油气流线模拟方法研究与系统研制

The modeling of petroleum flow path (petroleum charging) and the detail of corresponding software development are presented in this paper, containing principle of petroleum charging, quantitative method, and practical modeling in two oil fields. The Modeling of Petroleum Flow Path is based on the result of basin modeling, according to the principle of petroleum migrating along the shortest path from the source to trap, Petroleum System Dynamics (Prof. Wu Chonglong, 1998), the concept of Petroleum Migration and Dynamic Accumulation (Zhou Donyan, Li Honhui, 2002), etc. The simulation is done combing with all parameters of basin, and considering the flow potential, non-uniformity of source and porous layer. It's the extending of basin modeling, but not belong to it. It is a powerful simulating tool of petroleum system, and can express quantitatively every kind of geology elements of a petroleum basin, and can recuperate dynamically the geology processes with 3D graphics. At result, we can give a result that the petroleum flow shows itself the phenomena of main path, and without using the special theory such as deflection flow in fractures(Tian Kaiming, 1989, 1994, Zhang Fawang, Hou Xingwei, 1998), and flow potential(England, 1987). The contour map of petroleum flow quantitative show clearly where the coteau - dividing slot is, and which convergence region are the main flow path of petroleum, and where is the favorable play of petroleum. The farsighted trap can be determined if there are enough information about structural diagram and can be evaluated, such as the entrapment extent, spill point, area, oil column thickness, etc. Making full use of the result of basin modeling with this new tool, the critical moment and scheme of the petroleum generation and expulsion can be showed clearly. It's powerful analysis tool for geologist.

西北太平洋某海域40ka来的地磁场相对强度研究

Paleointensity changes of geomagnetic field help us to understand the evolutionprocess of earth completely and provide further constraints for earth interior process and geodynamo model. Marine sediments are good carriers for relative paleointensity of geomagnetic field. But in most cases, deep sea sediments that conform with magnetic "uniformity" usually have low sedimentation rate about l-2cm/ka and lie under the Carbonate Compensate Depth with little carbonate content. Therefore, the number of relative paleointensity records with detailed oxygen stratigraphy is still rare. This thesis focus on four cores from east of Ryukyu Trench which have foraminiferal content of 5-30% and sedimentation rate of lOcm/ka and wish to get centennial -millennial changes of relative paleointensity.The sediments from east of Ryukyu Trench conform with magnetic "uniformity" and remanences of four cores all show single component with stable direction and faithfully record the magnetic field. The NRM301T1T/ARM and NRMsomT/ x are still affected by grain size and concentration changes although the sediments are "uniform" , indicating the uniformity might not enough for relative paleointensity. After renomalized by grain size parameter MDF, the intensities remove the effect of grain size changes to different degrees and show coherency in 1-1 Oka scale with results from ODP983/984. The characteristics of paleointensity of geomagnetic field arefrom 32-24kaBP, paleointensity of geomagnetic field is low;24-12kaBP, paleointensity of geomagnetic field is high and shows two peaks boundary with 19kaBP.3) 12-5.3ka, paleointensity is low. Then increase from 5,3kaBP until a small trough at 2.7kaBP, then increase till now.

A multichannel detector array with 768 pixels developed for electron spectroscopy

Langstaff, David; Chase, T., (2007) 'A multichannel detector array with 768 pixels developed for electron spectroscopy', Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 573(1-2) pp.169-171 RAE2008

Non-Uniform Reductions

We study properties of non-uniform reductions and related completeness notions. We strengthen several results of Hitchcock and Pavan and give a trade-off between the amount of advice needed for a reduction and its honesty on NEXP. We construct an oracle relative to which this trade-off is optimal. We show, in a more systematic study of non-uniform reductions, that among other things non-uniformity can be removed at the cost of more queries. In line with Post's program for complexity theory we connect such 'uniformization' properties to the separation of complexity classes.

Development of large-scale colloidal crystallisation methods for the production of photonic crystals

