快速RFID 防冲突算法

在对现有ALOHA Bit-Slot 算法分析的基础上提出一种改进的时隙ALOHA RNS 算法。该算法改变Bit- Slot 算法中标签数据回传方式，减少标签与读卡器的数据传输量，缩短识别时间，提高系统吞吐率，并解决了现有读卡 器无法探测有几个标签反馈了相同的独一码的问题。在大量标签情况下，根据数目多少进行分类表示，动态适应大 数据量传输。仿真结果表明，RNS 算法在标签数量大于1 000 时，相比Bit-Slot 算法在系统吞吐率上有30% 的提高，从 而适用在大数据量、实时性强的射频识别场合

Rapid RFID anti-collision algorithm

在对现有AlOHA bIT-SlOT算法分析的基础上提出一种改进的时隙AlOHA rnS算法。该算法改变bIT-SlOT算法中标签数据回传方式,减少标签与读卡器的数据传输量,缩短识别时间,提高系统吞吐率,并解决了现有读卡器无法探测有几个标签反馈了相同的独一码的问题。在大量标签情况下,根据数目多少进行分类表示,动态适应大数据量传输。仿真结果表明,rnS算法在标签数量大于1000时,相比bIT-SlOT算法在系统吞吐率上有30%的提高,从而适用在大数据量、实时性强的射频识别场合。An improved ALOHA RNS(Random Number Slot) algorithm was proposed based on the analysis of ALOHA Bit-Slot algorithm.The algorithm changed the return method of tag data,reduced the data between tag and reader,shortened the recognizing time,improved the system throughput rate,and solved the problem of current reader which could not detect more than one tag responsing the same unique code.Under a large amount of tag,it dynamically classifed the number to fit large data transmission.The simulation results show that the improved RNS algorithm improves the system throughput rate by 30 percent compared with Bit-Slot algorithm,when tag number is more than 1 000.It is suitable to large amount of data and real-time RFID environments

Developing On-site,Quick Screening Platform for Artificial Pigments in Food Using Surface-enhanced Raman Spectroscopy

已有研究表明食品加工过程中添加的人工合成色素不仅不能提供营养物质,而且可能是导致小儿多动症的来源之一,影响儿童智力发育.基于表面增强拉曼光谱(SERS)原理和便携式拉曼光谱仪,提出了一种非定向的现场快速筛查方法.该方法只需对疑似含有人工合成色素的固体或液体状食品样品进行简单前处理,即可进行SERS检测.样品前处理和检测的总时长不超过15 min,检出质量浓度在1 mg/L水平,可有效满足政府职能部门的现场执法需求.除具有快速、方便、灵敏度高等特点之外,该检测方法的最大优势在于实现了未知样品的现场非定向测试:在同一种前处理过程和检测方法下,可对食品中常添加的亮蓝、胭脂红、日落黄、柠檬黄、苋菜红和诱惑红6种人工合成色素进行快速鉴定和半定量分析.As widely used additives in food processing,artificial pigments have no any nutrition but are potential sources of hyper-activity and affect the intellectual development of children.On the basis of surface-enhanced Raman spectroscopy( SERS) and portable Raman instrument,we developed a non-targeting,on-site and quick screening platform for artificial pigments in food matrix. SERS measurement could be carried out after the food matrix( either in solid or liquid states) being simply pretreated for 15 min.The detectable concentration is as low as 1 mg / L,a level meeting the demand of the on-site enforcement by the government.Besides the advantages of quick,easy-on-going,and high sensitivity,the most distinguished point of SERS is the non-targeting qualitative on-site detection for the typical pigment additives,including brilliant blue,carmine,sunset yellow,lemon yellow,amaranth and allura red,et al.,while both the pretreatment procedure and the SERS detection remain the same.国家自然科学基金(21473140);; 福建省高校产学合作项目(2016Y4012);; 中央高校基本科研业务费专项(2072016011

Principle and development of programmable RF transceiver CC1100

介绍了Chipcon公司推出的一款具有极低功耗的可编程RF收发器CC1100的功能特点,给出了CC1100的应用电路设计及芯片配置方法,最后讨论了RF开发中常见的问题及解决方案。The characteristics of the ultra low power RF transceiver CC1100 produced by Chipcon Company are introduced.The application circuit design and configuration are given.The general questions of RF research and its solutions are also discussed

无索引空间数据库的基于最优点的集合最近邻查找算法

针对度量空间中的无索引空间数据库, 提出一种基于最优点的集合最近邻查找算法及其改进算法 采用真实数据集与人工生成的数据集对算法进行测试, 评估所提出算法的效率 实验结果表明, 所提算法的 效率优于组最近邻居查询算法, 并且对于高维数据空间, 所提出的算法有较高的稳定性 由于查询区域中数 据点的数量比较少, 改进的基于最优点的集合最近邻查找算法的效率总体上要比改进前高福建省自然科学基金资助项目( 2009J01288

基于粒子群优化的无线传感器网络节点定位改进

针对无线传感器网络低成本、低功耗的要求, 提出了一种DV-Hop改进算法, 利用节点间的估计距离和锚节点的位置, 在DV-Hop算法的第三阶段使用粒子群优化的方法校正DV-Hop得到的估算位置。该算法不需要任何额外硬件设备和不增加通信量。仿真表明, 改进的算法可以使DV-Hop的平均定位误差下降30%, 并有效降低了成本

