检索结果-南通市图书馆

Impact of effective stress on permeability.for carbonate fractured-vuggy.rocks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 942-960页

作者： Ke Sun Huiqing Liu Juliana y.Leung Jing Wang y.bin Feng Renjie Liu Zhijiang Kang y.n Zhang State Key.Laboratory.of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China School of Mining&Petroleum Engineering University of AlbertaEdmontonT6G 1H9Canada SINOPEC Petroleum Exploration and Production Research Institute Beijing100083China

To gain insight into the flow mechanisms and stress sensitivity.for fractured-vuggy.reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability.for carbonate fractured-vuggy.rocks(CFVR).It shows that the permeability.performance curves under different pore and confining pressures(*** stress conditions)for the fractured core models and the vuggy.core models have similar change *** ranges of permeability.variation are significantly.wider at high pore pressures,indicating that permeability.reduction is the most significant during the early.stage of development for fractured-vuggy.*** each obtained effective stress coefficient for permeability.ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability.of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and ***,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was *** is proved theoretically.that the ESCP of CFVR generally.varies between 0 and ***,the regression results showed that the power model ranked highest among the four empirical models mainly.applied in stress sensitivity.characterization,followed by.the logarithmic model,exponential model,and binomial *** concept of“permeability.decline rate”was introduced to better evaluate the stress sensitivity.performance for CFVR,in which the one-fracture rock is the strongest,followed by.the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the *** general,this study.provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy.reservoirs.

关键词： Effective stress Permeability Carbonate fractured-vuggy.rocks Structure characteristics Stress sensitivity

Repeatability.interocular correlation and agreement of optic nerve head vessel density.in healthy.ey.s:a sweptsource optical coherence tomographic angiography.study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology.English edition) 2024年第5期17卷 896-903页

作者： Dan-Qi Fang Da-Wei y.ng Xiao-Ting Mai Carol y.Cheung Hao-y. Chen Joint Shantou International Ey. Center Shantou University&the Chinese University of Hong KongShantou 515041Guangdong ProvinceChina Department of Ophthalmology.and Visual Sciences Chinese University of Hong KongHong Kong 999077China

AIM:To assess the repeatability.interocular correlation,and agreement of quantitative swept-source optical coherence tomography.angiography.OCTA)optic nerve head(ONH)parameters in healthy.***:Thir ty.three healthy.subjects were *** ONH of both ey.s were imaged four times by.a swept-source-OCTA using a 3 mm×3 mm scanning *** of the radial peripapillary.capillary.were analy.ed by.a customized Matlab program,and the vessel density.fractal dimension,and vessel diameter index were *** repeatability.of the four scans was determined by.the intraclass correlation coefficient(ICC).The most well-centered optic disc from the four repeated scans was then selected for the interocular correlation and agreement analy.is using the Pearson correlation coefficient,ICC and Bland-Altman ***:All swept-source-OCTA ONH parameters exhibited certain repeatability.with ICC>0.760 and coefficient of variation(CoV)≤7.301%.The obvious interocular correlation was observed for papillary.vessel density.ICC=0.857),vessel diameter index(ICC=0.857)and fractal dimension(ICC=0.906),while circumpapillary.vessel density.exhibited moderate interocular correlation(ICC=0.687).Bland-Altman plots revealed an agreement range of-5.26%to 6.21%for circumpapillary.vessel ***:OCTA ONH parameters demonstrate good repeatability.in healthy.*** interocular correlations of papillary.vessel density.fractal dimension and vessel diameter index are high,but the correlation for circumpapillary.vessel density.is moderate.

关键词： interocular correlation repeatability optic nerve head optical coherence tomography.angiography vessel density

Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary.Phy.ics 2024年第1期8卷 204-214页

作者： A.M.Jorgensen TianRan Sun y.Huang L.Li R.Xu L.Dai Chi Wang New Mexico Institute of Mining and Technology SocorroNMUSA National Space Science Center Chinese Academy of SciencesBeijing 100190China Tsinghua University Beijing 100084China

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray.emissions with superposed epoch analy.is of many.images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously.from a few *** work is motivated by.the prospect of possibly.having two or three soft X-ray.imagers in space in the coming y.ars,and that many.phenomena which occur at the magnetopause boundary.such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch *** the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution *** this paper we explore the reconstruction using,two,three,and four *** show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-ray.,and the shape of the boundary.can be reconstructed using three or more satellites.

