Changes In Surface Structure Research Articles

Differential cytotoxicity to human cells in vitro of tire wear particles emitted from typical road friction patterns: The dominant role of environmental persistent free radicals

Tire wear particles (TWPs) have been recognized as one of the major sources of microplastics (MPs), however, effects of initial properties and photochemical behavior of TWPs on cytotoxicity to human cells in vitro have not been reported. Therefore, here, three TWPs generated from typical wear of tires and pavements (i.e., rolling friction (R-TWPs) and sliding friction (S-TWPs)) and cryogenically milled tire tread (C-TWPs), respectively, and their photoaging counterparts were used to study the reasons for their differential cytotoxicity to 16HBE cells in vitro. Results showed in addition to changes of surface structure and morphology, different preparation methods could also induce formation of different concentration levels of environmental persistent free radicals (EPFRs) (from 1.24 to 3.06 × 1017 spins/g with g-factors ranging 2.00307–2.00310) on surfaces of TWPs, which contained 7.3%–65.8% of reactive EPFRs (r-EPFRs). Meanwhile, photoaging for 90 d could strengthen formation of EPFRs (from 4.03 to 4.61 × 1017 spins/g) with containing 74.7%–78.1% r-EPFRs on surfaces of TWPs and improve their g-factor indexes (ranging 2.00309–2.00313). At 100 μg mL−1 level, compared to C-TWPs, both R-TWPs and S-TWPs (whether photoaging or not) carried higher intensity EPFRs could significantly inhibit 16HBE cells proliferation activity, cause more cells oxidative stress and induce more cell apoptosis/necrosis and secretion of inflammatory factor (P < 0.05). However, regardless of how TWPs were prepared, photoaged or not, exposure at a concentration of 1 μg mL−1 appeared to be non-acute cytotoxic. Correlation analysis suggested dominant toxicity of TWPs was attributed to the formation of r-EPFRs on their surfaces, which could promote accumulation of excess reactive oxygen species in cells and the massive deposition of intracellular particles. This study provides direct evidence of TWPs cytotoxicity, and underlining the need for a better understanding of the influences of initial properties and photochemical characteristics on risk assessment of TWPs released into the environment.

Electromagnetic scattering characteristics of a hypersonic vehicle with a microrough surface in the millimeter wave band

The rough structure may affect the flow field and electromagnetic (EM) scattering characteristics of a hypersonic vehicle. In this study, the EM scattering characteristics of the hypersonic vehicle RAM C-II with a microrough surface were investigated in the millimeter wave band. We first simulated the flow field of a smooth RAM C-II vehicle and calculated the radar cross section (RCS) in the wideband using the physical optics method. The calculation results show that many factors contribute to the variation in the RCS; however, it is occasionally difficult to predict. We then used a one-dimensional Gaussian random rough surface to generate a RAM C-II with a microrough surface through a point-coordinate transformation and simulated its flow field. The electron density flow field of the rough surfaced aircraft fluctuates greatly on the wall. Finally, we calculated the RCS of RAM C-II with different values of roughness in the millimeter wave band. The change of surface structure can be reflected in millimeter waves, and the RCS is determined by both plasma and rough structure.

Influence of interfacial interaction on the reliability of the bond between encapsulation epoxy and copper substrate

The need for power modules has been promoted by the emergence of electric vehicles. The requirements of small volume, high integrity, and high reliability for the next-generation power module lead to the change of encapsulation method from previous gel encapsulation to epoxy encapsulation. Efforts have been made to enhance epoxy materials, and commercialized high-end epoxy has shown excellent properties, but power module failures still exist. The possible reason may lie in the interfacial interaction between encapsulation epoxy and substrate, which is less noticed previously. This paper seeks to unveil the influence of interfacial interaction on the bonding reliability between encapsulation epoxy and copper substrate. Three reliability tests were performed: high-temperature storage test (HST), temperature cycling test (TCT), and pressure cooker test (PCT). The bonding strength after these reliability tests was evaluated, and the bonding interface and fracture surface were analyzed in a nanoscale. Our study discovered that interfacial interaction plays a vital role in encapsulation reliability. Copper can diffuse into the epoxy and catalyze epoxy thermal oxidative degradation, which results in bonding strength reduction after HST and PCT. The surface structure change caused by copper oxidation after HST and PCT also reduced the bonding strength. These findings will greatly benefit future power module design.

