High-Efficiency Pure-Red CsPbI3 Quantum Dot Light-Emitting Diodes Enabled by Strongly Electrostatic Potential Solvent and Sequential Ligand Post-treatment Process.

Efficient pure-red emission light-emitting diodes (LEDs) are essential for high-definition displays, yet achieving pure-red emission is hindered by challenges like phase segregation and spectral instability when using halide mixing. Additionally, strongly confined quantum dots (QDs) produced through traditional hot-injection methods face byproduct contamination due to poor solubility of metal halide salts in the solvent octadecene (ODE) at low temperatures. Herein, we introduced a novel method using a benzene-series strongly electrostatic potential solvent instead of ODE to prevent PbI2 intermediates and promote their dissolution into [PbI3]-. Increasing methyl groups on benzene yields precisely sized (4.4 ± 0.1 nm) CsPbI3 QDs with exceptional properties: a narrow 630 nm PL peak with photoluminescence quantum yield (PLQY) of 97%. Sequential ligand post-treatment optimizes optical and electrical performance of QDs. PeLEDs based on optimized QDs achieve pure-red EL (CIE: 0.700, 0.290) approaching Rec. 2020 standards, with an EQE of 25.2% and T50 of 120 min at initial luminance of 107 cd/m2.

Isomerization of surface functionalized SWCNTs and the critical influence on photoluminescence: static calculations and excited-state dynamics simulations.

Single-walled carbon nanotubes (SWCNTs) functionalized with sparse surface chemical groups are promising for a variety of optical applications such as quantum information and bio-imaging. However, the luminescence efficiencies and stability, two key aspects, undoubtedly govern their practical usage. Herein, we assess the surface migration of oxygen and triazine groups on as-modified SWCNT fragments by adopting transition state theory and explore the de-excitation of oxygen-functionalized SWCNT fragments by performing non-adiabatic excited-state dynamics simulations. According to the predicted moderate or even small reaction barriers, the migration of both oxygen and triazine groups is feasible from an sp3 defect configuration forming an energetically more stable sp2 configuration at moderate or even room temperatures. Such isomerization leads to drastically different light emission capabilities as indicated by the large or zero oscillator strengths. During the dynamics simulations, the lowest excited singlet (S1) state rapidly decays in energy within 20 fs and then fluctuates until the end, providing insights into the emission mechanism of SWCNTs. This study highlights the potential intrinsic limitations of surface-functionalized SWCNTs for luminescence applications.

Construction of Sugar-Gourd-Shaped Carbon Nanofibers Embedded with Heterostructured Zinc-Cobalt Selenide Nanocages for Superior Potassium-Ion Storage.

Transition metal selenides are considered as promising anode materials for potassium-ion batteries (PIBs) due to their high theoretical capacities. However, their applications are limited by low conductivity and large volume expansion. Herein, sugar-gourd-shaped carbon nanofibers embedded with heterostructured ZnCo-Se nanocages are prepared via a facile template-engaged method combined with electrospinning and selenization process. In this hierarchical ZnCo-Se@NC/CNF, abundant phase boundaries of CoSe2/ZnSe heterostructure can promote interfacial electron transfer and chemical reactivity. The interior porous ZnCo-Se@NC nanocage structure relieves volume expansion and maintains structural integrity during K+ intercalation and deintercalation. The exterior spinning carbon nanofibers connect the granular nanocages in series, which prevents the agglomeration, shortens the electron transport distance and enhances the reaction kinetics. As a self-supporting anode material, ZnCo-Se@NC/CNF delivers a high capacity (362 mA h g-1 at 0.1 A g-1 after 100 cycles) with long-term stability (95.9% capacity retention after 1000 cycles) and shows superior reaction kinetics with high-rate K-storage. Energy level analysis and DFT calculations illustrate heterostructure facilitates the adsorption of K+ and interfacial electron transfer. The K+ storage mechanism is revealed by ex situ XRD and EIS analyses. This work opens a novel avenue in designing high-performance heterostructured anode materials with ingenious structure for PIBs.

