Partial Pressure Research Articles

Comment on “Clinically-relevant reductions in oxygen partial pressure as possible contributor to cardiovascular benefits of sauna practice”

Comment on “Clinically-relevant reductions in oxygen partial pressure as possible contributor to cardiovascular benefits of sauna practice”

Formation of aluminum nitride in dross by contact-diffusion reaction during aluminum recycling

Secondary aluminum dross is a solid waste after aluminum extraction from the slag produced during aluminum recycling. It is classified as a hazardous waste due to the high content of active aluminum nitride (AlN). This work studied the thermodynamics and kinetics of AlN formation in aluminum dross. Aluminum tends to react with N2 to form AlN, when the partial pressure of nitrogen (N2) is much greater than that of oxygen (O2) (PN2≫PO2) in thermodynamics. Additionally, the reaction between aluminum and N2 is accelerated with the increasing temperature. Approximately 36.37% of aluminum was transformed into AlN at 700°C according to kinetic analysis. Aluminum recycling involves smelting, refining, and dross processing. The dross produced from these different processes has various compositions and hazardous properties. The formation mechanism of AlN from the three processes was revealed based on the thermodynamic and kinetic analyses. The reaction mechanisms in these processes were identified as surface contact reaction, internal and surface contact reaction, and rotational surface contact reaction between the aluminum melt and N2, respectively. X-ray diffraction (XRD) and electron probe microanalysis (EPMA) analyses were used to determine the phase and composition of the aluminum dross. The nitrogen content in the aluminum dross from smelting, refining, and dross processing was found to be 3.3%, 5.2%, and 9.6%, respectively. The monthly dross production were 276.3 tons, 22.7 tons, and 318.2 tons, respectively, according to statistics. It was calculated that the nitrogen generated in the three process was 9.12 tons, 1.18 tons, and 20.25 tons, respectively. Therefore, dross processing is the primary source of AlN. A rapid dross processing method with small-scale vertical stirring was proposed to shorten the reaction between the aluminum melt and N2, thereby reducing AlN formation. This work could provide guidance for reducing hazardous AlN in aluminum dross and optimizing the aluminum recycling process.

On the product phases and the reaction kinetics of carbothermic reduction of UO2+C at relatively low temperatures

The synthesis of UC using carbothermic reduction of UO2 and C mixtures has been well studied at high temperatures. However, the product phase behavior of carbothermic reduction at low temperatures (≤1773 K) is not well studied. Such a study is important as low temperatures permit single phase UC synthesis without forming secondary higher carbides, and it further supports the knowledge base of the process that needs to be used for transuranic elements such as plutonium that have high vapor pressures at elevated temperatures. Therefore, a low temperature carbothermic reduction of two different C/UO2 molar ratios under inert and reducing environments have been studied here. Two different sample holding crucibles, alumina (Al2O3) and graphite, were also used here to differentiate the hypostoichiometric (UC1-a) and oxygen dissolved (UC1-xOx) uranium monocarbide phases adding more details on the two systems. Also, the reaction kinetics involved in the formation of UC via the carbothermic reduction of UO2+C using product phases instead of evolved gases such as carbon monoxide is reported here. Under inert atmospheres but with significant oxygen partial pressures, the low temperature carbothermic reduction of UO2+C produced up to 90 wt.% UC1-xOx type oxycarbides as was confirmed by Xray powder diffraction. Reducing Ar-4%H2 environments at these temperatures were not successful in synthesizing UC as it reduces the amount of C required for the carbothermic reduction, leaving UC phase at a non-equilibrium state. Inert atmospheres with low or negligible oxygen partial pressures on the other hand produced near stoichiometric UC at high phase purity, especially at 1673 – 1773 K temperature range. An activation energy of 377±75 kJmol-1 was also calculated using product phase concentrations of the carbothermic reduction of UO2+C under these inert Ar(g) atmospheres.

