scholarly journals Size Effects of Closed Encounter Ag Nanoshell Pairs for SERS Application

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zhiguo Zhao ◽  
Wenwen Liu ◽  
Junfeng Zhao ◽  
Xiaoyan Dong ◽  
Caiqiong Li ◽  
...  
Keyword(s):  
Light Intensity ◽  
Electric Field ◽  
Size Effects ◽  
Optical Devices ◽  
Scattering Efficiency ◽  
Sers Substrates ◽  
Light Enhancement ◽  
Intensity Changes

Closed encounter Ag nanoshell pairs with remarkable improved plasmonic light enhancement in their gaps have been attracting much attention in the production of sensitivity SERS substrates. This work demonstrates the size effects of Ag nanoshell pairs on obtaining higher light intensity in their gaps. It is found that very complex light intensity changes occur in the gaps of Ag nanoshell pairs with their diameter enlargements ( diameters > 100  nm). By the calculation of scattering efficiency and electric field vectors, the size-related light intensity changes in the gaps have been revealed and been concluded systematically. This work fills in the gaps of application of nanoshell pairs with larger sizes in SERS detectors and could guide the design of some other Ag nanoshell pair-based optical devices.

Dim light vision of Squilla mantis L

1963 ◽  
Vol 205 (5) ◽  
pp. 927-940 ◽  
Author(s):  
H. Schiff
Keyword(s):  
Light Intensity ◽  
Mediterranean Sea ◽  
Environmental Conditions ◽  
Green Fluorescence ◽  
Fiber Analysis ◽  
Near Ultraviolet ◽  
Intensity Changes ◽  
Dim Light ◽  
Dim Light Vision ◽  
Shape And Size

The anatomy of the eye of Squilla mantis and the geometrical optics derived from it are briefly described. The shape and size of the electroretinogram (ERG) are dependent on a) position where it is picked up, b) the light intensity, and c) the change of intensity. Single-fiber analysis confirms the results obtained by the anatomy and the ERG of the eye. Frequency of response of a single secondary fiber to intensity changes of light is proportional to the derivate dI/dt ( I = intensity; t = time). The Squilla sees a moving object as the sum of the intensity changes caused by that object, varied in time and space. The eyes have a maximum of sensitivity for light of 535–555 mµ wavelength, and a second maximum in the near ultraviolet light, the latter partly seen as green fluorescence due to an eye pigment. Anatomy, physiology, and the environmental conditions have been combined to explain the vision of this animal, adapted to his life in the blue-violet twilight of the deeper Mediterranean sea.

scholarly journals The Effect of Light Intensity on the Expression of Leucoanthocyanidin Reductase in Grapevine Calluses and Analysis of Its Promoter Activity

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1156
Author(s):  
Jing Cheng ◽  
Keji Yu ◽  
Mingyue Zhang ◽  
Ying Shi ◽  
Changqing Duan ◽  
...  
Keyword(s):  
Light Intensity ◽  
Promoter Activity ◽  
Flavonoid Biosynthesis ◽  
Response Patterns ◽  
Flavonoid Pathway ◽  
Leucoanthocyanidin Reductase ◽  
Genes Encoding ◽  
Intensity Changes ◽  
Different Response ◽  
Effect Of Light

To investigate the effect of light intensity on flavonoid biosynthesis, grapevine calluses were subjected to high light (HL, 250 μmol m−2 s−1) and dark (0 μmol m−2 s−1) in comparison to 125 μmol m−2 s−1 under controlled conditions (NL). The alteration of flavonoid profiles was determined and was integrated with RNA sequencing (RNA-seq)-based transcriptional changes of the flavonoid pathway genes. Results revealed that dark conditions inhibited flavonoid biosynthesis. Increasing light intensity affected flavonoids differently—the concentrations of flavonols and anthocyanins as well as the expressions of corresponding genes were less affected, whereas flavan-3-ol concentrations were predominantly increased, which caused enhanced trans-flavan-3-ol concentrations. Moreover, genes encoding leucoanthocyanidin reductase (LAR) exhibited different response patterns to light intensity changes—VviLAR1 expression increased with an increased light intensity, whereas VviLAR2 expression was insensitive. We further confirmed that the known transcription factors (TFs) involved in regulating flavan-3-ol biosynthesis utilized VviLAR1 as a target gene in grapevine calluses. In addition, VviLAR1 promoter activity was more sensitive to light intensity changes than that of VviLAR2 as determined using a transgenic Arabidopsis leaf system. These results suggested that light intensity had the most prominent effect on trans-flavan-3-ols in grapevine calluses and demonstrated that the two LAR genes had different response patterns to light intensity changes.

scholarly journals Space Charge Fields in the Development of a Townsend Discharge in Nitrogen

1969 ◽  
Vol 22 (4) ◽  
pp. 447 ◽  
Author(s):  
AA Doran
Keyword(s):  
Light Intensity ◽  
Electric Field ◽  
Space Charge ◽  
Applied Electric Field ◽  
Dominant Role ◽  
Light Output ◽  
Exact Relation ◽  
Townsend Discharge ◽  
Discharge Gap ◽  
Infor Mation

As the CUlTent through a spark rises into the milliampere range, ionization due to fields produced by space charge plays an increasingly dominant role. Infor� mation on these fields can be obtained from analysis of the light intensity emitted at different points along the axis of the discharge. In an earlier publication (Doran 1968) photomultiplier records of the light output obtained at various times during the growth of a Townsend discharge in nitrogen (pd = 600 torr cm) were analysed by an approximate method. In the present paper a more exact relation between the light emitted and the variation in local electric field is derived, enabling the previous results to be re.analysed. This has provided a quantitative picture, spatially and temporally resolved, of the development of these fields, which are associated with luminous fronts observed to propagate back and forth across the discharge gap. The magnitude of the field variations is in general about 10-20% of the applied electric field.

