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| 1 | Some open problems in granular matter mechanics显示文摘Granular matter is a large assemblage of solid particles, which is fundamentally different from any other type of matters, such as solid and liquid. Most models presented for granular matter are phenomenological and are only suitable for solving engineering problems. Many fundamental mechanical problems remain open. By analyzing characteristics of internal state structure, we propose that granular matter is intrinsically multiscale, i.e. microscale of particle size, mesoscale of force chain, and macroscale of the bulk of granular matter. The correlations among difference scales would be crucial. The mesoscale force chain network is determined by both particle properties and macroscopic boundary conditions. The evolution of the force the chain network contributes to macroscopic mechanical properties of granular matter. In addition, we discuss the drawbacks in simplifying contact forces in the current models, and the difficulties in analyzing the interaction of interstitial fluid in wet granular matter. As an appropriate application of granular matter, debris flow can be studied with granular matter mechanics; meanwhile, debris flow brings more challenges which certainly motivate future studies on granular matter. | Qicheng Sun a, Guangqian Wanga, Kaiheng Hub a Department of Hydraulic Engineering, State Key Laboratory for Hydroscience and Engineering, Tsinghua University, Beijing 100084, China b Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China | 2009 | Progress in Natural Science:Materials International2009，19，5： | 25 |
| 2 | Zircon chronology and REE geochemistry of granulite xenolith at Hannuoba显示文摘The lower crustal xenolith of mafic two_pyroxene granulite (the majority) and hypersthene granulite in the Cenozoic basalt at Hannuoba have the characteristics of igneous blastic structure and granulite facies metamorphic recrystallization. Study on the zircon chronology and REE geochemistry of granulite xenolith shows that the underplating of basic magma into the lower crust during late Mesozoic led to the formation of mafic accumulate, which further through metamorphism of granulite facies formed the high_density and high_velocity crustal bottom layer at the lower crust. This suggests that the underplating of mantle magma is the important way for the vertical overgrowth of continental crust since the Phanerozoic and provides new evidence for crust_mantle interaction. | Qicheng Fan Ruoxin Liu Huimin Li Ni Li Jianli Sui Zhuoran Lin | 1998 | Chinese Science Bulletin1998，43，18： | 22 |
| 3 | Initiation and recession of the fluvial knickpoints:A case study from the Yalu River-Wangtian'e volcanic region,northeastern China显示文摘Initiation and recession of the knickpoints are significant boundary condition for processes of fluvial system.The distribution and recession rates of knickpoints contain information that provides a fundamental understanding of geomorphic processes.In the Yalu River-Wangtian'e volcanic region of northeastern China,broadly distributed flat lava terrain provides an ideal site to study the recession of fluvial knickpoints because knickpoints and waterfalls are well preserved here.Here we describe the distribution of knickpoints in the Yalu River-Wangtian'e volcanic region by combining DEM analysis and numerical modeling.Furthermore,we present a knickpoint celerity model,derived from stream-power incision model,to relate knickpoint recession rate to drainage area.We calibrate important empirical coefficients with our knickpoint celerity model;the best fit erosion coefficient (K) is 1.32×10 8,and the best fit drainage area exponent (m) is 0.69.Error analysis indicates a close correspondence between synthetic and real knickpoints.Finally,we show that knickpoint recession rates in the Yalu River-Wangtian'e volcanic region are ~1-10 mm/a during the early stages of transient incision,and that the present rates are ~1-6 mm/a.Our recession rate results are in good agreement with previous findings from the Aso Volcano and volcanoes near Boso Peninsula (Japan),which have a similar geologic history to the Yalu River-Wangtian'e volcanic region.Our present effort provides new insight into landscape evolution in the Yalu River-Wangtian'e volcanic region in northeastern China. | ZHANG HuiPing ZHANG PeiZhen FAN QiCheng | 2011 | Science China Earth Sciences2011，54，11： | 11 |
