Ordered Mesoporous MnAlO<i>_x</i> Oxides Dominated by Calcination Temperature for the Selective Catalytic Reduction of NO<i>_x</i> with NH₃ at Low Temperature

Manganese alumina composited oxides (MnAlOx) catalysts with ordered mesoporous structure prepared by evaporation-induced self-assembly (EISA) method was designed for the selective catalytic reduction (SCR) of NOx with NH3 at low temperature. The effect of calcination temperature of MnAlOx catalysts was investigated systematically, and it was correlated with SCR activity. Results showed that with an increase in calcination temperature, the SCR activity of MnAlOx catalysts increased. When the calcination temperature was raised up to 800 °C, the NOx conversion was more than 90% in the operation temperature range of 150~240 °C. Through various characterization analysis, it was found that MnAlOx-800 °C catalysts possessed enhanced redox capacities as the higher content of Mn4+/(Mn3+ + Mn4+). Moreover, the improved redox properties could contribute to a higher NOx adsorption and activation ability, which lead to higher SCR performance of MnAlOx-800 °C catalysts. In situ DRIFTs revealed that the adsorbed NO2 and bidentate nitrate are the reactive intermediate species, and NH3 species bonded to Lewis acid sites taken part in SCR progress. The SCR progress predominantly followed E–R mechanism, while L–H mechanism also takes effect to a certain degree

Research on Applicability of Hot-Bulb Anemometer under Low Pressure

In Mars and other deep space exploration missions, the planetary atmosphere makes the difference in heat transfer characteristics on the planetary surface and on-orbit environment. In order to achieve the purposes of thermal model correction and spacecraft verification in extreme environment, Mars rover needs to be tested in a simulated Mars environment including low pressure, solar heat flux, wind speed and background temperature. Thus, wind speed should be measured at multiple points in the Mars rover thermal test. In a general Mars rover thermal balance test, the requirement for wind speed control and measurement is 0-15m/s under 700Pa pressure. The current anemometer for industrial use is mainly based on the dynamic pressure, heat or ultrasound. They have a small signal and need to be recalibrated at low pressures. In this paper, a constant heat flux hot-bulb anemometer model has been built using dimensionless number analysis method, with which the anemometer response under low pressure has been calculated. A series of calibration test has been employed to verify the model in space environment chamber. The two methods above reached a similar result, which demonstrates the effectiveness of the analysis

Computer-aided Design for the Route of the Test Waveguides

With the rapid development of China's space industry, digitization and intelligent is the tendency of the future. The applications of the waveguide are gradually widespread. During the thermal test phase, the routes of the test waveguides are similar for each spacecraft. Although the waveguides are highly standardized, so far it needs engineers to design the particular route of the test waveguidess, then map the engineering drawing for every test. In order to efficiently design the route of waveguide, it needs to design an application to help the engineers. With the help of the MFC(Microsoft Foundation Classes) and the pro/toolkit, it is easily to do the modeling and simulation. After automatic design the particular the route of the waveguide, the API of AutoCAD type library is used to help to modify the engineer drawing. Engineers can supervise every step of this application, and easily to modify the key parameters

Characterization of sequence elements from Malvastrum yellow vein betasatellite regulating promoter activity and DNA replication

Abstract Background Many monopartite begomoviruses are associated with betasatellites, but only several promoters from which were isolated and studied. In this study, the βC1 promoter from Malvastrum yellow vein betasatellite (MYVB) was characterized and important sequence elements were identified to modulate promoter activity and replication of MYVB. Results A 991 nucleotide (nt) fragment upstream of the translation start site of the βC1 open reading frame of MYVB and a series of deletions within this fragment were constructed and fused to the β-glucuronidase (GUS) and green fluorescent protein (GFP) reporter genes, respectively. Agrobacterium-mediated transient expression assays showed that the 991 nt fragment was functional and that a 28 nt region (between −390 nt and −418 nt), which includes a 5′UTR Py-rich stretch motif, was important for promoter activity. Replication assays using Nicotiana benthamiana leaf discs and whole plants showed that deletion of the 5′UTR Py-rich stretch impaired viral satellite replication in the presence of the helper virus. Transgenic assays demonstrated that the 991 nt fragment conferred a constitutive expression pattern in transgenic tobacco plants and that a 214 nt fragment at the 3'-end of this sequence was sufficient to drive this expression pattern. Conclusion Our results showed that the βC1 promoter of MYVB displayed a constitutive expression pattern and a 5′UTR Py-rich stretch motif regulated both βC1 promoter activity and MYVB replication.</p

A GIS-Based Web Approach for Serving Land Price Information

Participants in the land market are usually hampered to browse and analyze the land price information due to the lack of information sources and available analysis tools. A service-oriented GIS-based web system was developed to provide a practical solution, its essential data sources contain basic geographic elements and benchmark land price (BLP)-related information. Core models for land price analysis were implemented, including land price index, spatial distribution, and parcel appraisal. The system was developed based on a four-level Browse Server (B/S) architecture using GIS and web service technologies, which enables the publishing, browsing, and analysis of the land price information via the Internet. With effective functionalities, the system has been employed in a project for updating BLP in a case study city located in China. The main advantage of the GIS-based web approach lies in its integration of spatial-temporal analysis models and web GIS technology, which allows more investors and administrators with limited domain knowledge to obtain further understanding on the change pattern and spatial distribution of land price by an online means. The experience in the case study city demonstrates that the approach has strong practicality for land price information services