Synthesis of Sn-catalyzed Ge nanowires and Ge/Si heterostructures via a gradient method

In this study, we investigate the growth of Ge nanowires (NWs) using a gas supply gradient method during plasma-enhanced chemical vapor deposition (PECVD), focusing on the effects of GeH4 partial pressure and total chamber pressure on NWs morphology. By adjusting either the GeH4 flow rate or the total pressure, we explored a gradient method to manipulate the growth process. Scanning electron microscopy (SEM) images revealed that, even with constant GeH4 partial pressure, variations in total pressure significantly influenced NWs diameter and structure. Furthermore, elemental mapping and compositional analysis demonstrated the presence of a Ge/Si heterostructure with a Sn catalyst at the apex and an amorphous Si layer encapsulating the NW surface.

Highly efficient CO2 capture by a non-aqueous amine-based absorbent of 3 aminopropanol/polyethylene glycol 200: Experimental and computational simulation

In the present work, a novel non-aqueous 3-aminopropanol/polyethylene glycol 200 (3AP/PEG200) absorbent for efficient carbon dioxide (CO2) capture was designed using environment-benign and non-toxic polyethylene glycol 200 (PEG200) as an alternative to water. The mechanism, physical, thermodynamic, and kinetic properties of absorption process was investigated through a combination of experimental and multi-scale computational simulation approaches including molecular dynamics (MD) simulation and quantum chemical (QC) calculations. It was found that the addition of PEG200 not only enhanced the thermal stability of the absorbent, but also did not significantly increase the viscosity. In addition, kinetic studies revealed that the absorption process conforms to a pseudo-first-order equation, with the activation energy (Ea) value of 20.40 kJ/mol, significantly lower than that of the benchmark 30 % monoethanolamine (MEA) aqueous solution used in industrial CO2 capture. Furthermore, the enthalpy change (ΔH) and entropy change (ΔS) values were found to be more negative than those of other liquid absorption systems, indicating that the 3AP/PEG200 absorbent is favorable for CO2 absorption even at low partial pressures. Most importantly, the absorption system exhibited good regeneration capability, as demonstrated by five absorption–desorption cycle experiments. In conclusion, the non-aqueous 3AP/PEG200 absorbent exhibits low viscosity, high thermal stability, enhanced absorption capacity, and excellent cyclic performance, positioning it as a promising candidate for CO2 absorption in industrial applications.

Numerical simulation of the temperature excursions of porous substrates during atomic layer deposition

Atomic layer deposition (ALD) processes are usually highly exothermic. For ALD on substrates with high specific surface area, the reaction heat per ALD cycle may lead to a substantial temperature rise of the substrates. The novelty of this study lies in quantifying the temperature excursions of porous substrates during ALD via numerical simulation and further addresses the issue of tuning this type of thermal effect. A comprehensive model has been developed and validated to investigate the ALD thermal effect with accounting for the roles of the precursor transport phenomena within the ALD reactor system, and the coupling among the precursor diffusion, heat transfer, film deposition, reaction heat generation within the porous substrates. The results show that the thermal effect of the sub-saturated ALD can change with different substrate thickness, precursor partial pressure profile, heat transfer coefficient, and kinetic parameters. In contrast, for saturated ALD with adiabatic condition, the maximum temperature rise of the substrate is a deterministic value, independent of the substrate thickness and precursor partial pressure profile. The thermal effect with the porous substrates can influence the ultimate deposit amount and its distribution for sub-saturated ALD and change the time required for attaining saturation for saturated ALD. The temperature rises of certain common substrates during typical half-ALD cycles have been simulated to demonstrate the capability of the present model in predicting the thermal effect of ALD.

