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Allergic reactions occur after the whole food is ingested, rather than the purified allergen. The present study explores the low-allergenic food processing for Litopenaeus vannamei by analysis of macrostructure, digestibility, and immunoreactivity. Furthermore, the presence of modified amino acids on the reported IgE epitopes was analyzed by mass spectrometry. Results showed that the combination processing of Maillard reaction (shrimp meat with galactose) with high temperature-pressure at 115 °C obviously changed the macrostructure and increased the digestibility for the shrimp meat. Meanwhile, the processing significantly reduced the IgG/IgE-binding activity of the shrimp meat. The hypo-IgE-binding activity in processed shrimp may be due to the modification of lysine, arginine, and cysteine residues in antigen epitopes. This is a comprehensive assessment of the specific amino acid residues modified by glycation of multiple allergens in processed L. vannamei, which provides a new research method to explore the hypo-IgE-binding activity in food.

Due to the increasingly strict emission standards of NOx on various industries, many traditional flue gas treatment methods have been gradually improved. Except for selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) methods to remove NOx from flue gas, theoxidation method is paying more attention to NOx removal now because of the potential to simultaneously remove multiple pollutants from flue gas. This paper summarizes the efficiency, reaction conditions, effect factors, and reaction mechanism of NO oxidation from the aspects of liquid-phase oxidation, gas-phase oxidation, plasma technology, and catalytic oxidation. The effects of free radicals and active components of catalysts on NO oxidation and the combination of various oxidation methods are discussed in detail. The advantages and disadvantages of different oxidation methods are summarized, and the suggestions for future research on NO oxidation are put forward at the end. The review on the NO removal by oxidation methods can provide new ideas for future studies on the NO removal from flue gas.

Mn-Based catalysts supported on γ-Al2O3, TiO2 and MCM-41 synthesized by an impregnation method were compared to evaluate their NO catalytic oxidation performance with low ratio O3/NO at low temperature (80–200 °C). Activity tests showed that the participation of O3 remarkably promoted the NO oxidation. The catalytic oxidation performance of the three catalysts decreased in the following order: Mn/γ-Al2O3 > Mn/TiO2 > Mn/MCM-41, indicating that Mn/γ-Al2O3 exhibited the best catalytic activity. In addition, there was a clear synergistic effect between Mn/γ-Al2O3 and O3, followed by Mn/TiO2 and O3. The characterization results of XRD, EDS mapping, BET, H2-TPR, XPS and TG showed that Mn/γ-Al2O3 had good manganese dispersion, excellent redox properties, appropriate amounts of coexisting Mn3+ and Mn4+ and abundant chemically adsorbed oxygen, which ensured its good performance. In situ DRIFTS demonstrated the NO adsorption performance on the catalyst surface. As revealed by in situ DRIFTS experiments, the chemically adsorbed oxygen, mainly from the decomposition of O3, greatly promoted the NO adsorption and the formation of nitrates. The Mn-based catalysts showed stronger adsorption strength than the corresponding pure supports. Due to the abundant adsorption sites provided by pure γ-Al2O3, under the interaction of Mn and γ-Al2O3, the Mn/γ-Al2O3 catalyst exhibited the strongest NO adsorption performance among the three catalysts and produced lots of monodentate nitrates (–O–NO2) and bidentate nitrates (–O2NO), which were the vital intermediate species for NO2 formation. Moreover, the NO–TPD studies also demonstrated that Mn/γ-Al2O3 showed the best NO desorption performance among the three catalysts. The good NO adsorption and desorption characteristics of Mn/γ-Al2O3 improved its high catalytic activity. In addition, the activity test results also suggested that Mn/γ-Al2O3 exhibited good SO2 tolerance.

Sarcoplasmic-calcium-binding protein (SCP) has been investigated as a novel allergen in Crassostrea angulata. Nevertheless, knowledge of its effector-cell-based allergic relevance and epitopes is limited. In this study, the heat-resistant allergen SCP was able to induce significant upregulation of CD63 and CD203c (p < 0.05), which showed obvious allergenicity in a basophil activation test. Furthermore, immunoinformatic tools, a one-bead-one-compound peptide library, and phage display technology were combined to analyze the allergenic epitopes of SCP. Five linear epitopes named L-SCP-1 (AA22-33), L-SCP-2 (AA64-75), L-SCP-3 (AA80-90), L-SCP-4 (AA107-116), and L-SCP-5 (AA144-159) were verified using serological tests. Additionally, two conformational epitopes (C-SCP-1 and C-SCP-2) were determined, and C-SCP-1 was located at one of the calcium-binding sites (AA106-117). Moreover, SCP showed weaker typical α-helical features and higher hydrophobicity after Ca2+ depletion, which reduced its IgE-binding capacity. Overall, these epitope data could enhance our understanding of oyster allergens, which could be used to develop hypoallergenic shellfish products.

In order to reduce the immunoreactivity of sarcoplasmic calcium-binding protein (SCP), site-directed mutations were used to replace key amino acids in the conformational epitopes and calcium-binding sites. The mutant SCPs (mSCPs) were expressed in Escherichia coli, and their immunoreactivities were analyzed using iELISA and basophil activation assays. Furthermore, the structural changes of mSCPs were determined from the circular dichroism spectra. The iELISA results showed that mSCPs could effectively inhibit the binding of wild-type SCP (wtSCP) to sensitive serum, with inhibition rates that reached 90%. Moreover, mSCPs could downregulate the expression levels of CD63 and CD203c on the basophil surface. Compared with wtSCP, the peak values were significantly changed, and the calcium binding ability was impaired, which explained the decline in immunoreactivities of the mSCPs. All of the data confirmed that this approach was effective in reducing the immunoreactivity of SCP and could be applied to other shellfish allergens.

The sol–gel method based on the rapid pyrolysis process was adopted to prepare Ni1−x Cu x O (x = 0–0.1) films on glass substrates. The effects of Cu doping on the structural, morphological, electrical and optical properties of the films were characterised by X-ray diffractometer, scanning electron microscope, Hall effect instrument and ultraviolet-visible spectrophotometer, respectively. The NiO-based films have a cubic rock salt structure and it was found that the film with x = 0.06 should have minimal residual stress. The transmittance and bandgap of the films decreased with increasing Cu-doping concentration. In addition, the compactness of the films increased along with the increase of Cu-doping concentration as a whole. The carrier concentration of the films was almost invariable, but the carrier mobility was determined by the competition between the effects of the morphology and the ionised impurity scattering. The resistivity of the films first decreases and then increases, and the minimum resistivity was 182.1 Ω cm at x = 0.06.

