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In pursuing high stability and power conversion efficiency for organic photovoltaics (OPVs), a sequential deposition (SD) approach to fabricate active layers with p-i-n structures (where p, i, and n represent the electron donor, mixed donor:acceptor, and electron acceptor regions, respectively, distinctively different from the bulk heterojunction (BHJ) structure) has emerged. Here, we present a novel approach that by incorporating two polymer donors, PBDBT-DTBT and PTQ-2F, and one small-molecule acceptor, BTP-3-EH-4Cl, into the active layer with sequential deposition, we formed a device with nanometer-scale twin p-i-n structured active layer. The twin p-i-n PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl device involved first depositing a PBDBT-DTBT:PTQ-2F blend under layer and then a BTP-3-EH-4Cl top layer and exhibited an improved power conversion efficiency (PCE) value of 18.6%, as compared to the 16.4% for the control BHJ PBDBT-DTBT:PTQ-2F:BTP-3-EH-4Cl device or 16.6% for the single p-i-n PBDBT-DTBT/BTP-3-EH-4Cl device. The PCE enhancement resulted mainly from the twin p-i-n active layer's multiple nanoscale charge carrier pathways that contributed to an improved fill factor and faster photocurrent generation based on transient absorption studies. The PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl film possessed a vertical twin p-i-n morphology that was revealed through secondary ion mass spectrometry and synchrotron grazing-incidence small-angle X-ray scattering analyses. The thermal stability (T80) at 85 °C of the twin p-i-n PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl device surpassed that of the single p-i-n PBDBT-DTBT/BTP-3-EH-4Cl devices (906 vs 196 h). This approach of providing a twin p-i-n structure in the active layer can lead to substantial enhancements in both the PCE and stability of organic photovoltaics, laying a solid foundation for future commercialization of the organic photovoltaics technology.
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This study delves into the factors influencing the willingness of rural land transfers in different terrain areas, aiming to promote the improvement of land transfer institutions and accelerate the process of scale farming. Based on rural survey data from Anhui and Qinghai provinces in China, this research uses geographical detector and Binary Logistic Model to explore the differential factors affecting the willingness of farmers to participate in land contract transfer in the first and third terrain areas of China. The study examines four dimensions, including individual characteristics, family endowments, social support strategies, and geographical environment. The findings reveal the following: (1) By comparing the mean values, standard deviations, and coefficients of variation of the data from both provinces, it is evident that the indicators of individual characteristics, family endowments, social support strategies, and geographical environment differ significantly between the two provinces. This indicates substantial disparities in the basic attributes of farmers and their living environments. (2) The single-factor explanatory power significantly influencing farmers' willingness to engage in land transfer varies considerably and is statistically significant at the 1% level. The types of interaction between two factors mainly include dual-factor enhancement, nonlinear enhancement, single-factor nonlinear attenuation, and nonlinear attenuation. (3) There are commonalities and differences in the factors that significantly influence farmers' willingness to participate in land transfer in the two provinces. Common factors influencing farmers' land transfer willingness in both provinces include: the educational level of household heads, the health status of household heads, the number of family laborers, the arable land area, the differentiation of agricultural management objectives, the proportion of agricultural operating income, labor service economy, and relocation policies. Factors showing different influences include: the age of household heads, school-age children, the number of family members engaged in different occupations, the proportion of income from off-farm employment, minimum guarantee policies credit support, location distance, and terrain undulation. Therefore, in formulating land transfer policies, the government should prioritize significant driving factors influencing farmers' decision-making behavior in different regions. It is essential to develop and implement land transfer policies tailored to local conditions with the primary goal of safeguarding the rights and interests of the principal stakeholders, thus achieving sustainable land utilization.
