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Simultaneous phosphorus and nitrogen removal in a continuous-flow two-sludge system

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Journal of Environmental Sciences 2006年第1期18卷 52-57页

作者： LI Xiang-kun HUANG Rong-xin BAO lin-lin shao Chun-hong ZHANG Jie School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs （phosphorus accumulating organisms） in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio （C/N）. Furthermore the SRT （sludge retention time） of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%, 75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR （bypass sludge flow rate） should be controlled at 0.35 around.

关键词： continue-flow two-sludge system denitrification phosphorus removal nitrification contact oxidation

HSE training matrices templates for grassroots posts in petroleum and petrochemical enterprises

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Petroleum Science 2017年第3期14卷 560-569页

作者： shao-lin Qiu Lai-Bin Zhang Mu Liu China University of Petroleum (Beijing) Beijing 102249China CNPC Research Institute of Safety and Environment Technology Beijing 102206 China

This paper aims to standardize health, safety and environment（HSE） training matrices for effectively identifying training requirements and enhancing job competency of grassroots posts in petroleum and petrochemical enterprises. After an investigation into HSE training performance in petroleum and petrochemical enterprises, HSE training matrices templates for 239 grassroots posts involving 22 primary petroleum and petrochemical disciplines were developed based on the technical requirements of HSE training matrices templates and the studies of template development processes and technical methods at grassroots level. Applications of these templates in 12 companies demonstrate their effectiveness in improving HSE training and management for grassroots posts,strengthening risk control and promoting the application of HSE system and tools in grassroots units.

关键词： Petroleum and petrochemical enterprise Grassroots posts HSE Training matrices Template

Parameters inversion of high central core rockfill dams based on a novel genetic algorithm

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Science China(Technological Sciences) 2016年第5期59卷 783-794页

作者： ZHOU Wei LI shao lin MA Gang CHANG Xiao lin MA Xing ZHANG Chao State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Changjiang Institute of Survey Planning Design and Research

Parameters identification of rockfill materials is a crucial issue for high rockfill dams. Because of the scale effect, random sampling and sample disturbance, it is difficult to obtain the actual mechanical properties of rockfill from laboratory tests. Parameters inversion based on in situ monitoring data has been proven to be an efficient method for identifying the exact parameters of the rockfill. In this paper, we propose a modified genetic algorithm to solve the high-dimension multimodal and nonlinear optimal parameters inversion problem. A novel crossover operator based on the sum of differences in gene fragments(So DX) is proposed, inspired by the cloning of superior genes in genetic engineering. The crossover points are selected according to the difference in the gene fragments, defining the adaptive length. The crossover operator increases the speed and accuracy of algorithm convergence by reducing the inbreeding and enhancing the global search capability of the genetic algorithm. This algorithm is compared with two existing crossover operators. The modified genetic algorithm is then used in combination with radial basis function neural networks(RBFNN) to perform the parameters back analysis of a high central earth core rockfill dam. The settlements simulated using the identified parameters show good agreement with the monitoring data, illustrating that the back analysis is reasonable and accurate. The proposed genetic algorithm has considerable superiority for nonlinear multimodal parameter identification problems.

关键词： rockfill dam parameters back analysis genetic algorithm crossover operator sum of differences in gene fragments

A Bio-Inspired Hopping Kangaroo Robot with an Active Tail

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Journal of Bionic Engineering 2014年第4期11卷 541-555页

作者： Guan-Horng Liu Hou-Yi lin Huai-Yu lin shao-Tuan Chen Pei-Chun lin Department of Mechanical Engineering National Taiwan University Taipei 106 Taiwan

Inspired by kangaroo＇s locomotion, we report on developing a kangaroo-style hopping robot. Unlike bipeds, quadrupeds, or hexapods which altemate the legs for forward locomotion, the kangaroo uses both legs synchronously and generates the forward locomotion by continuous hopping behavior, and the tail actively balances the unwanted angular momentum generated by the leg motion. In this work, we generate the Center of Mass （CoM） locomotion of the robot based on the reduced-order Rolling Spring Loaded Inverted Pendulum （R-SLIP） model, for matching the dynamic behavior of the empirical robot legs. In order to compensate the possible body pitch variation, the robot is equipped with an active tail for pitch variation compensation, emulating the balance mechanism of a kangaroo. The robot is empirically built, and various design issues and strategies are addressed. Finally, the experimental evaluation is executed to validate the performance of the kangaroo-style robot with hopping locomotion.

