检索结果-南通市图书馆

A new approach to pedestal differentiation for soil loss estimation-a case study from a burnt area in north-central Portugal

引用

journal of Forestry Research 2024年第3期35卷 45-54页

作者： Frank g.A.Verheijen Martinho A.S.Martins Sergio A.Prats jan j.Keizer Centre for Environmental and Marine Studies(CESAM) Department Environment and PlanningUniversity of Aveiro3810-193 AveiroPortugal Mediterranean Institute for Agriculture Environment and Development(MED-CHANGE)Institute for Advanced Studies and ResearchUniversity of EvoraPolo da MitraAp.947006-554 EvoraPortugal geoBiociencias Geotecnologias E Geoengenharias(GEOBIOTEC)Department Environment and PlanningUniversity of Aveiro3810-193 AveiroPortugal

Soil pedestals have long been used as qualitative indicators of soil splash *** rangelands,plant-capped pedestals,generally grass tussocks,have also been used to quantitatively estimate soil loss since the first half of the twentieth *** agricultural lands,forests,and bad-lands,stone-capped pedestals have been used as qualitative and semi-quantitative indicators of active,'extreme'*** work has been reported on using capstone pedestal data for quantifying soil *** postulate that three distinct capstone pedestal types may be present in any given location and that a detailed analysis of a pedestal height histogram may be used to recognize their *** analysis can subsequently inform if soil loss can be reliably estimated and if so,which of the existing methods using pedestal height data will provide more accurate *** three proposed capstone pedestal types are:(1)neo-pedestals formed underneath surface stones exposed by(partial)removal of the soil surface cover;(2)endo-pedestals formed underneath stones that were buried in the soil but have been exposed by erosion;and(3)phoenix-pedestals formed underneath stones from collapsed *** the pedestal height histogram of any given location,a skew to smaller heights may indicate the existence of endo-and/or phoenix-pedestals,which may be revealed as a bi-(or tri)modal distribution when using a smaller bin *** concept was applied to a case study where soil loss had been monitored for control plots and mulched plots during a 5-year period following wildfire in a eucalypt *** measured pedestal heights and used methods to quantitatively assess soil loss from soil pedestal data in the available *** pedestal data at the end of the 5-year period under or overestimated soil loss in the control treatment,with results ranging from 60 to 115%of measured soil loss,depending on the *** is postulated that phoenix-and endo-pedestals may be a driving fact

关键词： Soil pedestals Mulch Wildfire Soil erosion Char

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

引用

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE M.T.MUNIR g.j.WENg K.Y.RHEE Biomaterials and Tissue Engineering Research group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and Technology American University of the Middle EastEgaila 54200Kuwait Department of Mechanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of Mechanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously *** contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed model's accuracy is verified through numerous experimental *** further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are ***,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling *** dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/*** increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's ***,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation

引用

Earth and Planetary Physics 2024年第1期8卷 25-38页

作者： S.Parsons D.j.Hall o.Hetherington T.W.Buggey T.Arnold M.W.j.Hubbard A.Holland Centre for Electronic Imaging the Open UniversityMilton KeynesMK76AAUK

Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their *** order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance *** CCDs have been characterised,the two flight devices and the flight spa *** has been carried out at the open University in a bespo ke cleanroom measure ment *** results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe *** at the nominal ope rating tempe rature(-120℃) it is within the procure ment ***,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science *** se rial charge transfer inefficiency degrades with temperature in full frame *** any charge losses are recovered when binning/frame transfer is implemented.

关键词： CCD soft X-ray imager characterisation SMILE

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Photon orbits and phase transition for Letelier AdS black holes immersed in perfect fluid dark matter

引用

Chinese Physics C 2024年第6期48卷 247-259页

作者： Ashima Sood Md Sabir Ali j.K.Singh Sushant g.ghosh Department of Mathematics Netaji Subhas University of TechnologyNew Delhi-110078India Centre for Theoretical Physics Jamia Millia IslamiaNew Delhi 110025India Department of Physics Mahishadal Raj CollegePurba MedinipurWest Bengal721628India Institute of Theoretical Physics&Research Center of gravitation Lanzhou UniversityLanzhou 730000China Key Laboratory of Quantum Theory and Applications of MoE Lanzhou UniversityLanzhou 730000China Lanzhou Center for Theoretical Physics&Key Laboratory of Theoretical Physics of gansu Province Lanzhou UniversityLanzhou 730000China Astrophysics and Cosmology Research Unit School of MathematicsStatistics and Computer ScienceUniversity of KwaZulu-NatalPrivate Bag X54001Durban 4000South Africa

We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable,we analyze the thermodynamics of our black holes in the extended phase *** to the background clouds of strings parameter(a)and the parameter endowed with PFDM(β),we analyze the Hawking temperature,entropy,and specific ***,we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in *** the analysis,with a particular condition,non-monotonic behaviors are found between the photon sphere radius,impact parameter,PFDM parameter,temperature,and *** can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter;their critical exponents near the critical point are equal to the same value,1/2,similar to that in ordinary thermal *** indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.