Co-Doped Ni3V2O8 Nanofibers Achieving d-d Orbital Coupling for Electrocatalytic Oxygen Reduction.

Efficient and robust non-platinum-group metal electrocatalysts for O2 reduction are a prerequisite for practical high-performance fuel cells and metal-air batteries. Herein, we reported an integrated principle of gradient electrospinning and controllable pyrolysis to fabricate various Co-doped Ni3V2O8 nanofibers with high oxygen reduction reaction (ORR) activity. The representative Co1.3Ni1.7V2O8 nanofibers showed outstanding ORR performance in an alkaline solution with a half-wave potential (E1/2) of 0.874 V vs RHE, along with high long-term stability. Furthermore, the introduction of Co could effectively restrain the growth of nanoparticles and change the electronic structure of Ni3V2O8. Control experiments and theoretical calculations demonstrated that upon Co-doping, the hybridization between the 3d orbital for both Co and Ni guaranteed the stable adsorption interaction with O2 over Ni and Co metal centers. Meanwhile, the weakened binding ability of Ni3V2O8 to OH* reduced the ORR free energy. Overall, the synergistic effect of Co and Ni metal cations essentially reflected the origin of ORR activity on the Co-doped Ni3V2O8 nanofibers. This work offers new insights and practical guidance for designing highly active ORR catalysts for electrochemical clean energy conversion and storage.

Characterization of manganized soluble dietary fiber complexes from tigernut meal and study of the suppressive activity of digestive enzymes in vitro.

In this study, manganized soluble dietary fiber (SDF-Mn(II)) was prepared from tigernut meal using a microwave solid-phase synthesis method with SDF. Microscopic morphological and structural analyses of SDF-Mn(II) were carried out using scanning electron microscopy, Fourier infrared spectroscopy, UV full-band scanning, X-ray diffraction, a thermal analyzer, gel permeation chromatography, and nuclear magnetic resonance, and its in vitro hypoglycemic activity was initially investigated. The results of these analyses revealed that the reaction of Mn(II) with SDF mainly involved hydroxyl and carbonyl groups, with the Nuclear magnetic resonance (NMR) analysis showing that specific covalent binding was produced and substitution was mainly carried out at the C6 position. Moreover, compared with SDF, the SDF-Mn(II) complex exhibited a porous structure, red-shifted, and color-enhancing effects on the UV characteristic peaks, significantly increased crystallinity and decreased molecular weight, and improved thermal stability; in addition, SDF-Mn(II) afforded significantly enhanced inhibition of α-amylase and α-glucosidase and possesses good in vitro digestive enzyme inhibition activity.

A deep learning model for predicting selected organic molecular spectra.

Accurate and efficient molecular spectra simulations are crucial for substance discovery and structure identification. However, the conventional approach of relying on the quantum chemistry is cost intensive, which hampers efficiency. Here we develop DetaNet, a deep-learning model combining E(3)-equivariance group and self-attention mechanism to predict molecular spectra with improved efficiency and accuracy. By passing high-order geometric tensorial messages, DetaNet is able to generate a wide variety of molecular properties, including scalars, vectors, and second- and third-order tensors-all at the accuracy of quantum chemistry calculations. Based on this we developed generalized modules to predict four important types of molecular spectra, namely infrared, Raman, ultraviolet-visible, and 1H and 13C nuclear magnetic resonance, taking the QM9S dataset containing 130,000 molecular species as an example. By speeding up the prediction of molecular spectra at quantum chemical accuracy, DetaNet could help progress toward real-time structural identification using spectroscopic measurements.

Theoretical Investigation of Switch Effect on the Efficiency and Adaptivity of Molecular Optoelectronic Conversion Devices.

