The chemical coupling interaction has been explored extensively to boost heterogeneous catalysis, but the insight into how chemical coupling interaction works on CO2 electroreduction remains unclear. ...Herein we demonstrate how the chemical coupling interaction between porous In2O3 nanobelts and reduced graphene oxide (rGO) could substantially improve the electrocatalytic activity toward CO2 electroreduction. Such an In2O3–rGO hybrid catalyst showed 1.4-fold and 3.6-fold enhancements in Faradaic efficiency and specific current density for the formation of formate at −1.2 V versus reversible hydrogen electrode relative to the catalyst prepared by physically loading of In2O3 nanobelts onto rGO, respectively. The density functional theory calculations and electrochemical analysis together revealed that the chemical coupling interaction boosted CO2 electroreduction activity by improving electrical conductivity and stabilizing key intermediate HCOO–*. The present work not only deepens an understanding of chemical coupling effect but also provides an effective lever to optimize the catalytic performance toward CO2 electroreduction.
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IJS, KILJ, NUK, PNG, UL, UM
Abstract
Atomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO
2
. However, electron delocalization of ...the metal site with the carbon support via d-π conjugation strongly hinders CO
2
activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO
2
activation. As a result, for the electroreduction of CO
2
to CO in aqueous KHCO
3
electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO
2
concentration of only 30% in an H-type cell. In a flow cell under pure CO
2
at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm
2
with a FE above 90%.
Visual object tracking is challenging as target objects often undergo significant appearance changes caused by deformation, abrupt motion, background clutter and occlusion. In this paper, we exploit ...features extracted from deep convolutional neural networks trained on object recognition datasets to improve tracking accuracy and robustness. The outputs of the last convolutional layers encode the semantic information of targets and such representations are robust to significant appearance variations. However, their spatial resolution is too coarse to precisely localize targets. In contrast, earlier convolutional layers provide more precise localization but are less invariant to appearance changes. We interpret the hierarchies of convolutional layers as a nonlinear counterpart of an image pyramid representation and exploit these multiple levels of abstraction for visual tracking. Specifically, we adaptively learn correlation filters on each convolutional layer to encode the target appearance. We hierarchically infer the maximum response of each layer to locate targets. Extensive experimental results on a largescale benchmark dataset show that the proposed algorithm performs favorably against state-of-the-art methods.
The practical applications of Li‐ion batteries (LIBs) are challenged by their safety concerns when using liquid electrolytes (LEs). Solid‐state gel polymer electrolytes (GPEs) can address this ...challenge and have drawn increased attention recently. Normally, GPEs are prepared separately and then assembled into cells, which undoubtedly result in dissatisfactory solid/solid interfacial compatibility and low ionic conductivity. Fortunately, in situ GPEs are proposed to address the above challenges and simplify the preparation process. Typically, LE precursor is injected into the cells and gradually transformed into a quasi‐solid gel state under the conditions of thermal or chemical initiators. Consequently, the obtained in situ GPEs could fully infiltrate the electrode and better interface contact of gel electrolyte/electrode is thus inherited. In this review, the authors focus on the in situ GPEs used in lithium batteries (LBs), and summarize recent progress of the design, synthesis, and applications of in situ GPEs. Based on the different ways of triggering polymerization, there are mainly three methods: thermochemical gelation, polymerization by additional chemical initiators, and cross‐linking initiated by LiO bond. Composite GPEs based on in situ solidification method are introduced as a promising strategy to improve the electrochemical performances. Finally, up‐to‐date research progresses are discussed, and perspectives are provided on the development and challenges of in situ GPEs to meet the requirements for their practical applications in LBs.
In situ gel polymer electrolytes (GPEs) are being widely concerned as high‐priority materials for safe and high‐performance lithium batteries (LBs). This review intends to introduce in situ GPEs by reviewing their designs and applications in LBs. The challenges and prospects of in situ GPEs are proposed from the perspective of promoting the practical applications of this promising field.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The flavan‐3‐ols of 10 primarily plant food byproducts, including Muscat Hamburg grape seed, hawthorn sarcocarp, litchi pericarp, cocoa bean, peanut skin, lotus seedpod, Xinyang Maojian green tea, ...Cinnamomi cortex, Sargentodoxa cuneata stem, and Cyperus esculentus, leaves were analyzed. Ultrahigh‐performance liquid chromatography–triple quadrupole mass spectrometry was used for the analysis. Cyperus esculentus leaves contained a high amount of procyanidin B1 (198.9 mg/100 g), second only to Muscat Hamburg grape seed (292.9 mg/100 g). Unlike grape seed that contained several procyanidin B isomers with very similar retention times, C. esculentus leaves contained primarily procyanidin B1 with few isomers. Procyanidin B1 was enriched in the ethyl acetate fraction of a 70% methanol extract of C. esculentus leaves and purified at 95% purity by two runs of open column chromatography. Direct chromatography of the plant extract on octadecylsilane and Sephadex LH20 open columns improved the yield of the resultant leaf procyanidin B1 (95% purity) to 0.21‰. The present research demonstrated that the leaves of C. esculentus, byproducts of tigernut, are ideal plant sources for isolating and providing high‐purity procyanidin B1.
