A rapid method for the determination of dopamine in porcine muscle by pre-column derivatization and HPLC with fluorescence detection

A rapid method has been developed based on the sample preparation procedure named as QuEChERS （Quick, Easy, Cheap, Effective, Rugged and Safe）, combined with reversed-phase high performance liquid chromatography with fluorescence detector and C18 column after precolumn derivatization using o-phthalaldehyde and 2-mercaptoethanol to determine dopamine in porcine muscle. Methanol and deionized water （0.1% acetic acid, v/v） with a ratio of 60：40 was used as mobile phase. The flow rate was 0.8 mL/min and dopamine was eluted within 15 min. The linearity range was 0.003-8 μg/mL with r=0.9992. The detection limit for dopamine was 4 μg/kg and the quantification limit was 9 μg/kg. Recovery studies were carried out at 0.1, 0.5 and 1.0 mg/kg fortification levels and the average recoveries obtained ranged from 90.4% to 98.2% with relative standard deviations between 3.5% and 8.1%. The method was found to be suitable for detection of dopamine in animal product tissues at the maximum residue level.     

模具间隙对液态模锻溢料的影响

通过液态模锻成型压力和温度参数对模具间隙影响的研究,以及模具结构分析,找出了由于模具间隙变化造成溢料的原因,提出了解决方案,对液态模锻模具设计具有一定的参考价值。     

节温器布置形式对质子交换膜燃料电池电堆冷却性能的影响

运用一维仿真软件建立质子交换膜燃料电池液冷系统模型,研究了不同节温器布置形式对系统的性能影响。对某额定功率30 kW的燃料电池发动机在4个不同工况点进行液冷系统散热特性仿真:在节温器一进两出的布置形式下仿真结果与试验数据基本一致,电堆出口温度仿真值与实测值相对误差分别为0.5%、1.5%、2.4%、4.9%;节温器两进一出的布置形式下液冷系统中冷却液温度变化平缓而均匀,前10 s和第10~50 s之间的温度变化率之差较一进两出形式低36.85%,更有利于电堆的长期高效运行。     

浅谈我省公路桥涵勘察设计中液塑限试验与应用的两点修改意见

通过对利用液限直接计算塑限值以及粘性土的分类定名增加“轻亚粘土”的论述,建议《公路桥涵地基与基础设计规范》及试验规范进行修改,使之更加完善、精确,便于应用。     

局干北环OTN混缆组网的探讨

通过对济南局集团公司北环OTN系统组网的现状进行分析,具体论证了G.653+G.652混缆组网应用技术,阐述了优化方案的可实施性,进而实现系统组网开通.以期建立满足铁路需求的通信系统网络。     

Liquid sloshing in a swaying/rolling rectangular tank with a flexible porous elastic baffle

The flexible porous elastic baffle was proposed as an anti-slosh device to reduce the liquid sloshing in a swaying/rolling rectangular tank. The analytical model was developed to assess the effectiveness of the porous elastic baffle on liquid sloshing. A one-dimensional beam model, along with Darcy's model, was taken to implement the characteristics of porous elastic baffle. The matched eigenfunction expansion method (MEEM) with the Green function for the liquid sloshing interaction with the porous elastic baffle was employed. Numerical results were presented that illustrate the effects of the baffle's geometry (porosity, height), and structural parameters (flexural rigidity, stiffness of mooring line) on the liquid sloshing. Through parametric studies, the flexural rigidity, porosity, and mooring line's stiffness have to be adjusted properly to enhance the sloshing-reduction effect. The flexible porous elastic baffle showed the potential as a useful anti-slosh device within a limited application range compared with a rigid baffle.     

脉冲反射法液位测量系统研究

介绍了脉冲反射法液位测量系统，简要推导了脉冲反射法的测量原理，给出了系统结构及主要部件功能。该系统应用时域脉冲反射测量技术，适用于船舶及其它容器的动、静脉液位等参数的自动测量。     

基于OTN网络的南京地铁视频监控与调试

主要讨论OTN网络传输视频的原理和OTN视频管理服务器OVS的功能,讨论基于OTN网络视频传输的基础上进行的视频监控(CCTV)系统的实现与调试,分析调试过程中出现的问题。     

填料塔中液体分配对分离的影响

研究了填料塔中液体分配对分离的影响,详细讨论了液体分配不均程度对分离的影响以及液体的初始分布对分离的影响。为了使填料塔能够得到设计的分离效果,液体在填料层中的分布要尽快达到自然流分布,消除液体分配不均对分离的影响。     

加热面粗糙度与材料对低温流体闪蒸现象的影响

针对贮藏容器及输送管道的安全问题，以液化氮为工质，模仿在实际中可能遇到的容器及管理裂缝而引起的容器内压力变化，利用不同材质、不同粗糙度试验棒作为加热面进行实验，对减压后的压力变动情况及沸腾样态作了一定的研究。