Two new resin glycosides, cuses 3 (1) and 4 (2), were initially obtained from the seeds of Cuscuta chinensis. Both of them contained a reducing glucose unit, and thus existed as a pair of isomers. In order to solve the existing problem of tautomerism, the remanent resin glycoside fraction was converted into aminoalditol derivatives with p-anisidine, and then another eight new resin glycosides cuses 5–12 (3–10) were further isolated. Cuses 7–12 (6–10) were considered to be generated via glycosidation of two acylated oligosaccharides, and thus characterized as ether-type resin glycoside dimers. Their structures including absolute stereochemistry were elucidated by a combination of spectroscopic and chemical methods. Compounds 3–10 exhibited cytotoxic activity toward MCF-7, SMMC-7721, and MG-63 cell lines with IC50 values ranging from 8.72 to 59.35 μg/mL. 相似文献
In this study, spinel LiNi0.5Mn1.5O4 (LNMO) was successfully decorated with Al2O3 thin film by using atomic layer deposition (ALD) approach and evaluated as a cathode material for high-temperature applications in lithium ion batteries (LIBs). To optimize the LNMO-Al2O3 electrodes operated at elevated temperature (55 °C), the effects of Al2O3 thicknesses adjusted by controlling the ALD deposition cycle were systemically investigated. According to the series of electrochemical results, the LNMO coated with the Al2O3 thin layer in the thickness of ca. 2 nm was achieved by using one-cycle ALD and the LNMO-Al2O3 electrode exhibited superior electrochemical stability (capacity retention up to 93.7% after consecutive 150 charge/discharge cycles at 0.5 C to the pristine LNMO electrode at elevated temperature. This can be attributed to two factors: (i) the decoration of Al2O3 thin layer could not contribute remarkably to extra resistance for charge transfer; (ii) Al2O3 thin film deposition could efficiently stabilize the growth of cathode electrolyte interface (CEI) and suppress the dissolution of transition metals. Therefore, these results verify that the LNMO-Al2O3 electrode could be regarded as a promising cathode material for high-voltage LIBs, especially at elevated temperature operation.
This paper describes an experimental study on the oscillation flow characteristics of submerged supersonic gas jets issued
from Laval nozzles. The flow pattern during the jet development and the jet expansion feedback phenomenon are studied using
a high-speed camera and a pressure measurement system. The experimental results indicate that along the downstream distance,
the jet has three flow regimes: (1) momentum jet; (2) buoyant jet; (3) plume. In the region near the nozzle exit a so-called
bulge phenomenon is found. Bulging of the jet occurs many times before the more violent jet expansion feedback occurs. During
the feedback process, the jet diameter can become several times that of the original one depending on the jet Mach number.
The frequencies of the jet bulging and the jet expansion feedback are measured. 相似文献