confirm the change in the shape of the particle and aggregation of particles after co-doping with Ca^(2+).Fourier transform infrared spectroscopy(FTIR)and Raman vibrations also confirm the presence of Y-O vibration and subsequently explain the crystalline nature,structural properties,and purity of the *** the synthesized nanophosphors samples emit intense red emission at 613 nm(~5d_(0)→~7 F_(2))under excitation with 235,394 and 466 nm wavelengths of Eu^(3+)*** photoluminescence(PL)emission spectra excited with 235 nm illustrate the highest emission peak with two other emission peaks excited with 466 and 394 nm that is 1.4 times higher than 466 nm and 1.9 times enhanced by 394 nm wavelength,*** emission intensity of Y_(2)O_(3):Eu^(3+),χCa^(2+)(5 mol%)is increased 8-fold as compared to Eu:Y_(2)O_(3).doping with Ca^(2+)ions enhances the emission intensity of Eu:Y_(2)O_(3)nanopho sphors due to an increase in energy transfer in Ca^(2+)→Eu^(3+)through asymmetry in the crystal field and by introduction of radiative defect centers through oxygen vacancies in the yttria *** is also observed that the optical band gap and the lifetime of the~5d_(0)level of Eu^(3+)ions in Y_(2)O_(3):Eu^(3+),xCa^(2+)nanophosphor sample gets changed with a doping conce ntration of Ca^(2+)*** also reveals high thermal stability and quantum yield as estimating activation energy of 0.25 eV and 81%,***,CCT,and color purity values(>98%)show an improved red-emitting nanophosphor in the warm region of light,which m

关键词： Red emission Photoluminescence(PL) Y_(2)O_(3):Eu^(3+),xCa^(2+) Rare earths Nanophosphors LEds

The divergence of nearby trajectories in soft-sphere dEM

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Particuology 2022年第4期20卷 1-8页

作者： William d.Fullmer Roberto Porcu Jordan Musser Ann S.Almgren Ishan srivastava National Energy Technology Laboratory MorgantownWV 26507USA NETL Support Contractor MorgantownWV 26507USA Center for Computational Sciences and Engineering.Lawrence Berkeley National Laboratory BerkeleyCA 94720USA

The n-body instability is investigated with the soft-sphere discrete element *** divergence of nearby trajectories is quantifed by the dynamical memory *** the inverse proportionality between the dynamical memory time and the largest Lyapunov exponent,the soft-sphere discrete ele-ment method results are compared to previous hard-sphere molecular dynamics data for the first *** agreement is observed at low concentrations and the degree of instability is shown to increase asymptotically with increasing spring *** particle concentrations above 30%,the soft-sphere Lya-punov exponents increase faster than the corresponding hard-sphere *** paper concludes with a demonstration of how this case study may be used in conjunction with regression testing and code verification activities.

关键词： Soft-sphere dEM Chaos Lyapunov exponent

Application of IITM-RANS3d to free-fall water entry of prismatic and non-prismatic finite wedges

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水动力学研究与进展B辑:英文版 2023年第3期35卷 417-430页

作者： Shaswat Saincher Kshitij srivastava R.Vijayakumar V.Sriram Center for Maritime Experiments to Maritime Experience(ME2ME) Indian Institute of Technology MadrasChennaiIndia department of Ocean Engineering Indian Institute of Technology MadrasChennaiIndia

High-speed watercraft and ships undergo coupled motions which make the front portion of the hull exit and violently re-enter *** induces short-term slamming loads that may compromise the structural integrity of the *** slamming of the bow can be modeled as straight wedges of different deadrise angles(dRAs)falling into water from different *** advent of computational fluid dynamics has allowed the problem of wedge-slamming to be simulated using the full Navier-Stokes equations thus complementing the pioneering studies based on ***,most researchers are opting to use commercial software to simulate the wedge-impact problem as it allows access to overset meshing algorithms which are robust in modeling the wedge as a moving *** boundary methods(EBMs)offer some advantages over overset meshing in that the mesh only needs to be generated once and Cartesian mesh-based solvers can be ***,the application of EBMs to wedge-impact has been limited in the literature and merits further *** this context,we investigate the applicability of the fast-fictitious-domain(FFd)based embedded boundary treatment to simulate the violent water-entry of *** extend our in-house Navier-Stokes model IITM-RANS3d to handle floating bodies through integration of a rigid-body dynamics solver and an algorithm to embed three-dimensional stereolithography(STL)geometries as solids over a Cartesian *** proposed algorithm is extensively benchmarked against variable dRA wedge-slamming experiments reported in the literature as well as constant dRA wedge-slamming experiments performed *** good agreement is reported in terms of the time-history of hydrodynamic impact pressures measured at various locations on the hull as well as the wedge motion responses thus demonstrating the suitability of FFd for simulating the coupled hydrodynamics of slamming for simplified hull geometries.

关键词： Wedge water entry slamming fast-fictitious-domain IITM-RANS3d experiments

Synthesis and Biological Study of Some 4-oxo-Thiazolidine derivatives of 2-Aminothiazole

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Chinese Journal of Chemistry 2011年第5期29卷 1001-1010页

作者： Samadhiya Pushkal Sharma Ritu srivastava Santosh K. srivastava Savitri d. Synthetic Organic Chemistry Laboratory Department of Chemistry Dr. H.S. Gour University (A Central University) Sagar M.P. 470003 India

Conventional and microwave assisted synthesis of new series of N-[2-{2-（substituted phenyl）-4-oxo- 5-（substituted benzylidene）-1,3-thiazolidine}-iminoethyl]-2-aminothiazole 5a-Sin have been developed. The cycloaddition reaction of thioglycolic acid with N-{2-（substituted benzylidenehydrazino）-ethyl}-2-aminothiazole 3a--3m in the presence of anhydrous ZnC12 afforded new heterocyclic compounds N-[2-{2-（substituted phenyl）- 4-oxo-l,3-thiazolidine}-iminoethyl]-2-aminothiazole 4a---4m. The later product on treatment with several selected substituted aromatic aldehydes in the presence of C2HsONa undergoes Knoevenagel reaction to yield 5a--Sin. The structures of compounds 1, 2, 3a--3m, 4a---4m and 5a--Sm were confirmed by IR, IH NMR, 13C NMR, FAB-Mass and chemical analysis. All above compounds were screened for their antimicrobial activities against some selected bacteria and fungi and antituberculosis study against M. tuberculosis.

关键词： conventional microwave synthesis 2-aminothiazole 4-oxo-thiazolidine antimicrobial antitubercular

Synthesis of N1-3-{（4-Substituted aryl-3-chloro-2-oxo- azetidine）-iminocarbamyl}-propyl-6-nitroindazole derivatives and Their Biological Significance

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Chinese Journal of Chemistry 2011年第8期29卷 1745-1752页

作者： Samadhiya, Pushkal Sharma, Ritu srivastava, Santosh K. srivastava, Savitri d. Synthetic Organic Chemistry Laboratory Department of Chemistry Dr. H. S. Gour University (A Central Univer- sity) Sagar M.P. 470003 India

Synthesis of N1-3-{（4-substitute daryl-3-chloro-2-oxo-azetidine）-iminocarbamyl}-propyl-6-nitroindazole 4a-- 4s was conducted by a conventional method. All the compounds were synthesized and characterized by IR, 1H NMR, 13C NMR, FAB-Mass techniques and chemical methods. All the final synthesized compounds were evaluated for their antimicrobial activity and antitubercular activity with MIC values against some selected microorganisms.

关键词： synthesis 6-nitroindazole 2-azetidinone biological activity