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Goats have been used as animal models in research, and the need for achieving safer anesthesia for research or surgical intervention is gaining much attention. The objective of this study was to evaluate intraoperative effects and the immediate postoperative analgesia of nalbuphine–ketamine regimen in goats. Twenty clinically healthy adult female crossbred goats weighing 14 ± 2 kg were allocated randomly into each of two equally sized groups. All animals were sedated with intramuscular (IM) xylazine (0.07 mg/kg), then anesthesia was intravenously (IV) induced with ketamine alone (10 mg/kg) (XK group), or a combination of nalbuphine (0.5 mg/kg) and ketamine (5 mg/kg) (XNK group). Following induction, left flank laparotomy was performed and then sutured. The quality of anesthesia and immediate postoperative analgesia was evaluated. Immediate postoperative analgesia was assessed up to 5 h after standing, using a modified Unesp–Botucatu acute composite pain scale (USAPS). Serum cortisol, glucose, insulin, and C-reactive protein (CRP) were measured at ½, 1, 2, 4, 6, 12, and 24 h, postoperatively (PO).The USAPS pain scores were significantly lower in the XNK compared to the XK group (p < 0.05). The XNK group exhibited a statistically significant difference in the level of serum cortisol at ½ and 1 h PO (p = 0.018 and 0.045, respectively) compared to the XK group. At 2, 4, 6 h PO, CRP significantly decreased (p = 0.023, 0.040 and 0.005, respectively) in the XNK compared to the XK group. Nalbuphine–ketamine produced an acceptable induction of anesthesia and recovery compared to ketamine. Recovery with nalbuphine–ketamine was faster and better quality. The USAPS pain scores were lower in nalbuphine–ketamine, indicating that this novel combination produces better postoperative pain control than ketamine alone.

A 3D flower-like mesoporous Ce doped ZnO composite composed of nanosheets was prepared by a facile, one-step wet chemical method at room temperature. It was found that the moderate Ce doping can improve the light absorption of ZnO. The photocatalytic activities of the samples were studied by the degradation of Rhodamine B (RhB) and phenol under stimulated sunlight. The 1% mole ratio of Ce doped ZnO composites (denoted as CZ1) showed higher photocatalytic performance than other samples, where 85.1% of RhB and 69.6% of phenol can be removed within 125 min and 120 min, respectively. The Ce4+ doped in the lattice of ZnO can act as the electron trapping sites, which effectively improve the electron-hole separation. In addition, it was also found the annealing temperature had effect on the morphology and structure of Ce doped ZnO. The photocatalytic performance can be further enhanced at proper annealing temperature (500 °C) due to the increase of ZnO crystallinity with maintained flower-like structure and the formation of CeO2-ZnO heterojunction at their tight interface promoting the separation of photogenerated electron-hole pairs.

The promoting effects of SO42− on N2 selectivity for selective catalytic oxidation (SCO) of ammonia to nitrogen over RuO2/ZrO2 catalyst were systematically investigated. The catalysts were measured by different characterization methods (BET, XRD, TEM, NH3–TPD and in situ DRIFTS). The results showed that the introduction of SO42− into RuO2/ZrO2 presented obvious effects on the structure, surface acidity and N2 selectivity of RuO2/ZrO2. The introduction of SO42− obviously increased the amount of surface acid sites, which could promote the adsorption of ammonia species and prevent the excessive oxidation of ammonia to NOx, improving the N2 selectivity dramatically. The DRIFTS results confirmed that the SCO of ammonia over RuO2/ZrO2–SO42− followed the in situ selective catalytic reduction of NOx (i-SCR) mechanism, involving NH3 oxidation to NO species and –NH2 reacted with NO to form the main product N2. The presence of SO42− not only increased the surface acid sites of the catalyst, but also inhibited the production of nitrate species, which was beneficial to improve the N2 selectivity.

A series of CeO2-modified TiO2–ZrO2–SO42− catalysts were employed to the selective catalytic reduction (SCR) of NOx by NH3. The obtained results indicated that the interaction between CeO2 and TiO2–ZrO2–SO42− contributed to the increased reducibility and decreased surface acidity with the augment of CeO2. The in situ DRIFTS results suggested that suitable surface acidity and reducibility could be offered by increasing the ceria loadings from 24 to 40 wt%. The amount of adsorbed NH3 species, amide species (–NH2) and activated nitrate was increased with the augment of ceria. Excessive addition of CeO2 (80 wt%) resulted in the lacking of surface acid sites and induced the inert nitrate species generation on the catalysts surface.

