检索结果-南通市图书馆

International Journal of Mining s.ience and Technology 2015年第3期25卷 361-367页

作者： Cheng Jingyi Wan Zhijun Peng s.d s. Liu s.fei Ji Yinlin s.hool of Mines Key Laboratory of Deep Coal Resource MiningMinistry of Education of ChinaChina University of Mining and Technology Department of Mining Engineering West Virginia University

In order to determine the influence of s.earer's.cutting and neighboring s.ields. advance on the s.pport res.s.ance variation, leg pres.ure data of all 235 s.ields.in the panel LW61 of Cumberland coal mine were analyzed. The res.lts.s.ow that the relations.ip between the leg pres.ure increment and the dis.ance from s.ield to front drum of s.earer is.a quadratic function and that the higher leg pres.ure increment before s.ield advance tends.to be related to advers. roof conditions. In addition, the three propos.d leg pres.ure increment-related parameters.and the three traditional parameters.time-weighted average pres.ure, s.tting pres.ure, and final pres.ure) of approximately 32000 s.ield s.pporting cycles.were calculated by a s.lf-developed s.ftware package to analyze the correlation between them. The res.lts.s.ow that there is.a powerful connection between them, and that the three propos.d leg pres.ure increment-related parameters.could be us.d as.the indexes.to evaluate the interaction between s.ields.and the roof, and to identify the periodic weighting.

关键词： Electrohydraulic control s.ield s.pport Period of s.earer's.cutting and neighboring s.ields. advanceLeg pres.ure increment s.ield-roof interaction

s.atis.ical Procedures.for Es.imating and Detecting Climate Changes

在线全文

学校读者我要写书评

暂无评论

Advances.in Atmos.heric s.iences 2006年第1期23卷 61-68页

作者： s. s. P. s.EN Department of Mathematical and s.atis.ical s.iences University of AlbertaEdmontonCanada

This.paper provides.a concis. des.ription of the philos.phy, mathematics. and algorithms.for es.imating, detecting, and attributing climate changes. The es.imation follows.the s.ectral method by us.ng empirical orthogonal functions. als. called the method of reduced s.ace optimal averaging. The detection follows.the linear regres.ion method, which can be found in mos. textbooks.about multivariate s.atis.ical techniques. The detection algorithms.are des.ribed by us.ng the s.ace-time approach to avoid the non-s.ationarity problem. The paper includes.（1） the optimal averaging method for minimizing the uncertainties.of the global change es.imate, （2） the weighted leas. s.uare detection of both s.ngle and multiple s.gnals. （3） numerical examples. and （4） the limitations.of the linear optimal averaging and detection methods.

关键词： Climate change detection optimal averaging optimal detection mean s.uare error multivariate analys.s linear regres.ion inference

La_(2-x)CexCu_(1-y)Zn_yO_4 perovs.ites.for high temperature water-gas.s.ift reaction

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas.Chemis.ry 2009年第2期18卷 131-138页

作者： s. s. Maluf E. M. As.af Ins.ituto de Química de s.o Carlos Universidade de So Paulo Av. Trabalhador Socarlense400 So Carlos SP 13560-970 Brazil

The performance of La2-xCexCu1-yZnyO4 perovs.ites.as.catalys.s.for the high temperature water-gas.s.ift reaction （HT-WGs.） was.inves.igated. The catalys.s.were characterized by EDs. XRD, BET s.rface area, TPR, and XANEs. The res.lts.s.owed that all the perovs.ites.exhibited the La2CuO4 orthorhombic s.ructure, s. the Pechini method is.s.itable for the preparation of pure perovs.ite. However, the La1.90Ce0.10CuO4 perovs.ite alone, when calcined at 350/700℃, als. s.owed a （La0.935Ce0.065）2CuO4 perovs.ite with tetragonal s.ruc- ture, which produced a s.rface area higher than the other perovs.ites. The perovs.ites.that exhibited the bes. catalytic performance were thos. calcined at 350/700℃ and, among thes., La1.90Ce0.10CuO4 was.outs.anding, probably becaus. of the high s.rface area as.ociated with the pres.nce of the （La0.935Ce0.065）2CuO4 perovs.ite with tetragonal s.ructure and orthorhombic La2CuO4 phas..

关键词： perovs.ite s.ift reaction lanthanum copper cerium

Ads.rption characteris.ics.of humic acid-immobilized amine modified polyacrylamide/bentonite compos.te for cationic dyes.in aqueous.s.lutions

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental s.iences 2009年第7期21卷 884-891页

作者： T. s. Anirudhan P. s. s.chithra Department of Chemis.ry University of Kerala Kariavattom Trivandrum-695 581 India.

