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From a Dual Einstein-Kaluza Spacetime to ‘tHooft Renormalon and the Reality of Accelerated Cosmic Expansion 被引量:4
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作者 Mohamed S. El Naschie 《Journal of Modern Physics》 2017年第8期1319-1329,共11页
We use a dual Einstein-Kaluza spacetime to calculate the exact energy density of dark energy and dark matter using a novel topological computation method. Starting from the said spacetime and ‘tHooft’s topological r... We use a dual Einstein-Kaluza spacetime to calculate the exact energy density of dark energy and dark matter using a novel topological computation method. Starting from the said spacetime and ‘tHooft’s topological renormalon as well as the corresponding symmetry group, we show how the zero set quantum particle and the empty set quantum wave interact with the vacuum and give rise to pure dark energy and pure dark matter all along with ordinary energy density of the cosmos. The consistency of the exact calculation and the accurate observations attests to the reality of ‘tHooft’s renormalon dark matter, pure dark energy and accelerated cosmic expansion. 展开更多
关键词 Accelerated COSMIC expansion tHooft Renormalon Cantorian SPACETIME DARK Matter Pure DARK ENERGY Topological E-Infinity Computation Zero Set Quantum Particle Empty Set Quantum Wave Hausdorff MASS of Ordinary ENERGY Topological MASS of DARK ENERGY Mixed MASS of DARK Matter and Pure DARK ENERGY A Dual Einstein-Kaluza SPACETIME
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Pinched Material Einstein Space-Time Produces Accelerated Cosmic Expansion
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作者 M. S. El Naschie 《International Journal of Astronomy and Astrophysics》 2014年第1期80-90,共11页
An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a... An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a hyperbolic fractal Rindler space-time leading to the same robust results regarding real energy and dark energy being 4.5% and 95.5% respectively in full agreement with all recent cosmological measurements. 展开更多
关键词 Dark Energy Rindler SPACE-TIME CARTAN Torsion Pinched Elastic Shells Negative Gravity COSMIC ACCELERATED expansion Fractal SPACE-TIME Topological Defects Hardys Quantum Entanglement Hawkings Radiation COSSERAT Elasticity
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Extended Jacobian Elliptic Function Expansion Method and Its Applications in Biology
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作者 Emad H. M. Zahran Mostafa M. A. Khater 《Applied Mathematics》 2015年第7期1174-1181,共8页
In this work, an extended Jacobian elliptic function expansion method is proposed for constructing the exact solutions of nonlinear evolution equations. The validity and reliability of the method are tested by its app... In this work, an extended Jacobian elliptic function expansion method is proposed for constructing the exact solutions of nonlinear evolution equations. The validity and reliability of the method are tested by its applications to Dynamical system in a new Double-Chain Model of DNA and a diffusive predator-prey system which play an important role in biology. 展开更多
关键词 Extended JACOBIAN Elliptic Function expansion Method Dynamical SYSTEM in a New DOUBLE-CHAIN Model of DNA A Diffusive PREDATOR-PREY SYSTEM Traveling WAVE SOLUTIONS Solitary WAVE SOLUTIONS
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Exact Traveling Wave Solutions for the System of Shallow Water Wave Equations and Modified Liouville Equation Using Extended Jacobian Elliptic Function Expansion Method 被引量:6
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作者 Emad H. M. Zahran Mostafa M. A. Khater 《American Journal of Computational Mathematics》 2014年第5期455-463,共9页
In this work, an extended Jacobian elliptic function expansion method is proposed for constructing the exact solutions of nonlinear evolution equations. The validity and reliability of the method are tested by its app... In this work, an extended Jacobian elliptic function expansion method is proposed for constructing the exact solutions of nonlinear evolution equations. The validity and reliability of the method are tested by its applications to the system of shallow water wave equations and modified Liouville equation which play an important role in mathematical physics. 展开更多
关键词 Extended JACOBIAN Elliptic Function expansion Method The System of Shallow Water WAVE Equations MODIFIED LIOUVILLE Equation Traveling WAVE SOLUTIONS SOLITARY WAVE SOLUTIONS
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Semi-analytical solution for drained expansion analysis of a hollow cylinder of critical state soils 被引量:1
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作者 He Yang Jialiang Zhang +1 位作者 Haisui Yu Peizhi Zhuang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2326-2340,共15页
