复杂体系中的苯系物的气相色谱分离及测定

本文采用SE - 5 430m× 32 0um柱和PEG - 2 0M 30m× 2 5 0um柱进行复杂体系中苯系物的气相色谱测定 ,方法分离较高 ,可排除其它组份的干扰 ,分析灵敏度满足环境分析要求     

异硫氰酸苯酯柱前衍生法测定安尿通中3种氨基酸含量

本文介绍安尿通中 3种氨基酸的柱前衍生后以RP -HPLC测定的方法。PhenomenexLunaODS(4 .6× 2 5 0mm)色谱柱 ,移动相A∶0 . 1mol·L 1醋酸钠溶液 (pH6 . 5 ) -乙腈(93∶7) ,移动相B :水和乙腈 (2 0∶80 ) ,梯度洗脱检测波长是 2 5 4nm ,柱温 4 0℃ ,氨基酸的重复性是 99. 2 %～ 99 .5 %。     

毛细管气相色谱法分析甲基环己基二甲氧基硅烷

建立了甲基环己基二甲氧基硅烷的毛细管气相色谱分析法。色谱柱为SE - 5 4毛细管柱 (2 5m× 0 .2 5mmid) ,载气为高纯氮 ,检测器为FID。定量采用面积归一化法 ,与内标法进行比较 ,两者结果完全一致。本法准确快捷 ,8次平行测定结果 ,标准偏差为 0 .0 2 8,变异系数为 0 .0 2 9%。     

空气中硫酰氟气体浓度的气相色谱法测定

利用气相色谱－电子捕获检测器,PorapakQ色谱柱,在2min内对空气中痕量熏蒸剂硫酰氟（SO2F2）进行了测定。该方法线性范围为4．0×10－4～400mg／m3,当进样体积为0．2mL时,最低检测限可达2．0×10－6mg／m3。空气中的痕量硫酰氟不需要富集,即可直接测定。     

多元气体混合物的色谱特性及测定研究

本文提出了一种为分析测定氮中 H2 、O2 、CO、CO2 、CH4 、C2 H6、C2 H4 、C2 H2 等物质的气相色谱系统。采用二维柱切割与转化技术相结合 ,以Φ3× 1 2 0 cm1 3x分子筛柱以及 Φ3× 40 0 cm GDX— 50 2柱为主分离柱 ,TCD和 FID串联 ,通过对组份间分离与温度等条件之间的关系考察确定最佳色谱操作参数。设计了自动阀切换以及电信号切换以及电信号切换程序 ,实现一次进样全分析 ,方法具有快速、自动、准确、操作简便等特点     

2-酮基-L-古龙酸的高效液相色谱分析

建立了测定微生物混合菌株发酵液中 2 酮基 L 古龙酸 (2 KLG)浓度的高效液相色谱法。采用AminexA 2 7柱 4 6× 2 50mm ;流动相为 0 1mol/L甲酸铵 (PH3 40 ) ,流速 1 0mL/min ,柱温 45℃ ;用示差折光检测器检测。此方法回收率为 93 61 % ,RSD为 4 7%。同时还研究了pH、流速等因素对检测的影响。     

高效液相色谱法测定蜂胶中的黄酮成分

蜂胶是一种纯天然物质,具有生理和药理活性。本文提出一种分析蜂胶及其制品中总黄酮成分的高效液相色谱法(HPLC)。该法采用甲醇回流提取其有效成分,能同时分离测定9种黄酮成分。回收率96.7％,变质系数4.1％。     

GC—MS法分析比较贵州不同产地蜂胶挥发油化学成分

用水蒸汽蒸馏法对蜂胶挥发油进行提取,用GC毛细管柱进行分离,归一化法测其相对含量,气相色谱-质谱法对不同成分进行鉴定.结果贵州兴仁地区蜂胶含主要成分38个,德江地区含主要成分43个.通过对不同产地蜂胶挥发油成分的研究,为蜂胶的开发利用提供实验依据.     

研制蜂胶冻干粉的最佳工艺研究

本文探讨了以粗蜂胶为原料,研制蜂胶冻干粉的的工艺。结果表明：蜂胶冻干粉的工艺流程为粗蜂胶—→醇溶法提取—→赋形—→冻干—→冻干粉。最佳工艺条件为：（1）醇溶法提取蜂胶的最佳条件：固液比：1：25,乙醇溶液浓度75％,提取温度80℃,提取时间1．5h。（2）赋形剂为22％甘露醇,赋形的最佳条件为：22％甘露醇与4％的蜂胶乙醇溶液按76：24的比例混合。（3）冻干条件：预冻温度-74℃,预冻时间2小时,抽真空时间24小时,升温干燥20℃,升温干燥30分钟,冷阱温度为-52℃。在此条件下生产的蜂胶冻干粉的溶解度为87％,水分含量为0．93,总黄酮含量为0．49％。     

微生物发酵秸秆产氢的气相色谱分析

利用气相色谱法跟踪测定发酵液产氢含量 ,对微生物发酵农作物秸秆产氢菌种进行筛选。实验结果表明 ,C3(产气肠杆菌 ) ,M1(麦芽糖假丝酵母菌 ) ,H4[C3 +M 1+D2 (丁酸梭菌 )混合菌 ]是较好的产氢菌种 ,所产氢气的体积分数分别为C3( 6 0 0 4% ) ,H4( 5 9 4 1% ) ,M 1( 11 2 7% )。色谱柱为TDX 0 1( 2m× 0 .5mmid) ,鉴定器为TCD ,柱温 10 0℃ ,载气Ar 40mL/min。方法操作简单 ,快速方便 ,重现性好 ,灵敏度高。     

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...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

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。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.