AQF-离子色谱联用技术检测1,4-丁炔二醇中全氯

介绍了一种全新的“油相”样品前处理仪器--自动快速燃烧炉（AQF）与离子色谱联用技术,测定1,4-丁炔二醇中全氯的方法.选择色谱条件为：AS14A离子色谱分离柱,碳酸钠/碳酸氢钠缓冲溶液等度淋洗,抑制型电导检测.样品经过AQF装置分段燃烧约10分钟后,在线进入离子色谱系统进行分析.该方法的检测限（S/N=3）为60 μ g/L,线性相关系数r=0.9997,RSD为2.9%,回收率为100-104%,具有灵敏度高,选择性好,操作简单,节省时间,对环境友好等特点,用于实际样品的检测,所得结果令人满意.     

微波辅助提取-固相萃取净化-气相色谱三重四极杆质谱联用测定水产品中17种多氯联苯（PCBs）

为了给食品中持久性有机污染物残留的定性与定量检测提供技术支持,建立了一种微波辅助提取-固相萃取净化-气相色谱三重四极杆质谱联用测定水产品中17种多氯联苯（PCBs）的检测方法。样品用V（正己烷）∶V（丙酮）=1∶1的混合溶剂于微波提取,经佛罗里硅土固相萃取柱净化,以氦气为载气,HP5-MS色谱柱分离,MS/MS多反应监测扫描模式（MRM）检测。方法线性相关系数r＞0.999,仪器定量限为1.0~3.0 μg/kg。在5.0、10.0、20.0 μg/kg 3种浓度添加水平,其平均回收率为83.1%~100.8%,相对标准偏差(RSD)为4.36%~9.38%。该方法已成功应用于复杂基质样品中17种PCBs的检测。     

分散固相萃取-高效液相色谱-质谱联用法测定大米中的呋喃丹残留

建立了分散固相萃取-液相色谱-电喷雾质谱联用方法定量检测大米中呋喃丹残留量.应用分散固相萃取方法进行前处理,即以乙二胺-N-丙基硅烷(PSA)为吸附剂,乙腈为萃取溶剂,实现样品快速制备;在Agilent Eclipse C18色谱柱上,以甲醇-0.1%乙酸水溶液(50/50,V/V)为流动相,采用选择离子监测模式,以m/z222为检测定量离子.呋喃丹保留时间在6.7min左右,线性范围为0.003mg/L～1mg/L,相关系数0.9998,添加浓度在0.012,0.12,1.2mg/kg时,大米中呋喃丹的平均添加回收率在85%～96%之间,相对标准偏差(RSD,n=5)小于15%,最低检测浓度为0.012mg/kg.该方法灵敏、准确、可靠,定量范围宽,耐用性强,可作为大米中呋喃丹残留的可靠检测方法.     

HPLC法同时测定阿司匹林咀嚼片中阿司匹林和水杨酸的含量

目的用高效液相色谱法同时测定阿司匹林咀嚼片中阿司匹林和水杨酸的含量.方法采用VP-ODS色谱柱;以甲醇-醋酸-水(45∶1∶54)为流动相;流速1ml/min,检测波长为275nm.结果阿司匹林线性范围0.54～10.85μg(γ=0.99996),平均回收率为98.3%,RSD为0.76%(n=5);水杨酸线性范围2.65～31.77μg/ml(γ=1.00000),平均回收率为100.2%,RSD为0.53%(n=5).结论此方法简便、快速、准确,值得推广应用.     

HPLC法同时测定保健食品中五种违禁性功能药物

建立了高效液相色谱法同时测定保健食品中5种违禁性功能药物成分的方法。采Agilent C18（4.6×250mm）色谱柱分离,以乙腈-0.02%磷酸水溶液为流动相,梯度洗脱,流速为1.0mL/min,用紫外二极管阵列检测器检测,柱温30℃。5种违禁性功能药物成分在0.4-80μg/mL浓度范围内工作曲线线性关系良好,相关系数r为0.9996-0.9999,回收率为88.5%-96.5%,相对标准偏差为1.47%-2.46%（n=6）。该方法样品处理简便,结果准确可靠,重复性好,灵敏度高。     

