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Synthetic polymers:A review of applications in drilling fluids

Petroleum Science 2024年第1期21卷 475-518页

作者： Shadfar Davoodi mohammed Al-Shargabi David A.Wood Valeriy S.Rukavishnikov konstantin m.minaev School of Earth Sciences&Engineering Tomsk Polytechnic UniversityLenin AvenueTomskRussia DWA Energy Limited LincolnUnited Kingdom

With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various ***,reagents based on modified natural polymers(which are naturally occurring compounds)and synthetic polymers(SPs)which are polymeric compounds created industrially,are widely used to prevent emerging complications in the drilling ***,compared to modified natural polymers,SPs form a family of high-molecular-weight compounds that are fully synthesized by undergoing chemical polymerization *** provide substantial flexibility in their ***,their size and chemical composition can be adjusted to provide properties for nearly all the functional objectives of drilling *** can be classified based on chemical ingredients,type of reaction,and their responses to ***,some of SPs,due to their structural characteristics,have a high cost,a poor temperature and salt resistance in drilling fluids,and degradation begins when the temperature reaches 130℃.These drawbacks prevent SP use in some medium and deep ***,this review addresses the historical development,the characteristics,manufacturing methods,classification,and the applications of SPs in drilling *** contributions of SPs as additives to drilling fluids to enhance rheology,filtrate generation,carrying of cuttings,fluid lubricity,and clay/shale stability are explained in *** mechanisms,impacts,and advances achieved when SPs are added to drilling fluids are also *** typical challenges encountered by SPs when deployed in drilling fluids and their advantages and drawbacks are also *** issues also impact the applications of SPs in drilling ***,the cost of the most relevant SPs,and the monomers used in their synthesis,are *** impacts of SPs when deployed in drilling fluids,and t

关键词： Synthetic versus natural polymers Nanopolymers Drilling fluid additives Lubricity Clay swelling Hole cleaning

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A critical review of self-diverting acid treatments applied to carbonate oil and gas reservoirs

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Petroleum Science 2023年第2期20卷 922-950页

作者： mohammed Al-Shargabi Shadfar Davoodi David A.Wood mohsen Ali Valeriy S.Rukavishnikov konstantin m.minaev School of Earth Sciences&Engineering Tomsk Polytechnic UniversityLenin AvenueTomskRussia DWA Energy Limited LincolnUnited Kingdom Oil and Gas Fields Development and Operation Department Samara State Technical UniversityMolodogvardeyskaya StreetPerakSamaraRussia

Carbonate reservoirs generally achieved relatively low primary resource recovery *** is therefore often necessary to clean those reservoirs up and/or stimulate them post drilling and later in their production life.A common and basic carbonate reservoir cleanup technique to remove contaminating material from the wellbore is *** efficiency of acid treatments is determined by many factors,including:the type and quantity of the acid used;the number of repeated treatments performed,heterogeneity of the reservoir,water cut of the reservoir fluids,and presence of idle zones and ***-treatment production performance of such reservoirs frequently does not meet design *** is therefore much scope to improve acidizing technologies and treatment designs to make them more reliable and *** review considers acid treatment technologies applied to carbonate reservoirs at the laboratory scale and in field-scale *** range of acid treatment techniques commonly applied are *** between specific acid treatments,such as foamed acids,acid emulsions,gelled and thickened acid systems,targeted acid treatments,and acid hydraulic fracturing are described in terms of the positive and negative influences they have on carbonate oil production rates and *** to improve acid treatment techniques are identified,particularly those involving the deployment of nanoparticles(NPs).Due consideration is also given to the potential environmental impacts associated with carbonate reservoir acid *** are made regarding the future research required to overcome the remaining challenges pertaining to acid treatment applications.

关键词： Enhanced and improved resource recovery Hydraulic fracturing Nanofluids Viscoelastic surfactants Self-diverting acid Hydrophobic emulsions Gels

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HIV protease:late action to prevent immune detection

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Signal Transduction and Targeted Therapy 2021年第5期6卷 1408-1409页

作者： konstantin m.J.Sparrer Frank Kirchhoff Institute of molecular Virology Ulm University Medical CenterUlmGermany

A recent study published in Science by Wang and colleagues shows that premature activation of the HIV-1 protease leads to caspase activation and recruitment domain 8(CARD8)inflammasome-mediated pyroptosis of infected macrophages and CD4+T cells(Fig.1).These findings might help to improve approaches aiming to eliminate the latent viral reservoirs upon HIV-1 *** invading viral pathogens trigger the innate immune system and are usually rapidly controlled and eventually *** sense viral intruders via so-called pattern recognition receptors(PRRs)capable of detecting pathogen-associated molecular patterns(PAmPs)allowing discrimination between self and *** many cases,these patterns are viral nucleic acids that show pathogen-specific structures or emerge at the wrong localization in the ***,activation of PRRs by their respective ligands leads to the induction of various anti-viral signaling cascades,among them the inflammasome.

