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Anaerobic oxidation of methane coupled to sulfate reduction: Consortium characteristics and application in co-removal of H_2S and methane

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Journal of Environmental Sciences 2019年第2期31卷 238-248页

作者： Lin Li song xue Jingru Xi State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of Sciences National Engineering Laboratory for VOCs Pollution Control Material & Technology University of Chinese Academy of Sciences State Key Laboratory of Applied Microbiology Southern China Guangdong Institute of MicrobiologyGuangdong Academy of Sciences

Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial ***-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.

关键词： Anaerobic methane oxidation Sulphate reduction Microbial population 13C isotope-labelling Potential pathway Landfill gas

Microstructure, thermophysical property and ablation behavior of high thermal conductivity carbon/carbon composites after heat-treatment

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Chinese Journal of Aeronautics 2020年第5期33卷 1541-1548页

作者： xue-song LIU Qian-Gang FU Hui WANG Qiang song State Key Laboratory of Solidification Processing Shannxi Province Key Laboratory of Fiber Reinforced Light Composite MaterialsNorthwestern Polytechnical UniversityXi'an 710072PR China

Uni-directional carbon/carbon composites with high thermal conductivity are suitable to supply continuous thermal protection for future reentry vehicles since they could reduce surface temperature and ablation rates simultaneously in harsh *** this work,the high thermal conductivity carbon/carbon composites were prepared by chemical vapor *** heat-treatment,both their open porosity and internal friction increase due to the fiber/matrix thermal expansion mismatch;while their thermal conductive performance become better due to more complete carbon *** raising heat-treatment temperature from 1800℃to 2450℃,the mass and linear ablation rates of C/C composites with fibers vertical to the oxyacetylene torch for 60 s decrease from 0.66 mg/s and 2.95μm/s to 0.51 mg/s and 2.05μm/s *** improved ablation resistance is resulted from the increased thermal conductivity from 282 to 508 W/(m·K)and more carbon fibers exposed to the flame during ablation,which have better oxidation resistance than those of carbon *** such ablation rates become larger for composites with fibers parallel to the flame,from 1.02 mg/s and 3.73μm/s to 1.28 mg/s and 5.0μm/s respectively since the ablation occurred more easily through gaps at the fiber/matrix interfaces,which become larger and are always exposed to the flame for this case.

关键词： Ablation Carbon/carbon composites Fiber orientation Heat treatment Thermal conductivity

Saturation phenomenon of Ce and Ti in the modification of Al–Zn–Si filler metal

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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 184-189页

作者： Jin-long Yang song-bai xue Wei Dai Peng xue College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Zhejiang Xinrui Welding Material Co. Ltd.

Cerium and titanium were added to an A1-42Zn-5.5Si brazing alloy, and the subsequent microstructures of the brazing alloy and the 6061 AI alloy brazing seam were investigated. The microstructures of filler metals and brazed joints were characterized by scanning elec- tron microscopy and X-ray energy dispersion spectrometry. A new Ce-Ti phase formed around the silicon phase in the modified filler metal and this saturation phenomenon was analyzed. Interestingly, following brazing of the 6061 alloy, there is no evidence of the Ce--Ti phase in the brazing seam. Because of the mutual solubility of the brazing alloy and base metal, the quantity of the solvent increases, and the solute Ce and Ti atoms assume an undersaturated state.

关键词： filler metals aluminum alloys brazing cerium titanium saturation

Thoughts of Lao Tse and Chuang Tzu in Brecht＇ s Works

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学术界 2013年第9期 274-280页

作者： xue song School of Foreign Languages Chongqing University Chongqing 401331

Brecht once concentrated on the theories of Lao Tse and Chuang Tzu,which can be discovered in some works of *** in the turbulent times,Lao Tse and Chuang Tzu had dialectical observation of the troubled society,which evoked the critical thinking of Brecht,and he began to re-interpret the Chinese philosophy in his own *** the verfremdung,in which Brecht was expert,Brecht creatively combined the theories of Lao Tse and Chuang Tzu with the seemingly irrelative western thoughts to help him to further develop his theory *** philosophically rich stories helped him to achieve the verfremdungseffekt between the audience and the plot of the play.

