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China Geology 2019年第1期2卷 110-111页

作者： Jie Liang Jian-wen Chen Yin-guo Zhang guang-xi ou Peng-hui Zhang Yong Yuan Qingdao Institute of Marine Geology China Geological SurveyMinistry of Natural ResourcesQingdao 266071China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China Beijing Research Institute of Uranium Geology Beijing 100029China College of Oceanography Hohai UniversityNanjing 210098China

*** Fluid inclusions are the only way to obtain the volatile components in the process of hydrocarbon accumulation. The Marine Paleozoic strata in the South Yellow Sea Basin are of great thickness and widely distributed. The Lower Paleozoic source rocks, reservoirs and caprocks are developed and have generally good hydrocarbon geological conditions.

关键词： evidence inclusion hydrocarbon

Influences of cavity leakage on the design of low flow coefficient centrifugal impeller

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Science China(Technological Sciences) 2011年第2期54卷 311-317页

作者： WANG ZhiHeng xi guang School of Energy and Power Engineering Xi 'an Jiaotong University Xi'an 710049 China

The low flow coefficient centrifugal impeller(LFCCI)gives a relatively low efficiency and a special treatment is required for the design of this kind of *** paper investigates the influences of cavity leakage on the performance prediction and design of LFCCI based on Computational Fluid Dynamics(CFD)*** results show that,the reduction in the effi-ciency of impeller due to the introduction of cavity leakage varies with the blade shape of impeller in a wide range since there is a strong and complex interaction of main flow and leakage flow in the *** get a credible optimization result,the backside and foreside cavities should be considered in the CFD-based design of LFCCI.

关键词： cavity leakage optimization design low flow coefficient impeller

The effects of gas models on the predicted performance and flow of a centrifugal refrigeration compressor stage

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Science China(Technological Sciences) 2008年第8期51卷 1160-1168页

作者： WANG ZhiHeng xi guang School of Energy and Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

In this paper three perfect gas models with constant specific heat or with variable specific heat and one real gas model based on the gas property tables are respec- tively considered to implement into the three-dimensional CFD (computational fluid dynamics) analysis of a centrifugal refrigeration compressor stage. The results show that the gas models applied to the CFD code have significant influences on the performance of stage and the flow structures in the stage. Although the ther- modynamics operating condition of evolving fluid in the centrifugal refrigeration compressor has a significant deviation from the perfect gas, the perfect gas model with the modified value of gas constant and the variable specific heat offers a good prediction of stage performance. To predict some basic fluid flow parameters and flow structure accurately, the real gas effects should be considered and the rea- sonably accurate thermodynamic properties based on the analytical gas equation of state or numerical interpolation of gas tables should be applied to the CFD code.

关键词： gas model numerical analysis centrifugal refrigeration compressor

Biomass Inspired Nitrogen Doped Porous Carbon Anode with High Performance for Lithium Ion Batteries

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Chinese Journal of Chemistry 2016年第7期34卷 727-732页

作者： Junke ou Lin Yang xianghui xi School of Basic Medical Sciences & Nursing Chengdu University Chengdu Sichuan 610106 China College of Chemical Engineering Sichuan University Chengdu Sichuan 610064 China

Ginkgo leave, a naturally abundant resource, has been successfully employed as the raw material to prepare ni- trogen doped porous carbon （NDPC） materials. The preparation of the porous carbon does not involve assistance of any activation or template technique. The as-obtained NDPC shows favorable features for electrochemical energy storage, which can not only provide multiple sites for the storage and insertion of Li ions, but also facilitate rapid mass transport of electrons and Li ions. As a result, the NDPC when evaluated as an anode material for lithium ion batteries delivers high reversible capacity （505 mAh·g-1 at 0.1 C）, excellent rate capability （190 mAh·g-1 at 10 C）. These favorable properties suggest that the NDPC can be a promising anode material for lithium ion batteries （LIBs）.

