58 resultados para Allouez, Claude, 1622-1689.
Resumo:
The < 110 >-oriented perovskite is very rare in the hybrid perovskites family. In this work, an unusual layered < 110 >-oriented hybrid perovskite, which is stabilized by a special organic ligand, 2-(aminoethyl)isothiourea, has been obtained. This ligand combines a primary amine and a formamidine on the two ends of one molecule. Introduction of the special ligand brings about contorted inorganic sheets in the hybrid perovskite structure. The optical properties of the new < 110 >-oriented perovskite were studied.
Resumo:
利用电纺丝技术制得钯/碳纳米纤维复合材料(Pd/CNFs),并将其用于修饰玻碳电极Pd/CNF-GCE/CME。Pd/CNF-GCE/CME对邻苯二酚和对苯二酚的氧化还原反应具有较高的电催化活性,显著提高了二者电化学反应的可逆性。考察了支持电解质的酸度对邻苯二酚和对苯二酚电化学响应的影响,选用0.1mol/LPBS(pH8.0)作为支持电解质。用微分脉冲伏安(DPV)法对邻苯二酚和对苯二酚进行选择性检测:当混合溶液中存在50μmol/L对苯二酚时,邻苯二酚的氧化峰电流与其浓度在1~90μmol/L范围内呈线性关系,检出限为0.3μmol/L(S/N=3);当存在50μmol/L邻苯二酚时,对苯二酚的氧化峰电流与其浓度在2~100μmol/L范围内呈线性关系,检出限为1.0μmol/L。另外,此修饰电极具有较好的重现性和较强的抗干扰能力。将此修饰电极用于模拟水样中邻苯二酚和对苯二酚的测定,结果令人满意。
Resumo:
Procedures that allow the realization of resonance electron capture (REC) mode on a commercial triple-quadrupole mass spectrometer, after some simple modifications, are described, REC mass spectrometry (MS) and tandem mass spectrometry (MS/MS) experiments were performed and spectra for some compounds were recorded. In particular, the charge-remote fragmentation (CRF) spectra of [M - H](-) ions of docosanoic and docosenoic acids under low-energy collisionally activated dissociation (CAD) conditions were obtained, and showed that there were no significant differences for [M - H](-) ions produced at different resonances (i,e. for [M - H](-) ions with different structures). This observation was explained on the basis of results obtained from deuterium-labeled fatty acids, which showed that different CRF ions (but with the same m/z value in the absence of labels) could be produced by different mechanisms, and all of them were obviously realized under CAD conditions that made spectra practically indistinguishable. The other example, which compared the REC-MS/MS spectrum of [M - H](-) ions and EI-MS/MS spectrum of M+. ions of daidzein, demonstrated the potential of the REC-MS/MS technique for more complex structure elucidation. Copyright (C) 2000 John Wiley & Sons, Ltd.
Resumo:
用 Siemens P4四圆衍射仪,测得了1,4-二丙氧基-2,3-二氰基萘的晶体结构。晶体属单斜晶系,空间群为 C2/C。晶格参数 a=14.987(3)A,b=10.527(2),c=11.755(2),β=118.98°(3),晶胞体积 V=1622.4(6)3,Z=4,Dc=1.205Kg/m~3,μ(MoK_α)=0.079mm~(-1),F(000)=624,T=293(2)K_o晶体结构应用直接法,解出最后的偏离因子 R=0.0554[1425个Ⅰ≥2σ(Ⅰ)衍射点]。结构分析表明,萘环的1,4和2,3位碳原子上的氢原子分别被丙氧基和氰基所取代,由于取代基的引入使萘环的结构有所改变。
Resumo:
Two new brominated selinane sesquiterpenes, 1-bromoselin-4(14), 11-diene (1) and 9-bromoselin-4(14), 11-diene (2), one known cadinane sesquiterpene, cadalene (3), and four known selinane sesquiterpenes, alpha-selinene (4), beta-selinene (5), beta-dictyopterol (6), and cyperusol C (7), were isolated from a sample of marine brown alga Dictyopteris divaricata collected off the coast of Yantai (China). Their structures were established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data.