| 4 | Quaternary volcanism in the Nuomin River and Kuile River area of the Greater Hinggan Mountains显示文摘Field investigations have determined 24 Quaternary volcanoes and volcanic rocks with an area of about 600 km 2 in the Nuomin River and Kuile River area in the north of the Greater Hinggan Mountains.In the volcanic field,explosive eruption produced pyroclasts,which constitute volcanic cones,and effusive eruption produced aa,pahoehoe and block lava,which make up lava flows.There are three volcano types here,i.e.,cinder cone,spatter cone,and scutulum type volcano.Multi-vent pyroclastic cones and scutulum type volcanoes characterize this volcanic field.The volcanic features,stratigraphy,and weathering extent,in conjunction with dating data,indicate that the volcanism occurred in four periods:early Pleistocene,middle Pleistocene,late Pleistocene,and Holocene.Basalts of the early Pleistocene dominated by lava flows were distributed in a few valleys.Volcanic products of the middle Pleistocene constitute the main part of the Quaternary volcanic deposits,which indicates the peak season of volcanism.Volcanism in the late Pleistocene and Holocene were constrained in the Bila River valley,products of which make up fresh lava flows and spectacular volcanoes. | ZHAO YongWei FAN QiCheng BAI ZhiDa SUI JianLi | 2013 | Science China Earth Sciences2013，56，2： | 9 |
| 5 | A preliminary study of the failure mechanisms of cascading landslide dams显示文摘Landslide dams commonly form when mass earth or rock movements reach a river channel and cause a complete or partial blockage of the channel.Intense rainfalls can induce upstream flows along a sloping channel that significantly affect downstream landslide dams.If a series of landslide dams are collapsed by incoming mountain torrents(induced by intense rainfall),large debris flows can form in a very short period.Furthermore,the failure of these dams can amplify the magnitude and scale of debris flows in the flow direction.The catastrophic debris flows that occurred in Zhouqu County,China on 8 August 2010 were caused by intense rainfall and the upstream cascading failure of landslide dams along the gullies.Incorporating the role of outburst floods associated with the complete or partial failure of landslide dams is an interesting problem usually beyond the scope of analysis because of the inherent modeling complexity.To understand the cascading failure modes of a series of landslide dams,and the dynamic effect these failures have on the enlargement of debris flow scales,experimental tests are conducted in sloping channels mimicking field conditions,with the modeled landslide dams distributed along a sloping channel and crushed by different upstream flows.The failure modes of three different cascades of landslide dams fully or partially blocking a channel river are parametrically studied.This study illustrates that upstream flows can induce a cascading failure of the landslide dams along a channel.Overtopping is the primary failure mechanism,while piping and erosion can also induce failures for different constructed landslide dams.A cascading failure of landslide dams causes a gradually increasing flow velocity and discharge of the front flow,resulting in an increase in both diameter and percentage of the entrained coarse particles.Furthermore,large landslide blockages can act to enhance the efficiency of river incision,or conversely to induce aggradation of fluvial sediments,depending on the blockage factor of the landslide dams and upstream discharge. | Gordon G.D Peng Cui Xinghua Zhu Jinbo Tang Huayong Chen Qicheng Sun | 2015 | International Journal of Sediment Research2015，30，3： | 8 |
