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Journal of Earth Science 2013年第3期24卷 428-436页

作者： Anju Pandey ravi Mishra Centre for Climate Change research National Centre for Antarctic & Ocean research

High-precision, clay sediment oxygen and hydrogen isotopes analyses of Pleistocene-Holocene deep-sea sediments from the Bay of Bengal （BOB） are presented for the first time. Our study shows that the major source of sediments in the study area, since the last-25 000 years, is likely to be the Higher Himalayan crystalline rocks. Further, the study of these stable isotope data displays the variation of southwest monsoon （SWM） in the BOB region since the last-25 000 years and the cause behind the variation has been interpreted. The δ 18 O values of the clay sediments are compared with δ 18 O values of the BOB seawater. This comparison shows that the clay sediment δ 18 O values of the studied sediment cores temporally vary along with the changes in strength of the SWM. Based on the changes in the clay sediment δ 18 O values of the studied sediment, we evaluate the variance in the SWM since the last 25 000 years in the BOB. Our results are consistent with previous work in the region based on other proxies. To evaluate the factors influencing the intensity of the SWM since the last glacial maxima, we conducted comparative analyses of the studied clay sediment δ 18 O values with δ 18 O values in the Greenland ice cores （GISP2） and Tibetan ice cores （Guliya）. The results from this comparative study show that large-scale changes in the intensity of the SWM since 25 000 years are affected by the climate oscillations of the Northern Hemisphere, but rapid and abrupt fluctuations in the SWM seem to be controlled by the amount of snow cover in the Tibetan Plateau.

关键词： southwest monsoon Bay of Bengal Tibetan Plateau clay stable isotope.

Developmental pathways for shaping spike inflorescence architecture in barley and wheat

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Journal of Integrative Plant Biology 2019年第3期61卷 278-295页

作者： ravi koppolu Thorsten Schnurbusch Independant HEISENBErG-research Group Plant Architecture Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Faculty of Natural Sciences Ⅲ Institute of Agricultural and Nutritional Sciences Martin-Luther-University

Grass species display a wide array of inflorescences ranging from highly branched compound/panicle inflorescences to unbranched spike inflorescences. The unbranched spike is a characteristic feature of the species of tribe Triticeae, including economically important crops,such as wheat and barley. In this review, we describe two important developmental genetic mechanisms regulating spike inflorescence architecture in barley and *** include genetic regulation of(i) row-type pathway specific to Hordeum species and(ii) unbranched spike development in barley and wheat. For a comparative understanding, we describe the branched inflorescence phenotypes of rice and maize along with unbranched Triticeae inflorescences. In the end, we propose a simplified model describing a probable mechanism leading to unbranched spike formation in Triticeae species.

关键词： Developmental pathways Grass species

Concurrent removal of intravitreal lens fragments after phacoemulsification with pars plana vitrectomy prevents development of retinal detachment

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International Journal of Ophthalmology(English edition) 2015年第1期8卷 89-93页

作者： kak.rla V Chalam ravi k Murthy Joshua C Priluck Vijay khetpal Shailesh k Gupta Department of Ophthalmology University of Florida-College of Medicine

AIM: To evaluate the outcomes of "concurrent vitrectomy" to retrieve dislocated lens fragment during ***: In a retrospective, observational case series, data of patients who underwent "concurrent" pars plana vitrectomy(PPV) for dislocated lens fragments between the period 2000 and 2008 were reviewed. Data collected included patient demographics, pre-operative visual acuity, intra-operative occurrence of retinal breaks, duration of follow up, post-operative intraocular pressure, final best-corrected visual acuity(BCVA),presence of cystoid macular edema(CME) and occurrence of rhegmatogenous retinal detachment(rrD).· rESULTS: A total of 58 eyes of 58 patients were included in the study. At 12 mo the mean postoperative BCVA was log MAr 0.17(20/30) with a range of log MAr0 to 0.69(20/20 to 20/100), with 96.6%(56/58) of patients showing post- operative improvement in visual acuity(P =0.005). None of the patients developed postoperative retinal detachment, endophthalmitis or non-resolving uveitis at 12 ***: Our study results suggest concurrent PPV for retained lens fragments after cataract surgery is beneficial and may decrease the risk of glaucoma and prevent development of rrD.

关键词： phacoemulsification dislocated lens fragments vitrectomy glaucoma cystoid macular edema retinal detachment

Effect of gallium, aluminium, and chromium on silica supported V-Mg-O catalysts during oxidative dehydrogenation of propane: kinetic study

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Journal of Natural Gas Chemistry 2008年第3期17卷 256-263页

作者： B.ravi kumar rajeev kumar Department of Chemical Engineering Indian Institute of Technology

The oxidative dehydrogenation （ODH） of propane was conducted on gallium, aluminum, and chromium doped Si30VMgO catalysts. On doping, the concentrations of the phases responsible for the activity and selectivity increased in their concentrations. The reaction studies were conducted in a tubular steel reactor at temperatures of 753, 783, 813, and 843 k and atmospheric pressure. The total flow rates of the feed were chosen as 30, 40, 50, and 60 ml/min. The propane to oxygen ratios were chosen at 1 ： 1, 2 ： 1, and 3 ： 1, respectively. The effect of various dopants on the activity and selectivity of the catalysts was studied. Deactivation studies were conducted over all the catalysts. The kinetic data were analyzed in terms of power law models and Langmuir-Hinshelwood （LH） models. The kinetic data results were analyzed by comparing the effect of dopants. Statistical model discrimination was done for the proposed models. AIC and BIC criteria were used for discrimination of the models.

