Industrial Waste Derived Separators for Zn-Ion Batteries Achieve Homogeneous Zn(002) Deposition Through Low Chemical Affinity Effects.

Designing a cost-effective and multifunctional separator that ensures dendrite-free and stable Zn metal anode remains a significant challenge. Herein, a multifunctional cellulose-based separator is presented consisting of industrial waste-fly ash particles and cellulose nanofiber using a facile solution-coating method. The resulting fly ash-cellulose (FACNF) separators enable a high ion conductivity (5.76 mS cm-1) and low desolvation energy barrier of hydrated Zn2+. These features facilitate fast ion transfer kinetics and inhibit water-induced side reactions. Furthermore, experimental results and theoretical simulations confirm that the presence of fly ash particles in FACNF separators effectively accommodate the preferential deposition of Zn(002) planes, due to the weak chemical affinity between Zn(002) plane and fly ash, to mitigate dendrite formation and growth. Consequently, the utilization of FACNF separators causes an impressive cycling performance in both Zn||Zn symmetric cells (1600 h at 2 mA cm-2/1 mAh cm-2) and Zn||(NH4)2V10O25 (NVO) full cells (4000 cycles with the capacity retention of 92.1% at 5 A g-1). Furthermore, the assembled pouch cells can steadily support digital thermometer over two months without generating gas and volume expansion. This work provides new insights for achieving crystallographic uniformity in Zn anodes and realizing cost-effective and long-lasting aqueous zinc-ion batteries (AZIBs).

Vibrational frequencies of CO bound to all three low-index cerium oxide surfaces: A consistent theoretical description of vacancy-induced changes using density functional theory.

The facet-dependent adsorption of CO on oxidized and reduced CeO2 single crystal surfaces is reviewed, with emphasis on the effect of CO coverage and the ability of state-of-the-art quantum-mechanical methods to provide reliable energies and an accurate description of the IR vibrational frequency of CO. Comparison with detailed, high-resolution experimental infrared reflection absorption spectroscopy data obtained for single crystal samples allows the assignment of the different CO vibrational bands observed on all three low-index ceria surfaces. Good agreement is achieved with the hybrid density functional theory approach with the HSE06 functional and with saturation coverage. It is shown that CO is very sensitive to the structure of cerium oxide surfaces and to the presence of oxygen vacancies. The combined theoretical-experimental approach offers new opportunities for a better characterization of ceria nanoparticles and for unraveling changes occurring during reactions involving CO at higher pressures.

Erratum: Vibrational Frequencies of Cerium-Oxide-Bound CO: A Challenge for Conventional DFT Methods [Phys. Rev. Lett. 125, 256101 (2020)].

This corrects the article DOI: 10.1103/PhysRevLett.125.256101.

Association between childhood friendship and cognitive ageing trajectory in later life: evidence from the China Health and Retirement Longitudinal Study (CHARLS).

BACKGROUND: Childhood experience has been suggested to affect cognitive function in later life. However, the association between childhood friendship status and cognitive ageing trajectory in middle-aged and older adults has not been fully assessed. This study examined the association between childhood friendship status and cognitive ageing trajectory and identified factors modifying this association. METHODS: We used four waves of data from the China Health and Retirement Longitudinal Study (CHARLS), a national representative longitudinal study of adults aged 45 years or older, 2011-2018. The CHARLS included surveys on childhood friendship and cognitive assessments. Childhood friendship status was categorised as poor, fair, and good. To examine the association between childhood friendship and cognitive ageing trajectory in later life, we applied multilevel linear regression models, and explored potential influences of sociodemographic factors, health status and behaviours, and childhood conditions on this association. RESULTS: Of the 4,350 participants, 1,919 (44.1%) were women. The mean age was 56.29 ± 7.80 years. We found childhood friendship was significantly associated with cognitive ageing trajectory in later life, with a dose-response relationship. After adjusting for covariates, comparing to participants with poor childhood friendships, those with better childhood friendships had lower rates of cognitive decline (ß = 0.12, 95% confidence interval [CI]: 0.03 to 0.22 [interaction term of fair friendship and time]; ß = 0.19, 95% CI: 0.10 to 0.28 [interaction term of good friendship and time]) and higher level of cognitive functions (ß = 0.40, 95% CI: 0.22 to 0.58 [fair friendships]; ß = 0.61, 95% CI: 0.43 to 0.79 [good friendships]). These associations were stronger for those who were female, less educated, and had experienced more adverse childhood experiences. CONCLUSIONS: Childhood friendship is associated with cognitive ageing in later life. Enhancing childhood friendships can play an important role to promote healthy ageing in the future.