关键词： eventually action eliminate

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Cap snatch prevention:a novel approach to tackle influenza viruses

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Signal Transduction and Targeted Therapy 2023年第6期8卷 2435-2436页

作者： konstantin m.J.Sparrer Frank Kirchhoff Institute of molecular Virology Ulm University Medical CenterUlmGermany

A recent study published in Science1 by Tsukamoto and colleagues shows that a derivative of tubercidin,a natural product from Streptomyces,selectively inhibits influenza A and B viruses(IAV and IBV,respectively).The compound targets the host RNA methyltransferase mTr1,and thus prevents viral“cap snatching”(Fig.1).These results may help to develop novel drugs that target viral host dependency factors and are thus less likely to induce viral resistance.

关键词： prevention influenza likely

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Unexpected little helpers: microbiota stimulate systemic antiviral defenses

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Signal Transduction and Targeted Therapy 2022年第11期7卷 4001-4002页

作者： Susanne Klute Helene Hoenigsperger konstantin m.J.Sparrer Institute of molecular Virology Ulm University Medical CenterUlm89081Germany

In a recent study published in Immunity by Erttmann et al.,an unexpected beneficial role of gut microbiota in protecting mice against invading viruses by promoting low levels of systemic innate immune activation via t... 详细信息

关键词： al. interferon ed.

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Power absorption,plasma parameters and wave structure in inductive RF plasma source with low value external magnetic field

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Plasma Science and Technology 2020年第11期22卷 60-73页

作者： Elena KRALKINA konstantin VAVILIN Ilya ZADIRIEV Alexander NIKONOV Physical Electronics Department Faculty of PhysicsLomonosov Moscow State UniversityMoscow 119991Russia

The efficiency of radio-frequency(RF)power absorption,RF magnetic field structure and plasma parameters were measured in cylindrical inductive RF plasma sources 20 cm in diameter and 22,32,53 cm in length with a low value external magnetic *** experiments were carried out in argon at pressures of 13-140 m *** RF power supply changed from 200 W to 800 *** spiral antenna was used for sustaining the *** was shown that efficiency of RF power absorption depended nonlinearly on the external magnetic field *** maximal values of the RF power absorption efficiency,the axial distributions of longitudinal Bzand azimuthal Bφcomponents of RF magnetic field manifested the formation of the partially standing wave with a half wavelength close to 8 *** the same conditions,the axial dependence of the radial RF magnetic field component Brdiffered *** was concluded that the Bz and Bφamplitudes were largely determined by the RF field of Trivelpiece-Gould wave,while Br amplitude represented the radial RF field of the helicon wave.

关键词： radio-frequency plasma helicon Trivelpiece-Gould waves inductive discharge

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Band Structure and Optical Gain of InGaAs/GaAsBi Type-Ⅱ Quantum Wells modeled by the k·p model

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Chinese Physics Letters 2018年第5期35卷 133-136页

作者： Chang Wang Wenwu Pan konstantin Kolokolov Shumin Wang Key Laboratory of Terahertz Solid-State Technology Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 School of Physical Science and Technology Shanghai Tech University Shanghai 201210 University of Chinese Academy of Sciences Beijing 100190 Faculty of Physics M. V. Lomonosov Moscow State University Moscow 119991 Russia Department of microtechnology and Nanoscience Chalmers University of Technology Gothenburg 41296 Sweden

Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells（QWs） with W, N, and m shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-consistent k·p Hamiltonian, taking into account valence band mixing and the strain effect. Our calculations show that the m-shaped type-Ⅱ QWs are a promising structure for making 1.3 um lasers at room temperature because they can easily be used to obtain 1.3 um for photoluminescence with a proper thickness and have large wave-function overlap for high optical gain.

