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Spaceborne synthetic aperture radar (SAR) is an advanced microwave imaging technology that provides all-weather and all-day target information. However, as spaceborne SAR resolution improves, traditional echo signal models based on airborne SAR design become inadequate due to the curved orbit, Earth rotation, and increased propagation distance. In this study, we propose an accurate range model for high-resolution spaceborne SAR by analyzing motion trajectory and Doppler parameters from the perspective of the space geometry of spaceborne SAR. We evaluate the accuracy of existing range models and propose an advanced equivalent squint range model (AESRM) that accurately fits the actual range history and compensates for high-order term errors by introducing third-order and fourth-order error terms while maintaining the simplicity of the traditional model. The proposed AESRM's concise two-dimensional frequency spectrum form facilitates the design of imaging algorithms. Point target simulations confirm the effectiveness of the proposed AESRM, demonstrating significant improvements in fitting accuracy for range histories characterized by nonlinear trajectories. The developed AESRM provides a robust foundation for designing imaging algorithms and enables higher resolution and more accurate radar imaging. [ABSTRACT FROM AUTHOR]

With the advancement of spaceborne synthetic aperture radar (SAR) resolution, the conventional stop-and-go approximation-based motion model is no longer suitable for high-resolution imaging algorithms. This paper conducts a comprehensive analysis of the approximation errors resulting from the stop-and-go approximation and proposes corresponding compensation methods. Firstly, an accurate echo model based on continuous platform motion is derived from the SAR geometry configuration. The impact of these errors on range and azimuth imaging is analysed from a spectral perspective, and the applicable boundary conditions are examined. Subsequently, compensation methods are proposed to eliminate the introduced approximation errors, addressing both"fast time" and"slow time" effects, thus enabling high-resolution imaging through improvements in traditional imaging algorithms. Experimental simulations validate the effectiveness of the error analysis and compensation methods, using X-band low Earth orbit SAR as an illustrative example. The proposed methods are not only compatible with existing mature imaging algorithms, but the analytical approach and compensation methods are also applicable to SAR systems operating on different carrier frequencies, orbits, and platforms. [ABSTRACT FROM AUTHOR]

Simulated raw data have become an essential tool for testing and assessing system parameters and imaging performance due to the high cost and limited availability of real raw data from spaceborne synthetic aperture radar (SAR). However, with increasing resolution and higher orbit altitudes, existing simulation methods fail to generate SAR simulated raw data that closely resemble real raw data. This is due to approximations such as curved orbits, "stop-and-go" assumption, and Earth's rotation, among other factors. To overcome these challenges, this paper presents an accurate range model with a "nonstop-and-go" configuration for raw data simulation based on existing time-domain simulation methods. We model the SAR echo signal and establish a precise space geometry for spaceborne SAR. Additionally, we precisely identify the target illumination area based on elliptical beams through space coordinate transformation. Finally, the SAR raw data were accurately simulated using high-precision time-domain simulation methods. The accuracy of the proposed model was validated by comparing it with the traditional hyperbolic model and the curved orbit model with "stop-and-go" assumption through image processing of the generated raw data. Through the analysis of point target quality parameters, the errors of various parameters in our distance model compared with the other two models are within 1%. Furthermore, this simulation method can be adapted to simulate raw data of other modes and satellite orbits by adjusting beam control and satellite orbit parameters, respectively. The proposed simulation method demonstrated high accuracy and versatility, thereby providing a valuable contribution to the development of remote sensing technology. [ABSTRACT FROM AUTHOR]

Unmanned Aerial Vehicle (UAV) infrared detection has problems such as weak and small targets, complex backgrounds, and poor real-time detection performance. It is difficult for general target detection algorithms to achieve the requirements of a high detection rate, low missed detection rate, and high real-time performance. In order to solve these problems, this paper proposes an improved small target detection method based on Picodet. First, to address the problem of poor real-time performance, an improved lightweight LCNet network was introduced as the backbone network for feature extraction. Secondly, in order to solve the problems of high false detection rate and missed detection rate due to weak targets, the Squeeze-and-Excitation module was added and the feature pyramid structure was improved. Experimental results obtained on the HIT-UAV public dataset show that the improved detection model's real-time frame rate increased by 31 fps and the average accuracy (MAP) increased by 7%, which proves the effectiveness of this method for UAV infrared small target detection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Perovskites with anchored nanoparticles have been prepared by the sol–gel method. • A-site-deficient bulk perovskite phase with anchored nanoparticles are generated. • The best substitution proportion Co can be set in range of 0.2–0.6. • Over LSBFC64, CH 4 conversion is 84.3% and syngas yield is 15.23 mmol⋅g−1. • The excellent OCs exhibit the high stability during the successive redox cycles. Chemical looping dry reforming of methane (CL-DRM) has the potential as a viable technology to achieve carbon neutrality in terms of converting CH 4 and CO 2 to various value-added products with the minimal separation requirements. However, the design and development of an appropriate oxygen carrier (OC) with the remarkable reactivity and stability make the CL-DRM process challenging. Herein, the Co-substituted La 0.35 Sr 0.35 Ba 0.3 Fe 1-x Co x O 3 (LSBFC) perovskite oxides with the anchored nanoparticles as the novel OCs were synthesized and investigated for the redox performance in the CL-DRM process. It is found that the best substitution proportion of Co in the anchored perovskite oxides can be set in range of 0.2–0.6. The optimized OCs can greatly improve the reactivity of the chemical looping process based on various characterizations. Among all samples, La 0.35 Sr 0.35 Ba 0.3 Fe 0.6 Co 0.4 O 3 OC increases the oxygen mobility and shows a higher oxygen diffusion rate to achieve the CH 4 conversion of 84.3% and syngas yield of 15.23 mmol⋅g−1 in the CH 4 reduction step, respectively. A detailed analysis of the anchored perovskite oxides reveals the substitution of Co can greatly weaken the perovskite lattice to result in the migration of Fe and the formation of Fe nanoparticles, which tremendously promote the activation of CH 4 for the further conversion. Furthermore, the excellent OCs also exhibit the high stability in the enhanced reaction performance, the preservation of material structure and the stable regenerability by CO 2 during the successive redox cycles. These features demonstrate that the new perovskite materials with anchored nanoparticles can be the promising oxygen carriers for the CL-DRM process. [ABSTRACT FROM AUTHOR]