Molecular photoswitch can effectively regulate charge separation (CS) and charge recombination (CR) in donor-acceptor (D-A) systems. However, deformation of the donor-switch-acceptor (D-S-A) systems caused by the switch isomerization will destroy the geometrical stability of the battery. Here we take the planar platinum(II) terpyridyl complex of [Pt(t Bu3 tpy)(-C≡C-Ph)n ]+ as the typical D-A model, designed six D-S-A systems using different photoswitches (dimethyldihydropyrene, fulgimide, arylazopyrazole, N-salicylideneaniline, spiropyran, and dithienylethene, denoted as D-S-A 1-6 hereafter). Our investigations show that the D-S-A 1-6 can absorb visible light of 799 nm, 673 nm, 527 nm, 568 nm, 616 nm, and 629 nm, facilitating electrons transfer from the donor and the switch to the acceptor through the Switch-on channel. Then cationic character of the photoswitch can undergo much more rapid isomerization than the neutral form due to the lower energy barrier. The Switch-off isomer breaks the conjugation of the D-S-A system, effectively turning off the CT channel and forming the CS state. Based on the evaluated conjugated backbone twist (CBT) angle, we found that D-S-A 1, 2, 4, 6 exhibit little configurational change and can be good candidates as the organic solar cell. The proposed D-S-A design controlled by the molecular switch may help to develop a solution for solar-harvesting practical applications.

Effect of Fermentation Time on Molecular Structure and Physicochemical Properties of Corn Ballast Starch.

The effect of fermentation treatment on the surface morphology, crystal structure, molecular weight, chain length distribution, and physicochemical properties of corn starch was investigated using natural fermentation of corn ballast. The amylose content in corn ballast starch reduced at first after natural fermentation, then grew, following the same trend as solubility. There were certain erosion marks on the surfaces of fermented corn ballast starch granules. The crystalline structure of corn ballast starch remained the same, i.e., a typical A-type crystalline structure, at different fermentation times; however, the intensities of diffraction peaks were different. The weight-average molecular weight of starch first increased and then decreased after fermentation. The content of low-molecular-weight starch (peak 3) decreased from 25.59 to 24.7% and then increased to 25.76%, while the content of high-molecular-weight starch (peak 1) increased from 51.45 to 53.26%, and then decreased to 52.52%. The fermentation time showed a negative correlation with the viscosity of starch, and the pasting temperature first increased, and then decreased. Natural fermentation can be used as a technical means to produce corn starch products as a result of the experiments' findings, and future experiments will detect and analyze the bacterial structure of corn fermentation broth in order to better understand the molecular mechanism of natural fermentation affecting the structure and physicochemical properties of corn starch.

Designing Self-Adaptive Donor-Switch-Acceptor Systems for Molecular Opto-Electronic Conversion Based on Dimethyldihydropyrene/Cyclophanediene.

The introduction of a self-adaptive molecular switch is an appealing strategy to achieve complete charge separation (CS) in donor-acceptor (D-A) systems. Here, we designed donor-switch-acceptor (D-S-A) systems using a platinum(II) terpyridyl complex as the acceptor, dimethyldihydropyrene/cyclophanediene (DHP/CPD) as the bridge, and methoxybenzene, thieno[3,2-b]thiophene, 2,2'-bifuran, and 4,8-dimethoxybenzo[1,2-b:4,5-b']difuran as donors, respectively. We then systematically studied the whole opto-electronic conversion process of the donor-DHP/CPD-acceptor (D-DHP/CPD-A) systems based on time-dependent density functional theory, time-dependent ultrafast electron evolution, and electron transport property calculations. We first found that the substitution of -CH3 by -H and -CN groups in DHP/CPD can enlarge the range of the adsorption wavenumber in opto-electric conversion. Then the light absorption induces the cationization of DHP switch, largely accelerating the forth-isomerization to CPD form. Once the D-CPD-A molecule is formed, the poor conjugation can realize the complete CS state by inhibiting the radiative and nonradiative charge recombinations. Finally, the repeatable and complete CS can be achieved through the automatic back-isomerization of CPD to DHP. The present work provides valuable insights into design of D-S-A systems for practical utilization of molecule-based solar harvesting.

Effects of High-Temperature, High-Pressure, and Ultrasonic Treatment on the Physicochemical Properties and Structure of Soluble Dietary Fibers of Millet Bran.