The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by ... The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by the common self-similar-based similarity techniques.This paper proposes a novel,exact solution for rigorous drained expansion analysis of a hollow cylinder of critical state soils.Considering stress-dependent elastic moduli of soils,new analytical stress and displacement solutions for the nonself-similar problem are developed taking the small strain assumption in the elastic zone.In the plastic zone,the cavity expansion response is formulated into a set of first-order partial differential equations(PDEs)with the combination use of Eulerian and Lagrangian descriptions,and a novel solution algorithm is developed to efficiently solve this complex boundary value problem.The solution is presented in a general form and thus can be useful for a wide range of soils.With the new solution,the non-self-similar nature induced by the finite outer boundary is clearly demonstrated and highlighted,which is found to be greatly different to the behaviour of cavity expansion in infinite soil mass.The present solution may serve as a benchmark for verifying the performance of advanced numerical techniques with critical state soil models and be used to capture the finite boundary effect for pressuremeter tests in small-sized calibration chambers. 展开更多
关键词 Cavity expansion Drained analysis Boundary effect Critical state soil Non-self-similar Eulerian-Lagrangian approach
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Rapid Expansion of Supercritical Solution of Poly (1,1,2,2- Tetrahy-droperfluorodecyl Acrylate)
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作者 董擎之 《Journal of China Textile University(English Edition)》 EI CAS 1999年第2期35-37,共3页
Poly(1,1,2,2- tetrahydroperfluorodecyl acrylate) (poly (TA-N)) was synthesized in laboratory. The resulting morphology of rapid expansion of supercritical solution (RESS) sprays of poly(TA - N) was investigated. At ap... Poly(1,1,2,2- tetrahydroperfluorodecyl acrylate) (poly (TA-N)) was synthesized in laboratory. The resulting morphology of rapid expansion of supercritical solution (RESS) sprays of poly(TA - N) was investigated. At apre - expansion temperature of 45℃), amorphous polymer was formed. At temperature around 60 ℃ to 80 ℃ , fibers were formed. Increase of temperature increasesparticle size slightly. At temperature of 105℃ , most of particles are spheres. The RESS is an attractive process. To apply the polymers desired for coating applications in an organic solvent - free process that is economically viable , and it will have implications for pollution prevention during polymer film 展开更多
关键词 Rapid expansion of SUPERCRITICAL solution ( RESS ) Poly( 1 1 2 2 - tetrahydroperfluorodecyl ACRYLATE ) Synthesis POROUS sintered metal plate .
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An Interpolation Method for Karhunen-Loève Expansion of Random Field Discretization
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作者 Zi Han Zhentian Huang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期245-272,共28页
In the context of global mean square error concerning the number of random variables in the representation,the Karhunen–Loève(KL)expansion is the optimal series expansion method for random field discretization.T... In the context of global mean square error concerning the number of random variables in the representation,the Karhunen–Loève(KL)expansion is the optimal series expansion method for random field discretization.The computational efficiency and accuracy of the KL expansion are contingent upon the accurate resolution of the Fredholm integral eigenvalue problem(IEVP).The paper proposes an interpolation method based on different interpolation basis functions such as moving least squares(MLS),least squares(LS),and finite element method(FEM)to solve the IEVP.Compared with the Galerkin method based on finite element or Legendre polynomials,the main advantage of the interpolation method is that,in the calculation of eigenvalues and eigenfunctions in one-dimensional random fields,the integral matrix containing covariance function only requires a single integral,which is less than a two-folded integral by the Galerkin method.The effectiveness and computational efficiency of the proposed interpolation method are verified through various one-dimensional examples.Furthermore,based on theKL expansion and polynomial chaos expansion,the stochastic analysis of two-dimensional regular and irregular domains is conducted,and the basis function of the extended finite element method(XFEM)is introduced as the interpolation basis function in two-dimensional irregular domains to solve the IEVP. 展开更多
关键词 Random field discretization KL expansion IEVP MLS FEM stochastic analysis
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An agent-based model of agricultural land expansion in the mountain forest of Timor Island,Indonesia
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作者 PUJIONO Eko SADONO Ronggo +12 位作者 IMRON Muhammad Ali SUTOMO JANUAR Hedi Indra KUSWANDI Relawan KURNIAWAN Hery HADI Etik Erna Wati SAPUTRA Muhammad Hadi HIDAYAH Izhamil HUMAIDA Nida SUKMAWATI Jalma Giring HADIYAN Yayan NUGROHO Agung Wahyu HANI Aditya 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2263-2282,共20页