Benzocyclobutene barrier layer for suppressing conductance in nonlinear optical devices during electric field poling

2014 ◽  
Vol 104 (24) ◽  
pp. 243304 ◽  
Author(s):  
Wenwei Jin ◽  
Peter V. Johnston ◽  
Delwin L. Elder ◽  
Andreas F. Tillack ◽  
Benjamin C. Olbricht ◽  
...  
Keyword(s):  
Electric Field ◽  
Barrier Layer ◽  
Nonlinear Optical ◽  
Optical Devices ◽  
Nonlinear Optical Devices ◽  
Electric Field Poling

Light-induced alteration of leaf sterol content and late blight disease development in tomato

1982 ◽  
Vol 60 (12) ◽  
pp. 2724-2728 ◽  
Author(s):  
B. Bradford ◽  
L. D. Moore ◽  
D. M. Orcutt
Keyword(s):  
Light Intensity ◽  
Late Blight ◽  
Disease Incidence ◽  
Total Sterol ◽  
Disease Development ◽  
Low Light ◽  
Light Intensities ◽  
Intensity Changes ◽  
Late Blight Disease ◽  
Blight Disease

‘Nova’ and 'Beefsteak,' cultivars of tomato (Lycopersicon esculentum Mill.), were grown in chambers under light intensities of 240 or 120 μE∙m−2∙s−1. Thirty-five days after seeding, half of the tomato plants were harvested for sterol analysis and the others were inoculated with a tomato race O isolate of Phytophthora infestons (Mont.) de By. Late blight symptoms were assessed 10 days after inoculation from the number of leaves showing disease (disease incidence) and the amount of blighted area of each leaf (percent colonization). Disease incidence and percent colonization were not influenced by light intensity with 'Nova' plants, but 'Beefsteak' plants grown under low light were significantly [Formula: see text] more diseased than those exposed to the higher light intensity. Changes in free sterol, steryl ester, and total sterol concentrations between plants grown under different light intensities were similar for both cultivars. A significant decrease in the steryl glycoside concentration of low light grown 'Beefsteak' plants correlated with increased disease incidence. The possible role of steryl glycosides and their derivatives in late blight disease development is discussed.

scholarly journals Variable Step Length Incremental Conductance MPPT Control Based on the Power Prediction

2015 ◽  
Vol 9 (1) ◽  
pp. 452-458
Author(s):  
Yu Yunjun ◽  
Liu Tao ◽  
Wang Shisheng ◽  
Xin Jianbo ◽  
Ou Yang Haibing
Keyword(s):  
Light Intensity ◽  
Control Method ◽  
Step Length ◽  
Power Prediction ◽  
Photovoltaic Power ◽  
Incremental Conductance ◽  
Conductance Method ◽  
Variable Step ◽  
Intensity Changes ◽  
Power Generation System

The MPP of Photovoltaic power system undergoes migration or volatility under the influence of the external environments, especially light intensity changes. MPPT control is a very important method to increase the efficiency of the photovoltaic power generation system. But the existing variable step length incremental conductance method would produce misjudgment or even tracking failure when outside light intensity mutations. A variable step length incremental conductance MPPT control method based on power prediction has been proposed. This involves modeling, simulation and comparison of the different methods in the Matlab/Simulink environment. The proposed method can not only avoid misjudgments but can also track the MPP efficiently, improving the control accuracy compared with the variable step length incremental conductance method.

Electro-optic phenomena

2004 ◽  
Author(s):  
Robert E. Newnham
Keyword(s):  
Light Intensity ◽  
Electric Field ◽  
Electric Fields ◽  
Communication Systems ◽  
Ferroelectric Ceramics ◽  
Refractive Indices ◽  
Lead Lanthanum Zirconate Titanate ◽  
Lanthanum Zirconate ◽  
The Third ◽  
Electro Optic

Optical beams can be controlled by manipulating the refractive indices and absorption coefficients with applied electric fields. In communication systems electro-optic effects are used in phase and amplitude modulation, in beam deflectors, and in tunable filters. Three such effects are illustrated in Fig. 28.1. Lead lanthanum zirconate titanate (PLZT) is a transparent electroceramic that can be prepared in several different ferroelectric forms with large electro-optic coefficients. When prepared in a normal ferroelectric form it can be used in two different ways. A light-tunable shutter is constructed by coating a multidomain ceramic of PLZT with a photoconducting layer and transparent electrodes. A bias voltage on the electrodes is transferred to the ceramic when the photoconductor is illuminated. The electric field alters the domain structure and the degree of light scattering, controlling the intensity of light. Fully poled ferroelectric ceramics exhibit the linear electro-optic effect Using planar electrodes the PLZT is poled perpendicular to the optical beam. Polarizer and analyzer are positioned in the ±45◦ positions, and light intensity is controlled by altering the birefringence with an electric field. The third experiment utilizes a pseudo-cubic PLZT composition with a large quadratic electro-optic effect. No poling is required in this case. With polarizer and analyzer again in the ±45◦ positions, the transmitted light intensity is proportional to E2 rather than E. Linear and quadratic electro-optic coefficients are defined in terms of the fieldinduced changes in the optical indicatrix: . . . Bij(E) − Bij(0) = Δ

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