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The atrazine-resistant psbA gene of black nightshade was transferred to the chloroplast genome of atrazine-susceptible soybean by means of ovary microinjection during the stage of zygote. The identification was carried out by using the methods of spraying the leaves directly with atrazine solution, examining the change of leaf fluorescence kinetics under a brighter light induction, molecular hybridization, etc. The experimental results show that the transgenic soybean plants do have been obtained for the first time. 相似文献
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Thylakoid polypeptide components, Mg~(2+) -induced Chl a fluorescence at 77K and surface chargechanges were measured to investigate the functional sites of Mg~(2+) in the regulation of energy distri-bution between two photosystems in completely and incompletely developed barley chloroplasts. It wasfound that in contrast to the completely developed chloroplasts, the incompletely developed chloroplastslacked Chl b and did not contain the 23KDa and 25KDa polypeptide components of LHC-PSII. In themeantime, these membranes did nor present Mg~(2+) -induced Cbl a fluorescence and surface charge changesof thylakoids. These results provided strong evidence that the 23KDa and 25KDa polypeptides ofLHC-PSII are the specific acting sites of the cation that induced these two phenomena. It is suggested in this paper that Mg~(2+) -induced change of excitation energy distribution betweentwo photosystems is produced by the mechanism due to electrostatic neutralization of LHC-PSII bythe cation to cause a structural or con 相似文献
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STUDIES ON THE BEHAVIOR OF THE INTERNAL VIBRATIONAL MODES IN (NH4)2TexSn1-xCl6 MIXED CRYSTALS 下载免费PDF全文
The behavior of the internal lattice vibrational modes in (NH4)2TexSn1-xCl6 mixed crystals has been investigated by Raman scattering. All of the Raman-active [MX6]2- internal modes show two-mode property in the mixed crystals with compositions from x?=?0 to 1, and apart from the sample with x?=?0.5, their energy positions are composition-independent. Space group calculations including site symmetry considerations and frequency fittings describe a good force field model. It has been demonstrated that the composition-independent two-mode behavior may come from the strong clustering effect, rather than from the character of the gap and local modes of impurities in mixed crystals. For the sample with x?=?0.5, the two component elements seem to form a pseudo-periodic lattice structure. 相似文献
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一、前 言 在通常的(AlGa)As条形半导体双异质结激光器的输出功率随注入电流变化的过程中,由于非线性扭曲现象的存在,限制了输出功率的动态范围,带来了使用的局限性。尤其在模拟调制的通讯系统中,对讯号引入畸变,在与光纤的耦合上也造成困难。因此,非线性问题的研究成为重要课题之一。 目前对非线性问题的研究大多在固定温度条件下进行[1-3].对于非线性现象在低温下随温度的变化关系叙述不多.然而对激光器低温特性的研究还是重要的[4].我们在低温的不同温度下对激光器的非线性现象进行了观察。定性作了初步探讨,以便从实验结果进一步了解… 相似文献
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The Raman spectra of the three differently colored single-crystal SrTiO_3 have been measured.Atroom temperature the Raman effect of SrTiO_3 is a second order process.The Raman frequency shiftsof samples with variant color are similar,but the Raman scattering intensities are different.FromHall effect and XPS measurements we can conclude that the color centre of sample is caused by oxygenvacancy.Oxygen vacancy acts as donor in the samples. 相似文献
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The effects of trypsin on the light-induced variable fluorescence of both the normaland tris-washed spinach chloroplasts have been investigated and it is discovered that: (i)Trypsin clearly inhibits in both cases the light-induced variable fluorescence emissions;but when the exogenous electron donor SMC B is added, this inhibitroy effects of trypsinare greatly alleviated and the recovery efficiency is similar in both cases. (ii) In thepresence of DCMU, trypsin still inhibits the variable fluorescence intensity but theexogenous electron acceptor such as DCIP or Fecy has no influence on it. Based on the above results, the following conclusion can be drawn: trypsin can evident-ly inactivate the electron transport on the oxidizing side of PS-Ⅱ, which exists between thewater splitting enzyme system and SMCB binding site. However, the water splitting enzymeis not sensitive to trypsin. It might be assumed that there is some protein on the thylakoidmembrane that acts as regulator to the functional mechanism of 相似文献