The Mutis-Timau Forest Complex,located on Timor Island,Indonesia,is a mountainous tropical forest area that gradually decreases due to deforestation and forest degradation.Previous modelling studies based on patterns ... The Mutis-Timau Forest Complex,located on Timor Island,Indonesia,is a mountainous tropical forest area that gradually decreases due to deforestation and forest degradation.Previous modelling studies based on patterns indicate that deforestation primarily occurs at lower elevations and near the boundaries of forests and settlements,often associated with shifting cultivation by local farmers.This study adopts a process-based modelling approach,specifically the agent-based model,to simulate land changes,particularly farmers'expansion of agricultural land around the Mutis mountain forest.The underlying concept of this agent-based approach is the interaction between the human and environmental systems.Farmers,representing the human system,interact with the land,which represents the environmental system,through land use decision-making mechanisms.The research was conducted in the Community Forest of the Timor Tengah Utara District,one of the sites within the Mutis-Timau Forest Complex with the highest deforestation rate.Land use change simulations were performed using agent-based modelling from 1999 to 2030,considering the socio-economic conditions of farmers,spatial preferences,land use decisions,and natural transitions.The results revealed that the agricultural area increased by 14%under the Business as Usual scenario and 5%under the Reducing Emission from Deforestation and Forest Degradation scenario,compared to the initial agricultural area of 245 hectares.The probability of farmers deciding to extend agricultural activities was positively associated with the number of livestock maintained by farmers and the size of the village area.Conversely,the likelihood of farmers opting for agricultural extensification decreased with an increase in the area of private land and the farmer's age.These findings are crucial for the managers of the Mutis-Timau Forest Complex and other relevant stakeholders,as they aid in arranging actions to combat deforestation,designing proper forest-related policies,and providing support for initiatives such as reducing emissions from deforestation and forest degradation programs or further incentive schemes. 展开更多
关键词 Agricultural land expansion Simulation Agent-based model FARMER DEFORESTATION Mountainous tropical forest
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Gravity vs. Dark Energy, about the Expansion of the Universe
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作者 Olivier Serret 《Journal of Modern Physics》 2018年第1期84-97,共14页
Dark energy is argued by the accelerating expansion of the Universe but has not been directly measured. In this article, some uncertainties are pointed out, first one being the determination of the Hubble constant. An... Dark energy is argued by the accelerating expansion of the Universe but has not been directly measured. In this article, some uncertainties are pointed out, first one being the determination of the Hubble constant. And the main parameters (magnitude, distance, redshift, velocity) are checked. Distinguishing the instantaneous velocity from the average velocity, it is then concluded from the same data that the expansion would not be accelerating, and that the Gravity would slightly slow down the motion of explosion. Moreover, at the end of the paper, it is proposed a neo-Newtonian approach to get the computed values in a closer agreement with the observed values;this Neo-Newtonian Mechanics is in coherence with the Quantum Mechanics. 展开更多
关键词 Acceleration expansion Inflation Universe COSMOS Magnitude REDSHIFT HUBBLE Constant Uncertainties of Measure Dark Energy GRAVITATION Relativity Neo-Newtonian Mechanics
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Impelling force and current challenges by chemicals in somatic cell reprogramming and expansion beyond hepatocytes 被引量:2
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作者 Jian-Yun Ge Yun-Wen Zheng +2 位作者 Li-Ping Liu Hiroko Isoda Tatsuya Oda 《World Journal of Stem Cells》 SCIE 2019年第9期650-665,共16页
In the field of regenerative medicine,generating numerous transplantable functional cells in the laboratory setting on a large scale is a major challenge.However,the in vitro maintenance and expansion of terminally di... In the field of regenerative medicine,generating numerous transplantable functional cells in the laboratory setting on a large scale is a major challenge.However,the in vitro maintenance and expansion of terminally differentiated cells are challenging because of the lack of specific environmental and intercellular signal stimulations,markedly hindering their therapeutic application.Remarkably,the generation of stem/progenitor cells or functional cells with effective proliferative potential is markedly in demand for disease modeling,cell-based