10,914 research outputs found
(31(3):199-208)Investigation of Weed Species and Evaluation of Different Herbicides on the Growth of Sisal Hemp in Field
No full text自從人造纖維發明和取代部份之植物纖維用途後，瓊麻纖維之價格一落千丈，農民因無利可圖，未能如往年再僱工除草，於是麻園裡雜草叢生，威脅著瓊麻生長，遭致麻絲產量逐年降低，而不能充分供應國內需要。為要解決此問題，爰進行本計畫並於1977~1979 年問從事研究。經試驗調查結果，發現較常見生長於瓊麻園裡之雜草有39 種，其中禾本科（Gramineae）佔最多，次為莎草科（Cyperaceae）及菊科（Coopositae）。以不同種類殺草劑噴施調查各種雜草殘存率，獲知禾本科抗藥性較大，殘存率高，次為莎草科、豆科（Leguminosae）及石竹科（Cayophyllaceae）。莧科（Amarau - thaceae）及菊科之雜草，全部死亡。各處理間對殺草效果，成本分析及對瓊麻生長之評價，發現噴施混合藥劑之B 處理每公頃使用85% Dowpons 8 kg 加2-4-D 2kg 或D 處理每公頃使用80% Kamex 2 kg 殺草效果較佳，且比人工除草區各自增產13 和20%，比不除草區各自增產58 和68%，同時每公頃較人工除草區節省生產成本4,696 和5,400 元。
Because the uses of sisal hemp fiber can be substituted by the synthetic products, the cultivation and price of sisal hemp are greatly reduced. In addition, the widespread of different weeds in sisal hemp field also influences the growth of sisal hemp plants. Therefore, the total production of this crop becomes insufficient for the requirements of domestic demand. In order to solve this problem, experiments were conducted during the period of 1977 to 1979. The results are summarized as follows:
About 39 weed species were identified from the sisal hemp field in Pintung area. Most of them are Gramineae weed, next were Cyperaceae and Compositae weeds, the survival of weed species in field depended on the application of different herbicides. Granimeae are more tolerant to different herbicides than the others, While, Amaranthaceae and Compostiae weeds are more sensitive.
Evaluation of different herbicides on the growth of sisal hemp showed that 85% Dowpons (8kg/ha) plus 2-4-D (2kg/ha) or 80% Kamex (2kg/ha) plus 2-4-D (2kg/ha) increased the fiber production by 13 and 20% in comparing with the hand-weeding treatment; 58 and 68% for the non-till treatment, respectively, Furthermore, approximately 5,000 N. T. Dollars of the labor cost can be saved if both herbicides were used
(32(4):336-340)Studies on the Agronomic Characteristics and the Starch Contents of Two Edible Canna Varieties (Canna edulis Ker.)
No full text本文目的在探究食用美人蕉品種之農藝特性及澱粉性質，發現紫紅色種之生長勢較綠色種為強，公頃塊莖產量亦較高，但差異不大。不同生長序之塊莖產量與全部塊莖產量之比，兩品種均以第3 及第4 分蘗所佔之百分率較高分別為27.5%與28.7%（紫紅色種），及23.8%與23.5%（綠色種）。塊莖澱粉含量亦以第2 至第4 分蘗之塊莖較高，各為65.3%、61%、64%（紫紅色種）及59.2%，64%、65%（綠色種），顯示促進該等分蘗塊莖數量及發育為提高食用美人蕉產量之重要關鍵。不同生育日數對塊莖澱粉含量經測定結果，得知塊莖澱粉蓄積量隨著生育日數而增加，但最適當之收獲時期，應在植株開始枯萎且新芽未萌發前為宜。自澱粉粒觀測發現，該兩品種之澱粉粒均比其他澱粉作物之澱粉粒為大，澱粉純度高，尤以綠色種為最，此或可解釋綠色種廣被農民栽培之理由。
A comparative study on yield and starch content of two edible canna varieties, namely, the green and the purple canna, was carried out in 1982. The results showed that the growth of the purple variety was more vigorous than that of the green one. The tuber hectare yield of th purple variety was also higher than that of the green one, but without significant difference.
