"Atomic Topping" of MnOx on Al2O3 to Create Electron-Rich, Aperiodic, Lattice Oxygens that Resemble Noble Metals for Catalytic Oxidation.

Enhancing the catalytic oxidation activity of traditional transition-metal oxides to rival that of noble metals has been a prominent focus in the field of catalysis. However, existing synthesis strategies that focus on controlling the electronic states of metal centers have not yet fully succeeded in achieving this goal. Our current research reveals that manipulating the electronic states of oxygen centers can yield unexpected results. By creating electron-rich, aperiodic lattice oxygens through atomic topping of MnOx, we have produced a catalyst with performance that closely resembles supported Pt. Spherical aberration-corrected transmission electron microscopy and X-ray absorption spectra have confirmed that the atomic topping of the MnOx layer on Al2O3 can form an aperiodic arrangement oxide structure. Near-ambient pressure X-ray photoelectron spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy, reaction kinetics test, and theoretical calculations demonstrated that this structure significantly increases the electron density around the oxygen in MnOx, shifting the activation center for CO adsorption from Mn to O, thereby exhibiting catalytic activity and stability close to that of the precious metal Pt. This study presents a fresh perspective on designing efficient oxide catalysts by targeting electron-rich anionic centers, thereby deepening the understanding of how these centers can be altered to enhance catalytic efficiency in oxidation reactions.

Controlled Iodine Phase Transfer of Covalent Organic Framework Membranes for Instant but Sustained Disinfection.

Freestanding membranes of CuCl2-implanted TpPa covalent organic frameworks (COFs) were mechanochemically produced. The resulting membrane had a high I2 adsorption capacity (566.78 g·mol-1) in cyclohexane, which corresponds to 2.2I2 per unit cell with 1.3I2 immobilized on 3Cl- ions (60%) and 0.9 on 3N atoms (40%). Upon being placed in aqueous media, the membrane released 61.1% of its loaded I2 mainly by its Cl- ions within 10 min and the remaining 38.9% mainly from its N atoms within about 5 h. Thanks to that, the COF membranes loaded with 1.5 mg of I2 could be repetitively utilized to kill about 108 CFU/mL E. coli in 0.5-3 min at least five times, after which the membranes could retain their bactericidal activity for 4 h against 108 CFU/mL E. coli. This highlights the promising application of I2-loaded TpPa-CuCl2 COF membranes for instant and sustained disinfection.

Thermally Induced Reversible Fluorescence Switching of Lead Chloride Hybrids for Anticounterfeiting and Encryption.

Metal halide hybrids with thermally induced fluorescence transition have the potential to be utilized as the next generation of smart materials in optoelectronic devices. However, the fabrication of thermochromic materials with simultaneously reversible and lower transition temperatures is still a challenge. Herein, we present a novel one-dimensional (1D) organic-inorganic lead chloride hybrid (TPA)PbCl3-Green (TPA = tetrapropylammonium) single crystal that exhibits green emission and up to 30% photoluminescence quantum yield (PLQY). It is worth noting that the (TPA)PbCl3-Green crystal changes emission from green to blue light when heated at 323 K. The emission spectra indicate that the blue light is attributed to the combination of two emission peaks located at 438 and 520 nm, respectively. Furthermore, the green luminescence is restored after natural cooling to room temperature. The dynamic transition process is demonstrated via steady-state photoluminescence, single-crystal X-ray diffraction (SCXRD), and powder X-ray diffraction (XRD). (TPA)PbCl3-Green crystals and (TPA)PbCl3-Green@PVP complexes have also been explored as fluorescent security inks for dynamic anticounterfeiting and message encryption as well as optical logic gate applications due to the excellent cycling stability and low transition temperature. This material offers a completely new option for thermochromic materials used for security information.

Synthesis of Uniform Gold Nanorods with Large Width to Realize Ultralow SERS Detection.