Ganoderma lucidum is a valuable basidiomycete with numerous pharmacological compounds, which is widely consumed throughout China. We previously found that the polysaccharide content of Ganoderma lucidum fruiting bodies could be significantly improved by 45.63% with treatment of 42 °C heat stress (HS) for 2 h. To further investigate genes involved in HS response and explore the mechanisms of HS regulating the carbohydrate metabolism in Ganoderma lucidum , high-throughput RNA-Seq was conducted to analyse the difference between control and heat–treated mycelia at transcriptome level. We sequenced six cDNA libraries with three from control group (mycelia cultivated at 28 °C) and three from heat-treated group (mycelia subjected to 42 °C for 2 h). A total of 99,899 transcripts were generated using Trinity method and 59,136 unigenes were annotated by seven public databases. Among them, 2790 genes were identified to be differential expressed genes (DEGs) under HS condition, which included 1991 up-regulated and 799 down-regulated. 176 DEGs were then manually classified into five main responsive-related categories according to their putative functions and possible metabolic pathways. These groups include stress resistance-related factors; protein assembly, transportation and degradation; signal transduction; carbohydrate metabolism and energy provision-related process; other related functions, suggesting that a series of metabolic pathways in Ganoderma lucidum are activated by HS and the response mechanism involves a complex molecular network which needs further study. Remarkably, 48 DEGs were found to regulate carbohydrate metabolism, both in carbohydrate hydrolysis for energy provision and polysaccharide synthesis. In summary, this comprehensive transcriptome analysis will provide enlarged resource for further investigation into the molecular mechanisms of basidiomycete under HS condition. [ABSTRACT FROM AUTHOR]

Calcium oxide (CaO) is a very promising candidate energy storage material for concentrated solar power plants because of high energy storage density, high temperatures of energy release, and readily available precursors. However, CaO itself not only sinters severely at typical operating temperatures but also has low light absorption capacity. To overcome these challenges, modifying CaO with nanoparticle of magnesium (Mg) and manganese (Mn) oxides was proposed in this work. The Mg and Mn co-modified sample (Ca:Mn:Mg = 9:1:1) demonstrates exceptional thermal stability at 800 °C, the density of energy storage deceases by about 1.1 and 0.7% after 10 and 25 cycles, respectively. Microstructure analysis reveals that MgO and Ca 2 MnO 4 nanoparticles assemble into a net or chain that distributed in the CaO or CaCO 3 particles, which effectively suppresses sintering and provides stable channels for CO 2 to diffuse in CaO or CaCO 3 layer. After 60 cycles, the density of energy storage declines by 7.46%. Additionally, introducing manganese both makes O atoms have more electrons and creates more oxygen vacancies that favor CO 2 activation. The synergistic effect between Mn and Mg achieves high stability, fast calcination reaction and high conversion rate of the energy storage material. The presence of Mn also greatly improves the solar absorption capacity of CaO material, and the co-modified sample exhibits much higher solar absorptance after long-term testing. The proposed CaMnMg911 material could be applied in a concentrated solar power plant for solar energy storage. [Display omitted] • Mg and Mn modified CaO material was synthesized by a wet chemical method. • Cyclability of the material was enhanced by net or chain structure. • Synergistic effect between Mn and Mg achieves high performance. • The solar absorption capacity of modified CaO increases with cycles. [ABSTRACT FROM AUTHOR]

In recent years, with the vigorous development of the Chinese herbal medicine market in China, the government and various circles of society pay close attention to the safety of Chinese herbal medicine production. The cultivation and production of traditional Chinese herbal medicine already could not satisfy the current mak et demands. This paper summarized the forming, changing and the influencing factors of Chinese herbal medicines, and organized the research for the formation of traditional Chinese herbal medicines by modern scholars in China. It reached the following conclusion : the production of modern Chinese herbal medicines should ensure its unique properties, and the more important is to guarantee the quality and safety. With the continuous improvement of science and technolog innovation ability and the appraisal method of Chinese medicines, the better management system has been applied in the process of planting. This paper summarized the six attributes of modern production of Chinese herbal medicines, to ensure genuine, safe and standardized production of traditional Chinese medicines. [ABSTRACT FROM AUTHOR]

