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Journal of Environmental Sciences 2023年第7期129卷 79-89页

作者： Yong He xiangyu wang Zhaobin Zhang College of Urban and Environmental Sciences Peking UniversityBeijing 100871China

Sediment core is the recorder of polycyclic aromatic hydrocarbon(PAH)pollutions and the associated sedimentary organic matter(SOM),acting as crucial supports for pollution control and environmental ***,the sedimentary records of PAHs and SOM in the past century in Lake Taihu,China,were reconstructed from a 50-cm sediment *** the one hand,the presence of PAHs ranged from 8.99 to 199.2 ng/***,PAHs declined with the depth increased,and the sedimentation history of PAHswas divided into two stages with a discontinuity at 20 cm *** composition,PAHs in the sediment core were dominated by three-ring PAHs(44.6%±9.1%,mean±standard deviation),and were followed by four-ring(27.0%±3.3%),and five-ring(12.1%±4.0%)*** toxicity assessment,the sedimentary records of benzo[a]pyrene-based toxic equivalency were well described by an exponential model with R-square of 0.95,and the environmental background toxic value was identified as 1.62 ng/*** the other hand,different components of SOM were successfully identified by n-alkanemarkers(p<0.01)and the variations of SOMwerewell explained(84.6%).A discontinuity of SOM was recognized at 22 cm *** study showed that the sedimentary PAHs were associated with both anthropogenic and biogenic SOM(p<0.05)with explained variances for most individual PAHs of 60%.It indicated the vertical distributions of PAHs were driven by sedimentary ***,environmental processes such as biogenic factors should attract more attentions as well as PAH emissions to reduce the impacts of PAHs.

关键词： Polycyclic aromatic hydrocarbons (PAHs) N-alkanes Sedimentary records Composition Toxicity assessment Lake Taihu

Advanced purification and comprehensive utilization of yellow phosphorous off gas

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Frontiers of Environmental Science & Engineering 2015年第2期9卷 181-189页

作者： Ping NING xiangyu wang Faculty of Environmental Science and Engineering Kunrning University of Science and Technology Kunming 650500 China

Yellow phosphorous is an important raw material in the chemical industry. However, during the production of yellow phosphorous, high concentrations of carbon monoxide and other impurities are released. Without appropriate purification and removal, this off gas has potential to cause severe pollution problems once released. Purified yellow phosphorous off gas can be beneficially reused as a raw material in chemical production for synthesis of high value-added chemical reagents. In this paper, the significance of purification and reutilization of yellow phosphorous off gas are explored. The principles, processes, and main characteristics of the technologies for purification and reuse of yellow phosphorus off gas （including technical measurements of impurity reduction, relevant engineering cases, and public acceptance of the technologies） are summarized. In view of the existing problems and scientific development require- ments, this paper proposes green production based several recommendations for on the concept of recycle economics. We conclude that advanced purification and comprehensive reutilization can be an effective solution for heavy pollution resulting from yellow phosphorous off gassing.

关键词： yellow phosphorous off gas purification,comprehensive utilization

Enhancement of laminar flow heat transfer with single/doubleinclined ribs for unilaterally-heated channel

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Science China(Technological Sciences) 2023年第7期66卷 2108-2118页

作者： wang xiangyu XU XiangHua LIANG XinGang School of Aerospace Engineering Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationTsinghua UniversityBeijing 100084China

To deal with the aerodynamic heating on the aircraft surface,a potential solution is to utilize liquid cooling via the channels in part of the *** is a typical problem of flow and heat transfer in channels with unilaterally-heated *** enhancement of heat transfer in the channel is significant due to the high heating *** optimal velocity and temperature fields are obtained first based on the field synergy optimization *** rib configurations are proposed to produce the longitudinal vortices suggested by the optimal velocity *** flow and heat transfer characteristics of different rib configurations are obtained by numerical *** numerical simulations show that the heat transfer enhancement of the rib configurations are quite different,but the pressure drop increases similarly in the laminar flow range of Re = 500–*** mechanism of heat transfer enhancement with the single/double-inclined ribs for the unilaterally-heated channel is *** best enhancement of geometric parameter among the investigated parameters such as the angle,length,radius and the spacing of the ribs is obtained.

关键词： heat transfer enhancement field synergy optimization inclined ribs unilaterally-heated channel

Role of viscous heating in entransy analyses of convective heat transfer

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Science China(Technological Sciences) 2020年第10期63卷 2154-2162页

作者： CHENG XueTao wang xiangyu LIANG XinGang Department of Science and Technology of Anhui Province Hefei 230091China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education School of AerospaceTsinghua UniversityBeijing 100084China

The entransy theory is widely used and found to be effective in thermal analyses and *** researchers considered the entransy variation due to viscous heating as part of entransy dissipation and analyzed convective heat transfer based on the differential relationship between entropy and ***,it has been pointed out that the derivation of the differential relationship between entropy and entransy is *** this paper,the convective heat transfer processes with viscous heating is reconsidered and analyzed from the viewpoint of the energy conservation and the entransy balance *** is shown that the influence of the viscous heating is equivalent to that of an inner heat ***,the contribution of viscous heating to system entransy should not be treated as part of entransy dissipation,but entransy flow into the ***-stream parallel and counter flow heat exchangers with viscous heating and a thermal insulation transportation problem of heavy oil are taken as examples to verify the theoretical analyses *** the examples,the numerical results show that the entransy dissipation rates could be negative when the influence of the viscous heating on the system entransy is treated as part of the entransy *** is obviously ***,when the entransy contribution from the viscous heating to the system entransy is treated as entransy flow into the system,it is shown that the entransy dissipation rate is always positive,and the heat transfer processes can be well explained with the entransy theory.

