SearcharxivSearch

arXiv subjects

Zhi Liang

Publications and source records attributed to Zhi Liang.

5 recordsLinked to original sources

Gridspec: A standard for the description of grids used in Earth System models

The comparative analysis of output from multiple models, and against observational data analysis archives, has become a key methodology in reducing uncertainty in climate projections, and in improving forecast skill of medium- and long-term forecasts. There is considerable momentum toward simplifying such analyses by applying comprehensive community-standard metadata to observational and model output data archives. The representation of gridded data is a critical element in describing the contents of model output. We seek here to propose a standard for describing the grids on which such data are discretized. The standard is drafted specifically for inclusion within the Climate and Forecasting (CF) metadata conventions. The contents of this paper have been in the "grey literature" since 2007: it has been posted to arXiv to be citable. To preserve its integrity, the contents have not been updated.

physics.ao-ph

Protein token: a dynamic unit in protein interactions

In this study, we introduced a new unit, named "protein token", as a dynamic protein structural unit for protein-protein interactions. Unlike the conventional structural units, protein token is not based on the sequential or spatial arrangement of residues, but comprises remote residues involved in cooperative conformational changes during protein interactions. Application of protein token on Ras GTPases revealed various tokens present in the superfamily. Distinct token combinations were found in H-Ras interacting with its various regulators and effectors, directing to a possible clue for the multiplexer property of Ras superfamily. Thus, this protein token theory may provide a new approach to study protein-protein interactions in broad applications.

q-bio.BM

Low Temperature Dependence in 1H CRAMPS & 13C CP/MAS ssNMR Spectra of Alanine Enantiomers

1H RAMPS solid state NMR and 13C CP/MAS spectra of D- and L- alanine crystals were measured at temperature ranging from 220K to 295K. Some major points are as follows: (1)alpha-H and protons in the methyl group showed a spin-spin coupling effect as temperature went down in the 1H- MAS spectra of D-alanine. (2) In the 1H CRAMPS spectra, peak widths of alpha-H and beta-H showed a different trend between alanine enantiomers when temperature varied.(3) The dynamic behavior of 13C spectra showed an obvious change around 250K, which was supposed as a phase transition in alanine crystal. In the discussion section, we give these experimental phenomena a possible explanation related to chirality.

physics.bio-ph

Search for the Parity-Violating Effects between D- and L-alanine

The contribution of parity-violating effects to the phase transition of the D-/L-alanine crystals was confirmed by 1H CRAMPS solid state NMR, DC-magnetic susceptibilities and ultrasonic measurements. It was found that the spin relaxation mechanism of alpha-H nucleus of D-alanine molecule is different from L-alanine and the effect is stronger than that of L-alanine. In addition, D-alanine undergoes a magnetic phase transition at a field of 1.0T, which is confirmed by a peak-form ultrasonic attenuation curve. DC-magnetic susceptibilities measurements of L-alanine also indicate abnormal magnetic properties, which is accompanied by a step-form ultrasonic attenuation jump and its mechanism seems different from that of D-alanine. The phase transition is considered to act as a cooperating amplification mechanism of the P-odd effects at the molecular level.

physics.chem-ph