scholarly journals Thermal-responsive multicolor emission of single NaGdF4:Yb/Ce/Ho upconversion nanocrystals for anticounterfeiting application

Nanophotonics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2879-2885 ◽  
Author(s):  
Yanqing Hu ◽  
Qiyue Shao ◽  
Xinyi Deng ◽  
Jianqing Jiang
Keyword(s):  
Critical Factor ◽  
Temperature Dependent ◽  
Recognition Method ◽  
Promising Candidate ◽  
Thermally Induced ◽  
Quenching Effect ◽  
Security Authentication ◽  
Upconversion Nanocrystals ◽  
Nonradiative Transitions ◽  
High Level

AbstractThis study presents a novel and high-level anticounterfeiting strategy based on Ce/Yb/Ho triply-doped NaGdF4 nanocrystals with temperature-responsive multicolor emission. A critical factor leading to the multicolor emission is confirmed by comparing the luminescence thermal behaviors of nanocrystals in various atmospheres. Through analyzing the temperature-dependent lifetimes of Yb3+ ions in air, we demonstrate that thermally-induced multicolor emission mainly originates from the gradually-attenuated H2O quenching effect. Because the cross-relaxations between Ce3+ and Ho3+ ions and the nonradiative transitions of Yb3+ ions create plenty of phonon heat, the multicolor emission of nanocrystals can be achieved under 975 nm excitation at a relatively low power density. This recognition method is efficient and convenient for security authentication. The as-synthesized core nanocrystals can be directly used to fabricate anticounterfeiting ink without further processing (e.g. core/shell or hybrid). Therefore, the small-sized β-NaGdF4:Yb/Ce/Ho nanocrystals are promising candidate for security application.

scholarly journals When brain damage “improves” perception: neglect patients can localize motion-shifted probes better than controls

2015 ◽  
Vol 114 (6) ◽  
pp. 3351-3358 ◽  
Author(s):  
Stefania de Vito ◽  
Marine Lunven ◽  
Clémence Bourlon ◽  
Christophe Duret ◽  
Patrick Cavanagh ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Visual Fields ◽  
Critical Factor ◽  
Significant Shift ◽  
Stimulus Motion ◽  
Attentional Processes ◽  
Position Shift ◽  
The Right ◽  
High Level ◽  
Better Than

When we look at bars flashed against a moving background, we see them displaced in the direction of the upcoming motion (flash-grab illusion). It is still debated whether these motion-induced position shifts are low-level, reflexive consequences of stimulus motion or high-level compensation engaged only when the stimulus is tracked with attention. To investigate whether attention is a causal factor for this striking illusory position shift, we evaluated the flash-grab illusion in six patients with damaged attentional networks in the right hemisphere and signs of left visual neglect and six age-matched controls. With stimuli in the top, right, and bottom visual fields, neglect patients experienced the same amount of illusion as controls. However, patients showed no significant shift when the test was presented in their left hemifield, despite having equally precise judgments. Thus, paradoxically, neglect patients perceived the position of the flash more veridically in their neglected hemifield. These results suggest that impaired attentional processes can reduce the interaction between a moving background and a superimposed stationary flash, and indicate that attention is a critical factor in generating the illusory motion-induced shifts of location.

Juggling on the line

2015 ◽  
Vol 37 (4) ◽  
pp. 459-474 ◽  
Author(s):  
Samantha Evans
Keyword(s):  
Critical Role ◽  
Case Study Research ◽  
Critical Factor ◽  
Employee Relations ◽  
Front Line ◽  
Structured Interviews ◽  
Line Managers ◽  
Content Type ◽  
Nuanced Understanding ◽  
High Level

Purpose – The purpose of this paper is to examine the interplay between the role of front line managers (FLMs) and their contribution to the reported gap between intended and actual human resource management (HRM). Design/methodology/approach – The findings draw on case study research using 51 semi-structured interviews with managers across two UK retail organisations between 2012 and 2013. Findings – This paper argues that FLMs are key agents in people management and play a critical role in the gap between intended and actual employee relations (ER) and HRM. The research found that these managers held a high level of responsibility for people management, but experienced a lack of institutional support, monitoring or incentives to implement according to central policy. This provided an opportunity for them to modify or resist intended policy and the tensions inherent in their role were a critical factor in this manipulation of their people management responsibilities. Research limitations/implications – The data were collected from only one industry and two organisations so the conclusions need to be considered within these limitations. Practical implications – Efforts to address the gap between intended and actual ER/HRM within organisations will need to consider the role tensions of both front line and middle managers. Originality/value – This research provides a more nuanced understanding of the interplay between FLMs and the gap between intended and actual HRM within organisations. It addresses the issue of FLMs receiving less attention in the HRM-line management literature and the call to research their role in the translation of policy into practice.