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Agricultura , Fazendeiros , População Rural , China , Humanos , Inquéritos e Questionários , Fazendeiros/psicologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Fatores SocioeconômicosRESUMO
Few previous studies have investigated the impacts of coexposure to multiple urban environmental factors on the prognosis of acute myocardial infarction (AMI) events. This study aimed to evaluate the associations between the urban exposome and AMI recurrence. We used data from 88,509 AMI patients from a large cohort obtained from the Beijing Cardiovascular Disease Surveillance System between 2013 and 2019. Twenty-six types of urban exposures were assessed within 300-m, 500-m, and 1000-m buffers of patients' home addresses in the baseline and cumulative average levels. We used the Cox proportional hazard model along with the Elastic Net (ENET) algorithm to estimate the hazard ratios (HRs) of recurrent AMI per interquartile range increase in each selected urban exposure. The increased risk of AMI recurrence was significantly associated with lower urban function diversity in the 500-m buffer, longer distance to subway stations and higher PM2.5 for both baseline and cumulative average exposure. The cumulative averages of two urban factors, including the distance to parks, and the density of fruit and vegetable shops in the 1000-m buffer, were also identified as significant factors affecting the risk of AMI recurrence. These findings can help improve the urban design for promoting human cardiovascular health.
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Expossoma , Infarto do Miocárdio , Humanos , Material Particulado/análise , Pequim , Infarto do Miocárdio/epidemiologia , China/epidemiologia , SobreviventesRESUMO
BACKGROUND: The availability of physical activity (PA) facilities in neighborhoods is hypothesized to influence cardiovascular disease (CVD), but evidence from individual-level long-term cohort studies is limited. We aimed to assess the association between neighborhood exposure to PA facilities and CVD incidence. METHODS: A total of 4658 participants from the Chinese Multi-provincial Cohort Study without CVD at baseline (2007-2008) were followed for the incidence of CVD, coronary heart disease (CHD), and stroke. Availability of PA facilities was defined as both the presence and the density of PA facilities within a 500-m buffer zone around the participants' residential addresses. Time-dependent Cox regression models were performed to estimate the associations between the availability of PA facilities and risks of incident CVD, CHD, and stroke. RESULTS: During a median follow-up of 12.1 years, there were 518 CVD events, 188 CHD events, and 355 stroke events. Analyses with the presence indicator revealed significantly lower risks of CVD (hazard ratio [HR] 0.80, 95% confidence interval ([CI] 0.65-0.99) and stroke (HR 0.76, 95% CI 0.60-0.97) in participants with PA facilities in the 500-m buffer zone compared with participants with no nearby facilities in fully adjusted models. In analyses with the density indicator, exposure to 2 and ≥ 3 PA facilities was associated with 35% (HR 0.65, 95% CI 0.47-0.91) and 28% (HR 0.72, 95% CI 0.56-0.92) lower risks of CVD and 40% (HR 0.60, 95% CI 0.40-0.90) and 38% (HR 0.62, 95% CI 0.46-0.84) lower risks of stroke compared with those without any PA facilities in 500-m buffer, respectively. Effect modifications between presence of PA facilities and a history of hypertension for incident stroke (P = 0.049), and a history of diabetes for incident CVD (P = 0.013) and stroke (P = 0.009) were noted. CONCLUSIONS: Residing in neighborhoods with better availability of PA facilities was associated with a lower risk of incident CVD. Urban planning intervention policies that increase the availability of PA facilities could contribute to CVD prevention.
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Doenças Cardiovasculares , Exercício Físico , Características da Vizinhança , Acidente Vascular Cerebral , Humanos , Povo Asiático , Doenças Cardiovasculares/epidemiologia , Estudos de Coortes , Acidente Vascular Cerebral/epidemiologia , Academias de GinásticaRESUMO
Background Little is known about geographic variation in acute myocardial infarction (AMI) mortality within fast-developing megacities and whether changes in health care accessibility correspond to changes in AMI mortality at the small-area level. Methods and Results We included data of 94 106 AMI deaths during 2007 to 2018 from the Beijing Cardiovascular Disease Surveillance System in this ecological study. We estimated AMI mortality for 307 townships during consecutive 3-year periods with a Bayesian spatial model. Township-level health care accessibility was measured using an enhanced 2-step floating catchment area method. Linear regression models were used to examine the association between health care accessibility and AMI mortality. During 2007 to 2018, median AMI mortality in townships declined from 86.3 (95% CI, 34.2-173.8) to 49.4 (95% CI, 30.5-73.7) per 100 000 population. The decrease in AMI mortality was larger in townships where health care accessibility increased more rapidly. Geographic inequality, defined as the ratio of the 90th to 10th percentile of mortality in townships, increased from 3.4 to 3.8. In total, 86.3% (265/307) of townships had an increase in health care accessibility. Each 10% increase in health care accessibility was associated with a -0.71% (95% CI, -1.08% to -0.33%) change in AMI mortality. Conclusions Geographic disparities in AMI mortality among Beijing townships are large and increasing. A relative increase in township-level health care accessibility is associated with a relative decrease in AMI mortality. Targeted improvement of health care accessibility in areas with high AMI mortality may help reduce AMI burden and improve its geographic inequality in megacities.
