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971.
We collected centric diatom Stephanopyxis palmeriana samples in coastal waters of Xiamen for characteristic red light/far red light (R/FR) phytochrome reactions to identify its photoreceptor in the course of sexual reproduction. The result showed that pre-illumination of 2-3h red light before darkness could induce sexualization of S.palmeriana, while the follow-up illumination of far red light could reverse the effect of red light, which is a featured reaction of phytochrome. The Southern Dot Blot was carried out to identify the type of phytochrome that induces the sexualization. The result also showed high homogeneity of DNA fragment of S. palmeriana with phyB, but phyA. This means the photoreceptor in the process of sexual reproduction of S. palmeriana is phytochrome B (phyB). 相似文献
972.
We collected centric diatomStephanopyxis palmeriana samples in coastal waters of Xiamen for characteristic red light/far red light (R/FR) phytochrome reactions to identify its
photoreceptor in the course of sexual reproduction. The result showed that pre-illumination of 2–3h red light before darkness
could induce sexualization ofS. palmeriana, while the follow-up illumination of far red light could reverse the effect of red light, which is a featured reaction of
phytochrome. The Southern Dot Blot was carried out to identify the type of phytochrome that induces the sexualization. The
result also showed high homogeneity of DNA fragment ofS. palmeriana with phyB, but phyA. This means the photoreceptor in the process of sexual reproduction ofS. palmeriana is phytochrome B (phyB).
Supported by National Natural Science Foundation of China (No. 39670076) 相似文献
973.
974.
光照与日本沼虾繁殖和孵化关系极为密切。研究了不同波长的光对日本沼虾孵化的影响 ,结果表明 :在环境光谱主峰值 4 70 .5nm、4 77.9nm、4 92 .6nm、5 0 4 .8nm和 6 15 .2nm条件下 ,适度成熟的亲虾都能顺利孵化 ,日本沼虾孵化与否 ,与孵化环境中的光波波长无关 ,而与抱卵日本沼虾胚胎发育有关。日本沼虾在孵化期对不同波长的光谱有明显的视觉敏感度分布 ,在前 4种光谱条件下 ,日本沼虾视觉器官敏感 ,而在光谱主峰值 6 15 .2nm时日本沼虾视觉器官不敏感。这一特点在日本沼虾育苗生产上具指导意义 ,可防止抱卵亲虾在孵化过程中吞食幼体 ,提高幼体成活率 相似文献
975.
976.
977.
QI Yanxia JI Hongwei XIN Huizhen LIU Li 《中国海洋大学学报(英文版)》2007,6(2):143-146
A new kinetic-spectrophotometric method is proposed for the determination of copper ( Ⅱ ). The method is based on the catalytic effect of copper ( Ⅱ ) on the oxidation of weak acid brilliant blue dye (RAWL) by hydrogen peroxide. The copper ( Ⅱ ) can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ = 626 nm using the fix-time method. The optimum reaction conditions are as follows: pH 7.20, buffer solution NaOH-KH2PO4, RAWL (200 mgL-1) 5.00 mL, H2O2 (30%) 0.50 mL, reaction temperature 80 ?? and reaction time 20 min. The linear range of this method is between 0 μg L^-1 and 12 μg L^-1 and the limit of detection is 0.011 μg L-1, the relative standard deviation (RSD) in five replicate determinations for 2 and 8 μg L-1 copper ( Ⅱ ) are 3.2% and 2.3%, respectively. Twenty ions do not interfere in the determination of copper ( Ⅱ ). The method has been applied satisfactorily to the determination of copper ( Ⅱ ) in freshwater samples (tap water and Yellow River water from Lijin, Shandong, China) and seawater samples (from the South China Sea), the recovery rates are 98.0%, 102.5% and 96.0%, respectively. 相似文献
978.
979.
A self-similar, hydrodynamic model is derived and used to generate SNe light-curves. It is found that the temporal development
of the SN light-curve is governed by a ‘dynamic time’ parameter, and that the observed near-identical, normalized light-curves
of Type Ia SNe suggest that they have evolved from progenitor stars of the same central density. Fitting the model parameters
to observed Type Ia SNe light-curves suggests that the SNe have originated from the same mass progenitors. The model also
provides a theoretical basis for the Phillips observation relating the absolute magnitude of the Type Ia SN to its half-width.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
980.
H. Siemes B. Klingenberg E. Rybacki M. Naumann W. Schfer E. Jansen K. Kunze 《Ore Geology Reviews》2008,33(3-4):255-279
The critical resolved shear stresses (CRSSs) of hematite crystals were determined in compression tests for r-twinning, c-twinning and {a}<m>-slip in the temperature range 25 °C to 400 °C, at 400 MPa confining pressure, and a strain rate of 10− 5 s− 1 by Hennig-Michaeli, Ch., Siemes, H., 1982. Experimental deformation of hematile crstals betwen 25 °C and 400 °C at 400 MPa confining pressure. In: Schreyer, W. (Ed.) High Pressure Research in Geoscience, Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, p. 133–150. In the present contribution newly performed experiments on hematite single crystals at temperatures up to 800 °C at strain rates of 10− 5 s− 1 and 300 MPa confining pressure extends the knowledge about the CRSS of twin and slip modes. Optical observations, neutron diffraction goniometry, SEM forescatter electron images and electron backscatter diffraction are applied in order to identify the glide modes. Both twinning systems and {a}<m>-slip were confirmed by these methods. Besides the known glide systems the existence of the (c)<a>-slip system could be stated. Mechanical data establish that the CRSS of r-twinning decreases from 140 MPa at 25 °C to 5 MPa at 800 °C and for {a}<m>-slip from > 560 MPa at 25 °C to 40 MPa at 700 °C. At room temperature the CRSS for c-twinning is around 90 MPa and at 600 °C 60 MPa. The data indicate that the CRSSs above 200 °C seem to be between the values for r-twinning and {a}<m>-slip. For (c)<a>-slip only the CRSS at 600 °C could be evaluated to 60 MPa. Exact values are difficult to determine because other glide systems are always simultaneously activated. 相似文献