关键词：庄子老子作品中国哲学批判性思维辩证观

Sludge reduction with Tubificidae and the impact on the performance of the wastewater treatment process

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Journal of Environmental Sciences 2007年第3期19卷 257-263页

作者： GUO xue-song LIU Jun-xin WEI Yuan-song LI Lin Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

To reduce excess sludge, a Tubificidae reactor was combined with an integrated oxidation ditch with vertical circle （IODVC）, and a new integrated system was developed for wastewater treatment, A pilot-scale of this integrated system was tested to investigate the sludge reduction with Tubificidae and the impact on effluent quality and sludge production. The dominant worm was Branchnria Sowerbyi in the Tubificidae reactor after inoculation of Branchnria Sowerbyi and Limnodrilns sp., and the maximal volume density of wet Tubificidae in vessels of the Tubificidae reactor was 17600 g/m^3. Two operational modes, treating the excess sludge （first mode） and the returned sludge （second mode） of IODVC by the Tubificidae reactor, were used in this experiment. The results showed that the excess sludge reduction rate was 46.4% in the first mode, and the average sludge yield of the integrated system was 6.19× 10^-5 kg SS/kg COD in the second mode. Though the sludge returned to IODVC via the Tubificidae reactor, it had little impact on the effluent quality and the sludge characteristics of the IODVC. No new type of recalcitrant substance in the supernatant was discharged into the environment when the sludge was treated by Tubificidae. The experimental results also indicated that no significant changes occurred on the viscosity, specific resistance, and the floc size distribution of the sludge.

关键词： integrated wastewater treatment system sludge reduction wastewater treatment Tubificidae

Characterization of 4-Aryl-5-ethoxycarbonyl-6-methyl-3,4-dihydro-pyrimidin-2(1H)-thiones by EI-TOF Mass Spectrometry

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Chemical Research in Chinese Universities 2006年第1期22卷 40-44页

作者： LI Qian-rong xue song YIN Hao Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry University of Science and Technology of China Hefei 230026 P. R. China

The electron impact （EI） time-of-flight mass spectra （TOFMS） of the title compounds （ thioxo-Biginelli compounds） were studied to establish their fragmentation pathways. With a TOF instrument of high resolution, the exact mass for each fragment was determined. These data were used to infer the molecular formulas and the ionic elemental compositions for all the compounds through interpretation by software. By further applying chemical intuition, majority of the fragmentation ions were fully assigned. All the compounds give strong signals（ average 76% ） for their molecular ions in the El spectra. Two kinds of characteristic fragmentation pathways from the molecular ion were observed. One is related to the loss of the ester group, forming a resonance stabilized ion with a moderate abundance（ average 40% ）. The other concerns the loss of the aromatic-ring radical, forming another resonance stabilized ion at m/z 199 with a high abundance（ average 79% ）, from which further important fragmentations including the formation of an ion at m/z 171 （average 24% ） by the loss of C2H2 （via the McLafferty rearrangement）, and an ion at m/z 153（ average 10% ） by the elimination of a water molecule preceed. In addition, ion [ M - Et ]^＋ with a high abundance（average 62% ） is a characteristic for the Biginelli compounds with an ethoxycarbonyl group. Differences and similarities among the fragmentations observed from the EI-TOFMS of oxo-Biginelli compounds are discussed.

关键词： Beginelli compound 3,4-Dihydropyrimidinthione Time-of-flight mass spectrometry Electron impact

Intriguing magnetoelectric effect in two-dimensional ferromagnetic/perovskite oxide ferroelectric heterostructure

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npj Computational Materials 2022年第1期8卷 121-127页

作者： Ping Li xue-song Zhou Zhi-Xin Guo State Key Laboratory for Mechanical Behavior of Materials Center for Spintronics and Quantum SystemSchool of Materials Science and EngineeringXi’an Jiaotong UniversityXi’anShaanxi710049China Key Laboratory for Computational Physical Sciences(Ministry of Eduction) Fudan UniversityShanghai200433China Key Laboratory of Polar Materials and Devices(Ministry of Education) East China Normal UniversityShanghai200241China

