HYPERSONIC EIGENVIBRATIONS OF HOMOGENEOUS AND HETEROGENEOUS NANOPARTICLES

Ph.DDOCTOR OF PHILOSOPH

WOS-ELM-Based Double Redundancy Fault Diagnosis and Reconstruction for Aeroengine Sensor

In order to diagnose sensor fault of aeroengine more quickly and accurately, a double redundancy diagnosis approach based on Weighted Online Sequential Extreme Learning Machine (WOS-ELM) is proposed in this paper. WOS-ELM, which assigns different weights to old and new data, implements weighted dealing with the input data to get more precise training models. The proposed approach contains two series of diagnosis models, that is, spatial model and time model. The application of double redundancy based on spatial and time redundancy can in real time detect the hard fault and soft fault much earlier. The trouble-free or reconstructed time redundancy model can be utilized to update the training model and make it be consistent with the practical operation mode of the aeroengine. Simulation results illustrate the effectiveness and feasibility of the proposed method

Aqua­(6,6′-oxydipicolinato-κ2 O,N,N′,O′)copper(II)

In the title complex, [Cu(C12H6N2O5)(H2O)], the CuII ion is in a slightly distorted square-pyramidal coordination environment with two N and two O atoms from a 6,6′-oxydipicolinate ligand occupying the basal plane and a water ligand in the apical site. The dihedral angle between the two pyridine rings is 5.51 (6)°. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link mol­ecules into a two-dimensional network. In addition, weak inter­molecular C—H⋯O and C=O(lone pair)⋯π(ring) inter­actions, with O⋯ring-centroid distances of 3.697 (4) and 3.094 (4) Å, provide additional stabilization

Direct observation of structure-assisted filament splitting during ultrafast multiplepulse laser ablation

Laser-induced plasma evolution in fused silica through multipulse laser ablation was studied using pump-probe technology. Filament splitting was observed in the early stage of plasma evolution (before ~300 fs). This phenomenon can be attributed to competition between laser divergent propagation induced by a pre-pulse-induced crater and the nonlinear self-focusing effect. This effect was validated through simulation results. With the increasing pulse number, the appearance of filament peak electron density was postponed. Furthermore, a second peak in the filament and peak position separation were observed because of an optical path difference between the lasers propagating from the crater center and edge. The experimental results revealed the influence of a prepulse-induced structure on the energy distribution of subsequent pulses, which are essential for understanding the mechanism of laser–material interactions, particularly in ultrafast multiple-pulse laser ablation

N′-(3,5-Dichloro-2-hy­droxy­benzyl­idene)-4-(dimethyl­amino)­benzohydrazide methanol monosolvate

The title compound, C16H15Cl2N3O2·CH3OH, a Schiff base molecule, is prepared by the reaction of 3,5-dichloro­salicyl­aldehyde with 4-dimethyl­amino­benzohydrazide in methanol. The Schiff base mol­ecule is approximately planar, with a mean deviation from the least-squares plane defined by the non-H atoms of 0.0452 (3) Å, and with a dihedral angle between the benzene rings of 4.2 (3)°. This planarity is assisted by the formation of an intra­molecular O—H⋯N hydrogen bond. In the crystal, adjacent Schiff base mol­ecules are linked by two methanol mol­ecules through N—H⋯O and O—H⋯O hydrogen bonds, forming dimers

Age-related sensitivity and pathological differences in infections by 2009 pandemic influenza A (H1N1) virus

<p>Abstract</p> <p>Background</p> <p>The highly pandemic 2009 influenza A H1N1 virus infection showed distinguished skewed age distribution with majority of infection and death in children and young adults. Although previous exposure to related antigen has been proposed as an explanation, the mechanism of age protection is still unknown.</p> <p>Methods</p> <p>In this study, murine model of different ages were inoculated intranasally with H1N1 (A/Beijing/501/09) virus and the susceptibility and pathological response to 2009 H1N1 infection were investigated.</p> <p>Results</p> <p>Our results showed that the younger mice had higher mortality rate when infected with the same dose of virus and the lethal dose increased with age. Immunohistochemical staining of H1N1 antigens in mice lung indicated infection was in the lower respiratory tract. Most bronchial and bronchiolar epithelial cells in 4-week mice were infected while only a minor percentage of those cells in 6-month and 1-year old mice did. The young mice developed much more severe lung lesions and had higher virus load in lung than the two older groups of mice while older mice formed more inducible bronchus-associated lymphoid tissue in their lungs and more severe damage in spleen.</p> <p>Conclusions</p> <p>These results suggest that young individuals are more sensitive to H1N1 infection and have less protective immune responses than older adults. The age factor should be considered when studying the pathogenesis and transmission of influenza virus and formulating strategies on vaccination and treatment.</p