化学信息学网络考试系统的构建

在WindowsNT 4 .0服务器建立化学信息学的Access试题数据库 ,使用ASP编写网络考试系统 ,供学生在Internet上使用浏览器进行在线考试。该系统安全可靠、应用范围广 ,是发展远程教育的重要工具

直接统计模拟位置方法中的分子表面反射确定论判据

在直接模拟Ｍｏｎｔｅ－Ｃａｒｌｏ（ＤＳＭＣ）方法的位置元方法中准确判断分子是否与某一表面元相撞，直接关系着气动力热的计算精度，是方法需要解决的关键问题。本文发展的分子表面反射判据，使这个问题得到了有效的解决。此外，还讨论了分子空间位置坐标的记录方法、分子碰撞对的极限距离、网格自适应等实际模拟技术。与圆球自由分子流准确解和过渡领域贴体网格ＤＳＭＣ模拟结果的比较，证明了上述判据和技术的有效性

Distribution pattern of PAHs in Jiulong River Estuary by both measurement and simulation

于2011年12月(冬季)在厦门九龙江河口及西港采集9个表层海水水样,采用固相萃取—气质联用方法(SPE-GC-MS)分析其中16种多环芳烃含量。研究结果表明,总溶解态态∑PAH含量为157.9~858.0 ng/L。在河口区,随着盐度升高,PAHs含量逐渐降低。基于比值法分析,表明厦门九龙江及西港海域海水中的PAHs来源存在多种途径,呈现混合来源的态势。利用LEVEL III逸度模型研究菲,芘和苯并(a)芘在各介质间的分布以及水——气界面的交换通量。模拟结果与本文实测和文献中的实测值相吻合。在16℃时,三种多环芳烃的大气沉降通量分别为17.38,7.86和8.38μg/day/m2。其中菲在大气沉降中占主导地位,约三分之二。三种多环芳烃的大气沉降通量均随温度升高而减少。当温度高于32℃时,苯并(a)芘开始从水体释放。The concentration of 16 polycyclic aromatic hydrocarbons( PAHs) of nine water samples,collected in the Jiulong River Estuary in December,2011,were analyzed using the SPE-GC-MS method. The results showed that the concentration range of total dissolved PAHs( ΣPAHs) was from 157. 9 to 858. 0 ng / L. The horizontal distribution illustrated that the concentration of ΣPAHs decreased as salinity increased. Based on ratio analysis,PAHs have complicated sources. A Level III fugacity model was developed to simulate the multimedia fate of PAHs and to study the air-water exchange fluxes of three PAHs( phenanthrene,pyrene,benzo[a]pyrene) in the Jiulong River Estuary. The calculated concentration of PAHs was similar to that measured in this study or reported in earlier literature. At 16℃,the net atmosphere deposition fluxes of these PAHs were 17. 38,7. 86 and 8. 38 μg / day / m2. Phenanthrene was predominant in the atmospheric deposition. The net atmospheric deposition fluxes of these PAHs all decreased with tem-perature. When the temperature was above 32. 0℃,benzo[a]pyrene was released from the water into the air.国家自然科学基金(40776044);; 福建省自然科学基金(2012J05078);; 福建省杰出青年科学基金(2014J06014);; 中央高校基本科研专项(20720140507

Developing fast laboratory screening platform for sulfate dioxide in food by surface-enhanced Raman spectroscopy

基于表面增强拉曼光谱(SERS)的指纹图谱的高能量分辨率,以位于~630; cm~(-1)亚硫酸根的特征峰为定性和定量依据,本文开展了食品中滥用和非法添加二氧化硫的直接检测研究:一种检测流程实现了不同食品基质中二氧化硫的; 高灵敏检测,最低检出浓度达1 mg; kg~(-1)的水平.针对实际样本的传统蒸馏法前处理流程的一些不足以及SERS检测的指纹图谱优势,本文进行了三方面显著改进:; (1)碳酸钙和沸石取代氮气以提高二氧化硫的挥发提取效率; (2)草酸取代盐酸酸化蒸馏溶液,以有效避免挥发性强酸对操作环境的危害;; (3)氢氧化钠溶液代替乙酸铅溶液作为吸收液,以防止二次污染.环境友好、灵敏度高和不受基质干扰等特点使得本方法有望取代经典蒸馏法和比色法,用于食品; 中非法添加二氧化硫类添加剂的快速高效筛查.The direct detection of sulphur dioxide has been realized in various; food matrixes with high sensitivity and high selectivity, on the basis; of the integration of the high energy resolution of the finger-print; spectrum of surface-enhanced Raman spectroscopy and the universal but; easy-on-going pretreatment procedure. The characteristic peak of sulphur; dioxide at ~630 cm~(-1) was applied as the qualitative and quantitative; standard, which displayed a lowest detectable concentration at the 1 mg; kg~(-1) level for the spiked food samples. The key point of the high; sensitivity and selectivity is the effective pretreatment born out of; the standard distillation one, which has been improved in the three; parts. (1) Using CaCO_3 and Zeolite instead of N_2 gas as the bubbling; reagent. (2) Using oxalic acid as the acidic distillation solution to; eliminate the hazards from acid volatilization, such as hydrochloric; acid. (3) Using diluted sodium hydroxide solution as the absorption; reagent instead of lead acetate solution to avoid the secondary; pollution. With the three distinguished advantages of environment; friendly, high sensitivity and free of matrix interference, the proposed; method has great potential to replace the traditional ones for the fast; screening of the illegal or abused sulphur dioxide in food.国家自然科学基金; 福建省高校产学合作项目; 中央高校基本科研业务费专项资