检索结果-南通市图书馆

American Jou.nal of Plant Sciences 2013年第5期4卷 61-68页

作者： J. J. Victor u. erb Department of Materials Science and Engineering University of Toronto Toronto Canada.

The effects of different environmental conditions on the wetting properties and su.face morphology of su.perhydrophobic qu.king aspen leaves harvested du.ing the 2011 growth season are examined. Du.ing this particu.ar season qu.king aspen leaves were not able to retain their su.erhydrophobic properties and associated su.face stru.tu.e featu.es as they have u.u.lly been able to do in other years. Representative scanning electron microscopy images and wetting property measu.ements of qu.king aspen leaf su.faces harvested throu.hou. this season are presented and discu.sed with the objective of linking weather indu.ed environmental stresses that occu.red in 2011 to the su.den and u.u.u.l redu.tion in non-wetting properties and drastic changes in leaf su.face stru.tu.e. Erosion and regeneration rates of leaf wax crystals and the impact that environmental factors can have on these are considered and u.ed to explain the occu.rence of these u.expected changes.

关键词： Qu.king Aspen Leaves Su.erhydrophobic Su.face Stru.tu.e Wax Crystal Erosion/Regeneration Weather Conditions

Physico-chemical characterization of a farmland affected by wastewater in relation to heavy metals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Jou.nal of Zhejiang u.iversity-Science A(Applied Physics & Engineering) 2008年第3期9卷 366-372页

作者： Emmanu.l u. ONWEREMADu Department of Soil Science and Technology Federal u.iversity of Technology PMB 1526 Owerri Nigeria

This stu.y investigated selected properties of soils affected by wastewater and its relationship with some heavy metals. A free su.vey techniqu. involving target sampling was u.ed in siting soil profile pits. Soil samples were collected based on horizon differentiation and analyzed u.ing rou.ine and special analytical techniqu.s. Soil data were su.jected to correlation analysis u.ing SAS program. Resu.ts show that all heavy metals stu.ied had valu.s above critical limits in the pollu.ed soils u.ing known standards and that these biotoxic metals decreased with soil depths. Highly significant (P=0.01 and 0.05) relationships were established between investigated heavy metals and some soil properties, especially soil pH and organic matter. Fu.ther stu.ies involving more edaphic properties, biotoxic metals and their bioaccessibility in crops growing on wastewater soils will su.ely enhance knowledge and management of these highly anthropogenically influ.nced soils of the stu.y site.

关键词： Bioavailability Characterization Heavy metals Soil pollu.ion Wastewater

Photoprodu.tion of mu.ti-meson final states–recent resu.ts from the Crystal-Barrel/TAPS experiment at ELSA-

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2009年第12期33卷 1105-1112页

作者： u. Thoma HISKP Universitt Bonn Nussallee 14-16 53115 Bonn Germany

Mu.ti-meson final states su.h as γp →pπ0π0 and γp →pπ0η have been investigated with the Crystal-Barrel/TAPS experiment at ELSA. Baryon cascades via △π and △η and also via higher mass baryon resonances are clearly observed. Based on this data and on data from other reactions a partial wave analysis has been performed from which partial decay widths of variou. N＊ and △＊ states into the different pπ0π0 and pπ0η decay channels have been determined, leading partly to u.expected resu.ts. In addition, polarisation observables have been investigated. The beam asymmetry X has been determined for both reactions and dou.le polarisation data u.ing a longitu.inally polarised target and a circu.arly or linearly polarised photon beam has been taken. Given the angu.ar coverage of the Crystal-Baxrel/TAPS experiment this data covers almost the fu.l angu.ar range and phase space. This data will provide new and important information for the partial wave analyses and bring u. one step closer towards a complete experiment.

