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传统哲学的元转向——“广义元理论”研究之十一
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作者 张青松 《理论探讨》 CSSCI 北大核心 2010年第5期156-159,共4页
哲学已经经历了本体转向、历史转向、科学转向、主体转向、实践转向、语言转向、文化转向、价值转向、生存转向、生活转向、生态转向、经济转向、政治转向、等等,但也许更根本的是元转向。为此我将从唯物论和辩证法两个方面展开元转向分... 哲学已经经历了本体转向、历史转向、科学转向、主体转向、实践转向、语言转向、文化转向、价值转向、生存转向、生活转向、生态转向、经济转向、政治转向、等等,但也许更根本的是元转向。为此我将从唯物论和辩证法两个方面展开元转向分析,并作为"广义元理论"系列研究的又一个重要内容。 展开更多
关键词 唯物论 本元 辩证法 质元化 元转向
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Elemental Composition and Geochemical Characteristics of Iron-Manganese Nodules in Main Soils of China 被引量:11
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作者 TAN Wen-Feng LIU Fan +2 位作者 LI Yong-Hua HU Hong-Qing HUANG Qiao-Yun 《Pedosphere》 SCIE CAS CSCD 2006年第1期72-81,共10页
Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and funct... Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and functions of iron-manganese nodules in soils and sediment. Compared to the corresponding soils, Mn, Ba, Cd, Co and Pb had strong accumulation, Ni had moderate accumulation, while Ca, Cu, Fe, Na, P, Sr and Zn accumulated to a minor degree in the iron-manganese nodules. In contrast, Si, Al, K, Mg and Ti were reduced in the iron-manganese nodules. The contents of Ba, Cd, Co, Cu, Ni, Pb and Zn were positively and significantly correlated with that of MnO2 in the iron-manganese nodules, while the contents of Cr, Cu, Ni, Pb and Zn were positively and significantly correlated with that of Fe2O3 in soils. Based on a principle component analysis, the elements of iron-manganese nodules were divided into four groups: 1) Mn, Ba, Cd, Co, Cu, Li, Ni, Pb and Zn that were associated with Mn oxides, 2) Fe, Cr and P that were associated with Fe oxides, 3) Si, K, and Mg that were included in the elemental composition of phyllosilicate, and 4) Ca, Na, Al and Ti that existed in todorokite, birnessite, lithiophorite and phyllosilicate. It was suggested that accumulation, mineralization and specific adsorption were involved in the formation processes of soil iron-manganese nodules. 展开更多
关键词 elemental composition geochemical characteristics iron-manganese nodule soil
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Direct electrospinning method for the construction of Z-scheme TiO_2/g-C_3N_4/RGO ternary heterojunction photocatalysts with remarkably ameliorated photocatalytic performance 被引量:11
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作者 Liming Hu Juntao Yan +2 位作者 Chunlei Wang Bo Chai Jianfen Li 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第3期458-469,共12页
A series of Z-scheme TiO2/g-C3N4/RGO ternary heterojunction photocatalysts are successfully constructed via a direct electrospinning technique coupled with an annealing process for the first time. They are investigate... A series of Z-scheme TiO2/g-C3N4/RGO ternary heterojunction photocatalysts are successfully constructed via a direct electrospinning technique coupled with an annealing process for the first time. They are investigated comprehensively in terms of crystal structure, morphology, composition, specific surface area, photoelectrochemical properties, photodegradation performance, etc. Compared with binary TiO2/g-C3N4 and single-component photocatalysts, ternary heterojunction photocatalysts show the best photodegradation performance for RhB under stimulated sunlight. This can be attributed to the enlarged specific surface area (111.41 m2/g), the formation of Z-scheme heterojunction, and the high separation migration efficiency of photoexcited charge carriers. A potential Z-scheme mechanism for ternary heterojunction photocatalysts is proposed to elucidate the remarkably ameliorated photocatalytic performance based on active species trapping experiments, PL detection test of hydroxyl radicals, and photoelectrochemical properties. 展开更多
关键词 ELECTROSPINNING Z-scheme TiO2/g-C3N4/RGO Ternary heterojunction Photocatalysis
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Physical Properties of Ⅲ-Antiminodes—a First Principles Study 被引量:4
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作者 Rashid Ahmed Fazal-e-Aleem +2 位作者 S.Javad Hashemifar Haris Rashid H.Akbarzadeh 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第9期527-533,共7页
