Based on the coded and non-coded targets, the targets are extracted from the images according to their size, shape and intensity etc., and thus an improved method to identify the unique identity(D) of every coded ta...Based on the coded and non-coded targets, the targets are extracted from the images according to their size, shape and intensity etc., and thus an improved method to identify the unique identity(D) of every coded target is put forward and the non-coded and coded targets are classified. Moreover, the gray scale centroid algorithm is applied to obtain the subpixel location of both uncoded and coded targets. The initial matching of the uncoded target correspondences between an image pair is established according to similarity and compatibility, which are based on the ID correspondences of the coded targets. The outliers in the initial matching of the uncoded target are eliminated according to three rules to finally obtain the uncoded target correspondences. Practical examples show that the algorithm is rapid, robust and is of high precision and matching ratio.展开更多
Mafic intrusions and dykes are well preserved in the Yinmin and Lanniping districts, located within the western margin of the Yangtze Block, SW China. Although these mafic rocks from the two areas formed during differ...Mafic intrusions and dykes are well preserved in the Yinmin and Lanniping districts, located within the western margin of the Yangtze Block, SW China. Although these mafic rocks from the two areas formed during different periods, they share similar ranges of PGE concentration. Most of the Yinmin gabbroic dykes contain relatively high PGE concentrations (PGEs=13.9-87.0 ppb) and low S contents (0.003 %-0.020 %), higher than the maximum PGE concentrations of mafic magmas melting from the mantle. Two exceptional Yinmin samples are characterized by relatively low PGE (PGEs = 0.31-0.37 ppb)and high S (0.114 %-0.257 %) contents. In contrast, most samples from the Lanniping gabbroic intrusion have low PGE con- centrations (PGEs = 0.12-1.02 ppb) and high S contents (0.130 %-0.360 %), except that the three samples exhibit relatively high PGE (PGEs=16.3-34.8 ppb) and low S concentrations (0.014 %-0.070 %). All the Yinmin and Lanniping samples are characterized by the enrichment of PPGE relative to IPGE in the primitive-mantle normalized diagrams, and the high-PGE samples exhibit obvious Ru anomalies. This study suggests that during the ascent of the parental magma, removal of Os-Ir-Ru alloys and/or chro- mite/spinel leads to high Pd/Ir ratios and Ru anomalies for the Yinmin high-PGE samples and relatively lower Pd/lr ratios and Ru anomalies for the Lanniping low-PGE samples. We propose that the magmas parental to the Yinmin gabbroic dykes are initially S-unsaturated, and subsequently, minor evolved magma reached sulfur saturation and led to sulfide segregation. Although the Lanniping parental magmas are originally not saturated in S, the high Cu/Pd ratios (3.8× 10^4 to 3.2 × 10^6) for most of the Lanniping samples indicate the S-saturated state and sulfide segregation. A calculation shows that the PGE-poor magmas might have experienced 0.01%-0.1%sulfidesegregationinthemagma chamber. Therefore, our study provides a possible opportunity to discover PGE-enriched sulfide mineralization some- where near or within the Lanniping mafic intrusion.展开更多
As an important unconventional resource, oil shale has received widespread attention. The oil shale of the Chang 7 oil layer from Triassic Yanchang Formation in Ordos Basin represents the typical lacustrine oil shale ...As an important unconventional resource, oil shale has received widespread attention. The oil shale of the Chang 7 oil layer from Triassic Yanchang Formation in Ordos Basin represents the typical lacustrine oil shale in China. Based on analyzing trace elements and oil yield from boreholes samples, characteristics and paleo-sedi- mentary environments of oil shale and relationship between paleo-sedimentary environment and oil yield were studied. With favorable quality, oil yield of oil shale varies from 1.4% to 9.1%. Geochemical data indicate that the paleo-redox condition of oil shale's reducing condition from analyses of V/Cr, V/(V + Ni), U/Th, δU, and authi genic uranium. Equivalent Boron, Sp, and Sr/Ba illustrate that paleosalinity of oil shale is dominated by fresh water. The paleoclimate of oil shale is warm and humid by calculating the chemical index of alteration and Sr/Cu. Fe/Ti and (Fe + Mn)/Ti all explain that there were hot water activities during the sedimentary period of oil shale. In terms of Zr/Rb, paleohydrodynamics of oil shale is weak. By means of Co abundance and U/Th, paleo-water-depth of oil shale is from 17.30 to 157.26 m, reflecting sedimentary environment which is mainly in semi deep-deep lake facies. Correlation analyses between oil yield and six paleoenvironmental factors show that the oil yield of oil shale is mainly controlled by paleo-redox conditions, paleoclimate, hot water activities, and depth of water.Paleosalinity and paleohydrodynamics have an inconspicuous influence on oil yield.展开更多
