检索结果-南通市图书馆

Seasonal variations of PM10 -- Trace elements, PAHs and Levoglucosan: rural sugarcane growing area versus coastal urban area in Southeastern florida, USA. Part II: Elemental concentrations

引用

Particuology 2019年第5期17卷 99-108页

作者： Orhan Sevim oglu Wolfgang f. rogge Department of Environmental Engineering Cebze Technical University Cebze Kocaeli 41400 Turkey School of Engineering and Sierra Nevada research Institute University of California Merced. 5200 North Lake Road Merced CA 95343 USA

The largest sugarcane-growing area in the United States is in South florida. An estimated 7 million tons of dry sugarcane leafy biomass is removed from the fields before harvest by burning the leaves off the sugarcane stalks. Preharvest sugarcane leaf foliage burning is a major source of airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), biogenic trace elements such as K, volatile hydrocarbons and other pollutants. In one harvesting period, approximately 22 million tons of c02, a greenhouse gas, is released, 7 million tons from leaf foliage preharvest burning alone and 15 million tons from burning sugarcane bagasse in the sugar mills for power generation. In this study, PMio was collected from Belle Glade, close to the sugarcane-growing area, and from Delray Beach, an urbanized area along the East coast of florida. The PM samples were analyzed for trace elements and close to organic compounds. To elucidate the importance of preharvest sugarcane biomass smoke emissions on air quality, 39 trace elements, 18 PAHs, and levoglucosan were selected to apportion ambient PM constituents. Al, ca and to a great extend also Mg are the major soil-related trace elements and key markers for fugitive soil dust emissions. Similarly, sea salt aerosol blown from the Atlantic Ocean into florida added appreciably to PMio trace elements concentration, especially Na and cl. Approximately half of the sea salt aerosol (PMjo -portion) by mass is removed from the atmosphere during the transport of ocean air from Delray Beach to Belle Glade. Ambient acid displacement reactions caused a substantial portion of the cl (30%) to be liberated from the sea salt aerosol to the atmosphere during transport as gaseous Hc1. The PAH concentrations at Belle Glade were high when the biomass combustion markers levoglucosan and Iconcentrations. This indicates that during the sugarcane harvest season, when leaf foliage is burned off just before harvest, most of

关键词： Urban versus rural Trace elements Sugarcane burning rare earth elements Sea salt aerosol Potassium Levoglucosan PAHs

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

Magnetocaloric and magnetic properties of La_2NiMnO_6 double perovskite

引用

chinese Physics B 2016年第8期25卷 373-378页

作者： Masrour r Jabar A Laboratory of Materials Processes Environment and Quality Cady Ayyed University National School of Applied Sciences

The magnetic effect and the magnetocaloric effect in La_2NiMnO_6（LNMO） double perovskite are studied using the Monte carlo *** magnetizations,specific heat values,and magnetic entropies are obtained for different exchange interactions and external magnetic *** adiabatic temperature is *** transition temperature is *** relative cooling power is established with a fixed value of exchange *** to the master curve behaviors for the temperature dependence of △S_m^（max） predicted for different maximum fields,in this work it is confirmed that the paramagnetic-ferromagnetic phase transition observed for our sample is of a second *** near room-temperature interaction and the superexchange interaction between Ni and Mn are shown to be due to the ferromagnetism of LNMO.

关键词： oxides magnetocaloric Monte carlo simulation specific heat magnetic properties

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

Three-dimensional simulation of long-wavelength free-electron lasers with helical wiggler and ion-channel guiding

引用

chinese Physics B 2013年第7期22卷 183-191页

作者： f. Jafari Bahman B. Maraghechi Department of Physics Amirkabir University of Technology

A three-dimensional simulation of a steady-state amplifier model of a long-wavelength free-electron laser （fEL） with realizable helical wiggler and ion-channel guiding is presented. The set of coupled nonlinear differential equations for electron orbits and fields of TE 11 mode in a cylindrical waveguide are solved numerically by the runge–Kutta algorithm with averages calculated by the Gaussian quadrature technique. Self-fields and space-charge effects are neglected, and the electron beam is assumed to be cold and slippage is ignored. The parameters correspond to the compton regime. Evolution of the radiation power and growth rate along the wiggler is studied. Ion-channel density is chosen to obtain optimum efficiency. Simulations are preformed for the fEL operating in the neighborhood of 35 GHz and 16.5 GHz for the electron beam energies of 250 keV and 400 keV, respectively. The result of the saturated efficiency was found to be in good agreement with the simple estimation based on the phase-trapping model.

