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NOx removal by non-thermal plasma reduction: experimental and theoretical investigations

《化学科学与工程前沿(英文)》 2022年 第16卷 第10期   页码 1476-1484 doi: 10.1007/s11705-022-2165-z

摘要: Green and efficient NOx removal at low temperature is still desired. NOx removal via non-thermal plasma (NTP) reduction is one of such technique. This work presents the experimental and theoretical study on the NOx removal via NTP reduction (NTPRD) in dielectric barrier discharge reactor (DBD). The effect of O2 molar fraction on NOx species in the outlet of DBD, and effects of NH3/NO molar ratio and discharge power of DBD on NOx removal efficiency are investigated. Results indicate that anaerobic condition and higher discharge power is beneficial to direct removal of NOx, and the NOx removal efficiency can be up to 98.5% under the optimal operating conditions. It is also found that adding NH3 is favorable for the reduction of NOx to N2 at lower discharge power. In addition, the NOx removal mechanism and energy consumption analysis for the NTPRD process are also studied. It is found that the reduced active species ( N, N, N+, N2, NH2+, etc.) generated in the NTPRD process play important roles for the reduction of NOx to N2. Our work paves a novel pathway for NOx removal from anaerobic gas in industrial application.

关键词: ${\rm{NO}}_x $ removal     NTP reduction     mechanism     energy consumption    

Preparation and lithium storage performances of g-C

Zhengxu BIAN, Zehua TANG, Jinfeng XIE, Junhao ZHANG, Xingmei GUO, Yuanjun LIU, Aihua YUAN, Feng ZHANG, Qinghong KONG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 759-766 doi: 10.1007/s11708-020-0810-0

摘要: As the anode material of lithium-ion battery, silicon-based materials have a high theoretical capacity, but their volume changes greatly in the charging and discharging process. To ameliorate the volume expansion issue of silicon-based anode materials, g-C N /Si nanocomposites are prepared by using the magnesium thermal reduction technique. It is well known that g-C N /Si nanocomposites can not only improve the electronic transmission ability, but also ameliorate the physical properties of the material for adapting the stress and strain caused by the volume expansion of silicon in the lithiation and delithiation process. When g-C N /Si electrode is evaluated, the initial discharge capacity of g-C N /Si nanocomposites is as high as 1033.3 mAh/g at 0.1 A/g, and its reversible capacity is maintained at 548 mAh/g after 400 cycles. Meanwhile, the improved rate capability is achieved with a relatively high reversible specific capacity of 218 mAh/g at 2.0 A/g. The superior lithium storage performances benefit from the unique g-C N /Si nanostructure, which improves electroconductivity, reduces volume expansion, and accelerates lithium-ion transmission compared to pure silicon.

关键词: magnesium thermal reduction     g-C3N4/Si nanocomposites     volume expansion     electroconductivity     lithium-ion battery    

Synthesis and characterization of magnesium hydroxide by batch reaction crystallization

Xingfu SONG, Shuying SUN, Dengke ZHANG, Jin WANG, Jianguo YU

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 416-421 doi: 10.1007/s11705-011-1125-9

摘要: Magnesium hydroxide with high purity and uniform particle size distribution was synthesized by the direct precipitation method using MgCl and NaOH as reactive materials and NaCl as additive to improve the crystallization behavior of the product. The particle size distribution, crystal phase, morphology, and surface area of magnesium hydroxide were characterized by Malvern laser particle size analyzer, X-ray diffraction (XRD), scanning electron microscope (SEM) and Branauer-Emmett-Teller (BET) method, respectively. The purity of products was analyzed by the chemical method. The effects of synthesis conditions on the particle size distribution and water content (filtration cake) of magnesium hydroxide were investigated. The results indicated that feeding mode and rate, and reaction temperature had important effects on water content and the particle size distribution of the product, and sodium chloride improved the crystallization behavior of magnesium hydroxide. The ball-like magnesium hydroxides with the particle size distribution of 6.0–30.0 μm and purity higher than 99.0% were obtained. This simple and mild synthesis method was promising to be scaled up for the industrial production of magnesium hydroxide.