On the Acid Stability of PGM-Free OER Catalyst for H2 Production in PEMWE

Low temperature proton exchange membrane water electrolyzer (PEMWE) represents a critical technology for green hydrogen production. It offers the advantages of significantly higher current density and higher H2 purity, rendering it a preferred technology when high energy efficiency and low footprint are essential.Working in the oxidative and acidic environment under high polarization voltage, however, adds substantial demand to the electrode catalyst and the support. This is particularly the case at anode where the oxygen evolution reaction (OER) takes place. At present, the platinum group metal (PGM) materials such as Ir black or Ir oxide are catalysts of choice. Their high cost and limited reserve, however, adds a significant cost to PEM electrolyzer, which contributes to the overall expense of hydrogen production next only to the cost of electricity. Replacing Ir with earth-abundant transition metal oxides could help to reduce the electrolyzer system cost.Argonne National Laboratory has recently designed and prepared a new family of PGM-free OER catalyst for PEM electrolyzer. The new catalysts have high porosity and unique nanoarchitecture, and have demonstrated very promising activity and durability in both rotating disk electrode (RDE) and in operating PEMWE.The most challenging aspect of PGM-free OER catalyst is its stability in the acidic media. To this end, we conducted extensive structural characterizations as well as computational modeling. Particularly, in situ X-ray absorption spectroscopy combined with high resolution imaging revealed insightful information on the electronic and surface structural changes during the electrochemical reaction. Computational Pourbaix diagram also elucidated the catalyst stability under the acidic OER operating condition. Acknowledgement: This work is supported by U. S. Department of Energy, Hydrogen and Fuel Cell Technologies Office through Office of Energy Efficiency and Renewable Energy and by Office of Science, U.S. Department of Energy under Contract DE-AC02-06CH11357.

Tailoring of Mg and MgLi thin-film corrosion rates with dielectric barrier discharge plasma treatment

Magnesium and magnesium alloys such as magnesium-lithium are of great interest for the application as biodegradable implants. To control the degradation, a tailoring of the corrosion rate is needed. In this study, the effect of a short (5–20 s) dielectric barrier discharge plasma treatment in ambient air on the corrosion rate of magnetron sputtered Mg and MgLi thin films is presented. The treatment with atmospheric plasma of as sputtered samples leads to a decrease of the corrosion rate of 45%−50% in Hanks’ balanced salt solution. The higher corrosion resistance is influenced by a change in surface structure and a formation of an MgCO3 containing film.

Reversible switchable wettability of intrinsic micro/nanostructured pollen microcarriers via pH-induce from superhydrophobicity to superhydrophilicity

The wettability of microcarriers is influenced by surface chemistry and surface micro-nanostructure. Reproducible fabrication and precise control of microcarriers with complex structures are expensive and challenging. It is expected that the fabrication of reversible super-wetting carriers without the need for a template or complex winding processing will greatly promote the application of super-wetting materials. Hence, it should be possible to obtain super-wetting microcarriers by regulating intrinsic micro-nanostructured pollen microcarriers’ surface chemistry. A systematic study was performed using different solvents to regulate the wettability of sporopollenin. The changes in surface structure and surface chemistry were studied, and the regulation mechanism of sporopollenin reversible wettability was determined. Tuning pH could induce the wettability transition of sporopollenin, and this wettability transition was reversible. In addition, studies have also shown that the intrinsic micro-/nanostructures of sporopollenin were the basis for the realization of super-wettability, and the protonation and deprotonation of the carboxyl group of the pectin layer were the keys to switching between superhydrophobic and superhydrophilic properties. This is the first report on the fabrication of reversible wetting-regulated microcarriers based on intrinsic micro-nanostructures, indicating that it is possible to use sporopollenin to fabricate reversible wetting-regulated super-wetting microcarriers.