Amorphous NiO nanopyramids with superior electrochromic energy storage properties

In this work, amorphous NiO nanopyramid film has been obtained by using the pulsed magnetron sputtering technique. The uniform amorphous NiO nanostructures exhibit significant electrochromic modulation efficiency in the visible and near-infrared ranges, achieving a high modulation efficiency of 60.73 % at 550 nm and 21.58 % at 1500 nm. It exhibits rapid response time (coloring takes 2.4 s, and bleaching takes 1.0 s) and significant coloring efficiency (43.23 cm2C-1). Moreover, amorphous NiO nanopyramid film displays promising properties of energy storage. The NiO nanopyramid film shows high areal capacitance (7.08 mF/cm2), along with satisfying rate capability. The alteration in the electrode color offers a convenient method for monitoring the quantity of energy stored. Furthermore, the microstructure characteristic, degree of crystallization and electrochemical performance of the NiO film are significantly influenced by both oxygen partial pressure and sputtering time. These findings highlight the potential of employing this bifunctional amorphous NiO nanopyramid film in diverse advanced nanodevices, encompassing electrochromic energy storage applications with superior performance.

Electrical properties and redox stability of series novel high-entropy Bi2VO5.5-based oxides

Exceptional high ionic conductivities have been well documented in the Bi2VO5.5-based materials. However, the poor phase and redox stabilities under a reducing atmosphere hindered their wide applications. Herein, with the aim to improve the phase and redox stabilities under a reducing atmosphere, a high-entropy strategy of multiple-metal-doping was applied to prepare series Bi2V1–4x(GaSiTaZr)xO5.5-δ (0 ≤ x ≤ 0.1) materials by a traditional solid state reaction method. The results revealed that multiple-metal-doping could stabilize the tetragonal phase of Bi2VO5.5 to room temperature and shown good phase and structural stabilities under inert or high oxygen partial pressure atmospheres, as well as pure oxide ion conduction which was about two orders of magnitude higher than that of the parent material, e.g. ∼2.0×10−2 S/cm at 400 ºC for the x = 0.05 sample while ∼1.5×10−4 S/cm for the x = 0 sample. Although the Bi2V1–4x(CuNiNbTi)xO5.5-δ materials would still be readily reduced under a reducing environment and introduce strong electronic conduction, the phase stability was apparently improved. Thus, improving the redox stability and suppressing the electronic conduction of the stabilized Bi2VO5.5-based materials under a reducing atmosphere is still the direction we should strive for.

Improving Liquid Desiccant Dehumidifiers through Square Baffle Plate Design and Nanofluid Innovation

Enhancing the performance of the liquid desiccant dehumidifier (LDDs) is pivotal, with mass transfer playing a significant role. Compared to the previous method, using a baffles plate improved liquid desiccant dehumidification performance. The study utilized an aqueous solution containing nanocarbon tubes (NCTs) in LiCl/H2O as the desiccant, cascading over baffles plate with a square profile. The performance of this system was determined using numerical methods. The concentrations of NCTs ranged from 0.03% to 0.5% by weight. Furthermore, this paper investigates the impact of nanoparticles and parameters, including flow rates, solution concentration, humidity, solution temperature, etc. on the analysis through Computational Fluid Dynamics (CFD) simulation. The study shows a 29% increase in moisture removal and humidity change, along with a 15.57% improvement in film thickness. These findings are underpinned by the principle of a reduced in contact angle from 57° to 29°, resulting in reduced partial pressure of water vapor from the solution, thereby enhancing the mass transfer mechanism. Consequently, the utilization of baffles plate demonstrates a significant improvement in the moisture removal performance of the LDDs.

Preparation and Electrochemical Performance of Alkaline Earth Metal-Doped Nd2Ce2O7 Proton Conductor Hydrogen Separation Membranes

