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Hollow molybdenum phosphate microspheres derived from molybdenum phosphonates exhibit an excellent electrocatalytic activity for simultaneous electrochemical N2-to-NH3 and power ...generation in the aqueous Al-N2 battery during discharge process.
•Hollow spherical molybdenum phosphates derived from molybdenum phosphonates were prepared.•MoPi/HSNPC exhibits high performance toward NRR in alkaline electrolyte.•The phosphate groups of MoPi/HSNPC as the active contributor for NRR.•Aqueous Al-N2 battery was fabricated for simultaneous NH3 production and power generation during discharge process.
Developing controllable and facile devices beyond traditional N2 electrocatalysis cell is critical for the commercial production of NH3 through electrochemical N2 reduction reaction (NRR) under ambient condition. Herein, the aqueous Al-N2 battery, fabricated by coupling the hollow molybdenum phosphate microspheres as cathode and the Al plate as anode within KOH electrolyte, was assembled for the electrochemical reduction of N2 to NH3 and power generation during the discharge process. Benefiting from the desirable active components and the structural advantages, the hollow molybdenum phosphate microspheres derived from molybdenum phosphonates exhibit high NH3 yield rate of 18.66 μg h−1 mgcat.-1 with the Faradaic efficiency of 9.04% at − 0.2 V vs. reversible hydrogen electrode, associated with excellent robustness for cycling operation. The Mo4+ species of molybdenum phosphates are verified as the active components for NRR through the associative reaction pathway. When measured in the flow battery configuration with flowing N2 during discharge, the formed Al-N2 battery delivers the high NH3 yield rate of 13.47 μg h−1 mgcat.-1 and Faradaic efficiency of 5.06% at 1.0 V vs. Al(OH)4−/Al, which can be stably maintained in discharge cycling tests over 20 cycles. Moreover, the peak power density of 2.37 mW cm−2 and the long-term energy output are still achieved by this Al-N2 battery during the discharge process. This work not only supplies some guidelines for the rational design of active NRR electrocatalysts from earth-abundant elements but also provides a reasonable and promising devices for efficient electrochemical N2 fixation and power generation.
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•The regulatory mechanism of OH on lipid accumulation was revealed.•The high coefficient of 0.901 was observed between OH level and lipid content.•A Fenton-like reaction was used to ...induce cellular OH level.•The lipid accumulation was promoted by OH.•Most DEGs involved in fatty acid and glycerolipid biosynthesis were up-regulated.
An increase in the total lipid content in algal cells under stress conditions is often accompanied by an increase in reactive oxygen species (ROS). However, the link between these two events is unclear. In this study, the regulatory mechanism of ROS formation on lipid accumulation in C. pyrenoidosa was investigated using a Fenton-like reaction. A high Spearman correlation coefficient of 0.901 was obtained between the Hydroxyl radical (OH) level and lipid content. Importantly, the increase in the total lipid content was clearly coupled with a significant increase in the intracellular OH concentration rather than increases in the H2O2 and O2− concentrations. Transcriptome data confirms that most of the differential expression genes (DEGs) involved in fatty acid and glycerolipid biosynthesis were up-regulated by the increased OH under stress conditions. These results reveal that lipid accumulation in algal cells was promoted by OH.
A highly efficient and stable electrocatalyst with the novel heterostructure of Co-embedded and N-doped carbon nanotubes supported Mo2C nanoparticles (Mo2C/NCNTs@Co) is creatively constructed by ...adopting the one-step metal catalyzed carbonization–nitridation strategy. Systematic characterizations and density functional theory (DFT) calculations reveal the advanced structural and electronic properties of Mo2C/NCNTs@Co heterostructure, in which the Co-embedded and N-doped CNTs with tunable diameters present electron-donating effect and the work function is correspondingly regulated from 4.91 to 4.52 eV, and the size-controlled Mo2C nanoparticles exhibit Pt-like 4d electronic structure and the well matched work function (4.85 eV) with I–/I3 – redox couples (4.90 eV). As a result, the conductive NCNTs@Co substrate with fine-tuned energy level alignment accelerates the electron transportation and the electron migration from NCNTs@Co to Mo2C, and the active Mo2C shows high affinity for I3 – adsorption and high charge transfer ability for I3 – reduction, which reach a decent synergetic catalytic effect in Mo2C/NCNTs@Co heterostructure. The DSSC with Mo2C/NCNTs@Co CE achieves a high photoelectric conversion efficiency of 8.82% and exceptional electrochemical stability with a residual efficiency of 7.95% after continuous illumination of 200 h, better than Pt-based cell. Moreover, the synergistic catalytic mechanism toward I3 – reduction is comprehensively studied on the basis of structure–activity correlation and DFT calculations. The advanced heterostructure engineering and electronic modulation provide a new design principle to develop the efficient, stable, and economic hybrid catalysts in relevant electrocatalytic fields.
