The DFI-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system. More than a hundred scour pits under the pipeline were found, most of which have caused the span of the ...The DFI-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system. More than a hundred scour pits under the pipeline were found, most of which have caused the span of the pipeline to increase and threatened its safety. The maximum allowable free span length （MAFSL） of the pipeline was determined through the limitations re- garding maximum allowable stress under static or quasi-static loads and the onset of Vortex Induced Vibrations （VIV） under different hydrodynamic actions. The results show that the MAFSL under static conditions is 56m. However, the MAFSLs are 30m and 20m under ordinary weather conditions and hurricane-induced currents for the 100-year return period, respectively, to avoid VIV as cal- culated by using the highest safety class factor. It is suggested that spanning pipelines longer than 20 m should be supported. Addi- tionally, eight successive spans which may also threaten the pipeline were proposed. The most hazardous scour pits are along the pipeline section from KP42 to KP51.展开更多
Objective To evaluated the efficiency of low-dose cytosine arabinoside plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor （CAG） regimen for refractory biphenotypic acute leukem...Objective To evaluated the efficiency of low-dose cytosine arabinoside plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor （CAG） regimen for refractory biphenotypic acute leukemia （BAL）. Methods We treated 5 refractory BAL patients by CAG regimen （10 mg.m 2 cytosine arabinoside subcutaneously administrated every 12 hours, day 1-14; 5-7 mg·m^-2 aclarubicin intravenously administrated daily, day 1-8; and concurrently used 200 μg·m^-2·d^-1 granulocyte colony-stimulating factor subcutaneously） from November 2002 to April 2007. The efficacy of the regimen was evaluated by response rate, and the side effects were also measured. Results The complete remission rate was 80%, median duration of absolute neutrophil count〈5.0×10^8/L and platelet count〈2.0×10^10/L was day 13 and day 1, respectively; and the infection rate was low （Ⅲ-Ⅳ infection rate, 20.00%）.展开更多
Foundation is considered as one of the main parts of any structure. The type of foundation used is highly dependent on the type and properties of soil. The design of foundations requires many factors that should be de...Foundation is considered as one of the main parts of any structure. The type of foundation used is highly dependent on the type and properties of soil. The design of foundations requires many factors that should be defined. There are number of differences in the geological and soil conditions in Iraq. As a consequence, these differences are reflected on the type of foundation to be used. Despite these differences, same materials and style of buildings are used all over Iraq. The main problems of Iraqi soil are high gypsum content, salinity and shallow water table depth. These factors that influence the foundations are the soil properties and the amount of loads that transmitted by the superstructure. The situation has been analysed through a case study which illustrated the link between soil and foundation types in three different parts of Iraq （Mosul, Baghdad and Basra）. One building was analysed using ＂STAAD （structural analysis and design）. Pro＂ software in these regions. It is evident that Iraqi designers and engineers require local code to define all the loads, materials and design of the foundation to be used. The use of local materials might be very effective from both engineering and economic perspectives.展开更多
The aim of this paper is to investigate Hawking radiation of Dirac particles from the Dilaton space-time with squashed horizons by improving the method of Kerner and Man’s tunneling analysis.We construct appropriate ...The aim of this paper is to investigate Hawking radiation of Dirac particles from the Dilaton space-time with squashed horizons by improving the method of Kerner and Man’s tunneling analysis.We construct appropriate matrices for general covariant Dirac equation,and derive the tunneling probability and Hawking temperature.The results show that both Dirac particles and scalar particles radiate at the same Hawking temperature.展开更多
