scholarly journals Triplet–triplet annihilation upconversion with reversible emission-tunability induced by chemical-stimuli: a remote modulator for photocontrol isomerization

2021 ◽  
Author(s):  
Yaxiong Wei ◽  
Haitao Xian ◽  
Xialei Lv ◽  
Fan Ni ◽  
Xiaosong Cao ◽  
...  
Keyword(s):  
Low Energy ◽  
High Contrast ◽  
Stimuli Responsive ◽  
Photochromic Dye ◽  
Dual Color ◽  
Light Excitation ◽  
Chemical Stimuli ◽  
First Time ◽  
Triplet Triplet Annihilation

The chemical stimuli-responsive triplet–triplet annihilation upconversion (TTA-UC) system was demonstrated for the first time with high-contrast dual-color UC emission, and this platform was furtherly adopted to induce reversible photoswitching of a photochromic dye remotely under low-energy light excitation at a fixed wavelength.

Harnessing low energy photons (635 nm) for the production of H2O2 using upconversion nanohybrid photocatalysts

2016 ◽  
Vol 9 (3) ◽  
pp. 1063-1073 ◽  
Author(s):  
Hyoung-il Kim ◽  
Oh Seok Kwon ◽  
Sujeong Kim ◽  
Wonyong Choi ◽  
Jae-Hong Kim
Keyword(s):  
Hydrogen Peroxide ◽  
Low Energy ◽  
Time In Literature ◽  
First Time ◽  
Photocatalytic Synthesis ◽  
Triplet Triplet Annihilation

This study demonstrates, for the first time in literature, in situ photocatalytic synthesis of hydrogen peroxide (H2O2) through sensitized triplet–triplet annihilation (TTA) upconversion (UC) of low-energy, sub-bandgap photons.

scholarly journals Triplet-Triplet Annihilation Upconversion with Reversible Emission-Tunability Induced by Chemical-Stimuli: a Remote Modulator for Photocontrol Isomerization

2020 ◽  
Author(s):  
Yaxiong Wei ◽  
Xialei Lv ◽  
Haitao Xian ◽  
Xiaosong Cao ◽  
Chuluo Yang ◽  
...  
Keyword(s):  
Stokes Shift ◽  
Proof Of Concept ◽  
Ph Responsive ◽  
Acceptor Pair ◽  
Color Tunable ◽  
Chemical Stimuli ◽  
Anti Stokes ◽  
First Time ◽  
Further Development ◽  
Triplet Triplet Annihilation

Triplet-triplet annihilation upconversion (TTA-UC) has been widely studied, but color-tunable TTA-UC system triggered by chemical stimuli has not yet been proposed. Herein, reversible acid/base switching of TTA-UC emission wavelength is achieved for the first time by a simple platform, composed of a direct singlet-triplet (S<sub>0</sub>-T<sub>1</sub>) absorpting photosensitizer, and pH-responsive 9,10-di(pyridin-4-yl)anthracene (DPyA) as acceptor. The photosensitizer-acceptor pair exhibits efficient UC emission (quantum yield up to 3.3%, anti-Stokes shift up to 0.92 eV) with remarkable contrast upon base/acid treatment (Δ<i>λ</i><sub>em,max</sub> = 82 nm, 0.46 eV). In a proof-of-concept study, the color-adjustable TTA-UC emission was applied as a remote modulator to photo-control reversible chemical reactions for the first time. This platform enriches the portfolio of color-switchable TTA-UC, and the mechanism would inspire further development of smart UC systems and extend the application field of upconversion.

scholarly journals Triplet-Triplet Annihilation Upconversion with Reversible Emission-Tunability Induced by Chemical-Stimuli: a Remote Modulator for Photocontrol Isomerization

2020 ◽  
Author(s):  
Yaxiong Wei ◽  
Xialei Lv ◽  
Haitao Xian ◽  
Xiaosong Cao ◽  
Chuluo Yang ◽  
...  
Keyword(s):  
Stokes Shift ◽  
Proof Of Concept ◽  
Ph Responsive ◽  
Acceptor Pair ◽  
Color Tunable ◽  
Chemical Stimuli ◽  
Anti Stokes ◽  
First Time ◽  
Further Development ◽  
Triplet Triplet Annihilation

Triplet-triplet annihilation upconversion (TTA-UC) has been widely studied, but color-tunable TTA-UC system triggered by chemical stimuli has not yet been proposed. Herein, reversible acid/base switching of TTA-UC emission wavelength is achieved for the first time by a simple platform, composed of a direct singlet-triplet (S<sub>0</sub>-T<sub>1</sub>) absorpting photosensitizer, and pH-responsive 9,10-di(pyridin-4-yl)anthracene (DPyA) as acceptor. The photosensitizer-acceptor pair exhibits efficient UC emission (quantum yield up to 3.3%, anti-Stokes shift up to 0.92 eV) with remarkable contrast upon base/acid treatment (Δ<i>λ</i><sub>em,max</sub> = 82 nm, 0.46 eV). In a proof-of-concept study, the color-adjustable TTA-UC emission was applied as a remote modulator to photo-control reversible chemical reactions for the first time. This platform enriches the portfolio of color-switchable TTA-UC, and the mechanism would inspire further development of smart UC systems and extend the application field of upconversion.

