First principles investigation on Li or Sn codoped hexagonal tungsten bronzes as the near-infrared shielding material

The 52%energy of the solar radiation is contributed by near-infrared radiation(NIR,780-2500 nm).Therefore,the material design for the energy-saving smart window,which can effectively shield NIR and has acceptable visible transmittance,is vital to save the energy consumed on the temperature control system.It is important to find a non-toxic stable material with excellent NIR-shielding ability and acceptable visible transmittance.The systematic first-principles study on Li_(x)Sn_(y)WO_(3)(x=0,0.33,0.66,and y=0,0.33)exhibits that the chemical stability is a positive correlation with the doping concentration.After doping,the Fermi-energy upshifts into the conduction band,and the material shows metal-like characteristics.Therefore,these structures Li_(x)Sn_(y)WO_(3)(except the structure with x=0.33 and y=0)show pronounced improvement of NIR shielding ability.Our results indicate that when x=0 and y=0.33,the material exhibits the strongest NIR-shielding ability,satisfying chemical stability,wide NIR-shielding range(780-2500 nm),and acceptable visible transmittance.This work provides a good choice for experimental study on NIR shielding material for the energy-saving window.

Photoelectron imaging of resonance-enhanced multiphoton ionization and above-threshold ionization of ammonia molecules in a strong 800-nm laser pulse

In this work, we mainly investigate the NH3 molecular multiphoton ionization process by using the photoelectron velocity map imaging technique. Under the condition of femtosecond laser(wavelength at 800 nm), the photoelectron images are detected. The channel switching and above-threshold ionization(ATI) effect are also confirmed. The kinetic energy spectrum(KES) and the photoelectron angular distributions(PADs) are obtained through the anti-Abel transformation from the original images, and then three ionization channels are confirmed successfully according to the Freeman resonance effect in a relatively low laser intensity region. In the excitation process, the intermediate resonance Rydberg states are C^1 A 1(6 + 2 photons process), B^1 E(6 + 2 photons process) and C^1 A 1(7 + 2 photons process), respectively. At the same time, we also find that the photoelectron angular distributions are independent of laser intensity. In addition, the electrons produced by different processes interfere with each other and they can produce a spider-like structure. We also find ac-Stark movement according to the Stark-shift-induced resonance effect when the laser intensity is relatively high.

Imaging alignment of rotational state-selected CH_3I molecule

We experimentally and numerically investigate CH_3I molecular alignment by using a femtosecond laser and a hexapole. The hexapole provides the single |111〉rotational state condition at 4.5-kV hexapole rod voltage. Based on this single rotational state, an enhanced alignment degree of 0.73 is achieved. Our experimental results are in agreement with the simulation results. We experimentally obtain the ion velocity map images and show the influence of the initial rotational-state population. With the I+ion images and angular distributions at different pump-probe delay time, the alignment and anti-alignment phenomena are further demonstrated. The molecules will be under field-free conditions when the laser effect disappears completely at the full revival time. Our work shows that the quantum control and spatial control on CH_3I molecules can be realized and molecular coordinate frame can be obtained for further molecular experiment.

Influence of Nano-Al Concentrates on the Corrosion Resistance of Epoxy Coatings

A two-stage process was used to produce nano-composite epoxy coatings. The first step involved preparing nano-AI concentrates with high concentration and low viscosity, and the second step produced nano- composite epoxy coatings by mixing the nano-AI concentrates and epoxy resin. Later, the coating was examined with immersion and salt spray tests. The coatings were characterized by electrochemical impedance spectroscopy （EIS）, scanning electron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS）. The results showed that the 5% nano-AI significantly improves the corrosion resistance of the coatings. There are two effects of nano-AI on the coating. Nano-AI is corroded initially to protect the substrate from corrosion, and then the aluminum oxide and aluminum hydroxide were produced after corrosion of nano-AI, which hindered the transmission of corrosion fluid into the coatings.

Polar Influence of the Organic Modifiers on the Structure of Montmorillonite in Epoxy Nanocomposites

The epoxy nanocomposites with similar amines （CH3（CH2）17NH2 and CH3（CH2）17N（CH3）301） treated montmorillonite clays have been investigated by wide-angle X-ray scattering, transmission electron microscopy （TEM）, differential scanning calorimetry （DSC） and thermal gravimetric analysis （TGA）. Different nanocomposite structures, intercalation and exfoliation were formed by the reaction of octadecyltrimethylammonium chloride-exchanged and octadecylamine-exchanged clays with epoxy resin and phenalkamine as the curing agent, respectively. Results showed that the exfoliated nanocomposite can be obtained when octadecylamine with the lower polarity was used as a modifier. However, the intercalated nanocomposite can be obtained when octadecyltrimethylammonium chloride with higher polarity was used as a modifier.

Role of rotational state-selected for nonadiabatic alignment： OCS molecules in femtosecond laser fields

Nonadiabatic alignment by intense nonresonant the spatial direction of molecules： By solving the the degree of alignment of the molecules initially laser fields is a versatile technique to manipulate time-dependent SchrSdinger equation numerically in different rotational state are calculated and the results show that the degree of alignment strongly depends on the initial rotational state. Thus, the present study indicates that, for obtaining a high degree of alignment for molecules, appropriate selection of molecular rotational states is necessary.

Corrosion Protection of AA2024-T3 by Cerium Malate and Cerium Malate-Doped Sol-Gel Coatings

Cerium malate (CeMal) was tested as a corrosion inhibitor for AA2024-T3 in this work. Corrosion inhibition on bare AA2024-T3 indicated that the inhibiting effect was a result of the synergistic effect of cerium cations and maleic anions. The corrosion of AA2024-T3 was stagnated by greatly reducing the corrosion current when CeMal was present in NaCl solutions. CeMal was adsorbed on the surface of AA2024-T3 forming a protective film in the initial stage. Then, cerium cations transformed to cerium oxide/hydroxides, precipitating on the cathode sites to inhibit the further corrosion. The electrochemical impedance spectra results of the sol-gel coatings proved that CeMal was an effective corrosion inhibitor in the sol-gel coatings to provide corrosion protection for AA2024-T3.