Solution of impulsive boundary value problems on infinite intervals

In this paper, the upper and lower solution method and monotone iterative technique are employed to study the boundary value problem for a class of first-order impulsive ordinary differential equations with Carathéodory condition on infinite intervals. Several existence theorems are obtained.     

Obtaining mode mixity for a bimaterial interface crack using the virtual crack closure technique

We review, unify and extend work pertaining to evaluating mode mixity of interfacial fracture utilizing the virtual crack closure technique (VCCT). From the VCCT, components of the strain energy release rate (SERR) are obtained using the forces and displacements near the crack tip corresponding to the opening and sliding contributions. Unfortunately, these components depend on the crack extension size, Δ, used in the VCCT. It follows that a mode mixity based upon these components also will depend on the crack extension size. However, the components of the strain energy release rate can be used for determining the complex stress intensity factors (SIFs) and the associated mode mixity. In this study, we show that several—seemingly different—suggested methods presented in the literature used to obtain mode mixity based on the stress intensity factors are indeed identical. We also present an alternative, simpler quadratic equation to this end. Moreover, a Δ-independent strain energy release based mode mixity can be defined by introducing a “normalizing length parameter.” We show that when the reference length (used for the SIF-based mode mixity) and the normalizing length (used for Δ-independent SERR-based mode mixity) are equal, the two mode mixities are only shifted by a phase angle, depending on the bimaterial parameter ε.     

虚拟仪器技术在模拟电子技术实验中的应用

给出了虚拟仪器技术的概念。并提出了一种用于模拟电子技术实验的虚拟仪器设计方案。     

蓝芽技术的安全研究

本文首先提出蓝牙技术,然后分析了蓝牙的安全问题,最后,介绍了蓝牙技术的安全机制。     

柔度法测量三点弯曲试样弹性模量的影响因素

根据柔度法测量金属材料裂纹长度的原理,讨论了测量三点弯曲SE(B)试样弹性模量的影响因素,并分析了主要因素的影响。在此基础上,用柔度法测量了裂纹尖端张开位移(CTOD)试验用大尺寸SE(B)试样预制疲劳裂纹的长度。经断口测量发现,用柔度法测量的两组母材与焊缝试样的原始裂纹长度具有很好的同一性,为进一步进行CTOD试验提供了保证。     

电子产品先进设计技术与先进制造技术初探

文章针对当代IT产业中先进技术、先进材料、先进器件飞速发展给予电子产品设计技术和生产技术的挑战，基于高度保障产品质量的要求，基于充分发挥现代高技术的优势的出发点，就原理性样机开发、生产性样机转换和产品生产三大阶段中融合先进的技术、采用合理的步骤以及运用先进的管理理念等现代化手段作了一些试探性的阐述。     

葡醛内酯生产工艺改进研究

在实验研究的基础上，对现有葡醛内酯生产工艺中存在的的问题提出了相应的对策．为了提高产率，减轻污染以降低生产成本，进行了分阶段和全流程工艺实验，确认淀粉氧化工序中硝酸的浓度以70％适宜，氧化温度应控制在50℃或稍低，氧化淀粉水解前用硼氢化钠或氢气对氧化淀粉进行还原是提高葡醛内酯产率的有效手段．通过控制用酸量、改进加料方式和改善吸收可以有效地减轻环境污染．     

圆管临界热流密度的流体模化

为了评价现有的临界热流密度(CHF)流体模化技术,在氟里昂-12热工实验装置上完成了φ202.5圆管CHF实验。在此基础上,用不同的数据源,比较了Ahmad补偿失真模型、鲁钟琪模型、Groeneveld模型和Stevens-Kirby经验比例因子模型的预测精度和适用范围,为复杂流道中的CHF流体模化研究奠定了基础。     

从60 MeV/u18O离子辐照过的钍中分离Ra

对以^212Pb,^133Ba和^224Ra比作示踪剂，（NH4）2H2EDTA为淋洗剂，用阳离子交换法从Pb、Ba中分离Ra的工艺条件做了研究。提出了一个从60MeV／u ^18O离子辐照过的ThO2靶中分离Ra的放射化学流程。实验结果表明，该流程对主要反应产物，特别是Ba的去污较好，Ra的产额可达70％以上。     

用富集培养技术分离具有PAL活性的酵母菌

为获取具有ＰＡＬ活性的菌株，设计了从天然源分离酵母菌的定集培养技术，并从中国西南地区采集２０个样品中得到菌株１４０余株，结果表明本富集培养技术用于从天然源分离具有苯丙氨酸解氨酶活性的菌株是有效、可行的。