基于Msp430无线安防传感网的设计研究

文中给出了一种面向无线传感网络协议的改进方法,设计并实现了一种面向于中小型场所的远程智能安防系统。该改进方法采用只在中心节点形成与维护路由表的策略,形成多路径单跳网络。通信节点采用具有超低功耗特性的Msp430单片机和CC1101射频模块构架,中心节点采用PC机外接CC1101RS-232串口模块方案,将汇聚节点和基站服务器合二为一,实现通信协议的转换,同时为远端移动终端节点提供通信接口。通信过程增加接收确认信号环节以确保信号的有效发送。实验结果表明,文中的设计方法能够高效地完成在有效通信范围内的信息传感。     

水杨酸双酚A酯的合成与表征

研究了以水杨酸乙酯、双酚A为原料，二丁基氧化锡为催化剂合成水杨酸双酚A醇，考查了催化剂及用量、反应温度、反应时间及物料配比等因素的影响。结果表明：催化剂用量为0．6g，反应温度为120-130℃，反应时间为4h，物料配比为2．10：1，在此条件下，产率在94%以上。产物结构经元素分析、红外光谱、核磁氢谱进行了表征。     

带有中间储罐的塔用于间歇萃取精馏

Batch extractive distillation was studied in a column with a middle vessel. The process was simulated by a constant holdup model and solved by two point implicit method. Acetone and methanol mixture was separated in such a setup using water as solvent. The simulation agrees well with experimental results. The experimental and simulation results show that the solvent at the bottom and the product at the top of the column can be withdrawn simultaneously for a long period of time. It needs more time for the solvent to reach high purity than that required for the more volatile component to reach high purity, so that the time to withdraw solvent from the bottom is delayed.     

鄱阳湖流域水分盈亏时空变化特征分析

根据1960~2014年鄱阳湖流域13个气象站点的气象资料,采用FAO推荐的Penman-Monteith法、Mann-Kendall趋势检验法和相关分析法,研究鄱阳湖流域水分盈亏量时空分布变化趋势及其与气象因子的关系。研究结果表明:鄱阳湖流域近55 a来水分盈亏量多年平均盈余为565.88 mm,空间上呈由西北向东北和由西南向东北逐渐递增的趋势;水分盈亏量年内分布呈秋季亏缺,其他季节盈余,水分盈余量表现为春季夏季冬季秋季;在研究时段内流域各地水分盈余量均呈增加趋势,但各季节水分盈余量变化存在一定的差异性,其中春季和秋季呈减少趋势,但趋势不明显,而夏季和冬季均呈显著的增加趋势(p0.05)。鄱阳湖流域水分盈亏量与降雨、日照时数和日最高气温关系密切,流域年水分盈余量的增加是由于夏季和冬季降水量的增加、日照数和风速的减少。     

钾钙肥中氧化钾的溶出规律研究

目的是研究钾钙肥中有效氧化钾的溶出规律,分别采用单因素法、正交试验法和均匀设计法来进行试验,克服了单因素试验法不易考察不同因素间交互作用的缺点,得到更加全面准确的试验结论:提取液酸度是影响钾钙肥中氧化钾溶出的首要因素,振荡时间次之,两因素间的交互作用不明显,振荡温度影响可以忽略,酸度越大,振荡时间越长,氧化钾的溶出量越多。     

钛酸钡基铁电材料的介电非线性研究

通过A位或B位掺杂改性得到的钛酸钡基铁电材料,在外加直流偏置电场作用下,具有介电常数非线性可调的优异介电性能,可以广泛地应用于压控可调陶瓷电容器和微波可调器件领域。针对钛酸钡基铁电材料的介电非线性特性,讨论了BaTiO_3基铁电材料分别在铁电相、顺电相以及相转变温度场附近的介电非线性机理和相关理论;结合笔者近年来有关介电非线性研究的实验结果和相关文献报道,综述了不同A位离子(如Sr~(2-)和Ca~(2-)等)或B位离子(如Zr~(4 )和Sn~(4-)等)掺杂的BaTiO_3基铁电材料体系的介电非线性研究现状,分别对不同物质形态(陶瓷块体、薄膜和厚膜)的BaTiO_3基铁电材料的介电非线性研究及其应用进行了对比分析;并对钛酸钡基铁电材料今后的发展趋势和研究方向进行了展望。     

Rheological study on O−carboxymethylated chitosan/cellulose polyblends from LiCl/N,N‐dimethylacetamide solution

An O?carboxymethylated chitosan (O? CMCh) water solution (I) and N,N‐dimethylacetamide (DMAc) emulsion (II) were blended with a cellulose LiCl/DMAc solution, and corresponding polyblends (Polyblends I and II) were obtained. The rheology of the three fluids, that is, the cellulose solution and Polyblends I and II, was investigated. The cellulose solution was characterized by a power‐law fluid. When an O‐CMCh water solution or DMAc emulsion was added to the cellulose solution, the power‐law curve was preserved. The power‐law indexes (n) of all three fluids increased along with the temperature. Polyblend I displays an n close to but a little higher than that of the cellulose solution, while Polyblend II shows a much higher power index than those of the other two fluids. The values of the apparent viscosity (η_a) for all the three fluids are close and decrease along with an increase in the temperature. Adding O‐CMCh microparticles into Polyblends I and II results in a decrease in the structural viscosity index (Δη) in comparison to that of the cellulose solution, and this effect is very obvious for Polyblend I. A cellulose solution's Δη declines with the augmentation of temperature, while the Δη's of both Polyblends I and II show minimum values at about 323 K. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1719–1725, 2003     

变压吸附制氧机吸附器结构研究进展

介绍了变压吸附制氧机中吸附器的内部结构、分流板、分子筛布局与装填方式、压料部件与装配等内容,对影响制氧机性能的因素进行了剖析和论述,探讨了变压吸附制氧机设计中关键影响因素和技巧。     

非临氢降凝催化剂的研制与评价

以ZSM-5为主体，加入一定量的自制BCM沸石，采用水热合成法合成新型非临氢降凝催化剂。以催化裂化柴油和减一线馏分油为原料对其反应性能进行评价。结果表明, 该催化剂具有明显的降凝效果。当反应温度为340 ℃、空速为1 h^-1时，凝点降幅为45 ℃左右，液体产品收率均在95%以上。所生产的柴油十六烷值高，硫、氮含量低，凝点低，基本满足了产品调合出厂的质量要求。     

交联聚乙烯/丙烯酸/蒙脱土纳米复合材料的制备与表征

在制备交联聚乙烯／蒙脱土纳米复合材料的过程中,利用交联聚乙烯的特征,通过在与蒙脱土熔融复合的过程中加入单体丙烯酸作为相容剂,制得交联聚乙烯／蒙脱土纳米复合材料。用XRD、TEM进行表征,并对材料的力学性能进行测试。结果显示：复合材料的拉伸强度与原基材相比有所上升,而冲击强度有所下降。