A comprehensive first principles study of III-Antimonide binary compounds is hardly found in literature. We report a broad study of structural and electronic properties of boron antimonide (BSb), aluminium antimoni... A comprehensive first principles study of III-Antimonide binary compounds is hardly found in literature. We report a broad study of structural and electronic properties of boron antimonide (BSb), aluminium antimonide (AlSb), gallium antimonide (GaSb) and indium antimonide (InSb) in zineblende phase based on density functional theory (DFT). Our calculations are based on Full-PotentiM Lineaxized Augmented Plane wave plus local orbitals (FP- L(APWq-lo)) method. Different forms of exchange-correlation energy functional and corresponding potential are employed for structural and electronic properties. Our computed results for lattice parameters, bulk moduli, their pressure derivatives, and cohesive energy are consistent with the available experimental data. Boron antimonide is found to be the hardest compound of this group. For band structure calculations, in addition to LDA and GGA, we used GGA-EV, an approximation employed by Engel and Vosko. The band gap results with GGA-EV are of significant improvement over the earlier work. 展开更多
关键词 III-antimonides DFT FPLAPW exchange correlation functional structural properties of solids band structure of crystalline solids
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Simultaneous Cell Disruption and Aqueous Two-Phase Extraction for Isolation of Intracellular Recombinant Proteins 被引量:3
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作者 王光虎 冯小黎 苏志国 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1999年第2期139-144,共6页
A new technique was developed for the integrated processing of cell disruption and aqueous two-phase extraction in a high-speed bead mill to separate intracellular proteins from microbial cells. The process was named ... A new technique was developed for the integrated processing of cell disruption and aqueous two-phase extraction in a high-speed bead mill to separate intracellular proteins from microbial cells. The process was named as simultaneous cell disruption and aqueous two-phase extraction (SDATE). Advantages, such as high cell disruption efficiency, biochemical activities preservation of proteins, cell debris elimination, and prelimiary purification of the target protein were being claimed. When this technique was employed for isolating recombinant Tumor Necrosis Factor (TNF) from E. coli, overall protein concentration and TNF activity were found to have been increased. More than 95% of TNF was partitioned into the top phase and all cell debris were in the bottom phase. The partition coefficient was greater than 3 and the TNF purification factor was greater than 6. It is shown that less separation steps were being utilized in the new technique, meaning a reduction in separation time and less process extractors required. 展开更多
关键词 SDATE release of intracellular proteins high speed bead mill aqueous two-phase extraction tumor necrosis factor
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Ink Applied Research of Element Graphic Design Teaching in Intangible Cultural Context
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作者 Songqi YAO Xiao CHEN 《International Journal of Technology Management》 2014年第12期66-68,共3页
With spreading and deepening of intangible cultural heritage protection movement in this century, Chinese ink art is among the Masterpieces of the Oral and Intangible Heritage of Humanity. Institutions of higher educa... With spreading and deepening of intangible cultural heritage protection movement in this century, Chinese ink art is among the Masterpieces of the Oral and Intangible Heritage of Humanity. Institutions of higher education is an academic heritage, culture, communication, personnel training platform and carrier, we assume an important role in the protection of heritage and ink art. Modem design teaching is in order to better local cultural heritage, but also to change their design education, more and more traditional elements are used in the classroom student design works. This paper aims to cultural connotations of traditional Chinese ink painting itself carrying elements and aesthetic charm of the excavation, analysis and sorting, which will be teaching in their designs into modem art. The contemporary art and design are to make cultural connotation and aesthetic meaning, making a good combination of tradition and art. 展开更多
关键词 INK Graphic Design RESEARCH
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Catalytic Conversion of Biomass-Derived Polyols into Para-xylene over SiO2-Modified Zeolites 被引量:2
