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| 1 | INCIPIENT MOTION OF COARSE PARTICLES IN HIGH GRADIENT RIVERS显示文摘In Northwest China, there are many inland rivers that are characterized by high a gradient, coarse particles, a thick pebble and gravel layer, and small discharge and shallow water depth during the flood season. In these rivers, the motion of coarse particles has an important influence on the construction of various structures related to these rivers. In this study, the law of the motion of coarse particles is investigated in high gradient rivers. First, according to the rolling mode of particle motion, the forces acting on coarse particles were analyzed, and a formula was deduced to represent the incipient drag force for uniform coarse particles in a high gradient river. The flow velocity near the river bed, resistance coefficient, and weight of a coarse particle were taken into account to obtain the formula, which indicated that the incipient drag force is not related to the sediment Reynolds number, but closely related to the Froude number, which was also true for the Maxwell formula. Next, after comparing the various criteria for incipient motion of sediment, experiments were done to obtain data and determine the incipient motion of coarse particles. Based on the experiments, it was concluded that the motion type of “embedded” coarse material belongs to the motion of contact load, and the nondimensional unit-width sediment transport rate, which was put forward by Taylor in 1971, was chosen as the criterion in this study. Finally, based on the experimental data, the drag force formula was calibrated. The computed drag force agreed well with the measured values. Moreover, the formula derived in this study was compared with the Maxwell formula, another formula to study the incipient motion of particles in step-shaped mountainous rivers. The comparison indicates that the slope is the key factor in the two formulas, and the weight is an important force on the incipient motion of coarse particles in the current formula, but not in the Maxwell formula. | Shengfa YANG Jiang HU Xingkui WANG | 2006 | International Journal of Sediment Research2006，21，3： | 2 |
| 2 | Adjacent segment disease after anterior cervical decompression and fusion: analysis of risk factors on X-ray and magnetic resonance imaging显示文摘 | Zhao Yanbin Sun Yu Zhou Feifei Wang Shaobo Zhang Fengshan Pan Shengfa | 2014 | Chinese Medical Journal2014，，22： | 2 |
| 3 | Influence of Cerium on Corrosion of AZ91 Magnesium Alloy显示文摘Effect of cerium addition on corrosion resistance of AZ91 magnesium alloy was investigated using the static weight loss and polarization curve method as well as metallographical observation. The results indicate that a small amount of cerium (0.2%~0.8%) in AZ91 magnesium alloy can significantly reduce the corrosion rate, enhance the electrode voltage and lower corrosion current density in 3.5%NaCl aqueous solution, and AZ91-0.8%Ce alloy has better corrosion resistant performance. The reason for increasing corrosion resistance is attributed to the addition of Ce, refining the α-Mg grain, reducing the segregation of element Al, and improving the morphologies of β-Mg17Al12 phases. | Liu Shengfa Liu Linyan Huang Shangyu Xu Ping Wang Zhongfan | 2006 | Journal of Rare Earths2006，24，2： | 1 |
| 4 | Finite element analysis of the electromagnetic field of untouched permanent induction magnetic coupling显示文摘 | Yang Chaojun Wang Yuning Jiang Shengfa | 2006 | Materials Science Forum2006，，： | 1 |
| 5 | The biogenic silica variation and paleoproductivity evolution in the eastern Indian Ocean during the past 20 000 a显示文摘The biogenic silica of sediment samples from Core CJ01-185 which is collected from the eastern India Ocean off the Sunda Strait is analyzed to evaluate the impact of the opening of the Sunda Strait on a paleoproductivity evolution. The new results indicate that the biogenic silica mass values of Core CJ01-185 show the lowest 0.86% in the last glacial period, and reach its maxima of 1.89% in the late Holocene. Furthermore, the biogenic silica mass accumulation rate(MARBSi) values also vary with much higher during the late Holocene than during the last glaciation. The input of additional terrigenous materials from the Java Sea has enhanced the paleoproductivity and increased the biogenic silica mass and MARBSi values after the opening of the Sunda Strait. It is suggested that the paleoproductivity in the study area is mainly influenced by the southeast monsoon and upwelling before the opening of the Sunda Strait. However, the paleoproductivity is dominated by the terrigenous materials input other than by the southeast monsoon or upwelling in the Holocene. | Yonghang Xu Liang Wang Zhikun Lai Xiaohui Xu Feng Wang Shengfa Liu Xuefa Shi Rainer Arief Troa Rina Zuraida Eko Triarso Marfasran Hendrizan | 2019 | Acta Oceanologica Sinica2019，38，1： | 1 |
| 6 | Localized material growth by a dielectric barrier discharge显示文摘 | JIANG Nan QIAN Shengfa WANG Long | 2001 | Thin Solid Films2001，390，： | 1 |
| 7 | Deter- mining the Existence of the Fine Sediment Floccula- tion in the Three Gorges Reservoir显示文摘 | Li Weniie Wang Jie Yang Shengfa | 2015 | Journal of Hydraulic Engineering2015，14，05： | 1 |
| 8 | Localized material growth by a dielectric barrier discharge 显示文摘 | JIANG Nan QIAN Shengfa WANG Long | 2001 | Thin Solid Film2001，390，： | 1 |
| 9 | Transactions of Nonferrous Metals Society of China显示文摘 | Liu Shengfa Wang Huiyuan Kang Liugen | 2006 | 16(3): 4642006，16，3： | 1 |
