检索结果-南通市图书馆

Biochar 2020年第4期2卷 489-502页

作者： Patrick S.Michael department of Agriculture Papua New Guinea University of TechnologyPMBLae 411MPPapua New Guinea

Biochar amendment improves the physical,chemical and biological characteristics of different soil types under different climatic and environmental *** this study,effects of biochar or live pasture plants existing alone or co-existing on selected soil properties of sandy loam soil under humid lowland tropical climatic conditions were *** changes measured in the amended soil,with or without plants,were compared to the unamended and unplanted *** amendment with or without pasture improved moisture retention,lowered bulk density,increased pH and kept the electrical conductivity within ranges conducive for pasture ***,contents of all the nutrients increased following biochar amendment,however pasture establishment without amendment resulted in depletion of available potassium and *** all treatment conditions,soil organic carbon and soil organic matter were significantly *** grass is invasive under all land use systems and contributes to greenhouse gas emissions through *** biomass from the grass instead of burning would mitigate CO2 emissions from the tropics.

关键词： Biochar Effect Pasture Sandy loam soil PNG

Building egg-tray-shaped graphenes that have superior mechanical strength and band gap

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2019年第1期5卷 536-543页

作者： Wei Liu Lei Zhao Eva Zurek Jing Xia Yong-hao Zheng Hai-qing Lin Jing-yao Liu Mao-sheng Miao Beijing Computational Science Research Center 100193 BeijingPR China department of Optical Engineering Zhejiang A&F UniversityLin’an 311300 ZhejiangPR China department of Physics and Astronomy University of CaliforniaIrvineCA 92697USA department of Chemistry&Biochemistry California State UniversityNorthridgeCA 91330-8262USA School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China(UESTC)610054 ChengduPR China department of Chemistry State University of New York at BuffaloBuffaloNY 14260-3000USA Laboratory of Theoretical and Computational Chemistry Institute of Theoretical ChemistryJilin University130023 ChangchunPR China

The major hindrances of implementing graphene in two-dimensional(2D)electronics are both mechanical(the tendency to crumble and form ripples)and electrical(the lack of a band gap).Moreover,the inevitable structural defects in graphene have a profound influence on its physical and chemical ***,we propose a family of 2D egg-tray graphenes constructed by arranging pentagon and heptagon defects in the graphene lattice based on a careful analysis of the topological distribution of minima,maxima,and saddle ***-principles calculations show that the egg-tray graphenes are dynamically stable,and their energies,which depend on the concentration of pentagons and heptagons,are the lowest among carbon *** 2D carbon allotropes exhibit a large variation in their electronic properties,ranging from semimetallic to semiconducting,including some allotropes that have Dirac cones in their band ***,some egg-tray graphenes are predicted to have negative Poisson’s *** adsorption of Li atoms on the egg-tray graphenes is considerably stronger than the adsorption on perfect graphene,therefore they may absorb Li more effectively than graphene,which is important for improving the performance of rechargeable Li batteries.

关键词： adsorption band shaped

Fine root morphology and soil properties under influence of different tree stands along an altitudinal climosequence in the Carpathian mountains

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forest Ecosystems 2022年第5期9卷 692-700页

作者： Karolina Staszel Ewa Błonska Jarosław Lasota department of Ecology and Silviculture Faculty of ForestryUniversity of Agriculture in Krakow29 Listopada 46 Str31-425KrakowPoland

In an era of climate change, understanding the factors that impact root systems can improve our understanding of carbon cycling in forest ecosystems. The study objective was to determine the impact of climatic conditions on the biomass and morphology of roots of different tree species along an elevation gradient, and consequently on properties of montane forest soils. The study plots were established at three different elevations(600, 800 and1000 m a.s.l.) along a slope with an inclination of 15°. The research plots were located in a beech stand(Fagus sylvatica L.) and fir stand(Abies alba Mill.). Soil samples were collected from each study plot, for which basic physical and chemical properties were determined. Additionally, we determined the morphology, production and decomposition rate of fine roots. Our analyses confirmed the significance of climatic conditions in the formation of soil properties, in particular the amount of accumulated carbon and nitrogen content. A decrease of root biomass and reduced root growth were recorded with increasing elevation. The characteristics of roots were linked with the properties of the studied mountain soils, in particular p H, alkaline cation content and content of selected micronutrients. Limitation of root growth in higher elevations affected both study species. Additional research into the formation of tree root morphology is needed, especially in mountainous regions where changes may occur more dynamically. This will provide a better understanding of how stands can cope with different types of environmental stress.

