Finite element analysis of steep excavation slope failure by CFS theory

The distribution of Coulomb failure stress （CFS） change in the steep excavation slope is calculated by finite element method in this paper, and the failure mechanics under different conditions have been investigated. Comparing the CFSs before and after the slope excavation （stress loading and unloading processes）, the dangerous internal zone and the most likely failure external area are attained. Given the shear cracks on the top surface while tensile stress or cracks along the toe of the slope, we analyze the high cutting-angle steep slope in Kaixian county of the Three Gorges Reservoir region. We bring forward that the peak value of CFS after excavation can reach to the order of 0.1 MPa, which is greatly higher than that of before. Our preliminary results are useful for optimizing the reinforcement structure during the steep slope stabilization engineering.

Electron acceleration in interaction of magnetic islands in large temporal-spatial turbulent magnetic reconnection

A new combined Fermi, betatron, and turbulent electron acceleration mechanism is proposed in interaction of magnetic islands during turbulent magnetic reconnection evolution in explosive astrophysical phenomena at large temporal-spatial scale(LTSTMR), the ratio of observed current sheets thickness to electron characteristic length, electron Larmor radius for low-β and electron inertial length for high-β, is on the order of 10^(10)–10^(11); the ratio of observed evolution time to electron gyroperiod is on the order of 10~7–10~9).The original combined acceleration model is known to be one of greatest importance in the interaction of magnetic islands; it assumes that the continuous kinetic-dynamic temporal-spatial scale evolution occurs as two separate independent processes.In this paper, we reconsider the combined acceleration mechanism by introducing a kinetic-dynamic-hydro full-coupled model instead of the original micro-kinetic or macro-dynamic model.We investigate different acceleration mechanisms in the vicinity of neutral points in magnetic islands evolution, from the stage of shrink and breakup into smaller islands(kinetic scale), to the stage of coalescence and growth into larger islands(dynamic scale), to the stages of constant and quasi-constant(contracting-expanding) islands(hydro scale).As a result, we give for the first time the acceleration efficiencies of different types of acceleration mechanisms in magnetic islands' interactions in solar atmosphere LTSTMR activities(pico-, 10^(–2)–10~5 m; nano-, 10~5–10~6 m; micro-, 10~6–10~7 m; macro-, 10~7–10~8 m; large-,10~8–10~9 m).

Submicron Volume Roughness & Asperity Contact Friction Model for Principle Slip Surface in Flash Heating Process

Based on focused ion beam and shear friction apparatus data, the multi-resolutions （0.2 nm-5μm） volume roughness ＆ asperity contact （VR ＆ AC） three-dimensional structure on principle slip surface interface-surface （PSS-IS） is measured on high performance computational platform; and physical plastic-creep friction model is established by using hybrid hyper-singular integral equation ＆ lattice Boltzmann ＆ lattice Green function （BE-LB-LG）. The correlation of rheological property and VR ＆ AC evolution under transient （10 μs） macro-normal stress （18-300 MPa） and slip rate （0.25-7.5 m/s） are obtained; and the PSS-IS friction in co-seismic flash heating is quantitative analyzed for the first time.

Development and validation of abiotic ligand model for nickel toxicity to wheat(Triticum aestivum)

A terrestrial biotic ligand model（t-BLM） was developed to predict nickel toxicity to wheat（Triticum aestivum） root elongation in hydroponic solutions. The competitive effects of five major cations（Ca^（2＋）, Mg^（2＋）, Na~＋, K~＋and H~＋） on Ni toxicity were investigated and Mg^（2＋）was found to be a strong competitor, while H＋showed less competing effect. Besides free Ni^（2＋）,the toxicity induced by the species NiHCO_3~＋ was non-neglect able at pH 〉 7 because NiHCO_3~＋ occupied a significant fraction of total Ni under such condition. Thus, a t-BLM including Ni^（2＋）, NiHCO_3~＋, Mg^（2＋）, and H＋could successfully predict the nickel toxicity to wheat root elongation and it performed better prediction than the conventional free ion activity model.In addition, the model was examined with two sets of independent experiments, which contained multiple cations and low-molecular-weight organic acids to mimic the rhizosphere condition. The developed t-BLM well predicted nickel toxicity in both experiments since it can account in both complexation and competition effects, suggesting its potential to be used in a complicated matrix like soil solution. This study provides direct evidence that the t-BLM is a reliable method for the risk assessment of nickel in terrestrial system.

SPECIAL TOPICS: Extended Coulomb failure criteria for the Zipingpu reservoir and Longmenshan slip investigated by researchers at the Chinese Academy of Sciences

Describing the correlation of a reservoir and earthquake slip remains a great challenge. Professor SHI Yaolin and his group at the Key Laboratory of Computational Geodynamics of the Chinese Academy of Sciences and the College of Science of the Graduate University of the Chinese Academy of Sciences are attempting to solve this problem. On the basis of the laboratory's parallel central processing unit (CPU)

Application of StrucGP in medical immunology:site-specific N-glycoproteomic analysis of macrophages

The structure of N-glycans on specific proteins can regulate innate and adaptive immunity via sensing environmental signals.Meanwhile,the structural diversity of N-glycans poses analytical challenges that limit the exploration of specific glycosylation functions.In this work,we used THP-1-derived macrophages as examples to show the vast potential of a N-glycan structural interpretation tool StrucGP in N-glycoproteomic analysis.The intact glycopeptides of macrophages were enriched and analyzed using mass spectrometry(MS)-based glycoproteomic approaches,followed by the large-scale mapping of site-specific glycan structures via StrucGP.Results revealed that bisected GlcNAc,core fucosylated,and sialylated glycans(e.g.,HexNAc4Hex5Fuc1Neu5Ac1,N4H5F1S1)were increased in M1 and M2 macrophages,especially in the latter.The findings indicated that these structures may be closely related to macrophage polarization.In addition,a high level of glycosylated PD-L1 was observed in M1 macrophages,and the LacNAc moiety was detected at Asn-192 and Asn-200 of PD-L1,and Asn-200 contained Lewis epitopes.The precision structural interpretation of site-specific glycans and subsequent intervention of target glycoproteins and related glycosyltransferases are of great value for the development of new diagnostic and therapeutic approaches for different diseases.