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Infarto do Miocárdio , Humanos , Teorema de Bayes , Pequim/epidemiologia , Instalações de Saúde , Acessibilidade aos Serviços de Saúde , Infarto do Miocárdio/mortalidadeRESUMO
Timely arrival at a hospital capable of percutaneous coronary intervention (PCI) is critical in treating acute myocardial infarction (AMI). We examined the association between driving time to the nearest PCI-capable hospital and case fatality among AMI patients. A total of 142,474 AMI events during 2013-2019 from the Beijing Cardiovascular Disease Surveillance System were included in this cross-sectional study. The driving time from the residential address to the nearest PCI-capable hospital was calculated. Logistic regression was used to estimate the risk of AMI death associated with driving time. In 2019, 54.5% of patients lived within a 15-min drive to a PCI-capable hospital, with a higher proportion in urban than peri-urban areas (71.2% vs. 31.8%, p < 0.001). Compared with patients who had driving times ≤15 min, the adjusted odds ratios (95% CI, p value) for AMI fatality risk associated with driving times 16-30, 31-45, and >45 min were 1.068 (95% CI 1.033-1.104, p < 0.001), 1.189 (95% CI 1.127-1.255, p < 0.001), and 1.436 (95% CI 1.334-1.544, p < 0.001), respectively. Despite the high accessibility to PCI-capable hospitals for AMI patients in Beijing, inequality between urban and peri-urban areas exists. A longer driving time is associated with an elevated AMI fatality risk. These findings may help guide the allocation of health resources.
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Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Estudos Transversais , Infarto do Miocárdio/terapia , Hospitais , Fatores de Tempo , Resultado do TratamentoRESUMO
Near-infrared (NIR) small-molecule acceptors that absorb at wavelengths of up to 1000 nm are attractive for applications in organic photodetectors (OPDs) and biometrics. In this study, we incorporated IEICO-4F as the third component for PffBT4T-2OD:PC71BM-based OPDs to provide an efficient NIR response while greatly suppressing the leakage current at reverse bias. By varying the blend ratio and thickness (250-600 nm), we obtained an NIR OPD displaying an ultralow dark-current density (JD = 2.62 nA cm-2), ultrahigh detectivity [D* = 7.2 × 1012 Jones (850 nm)], high sensitivity, and photoresponsivity covering the region from the ultraviolet to the NIR. We used tapping-mode atomic force microscopy, optical microscopy, grazing-incidence wide-angle X-ray scattering, and contact angle measurements to investigate the effect of IEICO-4F on the performance of the ternary OPDs. The low compatibility of PffBT4T-2OD and IEICO-4F, originating from weak intermolecular interactions, allowed us to manipulate the degree of phase separation between the donor and acceptor in the ternary blends, leading to an optimized blend morphology featuring efficient charge separation, transport, and collection. To demonstrate its applicability, we integrated our OPD with two light-emitting diodes and used the system for precisely calculated transmissive pulse oximetry.
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Several methods have been applied to measure healthcare accessibility, ie, the Euclidean distance, the network distance, and the transport time based on speed limits. However, these methods generally produce less accurate estimates than actual measurements. This research proposed a method to estimate historical healthcare accessibility more accurately by using taxi Global Positioning System (GPS) traces. The proposed method's advantages were evaluated vis a case study using acute myocardial infarction (AMI) cases in Beijing in 2008. Comparative analyses of the new measure and three conventionally used measures suggested that the median estimated transport time to the closest hospital with percutaneous coronary intervention (PCI) capability for AMI patients was 5.72 minutes by the taxi GPS trace-based measure, 2.42 minutes by the network distance-based measure, 2.28 minutes by the speed limit-based measure, 1.73 minutes by the Euclidean distance-based measure; and the estimated proportion of patients who lived within 5 minutes of a PCI-capable hospital was 38.17%, 89.20%, 92.52%, 95.05%, respectively. The three conventionally used measures underestimated the travel time cost and overestimated the percentage of patients with timely access to healthcare facilities. In addition, the new measure more accurately identifies the areas with low or high access to healthcare facilities. The taxi GPS trace-based accessibility measure provides a promising start for more accurately estimating accessibility to healthcare facilities, increasing the use of medical records in studying the effects of historical healthcare accessibility on health outcomes, and evaluating how accessibility to healthcare changes over time.
