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Sediment transport capacity of hyperconcentrated flow

Science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 961-975页

作者： SHU AnPing1,2 & FEI XiangJun2 1 School of Environment & key laboratory of Water and Sediment Sciences,Ministry of Education,beijing Normal University,beijing 100875,china 2 state key laboratory of Hydroscience and Engineering,Tsinghua University,beijing 100084,china School of Environment & key laboratory of Water and Sediment Sciences Ministry of Education Beijing Normal University Beijing China state key laboratory of Hydroscience and Engineering Tsinghua University Beijing China

As one of the most important components of river mechanics,sediment transport capacity of sediment-laden flows has attracted much attention from many researchers working on river mechanics and hydraulic engineering. Based on the time-averaged equation for a turbulent energy equilibrium in solid and liquid two-phase flow,an expression for the efficiency coefficient of suspended load movement was derived for the two-dimensional,steady,uniform,fully-developed turbulent flow. A new structural expression of sediment transport capacity was achieved. Using 115 runs of flume experimental data,which were obtained through two kinds of sediment transport experiments in the state of equilibrium,in combination with the basic rheological and sediment transporting characteristics of hyperconcentrated flow,the main parameters in the structural expression of sediment transport capacity were calibrated,and a new formula of sediment transport capacity for hyperconcentrated flow was developed. A large amount of field data from the Yellow River,Wuding River,and Yangtze River,etc. were adopted to verify the new formula and good agreement was obtained. These results above contribute to an improved theoretical system of river mechanics and a reliable tool for management of rivers carrying high concentration of sediments.

关键词： hyperconcentrated flow turbulent energy equilibrium efficiency coefficient sediment transport capacity

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Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

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Science china Earth Sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2, ZHAO Zhidan1,2, ZHANG Hongfei3. ZHANG Benren3.& CHEN Yuelong2 1. state key laboratory of Geological Processes and Mineral Resources,{3. University of Geosciences, beijing 100083.{3. 2. School of Earth Science and Mineral Resources,{3. University of Geosciences, beijing 100083.{3. 3. Faculty of Earth Sciences,{3. University of Geosciences, Wuhan 43.074,{3. state key laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing China School of Earth Science and Mineral Resources China University of Geosciences Beijing China Faculty of Earth Sciences China University of Geosciences Wuhan China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.27). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2Nb-Zr/4-Y and Ti/100-Zr-YX3.tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143.Nd/^(144)Nd (0.512955-0.512978). Pb isotopes are in the rangeof ^(206)Pb/^(204)Pb (18.054-20.562), ^(207)Pb/^(204)Pb (15.53.-15.743. and ^(208)Pb/^(204)Pb(3..068-3..53.). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.

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Experimental study on interaction between simulated sandstone and acidic fluid

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Petroleum Science 2009年第1期6卷 8-16页

作者： Zhang Yongwang Zeng Jianhui Yu Bingsong state key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China Basin and Reservoir Research Center China University of Petroleum Beijing 102249 China state key laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China

In order to investigate the controlling mechanism of temperature, fluid and other factors on water-rock interaction in the diagenetic process, we performed a series of simulated experiments on the interaction between two kinds of fluids with different salinity and a composite mineral system （simulated sandstone）, which contains albite, K-feldspar and other minerals. The experimental results showed that acidity was the most important factor that affected the dissolution of minerals in the composite mineral system. The lower the pH value, the more easily the minerals dissolved. At the same pH value, the dissolution abilities of different acids for various mineral components were also different. Compared to hydrochloric acid （inorganic acid）, oxalic acid （organic acid） was more able to dissolve aluminosilicate minerals. However, the dissolution ability of oxalic acid for carbonate minerals was lower than that of hydrochloric acid. In the process of fluid-rock interaction, dissolution of feldspar was relatively complicated. Increase of temperature would accelerate the dissolution of feldspar. Under acidic conditions, albite had a higher dissolution rate than K-feldspar. K-feldspar could dissolve and convert into montmorillonite and kaolinite, while albite could dissolve and convert into kaolinite both at 40℃ and 80℃. Presence of organic acid, and decrease of pH value and water salinity were all favorable for the dissolution of feldspar, but weakened the ability to form clay minerals.

