水中易释放氰化物能力验证样品的研制及应用

根据国家地表水环境质量监测网监测任务要求和环境监测的实际需要,制备了水中易释放氰化物能力验证样品。通过均匀性、稳定性检验以及量值一致性评价,研制的样品均匀性良好,在3℃~6℃冷藏避光保存条件下1年内稳定,样品配制值与多家实验室协作测定结果一致。探讨了样品在能力验证活动中的应用,共有来自全国11个省的32家实验室参加了水中易释放氰化物的能力验证计划,实验室满意率在80%以上,实验室结果出现有问题或不满意主要是由于样品前处理以及检测过程质量控制不当导致的。经检测及实验室反馈的数据验证,该能力验证样品能够应用于能力验证活动。     

对大连石油七厂的场地地震易损性分析

场地地震易损性分析方法是在分析各种场地因素的基础上,通过建立定量化的表达方式,确立各种因素的易损性指数,以场地易损性指数的大小为依据,可以对同一地震作用下的场地破坏等级进行划分。以大连石油七厂场地为实例,进行针对性的易损性分析,阐明场地地震易损性分析的具体思路。     

概率统计课程教学效果的简易评价方法

应用积点分和值法及因子分析法,对概率统计课程教学效果进行简易评价,得到了课程教学效果的评价参考表．     

EPS轻质保温混凝土的制备及其物性特征研究*

聚苯乙烯颗粒表面具有明显的憎水性,以其为骨料制备轻质混凝土时,现有技术不能彻底解决水灰比小时流动性丧失或水灰比大时骨料上浮,还有可能解决方案不便捷,甚至解决方案成本较高;针对这些不足,试验以聚苯颗粒和普通硅酸盐水泥为基础材料,在机械力化学和粉体材料湿法改性作用下,制备了较为稳定的水泥悬浮液;最后借助搅拌机械力,制备了一种非牛顿流体状轻质混凝土;该流体状混凝土中轻质聚苯颗粒处于悬浮状态,解决了聚苯颗粒上浮等问题,并且适宜的水灰比下具有良好的流动性好,可实现自密实。另外,制备工艺技术路线简单,对搅拌机械和施工人员专业素质要求低,制备过程不受外界环境剧烈变化影响,可以实现大范围泵送,全程可实现机械化施工,降低了劳动强度,提高了施工效率。     

Analysis of multiple mycotoxins in cereals under ambient conditions using direct analysis in real time (DART) ionization coupled to high resolution mass spectrometry

Direct analysis in real time (DART) ionization coupled to an (ultra)high resolution mass spectrometer based on orbitrap technology (orbitrapMS) was used for rapid quantitative analysis of multiple mycotoxins isolated from wheat and maize by modified QuEChERS procedure. After initial evaluation of ionization efficiencies for major groups of mycotoxins achievable with DART technology, sample preparation procedure and instrument parameter settings were optimized to obtain sensitive and accurate determination of most intensively ionizing toxins (deoxynivalenol, nivalenol, zearalenon, actyldeoxynivalenol, deepoxy-deoxynivalenol, fusarenon-X, altenuene, alternariol, alternariolmethylether, diacetoxyscirpenol, sterigmatocystin). The lowest calibration levels (LCLs) estimated for the respective analytes ranged from 50 to 150 μg kg⁻¹. Quantitative analysis was performed either with the use of matrix-matched standards or by employing commercially available ¹³C-labeled internal standards (available for deoxynivalenol, nivalenol and zearalenon). Good recoveries (100-108%) and repeatabilities (RSD 5.4-6.9%) were obtained at spiking level 500 μg kg⁻¹ with isotope dilution technique. Based on matrix-matched calibration, recoveries and repeatabilities were in the range 84-118% and 7.9-12.0% (RSD), respectively. The trueness of data obtained for deoxynivalenol and zearalenon in wheat/maize by DART-orbitrapMS was demonstrated by analysis of certified reference materials (CRMs). Good agreement of these results with data generated by validated ultra-high pressure liquid chromatography-time-of-flight mass spectrometry method was documented.     