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Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Acessibilidade aos Serviços de Saúde , Pequim , Fatores de Tempo , Infarto do Miocárdio/terapiaRESUMO
Redox mediators (RMs) have a substantial ability to govern oxygen reduction reaction (ORR) in Li-O2 batteries, which can realize large capacity and high-rate capability. However, studies on understanding RM-assisted ORR mechanisms are still in their infancy. Herein, a quinone-based molecule, vitamin K1 (VK1), is first used as the ORR RM for Li-O2 batteries, together with 2,5-di-tert-butyl-1,4-benzoquinone (DBBQ), to elucidate key factors on the catalytic activity of RMs. By combining experiments and first-principle computations, we demonstrate that the reduced VK1 has strong oxygen affinity and can effectively retard the deposition of Li2O2 films on the electrode surface, thereby guaranteeing enough active sites for electron transfer. Besides, the low reaction free energy of disproportionation of the Li(VK1)O2 intermediate into Li2O2 also significantly accelerates the ORR process. Consequently, the catalytic activity of VK1 is significantly boosted, and the discharge capacity of VK1-assisted batteries is 3.2-4.5 times that of DBBQ-assisted batteries. This study provides new insight for better understanding the working roles of RMs in Li-O2 batteries.
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Reactive oxygen species are a fatal challenge to the plant pathogenic bacterium Pseudomonas syringae. In this study, we reveal that the global regulatory protein RsmA3 from the RetS-Gac/Rsm signalling pathway modulates RpoS in the early-log growth phase in the P. syringae wild-type strain MB03, thereby regulating oxidative tolerance to H2 O2 and ultimately affecting pathogenicity to the host plant. Following increased H2 O2 by external addition or endogenous induction by menadione, the resistance of the mutant strain ΔretS to H2 O2 is significantly enhanced due to rapid increases in the transcription of Rsm-related non-coding small RNAs (nc sRNAs), a sigma factor RpoS, and H2 O2 -detoxifying enzymes. Moreover, the ΔretS mutant is significantly less pathogenic in cucumber leaves. Seven Rsm-related nc sRNAs (namely, rsmZ, rsmY and rsmX1-5 ) show functional redundancy in the RetS-Gac-Rsm signalling pathway. External addition of H2 O2 stimulates increases in the transcription of both rsmY and rsmZ. Thus, we propose a regulatory model of the RetS-Gac-Rsm signalling pathway in P. syringae MB03 for the regulation of H2 O2 tolerance and phytopathogenicity in the host plant.
