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31.
In China, Camellia oleifera oil (COO) is not only a common edible oil but also a traditional remedy widely applied to ameliorate a variety of illnesses associated with inflammation, such as mouth ulcers, thrush, eczema, etc. However, there has been a lack of relevant biological research on the anti-inflammatory capacity of COO, and the specific bioactive lipid phytochemicals contributing to the anti-inflammatory effect need further research. In this study, the RAW 264.7 macrophages model was used to investigate the anti-inflammatory capacity of COO. Our data showed that 33–200 μg/mL COO markedly inhibited the lipopolysaccharide lipopolysaccharide (LPS)-stimulated nitric oxide (NO.) secretion via the suppression of Nos2 and Cox-2 expression. The enzyme immunoassay confirmed that COO also exhibited a strong suppressive effect on the expression of proinflammatory cytokines such as Tnf-α and Il-6. To further explore the correlation between the anti-inflammatory effects and the lipid phytochemicals in COO, 10 samples were collected and screened for their chemical compositions. It was interestingly demonstrated that the polyphenol extracts of COO play a vital role in its anti-inflammatory properties. In addition, an oil-in-water (O/W) emulsion-based system was also developed to deliver the liposoluble COO into the cells, and the feasibility of this system was confirmed. Our research confirms the anti-inflammatory potential of COO and highlights that the main functional ingredient is polyphenol extracts. This may provide a scientific basis for the comprehensive utilization and development of COO and related functional foods.  相似文献   
32.
设计了一种开关磁阻直线电机,使用JMAG软件对其进行了仿真和优化。进行了推力公式的推导,研究了导通顺序和初始位置对电机推力的影响,并分析了三种典型情况的磁力线分布。对电机的定子和动子的齿部和轭部高度、宽度及铁耗进行仿真优化,得出了最优参数。将有取向硅钢应用于该电机,研究了推力与轧制角的关系,并与使用普通硅钢的开关磁阻直线电机进行了对比,推力有一定提升。提出在动子齿部开切向槽的方案,结果表明,开切向槽对推力的影响较小,并能显著减小推力波动。  相似文献   
33.
SrLa[Ga1−x(R0.5Ti0.5)x]O4 (R = Mg, Zn) ceramics were prepared by a standard solid state sintering method. The single-phase ceramics with K2NiF4-type layered perovskite structure and I4/mmm space group were obtained, indicating that SrLa(R0.5Ti0.5) and SrLaGaO4 can form the unlimited solid solutions. With increasing x for = Mg and Zn, εr increases monotonously, the Qf value first increases and then decreases, while τf increases from a negative to a positive value. The optimized microwave dielectric properties were obtained as following: εr = 23.3, Qf = 89 400 GHz, τf = −0.8 ppm/°C for SrLa[Ga0.6(Mg0.5Ti0.5)0.4]O4 and εr = 23.3, Qf = 76 200 GHz, τf = 0.2 ppm/°C for SrLa[Ga0.7(Zn0.5Ti0.5)0.3]O4, indicating that the present solid solution ceramics are the promising candidates as microwave resonator materials for the telecommunication applications.  相似文献   
34.
以碘吸附值为评价指标,活化时间、活化温度和浸渍比为影响因素,采用响应面法试验设计对磷酸活化法制备咖啡渣活性炭的工艺条件进行优化,并通过静态吸附试验研究了不同吸附时间、溶液pH值和吸附温度条件下,活性炭对水溶液中Cr(Ⅵ)吸附性能的影响,最后利用Langmuir、Freundlich吸附等温方程、准一级动力学方程、准二级动力学方程和颗粒内部扩散方程进行拟合。试验结果表明,制备咖啡渣活性炭的最佳工艺条件为活化时间1 h、活化温度498℃、浸渍比1.72;在此条件下活性炭得率为30.4%,碘吸附值为(799±16)mg/g,比表面积为1 006 m2/g,孔容为0.779 cm3/g、微孔孔容为0.051 cm3/g、平均孔径为3.088 nm。较低pH值和较高温度能够促进活性炭对Cr(Ⅵ)的吸附;Langmuir等温方程能够更好地描述活性炭对Cr(Ⅵ)的吸附效果;活性炭对Cr(Ⅵ)的吸附分3个阶段:快速吸附阶段、慢速吸附阶段和吸附平衡阶段,10 min内可完成吸附总量的79%,360 min内达到吸附平衡,该吸附过程符合准二级吸附动力学方程。分析表明咖啡渣活性炭对Cr(Ⅵ)的吸附主要为单分子层的化学吸附。  相似文献   
35.