Petrography and geochemistry of the altered and unaltered host rocks surrounding the Koktokay No.3 pegmatite revealed that the unaltered amphibolite is mainly composed of hornblende, plagioclase, and ilmenite.Beyond t...Petrography and geochemistry of the altered and unaltered host rocks surrounding the Koktokay No.3 pegmatite revealed that the unaltered amphibolite is mainly composed of hornblende, plagioclase, and ilmenite.Beyond these primary components, the altered host rocks contain a few newly formed minerals, including biotite,tourmaline, chlorine, and muscovite. The alteration zone surrounding the Koktokay No.3 pegmatite is limited to 2.0 m, characterized by biotitization, tourmalization, and chloritization. In the altered host rocks, the contents of SiO2, MgO, MnO, Na2O, and TiO2 did not vary greatly.However, Al2O3 showed a weak decreasing trend with the increasing distance from the pegmatite contact zone, while Fe2O3 and CaO showed an increasing trend. The contents of Li, Rb, and Cs in the altered host rocks were much higher than those in the unaltered host rocks, decreasing with distance from the contact. The chondrite-normalized rare earth element(REE) pattern of the altered and unaltered host rock was right-inclined from La to Lu, but enriched in light REEs over heavy REEs after hydrothermal alteration. An isocon plot shows that some oxides migrated in with an order of P2O5〉K2O 〉TiO2〉Al2O3〉SiO2〉MnO≥MgO, while others migrated out with an order of Na2O 〉CaO 〉Fe2O3. For REEs, the migration ratios are positive values withCs 〉Rb 〉Li 〉Nb 〉Ta 〉Be, signifying that all REEs migrated from the exsolved magmatic fluid into the altered host rocks. It was concluded that diffusion was the only mechanism for migration of ore-forming elements in the alteration zone. The effective diffusion coefficients(Deff)of LiF, RbF, and CsF were estimated under a fluid temperature of 500–550℃. Using a function of concentration(C(x,t)) and distance(x), the order of migration distance was determined to be LiF 〉CsF 〉RbF, with diffusion times of (3.39 ± 0.35)× 10^6,(3.19 ± 0.28) × 10^5 and(6.33 ± 0.05) × 10^5 years, respectively.展开更多
Sedimentary sequence and sediment provenance are important factors when it comes to the studies on marine sedimentation. This paper studies grain size distribution, lithological characteristics, major and rare earth e...Sedimentary sequence and sediment provenance are important factors when it comes to the studies on marine sedimentation. This paper studies grain size distribution, lithological characteristics, major and rare earth elemental compositions, micropaleontological features and ^(14)C ages in order to examine sedimentary sequence and sediment provenance of the core BH6 drilled at the mouth of the Yellow River in Bohai Sea. According to the grain size and the micropaleontological compositions, 4 sedimentary units have been identified. Unit 1(0–8.08 mbsf) is of the delta sedimentary facies, Unit 2(8.08–12.08 mbsf) is of the neritic shelf facies, Unit 3(12.08–23.85 mbsf) is of near-estuary beach-tidal facies, and Unit 4(23.85 mbsf–) is of the continental lake facies. The deposits from Unit 1 to Unit 3 have been found to be marine strata formed after the Holocene transgression at about 10 ka BP, while Unit 4 is continental lacustrine deposit formed before 10 ka BP. The provenances of core BH6 sediments show properties of the continental crust and vary in different sedimentary periods. For Unit 4 sediments, the source regions are dispersed while the main provenance is not clear, although the parent rock characteristics of a few samples are similar to the Luanhe River sediments. For Unit 3, sediments at 21.1–23.85 mbsf have been mainly transported from the Liaohe River, while sediments above 21.1 mbsf are mainly from the Yellow River and partially from the Liaohe River. For Unit 2, the sediments have been mainly transported from the Yellow River, with a small amount from other rivers. For Unit 1, the provenance is mainly the Yellow River catchment. These results help in better understanding the evolution of the Yellow River Delta.展开更多
In order to clarify the role of organic matter in the enrichment of base metal, 10 samples of the Permian Kupferschiefer from southwestern Poland were analyzed by using microscopic and geochemical methods. The results...In order to clarify the role of organic matter in the enrichment of base metal, 10 samples of the Permian Kupferschiefer from southwestern Poland were analyzed by using microscopic and geochemical methods. The results indicate that the solvent extracts have been depleted in the samples with high Cu, Pb, Zn contents. This depletion occurred preferably in saturated hydrocarbons. Saturated hydrocarbons served as hydrogen donor for thermochemical sulfate reduction (TSR). The GC traces of saturated hydrocarbon show that the depletion occurred mainly in long chain n alkanes.展开更多
Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements. Proximate composition, amino acid an...Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements. Proximate composition, amino acid and fatty acid profiles, and toxic elements contents of fanned and wild Chanodichthys mongolicus were established and compared. Significantly higher crude protein content while lower moisture content in farmed fish compared to wild fish were observed (P〈0.05). The percentages of total amino acids (TAA), total essential amino acids (TEAA), total non-essential amino acids (TNEAA) and total delicious amino acids (TDAA) in farmed fish were all significantly higher than those in the wild equivalent (P〈0.05). Compared to the FAO/WHO recommended reference values, the ratios of TEAA/ TAA (39.84%o-40.33%) were comparable to 40% and TEAA / TNEAA (66.22%-67.60%) were above 60%. Fatty acid profiles in both farmed and wild C. mongolicus were dominated by monounsaturated fatty acid (MUFA), with farmed fish contained much more MUFA content compared to wild counterpart (P〈0.05). Notably, wild fish exhibited significantly higher levels of total polyunsaturated fatty acid (PUFA) including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than fanned fish (P〈0.05). The EPA (C20:503) and linoleic acid (C18:206) were the predominant PUFA in wild and farmed C. mongolicus, respectively. Moreover, farmed fish displayed an overall lower toxic element levels (As, Cd, Pb and Hg) in comparison with wild fish, and both were far lower than the established limit standard. In conclusion, our results suggest that the nutritional quality of fanned C. mongolicus was inferior to their wild counterpart with respect to fatty acids nutrition, and therefore further studies should focus on the improving C. mongolicus diet in order to enhance the overall nutritional composition.展开更多
H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and unique...H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and uniqueness of semidiscrete solutions are derived for problems in one space dimension.And the methods don't require the LBB condition.展开更多
The preservation of a historical building, whatever its architectural and/or artistic value, is more successful when undertaken with a deep understanding of the building's history, development, materials and construc...The preservation of a historical building, whatever its architectural and/or artistic value, is more successful when undertaken with a deep understanding of the building's history, development, materials and construction techniques. The preliminary phase of any restoration intervention must start with data acquisition regarding the characteristics and conditions of the building, including a survey of significant alterations. In a great number of cases, restorations are not respectful of the building's static efficiency, so its static requirement is weakened. In fact, a very high percentage of instances in which a restoration effort results in building damage is attributable to such modification's indifference to the structural balance of a structure, as consolidated over time. This study focuses on the restoration intervention on two trilobate pillars that separate the central space from the presbytery in the Cathedral of Matera, located in southern Italy. Through the use of sonic tests - carried out despite the complexity of the shape of the building and constructive elements that characterize these pillars -- it was possible to show the effectiveness of the implemented intervention, highlighting critical points and weaknesses. The research aims to show how -- despite the complexity of some structural elements of a building -- in-depth knowledge of a structure's structure and history is essential to for the success of restoration interventions, which are respectful of a building's type and material peculiarities.展开更多
To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of P...To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of Picea schrenkiana var. tianschanica at ten points along an altitudinal gradient from 1420 m to 2300 m a.s.l. on the northern slopes of the Tianshan Mountains in northwest China. Our results indicated that all the leaf traits differed significantly among sampling sites along the altitudinal gradient(P<0.001). LA, SD, LPC, LKC increased linearly with increasing elevation, whereas leaf δ13C, LNC, Chla+b, LDMC, LMA and Narea varied non-linearly with changes in altitude. Stepwise multiple regression analyses showed that four controlled physiological and morphological characteristics influenced the variation of δ13C. Among these four controlled factors, LKC was the most profound physiological factor that affected δ13C values, LA was the secondary morphological factor, SD was the third morphological factor, LNC was the last physiological factor. This suggested that leaf δ13C was directly controlled by physiological and morphological adjustments with changing environmental conditions due to the elevation.展开更多
