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Treatment and remediation of a wastewater lagoon using microelectrolysis and modified DAT/IAT methods

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Journal of Environmental Sciences 2011年第3期23卷 388-395页

作者： Qiong Wu tao Hua Qixing zhou Tianjin Key Laboratory of Environmental Remediation and Pollution Control/Key Laboratory of Pollution Process and Environmental Criteria (Ministry of Education) College of Environmental Science and Engineering Nankai University Tianjin 300071 China Key Laboratory of Terrestrial Ecological Process Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China

To examine treatment and remediation of a wastewater lagoon with poor biodegradability, a typical wastewater lagoon in Tianjin, China, was treated and remedied using microelectrolysis and modified demand aeration tank （DAT）/intermittent aeration tank （IAT） methods. After pretreatment by microelectrolysis, the removal efficiency of chemical oxygen demand （COD） was up to 64.6% and the ratio of BOC/COD in the effluent increased from 0.013 to 0.609. The removal rates of CODcr and NH4＋-N were affected by sludge backflow rate, mixed liquor suspended solids （MLSS）, and hydraulic retention time （HRT） in the modified DAT/IAT reactor. The highest removal rates of CODcr and NH4＋-N were up to 78.9% and 62.6%, respectively, when the sludge backflow rate was 38.0 mL/min, the total HRT was 8.0 hr and MLSS was 4088.0 mg/L. In this case, some protozoa and metazoa were observed in activated sludge and biofilm carriers. Most of chrominance was removed by microelectrolysis treatment, while the modified DAT/IAT methods were more effective for CODcr and NH4＋-N removal.

关键词： wastewater lagoon biodegradability microelectrolysis DAT/IAT ecological remediation

Quantifying lateral penumbra advantages of collimated spot-scanning beam for intensity-modulated proton therapy

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Nuclear Science and Techniques 2019年第11期30卷 52-59页

作者： Chun-Bo Liu Yun-tao Song Hong-Dong Liu Hai-zhou Xue han-Sheng Feng University of Science and Technology of China Hefei 230026China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Hefei CAS Ion Medical and Technical Devices Co. LtdHefei 230088China

Intensity-modulated proton therapy(IMPT)is becoming essential for proton therapy and is under rapid ***,for IMPT,the lateral penumbra of the spot-scanning proton beam is still an urgent issue to be ***-specific block collimators(PSBCs),which can block unnecessary doses,play a crucial role in passive scattering delivery technology but are rarely used in spot *** objective of this study is to investigate the lateral penumbra variations of intensity-modulated spot scanning with and without a *** fields with varying degrees of sharpness and at varying depths in a water phantom,the lateral penumbral widths were calculated using a Monte Carlo-based dose engine from RayStation *** results suggest that the lateral penumbral widths can be reduced by more than 30%for uniform target volumes,regardless of whether a range-shifter is used,and that the maximum dose beyond the field edges can be reduced *** results of patient cases show that the doses in organs-at-risk near the edge of the target volume decrease if a PSBC is *** study demonstrates that intensity-modulated spot scanning with a PSBC can effectively reduce the lateral penumbra and block unnecessary doses and is therefore promising for clinical applications in spot-scanning proton therapy.

关键词： Lateral penumbra Patient-specific block collimator Monte Carlo Intensity-modulated proton therapy

Effect of six years of nitrogen additions on soil chemistry in a subtropical Pleioblastus amarus forest, Southwest China

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Journal of Forestry Research 2018年第6期29卷 1657-1664页

作者： Guan-tao Chen Li-hua Tu Guang-sheng Chen Jin-yao Hu zhou-lin han Ecological Security and Protection Key Laboratory of Sichuan Province Mianyang Normal University College of Forestry Sichuan Agricultural University

Soil chemistry influences plant health and carbon storage in forest ecosystems. Increasing nitrogen(N) deposition has potential effect on soil chemistry. We studied N deposition effects on soil chemistry in subtropical Pleioblastus amarus bamboo forest ecosystems. An experiment with four N treatment levels(0, 50, 150,and300 kg N ha-1a-1,applied monthly, expressed as CK,LN,MN, HN,respectively) in three replicates. After6 years of N additions, soil base cations, acid-forming cations, exchangeable acidity(EA), organic carbon fractions and nitrogen components were measured in all four seasons. The mean soil pH values in CK,LN,MN and HN were 4.71, 4.62, 4.71, and 4.40, respectively, with a significant difference between CK and HN. Nitrogen additions significantly increased soil exchangeable Al3+,EA, and Al/Ca,and exchangeable Al3+ in HN increased by 70%compared to CK. Soil base cations(Ca2+, Mg2+, K+, and Na+) did not respond to N additions. Nitrogen treatments significantly increased soil NO3--N but had little effect on soil total nitrogen, particulate organic nitrogen, or NH4~+-N. Nitrogen additions did not affect soil total organic carbon, extractable dissolved organic carbon,incorporated organic carbon, or particulate organic *** study suggests that increasing N deposition could increase soil NO3--N, reduce soil pH, and increase mobilization of Al3+. These changes induced by N deposition can impede root grow and function, further may influence soil carbon storage and nutrient cycles in the future.