Resumo:
Cultivation of the endophytic fungus Chaetomium globosum, which was isolated from the inner tissue of the marine red alga Polysiphonia urceolata, resulted in the isolation of chaetopyranin (1), a new benzaldehyde secondary metabolite. Ten known compounds were also isolated, including two benzaldehyde congeners, 2-(2 ',3-epoxy-1 ',3 '-heptadienyl)-6-hydroxy- 5-(3-methyl-2-butenyl) benzaldehyde (2) and isotetrahydroauroglaucin (3), two anthraquinone derivatives, erythroglaucin (4) and parietin (5), five asperentin derivatives including asperentin ( 6, also known as cladosporin), 5 '-hydroxy-asperentin-8-methylether (7), asperentin-8-methyl ether (8), 4 '-hydroxyasperentin (9), and 5 '-hydroxyasperentin (10), and the prenylated diketopiperazine congener neoechinulin A (11). The structures of these compounds were determined on the basis of their spectroscopic data analysis (H-1, C-13, H-1-H-1 COSY, HMQC, and HMBC NMR, as well as low- and high-resolution mass experiments). To our knowledge, compound 1 represents the first example of a 2H-benzopyran derivative of marine algal-derived fungi as well as of the fungal genus Chaetomium. Each isolate was tested for its DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging property. Compounds 1-4 were found to have moderate activity. Chaetopyranin (1) also exhibited moderate to weak cytotoxic activity toward several tumor cell lines.
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对虾病害在世界范围内肆虐,给水产养殖和沿海农村经济造成了重大损失。在水产养殖的实践中快速检测水产动物的病害并及时采取隔离等措施对于控制病害尤为重要,其中关键的环节就是快速检测出病害,并在对虾免疫机制上寻找对虾疾病防治的有效方法。研究表明当对虾等甲壳动物受到外界病原刺激时,极微量的微生物多糖就可以激活proPO系统。激活过程中涉及和产生一系列活性物质,如黑色素、酚氧化酶原激活因子(PPA)、模式识别蛋白(BGBP、PGBP、LGBP、LBP)及其膜上受体和A2巨球蛋白等,它们可通过多种方式参与防御反应,包括提供调理素,促进血细胞吞噬作用,形成结节或包囊以及介导凝集和凝固,产生杀菌物质并且黑色素化。黑色素常常在节肢动物的体表形成黑色斑点,形成的色素沉着对机体起到保护作用。所以,酚氧化酶原激活的级联反应是节肢动物免疫的关键因素。本论文研究开发了以环等温介导技术(LAMP)为基础的检测对虾白斑病毒(WSSV)和鳗弧菌(V. anguillarum)的快速检测方法。并从对虾对病害的免疫机制为切入点,从中国明对虾体内克隆了酚氧化酶原(PrpPO)和丝氨酸蛋白酶FcSP3这两个免疫系统中重要的基因,分析了它们的分子结构特征,组织分布及应答鳗弧菌病原刺激的表达变化模式。 建立的对虾常见病害对虾白班病毒(WSSV)和鳗弧菌(V. anguillarum)的LAMP检测方法,经过实验比对和Blast检索,发现本研究中使用的引物,比已经报导的LAMP方法或者PCR方法具有更宽的检测范围(更低的假阴性)。检测WSSV的LAMP方法使用病毒的VP28基因设计引物,而鳗弧菌的检测方法使用empA基因设计引物。在方法中,首次提出加入UNG酶和dUTP的措施来预防污染,在实际检测中非常有效。