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一步浸渍合成具有多重孔隙的铸型炭体(英文)

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新型炭材料 2003年第4期18卷 265-270页

作者：陆安慧 Jan-Henrik smtt mika Lindn Ferdi Schüth max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1D-45470 Mülheim an der Ruhr max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 D-45470 Mülheim an der Ruhr

　以多孔块状硅体为模板,通过一步浸渍、炭化、酸处理工艺,制备出结构可控、孔隙联通且具有多重孔隙的铸型炭体。分别采用氮吸附技术、高分辨透射电镜和扫描电镜对模板硅、硅碳复合物及相应炭体进行了结构表征。从微米尺度分析,该炭体... 详细信息

　以多孔块状硅体为模板,通过一步浸渍、炭化、酸处理工艺,制备出结构可控、孔隙联通且具有多重孔隙的铸型炭体。分别采用氮吸附技术、高分辨透射电镜和扫描电镜对模板硅、硅碳复合物及相应炭体进行了结构表征。从微米尺度分析,该炭体是由高度联接的枝状结构单元为骨架构筑而成。与模板硅相比较,此炭体是硅体的正复本。从纳米尺度分析,这种炭体枝状骨架是由分布均匀且相互连接的中孔构成,此中孔及其孔壁对应于模板硅的孔壁及中孔,是多孔硅的负复本。此外构成中孔的炭骨架本体又含有大量炭化过程产生的微孔。因此该法合成的铸型炭具有孔隙高度发达和结构层层嵌套的特点。

关键词：铸型炭体一步浸渍法合成多重孔隙结构表征

Food Security: Impact of European Settlement and Infrastructure on Columbia River Salmon migration

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Open Journal of Soil Science 2021年第7期11卷 367-388页

作者： Kenneth R. Olson cory D. Suski College of Agricultural Consumer and Environmental Sciences University of Illinois Urbana Illinois USA Department of Natural Resources College of Agricultural Consumer and Environmental Sciences University of Illinois Urbana Illinois USA

the 2000 km Columbia River is the longest river in the Pacific Northwest region of North America. It starts in British Columbia, Canada and flows through the states of Oregon and Washington before discharging into Pacific Ocean near Cape Disappointment. the mouth of the Columbia River is a deep water harbor and 180 km of the river can be accessed by navigation. Based on flow volume, the river is the 4th largest river in the United States. the headwaters and approximately 800 km of the Columbia River lie in Canada. Columbia Lake and the Columbia Wetlands are located in British Columbia and are the headwaters of the Columbia River. the lake has an elevation of 820 m above sea level and drains to the Pacific Ocean near Astoria, Oregon. the Ocean tides flow up river to Portland, Oregon. this paper highlights how the geological and landscape resources of the Columbia River and tributaries watershed contributed to the economic development of this historically rich region of North America. the Columbia River is one of the most biologically diverse freshwater systems in the United States. the Columbia River system with trails and cruise ships was designed to increase use of the Columbia River, to promote recreational tourism, and to create a generation of people who are willing to protect and provide environmental stewardship of the river basin resources.

关键词： Bonneville Slide Land of Flowing milk and Honey Lewis and Clark Expedition missoula Flood mount St. Helens Oregon Trail Willamette Valley

Snake River: A Navigation and Spawning Dilemma

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Open Journal of Soil Science 2021年第10期11卷 479-503页

作者： Kenneth R. Olson cory D. Suski Department of Natural Resources College of Agricultural Consumer and Environmental Sciences University of Illinois Urbana USA

the Snake River in northwestern United States is 1735 km long, the largest tributary of the Columbia River and is the 13th longest river in the United States. the Snake River drainage basin includes parts of six U.S. states. the Snake River Plain was created by a volcanic hotspot that lies beneath Yellow-stone National Park. the previous Ice Age carved out canyons, cliffs and waterfalls along the middle and lower Snake River. the missoula Flood was to the north and Bonneville Flood to the south altered the Snake River and surrounding landscape. the Snake River has a drainage basin of 282,000 km2 in the states of Oregon, Washington, Utah, Nevada and Idaho. the Snake River drops from mountain elevations of 3000 m to its confluence with the Columbia River. the river is one of the most biologically diverse freshwater systems in the United States with trails designed to promote recreational tourism, increase use of the Snake River and create generations of people who care about the river and are willing to protect and provide environmental stewardship of the river watershed resources.

