Showing papers by "Chiba Institute of Technology published in 1981"
TL;DR: In this paper, the authors report that Nitrate in Antarctic soils is extremely depleted in 15N compared with biogenic nitrogen, and algae collected from a nitrate-rich saline pond and from a penguin rookery exhibit, respectively, the lowest and the highest 15N/14N ratios among terrestrial biogenic NOs so far observed.
Abstract: Antarctica offers a unique natural environment from the point of view of nitrogen cycling. Ice-free dry areas,‘Antarctic oases’, and penguin rookeries are of particular interest because of the characteristic distribution of nitrate deposits1–4 and biological materials such as algae and guano. As the distribution of 15N/14N in a geochemical system reflects sources and metabolic pathways of nitrogen5, a study of the nitrogen isotopic composition of Antarctic samples would help us to understand the Antarctic nitrogen cycle. Here we report that nitrate in Antarctic soils is extremely depleted in 15N compared with biogenic nitrogen, and that algae collected from a nitrate-rich saline pond and from a penguin rookery exhibit, respectively, the lowest and the highest 15N/14N ratios among terrestrial biogenic nitrogen so far observed. We also discuss possible causes of these extreme nitrogen isotopic compositions.
109 citations
TL;DR: The presence of very long-chain n-alkanoic acids extending to C40, having a small even-carbon predominance, and comprising a large proportion of the fatty acids in Antarctic soils is reported.
Abstract: Studies of geochemical samples have shown that fatty acids are widely distributed in sediments ranging in geological age from Recent to Precambrian1–9. Most n-alkanoic acids found in soils and Recent sediments show similarities in their distributions, such as a marked predominance of even-carbon numbered acids and a bimodal distribution with two maxima in carbon chain length of C14 to C18 and C24 to C28 (refs 1, 2, 4–7). Long-chain n-alkanoic acids (≥C20) predominate in the waxes of vascular plants10,11, whereas short-chain n-alkanoic acids (
24 citations
TL;DR: In this article, the appearance energy of NO 2 + from CH 3 NO 2 is close to the thermodynamic onset for CH 3 + NO 2+ while CH 3+ appears 1.2 eV above the onset.
23 citations
TL;DR: In this article, 5′-Se-(2-Nitrophenyl)-5′-selenoadenosine (3) was selectively synthesized by the reaction of adenosine with 2-nitrophensylselenocyanate and tri-n-butylphosphine.
Abstract: 5′-Se-(2-Nitrophenyl)-5′-selenoadenosine (3) was selectively synthesized by the reaction of adenosine with 2-nitrophenylselenocyanate and tri-n-butylphosphine. The selenide 3 was oxidized by treatment with excess hydrogen peroxide to the corresponding selenoxide (4), which readily undergo syn elimination under mild conditions to give the corresponding 9-(5-deoxy-β-D-erythro-pent-4-enofuranosyl)-adenine (5) in good yield.
7 citations
TL;DR: In this article, the wear and frictional behaviour of compressed molybdenum disulphide (MoS2) pellets were measured when the pellets were slid against a 0.45% C steel disk in air.
5 citations
TL;DR: In this article, an exponential function of the grain size was assumed in calculating the apparent (total) dielectric constant of BaTiO3 thick films with the average grain diameter known.
Abstract: An exponential function of the grain size was assumed in calculating the apparent (total) dielectric constant of BaTiO3 thick films with the average grain diameter known. The function was tested and estimated experimentally, for cases where the grain sizes were calculated using the following methods; the two-dimensional diameter analysis, the Schwartz-Saltykov method and Oel's method for converting a two-dimensional grain distribution to a spacial grain sizedistribution. Using the present assumed function and the extended logarithmic mixing rule to combine the dielectric constants of individual grains, the grain-size distribution-dependence of the dielectric constant was successfully simulated. From the simulated results it was concluded that the dielectric constants of coarse grains of thick films increase with increase of grain size in the range from room temperature up to 135°C.
5 citations
TL;DR: In this paper, an analytical study on the phenomenon called mid-frequency resonance is described, which is frequently observed with pronounced oscillation when a step motor is driven in open-loop mode at relatively high input pulse rate.
1 citations
TL;DR: A vacuum-pipeless laser strainmeter has been designed, tested, and is described and has successfully recorded solid tidal strains.
Abstract: A vacuum-pipeless laser strainmeter has been designed, tested, and is described. The strainmeter has a compensator for the change of the refractive index of air which is determined by Edlen’s formula using measured values of atmospheric pressure and temperature. The effect of air-condition change was compensated by the compensator, and residual of the effect was less than ±5 × 10−9 for 75 h. The strainmeter has successfully recorded solid tidal strains.
1 citations
TL;DR: In this article, a laser beam directed normally to the surface of the chip forms a reflection diffraction image which conisists of a pair of straight lines intersecting orthogonally on the optical axis.
Abstract: plane and the rotating angle (θ) in it's plane. This paper describes one of the methods how to control automatically these attitude angles of IC chip plane. A laser beam directed normally to the surface of the chip forms a reflection diffraction image which conisists of a pair of straight lines intersecting orthogonally on the optical axis. Then, by finding the point of intersection of these orthogonal lines it is possible to determine two degrees of inclination of the chip. Moreover, the displacement angle within the refraction image will be the unaltered angle of rotation of the chip. In order to observe these angles, the four photoelectric microscopes are arranged arround a fixed axis and rotated by a stepping motor to provide a circular scan. After computation based on the number of pulses by a minicomputer, the three control stepping motors are driven simultaneously while comparing the pulses count with computation results; at the appropriate time each of the stepping motors is stopped. We have confirmed that the angular positioning errors can be held within a standard deviation of approximately 20 seconds of arc, for θ, and 1