LAMP方法与PCR检测方法的灵敏性比较也进行了研究,二者灵敏性相当。 依据中国明对虾血液cDNA文库提供的部分片段信息,结合SMART-RACE技术,克隆了酚氧化酶原(PrpPO)基因,通过序列比对分析发现,PrpPO基因cDNA全长为3040 bp,其中开放阅读框2061 bp,编码686个氨基酸,其中推测的信号肽为12个氨基酸。推测的序列与斑节对虾(P. monodon)同源性为93%,与短钩对虾(P. semisulcatus.)同源性为92%。real time RT-PCR实验结果表明, ProPO在血细胞中的相对表达量最高,肝胰脏中表达量最低。弧菌刺激实验中注射弧菌,刺激了血细胞和淋巴器官中的ProPO mRNA显著增加,说明在血细胞和淋巴器官中存在快速反应的ProPO通路。而ProPO mRNA量在淋巴器官中在时间上早于血液中升至最高,说明该动物在在病原刚开始入侵的时候先有淋巴器官发挥主要的免疫作用,随着时间推移血细胞便变成主要的免疫器官。 根据中国明对虾肝胰脏cDNA文库提供EST信息,经过SMART-RACE克隆了一个丝氨酸蛋白酶FcSP3基因,通过序列比对分析发现,该丝氨酸蛋白酶基因cDNA全长为1622 bp,其中开放阅读框1431 bp,编码477个氨基酸,其中推测的信号肽为22个氨基酸。推测的序列与疟蚊的丝氨酸蛋白酶(A. gambiae)同源性为33%,与丽蝇蛹集金小蜂的酚氧化酶原激活因子(N. vitripennis)同源性为32%,与东北大黑鳃金龟的酚氧化酶原激活因子(H. diomphalia)同源性为34%。淋巴器官中PPAⅡ表达量约为血液中表达量的47560倍,肝胰脏中的FCSP3表达量为血细胞表达量的6226倍。鳗弧菌注射对虾后,淋巴器官中刺激组和对照组FcSP3的mRNA量在刺激后6小时显著降低,但是刺激组的表达量明显高于对照组。刺激组的血细胞与肝胰脏中FcSP3 mRNA的相对表达量增高。而病原刺激后的血液与肝胰脏中的FcSP3 mRNA的增长趋势也在时间上先与ProPO mRNA。这说明FcSP3对ProPO有正调控的作用,但这个调控有一个时间差,并且在不同组织中有不同的调控效率。
Resumo:
Dissolved inorganic carbon (DIC) account for more than 95% of total carbon in seawater, so it is necessary to make reliable and precise measurements of DIC to study marine carbon cycling. In order to establish a simple and speed method, an airproof device of gas extraction-absorption was designed. Finally a simple method was developed for the determination of DIC in seawater through a large mount of experiments. The determination procedure is as follows: 100 similar to 150 mL seawater was put into conical flask, then add 10% H3PO4, the DIC in seawater sample was dissolved to form CO2 gas and carried by pure N-2, then the CO2 gas was absorbed by two grades 0.1 mol/L NaOH solution. Finally the absorbed solution was titrated by HCl standard solution of 0.01000 mol/L with the end points detected with the indicator phenolphthalein and bromocresol green-methyl red mixture. The precision and accuracy of the method were satisfied. This method was used to analyse seawater samples from Jiaozhou bay in June, 2003. The result shows that the average DIC in surface seawater is 2066 mumol/L, DIC in bottom seawater is 2075 mumol/L inside bay, but the average DIC in surface seawater is 1949 mumol/L, DIC in bottom seawater is 2147 mumol/L outside bay.