Each canna plant usually produces five tuber-tillers. The ontogeny and weight of each tuber tiller were individually investigated. The third and the fourth tuber tillers were found to have the highest yield weight and averaged 27.5% and 28.7% of the total yield in the purple variety and 23.8% and 23.5% in the green variety, respectively. The starch content of each tuber tiller was also analysed, the second, third and fourth tuber tillers had higher starch content than the first or the fifth one. Therefore, the yields of the third and the fourth tuber tillers greatly influence the total production of edible canna.
Starch content at different growing stages in canna was also analysed. There was a positive correlation between the tuber starch content and the growth period. The highest starch content is obatined just before the plant is about to wilt. The observation of various starch granular indicated that the green canna had the largest granular size, and followed by the order of purple canna, potato, arrow root, sweet potato and cassava
Punch-through of spudcan foundations in two-layer clay
No full textSpudcan punch-through failure continues to be a major cause of foundation failure of offshore jack-up rigs. The resulting damage to the rig can range from minor structural damage of its leg and jacking mechanism to complete loss of the rig. Most punch-through failures happen during the jacking up and preloading and in stratified soil profiles with a relatively thin layer of sand or stiff clay overlying a weaker layer. Punch-through causes a reduction in bearing resistance with depth, causing instability during the load-controlled jacking-up process. To reveal the failure mechanism during punch-through, model spudcan foundation tests have been conducted on a two-layer clay sample (strong over weak) in a drum centrifuge. Half-spudcan model tests were carried against a transparent window to visualise the soil flow mechanisms around the spudcan during penetration. Particle Image Velocimetry (PIV) analysis was used to track the soil particle movements and hence obtain precise details of the failure mechanisms. Full-spudcan tests were also conducted to measure the vertical load-penetration responses. The study shows that punch-through failure and associated softening response are directly linked to the relative thickness of the top clay layer to the foundation diameter, and also the strength ratio between the two soil layers. A punching failure through the upper layer was observed as shear zones developed from the spudcan rim down to the layer interface. A soil plug was carried down beneath the spudcan. The thickness of the soil plug was ∼80% of the initial top layer thickness, and the cavity formed above the spudcan remained open until the spudcan fully penetrated into the soft layer. Softening penetration resistance profiles were observed.</p
Performance Evaluation of Distributed-Antenna Communications Systems Using Beam-Hopping
No full textDigital beamforming (DBF) techniques are capable of improving the performance of communications systems significantly. However, if the transmitted signals are conflicted with strong interference, especially, in the direction of the transmitted beams , these directional jamming signals will severely degrade the system performance. In order to efficiently mitigate the interference of the directional jammers, in this contribution a beam-hopping (BH) communications scheme is proposed. In the proposed BH communications scheme, only one pair of the beams is used for transmission and it hops from one to the next according to an assigned BH pattern. In this contribution a range of expressions in terms of the average SINR performance have been derived, when both the uplink and downlink are considered. The average SINR performance of the proposed BH scheme and that of the conventional single-beam (SB) as well as multiple-beam (MB) assisted beam-processing schemes have been investigated. Our analysis and results show that the proposed BH scheme is capable of efficiently combating the directional jamming, with the aid of utilizing the directional gain of the beams generated by both the transmitter and the receiver. Furthermore, the BH scheme is capable of reducing the intercept probability of the communications. Therefore, the proposed BH scheme is suitable for communications, when several distributed antenna arrays are available around a mobile
