Molecular Analysis of Evolution and Origins of Cultivated Hawthorn (Crataegus spp.) and Related Species in China

Hawthorn is of high economic value owing to its medicinal properties and health benefits. Crataegus is a member of the Rosaceae family; the genus has a complicated taxonomic history, and several theories on its origin have been proposed. In this study, 53 accessions from seven Crataegus taxa native to China and accessions of exotic Crataegus species (two from Europe and one from North America) were analyzed by specific locus amplified fragment sequencing (SLAF-seq). In total, 933,450 single-nucleotide polymorphisms were identified after filtering and used to investigate the species’ genomic evolution. Phylogenetic trees derived from nuclear simple sequence repeats (SSRs) and SLAF-seq data showed the same topology, in which Crataegus maximowiczii and Crataegus sanguineae formed a closely related cluster that was clearly separated from the cluster composed of Crataegus hupehensis, Crataegus pinnatifida, Crataegus pinnatifida var. major, Crataegus bretschneideri and Crataegus scabrifolia. Phylogenetic and structure analysis indicated that the seven Chinese Crataegus taxa had two separate speciation events. Plants that evolved the southwestern route shared the genepool with the European species, whereas plants along the northeastern route shared the genepool with the North American species. TreeMix genetic analysis revealed that C. bretschneideri may have a hybrid origin. This study provides valuable information on the origins of Chinese Crataegus and suggests an evolutionary model for the main Crataegus species that native to China

Submicroscopic metallic iron in lunar soils estimated from the in situ spectra of the Chang’E-3 mission

Submicroscopic metallic iron (SMFe) created by space weathering has strong effects on the optical properties of the lunar surface. Spectra measured in situ by the visible-near-infrared spectrometer (VNIS) on board the Chang’E-3 Yutu rover were used to investigate optical maturity differences at the CE-3 landing site caused by lander exhaust. SMFe abundances were estimated using Hapke’s radiative transfer model. Analysis of the spectrum for a minimally disturbed soil indicates that it contains 0.368 wt % SMFe, corresponding to an Is/FeO maturity index of ~53 and indicating that the landing site is submature. The soil at a location that was more disturbed contains 0.217 wt % SMFe, suggesting that the material removed by the rocket blast is more weathered than the regolith that remained behind. We conclude that maturity differences related to removal of the finest, highly mature particles play a major role in the observed reflectance changes associated with rocket blast.…This research was supported by the National High Technology Research and Development Program of China (863 Program: 2015AA123704), the National Natural Science Foundation of China (41422110 and 41490633), the Science and Technology Development Fund of Macau (020/2014/A1), and Minor Planet Foundation of Purple Mountain Observatory. The contribution of D.T.B. was made possible by the Chinese Academy of Sciences President’s International Fellowship Initiative, grant 2015VEB057 and by NASA Lunar Data Analysis Program grant NNX16AN55G. E.A.C. thanks NSERC and the Canadian Space Agency for supporting this study.https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL07265

Roadmap on exsolution for energy applications

Over the last decade, exsolution has emerged as a powerful new method for decorating oxide supports with uniformly dispersed nanoparticles for energy and catalytic applications. Due to their exceptional anchorage, resilience to various degradation mechanisms, as well as numerous ways in which they can be produced, transformed and applied, exsolved nanoparticles have set new standards for nanoparticles in terms of activity, durability and functionality. In conjunction with multifunctional supports such as perovskite oxides, exsolution becomes a powerful platform for the design of advanced energy materials. In the following sections, we review the current status of the exsolution approach, seeking to facilitate transfer of ideas between different fields of application. We also explore future directions of research, particularly noting the multi-scale development required to take the concept forward, from fundamentals through operando studies to pilot scale demonstrations

Influence of water on yields and isotopic fractionations of gas hydrocarbons generated from oil cracking

Few investigations have been made to discuss the influence of water on the yields and carbon and hydrogen isotopic ratios of gas hydrocarbons generated from oil cracking although water occurs in oil reservoirs. In this study, a pyrolysis experiment for a crude oil under hydrous and anhydrous conditions in a gold tube confined system was performed at T = 370°C, P = 21 MPa and times from 1 to 7 days. It is found that water has an obvious inhibition on the gas yields generated from oil cracking and a pronounced influence on the carbon and hydrogen isotopic fractionations of the cracking gas. Compared with the anhydrous pyrolysis, the hydrous pyrolysis has a smaller C_(1-5) alkane yields and lighter carbon and hydrogen isotopic ratios of the C_(1-3) hydrocarbons within maturity levels investigated. The differences in their C_(1-5) alkane yields reach 3-12 ml/g, in their δ^(13)CH_4, δ^(13)C_2H_6 and δ^(13)C_3H_8 values reach 1.0-2.7‰, 0.2-0.8‰ and 0.2-0.3‰, respectively, and in their δDCH_4, δDC_2H_6, δDC_3H_8 values reach 5-16‰, 22-80‰ and 4-13‰, respectively. Moreover, the hydrous pyrolysis experiment formed a greater amount of H_2 and alkenes and a smaller amount of CO_2 than the anhydrous pyrolysis experiment did. The differences of H_2, ethene, propene and CO_2 between the two experiment conditions are 0.44-2.12 ml/g, 0.03-0.05 ml/g, 0.20-0.34 ml/g and 0.08-0.98 ml/g, respectively. These results indicate that these differences in carbon and hydrogen isotopic ratios of generated gases between the hydrous and anhydrous experiments is possibly because water affects the free radical reactions of oil cracking and inhibits the combination between alkyl and hydrogen to form alkane to some extent, rather than due to the isotopic exchange reactions between water and some pyrolysates as usually believed for kerogen hydrous pyrolysis

Effects of Water and Fertilizer Flow Rates on the Mixing Process and Fertilization Uniformity of Cotton under Mulch Drip Irrigation

Water and fertilizer flow rates are the most convenient variable to control in the process of drip irrigation under mulch. Suitable water and fertilizer flow rates are beneficial to improve water and fertilizer uniformity. Nine groups of water and fertilizer rate combinations were set in the common water and fertilizer rate range to study the influence of the water and fertilizer rate on fertilization uniformity. The numerical simulation of the mixing process in the main pipe was first carried out based on the multiphase flow theory, and then the field experiment for the different water and fertilizer rate combinations in the machine-picked cotton-planting pattern (one film, three tubes and six rows) was conducted. Through the numerical simulation of the mixing process in the pipeline and the analysis of water and fertilizer uniformity field experiment results, it was found that the uniform mixing length is related to the water and fertilizer flow rate, and the water and fertilizer flow rate had some effect on fertilizer uniformity. In the irrigation system with a main pipe diameter of 100 mm and a fertilizer injection pipe diameter of 20 mm, the water fertilizer flow rate ratio should be between 3–8 to ensure the effect of the mixing process and fertilization uniformity. A water flow rate of 2 m s−1 and fertilizer flow rate of 0.35 m s−1 is recommended during the fertilizer process in northern Xinjiang. This paper shows the feasibility of numerical simulation in the study of cotton water and fertilizer mixing processes, and the results can provide some reference for cotton planting