张应力对铁磁/反铁磁体系交换偏置的影响

 采用能量极小原理及Stoner-Wohlfarth模型,研究了张应力对铁磁/反铁磁双层薄膜交换偏置的影响。在不施加外磁场时,根据体系能量与铁磁层磁化强度方向之间的关系,得到了内禀易轴与内禀难轴的位置。交换各向异性与单轴各向异性之间的竞争使体系存在单稳态与双稳态两种不同的状态,直接决定了交换偏置的角度依赖关系。分析磁化过程发现,外磁场在沿内禀易轴及内禀难轴方向施加时,磁滞回线的一支转换场发生突变,另一支转换场保持不变,最终导致交换偏置场和矫顽场出现阶跃行为。在阶跃点处,体系具有较大的交换偏置场和矫顽场。数值计算表明：张应力的大小与方向对交换偏置均有很大的影响,均可以使体系在单稳态与双稳态之间相互转变并导致角度依赖关系发生显著变化。研究表明,应力可作为一种可行的方法来控制和调节铁磁/反铁磁体系的交换偏置。     

Enantioselective determination of triazole fungicide simeconazole in vegetables, fruits, and cereals using modified QuEChERS (quick, easy, cheap, effective, rugged and safe) coupled to gas chromatography/tandem mass spectrometry

A rapid and effective method for enantioselective determination of simeconazole enantiomers in food products (cucumber, tomato, apple, pear, wheat and rice) has been developed. The enantiomers were resolved by capillary gas chromatography (GC) using a commercial chiral column (BGB-172) and a temperature program from 150 °C (held for 1 min) and then raised at 10 °C min⁻¹ to 240 °C (held for 10 min). This enantioselective gas chromatographic separation was combined with a clean-up/enrichment procedure based on the modification of QuEChERS (quick, easy, cheap, effective, rugged and safe) method. Co-extractives were removed with graphitized carbon black/primary secondary amine (GCB/PSA) solid-phase extraction (SPE) cartridges using acetonitrile:toluene (3:1, v/v) as eluent. Gas chromatography/ion trap mass spectrometry (GC–ITMS) with electron ionization (EI) was then used for qualitative and quantitative determination of the simeconazole enantiomers. Two precursor-to-product ion transitions (m/z 121–101 and 195–153) with the best signal intensity were chosen to build the multiple-reaction monitoring (MRM) acquisition method. The limits of detection for each enantiomer of simeconazole in six food products ranged between 0.4 and 0.9 μg kg⁻¹, which were much lower than maximum residue levels (MRLs) established by Japan. The methodology was successfully applied for the enantioselective analysis of simeconazole enantiomers in real samples, indicating its efficacy in investigating the environmental stereochemistry of simeconazole in food matrix.     

调整双棱镜同轴等高的简易方法

本文介绍一个调整双棱镜同轴等高的简易方法．该法采用先调节狭缝和目镜至基本等高，可使各光学部件快速调至同轴等高．通过随意移动棱镜和目镜在轨道上的位置，以便在实验中观察到清晰的干涉条纹；采用位移法测试，可从实验方法中加深理解光线直线传播和干涉现象的意义     

基于等离子体处理的羊毛织物易护理整理

基于等离子体处理的羊毛织物防缩抗皱整理.探求一种新的生产方法,即毛织物经等离子体处理后,其防缩性、抗皱性、防污性都有所提高,再经过整理剂整理,对毛织物损伤小,整理效果明显改善.     

易挥发溶剂中高聚物分子量的测定

提出一种测定仅溶于易挥发溶剂中的高聚物分子量的方法和粘度计，测定了聚苯乙烯、聚甲基丙烯酸甲酯、氯丁橡胶等高聚物的粘均分子量．