Search

Aims: Multiple guidance cues, such as netrin‐1 (NTN‐1)/deleted in colorectal carcinoma (DCC), control the guidance of axons and help establish functional neural circuits during development. However, the function of these guidance molecules during the neurodegenerative process is unclear. Methods: To access the alterations of NTN‐1 and DCC during the onset and progression of PD, we first established two subacute and one chronic PD model. Then, we investigated the relationship between the NTN‐1/DCC pathway and cell death in SH‐SY5Y cells. Finally, we conducted correlation studies between plasma NTN‐1 and parkinsonian symptoms in patients to understand how this pathway contributes to PD. Results: We found that the imbalance of NTN‐1 and DCC was a common feature of nigral DA neuron injury in PD mouse models. We investigated that MPP+ inhibited NTN‐1 expression and increased DCC expression in a concentration‐ and time‐dependent manner. We further discovered a significant decrease in plasma NTN‐1 levels and a positive correlation with UPDRS scores in PD patients. Conclusion: Our findings confirmed the imbalance of NTN‐1/DCC signaling during nigral degeneration in experimental PD models and found for the first time a correlation of plasma NTN‐1 with PD symptoms in patients. [ABSTRACT FROM AUTHOR]

Background: Previous studies showed the adverse impacts of air pollution on headache attacks in developed countries. However, evidence is limited to the impact of exposure to air pollutants on headache attacks. In this study, we aimed to explore the impact of nitrogen dioxide (NO2) exposure on neurology clinic visits (NCVs) for headache onsets. Methods: Records of NCVs for headaches, concentrations of ambient NO2, and meteorological variables were collected in Wuhan, China, from January 1st, 2017, to November 30th, 2019. A time-series study was conducted to investigate the short-term effects of NO2 exposure on daily NCVs for headaches. Stratified analyses were also computed according to season, age, and sex, and the exposure–response (E-R) curve was then plotted. Results: A total of 11,436 records of NCVs for headaches were enrolled in our study during the period. A 10-μg/m3 increase of ambient NO2 corresponded to a 3.64% elevation of daily NCVs for headaches (95%CI: 1.02%, 6.32%, P = 0.006). Moreover, females aged less than 50 years of age were more susceptible compared to males (4.10% vs. 2.97%, P = 0.007). The short-term effects of NO2 exposure on daily NCVs for headaches were stronger in cool seasons than in warm seasons (6.31% vs. 0.79%, P = 0.0009). Conclusion: Our findings highlight that short-term exposure to ambient NO2 positively correlated with NCVs for headaches in Wuhan, China, and the adverse effects varied by season, age, and sex. [ABSTRACT FROM AUTHOR]

Considering the practical use, it is of important value to design full-spectrum photocatalysts that can absorb natural sunlight for photodegrading organic contaminants. A series of BiPO 4 /WO 3 heterojunction catalysts with different WO 3 contents were readily synthesized via a facile hydrothermal route. Under simulant sunlight irradiation, the photocatalytic activity of the as-prepared products was evaluated by degrading rhodamine B (RhB) solution. Results demonstrated that the most enhanced RhB degradation of 77.2% could be achieved in the BiPO 4 /WO 3 composite with molar ratio of WO 3 to BiPO 4 to be 2:1, which was about 4.9 and 2.1 times higher than pure BiPO 4 (15.9%) and WO 3 (37.8%), respectively. During the photocatalytic process of BiPO 4 /WO 3 composite, the photoinduced electrons in BiPO 4 would transfer to WO 3 while the photoinduced holes in WO 3 could easily inject to BiPO 4 through their intimate contact interfaces, thus leading to an efficient transfer and separation of interfacial charge carriers. Moreover, the interaction of BiPO 4 and WO 3 could also extend the region of the absorption spectrum, which then benefited the improvement of photocatalytic activity. [ABSTRACT FROM AUTHOR]

We numerically study and analyze the light absorption enhancement in thin crystalline silicon solar cell with dual interface gratings. The structure combines the front dielectric nanowalls and the sinusoidal plasmonic grating at back reflector. We show that having specific interfaces with well-chosen period, fill factor and height can allow more efficient dielectric and plasmonic modes coupling into active layer and can improve the solar cell performance. For 1 µm active layer case, the optimal result for the proposed structure achieves short-circuit current of ~23.6 mA/cm 2 , which performs over 50% better than flat solar cell structure, the short-circuit current of which is ~15.5 mA/cm 2 . In addition, the active layer thickness and angular analysis show that the proposed structure maintains its advantage over flat structure. [ABSTRACT FROM AUTHOR]

A series of mesocellular siliceous foams (MCFs) with three-dimensional (3D) interconnected porous structure and tunable porosity were synthesized as supports to prepare triamine grafted sorbents using N'-[2-(3-trimethoxysilylpropylamino)ethyl]ethane-1,2-diamine for CO 2 capture, particularly focusing upon the impact of pore structure of support on the adsorptive properties of final sorbents. The results indicate that both pore volume and diameter of MCF played a critical role in both CO 2 adsorption capacity and kinetics at ambient temperature. Tested at 25 °C, the sorbent prepared by MCF with a large pore size of 33.7 nm and pore volume of 3.24 cm3/g exhibited remarkable CO 2 adsorption capacity at low CO 2 concentrations, which could achieve 2.14 mmol/g at 0.15 bar CO 2 and 1.34 mmol/g under simulated air of 500 ppm CO 2. Advanced characterization demonstrated that the increasing pore volume and diameter led to an increase of amine density on the MCF surface, which could enhance the steric hindrance and reduce the amine efficiency for CO 2 adsorption at ambient temperature. It was also found that large pore size benefits the CO 2 adsorption kinetics as the t 80 and t 90 of sorbents decreased with an increasing pore size of support. Moreover, the MCF-based sorbents exhibited superior thermo-stability with no adsorption loss during 50 cyclic adsorption-desorption tests. These results highlighted that the 3D MCF is a promising material for preparing amine grafted sorbents for flue gas CO 2 capture and air purification applications. [Display omitted] • MCF silicas with tunable porosity were used to fabricate triamine grafted sorbents. • Pore volume and diameter of MCF had a great impact on CO 2 adsorptive properties. • The sorbents showed high sorption capacity for CO 2 capture from air and flue gas. • The developed triamne grafted MCF exhibited superior thermo-stability. [ABSTRACT FROM AUTHOR]

