金电极表面植物原生质体的固定化

Barley protoplast was immobilized on poly(dially dimethylammonium) (PDADMAC) modified gold electrode via the electrostatic attraction between the positively charged amine groups of PDADMAC and the negatively charged barley protoplast. STM image reveals that PDADMAC/Au(111) surface displays a nano organized dot(4-6 nm) array structure. The processes of the PDADMAC adsorption and of the barley protoplast immobilization were monitored from the in situ QCM frequency change. The effects of the adsorbed mass and of the density and viscosity of medium on the frequency change of QCM were discussed, respectively. The QCM result shows that the thickness of the adsorbed PDADMAC layer is 2.4 nm

Chemical constituents of Vitis thunbergii var. taiwaniana

目的研究中国台湾传统中药材小叶山葡萄VITIS THunbErgII VAr.TAIWAnIAnA的化学成分。方法利用大孔树脂、SEPHAdEXlH-20、OdS及正相硅胶柱等色谱手段进行分离,通过多种波谱学数据分析进行单体化合物的结构鉴定。结果从小叶山葡萄60%乙醇提取物中分离得到12个化合物,分别鉴定为白藜芦醇(1)、TrAnS-ε-VInIfErIn(2)、(7r,8r)-THrEO-4,7,9,9′-TETrAHydrOXy-3,3′-dIMETHOXy-8-O-4′-nEOlIgnAn 7-O-β-d-gluCOPyrAnOSIdE(3)、(7S,8r)-urOlIgnOSIdE(4)、SCHIzAndrISIdE(5)、VITISInA(6)、VITISIn b(7)、dAVIdIOl A(8)、3,5,4′-TrIHydrOXySTIlbEnE 4′-O-β-d-gluCOPyrAnOSIdE(9)、蛇葡萄素C(10)、(7r,8S)-dIHydrOdEHydrOdICOnIfEryl AlCOHOl 9-O-β-d-gluCOPyrAnOSIdE(11)、表儿茶素(12)。结论化合物3~5为首次从葡萄属中分离,化合物8、9、11、12为首次从小叶山葡萄中分离。Objective To study the chemical constituents in Vitis thunbergii var.taiwaniana specially grown in Taiwan,China.Methods The compounds were isolated by repeated HP20 macroporous adsorption resin column combined with Sephadex LH-20,ODS,and silica gel column chromatography.Their structures were identified on the basis of extensive spectroscopic data analysis and by comparison of their spectral data reported.Results Twelve compounds were identified as resveratrol(1),trans-ε-viniferin(2),(7R,8R)-threo-4,7,9,9′-tetrahydroxy-3,3′-dimethoxy-8-O-4′-neolignan 7-O-β-D-glucopyranoside(3),(7S,8R)-urolignoside(4),schizandriside(5),vitisin A(6),vitisin B(7),davidiol A(8),3,5,4′-trihydroxystilbene 4′-O-β-D-glucopyranoside(9),ampelopsin C(10),(7R,8S)-dihydrodehydrodiconiferyl alcohol 9-O-β-D-glucopyranoside(11),and epicatechin(12).Conclusion Compounds 3—5 are separated from the plants of Vitis L.for the first time,and compounds 8,9,11,and 12 are separated from V.thunbergii var.taiwaniana for the first time.厦门市重大科技计划项目(3502Z20100006

Assessing ecological risks of heavy metals to marine organisms in the Jiulongjiang Estuary by species sensitivity distribution