关键词： Bonneville Flood Hells Canyon Ice Harbor Oregon Trail Shoshone Snake River Plain Wheat Growers Association

major,trace element and Sr-Nd isotope evidence for a sublithospheric mantle source for the Umkondo large igneous province

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Geoscience Frontiers 2024年第1期15卷 263-285页

作者： Ben Hayes Lewis D.Ashwal Khulekani B.Khumalo Linda m.Iaccheri School of Geosciences University of the WitwatersrandJohannesburg2050South Africa

the mesoproterozoic(1.11 Ga)Umkondo large igneous province(LIP)in southern Africa and Antarctica was emplaced in<5 myr and is dominated by low-Ti tholeiitic doleritic-gabbroic *** is of particular interest because it ... 详细信息

the mesoproterozoic(1.11 Ga)Umkondo large igneous province(LIP)in southern Africa and Antarctica was emplaced inmyr and is dominated by low-Ti tholeiitic doleritic-gabbroic *** is of particular interest because it is the least studied LIP in southern Africa with both sublithospheric and lithospheric mantle sources proposed and it coincides with the early assembly of Rodinia,so it has importance in understanding the nature of magmatism and tectonics in and around the Kalahari craton during the *** this study,we compiled a large database of existing(~750)and new(~100)major and trace element data for the Umkondo province,as well as 42 new Sr-Nd isotopic measurements,to provide constraints on its magma sources and geochemical *** element compositional variations in the low-Ti tholeiites are explained by low-pressure(1 kbar)three-phase fractional crystallisation(olivine,clinopyroxene and plagioclase)of a parent magma with~10 wt.%mgO in oxidising conditions(QFm+1).Inverse models show that the low-Ti tholeiitic magmas were derived as residual melts after the crystallization of 12%-33%olivine from primary komatiitic-basaltic magmas(up to~20 wt.%mgO)in equilibrium with mantle olivine(Fo90).Low sm/Yb and TiO2/Yb-Nb/Yb indicate that the primary magmas were derived by 2%-20%shallow(40-50 km)partial melting of spinel *** sm/Yb is restricted to dyke swarms and may imply limited magma production from deeper(up to~70 km)garnet lherzolite-like *** low-Ti tholeiites of the Umkondo province are enriched in large ion lithophile elements(Rb-Sr-Cs-K)and depleted in high-field strength elements(Zr-Hf-Nb-Ta),indicating the involvement of crustal material and/or the subcontinental lithospheric *** is supported by covariations in th/Nb,Nb/Yb,Nb/La and Ce/sm with generally negativeΔ***-Nd isotopes lend support to the notion that the Umkondo magmas were derived from depleted and/or enriched sublithospheric mantle sources and subs

关键词： Umkondo large igneous province Low-Ti magma Continental tholeiites Sublithospheric mantle sources Kalahari craton Rodinia

Coexistence and fluctuations phenomena with Davidson-like potentials in quadrupoleoctupole deformed nuclei

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Communications in theoretical Physics 2021年第3期73卷 105-118页

作者： m m Hammad W H mansour E m El-maghraby H A motaweh Ayman A Aly Faculty of Science Mathematics DepartmentDamanhour UniversityEgypt Faculty of Science Physics DepartmentDamanhour UniversityEgypt

the energy spectra of three types of two-dimensional potentials(we will call them‘Davidson-like potentials’(DLPs)),characterized by four minima separated by barriers,are *** predictions for spectra and wave functions are obtained by using the nine-point finite-difference *** these potentials,with the existence of a single configuration,a transition of spectra,as a function of barrier height,is covered from tunneling splitting modes to fluctuations phenomena,with equal peaks wave functions,crossing to the spectra of purely anharmonic oscillator potentials(AOPs).A different type of phase transition occurs when two(or more)configurations *** the change of the parameters,a transition of spectra is covered from coexistence phenomena of two distinct quantum tunneling modes to fluctuations phenomena,with unequal peaks wave functions,crossing to the spectra of purely *** DLPs,a particular application of the coherent quadropole-octupole model to describe energy bands with alternating parity of the nuclei^(100)mo,^(146,148)Nd,^(148,150)sm,^(220)Ra,^(220,222)Rn,and^(220,222)th is *** global parametrization of the model for the selected nuclei is achieved.