Betavoltaic batteries can meet long-term energy supply needs. However, due to the decay of the radioactive source, the output performance of battery will change over time, and the laws of this change require elucidation to aid the battery engineer. In this study, the influences of time on the apparent power density and β-energy spectrum of the 63 Ni source were clarified. Moreover, the structural parameters, including the p-region, n-region doping concentrations, and junction depth of GaN-based (hexagonal) p–n junction, were optimized, which are 2 × 1017 cm–3, 1014 cm–3, and 0.1 μm, respectively. In particular, the time-related performance trends were analyzed, and a formula for the maximum output power density deterioration was obtained, which can be used to evaluate the performance of 63 Ni GaN-based p–n junction betavoltaic battery within 200 years. The simulation results showed that the maximum output power density of battery after 50 years is 0.243 μW cm−2, which is only 60% of the initial value. In addition, the other output performances, namely, the short-circuit current density, open-circuit voltage, fill factor, and conversion efficiency are 0.096 μA cm−2, 2.67 V, 94.3%, and 20.5%, respectively. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal has been regarded as the "Holy Grail" of Li battery anodes thanks to its high theoretic specific capacity and low reduction potential, but uneven formation of Li dendrites and uncontrollable Li volume changes hinder the practical applications of Li metal anodes. A three-dimensional (3D) current collector is one of the promising strategies to address the above issues if it can be compatible with current industrialized process. Here, Au-decorated carbon nanotubes (Au@CNTs) are electrophoretically deposited on commercial Cu foil as a 3D lithiophilic skeleton to regulate Li deposition. The thickness of the as-prepared 3D skeleton can be accurately controlled by adjusting the deposition time. Benefitting from the reduced localized current density and improved Li affinity, the Au@CNTs-deposited Cu foil (Au@CNTs@Cu foil) achieves uniform Li nucleation and dendrite-free Li deposition. Compared with bare Cu foil and CNTs deposited Cu foil (CNTs@Cu foil), the Au@CNTs@Cu foil exhibits enhanced Coulombic efficiency and better cycling stability. In the full-cell configuration, the Au@CNTs@Cu foil with predeposited Li shows superior stability and rate performance. This work provides a facial strategy to directly construct a 3D skeleton on commercial Cu foils with lithiophilic building blocks for stable and practical Li metal anodes. [ABSTRACT FROM AUTHOR]

The bound state in the continuum (BIC) has paved a new way to achieve excellent localization of the resonant mode coexisting with a continuous spectrum in the metasurface. Here, we propose an all-dielectric metasurface consisting of periodic pairs of asymmetric crosses that supports multiple Fano resonances. Due to the sufficient degrees of freedom in the unit cell, we displaced the vertical bars horizontally to introduce in-plane perturbation, doubling the unit cell structure. Dimerization directly resulted in the folding of the Brillouin zone in k space and transformed the BIC modes into quasi-BIC resonances. Then, simultaneous in-plane symmetry breaking was introduced in both the x and y directions to excite two more resonances. The physical mechanisms of these BIC modes were investigated by multipole decomposition of the scattering cross section and electromagnetic near-field analysis, confirming that they are governed by toroidal dipole (TD) modes and magnetic dipole (MD) modes. We also investigated the flexible tunability and evaluated the sensing performance of our proposed metasurface. Our work is promising for different applications requiring stable and tunable resonances, such as optical switching and biomolecule sensing. [ABSTRACT FROM AUTHOR]

Developing efficient bifunctional electrocatalysts for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is crucial for the large-scale application of rechargeable zinc–air batteries. Perovskite oxides are attractive candidates as bifunctional electrocatalysts. Herein, Ln0.5Sr0.5CoO3-δ (Ln = La, Pr and Sm) was prepared by the sol-gel method and evaluated as bifunctional electrocatalysts for both ORR and OER. Compare with La0.5Sr0.5CoO3-δ (LSC) and Sm0.5Sr0.5CoO3-δ (SSC), Pr0.5Sr0.5CoO3-δ (PSC) demonstrated the enhanced catalytic activity towards ORR with the limiting current density of 4.19 mA cm−2 at 0.40 V vs. RHE and OER with the potential of 1.75 V vs. RHE at 10 mA cm−2 as well as the Tafel slope of 105 mV dec−1. The higher Co3+/Co2+ ratio in PSC played an essential part in boosting the bifunctional electrocatalytic activities for ORR and OER. For demonstration, rechargeable zinc–air batteries with PSC as the air electrode displayed the maximum power density of 72 mW cm−2, the low charge-discharge voltage gap (1.01 V) at 10 mA cm−2 over 80 cycles and outstanding cycling stability. This work highlights the importance of A-site cations of the perovskite oxide as a valid strategy to improve ORR and OER activities. [ABSTRACT FROM AUTHOR]

Carbon-encapsulated transition metal catalysts have caught the interest of researchers in the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) due to their distinctive architectures and highly tunable electronic structures. In this work, we synthesized N-doped carbon encapsulated with CoNi nanoalloy particles (CoNi@NC) as the electrocatalysts. The metal-organic skeleton ZIF-67 nanocubes were first synthesized, and then Ni2+ ions were inserted to generate CoNi-ZIF precursors by a simple ion-exchange route, which was followed by pyrolysis and with urea for the introduction of nitrogen (N) at a low temperature to synthesize CoNi@NC composites. The results reveal that ZIF-67 pyrolysis can dope more N atoms in the carbon skeleton and that the pyrolysis temperature influences the ORR and OER performances. The sample prepared by CoNi@NC pyrolysis at 650 °C has a high N content (9.70%) and a large specific surface area (167 m2 g−1), with a positive ORR onset potential (Eonset) of 0.89 V vs. RHE and half-wave potential (E1/2) of 0.81 V vs. RHE in 0.1 M KOH, and the overpotential of the OER measured in 1 M KOH was only 286 mV at 10 mA cm−2. The highly efficient bifunctional ORR/OER electrocatalysts synthesized by this method can offer some insights into the design and synthesis of complex metal-organic frameworks (MOFs) hybrid structures and their derivatives as functional materials in energy storage. [ABSTRACT FROM AUTHOR]

The solubility of Avermectin B 1a (AVM B 1a ) in the three binary solvent mixtures, (acetone + water), (acetone + n-hexane) and (isopropanol + n-hexane) was determined gravimetrically with the temperature ranging from 283.15 K to 313.15 K under atmospheric conditions. The experimental results indicate that the solubility of AVM B 1a increased with increasing temperature at certain solvent composition, and decreased with increasing mole fraction of water and n-hexane. Besides, the modified Apelblat equation, CNIBS/R-K model and Jouyban-Acree model were employed to correlate the solubility results obtained. All the selected models provide satisfactory results. Furthermore, the mixing thermodynamic properties were calculated based on the NRTL equation, a binary activity coefficient model. We also calculated the thermodynamic properties of the dissolution process of AVM B 1a . The calculated results indicate that the dissolution process of AVM B 1a in the tested solvents is endothermic and spontaneous. [ABSTRACT FROM AUTHOR]

In this study, the solubility of L-histidine in three different binary solvents, including (water + acetone), (water + ethanol) and (water + 2-propanol), was measured over temperatures from 283.15 K to 318.15 K by employing a gravimetric method at atmospheric pressure. It was found that the solubility of L-histidine in the binary mixed solvents increases with the increasing temperature at a given solvent composition, whereas it decreases with the rise of mole fraction of organic solvents. The experimental results were well correlated by the modified Apelblat equation, CNIBS/R-K model, combined version of the Jouyban-Acree model and NRTL model, respectively. This shows that these models can correlate the solubility in three binary mixed solvents accurately. Furthermore, the mixing thermodynamic properties of L-histidine in different binary solvent mixtures were also calculated based on the NRTL model. The result indicates that the mixing process of L-histidine is endothermic and spontaneous. [ABSTRACT FROM AUTHOR]