Pt-Pd-HMS catalyst had been prepared by a one-pot approach and tested for toluene combustion. Comparing with conventional impregnated Pt-Pd/HMS (Ea = 111.41 kJ/mol, Pt-Pd particle size = 23.4 nm), the Pt-Pd-HMS exhibited lower activation energy (Ea = 80.23 kJ/mol) and smaller Pt-Pd particle size (6.3 nm). Moreover, surface Pt0/Pttotal of the Pt-Pd-HMS (52.8%) was higher than that of the Pt-Pd/HMS (46.8%), and Pt-Pd-HMS obtained an optimal catalytic performance with T90 = 179 °C at a GHSV = 26,000 mL/(g·h). In-situ DRIFTS indicated that simultaneous generation of benzoate species and aliphatic compounds as intermediates occurred on the active sites of Pt-Pd-HMS. In contrast, the intermediates of toluene combustion on the active sites of Pt-Pd/HMS were dominated by benzoates.

CuO-Fe2O3 catalysts categorized by the thermal treatment were systematically investigated for ammonia oxidation to nitrogen. The activity results exhibited that the calcination temperature had a significant contribution to the difference of the catalytic performance. Lower calcination temperature (≤500 °C) resulted in the excellent catalytic activity owing to the formation of large surface area, superior redox behavior and abundant surface oxygen species. On the contrary, the catalytic activity of catalysts declined with further raising the calcination temperature (≥600 °C) due to the destroyed structure and acid sites. In addition to this, DRIFTS study revealed that the reaction of ammonia oxidation largely depended on the presence of surface active oxygen on the catalysts. In particular, fast ammonia activation was observed on CuO-Fe2O3–500 °C, which was reflected by the rapid formation of –NH2 and nitrate species on DRIFTS combining the XPS results. The intermediates –NH2 and NO of internal selective catalytic reduction (iSCR) predominantly accounted for the excellent catalytic activities.

The effect of Ce or La on the hydrothermal stability of Cu-SAPO-34 catalyst was evaluated by the selective catalytic reduction of NOx by ammonia (NH3-SCR) reaction after hydrothermal aging at 700 °C in 10 vol% H2O/air for 10 h. The hydrothermal stability of Cu-SAPO-34 was dramatically enhanced by introducing small amount Ce or La into Cu-SAPO-34. More than 93% NOx conversion was maintained over the aged Ce or La modified Cu-SAPO-34 at 175–350 °C, while extremely poor NH3-SCR activity was obtained over the aged Cu-SAPO-34. In situ diffuse reflection infrared Fourier transform spectrum (DRIFTS) results illustrated that the hydrothermal treatment cut off the intrinsic “E-R” reaction route over the Cu-SAPO-34 and opened the new reaction pathway (“L-H” mechanism) over the La modified Cu-SAPO-34 catalyst. Additionally, the introduction of Ce or La effectively mitigated the dealumination progress and restrained the aggregation of copper species over Cu-SAPO-34 during the hydrothermal aging, further maintaining the relatively large specific surface area and uniform pore size distribution. Meanwhile, the incorporation of Ce or La enhanced the redox property and stabilized the surface acid sites of Cu-SAPO-34, further facilitating the adsorption and activation of reactants.

In this paper, we report the first demonstration of using silicon photonic integrated circuits for 62 Gb/s 4-quadrature-amplitude-modulation (4-QAM) orthogonal frequency-division multiplexing (OFDM) and 112 Gb/s 16-QAM OFDM over an 80-km standard single-mode fiber (SSMF) transmission with the Kramers–Kronig (KK) direct detection. Single sideband optical signals are generated by two silicon micro-ring modulators, and directly detected by a single integrated germanium-on-silicon waveguide photodiode fabricated in a multi-project wafer run. The complex optical field can be fully re-constructed by KK detection after an 80-km SSMF transmission. The integrated transceivers with KK detection are suitable for future low-cost, low-power, and small-footprint data center interconnects in the short and medium reach.

A series of different manganese oxides supported Pd catalysts with low Pd loading of 0.3 wt.% have been synthesized and applied to CO catalytic oxidation at low-temperature. In situ DRIFTS was employed to dynamically trace CO oxidation process. It was found that the CO catalytic activity decreased in the order of Pd/OMS-2 > Pd/MnO2 > Pd/Mn2O3 >> Pd/Mn3O4. More interestingly, the Pd/OMS-2 catalyst exhibited exceptionally high activity of T99 = 16 °C, as well as higher reducibility. Furthermore, XPS and in situ DRIFTS results indicated that a substantial of lattice oxygen participated in CO oxidation, contributing to the optimal activity over Pd/OMS-2. While the low reactivity over Pd/Mn3O4 was ascribed to a small amount of lattice oxygen and the strongly adsorbed CO on Pd0.