In this work, we successfully demonstrate high-yield synthesis of high-quality gold nanorods (Au NRs) with width ranging from 6.5 nm to 175 nm by introducing heptanol molecules as secondary templating agents during cetyltrimethylammonium bromide-templated, seeded growth method. The results show that an appropriate concentration of heptanol molecules not only alter the micellization behavior of CTAB in water, but also help silver ions impact the symmetry-breaking efficiency of additional Au-NP seeds in addition to enhancing the utilization of gold precursors. Moreover, the generality and versatility of the present strategy for synthesis of Au NRs with flexible controlled dimensions are further demonstrated by successful synthesis of Au NRs with the assistance of other fatty alcohols with properly long alkyl chains. Furthermore, when arrays of vertically aligned Au NRs with large width (AVA-Au120×90 NRs) are used as SERS substrates, they can achieve the ultralow limit of detection for crystal violet (10-16  M) with good reliability and reproducibility, and the rapid detection and identification of residual harmful substances.

[Mechanism of Ficus hirta-Hypericum perforatum in treatment of microvascular angina based on network pharmacology and molecular docking].

The active ingredients of Ficus hirta and Hypericum perforatum were collected from Traditional Chinese Medicine Database and Analysis Platform(TCMSP) and related papers. The potential targets of these two medicinal herbs were searched from HERB database, and those associated with microvascular angina were screened out from GeneCards, Online Mendelian Inheritance in Man(OMIM), Therapeutic Target Database(TTD), and HERB. Cytoscape was used to construct a protein-protein interaction(PPI) network of the common targets shared by the two herbs and microvascular angina based on the data of String platform. Metascape was employed to identify the involved biological processes and pathways enriched with the common targets. Cytoscape was used to draw the "active ingredient-target-pathway" network. AutoDock Vina was used to dock the core ingredients with the key targets. A total of 19 potential active ingredients and 71 potential targets were identified to be associated with microvascular angina. Bioinformatics analysis showed that phosphatidylinositol-3-kinase/protein kinase B(PI3 K-AKT), interleukin-17(IL17), hypoxia-inducible factor 1(HIF-1) and other signaling pathways were related to the treatment of microvascular angina by F. hirta and H. perforatum. Molecular docking results showed that ß-sitosterol, luteolin and other ingredients had strong affinity with multiple targets including mitogen-associated protein kinase 1(MAPK1), epidermal growth factor receptor(EGFR) and so on. These findings indicated that F. hirta and H. perforatum may regulate PI3 K-AKT, IL17, HIF-1 and other signaling pathways by acting on multiple targets to alleviate oxidative stress, inhibit inflammatory response, regulate angiogenesis, and improve vascular endothelium and other functions. This study provides reference for in vitro and in vivo studies of the treatment of microvascular angina.

Light-Emitting Metal-Organic Halide 1D and 2D Structures: Near-Unity Quantum Efficiency, Low-Loss Optical Waveguide and Highly Polarized Emission.

Organic-inorganic metal-halide materials (OIMMs) with zero-dimensional (0D) structures offer useful optical properties with a wide range of applications. However, successful examples of 0D structural OIMMs with well-defined optical performance at the micro-/nanometer scale are limited. We prepared one-dimensional (1D) (DTA)2 SbCl5 ⋅DTAC (DTAC=dodecyl trimethyl ammonium chloride) single-crystal microrods and 2D microplates with a 0D structure in which individual (SbCl5 )2- quadrangular units are completely isolated and surrounded by the organic cation DTA+ . The organic molecular unit with a long alkyl chain (C12 ) and three methyl groups enables microrod and -plate formation. The single-crystal microrods/-plates exhibit a broadband orange emission peak at 610 nm with a photoluminescence quantum yield (PLQY) of ca. 90 % and a large Stokes shift of 260 nm under photoexcitation. The broad emission originates from self-trapping excitons. Spatially resolved PL spectra confirm that these microrods exhibit an optical waveguide effect with a low loss coefficient (0.0019 dB µm-1 ) during propagation, and linear polarized photoemission with a polarization contrast (0.57).

Color Tunable Self-Trapped Emissions from Lead-Free All Inorganic IA-IB Bimetallic Halides Cs-Ag-X (X = Cl, Br, I).

