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        검색결과 2,998

        2981.
        1998.12 KCI 등재 서비스 종료(열람 제한)
        Distribution and occurrence of weedy rice in Kyonggi region were surveyed in 1996. Weedy rice was observed in 1368 fields (54.9%) of total 2490 fields. Almost two thirds of paddy fields in northern mountainous region were contaminated by weedy rice and more severe contamination, three forths of paddy fields, was observed in suburban regions. In those regions, occurrence of weedy rice was greater than those in north-eastern inland and south-western plain regions. The occurrence of weedy rice was higher in water seeding cultivation (66.7%) than other cultivation methods. The number of weedy rice per 10a was 756.7 plants in direct seeding on dry paddy and 379.4 plants in water seeding. The occurrence of weedy rice was higher in fields planted by farmer's seeds than that of paddy fields cultivated by certified seeds, and the longer the farmer's seeds being used, the more weedy rice occurred in paddy field
        2984.
        1998.09 KCI 등재 서비스 종료(열람 제한)
        본 논문은 미국내의 다른 터미널 운용구조를 고찰하고, 크레인 사용을 위해서 가장 효과적인 터미널 관리장치유형(ACC, CUP, PTU)을 찾조자 시도하여 연구한 결과이다. 터미널 비교에 사용된 효율을 산정하기 위해서 시간당 순총 크레인 움직임을 사용했다. 가장 효과적인 장치를 찾기 위해서 총 31개 터미널을 비교하여 시도했다. 이 이론에서는 PTU 시설이 가장 효과적인운영장치임을 알게 되었으며, 보기로 든 터널이 너무 적어서 미국내 터미널에 이 결과를 직접적으로 적용하기에는 어려움이 있다.
        2986.
        1998.03 KCI 등재 서비스 종료(열람 제한)
        Direct-seeding has major advantages such as labor and cost saving by eliminating preparation of seed bed and transplanting. But, it required increased input of fertilizers and pesticides because of the extended paddy period. Direct seeding in wet paddy (DSWP) gives faster growth and more uniform seedling emergence than direct-seeding in dry paddy. This research had an objective to develop an efficient N management practices for DSWP with split application of N fertilizer. A paddy field experiment was conducted to evaluate effects of starter N and N-topdressing which was delayed N application until 5-leaf stage, with comparison to transplanting (TP). Total amount of N application were two levels; 110kg and 77kg/ha. The N applications were split four times during rice growth stages; starter, topdressing at 5-leaf stage, top dressing at tillering stage, and topdressing at panicle initiation stage. DSWP had more tillers/m2 than TP, but with the delayed heading. The DSWP plots which received N-topdressing at 5-leaf stage without starter N had higher leaf area index (LAI) and leaf greenness than the TP plot. Also, these DSWP plots had high leaf-N concentration at the heading stage, as calculated from leaf chlorophyll meter readings. Rice yield in DSWP with N-topdressing at 5-leaf stage was significantly higher than that in TP and in DSWP with starter N. Energy and N use efficiency were improved in DSWP with N-topdressing at 5-leaf stage. But, there were no significant differences in grain yield between the two levels of total amounts of N applications, 77kg and 110kg/ha. We concluded that starter N could not be used effectively by rice seedlings, but topdressing N at 5-leaf stage was an efficient N management for rice growth and yield in DSWP system.
        2994.
        1993.05 KCI 등재 서비스 종료(열람 제한)
        Many plants collected at Japan, China, Korea, Imdonesia and South America were applied to antitumor and / or cytotoxic screening tests against Sarcoma 180 ascites in mice and / or V-79, KB, P388 cultured cells. On the course of these screening tests, alcoholic extracts of Forsythia viridissima (Oleaceae), Eurycoma longifolia(Simaroubaceae), Rubia cordifolia and R. akane(Rubiaceae), Cissampelos pareira and Abuta concolor (Menispermaceae), Nardostachys chinensis (Valerianacese), Mansoa alliaceae (Bignoniaceae), Casearia sylvestris (Flacourtiacear), Maytenus ilicifolia (Celastraceae), Hedychium coronarium (Zingiberaceae), Croton palanostigma(Euphorbiaceae), Cocculus trilobus(Menispermaceae), Ginkgo biloba(Ginkgoaceae), Alpinia galanga and Cucculus zanthorrhiza(Zingiberaceae), Evodia rutaecarpa(Rutaceae), and Periploca sepium(Asclepiadaceae) showed significant activity and their active principles were clarified. In this paper, a few antitumor substances in above plants are introduced.
        2995.