关键词： Base cations Carbon fractions Nitrogen deposition Soil chemistry Soil acidification

Ultrathin Ni_(x)Co_(y)-silicate nanosheets natively anchored on CNTs films for flexible lithium ion batteries

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Journal of Energy Chemistry 2021年第3期30卷 746-753页

作者： Wenlei Guo Wenping Si tao Zhang Yonghuan han Lei Wang Ziyue zhou Pengyi Lu Feng Hou Ji Liang Key Laboratory of Advanced Ceramics and Machining Technology of the Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300072China Institute for Superconducting&Electronic Materials Australian Institute of Innovative MaterialsUniversity of WollongongInnovation CampusSquires WayNorth WollongongNSW 2500Australia

The rapid development of portable and wearable electronics has called for novel flexible electrodes with superior *** development of flexible electrode materials with excellent mechanical and electrochemical properties has become one of the key factors for this ***,a Ni_(x)Co_(y)-silicate@CNTs film is developed as a flexible anode for lithium ion batteries(LIBs).On this film,Ni_(x)Co_(y)-silicate nanosheets are firmly and intimately anchored on the surface of CNTs,which have a 3D network structure and link the adjacent nanosheets *** from this,the composite film is not only sufficient to withstand various deformations due to its excellent flexibility but also has excellent electrochemical properties,in terms of high reversible capacity of 1047 mAh g^(-1) at 0.1 A g^(-1) as well as a high rate and cycling performance(capacity retention up to 78.13% after 140 cycles).The pouch-type full flexible LIB using this material can stably operate under various bending conditions,showing the great potential of this 3 D Ni_(x)Co_(y)-silicate@CNTs film for flexible energy storage devices with high durability.

关键词： Nickel cobalt silicate Carbon nanotubes Flexible film In-situ conversion

Mechanical Properties of Interlocked-ring Polymers: A Molecular Dynamics Simulation Study

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Chinese Journal of Polymer Science 2019年第12期37卷 1298-1304,I0008页

作者： Zheng-tao Wu Jia-Jia zhou College of Engineering Zhejiang Normal UniversityJinhua 321004China School of Chemistry Beihang UniversityBeijing 100191China

Interlocked-ring polymers,also known as polycatenanes,possess an interesting molecular *** polymers are composed of many interlocked rings in a linear *** topological constrain between neighboring rings distinguishes the interlockedring polymer from its linear *** we present extensive molecular dynamic simulations on the interlocked-ring polymers and analyze the static properties of the *** applying external forces to the polymer,we also study the force-extension curves of the polymer,which provides rich information about the mechanical properties of the interlockedring polymers.

关键词： Poly catenanes Molecular dynamics simulation Force-extension Entanglement

Upper-bound limit analysis based on the natural element method

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Acta Mechanica Sinica 2012年第5期28卷 1398-1415页

作者： Shu-tao zhou Ying-Hua Liu Department of Engineering Mechanics AMLTsinghua University

The natural element method （NEM） is a newly- developed numerical method based on Voronoi diagram and Delaunay triangulation of scattered points, which adopts natural neighbour interpolation to construct trial functions in the framework of Galerkin method. Owing to its distinctive advantages, the NEM is used widely in many problems of computational mechanics. Utilizing the NEM, this paper deals with numerical limit analysis of structures made up of perfectly rigid-plastic material. According to kinematic the- orem of plastic limit analysis, a mathematical programming natural element formulation is established for determining the upper bound multiplier of plane problems, and a direct iteration algorithm is proposed accordingly to solve it. In this algorithm, the plastic incompressibility condition is handled by two different treatments, and the nonlinearity and nons- moothness of the goal function are overcome by distinguishing the rigid zones from the plastic zones at each iteration. The procedure implementation of iterative process is quite simple and effective because each iteration is equivalent to solving an associated elastic problem. The obtained limit load multiplier is proved to monotonically converge to the upper bound of true solution. Several benchmark examples are investigated to validate the significant performance of the NEM in the application field of limit analysis.

关键词： Upper bound limit analysis Meshless methodNatural neighbour interpolation Natural element methodMathematical programming Iteration algorithm

Revealing the role of calcium ion intercalation of hydrated vanadium oxides for aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第8期95卷 9-19,I0001页