Using the estimates of character sums over Galoi8 rings and the trace de-scription of primitive sequences over Z_(p^e), we obtain an estimate for the frequency of theoccurrences of any element in Z_(p^e) in one period...Using the estimates of character sums over Galoi8 rings and the trace de-scription of primitive sequences over Z_(p^e), we obtain an estimate for the frequency of theoccurrences of any element in Z_(p^e) in one period of a primitive sequence, which is betterthan Kuzmin's results if n >4e, where n is the degree of the generating polynomial ofthe primitive sequence.展开更多
Let F_q be a finite field of characteristic p. In this paper, by using the index sum method the authors obtain a sufficient condition for the existence of a primitive elementα∈ F_(q^n) such that α + α^(-1)is also ...Let F_q be a finite field of characteristic p. In this paper, by using the index sum method the authors obtain a sufficient condition for the existence of a primitive elementα∈ F_(q^n) such that α + α^(-1)is also primitive or α + α^(-1)is primitive and α is a normal element of F_(q^n) over F_q.展开更多
We investigate theoretically the quantum discord dynamics of a two-qubit composite system subject to a common finite-temperature reservoir by solving the Born-Markovian master equation analytically.The ultimate quantu...We investigate theoretically the quantum discord dynamics of a two-qubit composite system subject to a common finite-temperature reservoir by solving the Born-Markovian master equation analytically.The ultimate quantum discord,however,exhibits a relatively high stable value associated with the reservoir temperature despite the permanent disappearance of entanglement simultaneously.Further analysis shows that the unique characteristic depends strongly on the off-diagonal non-zero elements of the density matrix.Our result manifests the greater robustness of quantum discord compared with entanglement,which may be helpful in quantum-information technologies.展开更多
Systematic analyses were conducted including the petrographic features, major and trace elements, Sr and Nd isotopic compositions, and mineral structure and compositions of whole rocks. Mid-Pacific Mountain volcanic r...Systematic analyses were conducted including the petrographic features, major and trace elements, Sr and Nd isotopic compositions, and mineral structure and compositions of whole rocks. Mid-Pacific Mountain volcanic rocks are mainly phonotephrite with a porphyritic texture. Phenocrysts are mainly composed of Ca-rich plagioclase, clinopyroxene and nepheline.These volcanic rocks are significantly rich in large-ion lithophile and light rare earth elements, without obvious Eu anomalies(δEu=0.99–1.03), and with relatively enriched^(87) Sr/^(86) Sr(0.703829–0.704313) and^(143) Nd/^(144) Nd isotopic ratios(0.512857–0.512871), suggesting that they have similar but more enriched features than the OIB magmatic source. These volcanic rocks may originate from relatively deep magma source with the existence of spinel-garnet Iherzolites, and have undergone partial melting at a low degree of 1–3%. In addition, The residual Nb-Ta minerals(such as sphene, rutile, perovskite) may remain in the mantle source, and the magma components have undergone metasomatism by carbonate melt/fluid or alkali-rich fluid, causing high contents of incompatible elements and significant loss of Nb, Ta and Ti in these volcanic rocks. There are many similarities between the phonotephrites in the Mid-Pacific Mountain and the volcanic rocks in the Line Islands based on the tectonic settings and the geochemical characteristics. We thus speculate that Site 313 volcanic rocks in the Mid-Pacific Mountain is most likely to be a continuation of the Line Islands.展开更多
基金The National Natural Science Foundation of China(No50475041)
文摘Based on the coded and non-coded targets, the targets are extracted from the images according to their size, shape and intensity etc., and thus an improved method to identify the unique identity(D) of every coded target is put forward and the non-coded and coded targets are classified. Moreover, the gray scale centroid algorithm is applied to obtain the subpixel location of both uncoded and coded targets. The initial matching of the uncoded target correspondences between an image pair is established according to similarity and compatibility, which are based on the ID correspondences of the coded targets. The outliers in the initial matching of the uncoded target are eliminated according to three rules to finally obtain the uncoded target correspondences. Practical examples show that the algorithm is rapid, robust and is of high precision and matching ratio.