In the previous research, we found that thermal treatment at high temperature could induce the re-dispersion of Ni particles on SBA-15 for dry reforming of methane (DRM). Here, we aimed to study the re-dispersion behavior of Ni particles of Ni/SBA-15 at different temperatures. The results indicated that the mean Ni particle size of Ni/SBA-15 catalysts were 16.9 nm, 14.5 nm, 7.1 nm and 18.4 nm after thermal treatment at 700 °C, 800 °C, 900 °C and 1000 °C, respectively. It could be seen the optimal inducing temperature of Ni/SBA-15 was at 900 °C. The relatively lower inducing temperature did not drive the re-dispersion of Ni particles sufficiently, while the large Ni particles were formed by re-aggregation of re-dispersive Ni species at relatively higher inducing temperature. After 34 h DRM reaction, encapsulated carbon was formed over the catalyst induced by low temperature and the catalytic performance decreased. However, a slight amorphous carbon was discovered over the catalyst induced at 900 °C with highly dispersion. Interestingly, in spite of a large amount of carbon deposition, the 1000Ni/SBA-15 still maintained excellent catalytic activity.

A series of RuO2-Fe2O3 catalysts varied in RuO2 loading were prepared by sol-gel method and used for selective catalytic oxidation of ammonia to nitrogen. The results indicated that all the RuO2-Fe2O3 catalysts showed an excellent low-temperature catalytic activity and the RuO2 loading played a key role in catalytic activity of ammonia oxidation. Moreover, the characterizations of BET, XRD, H2-TPR and DRIFTS were employed to investigate the relation between the physicochemical property of catalysts and catalytic activity. The research results elucidated that the introduction of RuO2 increased the surface area. The synergistic effect between RuO2 and Fe2O3 enhanced the redox property and the catalytic activity of ammonia oxidation. Meanwhile, the RuO2 loading gave the significant effect on surface acidity of catalysts. Lewis acid sites were predominant on the catalyst surface.

Probabilistically shaped signals with intermediate constellation sizes are found to be relatively tolerant to laser phase noise. We demonstrate experimentally that PS-100 QAM is superior to PS-256 QAM for 200-kHz sum linewidth heterodyne detection.

Recent progress of stir bar sorptive extraction (SBSE) in the past six years is reviewed. The preparation methods including electrodeposition, self-assembly, solvent exchange, physical magnetic adsorption and electrostatic spinning, for the coated stir bar are summarized and compared, specifically for a specific material for coatings fabrication, e.g., carbon-based materials and metal organic frameworks. The emerging materials (e.g., graphene, graphene oxide, carbon nanotubes, monolith, metal-organic frameworks and porous organic polymers) applied for coated stir bar fabrication are one of the focus of this review, along with their respective advantages in extraction process and application in trace analysis. The development and application of extraction apparatus of SBSE are also involved. Based on these information, the development status and prospects of SBSE as an efficient sample pretreatment technique in real sample analysis are discussed.

Many effective solutions have been proposed to reduce the redundancy of models for inference acceleration. Nevertheless, common approaches mostly focus on eliminating less important filters or constructing efficient operations, while ignoring the pattern redundancy in feature maps. We reveal that many feature maps within a layer share similar but not identical patterns. However, it is difficult to identify if features with similar patterns are redundant or contain essential details. Therefore, instead of directly removing uncertain redundant features, we propose a \textbf{sp}lit based \textbf{conv}olutional operation, namely SPConv, to tolerate features with similar patterns but require less computation. Specifically, we split input feature maps into the representative part and the uncertain redundant part, where intrinsic information is extracted from the representative part through relatively heavy computation while tiny hidden details in the uncertain redundant part are processed with some light-weight operation. To recalibrate and fuse these two groups of processed features, we propose a parameters-free feature fusion module. Moreover, our SPConv is formulated to replace the vanilla convolution in a plug-and-play way. Without any bells and whistles, experimental results on benchmarks demonstrate SPConv-equipped networks consistently outperform state-of-the-art baselines in both accuracy and inference time on GPU, with FLOPs and parameters dropped sharply., Preprint version. The final version has been accepted to appear at IJCAI20

The effect of different pH values (8, 9, 10 and 11) on the catalytic activity over CeSiW catalysts was investigated for the selective catalytic reduction of NO by NH3. CeSiW-9 showed a remarkable higher NOx conversion. The strongest interaction was observed between silicotungstic acid and CeO2 over CeSiW-9, resulting in the improvement of redox ability and surface acidity, which could increase the catalytic activity. The superior catalytic performance of the CeSiW-9 catalyst was attributed to the favored pore structures, excellent redox ability and the abundance of surface acid sites, which depended on pH values in the preparation process of CeSiW catalysts.