scholarly journals High Sucrose Levels and Abnormal Enzyme Activity as a Function of Nutritional Stress in Sugarcane

1969 ◽  
Vol 51 (4) ◽  
pp. 325-333
Author(s):  
Alex G. Alexander
Keyword(s):  
Nutrient Deficiency ◽  
Critical Factor ◽  
Nutritional Stress ◽  
Nutrient Supply ◽  
Oxidative Enzymes ◽  
Sand Culture ◽  
High Level ◽  
To Receive ◽  
High Sucrose ◽  
Nitrogen Phosphorus

Deficiencies of nitrogen, phosphorus, potassium, and calcium were gradually induced in sugarcane grown by sand culture. There were three objectives: 1, To determine whether nutritional stress in general is a means of inducing higher sucrose production; 2, to determine whether sucrose increases can be triggered without reaching nutrient-deficiency levels which would reduce tonnage; and 3, to ascertain whether increased sucrose production can be traced to common behavior patterns of hydrolytic and oxidative enzymes. All plants received a moderately high level of all nutrients until 14 weeks of age. Thereafter, individual nutrients were gradually lowered at intervals of 2 weeks, while control plants continued to receive the original levels. All plants subjected to nutritional stress accumulated higher leaf sucrose than control plants, regardless of the nutrient withheld. In each instance sucrose increases were recorded before nutrient supply had reached deficiency proportions. General nutritional stress thus appears to trigger variations in sugar level, with nutritional imbalance rather than actual deficiency being a critical factor. All plants under nutritional stress revealed a concurrent suppression of amylase as sucrose increased. Peroxidase was greatly stimulated by all nutritional treatments. Phosphatase was suppressed by decreasing nitrate and phosphorus, but was generally unaffected by the potassium and calcium treatments. Several distinct mechanisms of increased sucrose formation are indicated by the enzyme data. Sensitivity of amylase to changing nutrient supply is discussed from the standpoint of a possible indicator of approaching deficiency.

scholarly journals Temperature-dependent nanomechanics and topography of bacteriophage T7

2018 ◽  
Author(s):  
Zsuzsanna Vörös ◽  
Gabriella Csík ◽  
Levente Herényi ◽  
Miklós Kellermayer
Keyword(s):  
Structural Changes ◽  
Mechanical Stability ◽  
Genetic Material ◽  
Heat Inactivation ◽  
Infectious Agents ◽  
Temperature Dependent ◽  
Thermally Induced ◽  
Partial Denaturation ◽  
Induced Changes ◽  
T7 Bacteriophage

AbstractViruses are nanoscale infectious agents which may be inactivated by heat treatment. Although heat inactivation is thought to be caused by the release of genetic material from the capsid, the thermally-induced structural changes in viruses are little known. Here we measured the heat-induced changes in the properties of T7 bacteriophage particles exposed to two-stage (65 °C and 80 °C) thermal effect by using AFM-based nanomechanical and topographical measurements. We found that exposure to 65 °C caused the release of genomic DNA due to the loss of the capsid tail which leads to a destabilization of the T7 particles. Further heating to 80 °C surprisingly led to an increase in mechanical stability due to partial denaturation of the capsomeric proteins kept within the global capsid arrangement.

scholarly journals Deep Learning-Based Classification of Weld Surface Defects

2019 ◽  
Vol 9 (16) ◽  
pp. 3312 ◽  
Author(s):  
Zhu ◽  
Ge ◽  
Liu
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Random Forest ◽  
Convolutional Neural Network ◽  
Surface Defects ◽  
Recognition Method ◽  
High Level ◽  
Intelligent Recognition ◽  
Non Destructive

In order to realize the non-destructive intelligent identification of weld surface defects, an intelligent recognition method based on deep learning is proposed, which is mainly formed by convolutional neural network (CNN) and forest random. First, the high-level features are automatically learned through the CNN. Random forest is trained with extracted high-level features to predict the classification results. Secondly, the weld surface defects images are collected and preprocessed by image enhancement and threshold segmentation. A database of weld surface defects is established using pre-processed images. Finally, comparative experiments are performed on the weld surface defects database. The results show that the accuracy of the method combined with CNN and random forest can reach 0.9875, and it also demonstrates the method is effective and practical.

