Solvent Isotope Effect on Transfer Hydrogenation of H2O with Glycerine under Alkaline Hydrothermal Conditions

Solvent isotope effect was investigated with 1H-, 2H-NMR, LC-MS and Gas-MS analyses on transfer hydrogenation of H2O with glycerine under alkaline hydrothermal conditions. The results from solvent isotope studies showed that (1) the H on the β-C of lactate was almost exchanged by D2O, which suggests that the hydroxyl (-OH) group on the 2-C of glycerine was first transformed into a carbonyl (C=O) group and then was converted back into a -OH group to form lactate; (2) The presence of large amounts of D was found in the produced hydrogen gas, which shows that the water molecules acted as a reactant; and (3) D% in the produced hydrogen gas was far more than 50%, which straightforwardly shows that acetol was formed in the first place as the most probable intermediate by undergoing a dehydration reaction rather than a dehydrogenation reaction

Solvent Isotope Effect on Hydrogen-Transfer Reduction of CO2 into Formate with Glycerine by Alkaline Hydrothermal Reaction

To examine the solvent isotope effect on hydrogen-transfer reduction of CO2 into formate with glycerine by alkaline hydrothermal reaction, intermediates were identified by 13C-NMR, 1H-NMR, 2H-NMR, LC-MS analyses. The results showed that (1) CO2 was indeed converted into abiogenic formate; (2) a ketone carbonyl group as intermediate product was formed on hydrogen-transfer reduction of CO2 into formate with glycerine by alkaline hydrothermal reaction; (3) acetol was the most probable intermediate in the first reaction by undergoing a dehydration rather than a dehydrogenation

Runtime Software Architecture-Based Reliability Prediction for Self-Adaptive Systems

Modern software systems need to autonomously adapt their behavior at runtime in order to maintain their utility in response to continuous environmental changes. Most studies on models at runtime focus on providing suitable techniques to manage the complexity of software at runtime but neglect reliability caused by adaptation activities. Therefore, adaptive behaviors may lead to a decrease in reliability, which may result in severe financial loss or life damage. Runtime software architecture (RSA) is an abstract of a running system, which describes the elements of the current system, the states of these elements and the relation between the elements and their states at runtime. The main difference between RSA and software architecture at design time (DSA) is that RSA has a causal connection with the running system, whereas DSA does not. However, RSA and DSA have both symmetry and asymmetry in software architecture. To ensure that architecture-centric software can provide reliable services after adaptation adjustment, a method is proposed to analyze the impact of changes caused by adaptation strategy on the overall software reliability, which will be predicted at the runtime architecture model layer. Based on a Java platform, through non-intrusive monitoring, an RSA behavioral model is obtained followed by runtime reliability analysis model. Following this, reliability prediction results are obtained through a discrete-time Markov chain (DTMC). Finally, an experiment is conducted to verify the feasibility of the proposed method

Using Earth Observation for Monitoring SDG 11.3.1-Ratio of Land Consumption Rate to Population Growth Rate in Mainland China

Urban sustainable development has attracted widespread attention worldwide as it is closely linked with human survival. However, the growth of urban areas is frequently disproportionate in relation to population growth in developing countries; this discrepancy cannot be monitored solely using statistics. In this study, we integrated earth observation (EO) and statistical data monitoring the Sustainable Development Goals (SDG) 11.3.1: “The ratio of land consumption rate to the population growth rate (LCRPGR)”. Using the EO data (including China’s Land-Use/Cover Datasets (CLUDs) and the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime light data) and census, we extracted the percentage of built-up area, disaggregated the population using the geographically weighted regression (GWR) model, and depicted the spatial heterogeneity and dynamic tendency of urban expansion and population growth by a 1 km × 1 km grid at city and national levels in mainland China from 1990 to 2010. Then, the built-up area and population density datasets were compared with other products and statistics using the relative error and standard deviation in our research area. Major findings are as follows: (1) more than 95% of cities experienced growth in urban built-up areas, especially in the megacities with populations of 5–10 million; (2) the number of grids with a declined proportion of the population ranged from 47% in 1990–2000 to 54% in 2000–2010; (3) China’s LCRPGR value increased from 1.69 in 1990–2000 to 1.78 in 2000–2010, and the land consumption rate was 1.8 times higher than the population growth rate from 1990 to 2010; and (4) the number of cities experiencing uncoordinated development (i.e., where urban expansion is not synchronized with population growth) increased from 93 (27%) in 1990–2000 to 186 (54%) in 2000–2010. Using EO has the potential for monitoring the official SDGs on large and fine scales; the processes provide an example of the localization of SDG 11.3.1 in China

Mapping the Population Density in Mainland China Using NPP/VIIRS and Points-Of-Interest Data Based on a Random Forests Model

Understanding the spatial distribution of populations at a finer spatial scale has important value for many applications, such as disaster risk rescue operations, business decision-making, and regional planning. In this study, a random forest (RF)-based population density mapping method was proposed in order to generate high-precision population density data with a 100 m × 100 m grid in mainland China in 2015 (hereafter referred to as ‘Popi’). Besides the commonly used elevation, slope, Normalized Vegetation Index (NDVI), land use/land cover, roads, and National Polar Orbiting Partnership/Visible Infrared Imaging Radiometer Suite (NPP/VIIRS), 16,101,762 records of points of interest (POIs) and 2867 county-level censuses were used in order to develop the model. Furthermore, 28,505 township-level censuses (74% of the total number of townships) were collected in order to evaluate the accuracy of the Popi product. The results showed that the utilization of multi-source data (especially the combination of POIs and NPP/VIIRS data) can effectively improve the accuracy of population mapping at a finer scale. The feature importances of the POIs and NPP/VIIRS are 0.49 and 0.14, respectively, which are higher values than those obtained for other natural factors. Compared with the Worldpop population dataset, the Popi data exhibited a higher accuracy. The number of accurately-estimated townships was 19,300 (67.7%) in the Popi product and 16,237 (56.9%) in the Worldpop product. The Root Mean Squared Error (RMSE) and Mean Absolute Error (MAE) were 14,839 and 7218, respectively, for Popi, and 18,014 and 8572, respectively, for Worldpop. The research method in this paper could provide a reference for the spatialization of other socioeconomic data (such as GDP)

