Psychological research has increasingly recognized the importance of integrating temporal dynamics into its theories, and innovations in longitudinal designs and analyses have allowed such theories to be formalized and tested. However, psychological researchers may be relatively unequipped to analyze such data, given its many characteristics and the general complexities involved in longitudinal modeling. The current paper introduces time series analysis to psychological research, an analytic domain that has been essential for understanding and predicting the behavior of variables across many diverse fields. First, the characteristics of time series data are discussed. Second, different time series modeling techniques are surveyed that can address various topics of interest to psychological researchers, including describing the pattern of change in a variable, modeling seasonal effects, assessing the immediate and long-term impact of a salient event, and forecasting future values. To illustrate these methods, an illustrative example based on online job search behavior is used throughout the paper, and a software tutorial in R for these analyses is provided in the Supplementary Materials.

A novel bismuth–carbon composite, in which bismuth nanoparticles were anchored in a nitrogen-doped carbon matrix (Bi@NC), is proposed as anode for high volumetric energy density lithium ion batteries (LIBs). Bi@NC composite was synthesized via carbonization of Zn-containing zeolitic imidazolate (ZIF-8) and replacement of Zn with Bi, resulting in the N-doped carbon that was hierarchically porous and anchored with Bi nanoparticles. The matrix provides a highly electronic conductive network that facilitates the lithiation/delithiation of Bi. Additionally, it restrains aggregation of Bi nanoparticles and serves as a buffer layer to alleviate the mechanical strain of Bi nanoparticles upon Li insertion/extraction. With these contributions, Bi@NC exhibits excellent cycling stability and rate capacity compared to bare Bi nanoparticles or their simple composites with carbon. This study provides a new approach for fabricating high volumetric energy density LIBs.Electronic supplementary materialThe online version of this article (10.1007/s40820-018-0209-1) contains supplementary material, which is available to authorized users.

All‐solid‐state zinc–air batteries are characterized as low cost and have high energy density, providing wearable devices with an ideal power source. However, the sluggish oxygen reduction and evolution reactions in air cathodes are obstacles to its flexible and rechargeable application. Herein, a strategy called MOF‐on‐MOF (MOF, metal‐organic framework) is presented for the structural design of air cathodes, which creatively develops an efficient oxygen catalyst comprising hierarchical Co 3 O 4 nanoparticles anchored in nitrogen‐doped carbon nano‐micro arrays on flexible carbon cloth (Co 3 O 4 @N‐CNMAs/CC). This hierarchical and free‐standing structure design guarantees high catalyst loading on air cathodes with multiple electrocatalytic activity sites, undoubtedly boosting reaction kinetics, and energy density of an all‐solid‐state zinc–air battery. The integrated Co 3 O 4 @N‐CNMAs/CC cathode in an all‐solid‐state zinc–air battery exhibits a high open circuit potential of 1.461 V, a high capacity of 815 mAh g −1 Zn at 1 mA cm −2 , a high energy density of 1010 Wh kg −1 Zn, excellent cycling stability as well as outstanding mechanical flexibility, significantly outperforming the Pt/C‐based cathode. This work opens a new door for the practical applications of rechargeable zinc–air batteries in wearable electronic devices.

Electrochemical impedance spectra (EIS) of Li+ insertion in spinel Li x Mn2O4 (0 ≤ x ≤ 1) were obtained by using a powder microelectrode. A new equivalent circuit, distinguishing the kinetic properties of Li+ insertion in Li x Mn2O4 at a lithium-rich state (0.5 ≤ x ≤ 1) from a lithium-depleted state (0 ≤ x < 0.5), is proposed to simulate the experimental EIS. The fitting results are in good agreement with the experimental results, and parameters for the kinetic process of Li+ insertion in Li x Mn2O4 at different Li+ inserted states can be obtained with the proposed equivalent circuits as well as the modified Voigt−FMG equivalent circuit proposed by Aurbach et al. At the lithium-depleted state, Li+ ions diffuse rapidly and then occupy the available Li+ insertion sites in the Li x Mn2O4 lattice. Thus, the diffusion process and occupation process occur successively at the lithium-depleted state, and this process can be well-simulated with the modified Voigt−FMG equivalent circuit, in which Warburg impedance and occupation capacitance are in series. At the lithium-rich state, however, the diffusion speed of the Li+ ions decreases due to the repulsive effect from the inserted Li+ ions. The diffusion of Li+ ions in the lattice takes place at the same time of the occupation of Li+ ions because the inserted Li+ ions have to hop and occupy their nearest neighbor vacant sites and vacate their sites for the incoming Li+ ions. Thus, the diffusion process and occupation process occur simultaneously, and Warburg impedance and occupation capacitance should be in parallel. The change of kinetic parameters of Li+ insertion in Li x Mn2O4 with potential and the influence of immersion time for Li x Mn2O4 in the electrolyte on the kinetic parameters are discussed in detail.