关键词： legged robot kangaroo hopping SLIP tail

Fatigue crack growth of titanium alloy joints by electron beam welding

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Rare Metals 2014年第5期33卷 516-521页

作者： Hong-Yu Qi Hao Shi shao-lin Li Xiao-Guang Yang School of Jet Propulsion Beijing University of Aeronautics and Astronautics

Electron beam welding（EBW） has been widely used in the manufacture of titanium alloy welded blisk for aircraft engines. Based on fatigue crack growth tests on titanium alloy electron beam welding（EBW） joints, mechanism of fracture was investigated under scanning electron microscope（SEM）. The results show that fatigue crack growth rate increases as the experimental load increases under the same stress ratio and stress intensity factor range. At the beginning of crack growth, the extension mechanism of fatigue crack is the typical mechanism of cleavage fracture. In the steady extention stage, crack extends along the weld seam ***, crack growth direction changes to extend along the base metal. The extension mechanism of fatigue crack in the weld seam is the main mechanism of cleavage fracture and the extension mechanism of fatigue crack in the base metal is the main extension mechanism of fatigue band. In the instantaneous fracture stage, the extension mechanism of fatigue crack is the typical dimple-type static fracture *** growth was simulated by conventional finite element method and extended finite element method.

关键词： Microforming Ti–6Al–4V alloy Electron beam welding Fatigue crack growth Fracture analysis

Effect of strata restraint on seismic performance of prefabricated sidewall joints in fabricated subway stations

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Frontiers of Structural and Civil Engineering 2023年第5期17卷 763-779页

作者： Hua-Fei HE Zhao-Ping LI shao-lin MA Xiang-Yang CUI School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China

A disadvantage of the conventional quasi-static test method is that it does not consider the soil restraint effect.A new method to test the seismic performance of prefabricated specimens for underground assembled structures is proposed,which can realistically reflect the strata restraint effect on the underground *** work combined with finite element(FE)analysis is performed in this *** full-scale sidewall specimens with different joint forms are designed and *** related to the seismic performance and damage modes are analyzed comprehensively to reveal the mechanism of the strata restraint effect on the prefabricated sidewall *** results show that the strata restraint effect effectively improves the energy dissipation capacity,load-bearing capacity,and the recoverability of the internal deformation of the precast sidewall ***,the strata restraint effect reduces the ductility of the precast sidewall components and aggravates the shear and bending deformations in the core region of the connection ***,the strata restraint effect significantly affects the seismic performance and damage mode of the prefabricated sidewall *** FE model that can be used to conduct a seismic performance study of prefabricated specimens for underground assembled structures is proposed,and its feasibility is verified via comparison with test data.

关键词： underground structures precast sidewall specimen seismic test method bearing capacity energy dissipation capacity plastic deformation

High-temperature oxidation behavior of DZ125 Ni-based superalloy under tensile stress

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Rare Metals 2022年第12期41卷 4188-4193页

作者： Hong-Yu Qi Xiao-Bo Liang shao-lin Li Xiao-Guang Yang School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China

The key in antioxidant capacity of aero-engine hot components is the protective oxide *** factors can affect the performance of oxide *** effect of tensile stress on high-temperature oxidation behavior of directionally solidified DZ125 Ni-based superalloy was investigated by thermogravimetric analysis(TGA).Tensile samples were subjected to stress of 100 MPa,and the oxidation behavior was studied at 980℃in *** surface and cross-sectional morphologies of the oxidized coating were analyzed by scanning electron microscope(SEM).The influence of tensile stress on the oxidation behavior of directionally solidified DZ125 Ni-based superalloy at high temperature was *** show that an applied tensile stress generally leads to larger Cr/Ni mass ratio in the oxide scales,greater overall chromium depletion values directly under the oxide scales,lower specific weight gain values and thinner oxide *** factors are attributed to the formation of fast diffusion paths for Cr atoms to diffuse to the surface under tensile stress,thus causing a reduction in the duration of the less protective transient oxidation period and promoting a faster formation of the protective Cr_(2)O_(3)layer.

