Abstract Electrochemical nitrogen reduction reaction (NRR) for ammonia synthesis has attracted great interest in recent years, which presents a carbon‐free alternative to the energy‐intensive ...Haber–Bosch process. Besides, NRR also provides a promising coverage route of renewable energy since NH 3 is considered the second generation of hydrogen energy while possessing established technologies of liquefaction, storage, and transport. However, there are long‐term challenges in catalyst design for NRR due to its low intrinsic activity and unsatisfied selectivity. Fortunately, by conducting extensive explorations in this field, much progress is achieved in boosting the NRR performance. Herein, from a view of the atomic/electronic level, three promotion effects are summarized for NRR (i.e., electron effect, geometry effect, and ligand effect), which tackle the challenges of activity and selectivity. Representative studies with taking fully advantages of the promotion effects are reviewed, which realized remarkable NRR performance. Finally, the future research directions and prospects are discussed. It is highly expected that this review will enable the advancement of NRR catalysts and promote the further development of electrochemical NRR.
Low grade process heat and geothermal energy with temperatures typically below 100°C are significant untapped environmentally friendly resources for desalination. This article reports on a novel ...multi-effect distillation (MED) desalination process that is boosted by a multi-stage flashing process. Specifically the low grade heat first heats up the multi-effect distillation plant and is then maximally exploited through a multi-stage flashing process, with the produced steam of which being judiciously introduced into the multi-effect distillation plant for enhanced freshwater production. Compared with optimized conventional MED processes, the performance improvement is up to around 50% better in terms of freshwater production, with a modest increase in the pumping power consumption and 4% to 6% decrease in the specific capital cost.
A novel waste heat powered flash boosted MED system delivering 50% more freshwater. Display omitted
•A flash-boosted multi-effect distillation process has been developed.•The process maximally exploits the potential of waste sensible heat source.•40–50% more freshwater compared with conventional multi-effect distillation process.•Auxiliary power consumption only increases modestly by 22–34%.•4% to 6% decrease in the specific capital cost
The fundamental thermodynamic bound for the specific energy consumption (SEC) of seawater desalination is independent of mechanism and relates to work-driven processes (exemplified by reverse ...osmosis, RO). There is a corresponding method-independent constrained thermodynamic bound for heat-driven desalination, e.g., multi-effect and multi-stage flash distillation, along with thermal vapor compression. Similar constrained limits exist when the finite capacity of heat or work reservoirs must be accounted for. We elucidate basic insights and consequences of these mechanism-independent limits relative to the measured performance of the most efficient seawater desalination plants, specifically: (1) the dramatic differences in SEC between RO and thermal desalination as well as the degree to which each of them differs from their respective basic performance bounds, (2) the strikingly different dependence of the SEC of RO vs. thermal desalination on feedwater salinity and feedwater temperature, and (3) the magnitudes and sources of potential reductions in SEC. The SEC of nature's thermal desalination scheme (the solar-rainfall cycle) is also estimated.
•Full thermodynamic perspective for work-driven and heat-driven seawater desalination•Method-independent constrained thermodynamic bounds for specific energy consumption•Understanding how and why desalination technologies fall short of fundamental limits•Nature's thermal desalination scheme vis-à-vis commercial technologies
WO3 modified LiNi0.8Co0.1Mn0.1O2 materials were got by a wet method. Structure parameters, micromorphology, element distribution of the modified and bare NCM materials were compared by different ...detection methods, such as XRD, SEM, EDS and TEM. The results reveal that there was no significant change in morphology before and after modification, and the distribution of tungsten was relatively uniform. In addition, tungsten oxide surface modification layer does exist by TEM, FFT and XPS analysis, and affects the distribution and valence states of surface elements. Furthermore, it is found that the micro amount of tungsten oxide modified NCM material is beneficial to the improvement of rate performance and cycle stability, especially at high cutoff voltage. Then the effect of modification on the electrochemical properties was conducted by CV, EIS and SEM detection after cycle. It is displayed that the particles after modification have no cracks, and the polarization and impedance decrease to varying degrees. This simple and feasible method has a good prospect for improving the cyclic stability of Ni-rich materials.