关键词： Beech Fir Forest ecosystem Root biomass Soil properties

A Robust and Efficient Adaptive Multigrid Solver for the Optimal Control of Phase Field Formulations of Geometric Evolution Laws

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2017年第1期21卷 65-92页

作者： FengWei Yang Chandrasekhar Venkataraman Vanessa Styles Anotida Madzvamuse department of Mathematics University of SussexUK School of Mathematics&Statistics University of St AndrewsUK.

We propose and investigate a novel solution strategy to efficiently and accurately compute approximate solutions to semilinear optimal control problems,focusing on the optimal control of phase field formulations of geometric evolution *** optimal control of geometric evolution laws arises in a number of applications in fields including material science,image processing,tumour growth and cell *** this,many open problems remain in the analysis and approximation of such *** the current work we focus on a phase field formulation of the optimal control problem,hence exploiting the well developed mathematical theory for the optimal control of semilinear parabolic partial differential *** of the resulting optimal control problemis computationally challenging,requiring massive amounts of computational time and memory *** main focus of this work is to propose,derive,implement and test an efficient solution method for such *** solver for the discretised partial differential equations is based upon a geometric multigrid method incorporating advanced techniques to deal with the nonlinearities in the problem and utilising adaptive mesh *** in-house twogrid solution strategy for the forward and adjoint problems,that significantly reduces memory requirements and CPU time,is proposed and investigated ***,parallelisation as well as an adaptive-step gradient update for the control are employed to further improve *** with a detailed description of our proposed solution method together with its implementation we present a number of computational results that demonstrate and evaluate our algorithms with respect to accuracy and efficiency.A highlight of the present work is simulation results on the optimal control of phase field formulations of geometric evolution laws in 3-D which would be computationally infeasible without the solution strategies proposed in the present work.

关键词： Optimal control geometric evolution law phase field multigrid parallel mesh adaptivity two-grid solution strategy

Laboratory-scale model of carbon dioxide deposition for soilstabilisation

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 2016年第2期8卷 178-186页

作者： Mohammad Hamed Fasihnikoutalab Afshin Asadi Bujang Kim Huat PaulWestgate Richard JBall Shahram Pourakbar department of Civil Engineering University Putra Malaysia43400 UPMSerdangSelangorMalaysia Housing Research Centre Department of Civil EngineeringUniversity Putra Malaysia43400 UPMSerdangSelangorMalaysia BRE Centre for Innovative Construction Materials Department of Architecture and Civil EngineeringUniversity of BathBathBA2 7AYUK

Olivine sand is a natural mineral,which,when added to soil,can improve the soil’s mechanical properties while also sequester carbon dioxide(CO2)from the surrounding *** originality of this paper stems from the novel two-stage *** the first stage,natural carbonation of olivine and carbonation of olivine treated soil under different CO2pressures and times were *** this stage,the unconfined compression test was used as a tool to evaluate the strength *** the second stage,details of the installation and performance of carbonated olivine columns using a laboratory-scale model were *** this respect,olivine was mixed with the natural soil using the auger and the columns were then carbonated with gaseous *** unconfined compressive strengths of soil in the first stage increased by up to 120% compared to those of the natural untreated *** strength development was found to be proportional to the CO2pressure and carbonation *** analyses indicated the presence of magnesite on the surface of carbonated olivinetreated soil,demonstrating that modified physical properties provided a stronger and stiffer *** performance of the carbonated olivine-soil columns,in terms of ultimate bearing capacity,showed that the carbonation procedure occurred rapidly and yielded a bearing capacity value of 120 k *** of this study are of significance to the construction industry as the feasibility of carbonated olivine for strengthening and stabilizing soil is *** applicability lies in a range of different geotechnical applications whilst also mitigates the global warming through the sequestration of CO2.