| 6 | Holocene volcanic rocks in Jingbo Lake region --Diversity of magmatism显示文摘During the time from 5500 a to 5200 a BP more than 10 Holocene volcanoes in Jingbo Lake region erupted and the volcanic rocks covered an area of about 500 km2. Holocene volcanic rocks in Jingbo Lake region belong to the potassium-rich rocks and contain three rock types: trachybasalts, basanites and phonotephrites. Various types of magmatism formed in a small area and in a short period of time came from partial melting of potassically-metasomatised lithospheric mantle. The diversity of magmatism can be explained by that Jingbo Lake is situated in the back-arc extensional region of East Asian continent subducted by the Pacific Ocean, and potassic fluid derived from mantle wedge or dehydration of subducted slab can result in a high heterogeneity of the mantle beneath this region. Based on the pressure estimation of clinopyroxene megacrysts, we estimate that phonotephrite magma fractionally crystallize at ca . 52-54 km down the earth. | FAN Qicheng SUN Qian LI Ni WANG Tuanhua | 2006 | Progress in Natural Science:Materials International2006，16，1： | 8 |
| 7 | Paddy System with a Hybrid Rice Enhances Cyanobacteria Nostoc and Increases N2 Fixation显示文摘Biological nitrogen (N) fixation (BNF) plays a significant role in maintaining soil fertility in paddy field ecosystems. Rice variety influences BNF, but how different rice varieties regulate BNF and associated diazotroph communities has not been quantified. Airtight, field-based 15N2-labelling grow th chamber experiments were used to assess the BNF capac 辻 y of different rice varie ties. In addition, both the 16S rRNA and nifH genes were sequenced to assess the influence of different rice varieties on bacterial and diazotrophic communities in paddy soils. After subjecting a rice-soil system to 74 d of continuous airtight, field-based 15N2 labelling in pots in a growth chamber, the amounts of fixed N were 22.3 and 38.9 kg ha^-1 in inbred japonica (W23) and hybrid indica (IIY) rice cultivars plan ted in the rice-soil systems, respectively, and only 1%—2.5% of the fixed N was allocated to the rice plants and weeds. A greater abundance of diazotrophs was found in the surface soil (0-1 cm) under IIY than under W23. Sequencing of the 16S rRNA gene showed significantly greater abundances of the cyanobacterial genera Nostoc, Anabaena, and Cylindrospermum under IIY than under W23. Sequencing of the nifH gene also showed a significantly greater abundance of Nostoc under IIY than under W23. These results indicate that the hybrid rice cultivar (IIY) promoted BNF to a greater extent than the inbred rice cultivar (W23) and that the increase in BNF might have been due to the enhanced heterocystous cyanobacteria Nostoc. | MA Jing BEI Qicheng WANG Xiaojie LIU Gang Georg CADISCH LIN Xingwu ZHU Jianguo SUN Xiaoli XIE Zubin | 2019 | Pedosphere2019，29，3： | 7 |
| 8 | Effects of Different Biochars on Pinus elliottii Growth,N Use Efficiency,Soil N_2O and CH_4 Emissions and C Storage in a Subtropical Area of China显示文摘Intensive management of planted forests may result in soil degradation and decline in timber yield with successive rotations.Biochars may be beneficial for plant production, nutrient uptake and greenhouse gas mitigation. Biochar properties vary widely and are known to be highly dependent on feedstocks, but their effects on planted forest ecosystem are elusive. This study investigated the effects of chicken manure biochar, sawdust biochar and their feedstocks on 2-year-old Pinus elliottii growth, fertilizer N use efficiency(NUE), soil N_2O and CH_4 emissions, and C storage in an acidic forest soil in a subtropical area of China for one year. The soil was mixed with materials in a total of 8 treatments: non-amended control(CK); sawdust at 2.16 kg m-^(2)(SD); chicken manure at 1.26 kg m-^(2)(CM); sawdust biochar at 2.4 kg m-^(2)(SDB); chicken manure biochar at 2.4 kg m-^(2)(CMB);^(15)N-fertilizer alone(10.23 atom%^(15)N)(NF); sawdust biochar at 2.4 kg m-^(2)plus15N-fertilizer(SDBN) and chicken manure biochar at 2.4 kg m-^(2)plus15N-fertilizer(CMBN). Results showed that the CMB treatment increased P. elliottii net primary production(aboveground biomass plus litterfall)and annual net C fixation(ANCF) by about 180% and 157%, respectively, while the the SDB treatment had little effect on P. elliottii growth. The15 N stable isotope labelling technique revealed that fertilizer NUE was 22.7% in CK, 25.5% in the NF treatment, and37.0% in the CMB treatment. Chicken manure biochar significantly increased soil p H, total N, total P, total K, available P and available K. Only 2% of the N in chicken manure biochar was available to the tree. The soil N_2O emission and CH_4 uptake showed no significant differences among the treatments. The apparent C losses from the SD and CM treatments were 35% and 61%, respectively;while those from the CMB and SDB treatments were negligible. These demonstrated that it is crucial to consider biochar properties while evaluating their effects on plant growth and C sequestration. | LIN Zhibin LIU Qi LIU Gang Annette L.COWIE BEI Qicheng LIU Benjuan WANG Xiaojie MA Jing ZHU Jianguo XIE Zubin | 2017 | Pedosphere2017，27，2： | 6 |