基金supported by the National Natural Science Foundation of China(41425011 and 41303016)
文摘Mafic intrusions and dykes are well preserved in the Yinmin and Lanniping districts, located within the western margin of the Yangtze Block, SW China. Although these mafic rocks from the two areas formed during different periods, they share similar ranges of PGE concentration. Most of the Yinmin gabbroic dykes contain relatively high PGE concentrations (PGEs=13.9-87.0 ppb) and low S contents (0.003 %-0.020 %), higher than the maximum PGE concentrations of mafic magmas melting from the mantle. Two exceptional Yinmin samples are characterized by relatively low PGE (PGEs = 0.31-0.37 ppb)and high S (0.114 %-0.257 %) contents. In contrast, most samples from the Lanniping gabbroic intrusion have low PGE con- centrations (PGEs = 0.12-1.02 ppb) and high S contents (0.130 %-0.360 %), except that the three samples exhibit relatively high PGE (PGEs=16.3-34.8 ppb) and low S concentrations (0.014 %-0.070 %). All the Yinmin and Lanniping samples are characterized by the enrichment of PPGE relative to IPGE in the primitive-mantle normalized diagrams, and the high-PGE samples exhibit obvious Ru anomalies. This study suggests that during the ascent of the parental magma, removal of Os-Ir-Ru alloys and/or chro- mite/spinel leads to high Pd/Ir ratios and Ru anomalies for the Yinmin high-PGE samples and relatively lower Pd/lr ratios and Ru anomalies for the Lanniping low-PGE samples. We propose that the magmas parental to the Yinmin gabbroic dykes are initially S-unsaturated, and subsequently, minor evolved magma reached sulfur saturation and led to sulfide segregation. Although the Lanniping parental magmas are originally not saturated in S, the high Cu/Pd ratios (3.8× 10^4 to 3.2 × 10^6) for most of the Lanniping samples indicate the S-saturated state and sulfide segregation. A calculation shows that the PGE-poor magmas might have experienced 0.01%-0.1%sulfidesegregationinthemagma chamber. Therefore, our study provides a possible opportunity to discover PGE-enriched sulfide mineralization some- where near or within the Lanniping mafic intrusion.
基金supported with funding from the National Natural Science Foundation of China (No. 41173055)the Fundamental Research Funds for the Central Universities (No. 310827172101)
文摘As an important unconventional resource, oil shale has received widespread attention. The oil shale of the Chang 7 oil layer from Triassic Yanchang Formation in Ordos Basin represents the typical lacustrine oil shale in China. Based on analyzing trace elements and oil yield from boreholes samples, characteristics and paleo-sedi- mentary environments of oil shale and relationship between paleo-sedimentary environment and oil yield were studied. With favorable quality, oil yield of oil shale varies from 1.4% to 9.1%. Geochemical data indicate that the paleo-redox condition of oil shale's reducing condition from analyses of V/Cr, V/(V + Ni), U/Th, δU, and authi genic uranium. Equivalent Boron, Sp, and Sr/Ba illustrate that paleosalinity of oil shale is dominated by fresh water. The paleoclimate of oil shale is warm and humid by calculating the chemical index of alteration and Sr/Cu. Fe/Ti and (Fe + Mn)/Ti all explain that there were hot water activities during the sedimentary period of oil shale. In terms of Zr/Rb, paleohydrodynamics of oil shale is weak. By means of Co abundance and U/Th, paleo-water-depth of oil shale is from 17.30 to 157.26 m, reflecting sedimentary environment which is mainly in semi deep-deep lake facies. Correlation analyses between oil yield and six paleoenvironmental factors show that the oil yield of oil shale is mainly controlled by paleo-redox conditions, paleoclimate, hot water activities, and depth of water.Paleosalinity and paleohydrodynamics have an inconspicuous influence on oil yield.
