一类不确定非线性系统的时滞依赖的鲁棒H_∞控制(英文)

考虑了一类带时变延滞和时变范数有界参数不确定性的非线性系统的鲁棒H∞控制.利用线性矩阵不等式(LMI)给出了问题可解的一个充分条件.针对该类系统,设计了一种满秩的无记忆线性状态反馈控制器.     

分数阶不确定奇异系统的镇定

研究阶数0α1的分数阶不确定奇异系统的鲁棒镇定问题.利用矩阵奇异值分解和线性矩阵不等式方法提出新的基于观测器的鲁棒状态反馈镇定的充分条件,同时给出该条件下观测器和状态反馈控制器的具体求解方法.最后通过数值例子验证该方法的有效性.     

分数阶不确定奇异系统的镇定

研究阶数0α1的分数阶不确定奇异系统的鲁棒镇定问题.利用矩阵奇异值分解和线性矩阵不等式方法提出新的基于观测器的鲁棒状态反馈镇定的充分条件,同时给出该条件下观测器和状态反馈控制器的具体求解方法.最后通过数值例子验证该方法的有效性.     

线性时滞不确定系统的H∞状态反馈控制器设计

研究了具有已知常数时滞和参数不确定性的线性系统的鲁棒H∞控制问题,系统的参数不确定但有界.给出了一个基于LMI的鲁棒H∞状态反馈控制器,通过使用一种新的凸优化算法,使系统具有更小的保守性.仿真结果表明:当时滞的取值范围0≤τ≤0.4350时,存在一个无记忆反馈控制器使系统可镇定.     

一类不确定离散时滞系统鲁棒稳定性判定与仿真

对范数有界不确定离散时滞系统,给出了鲁棒稳定性判定标准,构造相应的Lyapunov函数.采用线性矩阵不等式（LMI）技术,设计出基于LMI的状态反馈鲁棒控制器.通过仿真实例验证了该方法的正确性和有效性.     

线性定常系统的次最优控制及其在飞机侧向自动稳定装置设计中的应用

本文从理论上详细地推导了线性定常系统无限终端时间的次最优调节器的一些理论结果,並简要地说明了次最优调节器与最优线性调节器的一般关系。研究了线性定常输出反馈增益矩阵的数值计算方法,讨论了初始迭代值的选取问题。用BASIC语言编制了求解线性输出反馈增益矩阵和全状态反馈增益矩阵的应用软件並对系统进行了计算机仿真研究。通过和线性最优调节器的对比分析,得到了次最优调节器的可行性和经济性等结论。最后,结合飞机侧向自动稳定装置设计的实例,得到了令人满意的结果。     

不确定多时滞系统的输出变结构控制

研究了带有不匹配参量不确定性和匹配外扰的多时滞系统的鲁棒变结构控制,利用系统输出设计滑模面,通过线性矩阵不等式给出了滑模面存在的一个时滞无关充分性条件,利用到达条件设计控制律实现滑模控制.仿真实例表明所给定理正确,控制策略有效.     

不确定离散时滞系统的鲁棒H_∞保成本控制

对一类同时具有状态时滞和输入时滞的不确定离散时滞系统, 基于Lyapunov稳定性理论和线性矩阵不等式(LMI)处理方法, 得到系统H∞保成本状态反馈控制律存在的一个充分条件, 并利用线性矩阵不等式的可行解给出H∞保成本状态反馈控制律的设计方法. 进而, 通过求解凸优化问题解决了系统最优鲁棒H∞保成本控制律的设计问题. 最后, 通过数值算例说明了该设计方法的可行性.     

一类数据不确定的非线性规划在扰动集合下的鲁棒对应形式

研究一类数据不确定的非线性规划的鲁棒优化问题.推导此问题在一般不确定集下的鲁棒对应形式.利用凸分析的知识找到它在椭球型扰动集合,箱型集合,离散型集合,多面体扰动集合下的鲁棒对应形式.     

带有时滞和非线性不确定性的中立系统的鲁棒稳定性条件

研究一类带有时滞和非线性不确定性的不确定中立系统的鲁棒稳定性问题.通过选择适当的Lyapunov函数,使用Leibniz-Newton公式的变形,结合自由权矩阵思想,加入一些自由矩阵,并且利用线性矩阵不等式(LMI)技术,得到了新的带有时滞和非线性不确定性的中立系统的时滞依赖稳定性条件.最后,通过数值算例来验证此方法的可行性以及有效性.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press