作者： tao zhou Xuan Du Guo Gao Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education School of Sensing Science and EngineeringSchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Exploring suitable high-capacity V_(2)O_(5)-based cathode materials is essential for the rapid advancement of aqueous zinc ion batteries(ZIBs).However,the typical problem of slow Zn^(2+)diffusion kinetics has severely limited the feasibility of such *** this work,unique hydrated vanadates(CaVO,BaVO)were obtained by intercalation of Ca^(2+)or Ba^(2+)into hydrated vanadium *** the CaVO//Zn and BaVO//Zn batteries systems,the former delivered up to a 489.8 mAh g^(-1)discharge specific capacity at 0.1 A g^(-1).Moreover,the remarkable energy density of 370.07 Wh kg^(-1)and favorable cycling stability yard outperform BaVO,pure V_(2)O_(5),and many reported cathodes of similar ionic intercalation *** addition,pseudocapacitance analysis,galvanostatic intermittent titration(GITT)tests,and Trasatti analysis revealed the high capacitance contribution and Zn^(2+)diffusion coefficient of CaVO,while an in-depth investigation based on EIS elucidated the reasons for the better electrochemical performance of ***,ex-situ XRD,XPS,and TEM tests further demonstrated the Zn^(2+)insertion/extraction and Zn-storage mechanism that occurred during the cycle in the CaVO//Zn battery *** work provides new insights into the intercalation of similar divalent cations in vanadium oxides and offers new solutions for designing cathodes for high-capacity aqueous ZIBs.

关键词： Aqueous zinc ion batteries Cathode materials Ion pre-intercalation Vanadium oxides Energy storage mechanism

Three-dimensional numerical simulation and earth pressure analysis on double-row piles with consideration of spatial effects

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第10期12卷 758-770页

作者： Zi-han WANG Jian zhou Department of Geotechnical Engineering Tongji University Shanghai 200092 China

As a new kind of technology in retaining structures, the characteristics of double-row piles are significantly affected by spatial effects. In this paper, double-row piles as a retaining structure are simulated numerically in three-dimension by finite element software PLAXIS 3D FOUNDATION. The behavior differences of piles in different positions around the foundation pit are analyzed. By changing the parameters, including the length-width ratio, the excavation depth, the distance between rows and the diameter of piles, the variations of the lateral deformation, the bending moment and the earth pressure around the piles are determined. The reasonable values of parameters and some suggestions with consideration of earth pressure are proposed for the design of double-row piles as a retaining structure. The results show that the lateral deformation and bending moment are the largest in the middle of long side of the foundation pit, which is identified as the most unfavorable position. It is indicated that the earth pressure between rows above pit bottom is close to active earth pressure, while the earth pressure between rows under pit bottom is close to static earth pressure. It is suggested that 1/2-2/3 of pile length, 0.6-1.2 m, 3d-6d, and 2d-2.5d be chosen as embedded depth of piles, diameter of piles, distance between rows, and distance between piles, respectively, where d is the pile diameter.

关键词： Double-row piles Retaining structure Spatial effect Finite element Earth pressure

Impacts of native vegetation on the hydraulic properties of the concentrated flows in bank gullies

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Journal of Mountain Science 2021年第4期18卷 907-922页

作者： SU Zheng-an HE zhou-yao zhou tao WANG Jun-jie WANG Xiao-yi WANG Li-juan FANG Hai-dong SHI Liang-tao LIU Yi-han WU Zuo Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China Forestry College Sichuan Agricultural UniversityChengdu 611130China University of Chinese Academy of Sciences Beijing 100049China College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa’an 625014China lnstitute of Tropical Eco-agricultural Sciences Yunnan Academy of Agricultural SciencesYuanmou 651300China College of Geography and Resources Science Sichuan Normal UniversityChengdu 610101China

To quantify the impacts of native vegetation on the spatial and temporal variations in hydraulic properties of bank gully concentrated flows,a series of in situ flume experiments in the bank gully were performed at the Yuanmou Gully Erosion and Collapse Experimental Station in the dry-hot valley region of the Jinsha River,Southwest *** experiment involved upstream catchment areas withone-and two-year native grass(Heteropogon contortus)and bare land drained to bare gully headcuts,i.e.,Gullies 1,2 and *** Gully 4,Heteropogon contortus and Agave sisalana were planted in the upstream catchment area and gully bed,*** these experiments,the sediment concentration in runoff in Gully 3 was the highest and that in Gully 2 was the lowest,clearly indicating that the sediment concentration in runoff obviously decreased and the deposition of sediment obviously increased as the vegetation cover *** concentrated flows were turbulent in response to the flow *** concentrated flows in the gully zones with native grass and bare land were sub-and supercritical,*** flow rate and shear stress in Gully 3 upstream catchment area were highest among the four upstream catchment areas,while the flow rate and shear stress in the gully bed of Gully 4 were lowest among the four gully beds,indicating that native grass notably decreased the bank gully flow rate and shear *** Darcy–Weisbach friction factor(resistance f)and flow energy consumption in the gully bed of Gully 4 were notably higher than those in the other three gully beds,clearly indicating that native grass increased the bank gully surface resistance and flow energy *** Reynolds number(Re),flow rate,shear stress,resistance f,and flow energy consumption in the gully beds and upstream areas increased over time,while the sediment concentration in runoff and Froude number(Fr)***,increasing vegetation cover in upstream catchment areas and downstream gully

关键词： Soil erosion Indigenous grass species Bank gully Concentrated flows Flow energyconsumption Dry and hot valley