Search

An efficient and inexpensive double transition metal oxide catalyst, MoO2/β-MnO2 composite is developed for oxygen reduction reaction (ORR) and showing better performance than either MoO2 or β-MnO2. The composite catalyst was made into a multi-layered cathode (MLC) for a direct glucose fuel cell (GFC). The MLC consists of a graphite flake and several porous catalyst layers attached to both sides, allowing more adsorption and reaction sites for O2. The better cathode performance over single metal oxide catalysts or single-layer electrodes is confirmed by cyclic voltammetry (CV) and Tafel analysis. By coupling the MLC with a glucose oxidation system catalyzed by Fe(III)/H3PO4, a double-chambered GFC device has been built with an open-circuit potential of 0.68 V and a stable current density of 24 mA·cm−2. Therefore, the utilization of bimetallic multi-layer porous cathodes is a good method to improve the efficiency of ORR for fuel cells.

Since 1982, Landsat series of satellite sensors continuously acquired thermal infrared images of the Earth’s land surface. In this study, Landsat 5, 7, and 8 land surface temperature (LST) products...

Land surface temperature (LST) is an important parameter in various fields, including hydrological, meteorological, and agricultural studies. Passive microwave techniques provide a practicable method to retrieve LST under both clear and cloudy conditions. In this study, LST derived from Advanced Microwave Scanning Radiometer 2 (AMSR2) brightness temperature data during nighttime in the period 2015–2016 using a physically-based algorithm was compared with Moderate Resolution Imaging Spectroradiometer (MODIS) LST product MYD11A1 over 16 study sites that represent four different land cover types, i.e., barren/sparsely vegetated, grasslands, croplands, and evergreen broadleaf forest. Compared to MODIS-derived LST, the root-mean-square error (RMSE) of AMSR2-derived LST is 6.0 K and the bias is 4.4 K over all study sites. For barren/sparsely vegetated sites, LST was overestimated by 6.7 K. To eliminate the systematic bias induced by the penetration depth effect of microwave radiation over barren/sparsely vegetated sites, a linear regression between AMSR2- and MODIS-derived LST was applied and the RMSE decreases from approximately 7.8 to 3.5 K. For the other three land cover types, the bias ranges from approximately 1.4 to 4.2 K and the RMSE ranges from approximately 2.1 to 5.9 K. The bias between AMSR2- and MODIS-derived LST is related to vegetation coverage. The value of bias increases with the decrease of normalized difference vegetation index. Furthermore, the RMSE has a strong dependency on precipitable water vapor (PWV). It presents a descending pattern of RMSE with the increase of PWV.

Forcipomyia (Forcipomyia) makanensis Hou sp. n. (Diptera: Ceratopogonidae) is described and illustrated based on male and female specimens from China. It is characterized by the male aedeagus triangular, with large cone-shaped process at apex, basal arch high, basal arm slender and curved, parameres separate narrower distance at base, cone-shaped apically, and the female subgenital plate pliers-shaped, without lateral process, with two spermathecae, oval, nearly equal. The new species is compared with the similar congener F. (Forcipomyia) lochmocola Zou and Yu, 1991. We provide separate keys for identification of the males and females of the species of subgenus F. (Forcipomyia) Meigen in China.

Land surface temperature (LST) and soil moisture (SM) are two important parameters in land surface ecosystem at regional and global scale. The accurate acquisition of LST and SM can benefit various fields, including agriculture and climate which are closely related to human life. This study proposed a simultaneous retrieval method of LST and SM based on the approximate and correction of passive microwave radiation transfer equation. Compared to LST and SM in simulated database, the accuracy of retrieved LST is approximately 1.63 K and the accuracy of retrieved SM is about 0.063 m3/m3.

The authors would like to correct an error in the title paper [...]

