最高周轉率 的英文怎麼說
中文拼音 [zuìgāozhōuzhuǎnlǜ]
最高周轉率
英文
maximum turnover-
At present, people usually use birefrigence and quasi - phase - matching methods to achieve higher effiency in the process of conversion. a significant advantage of quasi - phase - matching method is that the interaction is occurred through the largest element of the x ( 2 ) tensor ; the period of optical superlattice can be designed randomly, and any interaction can be matched without walk - off angle ; they are fitted to be used in frequency conversion of lower power especially. the quasi - phase - matching method has some advantages over birefrigence method, improving the efficiency of frequency conversion ; the range of frequency conversion covers its whole transperant wavelength
由於準相位匹配技術有其獨特的優勢，可以利用非線性光學晶體的最大二階極化張量，如ppln 、 pplt 、 ppktp用的非線性極化張量都是d _ （ 33 ） ，其有效非線性系數高出普通非線性光學介質（如bbo 、 lbo 、 ktp ）一個數量級，而且可以人為靈活設計調制周期，通過周期設計其頻率變換范圍可以覆蓋準相位匹配介質的整個透明波段，選擇無走離效應，解決了常規pm難以解決的問題，拓寬了非線性晶體的應用范圍，極大地提高了頻率轉換效率，已成為非線性光學材料和固體激光器的研究熱點之一。The results shows that the community richness, species diversity indices and evenness of tree layer and shrub layer share the same order, of which is higher in pure limestone region than that of in pure dolomite region, but it reverse in herb layer ; the coefficient of similarity is considerably low between all plots, while species turnover rate is quite high among the plots and is higher in dolomite region than that of in limestone ; in different karst regions, karst processing leads to niches diversity characterized by special morphologies and special element geochamical features, and therefore affect the dynamic and features of plant communities
我們在最有代表性之一的貴州茂蘭喀斯特森林保護區選取純灰巖和純白雲巖兩種巖性的喀斯特環境，對其元素地球化學特徵及其中原生性植物群落的相異性和物種多樣性進行了對比，結果發現：不同巖性區域多樣性：喬木層和灌木層為純灰巖區純白雲巖區，草本層為純白雲巖區純灰巖區，總體上純灰巖區的高於純白雲巖區的；各樣地間的相似性系數都很低，相同巖性類型內的明顯高於不同巖性類型之間的相似度；物種周轉率高，且白雲巖區高於石灰巖區，種類組成差異明顯；喀斯特區可溶巖地球化學背景通過喀斯特作用導致特殊的地形條件與元素地球化學特徵，並引起局部小生境的分異從而影響植物群落特徵。Abstract : techniques of apple genetic transformation can improve apple trees and shorten the breeding cycle by molecular methods. in the last years, great progress has been made in this field, which involves a number of important apple genotypes developed. so far, apple genetic ransformation mainly adopts agrobacterium - mediated technique, involving infection and transgenic tissue regeneration, which are important steps to affect the transformation efficiency. the initial work to the date is to know and to search for the factors which can increase the efficiency
摘要蘋果的遺傳轉化技術通過分子手段改良蘋果，有助於縮短其育種周期.最近十年，在該領域的研究取得很大進展，涉及到一些重要的蘋果基因型及有用的外源基因.迄今，蘋果的遺傳轉化主要採用農桿菌介導法，侵染與轉化材料的再生是影響其轉化效率的關鍵過程，了解其影響因素，尋找有利因素以提高轉化效率是目前蘋果遺傳轉化研究的重點。Mature embryo - derived calli of japonica rice ( oryza sativa l. ) cultivars nipponbare were transformed using agrobacterium tumefaciens strain agl1 carrying a binary vector pcas04 harboring the marker gene, neomycin phosphotransferase gene ( nptii ), driven by a promoter from the ubiquitin gene in maize, a promoterless p - glucuronidase gene near to the left border of t - dna for trapping gene and a strong promoter, rice actin - gb promoter, near to the right border of t - dna as activation tagging. in this system, co - cultivation was simplified, special selection stages and pre - regeneration stage were omitted, the whole process was almost under continuous light at 30 ? except co - cultivation and transgenic plants began to generate only after 7 weeks calli were induced
在一步轉化系統中，光照高溫條件下培養的水稻愈傷組織從誘導開始經過4周時間就可以達到轉化實驗的要求，並且簡化、優化了整個共培養過程，省去了一篩、二篩和預分化步驟，只用7周的時間就可以初步得到再生轉化植株；共191塊愈傷組織得到125塊抗性愈傷組織，轉化頻率達到65 . 4 ，最後共得到99棵獨立來源的再生植株，抗性愈傷組織再生頻率達到79 . 2 。分享友人