检索结果-南通市图书馆

the current status of nitrogen fertiliser use efficiency and future research directions for the Australian cotton industry

在线全文

学校读者我要写书评

暂无评论

Journal of cotton Research 2018年第3期1卷 41-50页

作者： macdonald ben c.t. LAtIMER James O. ScHWENKE Graeme D. NAcHIMUtHU Gunasekhar BAIRD Jonathan c. cSIRO Agriculture and Food the Fenner School of Environment and Society the Australian National University NSW Department of Primary Industries Tamworth Agricultural Institute NSW Department of Primary Industries Australian Cotton Research Institute

Fifty years of sustained investment in research and development has left the Australian cotton industry well placed to manage nitrogen（N） fertiliser. the average production in the Australian cotton industry today is greater than two tonnes of lint per hectare due to improved plant genetics and crop management. However, this average yield is well below the yield that would be expected from the amount of N fertiliser used. It is clear from the recent studies that across all growing regions, conversion of fertiliser N into lint is not uniformly occurring at application rates greater than 200-240 kg·hm;of N. this indicates that factors other than N availability are limiting yield, and that the observed nitrogen fertiliser use efficiency（NFUE） values may be caused by subsoil constraints such as sodicity and compaction. there is a need to investigate the impact of subsoil constraints on yield and *** in NFUE will be made through improved N fertiliser application timing, better targeting the amount of fertiliser applied for the expected yield, and improved soil N management. there is also a need to improve the ability and confidence of growers to estimate the contribution of soil N mineralisation to the crop N budget. Many Australian studies including data that could theoretically be collated in a meta-analysis suggest relative NFUE values as a function of irrigation technique; however, with the extensive list of uncontrolled variables and few studies using non-furrow irrigation, this would be a poor substitute for a single field-based study directly measuring their efficacies. In irrigated cotton, a re-examination of optimal NFUE is due because of the availability of new varieties and the potential management and long-term soil resilience implications of the continued removal of mineralised soil N suggested by high NFUE values. NFUE critical limits still need to be derived for dryland systems.

关键词： Nitrogen fertiliser Nitrogen use efficiency Dryland Irrigated

Gaseous Nitrogen Losses from coastal Acid Sulfate Soils:A Short-term Study

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2011年第2期21卷 197-206页

作者： B.c.t.macdonald O.t.DENMEAD I.WHItE G.BYRANt cSIRO Land and Water CanberraACT 2601 (Australia) the Fenner School of Environment and Society Australian National UniversityCanberraACT 0200 (Australia) University of Wollongong WollongongNSW 2500 (Australia)

NOx and N2O emissions from coastal acid sulfate soils （cASS） cultivated for sugarcane production were investigated on the coastal lowlands of northern New South Wales, Australia. two series of short-term measurements were made using chambers and micrometeorological techniques. Series i occurred during the wet season, the water-filled pore space （WFPS） was between 60%-80% and the site flooded during the measurements. Measurements were made directly after the harvest of soybean crop, which fixed an estimated 100 kg N ha-1, and the emission amounted to 3.2 kg NOx-N ha-1 （12 d） and 1.8 kg N20-N ha-1 （5 d）. Series 2 was made towards the end of the dry season when the WFPS was less than 60%. In Series 2-1 after an application of 50 kg N ha-1, emissions were markedly less, amounting to 0.9 kg N ha 1 over 10 d. During both series when the soil was moist, emissions of NOx were larger than those of N2O. the emission of NOx appeared to be haphazard, with little time dependence, but there was a clear diurnal cycle for N2O, emphasising the need for continuous measurement procedures for both gases. these results suggest that agricultural production on cASS could be important sources of greenhouse gases and nitrogen practices will need to be optimised to reduce the offsite effects of atmospheric warming, acidification or nitrification. Many questions still remain unanswered such as the emissions during the soybean bean filling stage and crop residue decomposition, the longer-term losses following the fertiliser application and emissions from cASS under different land uses.

