新型套索冠醚-金属离子络合性能的紫外光谱法与质谱法研究

本文合成了3种套索冠醚4、5和6,分别测定了它们与Hg^2^ 、Pb^2^ 、Zn^2^ 、cd^2^ 、Ni^2^ 、Co^2^ 、Cu^2^ 、Ag^ 、Tb^3^ 和Eu^3^ 所形成的络合物的紫外吸收光谱,用电喷雾液相色谱-质谱联用仪分别表征了它们与TB^3^ 形成的络合物,结果显示它们对上述金属离子有很好的络合性。     

铜锌的反相离子对高效液相色谱分离测定

以α ,β ,γ ,δ 四 (5 磺基噻吩 )卟啉为柱前衍生试剂 ,用含 pH 9.0的 10mmol·L- 1的硼酸 氢氧化钠缓冲溶液和 2 .0× 10 - 3mol·L- 1四丁基溴化胺 (TBA .Br)的甲醇 水 (40∶6 0 )溶液作流动相 ,检测波长为 4 2 3nm ,在C18柱上同时分离和测定了铜、锌两种金属络合物 ,检出限 (S/N =3)分别为 0 .2 3和 0 .30ng·ml- 1,方法用于天然水样分析获得满意结果。     

银杏叶黄酮糖苷精制工艺的研究

银杏叶用5倍重的70%乙醇水溶液回流提取4次,每次30min,银杏叶黄酮糖苷的平均浸出率为93.8%,不同型号大孔吸附树脂的精制效果研究表明,在确定的精制条件下制备的银杏叶提取物,其得率为2.50%～2.92%,黄酮糖苷含量25.7%～34.6%．     

电厂汽轮机金属部件在役检查技术

随着无损检测技术的发展,除了常规超声、射线、磁粉、渗透等常规无损检测方法以外,相控阵超声、TOFD、阵列涡流等检测方法也开始应用在电厂汽轮机的检测中,这些新的检测方法和传统的检测方法相比拥有很多明显的优势,随着各电厂对检测要求的越来越高,这些新技术在电厂中的应用也越来越广泛,本文介绍了电厂汽轮机部件常用的检测方法,特别详细介绍了各类新技术在汽轮机检测中的应用.     

用于浆态床FT合成的Fe-Cu-K-Si催化剂的初步考察

使用连续共沉淀反应器制备了浆态床FT合成用的Fe-Cu-K-Si催化剂。考察了钾含量、粘合剂的添加以及催化剂还原方法等对催化剂性能的影响。1L高压搅拌釜的试验结果表明粘合剂添加方法B和低压CO还原条件下的No.9催化剂性能较好。在质量空速为无载体Fe-Cu-K催化剂1.5倍的条件下，No.9催化剂的合成气转化率，C1^ 和C5^ 产物的产率均高于无载体Fe-Cu-K催化剂，甲烷选择性为3．2％。特别在富CO合成气条件下C5^ 的单程产率达到130g/m^3(CO H2)以上。假设对氢为一级反应动力学的条件下，使用表观速率常数对o.9催化剂的反应活性的经时变化作了考察，结果表明表观速率常数较合成气转化率能相对地反映不同反应条件下的催化剂活性。     

Online restricted‐access material combined with high‐performance liquid chromatography and tandem mass spectrometry for the simultaneous determination of vanillin and its vanillic acid metabolite in human plasma

An automated online solid‐phase extraction with restricted‐access material combined with high‐performance liquid chromatography and tandem mass spectrometry was developed and validated for the simultaneous quantification of vanillin and its vanillic acid metabolite in human plasma. After protein precipitation by methanol, which contained the internal standards, the supernatant of plasma samples was injected to the system, the endogenous large molecules were flushed out, and target analytes were trapped and enriched on the adsorbent, resulting in a minimization of sample complexity and ion suppression effects. Calibration curves were linear over the concentrations of 5–1000 ng/mL for vanillin and 10–5000 ng/mL for vanillic acid with a coefficient of determination >0.999 for the determined compounds. The lower limits of quantification of vanillin and vanillic acid were 5.0 and 10.0 ng/mL, respectively. The intra‐ and inter‐run precisions expressed as the relative standard deviation were 2.6–8.6 and 3.2–10.2%, respectively, and the accuracies expressed as the relative error were in the range of –6.1 to 7.3%. Extraction recoveries of analytes were between 89.5 and 97.4%. There was no notable matrix effect for any analyte concentration. The developed method was proved to be sensitive, repeatable, and accurate for the quantification of vanillin and its vanillic acid metabolite in human plasma.     