Oysters are an important shellfish group known to cause food allergy; however, knowledge of their sensitization components and cross-reactivity is limited. This study aimed to identify a novel allergen in Crassostrea angulata and investigate its cross-reactivity. To this end, a 20 kDa protein was purified from oyster and confirmed to be a sarcoplasmic-calcium-binding protein (SCP) by LC-MS/MS. A 537 bp open reading frame was obtained from oyster SCP total RNA, which encoded 179 amino acids, and was expressed in Escherichia coli. According to the circular dichroism results, digestion assay, and inhibition ELISA, the recombinant SCP (rSCP) exhibited similar physicochemical properties and IgG-binding activity to native SCP. rSCP displayed stronger IgE-binding activity by immunological method. Moreover, a different intensity of cross-reactivity and sequence homology were demonstrated between shellfish species. Collectively, these findings provide novel insight into shellfish allergens, which can be used to aid in the in vitro diagnosis of oyster-sensitized patients.

Bulk-heterojunction (BHJ) blends are commonly used as active materials for optoelectronics. Ordering of molecular packing in blends is critical to their electronic properties, spurring investigatio...

The performance degradation of organic photovoltaics is one of the main limitations to their commercialization, especially an initial, rapid degradation-period, termed as a burn-in loss. Herein, we demonstrate that burn-in loss is caused by the presence of thermodynamically unstable mixed-amorphous phase in the active layer. By using a combination of grazing incidence small angle X-ray scattering and photophysical process experiments, we observe that [6,6]-Phenyl C61 butyric acid methyl ester (PC61BM) molecules rapidly move from the finely-mixed amorphous regimes into crystalline or ordered regimes under accelerated conditions (ISOS-D-2 protocol), resulting in a fast short circuit current (Jsc) burn-in loss. Following an ultraviolet radiation (UV) light processing to control amorphous phase, the kinetics of thermally induced PC61BM crystallization can be slowed down due to the formation of the photo-induced PC61BM dimers in the active layer leading to a smaller burn-in loss. In the case of UV irradiated films, even if the molecules migrated out of amorphous phase, the PC61BM-rich phase becomes loose, rather than the compact and sphere-shaped aggregation, which has been observed in pristine films. These analyses reveal the evolution of thermodynamically unstable amorphous phases eventually leading to a decline power conversion efficiency within a short period of time. The results provide a further design basis of organic photovoltaic materials with good thermal stability and high efficient simultaneously.

The composition ratio of donor and acceptor materials in organic bulk heterojunction (BHJ) is one of the key parameters to govern the performance in organic solar cells (OSCs). Therefore, high-performance non-fullerene organic bulk heterojunction consisting of poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene))-co-(1,3-di(5-thiophene-2-yl)–5,7-bis(2-ethylhexyl) benzo[1,2-c:4,5-c′]dithiophene-4,8-dione)] (PBDB-T) and 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))–5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]-dithiophene (ITIC) are used to investigate the correlation among various donor: acceptor (D:A) ratios, photophysical properties and photovoltaic performance. Interestingly, the function of short-circuit current (Jsc) and D:A ratios demonstrates an axisymmetric trend. When the blending ratio of D:A deviates from the optimal ratio, the symmetrically decreased Jsc is derived from a reduction in the D:A interface or amorphous region. Research on the steady-state photoluminescence (PL), the time-resolved fluorescence spectroscopy measurements, atomic force microscopic (AFM) and grazing-incidence small angle X-rays scattering (GIWAXS) indicates no significant variation in energy loss in the process of changing D:A ratios in BHJs. With high donor or acceptor content, the domain size improves significantly, but the distance of π-π stacking corresponding to molecular packing has not changed significantly, and the bi-continuous percolation pathways were not obviously influenced.

Aiming at extending the photoresponse range of the photodetectors based on Poly(3-hexylthiophene-2,5-diyl): [6,6]-Phenyl C71 butyric acid methyl ester (P3HT: PCBM) host system, Poly [(5,6-difluoro-2,1,3-benzothiadiazole-4,7-diyl)-alt-(3,3‴-di(2-octyldodecyl)-2,2’;5’,2’’;5’’,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) with wide spectral response range, proper energy levels and high crystallinity was integrated to fabricate ternary organic photodetectors. The PffBT4T-2OD introduces energy cascade and Forster resonance energy transfer (FRET) effect from P3HT to PffBT4T-2OD, which contributes to the photocurrent generation. Furthermore, PffBT4T-2OD creates films with desirable crystallinity to produce a favorable morphology resulting in the apparent d-spacing decrement of π-π stacking of P3HT: PCBM, which probably increases the intermolecular charge hopping efficiency. The optimal photodetector shows high on/off ratio of 6.7 × 104 with a broad spectral response from 300 nm to 800 nm via incorporating 15 wt% PffBT4T-2OD into polymer bulk heterojunction, which is an obvious improvement compared with the 2.6 × 104 on/off ratio of P3HT: PCBM. This work indicates that FRET and morphology optimization have a profound effect on photoresponse and electrical properties of organic photodetectors.

In solution-processed small molecule organic solar cells (SM-OSCs), morphology of the active layer is a critically important factor in determining photovoltaic performance improvements, which needs to be optimized by more effective morphology modulation approaches. Herein, a medium bandgap conjugated polymer, namely poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b′]dithiophene))-alt -(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′]dithio-phene-4,8-dione))] (PBDB-T), as a morphology regulator was incorporated into the dominating binary SM system comprising of (2,2′-((5Z,5′Z)-5,5′-((3,3‴,3′′′′,4′-tetraoctyl-[2,2′:5′,2′′:5″,2‴:5‴,2′′′′-quinquethio-phene]-5,5′′′′-diyl)bis(methanyly-lidene))bis(3-ethyl-4-oxothiazoli-dine-5,2-diylidene))dimalononitrile) (DRCN5T) donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) acceptor to fabricate efficient ternary devices. The PBDB-T not only exhibits the better compatibility and miscibility with DRCN5T but also modulates the crystallinity and molecular arrangement of blend films, which is beneficial to enhance the charge carrier mobility to yield the higher fill factor. Photophysical investigations demonstrate that charge transfer and Forster resonance energy transfer processes coexist between PBDB-T and DRCN5T, which enables the higher short-circuit current density to bring about the efficiency improvements in ternary devices. In addition, the relationship between underlying operating mechanisms and nanoscale morphology evolution is systematically studied. Based on the interwined multi-working mechanisms involving energy transfer and two distinct charge transfer manners associated with microstructure, a 22.1% increase of the PCE was obtained for the ternary devices. These results indicate that selecting the compatible and miscible polymer donor as the third component for SM:fullerene based binary system should be an effective method for morphology optimization to further achieve high performance ternary OSCs.

