搜索到29037篇“ REGULATOR“的相关文章
Low Level of Cystic Fibrosis Transmembrane Conductance Regulator Is Associated with Human Sperm Autophagy and Vitality
2024年
Low sperm motility is one of the main causes of male infertility. Cystic fibrosis transmembrane conductance regulator (CFTR, an anion channel protein) is related to the progressive motility of sperm. CFTR disruptor CFTRinh-172 or forskolin (FSK) in this study were used to treat human sperm separately, and the rates of sperm autophagy and progressive motility, mitochondrial membrane potential (MMP) and ATP concentration, and the expression levels of related factors were detected to explore their relationship. It was showed that sperms treated with CFTRinh-172 or FSK reduced the levels of cAMP, CFTR and PKA, but increased sperm autophagy rate, expression levels of AMPK and LC3B. However, reactive oxygen species content had no significant difference. It was indicated that low level of CFTR performed with cAMP and its downstream effectors such as PKA and AMPK to regulate mitochondrial structure and function, leading to increased autophagy rate and reduced vitality of sperm.
Jie HuHan LiuChaoyan OuLiangzhao LiuLinfeng MoXuming LiangYonghua He
一种高PSR低静态电流LDO设计
2024年
设计了一种基于0.18μm BCD工艺的高电源抑制(PSR)低静态电流低压差线性稳压器(LDO)。详细分析了多条电源噪声传递路径对系统PSR的影响。为优化系统中低频段PSR,设计了一种双轨供电的三级误差放大器。此外还引入了预稳压单元,降低了电压基准模块对系统低频段PSR的影响。为降低系统的静态电流,设计了一种基于耗尽管的超低静态电流电压基准。仿真结果表明,该LDO在不同输出电压下静态电流仅5μA,并且在250 mA负载电流内PSR<-110 dB@1 kHz, PSR<-55 dB@1 MHz。
王天凯张瑛程双杨华王宁
关键词:低压差线性稳压器电源抑制低静态电流
Pseudomonas aeruginosa regulator PvrA binds simultaneously to multiple pseudo-palindromic sites for efficient transcription activation
2024年
Tetracycline repressor(TetR)family regulators(TFRs)are the largest group of DNA-binding transcription factors and are widely distributed in bacteria and archaea.TFRs play vital roles in controlling the expression of various genes and regulating diverse physiological processes.Recently,a TFR protein Pseudomonas virulence regulator A(PvrA),was identified from Pseudomonas aeruginosa as the transcriptional activator of genes involved in fatty acid utilization and bacterial virulence.Here,we show that PvrA can simultaneously bind to multiple pseudo-palindromic sites and upregulate the expression levels of target genes.Cryo-electron microscopy(cryo-EM)analysis indicates the simultaneous DNA recognition mechanism of PvrA and suggests that the bound DNA fragments consist of a distorted B-DNA double helix.The crystal structure and functional analysis of PvrA reveal a hinge region that secures the correct domain motion for recognition of the promiscuous promoter.Additionally,our results showed that mutations disrupting the regulatory hinge region have differential effects on biofilm formation and pyocyanin biosynthesis,resulting in attenuated bacterial virulence.Collectively,these findings will improve the understanding of the relationship between the structure and function of the TetR family and provide new insights into the mechanism of regulation of P.aeruginosa virulence.
Yibo ZhuBingnan LuoXingyu MouYingjie SongYonghong ZhouYongbo LuoBo SunYoufu LuoHong TangZhaoming SuRui Bao
关键词:VIRULENCE
OH regulator of highly dispersed Ru sites on host Pd nanocrystals for selective ethanol electro-oxidation被引量:1
2024年
The ethanol oxidation reaction(EOR)is crucial in direct alcohol fuel cells and chemical production.However,the electro-oxidation of ethanol molecules to produce acetaldehyde and carbon monoxide can poison the active sites of nanocatalysts,resulting in reduced performance and posing challenges in achieving high activity and selectivity for ethanol oxidation.In this study,we employed a dynamic seed-mediated method to precisely modify highly dispersed Ru sites onto well-defined Pd nanocrystals.The oxyphilic Ru sites serve as"OH valves",regulating water dissociation,while the surrounding Pd atomic arrangements control electronic states for the oxidation dehydrogenation of carbonaceous intermediates.Specifically,Ru0.040@Pd nanocubes(Ru:Pd=0.04 at.%),featuring(100)facets in Ru-Pd4 configurations,demonstrate an outstanding mass activity of 6.53 A·mgPd^(-1) in EOR under alkaline conditions,which is 6.05 times higher than that of the commercial Pd/C catalyst(1.08 A·mgPd-1).Through in-situ experiments and theoretical investigations,we elucidate that the hydrophilic Ru atoms significantly promote the dynamic evolution of H_(2)O dissociation into OHads species,while the electron redistribution from Ru to adjacent Pd concurrently adjusts the selective oxidation of C_(2) intermediates.This host-guest interaction accelerates the subsequent oxidation of carbonaceous intermediates(CH_(3)CO_(ads))to acetate,while preventing the formation of toxic*CHx and*CO species,which constitutes the rate-determining step.