关键词： Ginkgo leave abundant porous carbon reversible capacity promising

SIMULATION OF HYDRAULIC TRANSIENTS IN HYDROPOWER SYSTEMS USING THE 1-D-3-D CouPLING APPROACH

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Journal of Hydrodynamics 2012年第4期24卷 595-604页

作者： ZHANG xiao-xi CHENG Yong-guang State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

Although the hydraulic transients in pipe systems are usually simulated by using a one-dimensional （l-D） approach, local three-dimensional （3-D） simulations are necessary because of obvious 3-D flow features in some local regions of the hydropower systems. This paper combines the 1-D method with a 3-D fluid flow model to simulate the Multi-Dimensional （MD） hydraulic transients in hydropower systems and proposes two methods for modeling the compressible water with the correct wave speed, and two strategies for efficiently coupling the 1-D and 3-D computational domains. The methods are validated by simulating the water hammer waves and the oscillations of the water level in a surge tank, and comparing the results ~with the 1-D solution data. An MD study is conducted for the transient flows in a realistic water conveying system that consists of a draft tube, a tailrace surge tank and a tailrace tunnel. It is shown that the 1-D-3-D coupling approach is an efficient and promising way to simulate the hydraulic transients in the hydropower systems in which the interactions between 1-D hydraulic fluctuations of the pipeline systems and the local 3-D flow patterns should be considered.

关键词： hydropower station hydraulic transients compressible water model coupling of 1-D and 3-D methods

Aerodynamic effects of impeller-diffuser axial misalignment in low-flow-coefficient centrifugal compressor

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Science China(Technological Sciences) 2015年第1期58卷 29-36页

作者： WANG ZhiHeng xi guang LIU QingFang School of Energy and Power Engineering Xi'an Jiaotong University School of Mathmatics and Statistics Xi'an Jiaotong University

A numerical investigation on the aerodynamic effects of impeller-diffuser axial misalignment in the low-flow-coefficient centrifugal compressor is conducted through three-dimensional CFD *** results show that the flow,especially near the diffuser inlet,is influenced by the axial misalignment *** the impeller offsets to one side,the pressure at diffuser inlet close to this side will descend,and the vortex in the cavity on the other side will partially enter the diffuser and then result in the back *** performances of the stage and its components also change with the impeller-diffuser axial *** exists an optimum offset making the efficiency maximum at a given operating ***,the effect of impeller-diffuser axial misalignment on the axial thrust is *** axial thrust is nearly increased linearly with the increase of axial *** aerodynamic effects of impeller-diffuser axial misalignment in the low-flow-coefficient centrifugal compressor behaves more remarkably at the large flow *** alleviate the aerodynamic effects of impeller-diffuser misalignment,a rounding in the meridional plane at the diffuser inlet can be applied.

关键词： misalignment compressor low flow coefficient impeller

Unsteady flow structures in the tip region for a centrifugal compressor impeller before rotating stall

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Science China(Technological Sciences) 2017年第6期60卷 924-934页

作者： ZHAO HuiJing WANG ZhiHeng xi guang School of Energy and Power Engineering Xi 'an Jiaotong University Xi'an 710049 China

To get an insight into the occurrence and the mechanism of flow unsteadiness in the tip region of centrifugal compressor impellers, the flow in Krain’s impeller is investigated by using both steady and unsteady RANS solver techniques. It is found that the flow unsteadiness on the pressure side is much stronger than that on the suction side. The periodical frequency of the unsteady flow is around half of the blade passing frequency. The originating mechanism of the flow unsteadiness is illustrated with the time-dependent tip leakage flow and blade loading at the tip region. Due to the blockage caused by the joint effects of broken-downed tip leakage vortex, separated fluids and tip leakage flow at downstream, a low pressure region is formed on the pressure side, consequently the blade loadings is altered. In turn, the changed blade loadings will alter the intensity of tip leakage flow. Such alternative behavior finally results in the periodic process. By comparing the calculated flow field in the cases of single-passage and four-passage models, it is confirmed that the investigated flow unsteadiness is confined in each single passage, as no phase differences are found in the model of four passages. This is different from the situation in axial compressor when the rotating instability is encountered. The flow unsteadiness only occurs at the working conditions with small mass flow rates, and the oscillation intensity will be enhanced with the decrease of mass flow rate. When the mass flow rate is too small, the flow unsteadiness in a single passage may trigger rotating stall, as the disturbance propagates in the circumferential direction.