MSnO4 (M = Mn, Zn, Co, Mg, etc.) has been widely investigated as an anode material for lithium-ion batteries in recent years, but its practical applications are limited by serious capacity loss caused by severe volume expansion during Li+ insertion/extraction. So far, hollow structures, carbon coating, and encapsulation by reduced graphene oxide have been introduced to improve the electrochemical properties of MSnO4. In this study, Mn2SnO4 nanoparticles@reduced graphene oxide (Mn2SnO4@rGO) composites were prepared using simple steps and applied as anode materials for lithium-ion batteries. The rGO sheet encapsulated Mn2SnO4 nanoparticles show improved electrochemical properties. The first discharge capacity of Mn2SnO4@rGO reaches 1223.5 mAh g-1 and remains at 542.0 mAh g-1 after 100 cycles at a current density of 0.1 A g-1. The electrochemical properties were significantly improved compared to those of pure Mn2SnO4 nanoparticles.

Catalytic desulfurization is favored for its ability to desulfurize low concentrations of SO

A series of CeO2 prepared with H2SO4 (C–S), H3PO4 (C–P) and H2SO4 + H3PO4 (C–P–S) were investigated in selective catalytic reduction of NOx with NH3. The sulfates contributed to the improvement of Bronsted (B) acid sites, while phosphates were prone to the enhancement of Lewis (L) acid sites, which could improve the catalytic activity. Furthermore, sulfates existed in the surface of C–P–S and C–S; phosphates occurred on the subsurface region or were highly dispersed on the surface of C–P–S and C–P. Besides, the nitrates adsorbed on the CeO2 and NH3 contacted with the sulfates, which followed the L–H mechanism at 200 °C on C–P–S and C–S. The adsorption and activation of NO and NH3 over C–P occurred at the same active sites, which obeyed the E–R mechanism at 200 °C. C–P–S possessed the best catalytic activity because of the appropriate surface acidity and redox property, and more than 80% conversion of NOx was obtained at 220–450 °C. CeO2 modified by H2SO4 (C–S), H3PO4 (C–P) and H2SO4 + H3PO4 (C–P–S) was prepared and used for selective catalytic reduction of NOx by NH3. The presence of sulfate species over C–S and C–P–S contributed to the formation of surface acidity. CeO2 modified by phosphoric acid favored excellent oxidation ability.

A series of silicotungstic acid modified CeO2 (SC-x, x represents the pH value of solution that is used for the preparation of catalysts) were prepared for the selective catalytic reduction (SCR) of NOx with NH3. SC-9 showed the best catalytic activity among the samples. The monodentate nitrate, bidentate nitrate, bridging nitrate and NO2 were detected over SC-9 and SC-10. Monodentate nitrate and bridging nitrate disappeared over SC-8. Furthermore, the monodentate nitrate and bridging nitrate could react with NH4+ on Bronsted acid sites to generate NH4NO3, and then was reduced by NO to form NO2, accompanied with the fast reaction between NO2 and coordinated NH3 on Lewis acid sites in the presence of gaseous NO. Besides, the SCR reaction pathway of SC catalysts followed by the Langmuir–Hinshelwood mechanism and the Eley–Rideal mechanism.

Mesoporous Al2O3-supported Pt-Pd catalyst was prepared via a one-step evaporation-induced self-assembly (EISA) process and employed for toluene combustion. It was found that the T90 (160 °C) and activation energy (43 kJ/mol) of the one-pot prepared Pt-Pd-Al2O3 catalyst are lower than the conventional Al2O3- supported Pt-Pd catalyst prepared by the wet impregnation method (250 °C, 49.8 kJ/mol). Moreover, the one-pot prepared Pt-Pd-Al2O3 catalyst shows the presence of nano Pt-Pd particles in the mesochannels. In terms of the one-pot EISA approach, the bi-metallic Pt-Pd-Al2O3 catalyst exhibits reduced noble-metal mean particle size (6.1 nm) and T90 than the mono-metallic Pt-Al2O3 and Pd-Al2O3 catalysts. It was demonstrated that the present Pt-Pd-Al2O3 catalytic system exhibits the lowest T90 and T50 parameter values and apparent activation energy at comparable space velocities and toluene feed composition compared to several best performed catalysts reported in the literature.