关键词: magnesium hydroxide     direct precipitation method     industrial crystallization     particle size distribution    

Local arc discharge mechanism and requirements of power supply in micro-arc oxidation of magnesium alloy

Ming CHEN, Yuezhou MA, Yuan HAO,

《机械工程前沿(英文)》 2010年 第5卷 第1期   页码 98-105 doi: 10.1007/s11465-009-0088-8

摘要: To study the requirements of the power supply in micro-arc oxidation (MAO) of magnesium alloy, many experiments were performed under the DC, unipolar, and ambipolar pulse output modes. Based on the experimental results and electric arc theory, the separate local arc discharge mechanism was put forward. It is considered that magnesium MAO process consists of three stages including anodic oxidation, micro-arc oxidation, and large-arc discharge in turn with increasing source voltage. The MAO film is composed of metal oxides that resulted from numerous discrete local arc discharges, which accumulate the non-equilibrium structure after undergoing sudden heating and cooling cycles. Separate local arc discharge is caused by the process in which the oxygen-based gas is ionized in the conduct channel bearing electric field intensity, changed from insulator to conductor that presents sharp negative resistance effect, and produced partially high temperature to ignite locally metal oxidation. The local arc discharge model is described as four courses: gas created from electrolysis, arc discharge, metals oxidization, and cooling and shrinking of oxides. The purpose of pulse supply is to inhibit the large-arc discharge by intervening proper cooling time, which cannot be actualized by a unipolar pulse mode because of the strong capacitive load characteristics but can be reached by an ambipolar pulse supply because the negative pulse period acts as cooling time. Using a discharge loop to remove the influence of load capacitive, a new type of pulse power supply for MAO is developed, so that the large-arc problem is resolved effectively, the film-forming efficiency is improved, and the pollution of the film and electrolyte caused by negative voltage is avoided.

关键词: micro-arc oxidation     local arc discharge     pulse power supply     magnesium alloy    

Experimental study on mechanical properties of a novel micro-steel fiber reinforced magnesium phosphate

《结构与土木工程前沿(英文)》 2021年 第15卷 第4期   页码 1047-1057 doi: 10.1007/s11709-021-0755-3

摘要: Magnesium phosphate cement (MPC) received increased attention in recent years, but MPC-based concrete is rarely reported. The micro-steel fibers (MSF) were added to MPC-based concrete to enhance its ductility due to the high brittleness in tensile and flexural strength properties of MPC. This paper investigates the effect of MSF volume fraction on the mechanical properties of a new pattern of MPC-based concrete. The temperature development curve, fluidity, cubic compressive strength, modulus of elastic, axial compressive strength, and four-point flexural strength were experimentally studied with 192 specimens, and a scanning electron microscopy (SEM) test was carried out after the specimens were failed. Based on the test results, the correlations between the cubic compressive strength and curing age, the axial and cubic compressive strength of MPC-based concrete were proposed. The results showed that with the increase of MSF volume fraction, the fluidity of fresh MPC-based concrete decreased gradually. MSF had no apparent influence on the compressive strength, while it enhanced the four-point flexural strength of MPC-based concrete. The four-point flexural strength of specimens with MSF volume fraction from 0.25% to 0.75% were 12.3%, 21.1%, 24.6% higher than that of the specimens without MSF, respectively.

关键词: magnesium phosphate cement-based concrete     micro-steel fibers     four-point flexural strength     compressive strength    

Thermal annealing synthesis of double-shell truncated octahedral Pt-Ni alloys for oxygen reduction reaction

Xiashuang LUO, Yangge GUO, Hongru ZHOU, Huan REN, Shuiyun SHEN, Guanghua WEI, Junliang ZHANG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 767-777 doi: 10.1007/s11708-020-0667-2

摘要: Shape-controlled Pt-Ni alloys usually offer an exceptional electrocatalytic activity toward the oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cells (PEMFCs), whose tricks lie in well-designed structures and surface morphologies. In this paper, a novel synthesis of truncated octahedral PtNi alloy catalysts that consist of homogeneous Pt-Ni alloy cores enclosed by NiO-Pt double shells through thermally annealing defective heterogeneous PtNi alloys is reported. By tracking the evolution of both compositions and morphologies, the outward segregation of both PtO and NiO are first observed in Pt-Ni alloys. It is speculated that the diffusion of low-coordination atoms results in the formation of an energetically favorable truncated octahedron while the outward segregation of oxides leads to the formation of NiO-Pt double shells. It is very attractive that after gently removing the NiO outer shell, the dealloyed truncated octahedral core-shell structure demonstrates a greatly enhanced ORR activity. The as-obtained truncated octahedral Pt Ni core-shell alloy presents a 3.4-folds mass-specific activity of that for unannealed sample, and its activity preserves 45.4% after 30000 potential cycles of accelerated degradation test (ADT). The peak power density of the dealloyed truncated octahedral Pt Ni core-shell alloy catalyst based membrane electrolyte assembly (MEA) reaches 679.8 mW/cm , increased by 138.4 mW/cm relative to that based on commercial Pt/C.