Water samples, sediments from three stations in Euphrates River, lraq were analyzed quantitatively for some physical and chemical characters and six heavy metals （Co, Cu, Fe, Mn, Ni and Pb） using flam atomic absorpt...Water samples, sediments from three stations in Euphrates River, lraq were analyzed quantitatively for some physical and chemical characters and six heavy metals （Co, Cu, Fe, Mn, Ni and Pb） using flam atomic absorption spectrophotpmeter in period Sept. 2009-Oct. 2010. The physical and chemical characters included temperature, pH, water flow, salinity, dissolved oxygen, BOD5, alkalinity total hardness, calcium and nutrients （nitrite, nitrate reactive phosphate and silicate）. The results showed variation in water flow 0.05-0.40 m/sec., according to the values of salinity 0.40%-0.60% values of the BOD5 were ranged between 0.2-4.3 mg/L. The mean concentration of the heavy metals （Pb, Ni, Mn, Co, Cu and Fe） of the dissolved phase in water were 0.13 μg/L, 0.021 μg/L, 0.31 μg/L, 4.29 μg/L, 7.78 μg/L, 6.46 μg/L and 79.04 μg/L, respectively, while their concentration in the particulate phase were 0.59 μg/g, 0.06 μg/g, 0.42 μg/g, 50.06 μg/g, 6.61 μg/g, 7.17 vg/g and 149.42 μg/g dry weight, respectively. Also the mean concentrations of heavy metals in sediment （exchangeable phase） were 0.51 vg/g,0.18 vg/g, 0.08 μg/g, 61.39 μg/g, 5.40 μg/g, 14.06 vg/g and 130.05 μg/g dry weight respectively, and 0.40 μg/g, 0.17 μg/g, 0.10 μg/g, 63.01 μg/g, 4.64 μg/g, 18.44 μg/g and 126.26 μg/g D.W. respectively in residual phase of sediment.展开更多
We propose a new family of 3D Dirac semimetals based on XAuTe(X = K, Na, Rb) ternary honeycomb compounds, determined based on first-principles calculations, which are shown to be topological Dirac semimetals in which ...We propose a new family of 3D Dirac semimetals based on XAuTe(X = K, Na, Rb) ternary honeycomb compounds, determined based on first-principles calculations, which are shown to be topological Dirac semimetals in which the Dirac points are induced by band inversion. Dirac points with four-fold degeneracy that are protected by C3 rotation symmetry and located on the Γ-A high-symmetry path are found. Through spatial-inversion symmetry breaking, a K(Au0.5 Hg0.5)(Te0.5As0.5) superlattice structure composed of KHgAs and KAuTe compounds is proven to be a Weyl semimetal with type-II Weyl points, which connect electronand hole-like bands. In this superlattice structure, the six pairs of Weyl nodes are distributed along the K-Γ high-symmetry path on the kz = 0 plane. Our research expands the family of topological Dirac and type-II Weyl semimetals.展开更多
A National Science Foundation of China （NSFC） major research project, Destruction of the North China Craton （NCC）, has been carried out in the past few years by Chinese scientists through an in-depth and systemati...A National Science Foundation of China （NSFC） major research project, Destruction of the North China Craton （NCC）, has been carried out in the past few years by Chinese scientists through an in-depth and systematic observations, experiments and theoretical analyses, with an emphasis on the spatio-temporal distribution of the NCC destruction, the structure of deep earth and shallow geological records of the craton evolution, the mechanism and dynamics of the craton destruction. From this work the foUowing conclusions can be drawn： （1） Significant spatial heterogeneity exists in the NCC lithospheric thickness and crustal structure, which constrains the scope of the NCC destruction. （2） The nature of the Paleozoic, Mesozoic and Cenozoic sub-continental lithospheric mantle （CLM） underneath the NCC is characterized in detail. In terms of water content, the late Mesozoic CLM was rich in water, but Cenozoic CLM was highly water deficient. （3） The correlation between magmatism and surface geological response confirms that the geological and tectonic evolution is governed by cratonic destruction processes. （4） Pacific subduction is the main dynamic factor that triggered the destruction of the NCC, which highlights the role of cratonic destruction in plate tectonics.展开更多
The North China Craton(NCC) hosts numerous gold deposits and is known as the most gold-productive region of China. The gold deposits were mostly formed within a few million years in the Early Cretaceous(130–120 Ma), ...The North China Craton(NCC) hosts numerous gold deposits and is known as the most gold-productive region of China. The gold deposits were mostly formed within a few million years in the Early Cretaceous(130–120 Ma), coeval with widespread occurrences of bimodal magmatism, rift basins and metamorphic core complexes that marked the peak of lithospheric thinning and destruction of the NCC. Stable isotope data and geological evidence indicate that ore-forming fluids and other components were largely exsolved from cooling magma and/or derived from mantle degassing during the period of lithospheric extension. Gold mineralization in the NCC contrasts strikingly with that of other cratons where gold ore-forming fluids were sourced mostly from metamorphic devolatization in compressional or transpressional regimes. In this paper, we present a summary and discussion on time-space distribution and ore genesis of gold deposits in the NCC in the context of the timing, spatial variation, and decratonic processes. Compared with orogenic gold deposits in other cratonic blocks, the Early Cretaceous gold deposits in the NCC are quite distinct in that they were deposited from magma-derived fluids