Colloidal photonic crystals have potential light manipulation applications including; fabrication of efficient lasers and LEDs, improved optical sensors and interconnects, and improving photovoltaic efficiencies. One road-block of colloidal selfassembly is their inherent defects; however, they can be manufactured cost effectively into large area films compared to micro-fabrication methods. This thesis investigates production of ‘large-area’ colloidal photonic crystals by sonication, under oil co-crystallization and controlled evaporation, with a view to reducing cracking and other defects. A simple monotonic Stöber particle synthesis method was developed producing silica particles in the range of 80 to 600nm in a single step. An analytical method assesses the quality of surface particle ordering in a semiquantitative manner was developed. Using fast Fourier transform (FFT) spot intensities, a grey scale symmetry area method, has been used to quantify the FFT profiles. Adding ultrasonic vibrations during film formation demonstrated large areas could be assembled rapidly, however film ordering suffered as a result. Under oil cocrystallisation results in the particles being bound together during film formation. While having potential to form large areas, it requires further refinement to be established as a production technique. Achieving high quality photonic crystals bonded with low concentrations (<5%) of polymeric adhesives while maintaining refractive index contrast, proved difficult and degraded the film’s uniformity. A controlled evaporation method, using a mixed solvent suspension, represents the most promising method to produce high quality films over large areas, 75mm x 25mm. During this mixed solvent approach, the film is kept in the wet state longer, thus reducing cracks developing during the drying stage. These films are crack-free up to a critical thickness, and show very large domains, which are visible in low magnification SEM images as Moiré fringe patterns. Higher magnification reveals separation between alternate fringe patterns are domain boundaries between individual crystalline growth fronts.

Intergenic and genic sequence lengths have opposite relationships with respect to gene expression.

Eukaryotic genomes are mostly composed of noncoding DNA whose role is still poorly understood. Studies in several organisms have shown correlations between the length of the intergenic and genic sequences of a gene and the expression of its corresponding mRNA transcript. Some studies have found a positive relationship between intergenic sequence length and expression diversity between tissues, and concluded that genes under greater regulatory control require more regulatory information in their intergenic sequences. Other reports found a negative relationship between expression level and gene length and the interpretation was that there is selection pressure for highly expressed genes to remain small. However, a correlation between gene sequence length and expression diversity, opposite to that observed for intergenic sequences, has also been reported, and to date there is no testable explanation for this observation. To shed light on these varied and sometimes conflicting results, we performed a thorough study of the relationships between sequence length and gene expression using cell-type (tissue) specific microarray data in Arabidopsis thaliana. We measured median gene expression across tissues (expression level), expression variability between tissues (expression pattern uniformity), and expression variability between replicates (expression noise). We found that intergenic (upstream and downstream) and genic (coding and noncoding) sequences have generally opposite relationships with respect to expression, whether it is tissue variability, median, or expression noise. To explain these results we propose a model, in which the lengths of the intergenic and genic sequences have opposite effects on the ability of the transcribed region of the gene to be epigenetically regulated for differential expression. These findings could shed light on the role and influence of noncoding sequences on gene expression.

Cuantificación del daño mecánico y la uniformidad de distribución de la semilla de soja (Glycine max (L) Merr.) mediante dos sistemas de dosificación

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Maximising heat transfer efficiency in the cold crucible induction melting process

Induction heating is an efficient method used to melt electrically conductive materials, particularly if melting takes place in a ceramic crucible. This form of melting is particularly good for alloys, as electromagnetic forces set up by the induction coil lead to vigorous stirring of the melt ensuring homogeneity and uniformity in temperature. However, for certain reactive alloys, or where high purity is required, ceramic crucibles cannot be used, but a water-cooled segmented copper crucible is employed instead. Water cooling prevents meltdown or distortion of the metal wall, but much of the energy goes into the coolant. To reduce this loss, the electromagnetic force generated by the coil is used to push the melt away from the walls and so minimise contact with water-cooled surfaces. Even then, heat is lost through the crucible base where contact is inevitable. In a collaborative programme between Greenwich and Birmingham Universities, computer modelling has been used in conjunction with experiments to improve the superheat attainable in the melt for a,number of alloys, especially for y-TiAl intermetallics to cast aeroengine turbine blades. The model solves the discretised form of the turbulent Navier-Stokes, thermal energy conservation and Maxwell equations using a Spectral Collocation technique. The time-varying melt envelope is followed explicitly during the computation using an adaptive mesh. This paper briefly describes the mathematical model used to represent the interaction between the magnetic field, fluid flow, heat transfer and change of phase in the crucible and identifies the proportions of energy used in the melt, lost in the crucible base and in the crucible walls. The role of turbulence is highlighted as important in controlling heat losses and turbulence damping is introduced as a means of improving superheat. Model validation is against experimental results and shows good agreement with measured temperatures and energy losses in the cooling fluid throughout the melting cycle.

Busbar sizing modeling tools: comparing an ANSYS® based 3D model with the versatile 1D model part of MHD-Valdis

The main goal of a cell stability MHD model like MHD-Valdis is to help locate the busbars around the cell in a way which leads to the generation of a magnetic field inside the cell that itself leads to a stable cell operation. Yet as far as the cell stability is concerned, the uniformity of the current density in the metal pad is also extremely important and can only be achieved with a correct busbar network sizing. This work compares the usage of a detailed ANSYS based 3D thermo-electric model with the one of the versatile 1D part of MHD-Valdis to help design a well balanced busbar network.

