Proton Content Research Articles

Molecular Hybrid Materials for Selective CO2 Electroreduction to Multicarbon Products

AbstractElectrochemical devices, using renewable energy sources, for CO2 reduction (CO2R) coupled with water oxidation is an attractive strategy for the carbon‐neutral generation of solar fuels and chemical feedstocks. Highly reduced multi‐carbon (C2+) products (e.g., ethylene, ethanol, and propanol) are among the most attractive CO2R chemicals because of their commercial value and high energy densities. Here a new molecular hybrid material is reported that combines the capacity of molecular CO2R catalyst to generate CO with the capacity of Cu(0) materials to achieve C2+ products and further tune their reactivity with organic modifiers. A Fe‐A2B2 porphyrin containing two quaternary ammonium groups that set the right CO2R onset potential for a synergistic tandem performance with Cu2O nanocubes as the precursors is prepared. Furthermore, Fe‐A2B2 porphyrin is functionalized with two thiolate substituents in order to covalently anchor the molecular catalyst onto Cu providing an intimate interaction and great stability. The structural design enables a substantially enriched CO species adsorbed on Cu facilitated by the iron porphyrin catalyst that in turn facilitates the evolution of C2+ products, as demonstrated by in situ Raman spectroscopy. In addition, the whole electrode is further coated with phenyl modifiers that regulate the proton content and hydrophilicity in the neighborhood of the active centers. This approach affords Faradaic efficiencies in the range of 50% for ethylene and 77% for C2+ products at an applied potential of −1.05 V versus RHE.

Phase Diagram of Nuclear Pastas in Neutron Star Crusts

Two neural networks were trained to predict, respectively, the Euler characteristic and the curvature of nuclear pastas in neutron star crust conditions generated by molecular dynamics simulations of neutron star matter with 0.1 < x < 0.5, 0.040 fm−3 < ρ < 0.085 fm−3 (0.68 × 1014 g/cm3 < ρ < 1.43 × 1014 g/cm3), and 0.2 MeV < T < 4.0 MeV, where x is proton content, the density is ρ, and the temperature is T. The predictions of the two networks were combined to determine the nuclear pasta phase that is thermodynamically stable at a given x, ρ, and T, and a three-dimensional phase diagram that extrapolated slightly the regions of existing molecular dynamics data was computed. The jungle gym and anti-jungle gym structures are prevalent at high temperature and low density, while the anti-jungle gym and anti-gnocchi structures dominate at high temperature and high density. A diversity of structures exist at low temperatures and intermediate density and proton content. The trained models used in this work are open access and available at a public repository to promote comparison to pastas obtained with other models.

Effect of fertilizers and growth stimulants on the content of coumarin and its derivatives in the vegetative mass of melilot.

The paper presents the results of determining the content of coumarin and its derivatives in the melilot using nuclear magnetic resonance spectroscopy, including the study of the effect of fertilizers on the quantitative content of coumarin and its derivatives in the composition of the melilot treated by phases using the method of 1H and 13C nuclear magnetic resonance spectroscopy. Based on the results of the nuclear magnetic resonance spectroscopy, the possibility of qualitative and quantitative determination of the content of coumarin and its derivatives isolated from extracts of fertilized melilot was evaluated. The effect of eight preparations on the plant and its concentration in solution on the content of coumarin substances in the Altynbas yellow melilot variety was studied. It was shown that the preparations have a slight effect on the coumarin content in the melilot and, accordingly, on the quality of feed based on it. In the control variant (variant 9), the coumarin proton content was 9.85%, and the maximum coumarin proton content was observed in the variant where BioEnergy was used as fertilizer and amounted to 22.44%.