under extensional settings and associated closely with destruction of cratonic lithosphere. We argue that Early Cretaceous gold deposits in the NCC cannot be classified as orogenic gold deposits as previously suggested, rather, they are a new type of gold deposits, termed as "decratonic gold deposits" in this study. The westward subduction of the paleo-West Pacific plate(the Izanagi plate) beneath the eastern China continent gave rise to an optimal tectonic setting for large-scale gold mineralization in the Early Cretaceous. Dehydration of the subducted and stagnant slab in the mantle transition zone led to continuous hydration and considerable metasomatism of the mantle wedge beneath the NCC. As a consequence, the refractory mantle became oxidized and highly enriched in large ion lithophile elements and chalcophile elements(e.g., Cu, Au, Ag and Te). Partial melting of such a mantle would have produced voluminous hydrous, Au- and S-bearing basaltic magma, which, together with crust-derived melts induced by underplating of basaltic magma, served as an important source for ore-forming fluids. It is suggested that the Eocene Carlin-type gold deposits in Nevada, occurring geologically in the deformed western margin of the North America Craton, are comparable with the Early Cretaceous gold deposits of the NCC because they share similar tectonic settings and auriferous fluids. The NCC gold deposits are characterized by gold-bearing quartz veins in the Archean amphibolite facies rocks, whereas the Nevada gold deposits are featured by fine-grained sulfide dissemination in Paleozoic marine sedimentary rocks. Their main differences in gold mineralization are the different host rocks, ore-controlling structures, and ore-forming depth. The similar tectonic setting and ore-forming fluid source, however, indicate that the Carlin-type gold deposits in Nevada are actually analogous to decratonic gold deposits in the NCC. Gold deposits in both the NCC and Nevada were formed in a relatively short time interval(<10 Myr) and become progressively younger toward the subduction zone. Younging of gold mineralization toward subduction zone might have been attributed to retreat of subduction zone and rollback of subducted slab. According to the ages of gold deposits on inland and marginal zones, the retreat rates of the Izanagi plate in the western Pacific in the Early Cretaceous and the Farallon plate of the eastern Pacific in the Eocene are estimated at 8.8 cm/yr and 3.3 cm/yr, respectively.展开更多
基金supported by the National Basic Research Program of China (973 Program) (Grant No.2005CB422304)the Ocean University of China Scientific Research Start-up Funds Project for Introduced Talents
文摘The DFI-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system. More than a hundred scour pits under the pipeline were found, most of which have caused the span of the pipeline to increase and threatened its safety. The maximum allowable free span length （MAFSL） of the pipeline was determined through the limitations re- garding maximum allowable stress under static or quasi-static loads and the onset of Vortex Induced Vibrations （VIV） under different hydrodynamic actions. The results show that the MAFSL under static conditions is 56m. However, the MAFSLs are 30m and 20m under ordinary weather conditions and hurricane-induced currents for the 100-year return period, respectively, to avoid VIV as cal- culated by using the highest safety class factor. It is suggested that spanning pipelines longer than 20 m should be supported. Addi- tionally, eight successive spans which may also threaten the pipeline were proposed. The most hazardous scour pits are along the pipeline section from KP42 to KP51.
基金Supported by the Development of Society Foundation of Suzhou (SS0813)the Natural Science Foundation of Jiangsu Province (2004BK424)+2 种基金the 135 Key Department Foundation of Jiangsu Province (135XY0416)the Outstanding Person Fund the Jiangsu Province (LJ200626)the Outstanding Person Fund of the First Affiliated Hospital of Soochow University (2004YQG05)
文摘Objective To evaluated the efficiency of low-dose cytosine arabinoside plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor （CAG） regimen for refractory biphenotypic acute leukemia （BAL）. Methods We treated 5 refractory BAL patients by CAG regimen （10 mg.m 2 cytosine arabinoside subcutaneously administrated every 12 hours, day 1-14; 5-7 mg·m^-2 aclarubicin intravenously administrated daily, day 1-8; and concurrently used 200 μg·m^-2·d^-1 granulocyte colony-stimulating factor subcutaneously） from November 2002 to April 2007. The efficacy of the regimen was evaluated by response rate, and the side effects were also measured. Results The complete remission rate was 80%, median duration of absolute neutrophil count〈5.0×10^8/L and platelet count〈2.0×10^10/L was day 13 and day 1, respectively; and the infection rate was low （Ⅲ-Ⅳ infection rate, 20.00%）.