Nd2Ce2O7 is a rare earth oxide with a fluorite structure and exhibits proton conductivity. Alkaline earth metals (Mg, Ca, Sr, Ba) doped Nd2Ce2O7 powders were synthesized using the citrate sol-gel method. The doped samples retain the fluorite structure, and enhanced oxygen vacancy concentration. Notably, Nd1.85Mg0.15Ce2O7-δ exhibited the highest oxygen vacancy concentration, reaching an electrical conductivity of 2.91×10-2 S•cm-1 in a humid atmosphere of 20%H2 and 80%N2 at 900°C. Hydrogen separation membranes were fabricated using alkaline earth metal-doped Nd2Ce2O7 as the proton-conducting phase and Pt as the electron-conducting phase. The results indicated that Pt-Nd1.85Mg0.15Ce2O7-δ had the optimal hydrogen permeation flux, reaching 8.35×10-9 mol•cm-2•s-1 at 900°C. It demonstrated short-term stability in environments containing CO2 and H2O, and an increase in temperature and hydrogen partial pressure on the feed side enhanced hydrogen permeation, highlighting its potential as a hydrogen separation membrane material.

Seasonal variation of CO2 air-sea flux and effects of warming in the Kuroshio current of the East China Sea

The partial pressure of CO2 (pCO2) and associated CO2 air-sea flux exhibit highly heterogeneous temporal and spatial patterns in ocean margins. In this study, we analyzed a three-year time-series data sampled during 2011–2014 along the Kuroshio Current within the East China Sea (ECS) to investigate the seasonal pattern of carbonate chemistry and CO2 air-sea fluxes. Annually, the Kuroshio within the ECS operates as a net CO2 sink at approximately 1.3 mol C m−2 yr−1, less than estimates over the ECS shelf (~1.8 mol C m−2 yr−1). The thermal control of pCO2 makes the Kuroshio a strong CO2 sink in winter, with a transition to net-neutral, or a weak CO2 source in summer. On an interannual basis, however, the seasonal CO2 air-sea fluxes in the Kuroshio may undergo potential shifts if warming conditions continue.

Impact of oxygen fugacity on the atmospheric structure and emission spectra of ultra-hot rocky exoplanets

Context. Atmospheres above lava-ocean planets (LOPs) hold clues related to the properties of their interiors, based on the expectation that the two reservoirs are in chemical equilibrium. Furthermore, such atmospheres are observable with current-generation space- and ground-based telescopes. While efforts have been made to understand how emission spectra are related to the composition of the lava ocean, the influence of oxygen fugacity has yet to be examined in a self-consistent way. Aims. Here, we investigate the sensitivity of atmospheric emission spectra of LOPs to key geochemical parameters, namely, temperature (T), composition (X), and oxygen fugacity (fO2). We also consider the precision involved in recovering these spectra from observations of hot, rocky exoplanets. Methods. We considered ‘mineral’ atmospheres produced in equilibrium with silicate liquids. We treated fO2 as an independent variable, together with T and X, to compute equilibrium partial pressures (p) of stable gas species at the liquid-gas interface. Above this boundary, the atmospheric speciation and the pressure–temperature structure are computed self-consistently to yield emission spectra. We explored a wide array of plausible compositions, oxygen fugacities (between 6 log10 units below and above the iron-wüstite buffer, IW), and irradiation temperatures (2000, 2500, 3000, and 3500 K) relevant to LOPs. Results. We find that SiO(g), Fe(g) and Mg(g) are the major species below ~IW, ceding to O2(g) and O(g) in more oxidised atmospheres. The transition between the two regimes demarcates a minimum in total pressure (P). Because p scales linearly with X, emission spectra are only modest functions of composition. By contrast, fO2 can vary over orders of magnitude, thereby causing commensurate changes in p. Atmospheres outgassed from reducing melts exhibit intense SiO emission, creating a temperature inversion in the upper atmosphere. Conversely, oxidised atmospheres have lower pSiO and lack thermal inversions, with their resulting emission spectra mimicking that of a black-body. Consequently, the intensity of SiO emission relative to the background, generated by MgO(g), can be used to quantify the fO2 of the atmosphere. Depending on the emission spectroscopy metric of the target, deriving the fO2 of known nearby LOPs is possible with a few secondary occultations observed by JWST.

