用动态力学粘弹谱研究PBT／PET共混体系的相容性

利用动态力学分析方法考察了ＰＢＴ／ＰＥＴ合金的动态力学粘弹谱，从谱图中分析得到：在ＰＢＴ／ＰＥＴ合金中除了完全互溶状态的ＰＢＴ／ＰＥＴ外，还存在独立的ＰＢＴ、ＰＥＴ区域。合金的特性粘度增加，其动态模量增加，而且相转变损耗峰向高温旃方向转移。其中β松弛损耗峰是由于酯基－ＣＯＯ－的运动引起的，它的峰值随合金特性粘度增加而下降。这些均可以由合金中ＰＢＴ、ＰＥＴ的相溶性及分子运动得到解释。     

不可达顶点剪枝算法及其在最短路径中的应用

[k]步可达性查询用于回答图[G]中从顶点[u]到达顶点[v]最多[k]步是否存在路径,但其多用于无权图的可达性研究。针对加权图,在图中构建了最早到达、逆向最早到达和最晚到达等三个索引,并应用这三个索引实现对不可达顶点的快速剪枝,从而有效地缩减了加权图的规模。运用该方法建立索引并剪枝顶点的时间复杂度与空间复杂度分别为[O(n+e)]和[O(n)],这里[n]和[e]分别为图中顶点的数目和边的数目。该方法可以与Dijkstra算法、Floyd算法和A*算法等多种传统算法相结合,并应用于最短路径求解,从而提高传统算法计算性能。最后以物流配送网络为例进行了实验验证,实验结果表明提出的方法可以正确并高效地对不必要计算的顶点进行剪枝,从而加快了最短路径求解速度,验证了提出方法的有效性。     

Performance of an M-QAM full-duplex wireless system with a nonlinear amplifier非线性功放对M-QAM全双工无线通信的影响分析

The effect of amplifier nonlinearity is analyzed for M-QAM full-duplex communications in additive white Gaussian noise channels. Two classical memoryless nonlinear amplifier models, i.e., a traveling-wave tube amplifier and a solid-state power amplifier, are considered. An analytical expression for the bit error ratio is derived using a characteristic function and numerical integration. Theoretical results show perfect agreement with those obtained by simulation. The analytical results could be used to evaluate the degradation in performance of an M-QAM full-duplex system caused by amplifier nonlinearity, and will be helpful in finding the optimal static operating point of an amplifier.     

无机盐晶须增强树脂基复合材料研究进展

介绍了新型增强增韧的钙、镁无机盐晶须材料的品种、性能、功能特征和研究现状，对比了这类晶须与其他晶须增强的复合材料的部分机械物理性能，探讨了一定工艺条件下复合材料良好的机械性能。对当前主要研制的无机盐晶须增强复合材料的作用形式、机理进行了归纳，提出今后该类型复合材料的研究特点，进而开发满足性能的新型复合材料。     

医院网络信息的安全隐患及预防对策分析

随着信息时代的来临,网络信息技术也探足到医疗卫生行业中以取代传统纸质记录传达的位置,也使得医院信息的处理向高效率,信息高度准确化发展.关于常见的一些医院信息系统的安全隐患本文做了如下分析,并简略阐述了相关的预防对策.     

建设虚拟建筑电气实验室的理论及研究

建筑电气实验室由于投资大,设备更新换代快,发展迅速,而大多数高校资源紧张,虚拟建筑电气实验室不失一个可行的缓解办法。本文研究了采用虚拟现实技术建立虚拟建筑电气实验室的可能性和相关技术,建立了其结构模块,为进一步开展相关研究打下良好基础。     

NetNMSP: Nonoverlapping maximal sequential pattern mining

Applied Intelligence - Nonoverlapping sequential pattern mining, as a kind of repetitive sequential pattern mining with gap constraints, can find more valuable patterns. Traditional algorithms...     

硬质PVC抗静电母料的研究

本文研究了几种抗静电剂母料的组成和制备工艺。具有良好分散性的母料可用于PVC-U制品,如层压板和矿用管。可使硬质PVC的表面电阻小于10~8Ω,能提高制品的抗冲击强度。     

Symbol error rate on fading self-interference channel in full-duplex

In-band full-duplex (FD) is being considered as a promising technology for the next generation wireless communication systems. In this paper, the performance of orthogonal frequency division multiplexing (OFDM) modulation system with different symbol duration and the code spreading system with different spreading sequence lengths under time-varying self-interference (SI) channel in FD mode is investigated respectively. Typically, the SI channel is estimated during the SI cancellation duration and used for SI suppression in the whole data transmission duration. First, the expressions of the residual SI power during the data transmission duration are derived under the classical, the uniform, and the two-way Doppler SI channels. Second, the signal-to-interference-and-noise-ratio after the SI mitigation is obtained. Third, the symbol error rates for the OFDM modulation and the code spreading systems are given. Simulation results show that OFDM symbol length should be selected longer when the symbol duration is significantly lower than the SI coherent time while the length of the coding spreading system should be chosen shorter.