采用物种敏感性分布法(SSd)构建常见重金属元素对海洋生物的SSd曲线,结合九龙江口水体5、8、11月份21个站位重金属调查数据,计算了九龙江口7种重金属(AS,Cd,Cr,Cu,Hg,Pb,zn)不同暴露浓度对海洋生物的潜在影响比例(PAf),并分析了在相应站位重金属复合污染生态风险(MSPAf)。结果表明,7种重金属中AS的生态风险最大(即PAf值最高);时间尺度上,5月份总的MSPAf较其他月份稍高;空间尺度上,西溪至海门岛(1~7号站位)污染较严重,其中又以位于西溪和玉枕洲的2号和5号站位的MSPAf为最。In the present work,a species sensitivity distribution( SSD) method was used to assess the ecological risk of common heavy metals to marine organisms.The ecological risk was characterized by potentially affected fraction( PAF) of species in relation to concentration of the toxic materials.According to the investigation data obtained at 21 stations in the Jiulongjiang Estuary in May,August and November,the PAFs of seven heavy metals( As,Cd,Cr,Cu,Hg, Pb,and Zn) to marine organisms were calculated.The results showed that As had the highest PAF among the seven heavy metals at each station of the Jiulongjiang Estuary.Spatially,the multi-substance PAF( msPAF) in May was higher than in other months.Temporally,the msPAF of the Stations 1-7( from the Xixi Stream to the Haimen Isle of the Jiulongjiang Estuary) suffered from heavier pollution.In particular,the pollution status of the Station 2 and Station 5 was the most serious among all the investigated stations.海洋公益性行业科研经费专项(201105015); 国家海洋局青年海洋科学基金项目(2011143); 国家自然科学基金项目(31101902); 福建省自然科学基金项目(2012J05074); 国家海洋局第三海洋研究所基本科研业务费专项(海三科2011006)资

壳聚糖衍生物处理碳纳米管改性聚丙烯腈基碳纤维

自制了邻苯二甲酰化壳聚糖、萘甲酰化壳聚糖、羧甲基化壳聚糖等3种壳聚糖衍生物对多壁碳纳米管(MWNTs)进行表面处理,发现邻苯二甲酰化壳聚糖(PhthCS)能有效提高MWNTs在极性6～10范围溶剂中的分散性及稳定性,并考察了PhthCS的分子量及浓度对MWNTs的分散性及稳定性的影响;通过微观形貌和元素分析,发现MWNTs部分表面包覆了一层厚度约为5～10 nm的包覆膜.经凝胶纺丝工艺制备了PhthCS-MWNTs/聚丙烯腈复合原丝,经预氧化、炭化制备了复合碳纤维,SEM结果表明PhthCS-MWNTs在复合原丝和复合碳纤维中分散均匀,良好取向;PhthCS-MWNTs对复合原丝和复合碳纤维的力学性能具有明显的改善作用,当PhthCS-MWNTs含量为0.5%时,复合碳纤维的拉伸强度提高了19.8%;增加PhthCS-MWNTs用量对复合碳纤维的拉伸模量具有显著提高,当PhthCS-MWNTs含量为3%时,复合碳纤维的杨氏模量从6.24 GPa提高到了13.86 GPa,增大了122%

Tailoring the optical property by a three-dimensional epitaxial heterostructure: A case of ZnO/SnO2

Epitaxial growth, as a best strategy to attain a heterostructure with a well-defined and clean interface, usually takes place on a planar substrate. In this paper, using a ZnO/SnO2 core-shell heterostructure as an example, we demonstrate the possibility of establishing a three-dimensional epitaxial interface between two materials with different crystal systems for the first time and show possible tailoring optical properties by building the heteroepitaxial crystal interface. The characterization results of element mapping, high-resolution transmission electron microscopy, and selected area electric diffraction reveal that the as-prepared ZnO/SnO2 heterostructure has a tetrapod-like ZnO core and a SnO2 shell with 15-30 nm, and their special epitaxial relation is (010)(SnO2)||(0110)(ZnO) and [100](SnO2)||[0001](ZnO). Such three-dimensional epitaxy between the ZnO core and SnO2 shell is quite different from the usual planar epitaxy or three-dimensional epitaxy between materials having the same crystal structure. A rational model of such complicated epitaxy has been proposed through investigating the certain structural comparability between the wurtzite ZnO and rutile SnO2 crystals. The as-prepared T-ZnO/SnO2 epitaxial heterostructure exhibits unique luminescence properties in contrast with individual tetrapod ZnO and SnO2 nanostructures, in which the epitaxial interface induces new luminescence properties. This result may inspire great interest in exploring other complicated epitaxy systems and their potential applications in laser, gas sensor, solar energy conversion, photo catalysis, and nanodevices in the future

Preparation and optical properties of ThO2 and Eu-doped ThO2 nanotubes by the sol-gel method combined with porous anodic aluminum oxide template