Carbon dioxide reforming of methane to syngas was investigated over a series of MgO promoted Ni/CNT catalysts. MgO played a critical role in improving the catalytic performance of Ni/CNT. The results showed that the addition of MgO strengthened the interaction of Ni and interior surface of CNT. Highly dispersed nickel particles with small size (less than 4.5 nm) were also observed in MgO modified CNT. Otherwise, the NiO nanoparticles were facilely reduced over the catalyst prepared with a narrow size of CNT, as shown in H2-TPR. The reaction tests demonstrated that the Ni-based catalyst with an addition of MgO and narrow size of CNT exhibited better catalytic activity. Furthermore, the lifetime of Ni-based catalyst was prolonged effectively after adding MgO, attributed to the stabilization and dispersion of Ni particles and the effective restraint on the gasification of CNT.

The promoting effects of WO3 on RuO2-Fe2O3 catalyst were systematically investigated for the selective catalytic oxidation of ammonia to nitrogen. It was found that the introduction of 5 wt.% WO3 led to a dramatic promoting effect on the high-temperature N2 selectivity of RuO2-Fe2O3 catalyst, giving 100% NH3 conversion at 250 °C and 94% N2 selectivity at a high temperature of 400 °C. In depth analysis using XRD, Raman and H2-TPR revealed that the addition of WO3 into the RuO2-Fe2O3 catalyst could strongly inhibit the crystallinity of Fe2O3 and decrease the reducibility of RuO2-Fe2O3 catalyst, which were related to the strong interaction between WO3 and Fe2O3. Moreover, in situ DRIFTS studies illustrated that the ammonia oxidation over 1RuO2-5WO3-Fe2O3 catalyst followed the iSCR mechanism, involving the oxidation of NH3 into NO species and the reaction of -NH2 with in situ-formed NO to form N2. The introduction of WO3 not only promoted the formation of more acid sites on the catalyst surface but also restrained the formation of nitrate species at high temperature, with few NOx formed, which contributed to the high N2 selectivity.

The solid superacid TiO2-ZrO2-SO42−-supported 20 wt.% CeO2 catalyst (20CeO2/Ti-Zr-S) was synthesized for selective catalytic reduction of NO with NH3 (NH3-SCR). The NH3-SCR performance was significantly enhanced by the construction of strong acid sites on the surface of 20CeO2/Ti-Zr-S and over 96% NO conversion was obtained at 225–425 °C. Meanwhile, the strong interaction between solid superacid and CeO2 resulted in excellent redox property and abundant surface oxygen species. Furthermore, the NH3-SCR reaction over 20CeO2/Ti-Zr-S catalyst mainly followed the Langmuir-Hinshelwood mechanism at low-temperature (250 °C). The M-NO2 (M = Ce, Ti, Zr) nitrate compounds, monodentate and bridging nitrates were the crucial intermediates in Langmuir-Hinshelwood mechanism. In addition, amide (–NH2) species were available at 350 °C over 20CeO2/Ti-Zr-S catalyst, which facilitated the high-temperature NH3-SCR activity via Eley-Rideal pathway.

We demonstrated high power green picosecond (ps) laser and high efficiency ultraviolet (UV) femtosecond (fs) laser through second harmonic generation (SHG) using type I phase-matched K3B6O10Br (KBOB) nonlinear optical crystals. The green ps laser was generated by using a homemade high power 1064 nm ps laser as the pump source. When the pump power was 28.2 W with a repetition rate of 800 kHz, 14.2 W ps green laser was obtained with the maximum optical conversion efficiency of 50.4%. When the pump power was 85.2 W with a repetition rate of 800 kHz, the maximum output power of 41.8 W of ps green laser was achieved with an optical conversion efficiency of 49.1%. During the UV fs laser generation, a 710 nm fs laser with a repetition rate of 1 kHz was used to pump the KBOB crystal. When the pump power of 710 nm laser was 54 mW, the 355 nm UV fs laser was obtained with output power of 18 mW and optical conversion efficiency of 33.3%. The experimental results show that the KBOB crystal is a highly qualified candidate for the application in generating high power ultrafast green and UV lasers.

Ni-CeZrAl catalyst prepared by a facile co-precipitation method was applied for dry reforming of methane (DRM). DRM catalytic performance of Ni-CeZrAl presented the highest methane conversion of 38.1% at 650 °C, and remained stable at 700 °C for 50 h without deactivation. Kinetic investigations further showed the lowest apparent activation energy (34.5 kJ/mol) of DRM reaction and the highest CH4 TOF value (7.62 × 10−2 s−1) at 640 °C over Ni-CeZrAl. The surface properties of these samples were systematically characterized by H2-chemisorption, H2-TPR, XPS, Raman, CO2-TPD and O2-TPD. It can be found that the superior catalytic behaviors of Ni-CeZrAl catalyst were closely associated with its high dispersion of surface Ni0 active phase. More importantly, ample oxygen vacancies and basic sites favored the formation of disordered carbon and effectively protected the Ni active sites. The inferior activity in Ni-CeAl was due to the formation of NiAl2O4 inactive spinel phase. Similarly, weak interaction and fewer active sites resulted in the inferior catalytic performance of Ni-CeZr. Hence, unique surface properties of Ni-CeZrAl with the optimum active site-support interaction were responsible for considerable performance. This work provides a guidance to design high performance Ni-based catalysts for DRM.

