面向服务的语义互操作性技术及其标准

面向服务的软件工程面临新的挑战。促进互联网环境中松耦合式服务资源之间的互操作性行为协作,是实现服务资源深度共享与按需服务的关键。文章对服务虚拟化的关键技术：可用资源的服务互操作性封装方法、虚拟化服务组织的互操作性聚合的基于本体的RGPS元建模方法、虚拟化服务管理的互操作性元模型框架及其注册与存储管理、虚拟化服务本体及其与RGPS关联呈现等进行了研究。对研究的互操作性元模型框架（MFI）及ISO系列标准工作新进展进行了介绍。     

基于相关向量机的网络入侵检测算法

针对支持向量机理论中存在的问题：训练样本数量多以及必须满足MerCer条件等,提出了一种基于相关向量机（RVM）的网络入侵检测方法。首先采用“删除特征”法对KDD99数据集中的41个特征进行评级,筛选出针对不同入侵类型的重要特征和非重要特征,然后只选择重要特征进行匹配。结果表明,这种方法与基于支持向量机（SVM）的入侵检测模型相比,具有更高的检测率和更低的误警率。     

New methods for nanotoxicology: synchrotron radiation-based techniques

Nanotoxicology, a new branch of bionanoscience, deals with the study and application of the toxic or biological effects of nanomaterials or nanostructures, and aims to fill gaps in our knowledge of interactions between nano- and biosystems. However, progress in this new discipline largely relies on developing methodology to characterize nanomaterials in biological samples, quantify nanoparticles in living systems, and study their uptake, translocation, biodistribution, location and chemical status in vitro and in vivo, etc. In this review article, we focus on the main features of synchrotron radiation-based methods and their application to the study of the toxicological activities of nanomaterials. Synchrotron radiation-based analytical techniques are shown to provide a potent means for characterizing the toxic or biological behaviors of nanoparticles in biological systems.     

pH‐induced on–off switching of polycarbonate track‐etched membranes by plasma‐induced surface grafting

Surface functionalization of the plasma‐pretreated polycarbonate (PC) track‐etched membranes via plasma‐induced thermally graft copolymerization of acrylic acid (AAc) was carried out. The resulting PC membranes with grafted AAc side chains were characterized by X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis. The morphology of the PC membranes was studied by scanning electron microscopy (SEM). The results showed that the grafted PAAc polymers were formed uniformly inside the pores throughout the entire membrane thickness. With increase in the pore‐filling ratio, the pore diameters of PAAc‐grafted membranes became smaller. The PC‐g‐PAAc membranes exhibit rapid and reversible response of the flux to the environmental pH as pH is switched between 3 and 9. Between pH 3.5 and 5.5, the membranes demonstrate a pH‐valve function as the carboxyl group changes from neutral to charged with a corresponding variation in chain configuration. Copyright © 2009 John Wiley & Sons, Ltd.     

Characterization of an exception to the ‘even‐electron rule’ upon low‐energy collision induced decomposition in negative ion electrospray tandem mass spectrometry

Electrospray‐generated precursor ions usually follow the ‘even‐electron rule’ and yield ‘closed shell’ fragment ions. We characterize an exception to the ‘even‐electron rule.’ In negative ion electrospray mass spectrometry (ES‐MS), 2‐(ethoxymethoxy)‐3‐hydroxyphenol (2‐hydroxyl protected pyrogallol) easily formed a deprotonated molecular ion (M‐H)^? at m/z 183. Upon low‐energy collision induced decomposition (CID), the m/z 183 precursor yielded a radical ion at m/z 124 as the base peak. The radical anion at m/z 124 was still the major fragment at all tested collision energies between 0 and 50 eV (E_lab). Supported by computational studies, the appearance of the radical anion at m/z 124 as the major product ion can be attributed to the combination of a low reverse activation barrier and resonance stabilization of the product ions. Furthermore, our data lead to the proposal of a novel alternative radical formation pathway in the protection group removal of pyrogallol. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and bioactivity of beta-carboline derivatives

The beta-carboline alkaloids possess a wide diversity of important biochemical effects and pharmacological properties. A series of beta-carboline derivatives were synthesized from L-tryptophan through the Pictet-Spengler reaction and oxidation of K2Cr2O7 by a sequential one-pot synthesis method. In vitro anti-bacterial, insecticidal, and cytotoxic activities of all synthesized compounds were investigated by the tablet diffusion, leaf disc, and MTT methods, respectively. Some of the compounds (1-1, 1-2, 1-3 and 1-12) exhibited obvious anti-bacterial effects and some (1-3) had significant cytotoxic activities against tumor cells 3LL, MCF-7, BGC-823 and QGY-7701, with IC50 values of 7.79, 5.75, 3.53 and 4.02 microg/mL, respectively. No insecticidal activity against third stage instar larvae of Mythimna separata Walker were observed under the tested concentration.     