Nanostructured Ni@SiO 2 core–shell catalyst is prepared from nickel oxide nanoparticles by a facile method. Calcination of as-synthesized core–shell nanoparticles creates a micro/meso-porous structure in the amorphous silica shell. The catalytic performance of core–shell catalyst toward dry reforming of methane was first evaluated in a thermogravimeter coupled with a mass spectrometer. Coking is negligible in a reforming period of 40 h on stream at 850 °C, while more than 0.32 g coke g cat −1 is produced on a commercial Ni-based reforming catalyst in 6.4 h at the same reforming condition. Dry reforming was also performed in a continuous flow, fixed-bed reactor at 750 °C. Characterization of spent catalyst further confirms that Ni@SiO 2 catalyst has high coke-resistance for dry reforming. The amount of coke deposited on the core–shell catalyst in 24.5 h is 0.012 g coke g cat −1 . [ABSTRACT FROM AUTHOR]

Developing cost-effective oxygen reduction reaction (ORR) catalysts is pivotal for development of fuel cells. While Fe–N–C catalysts were proposed for ORR, Fe–B–C catalysts have not been explored. This work introduces the B-doped carbon catalysts encapsulating iron cores using CO2 as a carbon source. The Fe–B–C catalysts show enhanced ORR activity and durability due to the iron core within the graphitic layers. [ABSTRACT FROM AUTHOR]

Abstract: Boron-doped porous carbon was produced from carbon dioxide (CO2) reaction with sodium borohydride at moderate conditions. The reaction was first investigated by using a combined thermogravity-differential scanning calorimeter, and then the transformation was carried out in a tubular reactor. Results demonstrated that, at temperatures below 500°C, CO2 can be reduced to porous carbon under atmospheric pressure. The incorporation of boron atoms into the carbon lattice was confirmed by using X-ray photoelectron spectroscopy. [Copyright &y& Elsevier]

Abstract: This infrared (IR) spectroscopic study addresses surfactant effects on cyclopentane (CP) hydrate–water interfaces by observing both ice-like (3100cm−1) and water-like (3400cm−1) bands in the bonded OH region together with free OH bands. IR spectroscopy of hydrates has not been actively employed due to the overwhelming signal saturation of the OH bonding. However, this work is able to utilize this large signal of the OH bonding to understand the water structure changes upon adding sodium dodecyl sulfate (SDS) to CP hydrate–water interfaces. The spectral data suggest a change to more ice like (3100cm−1) features starting from 100ppm to 750ppm SDS, indicating favorable nucleation. At the same instance, water like (3400cm−1) features are also shown in this range of SDS concentration, which suggests looser hydrogen bonding that is an indicator for facilitating hydrate growth. Additionally, this ATR-IR study firstly identifies both symmetric and anti-symmetric free OH bands of the hydrogen bond (HB) acceptors in the clathrate hydrate system. Relative area ratios of free and bonded OH bands provide important information about spatial arrangements of adsorbed SDS monomers. [Copyright &y& Elsevier]

Abstract: This work addresses the accelerated dehydrogenation of ammonia borane (AB, NH3BH3) in two separate processes of CO2 pre-treatment of AB and dehydrogenation of the treated AB. Decoupling these two processes can still keep the dehydrogenation activity of CO2-treated AB and eliminate the purification step of H2 from gas phase. When AB is exposed to 1.38 MPa of carbon dioxide (CO2) at 70 °C, it shows the most favorable and controllable operating condition for the CO2 pre-treatment. The pre-treatment enhances not only the rate but also the amount of hydrogen release at the dehydrogenation step; 1.5 mol H2 per mol of AB rapidly desorbs at 85 °C in 1 h, corresponding to 10.1 wt.% of hydrogen with regard to pristine AB. Also, our observations show that the fast dehydrogenation resulted from the CO2 pre-treatment is preserved for more than four days of storage. The degree of dehydrogenation is further confirmed by ATR-FTIR spectroscopic and elemental analyses of the solid product. The spectra display the N–H stretching mode involving π-bonded nitrogen (sp2 N) at ca. 3434 cm−1,while the atom ratio of H:B is found to be 2.84:1. Based on the hydrogen release measurements, spectroscopic observations and elemental analyses, we deduce that the predominant solid product of dehydrogenation of CO2-treated AB at 85 °C is a polymer with an empirical formula of (NBH3) n . It corresponds to the solid product after 1.5 equivalent hydrogen release of AB. [Copyright &y& Elsevier]

This paper discusses the dehydrogenation of ammonia borane (AB) and MCM-41/AB nanocomposites in which the loading level of AB (i.e., the mass ratio of AB to mesoporous silica) varies from 0.11 to 2.36. The dehydrogenation temperatures shift to low temperatures with decreasing loading levels. At loading levels of 0.11 and 0.15, only one dehydrogenation step is observed at temperatures less than 200 °C. Our results also show that 12.6 wt % of hydrogen in the incorporated AB is liberated from the nanocomposite at a loading level of 0.15 in 1 h at 89.5 °C. We deduce that AB confined within the mesopores is amorphous, while AB outside of the channels has a tetragonal structure. Furthermore, we deduce that at relative low loading levels AB coats the inner surface of mesoporous silica as a monolayer. [ABSTRACT FROM AUTHOR]