The Role of SO3 Poisoning in CU/SSZ-13 NH3-SCR Catalysts

To reveal the role of SO3 poisoning in Cu/SSZ-13 NH3-SCR catalysts, fresh and sulfated Cu/SSZ-13 catalysts were prepared in the presence or absence of SO3 flux. The deactivation mechanism is probed by the changes of structural, copper species, and selective catalytic reduction (SCR) activity. The variations concentrate on the changes of copper species as the Chabazite (CHA) framework of Cu/SSZ-13 catalysts could keep intact at high ratios of SO3/SOx. The thermal gravimetric analyzer (TGA) results reveal that the copper sulfate formed during sulfation and the amounts of sulfate species increased with an increase in the SO3/SOx ratio. In contrast to the changing trend of copper sulfate, temperature program reduction (H2-TPR), and electron paramagnetic resonance (EPR) results manifest that, since the number of active copper ions declines with an increase of the SO3/SOx ratio, the active sites transform to these inactive species during sulfation. Due to the combination of NH3-SCR activity and the kinetic tests, it is shown that the decreased number of active sites is responsible for the declined SCR activity at low temperature. As Cu/SSZ-13 catalysts show excellent acid-resistance ability, our study reveals that the Cu/SSZ-13 catalyst is a good candidate for NOx elimination, especially when SO3 exists

Correction: Liu et al. Anti-<i>Toxoplasma gondii</i> Effects of a Novel Spider Peptide XYP1 In Vitro and In Vivo. <i>Biomedicines</i> 2021, <i>9</i>, 934

In the original publication, there were mistakes in Figure 3C, Figure 6B and Figure S2A,B as published [...

Effect of Copper Precursors on the Activity and Hydrothermal Stability of CuII−SSZ−13 NH3−SCR Catalysts

A series of CuII&minus;SSZ&minus;13 catalysts are prepared by in-situ hydrothermal method using different copper precursors (CuII(NO3)2, CuIISO4, CuIICl2) for selective catalytic reduction of NO by NH3 in a simulated diesel vehicle exhaust. The catalysts were characterized by X&minus;ray diffraction (XRD), scanning electron microscope (SEM), X&minus;ray photoelectron spectroscopy (XPS), N2 adsorption-desorption, hydrogen-temperature-programmed reduction (H2&minus;TPR), ammonia temperature-programmed desorption (NH3&minus;TPD), and 27Al and 29Si solid state Nuclear Magnetic Resonance (NMR). The CuII&minus;SSZ&minus;13 catalyst prepared by CuII(NO3)2 shows excellent catalytic activity and hydrothermal stability. The NO conversion of CuII&minus;SSZ&minus;13 catalyst prepared by CuII(NO3)2 reaches 90% at 180 &deg;C and can remain above 90% at a wide temperature range of 180&ndash;700 &deg;C. After aging treatment at 800 &deg;C for 20 h, the CuII&minus;SSZ&minus;13 catalyst prepared by CuII(NO3)2 still exhibits above 90% NO conversion under a temperature range of 240&ndash;600 &deg;C. The distribution of Cu species and the Si/Al ratios in the framework of the synthesized CuII&minus;SSZ&minus;13 catalysts, which determine the catalytic activity and the hydrothermal stability of the catalysts, are dependent on the adsorption capacity of anions to the cation during the crystallization process due to the so called Hofmeister anion effects, the NO3&minus; ion has the strongest adsorption capacity among the three kinds of anions (NO3&minus;, Cl&minus;, and SO42&minus;), followed by Cl&ndash; and SO42&ndash; ions. Therefore, the CuII&minus;SSZ&minus;13 catalyst prepared by CuII(NO3)2 possess the best catalytic ability and hydrothermal stability

Anti-Toxoplasma gondii Effects of a Novel Spider Peptide XYP1 In Vitro and In Vivo

Toxoplasmosis, caused by an obligate intracellular parasite Toxoplasma gondii, is one of the most prevalent zoonoses worldwide. Treatments for this disease by traditional drugs have shown numerous side effects, thus effective alternative anti-Toxoplasma strategies or drugs are urgently needed. In this study, a novel spider peptide, XYP1, was identified from the cDNA library of the venom gland of the spider Lycosa coelestis. Our results showed that XYP1 has potent anti-Toxoplasma activity in vitro and in vivo. Specifically, treatment with XYP1 significantly inhibited the viability, invasion and proliferation of tachyzoites with low cytotoxicity (IC50 = 38.79 μΜ) on human host cells, and increased the survival rate of mice acutely infected with T. gondii. Next, scanning electron microscopy, transmission electron microscopy and RNA sequencing were employed to further explore the functional mechanism of XYP1, and the results indicated that XYP1 causes membrane perforation, swelling and disruption of tachyzoites, which could be closely associated with differential expression of several membrane-associated proteins including HSP29. In conclusion, XYP1 may be a promising new drug candidate for the treatment of toxoplasmosis