基金supported jointly by the Natural Science Foundation of China (Grant No.41372104)Research Project of Xinjiang Nonferrous Metals Industry (Group) Co.,Ltd.(Grant No.YSKY2011-02)
文摘Petrography and geochemistry of the altered and unaltered host rocks surrounding the Koktokay No.3 pegmatite revealed that the unaltered amphibolite is mainly composed of hornblende, plagioclase, and ilmenite.Beyond these primary components, the altered host rocks contain a few newly formed minerals, including biotite,tourmaline, chlorine, and muscovite. The alteration zone surrounding the Koktokay No.3 pegmatite is limited to 2.0 m, characterized by biotitization, tourmalization, and chloritization. In the altered host rocks, the contents of SiO2, MgO, MnO, Na2O, and TiO2 did not vary greatly.However, Al2O3 showed a weak decreasing trend with the increasing distance from the pegmatite contact zone, while Fe2O3 and CaO showed an increasing trend. The contents of Li, Rb, and Cs in the altered host rocks were much higher than those in the unaltered host rocks, decreasing with distance from the contact. The chondrite-normalized rare earth element(REE) pattern of the altered and unaltered host rock was right-inclined from La to Lu, but enriched in light REEs over heavy REEs after hydrothermal alteration. An isocon plot shows that some oxides migrated in with an order of P2O5〉K2O 〉TiO2〉Al2O3〉SiO2〉MnO≥MgO, while others migrated out with an order of Na2O 〉CaO 〉Fe2O3. For REEs, the migration ratios are positive values withCs 〉Rb 〉Li 〉Nb 〉Ta 〉Be, signifying that all REEs migrated from the exsolved magmatic fluid into the altered host rocks. It was concluded that diffusion was the only mechanism for migration of ore-forming elements in the alteration zone. The effective diffusion coefficients(Deff)of LiF, RbF, and CsF were estimated under a fluid temperature of 500–550℃. Using a function of concentration(C(x,t)) and distance(x), the order of migration distance was determined to be LiF 〉CsF 〉RbF, with diffusion times of (3.39 ± 0.35)× 10^6,(3.19 ± 0.28) × 10^5 and(6.33 ± 0.05) × 10^5 years, respectively.
基金supported by the National Natural Science Foundation of China (Nos. 41206049, 40976036 and 40906033)the Marine Public Welfare Research Project (No. 200805063)
文摘Sedimentary sequence and sediment provenance are important factors when it comes to the studies on marine sedimentation. This paper studies grain size distribution, lithological characteristics, major and rare earth elemental compositions, micropaleontological features and ^(14)C ages in order to examine sedimentary sequence and sediment provenance of the core BH6 drilled at the mouth of the Yellow River in Bohai Sea. According to the grain size and the micropaleontological compositions, 4 sedimentary units have been identified. Unit 1(0–8.08 mbsf) is of the delta sedimentary facies, Unit 2(8.08–12.08 mbsf) is of the neritic shelf facies, Unit 3(12.08–23.85 mbsf) is of near-estuary beach-tidal facies, and Unit 4(23.85 mbsf–) is of the continental lake facies. The deposits from Unit 1 to Unit 3 have been found to be marine strata formed after the Holocene transgression at about 10 ka BP, while Unit 4 is continental lacustrine deposit formed before 10 ka BP. The provenances of core BH6 sediments show properties of the continental crust and vary in different sedimentary periods. For Unit 4 sediments, the source regions are dispersed while the main provenance is not clear, although the parent rock characteristics of a few samples are similar to the Luanhe River sediments. For Unit 3, sediments at 21.1–23.85 mbsf have been mainly transported from the Liaohe River, while sediments above 21.1 mbsf are mainly from the Yellow River and partially from the Liaohe River. For Unit 2, the sediments have been mainly transported from the Yellow River, with a small amount from other rivers. For Unit 1, the provenance is mainly the Yellow River catchment. These results help in better understanding the evolution of the Yellow River Delta.