| 9 | Distribution and treatment of harmful gas from heavy oil production in the Liaohe Oilfield, Northeast China显示文摘The distribution and treatment of harmful gas (H 2 S) in the Liaohe Oilfield, Northeast China, were investigated in this study. It was found that abundant toxic gas (H 2 S) is generated in thermal recovery of heavy oil. The H 2 S gas is mainly formed during thermochemical sulfate reduction (TSR) occurring in oil reservoirs or the thermal decomposition of sulfocompounds (TDS) in crude oil. H 2 S generation is controlled by thermal recovery time, temperature and the injected chemical compounds. The quantity of SO 4 2-in the injected compounds is the most influencing factor for the rate of TSR reaction. Therefore, for prevention of H 2 S formation, periodic and effective monitoring should be undertaken and adequate H 2 S absorbent should also be provided during thermal recovery of heavy oil. The result suggests that great efforts should be made to reduce the SO 4 2-source in heavy oil recovery, so as to restrain H 2 S generation in reservoirs. In situ burning or desulfurizer adsorption are suggested to reduce H 2 S levels. Prediction and prevention of H 2 S are important in heavy oil production. This will minimize environmental and human health risks, as well as equipment corrosion. | Zhu Guangyou Zhang Shuichang Liu Qicheng Zhang Jingyan YangJunyin Wu Tuo Huang Yi Meng Shucui | 2010 | Petroleum Science2010，7，3： | 6 |
| 10 | Kinase domain insert containing receptor promotor controlled suicide gene system kills human umbilical vein endothelial cells显示文摘AIM: To evaluate the killing effect of double suicide gene mediated by adenovirus and regulated under kinase domain insert containing receptor (KDR) promoter on human umbilical vein endothelial cells. METHODS: By PCR technology, human KDR promoter gene, Escherichia coli(E. coli) cytosine deaminase (CD) gene and the herpes simple virus-thymidine kinase (TK) gene were cloned. Plasmid pKDR-CDglyTK was constructed with them. Then, a recombinant adenoviral plasmid pAdKDRCDglyTK was constructed in a 'two-step transformation protocol'. The newly constructed plasmids were transfected to 293 packaging cells to grow adenoviruses, which were further propagated and purified. Human umbilical vein endothelial cells (HUVEC) were infected with a different multiplicity of infection (MOI) of resultant recombinant adenovirus, the infection rate was measured with the aid of (GFP) expression. Infected cells were cultured in culture media containing different concentrations of (GCV) and/or 5-(FC), and the killing effects were measured.RESULTS: Recombinant adenoviruses AdKDR-CDglyTK were successfully constructed, and they infected HUVEC cells efficiently. Our data indicated that the infection rate was relevant to MOI of recombinant adenoviruses. HUVEC cells infected with AdKDR-CDglyTK were highly sensitive to the prodrugs, their survival rate correlated to both the concentration of the prodrugs and the MOI of recombinant adenoviruses. Our data also indicated that the two prodrugs used in combination were much more effective on killing transgeneic cells than GCV or 5-FC used alone. CONCLUSION: Prodrug/KDR-CDglyTK system is effective on killing HUVEC cells, its killing effect correlates to the concentration of prodrugs and recombinant adenovirus' MOI. Combined use of the two prodrugs confers better killing effects on transgeneic cells. | Zong-HaiHuang Wen-YuYang QiCheng Jing-LongYu ZhouLi Zong-YanTong Hui-JuanSong Xiao-YanChe | 2005 | World Journal of Gastroenterology2005，11，24： | 5 |