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作者 Sheng-fei Wang Ming-hui Fan +1 位作者 Yu-ting He Quan-xin Li 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第4期513-520,I0003,共9页
This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromat... This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts. 展开更多
关键词 Biomass-derived polyols PARA-XYLENE Catalytic conversion SiO2-modified HZSM-5
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Microstructure and mechanical properties of as-cast Mg-Sn-Ca alloys and effect of alloying elements 被引量:4
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作者 K.SURESH K.P.RAO +2 位作者 Y.V.R.K.PRASAD N.HORT K.U.KAINER 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3604-3610,共7页
The effect of Sn, Ca, Al, Si and Zn addition on the compressive strength of cast Mg-Sn-Ca (TX) alloys was studied in the temperature range of 25-250 °C and correlated with the microstructure. The Sn to Ca mass ... The effect of Sn, Ca, Al, Si and Zn addition on the compressive strength of cast Mg-Sn-Ca (TX) alloys was studied in the temperature range of 25-250 °C and correlated with the microstructure. The Sn to Ca mass ratio up to 2.5 contributes to the formation of Mg2Ca phase at the grain boundaries and CaMgSn in the matrix, while a ratio of 3 gives only CaMgSn phase mostly in the matrix. While the compressive strength decreases with the increase in temperature, for Sn/Ca up to 2.5, a plateau occurs in 100-175 °C, which is attributed to the strengthening by Mg2Ca. However, for ratio of 3, the strength is lower and decreases more gradually. Mg-3Sn-2Ca (TX32) has the highest strength and the addition of 0.4%Al increases its strength but simultaneous addition of Si lowers the strength. Likewise, the addition of Zn improves its strength but simultaneous addition of Al slightly decreases the strength. The results are correlated with the types of intermetallic phases that form in various alloys. 展开更多
关键词 Sn/Ca ratio Mg-Sn-Ca alloys alloying additions microstructure compressive strength
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Characterization of the start-up period of single-step autotrophic nitrogen removal in a sequencing batch reactor
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作者 郭劲松 《Journal of Chongqing University》 CAS 2008年第1期17-22,共6页
The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium ... The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium to low ammonia-nitrogen concentration, with dissolved oxygen (DO), hydraulic retention time (HRT) and temperature controlled. The experimental conditions were temperature at (30±2) ℃, ammonia concentration of (60 to 120) mg/L, DO of (0.8 to 1.0) mg/L, pH from 7.8 to 8.5 and HRT of 24 h. The rates of nitrification and nitrogen removal turn out to be 77% and 40%, respectively, after a start up period going through three stages divided according to nitrite accumulation: sludge domestication, nitrifying bacteria selection and sludge adaptation, It is demonstrated that dissolved oxygen is critical to nitrite accumulation and elastic YJZH soft compound packing is superior to polyhedral hollow balls in helping the bacteria adhere to the membrane. 展开更多
关键词 wastewater treatment single-step autotrophic nitrogen removal sequencing batch reactor NITRIFICATION
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Study on the basic nitrogen compounds from coal-derived oil 被引量:4
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作者 Xiao-hui GU Xue-feng MAO Yuan ZHAO Wen-bo LI Xiao-jing ZHANG 《Journal of Coal Science & Engineering(China)》 2013年第1期83-89,共7页
The distillation range analysis and elemental analysis of fractioned direct liquefied oil were conducted. Each fraction of liquefied oil contains some nitrogen compounds. Using the acid extraction method and gas chrom... The distillation range analysis and elemental analysis of fractioned direct liquefied oil were conducted. Each fraction of liquefied oil contains some nitrogen compounds. Using the acid extraction method and gas chromatography/mass spectrometry (GC-MS), the basic nitrogen compounds have been separated and identified. Compared with the nitrogen content of the liquefied oil before and after separation, the basic nitrogen compounds account for more than half of all nitrogen compounds. The basic nitrogen compounds in the light liquefied oil are easily separated, and contain more types of basic nitrogen compounds. The results also show that there are many basic nitrogen compounds in liquefied oil, such as pyrrole, aniline, pyridine, quinoline and so on. However, there are fewer other types of basic nitrogen compounds. 展开更多