Limiting cavity depth for spudcan foundations penetrating clay
No full textCentrifuge model tests and unite element (FE) analysis have been conducted to study the penetration of spudcan foundations in uniform clay with nominally constant strength with depth. In particular, the transition between shallow penetration, with soil heaving to the ground surface, and deep penetration, with a localised flow-round mechanism, has been investigated. This transition governs the onset of back-flow and hence the depth of soil lying on the installed spudcan, which in turn influences the bearing capacity and also the potential for suction to develop and hence the uplift capacity and moment resistance of the foundation. The maximum cavity depth above the spudcan prior to any back-flow is therefore a critical issue for spudcan assessment in clay. In the centrifuge model tests, a half-spudcan model penetrating against a transparent window has been used to visualise the soil flow mechanisms around the spudcan during penetration. The formation of a cavity above the spudcan is revealed by both centrifuge modelling and FE analysis. It is found that there are three distinct penetration mechanisms during spudcan installation: during initial penetration, an open cavity is formed with vertical walls; with further penetration, soil flows partially around the spudcan into the cavity; during deep penetration, the spudcan is fully embedded and the soil flow mechanism is entirely localised. Over the wide range of normalised soil strengths explored, the soil back-flow in the second stage was shown to be due to a flow failure that was triggered by the spudcan penetration and not by wall failure, that is, the collapse of the vertical sides of the soil cavity. This observation is supported by FE analysis. The cavity depth due to flow failure is much shallower than the criterion for wall failure that is incorporated in current design guidelines. Instead, a new design chart and expression is suggested with the normalised cavity depth expressed as a function of the soil shear strength, normalised by the effective unit weight of the soil and the spudcan diameter.</p
Tun hu: (du mu ju ji).
No full text復工之前 -- 母女們 -- 囤戶.吳天著.Drama.Wu Tian zhu.Fu gong zhi qian -- Mu nü men -- Tun hu
(35(2):180-185)Gross Composition of Four Hsian-tsao (Mesona procumbens Hoemsl) at Different Growth Stages
No full text以4個仙草品種為材料，於移值後120、150、180及190天分別收穫，以探討生育期長短對仙草莖葉主成份含量變化之影響。試驗結果發現仙草莖葉之粗蛋白質含量隨著生長日數增進而降低，但脂肪含量與纖維含量則隨著生長日數增進而增加。可溶性無氮物（Nitrogen free extract）和乾物質（Dry matter）含量於180天生長期較高。因此，以可溶性無氮物及乾物質含量作為仙草採收指標，則其最適採收期，應當於移植後180天為佳，不需待至植株花蕾形成期。
Four varieties of hsian-tsao (Mesona procumbens Hemsl), i. e., small leaf runner type, small leaf bunch type, big leaf bunch type, and big leaf runner type, were harvested on the 120th, 150th, 180th and 190th day after transplanting. Gross composition of stems and leaves were analyzed and compared at these different growth stages.
The results showed that crude protein content in the stems and leaves of hsian-tsao varieties all decreased during the developing stages. However, the crude fat and crude fiber content increased with the advance of maturity. Compared with the results of another three harvest days, both the NFE (nitrogen free extract) and dry matter cotnents were much higher on the 180th day, which could be used as the best harvest time. It is not necessary to harvest the leaves and stems until the formation of flower buds, because generative development of hsian-tsao plants could have some detrimental effect on vegetative growth both quantitatively and qualitatively
(30(4):350-356)Studies on fiber characters and pulp qualities of jute Corchorus olitorius L.
No full text經二年田間觀察與調查，獲悉所參試品種中，JRO-632與61-1-I-2098兩品種具有頗高生產潛力，精洗率前者達12.85%，後者達11.95%，公頃平均精洗麻產量均達3,000 kg以上，比對照種增產25%左右。纖維性狀調查，發現長莢種纖維層次有較圓果種多之趨勢，單位面積纖維束數亦較圓果種多。韌皮部及木質部厚度，確比圓果種細小，纖維拉力負荷值比圓果種大，耐屈力則反是。單纖長幅比，除JRO-753及JRO-632兩品種外，其餘參試品種略有近似或高於圓果種之趨勢。以全莖麻桿為材料供造紙，紙漿收率及未漂白紙張物理性能均比本省產濶葉假赤楊優異，實有取代濶葉樹之價值。以精洗麻為材料供造紙，雖紙漿收率及未漂白紙張物理性能亦可媲美美國南部松之紙漿品質，但較費工推行不易。The present studies dealt with the jute fiber cell characters as well as the qualities of pulp made of jute fibers.