Conversion of Sucrose into Lactic Acid over Functionalized Sn-Beta Zeolite Catalyst by 3‑Aminopropyltrimethoxysilane

The utilization of sucrose, an easily accessible disaccharide, in the production of a versatile platform chemical lactic acid (LA), is more attractive than a monosaccharide. In this work, we report a modification approach by 3-aminopropyltrimethoxysilane to introduce an amino group onto the surface of the Sn-Beta Lewis acid catalyst. Using the modified catalyst, a maximum LA yield of 58% was achieved under optimal hydrothermal conditions (190 °C, 4 h) from sucrose, along with a complete conversion and a reduced 5-hydroxymethylfurfural (HMF) yield of 8% compared to Sn-Beta. To evaluate the role of the amino group, different substrates were used as the reactants to produce LA. The experimental results suggested that both fructose and glucose were crucial intermediates in the initial 2 h, whereas glucose is the sole reactant after 2 h. Upon modification, not only the hydrolysis of sucrose was promoted, but the side reaction of HMF formation was also suppressed

Glucose Hydrogenolysis into 1,2-Propanediol Using a Pt/deAl@Mg(OH)2 Catalyst: Expanding the Application of a Core–Shell Structured Catalyst

To substitute fossil resources, it is necessary to investigate the conversion of biomass into 1,2-propanediol (1,2-PDO) as a high-value-added chemical. The Pt/deAl-Beta@Mg(OH)2 catalytic system is designed to obtain a higher 1,2-PDO production yield. The optimal yield of 1,2-PDO is 34.1%. The unique shell-core structure of the catalyst demonstrates stability, with a catalytic yield of over 30% after three times of use. The primary process path from glucose to 1,2-PDO, glucose-hexitol-1,2-PDO, is speculated by the experiments of intermediate product selectivity. The alkaline catalytic mechanism of the reaction process is elucidated by studying catalyst characterization and analyzing different time courses of products. The introduction of Mg(OH)2 improves the target yield by promoting the isomerization from glucose to fructose and retro-aldol condensation (RAC) conversion, with pseudo-yield increases of 76.1% and 42.1%, respectively. By studying the processes of producing lactic acid and 1,2-PDO from glucose, the glucose hydrogenolysis flow chart is improved, which is of great significance for accurately controlling 1,2-PDO production in industrial applications. The metal, acid, and alkali synergistic catalytic system constructed in this paper can provide a theoretical basis and route reference for applying biomass conversion technology in practice

Identification and Functional Characterization of <i>ZmSCYL2</i> Involved in Phytosterol Accumulation in Plants

Phytosterols are natural active substances widely found in plants and play an important role in hypolipidemia, antioxidants, antitumor, immunomodulation, plant growth, and development. In this study, phytosterols were extracted and identified from the seed embryos of 244 maize inbred lines. Based on this, a genome-wide association study (GWAS) was used to predict the possible candidate genes responsible for phytosterol content; 9 SNPs and 32 candidate genes were detected, and ZmSCYL2 was identified to be associated with phytosterol accumulation. We initially confirmed its functions in transgenic Arabidopsis and found that mutation of ZmSCYL2 resulted in slow plant growth and a significant reduction in sterol content, while overexpression of ZmSCYL2 accelerated plant growth and significantly increased sterol content. These results were further confirmed in transgenic tobacco and suggest that ZmSCYL2 was closely related to plant growth; overexpression of ZmSCYL2 not only facilitated plant growth and development but also promoted the accumulation of phytosterols

The Effect of Catalytic Structure Modification on Hydrogenolysis of Glycerol into 1,3-Propanediol over Platinum Nanoparticles and Ordered Mesoporous Alumina Assembled Catalysts

To increase the Brønsted acid sites and the dispersion of Pt, and decrease the loss of Pt during reuse, a structurally modified PtNPs-HSiW/mAl₂O₃ catalyst was synthesized by assembling platinum nanoparticles (PtNPs) into ordered mesoporous alumina. N₂ adsorption–desorption, X-ray diffraction, and transmission electron microscopy showed that PtNPs-HSiW/mAl₂O₃ exhibited a significantly different structure from impregnated Pt-HSiW/γ-Al₂O₃: short-range ordered mesopores, large surface area, and special structure where PtNPs were assembled in the mesopores of alumina. Further pyridine-IR, CO adsorption, and inductively coupled plasma analyses showed that with the structural modification, the Brønsted acidity increased from 12.0 to 30.3 μmol/g, the Pt dispersion increased from 15.0 to 35.4%, and the loss of Pt decreased from 4.54 to 0.59 wt % during reuse. Finally, PtNPs-HSiW/mAl₂O₃ exhibited a 13.8% higher 1,3-PDO selectivity and more stable yields over reuse than Pt-HSiW/γ-Al₂O₃. It provided a reference that structural modification influences 1,3-PDO production by altering Brønsted acidity, Pt dispersion, and loss of Pt during reuse