检索结果-南通市图书馆

Effect of Co substitution on the structural,dielectric and optical properties of KBiFe_(2)O_(5)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1861-1867页

作者： K.Chandrakanta r.Jena P.pal Md.F.Abdullah S.D.Kaushik A.K.Singh Department of Physics and Astronomy National Institute of TechnologyRourkela-769008OdishaIndia UGC-DAE Consortium for Scientific research Mumbai Centre R-5 ShedBARCMumbai-400085India

Cobalt(Co)-modified brownmillerite KBiFe_(2)O_(5)(KBFO;[KBiFe_(2(1−x))Co_(2x)O_(5)(x=0,0.05)])polycrystalline is synthesized following the solid-state reaction *** refinement of X-ray diffraction data confirmed the phase purity of KBFO and KBiFe_(1.9)Co_(0.1)O_(5)(KBFCO).The optical bandgap energy(Eg)of KBFO decreased from 1.59 to 1.51 eV because of Co *** decrease in bandgap can be attributed to the tilting of the Fe–O tetrahedral structure of *** observed room-temperature raman peaks of KBFCO shifted by 3 cm^(−1) toward a lower wavenumber than that of *** shift in raman active modes can be attributed to the change in the bond angles and bond lengths of the Fe–O tetrahedral structure and modification in response to oxygen deficiency in KBFO because of Co *** with that of KBFO,the frequency-dependent dielectric constant and dielectric loss of KBFCO decrease at room temperature,which is a consequence of the reduction in oxygen migration and modification in response to vibrational modes present in the sample.

关键词： brownmillerite rietveld refinement raman spectroscopy bandgap

Frequently Used Allopathic and Traditional Medicine for COVID-19 Treatment and Feasibility of Their Integration

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2022年第11期28卷 1040-1047页

作者： Aditya Upadhayay Gopal Patel dharm pal Awanish Kumar Department of Biotechnology National Institute of TechnologyRaipurCG(492010)India Laboratory of Medicinal Plant Biotechnology College of PharmacyZhejiang Chinese Medical UniversityHangzhou(310053)China Department of Chemical Engineering National Institute of TechnologyRaipurCG(492010)India

To date,no satisfactory treatment for COVID-19 is *** review reported few recent updates regarding the drugs(allopathy/traditional medicines)used for the treatment of COVID-19 concerning clinical *** of the article spotlight the contribution of allopathic and Ayurvedic drugs to the scientific basis for utilization as a potential therapy against COVID-19 infection and provide new insights on the integration of allopathy and traditional *** advocated the combination of these two systems of treatment will ascertain their integrations,and there would be a good possibility and scope for developing a model of integration in the management of *** discussion may help researchers,physicians,and healthcare policymakers to encourage for effective and integrated use of allopathic and Ayurvedic medicines to control the COVID-19 pandemic more effectively.

关键词： COVID-19 allopathy traditional medicine integration promising therapy

Enantioselective iridium-catalyzed allylic substitution with a reformatsky reagent: direct construction of β-stereogenic homoallylic esters

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第11期67卷 3791-3797页

作者： Debasis pal Kirana DVeeranna Yuk Fai Wong PAndrew Evans Department of Chemistry Queen’s University90 Bader LaneKingstonK7L 3N6Canada Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha410013China

The reformatsky reagent derived from ethyl bromoacetate circumvents the challenge associated with the direct regio-and enantioselective iridium-catalyzed allylic alkylation with an unstabilized aliphatic ester enolate. Notably, this work represents the first example of using a reformatsky reagent in a metal-allyl reaction, which permits the direct construction of enantioenriched β-stereogenic homoallylic esters without preactivation of the pronucleophile or post-reaction modification of the product(e.g., thermal decarboxylation of a 1,3-dicarbonyl). Moreover, the process allows the coupling of a broad range of sterically and electronically diverse electrophiles bearing aryl, heteroaryl and alkenyl derivatives, including the significantly more challenging alkyl-substituted allylic carbonates. The versatility of the ester product is exemplified by a series of functional group manipulations and the development of a concise and efficient enantioselective total synthesis of the natural product,(+)-descurainolide A. Finally, mechanistic studies indicate that the zinc enolate behaves as a soft nucleophile that undergoes outer-sphere alkylation.

