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91.
采用高温淬火方法制备了Tc在27.4K至92.4K之间的一组不同氧含量的PMP(粉末熔融工艺)法YBCO超导体。通过对这些超导体样品的磁滞回线及不可逆线的研究发现,随着氧空位的增加,超导体的磁通钉扎力减小 相似文献
92.
Effect of pulse parameters on microstructure of joint in laser beam welding for SiC_p/6063 composite
1 INTRODUCTIONSiC particlesreinforcedcomposites ,thankstotheirlowcostsandhighlevelofstructuralproperties ,areshowingtheirpotentialincivilandmilitaryappli cation .SiC particlesreinforcedaluminummatrixcomposites wideapplicationinaerospaceandautomo tiveareattributedtotheirperformanceofhighspecif icstrength ,highspecificstiffness ,highelasticmodu lusandexcellentwearresistance .Thecoefficientofthermalexpansionandthermalconductivitycanberegulatedbychangingthecontentandsizeofrein forcingparticl… 相似文献
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传统的基于微机的车牌识别系统的方案,使得评价识别效果的识别速率和识别成功率两个重要指标相互冲突.为了解决这个问题,很多文章提出了改进算法来调和识别算法的计算量和识别的成功率,但却没有考虑识别系统的成本问题.提出了一个基于DSP CPLD的硬件识别平台,可以大大提高各种识别算法的适应性和降低系统成本. 相似文献
95.
Myeongjoo Son Seyeon Oh Junwon Choi Ji Tae Jang Kuk Hui Son Kyunghee Byun 《International journal of molecular sciences》2021,22(8)
Hypertension induces renal fibrosis or tubular interstitial fibrosis, which eventually results in end-stage renal disease. Epithelial-to-mesenchymal transition (EMT) is one of the underlying mechanisms of renal fibrosis. Though previous studies showed that Ecklonia cava extracts (ECE) and dieckol (DK) had inhibitory action on angiotensin (Ang) I-converting enzyme, which converts Ang I to Ang II. It is known that Ang II is involved in renal fibrosis; however, it was not evaluated whether ECE or DK attenuated hypertensive nephropathy by decreasing EMT. In this study, the effect of ECE and DK on decreasing Ang II and its down signal pathway of angiotensin type 1 receptor (AT1R)/TGFβ/SMAD, which is related with the EMT and restoring renal function in spontaneously hypertensive rats (SHRs), was investigated. Either ECE or DK significantly decreased the serum level of Ang II in the SHRs. Moreover, the renal expression of AT1R/TGFβ/SMAD was decreased by the administration of either ECE or DK. The mesenchymal cell markers in the kidney of SHRs was significantly decreased by ECE or DK. The fibrotic tissue of the kidney of SHRs was also significantly decreased by ECE or DK. The ratio of urine albumin/creatinine of SHRs was significantly decreased by ECE or DK. Overall, the results of this study indicate that ECE and DK decreased the serum levels of Ang II and expression of AT1R/TGFβ/SMAD, and then decreased the EMT and renal fibrosis in SHRs. Furthermore, the decrease in EMT and renal fibrosis could lead to the restoration of renal function. It seems that ECE or DK could be beneficial for decreasing hypertensive nephropathy by decreasing EMT and renal fibrosis. 相似文献
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The amphiphilic block copolymer poly(methacrylic acid-co-2-nitroimidazole acrylate)-b-poly(2-(N,N-dimethylamino)ethyl methacrylate) (P(MAA-co-NIMA)-b-PDMAEMA) with the hypoxia/temperature/pH triple responsiveness is synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT), hydrolysis, and 3-(3-dimethylaminopropyl)-1-ethylcarbodiimide (EDC) reactions, and successfully self-assembled into micelles. The hypoxia response in vitro is realized, and then the sensitivity of the self-assembled micelles to the hypoxia condition is studied by controlling the grafting amount of aminated 2-nitroimidazole. Because 2-(N,N-dimethylamino) ethyl methacrylate (DMAEMA) is a typical material sensitive to temperature and pH conditions, the self-assembled micelles are also responsive to temperature and different acidic/basic conditions. In addition, the cumulative release rate of doxorubicin (DOX) at 42 °C, pH = 6.0, and hypoxic conditions increases significantly, and verifies the synergistic promotion effect of the above stimulations. This intelligent polymer with triple response mechanism improves the controllability and efficiency of drug release, and is expected to be a drug carrier for cancer treatment. 相似文献
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综合利用不同型号燃气轮机余热的发电系统,根据水泥厂自备电站的不同型号燃气轮机余热情况,拟定余热发电技术方案,分析比较不同方案下余热发电系统的技术指标,从而选择合理的技术方案。 相似文献
100.