It is highly profitable to transform glycerol - the main by-product from biodiesel production to high value-added chemicals. In this work, we develop a photoelectrochemical system based on nanoporous ...BiVO
for selective oxidation of glycerol to 1,3-dihydroxyacetone - one of the most valuable derivatives of glycerol. Under AM 1.5G front illumination (100 mW cm
) in an acidic medium (pH = 2) without adscititious oxidant, the nanoporous BiVO
photoanode achieves a glycerol oxidation photocurrent density of 3.7 mA cm
at a potential of 1.2 V versus RHE with 51% 1,3-dihydroxyacetone selectivity, equivalent to a production rate of 200 mmol of 1,3-dihydroxyacetone per m
of illumination area in one hour.
Lithium (Li)‐metal batteries promise energy density beyond 400 Wh kg−1, while their practical operation at an extreme temperature below −30 °C suffers severe capacity deterioration. Such battery ...failure highly relates to the remarkably increased kinetic barrier of interfacial processes, including interfacial desolvation, ion transportation, and charge transfer. In this work, the interfacial kinetics in three prototypical electrolytes are quantitatively probed by three‐electrode electrochemical techniques and molecular dynamics simulations. Desolvation as the limiting step of interfacial processes is validated to dominate the cell impedance and capacity at low temperature. 1,3‐Dioxolane‐based electrolyte with tamed solvent–solute interaction facilitates fast desolvation, enabling the practical Li|LiNi0.5Co0.2Mn0.3O2 cells at −40 °C to retain 66% of room‐temperature capacity and withstand remarkably fast charging rate (0.3 C). The barrier of desolvation dictated by solvent–solute interaction environments is quantitatively uncovered. Regulating the solvent–solute interaction by low‐affinity solvents emerges as a promising solution to low‐temperature batteries.
Desolvation is validated as the predominant contributor to energy loss at low temperatures, largely overwhelming the contributions from other interfacial ion transportation processes. A rational and original design by taming solvent–solute interaction with low‐affinity solvents like 1,3‐dioxolane is proposed to enable high capacity and durable operation of practical lithium‐metal batteries at −40 °C.
Effectively absorbing and converting electromagnetic (EM) energy for reutilization has an important implication in the fields of energy and environment. Herein, multi-walled carbon nanotubes (MWCNTs) ...are confinedly implanted into flower-like cobaltosic oxide (Co3O4) to tailor the conductive network and polarization genes. It controllably tunes the EM property and optimizes the low-frequency microwave absorption. The minimum reflection loss reaches −61.4 dB at 3.44 GHz. A novel self-powered device is constructed to achieve the effective conversion from waste EM energy to useful electric energy. Energy conversion process inside flower-like Co3O4-MWCNT architecture is investigated, and the contribution of dielectric loss and magnetic loss to energy conversion is exhibited. This work provides a promising approach in combating EM pollution and alleviating energy problem.
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•m-MWCNT is implanted into flower-like Co3O4 to tailor microstructure, tuning EM property and low-frequency absorption.•Energy conversion mechanism is dissected deeply, and the contribution of dielectric loss and magnetic loss is shown.•A novel self-powered device is constructed to harvest and convert waste EM energy to useful electric energy.
Lithium metal anodes demonstrate inferior cycling stability due to uncontrolled Li deposition and large volume fluctuation. Composite Li metal anodes with a 3D host show stable Li deposition. ...Nevertheless, the advantages of a host are achieved by the joint effect of various parameters. The effect of a single parameter of a host on Li deposition is veiled, hindering the rational design of a host. Herein, a decoupling method is demonstrated to decipher the effect of host electrical conductivity, a vital parameter, on the behaviors of Li deposition. In order to decouple the effect of host electrical conductivity, a conductive host is modulated by in situ formation of a polymer coating while maintaining the other parameters unchanged. The host electrical conductivity dictates the distribution of electric potential in the vicinity of the host, then the transport of Li ions, and finally behaviors of Li deposition. The cycling performance of the host with high electrical conductivity outperforms that with low electrical conductivity. This work initiates a decoupling methodology to probe the effect of host properties on the behaviors of Li deposition, and provides guidance for the rational design of Li metal anode host materials.