A molecular capacitor array provides sensitive and selective determination of ionizable and neutral compounds. To better recognize glucose, 3-(acrylamido) phenylboronic acid (AAPBA) was used in the preparation of a molecularly imprinted polyacrylamide cryogel. The coordination of boronic acid groups and the cis-diol structure leads to high affinity between glucose and the resulting polymer. During the molecular recognition, solvent molecules (water) in the imprinted sites were replaced by glucose. Thus, significant capacitance changes were observed due to the different permittivities of glucose and water. Hence, a portable capacitive sensor was obtained to determine glucose. The sensor shows unparalleled selectivity with preparation with operation like a chromatographic column. The interfering substances were removed by filtration or washing before determination of the template with a linear range from 1.17 ×10−11 to 1.44 ×10−4 mol/L and a detection limit of 3.72 ×10−12 mol/L. The sensor was employed to determine glucose in biological samples without pretreatment.

Gastrodia Rhizoma, as a precious Chinese materia medica, has attracted the attention of Chinese materia medica experts in the past dynasties for the commercial specification and experimental identification, and has gradually formed a wealth of terms concerning commercial specification and experimental identification. Through combing the literatures of successive dynasties, this paper discussed the change of the commercial specification of the Gastrodiae Rhizoma and formation of its identifying terms. It has found that the Gastrodiae Rhizoma mainly came from the dried rhizomes of the Gastrodia elata f.elata before the Qing Dynasty. Since the Qing Dynasty, G. elata in Yunnan and Guizhou gradually arose and become one of sources of mainstream commodities. After that, G. elata f. glauca and G. elata f. elata were becoming the main sources of Gastrodiae Rhizoma. Before the large-scale cultivation of G. elata in the 1970 s, there is only wild G. elata over the country. In terms of commercial specification, they were often classified into Chunma and Dongma according to their harvest time. With the successful promotion of cultivation technology and the endangered wild resources of G. elata, the Dongma became the mainstream in the market. The adulterants of G. elata increased significantly in the 1960 s and 1970 s, in this period, the terms of experimental identification for G. elata also increased obviously. Experimental identification is distinctive in different times, therefore, studying experimental identification of medicinal materials helps to promote the development of the Chinese materia medica.

In order to understand the structural characteristics of squalene synthase genes in the triterpenoids biosynthesis pathway of Crataegus pinnatifida, the squalene synthase genes of C. pinnatifida was cloned and analyzed by bioinformatics and prokaryotic expression. Two squalene synthase genes CpSQS1 and CpSQS2 were cloned from C. pinnatifida fruit by RT-PCR. The ORF length of CpSQS1 and CpSQS2 were 1 239 bp and 1 233 bp respectively, encoding 412 aa and 410 aa respectively. CpSQS1 and CpSQS2 were predicted to be stable acidic proteins by online tools. The secondary structure was mainly composed of α-helix structure, and the tertiary structure was predicted by homology modeling. Structural functional domain analysis showed that 35-367 aa of CpSQS1 and CpSQS2 cDNA containing conserved trans-isoprenyl pyrophosphate synthase domains. Transmembrane domain analysis predicted that two transmembrane domains were founded in CpSQS1 and CpSQS2. The squalene synthase amino sequence of C. pinnatifida had higher homology with the known SQS of Salvia miltiorrhiza and Glycyrrhiza glabra. Phylogenetic tree analysis showed that CpSQS1 and CpSQS2 were clustered into one branch of MdSQS1 and MdSQS2, which were consistent with the phylogenetic rule. Prokaryotic expression vector pGEX-4 T-1-CpSQS1 and pGEX-4 T-1-CpSQS2 were transformed into Escherichia coli Transetta(DE3) for induction, and the target protein was successfully expressed at 65 kDa. The expression levels of CpSQS2 were significantly higher than that of CpSQS1 in three different developmental stages of C. pinnatifida. In this study, the full-length cDNA sequences of C. pinnatifida SQS1 and SQS2 were cloned and analyzed for the first time, which provided the foundation for further study on the metabolic pathway of C. pinnatifida triterpenoids.