关键词： quantum phase transitions fluctuations phenomena coherent quadrupole-octupole motion model coexistence phenomena

Geotectonic significance of the Neoproterozoic ophiolitic metagabbros of muiswirab area,South Eastern Desert,Egypt:constraints from their mineralogical and geochemical characteristics

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Acta Geochimica 2020年第6期39卷 887-910页

作者： moustafa m.mogahed Wlaa mahmoud Saad Geology Department Faculty of ScienceBenha University-EgyptP.O.Box 13518BenhaEgypt

Petrological and geochemical studies of Neo-proterozoic metagabbros were carried out in the muiswirab area,South Eastern Desert of *** muiswirab area comprises of ophiolitic metagabbroic rocks(mOm),which are tectonically thrusted over a thick pile of metavolcanic rocks and intruded by syn-and post-tectonic granitoid *** whole-rock geochemical variations coupled with chemical compositions of mineral constituents are used to attain the genesis and tectonic evolution of the studied *** geothermobarometric investiga-tion of the analyzed amphiboles from(mOm)revealed that these metagabbros underwent regional metamorphism under lower to upper greenschist facies(biotite zone)conditions(at a temperature of 450 to 500℃and pressure of 1-3 kbar).Geochemically,the metagabbros(mOm)show tholeiitic affinity and cxhibiting both arc-and mORB-like characters as evidenced by their clinopyrox-ene compositions and the Ti/V ratios(11.84-31.65),which considered as prominent features of forearc tectonic *** geochemical features suggest a probable fractionation of olivine±clinopyroxene±plagioclase as well as insignificant crustal *** parental magma of the investigated mOm rocks seems to be developed in a sub-arc mantle wedge setting due to the enrichments of LILE(e.g..Rb,Ba,Sr,Pb)over HFSE(e.g,Ti,Nb,Y,Zr,Hf,Ta).the studied mOm rocks have lower values of Nb/U relative to mORB and OIB indicating that their geochemical variation produced due to the enrichment of a lithosphere mantle by OIB like *** ratios of Zn/Fet,La/sm,sm/Yb,th/Yb and Nb/Yb indicate that the mOm rocks represent a fragment of oceanic crust originated at a supra-subduction zone environment and their parental magma developed by 5-30%partial melting of a spinel lherzolite mantle rather than pyroxenite in an island arc setting and conformable with most of the Egyptian ophiolitic metagabbros.

关键词： Egypt Eastern Desert muiswirab area Ophiolitic metagabbros N-mORB Arc tholeiites Foreare tectonic regime Volcanic-arc setting

Hylocomium splendens (Hedw.) *** Pleurozium schreberi (Brid.) *** trace element bioindicators:Statistical comparison of bioaccumulative properties

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Journal of Environmental Sciences 2013年第2期25卷 340-347页

作者： Sabina Doegowska Zdzisaw m.migaszewski Artur michalik Geochemistry and the Environment Division Institute of ChemistryJan Kochanowski University15GSwietokrzyska St25-406 KielcePoland

the principal objective of this study was to compare bioaccumulative properties of two terrestrial moss species Hylocomium splendens and Pleurozium schreberi from the Kielce area （south-central Poland）, using various statistical techniques. Forty-six moss samples from 23 sampling sites located within the city limits were analyzed for 33 trace elements. the results indicated that 17 elements （Ba, Ce, Co, Cu, Eu, Fe, Gd, Hg, La, mo, Nd, Ni, Pb, Pr, sm, V, Y） dominated in H. splendens, whereas only three elements （mn, Sr, Zn） occurred in excessive amounts in P. schreberi. No differences in the distribution pattern of Dy, Er, Ho, Sn, Tb, th and Yb were observed. the element concentration ratio （PI/Hy） varied from 0.50 to 1.19. For 14 elements （Ce, Co, Cu, Fe, Gd, Hg, La, mo, Nd, Ni, Pb, sm, th, V）, PI/Hy 〈 1; for 4 elements （Cd, mn, Sr, Zn）, PI/Hy 〉 1; for 7 elements （Ba, Dy, Er, Eu, Pr, Y, Yb）, PI/Hy = equalled 1. Czekanowski＇s method showed similarities in rare earth element concentrations for both moss species. the cluster analysis exhibited three significant clusters at D link /D max × 100 〈 50 for both moss species. Strong positive Spearman correlations between both moss species were recorded for the following pairs：Ba-Ba, Co-Co, Er-Er, Eu-Eu, Gd Gd, mn-mn, Ni-Ni, Pb-Pb, Pr-Pr, sm-sm, th-th, Y-Y, and Yb-Yb. Nonparametric tests （Sign test, Wilcoxon tests） showed statistically significant differences only for Cd, Ce, Co, Cu, Hg, mo, Ni, Pb and Sr. the scanning electron microscope study of H. splendens and P. schreberi revealed a different morphology of these species with no injuries.