关键词： centrifugal compressor impeller flow unsteadiness tip leakage flow blade loading

Investigation of the spike-stall warning method using the blade passing signal

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Science China(Technological Sciences) 2018年第6期61卷 830-842页

作者： ZHAO JiaYi xi guang WANG ZhiHeng ZHAO Yang School of Energy and Power Engineering Xi＇an Jiaotong University Xi ＇an 710049 China

The vaned-diffuser usually brings compressor instability problems under the small flow rate, for instance the spike-type rotating stall phenomenon which restricts the operation range and may cause the trouble of blade fatigue. Since it is difficult to mathematically predict the spike-type stall for its randomness, finding out a practical method to warning this stall precursor appears to be meaningful. The paper explains the relationship between the spike-type precursor and the blade passing irregularity coefficient to analyze whether this coefficient is appropriate for the spike-stall warning inside a centrifugal compressor with the vaned-diffuser. The advanced wireless measurements were conducted on a 1.5 stages test centrifugal compressor to capture the unsteady behavior progressing from the design to stall inception within the region between the impeller trailing edge(TE) and diffuser leading edge(LE). The circumferential distribution of the blade passing irregularity has been quantitatively *** steep increase of the blade passing irregularity at some "special locations", which is responsible for the onset of the spiketype precursor, is highlighted. Also, to further understand the spike precursor inside the diffuser passage corresponding to the circumferential "special location" with maximum irregularity, the high-response transient measurement within this passage is presented. With the help of full-annulus computational fluid dynamics(CFD) simulation and the mathematical model, it is proved that the blade passing irregularity precisely reflects the flow characteristics during the spike precursor, which presents the guidance for this stall warning method.

关键词： centrifugal compressor transient measurement stall warning blade passing irregularity coefficient

A superarmoured lobopodian from the Cambrian Stage 4 of southern China

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Science Bulletin 2016年第17期61卷 1372-1376页

作者： De-guang Jiao Jie Yang xi-guang Zhang Key Laboratory for Palaeobiology Yunnan University Kunming 650091 China Yunnan Vocational College of Land and Resources Kunming 650217 China

A superarmoured lobopodian Collinsium *** the Cambrian(Stage 4) Wulongqing Formation in Kunming clearly exhibits dorsal sets of sclerotized spines,suspension feeding appendages with spiniform setae,and annulated walking limbs with a terminal *** distinctive body configuration reinforces the remarkable appendage specialization associated with feeding and locomotion and overall morphological disparity in lobopodians during the Cambrian *** finding extends the geographic and stratigraphic ranges of "Collins' monster"-like lobopodians,and provides additional information for a better understanding of the cryptic stemgroup Onychophora.

关键词： Lobopodians Body architecture Functional morphology Cambrian Stage 4 Onychophora Evolution

Spin Accumulation in a Rashba Nanoribbon

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Communications in Theoretical Physics 2009年第7期52卷 159-162页

作者： FU xi ZHou guang-Hui Department of Physics Hunan Normal University Changsha 410081 China Department of Electronics and Physics Hunan University of Science and Engineering Yongzhou 425100 China

We investigate theoretically the spin accumulation in a Rashba spin-orbit coupling (SOC) nanoribbon nonadiabatically connected to a normal *** the nanoribbon and conductor are described by a hard-wall confining *** the scattering matrix approach within the effective free-electron approximation,we have calculated the out-of-plane spin accumulation in the *** is found that the spin accumulation shifts toward the two edges of nanoribbon with the increasing of propagation ***,as the Rashba SOC strength increases the spin accumulation in the nanoribbon will be enhanced and this result may suggest us a simple method to control the spin accumulation of the system by Rashba SOC strength.

关键词： nanoribbon Rashba spin-orbit coupling spin accumlation