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Selective catalytic reduction of NO with CO (CO-SCR) has been suggested as an attractive and promising technology for removing NO and CO simultaneously from flue gas. Manganese-copper spinels are a promising CO−SCR material because of the high stability and redox properties of the spinel structure. Here, we synthesized CuxMn3−xO4 spinel by a citrate-based modified pechini method combining CuO and MnOx, controlling the molar Cu/Mn concentrations. All the samples were characterized by SEM, EDX, XRD, TEM, H2−TPR, XPS and nitrogen adsorption measurements. The Cu1.5Mn1.5O4 catalyst exhibits 100% NO conversion and 53.3% CO conversion at 200 °C. The CuxMn3−xO4 catalyst with Cu-O-Mn structure has a high content of high valence Mn, and the high mass transfer characteristics of the foam-like structure together promoted the reaction performance. The CO-SCR catalytic performance of Cu was related to the spinel structure with the high ratio of Mn4+/Mn, the synergistic effect between the two kinds of metal oxides and the multistage porous structure.

Phenanthrenequinone (PQ) doped poly-(methyl methacrylate) (PMMA) have been proven to be available material for volume polarization holographic recording. In our work, we introduced benzyl methacrylate (BzMA) into the PQ/PMMA to increase the concentration of PQ (up to 1.15wt%) within the polymeric media. The enhancement of concentration of PQ brings a mean for improving performance of material. Compared with the pure PQ/PMMA, photoinduced birefringence and diffraction intensity were multiplied by introducing BzMA. This investigation can provide a significant foundation for improving polarization holographic characteristics of PQ/PMMA by modifying the chemical composition of the material.

Recently, the hexacarbonyl diiron dithiolate complex ((bdt)Fe2(CO)6, bdt = benzene-1,2-dithiolate) was reported for electrochemical CO2 reduction in CH3OH/CH3CN solution. To further simulate the [NiFe] carbon monoxide dehydrogenase (CODH) active center, another diiron dithiolate complex (1) with phenolic hydroxyl as second coordination sphere group was introduced to catalyze CO2 reduction electrochemically. Cyclic voltammetry measurements revealed that the phenolic hydroxyl group of 1 could lower the onset potential of electrochemical CO2 reduction. Under the best conditions, the maximum turnover frequency (TOFmax) of about 35 s−1 and an almost equal amount of HCOOH, CO, and H2 were obtained. Fourier transform infrared reflectance spectroelectrochemistry (IR-SEC) experiments illuminated the intermediate with terminal coordinated –COOH and the changes of intermolecular hydrogen bonds during the catalytic cycle.

We report on the null reconstruction effect (NRE) of an elliptical polarization volume hologram with orthogonal elliptically, circularly, and linearly polarized waves, respectively. The NRE is a special phenomenon in polarization holography, which means the diffraction efficiency declines to zero when the hologram is reconstructed by an orthogonally polarized reading wave. In our previous work [Opt. Express24, 1641 (2016)OPEXFF1094-408710.1364/OE.24.001641; Opt. Lett.42, 1377 (2017)OPLEDP0146-959210.1364/OL.42.001377; Opt. Express23, 8880 (2015)OPEXFF1094-408710.1364/OE.23.008880], the NRE of polarization holography recorded by linear and circular polarization waves has been investigated. Compared with linear and circular polarization holography, elliptical polarization holography represents a more general and unified recording hologram. However, no work on the NRE of elliptical polarization holography, as far as we know, has been reported until now. In this paper, the NRE of elliptical polarization holography is investigated and demonstrated theoretically and experimentally. First, the conditions of achieving NRE in elliptical polarization holography are studied based on vector holography theory. The results indicate that the NRE is a common phenomenon in polarization holography written by linear, circular, and elliptical polarization waves. Then, a series of experiments of NRE in a polarization hologram written by orthogonal elliptically, circularly, and linearly polarized waves is carried out. The NRE of elliptical polarization holography is experimentally observed, and the results are in nice agreement with the theoretical analysis. The NRE of elliptical polarization holography is expected to be applied in high-density optical data storage and polarization-controlled holographic elements.

High-performance material plays a crucial role in holographic data storage, which is a noteworthy technology with potential applications in the field of high capacity data storage. We report on a new kind of holographic storage material based on aluminum nanoparticles (Al NPs) dispersed phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer. Al NPs are efficiently synthesized in a monomer solvent using laser ablation in liquids without chemical precursors. It is shown that an increase in diffraction efficiency and recording sensitivity is achieved in both traditional holography and polarization holography by doping with Al NPs. After 4 h of ablation, the new material exhibited an improvement in the diffraction efficiency for both traditional holography and polarization holography from 2.85% to 57.15% and from 0.6% to 4.07%, respectively. We also investigated the image recording and reconstruction performance for both traditional and polarization holography and the results indicate that the proposed material has noticeable potential as a holographic storage material. Additionally, it also possesses excellent potential for holographic position multiplexing recording. We conclude that laser ablation in a liquid is a promising option for processing low-cost nano-doped holographic storage material.

