MIXING/SEGREGATION POTENTIAL IN BINARY LIQUID FLUIDIZED BEDS

The mechanism underlying mixing/segregation of binary particles in liquid fluidized beds is reviewed and investigated in this paper. Binary mixtures of particles, when fluidized, sometimes segregate and display a behaviour called layer inversion, At low fluid velocities, one of the components is primarily found in a discrete layer at the bottom of the bed, while the other is predominantly at the top. At higher fluid velocities, the order of arrangement is reversed. The literature provides a variety of explanations for this phenomenon, derived from quite different theoretical bases. A comparative analysis of these different approaches is presented here together with the experimental results available in the literature. Based on the best model, further experimental investigation is carried out to provide; (i) comprehensive criteria to predict whether a given binary mixture of any type (both size and density variant, size variant only, density variant only) will mix/segregate or show layer inversion, and (ii) mixing/segregation regime map in terms of size ratio and density ratio of the particles for a given fluidizing medium. Therefore, knowing the properties of given particles, a second type of particles can be chosen in order to avoid or to promote segregation according to the particular process requirement.     

Local Electronic Structure Modulation Enables Fast-Charging Capability for Li-Rich Mn-Based Oxides Cathodes With Reversible Anionic Redox Activity

Anionic and cationic redox chemistries boost ultrahigh specific capacities of Li-rich Mn-based oxides cathodes (LRMO). However, irreversible oxygen evolution and sluggish kinetics result in continuous capacity decay and poor rate performance, restricting the commercial fast-charging cathodes application for lithium ion batteries. Herein, the local electronic structure of LRMO is appropriately modulated to alleviate oxygen release, enhance anionic redox reversibility, and facilitate Li⁺ diffusion via facile surface defect engineering. Concretely, oxygen vacancies integrated on the surface of LRMO reduce the density of states of O 2p band and trigger much delocalized electrons to distribute around the transition metal, resulting in less oxygen release, enhancing reversible anionic redox and the MnO₆ octahedral distortion. Besides, partially reduced Mn and lattice vacancies synchronously stimulate the electrochemical activity and boost the electronic conductivity, Li⁺ diffusion rate, and fast charge transfer. Therefore, the modified LRMO exhibits enhanced cyclic stability and fast-charging capability: a high discharging capacity of 212.6 mAh·g⁻¹ with 86.98% capacity retention after 100 cycles at 1 C is obtained and to charge to its 80%, SOC is shortened to 9.4 min at 5 C charging rate. This work will draw attention to boosting the fast-charging capability of LRMO via the local electronic structure modulation.     

煤泥水动电电位的测试与应用

通过对煤泥水动电电位的测试,推断出煤泥水的胶粒结构。通过对各种降低动电电位的混凝剂的测试,得出钙盐是较理想的混凝剂,并确定了电石渣与聚丙烯酰     

The effect of CuO coatings on the electrokinetic properties of stone wool fibres determined by streaming potential measurements

Commercial stone wool fibres were modified with copper(II) oxide coatings. This oxide is widely used in processes of surface modification for filter materials to improve its bacterial retention. The microorganisms are already susceptible to low concentrations of copper in contrast to humans for which copper is an inert material in the concentration range. Additionally, the coatings changed the electrokinetic properties of the fibres. As a result, the isoelectric point (IEP) of the untreated fibres was shifted from acidic towards a more basic pH range. A positive or no charge on the surface of the fibres allows them to be a substrate for the positively charged adsorbents of negatively charged waterborne contaminants with the use of electrostatic adsorption. The coatings were prepared by dip coating with the use of two different coating precursors: the aqueous suspension of CuO nanoparticles and aqueous solutions of copper(II) nitrate trihydrate or copper(II) acetate or a mixture of thereof. The zeta potential of the modified fibres was determined by a streaming potential method. The adhesion of the coatings was tested by flushing and ultrasonication of the modified fibres. The isoelectric point of the fibres was shifted towards a more basic pH range for all precursors with the largest impact of the copper(II) nitrate trihydrate precursor. This coating changed the IEP of the fibres from 4.1 to 8.3 pH value. The highest calculated coverage of the coatings was in the range of 54% and was obtained by using copper(II) nitrate trihydrate/CuO nanoparticles precursor. Although, we do not predict such modified fibres to act as a standalone water filter, we believe they have the potential to be an excellent support material for active adsorbents.     