关键词： denitrification greenhouse gases nitrification nitrogen oxides nitrous oxide

Radiolarian and Planktic Foraminifera Biostratigraphy of the Early Albian Organic Rich Beds of Fahdene Formation,Northern tunisia

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2014年第1期25卷 45-63页

作者： M ben Fadhel t Zouaghi A Amri M ben Youssef Département de Géologie Faculté des Sciences de Gafsa-Campus Universitaire Sidi Ahmed Zarrouk–2112 Département des Géoressources CERTE–Technopole de Borj Cédria

the lower part of Fahdene Formation outcropping in northeastern tunisia is repre- sented by pelagic sequences and characterized by an important siliciclastic fraction that includes ra- diolarian and organic-rich beds of Allam Member. Litho-biostratigraphic analysis based on planktic foraminifera and radiolaria shows that deposition of organic-rich beds of Allam Member is confined to the Microhedbergella rischi Zone through the lower part of ticinella primula Zone. Age diagnostic radiolaria recovered from these beds has been identified to constrain a direct age of black shale depo- sition. the assemblages can be correlated with the radiolarian biochronozone U.A.10-11 indicating an Early Albian to early Middle Albian in age. Radiolarian assemblages composed of species characteris- tic of U.A.10 biochronozone （A. montisserei, D. gracilis） are associated with radiolarian taxa belonging to costata Zone （U.A.9 Pseudoeucyrtis hanni and thanarla pseudodecora）, which can be correlated with Dercourt Member in the Ionian Zone and Paquier level of the Vocontian Basin （southeast of France）. Biostratigraphic and abundance curves analysis has demonstrated significant diversification of cryptocephalic Nassellaria and Archaeodictyomitrae, probably adapted to eutrophic conditions that characterized the Aptian-Albian transition. Ecological conditions may have governed the stratigraphic range of many cosmopolitan taxa （i.e., Pseudodictyomitrae lodogaensis） compared with stratigraphic distributions schemes reported from other domains. the timing of black shales deposition was dia- chronic due to local geodynamic conditions and upwelling currents distribution. the Allam black shales are correlative with the oceanic anoxic event OAElb which is characterized by the widespread of supraregionnally organic-rich beds in the Mediterranean tethys basins across the Aptian-Albian transition.

关键词： northeastern tunisia Albian Allam Member black shale radiolaria planktic foraminifera.

Extracellular vesicles as a potential therapeutic for age-related macular degeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第9期18卷 1876-1880页

作者： Lorraine L.c.chow ben Mead School of Optometry and Vision Sciences Cardiff UniversityCardiffUK

Age-related macular degeneration is a major global cause of central visual impairment and seve re vision *** an aging population,the already immense economic burden of costly anti-vascular endothelial growth fa ctor treatment is likely to *** addition,current conventional treatment is only available for the late neovascular stage of age-related macular degeneration,and injections can come with potentially devastating complications,introducing the need for more economical and ris kfree *** recent years,exosomes,which are nano-sized extracellular vesicles of an endocytic origin,have shown immense potential as diagnostic biomarkers and in the therapeutic application,as they are bestowed with characte ristics including an expansive cargo that closely resembles their parent cell and exceptional ability of intercellular communication and targeting neighboring *** are currently undergoing clinical trials for various conditions such as type 1 diabetes and autoimmune diseases;however,exosomes as a potential therapy for seve ral retinal diseases have just begun to undergo scrutinizing investigation with little literature on age-related macular degeneration *** article will focus on the limited literature availa ble on exosome transplantation treatment in age-related macular degeneration animal models and in vitro cell cultures,as well as briefly identify future research *** literature on exosome therapy using agerelated macular degeneration rodent models includes laser retinal injury,N-methyl-N-nitrosourea,and royal college of surgeon models,which mimic inflammatory and degenerative aspects of agerelated macular *** have shown promising results in preserving retinal function and morphology,as well as protecting photoreceptors from *** from their respective cellular origins may also act by regulating the expression of various inflammatory cyto kines,mRNAs,and proteins involved in photo

关键词： age-related macular degeneration exosomes extracellular vesicles miRNA neuroprotection photoreceptors retina retinal pigment epithelium