关键词: dealloyed Pt-Ni alloys     truncated octahedron     double-shell     thermal annealing     oxygen reduction reaction (ORR)    

Effects of operational and structural parameters on cell voltage of industrial magnesium electrolysis

Ze Sun,Chenglin Liu,Guimin Lu,Xingfu Song,Jianguo Yu

《化学科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 522-531 doi: 10.1007/s11705-015-1539-x

摘要: Electric field is the energy foundation of the electrolysis process and the source of the multiphysical fields in a magnesium electrolysis cell. In this study, a three-dimensional numerical model was developed and used to calculate electric field at the steady state through the finite element analysis. Based on the simulation of the electric field, the operational and structural parameters, such as the current intensity, anode thickness, cathode thickness, and anode-cathode distance (ACD), were investigated to obtain the minimum cell voltage. The optimization is to obtain the minimum resistance voltage which has a significant effect on the energy consumption in the magnesium electrolysis process. The results indicate that the effect of the current intensity on the voltage could be ignored and the effect of the ACD is obvious. Moreover, there is a linear decrease between the voltage and the thicknesses of the anode and cathode; and the anode-cathode working height also has a significant effect on the voltage.

关键词: finite element method     magnesium electrolysis cell     electric field    

Green process to recover magnesium chloride from residue solution of potassium chloride production plant

WANG Lin, HE Yunliang, WANG Yanfei, BAO Ying, WANG Jingkang

《化学科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 385-389 doi: 10.1007/s11705-008-0079-z

摘要: The green process to recover magnesium chloride from the residue solution of a potassium chloride production plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The residue solution contains magnesium chloride above 25 wt-%, potassium chloride and sodium chloride together below 5 wt-% and a few other ions such as Br, SO and Ca. The recovery process contains two steps: the previous impurity removal operation and the two-stage evaporation-cooling crystallization procedure to produce magnesium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

关键词: industrial production     chemical industrial     produced magnesium     chloride production     impurity carnallite    

Filtration ability of hollow fiber membrane for production of magnesium ammonium phosphate crystals by

H. Watamura, H. Marukawa, I. Hirasawa

《化学科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 55-59 doi: 10.1007/s11705-013-1312-y

摘要: Relationship between magnesium ammonium phosphate (MAP) crystal properties and the filtration ability of hollow fiber membrane (HFM) were investigated. Phosphorus recovery process by crystallization has a problem that it produces a large amount of fine crystals. So improvement of the crystallization process by combining with filtration was discussed. MAP crystals were obtained by batch reaction crystallization and the filtration characteristics were investigated. The filtration was evaluated by the specific filtration resistance ( ) on HFM. Filtered slurry was prepared with each suspension density and crystal size distribution. The solution was filtered at constant pressure of 0.02 MPa and the filtration time on each filtrated volume was recorded. As a result, decreases exponentially with suspension density increasing from 0.25 g/L to 0.5 g/L and decreases moderately with suspension density increasing from 0.5 g/L to 1.5 g/L. of large crystals decreases exponentially at less suspension density than of small crystals does. Also, increases as the ratio of the fractured crystals increases.

关键词: membrane separation     crystallization     MAP    

Capture of carbon dioxide over porous solid adsorbents lithium silicate, lithium aluminate and magnesium

P. V. Korake, A. G. Gaikwad

《化学科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 215-226 doi: 10.1007/s11705-010-1012-9

摘要: The capturing process for carbon dioxide over porous solid adsorbents such as lithium silicate, lithium aluminate, and magnesium aluminate at pre- combustion temperatures was studied. Lithium silicate was prepared by the sol gel and solid fusion methods. The lithium silicate adsorbent was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and surface area. The capturing of carbon dioxide over lithium silicate, lithium aluminate, and magnesium aluminate was explored at different experimental conditions such as exposure time, temperature variation, and exposure carbon dioxide pressure. The capturing process for carbon dioxide was investigated over these adsorbents with variation of their metal mole ratios. The effect of the addition of (promoter) sodium, potassium, and cesium in the lithium silicate adsorbent was explored to investigate the variation of the capture of carbon dioxide over these adsorbents.