关键词： allylic substitution asymmetric catalysis mechanistic studies natural product synthesis reformatsky reagent

Thermal Properties of Ni–Cr–Si–B–Fe Based Interlayer Material and Its Application in TLP Bonding of IN 718 Superalloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2020年第12期33卷 1666-1680页

作者： U.K.Tarai P.S.robi Sukhomay pal Department of Mechanical Engineering IIT GuwahatiGuwahati 781039India

A new Ni–Cr–Si–B–Fe fi ller material is prepared for transient liquid-phase(TLP)bonding of Inconel 718 superalloy by mechanical alloying *** melting temperature range of the fi ller material and its activation energy of melting are determined by diff erential scanning calorimetry *** activation energy and melting temperature of the alloy powder decrease with increasing milling *** 718 alloy was joined via TLP by using the newly developed fi ller *** eff ect of TLP bonding temperature and time on microstructural evolution and mechanical properties of the joint was *** distinct microstructural regions were observed in the bonding area:isothermal solidifi cation zone consisting of a single-phase solid solution,diff usion aff ected zone consisting of extensive diff usion-induced precipitates of metallic boride,and unaff ected base *** ultimate shear strength and microhardness of the TLP-bonded joint increase with bonding time and temperature.

关键词： Transient liquid-phase(TLP)bonding Kissinger plot Mechanical alloying Inconel 718

Pipes with Trapezoidal Cut Twisted Tape Inserts in the Laminar Flow regime:Nusselt Number and Friction Coefficient Analysis

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第2期19卷 501-511页

作者： Shrikant Arunrao Thote Netra pal Singh Department of Mechanical Engineering Oriental UniversityIndore453555India

The thermal behavior of pipes with a twisted tape inside(used to enhance heat transfer through the tube wall)is studied in the laminar flow *** is used as the work fluid with the corresponding reynolds Number spanning the interval 200–*** is found that in such conditions the‘Nusselt Number’(Nu)gradually increases with reducing the tape twist ratio,whereas the friction factor is detrimentally affected by the presence of the tape(as witnessed by the comparison with the companion case where a plain tube is considered).In particular,it is shown that the heat transfer efficiency can be improved by nearly 69%if tape inserts with a relatively low twist ratio are *** the basis of these findings,it is concluded that loose fit tape inserts are superior to tight fit tapes in terms of heat transfer and ease of replacement.

关键词： Friction factor laminar flow Nusselt Number trapezoidal-cut twisted tape

Analysis of Friction and Heat Transfer Characteristics of Tubes with Trapezoidal Cut Twisted Tape Inserts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第3期19卷 711-722页

作者： Shrikant Arunrao Thote Netra pal Singh Department of Mechanical Engineering Oriental UniversityIndore453555India

The thermo-hydraulic properties of circular tubes with a twisted tape inside(used accordingly to induce turbulence and enhance heat transfer through the tube wall)are described for reynolds Numbers ranging from 830 to *** twisted with the three distinct twist ratios are considered,namely,6,4.4 and *** is used as the working fluid in several *** the sake of comparison,the standard tube with no insert is also *** is shown that in the presence of the twisted tape,the‘frictional factor’,‘Nusselt Number’and the‘thermal performance factor’are much higher than those obtained for the plain ***,the tapes having the lowest twist ratio,i.e.,3,are more effective than the others in terms of heat transfer ***‘thermal performance factor’is greater than one for all the twisted tapes used in the experiments,which confirms the enhanced performances of the heat exchanger and the related savings in terms of total energy.