Studying water infiltration on bentonite/sand blocks with MRI and X-Ray μCT techniques

Radioactive waste management agencies all around the world are focusing their efforts to provide a reliable technical solution to the Deep Geological Disposal (DGD) concept, in order to store high level (HLW) and intermediate level long lived (IL-LLW) radioactive waste. The protection and isolation of radionucleides is guaranteed by a set of barriers. Bentonite/sand blocks -in proportion of 40/60 on dry mass of the mixture- constitute the main core of the sealing barrier in the French concept run by the French National Radioactive Waste Management Agency (Andra). Its high swelling potential (>2MPa) during hydration, its low hydraulic permeability (<10-11 m/s) and its gas entry pressure (<2MPa) make it ideal to seal the DGD galleries excavated inside the host rock used as geological barrier. Bentonite/sand blocks are placed at unsaturated state during construction. Afterwards, water migration –in both liquid and vapour states- from the saturated host rock to the blocks will induce the humidification of the blocks until hydraulic equilibrium is reached, hypothetically reaching the saturation state. As this natural process will take hundreds of years, a multitude of experimental devices have been reported at laboratory [3, 5] and real scale [4] to understand the evolution of water transfer in bentonite mixtures and support the predictions of numerical models [1]. In laboratory experiments, samples made of a compacted bentonite mixture are usually placed inside a rigid cell connected to a water source. The infiltration of water is not measured directly but deduced by relative humidity gradients measured along the specimen height.
 Numerical models and experimental results have not yet reached accurate predictions of how long it takes for bentonite mixtures to hydrate until complete saturation or how the unsaturated hydraulic permeability evolves. In this context, there is a motivation to study this phenomena by advanced techniques able to capture, image and quantify water transfer through porous media. Thus, an experimental campaign based on Magnetic Resonance Imaging (MRI) and 3D X-Ray micro computed tomography (µCT) is proposed to analyze water infiltration in bentonite/sand blocks. MRI is extensively used in health sciences to create images where the contrast is given by the water’s hydrogen proton content in the different tissues of the body. For geological media, where water content is much smaller than in biological tissues and relaxation times of the porewater are shorter -from 0.1 to 2 ms for compacted bentonite/sand [2]- the experimental requirements are different and less documented. On the other hand, µCT scanning provides high spatial resolution images based on the contrast between the X-Ray absorption properties of the constitutive phases observed. Its temporal variations, in a bentonite/sand mixture, might be the result of concurrent phenomena, namely, porosity and saturation changes together with heterogenous motions induced by hydromechanical couplings -the swelling of bentonite solids when they absorb water-.
 On going MRI and µCT experimental campaigns on a PEEK cell aim at proving the suitability of these techniques to track the evolution of water infiltration in compacted bentonite/sand mixtures, characterizing the water front and the water content along the specimen in function of time. At this stage, preliminary MRI tests have shown the potential of Single Point Imaging (SPI) sequence to quantify, with one-dimensional images, the water content along the bentonite/sand specimen based on a linear correlation with its signal intensity. Preliminary X-Ray radiography tests (Figure 1) run on a cylindric cell of PMMA filled with small blocks of 12 mm in diameter and 10 mm high, prove that X-Ray radiography image analysis gives access to observable and quantifiable increase of absorption associated to the measured decrease in grey level at different transversal sections of the sample. This evolution is linked to the increase of apparent density of the solids -that indeed are absorbing the water-, as described by the Beer-Lambert equation. Even though apparent density increase is goverened by the augmentation of water content, changes in porosity due to the hydromechanical coupling along the sample cannot be neglected. Thus, observing the liquid phase evolution (hydraulics) by MRI, as well as the evolution of the solid/liquid phase (hydromechanics) by 3D-µCT imaging, will potentially provide complementary insight into the mechanisms governing water infiltration in bentonite/sand mixtures.