关键词: capturing CO2     lithium silicate     lithium aluminate     magnesium aluminate    

A stepwise process for carbon dioxide sequestration using magnesium silicates

Johan FAGERLUND, Experience NDUAGU, Ron ZEVENHOVEN, Inês ROMÃO,

《化学科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 133-141 doi: 10.1007/s11705-009-0259-5

摘要: This work involves the production of magnesium in the form of Mg(OH) from serpentinite rock (nickel mine tailing) material followed by conversion into MgCO using a pressurised fluidised bed (PFB) reactor operating at 400°C–600°C and pressures up to 2.85MPa. Our approach is rooted in the thermodynamic fact that the reaction between Mg(OH) and gaseous CO forming MgCO and water releases significant amounts of heat. The main problem is, however, the chemical kinetics; the reaction is slow and has to be accelerated in order to be used in an economically viable process for large-scale (~1Mt/a) CO sequestration. We have constructed a lab-scale PFB reactor test-setup for optimising the carbonation reaction. At high enough temperatures and conversion levels the reaction should provide the heat for the proceeding Mg(OH) production step, making the overall process energy neutral. So far we have been able to achieve a conversion degree of 26% at 500°C and 2.85MPa after 30min (particle size 125–212μm). In this paper the test facility and our latest results and progress on CO mineral carbonation are summarised. Also, the possible integration of the iron as a feedstock for iron and steel production will be briefly addressed. An interesting side-effect of this carbon dioxide capture and storage (CCS) route is that significant amounts of iron are obtained from the serpentinite rock material. This is released during the Mg(OH) production and can be of great interest to the iron- and steel producing sector, which at the same time is Finland’s largest CO producer.

关键词: carbonation reaction     reactor     producer     large-scale     process    

我国先进镁合金材料产业2035发展战略研究

李芳,管仁国,铁镝,刘楚明,乐启炽,宋江凤,曾小勤,蒋斌

《中国工程科学》 2020年 第22卷 第5期   页码 76-83 doi: 10.15302/J-SSCAE-2020.05.014

摘要:

本文在梳理我国镁合金材料产业发展现状的基础上,分析了其发展面临的国内外主要问题,展望了我国镁合金材料产业在高性能稀土镁轻质结构合金材料、高强高导热镁合金材料、高强高导电镁合金材料、超高强镁合金材料等11个方面的未来市场需求前景。面向2030年和2035年的阶段性发展规划,本文从提高自主创新能力、优化资源配置、加强企业合作力度、构建完善的镁合金材料整体研究体系、完善平台建设等方面提出了促进我国先进镁合金材料产业可持续发展的相关战略。最后,从注重研究体系的构建、优化产业发展格局、构建高质高效产业、完善配套政策体系、构建精尖人才体系等方面提出了对策建议,以期满足国民经济、国家重大工程和社会可持续发展对先进镁合金材料的需求。

关键词: 金属材料产业     镁合金     稀土镁合金材料     低能耗     高效率     2035    

Protein phosphatase magnesium-dependent 1δ is a novel tumor marker and target in hepatocellular carcinoma

null

《医学前沿(英文)》 2016年 第10卷 第1期   页码 52-60 doi: 10.1007/s11684-016-0433-3

摘要:

Hepatocellular carcinoma (HCC) is a lethal liver malignancy worldwide. In this study, we reported that protein phosphatase magnesium-dependent 1δ (PPM1D) was highly expressed in the majority of HCC cases (approximately 59%) and significantly associated with high serum α-fetoprotein (AFP) level (P= 0.044). Kaplan-Meier and Cox regression data indicated that PPM1D overexpression was an independent predictor of HCC-specific overall survival (HR, 2.799; 95% CI, 1.346–5.818, = 0.006). Overexpressing PPM1D promoted cell viability and invasion, whereas RNA interference-mediated knockdown of PPM1D inhibited proliferation, invasion, and migration of cultured HCC cells. In addition, PPM1D suppression by small interfering RNA decreased the tumorigenicity of HCC cells in vivo. Overall, results suggest that PPM1D is a potential prognostic marker and therapeutic target for HCC.

