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201.
针对钝头机体用嵌入式大气数据传感(flush air data sensing,FADS)系统的4类攻角求解算法及算法的求解精度进行研究.针对典型的15°钝头体外形,在Mach数Ma=2.04,3.02,5.01,攻角α=-5°~30°,侧滑角β=0°的条件下,首先基于势流理论及修正的Newton流理论建立了钝头机体用... 相似文献
202.
珠光体材料由许多随机取向的珠光体团组成,每一珠光体团又由铁素体片和渗碳体片交替
叠合而成. 实验表明具有较小片层间距的珠光体材料具有较高的强度和寿命. 通过分析构成
珠光体团的各相及界面的损伤特征,利用损伤耗散功的概念,得到了铁素体、渗碳体与界面
损伤的具有统一形式的演化规律,将其嵌入基于细片层微结构和非经典塑性理论的珠光体团
的弹塑性本构方程,利用Hill自洽方法,得到了珠光体材料的损伤本构描述. 所得到的损
伤本构描述显含表征微结构特征的片层间距,容易证明具有较小片层间距的珠光体材料具有
较好的综合力学性能. 对珠光体材料的拉伸和循环拉压特性进行了分析,得到了与实验一
致的结果. 相似文献
203.
Baiji Xue Yanhua Yu Guoqiang Peng Mengmeng Sun Peng Lv Xuefeng Li 《Molecules (Basel, Switzerland)》2022,27(10)
Amphotericin B (AMB) is an antifungal drug used for serious fungal infections. However, AMB has adverse reactions such as nephrotoxicity, which limit the clinical application of AMB alone or in combination with other antifungal drugs. Nano or micro drug delivery systems (DDS) have been proven to be effective in reducing the toxic and side effects of drugs. Further, the combination of AMB with other compounds with antifungal activity, such as curcumin (CM), may enhance the synergistic effects. Herein, AMB and CM were co-loaded into porous poly (lactic-co-glycolic acid) (PLGA) microparticles (MPs) to prepare AMB/CM-PLGA MPs. The AMB/CM-PLGA MPs showed a remarkably reduced hemolysis (62.2 ± 0.6%) compared to AMB (80.9 ± 1.1%). The nephrotoxicity of AMB/CM-PLGA MPs is significantly lower than that of AMB. In vitro, AMB/CM-PLGA MPs had better inhibitory effects on the adhesion and biofilm formation of Candida albicans compared with AMB. Experiments on mice infected with C. albicans showed that AMB/CM-PLGA MPs have a better therapeutic effect than AMB in vivo. In summary, AMB/CM-PLGA MPs may be a novel and promising therapeutic candidate for fungal infection. 相似文献
204.
Chun-Yan Zhang Li-Jing Peng Guo-Ying Chen Hao Zhang Feng-Qing Yang 《Molecules (Basel, Switzerland)》2022,27(13)
The peroxidase-like activity of vitamin B6 (VB6) was firstly demonstrated by catalyzing the peroxidase chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) at the existence of H2O2. The influence of different factors on the catalytic property of VB6, including pH, temperature, VB6 concentration, and incubation time, were investigated. The steady-state kinetic study results indicate that VB6 possesses higher affinity to H2O2 than natural horseradish peroxidase and some other peroxidase mimics. Besides, the radical quenching experiment results confirm that hydroxyl radical (•OH) accounts for the catalytic process. Based on the excellent peroxidase-like catalytic activity of VB6, the colorimetric methods for H2O2 and gallic acid (GA) detection were developed by measuring the absorbance variance of the catalytic system. Under the optimal conditions, the linear ranges of the methods for H2O2 and GA determination with good selectivity are 50.0–600.0 μM and 10.0–50.0 μM, respectively. In addition, the developed method was applied in the detection of H2O2 in milk samples and evaluation of total antioxidant capacity of different tea infusions. This study may broaden the application prospect of VB6 in environmental and biomedical analysis fields, contribute to profound insight of the physiological functions of VB6, as well as lay foundation for further excavation of small-molecule peroxidase mimics. 相似文献
205.
206.