关键词： AdS black holes perfect fluid dark matter Letelier spacetime photon orbit extended phase space thermodynamics correlation of photon orbit and thermodynamics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

optimization of chemistry and process parameters for control of intermetallic formation in Mg sludges

引用

journal of Magnesium and Alloys 2024年第4期12卷 1431-1448页

作者： Y.Fu g.g.Wang A.Hu Y.Li K.B.Thacker j.P.Weiler H.Hu Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor401 Sunset AveWindsorOntario N9B 3P4Canada global Technology Centre Meridian Lightweight Technologies25 MacNab AveStrathroyOntario N7G 4H6Canada

Intermetallic formation in sludge during magnesium(Mg)melting,holding and high pressure die casting practices is a very important ***,very often it is overlooked by academia,original equipment manufacturers(oEM),metal ingot producers and even die *** aim of this study was to minimize the intermetallic formation in Mg sludge via the optimization of the chemistry and process *** Al8Mn5 intermetallic particles were identified by the microstructure analysis based on the Al and Mn *** design of experiment(DoE)technique,Taguchi method,was employed to minimize the intermetallic formation in the sludge of Mg alloys with various chemical compositions of Al,Mn,Fe,and different process parameters,holding temperature and holding *** sludge yield(SY)and intermetallic size(IS)was selected as two *** optimum combination of the levels in terms of minimizing the intermetallic formation were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,690℃ for the holding temperature and holding at 30 mins for the holding time,*** best combination for smallest intermetallic size were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,630℃ for the holding temperature and holding at 60 mins for the holding time,*** groups of sludge factors,Chemical Sludge(CSF),Physical Sludge(PSF)and Comprehensive Sludge Factors(and CPSF)were established for prediction of sludge yields and intermetallic sizes in Al-containing Mg *** CPSF with five independent variables including both chemical elements and process parameters gave high accuracy in prediction,as the prediction of the PSF with only the two processing parameters of the melt holding temperature and time showed a relatively large deviation from the experimental *** Chemical Sludge Factor was primarily designed for small ingot producers and die casters with a limited melting and holding capacity,of which process parameters could be fixed *** Physical Sludge Factor could be used f

关键词： Magnesium sludge Al-Mn intermetallic optimization Taguchi method Sludge factor Chemical composition Process parameter

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

on the analytical solution of transient friction in channel flows

引用

Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： F.j.gARCíA-gARCíA P.FARINAS-ALVARINo Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULF)and the purely turbulent component(PTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Energy and blast performance of beryllium in a model thermobaric composition in comparison with aluminum and magnesium

引用

Defence Technology（防务技术） 2024年第6期36卷 13-19页

作者： Thomas M.Klapotke Stanisław Cudziło Waldemar A.Trzcinski jozef Paszula Energetic Materials Research Department of ChemistryUniversity of Munich(LMU)Butenandtstrasse 5-13(D)81377MunichGermany Military University of Technology Faculty of Advanced Technologies and ChemistrySylwester Kaliski Str.200-908WarsawPoland

A direct comparison is made between the effectiveness of Al,Mg,and Be powders as additional fuels in model thermobaric compositions containing 20%fuel,20%ammonium perchlorate,and 60%RDX(1,3,5-Trinitro-1,3,5-triazacyclohexane)passivated with *** determined calorimetric measurements of the heat of detonation,along with the overpressure histories in an explosion chamber filled with nitrogen,were used to determine the quasi-static pressure(QSP)under anaerobic *** measurements were also performed in a semi-closed bunker,and all blast wave parameters generated after the detonation of 500 g charges of the tested explosives were *** calorimetry results,QSP values,and blast wave parameters(pressure amplitude,specific and total impulses)clearly indicate that Be is much more effective as an additional fuel than either Al or Mg in both anaerobic post-detonation reactions as well as the subsequent aerobic *** heat of detonation of the RDXwax/AP/Be explosive mixture is over 40%and 50%higher than that of the mixture containing aluminum and magnesium instead of beryllium,***,the TNT equivalent of the Be-containing composition due to the overpressure in the nitrogen-filled explosion chamber is 1.66,while the equivalent calculated using an air shock wave-specific impulse at a distance of 2.5 m is equal to *** high values of these parameters confirm the high reactivity of beryllium in both the anaerobic and aerobic stages of the thermobaric explosion.