关键词： oxidative dehydrogenation propane gallium aluminum chromium kinetic

Ammonia level at admission predicts in-hospital mortality for patients with alcoholic hepatitis

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Gastroenterology report 2017年第3期5卷 232-236,I0003页

作者： Sujan ravi kaely S.Bade Mohsen Hasanin Ashwani k.Singal Department of Internal Medicine University of Alabama at BirminghamBirminghamALUSA Division of Gastroenterology and Hepatology University of MissouriColumbiaMOUSA Division of Gastroenterology and Hepatology University of Alabama at BirminghamBirminghamALUSA

*** hepatitis(AH),a unique clinical syndrome among patients with chronic and active alcohol use,is associated with high short-term *** elevated ammonia level is associated with mortality in patients with acute liver failure;however,its impact in AH has not been ***.A retrospective study was performed on patients admitted to a tertiary-care hospital with the discharge diagnosis of *** meeting criteria for AH were included in the final data *** logistic regression models were built to examine the impact of serum ammonia in predicting in-hospital mortality(IHM)and 30-day mortality(TDM).Subgroup analysis was also performed,which was limited to patients who had hepatic *** the 105 AH patients included,26(25%)died during the initial *** the 79 patients who survived initial hospitalization,30(39%)died within 30 *** about ammonia levels at admission was available for 82 *** these,25 patients had IHM and significantly higher ammonia level(97 vs.69 lmol/L,Prvived hospitalization,ammonia levels were not significantly different(71 vs.67 lmol/L,P=0.69)in patients with and without *** addition of ammonia to the multivariate regression models including age,sex,cirrhosis,treatment and model for end-stage liver disease(MELD)score improved the C statistics for IHM from 0.708 to 0.801 and for TDM from 0.756 to 0.766,*** results were identical,even when limited to patients with hepatic *** patients with elevated ammonia levels at admission have higher IHM;however,they do not seem to play a significant role in 30-day mortality for patients who survived hospitalization.

关键词： alcoholic hepatitis hepatic encephalopathy ammonia mortality

High-resolution fabrication of nanopatterns by multistep iterative miniaturization of hot-embossed prestressed polymer films and constrained shrinking

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Microsystems & Nanoengineering 2022年第1期8卷 281-289页

作者： Shady Sayed P.ravi Selvaganapathy Department of Mechanical Engineering McMaster UniversityHamiltonON L8S 4L8Canada

The fabrication of nanostructures and nanopatterns is of crucial importance in microelectronics,nanofluidics,and the manufacture of biomedical devices and ***,the creation of nanopatterns by means of conventional nanofabrication techniques such as electron beam lithography is expensive and ***,we develop a multistep miniaturization approach using prestressed polymer films to generate nanopatterns from microscale patterns without the need of complex nanolithography *** polymer films have been used as a miniaturization technique to fabricate features with a smaller size than the initial imprinted ***,the height of the imprinted features is significantly reduced after the thermal shrinking of the prestressed films due to the shape memory effect of the polymer,and as a result,the topographical features tend to disappear after *** have developed a miniaturization approach that controls the material flow and maintains the shrunken patterns by applying mechanical constraints during the shrinking *** combination of hot embossing and constrained shrinking makes it possible to reduce the size of the initial imprinted features even to the *** developed multistep miniaturization approach allows using the shrunken pattern as a master for a subsequent miniaturization ***-defined patterns as small as 100 nm are fabricated,showing a 10-fold reduction in size from the original *** developed approach also allows the transfer of the shrunken polymeric patterns to a silicon substrate,which can be used as a functional substrate for many applications or directly as a master for nanoimprint lithography.

关键词： constrained polymer size

State of the art in finite element approaches for milling process:a review

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Advances in Manufacturing 2023年第4期11卷 708-751页

作者： Shailendra Chauhan rajeev Trehan ravi Pratap Singh Department of Industrial and Production Engineering Dr.B R Ambedkar National Institute of TechnologyJalandharPunjabIndia

Over a century,metal cutting has been observed as a vital process in the domain of *** the numerous available metal-cutting processes,milling has been considered as one of the most employable processes to machine a variety of engineering materials *** the milling process,material removal occurs when the workpiece is fed against a rotating tool with multiple cutting *** order to maximize the profitability of metal cutting operations,it is essential that the various input and output variable relationships are analyzed and *** experimental method of studying milling processes is costly and time demanding,particularly when a large variety of elements such as cutting tool shape,materials,cutting conditions,and so on,are *** to these issues,other alternatives emerged in the form of mathematical simulations that employ numerical *** finite element approaches have well-proven to be the most practical and commonly utilized numerical *** finite element model(FEM)can be used to determine the various physical interactions occurring during the machining process along with the prediction of various milling characteristics,such as cutting forces,cutting temperature,stresses,etc.,with the help of milling *** the present article,various research studies in the broad milling process domain practiced with numerous finite element approaches have been critically reviewed and *** further highlights the several experimental and finite element approaches-based research studies that attempted to analyze and optimize the overall performance of the different milling *** recent years,various investigators have explored numerous ways to enhance milling performance by probing the different factors that influence the quality *** of the studies have also been found to be focused on the economic impacts of milling and various process inputs that affect milling ***,various milli

