Nanoelectrode ensembles based on semi-interpenetrating network of carbon nanotubes

A method for preparing nanoelectrode ensembles based on semi-interpenetrating network (SIN) of multi-walled carbon nanotubes (MWNTs) on gold electrode through phase-separation method is initially proposed. Individual nanoelectrode owns irregular three-dimensional MWNTs networks, which is denoted as SIN-MWNTs. On the as-prepared SIN-MWNTs nanoelectrode ensembles, the assembled MWNTs clusters in nanoscale serve as individual nanoelectrode and the electroinactive lipid networks located on the top of alkanethiol monolayer are used as a shielding layer. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), tapping-mode atomic force microscopy (TM-AFM) and scanning electron microscopy (SEM) were used to characterize the as-prepared SIN-MWNT nanoelectrode ensembles. Experimental results indicate that the well-defined nanoelectrode ensembles were prepared through self-assembly technology. Meantime, sigmoid curves in a wide scanning range can be obtained in CV experiments. This study may pave the way for the construction of truly nanoscopic nanoelectrode arrays by bottom-up strategy.

Europium ion labeling anti-HBs

A microsecond time-resolved laser fluorescence spectroscopic analysis set was developed, A chelate-cyclic anhydride of diethylenetrimin pentaacetic acid anhydride (DTPAA) was synthesized. An anti-HBs antibody was purified, A EU3+ -DTPAA-anti-HBs label was prepared by two step procedure. We described the optimal condtion with EU3+ as marker and DTPAA as chelate bounding to antibody molecule. Labeling parameters such as solvent pH, protein and chelate molar ratio, reaction time, separation method were discussed in detail.

Studies on morphology and crystallization of polypropylene/polyamide 12 blends

Scanning electron microscopy (SEM) and an image analyser are used to study morphologies of the fractured surface, etched by hot phenol, of polypropylene/maleated polypropylene/polyamide 12 PP/PP-MA/PA12) = 65/10/25 blend and PP-MA/PA12 = 75/25 blend. The particle dimension and its distribution of PA12 dispersed phase in these blends are much lower and narrower than that of the PP/PA12. blends. Especially, most of the particles in the PP-MA/PA12 = 75/25 blend are smaller than 0.1 mu m. The effect of the morphology of PP/PA12 blends on their crystallization behaviour is studied using differential scanning calorimetry and SEM. PA12 dispersed phase coarsens during annealing in the PP/PP-MA/PA12 = 65/10/25 blend. The mechanism of coarsening of the PA12 dispersed phase is a coalescence process. The intense mixing between the PP component and the PA12 component through reaction of PP-MA and PA12 leads to a change of dynamic mechanical behaviour of the components. A separation method is used to separate the polyolefin parts (precipitated from hot phenol), from PA12 parts (hot phenol filtrate). Of PP/PP-MA/PA12 = 65/10/25 blend, infra-red measurements and elementary analysis show that the precipitate has a lower PA12 content than the feed, whereas the filtrate has a higher PA12 content. From PP-MA/PA12 = 75/25 blend, PA12 contents in the precipitate and the filtrate are the same as in the feed. This implies that all PA12 has reacted with all PP-MA in the latter case while not in the former case. Using the method of interface exposure, interfacial reaction of PP-MA with PA12 is studied by X-ray photoelectron spectrometry (X.p.s.). Copyright (C) 1996 Elsevier Science Ltd.

Effects of different light sources and illumination methods on growth and body color of shrimp Litopenaeus vannamei