The porous structure of oil shale plays a vital role in heat transfer and mass transport of its pyrolysis, particularly for the flow behavior of shale oil and gas during in-situ conversion. It is essential to clarify the pore evolution and give a mathematical description of the complex pyrolysis. In this study, the effect of temperature (100–800 °C) on Huadian oil shale pyrolysis, and the creation and evolution of the pore structure during thermal treatment were investigated. The oil shale and residues were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, ultimate analysis, scanning electron microscopy, gas permeability measurement, nitrogen isothermal adsorption/desorption, and mercury intrusion porosimetry method. Furthermore, the fractal theory was employed to understand the complex pore characteristics of the samples. The results demonstrated that heating temperature obviously affect the chemical composition and pore evolution of the residues. The removal of volatile matter resulted in pores with enhanced rough and irregular surface; the permeability of the residues is significantly increased, particularly at 350–450 °C. In addition, the fractal dimension and average pore size demonstrated a good linear relationship. [ABSTRACT FROM AUTHOR]

Key message : Over-production of functional PSK-α in Arabidopsis caused increases in both plant cell growth and biomass and induced male sterility by regulating cell wall development. Abstract: Phytosulfokine-α (PSK-α) is a novel disulfated pentapeptide hormone that is involved in promoting plant cell growth. Although a role for PSK-α in stimulating protoplast expansion has been suggested, how PSK-α regulates cell growth in planta remains poorly understood. In this study, we found that overexpression of the normal PSK-α precursor gene AtPSK4, which resulted in high levels of PSK-α, caused longer roots and larger leaves with enlarged cells. As expected, these changes were not observed in transgenic plants overexpressing mutated AtPSK4, which generated unsulfated PSK-α. These findings confirmed the role of PSK-α in promoting plant cell growth. Furthermore, we found that overexpressing AtPSK4, but not mutated AtPSK4, induced a phenotype of male sterility that resulted from the failure of fibrous cell wall development in the endothecium. In addition, overexpressing AtPSK4 enhanced expression of a number of genes encoding expansins, which are involved in cell wall loosening. Accordingly, in addition to its role in cell growth, we propose a novel function for PSK-α signaling in the modulation of plant male sterility via regulation of cell wall development. [ABSTRACT FROM AUTHOR]

Although phosphorus (P) is known to reduce zinc (Zn) uptake by roots and root-to-shoot translocation, how this interaction is affected by changes in root morphology and arbuscular mycorrhizae (AM) are poorly understood. The current study determined the effects of P application rate (0, 25, 50, 100, 200, and 400 kg P ha −1 ) on Zn uptake by roots and root-to-shoot translocation in a high-yielding winter wheat system on calcareous soil. Root dry weight (RDW), root length density (RLD), and root surface area (RSA) significantly increased as P application increased from 0 to 50 kg ha −1 but were unaffected by rates >50 kg ha −1 . Zn accumulation (mg m −2 or μg m −2 ) by roots at flowering increased with application of 25 and 50 kg P ha −1 but slightly decreased with application of 100–400 kg P ha −1 . Zn accumulation in roots and in shoots at flowering and grain yield at maturity were positively correlated with RDW, RLD, and RSA. Root Zn accumulation was increasing with increased AM colonization from low AM (<10%) to 30% AM colonization. Whereas, continuously increasing AM colonization induced root Zn accumulation decrease, which may be mainly due to the decrease of root dry weight affected by P deficiency. P application rate did not significantly affect the ratio of Zn concentrations in roots vs. shoots or the ratio of Zn accumulation in roots vs. total Zn accumulation in the plant, indicating that Zn translocation from roots to shoots is not the primary factor limiting Zn concentrations in grain. These results indicate 1) that P application affects the Zn accumulation of wheat by affecting Zn uptake by roots and 2) that the changes in Zn uptake by roots and Zn accumulation following P application reflect changes in root morphology and AM colonization of roots. [ABSTRACT FROM AUTHOR]

The compositions and surface facets of platinum (Pt)-based electrocatalysts are of great significance for the development of direct alcohol fuel cells (DAFCs). We reported an approach for preparing ultrathin PtnCo100−n nanowire (NW) catalysts with high activity. The PtnCo100−n NW alloy catalysts synthesized by single-phase surfactant-free synthesis have adjustable compositions and (111) plane and strain lattices. X-ray diffraction (XRD) results indicate that the alloy composition can adjust the lattice shrinkage or expansion of PtnCo100−n NWs. X-ray photoelectron spectroscopy (XPS) results show that the electron structure of Pt is changed by the alloying effect caused by electron modulation in the d band, and the chemical adsorption strength of Pt is decreased, thus the catalytic activity of Pt is increased. The experimental results show that the activity of PtnCo100−n for the oxidation of methanol and ethanol is related to the exposed crystal surface, strain lattice and composition of catalysts. The PtnCo100−n NWs exhibit stronger electrocatalytic performance for both methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). The dominant (111) plane Pt53Co47 exhibits the highest electrocatalytic activity in MOR, which is supported by the results of XPS. This discovery provides a new pathway to design high activity, stability nanocatalysts to enhance direct alcohol fuel cells. [ABSTRACT FROM AUTHOR]

Mixing of the turbine blade tip leakage and mainstream flows causes considerable aerodynamic loss. Its understanding is crucial to raise a consequential improvement of the turbine performance. In the present paper, a typical high pressure turbine rotor flow is simulated by detached eddy simulation. The complex mixing in the blade tip region is assessed by the dilution index algorithm in the streamwise direction. Influences of typical parameters on mixing are consecutively identified and analyzed. Relating the influences to flow structures, the mixing mechanism is obtained. It is revealed that the normal effective diffusion coefficient is key in mixing and is correlated with the unsteady tip leakage flow stick vortices. The latter induced by the Kelvin–Helmholtz instability can significantly enhance the local mass and energy transfer and hence diffusion. As a result, mixing is strengthened. Furthermore, the tip region is knowingly divided into the juxtaposing near and far fields. The former contains the tip leakage vortex, leakage jet, mainstream flow, and two entrainment zones. Meanwhile, the latter contains the leakage jet, mainstream flow, and entrainment zone. It was found that the entrainment zone is mixed to a high-degree, whereas the leakage jet is barely mixed. [ABSTRACT FROM AUTHOR]

In order to conveniently and rapidly detect Cr3+ ions in aqueous solution, novel functionalized gold nanoparticles (AuNPs) were designed with 4-mercaptobenzoic acid (4-MBA) and polyethyleneimine (PEI). In addition, we also compared the response signal of various functional AuNPs to Cr3+ ions on the detection system. The modifiers included 4-MBA, 4-nitrobenzene mercaptan (4-NTP) and PEI, respectively. The results showed that 4-MBA and PEI co-functionalized had better sensitiveness than others. Cr3+ ions in aqueous solution could be detected by naked eye and UV-Vis absorption spectrum and the limit of detection was 1 μM. The response was found to be proportional to Cr3+ ions concentration in the range from 2 μM to 10 μM. The developed platform with high selectiveness was successfully utilized to detect Cr3+ ions in simulated samples. Novel functionalized gold nanoparticles were synthesized with 4-mercaptobenzoic acid and polyethyleneimine for Cr3+ ions detection. Cr3+ ions in aqueous solution could be detected by naked eye and UV-Vis absorption spectrum, and the limit of detection can reach 1 μM. The response was found to be proportional to Cr3+ ions concentration in the range from 2 μM to 10 μM. The developed platform with high selectiveness was successfully utilized to detect Cr3+ ions in simulated samples. [ABSTRACT FROM AUTHOR]