| 11 | Identification of an endogenous glutamatergic transmitter system controlling excitability and conductivity of atrial cardiomyocytes显示文摘As an excitatory transmitter system,the glutamatergic transmitter system controls excitability and conductivity of neurons.Since both cardiomyocytes and neurons are excitable cells,we hypothesized that cardiomyocytes may also be regulated by a similar system. | Duanyang Xie Ke Xiong Xuling Su Guanghua Wang Qiang Ji Qicheng Zou Lingling Wang Yi Liu Dandan Liang Jinfeng Xue Luxin Wang Xueting Gao Xingdong Gu Hongyu Liu r Xiaoyu He Li Li Jian Yang Youming Lu Luying Peng Yi-Han Chen | 2021 | Cell Research2021，31，9： | 5 |
| 12 | Study on wear resistant cast B-containing 1Cr18Ni9Ti stainless steel显示文摘The developed 1Cr18Ni9Ti austenitic stainless steel containing 1.63 wt.%B have been characterized by X-ray diffraction(XRD),electron probe microanalyzer(EPMA),optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS)and Vickers microhardness measurement.The microstructural evolution and property of high boron stainless steel after solution treatment at the temperature of 1050℃are also investigated.The results show that the main compositions of borides are Fe,Cr and B,and with small amount of Ni,Mn and C elements.Silicon is insoluble in the borides.The hardness of borides is over 1,500 HV.It has been found that borides do not decompose during solution treatment,but part of borides dissolves into the matrix. The effect of increasing the solubility of boron element in the austenitic matrix favours the hardness enhancement by 8.54%.High boron stainless steel has excellent wear resistance in corrosive environment.Lifetime of transfer pipe made of high boron-containing stainless steel is 1.5-1.8 times longer than that of boron-free 1Cr18Ni9Ti stainless steel. | Kuang Jiacai Jiang Zhiqiang Zhang Shiyin Ye Chang Liu Qicheng | 2009 | China Foundry2009，6，1： | 5 |
| 13 | Induction of fibroblasts to neurons through adenoviral gene delivery显示文摘 | Fengxi Meng Siye Chen Qinglong Miao Kechun Zhou Qicheng Lao Xiaohui Zhang Wenyi Guo Jianwei Jiao | 2012 | Cell Research2012，22，2： | 4 |
| 14 | Influence of gravity on narrow input forced drainage in 2D liquid foams显示文摘Liquid foam is a dense packing of gas bubbles in a small amount of liquid containing surfactants or other surface-active macromolecules, which is one of the highly organized materials and possesses hallmark rheological behaviour of soft matters. Forced foam drainage is the flow of constantly inputted liquid through the network of interstitial channels between bubbles under actions of gravity and capil-larity. This process involves two mechanisms: minimal viscous flow dissipation of liquid and minimal surface energy of bubbles. For constant surfactant solution, viscous dissipation usually varies with gravity. This work reports simulations of 2D forced foam drainage with narrow input in a Hele-Shaw cell under 8 different gravities, g, ranging from 9.8 to 0 ms?2. The spread of liquid both vertical due to gravity action, and horizontal due to capillary suction, is recorded over time. Positions of drainage wave fronts in both directions with time are found to be well described in the power law form, and the exponents are 0.536+5.29×10-3g and 0.479?7.27×10-3g, respectively, while the sum is close to a constant of 1.015 which is independent of gravity. For g=9.8 ms-2, the calculated exponents are in good agreement with experimental results by Hutzler et al. and Wang. | SUN QiCheng GE Wei HUANG Jin | 2007 | Chinese Science Bulletin2007，52，3： | 4 |
| 15 | Kinetic granular temperature and its measurement using speckle visibility spectroscopy显示文摘The occurrence of a mesoscopic scale in granular materials leads to a sharp increase in the number of interaction processes at both intra-and inter-scale levels.The mesoscopic scale is the main source of the complex macroscopic properties of granular materials.The quantification of mesoscopic disordered movements is often referred to as granular temperature.In this paper,we first introduce the physical meaning of the original granular temperature of a kinetic nature,Tk,and then briefly summarize the advances made over the past few decades.Our research group has focused on Tk measurement using speckle visibility spectroscopy.The principle of this technique and the instruments developed in our research group are briefly introduced.Our work shows great promise in the measurement of kinetic granular temperature.Finally,a summary of granular temperature and some recent developments in speckle visibility spectroscopy measurements are presented. | Hui Yang Yonghai Zhu Ran Li Qicheng Sun | 2020 | Particuology2020，18，1： | 4 |