Integrating Validity Evidence to Revise a Child Abuse Knowledge Test for Early Childhood Education Providers: A Mixed Methods Approach.

Knowledge tests used to evaluate child protection training program effectiveness for early childhood education providers may suffer from threats to construct validity given the contextual variability inherent within state-specific regulations around mandated reporting requirements. Unfortunately, guidance on instrument revision that accounts for such state-specific mandated reporting requirements is lacking across research on evaluation practices. This study, therefore, explored how collection and integration of validity evidence using a mixed methods framework can guide the instrument revision process to arrive at a more valid program outcome measure.

Vibrational Frequencies of Cerium-Oxide-Bound CO: A Challenge for Conventional DFT Methods.

In ceria-based catalysis, the shape of the catalyst particle, which determines the exposed crystal facets, profoundly affects its reactivity. The vibrational frequency of adsorbed carbon monoxide (CO) can be used as a sensitive probe to identify the exposed surface facets, provided reference data on well-defined single crystal surfaces together with a definitive theoretical assignment exist. We investigate the adsorption of CO on the CeO_{2}(110) and (111) surfaces and show that the commonly applied DFT(PBE)+U method does not provide reliable CO vibrational frequencies by comparing with state-of-the-art infrared spectroscopy experiments for monocrystalline CeO_{2} surfaces. Good agreement requires the hybrid DFT approach with the HSE06 functional. The failure of conventional density-functional theory (DFT) is explained in terms of its inability to accurately describe the facet- and configuration-specific donation and backdonation effects that control the changes in the C─O bond length upon CO adsorption and the CO force constant. Our findings thus provide a theoretical basis for the detailed interpretation of experiments and open up the path to characterize more complex scenarios, including oxygen vacancies and metal adatoms.

Switchable microwave photonic filter based on a dual-parallel Mach-Zehnder modulator.

We present a switchable and tunable microwave photonic filter (MPF) based on a dual-parallel Mach-Zehnder modulator (DPMZM) and a tunable optical bandpass filter (TOBPF). The MPF is switchable between low-pass and bandpass responses by simply tuning the bias voltage of the DPMZM. In addition, the MPF is widely tunable in terms of bandwidth and center frequency by adjusting the TOBPF.

Optical vector network analyzer based on double-sideband modulation.

We report an optical vector network analyzer (OVNA) based on double-sideband (DSB) modulation using a dual-parallel Mach-Zehnder modulator. The device under test (DUT) is measured twice with different modulation schemes. By post-processing the measurement results, the response of the DUT can be obtained accurately. Since DSB modulation is used in our approach, the measurement range is doubled compared with conventional single-sideband (SSB) modulation-based OVNA. Moreover, the measurement accuracy is improved by eliminating the even-order sidebands. The key advantage of the proposed scheme is that the measurement of a DUT with bandpass response can also be simply realized, which is a big challenge for the SSB-based OVNA. The proposed method is theoretically and experimentally demonstrated.

Carbon Dioxide Adsorption on CeO2 (110): An XPS and NEXAFS Study.

The adsorption of CO2 on the surface of a CeO2 (110) bulk single crystal was studied by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The high-quality XPS and C K-edge NEXAFS data show that CO2 adsorbs as a carbonate species on both fully oxidized CeO2 (110) and partially reduced CeO2-x (110). No evidence for the formation of a carboxylate (CO2δ- ) intermediate could be found. On the fully oxidized CeO2 (110) substrate, the carbonate decomposes upon heating to above 400 K, leading to the desorption of CO2 . The NEXAFS data reveal the presence of a minor amount of formate (or carboxylate) and bicarbonate species, which are related to reactions of CO2 with surface hydroxyl groups. In the case of reduced CeO2-x (110), the carbonate species completely disappear upon heating to temperatures above 500 K. In contrast to conclusions presented in earlier works, the oxidation state of the surface is unchanged, that is, CO2 does not re-oxidize the reduced CeO2-x (110) surface.