Modelling studies suggest that the climate and the hydrological cycle are sensitive to the concentrations of ice-nucleating particles (INPs). However, the concentrations, composition, and sources of INPs in the atmosphere remain uncertain. Here, we report daily concentrations of INPs in the immersion freezing mode and tracers of mineral dust (Al, Fe, Ti, and Mn), sea spray aerosol (Na+ and Cl−), and anthropogenic aerosol (Zn, Pb, NO3-, NH4+, and non-sea-salt SO42-) at Alert, Canada, during a 3-week campaign in March 2016. In total, 16 daily measurements of INPs are reported. The average INP concentrations measured in the immersion freezing mode were 0.005±0.002, 0.020±0.004, and 0.186±0.040 L−1 at −15, −20, and −25 ∘C, respectively. These concentrations are within the range of concentrations measured previously in the Arctic at ground level or sea level. Mineral dust tracers all correlated with INPs at −25 ∘C (correlation coefficient, R, ranged from 0.70 to 0.76), suggesting that mineral dust was a major contributor to the INP population at −25 ∘C. Particle dispersion modelling suggests that the source of the mineral dust may have been long-range transport from the Gobi Desert. Sea spray tracers were anti-correlated with INPs at −25 ∘C (R=-0.56). In addition, INP concentrations at −25 ∘C divided by mass concentrations of aluminum were anti-correlated with sea spray tracers (R=-0.51 and −0.55 for Na+ and Cl−, respectively), suggesting that the components of sea spray aerosol suppressed the ice-nucleating ability of mineral dust in the immersion freezing mode. Correlations between INPs and anthropogenic aerosol tracers were not statistically significant. These results will improve our understanding of INPs in the Arctic during spring.

The crystallinity of non-fullerene acceptors as the third component has an important role on nanomorphology optimization and charge transfer dynamics of ternary organic solar cells (OSCs). Herein, efficient ternary OSCs were fabricated by incorporating two typical non-fullerene acceptors with different crystallinity, (Z)-5-{[5-(15-{5-[(Z)-(3-Ethyl-4-oxo-2-thioxo-1,3-thiazolidin-5-ylidene)methyl]-8-thia-7.9-diazabicyclo [4.3.0] nona-1 (9),2,4,6-tetraen-2-yl}-9,9,18,18-tetrakis (2-ethylhexyl)-5.14-dithiapentacyclo [10.6.0.03,10.04,8.013,17]octadeca-1(12),2,4(8),6,10,13 (17),15-heptaen-6-yl)-8-thia-7.9-diazabicyclo [4.3.0]nona-1 (9),2,4,6-tetraen-2-yl]methylidene}-3-ethyl-2-thioxo-1,3-thiazolidin-4-one (EH-IDTBR) or (5Z, 5′Z)-5,5'-((7,7'-(4,4,9,9-tetraoctyl-4,9-dihydro-s-indaceno [1,2-b:5,6-b']dithiophene-2,7-diyl)bis (benzo [c][1,2,5]thiadiazole7,4diyl)) bis(methanylylidene))bis (3-ethyl-2-thioxothiazolidin-4-one) (O-IDTBR), into the host donor/acceptor active layers comprising of poly (3-hexythiophene-2,5-diyl) (P3HT) and [6,6]-phenyl-C71-butyric acid methylester (PC71BM). As a result, the 21.5% and 22.7% increase of the power conversion efficiency (PCE) for the two ternary systems were achieved, respectively, which was attributed to the enhanced light harvesting capability, optimized bulk-heterojunction morphology and the formation of cascade energy level alignments that could introduce an additional pathway for efficient charge transfer. Although both the short-circuit current density (Jsc) and fill factor (FF) values were increased significantly by regulating the weight ratios of non-fullerene acceptors of two ternary systems, the O-IDTBR-based ternary OSCs showed the higher Jsc while P3HT:EH-IDTBR:PC71BM system exhibited the higher FF values. The main difference of improved photovoltaic performance in the two ternary systems could be associated with the different blend morphology and charge carrier mobilities. In addition, nanomorphology studies suggested that lamellar stacking coherence lengths of P3HT in face-on orientation for EH-IDTBR- and O-IDTBR-based systems can be increased from 18.48 nm to 20.94 nm and 21.67 nm respectively, resulting from the stronger crystallinity of O-IDTBR than that of EH-IDTBR, which was beneficial for charge transport in the vertical direction. These results indicate that selecting the appropriate crystalline non-fullerene acceptors may be an effective strategy to optimize nanomorphology to further achieve high efficiency ternary OSCs.

Removal of nitrogen oxides (NOx) is very crucial in coal-fired power plants, smelting plants and some other heavy industries. Herein, a new approach, in situ Fenton (IF) system with dual ions as reagents, was reported for the efficient oxidation removal of nitric oxide (NO). It demonstrated that the in situ Fenton (IF) system was more effective than the premixed Fenton (PF) system due to the increase of yield and utilization of (radOH) in the homogeneous reaction systems. The dual ions with Fe2+ and Mn+ (Mn+ = Ce3+, Cu2+, Co2+, Mn2+) as Fenton reagents were found to be more effective in NO oxidation than Fe2+ as single Fenton reagent. The obvious improvements on the oxidation efficiencies of NO were 18.85%, 16.72%, 16.58%, 16.38% in the Fe2+Ce3+/H2O2, Fe2+Cu2+/H2O2, Fe2+Mn2+/H2O2 and Fe2+Co2+/H2O2 when compared with that in Fe2+/H2O2. The corresponding optimal molar ratios of the dual ions solution were 20%:80%, 20%:80%, 50%:50% and 50%:50% for Fe2+Ce3+/H2O2, Fe2+Cu2+/H2O2, Fe2+Mn2+/H2O2 and Fe2+Co2+/H2O2, respectively. Under the optimal conditions, the oxidation efficiencies of NO were more than 85%. The improvement of NO oxidation efficiencies in the dual ionic IF system could be ascribed to the enhancement on the generation and utilization of oxidative species, which resulted from the continuous injection of fresh reagents and the oxidation of Fe2+Mn+ to Fe3+M(n+1)+ and subsequent re-reduction of them.

Achieving high-efficiency thick-film bulk heterojunction (BHJ) organic solar cells (OSCs) with thickness-independent power conversion efficiencies (PCEs) in a wide thickness range is still a challenge for the roll-to-roll printing techniques. The concept of diluting the transport sites within BHJ films with insulating polymers can effectively eliminate charge trapping states and optimize the charge transport. Herein, we first adopted the concept with insulating polypropylene (PP) in the efficient non-fullerene system (PM6:Y6) and demonstrated its potential to fabricate thick-film OSCs. The PP can form an insulating matrix prior to PM6 and Y6 within the BHJ film, resulting in an enhanced molecular interaction and isolated charge transport by expelling Y6 molecules. We thus observed reduced trap state density and improved charge transport properties in the PP-blended device. At around 300 nm, the PM6:Y6:PP device enjoys a high PCE of 15.5% and achieves over 100% of the efficiency of the optimal thin-film device, which is significantly improved compared to the binary PM6:Y6 counterpart. This research promotes an effective strategy with insulating polymers and provides knowledge of commercial production with response to the roll-to-roll technique demands.