| 16 | Simulations of Bingham plastic flows with the multiple-relaxation-time lattice Boltzmann model显示文摘Fresh cement mortar is a type of workable paste,which can be well approximated as a Bingham plastic and whose flow behavior is of major concern in engineering.In this paper,Papanastasiou’s model for Bingham fluids is solved by using the multiplerelaxation-time lattice Boltzmann model(MRT-LB).Analysis of the stress growth exponent m in Bingham fluid flow simulations shows that Papanastasiou’s model provides a good approximation of realistic Bingham plastics for values of m>108.For lower values of m,Papanastasiou’s model is valid for fluids between Bingham and Newtonian fluids.The MRT-LB model is validated by two benchmark problems:2D steady Poiseuille flows and lid-driven cavity flows.Comparing the numerical results of the velocity distributions with corresponding analytical solutions shows that the MRT-LB model is appropriate for studying Bingham fluids while also providing better numerical stability.We further apply the MRT-LB model to simulate flow through a sudden expansion channel and the flow surrounding a round particle.Besides the rich flow structures obtained in this work,the dynamics fluid force on the round particle is calculated.Results show that both the Reynolds number Re and the Bingham number Bn afect the drag coefcients CD,and a drag coefcient with Re and Bn being taken into account is proposed.The relationship of Bn and the ratio of unyielded zone thickness to particle diameter is also analyzed.Finally,the Bingham fluid flowing around a set of randomly dispersed particles is simulated to obtain the apparent viscosity and velocity fields.These results help simulation of fresh concrete flowing in porous media. | CHEN SongGui SUN QiCheng JIN Feng LIU JianGuo | 2014 | Science China(Physics,Mechanics & Astronomy)2014，57，3： | 4 |
| 17 | Enhanced sulfidization of azurite surfaces by ammonium phosphate and its effect on flotation显示文摘Although azurite is one of the most important copper oxide minerals,the recovery of this mineral via sulfidization-xanthate flotation is typically unsatisfactory.The present work demonstrated the enhanced sulfidization of azurite surfaces using ammonia phosphate((NH_(4))_(3)PO_(4)) together with Na_(2)S,based on micro-flotation experiments,time-of-flight secondary ion mass spectrometry(ToF-SIMS),X-ray photoelectron spectroscopy(XPS),zeta-potential measurements,contact angle measurements,Fourier-transform infrared(FT-IR)spectroscopy,and ultraviolet-visible(UV-Vis)spectroscopy.Micro-flotation experiments showed that the floatability of azurite was increased following the simultaneous addition of(NH_(4))_(3)PO_(4)and Na_(2)S.ToF-SIMS and XPS analyses demonstrated the formation of a high content of S species on the azurite surface and an increase in the number of Cu(I)species after exposure to(NH_(4))_(3)PO_(4)and Na_(2)S,compared with the azurite-Na_(2)S system.The zeta potential of azurite particles was negatively shifted and the contact angle on the azurite surface was increased with the addition of(NH_(4))_(3)PO_(4)prior to Na_(2)S.These results indicate that treatment with(NH_(4))_(3)PO_(4) enhances the sulfidization of azurite surfaces,which in turn promotes xanthate attachment.FT-IR and UV-Vis analyses confirmed that the addition of(NH_(4))_(3)PO_(4) increased the adsorption of xanthate with reducing the consumption of xanthate during the azurite flotation process.Thus,(NH_(4))_(3)PO_(4) has a beneficial effect on the sulfidization flotation of azurite. | Qian Zhang Shuming Wen Qicheng Feng Han Wang | 2022 | International Journal of Minerals,Metallurgy and Materials2022，29，6： | 4 |