关键词： entransy dissipation viscous heating convective heat transfer thermal analyses

Mission-oriented cooperative 3D path planning for modular solar-powered aircraft with energy optimization

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Chinese Journal of Aeronautics 2022年第1期35卷 98-109页

作者： xiangyu wang Yanping YANG Dong wang Zijian ZHANG The Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Army Academy of Artillery and Air Defense Hefei 230031China

Modular Solar-Powered Aircraft(M-SPA)is a kind of High-Altitude Long-Endurance(HALE)aircraft which exploits the mission advantage of swarm UAV and the HALE advantage of large aspect-ratio SPA.M-SPA’s separated mode and combined mode give it the potential to maximize the mission efficiency with limited solar *** this paper,firstly,oriented by the mission of maximizing the cruise area,the overall design of the M-SPA is modeled,including the energy model,the aerodynamic model and the flight environment ***,by analyzing the energy consumption of the flight modes,we design a multi-phase flight mission ***,a 24-hour three-dimensional(3D)flight profile of the M-SPA is optimized,including the sub-SPA cooperative path planning in the separation ***,inspired by the Traveling Salesman Problem(TSP),an improved Ant Colony Algorithm(ACA)is exploited to find the optimal path for each sub-SPA,which is further developed into a dynamic separation and combination scheme for the *** simulation results show that the mission performance of the M-SPA outperforms that of the conventional SPA,and explicitly,the mission coverage of the M-SPA is slightly less than a linear increase under comparable simulation conditions.

关键词： 3D path planning Ant colony optimization Energy optimization Modular Solar-Powered Aircraft(M-SPA) Separated and combined strategy

Reliability-based robust geotechnical design of braced excavations considering multiple failure modes

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Underground Space 2023年第2期9卷 43-52页

作者： Li Hong xiangyu wang Wengang Zhang School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing 400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing 400045China School of Design and the Built Environment Curtin UniversityBentley 6102Western AustraliaAustralia

Reliability design of braced excavation is still a challenge for geotechnical *** design is a normal method to control the safety and cost of braced *** study presents an advanced reliability-based robust geotechnical design method,which can consider multiple failures and uncertainty of statistical information.A universal design sample was conducted to verify the necessity of considering the uncertainty of statistical *** limit state and serviceability limit state of braced excavations were defined,and point estimating method was used to evaluate the standard deviation of failure ***-objective and three-objective optimization models were developed to illustrate the application of proposed methods in *** addition,the performance of optimization algorithms and further application of multiple-objective models were *** results from this study indicate that the proposed method has a good performance in determining the optimal design with reasonable robustness and *** algorithms have higher efficiency in solving nonlinear and multiple-objective optimization problems than the 2nd Non-dominated sorting genetic *** study can guide the design of retaining systems of braced excavations in clay.

关键词： Robust geotechnical design Multi-objective optimization Multiple failure modes Genetic algorithm Statistical uncertainty

Novel synthesis of aluminum hydroxide gel-coated nano zero-valent iron and studies of its activity in flocculation-enhanced removal of tetracycline

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Journal of Environmental Sciences 2020年第3期32卷 194-205页

作者： xiangyu wang Binbin Zhang Jun Ma Ping Ning Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China School of Environment Harbin Institute of TechnologyHarbin 150090China

A newly designed aluminum hydroxide gel-coated nanoscale zero-valent iron(AHG@NZVI)with enhanced activity and dispersibility of NZVI was successfully *** AHG@NZVI composite was synthesized via control of the surface AHG ***@NZVI-1,AHG@NZVI-2 and AHG@NZVI-3 were prepared under centrifugal mixing speeds of 1000,2000 and 4000 r/min,*** activity of AHG@NZVI was evaluated by its tetracycline(TC) removal *** effects of AHG content,pH value,reaction temperature,and presence of competitive anions on TC removal were *** could be removed by both adsorption and chemical reduction on AHG@NZVI-2(centrifugal speed 2000 r/min) in a short time with high removal efficiency(≥98.1%) at the optimal *** excellent performance can be attributed to a synergistic interaction between aluminum hydroxide gel and NZVI:(1) AHG could enhance the stability and dispersity of NZVI;(2) aluminum hydroxide gel could absorb a certain amount of TC and Fe^2+/Fe^3+,which facilitated the mass transfer of TC onto the NZVI surface,resulting in acceleration of the reduction rate of TC by the AHG@NZVI composite;and(3) AHG-Fe^2+/Fe^3+could absorb a certain amount of TC by *** kinetics of TC removal by AHG@NZVI composite was found to follow a two-parameter pseudo-first-order *** presence of competitive anions slightly inhibited the activity of AHG@NZVI systems for TC ***,this study provides a promising alternative material and environmental pollution management option for antibiotic wastewater treatment.

