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A pilot field-scale study on biotrickling filter treatment of NH_3-containing odorous gases from organic waste composting plants

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第9期11卷 629-637页

作者： Nian-tao xue Qun-hui WANG Chuan-fu WU Xiao-hong SUN Wei-min XIE Department of Environmental Engineering School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Agricultural Biotechnology Centre Be(jing Academy of Agriculture and Forestry Sciences Beijing 100089 China Japan TOHIN Company Group Profile Tokyo 346-0028 Japan

The use of a biotrickling filter was investigated for a pilot field-scale elimination of NH3 gas and other odorous gases from a composting plant in Tongzhou District, Beijing. The inlet gas flow rate was 3500 m3/h and NH3 concentration fluctuated between 2.76–27.84 mg/m3, while the average outlet concentration was 1.06 mg/m3 with an average of 94.9% removal. Critical volumetric loading (removal efficiency=100%) was 11.22 g-N/(m3·h). The odor concentration removal was 86.7%. NH3 removal efficiency decreased as the free ammonia (FA) in the trickling liquid increased. The pressure drop was maintained at about 50 Pa/m and was never more than 55 Pa/m. During the experiment, there was neither backflushing required nor any indication of clogging. Overall, the biotrickling filter was highly efficient and cost-effective for the simultaneous biodegradation of NH3 and other odorous gases from composting, suggesting the possibility of treating odorous gases at the industrial level.

关键词： Ammonia Biotrickling filter Odor Organic waste composting Pilot field-scale study Trickling liquid

Influence of cutterhead opening ratio on soil arching effect and face stability during tunnelling through non-uniform soils

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Underground Space 2024年第4期17卷 45-59页

作者： xue-Jian Chen Pei-Pei Fang Qiu-Nan Chen Jun Hu Kai Yao Yong Liu State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China Hubei Technology Innovation Center for Smart Hydropower Wuhan 430000China College of Civil Engineering Anhui Jianzhu UniversityHefei 230601China School of Civil Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Civil and Architectural Engineering Hainan UniversityHaikou 570228China School of Qilu Transportation Shandong UniversityJinan 250002China

Tunnelling has increasingly become an essential tool in the exploration of underground space.A typical construction problem is the face instability during tunnelling,posing a great threat to associated *** face instability often occurs with the soil arching *** study investigates the combined effect of cutterhead opening ratio and soil non-uniformity on soil arching effect and face stability,via conducting random finite-element analysis coupled with Monte–Carlo *** results underscore that the face stability is strongly associated with the evolution of stress *** obtained stability factors in the uniform soils can serve as a reference for the design of support pressure in practical tunnelling *** addition,non-uniform soils exhibit a lower stability factor than uniform soils,which implies that the latter likely yields an underestimated probability of face *** tunnel face is found to have a probability of failure more than 50%if the spatial non-uniformity of soil is *** the end,a practical framework is established to determine factor of safety(FOS)corresponding to different levels of probability of face failure considering various opening ratios in non-uniform *** required FOS is 1.70 to limit the probability of face instability no more than 0.1%.Our findings can facilitate the prediction of probability of instability in the conventionally deterministic design of face pressure.

关键词： Tunnel Face stability Soil arching effect Cutterhead opening ratio Non-uniform soil Random field

Roasting and leaching behaviors of vanadium and chromium in calcification roasting–acid leaching of high-chromium vanadium slag

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International Journal of Minerals,Metallurgy and Materials 2018年第5期25卷 515-526页

作者： Jing Wen Tao Jiang Mi Zhou Hui-yang Gao Jia-yi Liu Xiang-xin xue School of Metallurgy Northeastern University Liaoning Key Laboratory for Recycling Science of Metallurgical Resources

Calcification roasting–acid leaching of high-chromium vanadium slag(HCVS)was conducted to elucidate the roasting and leaching behaviors of vanadium and *** effects of the purity of Ca O,molar ratio between Ca O and V_2O_5(n(Ca O)/n(V_2O_5)),roasting temperature,holding time,and the heating rate used in the oxidation–calcification processes were *** roasting process and mechanism were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),and thermogravimetry–differential scanning calorimetry(TG–DSC).The results show that most of vanadium reacted with Ca O to generate calcium vanadates and transferred into the leaching liquid,whereas almost all of the chromium remained in the leaching residue in the form of(Fe_(0.6)Cr_(0.4))_2O_*** trends of the vanadium and chromium leaching ratios were always opposite because of the competitive reactions of oxidation and calcification between vanadium and chromium with Ca ***,Ca O was more likely to combine with vanadium,as further confirmed by thermodynamic *** the HCVS with Ca O added in an n(Ca O)/n(V_2O_5)ratio of 0.5 was roasted in an air atmosphere at a heating rate of 10°C/min from room temperature to 950°C and maintained at this temperature for 60 min,the leaching ratios of vanadium and chromium reached91.14%and 0.49%,respectively;thus,efficient extraction of vanadium from HCVS was achieved and the leaching residue could be used as a new raw material for the extraction of ***,the oxidation and calcification reactions of the spinel phases occurred at 592and 630°C for n(Ca O)/n(V_2O_5)ratios of 0.5 and 5,respectively.