AVirtual cloud Storage Architecture for Enhanced Data Security

在线全文

学校读者我要写书评

暂无评论

computer Systems Science & Engineering 2023年第2期44卷 1735-1747页

作者： M.Antony Joans Kumar c.christopher columbus E.ben George t.Ajith Bosco Raj Department of Information technology St.Xavier’s Catholic College of EngineeringNagercoil629003Tamil NaduIndia Department of computer Science Engineering PSN College of Engineering and TechnologyTirunelveli627152India Department of computer Science Engineering University of Technology and Applied SciencesMuscat112Oman Department of Electronics and communications Engineering PSN College of Engineering and TechnologyTirunelveli627152India

the sensitive data stored in the public cloud by privileged users,such as corporate companies and government agencies are highly vulnerable in the hands of cloud providers and *** proposed Virtual cloud Storage Archi-tecture is primarily concerned with data integrity and conﬁdentiality,as well as *** provide conﬁdentiality and availability,theﬁle to be stored in cloud storage should be encrypted using an auto-generated key and then encoded into distinct *** the encoded chunks ensured theﬁle integrity,and a newly proposed circular Shift chunk Allocation technique was used to determine the order of chunk ***ﬁle could be retrieved by performing the opera-tions in *** the regenerating code,the model could regenerate the missing and corrupted chunks from the *** proposed architecture adds an extra layer of security while maintaining a reasonable response time and sto-rage *** results analysis show that the proposed model has been tested with storage space and response time for storage and *** VcSA model consumes 1.5x(150%)storage *** was found that total storage required for the VcSA model is very low when compared with 2x Replication and completely satisﬁes the cIA *** response time VcSA model was tested with different sizedﬁles starting from 2 to 16 *** response time for storing and retrieving a 2 MBﬁle is 4.96 and 3.77 s respectively,and for a 16 MBﬁle,the response times are 11.06 s for storage and 5.6 s for retrieval.

关键词： Erasure code regenerating code cryptography virtual cloud storage architecture circular shift chunk allocation algorithm

Discrete energy transport in collagen molecules

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

chinese Physics B 2014年第9期23卷 544-548页

作者： Alain Mvogo Germain H.ben-Bolie timoléon c.Kofané Laboratory of Biophysics Department of PhysicsFaculty of ScienceUniversity of Yaounde I Laboratory of Nuclear Physics Department of PhysicsFaculty of ScienceUniversity of Yaounde I centre d'Excellence Africain en technologies de l'Information et de la communication University of Yaounde I Laboratory of Mechanics Department of PhysicsFaculty of ScienceUniversity of Yaounde I

the modulational instability in the three coupled α-polypeptide chains of a collagen molecule is investigated. choosing symmetric and asymmetric solutions, and applying the so-called rotating-wave approximation, we describe the dynamics of the system by the discrete nonlinear Schrodinger （DNLS） equation. the linear stability analysis of the continuous wave solution is performed. the numerical simulations show the generation of trains of solitonic structures in the lattice with increasing amplitude as time progresses. the effect of damping and noise forces of the physiological temperature （t = 300 K） introduces an erratic behavior to the formed patterns, reinforcing the idea that the energy used in metabolic processes is confined to specific regions for efficiency.

关键词： modulational instability collagen molecules damping noise force

Energy principle of ferroelectric ceramics and single domain mechanical model

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2007年第5期23卷 531-543页

作者： t.c.Wang LNM Institute of MechanicsChinese Academy of SciencesBeijing 100080China

Many physical experiments have shown that the domain switching in a ferroelectric material is a complicated evolution process of the domain wall with the variation of stress and electric field. According to this mechanism, the volume fraction of the domain switching is introduced in the constitutive law of ferroelectric ceramic and used to study the nonlinear constitutive behavior of ferroelectric body in this paper. the principle of stationary total energy is put forward in which the basic unknown quantities are the displacement ui, electric displacement Di and volume fraction pI of the domain switching for the variant I. Mechanical field equation and a new domain switching criterion are obtained from the principle of stationary total energy. the domain switching criterion proposed in this paper is an expansion and development of the energy criterion. On the basis of the domain switching criterion, a set of linear algebraic equations for the volume fraction PI of domain switching is obtained, in which the coefficients of the linear algebraic equations only contain the unknown strain and electric fields. then a single domain mechanical model is proposed in this paper. the poled ferroelectric specimen is considered as a transversely isotropic single domain. By using the partial experimental results, the hardening relation between the driving force of domain switching and the volume fraction of domain switching can be calibrated. then the electromechanical response can be calculated on the basis of the calibrated hardening relation. the results involve the electric butterfly shaped curves of axial strain versus axial electric field, the hysteresis loops of electric displacement versus electric filed and the evo- lution process of the domain switching in the ferroelectric specimens under uniaxial coupled stress and electric field loading. the present theoretic prediction agrees reasonably with the experimental results given by Lynch.