使用单层纳米氧化石墨烯(NGO)粒子对环氧树脂进行改性处理,采用真空辅助树脂传递模塑成型工艺制备了[±45/0/90]2S铺层角度下的纯树脂及单层NGO改性碳纤维复合材料(CFRP)层合板。通过落锤冲击试验、超声C扫描检测、冲击后压缩试验等对纯树脂及单层NGO改性CFRP进行实验研究。结果表明,纯树脂及单层NGO改性CFRP在损伤阻抗及损伤容限实验中均存在拐点现象,且拐点出现在相同深度位置,其中纯树脂CFRP拐点位置为0.51 mm,单层NGO改性CFRP拐点位置为0.43 mm;相对于纯树脂CFRP,单层NGO改性CFRP可以显著提高复合材料的抗冲击性能及冲击后的压缩性能;通过对冲击后凹坑深度及凹坑面积进行数据模拟,可以用拟合公式实现对复合材料的损伤预测。  相似文献   
36.
An obligate mutualistic relationship exists between the fungus Amylostereum areolatum and woodwasp Sirex noctilio. The fungus digests lignin in the host pine, providing essential nutrients for the growing woodwasp larvae. However, the functional properties of this symbiosis are poorly described. In this study, we identified, cloned, and characterized 14 laccase genes from A. areolatum. These genes encoded proteins of 508 to 529 amino acids and contained three typical copper-oxidase domains, necessary to confer laccase activity. Besides, we performed molecular docking and dynamics simulation of the laccase proteins in complex with lignin compounds (monomers, dimers, trimers, and tetramers). AaLac2, AaLac3, AaLac6, AaLac8, and AaLac10 were found that had low binding energies with all lignin model compounds tested and three of them could maintain stability when binding to these compounds. Among these complexes, amino acid residues ALA, GLN, LEU, PHE, PRO, and SER were commonly present. Our study reveals the molecular basis of A. areolatum laccases interacting with lignin, which is essential for understanding how the fungus provides nutrients to S. noctilio. These findings might also provide guidance for the control of S. noctilio by informing the design of enzyme mutants that could reduce the efficiency of lignin degradation.  相似文献   
37.
Chrysanthemum flower is among one of the highly sought after and widely planted flower crops, in particular for cultural and religious ceremonies. However, the chrysanthemum stem and stalk have little value and usually discard as by‐product waste from floristry. The objective of this research is to investigate the potential value of utilizing chrysanthemum stem and stalk as reinforcing fillers for thermoplastic composites. In this study, 2‐mm thick composite sheet containing predefined formulations of polylactic acid (PLA), chrysanthemum waste filler (CWF) ranging from 15 to 60 phr, and maleated polyethylene (MAPE) coupling agent up to 5 phr were prepared with the aid of Haake internal mixer and compression molding. The effect of MAPE loading on tensile, thermal, and morphological properties of PLA/CWF composites was investigated. The findings revealed that PLA/CWF composite attained improved tensile modulus compared to the neat PLA, and the tensile modulus increases with higher concentration of CWF. However, both tensile strength and elongation at break reduces with increase loading of CWF. Overall, PLA/CWF composites with MAPE shows better performance compared to those without MAPE, where an optimum strength of 21.8 MPa can be achieved with 60 phr CW and 3 phr MAPE. The measured tensile strength is comparable to alternatives natural fiber thermoplastic composites demonstrating its potential to be used in non‐structurally demanding application. J. VINYL ADDIT. TECHNOL., 26:10–16, 2020. © 2019 Society of Plastics Engineers  相似文献   
38.
Simulating the psychological experience of human vision,a road extraction model based on the format tower is proposed to extract the road in the high resolution remote sensing image from the perspective of morphology.Firstly,based on the spectral and texture information,the suspected road targets are extracted by using segmentation technology.Then these targets are classified according to their reliability and extract the road targets for each category.Finally,three types of identified road information are verified and merged,and the continuous smooth road extraction results are obtained.Experiments on real high resolution images show that the results are consistent with the visual perception of the human eye,and the overall classification accuracy is higher,indicating that the algorithm is effective and feasible and has good use value.  相似文献   
39.
2A12铝合金化学铣切加工工艺探讨   总被引:1,自引:0,他引:1  
付明  刘群 《材料保护》2018,(7):100-103
为了精确加工2Al2铝合金,探讨了化铣时间和温度对其化铣速率及表面粗糙度的影响,采用现代技术对化铣工件的力学性能进行了测试与分析.结果表明:延长非化铣部位保护胶固化时间并使保护部位向非加工面位移3~5 mm可很好地解决未化铣区域的腐蚀问题;随化铣时间的延长,化铣速率降低,且化铣温度与化铣速率呈现正相关性;化铣表面的粗糙度随化铣时间的延长而增加,随化铣温度的升高呈先减小后增加的趋势;化铣后材料的抗拉强度和屈服强度均有所提高.  相似文献   
40.
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