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Macro and micro issues in turbulent mixing

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Science China(Technological Sciences) 2013年第10期56卷 2355-2360页

作者： MELVIN J KAUFMAN R LIM H KAMAN T rao p GLIMM J Department of Applied Mathematics and Statistics Stony Brook UniversityStony Brook NY 11794 USA

Numerical prediction of turbulent mixing can be divided into two subproblems: to predict the geometrical extent of a mixing region and to predict the mixing properties on an atomic or molecular scale, within the mixing region. The former goal suffices for some purposes, while important problems of chemical reactions(e.g. flames) and nuclear reactions depend critically on the second goal in addition to the first one. Here we review recent progress in establishing a conceptual reformulation of convergence, and we illustrate these concepts with a review of recent numerical studies addressing turbulence and mixing in the high Reynolds number limit. We review significant progress on the first goal, regarding the mixing region, and initial progress on the second goal, regarding atomic level mixing properties. New results concerning non-uniqueness of the infinite Reynolds number solutions and other consequences of a renormalization group point of view, to be published in detail elsewhere, are summarized *** notion of stochastic convergence(of probability measures and probability distribution functions) replaces traditional pointwise convergence. The primary benefit of this idea is its increased stability relative to the statistical "noise" which characterizes turbulent flow. Our results also show that this modification of convergence, with sufficient mesh refinement, may not be needed. However, in practice, mesh refinement is seldom sufficient and the stochastic convergence concepts have a *** to this circle of ideas is the observation that turbulent mixing, in the limit of high Reynolds number, appears to be non-unique. Not only have multiple solutions been observed(and published) for identical problems, but simple physics based arguments and more refined arguments based on the renormalization group come to the same *** of the non-uniqueness inherent in numerical models of high Reynolds number turbulence and mixing, we also include here numeri

关键词： stochastic convergence turbulent mixing renormalization group dynamic subgrid scale models

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胃黏液表皮样癌2例

中华病理学杂志 2024年第9期53卷 965-967页

作者：徐柳袁静萍何惠华饶洁罗斌武汉大学人民医院病理科武汉

本文报道2例胃原发黏液表皮样癌临床病理学及免疫表型特征, 并总结相关文献。例1男, 61岁, 胃镜发现胃体下端近胃角处一溃疡, 覆污秽苔。例2男, 59岁, 胃镜于残胃与肠管交界处发现隆起型肿物。镜下观察:肿瘤由形态温和的中间细胞、表皮... 详细信息

本文报道2例胃原发黏液表皮样癌临床病理学及免疫表型特征, 并总结相关文献。例1男, 61岁, 胃镜发现胃体下端近胃角处一溃疡, 覆污秽苔。例2男, 59岁, 胃镜于残胃与肠管交界处发现隆起型肿物。镜下观察:肿瘤由形态温和的中间细胞、表皮样细胞和黏液细胞构成, 可见筛状腺腔/微囊结构, 其内含黏液或嗜酸性分泌物, 且伴有多处神经浸润。免疫组织化学结果显示:表皮样细胞及中间细胞p63和p40阳性, 黏液细胞MUC5AC阳性, 过碘酸雪夫染色阳性, p53为野生型, Ki-67阳性指数>60%。病理诊断为胃黏液表皮样癌。胃原发黏液表皮样癌罕见, 侵袭性高, 经验不足的医师对本病的诊断要点往往了解不充分, 应注意与腺鳞癌、低分化鳞状细胞癌等鉴别。

关键词：黏液表皮样癌黏液细胞

Maximum power point tracking using decision-tree machine-learning algorithm for photovoltaic systems

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Clean Energy 2022年第5期6卷 762-775页

作者： p.Venkata Mahesh S.Meyyappan ramaKoteswara rao Alla Department of Electronics and Instrumentation Engineering Annamalai UniversityChidambaramIndia Department of Instrumentation Engineering Madras Institute of TechnologyChennaiIndia Department of EEE RVR&JC College of EngineeringGunturIndia

This work presents a machine-learning(ML)algorithm for maximum power point tracking(MppT)of an isolated photovoltaic(pV)*** to the dynamic nature of weather conditions,the energy generation of pV systems is *** there is no specific method for effectively dealing with the non-linear data,the use of ML methods to operate the pV system at its maximum power point(Mpp)is desirable.A strategy based on the decision-tree(DT)regression ML algorithm is proposed in this work to determine the Mpp of a pV *** data were gleaned from the technical specifications of the pV module and were used to train and test the *** algorithms predict the maximum power available and the associated voltage of the module for a defined amount of irradiance and *** boost converter duty cycle was determined using predicted *** simulation was carried out for a 10-W solar panel with a short-circuit current of 0.62 A and an open-circuit voltage of 21.50 V at 1000 W/m^(2) irradiance and a temperature of 25℃.The simulation findings demonstrate that the proposed method compelled the pV panel to work at the Mpp predicted by DTs compared to the existing topologies such asβ-MppT,cuckoo search and artificial neural network *** the proposed algorithm,efficiency has been improved by>93.93%in the steady state despite erratic irradiance and temperatures.