关键词： Thermobaric explosives Beryllium Heat of detonation Quasi-static overpressure Blast wave parameters

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of mid-spatial frequency wavefront distortions from a liquid-cooled flash-lamp pumped Nd:phosphate laser amplifier

引用

High Power Laser Science and Engineering 2024年第1期12卷 24-29页

作者： Pierre-Marie Dalbies Sandy Cavaro Edouard Bordenave Nathalie Blanchot julien g.Moreau jérôme Neauport CEA CESTA Le BarpFrance

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition-rate amplifiers are used, the coolant flow is likely to induce such detrimental mid-spatial frequency wavefront deformations. Here, we describe the design and performance of a 90 mm × 90 mm aperture, liquid-cooled Nd:phosphate split-slab laser amplifier pumped by flash-lamps. The performance of the system is evaluated in terms of wavefront aberration and gain at repetition rates down to 1 shot per minute. The results show that this single cooled split-slab system exhibits low wavefront distortions in the medium to large period range, compatible with a focus on target, and despite the use of liquid coolant traversed by both pump and amplified wavelengths. This makes it a potential candidate for applications in large high-energy laser facilities.

关键词： flash-lamp pumping high-power laser laser cooling neodymium glass wavefront error

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Changes in calcium accumulation and utilization efficiency and their impact on recycling, immobilization, and export across the oil palm cycle

引用

oil Crop Science 2024年第3期9卷 143-150页

作者： Viégas I.D.j.M. Souza L.C.D. Ferreira E.V.D.o. Costa M.g. Nogueira g.A.D.S. Nascimento V.R.D. oliveira Neto C.F.D. Capanema Campus Federal Rural University of the Amazon (UFRA) Av. Barão de Capanema Caixa D'agua 5514-6434 Pará Brazil Center of Agricultural and Environmental Sciences Federal University of Maranhão (UFMA) Chapadinha BR-222 km 04 SN Boa Vista 65500000 Maranhão Brazil Capitão Poço Campus Federal Rural University of the Amazon (UFRA) Tv. Pau Amarelo S/n - Vila Nova Capitão Poço 68650-000 Pará Brazil Department of Soil Science São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences Jaboticabal Via de Acesso Prof. Paulo Donato Castelane Castellane - S/N - Vila Industrial São Paulo 14884-900 Brazil Institute of Agricultural Sciences (ICA) Federal Rural University of the Amazon (UFRA) Estr. Principal da Ufra 2150 Curió-Utinga Belém 66077-580 Pará Brazil

Effective calcium (Ca) management is crucial for optimizing oil palm cultivation and enhancing crop yield. This study aimed to gain insights into the dynamics of Ca concentration, accumulation, exportation, immobilization, and recycling in various oil palm organs relative to plant age. The experiment was conducted at the Agropalma enterprise site in the northeastern region of Pará State, Brazil, evaluating seven plant age treatments: 2, 3, 4, 5, 6, 7, and 8 years old. Employing a completely randomized design with four replications. The results demonstrated an age-related increase in Ca concentration in petioles, rachis, arrows, male inflorescences, peduncles, and fruits. Furthermore, Ca accumulation exhibited an upward trend in all organs with progressing plant age. Notably, the study revealed an enhanced Ca use efficiency across all plant organs in correlation with the age of oil palm cultivation. These findings underscore the dynamic nutritional demands of oil palm, influencing Ca immobilization, cycling, and export throughout its developmental stages. © 2024 the oil Crop Research Institute, Chinese Academy of Agriculture Sciences

关键词： Amazon Ca cycling Ca export Ca immobilization Ca use efficiency Elaeis guineensis jacq. Plant nutrition

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rodent management in Aotearoa New Zealand: approaches and challenges to landscape-scale control

引用

Integrative Zoology 2024年第1期19卷 8-26页

作者： john g.INNES grant NoRBURY Araceli SAMANIEgo Susan WALKER Deborah j.WILSoN Manaaki Whenua-Landcare Research HamiltonNew Zealand Manaaki Whenua-Landcare Research AlexandraNew Zealand Manaaki Whenua-Landcare Research AucklandNew Zealand Manaaki Whenua-Landcare Research DunedinNew Zealand

Aotearoa—New Zealand has only four rodent species,all *** order of arrival,they are Pacific rat Rattus exulans,brown rat ***,house mouse Mus musculus,and black rat *** management in New Zealand aims mainly to conserve indigenous biodiversity rather than to protect crops or manage diseases,as is usual *** describe four major“regimes”and one major vision for rodent control in New Zealand to meet ecological restoration *** challenges for island eradications are for large islands that are remote or populated by *** 1080 is the only large-scale(tens of thousands of hectares)option for black rat control,but its application requires adjustment to counter subsequent rapid black rat ***“ecosanctuaries”(mean 720 ha)use ground-based traps and poisons to target mainly black rats and face constant *** with mammal-resistant fences(up to 3500 ha)limit reinvasion and target more pest species and have enabled the return of previously extirpated taxa to the main *** Free 2050 aims to eradicate the rat species(but not mice)plus some other introduced mammals from New Zealand by *** vision is not attainable with current tools,but research and experimental management is exploring techniques and *** large scale(to 100000 ha)at which black rats are now targeted for control to extremely low abundance seems to be unique to New Zealand.

关键词： black rat brown rat eradication house mouse rodent control

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：