transplantation,and drug discovery.Despite the potent genetic manipulation of transcription factors,integration-free chemically defined approaches for the conversion of somatic cell fate have garnered considerable attention in recent years.This review aims to summarize the progress thus far and discuss the advantages,limitations,and challenges of the impact of full chemicals on the stepwise reprogramming of pluripotency,direct lineage conversion,and direct lineage expansion on somatic cells.Owing to the current chemical-mediated induction,reprogrammed pluripotent stem cells with reproducibility difficulties,and direct lineage converted cells with marked functional deficiency,it is imperative to generate the desired cell types directly by chemically inducing their potent proliferation ability through a lineagecommitted progenitor state,while upholding the maturation and engraftment capacity posttransplantation in vivo.Together with the comprehensive understanding of the mechanism of chemical drives,as well as the elucidation of specificity and commonalities,the precise manipulation of the expansion for diverse functional cell types could broaden the available cell sources and enhance the cellular function for clinical application in future. 展开更多
关键词 Chemical INDUCTION PLURIPOTENT REPROGRAMMING DIRECT LINEAGE conversion DIRECT LINEAGE expansion Hepatocyte expansion Cell fate specificity Transcriptional memory In vivo INDUCTION
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Significant lake expansion has accelerated permafrost degradation on the Qinghai-Tibet Plateau
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作者 LI Qingpeng LIU Wenhui +6 位作者 LIU Hairui ZHOU Guanghao SONG Xianteng LI Qing LUO Bingnan SONG Bangxu ZHANG Qi 《Journal of Mountain Science》 SCIE CSCD 2024年第1期68-83,共16页
In recent years, lakes on the Qinghai-Tibet Plateau have become more responsive to climate change. In September 2011, Zonag Lake in Hoh Xil experienced sudden drainage, the water eventually flowed into Yanhu Lake, whi... In recent years, lakes on the Qinghai-Tibet Plateau have become more responsive to climate change. In September 2011, Zonag Lake in Hoh Xil experienced sudden drainage, the water eventually flowed into Yanhu Lake, which caused Yanhu Lake to continue to expand. The potential collapse of Yanhu Lake could directly threaten the operational safety of the adjacent Qinghai-Tibet Highway, Qinghai-Tibet Railway. To explore the implications of expanding lakes on the surrounding permafrost, we selected Hoh Xil Yanhu Lake on the Qinghai-Tibet Plateau to study the effect of lake expansion on permafrost degradation. The permafrost degradation in the Yanhu Lake basin from October 2017 to December 2022 was inverted using Sentinel-1 satellite image data and small baseline subset interferometry synthetic aperture radar(SBAS-In SAR) technology. Additionally, permafrost degradation from February 2007 and February 2010 was analyzed using advanced land observing satellite phased array-type L-band synthetic aperture radar(ALOS PALSAR) satellite images and differential interferometric synthetic aperture radar(D-In SAR) technique. The results showed that the permafrost around Yanhu Lake experienced accelerated degradation. Prior to the expansion of Yanhu Lake, the average annual deformation rate along the line of sight(LOS) direction was 6.7 mm/yr. After the expansion, the rate increased to 20.9 mm/yr. The integration of spatial-temporal distribution maps of surface subsidence, Wudaoliang borehole geothermal data, meteorological data, Yanhu Lake surface area changes, and water level changes supports the assertion that the intensified permafrost degradation could be attributed to lake expansion rather than the rising air temperature. Furthermore, permafrost degradation around Yanhu Lake could impact vital infrastructure such as the adjacent Qinghai-Tibet Highway and Qinghai-Tibet Railway. 展开更多
关键词 Lake expansion SBAS-InSAR D-INSAR Permafrost deformation Qinghai-Tibet Plateau
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Can Industrial Structure Upgrading Restrain Industrial Land Expansion?Evidence from China
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作者 CHEN Wei LI Qiao +1 位作者 ZHANG Sun ZHOU Xue 《Chinese Geographical Science》 SCIE CSCD 2024年第3期504-518,共15页