Multi-metallic halides of group IA and IB metals are emerged as a new class of color tunable emitters. While chalcogenides and perovskites are extensively studied, these families of materials are little explored. In comparison, herein, lead and cadmium free bimetallic Cs-Ag-X (X = Cl, Br, I) halides are reported where the larger ion Ag+ helped in incorporating all the halide ions which in turn tune their emission color in spanning from 397 nm (violet) to 820 nm (near infrared) as a function of their composition. The synthesis method adopted here is the solvent free ball milling of respective halides of Cs and Ag and took the record shortest time and in bulk scale. From decay lifetimes, emissions from these bimetallic halides are found as a result of fast recombination of self-trapped excitons, which exhibited not only reasonably high quantum yield in the range of 17-68% but also excellent stability to air and moisture under ambient conditions. These also show wide Stokes shift with relatively longer decay lifetimes ranging above the exciton and below the surface trap or dopant induced emissions of inorganic semiconductors, indicating a new class of materials having unique identity of their optical behaviors.

Salinity Independent Flow Measurement of Vertical Upward Gas-Liquid Flows in a Small Pipe Using Conductance Method.

Flow measurement in gas-liquid two-phase flow is always a challenging work, because of the non-uniform phase distribution, severe slippage effect between phases, and different flow structures. Furthermore, the variation of salinity changes the water conductivity, which brings more difficulties to multiphase flow measurement. In this study, a methodology for flow measurement using the conductance method in gas-liquid two-phase flow with salinity change is proposed. The methodology includes the suitable conductivity detection method, the strategy of using combined sensors, and the measurement models of flow parameters. A suitable conductivity detection method that can guarantee that the sensor output is linearly proportional to the conductivity is proposed. This conductivity detection method can ensure that the sensors have a high and constant resolution in the conductivity variation caused by water holdup under the conditions of water conductivity change. Afterward, a combined sensor system consisting of a water holdup sensor, velocity sensor, and water conductivity sensor is designed and experimentally evaluated in gas-water two-phase flow in a 20 mm inner diameter pipe. Considering the non-uniform phase distribution, severe slippage effect between phases, different flow structures, and the variation of salinity, a new water holdup measurement model and flow velocity measurement models are established to achieve salinity independent water holdup measurement and flow velocity measurement for the first time.

Counterion-Dictated Self-Cleaning Behavior of Polycation Coating upon Water Action: Macroscopic Dissection of Hydration of Anions.

The counterions of polydiallyldimethylammonium (PDADMA) coatings were altered by incubation in aqueous solutions of different electrolytes. Oil de-wetting on the resulting polycationic surfaces upon water action exhibited a straightforward connection with the Jones-Dole viscosity B-coefficient (Bη) sign of surface counteranions. Upon water action, surface counteranions with negative Bη render PDADMA coatings oil-adhering, but those with positive Bη furnish PDADMA coatings with excellent self-cleaning. The oil-adhering PDADMA surfaces can become self-cleaning upon water action in response to the Bη of surface counteranions sign-switching with increasing water temperature. Courtesy of surface counter-anions with Bη>0, self-cleaning PDADMA coatings enable not only conversion of conventional meshes into self-cleaning membranes for oil/water separation, but also regioselective maneuver of oil flow on polycationic surfaces according to the Bη sign of surface counteranions patterned atop.

Using Hydrogel to Diversify the Adaptability and Applicability of Functional Nanoparticles: From Nanotech-Flavored Jellies to Artificial Enzymes.

The use of hydrogel to accommodate nanoparticles is generally aimed at a synergetic integration of the peculiar electronic, photonic, magnetic, mechanical, and chemical properties of the nanoparticles with the stimuli-response of the hydrogels into unprecedented, smart, collective functions. The intrinsic water-borne nature of hydrogels further endorses the significant implications of such nanocomposites in biology and medicine. This article will be an account with a special accent on how to introduce nanoparticles within hydrogels and utilize the hydrogels to assist the nanoparticles to adapt themselves into different environments, with a large span of polarity ranging from orthodox aqueous media to unorthodox organic ones. The related technological developments and the associated fundamental issues will be discussed under the umbrella of enabling nanoparticle/hydrogel composites to emulate the unique catalytic performances of enzymes.