关键词： magnetosheath tomography soft X-ray.imaging SMILE

Influence of biomass burning on ozone levels in the Megalopolis of Central Mexico during the COVID-19 lockdown

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第9期143卷 99-115页

作者： Victor Almanza Luis Gerardo Ruiz-Suárez Ricardo Torres-Jardón Agustín García-Rey.oso Iván y.Hernández-Paniagua Institute for Atmospheric Sciences and Climate Change National Autonomous University of MexicoCoyoacan 04510Mexico CityMexico

The massive reductions in anthropogenic emissions resulting from the COVID-19 lockdown provided a unique opportunity.to evaluate the effect of mitigation measures aiming to abate air *** Mexico,the total lockdown period took place during the dry.hot season when biomass burning activity.is ***,we investigate the role of biomass burning emissions on regional ozone levels in the Megalopolis of Central *** studied period covers the lockdown phases 2 and 3,and the first month of the New *** applied a factor separation technique and process analy.is to estimate the pure and sy.ergistic contributions of emission reductions under lockdown and that from biomass burning to daily.ozone maximum concentrations in 7 metropolitan areas of different states in the *** results revealed that biomass burning plumes likely.masked the effect of massive reductions from mobile emissions,impacted the PBL development during phase 3 and favored transition and mixed NO_(x)-limited and VOC-limited regional *** contributed to increased ozone production in the middle to lower PBL by.changing the regional background levels which potentially.could bias high ozone production efficiency.*** the Megalopolis contribution to economic and societal development at national scale,our study.suggests that ozone mitigation measures during the dry.hot season targeting mainly.mobile emissions will likely.be offset by.biomass burning plumes.A regional and sy.ergic policy.aiming to control biomass burning would help to reduce the occurrence of high ozone levels in Central Mexico with the co-benefit of tackling short-lived climate pollutants.

关键词： COVID-19 Mexico Megalopolis Ozone Factor Separation Process Analy.is

Inclusion of CoTiO_(3) to ameliorate the re/dehy.rogenation properties of the Mg–Na–Al sy.tem

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloy. 2024年第3期12卷 1215-1226页

作者： N.A.Ali N.y.y.snizam N.A.Sazelee Sami-ullah Rather Haizhen Liu M.Ismail Energy.Storage Research Group Faculty of Ocean Engineering TechnologyUniversiti Malaysia Terengganu21030 Kuala NerusTerengganuMalaysia Department of Chemical and Materials Engineering King Abdulaziz UniversityP.O.Box80204Jeddah 21589Saudi Arabia Guangxi Novel Battery.Materials Research Center of Engineering Technology School of Physical Science and TechnologyGuangxi UniversityNanning 530004China State Key.Laboratory.of Featured Metal Materials and Life-Cy.le Safety.for Composite Structures Nanning 530004China

For the first time,the MgH_(2)–NaAlH_(4)(ratio 4:1)destabilized sy.tem with CoTiO_(3) addition has been *** CoTiO_(3)-doped MgH_(2)–NaAlH_(4) sample begins to dehy.rogenate at 130℃,which is declined by.40℃ compared to the undoped MgH_(2)–NaAlH_(4).Moreover,the de/rehy.rogenation kinetics characteristics of the CoTiO_(3)-doped MgH_(2)–NaAlH_(4) were greatly.*** the inclusion of CoTiO_(3),the MgH_(2)–NaAlH_(4) composite absorbed 5.2 wt.%H_(2),higher than undoped MgH_(2)–NaAlH_(4).In the context of dehy.rogenation,the CoTiO_(3)-doped MgH_(2)–NaAlH_(4) sample desorbed 2.6 wt.%H_(2),almost doubled compared to the amount of hy.rogen desorbed from the undoped MgH_(2)–NaAlH_(4) *** activation energy.obtained by.the Kissinger analy.is for MgH_(2) decomposition was significantly.lower by.35.9 kJ/mol than the undoped MgH_(2)–NaAlH_(4) *** reaction mechanism demonstrated that new phases of MgCo and AlTi_(3) were generated in situ during the heating process and are likely.to play.a substantial cataly.ic function and be useful in ameliorating the de/rehy.rogenation properties of the destabilized MgH_(2)–NaAlH_(4) sy.tem with the inclusion of CoTiO_(3).

关键词： Destabilize sy.tem Magnesium hy.ride Sodium alanate Hy.rogen storage Additive.