Multiplet XPS analysis of the Mn 2p for Mn3O4 thin films

In this work, we performed a detailed analysis of the x-ray photoemission spectroscopy (XPS) of the Mn 2ppeak for Mn3O4(001) thin films. This is a challenging task since Mn3O4is composed of two different cations, Mn2+at tetrahedral and Mn3+at octahedral sites, which both contribute to the XPS spectra. The oxide spectra consist of many multiplets arising from the angular momentum coupling of the open Mn 2pand 3dshells, thus increasing the spectrums' complexity. Moreover, the energy spacing and intensities of the different multiplets also reflect the covalent mixing between Mn 3dand O 2pshells. However, we show that a detailed analysis, which provides relevant information about the cations in the oxide structure, is possible. We prepared experimentally different Mn3O4films on Au(111), and their structure was monitored with the diffraction pattern obtained with low-energy electron diffraction. The Mn 2pspectra were fit, guided by cluster model theoretical predictions, and checked for films prepared at different oxygen partial pressures. Therefore, we could observe the Mn2+and Mn3+cations' relative concentration in the Mn 2pmains peaks.

Investigation of arc spot splitting behavior on aluminum, titanium, and their alloy cathodes under different gas flows

This paper presents an experimental study on the spot splitting behavior of aluminum, titanium, and their alloy cathodes during electric arc discharge. Utilizing high-speed digital cameras, we dynamically captured the splitting motion of cathode arc spots and analyzed their behavior under different pressures of argon, nitrogen, and oxygen. The study also examined the effects of pulsed arc current parameters on spot splitting. We observed a ringlike expansion of pulsed arc spots during splitting, with aluminum cathodes showing better performance than titanium in promoting spot splitting and stabilizing the subsequent motion of the split spots. Oxygen was found to enhance spot splitting more effectively than nitrogen. Furthermore, the parameters of the pulsed arc can control the extent of spot splitting and expansion. These findings provide valuable insights for optimizing arc parameter control in metal film deposition processes.

Preparation and Characterization of Materials for Low- to Intermediate-Temperature CO2 Adsorption

Global carbon dioxide emissions are rising and the use of fossil fuels in several sectors are the leading causes. As global population and economies continue to grow significantly, the most practical method of lowering such emissions is to capture CO2. Although other technologies are more developed, adsorption is very promising and has attracted much attention. To ensure this technology’s success, it is essential to have suitable CO2 adsorbent materials. In this work, several new hydrotalcites (HTs) with different initial concentrations of ion precursors were prepared for the first time by the co-precipitation method—it was possible to verify that the ion concentrations influence the characteristics of the materials. The prepared HTs were characterized by thermogravimetric analysis (TG), X-Ray diffraction (XRD), surface area measurements and temperature-programmed desorption of CO2 (TPD-CO2) to relate their CO2 capture capacity to their physicochemical properties; the CO2 adsorption equilibrium isotherms were determined at 35 and 300 °C for the prepared samples, as well as for some commercial materials: magnesium oxide, calcium oxide, aluminium oxide and Zeolite 13X. After determining which materials present the best CO2 adsorption capacity, these were submitted to adsorption-desorption cycles to study their stability. The main objective of the work was to prepare and study different CO2 adsorbents for processes that are carried out at low and intermediate temperatures. From the experimental results, it was possible to conclude that the Zeolite 13X showed the best capacity at 35 °C, 3.38 mmol·g−1 (@ pCO2 = 1 bar), and a prepared calcined HT (c-HT2) was the best at 300 °C, 0.97 mmol·g−1 (@ pCO2 = 1 bar). Moreover, it seems there is an optimum initial concentration of the ions’ solutions for the tested HTs, which depends on the final application—c-HT1 showed a better capacity at 35 °C and c-HT2 at 300 °C. From the adsorption-desorption cycles—performed at 35 and 300 °C with the best materials using a magnetic suspension microbalance at 1 bar of CO2 partial pressure —, a working cyclic capacity of 2.69 mmol∙g−1 was achieved by the Zeolite at 35 °C; in turn, c-HT2 showed a working cyclic capacity of 0.79 mmol∙g−1 at 300 °C.