关键词： boost converter decision tree maximum power point tracking photovoltaic system regression machine learning

Exploring one material for dual applications:A red-emitting Mg2GeO4:Eu3+ nanophosphor for future generation energy efficient WLEDs and dosimetric applications

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Journal of Rare Earths 2024年第10期42卷 1835-1845页

作者： Akshay Arjun G.p.Darshan S.C.Sharma H.Nagabhushana D.V.Sunitha H.B.premkumar Department of physics Faculty of Mathematical and Physical SciencesM.S.Ramaiah University of Applied Sciences Jain University C.N.R.rao Centre for Advanced Materials Tumkur University School of Applied Sciences (physics) REVA University

The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly *** this in mind,a series of forsterite-structured Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was synthesized via a solution combustion method using oxalyl dihydrazide as a *** X-ray diffraction patterns confirm the orthorhombic crystal system with a puma space *** results clearly show irregularly shaped cluster-like structures with aggregation of the *** diffuse reflectance spectra,the optical energy band gap of the Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was estimated and obtained to be～4.12-4.32 *** photoluminescence emission spectra exhibit intense peaks at ～579,589,610,661,and 707 nm,which are due to characteristic5D0→7F0,5D0→7F1,5Do→7F2,5D0→7F3and5D0→7F4transitions of Eu3+ions,*** Commission International de L'Eclairage color coordinates are gradually tuned from pale red（0.5980,0.4012） to a pure red（0.6385,0.3611） *** glow peaks showcase excellent super-linear response at low doses of γ-irradiations,indicating that the prepared phosphor can be used in thermoluminescent personal dosimetry which is a biological tissue *** aforementioned results demonstrate that the prepared Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors are considered an excellent candidate for dual applications,i.e.,red component in future generation white-light-emitting diodes（WLEDs） and personal dosimetric applications.

关键词： Nanophosphors photoluminescence Thermoluminescence Dosimetry photometric properties

Experimental studies of water hammer in propellant feed system of reaction control system

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propulsion and power Research 2018年第1期7卷 52-59页

作者： Avanish Kumar p.Satya prasad M.Raghavendra rao Defence Research&Development Laboratory HyderabadTelangana 500058India

Water hammer pressure transient produces large dynamic forces which can damage the pipes and other assemblies in the feed line of a reaction control system(RCS).It has led to the failure of pressure transducers monitoring the manifold pressure in the feed line of ***,water hammer studies have been carried out to understand its effect in feed *** system has been simplified to develop a mathematical model and experiments have been carried out at extensive *** mathematical model was developed considering pipe of uniform c/s and moving liquid-gas *** experimental studies have been done using water as working medium instead of actual *** studies showed that rate of pressurization have a very critical role on the water hammer *** studies have been also carried out to study the effect of density,friction and initial liquid column length on water hammer amplitude.

关键词： Water hammer Reaction control system(RCS) propellant feed system Experimental study Testing

Thin Layer Chromatographic Study of Bauxite and Quantitative Estimation of Co-Existing Al^(3+), Fe^(2+) and Ti^(4+)

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色谱 2005年第5期23卷 555-561页

作者： MOHAMED NAJAR p A JEURKAR J U ramaNA rao K V Jawaharlal Nehru Aluminium Research Development and Design Centre Nagpur 440 023 IndiaJawaharlal Nehru Aluminium Research Development and Design Centre Nagpur 440 023 IndiaJawaharlal Nehru Aluminium Research Development and Design Centre Nagpur 440 023 India

Thin layer chromatography in combination with spectrophotometry and titrimetry has been used to evaluate chromatographic characteristics of bauxite constituents. The retention behaviors of four major constituents (Al 3+ , Fe 2+ , Ti 4+ , Si 4+ ) in bauxite mineral have been examined on plain and modified layers of silica gel G, silica gel H and cellulose with mobile phases containing aqueous sodium chloride, formic acid and hydrochloric acid. Ternary separation of Al-Fe-Ti was achieved on chromatographic plates made of silica gel H. The pH effect and presence of impurity elements in samples, nature of stationary phases on the ternary separation and detection limits of bauxite constituents were studied. Silicon in bauxite was detected on cellulose plates. Quantitative determinations of Al 3+ , Fe 2+ and Ti 4+ on silica gel H impregnated with sodium formate layers were achieved by titrimetry and spectrophotometry.