关键词 liquefied oil SEPARATION GC-MS nitrogen compounds coal-derived oil
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Physicochemical Properties, Baking Performance and Sensory Evaluation of Bakery Shortening Enriched with Diacylglycerol 被引量:1
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作者 Noor Hidayu Othman Ahmadilfitri Md Noor Mohd Suria Affandi Yusoff 《Journal of Food Science and Engineering》 2015年第2期58-66,共9页
The purpose of this study was to investigate the suitability of palm diacylglycerol (PDAG)-enriched formulations for bakery shortening. Three types of palm diacylglycerol olein (PDAGOL) at different degree of unsa... The purpose of this study was to investigate the suitability of palm diacylglycerol (PDAG)-enriched formulations for bakery shortening. Three types of palm diacylglycerol olein (PDAGOL) at different degree of unsaturation (PDAGOL1V56, PDAGOLIV62 and PDAGOLIV64) were used as main raw materials blended with palm stearin (PS). The blending compositions ranged from 30% to 70% of PDAGOLIV56/PS, PDAGOLIV62/PS and PDAGOLIV64/PS, respectively. The physicochemical properties of all binary blend systems were characterized for fatty acid composition (FAC), slip melting point (SMP) and solid fat content (SFC). The selected bakery shortening formulations were further characterised for polymorphic form of fat crystal and thermal behavior, using X-ray diffractometer (XRD) and differential scanning calorimetry (DSC). Bakery shortening enriched with diacylglycerol that were produced from 40DS56 (40% PDAGOLIV56/60% PS), 40DS62 (40% PDAGOL1V62/60% PS) and 40DS64 (40% PDAGOLIV64/60% PS) had 45%-50% unsaturated fatty acid and crystallized in β + β polymorphs; thus they were suitable for shortening system. Based on product's baking performance, it could be found that all Madeira cakes prepared from bakery shortening enriched with diacylglycerol had higher specific cake volume as compared to commercial shortening (CS). In customer acceptance test, Madeira cake made from 40DS56 shortening scored the highest rating for all sensory attributes, including overall customer acceptability. It had given an indication that 40DS56 shortening formulation was the most suitable fat blends to be used as bakery shortening. 展开更多
关键词 DIACYLGLYCEROL SHORTENING BAKING sensory.
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Study of Sandy Silica Properties in Area of Edree (Libya) and the Possibility of Using in Various Engineering Industries
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作者 Omar Asad Ahmad Mohamed A. A Rawashdeh Omar Musatfa Alomari 《Journal of Environmental Science and Engineering(A)》 2012年第9期1137-1141,共5页
Silica materials are located in various regions of Libya in large quantities and different mining conditions, so the purpose of this study is silica materials in the south-west of the Libyan region Edree in terms of q... Silica materials are located in various regions of Libya in large quantities and different mining conditions, so the purpose of this study is silica materials in the south-west of the Libyan region Edree in terms of quality and the possibility of using in various engineering industries, particularly construction. The results show that the sands of silica presented in Edree area are of a high degree of purity, as the percentage of silicon (SIO2) reached 99.5%, the percentage of impurities was negligible and represented in some chemical elements in different proportions, such as calcium 0.224%, sodium 0.004%, iron 0.0006%, zinc 0.0003%, boron 0.0003%, potassium 0.0001%, manganese 0.0001% and magnesium 0.0001%, making these materials very suitable in the manufacture of all types of glass, crystal and semi-crystalline high-quality without needing any important treatment, as well as its suitability as a refinement in manufacture of templates metal castings in addition to the possibility of use in the manufacture of cement, building materials and as a filler in paint and brick making and sand and concrete elements can also be used in electronic industries. A geological material of silica present in the form of a sequence of layers of clay and thin layers of sand stone and a large stock of high-quality near the surface, making mining operations of the type of surface and reduces the cost of extraction. 展开更多
关键词 Raw materials SILICA IMPURITIES INDUSTRIES treatment building materials.