Shrimps Litopenaeus vannamei with initial body weight of 2.108 +/- 0.036 g were sampled for specific growth rates (SGR) and body color measurements for 50 days under different light sources (incandescent lamp, IL; cool-white fluorescent lamp, FL; metal halide lamp, MHL; and control without lamp) and different illumination methods (illumination only in day, IOD, and illumination day and night, IDN). Body color of L. vannamei was measured according to the free astaxanthin concentration (FAC) of shrimp. The SGR, food intake (FI), feed conversion efficiency (FCE) and FAC of shrimps showed significant differences among the experimental treatment groups (P < 0.05). Maximum and minimum SGR occurred under IOD by MHL and IDN by FL, respectively (difference 56.34%). The FI of shrimp for the control group did not rank lowest among treatments, confirming that shrimp primarily use scent, not vision, to search for food. FI and FCE of shrimps were both the lowest among treatment groups under IDN by FL and growth was slow, thus FL is not a preferred light source for shrimp culture. Under IOD by MHL, shrimps had the highest FCE and the third highest FI among treatment groups ensuring rapid growth. FAC of shrimp were about 3.31 +/- 0.20 mg/kg. When under IOD by MHL and IDN by FL, FAC was significantly higher than the other treatments (P < 0.05). To summarize, when illuminated by MHL, L. vannamei had not only vivid body color due to high astaxanthin concentration but also rapid growth. Therefore, MHL is an appropriate indoor light source for shrimp super-intensive culture. SGR of shrimp was in significantly negative correlation to FAC of shrimp (P < 0.05). Thus, when FAC increased, SGR did not always follow, suggesting that the purpose of astaxanthin accumulation was not for growth promotion but for protection against intense light. (c) 2005 Elsevier B.V. All rights reserved.

高密度聚乙烯塑料压力管道热板焊接头应力分布有限元分析

基于热粘弹性积分型本构关系,考虑材料性能依赖于温度变化及相变潜热的影响,利用AN SYS热-力耦合及载荷步功能模拟结晶型高密度聚乙烯(HDPE)塑料压力管道热板焊接过程,并对焊接接头的应力分布进行有限元分析,得到了环向、轴向以及径向瞬态应力分布的基本规律。采用盲孔法和锯切法测量焊后残余应力,实测结果与数值分析基本符合

微量样品钕-锶-铅同位素分析方法在黄河下游悬浮颗粒物及沉积物的应用

Aim in Rb-Sr-REE-Pb isotopic analysis of river material, a single-stage, highly efficient and rapid chemical separation method of Rb-Sr-REE-Pb has been established by a combination of the SR special resin and the RE resin. At the same time, Feasibility of high precision analysis on micro-size Nd samples，which were chemically separated by using the LN resin, were systematicly studied using the NdO+ technique in thermal ionization mass spectrometer (TIMS). Results show that high precision measurement of Nd isotopic ratios can be successfully achieved on micro-sample of 1 ng size lever, by systematic experiments on isobar interferences and optimizing separation and measurement conditions. This method will greatly extend the application prospect of the NdO+ technique. Sr-Nd-Pb isotopic composition of suspending particle material (SPM) and sediment and Sr isotopic composition of river water in the low reaches of the Yellow Rriver have been systematically analysed in this study. Results can indicate followings: (1) relative stable Sr isotopic ratios around 0.7112 of river water suggest great influcence from dissolution of carbonate component of loss material on Sr isotopic composition of river water; (2) Nd isotopic compositions of SPM and sediment of the Yellow river are is similar, mean εNd value of SPM around -11.5 and mean εNd value of sediment -12.7, slightly lower than that of SPM. Nd isotopic composition of the Yellow River material is simarlar to or slightly lower than loss material (-9.5); (3) evidence of Sr and Pb isotopic compositions of both SPM and sediment reveals a mixing trend of two endmembers. Sr isotopic ratios of SPM after leaching are significantly different that those without leaching, possibly suggesting strong alteration of river water. Pb isotopic ratios of SPM remain unchangable after leaching compared with unleached SPM; (4) Pb-contents of SPM are commonly higher than those of sediments, while Pb isotopic ratios of SPM are significantly lower. Pb isotopic composition of the Yellow River is relatively constant, which can be a useful provenance indicator between the Changjiang and Yellow Rivers.

