The theory of phase control of coherence, entanglement and quantum steering is developed for an optomechanical system composed of a single mode cavity containing a partially transmitting dielectric ...membrane and driven by short laser pulses. The membrane divides the cavity into two mutually coupled optomechanical cavities resulting in an effective three-mode closed loop system, two field modes of the two cavities and a mechanical mode representing the oscillating membrane. The closed loop in the coupling creates interfering channels which depend on the relative phase of the coupling strengths of the field modes to the mechanical mode. Populations and correlations of the output modes are calculated analytically and show several interesting phase dependent effects such as reversible population transfer from one field mode to the other, creation of collective modes, and induced coherence without induced emission. We find that these effects result from perfect mutual coherence between the field modes which is preserved even if one of the modes is not populated. The inseparability criterion for the output modes is also investigated and we find that entanglement may occur only between the field modes and the mechanical mode. We show that depending on the phase, the field modes can act on the mechanical mode collectively or individually resulting, respectively, in tripartite or bipartite entanglement. In addition, we examine the phase sensitivity of quantum steering of the mechanical mode by the field modes. Deterministic phase transfer of the steering from bipartite to collective is predicted and optimum steering corresponding to perfect EPR state can be achieved. These different types of quantum steering can be distinguished experimentally by measuring the coincidence rate between two detectors adjusted to collect photons of the output cavity modes. In particular, we find that the minima of the interference pattern of the coincidence rate signal the bipartite steering, while the maxima signal the collective steering.
After isothermal aging at 850 °C for different hours, the microstructures as well as creep-rupture properties of a novel directionally solidified Ni-based superalloy M4706 are studied under the ...condition of 980 °C and 180 MPa. We found that the mean edge length of
γ
′ particles only increases up to 484 ± 99 nm after the aging treatment of 850 °C/5000 h, and the corner of the
γ
′ particle becomes more and more rounded with particle size, whereas the
γ
′ volume fraction remains unchanged with time. At grain boundaries, the carbide film, which is consisted of MC and M
23
C
6
carbides, is produced after thermal exposure for 1000 h, and its content increases with time. Creep-rupture tests reveal that the creep-rupture life is reduced only from 180 ± 15 to 106 ± 15 h, and the elongation to fracture decreases from 32 ± 2% to 21 ± 1% after isothermal aging for 5000 h. Microstructural observations disclose that creep deformation is achieved mainly by dislocation climb, although shearing of
γ
′ particles by pairs of
a
/2 < 011 > dislocations also takes place occasionally. Based on the experimental results, the relationship between the creep-rupture properties and microstructures together with the creep deformation mechanisms is discussed.
Graphical abstract
Chitosan (
β-1,4-
d-glucosamine), a polysaccharide with excellent biological properties, has been widely used in biomedical fields, but many barriers still exist to its broader usage due to its ...chemical and physical limitations. Further work is needed to improve these properties, but changes of the chemical and physical properties will influence its biocompatibility, so the biological attribute of modified chitosan must be evaluated. In this study, the biocompatibility of chitosan modified by several methods was carefully evaluated at the cellular and protein levels using different physical and biological methods. The results provide a theoretical basis for screening biomaterials.
We studied the properties of five kinds of materials made by blending chitosan with different types of polyethylene glycol (PEG). The properties included physical and chemical properties, such as mechanical strength, static contact angle, spectroscopy, thermodynamic attributes and so on. The mechanical properties were slightly improved with the proper amount of PEG, but the improvement was not obvious and was destroyed by the wrong proportion of PEG. Cultures of the cells and amounts and structures of the adsorbed proteins on different materials showed that the PEG effectively improved the biocompatibility of the materials. The PEG enhanced the protein adsorption, cell adhesion, growth and proliferation, but the effects were impaired by excessive PEG. The experiments also demonstrated that the optimum PEG concentration helped to maintain the natural structure of the protein adsorbed on the materials and that maintaining the natural structure benefited cell growth.
