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Friction 2021年第6期9卷 1749-1765页

作者： k.e.ch.vidyasagar R.k.PANDeY Dinesh kALYANASUNDARAM Center for Biomedical engineering Indian Institute of Technology DelhiNew Delhi 110016India Department of Biomedical engineering College of EngineeringOsmania UniversityTelangana 500007India Department of Mechanical engineering Indian Institute of Technology DelhiNew Delhi 110016India Department of Biomedical engineering Indian Institute of Technology DelhiNew Delhi 110016India

In case of lightly loaded radial ball bearings,failure mechanisms other than fatigue such as smearing of raceways due to increased frictional torque and vibrations often ***,attempts have been made herein for reducing the frictional torque and minimizing the vibrations of a radial deep groove ball bearing employing surface textures at the inner *** pulsed laser was used to create texture(involving micro-dimples having different dimple area density)on the inner race of test *** an in-house developed test rig,frictional torque and vibrational parameters were measured at different speeds and light loads(*** vicinity of 0.01C,where C is dynamic load capacity of radial ball bearing).Significant reduction in frictional torque and overall vibrations were found in the presence of micro-dimples on inner race at light loads irrespective of operating *** without satisfying the minimum load needed criteria for the satisfactory operation,substantial reduction in smearing marks was found on the races of textured ball bearings in comparison to conventional cases.

关键词： ball bearing textured inner race grease lubricated frictional torque vibration

Improvement of Deep Groove Ball Bearing’s Performance Using a Bionic Textured Inner Race

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Journal of Bionic engineering 2021年第4期18卷 974-990页

作者： k.e.ch.vidyasagar R.k.Pandey Dinesh kalyanasundaram Center for Biomedical engineering Indian Institute of Technology DelhiNew Delhi110016India Department of Biomedical engineering College of EngineeringOsmania UniversityHyderabad500007India Department of Mechanical engineering Indian Institute of Technology DelhiNew Delhi110016India Department of Biomedical engineering All India Institute of Medical SciencesNew Delhi110029India

Micro-textured surfaces have improved the tribological performance of contact surfaces under lubricated conditions;however,not practiced due to manufacturing *** addition to simpler micro-pits or straight-trench type textures,sophisticated bioinspired textures on commercial radial ball bearings have been scarcely *** this work,Dendroaspis polylepis(Mamba snake)skin-type textures were fabricated on the inner race of FAG radial ball bearings using a nanosecond fiber laser *** the snake textures were primarily meant to enhance friction,the dimensions of the texture have been carefully chosen to improve the tribological performance under lubricated *** textured bearings were assembled and experimented at various rotational speeds and lightly loaded conditions to measure vibrational amplitude,frictional torque,and temperature *** to untextured(conventional)bearing,the snake-skin type textured bearings resulted in improved tribo-dynamic performance.

关键词： bionic texture radial ball bearing frictional torque vibration temperature

enhanced saturation magnetization in La^(3+) doped NiCo ferrites prepared by sol-gel auto-combustion method

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Journal of Rare earths 2024年第8期42卷 1546-1554,I0005页

作者： Maddileti Jelli vidyasagar Thopudurthy krishna Reddy C.V. Department of Physics Rayalaseema UniversityKurnoolA.P518007.Iindia Department of Physics Government PolytechnicRayachotiA.P516269India

Lanthanum doped nickel-cobalt nano ferrites with chemical formula Ni_(0.5)Co_(0.5)LaxFe_(2-x)O_(4)(x=0.05,0,10,0.15 and 0,20) were prepared using a simple sol-gel auto combustion *** basic structural properties were determined by X-ray diffraction method and the formation of single phased spinel ferrite was *** crystalline size decreased from 25 to 11 nm and lattice parameter a increases with increase of La *** surface morphology of these ferrites was observed by field-emission scanning electron microscopy(FeSeM) and agglomerated irregular grains are observed with increase of the rare earth element La ***-dispersive X-ray spectroscopy(eDX) result confirms the presence of the required *** Fourier transform infrared spectroscopy(FTIR) spectrum indicates the formation of the spinel ferrite structure with M-O *** direct band measurements from ultraviolet-visible spectroscopy(UV-Vis) spectroscopy indicate that the direct band gap decreases from 1.39 to 1.19 eV for x=0.05 to x=0.15,then increases to 1.28 eV for x=*** room temperature magnetic properties of these ferrites were studied by a vibrating sample magnetometer(VSM).The enhanced saturation magnetization of 49.73 emu/g is observed for x=0.10 and then saturation magnetizations are gradually decreased for x=0.15 and x=*** the remanent magnetization and coercivity also follow the same trend.

