A 68-ns 4-Mbit CMOS EPROM with high-noise-immunity design

In a VLSI memory, noise generated by its own operation is a serious problem. The noise disturbs data sensing, especially in EPROMs which have a single-ended sensing scheme. To develop high-density and high-speed EPROMs, it is necessary to solve the noise problems. Incorrect EPROM functions due to the noise are discussed. High-noise-immunity circuit techniques for stable data sensing and high-speed access time are proposed. These are divided bit-line layout, reference line with dummy bit lines, and a chip-enable transition detector. Using these circuit techniques and 0.8-μm n-well CMOS technology, a 512 K×8-b CMOS EPROM was developed. A 68-ns access time was achieved. The die size is 5.62 mm×15.30 mm, and it is assembled in a 600-mil cerdip package     

Electrical and optical properties of electrochemically prepared polyselenophene film

The electrical, optical and magnetic properties of flexible shiny films of polyselenophene obtained by the electrochemical method are studied. The electrical conductivity of doped polyselenophene is found to be much lower than that of polythiophene and polypyrrole, which is consistent with its relatively wider ESR linewidth even after doping. The photovoltaic effect is also observed in this polymer and discussed in comparison with optical absorption spectra.     

Molecular evidence from retroposons that whales form a clade within even-toed ungulates

The origin of whales and their transition from terrestrial life to a fully aquatic existence has been studied in depth. Palaeontological, morphological and molecular studies suggest that the order Cetacea (whales, dolphins and porpoises) is more closely related to the order Artiodactyla (even-toed ungulates, including cows, camels and pigs) than to other ungulate orders. The traditional view that the order Artiodactyla is monophyletic has been challenged by molecular analyses of variations in mitochondrial and nuclear DNA. We have characterized two families of short interspersed elements (SINEs) that were present exclusively in the genomes of whales, ruminants and hippopotamuses, but not in those of camels and pigs. We made an extensive survey of retropositional events that might have occurred during the divergence of whales and even-toed ungulates. We have characterized nine retropositional events of a SINE unit, each of which provides phylogenetic resolution of the relationships among whales, ruminants, hippopotamuses and pigs. Our data provide evidence that whales, ruminants and hippopotamuses form a monophyletic group.     

Individual identification of cadaver parts after a bomb explosion using oligonucleotide fingerprinting by (GTG)5

A blind shell suddenly and unexpectedly exploded, and 20 dismembered human remains were discovered. DNA fingerprint was performed to determine whether the 20 human remains were derived from one person or not. DNA was isolated from each of the remains and digested by the restriction enzyme Hinf I and Hae III and hybridized with the oligonucleotide probe (GTG)5. DNA fingerprint using Hinf I demonstrated the same band pattern in 17 out of the 20 remains. However, in the remaining 3 samples, two novel strange bands were observed. DNA fingerprint using Hae III showed completely identical pattern in all of the remains.     

A 500-megabyte/s data-rate 4.5 M DRAM

A 512-kb×9 DRAM with a 500-Mbyte/s data transfer rate was developed. This high data rate was achieved by designing a DRAM core with a very high internal column bandwidth, and coupling this core with a block-oriented, small-swing, synchronous interface that uses skew-canceling clocks. The DRAM has a 1-kbyte×2-line sense-amp cache and is assembled in a 32-pin vertical surface-mount-type plastic package. The measurement results clearly verified the 500-Mbyte/s data rate     

Ionic conductivities of hollandites

Three kinds of hollandite, K_xZn_x/2Ti_8?x/2O₁₆ and K_xFe_xTi_8?x, were sintered at 1200°C for 5 h and the single phases were found in the composition range of 1.6 ≦ x ≦ 2.0 by X-ray diffraction. The measured impedances were plotted against three kinds of variable and the samples were electrolysed to make clear the mobile species. The polycrystalline hollandites showed the potassium ion conductivities of the order of magnitude of 10^?4 (Ohm·cm)^?1 at 300°C.     

Exact splice loss prediction for single-mode fiber

This paper describes the direct measurement method of spot size for single-mode fibers and its application to the splice loss prediction. Using a core-centering-type automatic fusion splicing machine, predicted splice loss is examined for several MCVD and VAD fibers. The accuracy of splice loss predicted by this method is better than that calculated from core radius and refractive index. The experimental splice loss is equal to the sum of the loss predicted by this method and the loss caused by the splicing technique.