Analysis of the results based on the intramolecular and intermolecular interaction forces leads to a basic theory for the modification of biomaterials.
This study was conducted to determine the mechanism by which di‐2‐ethylhexyl phthalate (DEHP) exposure influences lipid metabolism of juvenile yellow catfish Tachysurus fulvidraco. Fish were exposed ...to three DEHP concentrations (0, 0·1 and 0·5 mg l−1 DEHP) for 8 weeks. Fatty acid synthase (FAS) activity significantly decreased with increasing DEHP concentrations, the highest value was in the Tween control group, whereas the lowest activities of carnitine palmitoyltransferase (CPT) and lipoprotein lipase (LPL) were in this group. The messenger (m)RNA levels of 6‐phospho‐gluconate dehydrogenase (6PGD), FAS and acetyl‐CoA carboxylase a (ACCa) significantly increased with increasing DEHP concentration, the highest values were in the 0·5 mg l−1 DEHP group. The mRNA level of peroxisome proliferator‐activated receptor γ (PPARγ) was lower in Tween control than in fish exposed to 0·1 and 0·5 mg l−1 DEHP. The highest mRNA level of ACCb was in the 0·1 mg l−1 DEHP group. These results indicate that DEHP exposure can disturb lipid metabolism at the enzymatic and mRNA levels in Pelteobagrus fulvidraco.
A novel four-layer structured Cr–Al–O tandem nano-multilayer composite coating has been prepared by cathodic arc ion plating for solar selective absorbing. The four-layer structured coating consists ...of pure chromium layer, low oxygen content Cr–Al–O layer (LOCL), middle oxygen content Cr–Al–O layer (MOCL) and high oxygen content Cr–Al–O layer (HOCL). The composition, structure, and surface morphology of the coating were characterized using SEM, EDS, XPS, TEM, and AFM. The optical performances of the coating were measured by spectrophotometer, while the thermal stability of the coating was evaluated by Raman spectroscopy. Results showed that LOCL and MOCL, in which amorphous Cr–Al–Ox nanolayers and composite Cr–Al–Ox nanolayers embedded with Cr2Al nanograins alternated with each other, were the main absorbers, while HOCL acted as an antireflection layer. The coating exhibited a relatively high absorptance of 0.924 and a relatively low emittance of 0.21, as well as an outstanding thermal stability with a selectivity of 0.919/0.225 even after annealing at 700°C for 2h in air, which properties rendered the four-layer structured Cr–Al–O tandem coating a potential material for photo-thermal conversion at high temperatures.
•A Cr–Al–O tandem nanomultilayer composite coating was fabricated by arc ion plating under O2 ambient.•Amorphous Cr–Al–Ox nanolayers and Cr–Al–Ox nanolayers containing Cr2Al nanograins alternated with each other in absorbing layers.•The coating exhibited outstanding thermal stability annealing at 700°C for 2h in air.
The variation of the tensile ductility of a directionally solidified nickel-based superalloy M4706 with temperature is investigated in the temperature range from room temperature to 980 °C. It is ...found that intermediate temperature brittleness occurs in M4706 at temperatures between 400 and 650 °C. Tensile tests on single crystal M4706 and in-situ nano-compression tests on the freestanding γ′ particles show that the intermediate temperature brittleness of the experimental alloy is not associated with the grain boundary and the deformation capacity of γ′ precipitates in the temperature range. Scanning electron microscope and transmission electron microscope observations disclose that the phenomenon is associated with the glide plane decohesion, which in turn corresponds to the frequent stacking fault shearing during tensile deformation.