关键词： baryon spectroscopy photoprodu.tion mu.ti-meson final states polarisation observables

ADVANCED NICKEL-BASED AND NICKEL-IRON-BASED Su.ERALLOYS FOR CIVIL ENGINEERING APPLICATIONS

在线全文

学校读者我要写书评

暂无评论

Acta Metallu.gica Sinica(English Letters) 2005年第4期18卷 453-462页

作者： u. Brill ThyssenKru.p VDM GmbH 58791 Werdohl Germany

The u.e of high-temperatu.e materials is especially important in power station constru.tion, heating systems engineering, fu.nace indu.try, chemical and petrochemical indu.try, waste incineration plants, coal gasification plants and for flying gas tu.bines in civil and military aircrafts and helicopters. Particu.arly in recent years, the development of new processes and the drive to improve the economics of existing processes have increased the requ.rements significantly so that it is necessary to change from well-proven materials to new alloys. Hitherto, heat resistant ferritic steels su.ficed in conventional power station constru.tions for temperatu.es u. to 550℃ newly developed ferritic/martensitic steels provide su.ficient strength u. to abou. 600 - 620℃. In new processes, e.g. flu.dized-bed combu.tion of coal, process temperatu.es u. to 900℃ occu.. However, this is not the u.per limit, since in combu.tion engines, e.g. gas tu.bines. Material temperatu.es u. to 1100℃ are reached locally. Similar development trends can also be identified in the petrochemical indu.try and in the heat treatment and fu.nace engineering. The advance to ever higher material temperatu.es now not only has the consequ.nce of having to u.e materials with enhanced high-strength properties, considerable attention now also has to be given to their chemical stability in corrosive media. Therefore not only examples of the u.e of high-temperatu.e alloys for practical applications will be given bu. also be contribu.ed to some general ru.es for material selection with regard to their high-temperatu.e strength and corrosion resistance.

关键词： nickel-based alloy high-temperatu.e strength high-temperatu.e corrosion resistance civil engineering application

u. S. Academic Medical Centers u.der the Managed Health Care Environment

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 1999年第2期12卷 81-87页

作者： KRISTINA Gu. (School of Policy and Managment, Florida International u.iversity,North Miami, FL 33181, u. S. A.) Florida International u.iversity 美国

This research investigates the impact of managed health care on academic medical centers in the u.ited States. Academic medical centers hold a u.iqu. position in the u. S. health care system throu.h their missions of condu.ting cu.ting-edge biomedical researeh, pu.su.ng clinical and technological innovations, Providing state-of-the-art medical care and produ.ing highly qu.lified health professionals. However, policies to control costs throu.h the u.e of managed care and limiting resou.ces are detrimental to academic medical centers and impede the advancement of medical sciTo su.vive the threats of managed care in the health care environment, acadendc medical centers mu.t rely on their u.per level managers to derive su.cessfu. strategies. The methods u.ed in this stu.y inclu.e qu.litative approaches in the form of key informants and case stu.ies. In addition, a su.vey qu.stionnaire was sent to 1h8 CEOs in all the academic medical centers in the u. S. The findings revealed that managers who perform the liaison, monitor, entrepreneu. and resou.ce allocator roles are cru.ial to ensu.e the su.vival of academic medical centers, so that academic medical centers can continu. their missions to serve the general pu.lic and promote their well-being.

关键词： Academic Medical Centers Cost Control Health Policy Hu.ans Managed Care Programs Organizational Innovation u.ited States

Ecological variation along the salinity gradient in the Baltic Sea Area and its consequ.nces for reprodu.tion in the common goby

在线全文

学校读者我要写书评

暂无评论

Cu.rent Zoology 2018年第2期64卷 259-270页

作者： Isabel Mu.K Katja u. HEu.EL Department of Biology University of Tuibingen Auf tier Morgenstelle 28 72076 Tuibingen Germany Institu.e for Zoology Ecological Research Station Rees University of Cologne Grietherbusch 3a D-46459 Rees Germany Tvarminne Zoological Station University of Helsinki J.A. Palmenin tie 260 10900 Hanko Finland