关键词： Olivine Soil stabilisation CO_2 deposition Climate change Unconfined compressive strength Microstructure analysis

Integrating MEMS and ICs

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2015年第1期1卷 165-180页

作者： Andreas C.Fischer Fredrik Forsberg Martin Lapisa Simon J.Bleiker Göran Stemme Niclas Roxhed Frank Niklaus department of Micro and Nanosystems School of Electrical EngineeringKTH Royal Institute of TechnologySE-10044 StockholmSweden

The majority of microelectromechanical system(MEMS)devices must be combined with integrated circuits(ICs)for operation in larger electronic *** MEMS transducers sense or control physical,optical or chemical quantities,ICs typically provide functionalities related to the signals of these transducers,such as analog-to-digital conversion,amplification,filtering and information processing as well as communication between the MEMS transducer and the outside ***,the vast majority of commercial MEMS products,such as accelerometers,gyroscopes and micro-mirror arrays,are integrated and packaged together with *** are a variety of possible methods of integrating and packaging MEMS and IC components,and the technology of choice strongly depends on the device,the field of application and the commercial *** this review paper,traditional as well as innovative and emerging approaches to MEMS and IC integration are *** include approaches based on the hybrid integration of multiple chips(multi-chip solutions)as well as system-on-chip solutions based on wafer-level monolithic integration and heterogeneous integration *** are important technological building blocks for the‘More-Than-Moore’paradigm described in the International Technology Roadmap for *** this paper,the various approaches are categorized in a coherent manner,their merits are discussed,and suitable application areas and implementations are critically *** implications of the different MEMS and IC integration approaches for packaging,testing and final system costs are reviewed.

关键词： cofabrication platforms integrated circuits(ICs) microelectromechanical system(MEMS) More-Than-Moore multichip modules(MCMs) system-in-package(SiP) system-on-chip(SoC) three-dimensional(3D)heterogeneous integration

Decellularized adipose matrix provides an inductive microenvironment for stem cells in tissue regeneration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2020年第7期12卷 585-603页

作者： Ji-Zhong Yang Li-Hong Qiu Shao-Heng Xiong Juan-Li Dang Xiang-Ke Rong Meng-Meng Hou Kai Wang Zhou Yu Cheng-Gang Yi department of Plastic Surgery Xijing HospitalFourth Military Medical UniversityXi'an 710032Shaanxi ProvinceChina

Stem cells play a key role in tissue regeneration due to their self-renewal and multidirectional differentiation,which are continuously regulated by signals from the extracellular matrix(ECM)***,the unique biological and physical characteristics of the ECM are important determinants of stem cell *** the acellular ECM of specific tissues and organs(such as the skin,heart,cartilage,and lung)can mimic the natural microenvironment required for stem cell differentiation,the lack of donor sources restricts their *** the rapid development of adipose tissue engineering,decellularized adipose matrix(DAM)has attracted much attention due to its wide range of sources and good regeneration *** for DAM preparation involve various physical,chemical,and biological *** combinations of these methods may have different impacts on the structure and composition of DAM,which in turn interfere with the growth and differentiation of stem *** is a narrative review about *** summarize the methods for decellularizing and sterilizing adipose tissue,and the impact of these methods on the biological and physical properties of *** addition,we also analyze the application of different forms of DAM with or without stem cells in tissue regeneration(such as adipose tissue),repair(such as wounds,cartilage,bone,and nerves),in vitro bionic systems,clinical trials,and other disease research.

关键词： Extracellular matrix Decellularized adipose matrix Decellularized adipose tissue Adipose-derived extracellular matrix Adipose tissue extracellular matrix Adipose matrix Stem cells Soft tissue regeneration Decellularization methods

Phosphate Sorption-Desorption Characteristics in Two Inceptisols and an Alfisol of Chattisgarh, India

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2005年第5期15卷 611-619页

作者： A. K. DOLUI S. S. ROY department of Agricultural Chemistry and Soil Science Institute of Agricultural Science Calcutta University 35 Bally-gunge Circular Road Kolkata 700 019 (India).Department of Agricultural Chemistry and Soil Science Institute of Agricultural Science Calcutta University 35 Bally-gunge Circular Road Kolkata 700 019 (India).