Influence of direct fluorination treatment on surface and optical properties of colorless and transparent polyimides

Due to excellent comprehensive performance, colorless and transparent polyimide (CPI) films are the greatest potential substrates for flexible displays, lighting, and solar cells. In this work, CPI films were modified by direct fluorination to increase the wettability and transmittance. The effects of fluorination duration on the chemical structure and surface physical morphology of CPI films were investigated in detail by attenuated total reflection infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The results show that, depending on the fluorination duration, direct fluorination causes significant changes in surface composition and structure. The F/C and O/C ratios of the samples were enhanced as the fluorination time increased. Surface microcrack increased at initially, then decreased as fluorination time increased. The fluorinated surfaces exhibit a high hydrophily and lipophobicity, and consequently a very high surface energy, according to contact angle measurements. In comparison to original CPI film, the fluorinated CPI films exhibited higher optical transmittance in the ultraviolet–visible light region compared with original CPI film. In addition, the fluorinated CPI films showed good thermal stability up to 500 °C and higher glass transition temperatures (Tg) compared with original CPI film.

‘Newton’ fast shutter system for neutron scattering instruments at the ESS and ISIS neutron sources

Interfacial processes are involved in many areas of chemistry, physics and biochemistry, but following the structural changes of surfaces and thin films at relevant timescales remains challenging. Time-of flight neutron reflectometry can determine changes in surface composition and film thickness, but the speed of these measurements is typically limited by the neutron flux over the range of wavelengths available at existing instrumentation. This necessarily means that, even using the time-of-flight method, measurements over several angles of incidence are required to cover the full Q-range important for structural determination. The very high intensity of the ESS pulsed source makes such configuration changes very inefficient, as the measurements can potentially be recorded in seconds or even milliseconds. Here, we present a conceptual design and some preliminary results from a new type of fast beam shutter system that will allow efficient measurement of broad angular ranges at sub-second timescales. The shutter system is conceptually also potentially useful for a fast aperture application on the ZOOM instrument at the ISIS Target station 2. By using two perpendicular shutters with slits cut into them, it is possible to create a square aperture within the beam as the neutron pulse passes. We believe that the flexibility demonstrated will mean that this system has the potential to be generally useful in many neutron instrumentation applications.

Nano-Tactile Scanner with Dust-Proof and Drip-Proof Structure for High-Resolution Measurement of Skin Surface Textures.

In this study, we have successfully developed a scanner-type measurement device with a built-in nano-tactile sensor for measuring living organisms and skin surface. A complete sensor protection structure for sensitive tactile sensor device has been developed to achieve a sensing system that is capable of measuring texture changes on the skin surface. By using a highly flexible organic ultra-thin film (film adhesive bandage) as the protective structure, it is possible to prevent deterioration of sensor performance and the intrusion of droplets and dust present on the surface to be measured. This system was used in a clinical experiment at the university's medical faculty, and succeeded in accurately extracting changes in the properties of the patient's skin caused by different wiping methods. As a result, the measurement of tactile texture of the skin surface in various states between dry and wet could be accurately done. Finally, in addition to the ability to measure tactile characteristics of the skin surface, a new function has been realized to measure skin hardness distribution caused by skin changes due to blisters, moles, etc.Clinical Relevance- The developed micron scale was the first to explain the changes in the skin surface structure according to the type of skin surface stimulus and the time of its appearance. It is clinically useful to interpret the protective function of the skin and the function of sensory reception.

