13 resultados para SRS
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
水稻(Oryza sativa L.) 颖花开裂 (split rice spikelet,SRS) 突变体是从水稻品系 8902s 花药培养得到的双单倍体群体中筛选出的同源异型突变体。以窄叶青8号为母本,SRS突变体为父本配制杂交组合,其F2群体中正常植株和突变植株的分离比例符合3:1,说明颖花突变性状是由单隐性基因决定的。 利用扫描电镜观察 SRS突变体花器官形态发生过程。其性状表现为内外稃变软变长,不抱合,在外稃基部又着生一朵花,两浆片基部融合,质地呈稃片状,雄蕊和雌蕊形态正常,且可育。该突变体的突变性状与拟南芥APETALA1的突变表现相似,说明两者在形态建成方面具有相似之处。由于 SRS 突变体第一轮和第二轮花器官发生了变化,根据 ABC 模型,srs-l基因应属于同源异型 A 组基因。 采用BSA法在F2群体中建立DNA正常池和突变池,利用RAPD技术筛选与突变基因srs-l连锁的分子标记。从520条随机引物中筛选出了引物S465能在两池间扩增出分子量为900 bp的差异片段,并证明其在F2群体中表现共分离。将此DNA片段克隆后作为RFLP探针pS465A,该探针与srs-l基因紧密连锁,在DH群体的RFLP分子连锁图谱上成功地将它们定位于第三染色体上。 本研究是利用水稻同源异型突变体为材料,研究水稻花器官发育基因的首例报道。
Resumo:
Stimulated Raman scattering (SRS) of a relativistic laser in plasmas is studied in the framework of the standard equation set of a three-wave process. As far as every wave involved in the process is concerned, its evolution has two aspects: time-dependent amplitude and time-dependent frequency. These two aspects affect each other. Strict analysis and numerical experiment on the full three-wave equation set reveal that a fast growing mode of the instability, which could reach a balance or saturation point during a period far shorter than an estimation based on conventional analysis, could take place in a standard three-wave process without coupling with a fourth wave. This fast growing mode is found to stem from the constraint set by the background density on the amplitude of the driven Langmuir wave. The effect of various parameters on the development of the SRS instability is studied by numerical calculation of the history of the instability in different cases. (c) 2007 American Institute of Physics.
Resumo:
简要介绍了固体拉曼激光器的研究现状,总结了几种常用的同体拉曼晶体[LiIO3,Ba(NO3)2,CaWO4]的受激拉曼实验特性,并对如何设计各种形式的拉曼激光装置以取得良好的频率转换做了分析。最后对同体拉曼激光器的发展做了展望。
Resumo:
光纤激光器以其结构紧凑、转换效率高、易散热和光束质量好等优点正逐渐成为高功率全固态激光器的主要选择。目前,单根光纤激光器的输出功率已经超过千瓦量级,但是由于受受激拉曼散射(SRS)和受激布里渊散射(SBS)等非线性效应的影响,单根光纤激光器的最终输出功率还是受到限制。要在保证光束质量的同时进一步提高输出功率就需要采用相干组束技术。
Resumo:
由于硝酸钡晶体具有很强的对称振动(频率1047 cm^-1)和较高的拉曼增益,可以用来产生受激拉曼激光.采用单端泵浦的外置拉曼振荡腔与双棱镜分光装置进行了硝酸钡晶体拉曼激光实验,泵浦源为倍频Nd: YAG的532 nm激光,硝酸钡晶体通过水溶液降温法生长,尺寸为10 mm×10 mm×48 mm,采用特殊镀膜的腔镜对各阶斯托克斯光进行优化选择.在泵浦源达到65 mJ时,获得21 mJ一阶斯托克斯光,输出波长为563 nm,以及16 mJ的二阶斯托克斯光,输出波长为599 nm,受激拉曼散射SRS最大的整体
Resumo:
报道了利用重复频率为30HZ,波长为532nm的Nd:YAG倍频激光单次通过抽运硝酸钡(Ba(NO3)2)晶体(晶体由水溶液降温法生长,长度为48mm,横截面为10mm×10mm),获得高效率的一阶(563nm),二阶(599nm)和三阶(639nm)斯托克斯光的实验结果.硝酸钡晶体沿着[110]晶轴方向切割.观测到一、二、三阶斯托克斯光呈锥形环分布,一、二、三阶斯托克斯光的散射外边缘与抽运光轴线间的夹角大小分别为1.7°,3.5°,5.0°.同时也观测到Ba(NO3)2的SRS角度分布与抽运光强度无关.
