Electrochemical hydrogen storage performance of as-cast and as-spun RE-Mg-Ni-Co-Al-based alloys applied to Ni/MH battery

The La-Mg-Ni-Co-Al-based AB₂-type La_0.8–xCe_0.2Y_xMgNi_3.4Co_0.4Al_0.1 (x=0, 0.05, 0.1, 0.15, 0.2) alloys were prepared via melt spinning. The analyses of the X-ray diffraction (XRD) and scanning electron microscopy (SEM) proved that the experimental alloys contain the main phase LaMgNi₄ and the second phase LaNi₅. Increasing Y content and spinning rate lead to grain refinement and obvious change of the phase abundance without changing phase composition. Y substitution for La and melt spinning make the life-span of the alloys improved remarkably, which is attributed to the improvement of anti-oxidation, anti-pulverization and anti-corrosion abilities. In addition, the discharge capacity visibly decreases with increasing the Y content, while it firstly increases and then decreases with increasing spinning rate. The electrochemical kinetics increases to the optimum performance and then reduces with increasing spinning rate. Moreover, all the alloys achieve to the highest discharge capacities just at the initial cycle without activation.     

铸管厂球墨铸铁管烘干炉技术改造

随着铸管机的生产能力从14万吨增加到20万吨,烘干炉已不能满足生产与工艺要求,铸管出炉温度只有40℃左右,无法烘干固化表面防腐层,导致表面质量较差。在减少投资和运营成本的前提下,对烘干炉的燃烧系统、热风循环系统、控制系统进行改造。在不改变炉体整体结构与尺寸的情况下,把原有加热与循环系统分离的方式改为加热循环一体式。热风系统由原来的从头部到尾部的大循环方式改为上下对吹,中部回风的方式,提高风速及对流换热系数,使炉温从50℃升高到了100℃,铸管出炉温度达60℃以上,保证了扩能后的生产能力。     

A novel method for preparing LiFePO4 nanorods as a cathode material for lithium-ion power batteries

An effective method for synthesizing a one-dimensional nanostructure to improve the rate performance of LiFePO₄ as the cathode material for Li-ion power batteries is described. The crystal structure, composition, and morphology of the prepared LiFePO₄ were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM), respectively. The reaction mechanism of the LiFePO₄ nanorods is discussed herein. Electrodes consisting of the LiFePO₄ nanorods have better rate discharge capacities over a potential range of 2.5-4.2 V (vs. Li⁺/Li). These results are attributed to the shorter distance of electron transport and the fact that ion diffusion in the electrode material is limited by the nanorod radius. Our results indicate that the prepared LiFePO₄ nanorods are promising cathode materials for Li-ion power batteries. This new process for synthesizing nanorod products from nanorod raw material can be extended to the preparation of other one-dimensional materials.     

Friction stir welding of aircraft wings

ABSTRACT

To reduce the weight of the wings of the TU-204SM aircraft, investigations were carried out to design the upper wing panel made of the V-1469 high-strength aluminium–lithium alloy of the third generation. The technology of friction stir welding was developed and fragments of the welded panel produced. The tests of the stability under compression showed that the application of the welded panels reduces the weight of the wing by up to ~10% and increases the stability and load carrying capacity by up to ~30%.     

高比容量镍氢电池的制备及电化学性能

Cylindrical nickel metal hydride （Ni-MH） battery with high specific volume capacity was prepared by using the oxyhydroxide Ni（OH）2 and AB5 type hydrogen storage alloy and adjusting the designing parameters of positive and negative electrodes. The oxyhydroxide Ni（OH）2 was synthesized by oxidizing spherical β-Ni（OH）2 with chemical method. The X-ray diffraction （XRD） patterns and the Fourier transform infrared （PT-IR） spectra indicated that 7-NiOOH was formed on the oxyhydroxide Ni（OH）2 powders, and some H2O molecules were inserted into their crystal lattice spacing. The battery capacity could not be improved when the oxyhydroxide Ni（OH）2 sample was directly used as the positive active materials. However, based on the conductance and residual capacity of the oxyhydroxide Ni（OH）2 powders, AA size Ni-MH battery with 2560 mA.h capacity and 407 W·h·L^-1 specific volume energy at 0.2C was obtained by using the commercial spherical β-Ni（OH）2 and AB5-type hydrogen-storage alloy powders as the active materials when 10% mass amount of the oxyhydroxide Ni（OH）2 with 2.50 valence was added to the positive active materials and subsequently the battery designing parameters were adjusted as well. The as-prepared battery showed 70% initial capacity after 80 cycles at 0.5C. The possibility for adjusting the capacity ratio of positive and negative electrodes from 1 ： 1.35 to 1 ： 1.22 was demonstrated preliminarily. It is considered the as-prepared battery can meet the requirement of some special portable electrical instruments.     