高温高压CO_2状态方程研究

针对爆轰环境下高温高压气体的热力学状态描述,本研究提出了一种基于Lennard-Jones(LJ)势能函数的对比态维里型状态方程VHL(Viral-Han-Long)。基于该状态方程形式和优化的LJ势参数,计算了爆轰产物气体组分CO_2的压力、体积和温度(pVT)热力学关系,并与VLW状态方程的计算结果进行了比较,结果表明,采用VHL状态方程计算得到CO_2体积平均绝对偏差为0.971%,最大偏差为4.04%,采用VLW状态方程计算所得平均绝对偏差20.2%,最大偏差87.149%。VLW状态方程在描述CO_2的高温高压热力学状态时,具有明显的温度相关性,在爆轰环境温度下,计算所得体积偏差随温度的升高而逐渐减小。与VLW状态方程相比,VHL状态方程能够更好的描述爆轰环境下高温、高压CO_2气体的pVT热力学关系。     

Oxygen Potential Analysis to Evaluate Irradiation Behavior in MOX and MA-Bearing MOX Fuels

Oxygen potentials of oxide nuclear fuels are important thermodynamic data in development of nuclear fuel technologies. Minor actinide bearing MOX （mixed oxide） fuels have been developed as sodium cooled fast reactor fuels. Content of Am which is one of the minor actinide elements causes oxygen potentialto increase. The effects of the oxygen potential increase on the irradiation behavior were evaluated. Profiles of temperature and O/M （oxygen-to-metal） ratio in the pellets were evaluated to better understand the irradiation behavior. From these data, local oxygen potential in the radial direction of the pellets was calculated, and was compared with free energy of compounds composed of fission products. Based on this comparison, it was concluded that Cs2MoO4 was likely formed at pellet periphery of （U07Pu03）O1.98 and （U0.66Pu03Amoo16Npo.016）Ol.976 The extent of cladding tube inner surface oxidation was predicted by using the calculated oxygen potential. No significant difference between irradiation behaviors of （Uo.7Puo3）O2_x and （U0.66PUo 3Amo.016Npo.016）O2.x pellets was confirmed.     

Estimation on oil demand and oil saving potential of China's road transport sector

China is currently in the stage of industrialization and urbanization, which is characterized by rigid energy demand and rapid growth of energy consumption. Therefore, energy conservation will become a major strategy for China in a transition to low-carbon economy. China's transport industry is of high energy consumption. In 2010, oil consumption in transport industry takes up 38.2% of the country's total oil demand, of which 23.6% is taken up by road transport sector. As a result, oil saving in China's road transport sector is vital to the whole nation. The co-integration method is developed to find a long-run relationship between oil consumption and affecting factors such as GDP, road condition, labor productivity and oil price, to estimate oil demand and to predict future oil saving potential in China's transport sector under different oil-saving scenarios. Monte Carlo simulation is further used for risk analysis. Results show that under BAU condition, oil demand of China's road transport sector will reach 278.5 million ton of oil equivalents (MTOE) in 2020. Oil saving potential will be 86 MTOE and 131 MTOE under moderate oil-saving scenario and advanced oil-saving scenario, respectively. This paper provides a reference to establishing oil saving policy for China's road transport sector.     

全钒液流电池充放电测试系统设计

针对全钒液流电池的测试需求,文章对全钒液流电池的工作原理进行介绍,根据全钒液流电池运行参数,设计了一种用于全钒液流电池容量测试所需的自动充放电测试系统。该系统能对全钒液流电池进行恒压、恒流充电以及恒流放电测试,并具有监测单体电池电压功能,在测试过程对电池提供安全保护功能,并对数据进行保存和查看。使用设计的充放电测试系统对全钒液流电堆进行充放电测试,分析了能量效率与充电电流的关系。实验结果显示,该系统能够完成钒电池容量测试,对钒电池测试系统研究以及钒电池测试标准建立有重要参考意义。     

柴达木盆地石炭系油气勘探前景

柴达木盆地石炭系油气勘探长期以来一直未取得大的突破。在对研究区石炭系构造特征、沉积特征、烃源岩地球化学特征、油气源对比等综合分析的基础上,对其油气勘探前景进行评价。研究结果表明,柴达木盆地石炭系烃源岩类型主要包括泥岩、炭质泥岩、煤和灰岩;北缘烃源岩最具勘探潜力,有机质丰度高,有机质类型以Ⅱ型和Ⅲ型为主,处于成熟—高成熟阶段,具备良好的生烃潜力;多期构造运动控制了油气形成期次及其后期分布范围;露头区油气显示及油源对比结果进一步证实,石炭系烃源岩经历了生、排烃过程,油气成藏受构造控制作用明显,北缘石炭系具有早期生烃、断裂输导、调整成藏的成藏模式。     

阻垢缓蚀剂对不锈钢管缓蚀效果的评定方法

用点蚀电位法和失重法评价了七种阻垢缓蚀剂在不同冷却水样中对不锈钢的缓蚀效果。用腐蚀失重法评价阻垢缓蚀剂对不锈钢的缓蚀效果，既不合理也很难测准。点蚀电位法是评价阻垢缓蚀剂对不锈钢缓蚀效果的有效方法，但要选择合适的空白水样。