Machine Learning‐Enabled Correlation and Modeling of Multimodal Response of Thin Film to Environment on Macro and Nanoscale Using “Lab‐on‐a‐Crystal”

To close the feedback loop between artificial intellegence‐controlled materials synthesis and characterization, material functionality must be rapidly tested. A platform for high‐throughput multifunctional materials characterization is developed using a quartz crystal microbalance with auxiliary in‐plane electrodes and a custom gas/vapor flow cell, enabling simultaneous scanning probe microscopy and electrical, optical, gravimetric, and viscoelastic characterization on the same film under controlled environment. The lab‐on‐a‐crystal in situ multifunctional output allows direct correlations between the gravimetric/viscoelastic, electrical, and optical responses of polymer film in response to environment. When multiple film properties are used to augment the training set for machine learning regression, prediction of material response to the environment improves by a factor of 13 when <5% of the total dataset is used for model training.     

Effect of magnesium aluminum silicate glass on the thermal shock resistance of BN matrix composite ceramics

The effects of magnesium aluminum silicate (MAS) glass on the thermal shock resistance and the oxidation behavior of h‐BN matrix composites were systematically investigated at temperature differences from 600°C up to 1400°C. The retained strength rate of the composites rose with the increasing content of MAS showing a maximum value at the 60 wt% MAS. Compared with the original strength, the retained strength of the specimen after thermal shock increased to 77% (ΔT=1000°C). The strengthening effect of MAS and the surface microstructural evolution of composites are responsible for the improved thermal shock resistance. Surface oxidation of the composites during the thermal shock process plays a positive role in enhancing the retained strength by self‐healing cracks and the appearance of the compressive stress. The oxide layer also acted as a thermal barrier to decelerate the actual thermal stress. Furthermore, this dense layer also improved the oxidation resistance of h‐BN matrix composites by prevent diffusion of oxygen. These results indicated that short‐term surface oxidation during thermal shock process is favorable to the enhancement of the thermal shock resistance of BN‐MAS composite ceramics.     

Sliding mode control of boost and buck‐boost power converters using the dynamic sliding manifold

Non‐minimum phase tracking control is studied for boost and buck‐boost power converters. A sliding mode control algorithm is developed to track directly a causal voltage tracking profile given by an exogenous system. The approximate causal output non‐minimum phase asymptotic tracking in non‐linear boost and buck‐boost power converters is addressed via sliding mode control using a dynamic sliding manifold (DSM). Use of DSM allows the stabilization of the internal dynamics when the output tracking error tends asymptotically to zero in the sliding mode. The sliding mode controller with DSM links features of conventional sliding mode control (insensitivity to matched non‐linearities and disturbances) and a conventional dynamic compensator (accommodation to unmatched disturbances). Numerical examples demonstrate the effectiveness of the sliding mode controller even for a known time‐varying load. Copyright © 2003 John Wiley & Sons, Ltd.     

Changes in interleukin-1 beta and soluble interleukin-2 receptor levels in CSF and serum of schizophrenic patients

Some evidence points towards a possible autoimmune role in the aetiology of schizophrenia. Experimental findings provide contradictory results regarding abnormalities in cytokine production in this disorder. In the present study we tested the production of cytokines in CSF and serum in 16 schizophrenic patients and 10 healthy controls (tumor necrosis factor alpha - TNF alpha; interleukins IL-1 beta, IL-2, IL-6, soluble IL-2 receptor). Cytokine levels were evaluated by radioactively-labeled antibodies (IL-1 beta, IL-2, IL-6), by enzyme-linked immunoassay (TNF) and by a sandwich enzyme immunoassay (soluble IL-2 receptor). No significant differences were found in either CSF fluid or serum levels of TNF and IL-2 or IL-6. Interleukin-1 beta was significantly decreased in patients' CSF and serum as compared to controls. Soluble interleukin-2 receptor levels were decreased in CSF of patients, but highly increased in their serum in comparison with controls. Changes in various cytokine levels in CSF fluid and serum of schizophrenic patients probably reflect interrelated process of growth, degeneration or neuroimmunological abnormalities, which may all play a role in the pathophysiology of schizophrenia. The present study supports evidence for change in immune activation, probably of peripheral origin, in schizophrenic patients.     