Surface Faceting and Reconstruction of Ceria Nanoparticles.

The surface atomic arrangement of metal oxides determines their physical and chemical properties, and the ability to control and optimize structural parameters is of crucial importance for many applications, in particular in heterogeneous catalysis and photocatalysis. Whereas the structures of macroscopic single crystals can be determined with established methods, for nanoparticles (NPs), this is a challenging task. Herein, we describe the use of CO as a probe molecule to determine the structure of the surfaces exposed by rod-shaped ceria NPs. After calibrating the CO stretching frequencies using results obtained for different ceria single-crystal surfaces, we found that the rod-shaped NPs actually restructure and expose {111} nanofacets. This finding has important consequences for understanding the controversial surface chemistry of these catalytically highly active ceria NPs and paves the way for the predictive, rational design of catalytic materials at the nanoscale.

Rendering Photoreactivity to Ceria: The Role of Defects.

The photoreactivity of ceria, a photochemically inert oxide with a large band gap, can be increased to competitive values by introducing defects. This previously unexplained phenomenon has been investigated by monitoring the UV-induced decomposition of N2 O on well-defined single crystals of ceria by using infrared reflection-absorption spectroscopy (IRRAS). The IRRAS data, in conjunction with theory, provide direct evidence that reducing the ceria(110) surface yields high photoreactivity. No such effects are seen on the (111) surface. The low-temperature photodecomposition of N2 O occurs at surface O vacancies on the (110) surface, where the electron-rich cerium cations with a significantly lowered coordination number cause a local lowering of the huge band gap (ca. 6 eV). The quantum efficiency of strongly reduced ceria(110) surfaces in the photodecomposition of N2 O amounts to 0.03 %, and is thus comparable to that reported for the photooxidation of CO on rutile TiO2 (110).

O2 Activation on Ceria Catalysts-The Importance of Substrate Crystallographic Orientation.

An atomic-level understanding of dioxygen activation on metal oxides remains one of the major challenges in heterogeneous catalysis. By performing a thorough surface-science study of all three low-index single-crystal surfaces of ceria, probably the most important redox catalysts, we provide a direct spectroscopic characterization of reactive dioxygen species at defect sites on the reduced ceria (110) and (100) surfaces. Surprisingly, neither of these superoxo and peroxo species was found on ceria (111), the thermodynamically most stable surface of this oxide. Applying density functional theory, we could relate these apparently inconsistent findings to a sub-surface diffusion of O vacancies on (111) substrates, but not on the less-closely packed surfaces. These observations resolve a long standing debate concerning the location of O vacancies on ceria surfaces and the activation of O2 on ceria powders.

Microwave photonic bandstop filter with wide tunability and adjustable bandwidth.

A microwave photonic bandstop filter is proposed and experimentally demonstrated in this work. The filter exhibits promising performance combination of reconfigurability, frequency tunability, and bandwidth adjustment. The phase modulation on two orthogonal polarization states produces a bandpass and a lowpass MPF, respectively. The key concept of destructive interference between the bandpass and lowpass MPF enables the reconfiguration of MPF from bandpass to bandstop. By adjusting the wavelength of two orthogonally polarized optical carriers and the bandwidth of an optical bandpass filter, the bandstop filter is tunable in terms of center frequency and bandwidth.

UV-Induced Tetrazole-Thiol Reaction for Polymer Conjugation and Surface Functionalization.

A UV-induced 1,3-dipolar nucleophilic addition of tetrazoles to thiols is described. Under UV irradiation the reaction proceeds rapidly at room temperature, with high yields, without a catalyst, and in both polar protic and aprotic solvents, including water. This UV-induced tetrazole-thiol reaction was successfully applied for the synthesis of small molecules, protein modification, and rapid and facile polymer-polymer conjugation. The reaction has also been demonstrated for the formation of micropatterns by site-selective surface functionalization. Superhydrophobic-hydrophilic micropatterns were successfully created by sequential modifications of a tetrazole-modified porous polymer surface with hydrophobic and hydrophilic thiols. A biotin-functionalized surface could be fabricated in aqueous solutions under long-wavelength UV irradiation.

Chemical activity of oxygen vacancies on ceria: a combined experimental and theoretical study on CeO2(111).