Green solvents assisted de-novo synthesis and defect-engineered UiO-66 for improved CO2 adsorption and kinetics- experimental and DFT approach

The CO2 concentration in the atmosphere is increasing at an alarming rate, which is causing distress to human society and the natural environment. Adsorption is one of the most widely used methods of removing CO2 from flue gases, which reduces its adverse effects on our environment. For adsorption purposes, a facile green solvent-assisted de-novo synthesis approach was developed to construct a UiO-66′s structure to target CO2 at low pressure due to the partial pressure of CO2 in flue gases in the atmosphere (0.01⁓0.02 MPa). In the de-novo synthesis approach, a combination of various types of modulators and deep eutectic solvents (DES) are utilized to graft structural defects and induce quantitative and dispersive deep eutectic solvents onto the UiO-66 structure, respectively. The green solvent-assisted de-novo synthesis approach helped to tune all three structural parameters and preserve extra open metal sites (Lewis acid and Bronsted basis sites) with active NH2 and OH groups for improved CO2 adsorption and kinetics under flue gas conditions (CO2/N2=15/85 %). In comparison to the parent UiO-66, de-novo synthesized ChClPropx5@UiO-66 showed increased CO2 uptake (65.04 mg g-1) by 73 % at 0.15 bar and 25 °C, and the cyclic capacity remained almost similar over 10 consecutive cycles with an almost 94 % retention rate. After 3 times of regeneration at 105 °C under N2 atmosphere, the sample reserved almost similar adsorption capacity and could be recycled without dropping CO2 uptake. The strong and rapid interaction between guest CO2 and de-novo synthesized UiO-66 was confirmed by pseudo-first-order and second-order kinetics with reaction rate constants of 0.00026 and 0.00259, respectively. Furthermore, through periodic Density Functional Theory (DFT) calculations, a variety of linker defects are engineered onto the UiO-66 structure to preserve more open metal sites. For each of the engineering defects, free energies, adsorption energies, and the interaction of CO2 molecules on defect structures with bond length (Ɩ, Å) and bond angle (θ˚) are calculated for the most stable structures of UiO-66.

Correlations between coagulation abnormalities and inflammatory markers in trauma-induced coagulopathy.

In multiple trauma patients, the occurrence of trauma-induced coagulopathy (TIC) is closely associated with tissue damage and coagulation function abnormalities in the pathophysiological process. This study established a multiple trauma and shock model in Sprague-Dawley (SD) rats and comprehensively utilized histological staining and radiographic imaging techniques to observe injuries in the intestine, liver, skeletal muscles, and bones. Monitoring activated partial thromboplastin time (APTT), platelet (PLT) count, respiratory rate, blood pressure, and other physiological indicators revealed time-dependent alterations in coagulation function and physiological indicators. Enzyme-linked immunosorbent assay (ELISA) measurements of inflammatory factors Tumor Necrosis Factor-alpha (TNF-α), Interleukin-6 (IL-6) and vascular endothelial injury marker (Syndecan-1) were also conducted. Experimental results demonstrated significant changes in tissue structure after multiple traumas, although widespread necrosis or hemorrhagic lesions were not observed. There were time-dependent alterations in coagulation function and physiological indicators. ELISA measurements showed a strong positive correlation between the significant decrease in PLT count and the increase in TNF-α and IL-6 concentrations. The study provides crucial information for the early diagnosis and treatment of TIC. The findings suggest that structured monitoring of coagulation and inflammatory indicators can help in understanding the pathophysiological changes and aid in the management of TIC in multiple trauma patients.

Sodium propionate ameliorates lipopolysaccharide-induced acute respiratory distress syndrome in rats via the PI3K/AKT/mTOR signaling pathway.