Satellite remote sensing provides a unique way to measure land surface temperature (LST) at regional and global scales. Algorithms using thermal infrared (TIR) data provide a reliable way to retrie...

Land surface temperature (LST) is a key variable influencing the energy balance between the land surface and the atmosphere. In this work, a split-window algorithm was used to calculate LST from Sentinel-3A Sea and Land Surface Temperature Radiometer (SLSTR) thermal infrared data. The National Centers for Environmental Prediction (NCEP) reanalysis atmospheric profiles combined with the radiation transport model MODerate resolution atmospheric TRANsmission version 5.2 (MODTRAN 5.2) were utilized to obtain atmospheric water vapor content (WVC). The ASTER Global Emissivity Database Version 3 (ASTER GED v3) product was utilized to estimate surface emissivity in order to improve the accuracy of LST estimation over barren surfaces. Using a simulation database, the coefficients of the algorithm were fitted and the performance of the algorithm was evaluated. The root-mean-square error (RMSE) values of the differences between the estimated LST and the actual LST of the MODTRAN radiative transfer simulation at each WVC subrange of 0–6.5 g/cm2 were less than 1.0 K. To validate the retrieval accuracy, ground-based LST measurements were collected at two relatively homogeneous desert study sites in Dalad Banner and Wuhai, Inner Mongolia, China. The bias between the retrieved LST and the in situ LST was about 0.2 K and the RMSE was about 1.3 K at the Dalad Banner site, whereas they were approximately -0.4 and 1.0 K at the Wuhai site. As a reference, the retrieved LST was compared with the operational SLSTR LST product in this study. The bias between the SLSTR LST product and the in situ LST was approximately 1 K and the RMSE was approximately 2 K at the Dalad Banner site, whereas they were approximately 1.1 and 1.4 K at the Wuhai site. The results demonstrate that the split-window algorithm combined with improved emissivity estimation based on the ASTER GED product can distinctly obtain better accuracy of LST over barren surfaces.

The accumulation of chemical constituents of some medicinal plants, such as Paeonia ostii T. Hong et J. X. Zhang, Houpo&euml, a officinalis (Rehder and E. H. Wilson) N. H. Xia and C. Y. Wu. and Atractylodes lancea (Thunb.) DC, can precipitate on the surface and form frosts after natural or artificial intervention. The characteristics of these three medicinal plants and their frosts were analyzed by light microscope, polarizing microscope, stereomicroscope, and metalloscope. The results of ordinary Raman of P. ostii and H. officinalis showed that the frosts of P. ostii matched paeonol, while that of H. officinalis matched magnolol and honokiol. In P. ostii and its frost, 19 peaks were identified by UPLC-Q/TOF-MS, and the main component was paeonol. Eleven components were identified in H. officinalis and its frosts, and the main components were magnolol and honokiol. A. lancea and its frosts were analyzed by gas chromatography-mass spectrometry (GC-MS), 21 were identified, and its main components were hinesol and &beta, eudesmol. These three medicinal plants accumulate compounds and precipitate frosts on the surface. The results show that the components of the frosts provide a basis for quality evaluation and research on similar medicinal plants, and reveals the scientific connotation of &ldquo, taking the medicinal materials&rsquo, precipitated frosts as the best&rdquo, of P. ostii, H. officinalis, and A. lancea, to some extent.

Passive microwave data are much less affected by clouds than TIR data for the retrieval of land surface temperature (LST), providing its unique advantages in global mapping of LST. In this study, a physically-based algorithm for LST retrieval was applied to AMSR2 global brightness temperature data. The performances of this algorithm applied on different land cover types were further evaluated against nighttime MYD11A1 thermal infrared LST products. The results showed that (i) the overall accuracy of the algorithm is about 5.42 K by root mean square error (RMSE) and 2.99 K by bias against MODIS LST during nighttime; (ii) the algorithm overestimates the LST over all land types. The overestimation is most evident over barren/sparsely vegetated surfaces. The algorithm shows that the algorithm has a robust performance comparing with MODIS LST and could be applied to estimate LST effectively.