CULTURAL ADAPTATION OF A MINDFULNESS-BASED INTERVENTION FOR YOUNG ADULTS: AN APPLICATION OF HEURISTIC FRAMEWORK

The empirical evidence for Mindfulness-based interventions is auspicious. The socio-economic factors and political strife in low-middle-income countries puts young adults at heightened risk, which calls for preventive interventions grounded in cultural context. This study culturally adapted a mindfulness-based intervention for young adults by using the Heuristic framework. The outcome measures were also piloted. Study was carried out in four steps: First, information gathering, and second preliminary adaptation design. Third, preliminary adaptation testing was conducted by delivering the Mindfulness Training Course to students (n=8) and measuring preliminary pre-post intervention changes for stress, mindfulness, and psychological wellbeing. Feedback Interviews were conducted with stakeholders, to gain cultural equivalence, followed by the final adaptation refinement step. Results indicated universality in core principles of intervention components. However, major surface structure changes included language, length of the reading material, metaphorical expressions, and an additional orientation audio recording. Study provides a pragmatic methodological application for future intervention adaptation studies. Strong reliability of outcome measures and the post intervention improvement in young adults’ wellbeing and stress indicate probability of conducting future feasibility and effectiveness trials. Keywords: Mindfulness, cultural adaptation, preventive intervention, young adults, stress, youth

CULTURAL ADAPTATION OF A MINDFULNESS-BASED INTERVENTION FOR YOUNG ADULTS: AN APPLICATION OF HEURISTIC FRAMEWORK

The empirical evidence for Mindfulness-based interventions is auspicious. The socio-economic factors and political strife in low-middle-income countries puts young adults at heightened risk, which calls for preventive interventions grounded in cultural context. This study culturally adapted a mindfulness-based intervention for young adults by using the Heuristic framework. The outcome measures were also piloted. Study was carried out in four steps: First, information gathering, and second preliminary adaptation design. Third, preliminary adaptation testing was conducted by delivering the Mindfulness Training Course to students (n=8) and measuring preliminary pre-post intervention changes for stress, mindfulness, and psychological wellbeing. Feedback Interviews were conducted with stakeholders, to gain cultural equivalence, followed by the final adaptation refinement step. Results indicated universality in core principles of intervention components. However, major surface structure changes included language, length of the reading material, metaphorical expressions, and an additional orientation audio recording. Study provides a pragmatic methodological application for future intervention adaptation studies. Strong reliability of outcome measures and the post intervention improvement in young adults’ wellbeing and stress indicate probability of conducting future feasibility and effectiveness trials. Keywords: Mindfulness, cultural adaptation, preventive intervention, young adults, stress, youth

Surface Modification of Tea-Waste-Based Biochar Adsorbent: Synthesis, Characterization, and Batch Adsorption for the Removal of Zidovudine ARV Drug and Phenol

Domestic, agricultural, and industrial waste has been investigated as a substitute for activated carbon adsorbents. For instance, the transformation of tea waste to biochar can be utilized as a substitute for activated carbon adsorbents. In this study, tea waste-based biochar adsorbents (biochar, biochar/reduced graphene oxide (biochar/rGO), biochar/reduced graphene oxide/deep eutectic solvent-cetyltrimethylammonium bromide (biochar/rGO/DES-CTAB), and biochar/reduced graphene oxide/deep eutectic solvent-glycerol (biochar/rGO/DES-glycerol)) were synthesized by simple thermal treatment of tea waste and sucrose followed by modification with reduced graphene oxide and deep eutectic solvents. The obtained materials were characterized using a range of spectroscopy techniques, Fourier Transformed Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy–Energy-Dispersive X-ray Spectroscopy (SEM–EDS), Brunauer, Emmett, and Teller (BET) surface area analysis, and pH at point of zero charge (pH PZC). The obtained results showed that the principal material, i.e., biochar was modified, and FTIR results confirmed the presence of added functional groups. SEM images revealed surface structural changes, and BET showed a decrease in pore size from 10.16 nm to 6.87 nm. The synthesized materials were applied for the removal of ZDV and phenol from the aqueous medium. Batch adsorption studies were conducted to optimize operating parameters such as the adsorbent dose, solution pH, contact time, and initial concentration. Pseudo-first-order (PFO), Pseudo-second-order (PSO), and intraparticle diffusion (IPD) kinetic models were determined to investigate the mechanism of the adsorption process. The coefficient of correlation, R2, was used to determine the best fit of the kinetic models. The adsorption results showed that the DES-glycerol-modified adsorbent was more efficient in removing the pollutants ZDV and phenol than biochar, biochar/rGO, and biochar/rGO/DES-CTAB adsorbents. In addition, the results showed that an acidic medium of pH 2.00 and a contact time of 1 h 30 min and 30 min is sufficient for removing ZDV and phenol, respectively, from an aqueous medium.