关键词： Fluid simulated sandstone dissolution static experiment

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Effect of the RNA5 component on pathogenicity of beet necrotic yellow vein virus

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Chinese Science Bulletin 2003年第8期48卷 796-799页

作者： LIU Tao, HAN Chenggui, LI Dawei, CAI Zhunan, YU Jialin & LIU Yi state key laboratory for {3. and College of Biological Science, china Agricultural University, beijing 100094, china Correspondence should be addressed to Yu Jialin (e-mail: bnyvv@public. ***) state key laboratory for {3. College of Biological Science China Agricultural University Beijing 100094 China

The transcripts of beet necrotic yellow virus RNA5 were prepared from the cloned cDNA in a bacterio-phage T7 in vitro run-off transcription system. The RNA5 transcripts and RNAs extracted from two BNYVV mutants, Hu0 containing RNA1, 2 and Hu3.containing RNA1, 2, 3.respectively, were co-inoculated to Tetragonia expansa and sugar beet seedlings. The results indicated that the virus infections and accumulation in the hosts could be improved by presence of RNA5. Cooperating with RNA3. the RNA5 seems to cause more severe symptom and yield losses in sugar beet. These results suggest that, in addition of RNA3. BNYVV RNA5 is another important factor associated with the virus pathogenicity.

关键词： RNA 致病性甜菜 BNYVV 核糖核酸

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The least-square method in complex number domain

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Progress in Natural Science:Materials International 2006年第3期16卷 307-312页

作者： GU Xiangqian, KANG Hongwen and CAO Hongxing (state key laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, {3. 100081, china) state key laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

The classical least-square method was extended from the real number into the complex number domain, which is called the complex least-square method. The mathematical derivation and its applications show that the complex least-square method is different from one that the real number and the imaginary number are separately calculated with the classical least-square, by which the actual least-square estimation cannot be obtained in practice. Applications of this new method to an arbitrarily given series and to the precipitation in rainy season at 160 meteorological stations in china mainland show advantages of this method over other conventional statistical models.

关键词： complex least square Fourier transformation forecast in rainy season.

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The role of Smad signaling in vascular and hematopoietic development revealed by studies using genetic mouse models

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Science china(Life Sciences) 2010年第4期53卷 485-489页

作者： LAN Yu & YANG Xiao state key laboratory of Proteomics, Genetic laboratory of Development and Diseases, Institute of Biotechnology, beijing 100071, china state key laboratory of Proteomics Genetic Laboratory of Development and Diseases Institute of Biotechnology Beijing China

Smads are intracellular mediators of transforming growth factor β (TGF-β) superfamily signaling. In this review, we focus on the genetic mouse models for Smad pathways, which have provided functional evidence regarding the complex circuitry in angiogenesis and hematopoiesis during development. In the early stages of vascular development, TGF-β signaling is a contri buting factor in angiogenesis and vascular maturation. Whereas in the later embryogenesis, selected molecules of Smad pathways, such as TGF-β type II receptor (TbRII), ALK5, and Smad5, seem to be dispensable for vessel morphogenesis and integrity. TGF-β signaling is not required in the induction of hematopoietic precursors from mesoderm, but inhibits the subsequent expansion of committed hematopoietic precursors. By contrast, bone morphogenetic protein 4 (BMP4) has long been acknowledged pivotal in mesoderm induction and hematopoietic commitment during development. However, recent genetic evidence shows the BMP4-ALK3.axis is not crucial for the formation of hematopoietic cells from FLK1+ mesoderm. Because of the highly redundant mechanisms within the Smad pathways, the precise role of the Smad signaling involved in vascular and hematopoietic development remains nebulous. The generation of novel cell lineage restricted Cre transgenes would shed new light on the future relevant investigations.

关键词： Smad transforming growth factor β (TGF-β) bone morphogenetic protein (BMP) angiogenesis hematopoiesis knockout development

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Review of metal matrix composites with high thermal conductivity for thermal management applications

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Progress in Natural Science:Materials International 2011年第3期21卷 189-197页

作者： Xuan-hui QU,Lin ZHANG,Mao WU,Shu-bin REN state key laboratory for Advanced Metals and Materials, {3. key laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology {3.,{3. 100083.china state key laboratory for Advanced Metals and Materials Beijing Key Laboratory for Powder Metallurgy and Particulate Materials University of Science and Technology Beijing Beijing 100083 China

Metal matrix composites with high thermal conductivity and tailorable coefficient of thermal expansion are found widespread applications in electronic package and thermal *** latest advances in manufacturing process,thermal properties and brazing technology of SiC/metal,carbon/metal and diamond/metal composites were *** factors controlling the thermo-physical properties were discussed in *** problems involved in the fabrication and the brazing of these composites were elucidated and the main focus was put on the discussion of the methods to overcome these *** review shows that the combination of pressureless infiltration and powder injection molding offers the benefits to produce near-net shape composites. Improving wettability and optimizing interfacial structure are prerequisites for successful fabrication and further enhancement of thermal properties.A new Ag-Cu-Sn brazing alloy with low melting point is found to be effective to braze Al-matrix composites.