关键词： Friction factor nusselt number performance ratio trapezoidal cut twisted tape insert

Management of localized prostate cancer： the pendulum swings （back to the middle）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2014年第4期16卷 570-571页

Herein, we discuss 18-year follow-up data from the Scandinavian ProstateCancer Group-4 （SPCG-4） trial, a randomized study comparing observation and radical prostatectomy （rP） in patients with localized prostate cancer. The results of this study are contrasted with another study employing a similar randomization, the Prostate Cancer Intervention Versus Observation Trial （PIVOT）. We highlight several key differences in study eligibility and enrollment that may account for distinct results, and describe how these datasets impact the complex landscape of therapy for localized prostate cancer.

关键词： @@

Voacanga grandifolia(Miq.)rolfe protects against alcohol-induced liver toxicity in rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2022年第12期12卷 504-511页

作者： Lal Chand pal Shivankar Agrawal Arti Gautam Pharmacology Division CSIR-National Botanical Research InstituteLucknow 226001Uttar PradeshIndia Department of Phytochemistry ICMR-National Institute of Traditional MedicineNehru NagarBelagavi 590010KarnatakaIndia Department of Pharmaceutical Sciences Sam Higginbottom University of AgricultureTechnology&SciencesNainiPrayagraj 211007Uttar PradeshIndia

Objective:To evaluate the ethanol extract of Voacanga grandifolia for hepatoprotective and antioxidant potential against ethanol-induced liver toxicity in ***:Sprague-Dawley rats were administered ethanol(7 g/kg)and then treated with 100 and 200 mg/kg of Voacanga grandifolia *** phytochemical constituents and antioxidant potential of Voacanga grandifolia extract were evaluated by GC-MS and in vitro antioxidant *** indicators for liver damage and pro-apoptotic and antiapoptotic gene expression were determined using biochemical kits,ELISA,and qrT-PCr,***,histopathological study of the liver was ***:GC-MS identified propanoic acid,meso-erythritol,D-pinitol,myo-inositol,and hexadecanoic acid in Voacanga grandifolia *** grandifolia extract(100 and 200 mg/kg)increased the concentration of enzymatic antioxidants while diminishing the levels of inflammatory cytokines and biochemical ***-PCr assay showed that Voacanga grandifolia extracts upregulated antiapoptotic gene expression while downregulating pro-apoptotic gene ***,the plant extract improved the hepatic architecture of ethanol-intoxicated ***:Voacanga grandifolia extract demonstrates hepatoprotective activity against alcohol-induced liver injury in rats and could be a potential hepatoprotective agent.

关键词： Antioxidant Ethanol-induced toxicity Hepatoprotective Hepatic markers Voacanga grandifolia

Influence of magneto-thermo radiation on heat transfer of a thin nanofluid film with non-uniform heat source/sink

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Propulsion and Power research 2020年第2期9卷 169-180页

作者： Dulal pal Debranjan Chatterjee Kuppalapalle Vajravelu Department of Mathematics Institute of ScienceHsva-Bharati(A Central University)SantiniketanWest Bengal731235India Department of Mathematics Bahiri B.S High SchoolBolpurBirbhumWest Bengal731204India Department of Mathematics Department of MechanicalMaterial and Aerospace EngineeringUniversity of Central FloridaOrlandoFL32816USA

The objective of the present work is to analyze the flow,heat and mass transfer characteristics in a thin nanofluid film over a heated stretched sheet in the presence of a non-uniform heat source/sink and thermal *** variables are used to transform the partial differential equations into a system of ordinary differential *** resulting system of nonlinear ordinary differential equations is then solved numerically by using the runge-Kutta-Fehlberg integration scheme with a shooting *** effects of the unsteadiness parameter,the thermal radiation,the non-uniform heat source/sink parameter on flow and heat transfer fields are *** is found that an increase in the unsteadiness parameter is to increase the velocity and temperature gradient ***,an increase in the thermal radiation parameter affects the nanoparticle temperature gradient of the nanofluid film but the reversed is true with the concentration gradient.

关键词： Magnetohydrodynamic Thermal radiation Internal heat source/Stretching sheet Thin liquid film