This work presents the effect of NaCl and NaClO4on the kinetics of methane enclathration with cyclopentane (CP) and sodium dodecyl sulfate (SDS) in a nonstirred batch reactor. Methane and 1 cm3of CP were charged sequentially to 150 cm3of solutions in a high-pressure vessel and the reaction system was cooled down to 274.6 K with an initial pressure of 7.1 MPa. Hydrates are visually observed within 1 h after the onset of cooling at a SDS concentration range of 0−200 ppm. At the end of a growth period of 2.5 h, the pressure reduces to 6.4 MPa for SDS concentrations below 20 ppm, whereas it decreases to 3.2 MPa for SDS concentrations above 50 ppm without any salts, which is very close to the hydrate equilibrium pressure. With 20 ppm SDS and 1 cm3of CP, the average enclathration rate maximizes at 1.0 mM NaCl or 5.0 mM NaClO4as the salt concentration increases from 0 to 100 mM. However, with 100 ppm SDS, it decreases monotonically with the increased salt concentration. These results not only provide an implication of reducing the SDS dosage (down to 50 ppm or less) in regard to fast enclathration but also further our understanding of the promoting role of surfactants. [ABSTRACT FROM AUTHOR]

Abstract: Corn stover was pretreated with FeCl3 to remove almost all of the hemicellulose present and then hydrolyzed with cellulase and β-glucosidase to produce glucose. Enzymatic hydrolysis of corn stover that had been pretreated with FeCl3 at 160°C for 20min resulted in an optimum yield of 98.0%. This yield was significantly higher than that of untreated corn stover (22.8%). FeCl3 pretreatment apparently damaged the surface of corn stover and significantly increased the enzymatic digestibility, as evidenced by SEM and XRD analysis data. FTIR analysis indicated that FeCl3 pretreatment could disrupt almost all the ether linkages and some ester linkages between lignin and carbohydrates but had no effect on delignification. The FeCl3 pretreatment technique, as a novel pretreatment method, enhances enzymatic hydrolysis of lignocellulosic biomass by destructing chemical composition and altering structural features. [Copyright &y& Elsevier]

Abstract: Inorganic salts, NaCl, KCl, CaCl2, MgCl2, FeCl2, FeSO4, FeCl3, and Fe2(SO4)3, were studied as catalysts for the degradation of hemicellulose in corn stover. FeCl3 significantly increased the hemicellulose degradation in aqueous solutions heated between 140 and 200°C with high xylose recovery and low cellulose removal, amounting to ∼90% and <10%, respectively. Hemicellulose removal increased 11-fold when the corn stover was pretreated with 0.1M FeCl3 compared to pretreatment with hot water under otherwise the same conditions, which was also 6-fold greater than pretreatment with dilute sulfuric acid at the same pH. Optimum pretreatment conditions were found where the corn stover was pretreated with 0.1M FeCl3 at 140°C for 20min. Under such conditions, 91% of hemicellulose was removed, and the recovery of monomeric and oligomeric xylose in liquid fraction achieved 89%, meanwhile, only 9% of cellulose was removed. [Copyright &y& Elsevier]

Abstract: This paper presents the phase equilibria of quaternary systems containing gas hydrates and proposes a staged-separation scheme based on the thermodynamic data. The phase equilibria of HLLV of quaternary systems are determined by using a high-pressure differential scanning calorimeter (DSC). The equilibrium dissociation pressures are dependent on the vapor composition and they shift to lower values with the increase in the mole fraction. The difference in the dissociation pressures between various fractions vanishes as the temperature approaches the melting point of CP hydrates at 0.1 MPa. The hydrate dissociation enthalpy is independent of vapor compositions and it is over the temperature range. Experimental data are compared to the calculated ones from John–Holder''s three-shell model. The prediction matches well with experimental data. The presence of CP reduces the operation pressure of a hydrate-based capturing process from the pre-combustion stream. Two equilibrium stages of hydrate crystallization and dissociation can enrich in the vapor-phase significantly from 0.4 of mole fraction to 0.98 at 282K. This thermodynamic analysis provides a conceptual design for developing a new process of pre-combustion capture in IGCC plants. [Copyright &y& Elsevier]

Trapping CO2in hydrates is one of the new technologies for CO2capture and storage. One of the primary obstacles to this option is the low formation rate. This work presents the rapid formation of CO2hydrates with a small amount of cyclopentane (CP). The formation kinetics was investigated in a 474 cm3nonstirred batch reactor with 100 and 200 cm3of water. At volume ratios of CP to water between 0.01 and 0.1, the maximum growth rate is 0.32 mol h−1at CO2pressures ranging from 1.9 to 3.4 MPa and at 274 K. CO2hydrates (sI) and CO2+ CP (sII) binary hydrates coexist at the end of hydrate growth. The mole ratio of CO2entrapped in the sI hydrates to that in the sII binary hydrates is higher with 100 cm3of water than with 200 cm3of water. The same trend is also observed for the total amount of CO2entrapped in the hydrate phase. The growth rate depends not only on the water volume but also on the pressure. The hydrate growth rate and the water conversion reach a maximum at 3.06 MPa and then decrease as the pressure increases from 1.9 to 3.4 MPa with 100 cm3of water and 5 cm3of CP. The water conversion to the hydrates reaches 52% within 2 h. This accelerated formation kinetics can provide a stepping-stone for developing a new hydrate-based CO2capture and storage technique. [ABSTRACT FROM AUTHOR]