关键词： metal matrix composites electronic packaging thermal conductivity coefficient of thermal expansion brazing

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Hydrogen metabolic pathways of Rhodospirillum rubrum under artificial illumination

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Chinese Science Bulletin 2010年第1期55卷 32-37页

作者： ZHU RuiYan1,2,3.& LI JiLun1 1 College of Biological Sciences, state key laboratory for {3., china Agricultural University, beijing 100193. china 2 College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, china 3.Engineering Research Center for Bioenergy of Hebei Province, Qinhuangdao 066004, china College of Biological Sciences State Key Laboratory for Agrobiotechnology China Agricultural University Beijing China College of Environmental and Chemical Engineering Yanshan University Qinhuangdao China Engineering Research Center for Bioenergy of Hebei Province Qinhuangdao China

Multiple enzymes involved in hydrogen metabolism have been detected in photosynthetic bacterium Rhodospirillum rubrum un-der various growth conditions. To investigate hydrogen metabolic pathways and the contribution of each pathway to hydrogen photoproduction in R. rubrum under the artificial illumination condition, three mutants were constructed, including nifHanfDG double mutant lacking both Fe-nitrogenase and Mo-nitrogenase, anfDG mutant lacking Fe-nitrogenase and nifHhupL double mu-tant (uptake hydrogenase deficient mutant). Comparison of the hydrogen production of these 3.mutants with R. rubrum wild type and the uptake hydrogenase deficient mutant showed that there was a third pathway involved in hydrogen production besides Mo-nitrogenase and Fe-nitrogenase, which mainly contributed to hydrogen evolution. Only a small portion of hydrogen was gen-erated by the third pathway. The hydrogen produced by Mo-nitrogenase, Fe-nitrogenase and the third pathway was about 93.5%, 4.9% and 1.5%, respectively, while the hydrogen consumed by uptake hydrogenase was about 13.3.. The investigation of the formate-linked hydrogenase activity indicated that the third pathway for hydrogen production was not mediated by the for-mate-linked hydrogenase, but probably by some unknown enzyme.

关键词：氢代谢人工照明代谢途径红螺菌固氮酶脱氢酶突变体体吸收

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Study of the structure of unstable nuclei through the reaction experiments

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Science china(Physics,Mechanics & Astronomy) 2011年第S1期54卷 1-5页

作者： CAO ZhongXin & YE YanLin state key laboratory of Nuclear Physics and Technology, School of Physics, Peking University, {3. 100871, china state key laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing China

Along with the development of the radioactive nuclear beam facility, the study of the structure of unstable nuclei has progressed rapidly over the last few decades. Due to the weakly binding property, the structure information of the unstable nuclei comes primarily from the scattering or reaction experiments. Therefore it would be very important to understand clearly the reaction mechanism involved in the experiment. We outlined here the major reaction mechanisms which are adequate to the study of unstable nuclei, with the focus on the new phenomena and methods in comparison with those with traditional stable nucleus beam. Especially emphasized are the breakup and knockout reactions, developed as accurate tools for spectroscopy investigation into the nuclear structure with low intensity secondary beam. Couplings of the breakup channel to the elastic scattering and the fusion and transfer reactions are also reviewed.

关键词： binaries: unstable nuclei nuclear structure breakup reaction knockout reaction fusion reaction transfer reaction

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Giant Magnetostrictions of Tb-Dy-Fe Polycrystals with < 110 > Axial Alignment

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Journal of Materials Science & Technology 2000年第2期16卷 175-176页

作者： Shouzeng ZHOU, Xuexu GAO, Maocai ZHANG, Qing ZHAO and Zhenhlla SHI (state key laboratory for Advanced Metals and Materials, University of Science and Technology {3., {3. 100083. china) state key laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

Preparing method and processing of Tb-Dy-Fe alloy samples with [110] axial orientation as well as their magnetostrictive properties have been studied. It has been found that the magnetostrictive strains of polycrystal samples with [110] axial orientation can reach (1550-1900) ×10~-6 in a low magnetic field less than 80 kA/m, which are equal to or somewhat better than that of the polycrystal samples with [112] axial orientation.

关键词： 110 Giant Magnetostrictions of Tb-Dy-Fe Polycrystals with Axial Alignment Fe Dy

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