文摘Foundation is considered as one of the main parts of any structure. The type of foundation used is highly dependent on the type and properties of soil. The design of foundations requires many factors that should be defined. There are number of differences in the geological and soil conditions in Iraq. As a consequence, these differences are reflected on the type of foundation to be used. Despite these differences, same materials and style of buildings are used all over Iraq. The main problems of Iraqi soil are high gypsum content, salinity and shallow water table depth. These factors that influence the foundations are the soil properties and the amount of loads that transmitted by the superstructure. The situation has been analysed through a case study which illustrated the link between soil and foundation types in three different parts of Iraq （Mosul, Baghdad and Basra）. One building was analysed using ＂STAAD （structural analysis and design）. Pro＂ software in these regions. It is evident that Iraqi designers and engineers require local code to define all the loads, materials and design of the foundation to be used. The use of local materials might be very effective from both engineering and economic perspectives.
基金Supported by the National Natural Science Foundation of China under Grant No.60972164
文摘The aim of this paper is to investigate Hawking radiation of Dirac particles from the Dilaton space-time with squashed horizons by improving the method of Kerner and Man’s tunneling analysis.We construct appropriate matrices for general covariant Dirac equation,and derive the tunneling probability and Hawking temperature.The results show that both Dirac particles and scalar particles radiate at the same Hawking temperature.
文摘Water samples, sediments from three stations in Euphrates River, lraq were analyzed quantitatively for some physical and chemical characters and six heavy metals （Co, Cu, Fe, Mn, Ni and Pb） using flam atomic absorption spectrophotpmeter in period Sept. 2009-Oct. 2010. The physical and chemical characters included temperature, pH, water flow, salinity, dissolved oxygen, BOD5, alkalinity total hardness, calcium and nutrients （nitrite, nitrate reactive phosphate and silicate）. The results showed variation in water flow 0.05-0.40 m/sec., according to the values of salinity 0.40%-0.60% values of the BOD5 were ranged between 0.2-4.3 mg/L. The mean concentration of the heavy metals （Pb, Ni, Mn, Co, Cu and Fe） of the dissolved phase in water were 0.13 μg/L, 0.021 μg/L, 0.31 μg/L, 4.29 μg/L, 7.78 μg/L, 6.46 μg/L and 79.04 μg/L, respectively, while their concentration in the particulate phase were 0.59 μg/g, 0.06 μg/g, 0.42 μg/g, 50.06 μg/g, 6.61 μg/g, 7.17 vg/g and 149.42 μg/g dry weight, respectively. Also the mean concentrations of heavy metals in sediment （exchangeable phase） were 0.51 vg/g,0.18 vg/g, 0.08 μg/g, 61.39 μg/g, 5.40 μg/g, 14.06 vg/g and 130.05 μg/g dry weight respectively, and 0.40 μg/g, 0.17 μg/g, 0.10 μg/g, 63.01 μg/g, 4.64 μg/g, 18.44 μg/g and 126.26 μg/g D.W. respectively in residual phase of sediment.
基金supported by the National Natual Science Foundation of China (Grant Nos. 21373190, 11322434 and 21421063)sponsored by the DOE Office of Biological and Environmental Research
文摘We propose a new family of 3D Dirac semimetals based on XAuTe(X = K, Na, Rb) ternary honeycomb compounds, determined based on first-principles calculations, which are shown to be topological Dirac semimetals in which the Dirac points are induced by band inversion. Dirac points with four-fold degeneracy that are protected by C3 rotation symmetry and located on the Γ-A high-symmetry path are found. Through spatial-inversion symmetry breaking, a K(Au0.5 Hg0.5)(Te0.5As0.5) superlattice structure composed of KHgAs and KAuTe compounds is proven to be a Weyl semimetal with type-II Weyl points, which connect electronand hole-like bands. In this superlattice structure, the six pairs of Weyl nodes are distributed along the K-Γ high-symmetry path on the kz = 0 plane. Our research expands the family of topological Dirac and type-II Weyl semimetals.
