Relationship Between Warm Childhood Memories and Mobile Phone Addiction: A Moderated Mediation Model.

Childhood experiences have an important effect on mobile phone addiction, but the relationship between positive childhood experiences and mobile phone addiction and its underlying mechanisms should be explored further. This study aims to explore a model linking early memories of warmth and safeness to mobile phone addiction via the mediating role of alexithymia and moderating role of negative coping styles. A total of 379 Chinese college students (Mage = 19.80 years, SD = 1.38; 240 females) completed a questionnaire consisting of the Early Memories of Warmth and Safeness Scale, Toronto Alexithymia Scale, Mobile Phone Addiction Scale, and Negative Coping Styles Scale. Results indicate that early memories of warmth and safeness are negatively correlated with mobile phone addiction, and alexithymia plays a mediating role in the link between early memories of warmth and safeness and mobile phone addiction. In addition, negative coping styles significantly moderate the relationship between early memories of warmth and safeness and alexithymia, specifically, the negative association between early memories of warmth and safeness and alexithymia is highly significant at high (vs. low) negative coping styles levels. The findings suggest that early memories of warmth and safeness are an important protective factor against mobile phone addiction, which enrich the literature on mobile phone addiction and provide empirical support for the prevention of mobile phone addiction.

Comparative Study of Single Molecular Junctions with Para-Phthalic Acid and Meta-Phthalic Acid Binding to Different Metal Electrodes.

In this paper, single molecular junctions of Para-phthalic acid and Meta-phthalic acid with Au electrodes were studied by STM break junction approach. Conductance values of 10-3.55 G0 and 10-3.70 G0 were found for Para-phthalic acid and Meta-phthalic acid, respectively. The conductance order between Para-phthalic acid and Meta-phthalic acid with Au is different from that with Cu, which can be contributed to the different coupling between molecules and electrodes; different through-space interaction is proposed for such phenomenon between Cu and Au electrodes. Furthermore, the breaking off distances can reflect the length of molecules. The current work presents the important role of electrode in single molecular junctions with different position anchoring groups.

Low Tunneling Decay of Iodine-Terminated Alkane Single-Molecule Junctions.

One key issue for the development of molecular electronic devices is to understand the electron transport of single-molecule junctions. In this work, we explore the electron transport of iodine-terminated alkane single molecular junctions using the scanning tunneling microscope-based break junction approach. The result shows that the conductance decreases exponentially with the increase of molecular length with a decay constant ßN = 0.5 per -CH2 (or 4 nm-1). Importantly, the tunneling decay of those molecular junctions is much lower than that of alkane molecules with thiol, amine, and carboxylic acid as the anchoring groups and even comparable to that of the conjugated oligophenyl molecules. The low tunneling decay is attributed to the small barrier height between iodine-terminated alkane molecule and Au, which is well supported by DFT calculations. The work suggests that the tunneling decay can be effectively tuned by the anchoring group, which may guide the manufacturing of molecular wires.

Detecting Electron Transport of Amino Acids by Using Conductance Measurement.

The single molecular conductance of amino acids was measured by a scanning tunneling microscope (STM) break junction. Conductance measurement of alanine gives out two conductance values at 10-1.85 G0 (1095 nS) and 10-3.7 G0 (15.5 nS), while similar conductance values are also observed for aspartic acid and glutamic acid, which have one more carboxylic acid group compared with alanine. This may show that the backbone of NH2-C-COOH is the primary means of electron transport in the molecular junction of aspartic acid and glutamic acid. However, NH2-C-COOH is not the primary means of electron transport in the methionine junction, which may be caused by the strong interaction of the Au-SMe (methyl sulfide) bond for the methionine junction. The current work reveals the important role of the anchoring group in the electron transport in different amino acids junctions.

Comparative Study on Single-Molecule Junctions of Alkane- and Benzene-Based Molecules with Carboxylic Acid/Aldehyde as the Anchoring Groups.

We have measured the alkane and benzene-based molecules with aldehyde and carboxylic acid as anchoring groups by using the electrochemical jump-to-contact scanning tunneling microscopy break junction (ECSTM-BJ) approach. The results show that molecule with benzene backbone has better peak shape and intensity than those with alkane backbone. Typically, high junction formation probability for same anchoring group (aldehyde and carboxylic acid) with benzene backbone is found, which contributes to the stronger attractive interaction between Cu and molecules with benzene backbone. The present work shows the import role of backbone in junction, which can guide the design molecule to form effective junction for studying molecular electronics.