Flow Measurement of Oil-Water Two-Phase Flow at Low Flow Rate Using the Plug-in Conductance Sensor Array.

In order to improve the flow measurement accuracy of oil-water two-phase flow at low flow rate, this paper presents a plug-in conductance sensor array (PICSA) for the measurement of water holdup and cross-correlation velocity. Due to the existence of the insert body in PICSA, the effect of slippage and the non-uniform distribution of dispersed phase on the measurement of oil-water two-phase flow at low flow rate can be reduced. The finite element method is used to analyze the electric field distribution characteristics of the plug-in conductance sensor, and the sensor geometry is optimized. The dynamic experiment of oil-water two-phase flow is carried out where water cut Kw and mixture velocity Um are set in the range of 10-98% and 0.0184-0.2580 m/s respectively. Experimental results show that the PICSA has good resolution in water holdup measurement for dispersed oil-in-water slug flow (D OS/W), transition flow (TF), dispersed oil-in-water bubble flow (D O/W) and very fine dispersed oil-in-water bubble flow (VFD O/W). In addition, the cross-correlation velocity of the oil-water two-phase flow is obtained by using the plug-in upstream and downstream conductance sensor arrays. The relationship between the cross-correlation velocity and mixture velocity is found to be sensitive to the change of flow pattern, but it has a good linear relationship under the same flow pattern. Based on the flow pattern identification, a good prediction result of the mixture velocity is obtained using kinematic wave theory. Finally, a high precision prediction of the individual phase volume fraction of oil-water two-phase flow at low flow rate is achieved by using the drift flux model.

A Differential Pressure Sensor Coupled with Conductance Sensors to Evaluate Pressure Drop Prediction Models of Gas-Water Two-Phase Flow in a Vertical Small Pipe.

In the process of production logging to evaluate fluid flow inside pipe, logging tools that force all flow to pass through a small measuring pipe are commonly utilized for measuring mixture density. For these logging tools, studying the fluid flow phenomenon inside the small diameter pipe and improving the prediction accuracy of pressure drop are beneficial to accurately measure mixture density. In this paper, a pressure drop prediction system is designed based on a combination of an eight-electrode rotating electric field conductance sensor (REFCS), plug-in cross-correlation conductance sensor, and differential pressure sensor. This combination overcomes the limitation of the existing pressure drop prediction model that the inlet flow velocity needs to be known. An experiment is conducted in a flow loop facility with 20 mm inner diameter small pipe. The responses of the combination sensors are collected. The REFCS is used to identify flow pattern and measure water holdup. During which five flow patterns are identified by recurrence plot method, i.e., slug flow, bubble flow, churn flow, bubble-slug transitional flow, and slug-churn transitional flow. The mixture velocity of two-phase flow is determined by the plug-in conductance sensor. The differential pressure sensor provides a differential pressure fluctuation signal. Five models of prediction of pressure drop are evaluated. The mixture friction factor of gas-water two-phase flow is obtained by a fitting method based on the measured parameters and flow pattern identification using the optimal model. Then, the pressure drop can be predicted according to the measurement results of a conductance sensor and fitting relationship. The results of pressure drop prediction show that the model proposed by Ansari et al. presents a higher accuracy compared with the other four differential pressure models with the absolute average percentage deviation (AAPD) of less than 2.632%. Moreover, the accuracy of pressure drop prediction of the Zhang et al. model is improved by using the mixture friction factor.

Assessing the capacity of biochar to stabilize copper and lead in contaminated sediments using chemical and extraction methods.

Because of its high adsorption capacity, biochar has been used to stabilize metals when remediating contaminated soils; to date, however, it has seldom been used to remediate contaminated sediment. A biochar was used as a stabilization agent to remediate Cu- and Pb-contaminated sediments, collected from three locations in or close to Beijing. The sediments were mixed with a palm sawdust gasified biochar at a range of weight ratios (2.5%, 5%, and 10%) and incubated for 10, 30, or 60 days. The performance of the different treatments and the heavy metal fractions in the sediments were assessed using four extraction methods, including diffusive gradients in thin films, the porewater concentration, a sequential extraction, and the toxicity characteristic leaching procedure. The results showed that biochar could enhance the stability of heavy metals in contaminated sediments. The degree of stability increased as both the dose of biochar and the incubation time increased. The sediment pH and the morphology of the metal crystals adsorbed onto the biochar changed as the contact time increased. Our results showed that adsorption, metal crystallization, and the pH were the main controls on the stabilization of metals in contaminated sediment by biochar.

