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Water demand for ecosystem protection in rivers with hyper-concentrated sediment-laden flow

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Science china(Technological Sciences) 2004年第z1期47卷 186-198页

作者： LUO Huaming, LI Tianhong, NI Jinren & WANG Yudong Department of Environmental Engineering, Peking University, beijing 100871, china The key laboratory of Water and Sediment Sciences, ministry of education, beijing 100871, china Department of Environmental Engineering Peking University Beijing 100871 China

Sediment transport is one of the main concerns in a river system with hyper-concentrated flows. Therefore, the water use for sediment transport must be considered in study on the water demand for river ecosystem. The conventional methods for calculating the Minimum Water Demand for River Ecosystem (MWDRE) are not appropriate for rivers with high sediment concentration. This paper studied the MWDRE in wet season, dry season and the whole year under different water-and-sediment conditions in the Lower Yellow River, which is regarded as a typical river with sediment-laden flows. The characteristics of MWDRE in the river are analyzed. Firstly, the water demand for sediment transport (WDST) is much larger than the demands for other riverine functions, the WDST accounts for the absolute majority of the MWDRE. Secondly, in wet season when the WDST is satisfied, not only most of the annual incoming sediment can be transported downstream, but also the water demands for other river functions can be satisfied automatically, so that the MWDRE in wet season is identical to the WDST. Thirdly, in dry season, when the WDST is satisfied, the water demands for other river functions can also be satisfied, but the low sediment transport efficiency results in significant waste of water resources. According to these characteristics and aiming at decreasing sediment deposition in the riverbed and improving the utilization efficiency of water resources, hydrological engineering works can be used to regulate or control flow and sediment so that the sediment incoming in dry season can be accumulated and be transported downstream intensively and thus efficiently in wet season.

关键词： sediment-laden flow, the Lower Yellow River, water demand for river ecosystem, water demand for sediment transport

Emergency access mechanism in IEEE 802.15.4 for wireless body area sensor networks

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The Journal of china Universities of Posts and Telecommunications 2009年第6期16卷 24-31页

作者： GUO Yan-yan,KANG Gui-xia,CAO Yu,ZHANG Ping key laboratory of Universal Wireless Communications,ministry of education,beijing University of Posts and Telecommunications,beijing 100876,china key laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

IEEE 802.15.4 protocol has attracted much attention in research and industrial communities as candidate technology for wireless body area sensor networks（WBASNs）.IEEE 802.15.4 supports the exclusive use of a wireless channel through guaranteed time slot（GTS）.However,on one hand,bandwidth underutilization rate may be lower because of the variance between the guaranteed bandwidth and the arrival *** the other hand,the waiting time for transmitting emergency notification is getting longer when the GTSs assigned to the nodes increase in *** solve these problems,in this article,a new scheme is proposed to reduce transmission delay for the alarm notification in emergent *** results are presented to validate the efficiency of the proposed scheme by comparing it with the medium access control（MAC） protocol of IEEE 802.15.4.

关键词： WBASN GTS IEEE 802.15.4 emergency mechanism

Active-fault-alarm based pre-restoration mechanism in MPLS-TP optical network

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The Journal of china Universities of Posts and Telecommunications 2010年第3期17卷 97-103页

作者： BAI Hui-feng, LU Yue-ming, JI Yue-feng key laboratory of Information Photonics and Optical Communications, ministry of education, beijing University of Posts and Telecommunications, beijing 100876, china key laboratory of Information Photonics and Optical Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

The newly developed multi-protocol label switching transport profile （MPLS-TP） fails to actively alarm the fault in advance when conducting restoration in network, or to avoid the false-alarm when equipped with the active-fault-alarm （AFA） to support carrier-grade reliability. In order to solve this problem, a new AFA based pre-restoration mechanism （AFABPRM） is proposed for MPLS-TP controlled optical network, along with the three levels quality-of-service （QoS） based shortest path first rerouting algorithm （TQ-SPF） in this article. The AFABPRM takes full advantage of the AFA technologies, and can solve the false-alarm problem. Analytical and experimental results suggest the better performances of the new mechanism when compared restoration mechanism with or without AFA function, and show that the AFABPRM can solve the false-alarm problem efficiently.

关键词： MPLS-TP restoration AFA

Study on flow behavior and structure over chined fuselage at high angle of attack

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Science china(Technological Sciences) 2010年第8期53卷 2057-2067页

作者： TIAN Wei,DENG XueYing ,WANG YanKui,FAN GuoLei&DONG Chao ministry of education key laboratory of Fluid Mechanics,beijing University of Aeronautics and Astronautics,beijing 100191,china ministry of education key laboratory of Fluid Mechanics Beijing University of Aeronautics and Astronautics