关键词：铝土矿主成分共存离子 Ti^4+ Al^3+ Fe^2+ 薄层色谱法

Investigation of antioxidant and anti-inflammatory activity of leaves of Dalbergia paniculata(Roxb)

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Asian pacific Journal of Tropical Medicine 2012年第6期5卷 455-458页

作者： Ganga rao B Madhu Kiran p Vijaya Raju AD pharmacognosy and phytochemistry A.U College of Pharmaceutical SciencesAndhra UniversityVisakhapatnamA.P.India-530 003 A.U College of pharmaceutical Sciences Andhra UniversityVisakhapatnamA.PIndia-530 003

Objective:To investigate the antioxidant and anti-inflammatory activity of orally administered methanolic leaf extract of Dalbergia paniculala(***) in Carrageenan induced inflammation in ***:In vitro antioxidant activity was evaluated for superoxide radical, Hydroxyl radical and DppH radical scavenging *** doses 200 mg/kg,400 mg/kg and 800 mg/kg of *** were tested for anti-inflammatory activity in Carrageenan induced rat paw edema model and paw thickness was measured every one hour up to 6 h. Results:The melhanolic leaf extract of *** produced dose dependent inhibition of Superoxide radical,Hydroxyl radical and OppH *** Carrageenan induced inflammation model,all three doses produced significant percentage inhibition of rat paw edema and 800 mg/kg dose produced maximum percent inhibition of rat paw edema(47.83%) at 3h compared to control ***:In the present study we found that methanolic leaf extract of *** showed good in vitro antioxidant activity and in vivo anti-inflammatory activity in rats.

关键词： Anti-inflammatory activity Antioxidant activity Dalbergia paniculata Free radicals Carragenan Inflammation Edema

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一种紧凑型固态Marx发生器的研究

强激光与粒子束 2024年第2期36卷 35-41页

作者：姚皓伟李孜王永刚姜松饶俊峰上海理工大学机械工程学院上海200093 中国科学院苏州生物医学工程技术研究所江苏苏州215163

提出利用p型开关作为充电管、N型开关作为放电管串联形成半桥结构,将其门极也短接,以同一个信号同时驱动充电管和放电管。再利用共原边的串心磁环驱动方案,只需一个半桥电路就可以从原边同时传递驱动功率和信号,同步驱动所有充电管和放... 详细信息

提出利用p型开关作为充电管、N型开关作为放电管串联形成半桥结构,将其门极也短接,以同一个信号同时驱动充电管和放电管。再利用共原边的串心磁环驱动方案,只需一个半桥电路就可以从原边同时传递驱动功率和信号,同步驱动所有充电管和放电管,大幅简化了脉冲电源结构和尺寸,降低了成本。以此搭建了24级固态Marx发生器,在10 kΩ阻性负载上,获得了10 kV、1 kHz、5μs的高压方波脉冲,验证了方案的可行性,该电源主电路的尺寸仅为20 cm(长)×13 cm(宽)×5.5 cm(高)。

关键词：脉冲电源 Marx发生器高压脉冲同步驱动方波脉冲

Development and Validation of Stability Indicating LC Method for 10-Hydroxycamptothecin

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American Journal of Analytical Chemistry 2012年第7期3卷 470-477页

作者： Arala Venkateshwarlu A. V. rama rao Khagga Mukkanti Analytical Development Laboratory Avra Laboratories Private Limited Hyderabad India Institute of Science & Technology Jawaharlal Nehru Technological University Hyderabad India

The present method gives a detailed description for the development and validation of a simple stability indicating reverse phase liquid chromatographic method for 10-hydroxycamptothecin(10-HCTN) in the presence of its impurities namely Imp A and Imp B along with degradation products generated from forced degradation studies. The drug was subjected to stress conditions of hydrolysis (acid, base and neutral), oxidative, photolytic and thermal stress degradation. Degradation was observed when subjected to treatment with peroxides or under conditions normally used for typical acid and base hydrolysis. The drug was found to be stable under other stress conditions attempted such as photolytic and thermal. Successful separation and isolation of the drug from related impurities and degradation products formed under stress conditions was achieved on an Inertsil ODS-3V (250 mm × 4.6 mm, 5 μm) column using a phosphate buffer, acetonitrile, methanol and Nanopure water. The developed HpLC method was validated with respect to specificity, linearity, accuracy, precision, sensitivity, robustness and solution stability. The assay method was found to be linear in the range of 0.16 mg/mL to 0.24 mg/mL with a correlation coefficient of 0.999 and the linearity of the impurities was established from 0.02% (LOQ) to 0.3%. Recoveries of assay and impurities were found between 99.4% and 100.3%. The developed HpLC method can be used to determine the related substances and assay determinations of 10-HCTN and also to evaluate the quality and long term stability of production samples.

关键词： 10-Hydroxycamptothecin HpLC Method Validation Degradation Anti-Cancer Activity and Related Substances