The chemical activity of oxygen vacancies on well-defined, single-crystal CeO2(111)-surfaces is investigated using CO as a probe molecule. Since no previous measurements are available, the assignment of the CO ν1 stretch frequency as determined by IR-spectroscopy for the stoichiometric and defective surfaces are aided by ab initio electronic structure calculations using density functional theory (DFT).

Tuning Vertical Electrodeposition for Dendrites-Free Zinc-Ion Batteries.

Manipulating the crystallographic orientation of zinc deposition is recognized as an effective approach to address zinc dendrites and side reactions for aqueous zinc-ion batteries (ZIBs). We introduce 2-methylimidazole (Mlz) additive in zinc sulfate (ZSO) electrolyte to achieve vertical electrodeposition with preferential orientation of the (100) and (110) crystal planes. Significantly, the zinc anode exhibited long lifespan with 1500 h endurance at 1 mA cm-2 and an excellent 400 h capability at a depth of discharge (DOD) of 34% in Zn||Zn battery configurations, while in Zn||MnO2 battery assemblies, a capacity retention of 68.8% over 800 cycles is attained. Theoretical calculation reveals that the strong interactions between Mlz and (002) plane impeding its growth, while Zn atoms exhibit lower migration energy barrier and superior mobility on (100) and (110) crystal planes guaranteed the heightened mobility of zinc atoms on the (100) and (110) crystal planes, thus ensuring their superior ZIB performance than that with only ZSO electrolyte, which offers a route for designing next-generation high energy density ZIB devices.

High-Rate and Ultra-Stable aqueous Zinc-Ion batteries enabled by Potassium-Infused ammonium vanadate nanosheets.

Aqueous zinc-ion batteries (AZIBs), defined by low expenses, superior safety, and plentiful reserves, demonstrate tremendous development potential in energy storage systems at the grid scale. Whereas the cathode instability and the limited diffusion of Zn2+ have impeded the development of AZIBs. Herein, a high-performance K-NH4V4O10 (K-NVO) cathode with K+ doping synthesized successfully through one-step hydrothermal approach. Experiments and density functional theory (DFT) calculations indicate that K-NVO has Zn2+ diffusion pathways with lower barriers for smoother transport, and lower formation energy. The combination of the rapid Zn2+ diffusion and the stable structure results in outstanding electrochemical performance of K-NVO as demonstrated in tests. K-NVO cathode achieves a specific capacity of 406 mAh g-1 at 0.2 A g-1, maintains satisfactory cyclic stability with 81.6 % capacity retention after 1000 cycles at 5 A g-1, and possesses a high energy density of 350.9 Wh kg-1. Furthermore, confirmation of the zinc storage mechanism in K-NVO was carried out through Ex situ tests, such as XRD and XPS. This research contributes a unique perspective to the formulation of high-performance cathode materials for AZIBs.

Predictive value of C-reactive protein for disease severity and survival in COVID-19 patients: a systematic review and meta-analysis.

Coronavirus disease 2019 (COVID-19) is an infectious disease that can develop multiple complications and even be life-threatening. The aim of this study is to summarize current evidence of C-reactive protein's (CRP) predictive value for disease severity and survival of COVID-19 patients, focusing on curing patients and reducing the risk of death. We systematically searched related studies from four large databases: Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), and Wanfang Database, all published between December 2019 and June 2021. Then, we implemented meta-analysis using random-effects models through STATA 15.1 and Review Manager 5.3. We also implemented sensitivity analysis and used funnel plots to check publication bias. From the systematic search of the four databases, we were able to identify 18 studies containing a total of 3052 patients. Meta-analysis results showed that 1) CRP levels were lower in non-severe patients than in severe patients (Standardized Mean Difference (SMD) = - 0.87 mg/L, 95% Confidence Interval (CI) = [ - 1.27, - 0.47], p < 0.001); 2) CRP levels were lower in non-intensive care unit (ICU) patients than in ICU patients (SMD = - 1.39 mg/L, 95% CI = [- 1.68, - 1.11], p < 0.001), and 3) CRP levels were lower in survivors than in non-survivors (SMD =- 1.32 mg/L, 95% CI = [- 1.95, - 0.69], p < 0.001). Sensitivity analysis showed these results were stable. Funnel plots indicated no publication bias. The CRP level may timely reflect disease severity and predict survival of COVID-19 patients and may be worthy of further popularization and application in clinic practice.