通讯作者地址: Xie, ZX (通讯作者), Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] this paper, we report the synthesis of thorium oxide and Eu-doped thorium oxide nanotubes for the first time using the sol-gel method in porous anodic aluminum oxide template. Transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were applied to characterize the morphology and structure of the as-prepared nanotubes. It has been demonstrated that Eu3+ ions were homogeneously doped into the ThO2 crystal lattice. The optical properties resulting from Eu-doped products were investigated by means of photoluminescence spectroscopy. Strong visible light emissions were observed at low doping concentration, and the luminescent intensity decreased at high doping concentration. The luminescent centers were concluded to be the Eu3+ ions in the cubic (O-h) sites rather than the C-3 upsilon sites, which accounted well for the decrease of luminescent intensity at high doping concentration

Preparation and self-assembly of copper nanoparticles via discharge of copper rod electrodes in a surfactant solution: a combination of physical and chemical processes

地址: 1. Xiamen Univ, Dept Chem, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] nanoparticles with a mean diameter of 10-15 nm were prepared and self-assembled via discharge of bulk copper rods in a cetyltrimethylammonium bromide (CTAB)/ascorbic acid solution. Ascorbic acid was used as a protective agent to prevent the nascent Cu nanoparticles from oxidation in the solution;, otherwise spindle-like Cu2O/CuO structures, with a lateral dimension of 30-50nm and length of up to 100nm, were formed in pure deionized water. The surfactant CTAB had a critical influence on self-assembly of spherical Cu nanostructures (with diameter of 700 nm-1mum). Such a low-temperature and non-vacuum method, exhibiting the characters of both physical and chemical processes, provides a versatile choice for economical preparation and assembly of various metal nanostructures. (C) 2004 Elsevier Inc. All rights reserved

Combustion Synthesis and Electrochemical Properties of the Small Hydrofullerene C50H10

通讯作者地址: Xie, SY (通讯作者),Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 3. Xiamen Univ, Sch Life Sci, Xiamen 361005, Peoples R China 电子邮件地址: [email protected]; [email protected] hydrofullerene C50H10 is synthesized by low-pressure benzeneoxygen diffusion combustion. The structure of C50H10 is identified through NMR, mass spectrometry, and IR and Raman spectroscopy as a D5h symmetric closed-cage molecule with five pairs of fused pentagons stabilized by ten hydrogen atoms. UV/Vis and fluorescence spectrometric analyses disclose its optical properties as comparable with those of its chloride cousin (C50Cl10). Cyclic and square-wave voltammograms reveal that the first reduction potential of C50H10 is more negative than that of C50Cl10 as well as C60, with implications for the utilization of C50H10 as a promising electron acceptor for photovoltaic applications.973 projects 2011CB935901 NSFC 21031004 21021061 2077310

Progress of High-Resolution Liquid NMR Spectroscopy in Inhomogeneous and Unstable Fields

高分辨核磁共振(nuClEAr MAgnETIC rESOnAnCE,nMr)谱的获得通常需要高度稳定且均匀的强静磁场.阻抗磁体或阻抗-超导混合磁体可获得比超导磁体高得多的磁场,但它们的磁场的稳定性与均匀性比较差;另一方面,在活体定域波谱研究中,样品内部组分的磁化率差异,运动或生理活动等作用将不可避免地导致磁场的不均匀不稳定,并且这些不稳定不均匀性无法通过锁场匀场等传统的方法消除.基于分子间零量子相干的方法、空间编码单扫描快速方法、反卷积技术等日渐成为在不均匀不稳定磁场下获取高分辨率的nMr谱的研究热点.Strong and extremely homogeneous and stable static magnetic fields are usually required for high-resolution NMR.However,large inhomogeneity and drift of the magnetic fields exist in the resistive and hybrid magnets which can provide much higher magnetic fields than the superconducting counterpart.On the other hand,the susceptibility gradients and physiological motions in in vivo studies produce inhomogeneous and unstable magnetic fields.Therefore,the inhomogeneous and instable magnetic fields in the non-ideal condition are unavoidable and can hardly be eliminated by conventional methods such as shimming and locking.Some approaches had been proposed to obtain high-resolution NMR spectra in the inhomogeneous and instable field,such as intermolecular zero quantum coherences (iZQCs),spatially encoding single-scan scheme and deconvolution.In the paper,these four methods were discussed.国家自然科学基金资助项目(10774125;10974164