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Evaluation of the energy efficiency of rotary percussive drilling using dimensionless energy index

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1486-1500页

作者： v.n.Oparin v.n.Karpov v.v.Timonin A.I.Konurin Chinakal Institute of Mining Siberian BranchRussian Academy of SciencesKrasnyi Prospect 54Novosibirsk630091Russia

This paper sets forth a geomechanics framework for assessing the energy efficiency of rotary percussive drilling using the energy criterion, which has been proposed by victor Oparin for volumetric destruction of high-stress rocks having nonuniform physico-mechanical properties. We review the long-term research and development in the specified area of science and technology, including research and development projects implemented at the Institute of Mining, Siberian Branch of the Russian Academy of Sciences. A new modified expression of Oparin’s dimensionless energy criterion of volumetric rock destruction k is introduced. The range of in situ values is determined for the energy criterion of volumetric rock destruction at the optimized energy efficiency of rotary percussive drilling. The temporospatial intervals of geotechnical monitoring are found to control pneumatic drilling energy efficiency at subsoil use objects in Russia. The integrated experimental, theoretical and geotechnical approach to the comprehensive investigation of real-time processes of rock fracture in rotary percussive drilling using the energy concept possesses the necessary geomechanical performance-and-technology potential to create the next level geotechnical monitoring of drilling systems for various purposes, including determination of physico-mechanical properties and the stress-strain analysis of rock mass in full-scale drilling.

关键词： Rotary percussive drilling Geotechnical monitoring Drilling machine Energy criterion Energy efficiency

Synthesis of MoO_3 by glow discharge in contact with water

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Plasma Science and Technology 2019年第2期21卷 97-104页

作者： A v KHLYUSTOvA n A SIROTKIn A S KRAYEv v A TITOv A v AGAFOnOv Laboratory of Chemistry of Carbohydrate Coordination Compounds and Supermolecular System G.A.Krestov Institute of Solution Chemistry of RAS

An atmospheric pressure glow discharge was ignited between a molybdenum anode and the water surface of a cathode for the synthesis of MoO_3 powders. The action of glow discharge leads to the non-equilibrium evaporation of water, sputtering of the metal anode and formation of molybdenum(vI) oxide, which deposited on the anode. The chemical composition and morphology of the obtained powder were performed by using x-ray diffraction spectroscopy,scanning electron microscopy and Fourier transform infrared spectroscopy. It was found that the synthesized powders are pure α-MoO_3. The possible mechanism of the formation of molybdenum trioxide during glow discharge treatment was described. The photocatalytic performance of MoO_3 was estimated through the degradation of Rhodamine B under dark and Uv irradiation conditions. Orthorhombic MoO_3 exhibited the best photocatalytic activity for the photodegradation of Rhodamine B of 100% under Uv irradiation for 15 min.

关键词： molybdenum oxide glow discharge photocatalytic activity

Magnetic properties of melt-spun ribbons(Sm1-xZrx)(Fe0.92Ti0.08)10 with ThMn12 structure and their hydrides

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Journal of Rare Earths 2019年第10期37卷 1066-1071页

作者： A.G.popov A.v.Protasov v.S.Gaviko D.A.Kolodkin P.B.Terentev E.G.Gerasimov Tianli Zhang Chengbao Jiang M.n.Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences Str.S.Kovalevskoy18 Ekaterinburg620990Russia Institute of natural Sciences and Mathematics Ural Federal Universitypr.Mira19 Ekaterinburg620002Russia School of Materials Science and Engineering Beihang UniversityBeijing 100191China

The structure and magnetic hysteresis properties of the cast Sm1-xZrx(Fe0.92Ti0.08)10(x = 0-0.3)alloys and melt-spun ribbons prepared from them were *** the cast alloy with x>0.2, a considerable amount of the eutectic phase is found in the SEM *** of the temperature dependences of the magnetic susceptibility and XRD patterns allows amorphous state in the as-spun ribbons with x>0.2 to be *** specific magnetization measured in a field of 17 kOe and remanence decrease with increasing annealing temperature from 800 to 900 ℃ and weakly depend on Zr *** maximal value of coercivity Hc = 4.7 kOe is obtained on the ribbons with x = 0.2 after annealing at 850℃ for 10 *** additional hydrogenation of the ribbons,both the coercivity and remanence increase by 54% and 7%,respectively.