Practical Application
Procyanidin B1 has a broad range of health benefits. Cyperus esculentus is cultivated in many countries with nearly 6190 square hectares (hm2) in the Spanish Mediterranean region in 2020–2021 and over 16,700 hm2 in China in recent years, primarily for its tubers. The byproducts, the leaves of C. esculentus, contain high levels of procyanidin B1, with few isomers that interfere with its isolation and purification. Thus, the leaves of this plant provide a viable source for preparing high‐purity procyanidin B1.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
This paper provides a novel approach for identifying the process damping directly from chatter-free milling tests. First, power spectrum density matrix of cutter's deflections is theoretically ...derived by introducing transfer function and random excitation force, and the spectral decomposition of the power spectrum density matrix is formulated as an explicit function of modal parameters. Then, exponential attenuation method is adopted to extract the damping ratios from the inverse Fourier transformation result of the decomposed form. Finally, tangential and radial ploughing force coefficients, which are utilized to characterize process damping, are simultaneously calculated based on energy balance principle. Besides, experimental setup consisting of displacement sensors is specially designed to measure the cutter's deflections, which are further used to calculate the power spectrum density required in the above identification procedure. It is experimentally proven that the accuracy of chatter stability limits in milling process is improved when the proposed process damping model is considered.
•Process damping is directly identified from chatter-free milling tests based on operational modal analysis.•Power spectrum density matrix of cutter's deflections is analytically derived as an explicit function of modal parameters.•Experimental setup suitable for measuring the cutter's deflections is designed.•Effectiveness of the proposed process damping model is verified by chatter experiments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The paper aims to further explore the current situation of Chinese investment in overseas clean energy and analyze the development of the power industry in the field of clean energy. The paper ...elaborates the present development status of clean energy based on the Data Envelopment Analysis (DEA) model and investment efficiency theories, analyzing the potential risks taken by China’s electric power industry from the investment in overseas clean energy and calculating the power enterprises’ investment efficiency. The results reveal that China’s overseas investment in clean energy has developed rapidly. However, from 2016 to 2017, due to the accelerated investment in clean energy, the comprehensive investment efficiency of clean energy has dropped significantly, to 79.1% and 78.7%, respectively. Subsequently, the comprehensive investment efficiency increased significantly, reaching 80.4% in 2019. Between 2015 and 2019, effective investment in clean energy has reached the highest, 32% in 2015, while there are more ineffective investments in 2016. After 2017, the proportion of power enterprises’ investment in clean energy has increased significantly, accounting for 32% in 2019. In future development, the proportion of investment in this field will continue to rise. Hence, clean energy boasts good development prospects.
Real-time and remote monitoring of the state of charge (SOC) of a vanadium redox flow battery (VRFB) is technically desirable for achieving advanced compensation functions of VRFB systems. This ...paper, for the first time, proposes a novel SOC monitoring scheme based on an air-gap fiber Fabry–Perot interferometer (AGFFPI) sensor for the VRFB. The proposed sensing concept is based on real-time sensing of the refractive index (RI) of the positive electrolyte, which is found closely correlated to the VRFB’s SOC. The proposed SOC estimating scheme using fiber sensor has a number of merits, e.g., being precise, having lightweight, having strong acid resistance, and being easy to incorporate the state-of-the-art fiber communication technology for remote monitoring. It is found that the RI of the positive electrolyte solution exhibits distinct and linear variations in accordance with changes of the VRFB’s SOC value. Using the linear relationship between the electrolyte’s RI and SOC, a real-time SOC monitoring mechanism can be readily realized by the proposed AGFFPI. In this paper, existing SOC detecting methods for VRFB are firstly reviewed. The details concerning the proposed detecting method are then addressed. Typical experimental results are presented to verify the feasibility and effectiveness of the proposed SOC estimating scheme.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Wuhan was the epicentre of the COVID-19 outbreak in China. We aimed to determine the seroprevalence and kinetics of anti-SARS-CoV-2 antibodies at population level in Wuhan to inform the development ...of vaccination strategies.
