基于遗传算法的静态逻辑拓扑设计

设计了一种遗传算法,在使用较短通路情况下实现了链路和节点的负载均衡. 在算法中采用了自然数编码、随机选取种群、简单的“双亲单子”交叉策略和固定的突变概率. 以美国国家自然科学基金网络为例进行了仿真. 对目标函数中的权值进行了讨论,分析了适应性函数值与遗传代数之间的关系,对种群选取范围与适应性函数之间的关系进行了验证.     

多证明签名方案及在交叉认证中的应用

自证明签名对验证者来说一次仅验证2个签名,而在交叉认证中验证证书链上的证书不止2个,因此,自证明签名在实际的应用中不能满足需求. 针对此问题提出了多证明签名方案,它是在自证明签名的基础上做了一定的扩展,由验证2个签名扩展到可同时验证3个签名;此后又在多证明签名方案的基础上做了进一步的扩展,扩展后的多证明签名方案可同时验证n个签名.     

基于Mathematica的F分布表的计算方法

研究了F分布的上分位点Fα(n1,n2)的性质,指出了利用Mathematica软件提供的函数直接计算Fα(n1,n2)的缺陷,提出了计算Fα(n1,n2)的自定位二分算法,此算法可以求出比查表更广泛的数值,计算结果稳定可靠,方便实用,填补了在Mathematica软件里计算Fα(n1,n2)的空白.     

基于PIC单片机控制格斗机器人的研究

研究了基于PIC单片机为控制核心的格斗机器人.该机器人由动力系统、机械系统和控制系统组成,其控制系统主要由PIC单片机、电机驱动电路和传感器模块三部分组成.在机器人控制系统的软件设计中,采用了自救、搜索和攻击算法.利用灰度传感器和接近传感器将信号经模数转化为14位数字量.在精度问题上,通过软件实现只取其中的高8位,并在实际对抗中,取得较好的效果.     

一类全系数模糊规划问题及其求解方法

模糊规划是不确定规划的重要一类,对许多带有模糊信息的实际问题都能进行有效地处理,对模糊规划的求解方法进行讨论不仅具有理论意义,还具有实际意义.为寻求一类全系数模糊规划问题的求解方法,利用三角(或梯形)模糊数的排序准则并结合禁忌搜索算法设计了一种求解系数均为三角(或梯形)模糊数的规划模型的人工智能算法.数值算例表明笔者所提方法行之有效.     

基于列表的迭代分枝定界MIMO检测算法

提出了基于列表的迭代分枝定界算法,利用搜索到的候选列表计算比特软信息,降低了MAP计算复杂度,同时进一步提出了改进的列表分枝定界算法,每次迭代利用更新的先验信息重新计算候选列表,提高了列表质量。仿真结果表明列表分枝定界算法通过在MIMO信道检测和信道解码之间传递外信息,取得了逼近信道容量的性能,而修正的考虑先验信息的列表分枝定界算法在性能损失可忽略的情况下,减小了候选列表的大小。     

无线传感器网络基于置信因子的数据分发机制

无线传感器网络中节点的能量大部分用来传输数据,为减少数据的传输量,同时不增加数据包的延迟,提出了基于置信因子的数据分发概念。由于置信因子由传感器节点根据所感知的数据产生,反映了数据的真实性和重要性,由于设计了一种基于置信因子的发送退避策略和传输过滤器,解决了保证重要数据的优先信道访问权和减少冗余数据传输量的问题。大量仿真证明,这种数据分发机制在减少网络能耗和重要数据的时延方面是有效性的。     

Enhanced calcium–magnesium–aluminosilicate (CMAS) resistance of GdAlO3 (GAP) for composite thermal barrier coatings