GC/MS研究茶叶中拟除虫菊酯类农药残留的提取方法

针对茶叶中拟除虫菊酯类农药残留的提取方法进行研究,比较了加水浸泡对农残提取的影响。结果表明,加水浸泡的样品农残提取率反而降低,通过对样品净化淋洗剂种类和体积的优化选择,总结出一套简便实用的前处理方法。茶叶不用水浸泡,直接用50 mL V（丙酮）∶V（正己烷） =1∶1的溶液超声提取,提取液过活性炭柱,浓缩后再过Florisil柱,用15 mL V（正己烷）∶V（乙酸乙酯）=2∶1的溶液淋洗,浓缩后用GC/MS法测定。回收率为81%~120%,RSD为2.2%~7.8%,检测限为0.002~0.01 mg•kg^-1。     

茶叶中多种农药残留测定方法研究

采用气相色谱-串联质谱法同时测定了茶叶中多种农药残留。样品加水后用乙腈提取,采用GCB/PSA固相萃取柱净化,淋出液浓缩至近干后用正己烷-丙酮（9：1,V/V）溶液定容,气相色谱-串联质谱测定。结果表明目标农药添加于样品中质量浓度在0.050～0.500mg/kg（r〉0.9700）范围内与峰面积呈线性关系,检出限（3S/N）位在0.1～37.5ng/g之间。加入0.100和0.400mg/kg两个浓度水平的农药标准溶液,目标农药的回收率在66.5%～114.7%之间,相对标准偏差（n=5）均小于20%。     

快速溶剂萃取-固相萃取-液相色谱-串联质谱法同时检测小型家用电器中溴代阻燃剂

建立了快速溶剂萃取-固相萃取-超快速液相色谱-串联质谱(ASE-SPE-RRLC-MS/MS)测定小型家用电器中溴代阻燃剂残留(六溴环十二烷(HBCDs)、四溴双酚A(TBBP-A))的方法。试样经冷冻粉碎后,以V（丙酮）∶V（正己烷）=1∶1的溶液为萃取液,采用快速溶剂萃取法,萃取液经C₁₈固相萃取柱富集净化,以水 甲醇为流动相,经C₁₈柱分离后,以快速液相色谱 串联质谱法多反应监测扫描模式进行定性和定量分析。方法的线性相关系数r大于0.998,检出限为0.05～0.2 mg/kg,在0.05～800 mg/kg等浓度添加水平下,平均回收率为87.72%～95.71%;相对标准偏差（RSD）为4.42%～8.38%。该方法灵敏度高、重现性好、定性定量准确,适用小型家用电器的复杂基质样品检测,可为相关国家标准制定提供参考依据。     

反向离子对色谱法同时测定多维矿物质软胶囊中维生素B_1、B_6、烟酸、烟酰胺和咖啡因

优化了保健食品中维生素B1、B6、烟酸、烟酰胺和咖啡因同时测定的反向离子对色谱法。样品经简单提取后,以乙腈-1-辛烷磺酸钠-磷酸水溶液作流动相,进行梯度洗脱,二极管阵列检测器（DAD）双波长（260nm、290nm）检测。5种物质在较宽浓度范围内线性关系良好,检出限（S/N=3）分别在0.01～0.08mg.L-1之间,平均加标回收率为90.8%～99.0%,相对标准偏差（RSD）为1.06%～4.98%。该方法适用于保健食品中维生素B1、B6、烟酸、烟酰胺和咖啡因的同时测定。     

高效液相色谱-二极管阵列检测器测定饮料中甜蜜素添加量

目的:建立并验证了用高效液相色谱配二极管阵列检测器法测定饮料中甜蜜素添加量的方法.方法:样品在酸性条件下用次氯酸钠对甜蜜素进行衍生化处理,处理液经过正己烷萃取,过滤后,以高效液相色谱仪-二极管阵列检测器进行检测,以相对保留时间定性,峰面积定量.结果:该方法回收率为90.46％～100.20％,RSD％为3.48％ ～ 5.76％,最低检出限为0.5mg/kg.结论:实验表明该方法对饮料中甜蜜素添加量的测定操作简单,方便,结果准确.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.