关键词： Nanoscale zerovalent iron Aluminum hydroxide gel Synergistic effect Tetracycline Flocculation

Numerical investigation of co-flow jet airfoil with parabolic flap

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Chinese Journal of Aeronautics 2023年第5期36卷 78-95页

作者： Ruochen wang Xiaoping MA Guoxin ZHANG Pei YING xiangyu wang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100049China

Both the Active Flow Control(AFC)and the variable-camber technology are considered as efficient ways to enhance the aerodynamic performance of an *** present study investigated the feasibility of the combination of a Co-Flow Jet(CFJ)airfoil and a parabolic flap,where the Reynolds Average Navier-Stokes(RANS)equations and the Spalart-Allmaras(S-A)turbulence model were exploited for the numerical *** significant geometric parameters,including the injection slot location,the suction slot location,the injection slot angle,the suction slot angle and the airfoil Suction Surface Translation(SST),were selected to study their effects on the aerodynamics of the proposed ***,an optimized design was created and compared with the baseline *** results show that the CFJ airfoil combined with the parabolic flap is more beneficial to the aerodynamic performance enhancement at small angles of *** is preferable to locate the injection slot at a 2%chord-wise location and the suction slot at a 75%chord-wise *** the decrease of the injection slot angle and the augmentation of the suction slot angle could reduce the ***,the SST of 0.5%chord is selected due to its high gain in the corrected aerodynamic efficiency at small angles of *** with the baseline,the optimized design could increase the lift coefficient and the corrected lift-to-drag ratio by 32.1%and 93.8%respectively at the angle of attack a=4°.

关键词： Active flow control Aerodynamic performance Co-flow jet Parabolic flap Variable-camber technology

Research on Energy Efficiency Characteristics of Mining Shovel Hoisting and Slewing System Driven by Hydraulic-Electric Hybrid System

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Chinese Journal of Mechanical Engineering 2023年第6期36卷 197-211页

作者： xiangyu wang Lei Ge Yunhua Li Long Quan College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in ***,substantial energy waste occurs during the descent of the hoisting system or the deceleration of the slewing *** reduce the energy loss,an innovative hydrau-lic-electric hybrid drive system is proposed,in which a hydraulic pump/motor connected with an accumulator is added to assist the electric motor to drive the hoisting system or slewing platform,recycling kinetic and potential *** utilization of the kinetic and potential energy reduces the energy loss and installed power of the min-ing ***,the reliability of the mining shovel pure electric drive system also can be *** this paper,the hydraulic-electric hybrid driving principle is introduced,a small-scale testbed is set up to verify the feasibil-ity of the system,and a co-simulation model of the proposed system is established to clarify the system operation and energy *** test and simulation results show that,by adopting the proposed system,compared with the traditional purely electric driving system,the peak power and energy consumption of the hoisting electric motor are reduced by 36.7%and 29.7%,***,the slewing electric motor experiences a significant decrease in peak power by 86.9%and a reduction in energy consumption by 59.4%.The proposed system expands the application area of the hydraulic electric hybrid drive system and provides a reference for its application in over-sized and super heavy equipment.

关键词： Mining shovel Hoisting and slewing system Hydraulic-electric hybrid drive Energy saving

Concentration-dependent Morphology Control of Pt-coated-Ag Nanowires and Effects of Bimetallic Interfaces on Catalytic Activity

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Journal of Materials Science & Technology 2016年第1期32卷 41-47页

作者： Yongguang wang xiangyu wang Bo Sun Shaochun Tang Xiangkang Meng Institute of Materials Engineering National Laboratory of Solid State Microstructuresand College of Engineering Applied SciencesNanjing University

Silver nanowires （NWs） coated with platinum （Pt） nanoparticles were synthesized via a galvanic partial replacement of Ag NWs in an aqueous K2PtC16 solution at room temperature. The products were char- acterized using a combination of electron microscopies, selected area electron diffraction, energy- dispersive X-ray mapping and X-ray diffraction. The surface morphology and Pt/Ag composition ratios are controlled by adjusting the K2PtC16 concentration. Different concentrations result in various surface morphologies including rough nanoparticle coating, porous and relatively smooth surfaces. The forma- tion mechanism was discussed based on the lattice constants＇ difference, concentration driven nucleation, consumption of Ag NWs, and stoichiometry of the replacement reaction. The effects of the bimetallic interface on the catalytic activity toward the reduction of 4-nitrophenol by sodium borohydride were studied. The activity of Ag-Pt NWs is highly enhanced over monometallic nanostructures, and opti- mized by a low Pt loading of 1.34 at.%, which indicates a catalytic role of the inter-metallic interface for the elecrrnn transfer.

关键词： Nanowires silver-platinum Catalytic activity Bimetallic interfaces