物理-化学耦合作用下泥页岩坍塌周期应用研究

基于泥页岩地层井壁周期性失稳的特点,将泥页岩地层视为孔隙介质进行分析,根据多孔热弹性理论及泥页岩的本构关系,考虑泥页岩地层在温度、孔隙压力、泥页岩水化等因素的耦合作用,建立了耦合数学模型,得出了不同泥浆体系和不同泥浆密度下泥页岩井壁的坍塌周期。在西部巨厚、复杂的泥页岩地层井壁失稳的研究中表明,其应用效果和实际情况吻合较好。     

Peripheral Nerve‐Derived Matrix Hydrogel Promotes Remyelination and Inhibits Synapse Formation

Regeneration of injured nerve tissues requires intricate interplay of complex processes like axon elongation, remyelination, and synaptic formation in a tissue‐specific manner. A decellularized nerve matrix‐gel (DNM‐G) and a decellularized spinal cord matrix‐gel (DSCM‐G) are prepared from porcine sciatic nerves and spinal cord tissue, respectively, to recapitulate the microenvironment cues unique to the native tissue functions. Using an in vitro dorsal root ganglion–Schwann cells coculture model and proteomics analysis, it is confirmed that DNM‐G promotes far stronger remyelination activity and reduces synapse formation of the regenerating axons in contrast to DSCM‐G, Matrigel, and collagen I, consistent with its tissue‐specific function. Bioinformatics analysis indicates that the lack of neurotrophic factors and presence of some axon inhibitory molecules may contribute to moderate axonal elongation activity, while laminin β2, Laminin γ1, collagens, and fibronectin in DNM‐G promote remyelination. These results confirm that DNM‐G is a promising matrix material for peripheral nerve repair. This study provides more insights into tissue‐specific extracellular matrix components correlating to biological functions supporting functional regeneration.     

异构物联网的开放式架构研究

An open architecture for converged Internet of Things (IoT) is proposed in this paper. By  using  this model, the various and huge amount of data can be converted into converged data and then encapsulated as service packages. Moreover, a Representational State Transfer (REST) platform has been implemented in the lab environment. The merit of this architecture is the enhancement of data efficiency. Experimental results are provided to show the benefits of the proposed architecture.     

一种提高多速率WLAN公平性的MAC协议

DCF应用在多速率无线局域网中存在严重的不公平性：高速率站点占用信道的时间远小于低速率站点,只获得与低速率站点相同的吞吐量。该文利用区分服务的思想,提出接入时间公平的MDCF。MDCF通过为不同速率的站点设置不同的初始竞争窗口,来实现与发送速率成正比的接入概率,从而保证接入时间的公平性,理论分析和仿真结果都表明MDCF能够较大地提高多速率无线局域网中的时间公平性及吞吐量。     

一种新的多径相关瑞利信道的数学模型：理论分析及仿真比较

产生统计独立的多径相关瑞利信道是无线信道仿真的一个基本问题。Jakes模型得到了广泛应 用,但它在统计独立性方面还存在一些问题。该文提出一种新的相关瑞利信道的数学模型。理论分析和仿真比较表明它在计算复杂度和统计独立性方面比最初的Jakes模型及其近来发现的改进模型更加简单有效。     

谷物害虫图像识别中特征值提取技术的研究

本文阐述了在仓储物害虫分类识别研究中利用计算机数字图像处理技术，对谷物害虫图像的一阶灰度值直方图和图像的目标区域，自动提4取静态仓储物害虫图像的数理统计特征、纹理特征和几何形状特征的主要技术和方法。试验结果表明，该方法可以为谷物害虫的计算机自动模式识别(快速分类)提供稳定的特征参数值，有效地提高了识别率。该方法为仓储物害虫的快速鉴定和分类研究开辟了新的途径。     

高剂量Ge离子注入直接形成nc-Ge的研究

报道了分别采用剂量为1e1 6 ,1e1 7,5e 1 7和1e1 8cm- 2的高剂量Ge离子注入,不需退火即可在Si O2中直接形成Ge纳米晶的新现象.采用掠入射X射线衍射和激光喇曼谱等实验手段对样品进行了物相分析.结果表明,高剂量Ge离子注入可在SiO2 薄膜中直接形成Ge纳米晶(nc- Ge) ;非晶态Ge向晶态Ge发生相变的阈值剂量约为1e1 7cm- 2 ,离子注入直接形成的nc- Ge内部具有较大压应力,随着注入剂量的提高,nc- Ge的尺寸和含量均有提高.对纳米晶形成机理的研究认为,在Ge离子注入剂量达到阈值,此时膜中Ge非晶态团簇浓度达到饱和甚至过饱和,新入射的     

Design issues in a CDMA cellular system with heterogeneous traffictypes

In this paper, the performance of a code-division multiple-access (CDMA) cellular system with various traffic types is examined. Traffic integration and resource management are two major issues in the design of the next generation of wireless networks with integrated services. To provide design guidelines for traffic integration, the impact of the line rate (actual transmission bit rate in the radio channel) selection on the system capacity is examined. Since in a CDMA system the signal from one specific user is spread over the entire available bandwidth, the actual bandwidth resource occupied by a user depends on the amount of the transmission power of the user. In this paper, we also address how to assign suitable power levels to the different traffic types. A method for optimizing the power assignment for multiple traffic types is developed     

一种MPEG2视频编码的神经网络自适应量化算法

本文在ＭＰＥＧ２ＴＭ５建议我自适应量化策略的基础上，提出了一种ＭＰＥＧ２视频编码的神经网络自适应量化算法。     

合理使用大容量程控交换机SACETRA资源的探讨

合理使用SACETRA是维护大容量S1240程控交换机的一项重要工作。本文对如何提高SACETRA的使用效率进行了有益的探讨。