Synthesis by Spark Plasma Sintering: A new way to obtain electrode materials for lithium ion batteries

In the search of high-performance materials for lithium ion batteries, Li₂CoPO₄F offers many advantages like high theoretical capacity and high operating potential. The synthesis of Li₂CoPO₄F has been reinvestigated considering a conventional solid state reaction and an unconventional way. Due to the long heat-treatments required by the conventional approach, a beginning of grains coalescence is observed. Limiting particles growth has been allowed by a shorter reaction done by SPS (Spark Plasma Sintering). By this method, the synthesis of Li₂CoPO₄F was greatly shortened (from 10 h to 9 min), which favours the getting of submicrometric particles. The comparison of the electrochemical properties of the Li₂CoPO₄F obtained by the different ways confirms the advantages of SPS synthesis in performance enhancement.     

Electrochemical characteristics of Li2−xVTiO4 rock salt phase in Li-ion batteries

Li_2−xVTiO₄/C sample with a disordered rock salt structure was successfully prepared by annealing at a temperature of 850 °C. The electrochemical oxidation in the first cycle occurs at voltages above 4 V vs. metallic lithium, while the shapes of the electrochemical curves in consequent reduction-oxidation processes show a monotonous change of the potential between the selected cut-off voltages. A linear combination fit of individual XANES spectra was used for the determination of the oxidation states of as prepared sample and intermediate states during oxidation and reduction. In the as-prepared sample, vanadium was found to be in the average oxidation state of V^3.5+ and was additionally oxidized to V^3.8+ by the electrochemical charging. During the discharge process, the vanadium oxidation state was reduced to V^3.0+. In situ X-ray diffraction patterns and EXAFS analysis suggest good structural stability during oxidation and reduction, which is also reflected in the cycling stability if batteries were cycled in the voltage window between 2.0 V and 4.4 V. Extension of the lower cut-off voltage to 1.0 V doubles the capacity retention with the improved capacity stability if compared with several high capacity vanadium based materials.     

The inherently integrative approach of positive psychotherapy.

Positive Psychotherapy (PPT) is a therapeutic metatheory and approach that was developed in 1968 by Dr. Nossrat Peseschkian. His contribution to psychotherapy is not to be confused with what is being called PPT and is an outgrowth of Positive Psychology begun by Dr. Martin Seligman in the U.S. Peseschkian's approach to therapy is inherently and systematically integrative, along the lines of being cross-cultural, multidisciplinary, therapeutically, and psychologically intertheoretic. This article presents some basic premises of PPT: the use of stories; having a positive starting point; basic and actual capacities; five-stage therapeutic model; as well as mentioning other aspects of PPT and a case study. PPT is well suited to therapists advocating integrative psychotherapy as demonstrated by empirical research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

含有符号矩阵的Hadamard积的性质

给出了含符合矩阵的性质及数值特征．     

台北凹陷反转构造特征与油气关系浅析

分析解剖了吐哈盆地台北凹陷几个典型的反转构造，结合已知油气田的分布特点，从区域构造演化的角度，探讨了反转构造与油气聚集的关系。认为台北凹陷的反转构造主要发育在侏罗纪，表现为逆断层上盘的中，下侏罗统厚度明显加大，是由早期的同生正断层在晚期在逆断层方式活动形成的断层上盘的正反转构造，其发展演化与区域应力场的演变息息相关。     

La mesure de perfectionnisme: Validation canadienne-fran?aise du Positive and Negative Perfectionism Scale.

The purpose of this study was to verify the validity of a French version of the Positive and Negative Perfectionism Scale developed by L. A. Terry-Short (1995). This instrument measures the type as well as the level of perfectionism in adolescents. The instrument was first administered to 734 7th, 9th, and 11th grade students. Four weeks later, 596 Ss were invited to answer the questionnaire once more. The factorial structure, temporal stability and internal consistency of each subscales of the translated version of the instrument correspond to those of the original version. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

导电SBS/SBR复合材料的研究

本文研究了碳黑填充ＳＢＳ／ＳＢＲ复合材料的基本电性能，对复合材料电阻率随温度的变化特性进行了详细研究。讨论了碳黑种类、结构和性质、填充浓度以及ＳＢＳ含量对复合材料电阻率和电阻——温度特性的影响。实验结果指出，碳黑（Ｎ５５０）／ＳＢＳ／ＳＢＲ（ＳＢＳＳＢＲ＝１１ｗｔ）复合材料的电阻率随温度的变化呈一定强度的正温度系数（ＰＴＣ）效应。     

电子束曝光UV3正性抗蚀剂的工艺研究

为了在体硅CMOSFinFET中用等离子体腐蚀精细凹槽图形，研究了将电子束直写曝光用于原为深紫外光学曝光的UV3正性抗蚀剂的工艺技术；详细分析了包括膜厚、曝光能量、曝光剂量、显影时间、设计尺寸和衬底材料等在内的各类工艺参数与实际曝光图形效果的关系；特别指出了曝光过程中特有的延迟效应及解决办法。采用最终的优化工艺条件，得到了合适的图形效果。     

随机需求条件下供应链的补货及折扣策略研究

研究一个供应商和多个零售商围绕单品种商品组成的供应链体系中,以供应商为核心的供应链库存管理,目标是通过直接降低供应商的库存成本,从而降低供应链的总成本.假设每个零售商面对服从随机正态分布的提前期客户需求,在不考虑交货时间的情况下,供应商在固定的时间间隔满足零售商的补货需要,并以价格折扣的方式补偿零售商的成本增加.由此得到较优的补货间隔,并给出了求解方法.最后,通过仿真验证了该解法的可行性并评估了该策略对各方的影响.     

LiFePO4: From molten ingot to nanoparticles with high-rate performance in Li-ion batteries

LiFePO₄ (LFP) particles were obtained by grinding ingot synthesized in the molten state. This process, followed by jet milling, and then wet milling, provides a simple way to obtain powders with controlled particle size in the range from macroscopic to 25 nm. However, at this time, we find that these particles tend to agglomerate to form secondary particles of size ∼100 nm. The particles obtained by this process are characterized by X-ray diffraction (XRD). In situ and ex situ scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of milling was also investigated by analysis of physical properties using infrared spectroscopy (FTIR) and magnetic measurements. The electrochemical performance was evaluated in cells containing Li/1 M LiPF₆ in EC:DEC (1:1)/C-LiFePO₄. After carbon coating, the LFP particles which are free of impurities, exhibit high-rate capability. Even with a limited amount of carbon (2 wt.%) appropriate for commercial batteries, the capacity is 157 mAh g⁻¹ at 0.1 C, 120 mAh g⁻¹ at 10 C, without capacity fading after 60 cycles.