The fundamental understanding of ORR mechanism and active sites in M−N/C catalysts is introduced, and various precursors of M−N/C catalyst with the strategies for design and optimization are ...reviewed.
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It is of vital importance to accelerate the sluggish oxygen reduction reaction (ORR) process at the cathode with earth-abundant metal-based catalysts for the commercialization of low-temperature polymer electrolyte membrane fuel cells. In consideration of high catalytic activity, long-term stability and low cost of potential ORR electrocatalysts, transition metal species have attracted much interest and transition metal-nitrogen-carbon (M−N/C, M = Fe, Co, Ni, Mn, etc.) catalysts have been widely considered as the most promising non-precious metal catalysts for ORR. Herein, the fundamental understanding of ORR catalytic mechanism and the identification of active centers are briefly introduced, and then different M−N/C catalysts classified by precursors with the strategies for design and optimization are highlighted. The challenges and possible opportunity for future development of high-performance ORR catalysts are finally proposed.
Superconducting and topological states are two most intriguing quantum phenomena in solid materials. The entanglement of these two states, the topological superconducting state, will give rise to ...even more exotic quantum phenomena. While many materials are found to be either a superconductor or a topological insulator, it is very rare that both states exist in one material. Here, we demonstrate by first-principles theory as well as scanning tunnelling spectroscopy and angle-resolved photoemission spectroscopy experiments that the recently discovered 'two-dimensional (2D) superconductor' of single-layer FeSe also exhibits 1D topological edge states within an energy gap of ∼40 meV at the M point below the Fermi level. It is the first 2D material that supports both superconducting and topological states, offering an exciting opportunity to study 2D topological superconductors through the proximity effect.
Propylene is one of the most important building blocks for the chemical industry. Traditional propylene production, which is based on oil-based cracking processes, is being challenged by the drastic ...changes in the global energy situation. The nonoxidative propane dehydrogenation (PDH) technique has emerged as a high-value-rising and promising alternative to traditional propylene production techniques due to the distinct price variance between propane and propylene. Although this technique has been commercialized for decades, thermally induced deactivation is still a big problem. Substantial progress has been made to inhibit the deactivation of propane dehydrogenation catalysts. In this review, we briefly introduce the mechanism of catalytic deactivation, including coke deposition and sintering of active compounds. The design strategies of PDH catalysts, focused on improving the catalytic stability and recyclability, are highlighted from the aspects of active site regulation, metal–support interaction enhancement, and support modification. Finally, the current status and prospects of future catalyst development are also discussed.
Intravenous thrombolysis is increasingly used in patients with minor stroke, but its benefit in patients with minor nondisabling stroke is unknown.
To investigate whether dual antiplatelet therapy ...(DAPT) is noninferior to intravenous thrombolysis among patients with minor nondisabling acute ischemic stroke.
This multicenter, open-label, blinded end point, noninferiority randomized clinical trial included 760 patients with acute minor nondisabling stroke (National Institutes of Health Stroke Scale NIHSS score ≤5, with ≤1 point on the NIHSS in several key single-item scores; scale range, 0-42). The trial was conducted at 38 hospitals in China from October 2018 through April 2022. The final follow-up was on July 18, 2022.
Eligible patients were randomized within 4.5 hours of symptom onset to the DAPT group (n = 393), who received 300 mg of clopidogrel on the first day followed by 75 mg daily for 12 (±2) days, 100 mg of aspirin on the first day followed by 100 mg daily for 12 (±2) days, and guideline-based antiplatelet treatment until 90 days, or the alteplase group (n = 367), who received intravenous alteplase (0.9 mg/kg; maximum dose, 90 mg) followed by guideline-based antiplatelet treatment beginning 24 hours after receipt of alteplase.
The primary end point was excellent functional outcome, defined as a modified Rankin Scale score of 0 or 1 (range, 0-6), at 90 days. The noninferiority of DAPT to alteplase was defined on the basis of a lower boundary of the 1-sided 97.5% CI of the risk difference greater than or equal to -4.5% (noninferiority margin) based on a full analysis set, which included all randomized participants with at least 1 efficacy evaluation, regardless of treatment group. The 90-day end points were assessed in a blinded manner. A safety end point was symptomatic intracerebral hemorrhage up to 90 days.
Among 760 eligible randomized patients (median IQR age, 64 57-71 years; 223 31.0% women; median IQR NIHSS score, 2 1-3), 719 (94.6%) completed the trial. At 90 days, 93.8% of patients (346/369) in the DAPT group and 91.4% (320/350) in the alteplase group had an excellent functional outcome (risk difference, 2.3% 95% CI, -1.5% to 6.2%; crude relative risk, 1.38 95% CI, 0.81-2.32). The unadjusted lower limit of the 1-sided 97.5% CI was -1.5%, which is larger than the -4.5% noninferiority margin (P for noninferiority <.001). Symptomatic intracerebral hemorrhage at 90 days occurred in 1 of 371 participants (0.3%) in the DAPT group and 3 of 351 (0.9%) in the alteplase group.