The effect of sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB), and fatty alcohol EO/PO derivative (LS54) on unsteady-state CO2absorption in the metastable region of CO2hydrates and CO2enclathration with cyclopentane (CP) was investigated in an unstirred batch reactor. These surfactants have no measurable effect on the mass transfer of CO2across the gas−liquid interface into water. However, they retard CO2enclathration, and this inhibition effect becomes significant at 200 ppm of SDS and 100 ppm of LS54 or CTAB. A layer of clathrate hydrates is visually observed if charging CO2and CP sequentially. Even though this layer cannot be macroscopically detected when swapping the order of CO2and CP charge, the existence of this layer can be inferred from the unchanged pressure profile. This layer prevents CO2from contacting with water and thus delays CO2enclathration. The habit of clathrate hydrates growing along the reactor wall without agitation is discussed based on the magnitude of temperature spikes at the initial stage of the enclathration. [ABSTRACT FROM AUTHOR]

We analysed the effects of black geotextile inter-row mulch, grass mulch and clean tillage as a control on the microclimate, anthocyanin components and fruit quality of 'Xinyu' table grape in a semi-arid climate. Black geotextile inter-row mulch increased the air and soil temperatures, while grass mulch decreased these. Six types of anthocyanins were detected in the grapes. Around 50% of the total anthocyanins were malvidin based (38.60%–39.10%) and peonidin based (25.80%–31.10%), with malvidin-3-O-glucoside being the main pigment (38.75%–39.05%), followed by peonidin-3-O-glucoside (23.84%–28.68%). The soluble solid content, reducing sugar content and sugar-acid ratio for the black geotextile treatment group were 12.93%, 10.05% and 25.85% higher, respectively, than the control. By contrast, grapes in the grass mulch treatment group had a significantly lower soluble solid content than the control, with a 7.32% reduction being observed. Neither type of mulch had a large effect on the vitamin C content nor yield. However, both black geotextile inter-row mulch and grass mulch could regulate the orchard microclimate and increased the total anthocyanin content by 36.04% and 5.03%, respectively, compared with the control. These findings suggest that grass mulch is the preferable cultivation method in the Turpan area. [ABSTRACT FROM AUTHOR]

Examines the variation of terrestrial ecosystem recorded by stable carbon isotopes of fossils in northern China. Analysis of stable carbon isotopes; Collection of mammalian tooth enamel; Impact on the warming condition on the transition of plants.

Strontium ferrite (SrFeO 3-δ) is a very attractive oxygen transfer agent for chemical looping reactions and hydrogen-rich syngas generation. Dispersing SrFeO 3 in a medium such as Ca 0.5 Mn 0.5 O could enhance the activity and cyclability. In this study, SrFeO 3-δ -Ca 0.5 Mn 0.5 O (30 wt% SrFeO 3-δ) nanocomposite with a reticulated foam structure was explored as the oxygen carrier for chemical looping reforming of methane in a solar tubular reactor. The foam nanocomposite was prepared by a hard-templating method. The performance was investigated at temperatures of 850–1000 °C and methane flowrates of 25–250 STP mL/min, and the oxidative gas was either CO 2 or H 2 O in the oxidation step. In the reduction step of 27 successive redox cycles, the production rate of CO changed marginally and CO yield maintained at about 1.9 mmol/g, even though sintering occurred. The productivity of H 2 decreased first and then tended to be stable at 3.8 mmol/g (i.e., twice the CO yield) as the cycling number increased (the average oxygen storage capacity of the material was ∼1.95 mmol/g). Microscopic and X-ray diffraction investigations suggested that the element distribution pattern and crystalline phase of the foam nanocomposite remained almost unchanged after 27 redox cycles, confirming material stability. The maximum solar-to-fuel efficiency for the foam nanocomposite was 5.68%, which was 21.4% higher than that for the powder nanocomposite. To increase syngas productivity and solar-to-fuel efficiency, it is required to conduct the reforming reaction at high temperatures and methane flowrates. However, the energy upgrade factor will decrease as methane flowrate increases. [Display omitted] • SrFeO 3-δ -Ca 0.5 Mn 0.5 O nanocomposite foam was prepared for solar chemical looping methane reforming. • An indirectly-irradiated tubular reactor heated by concentrated solar energy was utilized. • The nanocomposite performance was stable over 27 isothermal cycles in the range 850–1000 °C. • The effects of methane flowrate and oxidative gas (H 2 O or CO 2) were investigated. • Strategy to improve syngas productivity and solar-to-fuel efficiency was proposed. [ABSTRACT FROM AUTHOR]

In this work, cellular silica was synthesized by using microbubbles as templates, which contain a mixture of argon and silicon tetrafluoride (SiF4). The latter is generated from decomposition of hexafluorosilicic acid (H2SiF6) at ambient conditions. The specific surface area of cellular silica can be as high as 130 m2/g, the size of the cavity is hundreds-of-nanometers, and the thickness of the cavity wall is around 30 nm. The cavity size, apparent packing density, and porosity of cellular silica strongly depend on the nature of the aqueous solutions; the cavity size appears to be negatively proportional to the surface tension, but thickness of cavity walls seems to be weakly affected by the aqueous properties. An attempt was made to introduce aluminum atoms in situ in the second-coordination sphere of Si atoms and/or load aluminum into the silica structure. Cellular silica with large pores facilitate the transfer of large molecules, including polymers and enzymes; thus, it could find applications in (bio)catalysis, sorption, controlled release and separations. [ABSTRACT FROM AUTHOR]