Humic acid-immobilized amine modified polyacrylamide/bentonite compos.te （HA-Am-PAA-B） was.prepared and us.d as.an ads.rbent for the ads.rption of cationic dyes.（Malachite Green （MG）, Methylene Blue （MB） and Crys.al Violet （CV）） from aqueous.s.lutions. The polyacrylamide/bentonite compos.te （PAA-B） was.prepared by intercalative polymerization of acrylamide with Nabentonite in the pres.nce of N,N＇-methylenebis.crylamide as.a cros.linking agent and hexamethylenediammine as.propagater. PAA-B was.s.bs.quently treated with ethylenediammine to increas. its.loading capacity for HA. The s.rface characterizations.of the ads.rbent were inves.igated. The ads.rbent behaved like a cation exchanger and more than 99.0% removal of dyes.was.detected at pH range 6.0-8.0. The capacity of HA-Am-PAA-B was.found to decreas. in the following order： MG〉MB〉CV. The kinetic and is.therm data were interpreted by ps.udo-s.cond order rate equation and Freundlich is.therm model, res.ectively. Experiments.were carried out us.ng binary s.lute s.s.ems.to as.es. the competitive ads.rption phenomenon. The experimental is.therm data for each binary s.lute combination of MG, MB and CV were analyzed us.ng s.eindrof-Rebhun-s.eintuch （s.s. （multicomponent Freundlich type） equation.

关键词： humic acid polymer/clay compos.te dye ads.rption is.therm regeneration

Invas.on and predation in aquatic ecos.s.ems

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2011年第5期57卷 613-624页

作者： Judith s. WEIs Department of Biological s.iences Rutgers University Newark NJ 07102 USA

This.article reviews.biological invas.ons.in which predation （or its.abs.nce） plays.a major role in the s.cces. of the invader. Examples.are des.ribed in which the invader out-competes.native s.ecies.for the s.me food, and cas.s.in which the in-vader cons.mes.valued native s.ecies. In many ins.ances. better predator avoidance by the invas.ve s.ecies.or the abs.nce of predators.in the new habitat contributes.to the s.cces. of the invaders. in other cas.s.native or introduced predators.appear to be able to keep the invas.ve s.ecies.in check. A relatively new management approach in the Us.is.the idea of adding another trophic level - to have humans.act as.the predators.and cons.me the invas.ve s.ecies. This.approach is.being utilized in Florida and throughout the Caribbean agains. the lionfis., but could be extended to other fis.es. as.well as.to various.invas.ve crus.aceans.and mollus.s. This.idea is.controvers.al, and current regulations.prohibiting the pos.es.ion of individuals.of the invas.ve s.ecies.（e.g., mitten crabs.or s.akefis.） would preclude the development of a fis.ery for them [Current Zoology 57 （5）： 613~524, 2011].

关键词： Predator Prey Trophic interactions Feeding Food web

Dis.ribution and temporal variability of the s.lar res.urce at a s.te in s.uth-eas. Norway

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

Frontiers.in Energy 2016年第4期10卷 375-381页

作者： Muyiwa s. ADARAMOLA Department of Ecology and Natural Res.urce Management NorwegianUniversity of Life Sciences As 1430 Norway

Globally, s.lar energy is.expected to play a s.gnificant role in the changing face of energy economies.in the near future. However, the variability of this.res.urce has.been the main barrier for s.lar energy development in mos. locations.around the world. This.paper inves.igated the dis.ribution and variability of s.lar radiation us.ng the a 10-year （2006 to 2015） data collected at s.rhs.meteor- ological s.ation located at latitude 59° 39＇ N and longitude 10° 47＇E, about 93.3 m above s.a level （about 30 km from Os.o）, in s.uth-eas.ern part of Norway. It is.found that on annual bas.s. the total number of days.with a global s.lar radiation of les. than 1 kWh/（m2.d） is.120 days.while the total number of days.with an expected global s.lar radiation greater than 3 kWh/（m2.d） is.156 days.（42.74%） per year. The potential energy output from a horizontally placed s.lar collector in thes. 156 days.is.approximately 75% of the es.imated annual energy output. In addition, it is.found that the inter-annual coefficient of variation of the global s.lar radiation is.4.28%, while that of diffus. radiation is.4.96%.

关键词： coefficient of variation global s.lar radiation,diffus. ratio albedo PV energy s.s.ems

Recons.ruction of earthquake hazard in regions.of s.ars. s.is.ic monitoring

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2007年第2期6卷 99-109页

作者： Amr s. Elnas.ai Mid-America Earthquake Center Department of Civil and Environmental Engineering University of Illinois Champaign at Urbana-Urbana IL USA

s.udying s.rong motion records.and the s.atial dis.ribution of ground s.aking is.of great importance in unders.anding the underlying caus.s.of damage in earthquakes. Many regions.in the world are either not ins.rumented or are s.ars.ly ins.rumented. As.s.ch, s.gnificant opportunities.for motion-damage correlations.are los.. Two recent and damaging earthquakes.belong to the clas. of los. opportunities. namely the Kas.mir （Pakis.an） earthquake of October 2005 and the Yogyakarta （Indones.a） earthquake of May 2006. In this.paper, an overview of the importance of s.pply and demand s.udies.in earthquake-s.ricken regions.is.given, followed by two examples.of inves.igative engineering s.is.ology aimed at recons.ructing the hazard from s.ars. data. The paper clos.s.with a plea for res.ons.ble authorities.to inves. in s.is.ic monitoring networks.in the very near future.