关键词： Sm-Zr-Fe-Ti ThMn12 Melt-spun ribbons Hydrogenation Magnetic properties

Rodent burrow network dynamics under human-induced landscape transformation from desert to steppe in Kalmykian rangelands

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Integrative Zoology 2019年第4期14卷 410-420页

作者： Elena SURKOvA Sergey popov Andrey TCHABOvSKY A.n.Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscowRussia Department of vertebrate Zoology Lomonosov Moscow State UniversityMoscowRussia

Rodents play an important role in rangelands through the engineering of extensive burrow systems,which provides key habitats for many animal and plant *** have analyzed the long-term variation in the abundance and distribution of rodent burrows in grazing ecosystems of southern Russia(Kalmykia)under the landscape change from desert to steppe caused by the drastic reduction of livestock after the collapse of the USSR in the early *** conducted burrow surveys in the“desert”(1980)and“steppe”(2017)periods on 193-km *** found considerable changes in burrow abundance and distribution,as well as evidence of desert habitat fragmentation and isolation caused by the expansion of tall-grass *** of the open-dwelling diurnal ground squirrel(Spermophilus pygmaeus),the dominant and the keystone species during the“desert”period,almost completely disappeared from the rodent burrow network by 2017,indicating significant habitat *** contrast,the burrows of the folivorous social vole(Microtus socialis)which was rare in the 1980s,became abundant and ubiquitously *** burrow density of the desert-dwelling psammophilous midday gerbil(Meriones meridianus)decreased,while the distances between occupied patches increased,indicating desert habitat fragmentation and loss of population *** of the folivorous tamarisk gerbils(***)were recorded only sporadically in both 1980 and *** observed changes in the rodent burrow network,the key component of grazing ecosystems,correlate with rodent species ecology and can have long-term and important consequences for ecosystem functioning.

关键词： burrows fragmentation grazing impact keystone species rodents

A review of the effects of dietary organic acids fed to swine

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Journal of Animal Science and Biotechnology 2016年第1期7卷 67-77页

作者： Mocherla v A n Suiryanrayna J v Ramana Livestock Research Station Sri Venkateswara Veterinary University

Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters （AGP） has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are （3-4 weeks age） exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coil These acids are the intermediary products in Kreb＇s cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth performa

关键词： Chelation Improved productivity Organic acids Pathogen inhibition Protein utility Swine

Second-Harmonic Response in Magnetic nodal-Line Semimetal Fe_(3)GeTe_(2)

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Chinese Physics Letters 2022年第9期39卷 62-66页

作者： v.D.Esin A.A.Avakyants A.v.Timonina n.n.Kolesnikov E.v.Deviatov Institute of Solid State Physics of the Russian Academy of Sciences ChernogolovkaMoscow District2 Academician Ossipyan Str.142432Russia

We experimentally investigate second-harmonic transverse voltage response to ac electrical current for a magnetic nodal-line semimetal Fe_(3)GeTe_(2)(FGT).For zero magnetic field,the observed second-harmonic voltage behaves as a square of the longitudinal current,as it should be expected for nonlinear Hall *** magnetic field behavior is found to be sophisticated:while the first-harmonic response shows the known anomalous Hall hysteresis in FGT,the second-harmonic Hall voltage is characterized by the pronounced high-field hysteresis and flat(B-independent)region with curves touching at low *** high-field hysteresis strongly depends on the magnetic field sweep rate,so it reflects some slow relaxation *** the lowest rates,it is also accomplished by multiple crossing *** shape of the second-harmonic hysteresis is known for skyrmion spin textures in nonlinear *** skyrmions have been demonstrated for FGT by direct visualization techniques,we can connect the observed high-field relaxation with deformation of the skyrmion ***,the second-harmonic Hall voltage response can be regarded as a tool to detect spin textures in transport experiments.