In comparison with various restaurant cuisines, common cooking methods are more represented in residential cooking. Rather than the exhaust pipe or the ambient environment in the cooking room, the respiration zone better reflects the health risks for operators. In this study, the concentrations of total volatile organic compound (TVOC) released from six typical cooking methods were monitored online in the respiratory zone, and the VOCs were analysed by GC-MS. The results demonstrated that the intensities of exposure to TVOC for the different cooking methods decreased as follows: stir-frying (3.809 mg/m3) > quick-frying (2.724 mg/m3) > deep-frying (2.465 mg/m3) > boiling (1.161 mg/m3)≈stewing (1.149 mg/m3) > limit in China (0.600 mg/m3) > steaming (0.440 mg/m3). The intense ventilation mode of the ventilator reduced exposure to TVOC by 45–63% relative to the medium mode. Eleven types of VOCs (approximately 200 compounds) were found in Chinese residential cooking fumes, and the predominant contaminants were aldehydes, followed by alkanes, unsaturated aldehydes, alcohols and alkenes. The mass percentage of aromatic hydrocarbons in all VOCs emitted from Chinese residential cooking was only 1%, while the value was 17–48% for commercial restaurants. The results of a health risk assessment revealed that the total potential carcinogenic risk level for VOCs released by six residential cooking methods decreased as follows: deep-frying (5.75) > stir-frying (3.95) > quick-frying (2.94) > stewing (1.99) > boiling (1.73) > steaming (1.48). Chinese residential cooking, and especially deep frying, has potential health impacts for the operator.

Mud crab (Scylla paramamosain) is widely consumed after thermal processing. It is necessary to comprehensively evaluate of the allergenic potential and epitopes of allergens in high temperature-pressure (HTP) treated S. paramamosain. Tropomyosin and arginine kinase presented higher prevalence (30.77% and 42.13%) than the other three important crab allergens by component-resolved diagnosis. The surface expression of basophils CD63 and CD203c were decreased in HTP treated crab, an effect that was even more evident after digestion and absorption by the intestinal Caco-2 cell model. Of the 35 stable epitope, six were for the first time identified in shellfish. Seven heat/digested stable peptides of tropomyosin retained IgE-binding capacity and were shown to interact with MHC-II. Five epitopes (amino acids 19-29, 99-109, 153-162, 170-188 and 211-221) were the first identified in crab. The study provides insight into prevention and therapy of crab allergy, as well as helps to reduce crab allergenicity during thermal processing.

Novel functionalized graphene oxide π-π stacking with conjugated polymers (P-GO) is fabricated via a simple ethanol-mediated mixing method, leading to better dispersion in organic nonpolar solvents and bypassing the inherent restrictions of hydrophilicity and oleophobicity. We analyze the mechanism of the incorporation of P-GO into inverted organic solar cells (OSCs) based on a poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4- b]thiophenediyl]] (PTB7):[6,6]-phenyl C71 butyric acid methyl ester (PC71BM) system to investigate the possibility of high-performance thick-film OSC fabrication. It is verified that the incorporation of P-GO into the PTB7:PC71BM blend films leads to a decreased π-π stacking distance, enlarged coherence length for polymer, and optimized phase separation, resulting in more effective charge dissociation, reduced bimolecular recombination, and more balanced charge transport. The OSCs with 1% P-GO incorporation demonstrate a thickness-insensitive fill factor (57.8%) and power conversion efficiency (PCE) (7.31%) even with 250 nm thick photoactive layers, leading to a dramatic PCE enhancement of 34% compared with the control devices with the same thickness.

Carbon nanotubes are reported as good candidates for carrier transport layers and electrodes in perovskite optoelectronics owing to their outstanding electronic and mechanical properties. In this work, perovskite and carbon nanotubes composites were fabricated by a facile solution method serving as the active layer in perovskite devices. The charge transfer mechanism between the perovskite and carbon nanotubes is different among three kinds of carbon nanotubes with different diameter. The addition of carbon nanotubes would not change the crystalline property of perovskite. Charge transfer from perovskite to carbon nanotubes at the interface was observed by spatially and temporally resolved fluorescence measurements. Carbon nanotubes serve as the effective charge transport pathways to improve the performance of photodetector by reducing the grain boundaries and pinholes in perovskite.

The underlying hole-transfer mechanism in high-efficiency OSC bulk heterojunctions based on acceptor-donor-acceptor (A-D-A) nonfullerene acceptors (NFAs) remains unclear. Herein, we study the hole-transfer process between copolymer donor J91 and five A-D-A NFAs with different highest occupied molecular orbital energy offsets (Δ

The triosephosphate isomerase (TIM), Scy p 8, is a crab allergen and shows cross-reactivity in the shellfish. Here, recombinant Scy p 8 was expressed, and its crystal structure was determined at a resolution of 1.8 Å. The three-dimensional structure of Scy p 8 is primarily composed of a (β/α)

Fe and Co co-doped Mn-Ce/TiO2 (MCT) catalysts were investigated for the simultaneous removal of nitric oxide (NO) and elemental mercury (Hg0) at reaction temperature lower than 200 °C. The catalysts were characterized by Brunauer–Emmett–Teller (BET), temperature program reduction (TPR), scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The experimental results showed that the co-doped 2Fe4Co-MCT catalyst exhibited better performance for the simultaneous removal of NO and Hg0 compared to Fe or Co doped catalysts. This could be due to higher BET surface area and better redox property of 2Fe4Co-MCT catalyst. In addition, we propose that chemisorbed O2 played a dominant role in selective catalytic reduction (SCR) of NO while lattice O2 played a key role in Hg0 oxidation. The results also indicate that the introduction of Fe species enhanced the activity of SCR, whereas the introduction of Co species enhanced the oxidation of Hg0. The synergistic effect of Fe and Co species in the 2Fe4Co-MCT catalyst are also suggested to be an important mechanism for simultaneously removing NO and Hg0.

Binary and ternary organic nanoparticles (NPs) comprising 7,7-(4,4-bis(2-Ethylhexyl)-4H-silolo [3,2-b:4,5-b′]dithiophene-2,6-diyl)bis (6-fluoro-4-(5′-hexyl-[2,2′-bithiophen]-5-yl)benzo-[c] [1,2,5]thiadiazole) (p-DTS(FBTTH2)2), poly (3-hexylthiophene) (P3HT) or/and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) were prepared by precipitation method. The formation of the organic NPs is confirmed by the atomic force microscope (AFM). The absorption spectra show that the blended organic NPs display increased interchain interactions compared to the polymer blends dissolved in the solution. The processes of exciton separation and charge transfer in the organic NPs have been investigated using time-resolved photoluminescence (TRPL) spectroscopy and anisotropy measurements. The results demonstrate that the charge transfer efficiency is improved in the NPs in comparison with that in solution, due to the enhanced interchain interactions and intimate contact between the donor and acceptor materials in NPs. Due to Forster resonance energy transfer (FRET) between P3HT and p-DTS(FBTTH2)2, the photodetectors with ternary NPs in the active layers exhibit improved on/off ratios and enhanced detectivity compared with the binary system, demonstrating the promising applications of organic NPs in the ecofriendly fabrication of organic optoelectronic devices.