文摘In order to clarify the role of organic matter in the enrichment of base metal, 10 samples of the Permian Kupferschiefer from southwestern Poland were analyzed by using microscopic and geochemical methods. The results indicate that the solvent extracts have been depleted in the samples with high Cu, Pb, Zn contents. This depletion occurred preferably in saturated hydrocarbons. Saturated hydrocarbons served as hydrogen donor for thermochemical sulfate reduction (TSR). The GC traces of saturated hydrocarbon show that the depletion occurred mainly in long chain n alkanes.
基金Supported by the Central-level Non-profit Scientific Research Institutes Special Funds(No.2014A07XK04)
文摘Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements. Proximate composition, amino acid and fatty acid profiles, and toxic elements contents of fanned and wild Chanodichthys mongolicus were established and compared. Significantly higher crude protein content while lower moisture content in farmed fish compared to wild fish were observed (P〈0.05). The percentages of total amino acids (TAA), total essential amino acids (TEAA), total non-essential amino acids (TNEAA) and total delicious amino acids (TDAA) in farmed fish were all significantly higher than those in the wild equivalent (P〈0.05). Compared to the FAO/WHO recommended reference values, the ratios of TEAA/ TAA (39.84%o-40.33%) were comparable to 40% and TEAA / TNEAA (66.22%-67.60%) were above 60%. Fatty acid profiles in both farmed and wild C. mongolicus were dominated by monounsaturated fatty acid (MUFA), with farmed fish contained much more MUFA content compared to wild counterpart (P〈0.05). Notably, wild fish exhibited significantly higher levels of total polyunsaturated fatty acid (PUFA) including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than fanned fish (P〈0.05). The EPA (C20:503) and linoleic acid (C18:206) were the predominant PUFA in wild and farmed C. mongolicus, respectively. Moreover, farmed fish displayed an overall lower toxic element levels (As, Cd, Pb and Hg) in comparison with wild fish, and both were far lower than the established limit standard. In conclusion, our results suggest that the nutritional quality of fanned C. mongolicus was inferior to their wild counterpart with respect to fatty acids nutrition, and therefore further studies should focus on the improving C. mongolicus diet in order to enhance the overall nutritional composition.
基金Supported by NNSF(10601022,11061021)Supported by NSF of Inner Mongolia Au-tonomous Region(200607010106)Supported by SRP of Higher Schools of Inner Mongolia(NJ10006)
文摘H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and uniqueness of semidiscrete solutions are derived for problems in one space dimension.And the methods don't require the LBB condition.
文摘The preservation of a historical building, whatever its architectural and/or artistic value, is more successful when undertaken with a deep understanding of the building's history, development, materials and construction techniques. The preliminary phase of any restoration intervention must start with data acquisition regarding the characteristics and conditions of the building, including a survey of significant alterations. In a great number of cases, restorations are not respectful of the building's static efficiency, so its static requirement is weakened. In fact, a very high percentage of instances in which a restoration effort results in building damage is attributable to such modification's indifference to the structural balance of a structure, as consolidated over time. This study focuses on the restoration intervention on two trilobate pillars that separate the central space from the presbytery in the Cathedral of Matera, located in southern Italy. Through the use of sonic tests - carried out despite the complexity of the shape of the building and constructive elements that characterize these pillars -- it was possible to show the effectiveness of the implemented intervention, highlighting critical points and weaknesses. The research aims to show how -- despite the complexity of some structural elements of a building -- in-depth knowledge of a structure's structure and history is essential to for the success of restoration interventions, which are respectful of a building's type and material peculiarities.