Polarization-Controlled dual images recording with linear polarization holography Jinliang Zang*, Fenglan Fan, Ying Liu, Yifan Hong, Long Shao, Xiaodi Tan （School of Optoelectronics, Beijing Institute of Technology, 5 South Zhongguancun Street, Haidian District, Beijing 100081, China 100081） *Corresponding author: jlzang@bit.edu.cn Abstract: Polarization holography is a promising technique for its unique capacity of recording intensity, phase as well as polarization of light wave field simultaneously. In recent years, dual-channel images recording by polarization holography has been proposed. However, in conventional dual-channel images recording, an unchanged polarized reference wave is employed while signal waves have orthogonal polarization, which makes two holographic images can only be read out simultaneously. In this paper, we report polarization-controlled dual images recording within polarization holography written by orthogonal linear polarization waves. In this method, two polarization multiplexed holographic images could be sequentially readout by shifting the polarization state of reference wave based on null reconstruction effect(NRE) of linear polarization holography. NRE is an unique phenomena in polarization holography which means the diffraction efficiency goes down to zero when the hologram is reconstructed by orthogonal polarized reading wave. In this paper, we study polarization holography recorded by orthogonal linear waves and find that the NRE of orthogonal linear polarization holography can be achieved at large cross-angle of inside the polarization-sensitive media. The NRE of linear polarization holography is experimentally demonstrated by recording orthogonal linear polarization hologram in fabricated cubic material PQ/PMMA whose size is 10 mm ×10 mm ×15 mm. Based on the NRE of orthogonal linear polarization holography, polarization-controlled dual images recording is carried out. Two images encoded by orthogonal linear polarization waves are sequentially recorded in same position of cubic PQ/PMMA by orthogonal linear polarization holography. In reconstruction stage, The two holographic images are sequentially readout by shifting the polarization state of reference wave with negligible inter-channel crosstalk. The experimental results agree well with theoretical predictions. And this polarization-controlled dual images recording method has promising applications in optical storage, vector light field modulation and multi-functional optical devices. Keywords: Polarization holography, Holographic data storage, Polarization-multiplex, Image processing

Polarization holography is the coherent interference of the beams that can have the different polarized states. The early-stage theory of polarization holography is based on Jones matrix, where the paraxial approximation is assumed, while the theory of polarization holography represented by dielectric tensor can describe the case with a large crossing angle. And it also depicts the relationship between diffraction light and interference light. During the research people find some extraordinary phenomenon, such as null reconstruction and inverse polarizing effect. But there is a disadvantage in this new polarization holography theory, where only under a peculiar circumstance can we get a faithful reconstruction. The circumstance can be expressed as “A+B=0”, where A and B refer to the coefficients for intensity and polarization holograms respectively. In this research, we calculate the formula of diffraction light’s polarization, and extract the A+B factor in it. Then we establish a series of equations which can let the diffraction light faithfully reconstruct, no matter what value of A plus B is. From the result, we can use an artificial reference beam which is corresponding to the signal beam to generate the hologram. Under this condition, the polarization of the diffraction light is similar to the signal. For simplification, we only discuss the signal wave with circular polarization and experimentally verify the result.

Holographic data storage has large storage capacity and high transfer rate, it becomes one of the next-generation information storage technologies. Bis(2,6-difluoro-3-(1-hydropyrrol-1-yl)phenyl)titanocene (IRG 784) is a good photoinitiator doped in photopolymer, poly(methyl methacrylate) （PMMA）is an excellent choice to making photopolymer with thickness of millimeter range. The solubility of phenanthrenequinone in MMA is a little low, for IRG 784 is very high. In this paper, I use IRG 784 as photoinitiator doped in PMMA made a kind of photopolymer with thickness of millimeter range for holographic data storage. We studied the optical characteristics of IRG 784–doped PMMA photopolymer with different weight ratio of IRG 784 doped. For the preparation of material, we use methyl methacrylate solution as the monomer, azo-bis-isobutyronitrile as the thermo-initiator. The samples with clear optical transmission is orangered. The wavelength of laser for recording and reconstructing we used was 532nm. In the recording process, recording waves interfered for 2 seconds with the cross angle of 60 degrees. After 2 seconds is the reconstruction process, the original reference wave reconstructed the grating for 0.6 seconds. These two processes cycled until the reaction ended. We set the polarization state of signal wave as s-polarization. Both s-polarization and p-polarization as reference wave we used to recording. Through a series of experiments, we can conclude that the weight ratio of IRG 784 dissolved in MMA is significant to increase diffraction efficiency. Although the diffraction efficiency is lower than in traditional holography, our material can be used in polarization holography.