After two years studies, varieties JRO 632 and 61-1-I-2098 were found to have a higher yield potential in the seven olitorius varieties tested. Vareities JRO 632 and 61-1-I-2098 each gave 12.85% ane 11.95% of retting rate which represented about 3000 kg of retted fiber production per hectare. This account for 25% higher fiber production than that of capsularis variety.
Olitorius varieties showed more fiber layers, more fiber bundles, thinner phleom and xylem and better fiber strength but inferior flex in comparison with capsularis variety. In general, the length-width ratios of olitorius varieties were similar or better than that of capsularis variety with the exception of varieties JRO 735 and JR 632. In view of the good quality of unbleached pulp made of the whole stem (fiber plus pith) of olitorius jute, it was considered that olitorius juts could be used as the good raw materials for pulp making in place of wood.
The unbleached pulp made of retted fibers only showed equally good quality as that made of southern pine of U. S. A. However, labor cost involved in fiber retting should be solved before it can be economically used as the raw materials for pulp making
(34(2):157-163)The Effect of Variety and Transplanting Date on The Yield and Gross Composition of Hsian-tsao(Mesona procumbens)
No full text以4 個仙草品種，分3 月16 日及4 月16 日二期移植，探討不同移植期對該等品種之農藝性狀，產量及主要化學成份含量之影響，結果顯示在二移植期公頃平均乾草量，小葉匍匐種（A）為4,529kg，小葉直立種（B）為5,043kg ，大葉直立種（C）為4,735kg 及大葉匍匐種（D）為6,915kg。但就移植期別加以探討，發現A 、C 和D 三品種第一移植期較第二移植期高產，尤以D 品種在第一期移植公頃乾草量6,932kg 為最高。另就仙草主要化學成份分析結果，發現品種間之可溶性無氮物（NFE）含量差異不大。至於影響仙草凍凝膠強度，可能因品種間之葉量百分率高低有關之假說，經就化學成份分析顯示並未被證實。
Four varieties (A-small leaf runner type; B-small leaf bunch type; C-big leaf bunch type; D-big leaf runner type) of hsian-tsao (Mesona procumbens Hemsi) were transplanted on March 16 (S1) and April 16 (S2) 1984 to evaluate the effect of variety and transplanting date on the agronomic characters, dry grass weight and gross composition. Based on the average of 2 transplanting dates, variety A, B, C and D produced 4529, 5043, 4735 and 6915 kg/ha dry grass, respectively. More yield was observed in transplanting date S1 than S2 in varieties A, C, and D. The highest yield was observed in variety D transplanted on S1 which produced 6932 kg/ha of dry grass. There were not many differences in nitrogen free extract among 4 varieties. We failed to confirm the hypothesis that Gelforming strength is positively -correlated to the leaf percentage of the plants by the analysis of gross composition
(31(4):291-297)Studies on Varieties of the Botanical Characteristics and Abaptability of Chick Pea (Cier arietinum L.)
No full text從印度ICRISAT 引進山藜豆（Chick pea）11 品系，第一年行缽栽觀察，第二年行田間栽培觀察，分別探討其植物性狀及其在本省適應性。經二年觀察結果，發現本類作物適合本省冬季期間栽培，且所參試品系中，以K1（白花種No. 4973）產量較高，平均公頃產量為1,019 kg。至於植物性狀之觀察，經調查詳述於本文中。
Eleven varieties of chick pea (Cier arietinum L. ) introduced from ICRISAT, India, were grown in pots as well as in the experimental field in TARI, Taichung, Taiwan, during the years of 1979-1980. The botanical characteristics and their adaptability were investgated.
We found that most varieties of chick pea grew vigorously in winter time. Among the entires tested, variety K1 (Kabuli type No. 4973) yielded 1019 kg/ha, which was the highest among the varieties tested
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