        1993.05 KCI 등재 서비스 종료(열람 제한)
        To data, many types of compounds having antineoplastic activity have been isolated from higher plants, that is, alkalodids, terpenes, lignans, steroids and so on. Some of ther were isolated from Indonesian plants, Curcuma xanthorrhiza and Eurycoma longifolia. Bisaborane type compounds were compounds were isolated as antimeoplastic compounds againest Sarcoma 180A from C. xanthorrhiza, and quassinoids and euryrene type triterpenes from triterpenes from El longifolia. Casearines, a kind of diterpene, had been isolated as cytotxic components from Casearia sylvestris distributed in South America. RA series Cyclic hexapeptides isolated from Rubia akane and R. cordifolia also have strong antineoplastic activity against various types of tumors. Till now, 16 kinds of RA series compounds were isolated and named as RA-I~XVI. Moreover, monoglucoside of RA-V newly isolated from same plant. Many kinds of derivatives including natural RA compounds were tested for QSAR, and one of them, RA-VII was screened up as a most suitable substance as an antitumor agent. RA-VII(=RA 700) has strong cytotoxic activity against KB cells, P388 lymphocytic leukemia and MM2 mammary carcinoma cells. In some solution, three conformers of RA-VII were observed by NMR. It was discussed the relationship between conformation and activity. Total synthesis was already completed, but there is left room for improvement. Phase I clinical trials for RA-VII has been finished, then Phase II trials will be started before long.
        2996.
        1990.06 KCI 등재 서비스 종료(열람 제한)
        본 시험은 식물생장 조절제 Hoe 78784를 처리하여 수도의 도복 방지효과를 조사하고, 식물생장 조절제의 농도와 처리 시기를 각기 달리하였을 때 수도의 영양생장, 형태적 특성 및 수량에 미치는 효과를 구명하기 위하여 실시하였던 바 몇가지 결과를 얻어 보고하는 바이다. Hoe 78784를 수도 신장기에 처리하였을 때 공시된 품종에서 도복 방지효과가 크게 나타났으며, 특히 도복성 품종인 IR21820-154-3-2-3에 있어서는 수량을 크게 증가시켰다. 생장 조절제 Hoe 78784는 초장 및 절간의 신장을 억제시켰고, 특히 형태학적 특징으로서는 Hoe 78784를 처리함으로써 셋째 및 넷째마디 간의 두께와 직경을 증가시켰으며, 또한 줄기속에 유관속의 수도 증가시켜서 도복 방지효과를 나타낸 것으로 사료되며, 영양 생장기관 및 수량구성 요소에 크게 영향을 미치지 못하였다. 처리시기와 농도별로 볼 때 Hoe 78784를 이앙후 30일날 처리하였을 때는 도복 방지효과가 뚜렷하였으며 수장 및 수량구성 요소에 영향을 미쳐 수량을 크게 감소시켰다. 그러나 출수기때 Hoe 78784 처리는 농도에 관계없이 도복 방지효과를 나타내지 않았고, 기타 제형질에도 영향을 미치지 못했다.
        2997.
        1986.10 KCI 등재 서비스 종료(열람 제한)
        엽녹소형광측정에 의한 수도 내냉성검정의 가능성을 검토하기 위하여 내냉성이 다양한 11개 품종을 1 /5000a pot에 원형직파하여 육성된 재료들을 수잉기에 10℃ 의 저온에 8 일간 처리하여 저온처리전후의 가변형광량( FVAR)과 형광증가속도(F/sun R/)의 변화를 비교하였다. 내냉성이 약한 품종들에서 저온처리에 의한 형광특성들의 감소가 커서 각 품종들의 저온장해정도와 가변형광량 및 형광증가속도의 저온처리전후의 대비지수는 부의 유의상관을 나타내어 이들 형광특성들은 도체형양기관에 나타나는 저온장해의 정도를 판단하는데 유용하게 이용될 수 있을 것으로 판단되었다. 엽록소형광을 이용한 내냉성검정방법은 다량의 육종재료 검정에 정밀성, 경제성, 신속성과 함께 검정에 공시된 개체를 계속 육종에 이용할 수 있어 이의 활용이 기대된다.다.
        2998.
        1976.12 KCI 등재 서비스 종료(열람 제한)
        This experiment was conducted to find out how to increase efficiency of fertilizer nitrogen and how to change the weed population with different methods of nitrogen application. Mudball deep placement, at 10-12cm soil depth, produced significantly the highest grain yield within the application methods with same amount of nitrogen (60kg N/ha). It produced also same grain yield with conventional application methods, timely split application method, with 90kg N/ha. Basal application of nitrogen increased weed population and it showed higher dry weight of weed than top dressing methods at early growth stage of rice.