Generation of pulsed proton beams in a vacuum diode with a passive anode

The paper presents the results of a study of a pulsed proton beam generated of in a diode with a metal anode (stainless steel, titanium, and copper) operating in bipolar-pulse mode. The experiments were carried out on the TEMP-6 accelerator (250–300 kV, 120 ns) with a focusing diode geometry in a mode of self-magnetic insulation of electrons. For analysis of the ion beam parameters, we used the infrared imaging diagnostics of the beam energy density (spatial resolution of 2 mm) and the time-of-flight diagnostics of the beam compositions (time resolution 1 ns). It was found that with continuous supply of hydrogen into a hollow anode (with holes on the working surface) and a hydrogen pressure in the diode chamber of 30–80 mPa, the proton content in the beam exceeds 80%. An increase in the first pulse duration leads to an increase in the ion current density up to 100 A/cm2 and the energy density at the focus up to 3 J/cm2. We analyzed various mechanisms of proton beam generation: ions acceleration from the gas plasma in the plasma erosion mode; ions acceleration from the explosive emission plasma of a metal anode the near-surface layer of which is saturated with metal hydrides (anode material). It was found that hydrogen embrittlement of the near-surface layer of the anode occurs during the injection of hydrogen, and during the explosive emission of electrons, part of the material is sprayed in the form of finely dispersed clusters.

Hot accretion flows in low-luminosity active galactic nuclei in NGC 4258 and NGC 7213

ABSTRACT We study the high energy emission of two active galactic nuclei (AGNs), NGC 4258 and NGC 7213. We directly apply the general-relativistic hot flow model, kerrflow, to the archival BeppoSAX, NuSTAR, and Suzaku observations of these objects. Most of these data sets indicate that about 10–20 per cent of the accretion power is used for the direct heating of electrons; however, we find also indications for significant changes of the electron heating efficiency in some cases. Furthermore, all these X-ray data sets indicate rather strongly magnetized flows, with the magnetic field close to the equipartition with the gas pressure. Comparison of the model prediction with the Fermi/LAT data for NGC 7213 allows us to constrain the content of non-thermal protons to at most 10 per cent.

Environmental sub-MeV neutron measurement at the Gran Sasso surface laboratory with a super-fine-grained nuclear emulsion detector

The measurement of environmental neutrons is particularly important in the search for new physics, such as dark matter particles, because neutrons constitute an often irreducible background source. The measurement of the neutron energy spectra in the sub-MeV scale is technically difficult because it requires a very good energy resolution and a very high $\ensuremath{\gamma}$-ray rejection power. In this study, we used a super-fine-grained nuclear emulsion, called nano imaging tracker, as a neutron detector. The main target of neutrons is the hydrogen (proton) content of emulsion films. Through a topological analysis, proton recoils induced by neutron scattering can be detected as tracks with submicrometric accuracy. This method shows an extremely high $\ensuremath{\gamma}$-ray rejection power, at the level of $5\ifmmode\times\else\texttimes\fi{}{10}^{7}\phantom{\rule{0.16em}{0ex}}\ensuremath{\gamma}/{\mathrm{cm}}^{2}$, which is equivalent to five years accumulation of environmental $\ensuremath{\gamma}$ rays, and a very good energy and direction resolution even in the sub-MeV energy region. In order to carry out this measurement with sufficient statistics, we upgraded the automated scanning system to achieve a speed of 250 g/(year machine). We calibrated the detector performance of this system with 880 keV monochromatic neutrons: a very good agreement with the expectation was found for all the relevant kinematic variables. The application of the developed method to a sample exposed at the INFN Gran Sasso surface laboratory provided the first measurement of sub-MeV environmental neutrons with a flux of $(7.6\ifmmode\pm\else\textpm\fi{}1.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\phantom{\rule{0.16em}{0ex}}n/({\mathrm{cm}}^{2}\phantom{\rule{0.16em}{0ex}}\mathrm{s})$ in the proton energy range between 0.25 and 1 MeV (corresponds to neutron energy range between 0.25 and 10 MeV), consistent with the prediction. The neutron energy and direction distributions also show a good agreement.

Supramolecular Anchoring of Polyoxometalate Amphiphiles into Nafion Nanophases for Enhanced Proton Conduction.