China has made great achievements in industrial development and is transforming into a powerful manufacturing country.Meanwhile,the industrial land scale is also expanding.However,whether industrial structure upgradin... China has made great achievements in industrial development and is transforming into a powerful manufacturing country.Meanwhile,the industrial land scale is also expanding.However,whether industrial structure upgrading achieves the purpose of restraining industrial land expansion remains unanswered.By calculating the industrial land structure index(ILSI)and industrial land expansion scale(ILES),this study analyzed their temporal and spatial distribution characteristics at both regional and city levels from 2007to 2020 in China.Results show that industrial land expansion presents a different trend in the four regions,the ILES in the eastern region is the largest,and the speed of industrial land expansion has declined since 2013,but it has gradually increased since 2016.The ILSI of the eastern and central regions is higher than that of the western and northeastern regions.Furthermore,a spatial Durbin model(SDM)has been established to estimate the spatial effect of industrial structure upgrading on industrial land expansion from 2007 to2020.Notably,industrial structure upgrading has not slowed industrial land expansion.The eastern and western regions require a greater amount of industrial land while upgrading the industrial structure.The improvement of the infrastructure level and international trade level has promoted industrial land expansion. 展开更多
关键词 industrial development industrial structure upgrading industrial land expansion regional differences China
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Modification of streamer-to-leader transition model based on radial thermal expansion in the sphere-plane gap discharge at high altitude
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作者 耿江海 林果 +3 位作者 王平 丁玉剑 丁杨 俞华 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第1期42-49,共8页
Historically,streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis,with limited attention paid to the sphere-plane gap at high altitude analysis.In this work,sphere-plane ... Historically,streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis,with limited attention paid to the sphere-plane gap at high altitude analysis.In this work,sphere-plane gap discharge tests were carried out under the gap distance of 5 m at the Qinghai Ultra High Voltage(UHV)test base at an altitude of 2200 m.The experiments measured the physical parameters such as the discharge current,electric field intensity and instantaneous optical power.The duration of the dark period and the critical charge of streamer-toleader transition were obtained at high altitude.Based on radial thermal expansion of the streamer stem,we established a modified streamer-to-leader transition model of the sphere-plane gap discharge at high altitude,and calculated the stem temperature,stem radii and the duration of streamer-to-leader transition.Compared with the measured duration of sphere-plane electrode discharge at an altitude of 2200 m,the error rate of the modified model was 0.94%,while the classical model was 6.97%,demonstrating the effectiveness of the modified model.From the comparisons and analysis,several suggestions are proposed to improve the numerical model for further quantitative investigations of the leader inception. 展开更多
关键词 streamer-to-leader transition model high altitude streamer stem convective diffusion radial thermal expansion
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Three-dimensional pseudo-dynamic reliability analysis of seismic shield tunnel faces combined with sparse polynomial chaos expansion
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作者 GUO Feng-qi LI Shi-wei ZOU Jin-Feng 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2087-2101,共15页
To address the seismic face stability challenges encountered in urban and subsea tunnel construction,an efficient probabilistic analysis framework for shield tunnel faces under seismic conditions is proposed.Based on ... To address the seismic face stability challenges encountered in urban and subsea tunnel construction,an efficient probabilistic analysis framework for shield tunnel faces under seismic conditions is proposed.Based on the upper-bound theory of limit analysis,an improved three-dimensional discrete deterministic mechanism,accounting for the heterogeneous nature of soil media,is formulated to evaluate seismic face stability.The metamodel of failure probabilistic assessments for seismic tunnel faces is constructed by integrating the sparse polynomial chaos expansion method(SPCE)with the modified pseudo-dynamic approach(MPD).The improved deterministic model is validated by comparing with published literature and numerical simulations results,and the SPCE-MPD metamodel is examined with the traditional MCS method.Based on the SPCE-MPD metamodels,the seismic effects on face failure probability and reliability index are presented and the global sensitivity analysis(GSA)is involved to reflect the influence order of seismic action parameters.Finally,the proposed approach is tested to be effective by a engineering case of the Chengdu outer ring tunnel.The results show that higher uncertainty of seismic response on face stability should be noticed in areas with intense earthquakes and variation of seismic wave velocity has the most profound influence on tunnel face stability. 展开更多
关键词 reliability analysis shield tunnel face sparse polynomial chaos expansion modified pseudo-dynamic approach seismic stability assessment
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Unveiling the adaptation strategies of woody plants in remnant forest patches to spatiotemporal urban expansion through leaf trait networks