Phase Engineering of Hydrophobic Meso-Environments in Silica Particles for Technical Performance Enrichment.

Hexadecyltrimethylammonium bromide (CTAB) was utilized to template the growth of mesoporous silica particles via ammonia-catalyzed hydrolysis and condensation of tetraethoxysilane (TEOS) in the reaction solutions with varied volume fractions of ethanol ( fR). The use of 9,10-bis(phenylethynyl) anthracene (BPEA) as a fluorescence probe unraveled a clear difference in interior structure between the CTAB micelles confined at different fR. At fR of 0.3, the confined CTAB micelles consisting of regularly and densely packed alkane chains, which created crystalline interiors, in which the doped BPEA molecules were effectively isolated in the monomeric form and well protected against aggressive attack from the surrounding environment. At fR of 0.4 or 0.5, the confined CTAB micelles consisting of less regularly but densely packed alkane chains created glassy interiors, which enabled reversible aggregation of the doped BPEA in response to the surrounding environmental change, for instance, the ethanol content in the particle dispersion. At fR of 0.6 or 0.7, the confined CTAB micelles consisting of loosely packed alkane chains created amorphous interiors, which offered sufficiently large free spaces to facilitate the material exchange with the surrounding environment, as evidenced by noticeable intake of the Pyronin Y molecules present in the particle dispersion. The revealed phase modulation of the interiors of surfactant micelles, confined in the pores of mesoporous particles, from crystalline to glassy and amorphous structures, which were scarcely reported in literature, will inspire rational design of mesoporous silica particles with desired technical performance according to the purposes of the practical application.

Mechanical behaviors of tension and relaxation of tongue and soft palate: Experimental and analytical modeling.

This study is to characterize mechanical properties of uniaxial tension and stress relaxation responses of muscle tissues of tongue and soft palate. Uniaxial tension test and stress relaxation test on 39 fresh tissue samples from four five-month-old boars (65 ±â€¯15 kg) are conducted. Firstly, the rationality of the samples' dimension design and experimenal data measurement is validated by one-way ANOVA F-type test. Mechanical properties, including stress-strain relationship and stress relaxation characteristic, are then investigated in details to show the nonlinear behaviors of the tissue samples clearly. Finally, a constitutive model of representing the mechanical properties is formulated within the nonlinear integral representation framework proposed by Pinkin and Rogers, and corresponding material parameters are fitted to the experimental data based on the Levenberg-Marquardt minimization algorithm. The results of the fitting comparison prove that the formulated constitutive model can capture the observed nonlinear behaviors of the muscle tissue samples in both the axial tension and stress relaxation experiments.

Review on utilization of biochar for metal-contaminated soil and sediment remediation.

Biochar is a carbon-neutral or even carbon-negative material produced through thermal decomposition of plant- and animal-based biomass under oxygen-limited conditions. Recently, there has been an increasing interest in the application of biochar as an adsorbent, soil ameliorant and climate mitigation approach in many types of applications. Metal-contaminated soil remediation using biochar has been intensively investigated in small-scale and pilot-scale trials with obtained beneficial results and multifaceted effects. But so far, the study and application of biochar in contaminated sediment management has been very limited, and this is also a worldwide problem. Nonetheless, there is reason to believe that the same multiple benefits can also be realized with these sediments due to similar mechanisms for stabilizing contaminants. This paper provides a review on current biochar properties and its use as a sorbent/amendment for metal-contaminated soil/sediment remediation and its effect on plant growth, fauna habits as well as microorganism communities. In addition, the use of biochar as a potential strategy for contaminated sediment management is also discussed, especially as regards in-situ planning. Finally, we highlight the possibility of biochar application as an effective amendment and propose further research directions to ensure the safe and sustainable use of biochar as an amendment for remediation of contaminated soil and sediment.