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Regulação Bacteriana da Expressão Gênica , Pseudomonas fluorescens , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Pseudomonas fluorescens/genética , Pseudomonas syringae/genética , Pseudomonas syringae/metabolismo , Espécies Reativas de Oxigênio/metabolismo , RNA não Traduzido , Fator sigma/genética , Fator sigma/metabolismo , Vitamina K 3/metabolismo , Peróxido de Hidrogênio/farmacologiaRESUMO
OBJECTIVES: To assess overall and gender-specific associations between marital status and out-of-hospital coronary death (OHCD) compared with patients surviving to hospital admission. DESIGN: A cross-sectional study based on linkage of administrative health databases. SETTING: Beijing, China. PARTICIPANTS: From 2007 to 2019, 378 883 patients with acute coronary event were identified in the Beijing Monitoring System for Cardiovascular Diseases, a validated city-wide registration system based on individual linkage of vital registration and hospital discharge data. OUTCOME MEASURES: OHCD was defined as coronary death occurring before admission. Multilevel modified Poisson regression models were used to calculate the prevalence ratios (PR) and 95% CIs. RESULTS: Among 378 883 acute coronary events, OHCD accounted for 33.8%, with a higher proportion in women compared with men (41.5% vs 28.7%, p<0.001). Not being married was associated with a higher proportion of OHCD in both genders, with a stronger association in women (PR 2.18, 95% CI 2.10 to 2.26) than in men (PR 1.97, 95% CI 1.91 to 2.02; p for interaction <0.001). The associations of OHCD with never being married (PR 1.98, 95% CI 1.88 to 2.08) and being divorced (PR 2.54, 95% CI 2.42 to 2.67) were stronger in men than in women (never married: PR 0.98, 95% CI 0.82 to 1.16; divorced: PR 1.47, 95% CI 1.34 to 1.61) (p for interaction <0.001 for both). Being widowed was associated with a higher proportion of OHCD in both genders, with a stronger association in women (PR 2.26, 95% CI 2.17 to 2.35) compared with men (PR 1.89, 95% CI 1.84 to 1.95) (p for interaction <0.001). CONCLUSIONS: Not being married was independently associated with a higher proportion of OHCD and the associations differed by gender. Our study may aid the development of gender-specific public health interventions in high-risk populations characterised by marital status to reduce OHCD burden.
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Morte , Armazenamento e Recuperação da Informação , Pequim/epidemiologia , Estudos Transversais , Feminino , Hospitais , Humanos , Masculino , Estado CivilRESUMO
In this paper, a novel adaptive feedback threshold (AFT) based demodulation for mobile visible light communication and positioning (VLCP) integrated system is proposed. The AFT can vary with the received signal without excessive fluctuation and support communication and positioning in mobile environment. For the VLCP integrated system with single light emitting diodes (LED) and multiple photodetectors (PDs), maximal ratio combining (MRC) and received optical power ratio (ROPR) based on the AFT is further achieved for communication and positioning with high performance, respectively. It is demonstrated that high credible communication and high accuracy positioning for the mobile integrated VLCP system can be realized by using the proposed AFT based demodulation. As a result, the implemented VLCP system with a moving speed of 1 m/s is evaluated experimentally. Average positioning error of 3.43 cm with 800 mA current and the bit error ratio (BER) with different currents are also obtained.
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Chronic diseases place a substantial financial burden on both the patient and the state. As chronic diseases become increasingly prevalent with urbanization and aging, primary chronic disease pharmacies should be planned to ensure that patients receive an equitable distribution of resources. Here, the spatial equity of chronic disease pharmacies is investigated. In this study, planning radiuses and Web mapping are used to assess the walkability and accessibility of planned chronic disease pharmacies; Lorenz curves are used to evaluate the match between the service area of the pharmacies and population; location quotients are used to identify the spatial differences of the allocation of chronic disease pharmacies based on residents. Results show that chronic disease pharmacies have a planned service coverage of 38.09%, an overlap rate of 58.34%, and actual service coverage of 28.05% in Wuhan. Specifically, chronic disease pharmacies are spatially dispersed inconsistently with the population, especially the elderly. The allocation of chronic disease pharmacies is directly related to the standard of patients' livelihood. Despite this, urban development does not adequately address this group's equity in access to medication. Based on a case study in Wuhan, China, this study aims to fill this gap by investigating the spatial equity of chronic disease medication purchases.
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Farmácias , Humanos , Idoso , Cidades , China , Urbanização , Caminhada , Acessibilidade aos Serviços de SaúdeRESUMO
Acute myocardial infarction (AMI) poses a serious disease burden in China, but studies on small-area characteristics of AMI incidence are lacking. We therefore examined temporal trends and geographic variations in AMI incidence at the township level in Beijing. In this cross-sectional analysis, 259,830 AMI events during 2007-2018 from the Beijing Cardiovascular Disease Surveillance System were included. We estimated AMI incidence for 307 consistent townships during consecutive 3-year periods with a Bayesian spatial model. From 2007 to 2018, the median AMI incidence in townships increased from 216.3 to 231.6 per 100,000, with a greater relative increase in young and middle-aged males (35-49 years: 54.2%; 50-64 years: 33.2%). The most pronounced increases in the relative inequalities was observed among young residents (2.1 to 2.8 for males and 2.8 to 3.4 for females). Townships with high rates and larger relative increases were primarily located in Beijing's northeastern and southwestern peri-urban areas. However, large increases among young and middle-aged males were observed throughout peri-urban areas. AMI incidence and their changes over time varied substantially at the township level in Beijing, especially among young adults. Targeted mitigation strategies are required for high-risk populations and areas to reduce health disparities across Beijing.