Thermally induced fullerene aggregation restricts the long-term stability in organic solar cells. Herein, we demonstrate an effective method of incorporating cross-linkable small-molecule ethoxylated (2) bisphenol-A dimethacrylate (BPA2EODMA) into poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PCBM) blends to form an insoluble framework and inhibit fullerene aggregation. The BPA2EODMA exhibits excellent heat and flexural endurance characteristics, which enhance the thermal and morphological stabilities of the active layer. By systematic research with time-resolved optical spectroscopy and microscopy, the morphological changes and charge-transfer dynamics in P3HT:PCBM blends are explored to unravel the underlying mechanisms for improved photovoltaic efficiency by incorporating the cross-linker. The power conversion efficiency (PCE) increased from 3.6 to 4.2% due to the BPA2EODMA incorporation into the active layer, which is ascribed to the enhancement of exciton dissociati...

The vertical phase distribution of components in bulk heterojunction is diversified in organic solar cells (OSCs). The electron donors (acceptors) can be accumulated (depleted) at the interface of active layer and charge extraction layer. The variation of vertical phase distribution significantly influences device performance because of its impact on the charge transport and charge recombination. In order to achieve favorable vertical phase distribution in OSCs based on poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene))-co-(1,3-di(5-thiophene-2-yl)–5,7-bis(2-ethylhexyl) benzo[1,2-c:4,5-c′]dithiophene-4,8-dione)] (PBDB-T):3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))−5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]-dithiophene (ITIC), phenyl-C71-butyric-acid-methyl ester (PC71BM) was incorporated into the binary system to fabricate ternary OSCs. In the ternary blend, PC71BM can effectively regulate the phase distribution of PBDB-T and ITIC in vertical direction, which provides favorable vertical phase distribution for charge transport. Moreover, the addition of PC71BM can also effectively increase the π-π stacking coherence length of both donor and acceptor, which facilitates charge transport and reduces the bimolecular recombination. The addition of an appropriate quantity of PC71BM can obviously improve both fill factor and short-circuit current density of the OSC based on PBDB-T:ITIC while open-circuit voltage reduces only about 0.01 V, which indicates a rational low energy loss. Consequently, the ternary OSC exhibits a best PCE of 11.0% compared to the 9.6% PCE of the binary counterpart.

Cu2ZnSnS4 (CZTS) films applicable to an absorber material in thin film solar cells were prepared at room temperature by pulsed DC magnetron sputtering from a CZTS ceramic target, and the effects of sputtering pressure on the phase, preferred orientation and composition of the deposited CZTS films were investigated. The results indicated that the dominant phase in the deposited films was Kesterite structure, only having the trace impurity phase of Cu2−xS. The preferred orientation was gradually converted from (2 2 0) to (1 1 2) with increasing sputtering pressure. Moreover, the composition of the deposited films was also affected by the sputtering pressures.

A facile method is proposed to obtain modified shorn graphene oxide (DDAB-sGO) with improved dispersion in organic solvents. Didodecyl dimethylammonium bromide (DDAB)-sGO, which exhibits good dispersibility in the nonpolar solvent o-dichlorobenzene, was obtained via the sono-Fenton reaction and DDAB ionic functionalization. DDAB-sGO was used in the preparation of conjugated polymer:fullerene blend composites. UV–visible absorption spectra, steady-state photoluminescence spectra, fluorescence decay, and grazing incidence X-ray scattering measurements were applied to characterize morphologies, structural features, and charge-transport characteristics of the composites. Doped into poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7):[6,6]-phenyl C71 butyric acid methyl ester (PC71BM) conjugated polymer blends, DDAB-sGO is shown to facilitate increased crystallinity and phase separation of PTB7 and PC71BM to achieve a m...

Perovskite microplates have important implications in the fields of functional electronics and optoelectronics. We report a facile strategy, antisolvent treatment for the growth of perovskite microplates. The morphology and crystalline quality of the microplates could be controlled by the amount of the chlorobenzene antisolvent used. An appropriate amount of antisolvent facilitates the formation of high-quality perovskite microplates with no residual precursor remaining. Spatially and temporally resolved fluorescence measurements demonstrate the heterogeneity of defect-state density and recombination processes in various perovskite microplate regions. The body center shows higher defect state density when compared with that at the edge or the corner of the microplate. Excessive antisolvent degrades the microplates into smaller particles. The results of this study reveal the factors that influence the crystallization process and photophysical dynamics of perovskite microplates.

The concept of judgment space was proposed by Wang et al. (Phys. Rev. A 95, 022320, 2017), which was used to study some important properties of quantum entangled states based on local distinguishability. In this study, we construct 15 kinds of seven-qudit quantum entangled states in the sense of permutation, calculate their judgment space and propose a distinguishability rule to make the judgment space more clearly. Based on this rule, we study the local distinguishability of the 15 kinds of seven-qudit quantum entangled states and then propose a (k, n) threshold quantum secret sharing scheme. Finally, we analyze the security of the scheme.

Mn-Ce loaded metal-organic framework (MnCe@MOF) catalyst was obtained by incipient wetness impregnation of MOF with manganese-cerium nitrate. The obtained materials were investigated as potential catalysts for elemental mercury (Hg 0 ) and NO removal from simulate flue gas and the results indicated that MnCe@MOF exhibited superior activity in comparison with the conventional catalysts Mn-Ce loaded ZrO 2 , especially at low temperatures ( 0 adsorption and enhancing oxygen utilization, which resulted in a desirable catalytic activity. To understand the mechanism of the Mn-Ce catalyst better, dynamic valence state evolution during the Hg 0 oxidation for the active components was investigated. The ratio of Mn 3+ /Mn 4+ remained constant during the reaction at various temperatures, indicating the stability of Mn in the catalytic process. However, the ratio of Ce 3+ /Ce 4+ gradually decreased with extended periods of reaction time, which most likely lead to the decreased of chemical adsorbed oxygen on the catalyst.

Low loss optical waveguides inside aluminosilicate glasses have been successfully fabricated using direct femtosecond laser writing. To establish the influence of pulse energy and host variations on the optical waveguides have been tentatively explored and systematically studied with the help of different spectroscopic techniques. Isochronal annealing treatment effectively reduces the insertion losses to 1.01 ± 0.28 dB at 632.8 nm. A red shift of the Raman band has been observed with increasing Al 2 O 3 content due to the bond angle variations. The point defects such as non-bridging oxygen hole centers have been corroborated by the photoluminescence studies and significant red-shift has also been documented with increasing Al 2 O 3 content. In addition, there is no NBOHC defects perceived after isochronal annealing treatment inside the glass waveguides. Our results envisage that the present glass waveguides should be promising and potential for applications in passive waveguides and integrated photonic devices.