Advanced proton exchange membranes (PEMs) are highly desirable in emerging sustainable energy technology. However, the further improvement of commercial perfluorosulfonic acid PEMs represented by Nafion is hindered by the lack of precise modification strategy due to their chemical inertness and low compatibility. Here, we report the robust assembly of polyethylene glycol grafted polyoxometalate amphiphile (GSiW11) into the ionic nanophases of Nafion, which largely enhances the comprehensive performance of Nafion. GSiW11 can coassemble with Nafion through multiple supramolecular interactions and realize a stable immobilization. The incorporation of GSiW11 can increase the whole proton content in the system and induce the hydrated ionic nanophase to form a wide channel for proton transport; meanwhile, GSiW11 can reinforce the Nafion ionic nanophase by noncovalent cross-linking. Based on these synergistic effects, the hybrid PEMs show multiple enhancements in proton conductivity, tensile strength, and fuel cell power density, which are all superior to the pristine Nafion. This work demonstrates the intriguing advantage of molecular nanoclusters as supramolecular enhancers to develop high-performance electrolyte materials.

How the Content of Protons and Vanadium Affects the Activity of H3+nPMo12-nVnO40 (n = 0, 1, 2, or 3) Catalysts on the Oxidative Esterification of Benzaldehyde with Hydrogen Peroxide

How the Content of Protons and Vanadium Affects the Activity of H3+nPMo12-nVnO40 (n = 0, 1, 2, or 3) Catalysts on the Oxidative Esterification of Benzaldehyde with Hydrogen Peroxide

Impacts of the hydroxyls crosslinking on lignin softening and pyrolysis via in situ 1H NMR, rheology, DRIFT and SPI-MS

The softening and foaming of lignin during pyrolysis are the main obstacles to the scale-up of lignin pyrolysis systems. In this study, the mechanism of borate crosslinking on lignin softening and pyrolysis process was investigated by combining in-situ physical and chemical techniques. First, the mobile protons and visco-elastic modulus during lignin pyrolysis were quantitatively analyzed by in-situ high temperature 1H NMR and rheology. It was found that the maximum content of mobile protons during the pyrolysis of raw lignin is around 90%. Hydroxyl crosslinking greatly inhibits the formation of mobile protons. The raw lignin produces a soft material from about 150 °C and starts to form a more rigid material from 200 °C. At 210 °C ~ 330 °C, mobile liquid-like intermediates are entrapped in the rigid char, forming “cavities”. With the addition of boron, the viscoelasticity tends to be stable and mainly elastic. Then, in-situ diffuse reflectance infrared Fourier transform spectroscopy and single photoionization time-of-flight mass spectrometry were used to characterize the evolution of functional groups and volatiles. It was found that the shielding of hydroxyl groups by borate inhibits the decomposition of lignin but improves the selectivity to phenols, and more oxygenated groups remain in the char.

Discrete superconducting phases in proton-intercalated FeSe thin flakes

We have successfully manipulated the electronic properties of FeSe thin flakes based on a field-effect transistor with a solid proton conductor as the gate dielectric. The phase diagram as a function of gate voltage demonstrates three evident discrete superconducting phases with ${T}_{\mathrm{c}}$ corresponding to $\ensuremath{\sim}8, \ensuremath{\sim}34$, and $\ensuremath{\sim}42$ K, respectively, which is similar to those observed in ${\mathrm{Li}}_{x}\mathrm{FeSe}$ and ${\mathrm{Na}}_{x}\mathrm{FeSe}$ by tuning Li or Na content with the solid-ion-conductor gating technique. In the protonation process, the final state with a saturation of the amount of hydrogen ions is reached at a moderately low gate voltage. It suggests that such a device based on a proton conductor can be used to modulate the physical properties by controlling the intercalated proton content and to explore the hydrogen storage capacity of materials.

