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41.
秦旭平 《机械工程与自动化》2000,(3)
对新型半流体蜗轮润滑脂—— BLTZ1进行了不同工况条件下的性能对比试验。大量的试验数据表明 ,BLTZ1新型润滑脂具有良好的润滑特性 ,同时具有显著的防漏节能效果。 相似文献
42.
Weikai Ding Yousef Sultan Shumei Li Wenjun Wen Bangjun Zhang Yiyi Feng Junguo Ma Xiaoyu Li 《International journal of molecular sciences》2022,23(11)
Previous studies have indicated that the harmful heavy metal lead (Pb) contamination in aquatic systems has caused intelligence development disorders and nervous system function abnormalities in juveniles due to the increased permeability of the blood–brain barrier. Ionic liquids (ILs) are considered “green” organic solvents that can replace traditional organic solvents. Studies have found the presence of ILs in soil and water due to chemical applications or unintentional leakage. Therefore, what would happen if Pb interacted with ILs in a body of water? Could ILs enable Pb to more easily cross the blood–brain barrier? Therefore, we examined the combined exposure of Pb and ILs in common carp at low concentration (18.3 mg L−1 of Pb(CH3COO)2•3 H2O and 11 mg L−1 of the IL 1-methyl-3-octylimidazolium chloride, 5% of their LC50) for 28 days in the present study. The result of a neurobehavioral assay showed that chronic exposure of lead at lower concentrations significantly altered fish movement and neurobehaviors, indicating that lead exposure caused neurotoxicity in the carp. Increases in the neurotransmitter dopamine levels and injuries in the fish brain accounted for neurobehavioral abnormalities induced by lead exposure. Moreover, we also found that lead could easily cross the blood–brain barrier and caused significant bioaccumulation in the brain. Particularly, our study indicated that the ionic liquid could not synergistically promote blood–brain barrier permeability and hence failed to increase the absorption of lead in the fish brain, suggesting that the combined exposure of lead and ILs was not a synergistic effect but antagonism to the neurotoxicity. The results of this study suggested that ILs could recede the Pb induced neurotoxicity in fish. 相似文献
43.
Pablo de Vera Simone Taioli Paolo E. Trevisanutto Maurizio Dapor Isabel Abril Stefano Simonucci Rafael Garcia-Molina 《International journal of molecular sciences》2022,23(11)
Energetic carbon ions are promising projectiles used for cancer radiotherapy. A thorough knowledge of how the energy of these ions is deposited in biological media (mainly composed of liquid water) is required. This can be attained by means of detailed computer simulations, both macroscopically (relevant for appropriately delivering the dose) and at the nanoscale (important for determining the inflicted radiobiological damage). The energy lost per unit path length (i.e., the so-called stopping power) of carbon ions is here theoretically calculated within the dielectric formalism from the excitation spectrum of liquid water obtained from two complementary approaches (one relying on an optical-data model and the other exclusively on ab initio calculations). In addition, the energy carried at the nanometre scale by the generated secondary electrons around the ion’s path is simulated by means of a detailed Monte Carlo code. For this purpose, we use the ion and electron cross sections calculated by means of state-of-the art approaches suited to take into account the condensed-phase nature of the liquid water target. As a result of these simulations, the radial dose around the ion’s path is obtained, as well as the distributions of clustered events in nanometric volumes similar to the dimensions of DNA convolutions, contributing to the biological damage for carbon ions in a wide energy range, covering from the plateau to the maximum of the Bragg peak. 相似文献
44.
以硫酸钾尾液为原料,研究低温冷冻回收高硫钾比矿物合理的工艺技术路线,探寻适宜的贮存条件,为加工车间夏季高温生产硫酸钾提供优质高硫钾比原料.在低温下进行冷冻试验,根据冷冻结晶矿物产率及其干基组分确定适宜的冷冻温度为-15~5℃,冷冻制得的结晶矿物硫钾比均在3.0~5.1,符合夏季生产硫酸钾所需原料硫钾比>2.5的要求.高... 相似文献
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46.
ABSTRACT: Swordfish fillets, dry-salted and treated with liquid smoke, were sliced and packed in vacuum conditions and under modified atmosphere (MA) (5% O2 ,45% CO2 , 50% N2 ) and stored at chilled temperature (4°C) to determine the effect of different packaging on shelf-life. Sensory attributes, total volatile basic nitrogen (TVB-N), pH, lipid oxidation by thiobarbituric acid test, and microbiological counts were monitored during 45 d of storage. The TVB-N increased to levels recommended by European regulation at the time of sensory rejection, resulting as the most reliable parameter of quality decay. Lipid oxidation was low and microbial counts could not be correlated with quality decay. Sensory rejection (at least 50% of the assessors scoring =5 in a scale from 1 to 9) was sooner for MA-packed samples (12d) than for vacuum-packed ones (42d). 相似文献
47.
C. D. Wick M. G. Martin J. I. Siepmann M. R. Schure 《International Journal of Thermophysics》2001,22(1):111-122
Accurate predictions of retention times, retention indices, and partition constants are a long sought-after goal for theoretical studies in chromatography. Although advances in computational chemistry have improved our understanding of molecular interactions, little attention has been focused on chromatography, let alone calculations of retention properties. Configurational-bias Monte Carlo simulations in the isobaric–isothermal Gibbs ensemble were used to investigate the partitioning of benzene, toluene, and the three xylene isomers between a squalane liquid phase and a helium vapor phase. The united-atom representation of the TraPPE (transferable potentials for phase equilibria) force field was used for all solutes and squalane. The Gibbs free energies of transfer and Kovats retention indices of the solutes were calculated directly from the partition constants (which were averaged over several independent simulations). While the calculated Kovats indices of benzene and toluene at T=403 K are significantly higher than their experimental counterparts, much better agreement is found for the xylene isomers at T=365 K. 相似文献
48.
推导了旋转轴液体密封中液-液界面由于相对运动引起的切应力,从相对速度角度对液体动密封界面稳定性问题进行了研究,并对结构进行了改进,将磁流体界面的稳定性问题转化为静态扩散处理. 相似文献
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