Solid electrolyte interphase (SEI) is considered as an effective way to suppress Li dendrite. However, most of the constructed SEI films are usually nonuniform and incompact due to the uncertain interface between Li and electrolyte, finally resulting in failure to Li anode protection. To overcome such disadvantage, a stable pristine SEI film is formed successfully by self‐diffusion and assembly when the surface reaction occur between the molten Li and the substrate, benefitting from the ultra‐high chemical activity, atomic level smoothness, and flowability of liquid lithium. It is an inside–outside process via the obtained Li composites migrating from reaction interface to the Li liquid metal surface. Then, the obtained SEI can lead to a stable and long‐lifespan Li integrated electrode, showing the self‐diffusion/assembly strategy upon liquid Li‐metal is a promising way for practical dendrite‐free anode. [ABSTRACT FROM AUTHOR]

This paper examined the impact of the isotope effect on the lattice structure of monocrystalline silicon, as well as the defects caused by proton irradiation. First, by using the molecular dynamics simulation, the number of point defects of monocrystalline silicon exposed to protons was calculated, and the number of stable defects in 30Si was 11%–14% lower than that in 28Si. Second, the structures of various isotopes at 300 K were simulated through ab initio molecular dynamics simulations based on the density functional theory. In addition, the thermal stability of the two structures was determined. The results indicated that pure 30Si had superior radiation resistance to pure 28Si, which suggested a new idea for the radiation resistance enhancement of silicon materials. [ABSTRACT FROM AUTHOR]

Reliable methods are always greatly desired for the practice of food inspection. Currently, most food inspection techniques are mainly dependent on the identification of special components, which neglect the combination effects of different components and often lead to biased results. By using Chinese liquors as an example, we developed a new food identification method based on the combination of machine learning with GC × GC/TOF-MS. The sample preparation methods SPME and LLE were compared and optimized for producing repeatable and high-quality data. Then, two machine learning algorithms were tried, and the support vector machine (SVM) algorithm was finally chosen for its better performance. It is shown that the method performs well in identifying both the geographical origins and flavor types of Chinese liquors, with high accuracies of 91.86% and 97.67%, respectively. It is also reasonable to propose that combining machine learning with advanced chromatography could be used for other foods with complex components. [ABSTRACT FROM AUTHOR]

This paper describes the theoretical calculation and optimization design of the PN junction betavoltaic batteries with 4H–SiC-based energy converter and titanium tritide source. The self-absorption of radioactive isotope sources and the energy deposition distribution in the semiconductor converter are simulated using the Monte Carlo method. The relationship between doping concentrations and basic factors such as minority carrier diffusion lengths and the width of the depletion region are analyzed via the calculation formulas. Then the maximum output power density and energy conversion efficiency are calculated. The optimal thickness of the titanium tritide film is about 0.7 μm, the doping concentrations are 2.5 × 1016 cm−3, and the junction depth of PN junction is 0.1 μm. The surface recombination velocities of electron and hole are 1 × 106 cm/s, respectively. The maximum output power density and energy conversion efficiency are 0.22 μW/cm2 and 2.37%, respectively. [ABSTRACT FROM AUTHOR]

Wide-bandgap semiconductors are more advantageous for betavoltaic batteries due to their high conversion efficiency and strong radiation resistance. However, there has been little comprehensive analysis of how wide-bandgap semiconductors lead to efficiency improvements. In this work, we proposed a simulation model to predict the output performance of betavoltaic batteries based on 4H-SiC, hexagonal-GaN, and diamond, in which the Monte Carlo code and COMSOL Multiphysics software were combined. The energy deposition of a 63 Ni source in semiconductors and the electrical characteristics of p–n junctions were investigated and compared. Our simulation results showed that the mass density and atomic number of semiconductor materials will cause the difference in energy deposition distribution, further leading to the different electron–hole pair generation rates. Then, the internal efficiency of batteries is co-determined by the energy band structure, depletion region width, built-in potential barrier, and minority carrier lifetime. The batteries based on wide-bandgap semiconductors can achieve the larger open-circuit voltage, further leading to higher efficiency. Additionally, to optimize the energy converter structure, the output parameters were calculated with a variation of doping concentrations and thicknesses of each region. Under the irradiation of a 63 Ni source, the diamond-based battery with a p–n junction structure has the highest internal efficiency of 31.3%, while the GaN-based battery has the lowest one (16.8%), which can be attributed to the larger carrier recombination rate. [ABSTRACT FROM AUTHOR]

The correct Table 1 is as below: Table 1 Clinical and intracranial plaque characteristics of study population and comparison between stroke and non-stroke patients. B Text Correction b In Abstract, the sentence "They were assigned to the posterior circulation stroke (49 patients) and non-posterior circulation stroke group (159 patients) based on clinical presentation and diffusion-weighted imaging (DWI)" should be replaced with "They were assigned to the posterior circulation stroke (59 patients) and non-posterior circulation stroke group (149 patients) based on clinical presentation and diffusion-weighted imaging (DWI)". A Predictive Model for the Risk of Posterior Circulation Stroke in Patients with Intracranial Atherosclerosis Based on High Resolution MRI. [Extracted from the article]

For the 63NiO-Si heterojunction betavoltaic nuclear battery, the energy deposition of the energy conversion material itself was simulated by Monte Carlo simulation, and the structure of the 63NiO-Si heterojunction was optimized based on the theoretical calculation results. When the thickness of 63NiO is 4 μm and the doping concentration of Si is 1 × 1015 cm−3, the short-circuit current density, open-circuit voltage, fill factor, and maximum output power density of the nuclear battery are 1.22 μA · cm−2, 3.17 V, 0.95, 3.67 μW · cm−2. In addition, the output performance of 63Ni/NiO-Si heterojunction betavoltaic nuclear cell was calculated in this study. Under the condition that the activity of the radioactive source and the thickness of NiO(63NiO) are the same in the two structures, the proposed structure (63NiO-Si) has greatly improved the output performance of the nuclear battery by reducing the energy lost from radioactive source self-absorption. [ABSTRACT FROM AUTHOR]

We describe a reversible fluorescent DNA-based INHIBIT logic gate for the determination of silver(I) and iodide ions using graphene oxide (GO) as a signal transducer and Ag(I) and iodide as mechanical activators. The basic performance, optimized conditions, sensitivity and selectivity of the logic gate were investigated and revealed that the method is highly sensitive and selective over potentially interfering ions. The limits of detection for Ag(I) and iodide are 10 nM and 50 nM, respectively. This logic gate was successfully applied to the determination of Ag(I) and iodide in (spiked) tap water and river water. It was also used for the determination of iodide in human urine samples with satisfactory results. Compared to other methods, this INHIBIT logic gate is simple in design and has small background interference. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