Acute respiratory distress syndrome (ARDS) is a severe lung disease characterized by significant hypoxemia, which impairs the oxygen supply necessary for optimal lung function. This study aimed to investigate the effects of sodium propionate (SP), the primary end product of intestinal flora fermentation of dietary fiber, on lipopolysaccharide (LPS)-induced ARDS in rats. The rats were treated with SP, after which the lung wet/dry ratio, arterial partial oxygen pressure (PaO2), levels of pro- and anti-inflammatory cytokines, tight junction proteins ZO-1 and Occludin, as well as LC3 and phosphorylated PI3K (p-PI3K)/p-AKT/p-mTOR protein levels, were measured. Additionally, histopathological analysis was conducted. The results indicated that SP effectively alleviated arterial hypoxemia in rats and mitigated the pathological damage to both intestinal and lung tissues caused by LPS. Notably, SP significantly reduced the levels of inflammatory factors TNF-α and IL-6 in the blood and bronchoalveolar lavage fluid (BALF) of ARDS rats, while increasing the concentration of the anti-inflammatory factor IL-10. Furthermore, SP inhibited the activation of the PI3K/AKT/mTOR signaling pathway and enhanced the LC3II/LC3I ratio in lung tissue. Therefore, SP may improve LPS-induced ARDS in rats by inhibiting the activation of the PI3K/AKT/mTOR signaling pathway, promoting autophagy, decreasing the production and release of inflammatory markers, and reducing alveolar epithelial damage.

Distribution and air-sea fluxes of CO2 in coral reefs in the Greater Bay Area, China

From May to June 2021, the sea surface partial pressure of CO2 (pCO2) and air-sea CO2 fluxes around six coral reefs in the Great Bay Area (contain Pearl River Estuary (PRE) and Daya Bay) were investigated respectively. The distribution of seawater pCO2 around different coral reefs were quite different. The seawater pCO2 of the coral reef region of Daya Bay is relatively high, ranging from 268 to 496 µatm. In contrast, the pCO2 levels in the coral reef area of the PRE are significantly lower, with measurements ranging from 84 to 374 µatm. Further analysis showed that the distribution of seawater pCO2 around the coral reefs of the PRE were mainly affected by biological metabolism and seawater mixing, while those in Daya Bay were mainly controlled by temperature and seawater mixing. During the survey, the three coral reefs in the PRE were affected by algal blooms showing strong sinks of atmospheric CO2 ranging from −12.3 to −19.2 mmol CO2 m−2 d−1. However, the difference between the seawater pCO2 and atmospheric pCO2 in the three coral reefs of Daya Bay were all very small, and they were weak sources or sinks of atmospheric CO2, respectively.

Key Sputtering Parameters for Precursor In2O3 Films to Achieve High Carrier Mobility.

Owing to their extremely high carrier mobility (μ) of >100 cm2/(V s) and suitable low carrier concentrations, transparent conducting films of solid-phase crystallized H-doped In2O3 (spc-IO:H) exhibit high conductivity with high optical transparency over a broad frequency range. These properties can be attributed to solid-phase crystallization of the amorphous precursor film. Therefore, the development of high-quality spc-IO:H films requires the deposition conditions of the precursor films to be optimized. This study systematically investigates the effects of three key sputtering parameters, namely, water vapor partial pressure (PH2O), radio frequency magnetron sputtering power (PRF), and flow ratio of O2 to total sputter gas (fO2) on the crystallographic texture evolution of spc-IO:H films during solid-phase crystallization. In addition, the carrier transport in the resulting films is examined. PH2O, PRF, and fO2 are found to be indispensable for producing high-mobility (>100 cm2/(V s)) spc-IO:H films. Furthermore, it is found that introducing a small amount of PH2O during deposition, a lower PRF, and a suitable fO2 facilitates the formation of precursor films having a lower crystallite density. Moreover, after annealing at a temperature of 200 °C, the IO:H precursor films with a lower crystallite density are found to have larger crystal grains. However, the μ values of the postannealed IO:H films are mainly correlated with the stoichiometric deviation.