Resumo:
利用1 064 nm的Nd∶YAG激光抽运振荡腔内的硝酸钡晶体,获得高效率、窄脉冲的喇曼激光输出.硝酸钡晶体由水溶液降温法生长,长度为48 mm.喇曼振荡腔由对抽运光、一阶、二阶斯托克斯光有不同反射率的双色平面镜构成.当抽运光功率达到4.5 W时,获得最高的一阶斯托克斯喇曼激光功率为1.48 W,相应的转换效率为32.9%,并测得斜率效率为40%.由于受激喇曼散射的作用,喇曼脉冲光由抽运脉冲光的19.8 ns压缩为2.4 ns,获得的喇曼激光脉冲波形具有的"上升沿陡峭、下降沿缓慢"的特性,对其形成过程作了
Resumo:
综述了光子晶体光纤(PCF)不同于传统光纤的各种性质,并详细讨论了光子晶体光纤在通信和光纤激光等领域的新发展。
Resumo:
Sodium rutin sulfate (SRS) is a sulfated rutin modified from the natural flavonol glycoside rutin. Here, we investigated its in vitro anti-HIV and -HSV activities and its cytotoxic profile. Fifty percent inhibitory concentration (IC50) values of SRS against HIV-1 X4 virus IIIB, HIV-1 R5 isolates Ada-M and Ba-L were 2.3 +/- 0.2, 4.5 +/- 2.0 and 8.5 +/- 3.8 mu M with a selectivity index (SI) of 563, 575 and 329, respectively. Its IC50 against primary R5 HIV-1 isolate from Yunnan province in China was 13.1 +/- 5.5 mu M, with a Sl of 197. In contrast, unsulfated rutin had no activity against any of the HIV-1 isolates tested. Further study indicated that SRS blocked viral entry and virus-cell fusion likely through interacting with the HIV- I envelope glycoprotein. SRS also demonstrated some activity against human herpes simplex virus (HSV) with an IC50 of 88.3 +/- 0.1 mu M and a Sl of 30. The 50% cytotoxicity concentration (CC50) of SRS was >3.0 mM, as determined in human genital ME 180, HeLa and primary human foreskin fibroblast cells. Minimum inhibitory concentration of SRS for vaginal lactobacilli was >3.0 mM. These results collectively indicate that SRS represents a novel candidate for anti-HIV-1/HSV microbicide development. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
A novel electroluminescence oxide phosphor (Gd2O3-Ga2O3):Ce has been prepared by electron beam evaporation. The emission peaks of photoluminescence lie at 390nm and a shoulder at 440nm. However, the electroluminescence of the (Gd2O3-Ga2O3):Ce thin film have four emission peaks at 358nm, 390nm, 439nm and 510nm, respectively. The optical absorption of (Gd2O3-Ga2O3):Ce thin film and the photoluminescence of composite materials with various ratios of Ga2O3/(Gd2O3+Ga2O3) have also been described to investigate the origin of emission of photoluminescence and electroluminescence.
Resumo:
UV-blue light was obtained from a thin-film electroluminescence device using Gd3Ga5O12:Ag as a light-emitting layer, which was deposited by using electron-beam evaporation. The crystal composition and structure of Gd3Ga5O12:Ag were studied by x-ray powder diffraction, The Gd3Ga5O12:Ag has a photoluminescence emission which peaked at around 397 and 467 nm, which were attributed to the oxide vacancies and Ag+, respectively. The brightness of 32 cd/m(2) was obtained when an alternating voltage of 130 V at 1 kHz was applied. (C) 2000 American Institute of Physics. [S0003-6951(00)05031-2].
Resumo:
When CaS:Sm3+, Eu2+ is excited at 476.5 nm (Ar+), the emission spectra taken at room temperature and at 77 K are different, indicating that there are two competitive energy transfer processes-Sm3+ --> Eu2+ and Eu2+ --> Sm3+ with phonon participation. So, the luminescence intensity of Sm3+ increases first, and then decreases as the concentration of Eu2+ is increasing. (C) 2001 Elsevier Science Ltd. All rights reserved.
Resumo:
The thermophily, fishing season and central fishing ground of Japanese pilchard (Sardinops melanosticta) were studied by using satellite remote sensing (SRS) and other methods in Haizhou Bay and Tsushima waters during 1986-1990. A rapid prediction method of fishing ground is presented. Moreover, the results indicated that the thermophilic values of the fish stock are 11-20 degrees C and both fishing grounds are in increasing temperature process from the beginning to the end of the fishing period. The Japanese pilchards gather vigorously at the sea surface temperature of 15-17 degrees C. The water temperature is a key factor affecting the fishing season and the catch of the fishing ground. The increasing temperature process restricts the fishing season development and central fishing ground formation. The accuracy of 15 predictions made in the Haizhou Bay fishing ground is up to 91.3%, and 37 predictions made in the Tsushima, fishing ground shorten the fish detection time by 13.4% - 22% on the average.