三维油藏数值模拟正反演算法研究

The dynamic prediction of complex reservoir development is one of the important research contents of dynamic analysis of oil and gas development. With the increase development of time, the permeabilities and porosities of reservoirs and the permeability of block reservoir at its boundaries are dynamically changing. How to track the dynamic change of permeability and porosity and make certain the permeability of block reservoir at its boundary is an important practical problem. To study developing dynamic prediction of complex reservoir, the key problem of research of dynamic prediction of complex reservoir development is realizing inversion of permeability and porosity. To realize the inversion, first of all, the fast forward and inverse method of 3-dimension reservoir simulation must be studied. Although the inversion has been widely applied to exploration and logging, it has not been applied to3-dimension reservoir simulation. Therefore, the study of fast forward and inverse method of 3-dimension reservoir simulation is a cutting-edge problem, takes on important realistic signification and application value. In this dissertation, 2-dimension and 3-dimension fluid equations in porous media are discretized by finite difference, obtaining finite difference equations to meet the inner boundary conditions by Peaceman's equations, giving successive over relaxation iteration of 3-dimension fluid equations in porous media and the dimensional analysis. Several equation-solving methods are compared in common use, analyzing its convergence and convergence rate. The alternating direction implicit procedure of 2-dimension has been turned into successive over relaxation iteration of alternating direction implicit procedure of 3-dimension fluid equations in porous media, which possesses the virtues of fast computing speed, needing small memory of computer, good adaptability for heterogeneous media and fast convergence rate. The geological model of channel-sandy reservoir has been generated with the help of stochastic simulation technique, whose cross sections of channel-sandy reservoir are parabolic shapes. This method makes the hard data commendably meet, very suit for geological modeling of containing complex boundary surface reservoir. To verify reliability of the method, theoretical solution and numerical solution are compared by simplifying model of 3-dimension fluid equations in porous media, whose results show that the only difference of the two pressure curves is that the numerical solution is lower than theoretical at the wellbore in the same space. It proves that using finite difference to solve fluid equations in porous media is reliable. As numerical examples of 3-dimension heterogeneous reservoir of the single-well and multi-well, the pressure distributions have been computed respectively, which show the pressure distributions there are clearly difference as difference of the permeabilities is greater than one order of magnitude, otherwise there are no clearly difference. As application, the pressure distribution of the channel-sandy reservoir have been computed, which indicates that the space distribution of pressure strongly relies on the direction of permeability, and is sensitive for space distributions of permeability. In this dissertation, the Peaceman's equations have been modified into solving vertical well problem and horizontal well problem simultaneously. In porous media, a 3D layer reservoir in which contain vertical wells and horizontal wells has been calculated with iteration. For channel-sandy reservoir in which there are also vertical wells and horizontal wells, a 3D transient heterogeneous fluid equation has been discretized. As an example, the space distribution of pressure has been calculated with iteration. The results of examples are accord with the fact, which shows the modification of Peaceman's equation is correct. The problem has been solved in the space where there are vertical and horizontal wells. In the dissertation, the nonuniform grid permeability integration equation upscaling method, the nonuniform grid 2D flow rate upscaling method and the nonuniform grid 3D flow rate upscaling method have been studied respectively. In those methods, they enhance computing speed greatly, but the computing speed of 3D flow rate upscaling method is faster than that of 2D flow rate upscaling method, and the precision of 3D flow rate upscaling method is better than that of 2D flow rate upscaling method. The results also show that the solutions of upscaling method are very approximating to that of fine grid blocks. In this paper, 4 methods of fast adaptive nonuniform grid upscaling method of 3D fluid equations in porous media have been put forward, and applied to calculate 3D heterogeneous reservoir and channel-sandy reservoir, whose computing results show that the solutions of nonuniform adaptive upscaling method of 3D heterogeneous fluid equations in porous media are very approximating to that of fine grid blocks in the regions the permeability or porosity being abnormity and very approximating to that of coarsen grid blocks in the other region, however, the computing speed of adaptive upscaling method is 100 times faster than that of fine grid block method. The formula of sensitivity coefficients are derived from initial boundary value problems of fluid equations in porous media by Green's reciprocity principle. The sensitivity coefficients of wellbore pressure to permeability parameters are given by Peaceman's equation and calculated by means of numerical calculation method of 3D transient anisotropic fluid equation in porous media and verified by direct method. The computing results are in excellent agreement with those obtained by the direct method, which shows feasibility of the method. In the dissertation, the calculating examples are also given for 3D reservoir, channel-sandy reservoir and 3D multi-well reservoir, whose numerical results indicate: around the well hole, the value of the sensitivity coefficients of permeability is very large, the value of the sensitivity coefficients of porosity is very large too, but the sensitivity coefficients of porosity is much less than the sensitivity coefficients of permeability, so that the effect of the sensitivity coefficients of permeability for inversion of reservoir parameters is much greater than that of the sensitivity coefficients of porosity. Because computing the sensitivity coefficients needs to call twice the program of reservoir simulation in one iteration, realizing inversion of reservoir parameters must be sustained by the fast forward method. Using the sensitivity coefficients of permeability and porosity, conditioned on observed valley erosion thickness in wells (hard data), the inversion of the permeabilities and porosities in the homogeneous reservoir, homogeneous reservoir only along the certain direction and block reservoir are implemented by Gauss-Newton method or conjugate gradient method respectively. The results of our examples are very approximating to the real data of permeability and porosity, but the convergence rate of conjugate gradient method is much faster than that of Gauss-Newton method.

