偏二甲肼自氧化产物的气质联用分析

本文应用GC/MS系统对黄色偏二甲肼进行了分析,实验合成了亚硝基二甲胺、四甲基四氮烯,从而确定了偏二甲肼发黄变质的主要产物,并推测偏二甲肼的自氧化机理。     

SPME-GC/MS方法分析水样中偏二甲肼降解产物

本文使用SPME-GC/MS技术分析不同时间水中偏二甲肼降解产物浓度变化规律,并得到SPME对偏二甲肼降解产物的最佳萃取条件。该方法快速、便捷,具有时间短、灵敏度高、操作简便等优点。     

高效液相色谱法测定偏二甲肼废水中的亚硝基二甲胺

采用反相高效液相色谱法定量分析偏二甲肼废水中亚硝基二甲胺。色谱条件选择:以甲醇:水=15:85(V/V)为流动相,柱温30℃,检测波长为230nm,流动相流量为1.0mL/min,加标回收率为86.2%～113.4%,15次测定结果 RSD为2.96%。结果表明该方法线性关系和准确度良好,可用于快速测定偏二甲肼废水中的亚硝基二甲胺。     

航天发射场科研试验场所环境污染物检测分析

为了评价航天发射场科研试验场所的环境质量,确保作业人员的健康和航天科研试验任务的顺利进行,建立了航天发射场科研试验场所总烃和非甲烷烃的气相色谱分析方法,并对航天发射场内多个科研试验场所的环境污染物进行了检测分析,包括甲醛、二氧化碳、苯、甲苯、二甲苯、总挥发性有机化合物、氡、偏二甲肼、二氧化氮、总烃和非甲烷烃等,明确了主要的污染源是甲醛和总挥发性有机化合物,并针对污染状况提出了相应的建议。     

偏二甲肼动态配气系统稳定性研究

采用分光光度法研究了偏二甲肼动态配气系统的稳定性。实验结果表明,在环境温度、载气温度和流量恒定的情况下,该动态系统可稳定地输出0～100mg/m~3的偏二甲肼标准气体,可用于肼类推进剂监测仪器的标定与校验;该配气系统还可用于制备用静态法难以配制其它极性化合物标准气体。     

陀螺电动机轴承化学表面处理工艺的试验研究

针对TAP化学表面处理工艺中的3个关键工艺参数,即试剂浓度、处理温度和处理时间进行了16组正交试验,通过对试验数据的统计分析,找出了3个因素对反应膜的影响程度,同时分析了单因素和双因素交互作用对膜厚的影响,为确定最佳的TAP化学表面处理工艺提供了数据支持。     

偏二甲肼中颗粒物的分析表征

采用热重与差热分析、裂解质谱分析、元素分析、X射线衍射分析等多种分析手段 ,对偏二甲肼中的颗粒物和絮状物的成分与结构进行分析表征 ,并对颗粒物和絮状物的来源进行分析     

肼类火箭推进剂分析检测技术研究进展

本文主要对近十多年来作为火箭推进剂的肼、甲基肼、偏二甲肼以及它们混合物的质量分析技术和在不同环境介质中的检测技术研究进展进行了综述,并对部分分析检测技术的应用前景进行了展望。     

超声处理乳化液在金属切削中的应用

为了减少机械加工中乳化液的使用量,达到节能减排的目的,对乳化液进行了超声波处理,并用它做切削液进行了正交切削试验,研究了乳化液流量、处理时间、水质、乳化液浓度等参数对主切削力的影响,给出了正交试验优化后的各因素取值为:流量2.0L/min,处理时间1.5h/L,水质用自来水,浓度10%.     

屏蔽电机主泵(冷却剂循环泵)试验回路的技术消化吸收

本文介绍屏蔽电机主泵(冷却剂循环泵)试验回路在技术引进历程中对技术的消化处理和吸收,分析了试验回路的主要结构特点、试验回路设计中的考虑因素、试验项目等。     

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.     

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....     

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.     

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.