为了便捷求出垂荡式波浪能发电装置垂荡浮子的平均功率,对现有的设计计算方法进行了研究。基于波浪理论和Froude-Krylov假定法求解波浪力,应用单自由度有阻尼系统受迫振动理论,将波浪激励力作为对垂荡浮体的输入动力,将发电机的电磁阻...为了便捷求出垂荡式波浪能发电装置垂荡浮子的平均功率,对现有的设计计算方法进行了研究。基于波浪理论和Froude-Krylov假定法求解波浪力,应用单自由度有阻尼系统受迫振动理论,将波浪激励力作为对垂荡浮体的输入动力,将发电机的电磁阻力作为主要的阻尼力,建立了质量-弹簧-阻尼振动力学模型,确定了垂荡浮子响应的计算方法,并对实际波浪能发电装置垂荡浮子Power Take Off(PTO)系统列举出计算实例。在算例基础上,对假设条件进行了扩展,应用频率响应曲线、MATLAB软件做出不同参数条件下平均功率三维曲线和输出平均功率数值表,清晰地表明了系统响应状况。研究显示,在波高和频率比一定的条件下,PTO系统平均机械功率随着浮体质量和阻尼力矩的变化具有峰值,围绕峰值区域设计装置的各项参数,能够取得较理想的效果。该建模与计算方法可为实际工程优化设计提供参考。展开更多
Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors known to play a pivotal role in regulations of metabolism.In order to yield soluble ligand binding domain of PPARδ(PPARδL...Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors known to play a pivotal role in regulations of metabolism.In order to yield soluble ligand binding domain of PPARδ(PPARδLBD) for screening ligands,the cDNA was amplified using total RNA from HepG2 cells by RT-PCR.Then the enzyme-digested product was inserted downstream of the malE gene in the vector pMAL-p2x,which encoded maltose-binding protein(MBP),resulting in the expression of an MBP-PPARδLBD fusion protein.The recombinant plasmid was transformed into E.coli TB1 that was cultured shakily at 30 °C,200 r/min and induced by 0.4 mmol/L IPTG for 6 h.The cells were harvested by centrifugation and broken by sonication.The expressed fusion protein was soluble and accounted for 0.31 of the total protein in the supernatant.Western blot analysis showed that the expressed MBP-PPARδLBD could bind to anti-MBP-antibody.The MBP-PPARδLBD fusion protein of 77 kDa and the PPARδLBD protein of 34 kDa were obtained by amylose-resin affinity chromatography without or with digestion of Factor Xa.They were both homogeneity,judged by SDS-PAGE.The recombinant MBP-PPARδLBD and PPARδLBD protein with high purity is obtained,which provides the necessary material for screening and researching PPARδ ligands.展开更多
X-ray luminescence computed tomography(XLCT) is an emerging hybrid imaging modality that can be used as a new tool in molecular imaging. XLCT has the potential to achieve the high spatial resolution of X-ray imaging a...X-ray luminescence computed tomography(XLCT) is an emerging hybrid imaging modality that can be used as a new tool in molecular imaging. XLCT has the potential to achieve the high spatial resolution of X-ray imaging and the high sensitivity feature of optical imaging in deep tissues. In XLCT,high energy X-ray photons are used to excite X-ray excitable particles emitting optical photons to be measured for reconstruction of the particle distribution inside tissues. Numerical simulations and experimental studies have been performed and proved that XLCT is suitable for in vivo small animal imaging. The aim of this review paper is to introduce the background of XLCT and to detail the concept of XLCT,including a brief review of tw o types of XLCT imaging system designs. The major challenges in the development of XLCT are also described. Finally,the future applications and development directions of XLCT are discussed.展开更多
文摘为了便捷求出垂荡式波浪能发电装置垂荡浮子的平均功率,对现有的设计计算方法进行了研究。基于波浪理论和Froude-Krylov假定法求解波浪力,应用单自由度有阻尼系统受迫振动理论,将波浪激励力作为对垂荡浮体的输入动力,将发电机的电磁阻力作为主要的阻尼力,建立了质量-弹簧-阻尼振动力学模型,确定了垂荡浮子响应的计算方法,并对实际波浪能发电装置垂荡浮子Power Take Off(PTO)系统列举出计算实例。在算例基础上,对假设条件进行了扩展,应用频率响应曲线、MATLAB软件做出不同参数条件下平均功率三维曲线和输出平均功率数值表,清晰地表明了系统响应状况。研究显示,在波高和频率比一定的条件下,PTO系统平均机械功率随着浮体质量和阻尼力矩的变化具有峰值,围绕峰值区域设计装置的各项参数,能够取得较理想的效果。该建模与计算方法可为实际工程优化设计提供参考。
基金Supported by the National Natural Science Foundation of China (30572353)
文摘Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors known to play a pivotal role in regulations of metabolism.In order to yield soluble ligand binding domain of PPARδ(PPARδLBD) for screening ligands,the cDNA was amplified using total RNA from HepG2 cells by RT-PCR.Then the enzyme-digested product was inserted downstream of the malE gene in the vector pMAL-p2x,which encoded maltose-binding protein(MBP),resulting in the expression of an MBP-PPARδLBD fusion protein.The recombinant plasmid was transformed into E.coli TB1 that was cultured shakily at 30 °C,200 r/min and induced by 0.4 mmol/L IPTG for 6 h.The cells were harvested by centrifugation and broken by sonication.The expressed fusion protein was soluble and accounted for 0.31 of the total protein in the supernatant.Western blot analysis showed that the expressed MBP-PPARδLBD could bind to anti-MBP-antibody.The MBP-PPARδLBD fusion protein of 77 kDa and the PPARδLBD protein of 34 kDa were obtained by amylose-resin affinity chromatography without or with digestion of Factor Xa.They were both homogeneity,judged by SDS-PAGE.The recombinant MBP-PPARδLBD and PPARδLBD protein with high purity is obtained,which provides the necessary material for screening and researching PPARδ ligands.
基金partially supported by Grant (R03 EB022305) from the National Institute of Health (NIH)Start-up fund from UC Merced
文摘X-ray luminescence computed tomography(XLCT) is an emerging hybrid imaging modality that can be used as a new tool in molecular imaging. XLCT has the potential to achieve the high spatial resolution of X-ray imaging and the high sensitivity feature of optical imaging in deep tissues. In XLCT,high energy X-ray photons are used to excite X-ray excitable particles emitting optical photons to be measured for reconstruction of the particle distribution inside tissues. Numerical simulations and experimental studies have been performed and proved that XLCT is suitable for in vivo small animal imaging. The aim of this review paper is to introduce the background of XLCT and to detail the concept of XLCT,including a brief review of tw o types of XLCT imaging system designs. The major challenges in the development of XLCT are also described. Finally,the future applications and development directions of XLCT are discussed.