Thermally Induced Activation Energy of Crystalline Silicon in Alkaline Solution

1970 ◽  
Vol 11 ◽  
pp. 215-222
Author(s):  
SK Lamichhane
Keyword(s):  
Activation Energy ◽  
Potassium Hydroxide ◽  
Etch Rate ◽  
Crystalline Silicon ◽  
Lattice Parameter ◽  
Device Fabrication ◽  
Strong Anisotropy ◽  
Temperature Dependent ◽  
Thermal Agitation ◽  
Thermally Induced

Etching of crystalline silicon by potassium hydroxide (KOH) etchant with temperature variation has been studied. Results presented here are temperature dependent ER (etch rate) along the crystallographic orientations. Etching and activation energy are found to be consistently favorable with the thermal agitation for a given crystal plane. Study demonstrates that the contribution of microscopic activation energy effectively controls the etching process. Such a strong anisotropy in ER on KOH allows us a precious control of lateral dimensions of the silicon microstructure as well as surface growth of the crystal during micro device fabrication. Key words: anisotropy; activation energy; etch rate; lattice parameter; micromachining DOI: 10.3126/njst.v11i0.4148Nepal Journal of Science and Technology 11 (2010) 215-222

scholarly journals Context Definition and Query Language: Conceptual Specification, Implementation, and Evaluation

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1478 ◽  
Author(s):  
Alireza Hassani ◽  
Alexey Medvedev ◽  
Pari Delir Haghighi ◽  
Sea Ling ◽  
Arkady Zaslavsky ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Data Structures ◽  
Query Language ◽  
Contextual Information ◽  
Critical Factor ◽  
Software Components ◽  
Context Management ◽  
Iot Applications ◽  
Research Organizations ◽  
High Level

As IoT grows at a staggering pace, the need for contextual intelligence is a fundamental and critical factor for IoT intelligence, efficiency, effectiveness, performance, and sustainability. As the standardisation efforts for IoT are fast progressing, efforts in standardising context management platforms led by the European Telecommunications Standards Institute (ETSI) are gaining more attention from both academic and industrial research organizations. These standardisation endeavours will enable intelligent interactions between ‘things’, where things could be devices, software components, web-services, or sensing/actuating systems. Therefore, having a generic platform to describe and query context is crucial for the future of IoT applications. In this paper, we propose Context Definition and Query Language (CDQL), an advanced approach that enables things to exchange, reuse and share context between each other. CDQL consists of two main parts, namely: context definition model, which is designed to describe situations and high-level context; and Context Query Language (CQL), which is a powerful and flexible query language to express contextual information requirements without considering details of the underlying data structures. An important feature of the proposed query language is its ability to query entities in IoT environments based on their situation in a fully dynamic manner where users can define situations and context entities as part of the query. We exemplify the usage of CDQL on three different smart city use cases to highlight how CDQL can be utilised to deliver contextual information to IoT applications. Performance evaluation has demonstrated scalability and efficiency of CDQL in handling a fairly large number of concurrent context queries.

The singlet-quintet transition in Tris[2-(pyridin-2-yl)benzothiazole]iron(II) Bis(tetraphenylborate)

1984 ◽  
Vol 37 (6) ◽  
pp. 1157 ◽  
Author(s):  
AT Baker ◽  
HA Goodwin
Keyword(s):  
Field Strength ◽  
Spectral Data ◽  
Magnetic Moment ◽  
Spin Transition ◽  
Empirical Treatment ◽  
Temperature Dependent ◽  
Thermally Induced ◽  
Thiazole Derivative

The tris[2-(pyridin-2-yl)benzothiazole]iron(II) ion has been isolated as the tetraphenylborate salt which is stable in the atmosphere for short periods. The deep red complex displays a temperature-dependent magnetic moment and thermochroism which are associated with a thermally induced singlet (1A1) ↔ quintet (5T2) spin transition. An empirical treatment of the transition, which is continuous, yields ∆H and ∆S values of 22.7 kJ mol-1 and 91 JK-1 mol-1 over the range 275-364 K. Spectral data for the corresponding nickel(11) complex confirm the intermediate nature of the field strength of the benzothiazole and indicate that it is a weaker ligand than the corresponding thiazole derivative.

Sign in / Sign up

Export Citation Format

Share Document