We demonstrate a method for incorporating plasmon metallic nanoparticles in hierarchical rutile TiO 2 clusters (RTC) assembled from single-crystal nanospindles. The RTC could efficiently improve the diffusion of the photoelectrons, which can be ascribed to the improvement of the connectivity by bridging the neighbouring microflowers through the single-crystal nanospindles. But not all the nanospindles are tightly interconnected, hence organic colloid has been prepared for post-treatment of the device based on RTC by the generation of TiO 2 nanoparticles. When added into Au nanoparticles, localized electric fields can be produced, because Au can excite dye molecules more intensively than incident far-field light. The surface plasmon synergistic effect had been investigated by Uv-vis absorption spectrum of Au@ organic colloid and the relative change of the IPCE. As a result, the cell based on RTC exhibits an overall conversion efficiency of 7.68%, indicating a 17% promotion compared with that derived from commercial P25 (6.58%) which could be ascribed to faster electron transfer of single-crystal nanospindles. With the Au nanoparticles incorporation in RTC, the device achieves a conversion efficiency of 9.15%, resulting in a 11% increase compared to the RTC device post-treated by organic colloid without Au nanoparticles (8.24%), which is attributed to the surface plasmon synergistic of Au nanoparticles. [ABSTRACT FROM AUTHOR]

Large neutral amino acid transporter 1 (LAT1) transports neutral amino acids with aromatic or branched side chains as well as their derivatives or prodrugs. Because the transporter is highly expressed at the blood–brain barrier and in some tumor cells, it is a potential target to treat brain disease and cancer. Therefore, it is essential to develop a method to screen for LAT1 inhibitors or for therapeutic compounds that it can transport. In this study, one such method was developed that combines an in vitro cell-based assay with high-throughput ultra-performance liquid chromatography triple quadrupole mass spectrometry (UPLC–QQQ–MS). Using this method, candidate compounds could be tested for the ability to inhibit or to compete with uptake of gabapentin, an LAT1 substrate, in HT-29 cells, which abundantly express the transporter. Gabapentin uptake is measured by mass spectrometry, which requires as little as 6 min/sample and will enable analysis of large numbers of samples. We anticipate that the method will be useful to identify LAT1 inhibitors or substrates without the need for animals or radioactive labeling. [ABSTRACT FROM AUTHOR]

In this work, we theoretically investigate the preparation of hole spin in a hybrid system consisting of a quantum dot (QD) and metal-dielectric interface. A cavity quantum electrodynamics (CQED) method is used to analyze the influence of surface plasmon polaritons (SPPs) on the emission of QD. Due to coupling between spin and interface (with a different value along different direction), a fast initialization beyond the GHz range can be achieved with high fidelity at reasonable external parameters, under both continuous wave and pulse excitation. Moreover, the distance between QD and metal is proved to be the most important element. [ABSTRACT FROM AUTHOR]

Intracranial atherosclerotic stenosis (ICAS) is a pathological condition characterized by progressive narrowing or complete blockage of intracranial blood vessels caused by plaque formation. This condition leads to reduced blood flow to the brain, resulting in cerebral ischemia and hypoxia. Ischemic stroke (IS) resulting from ICAS poses a significant global public health challenge, especially among East Asian populations. However, the underlying causes of the notable variations in prevalence among diverse populations, as well as the most effective strategies for preventing and treating the rupture and blockage of intracranial plaques, remain incompletely comprehended. Rupture of plaques, bleeding, and thrombosis serve as precipitating factors in the pathogenesis of luminal obstruction in intracranial arteries. Pericytes play a crucial role in the structure and function of blood vessels and face significant challenges in regulating the Vasa Vasorum (VV)and preventing intraplaque hemorrhage (IPH). This review aims to explore innovative therapeutic strategies that target the pathophysiological mechanisms of vulnerable plaques by modulating pericyte biological function. It also discusses the potential applications of pericytes in central nervous system (CNS) diseases and their prospects as a therapeutic intervention in the field of biological tissue engineering regeneration. [Display omitted] • The incidence and severity of intracranial atherosclerotic stenosis in the East Asian population are considerably elevated. • The maturation of Vasa vasorum structure is crucial in preventing the rupture and hemorrhage of intracranial plaques. • The dysfunction or deficiency of pericytes significantly compromises the integrity of CNS (brain and retina) capillary walls. • Focused strategies targeting pericyte and the transformation of pericyte-like stem cell for bioengineering exhibit diversity. [ABSTRACT FROM AUTHOR]

Radiative cooling is a groundbreaking technology for sustainable temperature regulation to combat global warming and the urban heat island effect. Traditional optimization algorithms for cooling system structures are often brute-force and even limited to local optimal solutions. Here, we propose a joint simulation method based on a multilayer perceptron (MLP) and a convolutional neural network (CNN) with position encoding (PE), namely the hybrid MLP-CNN model with PE. This method can significantly reduce simulation time, avoid getting trapped in local optima, and accurately predict the optical response and radiative cooling power of the structure. Applying PE enables the MLP model to learn the relationship between structural parameters and optical response more quickly and effectively, reducing loss during training and more minor root mean square error (RMSE) and mean relative error (MRE) during testing. In addition, the residual network can reduce the problem of overfitting in the network. Compared to using only an MLP, the hybrid MLP-CNN with PE model can effectively reduce loss and achieve more accurate prediction outputs. The hybrid model is much faster than traditional electromagnetic simulations, taking only 1% of the time, and the model dramatically reduces the time needed to predict the optical response of structures and effectively decreases the cost of designing optical devices. Utilizing this hybrid model not only avoids the potential drawbacks of being limited to suboptimal solutions and significantly reduces the simulation time, but also effectively predicts the optical response of the device. This approach can demonstrate remarkable adaptability in optimizing geometric parameters of various optical apparatuses, including polarization converters, beam splitters, metalens, and other two-dimensional nanostructures. • The hybrid model can reduce simulation time and accurately predict the optical response. • The application of position encoding accelerates the learning of the network. • The maximum predicted radiative cooling power by the hybrid model is up to 113 W/m2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Direct Z-scheme Mn 0.5 Cd 0.5 S/CoTiO 3 heterojunction was designed. • Mechanism for the enhanced photoactivity over Mn 0.5 Cd 0.5 S/CoTiO 3 heterojunction discussed. • High ammonia production rate achieved over heterojunction, 5.1-fold higher than Mn 0.5 Cd 0.5 S. The exploration and design of highly efficient and robust photocatalysts composed of earth-abundant materials for ambient photocatalytic N 2 fixation to ammonia remains a significant challenge. Here, we have fabricated a stable and highly efficient direct Z-scheme Mn 0.5 Cd 0.5 S/CoTiO 3 heterostructure for N 2 fixation by depositing Mn 0.5 Cd 0.5 S nanoparticles on CoTiO 3 surface. Under ambient conditions, the optimized Mn 0.5 Cd 0.5 S/CoTiO 3 heterojunction achieved a significant NH 3 production rate of 121.9 μmol g-1h−1 without cocatalyst modification, representing a 5.1- and 5.9-fold increase over pristine Mn 0.5 Cd 0.5 S and CoTiO 3 , respectively, and also exceeding most previously reported photocatalytic systems. The significant improvement in ammonia production primarily results from the Z-scheme charge transfer path between the Mn 0.5 Cd 0.5 S and CoTiO 3 components, which enables effective separation of photoinduced carriers while maintaining their robust redox capacity, thus dramatically boosting ammonia generation performance. This research may provide new insights for advancing other alternative Z-scheme photocatalytic systems with remarkable stability and exceptional efficiency in N 2 fixation. [ABSTRACT FROM AUTHOR]