Hydrophobic-Force-Driven Removal of Organic Compounds from Water by Reduced Graphene Oxides Generated in Agarose Hydrogels.

Hydrophobic reduced graphene oxides (rGOs) were generated in agarose hydrogel beads (AgarBs) by NaBH4 reduction of graphene oxides (GOs) initially loaded in the AgarBs. The resulting rGO-loaded AgarBs were able to effectively adsorb organic compounds in water as a result of the attractive hydrophobic force between the rGOs in the AgarBs and the organic compounds dissolved in aqueous media. The adsorption capacity of the rGOs was fairly high even toward reasonably water-soluble organic compounds such as rhodamine B (321.7 mg g-1 ) and aspirin (196.4 mg g-1 ). Yet they exhibited salinity-enhanced adsorption capacity and preferential adsorption of organic compounds with lower solubility in water. Such peculiar adsorption behavior highlights the exciting possibility for adopting an adsorption strategy, driven by hydrophobic forces, in practical wastewater treatment processes.

Van der Waals Emulsions: Emulsions Stabilized by Surface-Inactive, Hydrophilic Particles via van der Waals Attraction.

Surface-inactive, highly hydrophilic particles are utilized to effectively and reversibly stabilize oil-in-water emulsions. This is a result of attractive van der Waals forces between particles and oil droplets in water, which are sufficient to trap the particles in close proximity to oil-water interfaces when repulsive forces between particles and oil droplets are suppressed. The emulsifying efficiency of the highly hydrophilic particles is determined by van der Waals attraction between particle monolayer shells and oil droplets enclosed therein and is inversely proportional to the particle size, while their stabilizing efficiency is determined by van der Waals attraction between single particles and oil droplets, which is proportional to the particle size. This differentiation in mechanism between emulsification and stabilization will significantly advance our knowledge of emulsions, thus enabling better control and design of emulsion-based technologies in practice.

Unraveling the Growth Mechanism of Silica Particles in the Stöber Method: In Situ Seeded Growth Model.

In this work, we investigated the kinetic balance between ammonia-catalyzed hydrolysis of tetraethyl orthosilicate (TEOS) and subsequent condensation over the growth of silica particles in the Stöber method. Our results reveal that, at the initial stage, the reaction is dictated by TEOS hydrolysis to form silanol monomers, which is denoted as pathway I and is responsible for nucleation and growth of small silica particles via condensation of neighboring silanol monomers and siloxane network clusters derived thereafter. Afterward, the reaction is dictated by condensation of newly formed silanol monomers onto the earlier formed silica particles, which is denoted as pathway II and is responsible for the enlargement in size of silica particles. When TEOS hydrolysis is significantly promoted, either at high ammonia concentration (≥0.95 M) or at low ammonia concentration in the presence of LiOH as secondary catalyst, temporal separation of pathways I and II makes the Stöber method reminiscent of in situ seeded growth. This knowledge advance enables us not only to reconcile the most prevailing aggregation-only and monomer-addition models in literature into one consistent framework to interpret the Stöber process but also to grow monodisperse silica particles with sizes in the range 15-230 nm simply but precisely regulated by the ammonia concentration with the aid of LiOH.

A Simple Nanocellulose Coating for Self-Cleaning upon Water Action: Molecular Design of Stable Surface Hydrophilicity.

Coating solid surfaces with cellulose nanofibril (CNF) monolayers via physical deposition was found to keep the surfaces free of a variety of oils, ranging from viscous engine oil to polar n-butanol, upon water action. The self-cleaning function was well correlated with the unique molecular structure of the CNF, in which abundant surface carboxyl and hydroxy groups are uniformly, densely, and symmetrically arranged to form a polar corona on a crystalline nanocellulose strand. This isotropic core-corona configuration offers new and easily adoptable guidance to design self-cleaning surfaces at the molecular level. Thanks to its excellent self-cleaning behavior, the CNF coating converted conventional meshes into highly effective membranes for oil-water separation with no prior surface treatment required.