关键词： biomonitoring trace elements moss species accumulative properties comparison

Update on pythiosis immunobiology and immunotherapy

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World Journal of Immunology 2014年第2期4卷 88-97页

作者： érico S Loreto Juliana sm Tondolo Régis A Zanette Sydney H Alves Janio m Santurio Department of microbiology and Parasitology Universidade Federal de Santa Maria Programa de Pós-graduacao em Ciências Farmacêuticas Universidade Federal de Santa Maria

Pythiosis is an invasive, ulcerative, pyogranulomatous disease caused by Pythium insidiosum, a fungus-like oomycete that has been reported to affect humans, horses, dogs, and other mammals mainly in tropical and subtropical areas of the world. the disease is characterized by an eosinophilic granulomatous and a th2 immune response which in turn helps to protect the fungus from the host cells. Pythiosis can present clinically in subcutaneous, gastrointestinal, and vascular tissues or in a systemically disseminated form depending on the species and site of infection. Changes in iron metabolism and anemia are commonly observed. the diagnosis is accomplished through clinical and pathological features, laboratory characteristics of cultures, serological and molecular tests. Treatment includes radical surgery, antimicrobial drugs, immunotherapy or a combination of these treatments. Immunotherapy is a practical and non-invasive alternative for treating pythiosis which is believed to promote a switch from a th2 to th1 immune response, resulting in a favorableclinical response. this therapy has demonstrated cure rates above 70% and 55% in horses and humans but low cure rates in dogs and cats. Despite the curative properties of this type of immunotherapy, the antibodies that are produced do not prevent host reinfection. thus, development of effective adjuvants and new diagnostic techniques for early disease diagnosis are of utmost importance. the aim of this review was to promote pythiosis awareness and to provide an update about the immunotherapy and immunobiology of this disease.

关键词： Pythium insidiosum Treatment Pythiosis Immunotherapy Pathogenesis

Late Neoarchean crustal growth under paired continental arc-back arc system in the North China Craton

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Geoscience Frontiers 2021年第3期12卷 437-457页

作者： Xin He Wei Wang m.Santosh Jiachen Yao Kangting Gao Yuhan Zhang Denggang Lu Lishuang Guo the State Key Laboratory of Geological Processes and mineral Resources School of Earth Sciences and ResourcesChina University of GeosciencesBeijing 100083PR China Department of Earth Sciences University of AdelaideSA 5005Australia National Institute of Natural Hazards MEMCBeijing 100085PR China

the late Archean(~3.0-2.5 Ga)was a key period of continental growth globally,which is widely considered to reflect the onset of vigorous plate tectonic activity,although related continental growth modes remain *** we investigate a suite of late Neoarchean metavolcanic rocks from the southwest Qixia area of the Jiaobei terrane in the North China *** rocks in this suite include amphibolites,clinopyroxene amphibolites,and hornblende plagioclase *** present zircon U-Pb isotopic data which indicate that the protoliths of these rocks formed during~2549-2511 ***(clinopyroxene)amphibolites correspond to meta-basaltic rocks,with some containing high modal content of *** rocks show moderate to high FeO_(T)(8.96-13.62 wt.%)and TiO_(2)(0.59-1.59 wt.%),flat to less fractionated REE patterns,and mildly negative th,Nb,and Ta anomalies,resembling those of *** addition,they display positive zirconε_(Hf)(t)values(+2.6 to+8.7),and are devoid of crustal contamination or fractional *** with the low Nb/Yb(mostlysm)_N(mostlymoderate th/Yb(0.08-0.54),and low V/Sc(5.53-9.19)ratios,these basaltic rocks are interpreted to have been derived from a relatively reduced and depleted mantle source that was mildly metasomatized by hydrous *** hornblende plagioclase gneisses are meta-andesitic rocks,and occur interlayered with the basaltic *** are transitional between tholeiitic and calc-alkaline rock series,and show fractionated REE patterns with evidently negative th,Nb,and Ta *** depleted zirconε_(Hf)(t)values(+2.4 to+8.4)and quantitative chemical modeling suggest that the andesitic rocks were most likely generated by injection and mixing of juvenile felsic magmas with the tholeiitic basaltic *** general,the chemical features and genesis of late Neoarchean meta-basaltic rocks in our study area resemble those of mariana back-arc basin *** with regional ge

关键词： Late Neoarchean metavolcanic rocks Continental growth Paired continental arc-back arc Jiaobei terrane North China Craton