巻号一覧
37 巻 (1991)
- 4 号 p. 311-
- 3 号 p. 217-
- 2 号 p. 125-
- 1 号 p. 1-
37 巻, 2 号
選択された号の論文の6件中1～6を表示しています
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萩原 幸男1991 年 37 巻 2 号 p. 125-134
発行日: 1991/09/25
公開日: 2010/09/07
ジャーナル フリーRecently a somewhat mystifying hypothesis suggests that the inverse-square law of the Newtonian gravitation may not hold good for short mass separations. If this hypothesis is real, the conventional Newtonian gravitational constant behaves as a constant at very large distances but a function of the mass separation in the laboratory distance scale. On the basis of the elementary particle theory, this function is defined as an additional term exponentially decreasing with the mass separation, which is called "Yukawa potential term" on the analogy of meson dynamics in nucleonics. It was really surprizing that the Australian research group detected the Yukawa potential term and determined its parameters by gravity measurements in a 950-m deep mine shaft. Some experimental tests have followed in mine shafts and boreholes. It seems, however, that geological complexity around the test sites interrupted precise determinations of the newtonian constant. A 600-m high tower was used for a vertical gravity gradient determination in North Carolina. The tower survey group once reported that they obtained the parameters, but revised later their conclusion. The other two tower experiments, which were made in Nevada and Colorado, concluded that they gave no solid evidence for non-Newtonian gravitation. A German research group also could not detect any failure in the Newtonian gravitational law by a 22-day long continuous gravity measurement on a 60-m high tower. The above conclusions may imply that the non-Newtonian term will not exist or be too small to be detected even by highly-sensitive gravity measurements for a mass separation ranging from scores to hundreds of meters. The future searching efforts may be concentrated on laboratory tests using torsion-balances or gradiometers but not on field gravity experiments.抄録全体を表示PDF形式でダウンロード (1461K) -
後藤 常男, 花田 英夫, 後藤 幸夫, 佐々木 恒1991 年 37 巻 2 号 p. 135-149
発行日: 1991/09/25
公開日: 2010/09/07
ジャーナル フリーWe have developed a computer program which can calculate excess path delay for any observation point and for any direction. The program uses data based on the Japan Spectral Model developed by the Japan Meteorological Agency. The data are given at every 3 hours on grid points with separation of about 40 km for 12 layers. We calculated the excess path delay for various observation points in Japan as an example and confirmed that 1) a dry component is in proportion to an atmospheric pressure on the ground with a standard deviation of about 5 mm, 2) a wet component for a path of low elevation angle can be well estimated by multipjying that for 90 degrees by a certain coefficient, 3) the coefficients hardly depend on location though the scattering varies with it, 4) the wet component is hardly related to any single meteorological component on the ground, 5) we can reduce an error in the estimated wet component by using six parameters related to meteorological components on the ground, 6) the error in this estimation of the wet component is about a half of that in the Saastamoinen's model, and 7) it is very difficult to reduce the error for wet weather.抄録全体を表示PDF形式でダウンロード (1580K) -
阿部 茂, 岩舘 健三郎, 後藤 幸夫, 花田 英夫, 後藤 常男1991 年 37 巻 2 号 p. 151-163
発行日: 1991/09/25
公開日: 2010/09/07
ジャーナル フリーVERA(地球回転・基準座標系用VLBI)計画の水沢周辺局として阿原山山頂付近の候補地が選定され,そこにおける積雪と風の影響について調べた.阿原山は国立天文台水沢観測セソターからそれほど遠くなく,そこでは,VLBI観測結果の解釈に投立つ,地殻歪,傾斜,重力等の地球物理学的観測も行っている.今回の調査で,阿原山のような山間部においても,平野部の水沢と同程度の積雪,風速の場所を探すことが可能であり,今回選定された候補地においても,積雪と風の影響はVLBI観測に大きな支障は無いことが明かになった.今までの調査結果を総合すると,この候補地はVLBIの観測局として,地盤の安定性,電波雑音,地盤振動,積雪,風等の条件を満たしている.抄録全体を表示PDF形式でダウンロード (1207K) -
佐藤 裕, 許 華杷1991 年 37 巻 2 号 p. 165-173
発行日: 1991/09/25
公開日: 2010/09/07
ジャーナル フリーHorizontal movement of the Coastal Range relative to the Longitudinal Valley, a probable arc-continent collision boundary in eastern Taiwan, is reanalyzed using the horizontal strain in this area. The present analysis shows that the range is moving toward the direction of N5°W with the speed of 4-5 cm/yr. This result is different from that of our former calculation, but is accordant with the anaysis of retriangulation data by BIQ (1984). The new obtained direction of the moving vector of the Coastal Range is different significantly from that of the Philippine Sea plate, and this difference is considered to produce a large shear strain in the neibouring oceanic plate. The northward subduction of the Philippine Sea plate seen just off the northeastern coast of Taiwan is harmonious with the northward displacement of the Coastal Range. The characteristics of earthquakes in Taiwan area are also explainable with the shearing stress in the plate resulted from the movement of the Coastal Range.抄録全体を表示PDF形式でダウンロード (808K) -
関口 渉次, 平原 和朗, 辻 宏道, 仙石 新, 綿田 辰吾, 里村 幹夫, 島田 誠一1991 年 37 巻 2 号 p. 175-186
発行日: 1991/09/25
公開日: 2010/09/07
ジャーナル フリーGPS観測による座標決定精度を見積もるために1988年12月の6,7,8,12,14日に観測したGPS位相データを解析した日本列島中央部にある11観測点の位置を求めた.固定点としては筑波,下里のいずれかの点を用いた.筑波はVLBIによって,下里はSLRによってそれぞれ既に正確な位置座標が決められている.筑波と下里をそれぞれ固定した場合に得られる他の観測点の位置座標を比較した.すでに知られているVLBIとSLRの座標系問の差を補正したあとの観測点の平均的な位置の差は.依然として長さで約1.33mあった.一方,各観測点における再現性は0.87m以下であり,この値より小さい.この差の原因としては,ひとつに,日本付近では実際にこの程度の差がVLBI,SLRの両座標系間に存在することが考えられる.また,GPS衛星軌道の系統的な誤差も有力な原因の一つに考えられる.日本での衛星配置が良くないことももう一つの原因として可能性はある.抄録全体を表示PDF形式でダウンロード (1177K) -
多田 堯, 原田 健久1991 年 37 巻 2 号 p. 187
発行日: 1991/09/25
公開日: 2010/09/07
ジャーナル フリーPDF形式でダウンロード (153K)
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