Strengthening the Interface between Flower‐Like VS4 and Porous Carbon for Improving Its Lithium Storage Performance

Carbon materials are frequently used to improve the cycle and rate performance of VS₄ as anode material for lithium ion batteries. However, the interfacial interaction between VS₄ and carbon has not been elucidated clearly. Various VS₄@C composites are prepared and the interface between VS₄ and porous carbon is investigated by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and first‐principles calculations. The interfacial structure between VS₄ and carbon and the mechanism of flower‐like VS₄ growth on carbon substrate are revealed clearly. The results indicate that C?V bonds and C?O?V bonds are formed when oxygen functional groups are introduced into the porous carbon, and the C?V bonds and C?O?V bonds accelerate the electron transport and enhance structural stability of the VS₄@C composite. Deriving from the unique structure and robust interfacial interaction, the electrochemical performances of VS₄@C composite are much better than that of pure VS₄. Moreover, through the study of lithium storage mechanism of VS₄ anode, it is found that there is an irreversible amorphization change of the original VS₄ in the first cycle, and that during the following electrochemical process, the main storage behavior of lithium ions derives from the insertion?extraction reactions in the amorphous VS₄ with the reaction between V⁴⁺ and V³⁺.     

基于深度学习的电力服务调度工单智能处理的研究

为打造以客户为中心的现代供电服务体系,进一步提升为民服务的质量和水平,强化电力保障和优质服务,贵安供电局开展海量工单分析,从而实现服务调度业务薄弱点的发现和改进。因此,提出基于深度学习的工单识别分类技术应用,通过深度学习进行建模、工单的标签特征进行提炼、并建立训练模型进行学习、对故障单和意见单进行识别,优化投诉风险预警与管理工作,缓解服务调度工作人员服务压力。     

无功补偿技术在电气自动化中的应用探讨

电气自动化是我国工业中应用较为广泛的一种生产技术,随着相关技术的更新,逐渐为工业产业的发展注入了全新的活力。电气自动化的应用包括很多具体组成,因为电气自动化本身就是计算机技术和电气技术等多种技术的有机结合,能够代替不同技术的优势,达到工业生产的理想效果。     

不同Mn源对Li1+xMn2-xO4尖晶石正极材料的电化学性能的影响

以Li2CO3为Mn源,采用醇水混合溶剂分散与中温固相反应法考察了Mn(NO3)2@6H2O,Mn(MeCO2)2@4H2O,MnCO3,化学MnO2(CMD)和电解MnO2(EMD)等不同Mn前驱物对制备Li1+xMn2-xO4尖晶石正极材料的电化学性能的影响,并采用XRD,BET,TEM等手段对材料进行了表征.结果表明,由不同Mn前驱物制备的正极材料均呈尖晶石结构,其容量大小和循环性能(依Mn源为顺序)为EMD＞Mn(NO3)2@6H2O＞MnCO3＞Mn(MeCO)2@4H2O＞CMD.材料呈立方晶体,比表面积(依Mn源为顺序)为CMD＞MnCO3＞Mn(NO3)2@6H2OMn(MeCO2)2@4H2O＞EMD,正好与容量及稳定性顺序相反.采用本文的制备方法时,EMD和Mn(NO3)2@6H2O都是较好的Mn前驱物,Mn(MeCO2)2@4H2O和MnCO3也可以做Mn源,但焙烧时需要富氧气氛,CMD不适宜作Mn前驱物.