Charge Measurement of Cosmic Ray Nuclei with the Plastic Scintillator Detector of DAMPE

One of the main purposes of the DArk Matter Particle Explorer (DAMPE) is to measure the cosmic ray nuclei up to several tens of TeV or beyond, whose origin and propagation remains a hot topic in astrophysics. The Plastic Scintillator Detector (PSD) on top of DAMPE is designed to measure the charges of cosmic ray nuclei from H to Fe and serves as a veto detector for discriminating gamma-rays from charged particles. We propose in this paper a charge reconstruction procedure to optimize the PSD performance in charge measurement. Essentials of our approach, including track finding, alignment of PSD, light attenuation correction, quenching and equalization correction are described detailedly in this paper after a brief description of the structure and operational principle of the PSD. Our results show that the PSD works very well and almost all the elements in cosmic rays from H to Fe are clearly identified in the charge spectrum.Comment: 20 pages, 4 figure

Oregano essential oil modulates colonic homeostasis and intestinal barrier function in fattening bulls

Oregano essential oil (OEO) primarily contains phenolic compounds and can serve as a dietary supplement for fattening bulls. However, the precise molecular mechanism underlying this phenomenon remains largely elusive. Therefore, this study investigated the impact of adding OEO to diet on the integrity of the intestinal barrier, composition of the colonic microbiome, and production of microbial metabolites in fattening bulls. Our goal was to provide insights into the utilization of plant essential oil products in promoting gastrointestinal health and welfare in animals. We employed amplicon sequencing and metabolome sequencing techniques to investigate how dietary supplementation with OEO impacted the intestinal barrier function in bulls. The inclusion of OEO in the diet resulted in several notable effects on the colon of fattening bulls. These effects included an increase in the muscle thickness of the colon, goblet cell number, short-chain fatty acid concentrations, digestive enzyme activity, relative mRNA expression of intestinal barrier-related genes, and relative expression of the anti-inflammatory factor IL-10. Additionally, α-amylase activity and the relative mRNA expression of proinflammatory cytokines decreased. Moreover, dietary OEO supplementation increased the abundance of intestinal Bacteroides, Coprobacillus, Lachnospiraceae_UCG_001, and Faecalitalea. Metabolomic analysis indicated that OEO primarily increased the levels of 5-aminovaleric acid, 3-methoxysalicylic acid, and creatinine. In contrast, the levels of maltose, lactulose, lactose, and D-trehalose decreased. Correlation analysis showed that altered colonic microbes and metabolites affected intestinal barrier function. Taken together, these results demonstrate that OEO facilitates internal intestinal environmental homeostasis by promoting the growth of beneficial bacteria while inhibiting harmful ones

Maternal genetic and phylogenetic characteristics of domesticated cattle in northwestern China.

Northwestern China, an important part of the Silk Road, was the birthplace of the Zhouzu farming culture. The domestication of cattle as an important aspect of farming culture has had a long history in northwestern China. In this study, we assessed the maternal structure and phylogeny of cattle by analyzing the mitochondrial DNA hypervariable segment I (HVS-I) in 698 native cattle from eight areas of northwestern China. The phylogenetic analyses revealed two highly divergent mtDNA clades: clade T, which had four sub-clades (Ta-Td), and clade I. The cattle domesticated from Bos taurus showed a clear dominant distribution pattern in northwestern China. The nucleotide diversity of the Bos indicus clade was lower than that of clades from Bos taurus. In summary, our results suggest that the native cattle of northwestern China were domesticated from two different maternal ancestors, Bos taurus and Bos indicus, which migrated to the central plains of China from the north and south, respectively, with Bos taurus remaining at the edges of the region. The population expansion of the cattle domesticated from Bos taurus occurred in the Longdong region of Gansu Province, and these cattle formed four relatively independent evolutionary branches. Subsequent to this expansion event, Bos indicus migrated from southern to northern China

Multi-combination exploiting technique of ultra-heavy oil reservoirs with deep and thin layers in Shengli Oilfield