5‐Formylsalicylic acid and 5‐(benzimidazolium‐2‐yl)salicylate

Both title compounds are derivatives of salicylic acid. 5‐Formylsalicylic acid (systematic name: 5‐formyl‐2‐hydroxybenzoic acid), C₈H₆O₄, possesses three good hydrogen‐bond donors and/or acceptors coplanar with their attached benzene ring and abides very well by Etter's hydrogen‐bond rules. Intermolecular O—H...O and some weak C—H...O hydrogen bonds link the molecules into a planar sheet. Reaction of this acid and o‐phenylenediamine in refluxing ethanol produced in high yield the new zwitterionic compound 5‐(benzimidazolium‐2‐yl)salicylate [systematic name: 5‐(1H‐benzimidazol‐3‐ium‐2‐yl)‐2‐hydroxybenzoate], C₁₄H₁₀N₂O₃. Each imidazolium N—H group and its adjacent salicyl C—H group chelate one carboxylate O atom via hydrogen bonds, forming seven‐membered rings. As a result of steric hindrance, the planes of the molecules within these pairs of hydrogen‐bonded molecules are inclined to one another by ∼74°. There are also π–π stacking interactions between the parallel planes of the imidazole ring and the benzene ring of the salicyl component of the adjacent molecule on one side and the benzimidazolium component of the molecule on the other side.     

碳载Pt-Ni催化剂对直接甲醇燃料电池阴极氧电还原性能的影响

采用间歇式微波法制备了不同Pt、Ni原子比的碳载Pt-Ni催化剂。XRD结果表明,用这种方法制备的催化剂分散得比较好,具有较小的平均粒径,其中Pt-Ni/C(3∶1)催化剂的粒径最小。在旋转圆盘电极上进行氧的还原测试结果表明,当电解质溶液中没有甲醇和有甲醇存在时,Pt-Ni/C(3∶1)催化剂对氧的催化还原活性都很高,说明Pt-Ni/C(3∶1)催化剂对氧的催化还原受甲醇的影响较小。     

还原-氧化-还原过程对Co-ZrO_2共沉淀催化剂结构及其费托合成反应性能的影响

采用程序升温还原、氮吸附、X射线衍射、Raman、XPS和H2-TPD等方法研究了还原(400℃,氢还原)-氧化(室温,暴露空气中氧化)-还原(250℃或400℃,氢还原)预处理过程对Co-ZrO2共沉淀催化剂结构的影响,考察了催化剂在不同反应器中的费托反应性能。结果表明,催化剂还原氧化前后钴物种均以Co3O4形式存在,颗粒直径无明显变化;还原氧化处理后催化剂表面钴物种含量有所下降,但H2-TPD结果显示催化剂经还原-氧化-还原后氢吸附量增加。另外,还原氧化过程能够降低催化剂表层钴物种的还原温度。反应结果表明,催化剂经还原氧化还原处理后活性明显增加,甲烷选择性降低。     

大气气溶胶中溴、碘总量及其形态的提取和测定

比较了超声纯水提取不同时间和多种密封提取条件下大气气溶胶样品滤膜中溴、碘形态稳定性和提取率。结果表明:密封提取方法的提取率高于超声提取方法,但有可能破坏了某种未知的有机碘形态;在长时间纯水超声条件下,醋酸纤维(CF)空白滤膜加标回收中I-形态不稳定。因此,纯水超声提取5 min为最佳提取条件。对比醋酸纤维(CF)和玻璃纤维(GF)空白滤膜加标回收实验发现,各种提取条件下GF材质对样品中溴、碘形态稳定性的干扰比CF材质小。在优化大气气溶胶溴、碘形态提取方法的基础上,建立了HPLC-ICP-MS测定大气气溶胶中BrO3-、Br-、IO3-和I-的方法,并对合肥地区气溶胶样品中溴、碘总量及形态进行测定。合肥地区气溶胶中溴和碘总量浓度分别为883和231 pmol/m3。其中,Br-占总溴的69%,BrO3-未检出;70%的碘为未知形态,包括可溶性有机碘和不可溶性碘。