Metasurfaces with both multifunctionality and tunability hold great application potential in next-generation optical devices. In this paper, we propose a stretchable metasurface composed of arrays of identical dielectric rectangular resonators embedded in the polydimethylsiloxane (PDMS) substrate. It is shown that the metasurface possesses three functions at the operating wavelength of 532 nm. The switching of functions can be implemented by changing the period Px of the metasurface, induced by stretching the PDMS substrate along the x-direction. When the period Px is less than the operating wavelength of 532 nm, the behavior of metasurface can switch between transmissive window and reflective mirror. When the period Px of the metasurface varies from 532 nm to 700 nm, the metasurface act as a dynamic equal-power beam splitter with conversion efficiency higher than 90%, and the corresponding splitting angle can be adjusted from 90° to around 49.5°. Moreover, we achieve the switching of transmissive window/reflective mirror/split-ratio-variable splitter based on the metasurface consisting of arrays of identical L-shaped resonators embedded in the PDMS substrate. [ABSTRACT FROM AUTHOR]

Under the irradiation of a 63Ni source, the Al/diamond Schottky barrier diode and 2198 Al–Li alloy/diamond Schottky barrier diode can convert decay energy into electrical energy. Through the Monte Carlo method, the energy depositions of the 63Ni source in the energy converters are simulated separately. And then the electrical output properties of two betavoltaic batteries are calculated and compared. The short-circuit current density, open-circuit voltage, fill factor and maximum output power density of the Al/diamond and 2198 Al–Li alloy/diamond Schottky barrier batteries are 0.086 μA/cm2, 2.14 V, 0.93, 0.17 μW/cm2 and 0.089 μA/cm2, 2.66 V, 0.95, 0.22 μW/cm2, respectively. The maximum output power increased by about 29%, which indicates that using alloy as Schottky metal can significantly improve the output performance of a betavoltaic battery. [ABSTRACT FROM AUTHOR]

High temperature plays an important role in the conventional utilization of oil shale regardless of refining or burning. This paper describes the thermal and kinetic characteristics of pyrolysis and combustion of Huadian, Fushun, and Nongan oil shales from three northeast basins of China, particularly Nongan oil shale in Songliao Basin. Fourier transform-infrared spectroscopy and X-ray diffraction were performed to characterize the hydrocarbons and minerals in oil shale. Non-isothermal thermogravimetric analysis was used to investigate the pyrolysis and combustion behaviors of oil shales. The activation energy was calculated using Friedman, Starink, distributed activation energy model, and Ozawa iterative methods. Results indicated that the thermal decompositions of three oil shales exhibit multiple reaction processes, especially combustion process, and the diversity of organic and mineral compositions in oil shale have considerable effects on the thermal behavior and kinetic characteristics of the three samples. Novel exploitation technology for oil shale in Songliao Basin needs to be proposed. [ABSTRACT FROM AUTHOR]

We propose an ultra-thin film solar cell structure combining front semicircular dielectric grooves and back trapezoidal metal reflector. The back trapezoidal metal structure traps light by the excitation of plasmonic modes and the outstanding scattering effect of our optimized shape to enhance the absorption at long wavelengths. The front groove structure boosts absorption at short wavelengths by the mechanisms of Fabry–Perot resonance, scattering and the interaction with back plasmonic structure. The total absorption efficiency over the entire spectrum in 100 nm thick active layer is as high as 78.4% under normal incident light and it can also be maintained in a high level even if the incident angle varies from −60° to 60°. Broadband absorption, efficiency enhancement and insensitivity to the angle indicate the dual interface nanostructure to be a practical reference. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles (nano-TiO2) have been widely applied in daily life and subsequent problem on the potential health risk are raised. Studies on the toxicity of nano-TiO2 have shown that they could lead to toxic effects on human and environment. However, the mechanisms are still unclear. We investigated the change of amino acid levels in L929 cells after nano-TiO2 exposure using gas chromatography with time-of-flight mass spectrometry (GC/TOFMS)-based metabolomics approach. Spectral profiles were subjected to multivariate statistics, namely, Principal Component Analysis (PCA), and Orthogonal Projections to Latent Structures-Discriminant Analysis (OPLS-DA). Using MetaboAnalyst 2.0, it was found that 7 metabolic pathways (impact-value >0.10) among the regulated pathways were significantly perturbed. Twelve distinct amino acids are identified from these pathways, including l-α-alanine, β-alanine, glycine, l-aspartate, l-methionine, l-cysteine, glutamate, l-pyroglutamate, l-asparagine, l-glutamine, S-adenosylmethionine, and l-lysine. These results show that the disturbed amino acids played an important role in the nano-TiO2-induced cytotoxicity. Along with earlier findings, we successfully used the metabolomics approaches to manifest nano-TiO2 toxicity through triggering cellular oxidative stress, energy damage and the inhibition of DNA and RNA synthesis. [ABSTRACT FROM AUTHOR]

In the actual manufacturing process of photonic crystal structure, unavoidable error can generate slight disorder which may influence the performance of photonic crystal based device. In this work, randomly distributional disorders are applied to the air holes in the photonic crystal structure. Based on this, we investigate the influence of the slight disorder on the photonic crystal band structure and the performance of photonic crystal based devices (waveguide and slab cavity). The studies indicate that the slight disorder provides small influence on the band structure of the photonic crystal. But, the random disorder in photonic crystal waveguide may increase transmission loss obviously when the wavelength of the light and the distribution of disorder break the balance of multiple interferences. Also, the slight disorder can reduce the Q factor of the photonic crystal cavity at a certain degree. The studies may provide some useful guides for further photonic crystal device research. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we theoretically analyze the dynamic changes introduced by multiple quantum dots which strongly couple to a single mode microcavity, in both time and frequency domain. Pulse excitation condition is considered. For temporal dynamics, we demonstrate an increased oscillation frequency and non-monotonic decreased oscillation caused by the cooperativity of multiple quantum dots. An oscillation relationship between maximum cavity output photons and QDs numbers is observed. For frequency domain, we reveal enhanced relative intensity of doublet and attenuated relative intensity of single peak in two QDs case. Moreover, for short pulse excitation, the doublet in the time-dependent photon luminescence spectrum is broadened compared with one QD case. [Copyright &y& Elsevier]

