InP/Al2O3n-channel inversion-mode m.i.s.f.e.t.s using sulphur-diffused source and drain

InP metal-insulator-semiconductor field-effect transistors (m.i.s.f.e.t.s) have been fabricated using c.v.d. Al2O3 as the gate insulator and the sulphur-diffusion process for source and drain. The n-channel inversion-mode device exhibits normally off behaviour. A maximum d.c. transconductance gm of 10 mS (87 mS/mm of gate width) has been obtained.     

n-channel formation on semi-insulating InP surface by m.i.s.f.e.t.

InP m.i.s.f.e.t.s using Fe-doped semi-insulating material surface have been fabricated. The devices, composed of sulphur-diffused n-type source and drain and c.v.d. Al2O3 gate insulator, exhibited n-channel normally-off behaviour and a source drain capacitance two orders of magnitude smaller than that of p-InP m.i.s.f.e.t.s with the same dimensions.     

Selectively ion implanted Gunn-f.e.t. integrated circuits for pulse regenerator

A planar GaAs integrated Gunn-effect device and f.e.t. connected in cascade have been fabricated using selective sulphur-ion implantation. High-speed pulse regeneration and pulse amplification have been realised under d.c. bias condition. Output voltage and voltage gain of the regenerated pulse of 1 ns width were 1.7 V and 18.6 dB, respectively.     

Coplanar-guide and slot-guide junction circulators

A variety of Y circulators derived from the coplanar or slot guide, whose feasibilities are verified experimentally, are presented. The indication is added that the field-confinement scheme may profitably be resorted to.     

Production of anti-CD2 chimeric antibody by recombinant animal cells

Expression vectors for chimeric anti-CD2 antibody were constructed in order to clarify the importance of the expression ratio of heavy (H-) and light (L-) chains of antibody to antibody production in animal cells. The antibody genes were introduced into cells using plasmid DNA vectors or replication-defective retroviral vectors. Productivity was maximal when the expression ratio of H-and L-chains was 1:1, and decreased when the ratio was not equal. We also examined the expression of antibody using one-packed vectors in which the bicistronic expression of H- and L-chain genes was mediated by an internal ribosomal entry site (IRES) sequence derived from encephalomyocarditis virus (EMCV). The translation efficiency was unbalanced between 5'Cap- and IRES-dependent genes. Using the retroviral vectors, it was estimated that the IRES-dependent translation efficiency was 5-fold lower than the 5'Cap-dependent translation efficiency. The cells exhibiting an unbalanced expression of H- and L-chains tended to accumulate H-chain protein.     

Asymptotic Correlations Between Rotated Solutions in Factor Analysis

The asymptotic correlations between differently rotated solutions in exploratory factor analysis are derived. The solutions are orthogonally or obliquely rotated for unstandardized or standardized manifest variables. To obtain the asymptotic correlations between different solutions, the covariance models for manifest variables have been constructed so that two sets of solutions are involved in a single covariance structure. The asymptotic correlations can be used for the statistical test of the differences of rotated solutions. The correlation matrix between the rotated factors of the first solution and those of the second is also introduced in the models with appropriate restrictions to identify the models. The asymptotic standard errors of the estimates of the correlations between the factors in different solutions are simultaneously provided. A numerical example is presented with simulated values.

     

Hydrogen storage and thermal conductivity properties of Mg-based materials with different structures

Mg-based hydrogen storage materials can be very promising candidates for stationary energy storage application due to the high energy density and low cost of Mg. Hydrogen storage kinetics and thermal conductivity are two important factors for the material development for this kind of application. Here we studied several types of Mg-based materials with different structure-micrometer scale Mg powders, Mg nanoparticles, single crystal Mg, nanocrystalline Mg₅₀Co₅₀ BCC alloy and Mg thin film samples. It seems the Mg materials with good kinetics usually are the ones with nanostructure and tend to show poor thermal conductivity due to electron/phonon scattering resulting from more interfaces and boundaries in nanomaterials. Based on this work, good crystallinity Mg phase incorporated in carbon nano framework could be one promising option for energy storage.