AIMS: The response of microbial metagenome to polycyclic aromatic hydrocarbons (PAHs) degradation in the rice rhizosphere remains poorly understood. We investigated the spatial and temporal ...variations of microbial communities and reconstructed metagenomes along the rice rhizosphere gradient during PAHs degradation. METHODS AND RESULTS: The experiment was performed in rhizoboxes, in which the rhizosphere region was divided into five 1‐mm thick layers. Based on denaturant gradient gel electrophoresis profiling and sequencing of bacterial and archaeal 16S rRNA genes, predicted metagenomes were reconstructed. The microbial communities in the rice rhizosphere were influenced by the PAHs concentration and distance from the root surface during PAHs degradation. Correlation network analysis showed that archaea played an important role in PAHs degradation. Predicted metagenomes can be clustered into two groups with high and low PAHs degrading potential, respectively. The relative abundance of genes for defense mechanisms, replication, recombination and reparation was significantly higher in samples with high PAHs degrading potentials. The relative abundance of the dioxygenase gene was greater near the root surface of the rice. However, the abundance of aldolase and dehydrogenase was constant in rhizosphere soils at different distances from the root surface. CONCLUSIONS: Distance from root surface and PAH concentrations affected the microbial communities and metagenomes in rice rhizosphere. The abundance of dioxygenase genes relating to PAH degradation in metagenomes mirrored the PAH degradation potential in rice rhizosphere. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings suggested that the predicted metagenomes reconstructed from 16S rRNA marker gene sequences provide further insights into the spatial variation and dynamics of microbial functioning that occur during bioremediation.
The magnetic anisotropy of SmCo-based permanent magnetic thin films are generally controlled by introducing buffer layer or heating substrate. However, the design for the multi-layer thin film system ...is complicated and the thickness of SmCo is limited due to a short range of interfacial stress/strain between the buffer layer and SmCo layer. In this work, the effects of temperature gradients, generated by RTP (rapid thermal process), on the magnetic anisotropy of the SmCo-based films were systematically investigated. The results show that the as-deposited films exhibit amorphous state. The out-of-plane coercivity of RTP-treated films is strongly correlated with the heating rate, and its optimum value (2810 Oe) is larger than that of the CTA (conventional thermal annealing) treated films (1670 Oe). For the RTP-treated films, the intensity of characteristic diffraction peaks for in-plane oriented SmCo5 (200) and Sm2Co17 (300) decreases, together with reducing the roughness. Besides, the grain size is finer and the contrast of magnetic domains becomes stronger for the RTP-treated films due to that the easy axis of SmCo5/Sm2Co17 phase gradually changes from in-plane to out-of-plane direction. It is suggested that the RTP treatment with a shorter annealing time has beneficial effects on obtaining finer microstructure and improving the out-of-plane magnetic anisotropy of the SmCo-based films. This work provides a novel way to control the magnetic anisotropy via annealing temperature gradients for permanent magnetic thin films, compared with conventional methods, to induce the magnetic anisotropy.
•This work provides a novel way to control the magnetic anisotropy via annealing temperature gradients for permanent magnetic thin films.•The shorter heating time of RTP results in finer grains and smoother surface.•RTP can induce the easy axis of SmCo phase to change from in-plane to out-of-plane direction and enhance the out-of-plane magnetic anisotropy.
The compression deformation behavior and deformation mechanisms of 001-oriented single crystal CM247LC are investigated at 600 °C and at the strain rate of 5 × 10−6 to 5 × 10−3 s−1. We found that ...although the Protevin-Le Châtelier effect appears during plastic deformation under the investigated strain rates, its yield strength is strain-rate insensitive. Transmission electron microscopy observations on the slightly deformed specimens reveal that in contrast to previous findings, shearing of γ′ precipitates is accomplished by pairs of a/2 dislocations as well as partial dislocations, which result in the formation of superlattice stacking faults and extended stacking faults, in the experimental alloy at the early stage of plastic deformation at all the strain rates. Meanwhile, it is also found that the frequency of occurrence of the two shear processes is not influenced by the strain rate. Based on these observations, the formation of stacking faults and the relationship between operative deformation mechanisms and the yield strength of the experimental alloy are discussed.
•The PLC effect appears in CM247LC during compressive deformation at 600 °C.•The yield strength of CM247LC is strain-rate insensitive.•Stacking fault shearing operates in CM247LC at all the studied strain rates.•The process of stacking fault shearing is not rate-controlled.
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