Zhihe XiaoYueguang ChenRenjie WuYuwei HeChunfeng ShiLeyu Wang
Numerical study of steady flow characteristics of a rear variable-area bypass injector with alternating area regulator
2024年
The mixing effectiveness of the airflow between the inner and outer bypass inlets of a Rear Variable-Area Bypass Injector(RVABI)is the key to the afterburner performance of variable cycle engines.This paper describes an optimized RVABI design based on an alternating area regulator to improve the velocity/temperature uniformity of the incoming flow at the afterburner.Compared with a classical RVABI,numerical simulations show that the proposed alternating RVABI performs better in terms of thermal mixing efficiency and total pressure loss in different variable cycle engine modes.Both the increasing air contact area between the inner and outer bypass of alternating structure RVABI,and a larger streamwise vortex in the inner bypass inlet due to the proposed alternating lobe structure in the RVABI contribute to the significantly increase of mixing effectiveness.Besides,the alternating regulator induces strong streamwise vortex,which helps to improve the airflow mixing with its vortex-induced velocity.The interaction between the streamwise vortex and azimuthal vortex further promises the velocity/temperature uniformity after the RVABI.With the increase of alternating lobe’s height ratio,the covering area of the streamwise vortex and the azimuthal vortex is enlarged,which further enhances the thermal mixing efficiency of the RVABI.This design gives an insight into the future design and optimization of RVABI.
Runfu LIUZhenyao LIHuiliu ZHANGQixing WANGYue HUANGYancheng YOU
植物生长调节剂在大豆中的应用
2024年
植物生长调节剂可显著提升大豆产量,对保障国家粮食安全具有重要意义。文章综述大豆中应用的植物生长调节剂类型及常用植物生长调节剂研究现状,展望大豆化控发展前景,旨在为植物生长调节剂在大豆生产中的应用提供理论依据。
冯艳玲赵婧于德彬张鸣浩丛博韬孟凡钢
关键词:植物生长调节剂大豆烯效唑油菜素内脂乙烯利胺鲜酯
基于AMESim的压力调节器结构优化
2024年
针对现有某型涡桨飞机发动机的防冰系统配套压力调节器在真空环境下出口压力衰减及不能反馈开关位置信号的问题,采用真空波纹管结构对压力调节器先导阀进行结构改进,保证先导腔压力的稳定,并利用AMESim软件对压力调节器进行性能仿真,计算蝶板在正常工作压力状态下的最小开启角度,以此对微动开关进行调整,实现全部工作区下位置信号指示。试验结果表明:在真空环境下,真空波纹管结构压力调节器出口压力相对于地面环境波动较小,可满足要求;AMESim软件对蝶板开启角度的计算结果较为可靠,为开关状态信号的设置提供了有力支撑。
侯松峰李志珠贾远成
关键词:防冰系统压力调节器微动开关性能仿真
一种高瞬态响应Regulator电路
一种高瞬态响应Regulator电路,通过设置第一电阻和第一NMOS管组成的瞬态响应加速电路,利用电路内部电压的变化作用于所述第一NMOS管的栅极,当电源电压Vdd快速升高时能够产生第一NMOS管的导通电流以及时补充到R...
李纪桐
新型混合式功率调节器的设计与实现
2024年
目前常用的蓄电池通常存在着输出控制电路结构复杂、元器件较多、成本较高、稳定性较差等诸多问题,制约了蓄电池的应用范围。针对以上问题,提出一种新型混合式功率调节器设计与实现方法。该装置通过调节结构中的可变电阻器R上中间的弹簧铜片与电刷的接触位置来调节微型直流电机的旋转速度,进而控制直流电源的对外输出功率。实验结果表明,微型直流电机的旋转速度越快,直流电源可以对外输出的功率越大,反之,直流电源对外输出功率会越小,且该装置功能可靠、运行稳定。该新型混合式功率调节器还可以作为交流电机启动器和变频器使用。
马帅符元哲
关键词:调速功率调节器电刷
某型航空发动机转速调节器建模仿真与优化
2024年
为解决某型航空发动机大慢车状态下转速下调的故障问题,以其转速调节器为研究对象,根据其机械机构和工作原理在AMESim平台上构建模型。利用试验结果和转速反馈调节特性由仿真验证了模型的准确性;分析了引起该故障的机制,通过仿真确定了影响因素主要为油门杆角度、发动机进口温度、离心飞重结构参数变化、调节器内弹簧刚度系数衰减,并结合实际工况对上述前3种故障进行排除,最终通过为调节器内弹簧添加预紧力补偿、采用新型材料替代等优化方案解决该故障问题。
杨梦柯马静王剑胡永豪
关键词:航空发动机转速调节器

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叶以正
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作品数:39被引量:39H指数:3
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朱广文
作品数:5被引量:31H指数:3
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贾文涛
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研究主题:电源控制器 电源系统 ERROR SWITCHING SERIES