| 10 | Finite element analysis of the electromagnetic field of untouched permanent induction magnetic coupling 显示文摘 | Yang Chaojun Wang Yuning Jiang Shengfa | 2006 | Materials Science Forum2006，，： | 1 |
| 11 | Finite ele-ment analysis of the electromagnetic field of untouchedpermanent induction magnetic coupling显示文摘 | Yang Chaojun Wang Yuning Jiang Shengfa | 2006 | MaterialsScience Forum2006，，： | 1 |
| 12 | Triplet bismuthinidenes featuring unprecedented giant and positive zero field splittings显示文摘Isolation of triplet pnictinidenes,which bear two unpaired electrons at the pnictogen centers,has long been a great challenge due to their intrinsic high reactivity.Herein,we report the syntheses and characterizations of two bismuthinidenes MsFluindtBu-Bi(3)and MsFluind*-Bi(4)stabilized by sterically encumbered hydrindacene ligands.They were facilely prepared through reductions of the corresponding dichloride precursors with 2 molar equivalents of potassium graphite.The structural analyses revealed that 3 and 4contain a one-coordinate bismuth atom supported by a Bi-C singleσbond.As a consequence,the remaining two Bi 6p orbitals are nearly degenerate,and 3 and 4 possess triplet ground states.Experimental characterizations with multinuclear magnetic resonance,magne tome try and near infrared spectroscopy coupled to wavefunction based ab initio calculations concurred to evidence that there exist giant and positive zero field splittings(>4300 cm-1)in their S=1 ground states.Hence even at room temperature the systems almost exclusively populate the lowest-energy nonmagnetic Ms=0 level,which renders them seemingly diamagnetic. | Mengyuan Wu Wang Chen Dongmin Wang Yizhen Chen Shengfa Ye Gengwen Tan | 2023 | National Science Review2023，10，10： | 0 |
| 13 | Prismatic mesh generation based on anisotropic volume harmonic field显示文摘In this paper,we present an effective prismatic mesh generation method for viscous flow simulations.To address the prismatic mesh collisions in recessed cavities or slit areas,we exploit 3D tensors controlled anisotropic volume harmonic field to generate prismatic meshes.Specially,a well-fitting tetrahedral mesh is first constructed to serve as the discrete computation domain of volume harmonic fields.Then,3D tensors are exploited to control the volume harmonic field that better fits the shape geometry.From the topological perspective,the generation of the prismatic mesh can be treated as a topology-preserved morphing of the viscous wall.Therefore,iso-surfaces in the volume harmonic field should be homeomorphic to the viscous wall while fitting its shapes.Finally,a full prismatic mesh can be induced by estimating the forward directions and visible regions in the volume harmonic field.Moreover,to be compatible with different simulation situations,the thickness of prismatic meshes should be variable.Our approach provides local adjustable thickness of prismatic meshes,which can be achieved by controlling local 3D tensors.The proposed anisotropic volume harmonic field based prismatic meshes are efficient and robust,and a full prismatic mesh can be guaranteed without low quality collisions.Various experiments have shown that our proposed prismatic meshes have obvious advantages in terms of efficiency and effectiveness. | Yiming Zhu Shengfa Wang Xiaopeng Zheng Na Lei Zhongxuan Luo Bo Chen | 2021 | Advances in Aerodynamics2021，3，1： | 0 |
| 14 | Extent and spatial distribution of terrace abandonment in China显示文摘Driven by urbanization and industrialization,arable land in hilly and mountainous regions of China is gradually becoming marginalized,with the extent of arable land abandonment rapidly expanding from poor-quality sloping arable land to high-quality terraces.The abandonment of large-scale terraces will lead to a series of socio-economic and ecological effects.A national sample survey was used to investigate the extent and spatial distribution of terrace abandonment in China,and a total of 560 valid village questionnaires from 329 counties were collected in the mountainous areas of China.The main findings are as follows:(1)The phenomenon of terrace abandonment was widespread throughout the country,with 54% of the total surveyed villages exhibiting terrace abandonment,and the area of abandoned terraces accounting for 9.79% of the total.(2) The degree of terrace abandonment is high in the south and low in the north.The most serious region with abandonment was the hilly and mountainous areas in the south,especially in the middle and lower Yangtze River region.(3)The main driving factors of terrace abandonment were rural labor migration,agricultural mechanization level,irrigation conditions,and transportation conditions for cultivation.Targeted measures should be taken based on the specific conditions of each area to alleviate terrace abandonment.Measures such as improving terrace mechanization are universally applicable.Specifically,low-quality terraces can be withdrawn orderly,and for high-quality terraces,multiple measures are needed to consolidate agricultural production,such as adjusting the planting structure,strengthening agricultural infrastructure construction,and encouraging the transfer of land-use rights as well as large-scale operation. | DONG Shijie XIN Liangjie LI Shengfa XIE Hualin ZHAO Yuluan WANG Xue LI Xiubin SONG Hengfei LU Yahan | 2023 | Journal of Geographical Sciences2023，33，7： | 0 |
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