盐酸萃取火焰原子吸收法测定柴油中钠含量

本文所述方法是用ＨＣｌ（１＋９作为萃取剂萃取柴油中的Ｎａ,然后用火焰原子吸收光谱法测定Ｎａ含量。本法具有简便,快速、准确等特点。相对标准偏差６．２％,回收率为２１０１％－１０５％。     

半整数四极体系中心跃迁的多次激发NMR谱

本文对半整数四极体系中心跃迁的多次激发NMR进行了研究,结果表明该方法能够较大地提高接收信号的强度.另外对多次激发脉冲序列的激发带宽问题作了讨论,在实验上用40% NaCl+60% NaNO₂粉末混合物对以上结论作了验证.     

快扫相关核磁共振波谱学

本文阐述了快扫相关核磁共振的理论、实验条件,提出一种用参考信号作处理的快扫相关方法,可得到不失真的慢通过谱,且不需相位校正。还用计算机与CW谱仪配接成实验系统,实现了快扫核磁共振谱的测量。文中对该技术作了详细讨论,指出了它的特点及其重要应用。     

EXAFS STUDY OF THE LOCAL STRUCTURE NANOCRYSTALLINE FeZrB(Cu) SOFT MAGNETIC ALLOYS

The changes of local structures around Fe and Zr atoms in the nanocrystalline films of Fe₈₅Zr₉B₆ and Fe₈₄Zr₉B₆ Cu₁ alloys during annealing process were investigated by extended X-ray absorption fine structure (EXAFS) technique. It is confirmed that Zr atoms always exist in amorphous phase and do not dissolve in the bcc α-Fe crystalline phase. The addition of 1 at% Cu lowers the crystallization temperature.     

SOLID-STATE VARIABLE-TEMPERATURE NMR STUDY ON THE PHASE SEPARATION OF POLYETHER POLYURETHANE ZWITTERIONOMERS

Polyether-polyurethane zwitterionomers based on 4, 4'-diphenylmethane diisocyanate(MDI), methyl diethanolamine (MDEA), and polytetramethylene oxide glycol (PTMO) werestudied with variable-temperature wide-line ~1H NMR. It is found that upon ionization, degree ofphase separation in the polymer system decreased at first due to the loss of hard segmentregularity, while further ionization increased the degree of phase separation through increasinghard phase cohesion and difference of polarity between hard and soft segments.     

直接进样X射线荧光光谱法测定汽油中痕量锰和铁

将样品直接注入液体杯,用X射线荧光光谱法测定汽油中痕量锰和铁含量,锰、铁的检出限为0.2mg·L-1。采用康普顿散射线作内标,部分地校正了样品间的基体差异。     

数学模型的建立及其应用于聚丙烯树脂的近红外漫反射光谱分析

采用偏最小二乘(PLS)回归法,分别建立了近红外漫反射光谱法测定聚丙烯的正己烷提取物及熔体流动速率的数学模型,并选择了最佳光谱预处理方法、谱区范围及主因子数。正己烷提取物及熔体流动速率数学模型的决定系数(R2)分别为98.03%及96.65%、交叉验证均方差分别为0.0495及0.94。结果表明,预测值与标准法测定值较为接近,方法适用于大批量聚丙烯品质分析。     

A SOLID NMR STUDY OF POLYETHERESTER-UREAS

The morphology of some polyetherester-ureas were studied by ~(13)C CP/MAS and ~1H wide-line NMR spectroscopy. It was found that the HDI and MDI based polymers have well crystallized hard segments, whereas the TDI and HMDI based ones have not. For HDI/MDI based polymers, the presented results suggest that the distribution of two kinds of hard segment units is mainly in a block form. The influences of the different hard segment and chain length on the mobility of the soft segment were also studied.     

爆炸胀接铝/钢复合管的研究北大核心CSCD

为了得到一种兼具优良力学性能和优异防腐特性的复合管,结合一种高爆速爆炸纤维,利用水作为传压介质,爆炸胀接得到铝/钢复合管。经超声波探伤检测其贴合率达到100%,径向形变率仅为0.65%,弯曲度为0.12%。利用809MTS万能实验机对长径比为1∶1的复合管试样进行了压剪试验,得到了位移-力曲线,计算得到结合强度为3.27MPa,高于建筑和石化行业规定的0.2和0.5MPa最小值。金相实验显示,铝/钢结合界面良好,未出现界面局部过熔现象,发生了铝层与钢层的相互扩散现象。     

X射线荧光光谱法直接测定燃料油中铝、硅、硫、钒

提出了应用波长色散X射线荧光光谱法直接测定燃料油中铝、硅、硫及钒含量的方法,用理论α影响系数及内标法校正基体效应,试样预先在60℃及59 kHz超声水浴中搅拌45 min,达到有效地使样品均匀化.测得铝、硅、钒及硫4元素的检出限依次为1.0,0.9,0.7,0.6 mg·kg-1,对两个已知样品中4元素分别按所提出的方法测定7次,从而计算得方法的相对标准偏差在0.5%～12.6%范围内.对4个燃料油样品分别用此方法及标准方法作了分析,所测得4元素的含量互相吻合.