Isolation of Solid Solution Phases in Size‐Controlled LixFePO4 at Room Temperature

State‐of‐the‐art LiFePO₄ technology has now opened the door for lithium ion batteries to take their place in large‐scale applications such as plug‐in hybrid vehicles. A high level of safety, significant cost reduction, and huge power generation are on the verge of being guaranteed for the most advanced energy storage system. The room‐temperature phase diagram is essential to understand the facile electrode reaction of Li_xFePO₄ (0 < x < 1), but it has not been fully understood. Here, intermediate solid solution phases close to x = 0 and x = 1 have been isolated at room temperature. Size‐dependent modification of the phase diagram, as well as the systematic variation of lattice parameters inside the solid‐solution compositional domain closely related to the electrochemical redox potential, are demonstrated. These experimental results reveal that the excess capacity that has been observed above and below the two‐phase equilibrium potential is largely due to the bulk solid solution, and thus support the size‐dependent miscibility gap model.     

Effects of scatter and attenuation correction on quantitative assessment of regional cerebral blood flow with SPECT

The pyruvate dehydrogenase complex (PDC) plays a key role in the anaerobic mitochondrial metabolism of the parasitic nematode Ascaris suum. A cDNA coding for an A. suum pyruvate dehydrogenase kinase (APDK) has been cloned and sequenced from poly(A)+ RNA isolated from adult A. suum muscle.2 APDK exhibited significant sequence identity to mammalian PDKs. Nucleotide sequence analysis of the APDK cDNA revealed a 22-nucleotide spliced leader, characteristic of many nematode mRNAs, a 5'-UTR of 6 nucleotides, an open reading frame of 1197 nucleotides, and a 3'-UTR of 101 nucleotides that included a putative polyadenylation signal. The open reading frame predicted a protein of 399 amino acids with a molecular weight of 45,402 that included a putative 18-aminoacid leader peptide. Recombinant APDK (rAPDK) was functionally expressed in Escherichia coli with a his tag at its N-terminus and purified to apparent homogeneity on Ni-NTA-agarose. Recombinant APDK was a dimer and was not autophosphorylated and its activity was stimulated in the presence of APDK-deficient adult A. suum muscle PDC presumably by the binding of APDK to the dihydrolipoyl transacetylase (E2) core of the complex. After binding to the core, rAPDK activity was stimulated by elevated NADH/NAD+ and acetyl CoA/CoA ratios within the same ranges as observed for the native APDK. Immunoblotting suggested that native APDK focused as a series of 43-kDa spots (pI 6.1-6.8) on two-dimensional gels of the purified adult A. suum muscle PDC.     

Direct-vision-based reinforcement learning in a real mobile robot

It was confirmed that a real mobile robot with a simple visual sensor could learn appropriate motions to reach a target object by direct-vision-based reinforcement learning (RL). In direct-vision-based RL, raw visual sensory signals are put directly into a layered neural network, and then the neural network is trained using back propagation, with the training signal being generated by reinforcement learning. Because of the time-delay in transmitting the visual sensory signals, the actor outputs are trained by the critic output at two time-steps ahead. It was shown that a robot with a simple monochrome visual sensor can learn to reach a target object from scratch without any advance knowledge of this task by direct-vision-based RL. This work was presented in part at the 7th International Symposium on Artificial Life and Robotics, Oita, Japan, January 16–18, 2002     

Analysis of main pigments and other ingredients in lac color product

The contents of the main pigments and other ingredients in commercial lac color products were determined by HPLC using an RP-18 column with 0.1 mol/L citric acid buffer solution-methanol (16:5) as the mobile phase, and a photodiode array (PDA) detector set at 280 nm and 490 nm. The main pigments were confirmed by PDA and electrospray ionization mass spectrometry. Laccaic acids A, B, C and E were detected in all lac color products, and the ratio of content of laccaic acid A in all products was over 50%. The total contents of laccaic acids A, B and C in lac color food additive products and reagent products were 775-858, 797 and 779 g/kg, respectively. As for the contents of ingredients except pigments in commercial food additive products, the maximum moisture content was about 10%, and ether-soluble substances amounted to 0.5-3.6%.     

Exact Analysis of a One-Dimensional Attractive δ-Function Fermi Gas with Arbitrary Spin Polarization

We study a one-dimensional integrable system of N spin-1/2 fermions with attractive δ-function interaction at zero temperature. The Gaudin integral equation describing the ground state with arbitrary spin polarization is solved in the form of power series. We also study the ground state energy as a function of the coupling constant and the polarization.     

New DC Chopper Circuits Using Fast-Switching Reverse-Conducting Thyristors for Low-Voltage DC Motor Control

Fast- switching reverse-conducting thyristors have been developed and used in dc chopper apparatus to control the speed of highvoltage dc traction motors. The newly developed dc chopper circuit and its application for low-voltage dc motor control are discussed. The fast-switching reverse-conducting thyristor is utilized as the main thyristor to control load current.     

Power limits for secondary devices operating on TV white spaces

The use of TV white spaces as an alternative to overcome spectrum scarcity is a huge opportunity for new telecommunication systems and services. While being attractive for its desirable propagation characteristics, this part of the spectrum imposes a major difficulty from design and regulatory perspectives: how to optimize the use of spectrum and to ensure the protection of primary users, TV systems for example, at the same time. This paper discusses strategies to be adopted by geo-location database operators to calculate adaptive maximum permitted power levels for secondary devices, according to permissible levels of interference into the digital terrestrial television primary system.