巻号一覧
18 巻 (1962 - 1963)
- 4 号 p. 133-
- 3 号 p. 89-
- 2 号 p. 45-
- 1 号 p. 1-
18 巻, 4 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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小平 吉男, 根本 茂, 三寺 光雄, 徳植 弘1963 年 18 巻 4 号 p. 133-138
発行日: 1963/03/25
公開日: 2010/02/25
ジャーナル フリーIt seems that a role of turbulence which affects the wind break effect has been very little known. But it can be considered that decrease of turbulence is effective for the wind break as well as decrease of mean wind velocity. The present experiments have been done from this point of view and mainly dealt with the turbulence. The results obtained are summarized as follows:
(1) Friction velocity v* beyond which sands uniformly scattered over a constant area of aflat-plate begin to move is maximum in the case where the turbulence was not given and minimum is the case where the the turbulence was given (a value in the former case is more than three times as large as that of the latter case) and it takes an intermediate value when the turbulence with large scale generated by an obstacle of the leading-edge of the flat-plate is eliminated by setting a shelter behind the obstacle. Then, it should be noticed that removed quantities of sands can not be uniquely determined from v*, even if other conditions have been kept constant.
(2) Both the rate of decrease of mean wind velocity and. that of energy of turbulence due to a net are larger than those due to rod-belt and screen. Especially, the turbulence increases down stream from the distance of 7h-8h for the case of the screen (h denotes height of screen), a shelterhedge with large closed area such as a screen is not suitable. Each effective area of the wind break of screen, rod-belt and net is within 3h, 4h and 5h respectively (in this case, wind velocity:
U∝≅4m/sec, height from the flat-plate: z=3mm).
(3) Increase of the row of the rod-belt (corresponding to increase of thickness of shelter-belt) is not effective for the wind break, this rather results in increase of turbulence.
(4) The lattice is more effective than the the rod-belt, and the effective area covers the distance of 6h in this experiment.抄録全体を表示PDF形式でダウンロード (731K) -
気温分布武智 修, 松本 和夫1963 年 18 巻 4 号 p. 139-142
発行日: 1963/03/25
公開日: 2010/02/25
ジャーナル フリーThe space distribution of air temperature in two Citrus orchards, dense and open planting, was minutely measured by use of many radiation shielded thermo-couples, on clear summer days, 1955.
Fig. 1 and 2 show the temperature distributions at noon and midnight, respectively. Fig. 3 show the diurnal temperature march in or out the crowns and on the bare ground between the crowns.
Comparing the temperature distributions in two orchards, in the dense planting, the upper surface of the crown is especially heated up at noon-time and cooled down at night-time.
Then, it is almost similar to a forest type.
On the other hand, in the open planting, the inner snrface of the crown is heated up as well as the ground between the crowns.
However, the temperatures at the ground are cosiderably higher than those of the crowns.
At night, the crown as well as the ground is slightly cooled down.
These results are explained by the difference of leaf density, its distribution and wind velocity in two orchards.抄録全体を表示PDF形式でダウンロード (514K) -
葉層構造と直射光, 散光および自然光との関係黒岩 澄雄, 門司 正三1963 年 18 巻 4 号 p. 143-151
発行日: 1963/03/25
公開日: 2010/02/25
ジャーナル フリーUnder natural light conditions, the radiation impinging upon foliage from sky is composed of the direct and the diffuse radiation. The intensity of direct radiation within foliage is determined with the extinction coefficient for one beam, and the intensity of diffuse radiation with Monsi and Saeki's formula concerning the ratio of light intensity inside and outside of foliage in isotropic light beam.
Our theoretical extinction coefficient for one beam (KD) corresponds to the ratio of the horizontal projection to the actual area in a leaf. In the foliage that consists of leaves orientating at right angles to the sun, KD=cosecH (H, sun elevation). In the foliage with random arrangement of leaves inclined at a fixed angle (α) to the horizontal, KD=cosα in H≥α, and in H<α KD={cosα⋅sin-1 (cotα⋅tanH)+(sinα⋅cotH)√1-cot2α⋅tan2H}2/π. Using these equations and Monsi and Saeki's formula, the relative light intensities under sunny conditions were calculated as a function of leaf area index and sun elevation. The calculated light intensity had a diurnal minimum at H=30°, in α=80° as well as in leaves with a phototropic movement. This result agrees with the observation of Brougham in perennial ryegrass community and in white clover community under sunny conditions. Disagreement among some observers as to the relative light intensity measurements was elucidated on the basis of our theoretical analysis of extinction coefficient for one beam. Light transmission of each leaf leads to the increase of light intensity within foliage, and light reflection from foliage surface results in the decrease of light intensity. Consequently, the theoretical equations whether which include or not the terms concerned with transmission and reflection bring about the same light intensities.抄録全体を表示PDF形式でダウンロード (1371K) -
谷 信輝1963 年 18 巻 4 号 p. 152-153
発行日: 1963/03/25
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (268K) -
干ばつについて谷 信輝1963 年 18 巻 4 号 p. 154-155
発行日: 1963/03/25
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (266K) -
日下部 正雄1963 年 18 巻 4 号 p. 156-158
発行日: 1963/03/25
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (602K)
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