Adaptive neural network consensus tracking control for uncertain multi-agent systems with predefined accuracy

Nonlinear Dynamics - This paper proposes the consensus tracking control problem for a class of uncertain nonlinear multi-agent systems. By using a group of nonnegative functions, an adaptive neural...     

加速溶剂萃取-气相色谱-串联质谱法测定茶叶中10种吡唑和吡咯类农药的残留量

建立了加速溶剂萃取(ASE)-气相色谱-串联质谱(GC-MS/MS)法用于测定茶叶中10种吡唑和吡咯类农药残留。ASE萃取压力为1.03×107 Pa,萃取温度为100 ℃,萃取时间为5 min,萃取溶剂为乙酸乙酯-正己烷(1:1, v/v)。萃取循环1次,萃取液浓缩后用Envi-Carb/PSA固相萃取小柱净化,乙酸乙酯-正己烷(1:1, v/v)洗脱。洗脱液浓缩后,用正己烷定容,供GC-MS/MS测定,外标法定量。方法的准确度和精密度均符合残留分析要求。方法的定量限(LOQ)分别为唑螨酯0.003 mg/kg、氟虫腈硫化物0.001 mg/kg、氟虫腈0.002 mg/kg、氟虫腈砜化物0.005 mg/kg、溴虫腈0.002 mg/kg、氟硅唑0.006 mg/kg、野燕枯0.001 mg/kg、吡草醚0.001 mg/kg、吡螨胺0.0003 mg/kg、唑虫酰胺0.005 mg/kg。方法的灵敏度能满足各国有关农药的残留限量要求。     

串联固相萃取-液相色谱-串联质谱法测定食品中嘧啶胺类杀菌剂残留

建立了食品中嘧啶胺类杀菌剂嘧霉胺、嘧菌胺及嘧菌环胺残留的串联固相萃取-液相色谱-串联质谱(HPLC-MS/MS)检测方法。胡萝卜、辣椒等样品经乙酸乙酯提取,石墨化炭黑-弗罗里硅藻土串联固相萃取柱(ENVI-Carb-Florisil SPE)净化后,在HPLC-MS/MS仪上进行检测分析,采用外标法定量。质谱分析采用电喷雾电离,正离子扫描,多反应监测模式。结果表明,柱净化后无明显的基质效应,嘧霉胺、嘧菌胺和嘧菌环胺在1～20 μg/L内相关系数可达0.9990以上,具有良好的线性关系;每种杀菌剂选择两个离子对,其中一组用于定量: 嘧霉胺m/z 200.1/107.1,嘧菌胺m/z 224.0/106.0及嘧菌环胺m/z 226.0/108.1;另一组用于确证: 嘧霉胺m/z 200.1/183.1,嘧菌胺m/z 224.0/131.1和嘧菌环胺m/z 226.0/133.1。样品中添加0.1、0.5、1.0 μg/kg的标准品,其回收率为73.2%～98.7%,相对标准偏差(n=10)小于10%;嘧霉胺、嘧菌胺、嘧菌环胺的检出限(信噪比(S/N)=3)均为0.03 μg/kg;嘧霉胺、嘧菌胺、嘧菌环胺的定量限(S/N=10)均为0.1 μg/kg。实验结果表明,该方法提取效果好,具有良好的灵敏度、回收率和重复性。     

有机过氧化物与N-甲基-N-2-羟乙基苯胺引发体系的研究

测定了有机过氧化物与N-甲基-N-2-羟乙基苯胺(HMA)体系引发MMA聚合的动力学方程和聚合表现活化能。由过氧化物/HMA/MNP的ESR波谱证实芳叔胺HMA中,与氮原子相连的亚甲基的氢被摘去形成相应的碳自由基,它能引发单体聚合成为聚合物的端基。这也由聚合物的UV光谱所证实,由实验结果提出这类体系的引发机理。     

楔形双滑面稳定性动态分析及其在削坡治理中的应用──以神府-东胜和准格尔煤田露天采场斜坡为例

本文提出了可以连续地计算任何坡高不同坡角的双滑面楔形四面滑体的稳定系数, 以便求得某一稳定性系数的最优化坡角。本方法经神府-东胜及准格尔煤田采场斜坡验算, 得知两煤田采场斜坡还有较大的安全储备。     

JavaStat: a Java/R-based statistical computing environment

Architectures are described which allow a Java-based front-end to run R code on a server. The front-end described here is a Java application called JavaStat (). JavaStat is a highly-interactive program for data analysis and dynamic visualization with data management capabilities. The objective is to bring the high-level functions of R to JavaStat, without excessive duplicative development work. Results returned from R are wrapped and then displayed using linked, dynamic plots in JavaStat. The principal idea is to use Remote Method Invocation to communicate with a Java server program (JRIServer), which in turn communicates with R using Java/R Interface (JRI). Two versions have been implemented. The first (basic) architecture maintains a connection between the client and server in order to return the results from R. This is suitable for small to moderate data sets in which relatively simple models are run. The second (enhanced) architecture queues the requests and uses polling to fetch the results. It is suitable for large data sets and complex models, e.g., those encountered in genomic studies. JavaStat supports the basic architecture out of the box, but a user account is required to enable the enhanced architectures. The enhanced architecture supports workflows, e.g., genomic and modeling workflows.     

溶剂型智能驱动材料的研究进展

智能驱动材料可对光、电、温度、溶剂、湿度等外界刺激做出可控的力学响应,并将这些能量转化为机械能而被广泛关注.溶剂型驱动材料是基于简单的湿度或溶剂气氛变化将化学能转换成机械能,并在机械发电、微型器件制备等方面具有重要的潜在应用.本文综述了溶剂型智能驱动材料的驱动类型、驱动原理,性能及其相关应用进展,并对溶剂型智能驱动材料在未来人工智能方面的应用前景进行了展望.     

Multifunctional high-performance l O-J level laser system

In this letter, we report a multifunctional high-performance Nd：glass laser system. Laser pulses from an all-fiber front end are first amplified by a regenerative amplifier to 10 mJ level, and then further amplified in a four-pass amplifier. The laser system can provide 10.3-J, 3-ns laser pulses at 1053-nm wavelength. The shot-to-shot energy stability is better than 1.5% （RMS）. The output laser beam is near diffraction limit. Binary amplitude masks are used to maintain a flat top near-field profile with a 71% fill factor. After the frequency conversion process, 7 and 5.5 J pulses at 526.5 and 351 nm are obtained, respectively.     

Signal amplification by adsorption-induced catalytic reduction of dissolved oxygen on nitrogen-doped carbon nanotubes for electrochemiluminescent immunoassay

A signal amplification strategy was proposed for quantum dot-based electrochemiluminescence by an adsorption-induced catalytic reduction of dissolved oxygen at the sidewall of nitrogen-doped carbon nanotubes, which led to a 'signal-on' sandwich immunoassay with a linear range of 6 orders of magnitude.