Effect of freeze-thaw cycles and biochar coupling on the soil water-soil environment, nitrogen adsorption and N2O emissions in seasonally frozen regions

Freeze-thaw cycles (FTCs) usually occur in the nongrowing season of crops, and the temporal mismatch between soil nitrogen (N) supply and crop N utilization increases the risk of N loss. Crop straw burning is a seasonal air pollution source, and biochar provides new alternatives for waste biomass recycling and soil pollution remediation. To investigate the effect of biochar on N loss and N2O emissions under frequent FTCs, different biochar content treatments (0 %, 1 %, 2 %) were set, and laboratory simulated soil column FTC tests were conducted. Based on the Langmuir and Freundlich models, the surface microstructure evolution and N adsorption mechanism of biochar before and after FTCs were analyzed, and the change characteristics of the soil water-soil environment, available N and N2O emissions under the interactive effect of FTCs and biochar were studied. The results showed that FTCs increased the oxygen (O) content by 19.69 % and the N content by 17.75 % and decreased the carbon (C) content by 12.39 % of biochar. The increase in the N adsorption capacity of biochar after FTCs was related to changes in surface structure and chemical properties. Biochar can improve the soil water-soil environment, adsorb available nutrients, and reduce N2O emissions by 35.89 %–46.31 %. The water-filled pore space (WFPS) and urease activity (S-UE) were the main environmental factors determining N2O emissions. Ammonium nitrogen (NH4+-N) and microbial biomass nitrogen (MBN), as substrates of N biochemical reactions, significantly affected N2O emissions. The interaction of biochar content and FTCs in different treatments had significant effects on available N (p < 0.05). The application of biochar is an effective way to reduce N loss and N2O emissions under the action of frequent FTCs. These research results can provide a reference for the rational application of biochar and efficient utilization of soil hydrothermal resources in seasonally frozen soil areas.

Characterization of Synthetic Polymer Coated with Biopolymer Layer with Natural Orange Peel Extract Aimed for Food Packaging.

This research was aimed to make biolayer coatings enriched with orange peel essential oil (OPEO) on synthetic laminate, oriented poly(ethylene-terephthalate)/polypropylene (PET-O/PP). Coating materials were taken from biobased and renewable waste sources, and the developed formulation was targeted for food packaging. The developed materials were characterized for their barrier (O2, CO2, and water vapour), optical (colour, opacity), surface (inventory of peaks by FTIR), and antimicrobial activity. Furthermore, the overall migration from a base layer (PET-O/PP) in an acetic acid (3% HAc) and ethanol aqueous solution (20% EtOH) were measured. The antimicrobial activity of chitosan (Chi)-coated films was assessed against Escherichia coli. Permeation of the uncoated samples (base layer, PET-O/PP) increased with the temperature increase (from 20 °C to 40 °C and 60 °C). Films with Chi-coatings were a better barrier to gases than the control (PET-O/PP) measured at 20 °C. The addition of 1% (w/v) OPEO to the Chi-coating layer showed a permeance decrease of 67% for CO2 and 48% for O2. The overall migrations from PET-O/PP in 3% HAc and 20% EtOH were 1.8 and 2.3 mg/dm2, respectively. Analysis of spectral bands did not indicate any surface structural changes after exposure to food simulants. Water vapour transmission rate values were increased for Chi-coated samples compared to the control. The total colour difference showed a slight colour change for all coated samples (ΔE > 2). No significant changes in light transmission at 600 nm for samples containing 1% and 2% OLEO were observed. The addition of 4% (w/v) OPEO was not enough to obtain a bacteriostatic effect, so future research is needed.

Cell surface composition, released polysaccharides, and ionic strength mediate fast sedimentation in the cyanobacterium Synechococcus elongatus PCC 7942.