Resumo:
介绍了管线钢硫化物应力腐蚀裂开危险性智能探测仪的设计、结构和检测结果。该检测仪具有数据采集、存储处理、逻辑判断和现场制表打印输出评价/判断等功能,对及时发现和消除含硫油气管线的隐患,以防止恶性破坏事故的发生有重要意义。
Resumo:
Slide-debris flow is debris flow which is transformed from landslide consecutively in a short time, it comprises of two phases: First, Landslide starts to slide; Second, landslide changes to debris flow. Slide-debris flow which brings great property and life loss happens frequently at home and abroad. In order to forecast the happening possibility and scope of slide-debris flow, transfromation mechanism of Slide-debris flow must be studied. Research on transformation mechanism of slide-debris flow is intersectant science of landslide kinetics and debris flow starting theory, It is a fringe problem as well as front problem of geological hazard. This paper takes Qingning slide-debris flow in Da County, Sichuan Province for example and has studied the mechanism of its instability and transfromation into debris flow through indoor test (including usual soil test and ring shear test) and digital modeling method.The research gets the following conclusions. Qingning Landslide took place mainly because of confined water head arising from rainfall infiltration. Before Landslide occurring, it rained continuously for 22 days, accumulated precipitation arrived at 521.6mm.Investigation shows that strata of Qingning Landslide contains quaternary loose accumulation, slip soil and highly weathered bedrock, which is a good condition for formation of confined water in the slope. Further more, groundwater seepage in the slope body and corresponding slope safety factor before landslide occurring have been computed through finite element method. The result shows that because of infiltration of rainfall, confined water head in the slope arose sharply, accordingly, the safety factor of the slope declined quickly. The result also shows that force put on the slide body by the rock mass detached from Dazhaiyan mountain was the direct factor for landslide occurring. Qingning slide-debris transformation mode has been summarized, the process the landslide changed into debris flow is divided into three phases in the prospective of macroscopic geological condition: landslide occurring, transformation and debris flow. Landslide occurring phase is from slope’ local creeping slide to Landslide occurring; transformation phase contains slide body sliding on the slide bed after slide occurring and sliding on the slope after shearing opening; debris flow phase is that slide body breaks up completely and flows downward into the ditches. The transformation mechanism of Qingning slide-debris flow has been studied through indoor ring shear test of slip soil. The result shows that transformation mechanism contains two points: first, during slide body sliding on the slide bed and slope after shearing opening, shearing shrinkage, grain crushing and grain layering brought about declining of its volume and produced excess pore water pressure, and because producing velocity of excess pore water pressure is much greater than its dissipating velocity, shear strength of slide body decreased sharply because of accumulated pore water pressure. Second, grains crushing and grains layering during slide body sliding brought about thick liquefied layer at the bottom of the slidebody, liquefied layer contained high water content and its shear strength was very low, its thickness increased as the sliding displacement increasing. Liquefied layer makes slide body sliding fast and easily break down to debris flow. Excess pore water pressure and liquefied layer made shear strength of slidebody became very low, furthermore, water in the pit of slope joining in the slidebody was also a facter that made slidebody accelerate the transformation. Influence of slide body thickness and fine grains content to transformation of slide-debris flow has been studied through ring shear test. The result reaches two conclusions. First, thickness of slide body affects transformation of slide-debris flow by two ways, porewater pressure and effect of “soft base” increases as thickness of slide body increasing.so the thicker slide body is ,the easier transformation is. Second, actual dissipating velocity of porewater pressure should be considered when studying the influence of fine grains content to tranformation of slide-debris flow. There should be a critical content of fine grains which makes the difference of producing and dissipating velocity of water pore pressre greatest, this value is the best for slide-debris transformation. The whole process of slide-debris flow transformation is reproduced through discrete element method. Transformation mechanism of slide-debris flow is studied through monitoring various parameters including pore water pressure, grain crushing and grain layering in the slide body during the transformation. The result confirms and supplements the transformation mechanism of slide-debris flow got from ring shear test well.
Resumo:
在碳酸盐岩地区,流域侵蚀过程中硫酸是否参与,对于我们正确理解流域化学风化速率,以及流域侵蚀对大气CO2的消耗和全球碳循环等都有重要的意义。本工作在前期工作(乌江)的基础上,对贵州喀斯特地区的河流(北盘江)和支流的水化学特征以及水体溶解无机碳同位素组成进行了初步研究,研究结果证实硫酸参与了该喀斯特流域岩石/土壤化学风化过程。
Resumo:
The structure and properties of Sm overlayer and Sm/Rh surface alloy have been investigated with Auger electron spectroscopy (AES), low energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), and temperature programmed desorption spectroscopy (TDS). The growth of Sm on Rh(100) at room temperature (RT) appears following the Stranski-Krastanov growth mode and only the trivalent state Sm is observed from XPS results. Thermal treatment of the Sm film at 900 K leads to the formation of ordered surface alloy which shows the c(5 root2 x root2)R45 degrees and c(2 x 2) LEED patterns. Annealing the Sm film at temperature above 400 K makes the binding energy (B.E.) of Sm 3d(5/2) shift to higher energy by 0.7 eV, which indicates charge transfer from Sm to Rh(100) substrate, causing the increase of CO desorption temperature.