多波分量地震资料处理解释方法

To deal with some key problems in multi-component seismic exploration, some methods are introduced in this thesis based on reading amounts of papers about multi-component seismic theories and methods. First, to find a solution for the detection of the fracture density and orientation in igneous, carbonate and shale reservoirs, a large amount of which exist in domestic oil fields with low exploration and development degree, a new fast and slow shear waves separation method called Ratio Method based on S-wave splitting theory is discussed in this thesis, through which the anisotropy coefficient as well as fracture parameters such as density and azimuthal angle can be acquired. Another main point in this thesis involves the application of seismic velocity ratio (Vp/Vs) to predict the Hthological parameters of subsurface medium. To deal with the unfeasibility of velocity ratio calculation method based on time ratio due to the usually low single-noise ratio of S-wave seismic data acquired on land, a new method based on detailed velocity analysis is introduced. Third, pre-stack Kirchhoff integral migration is a new method developed in recent years, through which both S and P component seismic data as well as amplitude ratio of P/S waves can be acquired. In this thesis, the research on untilizing the P and S wave sections as well as amplitude ratio sections to interpret low-amplitude structures and lithological traps is carried out. The fast and slow shear wave separation method is then be applied respectively to detect the density and azimuthal angle of fractures in an igneous rock gas reservoir and the coal formation in a coal field. Two velocity ratio-calculating methods are applied respectively in the lithological prediction at the gas and coal field after summarizing a large amount of experimental results draw domestically and abroad. P and S wave sections as well as amplitude ratio sections are used to identify low-amplitude structures and lithological traps in the slope area of a oil-bearing sedimentary basin. The calculated data concerning fracture density and azimuthal angle through the introduced method matches well with the regional stress and actual drilling data. The predicted lithological data reflects the actual drilling data. Some of the low-amplitude and lithological traps determined by Kirchhoff migration method are verified by the actual drilling data. These results indicate that these methods are very meaningful when dealing with complex oil and gas reservoir, and can be applied in other areas.

Domain decomposition methods for welding problems

This paper, a 2-D non-linear electric arc-welding problem is considered. It is assumed that the moving arc generates an unknown quantity of energy which makes the problem an inverse problem with an unknown source. Robust algorithms to solve such problems e#ciently, and in certain circumstances in real-time, are of great technological and industrial interest. There are other types of inverse problems which involve inverse determination of heat conductivity or material properties [CDJ63][TE98], inverse problems in material cutting [ILPP98], and retrieval of parameters containing discontinuities [IK90]. As in the metal cutting problem, the temperature of a very hot surface is required and it relies on the use of thermocouples. Here, the solution scheme requires temperature measurements lied in the neighbourhood of the weld line in order to retrieve the unknown heat source. The size of this neighbourhood is not considered in this paper, but rather a domain decomposition concept is presented and an examination of the accuracy of the retrieved source are presented. This paper is organised as follows. The inverse problem is formulated and a method for the source retrieval is presented in the second section. The source retrieval method is based on an extension of the 1-D source retrieval method as proposed in [ILP].

