Interference by Near Ultraviolet and Green Light with Mitosis in the Onion Root Tip Meristem

1967 ◽  
Vol 94 (5) ◽  
pp. 411 ◽  
Author(s):  
Ellen G. Wolff ◽  
Dorothy Marie Fives ◽  
Richard M. Klein
2002 ◽  
Vol 25 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Marjori Leiva Camparoto ◽  
Rosangela de Oliveira Teixeira ◽  
Mário Sérgio Mantovani ◽  
Veronica Elisa Pimenta Vicentini

2009 ◽  
Vol 24 (8) ◽  
pp. 2589-2595 ◽  
Author(s):  
Mei Zhang ◽  
Baohong Li ◽  
Jing Wang ◽  
Zhiyang Zhang ◽  
Qiuhong Zhang ◽  
...  

The influences of (SiN)+ and Eu2+ concentration on the optical properties of BaAl2−xSixO4−xNx:Eu2+ were investigated. The lifetime results show that there are two different cation sites occupied by Eu2+ ions and the energy transfer occurs between them. The Huang–Rhys factor and the Stokes energy shift were determined, and thermal quenching with increasing temperature was observed. Finally, intense yellowish-green light emitting diodes (LED) with the color coordinate of (0.2936, 0.4483) under a forward-bias current of 20 mA was successfully fabricated on the basis of a structure consisting of BaAl2−xSixO4−xNx:Eu2+ phosphor and near-ultraviolet (∼395 nm) GaN chip.


1982 ◽  
Vol 44 (2) ◽  
pp. 127-127
Author(s):  
Marshall D. Sundberg
Keyword(s):  
Root Tip ◽  

1973 ◽  
Vol 21 (5) ◽  
pp. 417-425 ◽  
Author(s):  
W. D. KLOHS ◽  
C. W. GOFF

Inosine diphosphatase of a Golgi-enriched fraction of the onion root tip was characterized. Peak enzyme activity occurred at pH 4.8 and 7.0, although considerable activity was present between the peaks. The activity at neutral pH approximately doubled during a 4-day cold storage; no such increase of the pH 4.8 activity occurred under similar conditions. Treatment with deoxycholate or Triton X-l00 also activated the pH 7.0 enzyme. Although magnesium, manganese and calcium all supported inosine diphosphatase activity, 2 mM manganese supported maximal activity. Uridine diphosphate, guanosine diphosphate and inosine diphosphate were hydrolyzed much more rapidly than the other substrates tested. Sodium fluoride, uranyl nitrate, potassium chloride and heat all partially inhibited the enzyme. Glutaraldehyde and lead nitrate, two reagents to which nucleoside diphosphatase is exposed when studied cytochemically, greatly reduced enzyme activity.


2014 ◽  
Vol 989-994 ◽  
pp. 395-398
Author(s):  
Xiao Qi Zhang ◽  
Li Min Dong ◽  
Xin Cheng Tang ◽  
Qin Li ◽  
Zhi Dong Han

Ca2MgSi2O7: Eu3+, Ce3+, Tb3+, a single white Phosphor, was synthesized by the conventional solid-state reaction. The structure, surface morphology and luminescence properties of the prepared samples were investigated to evaluate its potentiality. XRD results confirm the orthorhombic phase of Ca2MgSi2O7: Eu3+, Ce3+, Tb3+ phosphors. The excitation spectra indicates the phosphor can be excited by 393 nm wavelength. The phosphor exhibits blue light at 467 nm, green light at 588 nm, red light at 618 nm. CIE chromaticity diagram indicates that Ca2MgSi2O7: Eu3+, Tb3+, Ce3+ exhibits white light. All properties show that the prepared phosphor is a single white phosphor suitable for near ultraviolet excitation which can be applied to new generation white LED lighting.


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