喷丸加工的工艺特性及参数控制研究

提出了喷丸加工新算法,该算法是模拟喷丸过程中零件表面层的塑性变化,从而控制能量参数。在喷丸加工时,表面层塑性变形积聚了大量压缩能量,通过进行能量参数优化,得到零件的最大疲劳强度并绘出曲率参数曲线。     

木结构剪力墙钉节点变形研究

对已有木结构剪力墙钉节点变形公式与实验数据进行比较,分析影响钉节点变形性能的主要因素,进而通过对大量实验数据的拟和,提出另一种钉节点变形公式以求更符合试验结果.将提出的公式代入到剪力墙整体变形公式中与实验结果相比较,二者吻合情况较好,说明提出的钉节点变形公式具有较好的实用价值.     

中厚板矫直过程中中性层偏移动态研究

研究中性层偏移对矫直力的影响,以提高矫直力精度。通过对矫直件三维弹塑性变形进行分析,提出中性层偏移理论,利用数值模拟和实验讨论中性层偏移的动态变化规律,说明中性层偏移是影响矫直力精度的重要因素之一,并验证了理论推导公式与数值计算结果之间的误差,为建立更为准确的矫直力模型提供理论基础和数据。     

Waves Past Porous Structures in a Two-layer Fluid

Havelock’s type of expansion theorems, for an integrable function having a single discontinuity point in the domain where it is defined, are utilized to derive analytical solutions for the radiation or scattering of oblique water waves by a fully extended porous barrier in both the cases of finite and infinite depths of water in two-layer fluid with constant densities. Also, complete analytical solutions are obtained for the boundary-value problems dealing with the generation or scattering of axi-symmetric water waves by a system of permeable and impermeable co-axial cylinders. Various results concerning the generation and reflection of the axisymmetric surface or interfacial waves are derived in terms of Bessel functions. The resonance conditions within the trapped region are obtained in various cases. Further, expansions for multipole-line-source oblique-wave potentials are derived for both the cases of finite and infinite depth depending on the existence of the source point in a two-layered fluid.     

From Reparative Surgery to Regenerative Surgery: State of the Art of Porous Hydroxyapatite in Cranioplasty

Decompressive craniectomy is one of the most common neurosurgical procedures, usually performed after neuropathological disorders, such as traumatic brain injury (TBI), but also vascular accidents (strokes), erosive tumours, infections and other congenital abnormalities. This procedure is usually followed by the reconstruction of the cranial vault, which is also known as cranioplasty (CP). The gold-standard material for the reconstruction process is the autologous bone of the patient. However, this is not always a feasible option for all patients. Several heterologous materials have been created in the last decades to overcome such limitation. One of the most prominent materials that started to be used in CP is porous hydroxyapatite. PHA is a bioceramic material from the calcium phosphate family. It is already widely used in other medical specialties and only recently in neurosurgery. In this narrative review of the literature, we summarize the evidence on the use of PHA for cranial reconstruction, highlighting the clinical properties and limitations. We also explain how this material contributed to changing the concept of cranial reconstruction from reparative to regenerative surgery.     

多孔PZT95/5铁电陶瓷的机械性能和铁电性能研究

采用添加造孔剂的方法制备多孔锆钛酸铅(PZT95/5)铁电陶瓷, 研究了孔结构包括孔隙率、孔径及孔形状对多孔PZT95/5陶瓷机械性能和电性能的影响及机理, 并揭示多孔PZT95/5陶瓷微观结构、机械性能和铁电性能的内在联系。研究表明: 孔隙率的增加降低了多孔PZT95/5陶瓷的声阻抗, 改善了陶瓷与封装材料的声阻抗匹配. 孔隙率增加, 多孔PZT95/5陶瓷的屈服应力和剩余极化强度降低, 矫顽场强增大。孔结构对多孔PZT95/5陶瓷屈服应力的影响可由应力集中理论解释; 多孔PZT95/5陶瓷剩余极化强度随孔结构的变化可用内应力结合空间电荷理论加以解释。     

轴对称锥形件缩口成形非强制变形规律的研究

论述了轴对称圆筒件在锥形凹模中缩口时口部自由弯曲区的变形趋向,对3种变形模式进行了比较,并通过实例计算,证实了按自由弯曲变形模式计算口部应力与变形是合理性.     

Serum-Free Cultures: Could They Be a Future Direction to Improve Neuronal Differentiation of Mesenchymal Stromal Cells?

Mesenchymal stem/stromal cells (MSCs) are undifferentiated cells with multilinear potential, known for their immunomodulatory and regenerative properties. Although the scientific community is working to improve their application, concerns limit their use to repair tissues following neurological damage. One of these obstacles is represented by the use of culture media supplemented with fetal bovine serum (FBS), which, due to its xenogenic nature and the risk of contamination, has increased scientific, ethical and safety problems. Therefore, the use of serum-free media could improve MSC culture methods, avoiding infectious and immunogenic transmission problems as well as MSC bioprocesses, without the use of animal components. The purpose of our review is to provide an overview of experimental studies that demonstrate that serum-free cultures, along with the supplementation of growth factors or chemicals, can lead to a more defined and controlled environment, enhancing the proliferation and neuronal differentiation of MSCs.