The change of global thermal environment plays an important role in land surface processes. In this study, global thermal environment was analyzed using the vertically polarized brightness temperature at 36.5 GHz. The daily brightness temperature from 2003 to 2010 were decomposed using the annual temperature cycle (ATC) model, and the annual cycle parameters (ACPs) were obtained. The results show that the brightness temperature decreases with the increasing latitudes respectively for the northern hemisphere and the southern hemisphere. The land covered by vegetation is colder than the desert and barren. Some plateaus lead to lower brightness temperature than surrounding areas. In addition, the atmospheric and ocean circulation also affect global brightness temperature. The ACPs from brightness temperature can generally characterize the global thermal environment.

Evapotranspiration (ET) plays a key role for energy transfer and water circulation in the biosphere, lithosphere, hydrosphere, cryosphere and atmosphere. In present study, spatially complete ET over the Heihe river basin, Northwest of China, was estimated from the synergistic use of MODIS (MODerate-resolution Imaging Spectroradiometer) data and CLDAS (China Meteorological Administration Land Data Assimilation) gridded meteorological data from June 1 to September 15 in 2012. For the estimation of ET over clear-sky pixels, a pixel-to-pixel pattern of land surface temperature (LST)-vegetation index (VI) feature space was developed where meteorological data were used to determine the dry and wet edges for each pixel; whereas the traditional Penman-Monteith equation was implemented to obtain ET over clouds pixels. Finally, ground ET measurements collected at two sites (corn and orchard) were used to evaluate the estimated results, root mean square error (RMSE) of 77.2W/m2 and 74.9W/m2 can be obtained for the two sites, respectively, indicating that spatially complete ET can be derived from currently available satellite images and meteorological data.

Although intravenous injection is the most convenient and feasible approach for mesenchymal stem cells (MSCs) delivery, the proportion of donor stem cells in the target myocardium after transplantation is small. It is believed that TCM enhances the effect of stem cell therapy by improving the hostile microenvironment and promoting the migration and survival of stem cells. Guanxin Danshen (GXDS) formulation is one of the main prescriptions for clinical treatment of ischemic heart diseases in China. The purpose of this study was to evaluate the effects of GXDS formulation administration combined with MSCs transplantation on cardiac function improvement, apoptosis, angiogenesis and survival of transplanted cells in an acute model of acute myocardial infarction (MI). After being labeled with GFP, MSCs were transplanted via intravenous injection. Meanwhile, GXDS dripping pills were given by intragastric administration for 4 weeks from 2 days before MI. Echocardiography showed moderate improvement in cardiac function after administration of GXDS formulation or intravenous transplantation of MSCs. However, GXDS formulation combined with MSCs transplantation significantly improved cardiac function after MI. The myocardial infarct size in rats treated with MSCs was similar to that in rats treated with GXDS formulation. However, GXDS formulation combined with MSCs transplantation significantly reduced infarction area. In addition, GXDS formulation combined with MSCs transplantation not only decreased cell apoptosis according to the TUNEL staining, but also enhanced angiogenesis in the peri-infarction and infarction area. Interestingly, the use of GXDS formulation increased the number of injected MSCs in the infarct area. Furthermore, GXDS formulation combined with MSCs transplantation increased SDF-1 levels in the infarcted area, but did not affect the expression of YAP. Our study provided a more feasible and accessible strategy to enhance the migration of stem cells after intravenous injection by oral administration of GXDS formulation. The combination of GXDS formulation and stem cell therapy has practical significance and application prospects in the treatment of ischemic cardiomyopathy such as MI.

