CO-OFDM系统中一种新颖相位噪声抑制算法

针对相干光正交频分复用(CO-OFDM)系统中相位噪声造成的严重影响,提出了一种采用线性插值和卡尔曼滤波相结合的相位噪声抑制算法.该算法在第一阶中对接收端的时域信号进行线性组合,之后利用线性插值算法对相位噪声进行初步抑制,在第二阶中采用卡尔曼滤波技术来抑制残余的相位噪声.分析和仿真表明:提出的二阶算法能够有效地抑制相位噪声对OFDM符号的影响,在相位噪声线宽较大时明显地降低错误平层,利用所提出的二阶算法可使误码率达到10-7以下,有效地提高了系统的性能.     

新型α和β成核剂对PP结晶和力学性能的影响

在聚丙烯(PP)中加入两种新型成核剂:二苄叉山梨醇衍生物YS-688(α成核剂)和芳酰胺类化合物TMB-5(β成核剂),通过密炼–挤出的方法制备了PP/成核剂共混物材料。通过偏光显微镜、X射线衍射、差示扫描量热和力学性能测试研究了这两种成核剂对共混物结晶和力学性能的影响。结果表明,两种成核剂在适量时均能提高PP的结晶速率和结晶度,细化晶粒,且使晶体界面模糊,其中TMB-5具有较强的诱导PPβ晶成核的能力,当其质量分数为0.075%时,可使PP形成树枝状的β晶,而YS-688未改变PP的晶型,只生成了α晶。YS-688可提高共混物的拉伸强度,而TMB-5对共混物的拉伸强度影响很小;当两种成核剂质量分数均为0.075%时,共混物的韧性最好,相对于纯PP,PP/YS-688共混物的常温和–30℃缺口冲击强度分别提高了37.41%和12.76%,拉伸强度提高了11.11%;PP/TMB-5共混物的常温和–30℃缺口冲击强度分别提高了100%和55.41%。     

南方酸性稻田土壤中有效态Cd的提取研究

采用现场采样及室内分析方法,研究比较了0.20%Ca Cl_2、Mg Cl_2、NH_4Cl,1.00%CaCl_2、MgCl_2、NH_4Cl,2.00%CaCl_2、MgCl_2、NH_4Cl三种提取剂在三种不同浓度下对南方酸性稻田土壤有效态Cd的提取效果。研究结果表明,不同浓度下三种提取剂对土壤pH值的影响存在差异,Mg Cl_2、NH_4Cl提取剂随着浓度的增加土壤pH值下降,而Ca Cl_2提取剂随着提取浓度的增加土壤pH值呈现上升-下降-上升的趋势;随着提取剂浓度的增加三种提取剂浸提率均表现为上升的趋势,以2.00%浓度下NH_4Cl提取剂对酸性稻田土壤有效态Cd的提取率最好,最大浸提率为71.43%;试验结果可对南方酸性稻田Cd污染土壤提供一种有效的提取方法及数据支撑。     

Tuneable elastomeric nanochannels for nanofluidic manipulation

Fluidic transport through nanochannels offers new opportunities to probe fundamental nanoscale transport phenomena and to develop tools for manipulating DNA, proteins, small molecules and nanoparticles. The small size of nanofabricated devices and the accompanying increase in the effect of surface forces, however, pose challenges in designing and fabricating flexible nanofluidic systems that can dynamically adjust their transport characteristics according to the handling needs of various molecules and nanoparticles. Here, we describe the use of nanoscale fracturing of oxidized poly(dimethylsiloxane) to conveniently fabricate nanofluidic systems with arrays of nanochannels that can actively manipulate nanofluidic transport through dynamic modulation of the channel cross-section. We present the design parameters for engineering material properties and channel geometry to achieve reversible nanochannel deformation using remarkably small forces. We demonstrate the versatility of the elastomeric nanochannels through tuneable sieving and trapping of nanoparticles, dynamic manipulation of the conformation of single DNA molecules and in situ photofabrication of movable polymeric nanostructures.     