Abstract: Seedless grapevine cultivars (Vitis vinifera L.) are widely grown in Europe, America and Asia. Abortion of zygotic embryos in seedless grapes largely limits the efficiency of breeding of seedless cultivars through genetic crossing. The present study was designed to investigate effects of exogenously applied plant growth regulators (PGRs) to the grapevines in field condition on ovule and subsequent embryo rescue of seedless grapes of small seed traces. First experiment was performed by measuring ovules weight, proportion of each category ovules in maturity and embryo development in vitro of seedless grape cv. Centennial Seedless, Thompson Seedless and Crimson Seedless sprayed by chlormequat (CCC), benzyladenine (BA), ethephon (CEPA) and putrescine (Put). The effects of different application concentration and date of CCC were further evaluated in Centennial Seedless in later experiment. The results showed that exogenous application of all PGRs did not affect the total number of ovules per berries in maturity. CCC increased the ovules weight and proportion of ovules >4mm in length of three varieties in maturity. The effects of two application times of PGRs on weight of berries and ovules and proportion of each category ovules in maturity were not significantly different. In the proceeding of embryo rescue, CCC at 100 and 1000mgl−1, BA at 100mgl−1 and Put at 20mgl−1 increased the percentage of developed embryos of Centennial Seedless and Thompson Seedless. The results showed that the size of ovules excised for embryo rescue significantly affected embryo formation and plant regeneration. The percentage of embryos formation in ovules >4mm in length was significantly more than in ovules 2–4mm in length, no embryo was found in ovules <2mm in length. Exogenous application of CCC at 100–500mgl−1 significantly increased percentage of ovules >2mm in length by 80.0–82.7% in Centennial Seedless, therefore improving embryo formation. The statistical correlation was found between the proportion of ovules >2mm and embryo formation (r =0.92) in Centennial Seedless. Among the different spraying time in Centennial Seedless, CCC applied 14 days before bloom produced significantly more ovules >2mm in length and embryos formation. [Copyright &y& Elsevier]

Data-driven intelligent models have received more and more attention in liquid rocket engine (LRE) state recognition. However, due to practical limitations, the fault data are rare for model training, which results in poor testing results. To better recognize the state of LRE, we proposed a supervised recognition framework without fault samples. First, we proposed a negative sample generation method. Then, fusion recurrent convolutional neural network (FRCNN) is constructed for data fusion and feature extraction. Finally, we evaluated the recognition results with several quantization indicators. The proposed method is verified with the real monitoring data, which is obtained from the static firing tests of a certain type of LRE. Results show that the FRCNN could recognize the state of LRE with accuracy over 93% under the confidence of 96%, which shows the effectiveness of the proposed framework. And the comparison with the literature method shows the superiority of the proposed framework. In addition, it could also perform real-time monitoring for LRE, and recognize the abnormal at the initial stage of the steady state, which has practical potential in monitoring task. At last, we further discuss and analyze the generated negative sample and the proposed framework. [ABSTRACT FROM AUTHOR]

Biomimetic porous ceramics have great application potential in the petrochemical industry; their biomimetic porous structure is conducive to mass transfer, energy exchange and catalytic reactions. However, it is challenging to produce biomimetic porous ceramics with complex shapes using conventional processes. Herein, we demonstrate a novel structural bionic and 3D printing strategy and a pseudo-boehmite-based slurry for fabricating hierarchical alumina ceramic carriers with biomimetic vein structures. Tuneable hierarchical porosity from nm to mm scales, high specific surface area, and superior strength have been achieved by innovatively combining dehydroxylation and peptisation of pseudo-boehmite, direct ink writing (DIW), and post-sintering processes. The effects of post-sintering temperature and impregnation treatment on the crush strength, porosity, and specific surface area were systematically investigated. The optimised porous ceramics exhibited a crush strength of 54.453 ± 7.359 N/cm, specific surface area of 109.870 ± 0.143 m2/g, and porosity of 60.03 ± 2.72%. The catalytic test for dry reforming of methane was conducted on biomimetic catalysts loaded with nickel (Ni) and phosphorus (P). The biomimetic catalyst had a remarkable methane conversion of 41.27%, in addition to mass transfer and coke inhibition effects. Through the integrated biomimetic design of macro–micro structures, monolithic alumina catalyst carriers with biomimetic vein structures prepared by DIW can potentially be used more efficiently in industrial catalytic reactions. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined the evidence of fossil carbon isotopes of the climate event at the beginning of Quaternary. Materials and methods; Results; Discussion and conclusion.