Two Inceptisols and an Alfisol of the Indravati Catchment area in Chattisgarh, India, comprising several gradientsin physical and chemical properties were studied to relate phosphate sorption and desorption to soil properties. Fromthe P isotherm curve, the standard P requirement (SPR) of the soils was determined. Phosphate sorption data were alsofitted both to the Langmuir and Freundlich Equations. The mean sorption maximum values for three different soil serieswere: Bastar > Geedam > Mosodi. The fraction of added phosphate sorbed for the 3 series followed this same trend asdid SPR; the phosphate sorption maximum and the maximum phosphate buffering capacity, which were estimated by theLangmuir isotherm; and the Freundlich constant 1/n. However, phosphate desorption, as well as the maximum recoverypercent did not follow this order. The phosphate affinity constant (K) was also different following the same progressionfor the 3 soil series as the Freundlich constant K’, which measured sorption strength. Meanwhile, an inverse order existedfor K and K’ versus the percent desorbed relative to the sorbed as well as the maximum recovery percent. In addition,significant correlation coefficients among sorption parameters of P and soil factors were found.

关键词： Alfisols Inceptisols phosphate sorption-desorption

AModeling Study on ParticleDispersion inWall-Bounded Turbulent Flows

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2014年第6期6卷 764-782页

作者： Jian-Hung Lin Keh-Chin Chang department of Aeronautics and Astronautics National Cheng Kung UniversityNo.1University RdTainan 701Taiwan

Three physicalmechanismswhichmay affect dispersion of particle’smotion in wall-bounded turbulent flows,including the effects of turbulence,wall roughness in particle-wall collisions,and inter-particle collisions,are numerically investigated in this *** studies with differentwall roughness extents and with different mass loading ratios of particles are performed in fully developed channel flows with the Eulerian-Lagrangian approach.A low-Reynolds-number k−ǫturbulence model is applied for the solution of the carrier-flow field,while the deterministic Lagrangian method together with binary-collision hard-sphere model is applied for the solution of particle *** is shown that the mechanism of inter-particle collisions should be taken into account in the modeling except for the flows laden with sufficiently low mass loading ratios of *** of wall roughness on particle dispersion due to particle-wall collisions are found to be considerable in the bounded particleladen *** the investigated particles are associated with large Stokes numbers,i.e.,larger than O(1),in the test problem,the effects of turbulence on particle dispersion aremuch less considerable,as expected,in comparison with another two physical mechanisms investigated in the study.

关键词： Particle-laden flow turbulent dispersion inter-particle collision particle-wall collision.

Manipulation of immune-vascular crosstalk:new strategies towards cancer treatment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2020年第11期10卷 2018-2036页

作者： Yang Zhao Xiangrong Yu Jia Li Centre for the Endothelium Vascular Biology ProgramCentenary InstituteThe University of SydneySydney NSW 2042Australia department of Radiology Zhuhai People’s HospitalJinan UniversityZhuhai 519000China department of Biomedical Sciences Faculty of MedicineHealth and Human SciencesMacquarie UniversitySydney NSW 2109Australia

Tumor vasculature is characterized by aberrant structure and function,resulting in immune suppressive profiles of tumor microenvironment through limiting immune cell infiltration into tumors,endogenous immune surveillance and immune cell *** normalization as a novel therapeutic strategy tends to prune some of the immature blood vessels and fortify the structure and function of the remaining vessels,thus improving immune stimulation and the efficacy of ***,the presence of"immune-vascular crosstalk"enables the formation of a positive feedback loop between vascular normalization and immune reprogramming,providing the possibility to develop new cancer therapeutic *** applications of nanomedicine in vascular-targeting therapy in cancer have gained increasing attention due to its specific physical and chemical ***,we reviewed the recent advances of effective routes,especially nanomedicine,for normalizing tumor *** also summarized the development of enhancing nanoparticle-based anticancer drug delivery via the employment of transcytosis and mimicking immune cell *** review explores the potential to optimize nanomedicine-based therapeutic strategies as an alternative option for cancer treatment.

关键词： Immune-vascular crosstalk Vascular normalization Nanoparticles Transcytosis Immune cells Antiangiogenesis Immunotherapy Tumor microenvironment