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Degradation of Soils in the Lowland of Kur-Araz
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作者 E. A. Gurbanov S. A. Ganiyeva 《Journal of Agricultural Science and Technology(A)》 2011年第2X期249-254,共6页
The research works were carried out for determination of the washout, types, sorts and level of the development reasons of degradation with the purpose of preparation of the measures of fight against degradation in th... The research works were carried out for determination of the washout, types, sorts and level of the development reasons of degradation with the purpose of preparation of the measures of fight against degradation in the soils in 2005-2009 in the lowland of Kur-Araz. The investigations were fulfilled by using of geographical and stasionar methods. It is revealed that 333.6 thous, ha of the soils of the lowland of Kur-Araz have been exposed to erosion. 97.4 thousand ha of them have been exposed to rainstorm erosion, 127.1 thous, have been exposed to irrigative and 122.1 thous, ha to wind erosion. The most dangerous of them are considered irrigative erosion. Under the influence of erosion process in deposited over the length of furrow, deposits the changes happened in maintenance of humus and nutritions elements. In dependence on slope and water expenditure on 1 ha 2.23-14.86 t of soil are leached. As a result of out wash from 1 ha of soil 55.88-304.59 kg of humus, 4.06-20.80 kg of nitrogen, 4.57-26.55 of phosphorus and 57.40-372.99 of potassium are lost. The soil is exposed to degradation and as a result a process of desertification begins. On the basis of the quantitative an intensity of soil outwash the possible losses of dry matter including humus and main elements of nutrition of plants as a result of erosion, their deposit with the water way, are calculated, too. 展开更多
关键词 Irrigative erosion erosion degradation wind erosion defination capacity removal of humus.
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Geochemistry of Neoproterozoic mixosedimentite in northern Anhui and its geological significance
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作者 SUN Linhua GUI Herong CHEN Song 《Global Geology》 2010年第3期128-134,共7页
Major oxides,as well as trace elements (including rare earth elements) compositions have been analyzed for the mixosedimentites from Neoproterozoic Jiayuan Formation in northern Anhui,China. The results show that the ... Major oxides,as well as trace elements (including rare earth elements) compositions have been analyzed for the mixosedimentites from Neoproterozoic Jiayuan Formation in northern Anhui,China. The results show that the concentrations of elements are closely related to the relative proportions of carbonates and terrigenous detritus (varying from 2/3 to 1/9 based on petrographic study). The ratios between some immobile elements (e.g. La,Th,Zr and Sc) are constant and then can be used as tracers for the discrimination of provenance and tectonic setting of terrigenous detritus. The results indicate that the terrigenous detritus mainly came from the felsic volcanics related to continental arc,with minor contribution from the old basement. Combined with recent research progresses,these mixosedimentites imply that the Neoproterozoic sedimentation in northern Anhui was probably taken place in a back arc basin during the convergence of Rodinia super continent between 1.0 and 0.8 Ga. 展开更多
关键词 PROVENANCE tectonic setting mixosedimentites NEOPROTEROZOIC northern Anhui
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Analysis of Penetration Model for Geo-Material by Rigid Projectile
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作者 LI Jianchun MA Guowei YU Maohong 《Transactions of Tianjin University》 EI CAS 2006年第B09期188-192,共5页
Based on the cylindrical cavity expansion theory, a plastic-damage-elastic model is proposed for the penetration problem of geo-material. In the model, the unified strength criterion (Yu, 1991) is adopted as the failu... Based on the cylindrical cavity expansion theory, a plastic-damage-elastic model is proposed for the penetration problem of geo-material. In the model, the unified strength criterion (Yu, 1991) is adopted as the failure criterion. The distributions of the radial stress and velocity are analyzed. According to the Newton's second law, a series results of the final penetration depth and the impedance load are obtained to different parameter b, when a rigid projectile normally impacts and penetrates a semi-infinite geo-material target with an impact velocity of 300-1200 m/s. By comparing with the test data available, it appears that the method can be used in analyzing the final depth and the impedance load of a rigid projectile penetrating into a semi-infinite target with different impact velocities. 展开更多