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作者 Mengping Jian Jingyi Yang 《Forest Ecosystems》 SCIE CSCD 2024年第2期247-254,共8页
Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion... Background:With the expansion of urban areas,the remnants of forested areas play a crucial role in preserving biodiversity in urban environments.This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches,thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.Methods:Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang,China.We constructed leaf trait networks (LTNs) based on 26 anatomical,structural,and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.Results and conclusions:Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees.With increasing urban expansion intensity,we observed a rise in the edge density of the LTN-shrubs.Additionally,modularity within the networks of shrubs decreased as road density and urban expansion intensity increased,and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index.Notably,patches subjected to‘leapfrog’expansion exhibited greater average patch length and diameter than those experiencing edge growth.Stomatal traits were found to have high degree centrality within these networks,signifying their substantial contribution to multiple functions.In urban remnant forests,shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks. 展开更多
关键词 Urban remnant forest patch Woody plant Leaf trait network Plant adaptation strategy Spatiotemporal urban expansion
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Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring
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作者 D.LEE S.CHANG J.LEE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第5期819-836,共18页
This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random inputs.The method consists of a gen... This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random inputs.The method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data set.In the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random inputs.This allows for avoiding repeated computations of invariant substructures while generating the input-output data set.Combining substructuring with static condensation further improves the computational efficiency of the reanalysis without losing accuracy.Consequently,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional inputs.The numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs. 展开更多
关键词 forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCE) static reanalysis method static condensation SUBSTRUCTURING
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Series of cataract surgeries with I-ring pupil expansion ring
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作者 Kenneth Lu Martin Garcia +1 位作者 Jack Tian Rustum Karanjia 《World Journal of Ophthalmology》 2019年第1期1-6,共6页
BACKGROUND The retrospective review of I-ring pupil expansion ring use is designed to examine the patient characteristics and associated surgical challenges in a clinical practice.The hypothesis is that I-ring provide... BACKGROUND The retrospective review of I-ring pupil expansion ring use is designed to examine the patient characteristics and associated surgical challenges in a clinical practice.The hypothesis is that I-ring provides a necessary additive tool in dealing with challenging cataract surgeries with small pupils.AIM To document the safety profile and use of I-ring pupil expansion ring in a clinical practice.METHODS A retrospective chart review of 12 consecutive cases within the same year(2016)of cataract surgeries employing I-ring pupil expansion ring(Beaver-Visitec,International)by a single surgeon at the same ambulatory surgical center was conducted.Demographic,pre-op,intra-op,and post-op data were recorded.Total number of cataract cases performed was also recorded.RESULTS 8 of 12 cases were planned I-ring cases.1 case was decided intraoperatively when femtosecond laser caused the pupil to shrink.The other 3 cases were also decided upon intraoperatively when pupil was deemed to be small.7 patients had IFIS from Flomax use.2 patients had pseudoexfoliation syndrome as the cause of small pupil.2 patients had narrow angles with brunescent cataracts.2 patients had pre-op partial zonular dehiscence.1 patient had 360o of posterior synechiae.2 cases had ruptured posterior capsule that required anterior vitrectomy.No complications were attributed to the pupil expansion ring.A total of 296 cataract surgeries were performed that year by the surgeon,making the rate of pupil ring use 4.1%.CONCLUSION Small pupil requiring pupil expansion ring during cataract surgery is often associated with other challenges,such as brunescent cataract,zonular weakness,and posterior synechiae in this series.I-ring helped to reduce at least one challenge in these difficult cases. 展开更多
关键词 Malyugin RING I-ring Small PUPIL PSEUDOEXFOLIATION syndrome CATARACT Iris retraction IFIS Zonular dehiscence Challenging CATARACT surgeries PUPIL expansion device