Fast Pyrolysis Oil Upgrading via HDO with Fe-Promoted Nb2O5-Supported Pd-Based Catalysts

Due to the high acid, oxygen and water contents of fast pyrolysis oil, it requires the improvement of its fuel properties by further upgrading, such as catalytic hydrodeoxygenation (HDO). In this study, Nb2O5 was evaluated as a support of Pd-based catalysts for HDO of fast pyrolysis oil. A Pd/SiO2 catalyst was used as a reference. Additionally, the impact of iron as a promoter in two different loadings was investigated. The activity of the synthesized catalysts was evaluated in terms of H2 uptake and composition of the upgraded products (gas phase, upgraded oil and aqueous phase) through elemental analysis, Karl Fischer titration, GC-MS/FID and 1H-NMR. In comparison to SiO2, due to its acid sites, Nb2O5 enhanced the catalyst activity towards hydrogenolysis and hydrogenation, confirmed by the increased water formation during HDO and a higher content of hydrogen and aliphatic protons in the upgraded oil. Consequently, the upgraded oil with Nb2O5 had a lower average molecular weight and was therefore less viscous than the oil obtained with SiO2. When applied as a promoter, Fe enhanced hydrogenation and hydrogenolysis, although it slightly decreased the acidity of the support, owing to its oxophilic nature, leading to the highest deoxygenation degree (42.5 wt.%) and the highest product HHV (28.2 MJ/kg).

Unveiling the proton structure via transverse-momentum-dependent gluon distributions

We present exploratory studies of the proton content via unpolarized and polarized transverse-momentum-dependent gluon distributions in the proton at leading twist. We make use of an enhanced spectator-model approach to encode in our densities both small- and moderate-$x$ effects. These studies are relevant to the investigation of the inner structure of hadrons via tomographic analyses at new-generation colliding machines.

Lower Macromolecular Content in Tendons of Female Patients with Osteoporosis versus Patients with Osteopenia Detected by Ultrashort Echo Time (UTE) MRI.

Tendons and bones comprise a special interacting unit where mechanical, biochemical, and metabolic interplays are continuously in effect. Bone loss in osteoporosis (OPo) and its earlier stage disease, osteopenia (OPe), may be coupled with a reduction in tendon quality. Noninvasive means for quantitatively evaluating tendon quality during disease progression may be critically important for the improvement of characterization and treatment optimization in patients with bone mineral density disorders. Though clinical magnetic resonance imaging (MRI) sequences are not typically capable of directly visualizing tendons, ultrashort echo time MRI (UTE-MRI) is able to acquire a high signal from tendons. Magnetization transfer (MT) modeling combined with UTE-MRI (i.e., UTE-MT-modeling) can indirectly assess macromolecular proton content in tendons. This study aimed to determine whether UTE-MT-modeling could detect differences in tendon quality across a spectrum of bone health. The lower legs of 14 OPe (72 ± 6 years) and 31 OPo (73 ± 6 years) female patients, as well as 30 female participants with normal bone (Normal-Bone, 36 ± 19 years), are imaged using UTE sequences on a 3T MRI scanner. Institutional review board approval is obtained for the study, and all recruited subjects provided written informed consent. A T1 measurement and UTE-MT-modeling are performed on the anterior tibialis tendon (ATT), posterior tibialis tendon (PTT), and the proximal Achilles tendon (PAT) of all subjects. The macromolecular fraction (MMF) is estimated as the main measure from UTE-MT-modeling. The mean MMF in all the investigated tendons was significantly lower in OPo patients compared with the Normal-Bone cohort (mean difference of 24.2%, p < 0.01), with the largest Normal-Bone vs. OPo difference observed in the ATT (mean difference of 32.1%, p < 0.01). Average MMF values of all the studied tendons are significantly lower in the OPo cohort compared with the OPe cohort (mean difference 16.8%, p = 0.02). Only the PPT shows significantly higher T1 values in OPo patients compared with the Normal-Bone cohort (mean difference 17.6%, p < 0.01). Considering the differences between OPo and OPe groups with similar age ranges, tendon deterioration associated with declining bone health was found to be larger than a priori detected differences caused purely by aging, highlighting UTE-MT MRI techniques as useful methods in assessing tendon quality over the course of progressive bone weakening.