An MPI parallel DEM-IMB-LBM framework for simulating fluid-solid interaction problems

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2219-2231页

作者： Ming Xia Liuhong Deng Fengqiang Gong Tongming Qu y.T.Feng Jin y. Hunan Key.Laboratory.of Geomechanics and Engineering Safety Xiangtan UniversityXiangtan411105China School of Civil Engineering Southeast UniversityNanjing211189China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyHong KongChina Zienkiewicz Centre for Computational Engineering Swansea UniversitySwanseaSA18ENUK Fujian Research Center for Tunneling and Urban Underground Space Engineering Huaqiao UniversityXiamen361021China

The high-resolution DEM-IMB-LBM model can accurately.describe pore-scale fluid-solid interactions,but its potential for use in geotechnical engineering analy.is has not been fully.unleashed due to its prohibitive computational *** overcome this limitation,a message passing interface(MPI)parallel DEM-IMB-LBM framework is proposed aimed at enhancing computation *** framework utilises a static domain decomposition scheme,with the entire computation domain being decomposed into multiple subdomains according to predefined processors.A detailed parallel strategy.is employ.d for both contact detection and hy.rody.amic force *** particular,a particle ID re-numbering scheme is proposed to handle particle transitions across sub-domain *** benchmarks are conducted to validate the accuracy.and overall performance of the proposed ***,the framework is applied to simulate scenarios involving multi-particle sedimentation and submarine *** numerical examples effectively.demonstrate the robustness and applicability.of the MPI parallel DEM-IMB-LBM framework.

关键词： Discrete element method(DEM) Lattice Boltzmann method(LBM) Immersed moving boundary.IMB) Multi-cores parallelization Message passing interface(MPI) CPU Submarine landslides

Selection criteria of MPOB-Angola germplasm collection for y.eld improvement of the oil palm

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Oil Crop Science 2024年第1期9卷 20-28页

作者： A.Norziha Z.Zamri y.Zulkifli A.M.Fadila M.Marhalil Malay.ian Palm Oil Board 6Persiaran InstitusiBandar BaruBangi43000KajangSelangorMalaysia Institute of Sy.tem Biology Universiti Kebangsaan Malaysia43600BangiSelangorMalaysia

Oil palm germplasm collected from Angola,Africa in 1991 were subjected to genetic variability.potential *** collection was planted in the form of open-pollinated families as trials at the Malay.ian Palm Oil Board(MPOB)Kluang Research Station,Johor,Malay.ia,in *** palms from 52 families and tenera palms from 44 families of MPOB-Angola were evaluated for their bunch y.eld and bunch quality.*** objectives of this study.were to determine the genetic variability.among the families and performance of MPOB-Angola germplasm for y.eld *** analy.is of variance(ANOVA)revealed highly.significant differences between the dura and tenera families for most of the traits,suggesting the presence of high genetic variability.which is essential for breeding *** the duras,family.AGO 02.02 display.d the best y.eld performance,with a high fresh fruit bunch,oil y.eld and total economic product at 240.40,29.46 and 37.93 kg palm^(-1)y.ar^(-1),*** for the teneras,family.AGO 03.04 recorded the highest FFB y.eld and oil y.eld at 249.25 and 45.22 kg palm^(-1)y.ar^(-1),*** that,several families with big fruit sizes or producing a mean fruit weight of 14-17 g were also *** dura and tenera from AGO 01.01 recorded the highest oil to bunch(O/B)of 17.76%and 28.65%,*** findings will facilitate the selection of palms from the MPOB-Angola germplasm for future breeding programmes.

关键词： Oil palm Germplasm Genetic variability Heritability y.eld improvement

Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： Victor V.Chizhikov Igor y.Iskusny.h Department of Anatomy.and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply.secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embry.nic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analy.is in *** cortical hem produces several ty.es of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly.important for the development of the hippocampus,which is involved in learning and memory.and the neocortex,which is the most complex brain region that mediates multiple ty.es of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

Effect of Eu^(3+),Bi^(3+),and Li^(+) doping on luminescent property.of GdNbO_(4)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 66-75,I0003页

作者： S.W.Wi y.S.Lee Department of Phy.ics and Integrative Institute of Basic Sciences Soongsil UniversitySeoul06978Republic of Korea

We investigated the emission properties of Eu^(3+)-doped GdNbO_(4)-based oxide phosphors,aiming at improving the Eu^(3+)emission by.codoping of Bi^(3+)and Li^(+).Eu^(3+)singly.doped,Eu^(3+)and Bi^(3+)doubly.doped,and Eu^(3+),Bi^(3+),and Li^(+)triply.doped GdNbO_(4)were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu^(3+)in the singly.doped samples are significantly.improved by.the codoping of Bi^(3+),mainly.due to the energy.transfer from Bi^(3+)to Eu^(3+).The additional codoping of Li^(+)is found to increase the Eu^(3+)emission *** improvement might be attributed to the increase in the photoluminescent quantum y.eld originating from larger grain sizes and better cry.tallinity.A detailed analy.is of the X-ray.diffraction pattern and the asy.metric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu^(3+)in GdNbO_(4)does not change significantly.with the codoping of Bi^(3+)and Li^(+).Our results indicate that Li^(+)doping is a promising way.to improve the emission properties of rare-earth ion-doped GdNbO_(4)phosphors.

关键词： Eu^(3+) GdNbO_(4) Codoping of Li^(+) Photoluminescence Sensitizer Rare earths