多功能双螺杆挤出机的开发与应用

介绍一种多功能双螺杆挤出机,成功地开发了双螺杆挤出机用传动箱,新型止推装置可替代传统的止推包。     

网贴玻璃马赛克胶粘剂的研制

以氯丁改性苯丙乳液用做网贴玻璃马赛克的胶粘剂,研究了氯丁橡胶与苯乙烯、丙烯酸酯共聚时聚合温度、种子单体用量、氯丁用量等因素对乳胶性能的影响,分析了中试放大时产生粒子的原因,提出了解决的方法,得到了一种粘接牢、耐水性好、可满足出口产品生产要求的网贴马赛克胶粘剂。     

FMS的可靠性建模研究

ＦＭＳ的可靠性建模是ＦＭＳ可靠性设计与分析的基础,本文对ＦＭＳ可靠性建模的几种方法进行了介绍和分析,提出了ＦＭＳ可靠性建模的要求和建模的途径。     

Extracting bio-zinc and taurine from Pinctada martensii meat

Recently, intensive processing of marine resources has attracted considerable attention. In order to further utilize the byproducts of aquatic shellfish (Pinctada martensii meat) with high value, this study proposes a method of extracting zinc and taurine from P. martensii meat. Zinc was first extracted from P. martensii meat with an ultrasonic crusher, and then taurine was further extracted by ultrasonic-assisted water extraction from the remaining shellfish. After optimization, the biological zinc extraction rate reached 8.63%, and the taurine extraction rate reached 0.71%. Meanwhile, the parameters for cation exchange separation and taurine purification were optimized, in which the injection volume, pH value, and elution rate were set to 8.0 mL, 4.5, and 3.0 mL/min, respectively. Ultimately, the purity the extracted taurine reached 98.16%. This study provides a novel method for the extraction of biological zinc and taurine by deep processing of shellfish meat.     

金银花提取物对冷却肉中假单胞菌黏附性的影响

研究冷却肉中假单胞菌的黏附能力及金银花提取物的降黏附效果。结果表明：从15 份市售冷却肉中分离 得到46 株假单胞菌,经16S rDNA结合VITEK 2系统鉴定为恶臭假单胞菌22 株,占47.8%;荧光假单胞菌10 株,占 21.7%;铜绿假单胞菌6 株,占13.0%;浅黄假单胞菌8 株,占17.4%;33 株（71.7%）假单胞菌具有黏附能力,具有 强黏附能力的菌株占17.4%,其中恶臭假单胞菌数量最多;金银花提取物能够降低4 种假单胞菌的黏附能力,且对 恶臭假单胞菌5-3和铜绿假单胞菌5-1作用效果更强,作用效果与金银花提取物质量浓度有关;金银花提取物质量浓 度高于最小抑菌质量浓度（minimum inhibitory concentration,MIC）时,主要通过抑制菌体生长、减少胞外多糖产 生而降低假单胞菌的黏附能力;金银花提取物质量浓度低于MIC时,主要通过溶解菌体胞外多糖、增强通透性、降 低均匀度而降低假单胞菌的黏附能力。     

基于二维激光扫描的复合材料层合板热振试验装置研发与应用

研发了一套基于二维激光扫描测试装置的复合材料层合板热振试验装置。利用PLC控制器、触摸屏、滑台型导轨、步进电机、激振器、功率放大器、激光测振仪、加热及温控装置、振动控制仪及数据采集分析装置等,建立了满足层合板高温测振需求的硬件系统。基于PLC梯形图语言编写了二维激光扫描测试装置的控制软件,并详细介绍了手动、自动控制模块对应的操作界面与测控优势。以HF10碳纤维/树脂基层合板试件为例,对该装置进行了研究。结果表明:该装置可显著提高热环境下层合板结构模态振型的测试效率,且有利于研究不同温度对结构振动特性的影响。研究发现热环境对层合板固有频率和阻尼性能有着复杂影响,且随着温度的不断升高,模态阻尼比呈现减速增大的趋势。