Phytosulfokine-α (PSK-α), a tyrosine-sulfated pentapeptide with the sequence YSO3IYSO3TQ, is widely distributed across the plant kingdom and plays multiple roles in plant growth, development, and immune response. Here, we report a novel type of phytosulfokine, PSK-δ, and its precursor proteins (MtPSKδ, LjPSKδ, and GmPSKδ1), specifically from legume species. The sequence YSO3IYSO3TN of sulfated PSK-δ peptide is different from PSK-α at the last amino acid. Expression pattern analysis revealed PSK-δ-encoding precursor genes to be expressed primarily in legume root nodules. Specifically, in Medicago truncatula , MtPSKδ expression was detected in root cortical cells undergoing nodule organogenesis, in nodule primordia and young nodules, and in the apical region of mature nodules. Accumulation of sulfated PSK-δ peptide in M. truncatula nodules was detected by LC/MS. Application of synthetic PSK-δ peptide significantly increased nodule number in legumes. Similarly, overexpression of MtPSKδ in transgenic M. truncatula markedly promoted symbiotic nodulation. This increase in nodule number was attributed to enhanced nodule organogenesis induced by PSK-δ. Additional genetic evidence from the MtPSKδ mutant and RNA interference assays suggested that the PSK-δ and PSK-α peptides function redundantly in regulating nodule organogenesis. These results suggest that PSK-δ, a legume-specific novel type of phytosulfokine, promotes symbiotic nodulation by enhancing nodule organogenesis. [ABSTRACT FROM AUTHOR]

Intracranial vertebrobasilar atherosclerosis is the main cause of posterior circulation ischemic stroke. We aimed to construct a predictive model for the risk of posterior circulation ischemic stroke in patients with posterior circulation atherosclerosis based on high-resolution MRI (HR-MRI). A total of 208 consecutive patients with posterior circulation atherosclerosis confirmed by HR-MRI, from January 2020 to July 2021, were retrospectively assessed. They were assigned to the posterior circulation stroke (49 patients) and non-posterior circulation stroke group (159 patients) based on clinical presentation and diffusion-weighted imaging (DWI). Demographic data, risk factors of atherosclerosis, laboratory findings, and imaging characteristics were extracted from electronic health records. Plaque features were investigated by HR-MRI. Fifty-three clinical or imaging features were used to derive the model. Multivariable logistic regression analysis was employed to construct the prediction model. The nomogram was evaluated for calibration, differentiation, and clinical usefulness. Plaque enhancement, plaque irregular surface morphology, artery location of plaque, and dorsal quadrant of plaque location were significant predictors for posterior circulation stroke in patients with intracranial atherosclerosis. Subsequently, these variables were selected to establish a nomogram. The model showed good distinction (C-index 0.830, 95% CI 0.766-0.895). The calibration curve also showed excellent consistency between the prediction of the nomogram and the observed curve. Decision curve analysis further demonstrated that the nomogram conferred significantly high clinical net benefit. The nomogram calculated from plaque characteristics in HR-MRI may accurately predict the posterior circulation stroke occurrence and be of great help for stratification of stroke decision making. [ABSTRACT FROM AUTHOR]

The intersubband plasmons (ISBPs) of single‐wall carbon nanotubes (SWCNTs) endow SWCNT‐based optoelectronic devices with more functions. However, the structural dependence of the ISBPs of SWCNTs is not fully understood. Here, the effect of electronic types and diameters of SWCNTs on the energy and intensity of their ISBPs is investigated systematically. The results show that the ISBP energy of semiconducting SWCNTs is ≈50–250 meV larger than that of metallic SWCNTs with the same diameters, while the ISBP integral intensity is approximately 1.25 to 4 times stronger. Diameter dependence of ISBPs for both semiconducting and metallic SWCNTs is also observed. With a decrease in diameter, the ISBPs shift to higher energies, while the intensity decreases dramatically. When the diameter is reduced to less than 1 nm, the ISBPs become unobservable. Interestingly, the energy separation between the ISBPs and interband transition S22 (M11) decreases with an increase in diameter. Theoretical calculations show that the structure‐dependent ISBP characteristics are dominated by the electronic states of SWCNTs. Based on the ISBP characteristics of different SWCNTs, high‐performance SWCNT‐based near‐infrared electrochromic devices are fabricated by mixing small‐diameter metallic SWCNTs with semiconducting SWCNTs due to their high conductivity and negligible ISBP signals. [ABSTRACT FROM AUTHOR]

Abstract: In-doped TiO2 thin film was introduced at the interface of fluorine-doped tin oxide (FTO) substrate and mesoporous TiO2 film by spin-coating method, and its application as a new compact layer material for dye-sensitized solar cells (DSSCs) was investigated. The scanning electron microscopy (SEM), UV-visible spectroscopy, current-voltage characteristics, Mott-Schottky analysis, electrochemical impedance spectroscopy (EIS) analysis and open-circuit voltage decay (OCVD) technique are used to characterize the morphology, optical transmittance and flat-band potentials (V fb ) of In-doped titania compact film and its effect to the photoelectron conversion process. It was found that In-doping increased the transmittance of TiO2 compact layer, the interfacial resistance between FTO substrate and porous TiO2 film and the flat-band potential of TiO2 film. The In-doped TiO2 compact layer effectively suppressed the charge recombination from FTO to the electrolyte, increased the optical absorption of dye and then increased the short-circuit photocurrent density (J sc ). Furthermore, In-doped TiO2 compact layer acted as a weak energy barrier, which increased the electron density in the mesoporous TiO2 film, thus improved open-circuit photovoltage (V oc ). As a result, the overall energy conversion efficiency of the DSSC with In-doped TiO2 compact layer was enhanced by 11.9% and 6.9% compared to the DSSC without compact layer and with pure TiO2 compact layer, respectively. It indicated that In-doped TiO2 is a promising compact layer material for dye-sensitized solar cells. [Copyright &y& Elsevier]

[Display omitted] • Novel heterojunction consisting of multishelled hollow CaTiO 3 cubes and Co 0.2 Cd 0.8 S nanoparticles was designed. • An S-scheme charge transfer route within the heterojunction was confirmed. • Mechanism for the enhanced photoactivity over Co 0.2 Cd 0.8 S/CaTiO 3 heterojunction discussed. • High H 2 -production rate achieved over heterojunction, 3.58-fold higher than Co 0.2 Cd 0.8 S. Rationally designing S-scheme heterostructures with boosted charge separation efficiency and superior redox ability is regarded as an appealing strategy to conquer the shortcomings of mono-component and conventional heterojunction photocatalysts. Herein, a novel hierarchical S-scheme heterostructured photocatalyst was constructed by integrating Co 0.2 Cd 0.8 S nanoparticles on multishelled hollow CaTiO 3 cubes to substantially improve the photocatalytic hydrogen production activity. An internal electric field (IEF) is formed at the heterojunction interfaces owing to the significant disparity in Fermi level (E F) between Co 0.2 Cd 0.8 S and CaTiO 3 , accompanied by the energy band bending, which enables the S-scheme charge transport route in the Co 0.2 Cd 0.8 S/CaTiO 3 heterostructure, as verified by electron paramagnetic resonance and theoretical calculations. Benefiting from the boosted separation efficiency and superior redox capability of photocarriers within the constructed S-scheme heterostructure, the optimized Co 0.2 Cd 0.8 S/CaTiO 3 sample exhibited a significantly improved photocatalytic hydrogen evolution rate of 8.13 mmol h−1 g−1, far exceeding that of mono-component counterparts and previously reported Co 0.2 Cd 0.8 S- or CaTiO 3 -based photocatalysts. This study is anticipated to inspire the strategic development of other economical and efficient S-scheme photocatalytic systems with enhanced H 2 evolution activity. [ABSTRACT FROM AUTHOR]