A miniaturized radiation monitor for continuous dosimetry and particle identification in space

A Miniaturized Radiation Monitor (MIRAM) has been developed for the continuous measurement of the radiation field composition and ionizing dose rates in near earth orbits. Compared to currently used radiation monitors, the presented device has an order of magnitude lower weight while being comparable in power consumption and functionality. MIRAM is capable of on-board real-time self-diagnostic. Furthermore, it supports on-board analysis of the measured data to be able to work autonomously. The dose rate is calculated continuously based on the energy deposition in the Timepix3 detector. For the estimation of the particle species composition of the radiation environment, two methods are applied depending on the current flux. At lower fluxes (<104 particles per cm2 per s), a track-by-track analysis based on temporal coincidence is applied. At higher fluxes, a less power and memory consuming method is utilized. This method is using the averaged deposited energy per pixel to estimate the electron and proton content of the radiation field.

Use of NMR relaxometry for determination of meat properties: a brief review

Nuclear magnetic resonance spectroscopy (NMR) is a non-destructive and rapid meat analytical technique. Since meat has high proton content, the quality of fresh meat can be assessed by exciting proton spin using NMR laboratory apparatus. NMR allows the assessment of intrinsic properties including animal development stages and muscle type, as well as extrinsic factors including processing and storage conditions that affect the technological traits of meat. It can be used to determine the water-holding capacity of meat, water distribution in muscles, meat authentication, fat content, post mortem aging, rigor mortis, and changes in metabolomes, among others. Changes in NMR relaxation times are associated with the changes in muscle components and their distribution as affected by various processing conditions. Since, industrial assessment is now demanding rapidity and real-time assessment, it is therefore essential to evaluate the potential of NMR in contrast to other techniques. Therefore, this review article presents the principle of working of NMR, various methods available, quality traits of meat that can be evaluated using this technique, and a brief history. This review article will help the industry to adopt novel NMR-based meat quality assessment tools for rapid quality determinations.

PeV Emission of the Crab Nebula: Constraints on the Proton Content in Pulsar Wind and Implications

Abstract Recently, two photons from the Crab Nebula with energy of approximately 1 PeV were detected by the Large High Altitude Air Shower Observatory (LHAASO), opening an ultrahigh-energy window for studying pulsar wind nebulae (PWNe). Remarkably, the LHAASO spectrum at the highest-energy end shows a possible hardening, which could indicate the presence of a new component. A two-component scenario with a main electron component and a secondary proton component has been proposed to explain the whole spectrum of the Crab Nebula, requiring a proton energy of 1046–1047 erg remaining in the present Crab Nebula. In this paper, we study the energy content of relativistic protons in pulsar winds using the LHAASO data of the Crab Nebula, considering the effect of diffusive escape of relativistic protons. Depending on the extent of the escape of relativistic protons, the total energy of protons lost in the pulsar wind could be 10–100 times larger than that remaining in the nebula presently. We find that the current LHAASO data allow up to (10–50)% of the spindown energy of pulsars being converted into relativistic protons. The escaping protons from PWNe could make a considerable contribution to the cosmic-ray flux of 10–100 PeV. We also discuss the leptonic scenario for the possible spectral hardening at PeV energies.

Study on the Physical, Chemical and Nano-Microstructure Characteristics of Asphalt Mixed with Recycled Eggshell Waste

Green economy is a major them of sustainable development. The application of biological waste in engineering is conducive to green development. This study reveals the effect of recycled eggshell waste on the physical and chemical properties as well as nano-microstructure characteristics of asphalt. The hardness, thermal stability and ductility of asphalt were explored by the penetration, softening point and ductility tests. The distribution and relative content of protons in asphalt were revealed by nuclear magnetic resonance hydrogen spectrum (1H-NMR). The microscopic characteristics of the particle morphology and surface structure of the eggshell powder were explored by scanning electron microscopy (SEM). An atomic force microscope (AFM) was used to analyze the evolution laws of asphalt nano-microstructures. The experiment results indicate that (1) the eggshell waste increases the hardness, thermal stability and reduces the ductility of asphalt; (2) the chemical environment in which the protons of the eggshell waste asphalt are located and the H index have no obvious changes; (3) the eggshell powder is characterized by a rough, wrinkled, porous and loosened structure; (4) the nano-microstructure of eggshell waste asphalt exhibits “bee-like structures”, and the different proportion of eggshell waste changes the maturity, size and quantity of the “bee-like structures” and roughness, which can be attributed to the interaction of the asphaltene-waxiness system.