方钠石的合成及其吸水性能研究

以工业原料采用水热法在不同硅铝比(投料比)下合成了方钠石,利用XRD对产物进行了表征,讨论了碱度(H_2O/Na_2O、Na_2O/SiO_2)、晶化温度、晶化时间对沸石结晶的影响,通过实验研究得到了在不同硅铝比(投料比)下方钠石的结晶变化规律,并优化出最佳合成工艺条件;另外,对合成的方钠石进行了Li~+、K~+离子交换,研究了其吸水性能。     

Isolation,Culture and Comprehensive Characterization of Biological Properties of Human Urine-Derived Stem Cells

Mesenchymal stem cells (MSCs) represent an attractive source within the field of tissue engineering. However, their harvesting often requires invasive medical procedures. Urine-derived stem cells (UDSCs) display similar properties to MSCs, and their obtention and further processing is non-invasive for the donors as well as low cost. Here, we offer a comprehensive analysis of their biological properties. The goal of this study was to analyze their morphology, stemness, differentiation potential and cytokine profile. We have successfully isolated UDSCs from 25 urine samples. First colonies emerged up to 9 days after the initial seeding. Cell doubling time was 45 ± 0.24 SD, and when seeded at the density of 100 cells/cm², they formed 42 ± 6.5 SD colonies within 10 days. Morphological analyzes revealed that two different types of the cell populations have been present. The first type had a rice-grain shape and the second one was characterized by a polyhedral shape. In several cell cultures, dome-shaped cells were observed as well. All examined UDSCs expressed typical MSC-like surface markers, CD73, CD90 and CD105. Moreover, conditioned media from UDSCs were harvested, and cytokine profile has been evaluated showing a significantly higher secretory rate of IL-8, IL-6 and chemokines MCP-1 and GM-CSF. We have also successfully induced human UDSCs into chondrogenic, osteogenic and myogenic cell lineages. Our findings indicate that UDSCs might have immense potential in the regeneration of the damaged tissues.     

过磷酸钙装置的技术改造

广东云浮硫铁矿企业集团公司化工厂利用少量资金,在4年时间里,对过磷酸钙装置进行一系列技术改造,使1套原设计为5万吨／年生产能力的过磷酸钙装置达到了20万吨／年,产品成本降低,市场竞争力加强。     

Implications from γ-globulin adsorption onto cation exchangers fabricated by sequential alginate grafting and sulfonation

Our previous work proved that high adsorption capacity and uptake rate of lysozyme were achieved on alginate(Alg)-grafted re sin with an ionic capacity(IC) of 240 mmol·L~(-1)(Alg-FF-240).Moreover,the salt-tolerant feature of Alg-FF-230 was improved by using sequential alginate grafting and sulfonation strategy.Inspired by the enhanced adsorption performance of lysozyme,we have herein proposed to investigate the static and dynamic adsorption behaviors of γ-globulin on a series of Alg-grafted resins with different grafting densities and sulfonation degrees.The adsorption ca pacity of γ-globulin decreased with increa sing alginate-grafting density(IC) from 160 to 230 mmol·L~(-1) at 0 mmol·L~(-1) NaCl because of the steric hindrance caused by the alginate-grafting layer.Effects of ionic strength(IS) indicated that the adsorption capacities of the resins with the IC value of 230-370 mmol·L~(-1) were much higher than CM Sepharose FF at 50-100 mmol·L~(-1) NaCl,and the uptake rate of Alg-FF-230 was about twice as much as that of CM Sepharose FF.This work demonstrated the important effects of alginate-grafting layer and IS in γ-globulin adsorption behavior,which would be helpful in the design of Alggrafted resins and the selection of proper IS condition for protein purification.     

Prediction and verification of heat capacities for pure ionic liquids

The heat capacity of ionic liquids is an important physical property,and experimental measuring is usually used as a common method to obtain them.Owing to the huge number of ionic liquids that can be potentially synthesized,it is desirable to acquire theoretical predictions.In this work,the Conductor-like Screening Model for Real Solvents(COSMO-RS) was used to predict the heat capacity of pure ionic liquids,and an intensive literature survey was conducted for providing a database to verify the prediction of COSMO-RS.The survey shows that the heat capacity is available for 117 ionic liquids at temperatures ranging 77.66-520 K since 2004,and the 4025 data points in total with the values from 76.37 to 1484 J·mol~(-1)·K~(-1) have been reported.The prediction of heat capacity with COSMO-RS can only be conducted at two temperatures(298 and 323 K).The comparison with the experimental data proves the prediction reliability of COSMO-RS,and the average relative deviation(ARD) is 8.54%.Based on the predictions at two temperatures,a linear equation was obtained for each ionic liquid,and the heat capacities at other temperatures were then estimated via interpolation and extrapolation.The acquired heat capacities at other temperatures were then compared with the experimental data,and the ARD is only 9.50%.This evidences that the heat capacity of a pure ionic liquid follows a linear equation within the temperature range of study,and COSMO-RS can be used to predict the heat capacity of ionic liquids reliably.