The impact of calcium–magnesium–alumino-silicate (CMAS) degradation is a critical factor for development of new thermal and environmental barrier coatings. Several methods of preventing damage have been explored in the literature, with formation of an infiltration inhibiting reaction layer generally given the most attention. Gd₂Zr₂O₇ (GZO) exemplifies this reaction with the rapid precipitation of apatite when in contact with CMAS. The present study compares the CMAS behavior of GZO to an alternative thermal barrier coating (TBC) material, GdAlO₃ (GAP), which possesses high temperature phase stability through its melting point as well as a significantly higher toughness compared with GZO. The UCSB laboratory CMAS (35CaO–10MgO–7Al₂O₃–48SiO₂) was utilized to explore equilibrium behavior with 50:50 mol% TBC:CMAS ratios at 1200, 1300, and 1400°C for various times. In addition, 8 and 35 mg/cm² CMAS surface exposures were performed at 1425°C on dense pellets of each material to evaluate the infiltration and reaction in a more dynamic test. In the equilibrium tests, it was found that GAP appears to dissolve slower than GZO while producing an equivalent or higher amount of pore blocking apatite. In addition, GAP induces the intrinsic crystallization of the CMAS into a gehlenite phase, due in part to the participation of the Al₂O₃ from GAP. In surface exposures, GAP experienced a substantially thinner reaction zone compared with GZO after 10 h (87 ± 10 vs. 138 ± 4 μm) and a lack of strong sensitivity to CMAS loading when tested at 35 mg/cm² after 10 h (85 ± 13 versus 246 ± 10 μm). The smaller reaction zone, loading agnostic behavior, and intrinsic crystallization of the glass suggest this material warrants further evaluation as a potential CMAS barrier and inclusion into composite TBCs.     

Site-selective occupation and luminescence property investigation of Ca18Na3Y(PO4)14:Eu2+ phosphor for full-spectrum LED

Cyan-emitting phosphors have attracted widespread attention as an integral part to realize full-spectrum lighting. Understanding the site occupation of luminescence centers is of great importance to design and clarify the luminescent mechanism for new cyan-emitting phosphors. Here, we report a cyan-emitting phosphor Ca₁₈Na₃Y(PO₄)₁₄:Eu²⁺ synthesized by the high-temperature solid-state method. The crystal structure is characterized by X-ray diffraction and refined by the Rietveld method. The diffuse reflectance spectra, excitation/emission spectra, fluorescence decay curves, thermal stability, and related mechanism are systematically studied. The results show that Ca₁₈Na₃Y(PO₄)₁₄:Eu²⁺ crystallizes in a trigonal crystal system with space group R3c. Under excitation at 350 nm, a broadband cyan emission can be obtained at 500 nm with a half-width of about 120 nm, which is caused by Eu²⁺ occupying five different sites in host, namely, Na2O₁₂ (450 nm), (Ca3/Na1)O₈ (485 nm), Ca2O₈ (515 nm), Ca1O₇ (565 nm), and (Ca4/Y)O₆ (640 nm), respectively. Moreover, crystal structure, room and low temperature spectroscopy, and luminescence decay time are used to skillfully verify the site-selective occupation of Eu²⁺. Finally, a full-spectrum light-emitting diode (LED) lamp is fabricated with an improved color rendering index (∼90.3), CCT (∼5492 K), and CIE coordinates (0.332, 0.318). The results show that Ca₁₈Na₃Y(PO₄)₁₄:Eu²⁺ has the potential to act as a cyan emission phosphor for full-spectrum white LEDs.     

不同采收期水冬瓜叶的主成分分析及抗炎镇痛谱效关系研究

为筛选水冬瓜叶抗炎镇痛活性成分,采用高效液相色谱(HPLC)建立不同采收期10批次水冬瓜叶药材指纹图谱,对其进行主成分分析,并基于皮尔逊相关分析法探讨不同采收期水冬瓜叶药材抗炎镇痛的谱效关系。结果显示,不同采收期水冬瓜叶药材HPLC指纹图谱中有17个共有峰,10批次药材的相似度为0.875~0.973。聚类分析将不同采收期水冬瓜叶药材分为3类。主成分分析共得到3个主成分。经皮尔逊相关分析,峰17、峰14、峰12、峰15、峰13、峰5、峰16和峰4可能为水冬瓜叶药材镇痛作用的物质基础,峰6、峰8(异槲皮苷)、峰11、峰7(金丝桃苷)、峰5、峰3、峰4、峰13、峰9和峰1可能为水冬瓜叶药材抗炎作用的物质基础。