关键词： Ferrites Sol-gel auto combustion La doping Magnetic properties Rare earths

Geochemistry and mineral chemistry of the armoor granitoids,eastern dharwar craton: implications for the redox conditions and tectono-magmatic environment

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Acta Geochimica 2024年第1期43卷 110-133页

作者： A.Ajay kumar ch.Ashok Department of Geology Osmania UniversityHyderabad 500007India CSIR-National Geophysical Research Institute UppalHyderabad 500007India

The mineralogical and geochemical characteristics of the k-rich granites from the Armoor granitic rocks in the northeastern portion of the eastern Dharwar Craton(eDC) are *** order to understand its physicochemical conditions,the petrogenesis of the granitoid was explained from biotite chemistry and geochemical *** of mineral chemistry expose that compositionally,k-feldspar and plagioclase in Armoor granite rocks range from An0,Ab_(3-5.9),Or_(94-96.9) and An_(5-29,-Ab71.9-94.9),Or_(0-1.5),*** mineral chemistry of biotite crystals exhibits composition that varies from primary to re-equilibrated primary *** biotites from the Armoor granites generally exhibit an I-type trend,with calc-alkaline parental magma in a subduction *** chemistry of granites displays magnetite(oxidized)series nature,which has oxygen fugacity(fO_(2))=-15.1 to-16.7(log_(10) bar),under high oxidizing *** and pressure estimates for the crystallization of Armoor granites based on biotite composition are T=612-716 ℃ and 1.0-0.4 kbar,***,these rocks are metaluminous to slightly peraluminous and magnesian,with calc-alkaline potassiumrich *** the chondrite normalized Ree diagram,the granites have positive europium anomalies;rich Sr/Y,(Dy/Yb)_(N) ratios and reduced Mg#,Rb/Sr,Rb,Sr indicate that the melting of earlier rocks,crystal accumulation and residual garnet source formed at high *** examined granites show that they are produced from the melting of crustal ***,the extensive analyses of the described Armoor granite suggest that they were produced by crust sources and developed under oxidizing conditions in subduction setting.

关键词： Armoor granites Oxygen fugacity Crystal accumulation Remelting Subduction

exploration of chromene-based BioAIegens

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National Science Review 2024年第3期11卷 47-48页

作者： Fritz e.kühn Department of chemistry&Catalysis Research Center School of Natural Sciences Technical University of Munich

Photoemission efficiency is usually higher in solution than in solid *** compounds however, display a reverse behavior. Such a behavior is called aggregation-induced emission(AIe).

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evolution of tectonic landscapes and deformation in the southeast kumaun and western Nepal Himalaya

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Journal of Mountain Science 2024年第8期21卷 2592-2617页

作者： khayingshing LUIReI Girish ch.kOTHYARI Param k GAUTAM Ambar SOLANkI Atul kumar PATIDAR Sentisenla JAMIR Anirudh DATTA Tanupriya chOUDHURY Wadia Institute of Himalayan Geology Dehradun 248001India Department of Petroleum engineering and earth Sciences University of Petroleum and Energy StudiesDehradun248007India Department of Geology Nagaland UniversityKohima 797004India Academy of Scientific and Innovative Research Ghaziabad 201002India CSe Department Graphic Era deemed to be UniversityDehradun 248002India CSe Department Symbiosis Institute of TechnologySymbiosis International(Deemed University)Pune 412114India