Among patients with minor nondisabling acute ischemic stroke presenting within 4.5 hours of symptom onset, DAPT was noninferior to intravenous alteplase with regard to excellent functional outcome at 90 days.
ClinicalTrials.gov Identifier: NCT03661411.
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•Fenton-SBR process was applied to treat HPAM-containing drilling wastewater.•COD, HPAM, NH4+-N, and TP in raw and treated wastewater were effectively removal.•The maximal COD and ...HPAM removal efficiencies were 98.35% and 87.58%.•HPAM structure analysis was performed using FT-IR and UV spectroscopy.•Functional microorganisms was determined by Illumina MiSeq Sequencing.
An efficient way to solve the environmental pollution deriving from hydrolyzed polyacrylamide (HPAM)-containing drilling wastewater is urgent. This work adopted a novel method coupling Fenton oxidation with sequencing batch reactor (SBR) to treat gas-field drilling wastewater successively. This Fenton-SBR process reduced COD, HPAM, NH4+-N and total phosphorus (TP) concentrations of drilling wastewater by 98.35%, 87.58%, 94.50% and 93.52%, respectively. While simulated HPAM wastewater with similar HPAM concentration to Fenton-oxidized drilling wastewater was treated only by biological process, and the COD and HPAM removal efficiencies reached 78.26% and 62.95%. The result indicates that the biodegradability of the drilling wastewater was enhanced after Fenton oxidation. Moreover, the analysis on microbial community structure indicates the dominant bacteria in treated drilling wastewater were different from that in treated simulated-wastewater. It can be considered the Fenton-SBR process possesses potential to be applied to treating the drilling wastewater.
Compared with wet anaerobic digestion, solid-state fermentation possesses many merits such as low water consumption, high biogas yield and low processing cost. In this work, co-producing biogas and ...humic acid (HA) by two-step solid-state fermentation was innovatively investigated using rice straw and pig manure as materials. The result indicates that C/N ratio, straw particle size, and total solid content (TS%) caused significant effects on the solid-state fermentation process. At the first step for anaerobic biogas fermentation, the optimal fermentation conditions included C/N ratio of 27.5, straw particle size of 0.85 mm and TS% of 25%. The maximal biogas productivity and methane content were up to 0.43 m3/(m3·d) and 64.88%, respectively. This means that biogas production was significantly improved by adjusting C/N ratio during the co-fermentation of rice straw and pig manure. Following, the digested residue was aerobically composted for HA biosynthesis to improve the fertilizer efficiency of the fermented substrate. The optimal aeration rate of 0.75 L/min was obtained, and the volatile solid (VS) degradation rate, HA content, and the germination index (GI) value were up to 19.16%, 100.89 mg/g, and 103.07%, respectively, which indicates that HA biosynthesis and compost maturity were significantly enhanced. Therefore, the co-production of biogas and HA using rice straw and pig manure as fermentation materials was achieved by adopting the two-step solid-state fermentation, and the bioconversion efficiencies of livestock manure and straw were significantly improved.
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•Two-step fermentation method for biogas and humic acid production was adopted.•Co-fermentation of rice straw and pig manure provided a suitable C/N for microbes.•Biogas production was enhanced by optimizing C/N ratio, particle size and TS%.•HA content and maturity were increased through aerobic compost at the second step.
This paper presents the detailed design and demonstration of a Ka-band single-chip transmit (TX)/receive (RX) front-end in 0.13-μm SiGe BiCMOS technology. The front-end includes single-pole ...double-throw (SPDT) switches, low-noise amplifier, loss compensation amplifiers (LCAs), phase shifter, and power amplifier. Distributed structures are utilized in gain amplifiers to ensure broadband performance while stacked structure is adopted in power amplifier to deliver high output power in the TX mode. A 5-b phase shifter with design strategies for low rms phase/gain errors serves as the common leg of the RX and TX paths. In the RX mode, measurements show a gain of 17 dB, an output P -1 dB of -1 dBm, an rms phase error less than 4°, and an rms gain error less than 0.6 dB with 0.528-W dc power from 30 to 40 GHz. In the TX mode, measurements show a gain of 14 dB, an output P -1 dB of 20.5 dBm, an rms phase error less than 3.7°, and an rms gain error less than 0.55 dB with 1.587-W dc power from 30 to 40 GHz. The whole front-end occupies 3.2 × 2.2 mm 2 including the testing pads. By choosing inductors and capacitors with reasonable values, designing a well-matched SPDT switch with high isolation, and optimum ordering of phase shift cells and LCAs in the phase shifter design, this TX/RX frontend achieves excellent rms phase/gain error performance without any trimming in a system-level measurement at Ka-band.