Structure-Mediated Excitation of Air Plasma and Silicon Plasma Expansion in Femtosecond Laser Pulses Ablation

Femtosecond laser-induced surface structures upon multiple pulses irradiation are strongly correlated with the pulse number,which in turn significantly affects successive laser-material interactions. By recording the dynamics of femtosecond laser ablation of silicon using time-resolved shadowgraphy, here we present direct visualization of the excitation of air plasma induced by the reflected laser during the second pulse irradiation.The interaction of the air plasma and silicon plasma is found to enhance the shockwave expansion induced by silicon ablation in the longitudinal direction, showing anisotropic expansion dynamics in different directions. We further demonstrate the vanishing of air plasma as the pulse number increases because of the generation of a rough surface without light focusing ability. In the scenario, the interaction of air plasma and silicon plasma disappears; the expansion of the silicon plasma and shockwave restores its original characteristic that is dominated by the laser-material coupling.The results show that the excitation of air plasma and the laser-material coupling involved in laser-induced plasma and shockwave expansion are structure mediated and dependent on the pulse number, which is of fundamental importance for deep insight into the nature of laser-material interactions during multiple pulses ablation

Effects of biochar application and nutrient fluctuation on the growth, and cadmium and nutrient uptake of Trifolium repens with different planting densities in Cd-contaminated soils

Biochar has been used to remediate contaminated-soil with heavy metals, however, less is known on how biochar interacts with planting density and nutrient fluctuation to affect the remediation. A pot experiment was conducted in the greenhouse to investigate the effects of biochar application (without vs. with 1% biochar, g/g substrate), nutrient fluctuation (constant vs. pulsed) and planting density (1-, 3- and 6-individuals per pot) on the growth, and cadmium (Cd) and nutrient uptake of Trifolium repens population. Our results found that the growth of T. repens population increased significantly with increasing planting density, and the increment decreased with increasing planting density. Both the Cd and nutrient uptake were higher at higher planting density (e.g., 3- and 6-individuals) than at lower planting density (e.g., 1-individual). Biochar application increased the biomass and shoot Cd uptake, but decreased the ratio of root to shoot and root Cd uptake of T. repens population, the effects of which were significantly influenced by planting density. Although nutrient fluctuation had no effect on the growth of T. repens population, but its interaction with planting density had significant effects on Cd uptake in tissues. Overall, the effects of biochar application and nutrient fluctuation on the growth and Cd uptake were both influenced by planting density in the present study. Our findings highlight that biochar application and constant nutrient supply at an appropriate planting density, such as planting density of 3-individuals per pot in the present study, could promote the growth, and Cd and nutrient uptake of T. repens population

Vaccines targeting preS1 domain overcome immune tolerance in hepatitis B virus carrier mice

Strong tolerance to hepatitis B virus (HBV) surface antigens limits the therapeutic effect of the conventional hepatitis B surface antigen (HBsAg) vaccination in both preclinical animal models and patients with chronic hepatitis B (CHB) infection. In contrast, we observed that clinical CHB patients presented less immune tolerance to the preS1 domain of HBV large surface antigen. To study whether targeting the weak tolerance of the preS1 region could improve therapy gain, we explored vaccination with the long peptide of preS1 domain for HBV virions clearance. Our study showed that this preS1-polypeptide rather than HBsAg vaccination induced robust immune responses in HBV carrier mice. The anti-preS1 rapidly cleared HBV virions in vivo and blocked HBV infection to hepatocytes in vitro. Intriguingly, vaccination of preS1-polypeptide even reduced the tolerized status of HBsAg, opening a therapeutic window for the host to respond to the HBsAg vaccine. A sequential administration of antigenically distinct preS1-polypeptide and HBsAg vaccines in HBV carrier mice could finally induce HBsAg/hepatitis B surface antibody serological conversion and clear chronic HBV infection in carrier mice. Conclusion: These results suggest that preS1 can function as a therapeutic vaccine for the control of CHB. (Hepatology 2017;66:1067-1082)