As a new remote sensing monitoring information, sun-induced chlorophyll fluorescence (SIF) has been widely used in the detection of changes in vegetation state at global and regional scales in recent years. SIF study in agricultural field has quickly become a research hotspot. TanSat is a global scientific experiment satellite for carbon dioxide monitoring launched in December 2016 with SIF monitoring capability. This paper aims to retrieve SIF based on a simplified physical model using TanSat data. The KI Fraunhofer Line at 770.1 nm was selected, which is less affected by the atmosphere. L1B-level data of TanSat was used to extract SIF of southeast China in July 2017. We used cloud mask products from MODIS data at the same period to eliminate cloud-affected areas and obtain SIF under clear sky conditions. The SIF value of our retrieval result is between −2 mW.m−2. sr−1. nm−1 and 5 mW. m−2. sr−1. nm−1. Comparing the result with SIF products showed that there is an encouraging consistency between them. This indicated that the inversion algorithm based on the simplified physical model can be used to retrieve SIF from TanSat data.

International audience; Land surface temperature (LST) plays an important role in land surface processes, and it is a key input for estimating important hydrological states and fluxes, such as soil moisture and evapotranspiration. In this study, a three-channel method is proposed to retrieve cloudy LST values from passive microwave data based on the relationship among surface emissivities at 18.70, 36.50, and 89.00 GHz over a bare soil surface. The performance of the method was evaluated using simulated data, resulting in a root mean square error (RMSE) of approximately 1.4 K over the bare soil surface. This method was further extended to retrieve cloudy LST values over a natural surface. Due to the lack of in situ LST measurements, ground-based air temperatures were used as proxy data to validate the cloudy LST values retrieved from AMSR-E data. The RMSE values of the differences between the retrieved cloudy LST values and the ground-based air temperatures are approximately 3.4 K and 4.3 K for the descending and ascending overpasses, respectively. The results demonstrate that the three-channel method can be used to retrieve cloudy LST values from passive microwave data with reasonable accuracy.

Background Acupuncture is a potential therapy for Alzheimer's disease (AD), but its clinical effects and underlying mechanisms are not fully understood. Emerging evidence suggests autophagy is involved in β-amyloid (Aβ) clearance. We hypothesised that electroacupuncture (EA) treatment of AD involves the autophagy pathway in rats. Methods We injected 2μl Aβ1–40 bilaterally into the hippocampi of 42 rats to establish AD. Rats remained untreated (AD group, n=14) or received 24 EA treatments at GV20+BL23 over 28 days from day 7 post-injection with/without co-treatment with 3-methyladenine (3-MA), an autophagy inhibitor (AD+EA+3-MA and AD+EA groups, respectively, n=14 each). Cognitive function was evaluated by Morris water maze (MWM) testing. Hippocampi were examined by transmission electron microscopy (TEM) and stained with haematoxylin and eosin/transferase dUTP nick end labelling (TUNEL) to assess neuronal morphology/apoptosis, respectively. Protein expression of Beclin-1, LC3 and Aβ1-40 was examined. Results In the MWM test, the AD+EA group showed an improvement in parameters consistent with improved learning/memory compared to untreated AD rats, and 3-MA attenuated these effects. EA mitigated cellular apoptosis resulting from Aβ infusion in the CA1 region and enhanced LC3II/LC3I ratios and Beclin-1 expression. Numerous autophagosome precursors and enlarged autophagosomes were observed by TEM in the hippocampi of EA-treated rats. Reduced Aβ levels, and co-localisation of Aβ and LC3II, were observed following EA treatment by immunofluorescence staining. EA+3-MA treated rats had much higher TUNEL-positive neurons, lower LC3II/LC3I ratios and Beclin-1 expression, and elevated Aβ levels compared with EA alone. Conclusions EA reduces neuronal apoptosis, enhances degradation of Aβ, and improves learning/memory in AD rats by upregulating the autophagy pathway.