Femto-second laser irradiation on P3HT:PCBM solutions have been demonstrated to have a significant impact on the conformational structures and photovoltaic performance of the resultant thin films. The crystallinity and edge-on/face-on conformations of P3HT and the aggregation of PCBM can be manipulated by controlling the wavelength (400–800 nm) and illumination duration (1–3 h) of the lasers. Grazing incidence wide- and small-angle X-ray scattering (GIWAXS and GISAXS) have been simultaneously utilized to characterize the nanostructures of the P3HT:PCBM blend films spin-cast from pristine and laser-irradiated solutions. The results show that the crystallinity, π-π* stacking and face-on conformations of P3HT can be enhanced as a result of the laser irradiation at 500 nm for 3 h. Furthermore, the diffusion and aggregation of PCBM molecules are suppressed by the photo-induced dimerization, as evidenced by the Raman spectra of the films cast from laser-irradiated PCBM solutions. The time-resolved fluorescence decay profiles show the charge transfer efficiency is improved, which may correlate to the supramolecular ordering of the polythiophene chains and the optimized phase separation in P3HT:PCBM composite. In the P3HT:PCBM active layer of the organic solar cells, more efficient charge transport and fine interpenetrating networks can be achieved due to the improved conformational microstructures. Consequently, the short-circuit current densities and power conversion efficiencies can be enhanced in organic solar cells based on the laser-irradiation processed P3HT:PCBM solutions.

The molecular packing and optical properties of exposed and buried layers (i.e. the layers at the top surface and near the substrate, respectively) were systematically studied in 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) films coated by spin-coated (SC) and droplet-pinned-crystallization (DPC) methods. Buried layers in both films exhibit intense photoluminescence (PL) resembling the behaviors of the molecules in dilute solution ascribing to weak π-π stacking, while the exposed layers show extremely weak PL due to strong crystallinity. Polarized excitation PL spectra demonstrate that molecular orientation of the buried layers is quasi-ordered in the film coated by DPC method and completely disordered in the film coated by SC method. Besides, the strong crystallinity of the exposed TIPS-pentacene is verified by grazing incident wide-angle X-ray scattering measurement. The distinct differences in optical and structural properties between the exposed and buried layers indicate that TIPS-pentacene films are inhomogeneous in vertical direction due to interfacial effect, which affects the performance of photodiode fabricated with both films. The understanding of the molecular packing correlated fluorescence in TIPS-pentacene films is vital for optimizing the film structure to achieve high performance organic electronic devices.

The myofibril-bound serine proteinase (MBSP) from the skeletal muscle of fish belongs to a class of trypsin-like serine proteinases with higher thermal stability than trypsin. To investigate the mechanism responsible for the thermal stability of MBSP from Crucian carp , mutagenesis of key residues were identified by amino acid sequence alignments and Protein Mutant Stability Prediction online prediction software. Meanwhile, five mutants (MutP95T, MutR125N, MutA127S, MutI130D, and MutA127S/I130D) were obtained using site-directed mutagenesis. The mutants and wild-type enzymes were expressed in Pichia pastoris (SMD1168), the secondary structure of the mutants of MBSP was approximately similar to that of wild-type MBSP by circular dichroism spectroscopy analysis. The thermal Inactivation parameters showed that the half-life for thermal inactivation ( t 1/2 ) of MutP95T was reduced by approximately 10 min, whereas MutA127S, MutI130D and MutA127S/I130D were more stable than the wild-type and increased by approximately 18 min, 15 min and 24 min, respectively. The unfolding free energy difference (ΔΔG) between the variants and wild-type of MutA127S, MutI130D and MutA127S/I130D was enhanced when compared with the wild-type. As a result, the mutants were efficiently produced with altered thermal stability, and MBSP could potentially be used as novel tool enzyme for mass spectrometric identification.

Perovskite microfibers with high crystallinity were synthesized with aqueous self-assembling method. The crystallization dynamics of perovskite were studied by in-situ X-ray diffraction, demonstrating that the optimum crystallization time is 9 h. Spatially and temporally resolved fluorescence measurement clearly shows the different recombination mechanism at the interface and bulk regions in the perovskite microfibers. The photodetector based on perovskite microfiber exhibits high photo-response sensitivity and on/off ratio due to the high crystallinity and relatively long carrier lifetime. This research will be beneficial for low-dimension perovskite synthesis and optoelectronics application.

An effective method for preparing poly(3-hexylthiophene) (P3HT) coated graphene oxide (GO), (P-GO), based on an ethanol mediated mixing and solvent evaporation method is described. P-GO exhibits good dispersibility in the non-polar solvent o-dichlorobenzene (DCB) allowing the preparation of polymer blend composites. P-GO was doped into P3HT: PCBM blends by solution mixing and shown to facilitate phase separation of P3HT and PCBM in P3HT: PCBM blend films to achieve a more optimum morphology for polymer photovoltaic cells. Bulk heterojunction P3HT: PCBM solar cells exhibit ∼18% power conversion efficiency enhancement in the presence of P-GO.

Topic evolution is a hybrid dynamics of information propagation and opinion interaction. The dynamics of opinion interaction is inherently interwoven with the dynamics of information propagation in the network, owing to the bidirectional influences between interaction and diffusion. The degree of sentiment determines if the topic can continue to spread from this node, and the selective attention determines the information flow direction and communicatee selection. For this end, we put forward a sentiment-based mixed dynamics model with selective attention, and applied the Bayesian updating rules on it. Our model can indirectly describe the isolated users who seem isolated from a topic due to some reasons even everybody around them has heard about it. Numerical simulations show that, more insiders initially and fewer simultaneous spreaders can lessen the extremism. To promote the topic diffusion or restrain the prevailing of extremism, fewer agents with constructive motivation and more agents with no involving motivation are encouraged.

2-Chlorophenyl isocyanate (CI) reacts with didodecyl dimethyl ammonium bromide (DDAB) functionalized graphene oxide (DDAB-GO) dispersed in ortho-dichlorobenzene under mild conditions. The CI treatment complements DDAB functionalization to further decrease the hydrophilicity of pristine GO sheets. The resulting CI–DDAB-GO exhibits improved compatibility with the conjugated polymer poly(3-hexylthiophene) (P3HT), compared to DDAB-GO. CI–DDAB-GO sheets can be homogeneously dispersed when blended with P3HT, resulting in an improved morphology compared to P3HT:DDAB-GO composites. The incorporation of CI–DDAB-GO can effectively reduce the dark current of photo-diodes based on P3HT composites, showing potential to enhance the performance of electronic devices based on conjugated polymer composites.