Identification of arsenic species in sheep-wool extracts by different chromatographic methods

Sheep on the island of North Ronaldsay (Orkney, UK) feed mostly on seaweed, which contains high concentrations of dimethylated arsenoribosides. Wool of these sheep contains dimethylated, monomethylated and inorganic arsenic, in addition to unidentified arsenic species in unbound and complexed form. Chromatographic techniques using different separation mechanisms and detectors enabled us to identify five arsenic species in water extracts of wool. The wool contained 5.2 ± 2.3 μg arsenic per gram wool. About 80% of the arsenic in wool was extracted by boiling the wool with water. The main species is dimethylarsenic, which accounted for about 75 to 85%, monomethylated arsenic at about 5% and the rest is inorganic arsenic. Depending on the separation method and condition, the chromatographic recovery of arsenic species was between 45% for the anion exchange column, 68% for the size exclusion chromatography (SEC) and 82% for the cation exchange column. The SEC revealed the occurrence of two unknown arsenic compounds, of which one was probably a high molecular mass species. Since chromatographic recovery can be improved by either treating the extract with CuCl/HCl (CAT: 90%) or longer storage of the sample (CAT: 105%), in particular for methylated arsenic species, it can be assumed that labile arsenic -protein-like coordination species occur in the extract, which cannot be speciated with conventional chromatographic methods. It is clear from our study of sheep wool that there can be different kinds of 'hidden' arsenic in biological matrices, depending on the extraction, separation and detection methods used. Hidden species can be defined as species that are not recordable by the detection system, not extractable or do not elute from chromatographic columns. Copyright © 2003 John Wiley & Sons, Ltd.

Extension of Wu-Peters bounds to Catmull-Clark and 4-8 subdivision

La méthode de subdivision Catmull-Clark ainsi que la méthode de subdivision Loop sont des normes industrielle de facto. D'autre part, la méthode de subdivision 4-8 est bien adaptée à la subdivision adaptative, parce que cette méthode augmente le nombre de faces ou de sommets par seulement un facteur de 2 à chaque raffinement. Cela promet d'être plus pratique pour atteindre un niveau donné de précision. Dans ce mémoire, nous présenterons une méthode permettant de paramétrer des surfaces de subdivision de la méthode Catmull-Clark et de la méthode 4-8. Par conséquent, de nombreux algorithmes mis au point pour des surfaces paramétriques pourrant être appliqués aux surfaces de subdivision Catmull-Clark et aux surfaces de subdivision 4-8. En particulier, nous pouvons calculer des bornes garanties et réalistes sur les patches, un peu comme les bornes correspondantes données par Wu-Peters pour la méthode de subdivision Loop.

Développement d’un microréacteur à base d’enzyme microencapsulée en vue d’un couplage en ligne à un système d’électrophorèse capillaire

Réalisé en codirection avec Karen C. Waldron et Dominic Rochefort.

Rôle et localisation intraspinale du récepteur B1 des kinines dans la douleur neuropathique

Le récepteur B1 des kinines (RB1) joue un rôle important dans l'inflammation et la nociception. Les sites de liaison du RB1 sont augmentés dans la moelle épinière et le ganglion de la racine dorsale (GRD) chez le rat après la ligature partielle du nerf sciatique (LPNS). Dans ce modèle classique de douleur neuropathique, le traitement aigu avec des antagonistes sélectifs du RB1 renverse l'hyperalgésie thermique mais non pas l’allodynie. Cette étude vise à définir dans ce modèle de LPNS: 1- les effets de traitements aigu et chronique avec des antagonistes du RB1 sur l’hyperalgésie thermique et les allodynies tactile et au froid; 2- la contribution du TRPV1 et du stress oxydatif dans la composante de la douleur neuropathique associée au RB1; 3- l’expression du RB1 au niveau de la moelle épinière lombaire, le GRD et le nerf sciatique par RT-PCR quantitatif (Reverse transcriptase-polymerase chain reaction); 4- la localisation cellulaire du RB1 dans la moelle épinière lombaire par microscopie confocale. L’hyperalgésie thermique et les allodynies tactile et au froid ont été mesurées par le réflexe de retrait de la patte arrière après l’application à la surface plantaire d’une source radiante de chaleur (méthode Hargreaves), de filaments de Von Frey et d’une goutte d’acétone qui produit une sensation de froid par évaporation. Nous avons montré, dans un premier temps, que l'hyperalgésie thermique et les allodynies tactile et au froid sont renversées par un traitement chronique avec l’antagoniste du RB1, SSR240612, administré par gavage à raison de 10 mg /kg/jr entre le 15 e et le 20 e jour après la ligature du nerf sciatique et par un traitement antioxydant, la N-acétyl-L-cystéine, administrée par gavage à la dose de 1g/kg/jr, 4jours précédant la ligature et pendant les 2 semaines après la ligature. Un traitement aigu avec le ii SSR240612 (10 mg/kg) ou avec un antagoniste du RB1 qui ne traverse pas la barrière hémato-encéphalique, le R-954 (2mg/kg, s.c.), n’a bloqué que l’hyperalgésie thermique. Dans un second temps, l’antagoniste du TRPV1, le SB366791, administré à raison de 1 mg/kg/jr par voie sous-cutanée du j-1 au j-14 a renversé l’allodynie tactile et l’hyperalgésie thermique. De plus, nous avons noté deux semaines après la LPNS, des augmentations significatives des niveaux d'ARNm du RB1 dans la moelle épinière lombaire, le nerf sciatique et le GRD du côté ipsilatéral à la ligature. Ces augmentations ont été renversées par le traitement avec la N-acétyl-L-cystéine et l’antagoniste du TRPV1. Le RB1 a été localisé au niveau des fibres de type C avec le marquage au CGRP (Calcitonin Gene-Related Peptide) et au niveau de la microglie utilisant le marquage au Iba-1 dans la moelle épinière lombaire des rats ayant subi une LPNS, 2 semaines plus tôt. Au terme de cette étude, nous avons suggéré que la surexpression du RB1 sur les fibres de type C contribuerait à l’hyperalgésie thermique alors que le RB1 sur la microglie dans la moelle épinière contribuerait aux allodynies tactile et au froid dans le modèle LPNS chez le rat. Le stress oxydatif pourrait être impliqué dans l’induction du RB1. Bien que le rôle du TRPV1 semble plutôt limité à la douleur thermique, il pourrait cependant agir via le RB1 sur les fibres de type C.