A study of leeward vortex structure over chined fuselage and the effects of micro tip perturbation on its vortex flow have been carried out in wind tunnel experiments at Reynolds numbers from 1.26×105 to 5.04×105 with PIV and pressure measurement ***,the experiment results have proved that micro tip perturbation has no effects on the vortex flow and its aerodynamic characteristics over chined fuselage at high angle of attack,in which there are not any non-deterministic flow ***,the evolution of leeward vortex structure over chined fuselage along the axis of model can be divided into four flow regimes:linear conical developed regime,decay regime of leeward vortex intensity,asymmetric leeward vortex break down regime and completely break down *** a correlation between leeward vortex structure and sectional aerodynamic force was also revealed in the present ***,the experiment results show the behavior of leeward vortex core trajectories and zonal characteristics of leeward vortex structure with angles of ***,the experiment results of Reynolds number effect on the leeward vortex flow have further confirmed research conclusions from previous studies:the flows over chined fuselage at high angles of attack are insensitive to variation of Reynolds number,and there is a little effect on the secondary boundary layer separation and the suction peak induced by leeward vortex.

关键词： high angle of attack aerodynamics chined fuselage tip perturbation leeward vortex structure zonal characteristics

Calcitonin gene-related peptide inhibits interleukin-1β-induced interleukin-8 secretion in human type Ⅱ alveolar epithelial cells

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Acta Pharmacologica Sinica 2006年第10期27卷 1340-1345页

作者： Wen-jing LI Teng-ke WANG Xian WANG~2 Department of Physiology,School of Basic Medical Sciences,Peking University,key laboratory of Molecular Cardiovascular Science,ministry of education,beijing 100083,china Department of Physiology School of Basic Medical Sciences Peking University Key Laboratory of Molecular Cardiovascular Science Ministry of Education Beijing 100083 China

Aim:Our previous data have shown that type Ⅱ alveolar epithelial(AEⅡ)cellsexpress neuropeptide calcitonin gene-related peptide(CGRP),and that pro-in-flammatory factor interleukin 1-β(IL-1β)induces CGRP secretion in the A549 hu-man AEⅡ cell *** the present study,we investigated the effect of endogenousand exogenous CGRP on IL-1β-induced chemokine interleukin-8(IL-8)***:We used enzyme-linked immunosorbent assay(ELISA)and RT-PCR todetect IL-8 protein and mRNA levels,respectively,siRNA and the stably trans-fected cell line were used to knock down and overexpress the CGRP gene,respectively,and chemiluminescence assay was used to detect reactive oxygenspecies(ROS)***:CGRP-1 receptor antagonist hCGRP8-37(0.1-1nmol·L-1)greatly amplified IL-1β-induced IL-8 *** inhibition of CGRPexpression by siRNA significantly increased IL-8 secretion upon IL-1β ***,cell clones stably transfected with CGRP showed significantly inhibitedmRNA and protein levels of IL-8 induced by 1L-1β.Conclusion:These data implythat AEⅡ cell-derived CGRP suppress IL-1β-induced IL-8 secretion in an autocrine/paracrine *** investigation showed that CGRP attenuated IL-1β-arousedROS formation,which is an early indication of pro-inflammatory factor signaling.

关键词： type Ⅱ alveolar epithelial cells interleukinl interleukin-8 calcitonin gene-related peptide anti-inflammation lung reactive oxygen species

Paper sludge as a feasible soil amendment for the immobilization of Pb^(2+)

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Journal of Environmental Sciences 2010年第3期22卷 413-420页

作者： Xiaojia He, Lei Yao, Zhu Liang, Jinren NiThe key laboratory of Water and Sediment Sciences, ministry of education, Department of Environmental Engineering, Peking University, beijing 100871, china. The key laboratory of Water and Sediment Sciences Ministry of Education Department of Environmental Engineering Peking University Beijing 100871 China

The possibility of amending Pb 2＋ contaminated soil （S） with paper sludge （P） was investigated through adsorption and desorption experiments. The adsorption process of Pb 2＋ in soil containing paper sludge （SP） could be well described by pseudo second-order kinetic model and the Langmuir isotherm model. After P addition, the equilibrium time decreased greatly （from 28 to 8 hr） and the Pb 2＋ maximum adsorbed amount （Q max ） increased by a factor of more than three to 102.04 mg/g. Q max reached its maximum as S：P was 9：1 （m/m） after 10 days contact between S and P. Moreover, Pb 2＋ adsorbed amount increased with the rise of pH during the adsorption process. Desorption experiments indicated that Pb 2＋ adsorption in SP was irreversible. The metal ion fraction was analyzed with Energy Dispersive Spectrometer and Environmental Scan Electron Microscope. As a result, the addition of P to soil was found to induce a decrease in the mobile forms. The Pb 2＋ complexes formation in the presence of carbonates was the main adsorption mechanism. Overall, the paper sludge could be one of the promising soil amendments for the remediation of soil with Pb 2＋ contamination.