基金supported by National Natural Science Foundation of China (Grant Nos.90714001,90714004,90714008,90714009,91014006,91114206)
文摘A National Science Foundation of China （NSFC） major research project, Destruction of the North China Craton （NCC）, has been carried out in the past few years by Chinese scientists through an in-depth and systematic observations, experiments and theoretical analyses, with an emphasis on the spatio-temporal distribution of the NCC destruction, the structure of deep earth and shallow geological records of the craton evolution, the mechanism and dynamics of the craton destruction. From this work the foUowing conclusions can be drawn： （1） Significant spatial heterogeneity exists in the NCC lithospheric thickness and crustal structure, which constrains the scope of the NCC destruction. （2） The nature of the Paleozoic, Mesozoic and Cenozoic sub-continental lithospheric mantle （CLM） underneath the NCC is characterized in detail. In terms of water content, the late Mesozoic CLM was rich in water, but Cenozoic CLM was highly water deficient. （3） The correlation between magmatism and surface geological response confirms that the geological and tectonic evolution is governed by cratonic destruction processes. （4） Pacific subduction is the main dynamic factor that triggered the destruction of the NCC, which highlights the role of cratonic destruction in plate tectonics.
基金financially supported by the National Natural Science Foundation of China(Grant No.91414301)project of the State Key Laboratory of Lithospheric Evolution(Grant No.1303)
文摘The North China Craton(NCC) hosts numerous gold deposits and is known as the most gold-productive region of China. The gold deposits were mostly formed within a few million years in the Early Cretaceous(130–120 Ma), coeval with widespread occurrences of bimodal magmatism, rift basins and metamorphic core complexes that marked the peak of lithospheric thinning and destruction of the NCC. Stable isotope data and geological evidence indicate that ore-forming fluids and other components were largely exsolved from cooling magma and/or derived from mantle degassing during the period of lithospheric extension. Gold mineralization in the NCC contrasts strikingly with that of other cratons where gold ore-forming fluids were sourced mostly from metamorphic devolatization in compressional or transpressional regimes. In this paper, we present a summary and discussion on time-space distribution and ore genesis of gold deposits in the NCC in the context of the timing, spatial variation, and decratonic processes. Compared with orogenic gold deposits in other cratonic blocks, the Early Cretaceous gold deposits in the NCC are quite distinct in that they were deposited from magma-derived fluids under extensional settings and associated closely with destruction of cratonic lithosphere. We argue that Early Cretaceous gold deposits in the NCC cannot be classified as orogenic gold deposits as previously suggested, rather, they are a new type of gold deposits, termed as "decratonic gold deposits" in this study. The westward subduction of the paleo-West Pacific plate(the Izanagi plate) beneath the eastern China continent gave rise to an optimal tectonic setting for large-scale gold mineralization in the Early Cretaceous. Dehydration of the subducted and stagnant slab in the mantle transition zone led to continuous hydration and considerable metasomatism of the mantle wedge beneath the NCC. As a consequence, the refractory mantle became oxidized and highly enriched in large ion lithophile elements and chalcophile elements(e.g., Cu, Au, Ag and Te). Partial melting of such a mantle would have produced voluminous hydrous, Au- and S-bearing basaltic magma, which, together with crust-derived melts induced by underplating of basaltic magma, served as an important source for ore-forming fluids. It is suggested that the Eocene Carlin-type gold deposits in Nevada, occurring geologically in the deformed western margin of the North America Craton, are comparable with the Early Cretaceous gold deposits of the NCC because they share similar tectonic settings and auriferous fluids. The NCC gold deposits are characterized by gold-bearing quartz veins in the Archean amphibolite facies rocks, whereas the Nevada gold deposits are featured by fine-grained sulfide dissemination in Paleozoic marine sedimentary rocks. Their main differences in gold mineralization are the different host rocks, ore-controlling structures, and ore-forming depth. The similar tectonic setting and ore-forming fluid source, however, indicate that the Carlin-type gold deposits in Nevada are actually analogous to decratonic gold deposits in the NCC. Gold deposits in both the NCC and Nevada were formed in a relatively short time interval(<10 Myr) and become progressively younger toward the subduction zone. Younging of gold mineralization toward subduction zone might have been attributed to retreat of subduction zone and rollback of subducted slab. According to the ages of gold deposits on inland and marginal zones, the retreat rates of the Izanagi plate in the western Pacific in the Early Cretaceous and the Farallon plate of the eastern Pacific in the Eocene are estimated at 8.8 cm/yr and 3.3 cm/yr, respectively.