| 18 | Experimental study on the P wave velocity in rocks from lower crust and crust-mantle transitional zone beneath the Hannuoha显示文摘Cenozoic basalt-borne mafic granulite-facies plagioclase pyroxenite and eclogite-facies garnet pyroxenite xenoliths from the Hannuoba, as well as nearby Archean terrain granulites, are selected for the experimental study on the P wave velocity at high temperature and high pressure in order to reveal the present-day compositional features for the lower crust and crust-mantle transitional zone. Results show that mafic xenoliths have high Vp (7.0~8.0 km/s), in contrast, the Archean terrain granulites have low Vp (<7.0 km/s). High Vp mafic xenoliths can represent the present-day compositional features for the lower crust and crust-mantle transitional zone beneath the Hannuoba. This provides new evidence for the crust vertical growth and the formation of the crust-mantle transitional zone resulting from the magma underplating. Low Vp Archean granulite still remains the characteristics of the early lower crust. | FAN Qicheng SUI Jianli ZHANG Hongfu ZHAI Mingguo and XIE Hongsen(1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. Institute of Geology, China Seismo logical Bureau, Beijing 100029, China 3. Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China) | 2002 | Progress in Natural Science:Materials International2002，12，12： | 4 |
| 19 | Numerical study of flow pattern modulation in a vertical phase separation condenser tube显示文摘The passive phase separation concept was proposed to modulate flow patterns for heat transfer enhancement. By the flow pattern modulation, the gas tends to be near the wall and the liquid tends to be in the tube core. Experiment has been performed to verify the fresh idea and the flow pattern modulation mechanism was analyzed qualitatively. This paper focuses on the numerical simulation of the bubble dynamics for a single bubble in the vertical phase separation condenser tube to quantitatively explore the flow pattern mechanism, based on a multiscale grid system and the volume-of-fluid (VOF) method. It is found that: (1) the modulated liquid film thickness can be decreased by 70% compared to that in the bare tube region; (2) the modulated bubble traveling velocity can be doubled, causing the increased liquid velocity and velocity gradient in the annular region to weaken the fluid boundary layer; (3) the significantly increased bubble traveling velocity in the annular region promotes the mass and momentum exchange between the annular region and the core region, and yields the self-sustained pulsating flow in the core region. The above three factors are benefit for the performance improvement of the heat transfer facilities. | SUN DongLiang XU JinLiang CHEN QiCheng CAO Zhen | 2013 | Chinese Science Bulletin2013，58，13： | 4 |
| 20 | Activation mechanism of ammonium oxalate with pyrite in the lime system and its response to flotation separation of pyrite from arsenopyrite显示文摘The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated pyrite in high alkalinity and high Ca^(2+)system,whereas arsenopyrite was almost unaffected.In mineral mixtures tests,the recovery difference between pyrite and arsenopyrite after adding ammonium oxalate is more than 85%.After ammonium oxalate and ethyl xanthate treatment,the hydrophobicity of pyrite increased significantly,and the contact angle increased from 66.62°to 75.15°and then to 81.21°.After ammonium oxalate treatment,the amount of ethyl xanthate adsorption on the pyrite surface significantly increased and was much greater than that on the arsenopyrite surface.Zeta potential measurements showed that after activation by ammonium oxalate,there was a shift in the zeta potential of pyrite to more negative values by adding xanthate.X-ray photoelectron spectroscopy test showed that after ammonium oxalate treatment,the O 1s content on the surface of pyrite decreased from 44.03%to 26.18%,and the S 2p content increased from 14.01%to 27.26%,which confirmed that the ammonium oxalatetreated pyrite surface was more hydrophobic than the untreated surface.Therefore,ammonium oxalate may be used as a selective activator of pyrite in the lime system,which achieves an efficient flotation separation of S-As sulfide ores under high alkalinity and high Ca2+concentration conditions. | Runpeng Liao Shuming Wen Qicheng Feng Jiushuai Deng Hao Lai | 2023 | International Journal of Minerals,Metallurgy and Materials2023，30，2： | 3 |
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