OBJECTIVES: The effects of high-temperature, high-pressure, and ultrasonic treatment on the physicochemical properties and structure of soluble dietary fibers in millet bran were studied to provide a comprehensive reference for the utilization of millet bran. METHODS: Different physical methods were used to treat millet bran dietary fibers, and their microstructures and Fourier-transform infrared spectra before and after modification were compared. The physicochemical properties (water-holding capacity, swelling capacity, oil-holding capacity, fat-binding capacity, cation exchange capacity), total antioxidant capacity, and thermal characteristics were also analyzed. RESULTS: There were no significant changes in the chemical groups of millet bran's soluble dietary fibers after modification, but cracks appeared on the surface of the fibers and the structure became loose and porous. Fiber agglomeration was observed, as well as improved thermal stability. After modification, the water-holding capacity, swelling capacity, oil-holding capacity, fat-binding capacity, and cation exchange capacity of millet bran were improved. When compared to the original soluble dietary fibers, ultrasound-treated fibers showed the most substantial improvement in all four capabilities, with increases of 140, 50, 78.1, 65.7, and 37.8%, respectively, compared with the original soluble dietary fibers (P < 0.05). The total antioxidant capacity of the ultrasound-treated fibers was found to be higher than those of the fibers that underwent the other three treatments (P < 0.05). CONCLUSIONS: The physicochemical qualities and structural characteristics of the soluble dietary fibers in millet bran are affected by all three physical modification methods; however, the physicochemical properties of the ultrasound-treated fibers are most significantly improved.

Electrospun Mesoporous InVO4 /TiO2 Nanobelts with Enhanced Photocatalytic Properties.

In the present paper, mesoporous InVO4 /TiO2 nanobelts with diameter about 400 nm have been synthesized by elaborately designed electrospinning process. The microstructures of InVO4 /TiO2 nanobelts are characterized in detail, and their photoelectrocatalytic properties are comprehensively investigated by the photocatalytic degradation tests with tetracycline (TTC) and rhodamine B (RhB) waste water. Furthermore, the energy bandgap and density of states of orthorhombic InVO4 and anatase TiO2 are modeled and analyzed by density functional theory. Compared with single InVO4 nanobelts and TiO2 nanofibers, mesoporous InVO4 /TiO2 nanobelts possess the extraordinary photocatalytic efficiencies and exceptional cycle performances, which may be ascribed to the successful construction of heterostructures between InVO4 and TiO2 and unique one-dimensional belt structures.

Phosphorus-doped cerium vanadate nanorods with enhanced photocatalytic activity.

CeVO4-based photocatalysts have been actively studied, but to the best of our knowledge, P-doped CeVO4 with enhanced photocatalytic activity has not been reported. Herein, novel P-doped CeVO4 nanorods were synthesized via a facile hydrothermal method. The doped P exists as PO4 tetrahedron which replaces VO4 tetrahedron. The crystal size, specific surface area, and light absorption ability of CeVO4 were tuned after doping CeVO4 by P. In particular, the separation and transmission efficiency of photogenerated electron-hole pairs were improved due to the internal electric field caused by the large charge density around PO4 tetrahedron. This conclusion was also confirmed by DFT calculations. The photocatalytic activities of different samples were tested via photodegradation of aqueous organic pollutants, and a feasible mechanism of photocatalytic reaction was proposed.

Enhanced adsorption of anionic toxic contaminant Congo Red by activated carbon with electropositive amine modification.

Anionic ionizable toxic organic contaminants, such as pesticides, herbicides, pharmaceuticals and dyestuffs, are widely detected in aqueous and can exert specific toxicity in organisms. They are hard removed by traditional adsorbents with negative surface charges and hydrophilic property. To solve that bottleneck problem, this study synthesized a carbon-based electropositive absorbent via surface activation and radical impregnation. The monolayer adsorption capacity and favorability of the novel adsorbent increased 4.2 and 16 times compared with activated carbon, evaluated by Congo Red. The adsorption kinetics could be described by pseudo-second-order equation, dominated by chemisorption and shortened 75% equilibrium time. The excellent adsorption behavior of synthesized material was attributed to created and bridged electropositive quaternary ammonium structure onto activated carbon, identified with XPS and FT-IR. Additionally, the abundant mesoporous structures of modified carbon provide more tunnels and facilitate adsorption of Congo Red, identified by AutoSorb-iQ. With the batch experiments of pH and ion strength influence, the absorbent behaved well in acidic low ion strength conditions and attenuated by coexisting cations. The study provides a high efficiency, large capacity and low cost materials to remove anionic ionizable organic contaminants in aqueous.