基金supported by the Major Research Plan of the National Natural Science Foundation of China (Grant No. Y411381001)the National Natural Science Foundation of China (Grant No. 91125025)the Postdoctoral Science Foundation of China (Grant No. 2013M532096)
文摘To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of Picea schrenkiana var. tianschanica at ten points along an altitudinal gradient from 1420 m to 2300 m a.s.l. on the northern slopes of the Tianshan Mountains in northwest China. Our results indicated that all the leaf traits differed significantly among sampling sites along the altitudinal gradient(P<0.001). LA, SD, LPC, LKC increased linearly with increasing elevation, whereas leaf δ13C, LNC, Chla+b, LDMC, LMA and Narea varied non-linearly with changes in altitude. Stepwise multiple regression analyses showed that four controlled physiological and morphological characteristics influenced the variation of δ13C. Among these four controlled factors, LKC was the most profound physiological factor that affected δ13C values, LA was the secondary morphological factor, SD was the third morphological factor, LNC was the last physiological factor. This suggested that leaf δ13C was directly controlled by physiological and morphological adjustments with changing environmental conditions due to the elevation.
文摘Using the estimates of character sums over Galoi8 rings and the trace de-scription of primitive sequences over Z_(p^e), we obtain an estimate for the frequency of theoccurrences of any element in Z_(p^e) in one period of a primitive sequence, which is betterthan Kuzmin's results if n >4e, where n is the degree of the generating polynomial ofthe primitive sequence.
基金supported by the National Natural Science Foundation of China(No.11401408)the Natural Science Foundation of Sichuan Province(No.14ZA0034)+2 种基金the Sichuan Normal University Key Project Foundation(No.13ZDL06)supported by the National Natural Science Foundation of China(No.11001170)the Natural Science Foundation of Shanghai Municipal(No.13ZR1422500)
文摘Let F_q be a finite field of characteristic p. In this paper, by using the index sum method the authors obtain a sufficient condition for the existence of a primitive elementα∈ F_(q^n) such that α + α^(-1)is also primitive or α + α^(-1)is primitive and α is a normal element of F_(q^n) over F_q.
基金supported by the National Basic Research Program of China (Grant No.2012CB921900)the National Natural Science Foundation of China (Grant No.10574166)the Guangdong Natural Science Foundation (Grant No.8151027501000062)
文摘We investigate theoretically the quantum discord dynamics of a two-qubit composite system subject to a common finite-temperature reservoir by solving the Born-Markovian master equation analytically.The ultimate quantum discord,however,exhibits a relatively high stable value associated with the reservoir temperature despite the permanent disappearance of entanglement simultaneously.Further analysis shows that the unique characteristic depends strongly on the off-diagonal non-zero elements of the density matrix.Our result manifests the greater robustness of quantum discord compared with entanglement,which may be helpful in quantum-information technologies.
基金supported by National Natural Science Foundation of China(Grant Nos.41476034,41272369,40802038,41320104006&41302102)
文摘Systematic analyses were conducted including the petrographic features, major and trace elements, Sr and Nd isotopic compositions, and mineral structure and compositions of whole rocks. Mid-Pacific Mountain volcanic rocks are mainly phonotephrite with a porphyritic texture. Phenocrysts are mainly composed of Ca-rich plagioclase, clinopyroxene and nepheline.These volcanic rocks are significantly rich in large-ion lithophile and light rare earth elements, without obvious Eu anomalies(δEu=0.99–1.03), and with relatively enriched^(87) Sr/^(86) Sr(0.703829–0.704313) and^(143) Nd/^(144) Nd isotopic ratios(0.512857–0.512871), suggesting that they have similar but more enriched features than the OIB magmatic source. These volcanic rocks may originate from relatively deep magma source with the existence of spinel-garnet Iherzolites, and have undergone partial melting at a low degree of 1–3%. In addition, The residual Nb-Ta minerals(such as sphene, rutile, perovskite) may remain in the mantle source, and the magma components have undergone metasomatism by carbonate melt/fluid or alkali-rich fluid, causing high contents of incompatible elements and significant loss of Nb, Ta and Ti in these volcanic rocks. There are many similarities between the phonotephrites in the Mid-Pacific Mountain and the volcanic rocks in the Line Islands based on the tectonic settings and the geochemical characteristics. We thus speculate that Site 313 volcanic rocks in the Mid-Pacific Mountain is most likely to be a continuation of the Line Islands.