Modeling High-Dimensional Audio Sequences with Recurrent Neural Networks

Cette thèse étudie des modèles de séquences de haute dimension basés sur des réseaux de neurones récurrents (RNN) et leur application à la musique et à la parole. Bien qu'en principe les RNN puissent représenter les dépendances à long terme et la dynamique temporelle complexe propres aux séquences d'intérêt comme la vidéo, l'audio et la langue naturelle, ceux-ci n'ont pas été utilisés à leur plein potentiel depuis leur introduction par Rumelhart et al. (1986a) en raison de la difficulté de les entraîner efficacement par descente de gradient. Récemment, l'application fructueuse de l'optimisation Hessian-free et d'autres techniques d'entraînement avancées ont entraîné la recrudescence de leur utilisation dans plusieurs systèmes de l'état de l'art. Le travail de cette thèse prend part à ce développement. L'idée centrale consiste à exploiter la flexibilité des RNN pour apprendre une description probabiliste de séquences de symboles, c'est-à-dire une information de haut niveau associée aux signaux observés, qui en retour pourra servir d'à priori pour améliorer la précision de la recherche d'information. Par exemple, en modélisant l'évolution de groupes de notes dans la musique polyphonique, d'accords dans une progression harmonique, de phonèmes dans un énoncé oral ou encore de sources individuelles dans un mélange audio, nous pouvons améliorer significativement les méthodes de transcription polyphonique, de reconnaissance d'accords, de reconnaissance de la parole et de séparation de sources audio respectivement. L'application pratique de nos modèles à ces tâches est détaillée dans les quatre derniers articles présentés dans cette thèse. Dans le premier article, nous remplaçons la couche de sortie d'un RNN par des machines de Boltzmann restreintes conditionnelles pour décrire des distributions de sortie multimodales beaucoup plus riches. Dans le deuxième article, nous évaluons et proposons des méthodes avancées pour entraîner les RNN. Dans les quatre derniers articles, nous examinons différentes façons de combiner nos modèles symboliques à des réseaux profonds et à la factorisation matricielle non-négative, notamment par des produits d'experts, des architectures entrée/sortie et des cadres génératifs généralisant les modèles de Markov cachés. Nous proposons et analysons également des méthodes d'inférence efficaces pour ces modèles, telles la recherche vorace chronologique, la recherche en faisceau à haute dimension, la recherche en faisceau élagué et la descente de gradient. Finalement, nous abordons les questions de l'étiquette biaisée, du maître imposant, du lissage temporel, de la régularisation et du pré-entraînement.