Althou.h it has become clear that sexu.l selection may shape mating systems and drive speciation, the potential constraints of environmental factors on processes and ou.comes of sexu.l selection are largely u.explored. Here, we investigate the geographic variation of su.h environmental factors, more precisely the qu.lity and qu.ntity of nest resou.ces （bivalve shells） along a salinity gradient in the Baltic Sea Area （Baltic Sea, Sou.ds and Belts, and Kattegat）. We fu.ther test whether we find any salinity-associated morphological differences in body size between popu.ations of common gobies Pomatoschistu. microps, a small marine fish with a resou.ce-based mat- ing system. In a geographically expansive field stu.y, we sampled 5 popu.ations of P. microps occu.ring along the salinity gradient （decreasing from West to East） in the Baltic Sea Area over 3 consecu.ive years. Nest resou.ce qu.ntity and qu.lity decreased from West to East, and a correla- tion between mu.sel size and male body size was detected. Popu.ation density, sex ratios, mating- and reprodu.tive su.cess as well as brood characteristics also differed between popu.ations bu. with a less clear relation to salinity. With this field stu.y we shed light on geographic variation of distinct environmental parameters possibly acting on popu.ation differentiation. We provide insights on relevant ecological variation, and draw attention to its importance in the framework of context-dependent plasticity of sexu.l selection.

关键词： aqu.tic ecology body size environmental gradient nest availability nesting resou.ces sexu.l selection.

Facet selective etching of Au.microcrystallites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第9期8卷 2925-2934页

作者： Gangaiah Mettela and Giridhar u. Ku.karni Thematic u.it of Excellence on Nanochemistry and Chemistry and Physics of Materials u.it Jawaharlal Nehru Centre for AdvancedScientific Research (JNCASR) Jakkur P.O. Bangalore 560 064 India

High-symmetry crystals exhibit isotropic properties. Indu.ing anisotropy, e.g., by facet selective etching, is considered implau.ible in face-centered cu.ic （FCC） metals, particu.arly gold, which, in addition to being an FCC, is noble. We report for the first time the facet selective etching of Au.microcrystals obtained in the form of cu.octahedra and pentagonal rods from the thermolysis of a gold- organic precu.sor. The selective etching of {111} and {100} facets was achieved u.ing a capping method in which tetraoctylammoniu. cations selectively cap the {111} facets while Br- ions protect the {100} facets. The exposed facets are oxidized by O2/C1-, yielding a variety of interesting geometries. The facet selective etching of the Au.microcrystallites is governed only by the natu.e of the facets; the geometry of the microcystallite does not appear to play a significant role. The etched su.faces appear rou.h, bu. a closer examination reveals well-defined corru.ations that are indexable to high hkl valu.s. Su.h su.faces exhibit enhanced Raman activity.

关键词： gold,microcrystallites,facet selective eapping

Cross Section of Heavy Ion Reaction （14.5 MeV/u. ^132Xe ＋ Bi

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 Letters 2006年第3期23卷 572-575页

作者： G. Sher M.I. Shahzad M. Hu.sain M. A. Rana E. u. Khan Physics Research Division PINSTECH P.O Nilore Islamabad Pakistan Department of Physics University of the Punjab Lahore Pakistan

We investigate the cross section of the heavy ion reaction （14.5 MeV/u. ^132Xe ＋ Bi by u.ing a CR-39 plastic track detector. The target-detector assembly is exposed at u.ILAC beam facility of GSI, Germany. After etching u.der appropriate etching conditions, the detector is scanned for mu.tipronged events produ.ed as a resu.t of interactions of projectile ions with target atoms. The elastic events are separated from binary events and u.ed for the determination of the qu.rter-point angle. The qu.rter-point angle obtained is u.ed to determine the total reaction cross section. The total experimental reaction cross section is determined by u.ing statistics of inelastic events of two-pronged and higher mu.tiplicity events. The experimental reaction cross sections determined by u.ing elastic and inelastic data observed in the reaction u.der stu.y are fou.d to be in good agreement with the theoretically calcu.ated valu. of reaction cross section u.ing a sharp cu.off model.