关键词: PPM1D     hepatocellular carcinoma     prognosis     target therapy    

Effect of circulating ash from CFB boilers on NO and N

Xiangsong HOU, Shi YANG, Junfu LU, Hai ZHANG, Guangxi YUE

《能源前沿(英文)》 2009年 第3卷 第2期   页码 241-246 doi: 10.1007/s11708-009-0006-0

摘要: NO and N O emissions from circulating fluidized bed (CFB) boilers are determined by their formation and destruction rates in the furnace. The effect of circulating ash from a CFB boiler on NO and N O emissions were investigated in a laboratory-scale fluidized bed reactor. The results show that the residue char in circulating ash and the CO generated from the char play an important role in NO reduction and N O formation; however, active components of circulating ash such as CaO, Fe O accelerate the decomposition of N O. Experiment was also conducted on a 75 t/h CFB boiler fueled with the mixture of anthracite and biomass. The lower residue carbon content of circulating ash in this experiment is lower; therefore, the reacting rate of NO deoxidize is limited. This result verified the conclusion of laboratory research.

关键词: CFB boiler     circulating ash     NO reduction     N2O thermal decomposition     biomass    

汽车轻量化技术:铝/镁合金及其成型技术发展动态

付彭怀,彭立明,丁文江

《中国工程科学》 2018年 第20卷 第1期   页码 84-90 doi: 10.15302/J-SSCAE-2018.01.012

摘要:

为了推动我国汽车工业轻量化进程,文章从新材料、成型新技术、新应用三个方面对铝合金、镁合金两类轻金属材料的国内外研究动态进行了回顾,分析了两类轻金属材料在汽车工业应用的阻力,提出了我国汽车工业铝/镁合金可能的发展建议。

关键词: 汽车     轻量化     铝合金     镁合金     成型技术     发展动态    

标题 作者 时间 类型 操作

NOx removal by non-thermal plasma reduction: experimental and theoretical investigations

期刊论文

Preparation and lithium storage performances of g-C

Zhengxu BIAN, Zehua TANG, Jinfeng XIE, Junhao ZHANG, Xingmei GUO, Yuanjun LIU, Aihua YUAN, Feng ZHANG, Qinghong KONG

期刊论文

Synthesis and characterization of magnesium hydroxide by batch reaction crystallization

Xingfu SONG, Shuying SUN, Dengke ZHANG, Jin WANG, Jianguo YU

期刊论文

Local arc discharge mechanism and requirements of power supply in micro-arc oxidation of magnesium alloy

Ming CHEN, Yuezhou MA, Yuan HAO,

期刊论文

Experimental study on mechanical properties of a novel micro-steel fiber reinforced magnesium phosphate

期刊论文

Thermal annealing synthesis of double-shell truncated octahedral Pt-Ni alloys for oxygen reduction reaction

Xiashuang LUO, Yangge GUO, Hongru ZHOU, Huan REN, Shuiyun SHEN, Guanghua WEI, Junliang ZHANG

期刊论文

Effects of operational and structural parameters on cell voltage of industrial magnesium electrolysis

Ze Sun,Chenglin Liu,Guimin Lu,Xingfu Song,Jianguo Yu

期刊论文

Green process to recover magnesium chloride from residue solution of potassium chloride production plant

WANG Lin, HE Yunliang, WANG Yanfei, BAO Ying, WANG Jingkang

期刊论文

Filtration ability of hollow fiber membrane for production of magnesium ammonium phosphate crystals by

H. Watamura, H. Marukawa, I. Hirasawa

期刊论文

Capture of carbon dioxide over porous solid adsorbents lithium silicate, lithium aluminate and magnesium

P. V. Korake, A. G. Gaikwad

期刊论文

A stepwise process for carbon dioxide sequestration using magnesium silicates

Johan FAGERLUND, Experience NDUAGU, Ron ZEVENHOVEN, Inês ROMÃO,

期刊论文

我国先进镁合金材料产业2035发展战略研究

李芳,管仁国,铁镝,刘楚明,乐启炽,宋江凤,曾小勤,蒋斌

期刊论文

Protein phosphatase magnesium-dependent 1δ is a novel tumor marker and target in hepatocellular carcinoma

null

期刊论文

Effect of circulating ash from CFB boilers on NO and N

Xiangsong HOU, Shi YANG, Junfu LU, Hai ZHANG, Guangxi YUE

期刊论文

汽车轻量化技术:铝/镁合金及其成型技术发展动态

付彭怀,彭立明,丁文江

期刊论文