Mn and Ce were loaded on metal–organic frameworks (MOFs) via impregnation and in situ doping methods. The catalytic capacities of the obtained composite materials were evaluated in the selective catalytic reduction (SCR) of NO. The existing form of Mn–Ce in the MOF originates from different doping methods and its effect on the catalytic performance was investigated. Mn–Ce introduced by impregnation was deposited on the surface of the MOF and exhibited high catalytic efficiency of more than 98% from 200 °C to 300 °C. According to the results of BET, XRD, XPS, and ICP analyses, it was concluded that Mn–Ce introduced via the in situ doping method was inserted in the crystal lattice structure of the MOF, which resulted in an enlarged surface area, low Mn concentration, and poor redox property as compared to that introduced via the impregnated method. By exploring these factors, it was proven that the limited redox ability was the direct reason that resulted in the low activity of the MnCeMOF. Using thermal decomposition, the in situ doped Mn–Ce was liberated from the MnCeMOF crystal lattice and subsequently, exhibited recovered redox properties and catalytic activity. In this study, we proved that different doping methods lead to different forms of Mn–Ce in the MOF, which exhibit different redox properties and thus directly lead to different catalytic performance.

Non-fullerene ternary organic solar cells (OSCs) are new promising candidates for future applications in the area of organic photovoltaics. However, their low short-circuit current (JSC) values impede efforts at increasing their power conversion efficiency (PCE) levels. Maximizing the JSC is one of the critical elements for enabling high performances of OSCs. To improve the JSC of the non-fullerene ternary OSCs based on poly[[2,6′-4,8-di(5-ethylhexylthienyl)benzo[1,2-b:3,3-b]dithiophene][3-fluoro-2[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]]:3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]-dithiophene (PTB7-Th:ITIC), a polymer of poly[N-9′′-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) was added to the binary system. The PCDTBT was shown to embed in both PTB7-Th and ITIC, and introduced dual Forster resonance energy transfer (FRET) effects in the resulting ternary system. In addition, the PCDTBT may have decreased the molecular coherence lengths of PTB7-Th and ITIC and influenced the charge transport. Furthermore, the PCDTBT apparently also decreased the d-spacing of the π–π stacking of PTB7-Th and ITIC, which likely increased the intermolecular charge hopping efficiency. Doping an appropriate amount of PCDTBT in the system yielded an increase in the JSC from 13.89 to 16.71 mA cm−2. The increased JSC resulted in a 15% enhancement of the PCE, which indicated that introducing dual FRET effects is an effective way to enhance the JSC and thus the performance of the OSCs.

The migratory insertion of isonitriles into the metal–C bond is important for constructing C–C bonds in organic and pharmaceutical syntheses. We examine the reaction of Cp*(Cl)Ti(diene) with isonitriles using density functional theory calculations. At room temperature, the bis-insertion reaction occurs easily for N-tert-butyl (tBu), methyl (Me), ethyl (Et), 2,6-dimethylphenyl (Ar), and N-1-adamantyl (1-Ad)-substituted isonitriles. The elementary reactions include the isomerisation of Cp*(Cl)Ti(diene), migratory insertion of the first isonitrile into a Ti–C bond, C–C reductive elimination, β-H elimination, migratory insertion of the second isonitrile into a Ti–H bond, and C–C reductive coupling. Two reliable fragmentation mechanisms are suggested for the bis-insertion products. For the bulkier tBuNC, ArNC, and 1-AdNC, the β-H elimination reaction pathway is dominant. For the smaller MeNC and EtNC, the γ-H elimination reaction pathway competes with the β-H elimination. For ArNC, the isomerisation reaction pathway to a newly predicted “σ complex” is kinetically favourable.

Mud crab (Scylla paramamosain) is a commonly consumed seafood as a result of its high nutritional value; however, it is associated with food allergy. The current understanding of crab allergens remains insufficient. In the present study, an 18 kDa protein was purified from crab muscle and confirmed to be myosin light chain 1 (MLC1) by matrix-assisted laser desorption/ionization-tandem time-of-flight mass spectrometry. Total RNA was isolated and amplified to obtain a MLC1 open reading frame of 462 bp, encoding 154 amino acids. A structural analysis revealed that recombinant MLC1 (rMLC1) expressed in Escherichia coli contained α-helix and random coil. Moreover, rMLC1 displayed strong immunoactivity by dot blot and a basophil activation test. Furthermore, seven allergenic epitopes of MLC1 were predicted, and five critical epitope regions were identified by an inhibition enzyme-linked immunosorbent assay and human mast cell degranulation assay. This comprehensive research of an allergen helps to conduct component-resolved diagnoses and immunotherapies related to crab allergies.

Atmospheric aerosol particles that can nucleate ice are referred to as ice-nucleating particles (INPs). Recent studies have confirmed that aerosol particles emitted by the oceans can act as INPs. This very relevant information can be included in climate and weather models to predict the formation of ice in clouds, given that most of them do not consider oceans as a source of INPs. Very few studies that sample INPs have been carried out in tropical latitudes, and there is a need to evaluate their availability to understand the potential role that marine aerosol may play in the hydrological cycle of tropical regions. This study presents results from the first measurements obtained during a field campaign conducted in the tropical village of Sisal, located on the coast of the Gulf of Mexico of the Yucatan Peninsula in Mexico in January–February 2017, and one of the few data sets currently available at such latitudes (i.e., 21∘ N). Aerosol particles sampled in Sisal are shown to be very efficient INPs in the immersion freezing mode, with onset freezing temperatures in some cases as high as −3 ∘C, similarly to the onset temperature from Pseudomonas syringae. The results show that the INP concentration in Sisal was higher than at other locations sampled with the same type of INP counter. Air masses arriving in Sisal after the passage of cold fronts have surprisingly higher INP concentrations than the campaign average, despite their lower total aerosol concentration. The high concentrations of INPs at warmer ice nucleation temperatures (T>-15 ∘C) and the supermicron size of the INPs suggest that biological particles may have been a significant contributor to the INP population in Sisal during this study. However, our observations also suggest that at temperatures ranging between −20 and −30 ∘C mineral dust particles are the likely source of the measured INPs.

The mud crab ( Scylla paramamosain) is widely consumed but can cause a severe food allergic reaction. To reduce allergenicity to arginine kinase (AK), site-directed mutagenesis was used to destroy disulfide bonds or mutate critical amino acids of conformational epitopes. Three hypoallergenic mutant AKs (mAK1, mAK2, and mAK3) were generated, with the immunoreactivity decreasing by 54.2, 40.1, and 71.4%, respectively. In comparison to recombinant AK (rAK), the structure of mAKs was clearly changed. Additionally, antisense peptides were designed on the basis of linear epitopes and pepsin-cutting sites of AK. Five peptide aptamers were screened by molecular docking and then analyzed by the immunoglobulin E inhibition enzyme-linked immunosorbent assay and human Laboratory of Allergic Diseases 2 mast cell degranulation assay. The peptide aptamers could significantly inhibit allergenicity of rAK and mAKs, and the inhibitory effect of peptide aptamer 3 was slightly better than the others. These results provide synergistic methods to reduce allergenicity to AK, which could be applied to other shellfish allergens.

Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea) and one in the Arctic (Lancaster Sound). For Amphitrite Point, 23 sets of samples were analyzed, and for Labrador Sea and Lancaster Sound, one set of samples was analyzed for each location. At all three sites, the ice-nucleating ability on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the particle size. For example, at diameters of around 0.2 µm, approximately 1 in 106 particles acted as an INP at −25 ∘C, while at diameters of around 8 µm, approximately 1 in 10 particles acted as an INP at −25 ∘C. The ice-nucleating ability on a per surface-area basis (expressed as the surface active site density, ns) was also dependent on the particle size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosols, suggesting that sea spray aerosols were not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25 ∘C, but under-predicted INP concentrations at −15 ∘C, suggesting that the model is missing a source of INPs active at a freezing temperature of −15 ∘C.

Motivated by the need to predict how the Arctic atmosphere will change in a warming world, this article summarizes recent advances made by the research consortium NETCARE (Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments) that contribute to our fundamental understanding of Arctic aerosol particles as they relate to climate forcing. The overall goal of NETCARE research has been to use an interdisciplinary approach encompassing extensive field observations and a range of chemical transport, earth system, and biogeochemical models. Several major findings and advances have emerged from NETCARE since its formation in 2013 . (1) Unexpectedly high summertime dimethyl sulfide (DMS) levels were identified in ocean water and the overlying atmosphere in the Canadian Arctic Archipelago (CAA). Furthermore, melt ponds, which are widely prevalent, were identified as an important DMS source. (2) Evidence was found of widespread particle nucleation and growth in the marine boundary layer in the CAA in the summertime. DMS-oxidation-driven nucleation is facilitated by the presence of atmospheric ammonia arising from sea bird colony emissions, and potentially also from coastal regions, tundra, and biomass burning. Via accumulation of secondary organic material (SOA), a significant fraction of the new particles grow to sizes that are active in cloud droplet formation. Although the gaseous precursors to Arctic marine SOA remain poorly defined, the measured levels of common continental SOA precursors (isoprene and monoterpenes) were low, whereas elevated mixing ratios of oxygenated volatile organic compounds were inferred to arise via processes involving the sea surface microlayer. (3) The variability in the vertical distribution of black carbon (BC) under both springtime Arctic haze and more pristine summertime aerosol conditions was observed. Measured particle size distributions and mixing states were used to constrain, for the first time, calculations of aerosol–climate interactions under Arctic conditions. Aircraft- and ground-based measurements were used to better establish the BC source regions that supply the Arctic via long-range transport mechanisms. (4) Measurements of ice nucleating particles (INPs) in the Arctic indicate that a major source of these particles is mineral dust, likely derived from local sources in the summer and long-range transport in the spring. In addition, INPs are abundant in the sea surface microlayer in the Arctic, and possibly play a role in ice nucleation in the atmosphere when mineral dust concentrations are low. (5) Amongst multiple aerosol components, BC was observed to have the smallest effective deposition velocities to high Arctic snow.

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) are attractive for their novel physical properties. However, the photoluminescence (PL) quantum yield of TMDCs has been limited, due to their abundant defects and strong many-body effect. Here, we present a vertical energy funneling channel which is constructed in organic–inorganic heterostructures comprising MoSe2, pentacene and graphene oxide. These heterostructures show efficient PL enhancement (3.7 times) ratio of monolayer MoSe2. Besides, the PL signal is further increased as high as 4.7 times at low temperature due to reduced electron-phonon interactions and also sensitive to the gradient magnetic field. Apart from the efficient PL enhancement, the photocarrier pumping efficiency which is modulated by energy offset of top layer and external field is >130 times greater than that in isolated MoSe2. These findings focused on manipulating the efficient photocarrier transfer open up a new route to adjust the luminescent properties of monolayer TMDCs for designing future 2D material based optoelectronic devices.

Reported here is the induced helical aggregation of an achiral cationic perylene-3,4-dicarboximide (1) that contains a phenylboronic acid group, together with UMP that bears a cis-diol moiety able to interact with boronic acid and an imide group known to coordinate with Hg2+. In selected solvents, 1 exists in monomer form, even in the presence of either UMP or Hg2+. Helical aggregation only takes place if 1 is mixed with both UMP and Hg2+, which is shown to result from the formation of a building block consisting of five components in the form 1–U–Hg2+–U–1. Strong exciton-coupled circular dichroism signals were observed in the absorption window of the achiral dye chromophore, demonstrating the transfer of the chirality of UMP to the supramolecular aggregates of P-helicity. Synergism was shown to occur upon aggregation of the 1–U–Hg2+–U–1 building block, as substantially enhanced affinity and binding selectivity were observed for UMP and Hg2+, despite the otherwise weak and less selective interactions of 1–UMP and UMP–Hg2+. In support of this synergism, the g-factor of the aggregates was found to be 1.4×10−2, which represents a high value. We thus show a strategy of in situ construction of a building block from multiple components, among which the interactions can be weak and less selective. Therefore, the design and syntheses of the constituent components are substantially simplified, yet diverse functions can be expected from their supramolecular aggregates.

This study addresses, through two types of experiments, the potential for the oceans to act as a source of atmospheric ice-nucleating particles (INPs). The INP concentration via deposition mode nucleation was measured in situ at a coastal site in British Columbia in August 2013. The INP concentration at conditions relevant to cirrus clouds (i.e., −40 °C and relative humidity with respect to ice, RH ice = 139%) ranged from 0.2 L −1 to 3.3 L −1 . Correlations of the INP concentrations with levels of anthropogenic tracers (i.e., CO, SO 2 , NO x , and black carbon) and numbers of fluorescent particles do not indicate a significant influence from anthropogenic sources or submicron bioaerosols, respectively. Additionally, the INPs measured in the deposition mode showed a poor correlation with the concentration of particles with sizes larger than 500 nm, which is in contrast with observations made in the immersion freezing mode. To investigate the nature of particles that could have acted as deposition INP, laboratory experiments with potential marine aerosol particles were conducted under the ice-nucleating conditions used in the field. At −40 °C, no deposition activity was observed with salt aerosol particles (sodium chloride and two forms of commercial sea salt: Sigma-Aldrich and Instant Ocean), particles composed of a commercial source of natural organic matter (Suwannee River humic material), or particle mixtures of sea salt and humic material. In contrast, exudates from three phytoplankton ( Thalassiosira pseudonana, Nanochloris atomus, and Emiliania huxleyi ) and one marine bacterium ( Vibrio harveyi ) exhibited INP activity at low RH ice values, down to below 110%. This suggests that the INPs measured at the field site were of marine biological origins, although we cannot rule out other sources, including mineral dust.