Cyanobacteria are photosynthetic prokaryotes of high ecological and biotechnological relevance that have been cultivated in laboratories around the world for more than 70 years. Prolonged laboratory culturing has led to multiple microevolutionary events and the appearance of a large number of 'domesticated' substrains among model cyanobacteria. Despite its widespread occurrence, strain domestication is still largely ignored. In this work we describe Synechococcus elongatus PCC 7942-KU, a novel domesticated substrain of the model cyanobacterium S. elongatus PCC 7942, which presents a fast-sedimenting phenotype. Under higher ionic strengths the sedimentation rate increased leading to complete sedimentation in just 12 h. Through whole genome sequencing and gene deletion, we demonstrated that the Group 3 alternative sigma factor F plays a key role in cell sedimentation. Further analysis showed that significant changes in cell surface structures and a three-fold increase in released polysaccharides lead to the appearance of a fast-sedimenting phenotype. This work sheds light on the determinants of the planktonic to benthic transitions and provides genetic targets to generate fast-sedimenting strains that could unlock cost-effective cyanobacterial harvesting at scale.

Effect of Heated Sodium Hypochlorite Irrigant on Structural Changes and Microhardness of Radicular Dentin: An In Vitro Study.

This study is aimed to evaluate the combined effect of sodium hypochlorite at varied concentrations and temperatures on radicular dentin microhardness along with its surface structural changes using an FTIR spectrometer. Mandibular premolars were cleaned and shaped up to F3 Protaper gold rotary files, after which they were subjected to five experimental conditions - group I - neutral saline as negative control, group II - 3% NaOCl solution, group III - 5% NaOCl solution, group IV - 3% intracanal-heated NaOCl solution, and group V - 5% intracanal-heated NaOCl solution. Following this, the microhardness of radicular dentin at 100 µm and 300 µm from the canal lumen and Fourier-transform infrared (FTIR) spectroscopic analysis were performed. The results showed that intracanal-heated sodium hypochlorite group reduced root dentin microhardness at 300 µm than its nonheated counterpart. No difference in microhardness values was observed between 3% intracanal-heated and room-temperature sodium hypochlorite groups at 100 µm. Reduction in amide/phosphate ratio was noted in all the groups treated with sodium hypochlorite irrespective of temperature and concentration. Thus, considering that the level of alteration in physical and structural changes of root dentin with or without heating is insignificant, intracanal-heated low-concentration sodium hypochlorite solutions could be used as an alternative to high-concentration sodium hypochlorite. Intracanal-heated low-concentration sodium hypochlorite enables the clinicians to achieve maximum disinfection while keeping the structural and physical properties of the dentin similar to room-temperature sodium hypochlorite.

In Situ EC-AFM Study of the Initial Stages of Cathodic Corrosion of Pt(111) and Polycrystalline Pt in Acid Solution.

An atomic scale understanding of the surface degradation mechanism during cathodic corrosion of a platinum electrode is still lacking. Here, we present results of surface structural changes observed during cathodic polarization of a polycrystalline Pt electrode and single crystalline Pt(111) in acid electrolytes in the absence and presence of cations (Na+) by in situ electrochemical atomic force microscopy (EC-AFM) imaging. The electrolyte cation is proved to be a prerequisite to trigger cathodic etching of the polycrystalline Pt surface. Further examination of the evolution of electrochemical signals and distinct surface structural transformations of an atomically defined Pt(111) single-crystal electrode during cathodic corrosion reveals clearly that the roughening process commences at the under-coordinated sites of the Pt(111) surface. The created triangular-shape pattern, actually a 100-oriented pit in a 111-terrace, grows primarily laterally in the initial regime, while prolonged cathodic corrosion leads to the existing etching pits growing in depth until ultimately they coalesce with each other, generating a highly roughened surface.