A novel photonic analog-to-digital conversion (ADC) scheme based on time-to-frequency mapping is proposed and experimentally demonstrated. In the approach, the amplitude of the input analog signal is firstly converted into a time-varying signal by pulse position modulation, then the time variation is mapped into the optical spectrum with the help of time-to-frequency mapping offered by the chirped optical pulse. The optical spectral information can be directly encoded by using interleaving filters and a binary receiver array, which outputs the digital records of the input analog signal. Compared with the existing photonic ADC schemes, the proposed approach greatly simplifies the system configuration and uses only one modulator with a dispersive element to achieve 2 N quantization levels. Meanwhile, it also avoids the limitation of optical nonlinearity and realizes the linear mapping between the analog voltage and optical spectrum. A proof-of-concept experiment of the proposed approach based on time-to-frequency mapping is successfully carried out to verify the feasibility of the scheme. In addition, we also discuss the performance limitations induced by the frequency ambiguity in chirped spectra and the timing jitter in sampling.

A series of Ce/Fe-Zr-SO42- catalysts have been prepared and developed for selective catalytic reduction of NO with ammonia (NH3-SCR). The catalysts were characterized by XRD, H2-TPR, N2 adsorption-desorption, NH3-TPD and DRIFTS. The characterization results demonstrated that the coexistence of cerium and sulfuric acid on Fe-Zr catalyst could contribute to excellent SCR performance. Among all samples, Ce/Fe-Zr-0.3 S catalyst showed the optimal NOX conversion, reaching more than 80% at 250 °C at a GHSV of 60000 h-1. Moreover, the optimum concentration of SO42- to modify Ce/Fe-Zr catalyst was 0.3 mol/L. The low sulfuric acid concentration contributed to improving low-temperature activity, while high concentration leaded to outstanding high-temperature activity. According to H2-TPR and NH3-TPD, the presence of SO42- increased the total amount of acid sites and more stable sulfate species were formed with higher concentration of sulfuric acid. In situ DRIFTS revealed the NH3 molecule was mainly activated at the Lewis acid site and reacted with the adsorbed NOX species (such as bidentate nitrates) to produce N2 and H2O, which conformed to the L-H reaction mechanism.

During the high-temperature hydrothermal aging process, the tolerance of the zeolite structure and the stability of the active Cu2+ ions directly determined the denitration (deNOx) performance of the copper-based zeolite catalysts in automobile exhaust treatment. Herein, we displayed the hydrothermal aging stability of La-free and La-doped Cu/SAPO-34 catalysts at variant temperatures (650, 750 and 850 °C). A series of characterization results signified that the addition of La into SAPO-34 framework by ion exchange method had obvious contribution to hold back the collapse of SAPO-34 structure and transformation of isolated Cu2+ ions. Different from Cu/SAPO-34 catalyst, Cu/La-SAPO-34 catalyst was more prone to maintain its superior catalytic activity after hydrothermal aging at 750 °C, which possessed great application potential. In addition, NH3-TPD and DRIFT spectra shed light on the variation of surface acidity over two kinds of catalysts inducing by hydrothermal treatment. It could be discovered that doping of La provided moderate surface acidity and excellent hydrothermal stability for Cu/SAPO-34 even up to 750 °C, which was in favor of the NH3-SCR reaction.

The use of porous carrier and coating sorbents in stir bar sorptive extraction (SBSE) contributes to the improvement of extraction efficiency and dynamics. Herein, porous nickel foam (NF) with large surface area and magnetic property was used as the carrier of stir bar. NF was added into the mixture of graphene oxide (GO) and reducing agent, and reduced graphene oxide (RGO) coating was obtained on the surface of NF substrate by in situ hydrothermal reduction. The characterization results of Fourier transform infrared spectroscopy, X-ray power-diffraction and scanning electron microscope showed that GO was partially reduced into RGO, and the RGO coating was uniformly loaded on the NF surface. The obtained RGO-NF composite was used as the stir bar coating for the analysis of six benzotriazole (BZTs) UV absorbents. The extraction efficiency was between 48 and 64% for six BZTs. RGO-NF stir bar exhibited faster adsorption/desorption kinetics than commercial polydimethylsiloxane coated stir bar (50 min vs 120/360 min) due to its porous structure and large specific surface area. On this basis, a method of RGO-NF coated stir bar sorptive extraction combined with high performance liquid chromatography (HPLC)-DAD was established for the determination of six BZTs. Under the optimized conditions, the limits of detection were 0.33–0.50 μg/L for six target BZTs, and the linear range was 1–100 μg/L. The proposed method merits good ability to resist matrix and was used to analyze six BZTs in environmental water samples. The recoveries of target BZTs were obtained within 83.0–112% in the spiked East Lake water and 97.0–111% in the spiked Yangtze River water, respectively.