The area of the present investigation’s expanse constitutes the southernmost extent of the southeast kumaun Himalaya and western Nepal *** approaches have been employed to understand the landforms associated with tectonic deformation,through detailed field investigation supplemented by the geodetic,chronological,and morphometric *** morphogenic expressions of the Main Boundary Thrust(MBT)are reflected in the form of~25 km long e-W trending north dipping fault *** deformation along the strike length of the Himalayan Frontal Thrust(HFT)is noticed in the form of uplifted and incised fill terraces,and strath *** deformation within the fluvial sequences in the study area can be visualized in the form of sheared boulders and pebbles,tilted and faulted terrace ***,the chronological data of fluvial landforms in the study area suggests two major phases of tectonic deformations that have occurred around 58.7±10.8 ka and 3.88±0.4 *** chronology of late-Quaternary landforms advocates that the initial stage of aggradations in the Himalayan foothills commenced around 75.1±0.58 *** aggradational landforms resulted from the diverse depositional regime as evident from the nature of the sediment sequences from clasts dominated to thick mud *** rate of deformation in the southeastern kumaun and western Nepal Himalaya is±7 mm/yr,as per the data obtained from the Persistent Scatterer Interferometric Synthetic Aperture Radar(PSInSAR).The landform deformation pattern,phase of incision and aggradation,frequent occurrence of landslides,and recent past earthquake activity within the wide zone of the HFT,the MBT,and Ramgarh Thrust suggests that the southernmost front of the kumaun Himalaya is active and has potential for future *** foothill zone of Himalayan towns are actively growing in terms of population and infrastructural ***,such intradisciplinary studies for tectonically active r

关键词： MBT HFT Fault trace Quaternary deposits sheared boulders

Bile acids,gut microbiota,and therapeutic insights in hepatocellular carcinoma

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Cancer Biology & Medicine 2024年第2期21卷 144-162页

作者： Yang Song Harry ch Lau Xiang Zhang Jun Yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesCUHK Shenzhen Research InstituteThe Chinese University of Hong KongHong KongChina Department of Gastroenterology Zhongshan Hospital Xiamen UniversityXiamen 361004China

Hepatocellular carcinoma(HCC)is a prevalent and aggressive liver *** interplay between bile acids(BAs)and the gut microbiota has emerged as a critical factor in HCC development and *** normal conditions,BA metabolism is tightly regulated through a bidirectional interplay between gut microorganisms and *** gut microbiota plays a critical role in BA metabolism,and BAs are endogenous signaling molecules that help maintain liver and intestinal *** note,dysbiotic changes in the gut microbiota during pathogenesis and cancer development can disrupt BA homeostasis,thereby leading to liver inflammation and fibrosis,and ultimately contributing to HCC ***,understanding the intricate interplay between BAs and the gut microbiota is crucial for elucidating the mechanisms underlying *** this review,we comprehensively explore the roles and functions of BA metabolism,with a focus on the interactions between BAs and gut microorganisms in ***,therapeutic strategies targeting BA metabolism and the gut microbiota are discussed,including the use of BA agonists/antagonists,probiotic/prebiotic and dietary interventions,fecal microbiota transplantation,and engineered *** summary,understanding the complex BA-microbiota crosstalk can provide valuable insights into HCC development and facilitate the development of innovative therapeutic approaches for liver malignancy.

关键词： Bile acid gut microbiota hepatocellular carcinoma therapeutics microbiota modulation

emission colour tuning in kLnF_(4):Yb^(3+),er^(3+)/Ho^(3+)phosphor

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Journal of Rare earths 2024年第1期42卷 57-65,I0002页

作者： Janani k Gayathri e Vijayatha V Ramasubramanian S Thiyagarajan P Department of Science and Humanities Nehru Institute of TechnologyKaliapuramThirumalayampalayamCoimbatoreIndia Department of Sciences Amrita School of Physical SciencesAmrita Vishwa VidyapeethamCoimbatoreIndia Department of Physics Anna UniversityChennaiIndia

kLnF_(4):Yb^(3+),er^(3+)/Ho^(3+)(Ln=Y,Yb,Gd)phosphors were prepared by solid-state reaction *** each of the Yb^(3+)/er^(3+)and Yb^(3+)/Ho^(3+)co-doped phosphors independently,phase confirmation and morphological examination were accomplished using the X-ray diffraction technique and scanning electron microscope analysis.X-ray photoelectron spectroscopy analysis shows the charge state and existence of lanthanides and *** luminescence emissions of green and red colour were detected for the synthesized *** changes in the upconverted emission intensities and colour output pertaining to the change of the lanthanide host matrix along with dopants were investigated for the prepared *** the upconversion luminescence,erbium-doped samples exhibit a predominance of red emission while holmium-doped samples display a prevalence of green *** rare-earth er/Ho doped kYbF4shows strong red emission compared to other ***_(4):Yb,er/Ho exhibits relatively significant green upconve rsion emissions,while Yb,er-doped kGdF_(4)host displays a 10-fold increase in green/red emission ratio with an increase in the input power of 20-780 *** photoluminescence studies and decay curve analysis were carried out using UV light excitation for the developed phosphors.A higher lifetime of 2.2 ms was measured for the downshifting red emission in the Ho doped kYbF_(4)*** study suggests a potential for colour tunability in the upconversion and downshifting emissions through host modifications to the fluoride phosphor.