A decoupling method is proposed to decipher the effect of the electrical conductivity of the host on the behavior of Li plating. The electrical conductivity of a host dictates the uniform distribution of electric potential around the host. The conductive host significantly reduces the overpotential of ionic transport, which facilitates homogeneous Li‐ion flux and finally improves the uniformity of Li deposition.
The Search for Extraterrestrial Intelligence (SETI) attempts to address the possibility of the presence of technological civilizations beyond the Earth. Benefiting from high sensitivity, large sky ...coverage, and an innovative feed cabin for China's Five-hundred-meter Aperture Spherical radio Telescope (FAST), we performed SETI's first observations with FAST's newly commissioned 19 beam receiver; we report preliminary results in this paper. Using the data stream produced by the SERENDIP VI real-time multibeam SETI spectrometer installed at FAST, as well as its off-line data processing pipelines, we identify and remove four kinds of radio frequency interference (RFI): zone, broadband, multibeam, and drifting, utilizing the Nebula SETI software pipeline combined with machine-learning algorithms. After RFI mitigation, the Nebula pipeline identifies and ranks interesting narrowband candidate ET signals, scoring candidates by the number of times candidate signals have been seen at roughly the same sky position and same frequency, signal strength, proximity to a nearby star or object of interest, along with several other scoring criteria. We show four example candidate groups that demonstrate this RFI mitigation and candidate selection. This preliminary testing on FAST data helps to validate our SETI instrumentation techniques as well as our data processing pipeline.
A 3D host decorated with lithiophilic sites has emerged as a promising strategy to stabilize lithium metal anode by guiding uniform Li deposition and relieving volume fluctuations. Herein, the ...evolution process of lithiophilic sites in a 3D host under practical conditions is disclosed in a typical system with metal‐based lithiophilic sites. Lithiophilic sites decreasing nucleation overpotential, however this effect gradually disappears during cycles under practical conditions. The significantly increased cycling capacity under practical conditions results in a rapid accumulation of dead Li compared with mild conditions. The dead Li covers the lithiophilic sites and blocks the diffusion channels of Li ions to the lithiophilic sites, failing to decrease the nucleation overpotentials. Once the dead Li has been removed after long cycles, the lithiophilic sites can still work. This work discloses the failure mechanism of lithiophilic sites and provides a guideline for designing lithiophilic hosts under practical conditions.
The failure mechanism of lithiophilic sites in a 3D host under practical conditions is investigated. The advantage of lithiophilic sites, ie. decreasing the nucleation overpotential, gradually disappears during cycling under practical conditions. The rapid accumulation of dead Li covers lithiophilic sites and blocks the diffusion channels of Li ions to lithiophilic sites, inducing the disappearance of decreased nucleation overpotentials.
High‐energy‐density lithium (Li) metal batteries suffer from a short lifespan owing to apparently ceaseless inactive Li accumulation, which is accompanied by the consumption of electrolyte and active ...Li reservoir, seriously deteriorating the cyclability of batteries. Herein, a triiodide/iodide (I3−/I−) redox couple initiated by stannic iodide (SnI4) is demonstrated to reclaim inactive Li. The reduction of I3− converts inactive Li into soluble LiI, which then diffuses to the cathode side. The oxidation of LiI by the delithiated cathode transforms cathode into the lithiation state and regenerates I3−, reclaiming Li ion from inactive Li. The regenerated I3− engages the further redox reactions. Furthermore, the formation of Sn mitigates the corrosion of I3− on active Li reservoir sacrificially. In working Li | LiNi0.5Co0.2Mn0.3O2 batteries, the accumulated inactive Li is significantly reclaimed by the reversible I3−/I− redox couple, improving the lifespan of batteries by twice. This work initiates a creative solution to reclaim inactive Li for prolonging the lifespan of practical Li metal batteries.
A triiodide/iodide (I3−/I−) redox couple is introduced with a SnI4 initiator to reclaim inactive Li. The reduction of I3− converts inactive Li into soluble LiI, and the oxidation of LiI by a delithiated cathode realizes the restoration of Li ion in cathode from inactive Li. The regenerated I3− by oxidation engages the further redox reactions.
To evaluate the relative performance of clinical readouts including serum C-reactive protein (CRP) levels, the erythrocyte sedimentation rate (ESR), globulin (GLB) levels, the albumin to GLB ratio ...(A/G), and the neutrophil to lymphocyte ratio (NLR) when diagnosing periprosthetic joint infection (PJI).