分别选取菠菜、洋白菜、苹果、大米和大豆5种基质,利用微型固相萃取柱对样品进行前处理,采用胃袋式大体积进样技术结合气相色谱-质谱(GC-MS),建立了同时测定日本通关检测项目要求的205种农药残留的快速分析方法.通过增加进样量提高检测灵敏度,通过减少样品处理量缩短前处理时间,以保留时间和特征离子丰度比进行定性,以特征离子强度进行定量.该方法与日本通知法进行了比对,结果表明两种方法净化效果、检出限、回收率和RSD等指标水平相当,平均回收率在80%~120%之间,RSD(n=7)小于10%,满足残留分析方法的要求. 相似文献
207.
Bingchao Qi Liqiang Song Lang Hu Dong Guo Gaotong Ren Tingwei Peng Mingchuan Liu Yexian Fang Chunyu Li Mingming Zhang Yan Li 《Experimental & molecular medicine》2022,54(7):946
Myocardial infarction (MI) is the leading cause of premature death among adults. Cardiomyocyte death and dysfunction of the remaining viable cardiomyocytes are the main pathological factors of heart failure after MI. Mitochondrial complexes are emerging as critical mediators for the regulation of cardiomyocyte function. However, the precise roles of mitochondrial complex subunits in heart failure after MI remain unclear. Here, we show that NADH:ubiquinone oxidoreductase core subunit S1 (Ndufs1) expression is decreased in the hearts of heart failure patients and mice with myocardial infarction. Furthermore, we found that cardiac-specific Ndufs1 overexpression alleviates cardiac dysfunction and myocardial fibrosis in the healing phase of MI. Our results demonstrated that Ndufs1 overexpression alleviates MI/hypoxia-induced ROS production and ROS-related apoptosis. Moreover, upregulation of Ndufs1 expression improved the reduced activity of complex I and impaired mitochondrial respiratory function caused by MI/hypoxia. Given that mitochondrial function and cardiomyocyte apoptosis are closely related to heart failure after MI, the results of this study suggest that targeting Ndufs1 may be a potential therapeutic strategy to improve cardiac function in patients with heart failure.Subject terms: Heart failure, Myocardial infarction, Myocardial infarction 相似文献
208.
Lei Wang Qin Zhou Zilong Zhang Wenbo Li Xiaobing Wang Qi ng Tian Xiaoyan Yu Ting Sun Jihuai Wu Bao Zhang Peng Gao 《Journal of Energy Chemistry》2022,(1):179-189
While serious stability issues impede the commercialization of perovskite solar cells(PSCs),twodimensional(2 D) perovskites based on fluorinated bulky cations have emerged as more intrinsically stable materials.However,the influence of fluorination degree of the bulky aromatic cation on the performance of resulting PSCs has not been scrutinized.Here,2 D perovskites(FxPEA)2 PbI4(x=1,2,3,5) are grown in situ on the surface of the three-dimensional(3 D) perovskite and demonstrate effecti... 相似文献
209.
Ruiyang Li Haiming Hua Yuejing Zeng Jin Yang Zhiqiang Chen Peng Zhang Jinbao Zhao 《Journal of Energy Chemistry》2022,(1):395-403
Poly(ethylene oxide)(PEO) is a classic matrix model for solid polymer electrolyte which can not only dissociate lithium-ions(Li+),but also can conduct Li+through segmental motion in long-range.However,the crystal aggregation state of PEO restricts the conduction of Li+ especially at room temperature.In this work,an amorphous polymer electrolyte with ethylene oxide(EO) and propylene oxide(PO) block structure(B-PEG@DMC) synthesized by the transesterification is firstly obtained,showing ... 相似文献
210.
Noether-Mei Symmetry of Mechanical System in Phase Space 总被引:1,自引:0,他引:1
In this paper, a new kind of symmetry and its conserved
quantities of a mechanical system in phase space are studied.
The definition of this new symmetry, i.e., a Noether-Mei symmetry,
is presented, and the criterion of this symmetry is also given.
The Noether conserved quantity and the Mei conserved quantity
deduced from the Noether-Mei symmetry of the system are obtained.
Finally, two examples are given to illustrate the application of the results. 相似文献