关键词 PENETRATION rigid projectile geo-material plastic-damage-elastic unified strength criterion
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Crystallographic Characterization of the Novel Inorganic-organic Hybrid Coordinated Polymer: [(C_(22)H_(50)N_2)(Ag_2I_4)]_n
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作者 李浩宏 陈之荣 +2 位作者 黄长沧 肖光参 任永刚 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2004年第9期1009-1012,共4页
A novel coordinated polymer [(C22H50N2)(Ag2I4)]n([C22H50N2]2+ = N,N?-1,2- ethylence-bis(N,N?-dimethyl octane ammonium) (EDO)) was synthesized by the reaction of AgI and EDO at room temperature with pH = 6.8, and struc... A novel coordinated polymer [(C22H50N2)(Ag2I4)]n([C22H50N2]2+ = N,N?-1,2- ethylence-bis(N,N?-dimethyl octane ammonium) (EDO)) was synthesized by the reaction of AgI and EDO at room temperature with pH = 6.8, and structurally characterized by means of X-ray single- crystal diffraction. It crystallizes in triclinic, space group P1 with a = 9.6080(1), b = 12.7643(2), c = 7.2157(8) ? a = 100.835(8), ?= 91.030(3), ? = 91.297(9)o, (C21.50H48.50Ag2I4N2), Mr = 1058.46, V = 868.71(19) 3, Z = 1, Dc = 2.023g/cm3, F(000) = 497.5, ?MoKa) = 4.692 mm-1, the final R = 0.0623 and wR = 0.1949 for 2641 observed reflections with I > 2s(I). The title compound consists of cations ([C22H50N2]2+) and anion chain (Ag2I42-)∞ which are combined by static attracting forces in the crystal to form the so-called organic-inorganic hybrid material. 展开更多
关键词 coordination polymers template synthesis IODIDE quaternary ammonium
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Distribution characteristic and geological signiflcance of rare earth elements in Lopingian mudstone of Permian,Panxian county,Guizhou province 被引量:23
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作者 Shao Yubao Guo Yinghai +2 位作者 Qin Yong Shen Yulin Tian Li 《Mining Science and Technology》 EI CAS 2011年第4期469-476,共8页
In order to discuss the geochemical characteristic of REEs (rare earth elements) and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian (Late ... In order to discuss the geochemical characteristic of REEs (rare earth elements) and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian (Late Permian) mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs (185.56-729.46 ×10-6) is high. The ratios of w(LREE)/w(HREE) (6.84- 13.86) and W(La)N/w(Yb)N (1.01-3.02) show clear differentiation of LREEs and HREEs. ZREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ca, Sc, Cs, Zr, Hf, Sr, Be and chaicophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase, Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and w(∑REE)- w(La)/w(Yb) diagram. Moreover, abnormal surfaces near the sequence boundaries (SB2, SB3, SB4) are related wiLth the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE. w(LREE)/w(HREE), Eu/Eu* and Ceanom. 展开更多
关键词 Rare earth element Provenance Sequence boundary Lopingian Panxian county
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Mechanical Characteristics of Chemically Degraded Surface Layers of Wood
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作者 Jiri Frankl Michal Kloiber +2 位作者 Milos Dradacky Jan Tippner Jan Bryscejn 《Journal of Mechanics Engineering and Automation》 2012年第11期694-700,共7页
The aim of this research was to find out whether the effect of chemical corrosion changes mechanical characteristics of surface layers of wooden construction elements. Degradation of the surface layers of wood was cau... The aim of this research was to find out whether the effect of chemical corrosion changes mechanical characteristics of surface layers of wooden construction elements. Degradation of the surface layers of wood was caused by chemical reactions of the basic substances of wood mass with compounds contained in antifire coatings. Fire retardants containing corrosive substances were often and repeatedly used in the Czech Republic on many wooden building constructions. This process of chemical corrosion is in practise called as "surface defibering of wood". This contribution presents standard and special experimental methods used for measuring the selected mechanical characteristics (compression strength, tension strength, bending strength, hardness and impact resistance) in the damaged surface layer of wooden construction elements. The material for experimental measuring was a construction element removed from a historical roof (ca 150 years old). Mechanical characteristics of the surface layer of the defibered element were compared with the values measured in the deeper subsurface layer of non-damaged wood. The results of the experiments proved loss of cohesive strength and decrease of mechanical characteristics of wood only in a thin surface layer. 展开更多
关键词 WOOD CORROSION defibering mechanical properties.