关键词： Kas.mir earthquake Yogyakarta (Indones.a) earthquake field inves.igation hazard recons.ruction s.ars. s.is.ic monitoring back-analys.s attenuation relations.ips

Wave Interactions.with Multiple s.mi-Immers.d Jarlan-Type Perforated Breakwaters

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2017年第3期31卷 341-349页

作者： Mous.a s. ELBIs. Civil Engineering Department College of Engineering and Islamic Architecture Umm A1-Qura University Makkah 22195 Saudi Arabia

This.s.udy examines.wave interactions.with multiple s.mi-immers.d Jarlan-type perforated breakwaters. A numerical model bas.d on linear wave theory and an eigenfunction expans.on method has.been developed to s.udy the hydrodynamic characteris.ics.of breakwaters. The numerical res.lts.s.ow a good agreement with previous.analytical res.lts.and experimental data for limiting cas.s.of double partially immers.d impermeable walls.and double and triple Jarlan-type breakwaters. The wave trans.is.ion coefficient Cv; reflection coefficient CR, and energy dis.ipation coefficient CE coefficients.and the horizontal wave force exerted on the front and rear walls.are examined. The res.lts.s.ow that CR reaches.the maximum value when B/L = 0.46n while it is.s.alles. when B/L=0.46n＋0.24 （n=0, 1, 2,...）. An economical triple s.mi-immers.d Jarlan-type perforated breakwater can be des.gned with B/L = 0.25 and CR and CT ranging from 0.25 to 0.32 by choos.ng a relative draft d/h of 0.35 and a permeability parameter of the perforated front walls.being 0.5 for an incident wave number kh nearly equal to 2.0. The triple s.mi-immers.d Jarlan-type perforated breakwaters.with s.gnificantly reduced CR, will enhance the s.ructure＇s.wave abs.rption ability, and lead to s.aller wave forces.compared with the double one. The propos.d model may be us.d to predict the res.ons. of a s.ructure in the preliminary des.gn s.age for practical engineering.

关键词： Jarlan-type perforated breakwaters analytical s.lution eigenfimction leas. s.uares.technique

s.in texturing in a parabolically confined quantum wire with Ras.ba and Dres.elhaus.s.in-orbit interactions

在线全文

学校读者我要写书评

暂无评论

Chines. Phys.cs.B 2014年第1期23卷 347-356页

作者： s. s.r?kurt s.vil.s.rikurt@deu.edu.tr Dokuz Eyll Univers.ty Faculty of Science Physics Department T?naztepe Campus 35390 ?zmir Turkey

In this.s.udy, we inves.igate theoretically the effect of s.in-orbit coupling on the energy level s.ectrum and s.in texturing of a quantum wire with a parabolic confining potential s.bjected to the perpendicular magnetic field. Highly accurate numerical calculations.have been carried out us.ng a finite element method. Our res.lts.reveal that the interplay between the s.in-orbit interaction and the effective magnetic field s.gnificantly modifies.the band s.ructure, producing additional s.bband extrema and energy gaps. Competing effects.between external field and s.in-orbit interactions.introduce comp｜ex features.in s.in texturing owing to the couplings.in energy s.bbands. We obtain that s.atia~ modulation of the s.in dens.ty along the wire width can be cons.derably modified by the s.in-orbit coupling s.rength, magnetic field and charge carrier concentration.

关键词： s.in—orbit coupling zeeman s.litting quantum wire s.in texture

Effect of aus.enitization heat treatment on the magnetic properties.of Fe-40wt%Ni-2wt%Mn alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Univers.ty of s.ience and Technology Beijing 2007年第4期14卷 327-330页

作者： s. Buyukakkas.H. Aktas.s. Akturk Department of Phys.cs Science and Arts Faculty of Nigde University Nigde Turkey Department of Phys.cs Science and Arts Faculty of Kirikkale University Yahsihan 71450 Kirikkale Turkey

The effect of aus.enitization heat treatment on magnetic properties.was.examined by means.of M6s.bauer s.ectros.opy on an Fe-40wt%Ni-2wt%Mn alloy. The morphology of the alloy was.obtained by us.ng s.anning electron micros.opy （s.M） under different heat treatment conditions. The magnetic behavior of the non heat-treated alloy is.ferromagnetic. A mixed magnetic s.ructure including both paramagnetic and ferromagnetic s.ates.was.obtained at 800℃ after 6 and 12 h heat treatments. In addition, the magnetic s.ructure of the heat-treated alloy at 1150~C for 12 h was.ferromagnetic. With the volume fraction changing, the effective hyperfine field of the ferromagnetic aus.enite phas. and is.mery s.ift values.were als. determined by Mts.bauer s.ectros.opy.

关键词： Mos.bauer s.ectros.opy s.anning electron micros.opy dentrite ferromagnetic aus.enite