关键词： free-electron laser helical wiggler ion-channel guiding

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

Low-frequency Dependence of conductivity and Dielectric Properties of Polyaniline/Znfe_(2)O_(4) Nanocomposites

引用

chinese Physics Letters 2011年第11期28卷 218-221页

作者： G.D.Prasanna H.S.Jayanna Ashok r Lamani M.L.Dinesha c.S.Naveen G.J.Shankaramurthy Department of PG Studies and research in Physics Kuvempu UniversityShankarghatta-577451KarnatakaIndia Bapuji Institute of Engineering and Technology Davangere-577004KarnatakaIndia

conducting polyaniline/Znfe_(2)O_(4) nanocomposites are synthesized by using a simple and inexpensive one-step in-situ polymerization method in the presence of Znfe2O4 *** structural,morphological and electrical properties of the samples are characterized by x-ray diffraction,fourier transform infrared spectra and scanning electron *** results reveal the formation of polyaniline/Znfe2O4 *** morphology of these samples is studied by scanning electron ***,the ac conductivity(σac)of these composites is investigated in the frequency range of 1 kHz–10 *** presence of polarons and bipolarons are responsible for the frequency dependence of ac conductivity in these *** ac conductivity is found to be constant up to 1MHz and thereafter it increases *** ac conductivity of 0.695 S・cm^(−1) at room temperature is observed as the maxima for the polyaniline with 40wt%of the Znfe2O4 nanocomposite.

关键词： composites Znfe2O4 conductivity

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

Novel heating-and deformation-induced phase transitions and mechanical properties for multicomponent Zr_(50)M_(50),Zr_(50)(M,Ag)_(50)and Zr_(50)(M,Pd)_(50)(M=fe,co,Ni,cu)amorphous alloys

引用

Journal of Materials Science & Technology 2022年第9期104卷 109-118页

作者： J.Ding A.Inoue f.L.Kong S.L.Zhu Y.L.Pu E.Shalaan A.A.Al-Ghamdi A.L.Greer School of Materials Science and Engineering Tianjin UniversityTianjin 300072China International Institute of Green Materials Josai International UniversityTogane 283-8555Japan Institute of Massive Amorphous Alloy Science China University of Mining TechnologyXuzhou 221116China Department of Physics King Abdulaziz UniversityJeddah 22254Saudi Arabia MISiS National University of Science and TechnologyMoscow 119049Russia School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China Department of Materials Science and Metallurgy University of CambridgeCambridge CB30FSUK

Multicomponent alloys of Zr_(50)M_(50),Zr_(50)(M,Ag)_(50)and Zr_(50)(M,Pd)_(50)(M=fe,co,Ni,cu)can be melt-spun to obtain amorphous *** maximum thickness for fully amorphous ribbons varies with composition in the range 34-53μ*** contrast,fully amorphous ribbons are not obtainable for binary Zr_(50)Ni_(50)or ternary Zr_(50)(Ni,cu)_(50)***-induced crystallization occurs through:two stages of amorphous[am]→[~(am')+B2]→[B2+B33]for Zr_(50)M_(50);and[am]→[am'+B2]→[B2+AgZr]for Zr_(50)(M,Ag)_(50);and a single stage of[am]→[B2]for Zr_(50)(M,Pd)_(50),while no B2 phase is formed for the binary and ternary Zr_(50)Q_(50)(Q=Ni or/and cu)***-spun amorphous ribbons have good bending ***,Zr_(50)M_(50)ribbons in tension show 0.22-0.28%plastic elongation and work-hardening(the yield stress is~820 MPa,the fracture stress is~1200 MPa).When cold-rolled at room temperature to 30%reduction in thickness,Zr_(50)M_(50)ribbons show 10%increase in hardness,while retaining good bending ***-rolling induces precipitation of spheroidal B2 and irregular B33 particles,while deformation in tension induces B2,B33 and also plate-like monoclinic *** B2 and B33 particles form by polymorphic transformation,and include a high density of internal *** novel deformationinduced precipitation has not been recognized for any Zr_(50)Q_(50)binary or ternary *** new multicomponent systems are encouraging for future progress as structural amorphous alloys.

关键词： Multicomponent Microstructure Mechanical properties Phase transition Amorphous alloy

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

Early history of inflatable penile prosthesis surgery： a view from someone who was there

引用

Asian Journal of Andrology 2015年第2期17卷 225-229页

作者： David f Mobley Institute for Academic Medicine Houston Texas18300 Katy Fwy Ste 325 Houston TX 77094 USA.

The publication of the use of an inflatable penile prosthesis （IPP） in 1973 by Dr. fB Scott. changed the world of treatment options for erectile dysfunction （ED）. Much has been written since then about techniques, improvements, management of difficult cases, complications and their management, and mechanical and device changes over time. few reports, if any, are available in the medical literature regarding the early development, surgical techniques, and controversies surrounding its introduction to the world＇s urological community. This article is, for the most part, the observations of one who was ＂there＂ in the early and mid 1970＇s and was a witness to the history of this remarkable marvel of creativity, engineering, design, and to the personalities involved.