关键词： high-chromium vanadium slag calcification roasting roasting behaviors leaching behaviors vanadium extraction

High-temperature properties and microstructure of Mo microalloyed ultra-high-strength steel

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International Journal of Minerals,Metallurgy and Materials 2011年第4期18卷 407-412页

作者： Qi-hang Han Yong-lin Kang Xian-meng Zhao Lu-feng Gao xue-song Qiu School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

The high-temperature mechanical properties and microstructure of forging billets of C-Si-Mn-Cr and C-Si-Mn-Cr-Mo ultra-high-strength cold-rolled steels（tensile strength≥1000 MPa,elongation≥10%） were *** the comparison of reduction in area and hot deformation resistance at 600-1300°C,the Mo-containing steel was found to possess a higher strength and a better plasticity than the Mo-free *** equilibrium phase diagram and atom fraction of Mo in different phases at different temperatures were calculated by Thermo-Calc software（TCW）.The results analyzed by using transmission electron microscopy and TCW show that precipitates in the Mo-containing steel are primarily M23C6,which promote pearlite *** experimental data also show that a lower ductility point existing in the Mo-free steel at 850°C is eliminated in the Mo-containing *** is mainly due to the segregation of Mo at grain boundaries investigated by electron probe microanalysis（EPMA）,which improves the strength of grain boundaries.

关键词： high strength steels high temperature properties microstructure molybdenum thermodynamics

Discovering Cohesive Temporal Subgraphs with Temporal Density Aware Exploration

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Journal of Computer Science & Technology 2022年第5期37卷 1068-1085页

作者： Chun-xue Zhu Long-Long Lin Ping-Peng Yuan Hai Jin National Engineering Research Center for Big Data Technology and System Huazhong University of Science and TechnologyWuhan 430074China Service Computing Technology and System Laboratory Huazhong University of Science and TechnologyWuhan 430074China Cluster and Grid Computing Laboratory Huazhong University of Science and TechnologyWuhan 430074China School of Computer Science and Technology Huazhong University of Science and TechnologyWuhan 430074China

Real-world networks,such as social networks,cryptocurrency networks,and e-commerce networks,always have occurrence time of interactions between *** networks are typically modeled as temporal *** cohesive subgraphs from temporal graphs is practical and essential in numerous data mining applications,since mining cohesive subgraphs gets insights into the time-varying nature of temporal ***,existing studies on mining cohesive subgraphs,such as Densest-Exact and k-truss,are mainly tailored for static graphs(whose edges have no temporal information).Therefore,those cohesive subgraph models cannot indicate both the temporal and the structural characteristics of *** this end,we explore the model of cohesive temporal subgraphs by incorporating both the evolving and the structural characteristics of temporal ***,the volume of time intervals in a temporal network is *** a result,the time complexity of mining temporal cohesive subgraphs is *** efficiently address the problem,we first mine the temporal density distribution of temporal *** by the distribution,we can safely prune many unqualified time intervals with the linear time ***,the remaining time intervals where cohesive temporal subgraphs fall in are examined using the greedy *** results of the experiments on nine real-world temporal graphs indicate that our model outperforms state-of-the-art solutions in efficiency and ***,our model only takes less than two minutes on a million-vertex DBLP and has the highest overall average ranking in EDB and TC metrics.

关键词： temporal network temporal feature distribution cohesive subgraph convex property

Application of Wood Char in Processing Oolitic High-phosphorus Hematite for Phosphorus Removal

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Journal of Iron and Steel Research International 2016年第2期23卷 109-115页

作者： Hui-qing TANG Yan-qi QIN Teng-fei QI Zhi-lei DONG Qing-guo xue State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Phosphorus removal from oolitic high-phosphorus hematite using direct reduction followed by melting sep aration was investigated. At the direct reduction stage, highly volatile wood char was prepared by carbonizing jujube wood at 673 K for 2 h and was used as reducing agent. The results of the direct reduction tests show that at a tem- perature of 1373 K, a char mixing ratio of 0.8, and a reduction time of 10-25 min, the briquettes reached a metal- lization degree of 80% -84% and a residual carbon content of 0.13 -1.98 mass%. Phosphorus remained in the gangue as calcium phosphate after reduction. The results of the melting separation tests show that residual carbon in reduced briquette negatively affects the phosphorus content （W[p]） in hot metal. When the reduced briquettes ob- tained under the aforementioned conditions were used for melting separation, hot metal suitable for basic oxygen steelmaking （w[p]〈0.4 mass%） could not be obtained from metallic briquettes with a residual carbon content more than 1.0 mass~. In contrast, it could be obtained from metallic briquettes with residual carbon content less than 0.35 mass% by mixing with 2%-4% Na2CO3.