Land surface temperature (LST) is an important variable in the physics of land–surface processes controlling the heat and water fluxes over the interface between the Earth’s surface and the atmosphere. Space-borne remote sensing provides the only feasible way for acquiring high-precision LST at temporal and spatial domain over the entire globe. Passive microwave (PMW) satellite observations have the capability to penetrate through clouds and can provide data under both clear and cloud conditions. Nonetheless, compared with thermal infrared data, PMW data suffer from lower spatial resolution and LST retrieval accuracy. Various methods for estimating LST from PMW satellite observations were proposed in the past few decades. This paper provides an extensive overview of these methods. We first present the theoretical basis for retrieving LST from PMW observations and then review the existing LST retrieval methods. These methods are mainly categorized into four types, i.e., empirical methods, semi-empirical methods, physically-based methods, and neural network methods. Advantages, limitations, and assumptions associated with each method are discussed. Prospects for future development to improve the performance of LST retrieval methods from PMW satellite observations are also recommended.

Portable sensors have been developed for the determination of ionizable compounds based on molecularly imprinted polymers (MIPs). These polymers are charged due to the utilization of ionizable monomers such as diallylamine and sodium vinyl sulfonate (SVS). Mediated by the charged templates, imprinted sites with specific shapes and charge distributions were build in the MIPs. At the time of molecular recognition, the imprinted sites were reoccupied by the templates, making the polymer charges neutralized. This procedure led to significant permittivity changing and contributed much to device sensitivity. The capacitive signal drop of 1 million molecules (~1.66 × 10−18 mol) adds up to >10−12 f, which is detectable to a current portable multimeter. At the same time interferent components were expediently washed off because of poor affinities to an MIP. Consequently a handheld LCR (Inductance Capacitance Resistance) meter was used to successfully monitor the molecular recognition signals. High sensitive and selective analysis has been achieved for three exemplified compounds, i.e. aspirin, propranolol hydrochloride, and glyphosate, with linear ranges as 5.50 × 10−13–10−9 mol·L−1, 3.39 × 10−13–10−6 mol·L−1 and 5.89 × 10−16–10−6 mol·L−1. Meanwhile the related detection limits are 1.68 × 10−13 mol·L−1, 3.02 × 10−13 mol·L−1 and 1.94 × 10−16 mol·L−1. The more charges the template possesses, the more sensitive the sensor is.

Thermal inertia is an important parameter in geological and agricultural applications. In this study, we present a method that combines models of thermal inertia and the diurnal temperature difference cycle to estimate the thermal inertia from Meteosat Second Generation Spinning Enhanced Visible and Infrared Imager MSG-SEVIRI data. This method can directly derive thermal inertia from MSG-SEVIRI brightness temperatures without the need to include the land surface temperature and emissivity. Two important parameters the time of the maximum temperature and the diurnal temperature difference that were input into the thermal inertia model were obtained by fitting the diurnal temperature difference cycle model to the diurnal cycle of land surface temperatures. The spatial distribution of thermal inertia shows that high thermal inertia values occur over vegetated areas, whereas low thermal inertia values occur over bare areas. The uncertainty in thermal inertia is investigated in terms of the uncertainties in the surface albedo, the time of the maximum temperature, and the diurnal temperature difference. The results indicate that the uncertainty in thermal inertia over vegetated areas is greater than that over bare areas. The consistency of the thermal inertia model is evaluated by analysing the difference in thermal inertia values on two consecutive days. The root mean square error of the thermal inertia differences under nearly identical surface and atmospheric conditions on two consecutive days is considered to be the error of the thermal inertia model.

Soil moisture plays a critical role in the energy exchange and water redistribution of the land-atmosphere system. Knowledge of the temporal variations in soil moisture is vital in agricultural applications. Microwave indices are often used to characterize the temporal variations in soil moisture. In this study, we evaluate the temporal variations in soil moisture based on the microwave polarization difference index MPDI using ground-based measurements in China. In situ soil moisture at six test sites during the crop-growing season from 2009 to 2011 is obtained. The consistency of the temporal variations between the MPDI values and the in situ soil moisture is analysed in terms of 1 microwave frequencies, 2 satellite overpass times, and 3 measurement depths of soil moisture. The results show that the accuracies of the consistency vary from approximately 40% to 90%. Compared with the in situ soil moisture at 0–10 cm, the temporal variations in soil moisture are best characterized by the 6.9 GHz MPDI values from the ascending overpasses MPDI_06A. Furthermore, the accuracies of the consistency between MPDI_06A and the in situ soil moisture at 0–10 cm are greater than those between MPDI_06A and the in situ soil moisture at 10–20 cm.