关键词： Ferroelectric ceramic Domain switching the volume fraction of domain switching Single domain mechanical model

Zircon U-Pb dating and geochemical study of the Xianggou granite in the Ma'anqiao gold deposit and its relationship with gold mineralization

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第2期53卷 220-240页

作者： LEE ben State Key Laboratory of continental Dynamics Department of GeologyNorthwest University

Single zircon LA-IcP-MS U-Pb dating and lithogeochemical studies have been performed on the Xianggou monzonitic granitic porphyry outcropped in the Ma’anqiao gold deposit.A weighted average U-Pb age of 242.0±0.8 Ma for Xianggou monzonitic porphyry has been *** corresponds with the conclusions of previous studies indicating a syn-orogenic age (242±21 Ma) of the Qinling Orogenic Belt,suggesting that the formation of the Xianggou granite should be associated with the collisional event of the North china Plate and the Yangtze Plate in the Indosinian *** Xianggou granite is characterized by the high silicon and alkali of high K calc-alkaline series *** is rich in Al (Al2O3=14.49%-15.61%) and Sr (457.10-630.82 ppm),poor in Y (<16 ppm) and HREE (Yb<0.45 ppm),and exhibits high ratios of Sr/Y (76.24-97.34) and (La/Yb)N (29.65-46.10),as well as strongly fractionated REE *** geochemical characteristics suggest the Xianggou granite can be classified as c-type adakitic *** initial Sr isotope ratios for the Xianggou granite vary from 0.70642 to 0.70668,εNd(t) values from -4.54 to -3.98,and tDM values from 1152 Ma to 1220 *** low εNd(t) and ISr and high tDM values,as well as Na2O/K2O ratios of the Xianggou granite are close to 1 (Na2O/K2O=0.95-1.10),indicating that it is not an I-type adakite formed by partial melting of the subducting oceanic crust,nor adakitic rock formed by melting of the underplated basaltic lower crust,but the product of partial melting of the nonunderplated basaltic thickened lower *** from the Xianggou pluton have a homogeneous Hf isotopic composition with negative εHf(t) values (between -9.7 and -5.9,with an average of -6.9),indicating that the rock-forming materials were mostly extracted from the ancient crust,not from the depleted *** Xianggou monzonitic granitic porphyry is rich in LILE and LREE and depleted in HSFE,HREE and Y;the composition of trace element and REE are similar to those

关键词： zircon U-Pb dating Xianggou monzonitic granitic porphyry carlin type and carlin-like type gold deposits petrologenic and metallogenic dynamic background

Natural convection in a Horizontal cylinder with Partial Heating: Energy Efficiency Analysis

在线全文

学校读者我要写书评

暂无评论

Journal of thermal Science 2020年第6期29卷 1531-1550页

作者： MAZGAR Akram JARRAY Khouloud HAJJI Fadhila ben NEJMA Faycal the Higher Institute of Applied Sciences and technology of Sousse University of SousseTunisia-Ibn Khaldun StreetTaffala City4003 SousseTunisia the Preparatory Institute for Engineering Studies of Monastir University of MonastirTunisia-Rue Ibn El Jazzar5019 MonastirTunisia

the current study reports a numerical analysis of free convection of air in an isothermal horizontal cylinder,cooled and heated at different wall *** heater sizes are discussed in this *** first heated zone is spread across one-quarter of the sidewall;the second is uniformly distributed over the half of the wall and the third active wall covers three-quarters of the *** various locations are considered and examined for each active zone of the *** computation is carried out for Rayleigh number ranging from 102 to *** results characterizing heat transfer and flow features are achieved using an iterative model developed in cOMSOL *** effect of Rayleigh number on heat transfer and fluid flow characteristics within the cavity are *** attention is paid to the influence of heater location and heater size on energy *** is found that the mean Nusselt number and dimensionless velocity increase when increasing the Rayleigh ***,the optimal level of energy efficiency is achieved if the heating zone is centered at the upper part of the cylinder,regardless of the heater *** is also shown that the optimal configuration providing higher energy efficiency is obtained when three-quarters of the sidewall are locally heated,and more precisely,if the active zone is centered at the top of the cylinder.

关键词： natural convection cylinder partial heating energy efficiency Rayleigh number