A new pathway for the formation of radial nematic droplets within a lipid-laden aqueous-liquid crystal interface

RSC Advances ◽  
2014 ◽  
Vol 4 (36) ◽  
pp. 18889-18893 ◽  
Author(s):  
Sumyra Sidiq ◽  
Dibyendu Das ◽  
Santanu Kumar Pal
Keyword(s):  
Liquid Crystal ◽  
Topological Defects ◽  
Soft Materials ◽  
Stimuli Responsive ◽  
First Time ◽  
Crystal Interface

A new pathway for the formation of liquid crystal (LC) droplets with radial LC ordering is reported for the first time in the presence of surfactants and lipids. Interactions of an enzyme with the topological defects in the LC mediate the response of these droplets and thus provide new designs for stimuli-responsive soft materials.

Stimuli responsive reversible high contrast off–on fluorescence switching of simple aryl-ether amine based aggregation-induced enhanced emission materials

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98618-98625 ◽  
Author(s):  
Anu Kundu ◽  
P. S. Hariharan ◽  
K. Prabakaran ◽  
Dohyun Moon ◽  
Savarimuthu Philip Anthony
Keyword(s):  
Schiff Base ◽  
High Contrast ◽  
Stimuli Responsive ◽  
Aryl Ether ◽  
Fluorescence Switching

Aryl-ether amine based simple Schiff base molecules showed rare stimuli responsive off–on fluorescence switching with high contrast.

scholarly journals Detection of the Geminga pulsar with MAGIC hints at a power-law tail emission beyond 15 GeV

2020 ◽  
Vol 643 ◽  
pp. L14
Author(s):  
◽  
V. A. Acciari ◽  
S. Ansoldi ◽  
L. A. Antonelli ◽  
A. Arbet Engels ◽  
...  
Keyword(s):  
Energy Range ◽  
Power Law ◽  
Gamma Ray ◽  
Low Energy ◽  
Significance Level ◽  
Inverse Compton Scattering ◽  
Curvature Radiation ◽  
Sensitivity Range ◽  
Inverse Compton ◽  
First Time

We report the detection of pulsed gamma-ray emission from the Geminga pulsar (PSR J0633+1746) between 15 GeV and 75 GeV. This is the first time a middle-aged pulsar has been detected up to these energies. Observations were carried out with the MAGIC telescopes between 2017 and 2019 using the low-energy threshold Sum-Trigger-II system. After quality selection cuts, ∼80 h of observational data were used for this analysis. To compare with the emission at lower energies below the sensitivity range of MAGIC, 11 years of Fermi-LAT data above 100 MeV were also analysed. From the two pulses per rotation seen by Fermi-LAT, only the second one, P2, is detected in the MAGIC energy range, with a significance of 6.3σ. The spectrum measured by MAGIC is well-represented by a simple power law of spectral index Γ = 5.62 ± 0.54, which smoothly extends the Fermi-LAT spectrum. A joint fit to MAGIC and Fermi-LAT data rules out the existence of a sub-exponential cut-off in the combined energy range at the 3.6σ significance level. The power-law tail emission detected by MAGIC is interpreted as the transition from curvature radiation to Inverse Compton Scattering of particles accelerated in the northern outer gap.

scholarly journals A triple star in disarray

2020 ◽  
Vol 644 ◽  
pp. A114
Author(s):  
M. Kasper ◽  
K. K. R. Santhakumari ◽  
T. M. Herbst ◽  
R. van Boekel ◽  
F. Menard ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
State Of The Art ◽  
High Contrast ◽  
Compelling Evidence ◽  
T Tauri ◽  
Reflected Light ◽  
First Time ◽  
Triple Star ◽  
Outflow System