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Infarto do Miocárdio , Teorema de Bayes , Pequim/epidemiologia , Estudos Transversais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologiaRESUMO
Non-fullerene organic photovoltaics (OPVs) have displayed the highest power conversion efficiencies (PCEs) among OPVs. Herein, we describe a two-donor (PM6, TPD-3F)/one-acceptor (Y6) ternary blend having an optimized blend morphology that leads to improved OPV performance. Because TPD-3F has a HOMO energy level deeper than that of PM6, the value of VOC of the corresponding ternary device increased. Good miscibility between PM6 and TPD-3F, in conjunction with device optimization through the use of 1-chloronaphthalene as an additive, provided an optimized ternary blend morphology for efficient exciton dissociation and carrier transport and, therefore, larger PCE. Compared with the preoptimized PM6:Y6 binary device, the ternary device functioned with improvements in its short-circuit current density, value of VOC, and fill factor. As a result, the device PCE improved from 15.5 ± 0.19 to 16.6 ± 0.25% under AM 1.5G (100 mW cm-2) irradiation. The champion cell exhibited a PCE of 17.0%-a value that is one of the highest for a ternary OPV. Furthermore, such devices exhibited outstanding shelf lifetimes, with long-term stability in air (25 °C, 40% humidity) without encapsulation; the performance remained high (at 15.4%) after storage for 820 h.
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Li-CO2 batteries are promising energy storage devices owing to their high energy density and possible applications for CO2 capture. However, still some critical issues, such as high charging overpotential and poor cycling stability caused by the sluggish decomposition of Li2CO3 discharge products, need to be addressed before the practical applications of Li-CO2 batteries. Exploring highly efficient catalysts and understanding their catalytic mechanisms for the CO2 reduction reaction (CORR) and evolution reaction (COER) are critical for the application of Li-CO2 batteries. However, the direct imaging of electrocatalysis during CORR and COER is still elusive. Herein, we report the in situ imaging of electrocatalysis during CORR and COER in a Li-CO2 nanobattery using a Ni-Ru-coated α-MnO2 nanowire (Ni-Ru/MnO2) cathode in an advanced aberration corrected environmental transmission electron microscope. During the CORR, a thick Li2CO3 and carbon mixture layer was formed on the surface of the Ni-Ru/MnO2 nanowires via 4Li+ + 3CO2 + 4e-â 2Li2CO3 + C. During the COER, the as-formed Li2CO3 decomposed via 2Li2CO3â 2CO2 + O2 + 4Li+ + 4e-, while the as-formed amorphous carbon remained. In contrast, the decomposition of Li2CO3 on bare MnO2 nanowires was difficult, underscoring the important Ni-Ru bimetal electrocatalytic role in facilitating the COER. Our results provide an important understanding of the CO2 chemistry in Li-CO2 batteries, possibly helping in the designing of Li-CO2 batteries for energy storage applications.
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In this paper, an improved polar decoder based on non-identical Gaussian distributions is proposed and experimentally demonstrated for optical pulse amplitude modulation (PAM) interconnection. The principle of the polar coded PAM system is illustrated theoretically and the non-identical Gaussian distributions based log-likelihood ratio (LLR) estimation is introduced in the polar decoder to mitigate nonlinearity. Transmission systems of 28-Gbaud 4-level pulse amplitude modulation (PAM-4) and 8-level pulse amplitude modulation (PAM-8) based on commercial 10-GHz directly modulated laser (DML) are both demonstrated over 10-km standard single-mode fiber (SSMF) in C-band without dispersion compensation. Experimental results show that, aided by the improved polar decoder, the channel nonlinearity can be taken into consideration and additional sensitivity gains of 0.7 dB and 1 dB are respectively achieved compared with traditional polar decoder for PAM-4 and PAM-8 systems.