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Discussion on the Implications of Expansion in Postgraduate Education
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作者 Jingyu Zhu 《Journal of Contemporary Educational Research》 2024年第6期128-134,共7页
This paper explores the development of postgraduate education in China,including the overall situation of postgraduate education,the trend in enrollment expansion in professional degrees as well as in various academic... This paper explores the development of postgraduate education in China,including the overall situation of postgraduate education,the trend in enrollment expansion in professional degrees as well as in various academic fields;it also triggers the impact and discussion about the postgraduate enrollment expansion,such as over-education and credential inflation,as well as the concerns about the quality of education and talent cultivation and so forth.Although the expansion brings various problems,the challenges may also become new opportunities for higher education reform,this paper also provides some suggestions on the expansion of postgraduate education. 展开更多
关键词 expansion of postgraduate education OVER-EDUCATION Credential inflation IMPLICATIONS Employment crisis Education quality
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On Thermodynamic Analysis of Substances with Negative Coefficient of Thermal Expansion
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作者 Kal Renganathan Sharma 《Engineering(科研)》 2013年第11期844-849,共6页
There are reports in the literature on the discovery of novel materials that were observed to shrink upon heating. Treatment of these materials in the same manner as the materials with positive coefficient of thermal ... There are reports in the literature on the discovery of novel materials that were observed to shrink upon heating. Treatment of these materials in the same manner as the materials with positive coefficient of thermal expansion can lead to the misinterpretation of the laws of thermodynamics. This is because volume expansivity is usually defined at constant pressure. Negative values for volume expansivity can be shown using Maxwell’s reciprocity relations to lead to negative values for absolute temperature for ideal gas. For real systems, using Helmholz free energy analysis at equilibrium an expression for the volume expansivity was derived. It can be seen that this expression would be always positive for real physical changes, either heating or cooling. Isentropic volume expansivity is proposed as better suited for analysis of materials with negative thermal expansion, NTE and composites used in space such as Hubble telescope and Chandra telescope with zero coefficient of thermal expansion. This kind of a switch from isobaric to isentropic has precedence in the history of development of speed of sound. 展开更多
关键词 NEGATIVE Thermal expansion NTE Materials Helmholz Free Energy SECOND LAW of THERMODYNAMICS Speed of SOUND Volume Expansivity
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Processing of AM60 magnesium alloy by hydrostatic cyclic expansion extrusion at elevated temperature as a new severe plastic deformation method 被引量:8
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作者 Farshad Samadpour Ghader Faraji Armin Siahsarani 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第5期669-677,共9页
Hydrostatic cyclic expansion extrusion(HCEE) process at elevated temperatures is proposed as a method for processing less deformable materials such as magnesium and for producing long ultrafine-grained rods. In the HC... Hydrostatic cyclic expansion extrusion(HCEE) process at elevated temperatures is proposed as a method for processing less deformable materials such as magnesium and for producing long ultrafine-grained rods. In the HCEE process at elevated temperatures, high-pressure molten linear low-density polyethylene(LLDPE) was used as a fluid to eliminate frictional forces. To study the capability of the process,AM60 magnesium rods were processed and the properties were investigated. The mechanical properties were found to improve significantly after the HCEE process. The yield and ultimate strengths increased from initial values of 138 and 221 MPa to 212 and 317 MPa, respectively.Moreover, the elongation was enhanced due to the refined grains and the existence of high hydrostatic pressure. Furthermore, the microhardness was increased from HV 55.0 to HV 72.5. The microstructural analysis revealed that ultrafine-grained structure could be produced by the HCEE process. Moreover, the size of the particles decreased, and these particles thoroughly scattered between the grains. Finite element analysis showed that the HCEE was independent of the length of the sample, which makes the process suitable for industrial applications. 展开更多
关键词 high-pressure fluid ELEVATED temperature severe plastic deformation HYDROSTATIC CYCLIC expansion EXTRUSION mechanical properties magnesium alloy
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