平滑相位的π/4DQPSK调制及其在移动通信系统中的应用

本文详细介绍了一种新型π/ 4DQPSK调制解调方法 ,该方法将π/ 4DQPSK调制中的相位跳变改为平滑变化。仿真实验表明 ,与普通的π/ 4DQPSK相比 ,该方法使高次谐波分量大幅下降 ,可以有效降低功耗 ,压缩频带宽度。     

镍镀层与黄铜抗冲刷腐蚀性能比较研究

利用自制的汽轮机凝汽器铜管模拟试验装置,进行Ni P、Ni W镀层与黄铜HSn70 1A模拟管端冲刷腐蚀试验。结果表明,黄铜管管端采用Ni P、Ni W镀层可防止冲刷腐蚀,显著提高黄铜管抗冲刷腐蚀能力和使用寿命。与HSn70 1A黄铜管段试样相比,Ni W镀层可提高抗冲刷腐蚀能力近5倍,Ni P镀层可提高抗冲刷腐蚀能力3倍多。     

基于响应面法的碳酸钠活化铜尾矿胶凝性能机制研究

为了有效激发铜尾矿活性制备性能良好的胶凝材料,以铜尾矿为主要原材料,水玻璃和NaOH为碱激发剂,采用响应面优化法开展胶凝材料配比优化实验,并通过方差分析以及三维曲图研究自变量及其交互作用对28d抗压强度的影响;利用XRD、SEM、FT-IR、TG-DTG等对试样的矿相成分、微观形貌等特征进行分析。结果表明：通过优化实验获得最优配比为碳酸钠掺量50%、氢氧化钠掺量1%、水玻璃掺量22g/100g,此参数下铜尾矿胶凝材料28d抗压强度为30.41MPa。经过机械球磨40min后,碳酸钠在适当的碱性环境下使铜尾矿的活性激发到较佳状态,铜尾矿经水化反应生成了大量结晶度较高的C-S-H凝胶与棱柱状钙钒石等水化产物,彼此相互连接构成网状结构,使胶凝材料保持较高的强度性能。     

150t/h循环流化床锅炉冷态试验分析

针对某热电厂新建的150 t/h循环流化床锅炉,介绍了流化床锅炉冷态试验的内容及方法,通过测定布风板、料层及返料器阻力,确定了最小流化风量(风压)及返料风量(风压),同时对布风均匀性、分离器及返料器的工作状况进行了测试和分析,为锅炉的顺利点火及稳定运行提供了依据。     

Rheological and Structural Properties of Egg White/Oat Globulin Co-Gels

Co-gels of egg white (EW) and oat globulin (native and deamidated) were prepared by heating mixtures of the two proteins at different ratios. Rheological properties of the co-gels were assessed by small amplitude oscillatory tests. Storage (G′) and loss (G″) moduli of the co-gels increased with increases in EW content in the mixtures. At comparable EW/non-EW ratios, EW formed much stronger co-gels with deamidated oat globulin (DOG) than with native globulin (OG) or several other non-EW proteins. Microscopic examination of mixed gels revealed structural differences between EW/OG and EW/DOG co-gels. The former exhibited a two gel system with OG distributed discontinuously throughout the supporting EW matrix. DOG and EW formed a homogenous gel network, demonstrating compatibility between the two proteins.     

Stereological estimation of surface area and barrier thickness of fish gills in vertical sections

Previous morphometric methods for estimation of the volume of components, surface area and thickness of the diffusion barrier in fish gills have taken advantage of the highly ordered structure of these organs for sampling and surface area estimations, whereas the thickness of the diffusion barrier has been measured orthogonally on perpendicularly sectioned material at subjectively selected sites. Although intuitively logical, these procedures do not have a demonstrated mathematical basis, do not involve random sampling and measurement techniques, and are not applicable to the gills of all fish. The present stereological methods apply the principles of surface area estimation in vertical uniform random sections to the gills of the Brazilian teleost Arapaima gigas. The tissue was taken from the entire gill apparatus of the right‐hand or left‐hand side (selected at random) of the fish by systematic random sampling and embedded in glycol methacrylate for light microscopy. Arches from the other side were embedded in Epoxy resin. Reference volume was estimated by the Cavalieri method in the same vertical sections that were used for surface density and volume density measurements. The harmonic mean barrier thickness of the water‐blood diffusion barrier was calculated from measurements taken along randomly selected orientation lines that were sine‐weighted relative to the vertical axis. The values thus obtained for the anatomical diffusion factor (surface area divided by barrier thickness) compare favourably with those obtained for other sluggish fish using existing methods.     

Probiotic buttermilk-like fermented milk product development in a semiindustrial scale: Physicochemical, microbiological and sensory acceptability

Probiotic buttermilk-like fermented milk in different flavors in versions with sucrose and sucralose were processed in a pilot plant. The Mesophilic Aromatic Culture CHN-22 and Bifidobacterium animalis Bb12 were the cultures employed for fermentation. Physicochemical composition, apparent viscosity, diacetyl content, viability of cultures during storage, and acceptance of product via sensorial analysis were assessment factors. The high viability of the probiotic culture was observed (average 8.08 log cfu/ml) during refrigerated storage (28 days) of buttermilk and good acceptance of the product via sensory test. However, the probiotic culture might have been responsible for the loss of diacetyl, a volatile compound that is a characteristic feature of the product.     

Rheological and Structural Properties of Wiener-Type Products Substituted with Vital Wheat Gluten

Mechanical properties of wiener batters substituted with vital wheat gluten (VWG) or acid-solubilized (deamidated) VWG were studied. Substitution led to decreased storage (G') and loss (G”) moduli. Cooking profiles showed initial modulus decreases due to fat melting, with G’ reaching minimum around 50-55°C, followed by rapid increases. Sharp G” and tan 5 transitions appeared near 48°C. Substitution caused upward shift in transition temperatures, and at 20%, decreased moduli. Substitution caused no significant (p < 0.05) decreases in cook yield or texture. Microscopical examination revealed random binding of gluten to meat protein, forming continuous networks. Batters containing deamidated gluten had structure similar to all-meat or VWG-substituted batters.     

静态环境下移动机器人MFNN全局路径规划算法研究

针对移动机器人的路径规划计算问题,通过对其系统特性的分析,提出一种MFNN全局路径规划计算方法,并从理论上进行建模与推导.仿真结果表明:此方法计算简单,收敛速度快,能显著提高求解移动机器人全局最优化问题的计算效率,并避免了某些局部极值情况.     

水煎苦参废渣中苦参碱的提取工艺研究

运用正交实验L9(34)研究了水煎苦参提取苦参碱,以及利用超声强化乙醇法提取苦参废渣中苦参碱的最佳工艺,并对两种方法的提取效果进行了比较。研究表明,水煎苦参碱提取量可达26.35mg/g苦参粉,超声强化乙醇提取法提取量可达5.632mg/g苦参渣,即超声醇的二次提取量可以达到一次水提取量的21.37%,因此可有效减少苦参碱资源浪费。