There isn't any mature technique to develop ultra-heavy oil reservoirs in the Shengli Oilfield because of large oil viscosity, deep and thin layer, high rate of resin and asphaltene. The multi-combination exploiting technique is developed which combines the techniques of under-pressure foam flow-back, efficient oil-soluble viscosity reducer, CO2 immiscible and steam huff and puff. The following experiments were conducted about the recovery mechanism of the technique: (1) measuring foam viscosity, sands suspension property and sands washing capacity; (2) comparing the capacities of viscosity breaking and emulsion breaking of oil-soluble viscosity reducer with the conventional viscosity reducer; (3) measuring emulsion breaking of CO2. The experimental results show: Foam has the advantages of greater viscosity, remarkable capacities of suspending and washing sands; the combination viscosity reducer has greater advantage on viscosity breaking over xylene. The emulsion breaking capacity of the combination viscosity reducer and CO2 is excellent, and the higher the W/O emulsion, the greater the capacity of emulsion breaking. Field tests show that the multi-combination exploiting technique is good in improving production of ultra-heavy oil reservoirs. 摘要: ： 胜利油田超稠油埋藏深、储集层薄、原油黏度大、胶质和沥青质含量高，采用目前成熟的稠油开发方式无法有效动用。结合超负压泡沫混排技术、高效油溶性降黏剂降黏技术、CO2非混相驱油技术和蒸汽吞吐技术，提出深薄层超稠油多元复合开采技术。针对多元复合开采技术的开采机理，进行相关实验：①测定泡沫黏度以及泡沫悬砂、冲砂性能；②油溶性复合降黏剂与常规降黏剂降黏效果对比实验和破乳实验；③CO2破乳能力实验。实验表明：泡沫具有良好的悬砂、冲砂性能；复合降黏剂的降黏效果远好于二甲苯，复合降黏剂和CO2均具有很好的破乳效果，原油乳化程度越高，破乳效果越好。现场试验显示多元复合开采技术开发深薄层超稠油具有良好效果。图5表4参14 Key words: ultra-heavy oil, multi-combination exploiting technique, foam, viscosity reducer, CO

Mass screening is a key component to fight against SARS-CoV-2 and return to normalcy

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had highly transmissible and pathogenic, which caused serious economic loss and hazard to public health. Different countries have developed strategies to deal with the COVID-19 pandemic that fit their epidemiological situations, capacities, and values. Mass screening combined with control measures rapidly reduced the transmission of the SARS-CoV-2 infection. The COVID-19 pandemic has dramatically highlighted the essential role of diagnostics capacity in the control of communicable diseases. Mass screening has been increasingly used to detect suspected COVID-19 cases and their close contacts, asymptomatic case, patients attending fever clinics, high-risk populations, employees, even all population to identify infectious individuals. Mass screening is a key component to fight against SARS-CoV-2 and return to normalcy. Here we describe the history of mass screening, define the scope of mass screening, describe its application scenarios, and discuss the impact and challenges of using this approach to control COVID-19. We conclude that through a comprehension screening program and strong testing capabilities, mass screening could help us return to normalcy more quickly.</p

A Study of the Solid-Liquid-Gas Three-Phase Coupling Relationship of Coal, Water and Gas

At the present time, it is of major significance to study the solid-liquid-gas three-phase coupling relationship of coal, water, and gas in deep-mining stopes in order to prevent and control coal and gas outbursts in high-gas mines. In this study, the influence rules of water on the mechanical characteristics of coal, as well as gas diffusion and migration processes, was examined by combining theoretical analysis and laboratory testing procedures. The results showed that with increases in water content, the mechanical characteristics of coal bodies presented change trends of first increasing and then decreasing. In this study, it was found that the water content levels which corresponded to the maximum shear strength of the coal in the No. 8 coal seam in the study area had ranged between 6.77% and 11.9%, and the water content level corresponding to the extreme point was 8.66%. It was observed that under different water content conditions, the gas desorption speeds of the coal bodies gradually decreased over time. The gas desorption speeds rapidly decreased during the initial desorption stage and then gradually decreased over time. Furthermore, under the different water content conditions, the amount of gas desorption in the coal bodies was observed to gradually increase over time, with the initial desorption amounts displaying rapid increases. Then, with the passage of time, the increase speeds of the gas desorption amount gradually decreased and finally tended to remain at a stable value. It was found that with the increases in water content, the desorption speeds, initial desorption speeds, and desorption amount of gas in the coal bodies continuously decreased. In other words, the water content levels in the coal bodies were negatively correlated with the gas desorption speeds and desorption amounts of the coal bodies. In addition, the gas desorption speeds, initial desorption speeds, and desorption amounts were observed to change more sharply with the increases in water content. The results of this research hold important guiding significance for the improvement of the understanding of the mechanical properties of high-gas coal seams and the implementation of effective gas control measures

Surface Wettability of Oxygen Plasma Treated Porous Silicon

Oxygen plasma treatment on porous silicon (p-Si) surfaces was studied as a practical and effective means to modify wetting properties of as-fabricated p-Si surfaces, that is, contact angles of the p-Si materials. P-Si samples spanning a wide range of surface nanostructures have been fabricated which were subjected to a series of oxygen plasma treatments. Reduction of the p-Si surface contact angles has been systematically observed, and the surface activation rate constant as a function of different pore geometries has been analyzed to achieve an empirical equation. The underlying diffusion mechanisms have been discussed by taking into account of different pore diameters of p-Si samples. It is envisaged that such an approach as well as the corresponding empirical equation may be used to provide relevant process guidance in order to achieve precise control of p-Si contact angles, which is essential for many p-Si applications especially in biosensor areas