We investigate the photonic crystal slab cavities with different symmetries (C2,σv, C3,σv, C6,σv), and try to find out the rules for increasing the Q factor and reducing the effective modal volume value. The results indicate that the cavity with C2,σv symmetry may be the most suitable candidate, which has high Q factor and small effective modal volume. Based on the cavity with C2,σv symmetry, we use the improved geometry projection method to optimize the shapes of neighbor holes of the cavity and obtain a new slab cavity structure with a high Q value of 5.15 × 105 and small effective modal volume value of 0.09(λ0/n)3. The performance of such a structure is better than in previous reports, which is significant for developing photonic crystal cavity based devices. [ABSTRACT FROM AUTHOR]

Abstract: Light harvesting in dye-sensitized solar cells (DSSCs) mediated by plasmonic metallic nanoparticles and sub-micron light-scattering metal oxides is a facile and cost-effective approach to achieving high device performance. Ag nanoparticles, protected by thin shells of TiO2, were incorporated in TiO2 photoanode. The large plasmonic near-field intensity generated by these nanoparticles caused an 18.3% rise in photocurrent, which resulted in an enhanced efficiency of 6.23% as compared to 5.29% efficiency of DSSC based on unmodified TiO2 photoanode. In addition, DSSC with TiO2 nanofibers (NFs) embedded in TiO2 photoanode was also constructed, which because of the efficient light scattering ability of the nanofibers, attained an efficiency of 7.14% as a result of a current rise of 36.9%. Another DSSC was assembled with Ag NPs added to the photoanode of the NFs-based DSSC to further boost cell performance. The addition of Ag NPs, however, did not produce an appreciable change in the cell performance. The reason for this unexpected outcome was probably due to the low internal resistance associated with charge recombination and large resistance to electron transport in the cell as determined by electrochemical impedance analysis computed in this work. [Copyright &y& Elsevier]

Hydro-Fluctuation Belt (HFB), a periodically exposed bank area formed by changes in water level fluctuations, is critical for damaging the reservoir wetland landscape and ecological balance. Thus, it is important to explore the mechanism of hydrological conditions on the plant-soil system of the HFB for protection of the reservoir wetland and landscape restoration. Here, we investigated the response of plant community characteristics and soil environment of the HFB of Tonghui River National Wetland Park (China), is a typical reservoir wetland, to the duration of inundation, as well as the correlation between the distribution of dominant plants and soil pH, nutrient contents, and enzyme activity by linear regression and canonical correlation analyses. The results show that as the duration of inundation decreases, the vegetation within the HFB is successional from annual or biennial herbs to perennial herbs and shrubs, with dominant plant species prominent and uneven distribution of species. Soil nutrient contents and enzyme activities of HFB decreased with increasing inundation duration. Dominant species of HFB plant community are related to soil environment, with water content, pH, urease, and available potassium being principle soil environmental factors affecting their distribution. When HFB was inundated for 0–30 days, soil pH was strongly acidic, with available potassium content above 150 mg kg−1 and higher urease activity, distributed with Arundo donax L., Polygonum perfoliatum L., Alternanthera philoxeroides (Mart.) Griseb., and Daucus carota L. communities. When inundated for 30–80 days, soil pH was acidic, with lower available potassium content (50–150 mg kg−1) and urease activity, distributed with Beckmannia syzigachne (Steud.) Fern.+ Polygonum lapathifolium L., Polygonum lapathifolium L., Medicago lupulina L. + Dysphania ambrosioides L. and Leptochloa panicea (Retz.) Ohwi communities. Using the constructed HFB plant-soil correlation model, changes in the wetland soil environment can be quickly judged by the succession of plant dominant species, which provides a simpler method for the monitoring of the soil environment in the reservoir wetland, and is of great significance for the scientific management and reasonable protection of the reservoir-type wetland ecosystem. [Display omitted] • Inundation duration determines plant communities and soils within the HFB. • There was a correlation between the succession of dominant plants and soil in HFB. • The plant‒soil association model can quickly indicate soil environment by plant. [ABSTRACT FROM AUTHOR]

Waveguide-integrated reconfigurable nanophotonic devices are of importance for on-chip all-optical connection and flexible photonic circuits. In this paper, we propose inversely designed reconfigurable TE0-to-TE1 and TE0-to-TE2 mode converters based on digital metamaterials consisting of nanoscale silicon and non-loss phase change material Sb 2 Se 3 pixels. The design strategy combines finite element method, density method and method of moving asymptotes. Only 73 and 56 optimization iterations are taken to obtain the optimal digital metamaterials for targeted mode conversions. The footprints of ultra-compact functional regions are 0.92 and 1.04 square center wavelengths, respectively. TE0-to-TE1 and TE0-to-TE2 mode conversions with high transmission efficiency and output mode purity are realized with crystalline Sb 2 Se 3 , while TE0 mode directly pass through with amorphous Sb 2 Se 3. Meanwhile, by cascading these two mode converters, TE1-to-TE2 mode conversion is achieved as well. Moreover, the robustness of these designs is demonstrated by introducing random wrong pixels. • Reconfigurable mode order converters are inversely designed with pixelated Sb 2 Se 3 phase change material. • Highly efficient inverse design scheme combines finite element method, density model and method of moving asymptotes. • Footprints of functional regions are as compact as 0.92 and 1.04 square center wavelengths. • Performances of the reconfigurable mode converters are comparable and satisfactory. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 doping has been widely used to improve the performance of dye-sensitized solar cells. In this paper, we study the use of N as a dopant of TiO2 in dye-sensitized solar cells (DSSCs), analyzing the effect on the photovoltaic properties of the cells based on different amounts of N doping. Results indicate that the dye absorption is increased, which would enhance the amount of photoelectron; moreover, the resistance (R 3) of the electron transport within photoelectrode and electron lifetime of it are improved by N doping. The above two reasons would lead the high short circuit current density (J sc). However, owing to the sites of recombination and severe defects introduced, the trend of dye absorption, R 3 and electron lifetime is opposite when the amount of N doping is more than 3%. Finally, we find that the optimal amount of N doing is 3%, which outstandingly increase the performance of DSSCs. The conversion efficiency of the DSSCs can be reached to 6.25% when using the 3% N-doped TiO2 photoelectrode, and this efficiency is 23.03% higher than that of the pure TiO2. [Copyright &y& Elsevier]

Abstract: A novel transparent and stable polypyrrole (PPy) electrode that can properly serve as a counter electrode for the bifacial dye-sensitized solar cell (DSSC) has been prepared by in situ polymerization of pyrrole monomer on FTO glass. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurement show the considerable catalytic activity of PPy counter electrode. The photovoltaic parameters of bifacial DSSCs are strongly dependent on the initial monomer concentration of pyrrole. The optimized PPy counter electrode has been fabricated under the initial monomer concentration of 0.3 M, a bifacial DSSC based on this PPy electrode shows conversion efficiencies of 5.74% and 3.06% corresponding to front- and rear-side illumination, respectively. Compared to the conventional Pt-based DSSCs, the design of bifacial DSSC with transparent PPy counter electrode improves the utilization ratio of incident light. Moreover, the considerable conversion efficiency and the good long-term stability of PPy-based device demonstrated by the stability test highlight the potential large-scale commercial application of this transparent PPy counter electrode. [Copyright &y& Elsevier]