Highly dispersed Ni/SBA-15 catalysts were prepared via template extraction with varying different extraction times (Ni/S-x, x = 0.5, 3.5, 6.5 h) for methane reforming with carbon dioxide. Based on the various characterization results and initial activity evaluation, Ni/S-3.5 h catalyst showed the best catalytic performance. Compared with the catalyst prepared via template calcination (Ni-S), Ni/S-3.5 h catalyst held steady with CH4 and CO2 conversions while those of the Ni-S catalyst respectively decreased by 15 and 11% during the long-term stability test at 700 °C for 50 h. As TEM and TG–DSC results confirmed, Ni particles in spent Ni/S-3.5 h catalyst stayed well-dispersed with size slightly increasing from an initial 3.9–4.1 nm and nearly no carbon deposition was observed. On the contrary, Ni-S catalyst was subjected to sintered metal particles (increased from 11.6 to 18 nm) and formed carbon fibers. The prominent resistance to sintering and coking over stable Ni/S-3.5 h catalyst was attributed to the high dispersion and strengthened metal-support interaction induced via the residual in situ templates.

A series of CuO-Fe 2 O 3 composite oxides were successfully prepared for low temperature selective catalytic oxidation of ammonia (NH 3 -SCO). Higher Cu/Fe ratio in CuO-Fe 2 O 3 catalysts led to higher activity for NH 3 oxidation and the lower Cu/Fe ratio improved the N 2 selectivity. The optimal catalyst with a Cu/Fe molar ratio of 5:5 displayed a low complete conversion temperature ( 2 selectivity (>91%). H 2 -TPR results indicated that the synergistic effect existed between Fe 2 O 3 and CuO, which was beneficial to the catalytic performance. The results of the DRIFTS showed that NH 3 -SCO reaction mainly followed the internal SCR (i-SCR) mechanism. The adsorbed NH 3 was first activated and reacted with atomic oxygen to form the nitrosyl (-HNO). Then the -HNO was oxidized by oxygen atoms from O 2 to form NO species. Meanwhile, the in situ -formed NO could react with -NH 2 to form the main product of N 2 .

Ni/SBA-15 catalyst was prepared by homogeneous precipitation method (Ni-HP) and used for dry reforming of methane (DRM). The related characterization results indicated that the Ni particles were highly dispersed with a size range of 2-5 nm. Compared with Ni/SBA-15 catalyst prepared by impregnation (Ni-IM), the reduction temperature of Ni-HP obtained from H2-TPR was greatly improved, suggesting the stronger metal-support interaction. After reacting at 700 °C for 100 h, the CH4 conversion of DRM over Ni-HP catalyst slightly decreased from 74.5% to 73.8%. While, for the Ni-IM catalyst, the CH4 conversion dropped from 61.7% to 37.3%. Furthermore, the average particle size of Ni-HP was 3.7 nm and 4.7 nm before and after the long-time stability test, respectively, ascribed to the good anti-sintering property. Although a certain amount of coke was produced, mainly with disorder filamentous carbon of base-growth, the Ni/SBA-15 prepared by homogeneous precipitation exhibited excellent catalytic activity and stability.

The CeO 2 -ZrO 2 -WO 3 catalysts were investigated for the selective catalytic reduction of NO x by NH 3 (NH 3 -SCR). The results indicated that monodentate nitrate species generated from amorphous WO 3 , and these species could not be observed over CeO 2 -ZrO 2 -WO 3 with the presence of Ce 2 (WO 4 ) 3 compounds. The formation of amorphous W species resulted in the abundant of Ce 3+ and oxygen vacancies. Besides, the amorphous W species could enhance the surface acidity and NO oxidation ability. Nitrate species (bridging nitrate and monodentate nitrate), coordinated NH 3 and NH 4 + all participated in the NH 3 -SCR process. The NH 3 -SCR reaction pathway of CeO 2 -ZrO 2 -WO 3 mainly followed Langmuir-Hinshelwood mechanism.