In this longitudinal cross-sectional study, we used a multistage, population-stratified, cluster random sampling method to systematically select 100 communities from the 13 districts of Wuhan. Households were systematically selected from each community and all family members were invited to community health-care centres to participate. Eligible individuals were those who had lived in Wuhan for at least 14 days since Dec 1, 2019. All eligible participants who consented to participate completed a standardised electronic questionnaire of demographic and clinical questions and self-reported any symptoms associated with COVID-19 or previous diagnosis of COVID-19. A venous blood sample was taken for immunological testing on April 14–15, 2020. Blood samples were tested for the presence of pan-immunoglobulins, IgM, IgA, and IgG antibodies against SARS-CoV-2 nucleocapsid protein and neutralising antibodies were assessed. We did two successive follow-ups between June 11 and June 13, and between Oct 9 and Dec 5, 2020, at which blood samples were taken.
Of 4600 households randomly selected, 3599 families (78·2%) with 9702 individuals attended the baseline visit. 9542 individuals from 3556 families had sufficient samples for analyses. 532 (5·6%) of 9542 participants were positive for pan-immunoglobulins against SARS-CoV-2, with a baseline adjusted seroprevalence of 6·92% (95% CI 6·41–7·43) in the population. 437 (82·1%) of 532 participants who were positive for pan-immunoglobulins were asymptomatic. 69 (13·0%) of 532 individuals were positive for IgM antibodies, 84 (15·8%) were positive for IgA antibodies, 532 (100%) were positive for IgG antibodies, and 212 (39·8%) were positive for neutralising antibodies at baseline. The proportion of individuals who were positive for pan-immunoglobulins who had neutralising antibodies in April remained stable for the two follow-up visits (162 44·6% of 363 in June, 2020, and 187 41·2% of 454 in October–December, 2020). On the basis of data from 335 individuals who attended all three follow-up visits and who were positive for pan-immunoglobulins, neutralising antibody levels did not significantly decrease over the study period (median 1/5·6 IQR 1/2·0 to 1/14·0 at baseline vs 1/5·6 1/4·0 to 1/11·2 at first follow-up p=1·0 and 1/6·3 1/2·0 to 1/12·6 at second follow-up p=0·29). However, neutralising antibody titres were lower in asymptomatic individuals than in confirmed cases and symptomatic individuals. Although titres of IgG decreased over time, the proportion of individuals who had IgG antibodies did not decrease substantially (from 30 100% of 30 at baseline to 26 89·7% of 29 at second follow-up among confirmed cases, 65 100% of 65 at baseline to 58 92·1% of 63 at second follow-up among symptomatic individuals, and 437 100% of 437 at baseline to 329 90·9% of 362 at second follow-up among asymptomatic individuals).
6·92% of a cross-sectional sample of the population of Wuhan developed antibodies against SARS-CoV-2, with 39·8% of this population seroconverting to have neutralising antibodies. Our durability data on humoral responses indicate that mass vaccination is needed to effect herd protection to prevent the resurgence of the epidemic.
Chinese Academy of Medical Sciences & Peking Union Medical College, National Natural Science Foundation, and Chinese Ministry of Science and Technology.
For the Chinese translation of the abstract see Supplementary Materials section.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Uveal melanoma (UM) is the most common intraocular tumor in adults. Ferroptosis is a newly recognized process of cell death, which is different from other forms of cell death in terms of morphology, ...biochemistry and genetics, and has played a vital role in cancer biology. The present research aimed to construct a gene signature from ferroptosis-related genes that have the prognostic capacity of UM.
UM patients from The Cancer Genome Atlas (TCGA) were taken as the training cohort, and GSE22138 from Gene Expression Omnibus (GEO) was treated as the validation cohort. A total of 103 ferroptosis-related genes were retrieved from the GeneCards. We performed Kaplan-Meier and univariate Cox analysis for preliminary screening of ferroptosis-related genes with potential prognostic capacity in the training cohort. These genes were then applied into an overall survival-based LASSO Cox regression model, constructing a gene signature. The discovered gene signature was then evaluated via Kaplan-Meier (KM), Cox, and ROC analyses in both cohorts. The Pearson correlation coefficient examined the correlations between risk score and UM common mutations and autophagy. The analyses of GSEA and immune infiltrating were performed to better study the functional annotation of the gene signature and the character of each kind of immune cell in the tumor microenvironment.
A seven-gene signature was found from the training cohort and validated in all cohorts by Kaplan-Meier and Cox regression analyses, revealing its independent prognosis value in UM. Moreover, ROC analysis was conducted, confirming the strong predictive ability that this signature had for UM prognosis. A total of 52.24% (256/490) autophagy-related genes were significantly correlated with risk scores. Analyses of GSEA and immune infiltrating detailed exhibited specific pathways associated with the seven-gene signature, also confirming the crucial role that Mast cells resting played in the prognosis of the seven-gene signature.
In this study, a novel ferroptosis-related seven-gene signature (ALOX12, CD44, MAP1LC3C, STEAP3, HMOX1, ITGA6, and AIFM2/FSP1) was built. It could accurately predict UM prognosis and was related to Mast cells resting, which provides the potential for personalized outcome prediction and the development of new therapies in the UM population.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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