关键词： harmonic relaxation hysteresis

Multiscalar B-L extension based on S_(4)flavor symmetry for neutrino masses and mixing

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Chinese Physics C 2021年第4期45卷 181-191页

作者： v.v.vien H.n.Long Institute of Research and Development Duy Tan University182 Nguyen Van LinhDa Nang CityVietnam Department of Physics Tay Nguyen University567 Le DuanBuon Ma ThuotDakLakVietnam Theoretical Particle Physics and Cosmology Research Group Advanced Institute of Materials ScienceTon Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Applied Sciences Ton Due Thang UnivesityHo Chi Minh CityVietnam

A multiscalar and nonrenormalizable B-L extension of the standard model(SM)with S_(4)symmetry which successfully explains the recently observed neutrino oscillation data is *** tiny neutrino masses and their hierarchies are generated via the type-I seesaw *** model reproduces the recent experiments of neutrino mixing angles and Dirac CP violating phase in which the atmospheric angle(θ_(23))and the reactor angle(θ_(13))get the best-fit values while the solar angle(θ_(12))and Dirac CP violating phase(δ)are in 3σrange of the best-fit value for the normal hierarchy(nH).For the inverted hierarchy(IH),θ13 gets the best-ft value andθ_(23)together withδare in the lσrange,whileθ12 is in 3δrange of the best-fit *** effective neutrino masses are pre-dicted to be(m_(ee))=6.81 mev for the nH and(m_(ee))=48.48 mev for the IH,in good agreement with the most re-cent experimental data.

关键词： neutrino mass and mixing extensions of electroweak Higgs sector flavor symmetries

Raman spectra of fine-grained materials from first principles

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npj Computational Materials 2020年第1期6卷 616-622页

作者： Maxim n.popov Jürgen Spitaler vignaswaran K.veerapandiyan Eric Bousquet Jiri Hlinka Marco Deluca Materials Center Leoben(MCL)Forschung GmbH Roseggerstrasse 12A-8700 LeobenAustria Physique Théorique des Matériaux QMATCESAMUniversite de LiègeB-4000 Sart-TilmanBelgium Institute of Physics Academy of Sciences of the Czech RepublicNa Slovance 218221 PragueCzech Republic

Raman spectroscopy is an advantageous method for studying the local structure of materials,but the interpretation of measured spectra is complicated by the presence of oblique phonons in polycrystals of polar *** group theory considerations and standard ab initio calculations are helpful,they are often valid only for single *** this paper,we introduce a method for computing Raman spectra of polycrystalline materials from first principles.

关键词： materials spectra principles

Prolonged intermittent theta burst stimulation restores the balance between A_(2A)R-and A_(1)R-mediated adenosine signaling in the 6-hydroxidopamine model of Parkinson's disease

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neural Regeneration Research 2025年第7期20卷 2053-2067页

作者： Milica Zeljkovic Jovanovic Jelena Stanojevic Ivana Stevanovic Milica ninkovic Tihomir v.Ilic nadezda nedeljkovic Milorad Dragic Laboratory for neurobiology Department of General Physiology and BiophysicsFaculty of BiologyUniversity of BelgradeBelgradeSerbia Medical Faculty of Military Medical Academy University of DefenceBelgradeSerbia

An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's *** therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in *** transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's ***,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain *** purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated *** with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod ***,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate *** intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate *** with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor *** treatment with prolonged intermittent theta burst stimulation,complete motor recovery was *** improvement was accompanied by downregulation of the e n/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst *** results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)***

关键词： A_(1)R A_(2A)R adenosine receptors adenosine ecto-5′-nucleotidase intermittent theta burst stimulation non-invasive brain stimulation Parkinson's disease purinergic signalling