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Pharmacopoeia of acute pancreatitis:Is the roster complete?

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World Journal of Gastroenterology 2008年第38期14卷 5938-5939页

作者： Maxim s petrov Department of surgery Nizhny Novgorod State Medical AcademyNizhny Novgorod Russia

Acute pancreatitis is one of the most common diseases in the everyday's practise of gastroenterologists and surgeons. However, the physicians' therapeutic armamentarium is very limited. The present letter to the editor briefly describes the recent evidence from the literature with the aim to optimize a conservative management of patients with acute pancreatitis.

关键词： Acute pancreatitis Conservative treatment Enteral nutrition

Infected pancreatic necrosis: Not necessarily a late event in acute pancreatitis

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World Journal of Gastroenterology 2011年第27期17卷 3173-3176页

作者： Maxim s petrov Vincent Chong John A Windsor Department of surgery The University of AucklandAuckland 1010New Zealand

It is widely believed that infection of pancreatic necrosis is a late event in the natural course of acute pancreatitis. This paper discusses the available data on the timing of pancreatic infection. It appears that infected pancreatic necrosis occurs early in almost a quarter of patients. This has practical implications for the type, timing and duration of preventive strategies used in these patients. There are also implications for the classification of severity in patients with acute pancreatitis. Given that the main determinants of severity are both local and systemic complications and that they can occur both early and late in the course of acute pancreatitis, the classification of severity should be based on their presence or absence rather than on when they occur. To do otherwise, and in particular overlook early infected pancreatic necrosis, may lead to a misclassification error and fallacies of clinical studies in patients with acute pancreatitis.

关键词： Acute pancreatitis Classification Enteralnutrition Infected pancreatic necrosis Pancreatic in-fection

An application of space-filling curves to improve results of turbulent aerodynamics modeling with convolutional neural networks

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Chinese Journal of Aeronautics 2024年第2期37卷 81-92页

作者： Mikhail petrov sofia ZIMINA Moscow Institute of Physics&Technology Dolgoprudny 141701Russia

When carrying out calculations for turbulent flow simulation,one inevitably has to face the choice between accuracy and speed of *** order to simultaneously obtain both a computationally efficient and more accurate model,a surrogate model can be built on the basis of some fast special model and knowledge of previous calculations obtained by more accurate base models from various test bases or some results of serial *** objective of this work is to construct a surrogate model which allows to improve the accuracy of turbulent calculations obtained by a special model on unstructured *** this purpose,we use 1D Convolutional Neural Network(CNN)of the encoder-decoder architecture and reduce the problem to a single dimension by applying space-filling *** an approach would have the benefit of being applicable to solutions obtained on unstructured *** this work,a non-local approach is applied where entire flow fields obtained by the special and base models are used as input and ground truth output ***-Allmaras(sA)model and Near-wall Domain Decomposition(NDD)method for sA are taken as the base and special models *** efficiency and accuracy of the obtained surrogate model are demonstrated in a case of supersonic flow over a compression corner with different values for angleαand Reynolds number *** conducted an investigation into interpolation and extrapolation by Re and also into interpolation byα.

关键词： space-filling curves Convolutional neural network Domain decomposition Turbulent flows Unstructured mesh

Central Asia—A Global Model for the Formation of Epigenetic Deposits in a Platform sedimentary Cover

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Journal of Earth science 2022年第2期33卷 278-288页

作者： Igor Pechenkin Vladislav petrov FsBI All-Russian scientific-Research Institute of Mineral Resources MoscowRussia Institute of Geology of Ore Deposits Petrography Mineralogy and Geochemistry RAs MoscowRussia

Metallogenic specialization of sedimentary cover in Central Asia is determined by its tectonic setting that governs the hydrodynamic regime(exfiltrational or infiltrational)and as a consequence,the hydrogeochemical zonality(type of water and its gaseous and microcomponent composition).Hydrodynamic conditions(distribution of recharge and discharge areas)determine the direction of stratal water flow and location of mineralization resulted from the change in geochemical,thermodynamic,lithological,structural and other *** exfiltrational regime suggests a dependence of the epigenetic mineralization upon the distribution and degree of preservation of hydrocarbon ***,hydrocarbon matter serves as a reducing barrier and ore-concentrating factor during the formation of polymineral concentrations related to stratal oxidation *** supergene epigenetic ore-forming processes are induced by the interaction between the Earth’s sedimentary cover and *** rocks themselves commonly serve as a source of ore *** ore deposition zones on geochemical barriers and ore material source are often located significantly apart from each *** trend of these processes is determined by the position of ore-bearing depressions in large tectonic blocks.

关键词： Central Asia Kyzyl Kum Bukantau ore-forming systems epigenetic ore deposit geology

Optimal control of natural resources in mining industry

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International Journal of Mining science and Technology 2015年第2期25卷 193-198页

作者： petrov Nikolay Tanev Angel Electrical Engineering Electronics and AutomationTechnical University-Sofia Faculty of Mathematics and Informatics Sofia University

The paper focuses on the optimal control of natural resources in mining industry. The purpose is to pro- pose an optimal extraction series of these resources during the lifetime of the Mine＇s maintenance. Fol- lowing the proposed optimal control model, a sensitivity analysis has been performed that includes the interest rate impact on the optimal solution. This study shows that the increasing of the interest rate sti- mulates faster extraction of the resources. The discounting factor induces that the resource has to be extracted faster hut this effect is counterbalanced by the diminishing returns of the annual cash flow. At higher parameters of ＂alpha＂ close to one of the power function about 80% from the whole resource will be extracted during the first 4 years of object/mine maintenance. An existence of unique positive root with respect to return of investment has been proposed and proved by two ways： by the ＂method of chords＂ and by using specialized software.