Aims. T Tauri remains an enigmatic triple star for which neither the evolutionary state of the stars themselves, nor the geometry of the complex outflow system is completely understood. Eight-meter class telescopes equipped with state-of-the-art adaptive optics provide the spatial resolution necessary to trace tangential motion of features over a timescale of a few years, and they help to associate them with the different outflows. Methods. We used J-, H-, and K-band high-contrast coronagraphic imaging with VLT-SPHERE recorded between 2016 and 2018 to map reflection nebulosities and obtain high precision near-infrared (NIR) photometry of the triple star. We also present H2 emission maps of the ν = 1-0 S(1) line at 2.122 μm obtained with LBT-LUCI during its commissioning period at the end of 2016. Results. The data reveal a number of new features in the system, some of which are seen in reflected light and some are seen in H2 emission; furthermore, they can all be associated with the main outflows. The tangential motion of the features provides compelling evidence that T Tauri Sb drives the southeast–northwest outflow. T Tauri Sb has recently faded probably because of increased extinction as it passes through the southern circumbinary disk. While Sb is approaching periastron, T Tauri Sa instead has brightened and is detected in all our J-band imagery for the first time.

Epilogue

2017 ◽  
Author(s):  
Robert G. Lawson
Keyword(s):  
The State ◽  
Low Energy ◽  
Withdrawal Symptoms ◽  
High Anxiety ◽  
Mind Reading ◽  
Self Confidence ◽  
State Of Mind ◽  
First Time

Did Alex Arnold kill Betty Gail Brown? I have been asked that question hundreds of times and have never found it easy to answer. My difficulty with the question began almost as soon as I saw Arnold for the first time, in a jail cell in Lexington two or three days after he had confessed to the killing and been charged with murder. Although Arnold was not at the time hallucinating about mind-reading machines or talking to creatures on the walls of his jail cell, he was quite obviously still suffering mental impairments. He had lost his access to alcohol a little more than a week earlier and had been sitting alone in jail for most of that period; he seemed to have passed through the worst of his withdrawal symptoms, but was not even close to a total escape from the consequences of at least ten years of drunkenness. He had lost the “good feelings” he gained from drinking (elevated mood, self-confidence, and nonexistent inhibitions) and had found in their place high anxiety, low energy, some disorientation, and a crystal-clear desire to be left alone. It was under these conditions, speaking very softly and seeming almost to be talking to himself, that he said, “I killed her.” Had he made this statement under normal circumstances, in a clean and clear state of mind, it would have been easy to believe that the state had found the killer of Betty Gail Brown. But the circumstances under which the statement was made were far from normal, although they were much closer to normal that those that prevailed a few days earlier when he signed the confession that led to his prosecution for murder....

scholarly journals Enzyme-hydrolyzed Fruit of Jurinea mollis: A Rich Source of (-)-(8R,8′R)-Arctigenin

2016 ◽  
Vol 11 (10) ◽  
pp. 1934578X1601101 ◽  
Author(s):  
Rita Könye ◽  
Ágnes Evelin Ress ◽  
Anna Sólyomváry ◽  
Gergő Tóth ◽  
András Darcsi ◽  
...  
Keyword(s):  
Low Energy ◽  
Plant Tissues ◽  
Selective Isolation ◽  
Isolation Method ◽  
Specific Accumulation ◽  
Fruit Wall ◽  
Lignan Glycoside ◽  
Nmr Methods ◽  
First Time ◽  
Low Energy Conformations

In Jurinea mollis fruit, the dibenzylbutyrolactone-type lignan glycoside arctiin and its aglycone arctigenin were determined for the first time using a combination of optimized enzymatic treatment and complementary spectrometric (HPLC-MS, GC-MS) and spectroscopic (CD and NMR) methods. Analysis of separated fruit parts, i.e., the fruit wall and embryo, demonstrated the specific accumulation of arctiin, since it was exclusively found in the embryo. Arctiin in the embryo samples (71.5 mg/g) was found to be quantitatively converted into arctigenin (50.7 mg/g) by endogenous enzymatic hydrolysis, resulting in one of the highest arctigenin-containing plant tissues reported to date and allowing the selective isolation of arctigenin by our recently reported three-step isolation method. The absolute configuration of the isolated arctigenin was determined to be (-)-(8 R,8′ R). Conformational analysis of arctigenin was also performed, resulting in three major low energy conformations.

High-contrast mechanochromism and polymorphism-dependent fluorescence of difluoroboron β-diketonate complexes based on the effects of AIEE and halogen

RSC Advances ◽  
2016 ◽  
Vol 6 (40) ◽  
pp. 33755-33762 ◽  
Author(s):  
Yunpeng Qi ◽  
Yongtao Wang ◽  
Yongjiang Yu ◽  
Zhiyong Liu ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Quantum Yields ◽  
High Contrast ◽  
Stimuli Responsive ◽  
Responsive Materials

A series of AIEE-active difluoroboron β-diketonate complexes derivatives exhibit high-contrast mechanochromism, polymorphism-dependent fluorescence, and extremely high fluorescent quantum yields which could be as promising stimuli-responsive materials.

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