有关led的毕业论文外文翻译--高亮高效节能led灯的来源及其在室内植物栽培中的潜力(编辑修改稿)

有关led的毕业论文外文翻译--高亮高效节能led灯的来源及其在室内植物栽培中的潜力(编辑修改稿)内容摘要：

based growth process that uses only 60% of electricity than a fluorescent lighting based one. Tennessen et al. have pared photosynthesis from leaves of kudzu (Pueraria lobata) enclosed in a leaf chamber illuminated by LEDs versus by a xenon arc lamp. The responses of photosynthesis to CO2 are similar under the LED and xenon arc lamps at equal photosynthetic irradiance. There is no statistical significant difference between the white light and red light measurements in high CO2. Some leaves exhibited feedback inhibition of photosynthesis which is equally evident under irradiation of either lamp type. The results suggest that photosynthesis research including electron transport, carbon metabolismand trace gas emission studies should benefit greatly from the increased reliability, repeatability and portability of a photosynthesis lamp based on LEDs. Okamoto et al. have investigated the effects of different ratios of red and blue (red/blue) photosynthetic photon flux density (PPFD) levels on the growth and morphogenesis of lettuce seedlings. They have found that the lettuce stem length decreases significantly with an increase in the blue PPFD. The research has also identified the respective PPFD ratio that (1) accelerates lettuce seedlings’ stem elongation, (2) maximizes the whole plant dry weight, (3) accelerates the growth of whole plants, and (4) maximizes the dry weights of roots and stems. Photosynthesis does not need to take place in continuous light. The solid state nature allows LEDs to produce sufficient photon fluxes and can be turned fully on and off rapidly (200 ns), which is not easily achievable with other light sources. This rapid on– off feature has made LEDs an excellent light source for photosynthesis research such as pulsed lighting for the study of photosynthetic electron transport details. The off/dark period means additional energy saving on top of the LEDs’ low power consumption. 4. LEDs and indoor plant cultivation . Plant tissue culture and growth Tissue culture (TC), used widely in plant science and a number of mercial applications, is the growth of plant tissues or cells within a controlled environment, an ideal growth environment that is free from the contamination of microorganisms and other contaminants. A controlled environment for PTC usually means filtered air, steady temperature, stable light sources, and specially formulated growth media (such as broth or agar). Micropropagation, a form of plant tissue culture (PTC), is used widely in forestry and floriculture. It is also used for conserving rare or endangered plant species. Other uses of PTC include: 1shortterm testing of geic constructions or regeneration oftrans genic plants, 7 2 cross breeding distantly related species and regeneration of the novel hybrid, 3 screening cells for advantageous characters (. herbicidere sistance/tolerance), 4embryo rescue (. to crosspollinate distantly related specie sand then tissue culture there sulting embryo which would normally die), 5 largescale growth of plant cells in liquid culture inside bioreactors as a source of secondary products (like rebinant proteins used as biopharmaceuticals). 6production of doubled monoploid plants from haploid cultures to achieve homozygous lines more rapidly in breeding programs (usually by treatment with colchicine which causes doubling of the chromosome number). Tissue culture and growth room industries have long been using artificial light sources for production. These light sources include TFL, high pressure sodium lamp (HPS), metal halide lamp (MHL) and incandescent lamp, etc. Among them, TFL has been the most popular in tissue culture and growth room industries. However, the use of TFL consumes 65% of the total electricity in a tissue culture lab. That is the highest nonlabor costs. As a result, these industries continuously seek for more efficient light sources. The development of highbrightness LED has made LED a promising light source for plant growth in controlled environments. Nhut et al. have cultured strawberry plantlets under different blue to red LED ratios as well as irradiation levels and pared its growth to that under plant growth fluorescent. The results suggest that a culture system using LED is advantageous for the micropropagation of strawberry plantlets. The study also demonstrates that the LED light source for in vitro culture of plantlets contributes to an improved growth of the plants in acclimatization. Brown et al. have measured the growth and dry matter partitioning of ‘ Hungarian Wax’ pepper (Capsicum annuum L.) plants grown under red LEDs pared with similar plants grown under red LEDs with supplemental blue or farred radiation. Pepper biomass reduces when grown under red LEDs without blue wavelengths pared to plants grown under supplemental blue fluorescent lamps. The addition of farred radiation results in taller plants with greater stem mass than red LEDs alone. Fewer leaves developed under red or red plus farred radiation than with lamps producing blue wavelengths. The results of their research indicate that with proper bination of other wavelengths, red LEDs may be suitable for the culture of plants in tightly controlled environments. . Space agriculture Because resupply is not an option, plants are the only options to generate enough food, water and oxygen to help make future explorers selfsufficient at space colonies on the moon, Mars or beyond. In order to use plants, there must be a light source. Standard light sources that used in homes and in greenhouses and in growth chambers for controlled agriculture here on Earth are not efficient enough for space travel. While a human expedition outside Earth orbit still might be years away, the space farming efforts are aimed at developing promising artificial light sources. LEDs, bec。