关键词： Optimal control Natural resources Interest rate sensitivity analysis Method of chords

Diversity considerations in wideband radar detection of migrating targets in clutter

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science China(Information sciences) 2019年第4期62卷 31-40页

作者： Franois LE CHEVALIER Nikita petrov Department Microwave sensing Signals and Systems (MS3) Delft University of Technology

Wideband radars have been proposed for detection of moving targets, with unique capability of non-ambiguous detection due to range migration. Moreover, frequency diversity has long been used for mitigating the fading effects caused by target and clutter fluctuations. The real benefits of wideband radars are difficult to analyze, since they derive from the combined effects of target resolution in range, migration over successive cells of clutter, Doppler resolution and instantaneous bandwidth, and residual ambiguities in Doppler. In order to contribute to a better understanding of the benefits of agile transmissions for detection of moving targets, clutter cancelling performances of wideband radars are examined, demonstrating clear benefits from diversity on clutter and target, primarily – but not only – obtained through target migration effects. special attention is given to long-range surveillance and tracking, and new results on detection of moving targets in clutter will be provided to demonstrate the effectiveness of these new architectures for small targets detection at long range, in difficult environments. Finally, recommendations for system designs that improve the discrimination of moving targets against fixed and diffuse clutter are presented.

关键词： radar extended target frequency diversity wideband detection target migration clutter cancelling

Extension of Near-Wall Domain Decomposition to Modeling Flows with Laminar-Turbulent Transition

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Communications in Computational Physics 2022年第2期31卷 645-668页

作者： M.petrov s.Utyuzhnikov A.Chikitkin N.smirnova Moscow Institute of Physics&Technology Dolgoprudny 141700Russia Department of Mechanical Aerospace&Civil EngineeringThe University of ManchesterManchesterM139PLUK

The near-wall domain decomposition method(NDD)has proved to be very efficient for modeling near-wall fully turbulent *** this paper the NDD is extended to non-equilibrium regimeswith laminar-turbulent transition(LTT)for the first *** LTT is identified with the use of the e^(N)-method which is applied to both incompressible and compressible *** ismodified to take into account LTT in an *** addition,implementation of the intermittency expands the capabilities of NDD to model non-equilibrium turbulent flows with *** of the modified NDD approach is demonstrated on various test problems of subsonic and supersonic flows past a flat plate,a supersonic flow over a compression corner and a planar shock wave impinging on a turbulent boundary *** results of modeling with and without decomposition are compared in terms of wall friction and show good agreement with each other while NDD significantly reducing computational resources *** turns out that the NDD can reduce the computational time as much as three times while retaining practically the same accuracy of prediction.

关键词： Domain decomposition laminar-turbulent transition interface boundary condition near-wall flow low-Reynolds-number model

sol-gel synthesis, surface and magnetic properties of nanocrystalline smAlO_3

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Journal of Rare Earths 2010年第4期28卷 602-605页

作者： Dimitar petrov Bogdan Angelov Vasil Lovchinov Department of Inorganic and Physical Chemistry University of Food Technologies 26 Maritsa Blvd. 4002 Plovdiv Bulgaria Institute of solid state Physics Bul garian Academy of Sciences 72Tzarigradsko Chaussee Blvd. 1784 Sofia Bulgaria

Nanocrystals of single-phase samarium monoaluminate (smAlO3) were synthesized and studied for the first time. Malic acid was employed as a new complexing agent in the sol-gel process. The material was characterized by X-ray diffraction (XRD), scanning electron microscopy (sEM), energy-dispersive X-ray analysis (EDs), specific surface area and density. The lowest size of the nanoparticles was about 50–60 nm and some of them formed agglomerates. The binding energies of core-level electrons of sm (3d, 4d, 4f, ...

关键词： smAlO3 nanocrystals surface properties magnetic susceptibility rare earths

Determining effects of impact loading on residual strength of fiber-metal laminates with grid-characteristic numerical method

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Chinese Journal of Aeronautics 2021年第7期34卷 1-12页

作者： Katerina BEKLEMYsHEVA Vasily GOLUBEV Igor petrov Alexey VAsYUKOV Moscow Institute of Physics and Technology DolgoprudniyRussia

The Grid-Characteristic numerical Method(GCM)that is quite common in solving aero and hydrodynamic problems can also be applied for mechanics of *** allows to implement complex border and contact conditions,including the non-reflecting border and the destructible *** this conditions are very important for the precise and effective modeling of LowVelocity Impacts(LVI)on fiber and Fiber-Metal Laminates(FML)and the resulting Barely Visible Impact Damage(BVID)that influences the residual strength of a composite aircraft *** is the type of damage that is not visible by the naked eye and can be hardly detected by a standard ultrasound equipment that is used for regular *** can appear during any weak impacts like bird strike or *** its influence on the residual strength of the part is very important to define the priorities of development of ultrasound *** this paper,the GCM was applied for a full cycle of loading of an FML aircraft cover *** FML consisted of a Carbon Fiber Reinforced Polymer(CFRP)and a single titanium layer on the upper *** cycle of loading in a single calculation consisted of an LVI caused by a small striker and a comparatively slow compressive in-plane ***-dimensional patterns of velocity and stress distributions over the time of calculation are *** patterns,obtained via the Hashin failure criterion are given and analyzed.

关键词： Fiber-metal laminate Grid-characteristic method Low-velocity impact Numerical modeling Residual strength