关键词： @@

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

Impact of invasive Ageratina adenophora on relative performance of woody vegetation in different forest ecosystems of Kumaun Himalaya,India

引用

Journal of Mountain Science 2023年第9期20卷 2557-2579页

作者： Bhawna NEGI Kavita KHATrI Surendra S.BarGALI Kiran BarGALI archana farTYAL r.K.cHATUrVEDI Department of Botany D.S.B CampusKumaun UniversityNainital-263002UttarakhandIndia center for Integrative conservation Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglun 666303China

Invasive plant Ageratina adenophora(Sprengel)***&*** has invaded majority of the temperate forests in Kumaun,central *** on *** invaded forest types,their structural attributes,population demography and regeneration status are still at rudimentary *** this,the present study was conducted to assess the impacts of *** on vegetational attributes and regeneration status of three forest types,viz.,Oak(Quercus oblongata ***),Pine(Pinus roxburghii Sarg.)and cypress(cupressus torulosa ***).We selected three sites for each forest type and each site was further purposively stratified into paired sampling plots of 1 ha each i.e.,*** invaded and uninvaded *** results showed large densities of cut stumps or felled trees throughout invaded sites,but with fewer fire signs in comparison to uninvaded *** uninvaded sites,total density and basal area calculated for woody species were relatively higher than those in invaded sites,although results were insignificant(p>0.05).With the exception for cypress forests,vegetation indices showed low woody species richness and diversity in invaded Oak and Pine ***,regeneration of ***,*** and *** tree species did not differ significantly(p>0.05)between invaded and uninvaded *** insignificant differences clearly imply that ***'s presence has not entirely changed the perennial plant communities in terms of composition,structure and natural ***,tree species with poor or no regeneration status requires special attention and needs management strategies involving control of invasive species in forest ecosystems.

关键词： Ageratina adenophora Seedling density forests Population structure regeneration

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

Interactive early warning technique based on SVDD

引用

Journal of Systems Engineering and Electronics 2007年第3期18卷 527-533页

作者： Lin Jian~(1,2) Peng Minjing~(1,2) 1.School of Business Administration,South china Univ.of Technology,Guangzhou 510641,f.r.china 2.Systems Science & Technology Inst,Wuyi Univ.,Jiangmen 529020,P.r.china School of Business Administration South China Univ. of Technology Guangzhou 510641 P. R. China Systems Science Technology Inst Wuyi Univ. Jiangmen 529020 P. R. China

After reviewing current researches on early warning, it is found that “bad”data of some systems is not easy to obtain, which makes methods proposed by these researches unsuitable for monitored systems. An interactive early warning technique based on SVDD （support vector data description） is proposed to adopt “good” data as samples to overcome the difficulty in obtaining the “bad” data. The process consists of two parts：（1） A hypersphere is fitted on “good” data using SVDD. If the data object are outside the hypersphere, it would be taken as “suspicious”; （2） A group of experts would decide whether the suspicious data is “bad” or “good”, early warning messages would be issued according to the decisions. And the detailed process of implementation is proposed. At last, an experiment based on data of a macroeconomic system is conducted to verify the proposed technique.

关键词： interactive data mining early warning support vector data description group decision making.

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 the Dynamics of a rössler Oscillator by an External forcing

引用

chinese Physics Letters 2013年第3期30卷 22-25页

作者： Amanda c.Mathias Paulo c.rech Departamento de física Universidade do Estado de Santa Catarina89219-710 JoinvilleBrazil

We report some results indicating changes in the observed dynamics of the rössler model under the influence of external sinusoidal *** varying the control parameters of the external sinusoidal forcing,namely the amplitude and the angular frequency,we show,through numerical simulations which include parameter planes and Lyapunov exponents,that the external forcing can produce both chaos-order and order-chaos *** also show that the sinusoidal forcing may generate hyperchaos.

关键词： chaos sinusoidal transitions

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

Separation Efficiency of Thin-film Evaporators

引用

chinese Journal of chemical Engineering 2004年第2期12卷 179-184页

作者： r.Billet Institute of Thermo- and fluid-Dynamics Ruhr-University Bochum D-44780 Bochum Germany

The recovery of contaminants and useful substances from liquid wastes, the purification of production effluents and the separation of thermally instable mixtures are some of the multivarious applications of thin-film distillors in many processes of the chemical and allied industries and of the food industries. In a study carried out in pilot plants with distillation test systems there was found a good agreement between the experimental separation results and those obtained by computing with a theorectical model; the latter is based on the assumption of phase equilibrium between the vapour formed on an infinitely small element of area in a liquid film of any given concentric periphery of the vertically arranged evaporator. These tests were perfomed under various phase loads.

关键词：薄膜式蒸发器分离效率相变平衡蒸馏技术废水处理

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

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：