Clinical data was collected from 115 individuals diagnosed in our department between January 2017 and December 2020 with either chronic PJI (29 female, 24 male; median age 71.00 years range, 41-94 years) or aseptic loosening (30 female, 32 male; median age 68.50 years range, 34-85 years). Patient demographic data were compared, and the relative sensitivity and specificity of preoperative GLB, ESR, CRP, NLR, and A/G values as predictors of PJI diagnosis were assessed.
Median globulin levels in the PJI and aseptic groups were 31.700 g/L (interquartile range IQR, 28.400-35.300) and 26.600 g/L (IQR, 24.375-30.550), respectively (p < 0.001). The median A/G values in the PJI and aseptic groups were 1.150 (IQR, 0.960-1.255) and 1.510 (IQR, 1.265-1.670), respectively (p < 0.001). The median NLR values in the PJI and aseptic groups were 2.510 (IQR, 1.900-3.335) and 1.850 (IQR, 1.425 to 2.362), respectively (p < 0.001). The median ESR values in the PJI and aseptic groups were 53.000 mm/h (IQR, 35.000-76.500) and 16.000 mm/h (IQR, 7.000-33.000), respectively (p < 0.001). Median CRP levels in the PJI and aseptic groups were 24.890 mg/L (IQR, 10.595-54.095) and 2.245 mg/L (IQR, 0.865-8.6075), respectively (p < 0.001). Area under the receiver operating characteristic (ROC) curve (AUC) values for CRP, ESR, GLB, A/G, and NLR were 0.841 (95% confidence interval, 0.761-0.903), 0.850 (0.771-0.910), 0.747 (0.658-0.824), 0.779 (0.692-0.851), and 0.708 (0.616-0.789), respectively. When GLB > 26.6 g/L, A/G < 1.32, and NLR > 2.1 were utilized as threshold values to diagnose PJI, GLB and A/G were found to exhibit superior sensitivity (90.57%, 81.13%) to that observed for CRP (71.70%) and ESR (79.25%), but the specificity of these two metrics (GLB: 51.61%, A/G: 72.58%) was significantly reduced relative to that for CRP (87.10%) or ESR (75.81%). ROC analyses further revealed that NLR did not exhibit significant advantages in sensitivity (73.58%) or specificity (70.97%) relative to CRP or ESR.
Globulin levels, NLR values, and A/G values do not outperform ESR or CRP levels when used to diagnose PJI.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Stability is an important constraint in power system operation and the transient stability constrained optimal power flow (OPF) has always received considerable attention in recent years. In this ...paper, the defects of the existing models and algorithms around this topic are firstly analyzed, on the basis of which, a multi-objective optimization method is proposed. The basic idea of the proposed method is to model transient stability as an objective function rather than an inequality constraint and consider classic transient stability constrained OPF (TSCOPF) as a tradeoff procedure using Pareto ideology. Second, a master-slave parallel elitist non-dominated sorting genetic algorithm II is used to solve the proposed multi-objective optimization problem, the parallel algorithm shows an excellent acceleration effect and provides a set of Pareto optimal solutions for decision makers to select. An innovative weight assigning technique based on fuzzy membership variance is also introduced for a more scientific and objective optimal solution decision. Case study results demonstrate the proposed multi-objective method has many advantages, compared with traditional TSCOPF methods.
During chronic viral infection or cancer, the immune system usually induces a corresponding immune response against pathogens or cancer cells so as to prevent worsening disease. T cell exhaustion in ...which reduced and dysfunctional effector T cells lead to immune escape is one of the mechanisms that pathogens or cancer cells get rid of control from the immune system. In this review, we discuss some mechanisms associated with T cell exhaustion and enumerate current methods of reversing T cell exhaustion. We also summarize current targeted treatment strategies and put forward following aspects that required to research.
T cell exhaustion in which reduced and dysfunctional effector T cells lead to immune escape is one of the mechanisms that pathogens or cancer cells get rid of control from the immune system. In this review, we discuss some mechanisms associated with T cell exhaustion and enumerate current methods of reversing T cell exhaustion. We also summarize current targeted treatment strategies and put forward following aspects that required to research.
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