关键词： As Bi In Ga Band Structure and Optical Gain of InGaAs/GaAsBi Type Quantum Wells modeled by the k p model

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mechanisms of cast structure and stressed state formation in Hadfield steel

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China Foundry 2016年第6期13卷 433-442页

作者： Dmitri Gorlenko konstantin Vdovin Nikolay Feoktistov Nosov magnitogorsk State Technical University Magnitogorsk Russia

The paper describes the investigation of mechanisms of cast structure formation in Hadfield steel depending on the changes in the cooling rate of a casting in the following two temperature ranges： crystallization temperature（1,200-1,390 ℃） and the temperature of excessive phase separation（560-790 ℃）. Changes in the cooling rate of the crystallization temperature range from 1.1 to 25.0 ℃s^-1 result in the reduction of the average size of austenite grains from 266 to 131 μm. At the same time, the magnitude of developing shrinkage stresses changes from ＋195 to 0 mPa. When the cooling rate is higher than 16 ℃^-1, no shrinkage stresses are formed in the casting. Changes in the cooling rate of the casting in the temperature range of the excessive phase separation influence the number of phases, their morphology and chemical composition, the values of phase stresses, and the possibility of martensitic transformation. Changing in the cooling rate from 0.24 to 5.46 ℃^-1 results in the decrease of the amount of the excessive phase from 14.8% to 2.1%, which is composed of eutectic and carbides depending on the cooling rate, their quantitative ratio and morphology change. Such changes in the microstructure are reflected on the changes of value of developing phase stresses. When the cooling rate is 0.24 ℃^-1, it is ＋100 mPa, while the increase of the cooling rate to 1.4 ℃^-1 results in the decrease of tensile stresses to 0 mPa and their qualitative stresses change to compressive ones. Further increase of the cooling rate results in the increase of the value of compressive stresses. When the cooling rate is 5.5 ℃^-1, their value reaches-92 mPa. martensite forming in the structure of Hadfield steel is possible if the cooling rate of the casting in the range of excessive phase separation is less than 0.25 ℃^-1.

关键词： Hadfield steel crystallization austenite excessive phase stress

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High-resolution photoacoustic microscope for rat brain imaging in vivo

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Chinese Optics Letters 2010年第6期8卷 609-611页

作者：杨孝全蔡鑫 konstantin maslov 汪立宏骆清铭 Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and Technology Optical Imaging Laboratory Department of Biomedical EngineeringWashington University in Saint LouisSaint Louis63130-4899USA

A reflection-mode photoacoustic microscope（PAm） for rat brain imaging in vivo is constructed.A pulsed laser is used as an excitation source,and a focused ultrasound transducer is adopted to collect the photoacoustic *** scanning is applied to acquire three-dimensional（3D） *** obtained measurements of the lateral and axial resolutions of the microscope are 45 and 15μm,*** imaging depth in the chicken breast tissue is 3.1 mm at a signal-to-noise ratio（SNR） of 20 dB without any signal *** imaging speed is 30 A-line/*** results in vivo demonstrate the capability of 3D imaging of the brain vessels of the rat after removing the skull.

关键词： Acoustic microscopes Laser excitation Photoacoustic effect Photoacoustic microscopy Pulsed laser applications Pulsed lasers Signal to noise ratio Ultrasonic transducers

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Using density functional calculations to elucidate atomic ordering of Pd-Rh nanoparticles at sizes relevant for catalytic applications

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Chinese Journal of Catalysis 2019年第11期40卷 1749-1757页

作者： Lorena Vega Hristiyan A.Aleksandrov konstantin m.Neyman Departament de Ciència dels materials i Química Física&Institut de Química Teòrica i Computacional Universitat de Barcelona08028 BarcelonaSpain Faculty of Chemistry and Pharmacy University of Sofia1126 SofiaBulgaria InstitucióCatalana de Recerca i Estudis Avan?ats(ICREA) 08010 BarcelonaSpain

Pd-Rh nanoparticles are known to easily undergo surface restructuring in reactive environment. This study quantifies, with the help of density functional(DFT) calculations and a novel topological approach, atomic ordering and surface segregation effects in Pd-Rh particles with compositions 1:3, 1:1 and 3:1 containing up to 201 atoms(ca. 1.7 nm). The obtained data are used to reliably optimise energetically preferred atomic orderings in inaccessible by DFT Pd-Rh particles containing thousands of atoms and exhibiting sizes exceeding 5 nm, which are typical for catalytic metal particles. It is outlined, how segregation effects on the surface arrangement of Pd-Rh nanoalloy catalysts induced by adsorbates can be evaluated in a simple way within the present modelling setup.

关键词： Density functional calculations Atomic ordering Pd Rh nanoparticles Size relevant

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