复合结构弹头对多层靶的侵彻效能研究

为改善斜侵彻多层靶情况下弹丸的弹道稳定性,设计一种多层复合结构弹头.运用ansys/ls-dyna对复合结构弹头斜侵彻多层靶进行数值模拟,分析弹头结构不同材料组合对弹体剩余动能和弹道稳定性的影响.结果表明:在20°着角下,设计的多层结构弹头具有自砺性;2层和3层结构弹头在弹道稳定性和质量损耗上均明显优于制式弹;设计的多层结构弹头最优方案为2层合金钢结构弹头.该研究可为穿甲弹头结构设计以及小口径枪弹与多层靶的斜侵彻弹道分析提供参考.     

Locating active actors in the scientific collaboration communities based on interaction topology analyses

While implementing a large-scale research project, it is necessary to appoint some principle scientists, and let each principle scientist lead a research group. In a scientific collaboration community, different scientists perform different roles while they implement the project, and some scientists may be more active than others; these active scientists often undertake the role of leadership or key coordinator in the project. Obviously, we should assign the role of principle scientists onto those active actors in the communities. In this paper, we present the model and algorithms for locating active actors in the community based on the analyses of scientists’ interaction topology, the actors with high connection degrees in the interaction topology can be considered as active ones. Finally, we make some case studies for our model and algorithms.     

轻钢-混凝土混合结构周期折减系数研究

轻钢-混凝土混合结构是一种既符合中国国情,又适宜工业化和模块化生产的新型结构体系。该体系中的轻钢次结构能增大混凝土主结构的抗侧刚度,采用只考虑主结构的简化模型进行设计分析时,可采用周期折减系数来考虑这种影响。推导了2层或3层轻钢次结构抗侧刚度以及轻钢-混凝土混合结构周期折减系数简化计算公式;在混合框架试验的基础上,用ABAQUS有限元软件建立了轻钢-混凝土混合框架的精细化分析模型和简化分析模型,试验结果和模拟分析结果吻合较好;通过有限元模拟分析,验证了轻钢次结构抗侧刚度和混合结构周期折减系数简化计算公式的正确性。     

Atmospheric pressure covalent adduct chemical ionization tandem mass spectrometry for double bond localization in monoene- and diene-containing triacylglycerols

We report a method to elucidate the structure of triacyl-glycerols (TAGs) containing monoene or diene fatty acyl groups by atmospheric pressure covalent adduct chemical ionization (APCACI) tandem mass spectrometry using acetonitrile as an adduct formation reagent. TAGs were synthesized with the structures ABB and BAB, where A is palmitate (C16:0) and B is an isomeric C18 monoene unsaturated at position 9, 11, or 13 or an isomeric diene unsaturated at positions 9 and 11, 10 and 12, or 9 and 12. In addition to the species at m/z 54 observed in previous CI studies of fatty acid methyl esters, we also found that ions at m/z 42, 81, and 95 undergo covalent reaction with TAGs containing double bonds to yield ions at m/z 40, 54, 81, and 95 units greater than that of the parent TAG: [M + 40]+, [M + 54]+, [M + 81]+, and [M + 95]+ ions. When collisionally dissociated, these ions fragment to produce two or three diagnostic ions that locate the double bonds in the TAG. In addition, ions [RCH=C=O + 40]+ and [RCH=C=O + 54]+ formed from collisional dissociation are of strong abundance in MS/MS spectra, and collisional activation of these ions produces two intense confirmatory diagnostic ions in the MS3 spectra. Fragment ions reflecting neutral loss of an sn-1-acyl group from [M + 40]+ and [M + 54]+ are more abundant than those reflecting neutral loss of an sn-2-acyl group, analogous to previous reports for protonated TAGs. The position of each acyl group on the glycerol backbone is thus determined by the relative abundances of these ions. Under the conditions in our instrument, the [M + 40]+ adduct is at the highest signal and also yields all information about the double bond position and TAG stereochemistry. With the exception of geometries about the double bonds, racemic TAG isomers containing two monoenes or dienes and a saturate can be fully characterized by APCACI-MS/MS/MS.     

船舶柴电混合动力系统在电力助推模式下的性能仿真研究

应用AMESim软件对船舶柴电混合动力系统建模并进行试验验证。试验验证表明:所建立的模型稳态误差≤5%,满足精度要求。采用所建立的模型仿真分析了Booster模式下系统在不同工况下的匹配特性;并研究了柴油机与轴带电机稳定运行的控制策略。     

机床导轨技术研究综述

对机床技术中的关键技术之一——导轨技术的研究进行了梳理,论述了其形式分类、原理及目前的研究现状和研究重点,对今后导轨技术的研究发展进行了展望.     

地震记录中工业电干扰噪声识别与压制

在工业化采油区中,油井和工业电网产生的50 Hz工业电干扰对地震资料成像有较大影响.在综合研究50 Hz工业电干扰压制技术的基础上,利用工业电的特性探索了一套高精度自适应压制技术.实际地震资料处理效果表明,采用该方法压制50 Hz 工业电干扰的效果较好,既保持了地震波的动力学和运动学特征,也提高了地震资料的信噪比,保真度高且节约处理成本.     

基于PLC的水下切割装置速度控制系统研制

水下切割装置在进行切割作业时,在水面不能直接获知其运行状态。原有系统用液压马达的流量对水下切割装置的运行速度进行估计,误差较大,响应速度慢。为解决速度检测精度等问题,对原有系统进行改造,采用深水码盘实现切割速度检测,使用比例流量阀调整液压马达流量,实现转速的实时精确控制。基于可编程逻辑控制器实现了水下切割装置的速度控制。     

几种电子陶瓷材料的研究进展与应用前景

电子科学,信息技术发展日新月异,高速奔向集成化和微型化.在电子产品中,元器件是其重要的组件之一.所以对核心元件提出更高的标准:必须具有高速,微型,轻薄,高可靠性等特点.电子元器件的核心技术就是如何利用功能陶瓷材料的电、磁、声、光、力、热等特性.元器件的发展趋势是小型化、片式化、多层化、模块化、集成化和多功能化,以及高性能低花费,方便使用.本文综合介绍了微波介电,铁电压电,磁性以及热释电等新型功能陶瓷材料,同时也介绍了最新的研究进展及可能的应用前景.     

面向可信和行为模式匹配的两层服务选择方法

在面向服务框架下,用户对服务有着不同的交互经验,并根据这些经验建立信任且对其评价,然而用户可能产生错误的评价进而影响公正的选择．为解决这一问题,提出一种两层选择算法选取可信并且符合用户偏好的服务．第1层用户将自己的经验与群体的评价趋势进行比对,优化自身的记录,生成更加可靠的经验信息．第2层用户由自己的偏好选出最符合需求的建议者．结果表明,这个方案可以过滤掉恶意的或经验不足的评价者,并选择出符合用户行为模式的服务．