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In this research, we performed scanning electrochemical microscopy to screen M x (In0.2Cd0.8)1-x S (M = V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Ag, W, Ir, Pt, and Te) photocatalyst arrays for efficient photoelectrochemical reaction. Doping 30% Ag to form the Ag0.3(In0.2Cd0.8)0.7S electrode could result in the highest photocurrent, and also, the anode photocurrents were found to be 1 and 0.53 mA/cm2 under UV-visible and visible light, respectively, comparatively higher than that of the In0.2Cd0.8S electrode (0.45 and 0.25 mA/cm2). The highest incident photo-to-current conversion efficiency of the Ag0.3(In0.2Cd0.8)0.7S photocatalyst and In0.2Cd0.8S were found to be 64% (λ = 450 nm) and 57% (λ = 400 nm), respectively. The Mott-Schottky plots showed that In0.2Cd0.8S and Ag0.3(In0.2Cd0.8)0.7S photoelectrodes could exhibit a flat-band potential of -0.85 and -0.55 V versus Ag/AgCl, respectively. Based on these findings, the superior photocatalytic activity of the Ag0.3(In0.2Cd0.8)0.7S photoelectrode was mainly attributed to its high crystalline structure for efficient charge separation and reduction of charge recombination in the heterojunction of Ag0.3(In0.2Cd0.8)0.7S and Ag2S.
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A trace-O2-assisted aprotic Li-CO2 battery represents a promising approach for CO2 recycling. However, cathode passivation and large overpotential are frequently observed for current Li-CO2 batteries because of the insolubility and nonconductivity of the discharge product of lithium carbonate (Li2CO3). Toward maximizing the energy capabilities of the Li-CO2 electrochemistry, it is crucially important to have a fundamental understanding of the Li2CO3 formation mechanism in Li-CO2 batteries. In this report, the discharge reaction of a trace-O2-assisted Li-CO2 battery has been interrogated with in situ surface-enhanced Raman spectroscopy. It was found that in high-donor-number (DN) solvents Li2CO3 formation proceeds primarily via an "electrochemical solution route", with peroxodicarbonate (C2O62-) as the key intermediate, whereas in low-DN solvents Li2CO3 forms via a chemical reaction of Li2O2 and CO2 on the cathode surface, namely, a "chemical surface route". It is notable that during discharge the trace-O2 acts as a "pseudo-catalyst" to activate CO2 in high-DN solvents but not in low-DN solvents. The mechanistic study presented here will assist us in tailor-designing better electrolyte systems and enable more energetic electrochemistry operation far away from the poison of Li2CO3.
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In this study, we synthesized 5,11-dihexyl-4,4,10,10-tetraoctylbenzo[1,2- b:4,5- b']bisthieno[4â³,5â³- bâ³:4â´,5â´- bâ´]silolo[2â³,3â³- d:2â´,3â´- d']thiophene (ArSi) as a ladder-type electron-rich core for the preparation of three acceptor-donor-acceptor-type nonfullerene acceptors (NFAs)-ArSiID, ArSiID-F, and ArSiID-Cl-featuring (3-oxo-2,3-dihydro-1 H-inden-1-ylidene)malononitrile (ID), 2-(5,6-difluoro-3-oxo-2,3-dihydro-1 H-inden-1-ylidene)malononitrile (ID-F), and 2-(5,6-dichloro-3-oxo-2,3-dihydro-1 H-inden-1-ylidene)malononitrile (ID-Cl) as peripheral electron-poor units, respectively. These molecules exhibit strong absorption covering the region of 600-850 nm. The incorporation of the halogen atoms onto the terminal units adjusted the energy levels and light-harvesting ability of these materials. We employed the conjugated polymers J51 and PBDB-T, having middle optical energy gaps as donor together with these ArSi derivatives as acceptor to study the blend film morphology and the corresponding organic photovoltaic (OPV) performances. After optimization with device engineering works, a PBDB-T:ArSiID-F-based device with a power conversion efficiency up to 9.4% was achieved. This study is the first case to examine the effects of various halogen modifications on the performance of ArSi derivatives that serve as NFAs for OPVs. Our findings should encourage further investigations on this rarely studied core structure for optoelectronic applications.