关键词： Rare earths energy transfer upconversion Downshifting Colour coordinates

enhanced quantum resources via two distant atom-cavity systems under the influence of atomic dissipation

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Communications in Theoretical Physics 2024年第2期76卷 62-73页

作者： M Setodeh kheirabady M k Tavassoly M Rafeie e Ghasemian Laser and Optics Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran Department of electrical engineering Faculty of Intelligent Systems Engineering and Data SciencePersian Gulf UniversityBushehrIran

Quantum resources such as entanglement and coherence are the holy grail for modern quantum technologies. Although the unwanted environmental effects tackle quantum information processing tasks, suprisingly these key quantum resources may be protected and even enhanced by the implementation of some special hybrid open quantum systems. Here, we aim to show how a dissipative atom-cavity-system can be accomplished to generate enhanced quantum *** do so, we consider a couple of dissipative cavities, where each one contains two effective two-level atoms interacting with a single-mode cavity field. In practical applications, a classical laser field may be applied to drive each atomic subsystem. After driving the system, a Bell-state measurement is performed on the output of the system to quantify the entanglement and coherence. The obtained results reveal that the remote entanglement and coherence between the atoms existing inside the two distant cavities are not only enhanced, but can be stabilized, even under the action of dissipation. In contrast, the local entanglement between two atoms inside each dissipative cavity attenuates due to the presence of unwanted environmental ***, the local coherence may show the same behavior as the remote ***, the system provides the steady state entanglement in various interaction regimes,particularly in the strong atom-cavity coupling and with relatively large detuning. More interestingly, our numerical analyses demonstrate that the system may show a memory effect due to the fact that the death and revival of the entanglement take place during the interaction. Our proposed model may find potential applications for the implementation of long distance quantum networks. In particular, it facilitates the distribution of quantum resources between the nodes of large-scale quantum networks for secure communication.

关键词： remote entanglement and coherence atomic dissipation steady state entanglement Bell-statemeasurement

Phosphine/Benzocyclone-based Neutral Nickel Catalysts for ethylene Polymerization and Copolymerization with Polar Monomers

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chinese Journal of Polymer Science 2024年第2期42卷 202-212,I0007页

作者： Fei Wang Li Pan Vladislav A.Tuskaev Svetlana ch.Gagieva Yue-Sheng Li Tianjin key Lab of Composite&Functional Materials School of Material Science and EngineeringTianjin UniversityTianjin300072China Department of chemistry Lomonosov Moscow State UniversityRussian Federation InstitutionLeninskie Gory 1Moscow119991Russian Federation A N Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesVavilova st.28Moscow119991Russian Federation

The efficient copolymerization of olefin with polar monomers using nickel-based catalysts presents a longstanding challenge. In this contribution, three phosphine-benzocyclone ligands and corresponding neutral nickel catalysts(Ni1: Ar = Ph;Ni2: Ar = 2-(C_(6)H_(5))C_(6)H_(4);Ni3: Ar = 2-[2',6'-(Me O)_(2)-C_(6)H3]C_(6)H_(4)) were prepared and applied for the ethylene polymerization and copolymerization with polar monomers without any cocatalyst. The bulky substituent groups in complexes Ni2 and Ni3 contributed to high catalytic activities(up to 7.24×10^(6) and 9.04×10^(6)g·mol Ni^(-1)·h^(-1), respectively), and produced high-molecular-weight polyethylene(Mw up to 545.7 k Da). Complex Ni3 exhibited high activities for ethylene polymerization at the level of 10^(6) g·mol Ni^(-1)·h^(-1) across a wide range from 30 ℃ to 120 ℃, exhibiting excellent high temperature tolerance. These nickel complexes were also effectively employed in the copolymerization of ethylene with methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate, producing copolymers with high molecular weights(Mw up to 80.5 k Da) and high polar monomer incorporation(up to 8.2 mol%). Microstructure analyses revealed that the introduction of large sterically hindered substituents facilitated the incorporation of polar functional units into the polymer backbone. This study demonstrates the potential of these nickel-based catalysts for efficient copolymerization of olefin with polar monomers.

关键词： Neutral nickel catalyst ethylene polymerization Copolymerization Polar acrylate monomers