•Tungsten oxide modified LiNi0.8Co0.1Mn0.1O2 material were first put forward.•This simple and feasible method has a good prospect for improving the cyclic stability of Ni-rich materials.•The different amounts of tungsten oxide were compared, the addition of 0.25% has the best effect.
Developing robust nonprecious-metal electrocatalysts with high activity towards sluggish oxygen-evolution reaction is paramount for large-scale hydrogen production via electrochemical water ...splitting. Here we report that self-supported laminate composite electrodes composed of alternating nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride (FeCo/CeO
N
) heterolamellas hold great promise as highly efficient electrocatalysts for alkaline oxygen-evolution reaction. By virtue of three-dimensional nanoporous architecture to offer abundant and accessible electroactive CoFeOOH/CeO
N
heterostructure interfaces through facilitating electron transfer and mass transport, nanoporous FeCo/CeO
N
composite electrodes exhibit superior oxygen-evolution electrocatalysis in 1 M KOH, with ultralow Tafel slope of ~33 mV dec
. At overpotential of as low as 360 mV, they reach >3900 mA cm
and retain exceptional stability at ~1900 mA cm
for >1000 h, outperforming commercial RuO
and some representative oxygen-evolution-reaction catalysts recently reported. These electrochemical properties make them attractive candidates as oxygen-evolution-reaction electrocatalysts in electrolysis of water for large-scale hydrogen generation.
Aqueous aluminum‐ion batteries are attractive post‐lithium battery technologies for large‐scale energy storage in virtue of abundant and low‐cost Al metal anode offering ultrahigh capacity via a ...three‐electron redox reaction. However, state‐of‐the‐art cathode materials are of low practical capacity, poor rate capability, and inadequate cycle life, substantially impeding their practical use. Here layered manganese oxide that is pre‐intercalated with benzoquinone‐coordinated aluminum ions (BQ‐AlxMnO2) as a high‐performance cathode material of rechargeable aqueous aluminum‐ion batteries is reported. The coordination of benzoquinone with aluminum ions not only extends interlayer spacing of layered MnO2 framework but reduces the effective charge of trivalent aluminum ions to diminish their electrostatic interactions, substantially boosting intercalation/deintercalation kinetics of guest aluminum ions and improving structural reversibility and stability. When coupled with Zn50Al50 alloy anode in 2 m Al(OTf)3 aqueous electrolyte, the BQ‐AlxMnO2 exhibits superior rate capability and cycling stability. At 1 A g−1, the specific capacity of BQ‐AlxMnO2 reaches ≈300 mAh g−1 and retains ≈90% of the initial value for more than 800 cycles, along with the Coulombic efficiency of as high as ≈99%, outperforming the AlxMnO2 without BQ co‐incorporation.
An organic–inorganic hybrid material of manganese oxide pre‐intercalated with benzoquinone‐coordinated aluminum ions is developed as a cathode material of an aqueous aluminum‐ion battery. Owing to the coordination of flexible benzoquinone with Al3+ ions to extend interlayer spacing and weaken the electrostatic field of Al3+, it exhibits reversible Al3+ intercalation/extraction behaviors, with high capacity and rate capability, and long‐term stability.
In China, medical staff of children's hospitals are commonly exposed to violence. However, few studies on medical violence are conducted in the settings of children's hospitals. The aim of this study ...is to assess the incidence, magnitude, consequences, and potential risk factors of workplace violence (WPV) against medical staff of children's hospitals.
A retrospective cross-sectional design was used. A self-administered questionnaire was utilized to collect data on 12 children's hospitals. The questionnaires were distributed to a stratified proportional random sample of 2,400 medical staff; 1,932 valid questionnaires were collected. A chi-square test and multiple logistic regression analysis were conducted.