A series of ethylene glycol monomethyl ether (EGME) fatty acid monoesters were prepared by the transesterification of different fatty acid methyl esters (FAMEs) with EGME. A solid basic catalyst, namely, calcined sodium silicate, was used. Various parameters, such as the calcination temperature, amount of catalyst, molar ratio of FAME/EGME, reaction temperature, and time on the yield of EGMEML (ML = methyl laurate), were optimized; the reusability of calcined sodium silicate was also examined. Calcined sodium silicate was also used as a catalyst for examining the catalytic activity of soybean oil biodiesel with EGME. Thermogravimetry, X-ray diffraction, carbon dioxide temperature-programmed desorption, Fourier transform infrared spectroscopy, and scanning electron microscopy were employed to characterize the properties of calcined sodium silicate. The results indicated that calcined sodium silicate was effective for the synthesis of novel biodiesel by FAMEs, with EGME as reactants. Centrifugation and deca...

A novel ZnO/Ca(OH)2/KF solid base catalyst was prepared by the grinding method and applied to biodiesel synthesis by the transesterification of soybean oil. The effect of various parameters such as KF molar amount, calcination temperature, the amount of catalyst, molar ratio of methanol to oil, reaction temperature, and time on the activity of the catalyst were investigated. The catalysts were characterized by several techniques of thermogravimetry/derivative thermogravimetry, X–ray diffraction, Hammett indicator method, and scanning electron microscopy. The analysis results indicated that the KF interacted with Ca(OH)2 and formed KCaF3 phase before calcination of the catalyst. The formed KCaF3 crystal phase was the main catalytic active component for the catalyst activity. In addition, the basicity of ZnO/Ca(OH)2/KF was greatly influenced by the different calcination temperates, and the catalyst activity was correlated closely with the basicity. A desired biodiesel yield of 97.6 % was obtained at catalyst amount of 3 %, methanol/oil of 12:1, and reaction time of 1.5 h at 65 °C.

Increasing photosensitizer concentration has been considered as an effective approach to improve the performance of holographic material. In this paper, we report on new method for increasing the saturated dissolvability of photosensitizer PQ within polymeric media by introducing copolymerization monomer into the PQ/PMMA. The photosensitizer concentration of PQ was increased from 0.7wt% to 1.3wt%, compared with the typical PQ/PMMA sample. Besides, we investigated performance of polarization holographic recordings in typical PQ/PMMA and copolymerization monomer-containing PQ/PMMA with the orthogonally polarized signal and reference waves. And the doping of THFMA component resulted in a significant improvement of diffraction intensity and photosensitivity. In addition, high-quality holographic image reconstruction was realized in our home-made material.

Faithful reconstruction, the polarization state of the diffraction wave being identical to that of the signal wave, is the primary target in polarization holography. With the large crossing angle between signal and reference wave, namely, nonparaxial approximation, attaining a balance between intensity and polarization grating is generally known as a prerequisite for faithful reconstruction. However, obtaining such a balance point within polarization-sensitive material has long been known as a challenging job, due to its extremely strict exposure condition. In this paper, we report on a smart method with the well-designed reference and reading wave to faithfully reconstruct the signal wave at an arbitrary exposure energy. Moreover, when the signal is circularly polarized, the diffraction efficiency can be precisely manipulated by changing the reading wave’s polarization state, which is favorable for optical storage and functional diffractive optical elements.

Photoinitiator plays a crucial role on photopolymer. Unlike photoinitiator phenanthrenequinone (PQ), the solubility of Irgacure 784 dissolved in MMA is very high. In this paper, we use Irgacure 784 as photoinitiator doped in poly(methyl methacrylate)(PMMA)to make a bulk photopolymer with high photoinitiator concentration for holographic data storage. The effect of concentration of photoinitiator and record intensity are experimentally investigated. The results reveal the material has an optimum condition in holographic recording. A comparison between our material and the material of PQ doped PMMA is carried out by experiment. It is found that our material has better performance on diffraction efficiency, refractive index modulation and recording sensitivity. Besides, this material also has polarization sensitivity, which can be applied to polarization holography. With the capacity of recording polarization holography and conventional intensity holography simultaneously, the Irgacure 784 doped PMMA material is expected to be applied in holographic data storage.

We report on dual-channel recording within polarization holography written by orthogonal linear polarization waves. The null reconstruction effect (NRE) of linear polarization holography was experimentally achieved at a large cross-angle of π/2 inside the polarization-sensitive media. Based on the NRE, two polarization encoded holograms were recorded in a dual-channel recording system with negligible inter-channel crosstalk. The two polarization multiplexed holograms could then be sequentially or simultaneously readout by shifting the polarization state of reference wave with the best signal-to-noise of 18:1 obtained within the experiment.