Here we demonstrate that phosphorus (P) can affect both reforming and coking of alumina-supported nickel (10 wt% Ni with respect to alumina) at 750 °C and 1 atm. The P-containing catalysts were prepared by incipient wetness co-impregnation. Compared with the P-free nickel catalyst, the reforming activity is enhanced but the coke content decreases 8-fold at Ni:P atomic ratio of 4; the latter further reduces 55-fold at a ratio of 2, without a substantial decline in the reforming activity. Phosphorus not only improves nickel dispersion but also reduces the surface acidity and facilitates CO 2 activation. At high P loadings, a portion of nickel transforms into nickel oxide during reforming. Besides tuning the reforming and coking activity, phosphorus changes the behavior of carbon crystallization. In methane pyrolysis and dry reforming, filamentous carbon occurs on the P-free catalyst but it is absent on the P-containing catalyst. Image 1 • At a Ni:P ratio of 4, the reforming activity improves but coke content reduces 8-fold. • At a Ni:P ratio of 2, coking reduces 55-fold without dramatic decline in activity. • Phosphate promotes CO 2 splitting and makes the surface more basic. • Phosphorus affects the morphology of carbon deposited. [ABSTRACT FROM AUTHOR]

The traditional modal test of steel bars has two chief disadvantages of being time-consuming and having a complex detection operation. This paper presents the effective independence driving-point residue (EI-DPR) method for sensor optimal placement, which identifies cracks of steel bars based on the modal assurance criterion (MAC) and minimum mean square error (MMSE) criterion. The steel bars with cracks are tested separately by the uniform measuring point method and the optimal sensor placement method according to the vibration modal test. By comparing the test results, the optimal sensor placement method can identify cracks rapidly and accurately, which is more efficient than the uniform measuring point method. The study provides a reference for the rapid non-destructive testing of large-aspect ratio steel bars. [ABSTRACT FROM AUTHOR]

Recursive Least Square (RLS) filter has been applied to real-time lossless compression of hyperspectral imagery and been proved a high performance onboard algorithm. Recent research has revealed that the RLS filter with Adaptive-Length-Prediction (ALP) can significantly improve the compression performance. However, the prediction procedure with numerous bands slows down the run-time and is nearly impossible to be applied onboard. In this letter, we proposed a fast RLS algorithm which can accelerate the ALP stage by exploiting the feature of the projection matrix of the RLS algorithm. The experiment results illustrated that with the same compression ratio, the proposed algorithm is 100 times faster than the traditional RLS algorithm with ALP. [ABSTRACT FROM AUTHOR]

This work presents the kinetic promotion effect of sII cyclopentane (CP) hydrate seeds on sI CH 4 hydrate formation in sodium dodecyl sulfate (SDS) solutions. Gas hydrates are one of the promising materials for natural gas storage due to their high volumetric capacity and safety aspect. Generally, a crystal layer of gas hydrate is preferentially created on the surface of an aqueous phase which results in both low hydrate conversion and slow reaction without mechanical agitations. This study introduces CP hydrate seeds at very small quantities to accelerate the nucleation and growth of the CH 4 hydrate with SDS. To choose the appropriate amount of CP in the system for massive sI CH 4 hydrate formation, several hydrate slurries with various amounts of CP were characterized by powder X-ray diffraction and Raman spectroscopy. Additionally, from the visual observations of the hydrate growth behavior, the direction of hydrate crystallization significantly affected the hydrate growth and conversion rate. With the highest degree of subcooling, the volumetric storage efficiency reached 90% of the theoretical values in 50 min with no induction period, and this promotion effect was also confirmed in an expanded reactor system. Thus, sII CP hydrate seeds result in a dramatic improvement in the sI CH 4 hydrate formation rate and high volumetric storage capacity. [ABSTRACT FROM AUTHOR]

Ganoderma lucidum is a typical polypore fungus used for traditional Chinese medical purposes. The taxonomic delimitation of Ganoderma lucidum is still debated. In this study, we sequenced seven internal transcribed spacer (ITS) sequences of Ganoderma lucidum strains and annotated the ITS1 and ITS2 regions. Phylogenetic analysis of ITS1 differentiated the strains into three geographic groups. Groups 1–3 were originated from Europe, tropical Asia, and eastern Asia, respectively. While ITS2 could only differentiate the strains into two groups in which Group 2 originated from tropical Asia gathered with Groups 1 and 3 originated from Europe and eastern Asia. By determining the secondary structures of the ITS1 sequences, these three groups exhibited similar structures with a conserved central core and differed helices. While compared to Group 2, Groups 1 and 3 of ITS2 sequences shared similar structures with the difference in helix 4. Large-scale evaluation of ITS1 and ITS2 both exhibited that the majority of subgroups in the same group shared the similar structures. Further Weblogo analysis of ITS1 sequences revealed two main variable regions located in helix 2 in which C/T or A/G substitutions frequently occurred and ITS1 exhibited more nucleotide variances compared to ITS2. ITS1 multi-alignment of seven spawn strains and culture tests indicated that a single-nucleotide polymorphism (SNP) site at position 180 correlated with strain antagonism. The HZ, TK and 203 fusion strains of Ganoderma lucidum had a T at position 180, whereas other strains exhibiting antagonism, including DB, RB, JQ, and YS, had a C. Taken together, compared to ITS2 region, ITS1 region could differentiated Ganoderma lucidum into three geographic originations based on phylogenetic analysis and secondary structure prediction. Besides, a SNP in ITS 1 could delineate Ganoderma lucidum strains at the intraspecific level. These findings will be implemented to improve species quality control in the Ganoderma industry. [ABSTRACT FROM AUTHOR]