Two-dimensional (2D) magnets have broad application prospects in the spintronics,but how to effectively control them with a small electric field is still an *** we propose that 2D magnets can be efficiently controlled in a multiferroic heterostructure composed of 2D magnetic material and perovskite oxide ferroelectric (POF) whose dielectric polarization is easily flipped under a small electric *** illustrate the feasibility of such strategy in the bilayer CrI_(3)/BiFeO_(3)(001) heterostructure by using the first-principles *** from the traditional POF multiferroic heterostructures which have strong interface interactions,we find that the interface interaction between CrI_(3) and BiFeO_(3)(001) is van der Waals ***,the heterostructure has particular strong magnetoelectric coupling where the bilayer CrI_(3) can be efficiently switched between ferromagnetic and antiferromagnetic types by the polarized states P↑ and P↓ of BiFeO_(3)(001).We also discover the competing effect between electron doping and the additional electric field on the interlayer exchange coupling interaction of CrI_(3),which is responsible to the magnetic phase *** results provide a avenue for the tuning of 2D magnets with a small electric field.

关键词： magnets perovskite ferromagnetic

Receptivity of hypersonic boundary layer due to fast-slow acoustics interaction

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Acta Mechanica Sinica 2015年第6期31卷 899-909页

作者： Jun Gao Ji-Sheng Luo xue-song Wu Department of Mechanics Tianjin University Department of Mathematics Imperial College London

The objective of receptivity is to investigate the mechanisms by which external disturbances generate unsta- ble waves. In hypersonic boundary layers, a new receptivity process is revealed, which is that fast and slow acoustics through nonlinear interaction can excite the second mode near the lower-branch of the second mode. They can generate a sum-frequency disturbance though nonlinear interaction, which can excite the second mode. This receptivity process is generated by the nonlinear interaction and the nonparal- lel nature of the boundary layer. The receptivity coefficient is sensitive to the wavenumber difference between the sumfrequency disturbance and the lower-branch second mode. When the wavenumber difference is zero, the receptivity coefficient is maximum. The receptivity coefficient decreases with the increase of the wavenumber difference. It is also found that the evolution of the sum-frequency disturbance grows linearly in the beginning. It indicates that the forced term generated by the sum-frequency disturbance resonates with the second mode.

关键词： Hypersonic boundary layer · Receptivity·Nonlinear interaction · Acoustic

Interaction of subway LIM vehicle with ballasted track in polygonal wheel wear development

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Acta Mechanica Sinica 2011年第2期27卷 297-307页

作者： Ling Li Xin-Biao Xiao xue-song Jin State Key Laboratory of Traction Power Southwest Jiaotong University 610031 Chengdu China

This paper develops a coupled dynamics model for a linear induction motor （LIM） vehicle and a subway track to investigate the influence of polygonal wheels of the vehicle on the dynamic behavior of the system. In the model, the vehicle is modeled as a multi-body system with 35 degrees of freedom. A Timoshenko beam is used to model the rails which are discretely supported by sleepers. The sleepers are modeled as rigid bodies with their vertical, lateral, and rolling motions being considered. In order to simulate the vehicle running along the track, a moving sleeper support model is introduced to simulate the excitation by the discrete sleeper supporters, in which the sleepers are assumed to move backward at a constant speed that is the same as the train speed. The Hertzian contact theory and the Shen– Hedrick–Elkins’ model are utilized to deal with the normal dynamic forces and the tangential forces between wheels and rails, respectively. In order to better characterize the linear metro system （LMS）, Euler beam theory based on modal superposition method is used to model LIM and RP. The vertical electric magnetic force and the lateral restoring force between the LIM and RP are also taken into consideration. The former has gap-varying nonlinear characteristics, whilst the latter is considered as a constant restoring force of 1 kN. The numerical analysis considers the effect of the excitation due to polygonal wheels on the dynamic behavior of the system at different wear stages, in which the used data regarding the polygonal wear on the wheel tread are directly measured at the subway site.

关键词： Linear induction motor Uneven wear Wheel out of roundness Vehicle-track coupling dynamics