关键词： high-phosphorus hematite wood char direct reduction melting separation phosphorus removal

Preparation, Curing Reactivity and Thermal Properties of Titanium-doped Silicone Resins

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Chemical Research in Chinese Universities 2010年第5期26卷 851-856页

作者： WANG xue-mei WU Ya-hong HAO Zhi-feng YU Jian YU Lin Faculty of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China

Novel titanium-doped silicone resins were synthesized from low-cost silane monomers and tetrabutyl titanate as raw materials and hydrochloric acid as catalyst, with titanium element as dopant into principal chain of Si-O-Si. The resins were characterized by means of FTIR, IH NMR and 13C NMR spectra, their thermal properties and curing properties were investigated and their corresponding films were determined. The results show that the thermal stability and storage stability of the resins were influenced by the types of silane monomers containing dif- ferent carbon atomicities of organic group. The thermal stability of the titanium-doped silicone resin with a molar ratio of silane monomer B（n-propyl triethoxysilane） to silane monomer C（n-octyl triethoxysilane） being 1：1 is superior to that of the resin with a molar ratio of silane monomer B to silane monomer C being 1：3. However, the storage stability of the former is inferior to that of the latter. This work also showed that the synthesized titanium-doped silicone resins have the highest thermal stability up to 450--500℃ with an atomicity molar ratio of 1：4 of titanium to silicon in the reactants. But the best storage stability of the resin prepared from the reactants with an atomicity molar ratio of 1：6[n（Ti）：n（Si）] was obtained. The effect of the type and content of curing agent on the curing properties of the resin was also studied. Moreover, thermal mechanism and curing mechanism were proposed in this work.

关键词： Titanium-doped silicone resin Synthesis Thermal stability Curing Mechanism

Effects of boron number per unit volume on the shielding properties of composites made with boron ores from China

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Nuclear Science and Techniques 2012年第6期23卷 344-348页

作者： LI Zhefu xue Xiangxin LIU Sulan LI Yong DUAN Peining School of Materials & Metallurgy Northeastern University Liaoning Key Laboratory for Ecologically Comprehensive Utilization of Boron Resources and Materials

The total macroscopic removal cross sections,deposited energies and the absorbed doses of three new shielding composites loaded with specific boron-rich slag,boron concentrate ore and boron mud of China for 252Cf neutron source were investigated by experimental and Monte Carlo *** results were evaluated by boron mole numbers per unit volume in *** half value layers of the composites were calculated and compared with that of Portland concrete,indicating that ascending boron mole numbers per unit volume in the composites can enhance the shielding properties of the composites for 252Cf neutron source.

关键词：复合材料屏蔽性能硼矿石体积单位蒙特卡罗计算中国吸收剂量

Succession of Denitrifying Community Composition in Coastal Wetland Soils Along a Salinity Gradient

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Pedosphere 2012年第3期22卷 367-374页

作者： PIAO Zhe ZHANG Wen-Wen MA Shuai LI Yu-Min YIN Shi-xue Microbiology Section College of Environmental Science and EngineeringYangzhou UniversityYangzhou 225009(China)

To better understand the effect of salinity on denitrification communities, soils along a salinity gradient （ranging from 7.32 to 1.70 mS cm 1） in a wetland along the Yellow Sea coastline in Jiangsu Province, China, were studied using both culture-dependent and -independent methods. Culture efforts yielded 82 isolates in total, 81.7% of which were close relatives of Bacillus sp. based on partial sequences of their 16S rRNA genes. Denaturing gradient gel electrophoresis （DGGE） analysis based on 16S rRNA sequences suggested possible existence of bacterial community succession along the salinity gradient. Clone library analysis based on nosZ gene sequences （coding nitrous oxide reductase） showed that operational taxonomic units （OTUs） associated with α-proteobacteria dominated in all three soils, whereas those associated with β- and γ-subdivisions showed a clear succession. In the high salinity soil, only the OTUs associated with a-subdivision were found. In the medium salinity soil, small proportions of β- （6.5%） and γ-associated （19.6%） OTUs were found. In the low salinity soil, the proportions were further increased to 33% and 25% for β- and γ-Proteobacteria, respectively. Statistic analysis using Unifrac P test showed that nosZ-communities in different saline soils were significantly different from each other. It could be concluded that α-subdivision of nosZ-community tended to be sustained in high salinity environments whereas β and γ-subdivisions, especially the former, tended to be sustained in low salinity environments. Salinity was the key determinant of nosZ-community composition in the environment.

关键词： clone library denaturing gradient gel electrophoresis (DGGE) nosZ gene Yellow Sea coastline