• A fault detection method is proposed to solve the problem that LRE fault data is difficult to obtain. • Propose a soft-target difference scaling method to accurately define the boundary of normal sample distribution. • Propose a soft relational knowledge metric method to difference-metric between individuals. The detection of anomalies in liquid rocket motors is a challenge at this stage. On the one hand, numerous key components and extreme working environment easily leads to multi-source, strong nonlinear and non-stationary characteristics of monitoring data. On the other hand, the difficulties of fault detection are further aggravated by the few fault monitoring data during equipment acceptance period. In view of the above problems of engine working state identification, this paper takes the hot commissioning data as the research object to carry out the study about the intelligent fault detection of liquid rocket engine. Firstly, the original data is reconstructed by hierarchical task training. Then the soft target of rocket engine samples is constructed, which is used to define the sample distribution range. The soft target difference scaling method is specially designed to assist relevant knowledge extraction. Combining with metric learning, the fault prototype features are constructed to calculate the engine state discrimination threshold. Finally, the state identification without fault samples is realized by integrating the above methods. Multiple sets of measured data of liquid rocket engines are analyzed and discussed to verify the feasibility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Selective hydrogen combustion in-situ can break the thermodynamic limit of methane dehydroaromatization, which enhances the yield of aromatic hydrocarbons at a given operating temperature. In this study, sodium tungstate (Na 2 WO 4) was loaded on manganese ore by incipient wetness impregnation, which improved the selectivity of hydrogen combustion dramatically. The selectivity of hydrogen combustion (the percentage of lattice oxygen species involved in hydrogen combustion) is 86% and 53% for Na 2 WO 4 -tuned and pristine manganese ore at 750 °C, respectively. Introducing Na 2 WO 4 causes a decrease in both the Mn(IV) fraction and oxygen vacancies in the surface layer as well as changes the crystal structure and the morphology of Mn ore. They are attributed to W ions substituting Mn ions, which makes benzene becomes more difficult to be activated compared with hydrogen at the metal oxide/Na 2 WO 4 interface. [Display omitted] • Cheap and readily available manganese ore acts as the redox catalyst for SHC. • Na 2 WO 4 significantly improves the selectivity of hydrogen combustion. • Introducing sodium tungstate causes a decrease in both Mn(IV) concentration and oxygen vacancies in the surface layer. • The changes come from W ions substituting Mn ions. [ABSTRACT FROM AUTHOR]

The extreme process condition of high temperature and high alkali limits the applications of most of natural xylanases in pulp and paper industry. Recently, various methods of protein engineering have been used to improve the thermal and alkalic tolerance of xylanases. In this work, directed evolution and site-directed mutagenesis were performed to obtain a mutant xylanase improved both on alkali stability and thermostability from the native Paenibacillus campinasensis Family-11 xylanase (XynG1-1). Mutant XynG1-1B43 (V90R/P172H) with two units increased in the optimum pH (pH 7.0-pH 9.0) and significant improvement on alkali stability was selected from the second round of epPCR library. And the further thermoduric mutant XynG1-1B43cc16 (V90R/P172H/T84C-T182C/D16Y) with 10 °C increased in the optimum temperature (60-70 °C) was then obtained by introducing a disulfide bridge (T84C-T182C) and a single amino acid substitution (D16Y) to XynG1-1B43 using site-directed mutagenesis. XynG1-1B43cc16 also showed higher thermostability and catalytic efficiency ( k/ K) than that of wild-type (XynG1-1) and XynG1-1B43. The attractive improved properties make XynG1-1B43cc16 more suitable for bioleaching of cotton stalk pulp under the extreme process condition of high temperature (70 °C) and high alkali (pH 9.0). [ABSTRACT FROM AUTHOR]

The application of strongly acidic electrolyzed water (SAEW) in a flow-through system for the treatment of recalcitrant corn stover resulted in enhanced hemicellulose degradation at 160 °C and 180 °C compared to hydrochloric acid treatment under the same pH. Pretreatment conditions were optimized by varying the four main factors: pH, flow rate, temperature, and reaction time. About 96% of the hemicellulose was removed when corn stover was treated at 180 °C for 20 min, with SAEW at pH 2.0 and a flow rate of 10 mL/min. The recovery of total monomeric and oligomeric xylose in the liquid fraction reached 93%. Using 30 filter paper units of cellulase per gram of cellulose, a digestibility of 100% was achieved under these conditions. Therefore, flow-through SAEW pretreatment is an efficient way to remove hemicellulose and improve enzymatic digestibility of corn stover. [ABSTRACT FROM AUTHOR]

Abstract: Broad-folded frogs (Hylarana latouchii), one member of 12 species of the genus Hylarana in the Chinese frog fauna, are widely distributed in the South of China. In this study, we purified and characterized three antimicrobial peptides from the skin secretion of H. latouchii. Five different cDNA fragments encoding the precursors of these antimicrobial peptides were cloned, and five mature antimicrobial peptides belonging to two different families were deduced from the five cDNAs. Structural characterization of the mature peptides had identified them as members of the brevinin-1 and temporin families. They were named brevinin-1LTa (FFGTALKIAANVLPTAICKILKKC), brevinin-1LTb (FFGTALKIAANILPTAICKILKKC), temporin-LTa (FFPLVLGALGSILPKIF-NH2), temporin-LTb (FIITGLVRGLTKLF-NH2) and temorin-LTc (SLSRFLSFLKIVYPPAF-NH2). Brevinin-1LTa, temporin-LTa, temporin-LTb and temporin-LTc with different antimicrobial activities induced significant morphological alterations of the tested microbial surfaces as shown by scanning electron microscopy, which indicated strong membrane disruption. [Copyright &y& Elsevier]