A number of Co3O4 catalysts with various structures and exposed crystal planes were prepared by different methods. The effects of the structures and exposed crystal planes on the catalytic activity of Co3O4 catalysts were investigated for the catalytic decomposition of N2O. The Co3O4 with nanorod structure was enclosed by (220) planes; Co3O4 with irregular shape crystallites predominantly exposed (111) and (040) lattice planes; Co3O4 with bulk particles only showed the single exposure of (040) planes; the spherical particles of Co3O4 presented the (220) and (311) planes. The results indicated that Co3O4 with irregular shape crystallites showed the best catalytic activity and over 80% of N2O conversion was obtained at 384–450°C. The bulk particles of Co3O4 showed inferior performance. In addition, the exposed crystal planes of Co3O4 prepared by different methods can affect the catalytic decomposition of N2O.

A series of precipitants and commercial surfactants (soft templates) were employed to synthesize mesoporous/nano CeO2 by a hydrothermal method. As-prepared CeO2 was impregnated with palladium and employed for low-temperature catalytic oxidation of CO. It was found that both soft templates and precipitants had significant effects on the morphology, particle size, crystallinity, and porous structure of the CeO2, having a significant effect on the surface palladium abundance, molar ratios of surface species, and catalytic activity of the final impregnated Pd/CeO2. Using ammonia as precipitant could facilitate increased surface palladium abundance and surface molar ratios of PdO/Pd SMSI , Ce3+/(Ce3+ + Ce4+), and Osurface/Olattice. The catalytic activity of the final Pd/CeO2 catalysts could be enhanced as well. The optimal P123-assisted ammonia-precipitated Pd/CeO2 catalyst exhibited over 99% catalytic conversion of CO at 50 °C.

A series of Ni/SBA-15 (AM) catalysts were prepared by chelating ligand assisted impregnation method. The results showed that the chelating ligand played a positive promoting role for CH4 dry reforming with CO2 over Ni/SBA-15. The electron-pair donor atoms and the high viscosity of chelating agent could inhibit the aggregation of nickel species and contribute to the well-dispersed Ni particles with size of

Mesoporous silica-supported Ni can serve as alternative effective catalysts for dry reforming of methane. However, conventional synthesis method requires long synthetic time and high cost, and the resulting catalysts show unsatisfactory catalytic stability due to coking and sintering. In this paper, we reported a facile, low-cost and environmental benign method to introduce Ni species into HMS mesoporous silica (Ni-HMS) in a self-assembled way. FT-IR, H 2 -TPR, and TEM manifested that the obtained Ni-HMS established uniform distributed Ni particles (3.9 ± 0.5 nm) and strong metal-support interaction derives from Si-O-Ni bonding. The dry reforming of methane results demonstrated that the Ni-HMS showed more active and stable catalytic performance than that of Ni impregnated HMS catalyst (Ni/HMS). Notably, the catalytic activity was well maintained even after reacting at 700 °C for 100 h. HAADF-STEM and TG-DSC revealed that coking and sintering were unnoticeable over the endurance-tested Ni-HMS catalysts. The strong anchor effect of pore wall to Ni nanoparticles inherent to the one-pot synthesis was suggested to be the original reason for enhanced resistance toward coking and sintering.

The mechanism of phosphotungstic acid modification CeO 2 catalysts (P-W/CeO 2 ) with different CeO 2 supports were investigated by in situ diffuse reflectance infrared transform spectroscopy for the selective catalytic reduction of NO by NH 3 . The results indicated that the NH 3 -SCR reaction over P-W/CeO 2 followed both the Langmuir–Hinshelwood mechanism and the Eley–Rideal mechanism. The reaction between NH 4 + and bidentate nitrate (NO 3 − ) took place, and then the H 2 O, N 2 and adsorbed NO 2 were formed. The coordinated NH 3 species reacted with adsorbed NO 2 and gaseous NO to generate N 2 and H 2 O. The interaction between CeO 2 and phosphotungstic acid contributed to the favored surface acidity (Lewis and Bronsted acid sites) and excellent redox property. The Bronsted acid sites facilitated the generation of NO 2 -adsorbed and Lewis acid sites accelerated the Eley–Rideal mechanism, while the NO oxidation to bidentate nitrate or NO 2 -adsorbed species was an important step in the reaction mechanism of P-W/CeO 2 .

The signal-signal beat noise mitigation performances of the original received signal, the square root processed signal, and the Kramers-Kronig processed signal are experimentally compared in a 110 Gbit/s probabilistically-shaped 64 QAM direct detection system.

In probabilistic shaping, a smaller constellation size leads to a lower peak-to-average power ratio but a higher average power. By jointly considering the signal-to-noise ratio and the DAC resolution, we determine the optimal constellation size.

We propose an artificial neural network based demodulation block to mitigate the effect caused by signal to signal beating noise. Experimental results show that our proposed scheme outperforms Volterra equalizer assisted scheme.