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π-Conjugated Unit-Dependent Optical Properties of Linear Conjugated Oligomers
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作者 Ning Sui Lu Zou +7 位作者 Yun-fei Song Qiu-lin Zhong Ying-hui Wang Xiao-gang Wei Zeng-bin Wang Yu-guang Ma Yan-qiang Yang Han-zhuang Zhang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第3期315-320,共6页
The optical properties of three linear conjugated oligomers (F-P, F-P-F, and P-F-P-F-P), where phenothiazine (P) and fluorene (F) groups arrange alternately, are investigated. With the enhancement of the π-conj... The optical properties of three linear conjugated oligomers (F-P, F-P-F, and P-F-P-F-P), where phenothiazine (P) and fluorene (F) groups arrange alternately, are investigated. With the enhancement of the π-conjugated system, their absorption and emission bands both gradually red shift, and their two-photon properties are also improved. Meanwhile, their fluorescence dynamic traces are analyzed with continuous rate distribution model, exhibiting that their decay rates gradually accelerate and the rate distribution width become narrower. The quantum chemical calculation offers their molecular structures and transition mechanism, showing that the enhancement of π-conjugated system should be responsible for tile improvement of two-photon properties. 展开更多
关键词 OLIGOMER Z-SCAN Fluorescence dynamics
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Geology and fluid inclusion of Wadi Sharis Neoproterozoic orogenic gold deposits in northwestern Yemen
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作者 Moteea A.Al-Shameery SUN Fengyue 《Global Geology》 2011年第1期21-28,共8页
The Wadi Sharis orogenic gold deposit in northwestern Yemen is related to the fault and shear zones vein at medium depth in the crust in the Neoprotcrozoic meta-sedimentary and meta-volcanosedimentary succes- sion of ... The Wadi Sharis orogenic gold deposit in northwestern Yemen is related to the fault and shear zones vein at medium depth in the crust in the Neoprotcrozoic meta-sedimentary and meta-volcanosedimentary succes- sion of greenschist to amphibolite facies metamorphism. Three distinct fluid inclusion types have been identified in the gold-bearing quartz sulphide veins of the deposit: (1) type I: vapour-liquid two-phase (VH2O-LH2O ), (2) type II : three-phase CO2 ( VCO2 - LH2O - LCO2 ) and (3) type III: vapour-rich (LCO2 - VCO2 ) inclusions. Six analysis of individual fluid inclusion indicate the fluid inclusions comprise mainly of H2O and CO2. Forma- tion P-T conditions recorded by fluid inclusions in quartz crystals correspond to 180℃-380℃ and up to 130 MPa, as indicated by high-density CO2 bubbles (up to 0. 98 g/cm3 ) observed in some inclusions. The esti- mated crystallization pressures correspond to approximately 4-10 km of overburden, assuming a lithostatic load. The salinity ranges from 0 to 22 wt%. The deposit holds at 0.2-5 g/t Au and contains low-moderate salinity. 展开更多
关键词 orogenic gold fluid inclusion Wadi Sharis quartz vein
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