Single-crystal microplates of two-dimensional organic–inorganic lead halide layered perovskites for optoelectronics

Organic-inorganic hybrid perovskites attract considerable attention owing to their applications in high-efficiency solar cells and light emission.Compared with three-dimensional perovskites,two-dimensional (2D) layered hybrid perovskites have a higher exciton binding energy and potentially higher light-emission efficiency.The growth of high-quality crystalline 2D perovskites with a well-defined nanoscale morphology is desirable because they can be suitable building blocks for integrated optoelectronics and (nano)photonics.Herein,we report the facile solution growth of single-crystal microplates of 2D perovskites based on a 2-phenylethylammonium (C6H5CH2CH2NH3+,PEA) cation,(PEA)2PbX4 (X =Br,I),with a well-defined rectangular geometry and nanoscale thickness through a dissolution-recrystallization process.The crystal structures of (PEA)2PbX4 are first confirmed using single-crystal X-ray diffraction.A solution-phase transport-growth process is developed to grow microplates with a typical size of tens of micrometers and thickness of hundreds of nanometers on another clean substrate different from the substrate coated with lead-acetate precursor film.Surface-topography analysis suggests that the formation of the 2D microplates is likely driven by the wedding-cake growth mechanism.Through halide alloying,the photoluminescence emission of (PEA)2Pb(Br,I)4 perovskites with a narrow peak bandwidth is readily tuned from violet (～410 nm) to green (～530 nm).     

Patterns of stability in adult attachment: An empirical test of two models of continuity and change.

One of the core assumptions of attachment theory is that attachment representations are stable over time. Unfortunately, the data on attachment stability have been ambiguous, and as a result, alternative theoretical perspectives have evolved to explain them. The objective of the present research was to evaluate alternative models of stability by studying adults in 2 intensive longitudinal investigations. Specifically, we assessed attachment representations in 1 sample (N = 203) daily over a 30-day period and in the other sample (N = 388) weekly over a year. Analyses show that the patterns of stability that exist in adult attachment are most consistent with a prototype model—a model assuming that there is a stable factor underlying temporary variations in attachment. Moreover, although the Big Five personality traits exhibited a pattern of stability that was similar to that of attachment, they did not account for the stability observed in attachment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A maximum entropy type test of fit

In this paper, we propose a test of fit based on maximum entropy. The asymptotic distribution of the proposed test statistic is established and a corrected form for small and medium sample sizes is furnished. The performance of the test is investigated through extensive Monte Carlo simulations. Real examples are also presented and analyzed.     

A taxometric study of the Adult Attachment Interview.

This study is the first to examine the latent structure of individual differences reflected in the Adult Attachment Interview (AAI; C. George, N. Kaplan, & M. Main, 1985), a commonly used and well-validated measure designed to assess an adult's current state of mind regarding childhood experiences with caregivers. P. E. Meehl's (1995) taxometric methods (i.e., MAXCOV-HITMAX) were applied to data from 504 AAIs. Analyses revealed that the variation underlying secure versus dismissing states of mind was more consistent with a dimensional than a taxonic model. (Taxometric analyses of preoccupation were indeterminate.) In addition, variation in secure adults' (n = 278) reports about their early experiences revealed little evidence for qualitative groups of earned- and continuous-secures. Rather, the inferred life experiences of secure adults appeared to be distributed continuously. Findings are discussed in terms of their theoretical implications regarding the phenomenon of earned-security specifically and variation underlying secure and insecure states of mind more generally. The consequences of these analyses for AAI reliability training and coding are also explored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)