Effect of partial substitution of sodium salt on the quality of salted quail eggs.

To improve the quality of salted quail eggs and solve the problem of excessive sodium content in salted eggs, we selected substitutes (K2 CO3 , CaCl2 , MgCl2 , ZnCl2 , and FeC6 H5 O7 ) to partially replace NaCl and study its effect on water migration, physicochemical properties, and textural characteristics. The low-field nuclear magnetic resonance technology (LF-NMR) was used to qualitatively analyze the moisture and proton content of quail eggs during the pickling process. The results showed that the relaxation curves of ZnCl2 and FeC6 H5 O7 groups were significantly different from those of other groups. The bound water content of the ZnCl2 group increased significantly, and FeC6 H5 O7 made the binding degree of water closer. The Na+ of different substitute groups was determined by atomic absorption spectrometry; it was found that the permeation rate of NaCl in the curing process was in the following order: K2 CO3 > control group > MgCl2 > FeC6 H5 O7 > CaCl2 > ZnCl2 . Through the electronic tongue study and comparing the ripening period of salted quail eggs, it was found that the flavor and ripening time of salted quail eggs cured by ZnCl2 and FeC6 H5 O7 were not suitable for low-sodium pickling preparation. At the same time, CaCl2 and MgCl2 were suitable for low-sodium pickling and could improve the product quality. When using K2 CO3 , the substitution ratio can be reduced and two or more compound-curing agents can be formed with CaCl2 and MgCl2 , thus reducing the content of sodium salt in salted eggs. PRACTICAL APPLICATIONS: We simulated the metallic elements contained in the traditional black ash-salted eggs and salt mud coatings. By partial substitution of sodium chloride (NaCl) with different metal salts (K2 CO3 , CaCl2 , MgCl2 , ZnCl2 , and FeC6 H5 O7 ), we studied the effects of these metal salts on the physical and chemical properties, texture, and microstructure of quail eggs during the pickling process. Several suitable low-sodium substitutes were screened out to provide a theoretical foundation for the process optimization of low-sodium-salted quail eggs.

Molecular Crowding Effect in Aqueous Electrolytes to Suppress Hydrogen Reduction Reaction and Enhance Electrochemical Nitrogen Reduction

AbstractThe H2 evolution reaction (HER), one of the most intractable issues for the electrochemical N2 reduction reaction (NRR), seriously hinders NH3 production selectivity and yield rate. Considering that hydrogenation reactions are essential to the aqueous NRR process, acidic electrolytes would be an optimum choice for NRR as long as the proton content and the HER kinetics can be well balanced. However, there is a striking lack of strategies available for electrolyte optimization, i.e., rationally regulating electrolytes to suppress HER and promote NRR, to achieve impressive NRR activity. Herein, a HER‐suppressing electrolytes are developed using hydrophilic poly(ethylene glycol) (PEG) as the electrolyte additive by taking advantage of its molecular crowding effect, which promotes the NRR by retarding HER kinetics. On a TiO2 nanoarray electrode, a significantly improved NRR activity with NH3 Faraday efficiency (FE) of 32.13% and yield of 1.07 µmol·cm−2·h−1 is achieved in the PEG‐containing acidic electrolytes, 9.4‐times and 3.5‐times higher than those delivered in the pure acidic electrolytes. Similar enhancements are achieved with Pd/C and Ru/C catalysts, as well as in an alkaline electrolyte, demonstrating a universally positive effect of molecular crowding in the NRR. This work casts new light on aqueous electrolyte design in retarding HER kinetics and expediting the NRR.