Fabrication of TiO2 Nanosheet Aarrays/Graphene/Cu2O Composite Structure for Enhanced Photocatalytic Activities.

TiO2 NSAs/graphene/Cu2O was fabricated on the carbon fiber to use as photocastalysts by coating Cu2O on the graphene (G) decorated TiO2 nanosheet arrays (NSAs). The research focus on constructing the composite structure and investigating the reason to enhance the photocatalytic ability. The morphological, structural, and photocatalytic properties of the as-synthesized products were characterized. The experimental results indicate that the better photocatalytic performance is ascribed to the following reasons. First, the TiO2 NSAs/graphene/Cu2O composite structure fabricated on the carbon cloth can form a 3D structure which can provide a higher specific surface area and enhance the light absorption. Second, the graphene as an electron sink can accept the photoelectrons from the photoexcited Cu2O which will reduce the recombination. Third, the TiO2 nanosheet can provide more favorable carrier transportation channel which can reduce the recombination of carriers. Finally, the Cu2O can extend the light absorption range.

Enhanced Photocatalytic Performance Using One Dimensional Ordered TiO2 Nanorods Modified by Graphene Oxide.

A new architecture of one dimensional ordered TiO2 nanorods modified by graphene oxide (GO) was assembled. The GO as the higher carrier mobility can reduce the recombination of carriers, which is more favourable for the methy orange (MO) degradation. Incorporating GO with the unblocked passageway for carrier transportation of the TiO2 nanorods can separate the transport pathway of electron and hole effectively. Furthermore, the large surface areas of TiO2 nanorods grown on the GO are beneficial to the enhancement of photocatalytic properties, and the reasonable band energy level can be obtained for the architecture, which is favorable for enhancing carrier separation and transportation. Finally, the higher transparency of the structure can enhance the light absorption. The photocatalyst grown on FTO substrates makes it easier to collect and recycle.

Facile Electrospinning of CeO2 /Bi2 WO6 Heterostructured Nanofibers with Excellent Visible-light-driven Photocatalytic Performance.

One-dimensional (1D) CeO2 /Bi2 WO6 heterostructured nanofibers with a diameter of about 300 nm were successfully synthesized by using a straightforward strategy combining an electrospinning technique with a sintering process. The acquired products were characterized by thermogravimetric and differential scanning calorimetric (TG-DSC), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area measurements, and UV/Vis spectroscopy. The obtained CeO2 /Bi2 WO6 heterostructured nanofibers exhibited an excellent photocatalytic property for the degradation of Rhodamine B (RhB) dye driven by visible light due to the promoted separation of photoelectrons and holes and the large contact area between the photocatalyst and organic pollutant.

Using off-the-shelf lossy compression for wireless home sleep staging.

BACKGROUND: Recently, there has been increasing interest in the development of wireless home sleep staging systems that allow the patient to be monitored remotely while remaining in the comfort of their home. However, transmitting large amount of Polysomnography (PSG) data over the Internet is an important issue needed to be considered. In this work, we aim to reduce the amount of PSG data which has to be transmitted or stored, while having as little impact as possible on the information in the signal relevant to classify sleep stages. NEW METHOD: We examine the effects of off-the-shelf lossy compression on an all-night PSG dataset from 20 healthy subjects, in the context of automated sleep staging. The popular compression method Set Partitioning in Hierarchical Trees (SPIHT) was used, and a range of compression levels was selected in order to compress the signals with various degrees of loss. In addition, a rule-based automatic sleep staging method was used to automatically classify the sleep stages. RESULTS: Considering the criteria of clinical usefulness, the experimental results show that the system can achieve more than 60% energy saving with a high accuracy (>84%) in classifying sleep stages by using a lossy compression algorithm like SPIHT. COMPARISON WITH EXISTING METHOD(S): As far as we know, our study is the first that focuses how much loss can be tolerated in compressing complex multi-channel PSG data for sleep analysis. CONCLUSIONS: We demonstrate the feasibility of using lossy SPIHT compression for wireless home sleep staging.