A total of 68.6% of respondents had experienced at least one WPV incident involving non-physical and/or physical violence in the past year. The perpetrators were mainly family members of patients (94.9%). Most of the WPV occurred during the day shift (70.7%) and in wards (41.8%). Males were 1.979 times (95% CI, 1.378 to 2.841) more likely than females to experience physical violence. Emergency departments were more exposed to physical violence than other departments. Oncology was 2.733 times (95% CI, 1.126 to 6.633) more exposed to non-physical violence than the emergency department. As a result of WPV, victims felt aggrieved and angry, work enthusiasm declined, and work efficiency was reduced. However, only 5.6% of the victims received psychological counseling.
Medical staff are at high risk of violence in China's children's hospitals. Hospital administrators and related departments should pay attention to the consequences of these incidents. There is a need for preventive measures to protect medical staff and provide a safer workplace environment. Our results can provide reference information for intervention strategies and safety measures.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fe(III) oxyhydroxides play critical roles in arsenic immobilization due to their strong surface affinity for arsenic. However, the role of bacteria in Fe(II) oxidation and the subsequent ...immobilization of arsenic has not been thoroughly investigated to date, especially under the micro-oxic conditions present in soils and sediments where these microorganisms thrive. In the present study, we used gel-stabilized gradient systems to investigate arsenic immobilization during microaerophilic microbial Fe(II) oxidation and Fe(III) oxyhydroxide formation. The removal and immobilization of dissolved As(III) and As(V) proceeded via the formation of biogenic Fe(III) oxyhydroxides through microbial Fe(II) oxidation. After 30 days of incubation, the concentration of dissolved arsenic decreased from 600 to 4.8 μg L−1. When an Fe(III) oxyhydroxide formed in the presence of As(III), most of the arsenic ultimately was found as As(V), indicating that As(III) oxidation accompanied arsenic immobilization. The structure of the microbial community in As(III) incubations was highly differentiated with respect to the As(V)-bearing ending incubations. The As(III)-containing incubations contained the arsenite oxidase gene, suggesting the potential for microbially mediated As(III) oxidation. The findings of the present study suggest that As(III) immobilization can occur in micro-oxic environments after microbial Fe(II) oxidation and biogenic Fe(III) oxyhydroxide formation via the direct microbial oxidation of As(III) to As(V). This study demonstrates that microbial Fe(II) and As(III) oxidation are important geochemical processes for arsenic immobilization in micro-oxic soils and sediments.
The purpose of this study was to assess the value of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) for the diagnosis of severe respiratory diseases based on ...interpretation of sequencing results. BALF samples were harvested and used for mNGS as well as microbiological detection. Infectious bacteria or fungi were defined according to relative abundance and number of unique reads. We performed mNGS on 35 BALF samples from 32 patients. The positive rate reached 100% in the mNGS analysis of nine immunocompromised patients. Compared with the culture method, mNGS had a diagnostic sensitivity of 88.89% and a specificity of 74.07% with an agreement rate of 77.78% between these two methods. Compared with the smear method and PCR, mNGS had a diagnostic sensitivity of 77.78% and a specificity of 70.00%. In 13 cases, detection results were positive by mNGS but negative by culture/smear and PCR. The mNGS findings in 11/32 (34.4%) cases led to changes in treatment strategies. Linear regression analysis showed that diversity was significantly correlated with interval between disease onset and sampling. Dynamic changes in reads could indirectly reflect therapeutic effectiveness. BALF mNGS improves sensitivity of pathogen detection and provides guidance in clinical practice. Potential pathogens can be identified based on relative abundance and number of unique reads.
This article studies whether the volume and composition of capital flows affect the degree of credit crunch during the 2007—2009 crisis. Using data on 3,823 firms in 24 emerging countries, we find ...that, on average, the decline in stock prices was more severe for firms that are intrinsically more dependent on external finance for working capital. Interestingly, while the volume of capital flows per se has no significant effect, the composition matters a lot. In particular, greater dependence on non-FDI capital inflows before the crisis worsens the credit crunch during the crisis, while exposure to FDI alleviates the liquidity constraint.
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