关键词： paper sludge pb^2+ adsorption

Wave tectono-sedimentary processes in Tarim basin

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Science china Earth Sciences 2005年第11期48卷 1949-1959页

作者： JIN Zhijun1,2, ZHANG Yiwei1 & CHEN Shuping1 1. key laboratory for Hydrocarbon Accumulation, ministry of education, china University of Petroleum, beijing 102249, china 2. Exploration and Production Research Institute, china Petroleum & Chemical Corporation, beijing 100083, china key laboratory for Hydrocarbon Accumulation ministry of education China University of Petroleum Beijing China Exploration and Production Research Institute China Petroleum & Chemical Corporation Beijing China

Based on the unconformities, the formation times of structures, and geological wave filtering applied to basin fills of typical wells around the Manjiaer area in the Tarim basin, the wave tectono-sedimentary processes in the Tarim Basin are discussed. The results of geological wave filtering of basin fills of typical wells show that, in time domain, the evolution of the Tarim basin was controlled by various wave processes with the periods of 740±Ma, 200±Ma, 100±Ma and 30±Ma. The analyses of basin fills, basin subsidence and unconformities show that the trends of the sedimentary facies belts, depocenters, and centers of subsidence migrated and interchanged periodically with periods of 200±Ma. These show the propagation of wave movements in space domain. The wave evolution of the Tarim basin is of significance to understanding the formation of the oil and gas reservoirs in the basin.

关键词： Tarim basin, tectonics, sedimentation, crustal undation, wave evolution

Preparation, Properties and Characterization of Modified CeO_2/La_2Zr_2O_7 Buffer Layers

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稀有金属材料与工程 2011年第S3期40卷 350-353页

作者： Cheng Yanling, Suo Hongli, Liu Min, Ma Lin, Zhang Teng key laboratory of Advanced Functional Materials, ministry of education, beijing University of Technology, beijing 100124, china beijing Univ Technol Coll Mat Sci & Engn Minist Educ Key Lab Adv Funct Mat Beijing 100124 Peoples R China

The metal organic deposition (MOD) method was used for the epitaxial growth of the CeO2/La2Zr2O7(LZO)/LZO seed layer structure on a cube-textured Ni5W substrate layer by layer. The material phase and the macro-orientations were analyzed by XRD. The surface morphology and the blocking performance of the buffer layer were investigated by SEM and AES. The grain orientation and the crystallographic growth mode of the CeO2 layer were first characterized by electron backscattering diffraction (EBSD). The uniformly distributed islanded LZO seed layer optimized both the in-plan and the out-plan orientation of the CeO2/LZO buffer layers, and the CeO2/LZO buffer layers with a thickness of 175 nm acted as an efficient Ni,W barrier. The EBSD analysis indicated that the crystallographic orientation of each layer can be obtained at various accelerating voltages for the multilayer sample, the percentage of {001} rotated cube texture of CeO2 layer reaching 97.4% at the accelerating voltage of 15 kV, thus showing epitaxial deposition with a high texture.

关键词： coated conductor buffer layer La2Zr2O7 seed layer CeO2 rotated cube texture accelerating voltage

Structures,kinematics,thermochronology and tectonic evolution of the Ramba gneiss dome in the northern Himalaya

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Progress in Natural Science:Materials International 2008年第7期18卷 851-860页

作者： Lei Guo,Jinjiang Zhang,Bo Zhang The key laboratory of Orogenic Belts and Crustal Evolution,ministry of education,china School of Earth and Space Sciences,Peking University,beijing 100871,china The key laboratory of Orogenic Belts and Crustal Evolution Ministry of Education China School of Earth and Space Sciences Peking University Beijing 100871 China

The Ramba gneiss dome,one of the north Himalayan gneiss domes,is composed of three tectono-lithologic units separated by an upper and a lower detachment ***-grade metamorphic Tethyan Himalayan sedimentary sequence formed the upper unit above the brittle upper detachment *** gneiss and a leucogranite pluton made up the lower unit beneath the ductile lower detach- ment *** middle-grade garnet-,staurolite-and andalusite-schist constituted the middle unit between the two faults,which may be that the basal part of the upper unit experienced detachment *** Ramba dome underwent three episodes of deformation in its tectonic *** first episode was a top-down-to-north-northwest sliding possibly related to the activity of the south Tibetan detachment system(STDS).The second episode was the dominant deformation related to a east–west extension,which resulted in a unique top-down-to-east kinematics and the major tectonic features of the *** third episode was a collapse sliding toward the outsides of the *** Ramba gneiss dome is possibly a result of the east–west extension and magmatic *** lower detachment fault is probably the main detachment fault separating the sedimentary sequence from the crystalline basement during the east–west extension in the dominant deformation *** diapir of the leucogranite pluton formed the doming shape of the Ramba gneiss *** pluton intruded in the core of the dome in a late stage of the dominant deformation,and its Ar–Ar cooling ages are about 6 *** indicates that the dominant deformation of the dome happened at the same time of the east–west extension represented by the north–south trending rifts throughout the northern Himalaya and southern ***,the formation of the Ramba gneiss dome should be related to this east–west extension.

关键词： Ramba gneiss dome North Himalayan gneiss domes East–west extension