Timeliness of Correcting Baseline Error in Wide-Swath Altimeter Based on Reference Topography Data

The baseline error is a primary error source of the wide-swath altimeter, directly related to the cross-track distance, and can lead to serious height errors at the swath’s outer edge. Cross-calibration using discrepancies with reference data can effectively estimate and correct the baseline error. However, building a reference surface that accurately describes the sea surface at the observation time is necessary to use this cross-correction method. The dynamic ocean environments where the sea surface structure changes over time are challenging. This paper proposes a method for constructing reference topography data (RTD) based on multi-source data products to correct the baseline error of the wide-swath altimeter. The effectiveness of the proposed method is evaluated using HYCOM ocean model data to assess the timeliness of the baseline error correction. The results demonstrate that using RTD at the observation time of the wide-swath altimeter can significantly correct the baseline error. The RMSE of the corrected sea surface height (SSH) in different regions is typically between 1~2 cm, except in some regions with strong currents where the RMSE is approximately 3~4 cm. However, the time interval between the RTD and the observation time of the wide-swath altimeter can affect the accuracy of the baseline error correction. The timeliness of this correction is influenced by the variability of SSH in different regions. In regions with relatively slow SSH changes near the equator, the effective time based on HYRTD and MORTD can basically reach more than 7 days. In regions where the SSH changes more rapidly, the correction result may no longer be reliable in only 1~3 days.

An analysis of regional carbon stock response under land use structure change and multi-scenario prediction, a case study of Hefei, China

As the largest global carbon pool system, terrestrial ecosystems have an important role to maintain the stability of ecosystems. Human activities affect the structural changes in the ground surface and interfere with terrestrial ecosystem evolution, and consequently, carbon stock is changed in the region. Therefore, forecasting future carbon stock changes under different land use scenarios has important research implications for promoting stable evolution and cycling of terrestrial ecosystems. This study is conducted with the land use data from 2000 to 2020, and incorporates the Patch-generating Land Use Simulation model with the Integrated Valuation of Ecosystem Services and Trade-Offs model to analyze the changes in land use in Hefei, and its influence on the carbon stock in Hefei in various scenarios. During the study period, the mutual conversion between different land types in Hefei City made the land structure change within the study area more significant. The rapidly evolving surface structure is the reason for the decrease of carbon storage in terrestrial ecosystems, with a cumulative decrease of 1.2 × 108 t. The spatial distribution in carbon storage in the study area shows a distribution pattern of low in the north and high in the south. The high carbon storage area is obviously banded in the study area. The area with obvious changes in surface structure has more obvious changes in carbon storage. Compared with the natural development scenario, the downward trend of carbon storage in the ecological protection scenario and the comprehensive development scenario has slowed down due to the restrictions on the structural transformation of land types and the implementation of relevant ecological protection policies. Therefore, this study will support the future management and policy making of Hefei City with the background of China's “double carbon” target and the significant position of Hefei City.

New Insights into Cation- and Temperature-Driven Protein Adsorption to the Air–Water Interface through Infrared Reflection Studies of Bovine Serum Albumin

The chemistry and structure of the air-ocean interface modulate biogeochemical processes between the ocean and atmosphere and therefore impact sea spray aerosol properties, cloud and ice nucleation, and climate. Protein macromolecules are enriched in the sea surface microlayer and have complex adsorption properties due to the unique molecular balance of hydrophobicity and hydrophilicity. Additionally, interfacial adsorption properties of proteins are of interest as important inputs for ocean climate modeling. Bovine serum albumin is used here as a model protein to investigate the dynamic surface behavior of proteins under several variable conditions including solution ionic strength, temperature, and the presence of a stearic acid (C17COOH) monolayer at the air-water interface. Key vibrational modes of bovine serum albumin are examined via infrared reflectance-absorbance spectroscopy, a specular reflection method that ratios out the solution phase and highlights the aqueous surface to determine, at a molecular level, the surface structural changes and factors affecting adsorption to the solution surface. Amide band reflection absorption intensities reveal the extent of protein adsorption under each set of conditions. Studies reveal the nuanced behavior of protein adsorption impacted by ocean-relevant sodium concentrations. Moreover, protein adsorption is most strongly affected by the synergistic effects of divalent cations and increased temperature.