[Stable Isotopes of Precipitation in the Eastern Tarim River Basin and Water Vapor Sources].

The in-situ monitoring of stable hydrogen and oxygen isotopes (δ18O and δ2H) in precipitation is helpful to understand the processes of water phase change, mixing, and transportation. Due to the arid climate in the eastern Tarim River basin, water resources are the key factor affecting the regional sustainable development. However, the understanding of stable hydrogen and oxygen isotopes in precipitation is still limited for this region. Based on the isotope data of 103 precipitation samples collected at four stations in the eastern Tarim River basin from June 2019 to September 2020, the spatial and temporal characteristics of stable hydrogen and oxygen isotopes in precipitation were analyzed, and the connections between stable isotopes and moisture sources were discussed. The findings provide a reference for the application of environmental isotope tracers in arid areas. The results show that, ① the four sampling stations generally presented an increasing trend in precipitation stable isotopic values from north to south, and the isotopic values were higher in summer and lower in winter. The d-excess value in the study region was smaller than the national average, and the slope of the local meteoric water line exhibited a significant arid characteristic. ② There was a positive correlation between precipitation stable isotopes and air temperature in the study region, whereas a weak negative relationship was seen between d-excess and air temperature. The negative correlation occurred between δ18O and relative humidity, and the d-excess value exhibited a positive correlation with relative humidity. ③ The backward trajectory showed that the eastern Tarim River basin is mainly controlled by the westerlies paths. The proportion of air mass that comes from the middle and short distance is relatively large. The concentration weighted trajectory method showed that the farther from the precipitation sampling site, the more stable the d-excess value was. The closer to the sampling site, the more frequently the concentration changed, indicating that the d-excess value was greatly affected by the local water vapor recycling.

Composition, formation mechanism, and removal method of off-odor in soymilk products.

Soybean is a protein-rich material for plant-based products, and its application in soymilk products is limited due to its off-odor such as beany. In order to explore a solution to address this issue, composition, formation mechanism, and removal methods of the off-odor produced in the processing of soymilk products are comprehensively described in this paper. The main off-odor compounds in soymilk products include hexanal, hexanol, 1-octene-3-ol, (E,E)-2, 4-decadienal, 2-pentylfuran, (E,E)-2,4-nonadienal, (E)-2-nonenal, (E) -2-hexenal, and so on. These odor compounds are mainly produced by the enzymatic and nonenzymatic oxidation of unsaturated fatty acids. At present, physical methods are used to remove off-odor in the industrial production of soymilk products, of which heat treatment is still the most effective. With the development of no beany soybean breeding technology, the combination of multiple methods will become a technical trend for removing off-odor. Some new research directions are also explored about removal methods, which can provide a theoretical reference for the production and technical research of soymilk products.

The chemical composition of human milk from Inner Mongolia of China.

In Inner Mongolia, China, the chemical composition of 66 breast milk samples at three lactation stages was analysed. Except for total nitrogen content, the contents of total solid, fat, NPN, lactose and ash were not significantly different between colostral, transitional and mature milk. Fatty acids did not vary over the three lactation stages, while unsaturated fatty acids accounted for 59.95-63.22% of the total fatty acids. Relatively low contents of vitamins were in the milk because the volunteer mothers did not take any vitamin supplementation over the entire lactation period. Besides sodium and phosphate, the concentrations of most minerals in the breast milk remained fairly constant across the three lactation stages.

Control of the Crystalline Morphology of Poly(l-lactide) by Addition of High-Melting-Point Poly(l-lactide) and Its Effect on the Distribution of Multiwalled Carbon Nanotubes.

The key to fabricating conductive polymer/carbon nanotube (CNT) nanocomposites is controlling the distribution of CNTs in the polymer matrix. Here, an effective and simple approach for controlling the distribution of multiwalled CNTs (MWCNTs) is reported to largely improve the electrical conductivity of biodegradable poly(l-lactide) (PLLA) through crystalline morphology development by addition of high-melting-point PLLA (hPLLA) crystallites. hPLLA crystallites are efficient nucleating agents, increasing the crystallinity and crystallization rate of PLLA/MWCNT nanocomposites. Furthermore, the diameter of spherulites decreases from 9.7 to 1.0 µm with an increase in the concentration of hPLLA from 0.03 to 3.0 wt %. The electrical conductivity of PLLA/MWCNT nanocomposites with 0.3 wt % MWCNTs greatly increases from 1.89 × 10(-15) to 1.56 × 10(-8) S/cm with an increase in the matrix crystallinity from 2.4 to 46.8% on introducing trace amounts of hPLLA (0.07 wt %). The percolation threshold of PLLA/MWCNT nanocomposites is reduced from 0.51 to 0.21 wt % on addition of 0.07 wt % hPLLA. The high electrical conductivity and low percolation threshold of PLLA/MWCNT nanocomposites incorporated with hPLLA are related to the high crystallinity and crystalline morphologies of the PLLA matrix. Big spherulites lock a lot of MWCNTs at the intervals in the spherulites, which is harmful to the electrical conductivity. Small spherulites, with large surface areas, also need more MWCNTs to form conductive networks in the amorphous regions. Most MWCNTs that are bundled together to form conductive paths are found in samples with mid-sized spherulites of ∼6.7 µm. More interestingly, the high crystallinity and reconstructed MWCNT network also enhanced the Young modulus, elongation at break, and elastic modulus at high temperature of PLLA/MWCNT nanocomposites with small amounts of hPLLA.