关键词： DZ125 Ni-based superalloy High-temperature oxidation Tensile stress Diffusion

Thermodynamic property of ternary compound MgCaSi: A study from ab initio Debye-Grüneisen model

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Chinese Journal of Chemical Engineering 2021年第12期34卷 315-322页

作者： Rui Wu Ya-Ping Wang lin shao Wei Wang Bi-Yu Tang School of Chemistry and Chemical Engineering Guangxi UniversityNanning 530004China Institute of Biological Manufacturing Technology Co.Ltd Guangxi Institute of Industrial TechnologyNanning 530022China

The thermodynamic properties of Mg Ca Si and its mother phase Ca2 Si are comparatively investigated from ab initio calculations and quasi-harmonic Debye-Grüneisen model. At 0 K, Mg Ca Si is more thermodynamically stable. Under high temperature, the advantage of higher thermodynamically stability of Mg Ca Si is reduced, originating from the less negative entropy contribution because the thermodynamic entropy of Mg Ca Si increases more slowly with temperature and the entropy values are slightly *** increasing temperature, the anti-softening ability for Mg Ca Si is slightly smaller due to the slightly faster decrease trend of bulk modulus than that of Ca2 Si, although the bulk modulus of Mg Ca Si is higher in the whole temperature range considered. The thermal expansion behaviors of both Mg Ca Si and Ca_(2)Si exhibit similar increase trend, although thermal expansion coefficient of MgCaSi is slightly lower and the increases is slightly slower at lower temperature. The isochoric heat capacity CVand isobaric heat capacity CPof MgCaSi and Ca_(2)Si rise nonlinearly with temperature, and both CVare close to the Dulong–Petit limit at high temperature due to the negligibly small electronic contribution. The Debye temperature of both phases decrease with increasing temperature, and the downtrend for Mg Ca Si is slightly ***, MgCaSi possess slightly higher Debye temperature, implying the stronger chemical bonds and higher thermal conductivity than the mother phase Ca_(2)Si. The Grüneisen parameter of MgCaSi and Ca_(2)Si increase slightly with temperature, the values of MgCaSi are slightly larger. The investigation of electronic structures shows that with substitution of partial Ca by Mg in Ca_(2)Si, the stronger MgASi,MgACa and SiASi covalent bonds are formed, and plays a very significant role for the structural stability and mechanical properties.

关键词： MgCaSi alloys Density functional theory Thermodynamic properties Structural stabilities Quasi-harmonic Debye-Grüneisen model

linear Connectivity, Schwarz–Pick Lemma and Univalency Criteria for Planar Harmonic Mapping

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Acta Mathematica Sinica,English Series 2016年第3期32卷 297-308页

作者： shao lin CHEN Saminathan PONNUSAMY Antti RASILA Xian Tao WANG Department of Mathematics and Computational Science Hengyang Normal University Indian Statistical Institute (ISI) Chennai CentreSETS (Society for Electronic Transactions and Security)MGR Knowledge CityCIT Campus Department of Mathematics and Systems Analysis Aalto University Department of Mathematics Shantou University

In this paper, we first establish a Schwarz-Pick lemma for higher-order derivatives of planar harmonic mappings, and apply it to obtain univalency criteria. Then we discuss distortion theorems, Lipschitz continuity an... 详细信息

关键词： Harmonic mapping linearly connected domain Schwarz-Pick lemma a-close-to-convex function John constant univalency