Accurate characterization of land surface evaporation is essential for understanding climate dynamics and the terrestrial ecosystem productivity because it is closely related to energy transfer processes. A practical all-weather method for estimating the annual daily averaged evapotranspiration (ET) was proposed using the passive microwave brightness temperature (22 and 37 GHz) and latitude, and a favorable accuracy with RMSE = 0.27 mm/day was obtained. Moreover, the annual daily averaged ET across China from 1996 to 2015 was calculated using the proposed method. The results showed that annual daily averaged ET decreases from southeast to northwest China. The annual ET over all of China ranges from 128 to 1223mm/yr. The interannual variability of ET showed a slightly increase from 1996 to 2007, a sudden decrease in 2008 and a relatively increase from 2008 to 2015. The mean annual ET over all of China ranges from 340 to 400 mm/yr.

International audience; An analysis of the atmospheric impact on ground brightness temperature (Tg) is performed for numerous land surface types at commonly-used frequencies (i.e., 1.4 GHz, 6.93 GHz, 10.65 GHz, 18.7 GHz, 23.8 GHz, 36.5 GHz and 89.0 GHz). The results indicate that the atmosphere has a negligible impact on Tg at 1.4 GHz for land surfaces with emissivities greater than 0.7, at 6.93 GHz for land surfaces with emissivities greater than 0.8, and at 10.65 GHz for land surfaces with emissivities greater than 0.9 if a root mean square error (RMSE) less than 1 K is desired. To remove the atmospheric effect on Tg, a generalized atmospheric correction method is proposed by parameterizing the atmospheric transmittance τ and upwelling atmospheric brightness temperature Tba↑. Better accuracies with Tg RMSEs less than 1 K are achieved at 1.4 GHz, 6.93 GHz, 10.65 GHz, 18.7 GHz and 36.5 GHz, and worse accuracies with RMSEs of 1.34 K and 4.35 K are obtained at 23.8 GHz and 89.0 GHz, respectively. Additionally, a simplified atmospheric correction method is developed when lacking sufficient input data to perform the generalized atmospheric correction method, and an emissivity-based atmospheric correction method is presented when the emissivity is known. Consequently, an appropriate atmospheric correction method can be selected based on the available data, frequency and required accuracy. Furthermore, this study provides a method to estimate τ and Tba↑ of different frequencies using the atmospheric parameters (total water vapor content in observation direction Lwv, total cloud liquid water content Lclw and mean temperature of cloud Tclw), which is important for simultaneously determining the land surface parameters using multi-frequency passive microwave satellite data.

A three-dimensional model of a diesel Urea-SCR（Selective Catalytic Reduction）catalytic converter system was set up with aid of CFD software AVL FIRE coupled with available knowledge of SCR chemical reaction kinetics. Basing on the validation of the spray injection model of Urea-water-solution, the numerical simulation was made to get the distribution of pressure, velocity, temperature and species concentration in the converter and NOxconversion in different conditions by considering the injection and evaporation of the urea-water-solution, the thermal decomposition and hydrolysis into ammonia and the surface catalytic reactions in the monolith. The simulated results have some reference meaning for improving NOxconversion efficiency and optimizing the diesel SCR catalytic converter.

In this paper, the Urea-SCR system is first introduced; then change of the urea solution concentration under different temperatures with time lapsing is given. Meanwhile, conditions for the urea crystallization are analyzed and SCR converter adaptability is tested under high sulfur environment on engine test bench. As the efficiency of NOx conversion is not significantly reduced after aging and the activity of the catalyst is very little damaged by dense sulfur content in fuel, SCR catalyst is able to adapt to the application of high-sulfur-contained fuel environment in our country.