关键词： Milling Finite element modeling(FEM) Micro milling Turn-milling

Federated Approach for Privacy-Preserving Traffic Prediction Using Graph Convolutional Network

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Journal of Shanghai Jiaotong university(Science) 2024年第3期29卷 509-517页

作者： LONArE Savita BHrAMArAMBA ravi Pimpri Chinchwad College of Engineering Pune 411044India Department of Computer Science and Engineering GITAMViskhapatnam 530045India

Existing traffic flow prediction frameworks have already achieved enormous success due to large traffic datasets and capability of deep learning ***,data privacy and security are always a challenge in every field where data need to be uploaded to the *** learning(FL)is an emerging trend for distributed training of *** primary goal of FL is to train an efficient communication model without compromising data *** traffic data have a robust spatio-temporal correlation,but various approaches proposed earlier have not considered spatial correlation of the traffic *** paper presents FL-based traffic flow prediction with spatio-temporal *** work uses a differential privacy(DP)scheme for privacy preservation of participant's *** the best of our knowledge,this is the first time that FL is used for vehicular traffic prediction while considering the spatio-temporal correlation of traffic data with DP *** proposed framework trains the data locally at the client-side with *** then uses the model aggregation mechanism federated graph convolutional network(FedGCN)at the server-side to find the average of locally trained *** results of the proposed work show that the FedGCN model accurately predicts the *** scheme at client-side helps clients to set a budget for privacy loss.

关键词： federated learning(FL) traffic flow prediction data privacy graph convolutional network(GCN) differential privacy(DP)

Studies on long lasting optical properties of Eu^(2+) and Dy^(3+) doped di-barium magnesium silicate phosphors

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Chinese Chemical Letters 2015年第9期26卷 1187-1190页

作者： ravi Shrivastava Jagjeet kaur Govt.VYT PG Autonomous College

Di-barium magnesium silicate phosphors doped with europium and dysprosium were prepared under a weak.reducing atmosphere.X-ray diffraction pattern of the sample was also done that confirmed the proper preparation of the *** electron microscope（SEM） images confirmed that the sample has regular surface and uniform grain size *** studies of phosphorescence decay of Ba2MgSi2O7：Eu^2＋,Dy^3＋ phosphors with different concentration of Dy^3＋ were *** phosphor with 0.5/1.5 mol%of Eu/Dy,exhibited optimum green color afterglow *** emission is expected to arise due to transition of Eu^2＋ ions from any of the sublevels of 4f^65d^1 configuration to ^8S（7/2） level of the 4f7 *** a suitable trap depth,the trap concentration is expected to be proportional to the concentration of Dy^3＋.These traps are responsible for holding the charge career for a reasonable time,subsequently for increasing the time of ***,optimum Dy3＊ concentration produces the longer afterglow duration with higher intensity of luminescence *** depth were also calculated using thermoluminescence glow curve which was indicative of formation of traps suitable for long afterglow.

关键词： Phosphorescence XrD Persistence luminescence Trapping center

Degradation of Methylene Blue and rhodamine B Using a New Visible Light-responsive Photocatalyst, kSb_2PO_(8-x)N_y

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Acta Metallurgica Sinica(English Letters) 2016年第4期29卷 335-343页

作者： G.ravi CH.Sudhak.r reddy k.Sreenu ravinder Guje radha Velchuri M.Vithal Department of Chemistry University College of ScienceOsmania University

Potassium phosphatoantimonates, kSb2PO8 （kSbPO） and kSb2PO8-xNy （kSbPON）, are prepared by solidstate method. Urea is employed as a source of nitrogen for N-doping. Structural, morphological and optical properties of both kSbPO and kSbPON are characterized by powder X-ray diffraction （PXrD）, scanning electron microscopy, energydispersive spectroscopy, Fourier transform infrared spectroscopy and UV-visible diffuse reflectance spectroscopy. Both samples are found to crystallize in a monoclinic lattice with Cc space group. The d-lines of kSbPO and kSbPON are refined by least square fitting the PXrD data, using POWD software to obtain their unit cell parameters. The bandgap energy （Eg） of both pristine and N-doped kSbPO is found from their kubelka-Munk plot. The kSbPON/visible photocatalytic degradation of methylene blue and rhodamine B has been investigated in aqueous heterogeneous suspension. The generation of .OH in the presence of kSbPON during the photoreaction is verified by a fluorescence technique using terephthalic acid （TA） as a probe.

关键词： Potassium phosphatoantimonates Characterization Organic dyes Photodegradation