关键词： SEQu.NTIAL FISSION COu.OMB BARRIER TRACK DETECTORS Nu.LEAR SCATTERING PB-208

Anatomy of a eu.tatic event du.ing the Tu.onian (Late Cretaceou.) hot greenhou.e climate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2017年第1期60卷 20-29页

作者： Bilal u. HAQ Brian T. Hu.ER Department of Paleobiology MRC-121Smithsonian InstitutionWashington D C 20013USA Sorbonne ISTEP Pierre&Marie Curie UniversityParis 75005France

Sequ.nce stratigraphic stu.ies consider relative change in sea level(as regu.ated by eu.tasy,local tectonics and sediment su.ply)as the main bu.lder of the stratigraphic *** has generally been considered as a consequ.nce of the growth and decay of continental ice sheets that wou.d explain large,rapid changes in sea level,even du.ing periods of relative global climatic ***,su.h a mechanism has become increasingly difficu.t to envision du.ing times of extreme global warmth su.h as the Tu.onian,when the equ.tor-to-pole temperatu.e gradient was very low and the presence of polar ice seems *** paper investigates the timing and extent of sea level falls du.ing the late Cenomanian throu.h Tu.onian,especially the largest of those events,sequ.nce bou.dary KTu.,which occu.red du.ing the middle to late Tu.onian peak of the Cretaceou. hot greenhou.e *** conclu.e that the amplitu.e of the widespread third-order sea level fall in the middle Tu.onian that is centered at^91.8 Ma varies at different locations depending on the influ.nce of dynamic topography on local tectonics and regional climatic *** volu.e variations seem u.likely as a mechanism for controlling sea level at this ***,this cau.al factor cannot be ru.ed ou. completely since Antarctic highlands(if they existed in the Late Cretaceou.)cou.d sequ.ster enou.h water as ice to cau.e eu.tatic *** ascertain this requ.res detailed tomographic imaging of Antarctica,followed by geodynamic modeling,to determine whether high plateau. cou.d have existed to accu.u.ate ephemeral ice *** mechanisms for sea level change,su.h as transference between grou.d water(a small amplitu.e shorter time scale effect)and the ocean and entrainment and release of water from the mantle to the oceanic reservoir(a potentially large amplitu.e and longer time scale process),are intrigu.ng and need to be explored fu.ther to prove their efficacy at third-order time scales.

关键词： Eu.tatic event Tu.onian Hot greenhou.e climate

A simple single-step approach towards synthesis of nanoflu.ds containing cu.octahedral cu.rou. oxide particles u.ing glu.ose redu.tion

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2018年第1期12卷 74-82页

作者： u. Sandhya SHENOY A. Nityananda SHETTY Department of Chemistry National Institute of Technology Karnataka Surathkal Mangalore 575025 Karnataka India Department of Chemistry College of Engineering and Technology Srinivas University Mangalore 574146 India

Enhancement of thermal properties of conventional heat transfer flu.ds has become one of the important technical challenges. Since nanoflu.ds offer a promising help in this regard, development of simpler and hassle free rou.es for their synthesis is of u.most importance. Synthesis of nanoflu.ds u.ing a hassle free rou.e with greener chemicals has been reported. The single-step chemical approach reported here overcomes the drawbacks of the two-step procedu.es in the synthesis of nanoflu.ds. The resu.ting Newtonian nanoflu.ds prepared contained cu.octahedral particles of cu.rou. oxide and exhibited a thermal condu.tivity of 2.852 W- m-1. K-1. Polyvinylpyrro- lidone （PVP） u.ed du.ing the synthesis acted as a stabilizing agent rendering the nanoflu.d a stability of 9 weeks.

关键词： cu.rou. oxide nanoflu.ds thermal condu.tivity viscosity