Incorporation of graphene oxide in quantum dot sensitized photocatalyst based on ZnO nanorods.

The novel efficient architecture of photocatalyst is fabricated by incorporating graphene oxide (GO) in quantum dots (QDs) sensitized ZnO nanorods and the photocatalytic properties for methyl orange (MO) degradation are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis-NIR absorption spectroscopy. The results indicate that the incorporating of grapheme oxide is more favourable for the degradation. The improved photocatalytic properties can take several advantages given that the higher carrier mobility of GO which can reduce the recombination of carriers, and assembled quantum dots which can facilitate the absorption of solar light. The paper provides the clue to design the effective and easy recyclable photocatalyst.

[Monitoring indexes for early renal injury in the workers exposed to mercury].

OBJECTIVE: To study the diagnostic method for early renal injury in the workers exposed to mercury (Hg). METHODS: The contents of urinary Hg were determined by chemical method. Urinary microalbumin (mALB), beta(2)-microglodulin (beta(2)-MG) and retinol binding protein (RBP) levels were measured with total quantitative enzyme immunoassay. The activities of urinary N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyl transferase (gamma-GT) were determined by rate methods. Urinary creatinine (Cr) was measured by using picric acid method. RESULTS: The levels of urinary BRP, beta(2)-MG, NAG and gamma-GT in exposed workers [(439.7 +/- 201.4), (141.4 +/- 56.3) micro g/g Cr and (12.3 +/- 5.7), (60.3 +/- 18.5) U/g Cr respectively] were significantly higher than those in controls (P < 0.05, P < 0.01). The levels were increased gradually with the increasing contents of urinary Hg. The positive detection rate for single or two combined indexes was rather lower whereas that for 4 combined indexes was as high as 85.5%. A positive correlation was noted between the contents of urinary Hg and urinary BRP, beta(2)-MG, NAG and gamma-GT (r: 0.466, 0.379, 0.323, 0.311, P < 0.05). Urinary RBP was correlated to urinary beta(2)-MG, NAG and gamma-GT (r: 0.362, 0.354, 0.332, P < 0.05). CONCLUSION: Combined detection of urinary RBP, beta(2)-MG, NAG and gamma-GT is a sensitive method for the diagnosis of early renal injury in the workers exposed to Hg.

[The investigation on the changes of haematological parameters in the occupationally lead exposed workers].

OBJECTIVE: To estimate the level of blood lead and some haematological parameters in the workers occupationally exposed to lead so as to know the effect of lead exposure on hematopoietic system in exposed workers. METHODS: The graphite furnace atomic absorption spectrocopy was used to determine blood lead (BPb). The haematological parameters were determined by Sysmex KX-21 automated haematology analyzer. RESULTS: Hemoglobin (Hb) in the lead-absorption group[male: (129.3 +/- 12.3) g/L, female: (112.2 +/- 9.4) g/L], and hematocrit (HCT) in the lead-absorption group[male: (0.338 +/- 0.030) L/L, female: (0.302 +/- 0.028) L/L] were significantly lower than those in normal people group and lead-exposed group (P < 0.05, P < 0.01). The relationships between BPb and Hb, HCT were weakly negative correlation. Red cell distribution width (RDW) in the lead-absorption group(male: 16.68% +/- 0.80%, female: 16.98% +/- 0.98%) were significantly higher than those in normal people group and lead exposed group, and RDW in lead exposed group (male: 14.77% +/- 0.83%, female: 14.92% +/- 1.13%) were higher than that in normal people group. BPb was weakly positively correlated with RDW. CONCLUSION: Hb, HCT and RDW were three indices which may reflect the occurrences and degrees of anaemia in lead exposed workers.