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來源資料
頁籤選單縮合
題 名 | 從非晶質.超微晶構造控制材料探究超級金屬的研發動向 |
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作 者 | 林美雲; | 書刊名 | 工業材料 |
卷 期 | 112 1996.04[民85.04] |
頁 次 | 頁106-112 |
分類號 | 440.35 |
關鍵詞 | 非晶質; 超微晶構造控制材料; 超級金屬; |
語 文 | 中文(Chinese) |
中文摘要 | 為了解網目形狀及網目結構不同之袋網對網目選擇性之影響,製作54、60、 68、及75mm網目尺寸的菱形、正方形兩種不同形狀袋網,及54mm尺寸的結節和無節結構的袋 網,於1989∼1990年間使用海研一號與漁訓壹號訓練船,在臺灣海峽進行6航次、97網次的 漁獲試驗。其中正方形網與菱形網目袋網之試驗調查計進行67網次,結節構造不同之袋網計 執行30網次,漁獲魚種計22種一般C.P.U.E.偏低。試驗採用覆蓋網式進行。 67網次之試驗結果,各別項目試驗的主要漁獲魚種例如:帶魚、肉魚、銷管、紅目鰱及 巴弄等魚種的漁獲體長分佈大致相類似。而各魚種的選擇係數(SF)和選擇尖銳度(CS),方形 與菱形大致相類似,但小型魚或柔軟體質魚類如天竺鯛、臺灣鎖管之選擇性,方形網目似較 佳。 30網次的結節與無結節網目(Russell type)的比較試驗結果顯示:結節網袋網的50%選 擇體長大部份較無結節袋網為大,究其原因,或許是本試驗使用的無結節網日之袋網,其柔 軟性及伸縮性均較小,致魚類不易從網目逃竄所致。 |
英文摘要 | In order to realize effects of codend mesh shape and construction differences on the catch selectivity, a comparative study was conducted for square and diamond mesh codends of 54, 60, 68 and 75 mm, and on knotted and knotless diamond mesh codends of 54 mm. A total of six cruises and 97 tows were made on R/V Ocean Research I and on T/ V Yu Shun I in the Taiwan Strait during 1989 and 1990. Twenty two species were caught with low catch per unit efforts (CPUE). Experiments were carried out with a cover net attached to codend. Major species exhibiting similar body-length distribution were: hailtail, butter fish, small squid, amber fish, and bigeye. Most of the selection factors (SF) and the coefficients of selection (CF) for square and diamond mesh codends show similarities among different species. In the case of catch with small body size (cardinal fish), and with flexible body (squid), square mesh codend has higher selectivity. From results of comparisons between knotted and knotless (Russell type) diamond mesh codends, most of the 50% retention lengths for different species are higher in knotted mesh codend. This may be due to the stiffness of knotless meshes which reduce the flexibility of a mesh and may further hinder fish from escaping. |
本系統中英文摘要資訊取自各篇刊載內容。