Vacuum arc remelting time dependent modelling

Vacuum arc remelting (VAR) aims at production of high quality, segregation-free alloys. The quality of the produced ingots depends on the operating conditions which could be monitored and analyzed using numerical modelling. The remelting process uniformity is controlled by critical medium scale time variations of the order 1-100 s, which are physically initiated by the droplet detachment and the large scale arc motion at the top of liquid pool [1,2]. The newly developed numerical modelling tools are addressing the 3-dimensional magnetohydrodynamic and thermal behaviour in the liquid zone and the adjacent ingot, electrode and crucible.

Megasonic agitation for enhanced electrodeposition of copper

In this paper we propose an agitation method based on megasonic acoustic streaming to overcome the limitations in plating rate and uniformity of the metal deposits during the electroplating process. Megasonic agitation at a frequency of 1 MHz allows the reduction of the thickness of the Nernst diffusion layer to less than 600 nm. Two applications that demonstrate the benefits of megasonic acoustic streaming are presented: the formation of uniform ultra-fine pitch flip-chip bumps and the metallisation of high aspect ratio microvias. For the latter application, a multi-physics based numerical simulation is implemented to describe the hydrodynamics introduced by the acoustic waves as they travel inside the deep microvias.

Parametrical modeling and design optimization of blood plasma separation device with microchannel mechanism

This paper presents an analysis of biofluid behavior in a T-shaped microchannel device and a design optimization for improved biofluid performance in terms of particle liquid separation. The biofluid is modeled with single phase shear rate non-Newtonian flow with blood property. The separation of red blood cell from plasma is evident based on biofluid distribution in the microchannels against various relevant effects and findings, including Zweifach-Fung bifurcation law, Fahraeus effect, Fahraeus-Lindqvist effect and cell free phenomenon. The modeling with the initial device shows that this T-microchannel device can separate red blood cell from plasma but the separation efficiency among different bifurcations varies largely. In accordance with the imbalanced performance, a design optimization is conducted. This includes implementing a series of simulations to investigate the effect of the lengths of the main and branch channels to biofluid behavior and searching an improved design with optimal separation performance. It is found that changing relative lengths of branch channels is effective to both uniformity of flow rate ratio among bifurcations and reduction of difference of the flow velocities between the branch channels, whereas extending the length of the main channel from bifurcation region is only effective for uniformity of flow rate ratio.

Rheumatologists' judgements about the efficacy of anti-TNF therapy in two neighbouring regions

Objectives: The requirement in Northern Ireland to prescribe biologic agents according to NICE/BSR guidelines and within a fixed budget has created a waiting list for treatment that has no parallel in the Republic of Ireland. The study investigated the bearing this situation may have on had on the consultants’ judgements in the respective areas.

Methods: 78 case vignettes created from the data on real patients with RA treated with biologics in the north and south of Ireland were appraised by 9 southern and 8 northern consultants who judged the clinical benefit and significance of the patients’ condition after a trial of therapy. Quantitative (Clinical Judgement Analysis) and Qualitative (Focus groups) techniques were used.

Results: Northern consultants perceived a slightly greater degree of clinical benefit after a trial of therapy than southern consultants. Judgment models of northern and southern consultants were broadly comparable. The latter tended to be more uniform in their judgments than the southern group. Focus group discussions with consultants largely validated the findings of the quantitative analysis but revealed how clinical judgment analysis might be misled by gaming strategies.

Conclusions: Despite the absence of overt rationing in the south of Ireland, as far as the judgment of therapeutic benefit from biologics was concerned, the clinical judgment policies of practitioners were very similar to those in the north. The adoption of NICE/BSR guidelines in the north may have improved the uniformity of clinical practice in Northern Ireland.

An Investigation of the Flow Field through a Variable Geometry Turbine Stator with Vane Endwall Clearance

Variable geometry turbines provide an extra degree of flexibility in air management in turbocharged engines. The pivoting stator vanes used to achieve the variable turbine geometry necessitate the inclusion of stator vane endwall clearances. The consequent leakage flow through the endwall clearances impacts the flow in the stator vane passages and an understanding of the impact of the leakage flow on stator loss is required. A numerical model of a typical variable geometry turbine was developed using the commercial CFX-10 computational fluid dynamics software, and validated using laser doppler velocimetry and static pressure measurements from a variable geometry turbine with stator vane endwall clearance. Two different stator vane positions were investigated, each at three different operating conditions representing different vane loadings. The vane endwall leakage was found to have a significant impact on the stator loss and on the uniformity of flow entering the turbine rotor. The leakage flow changed considerably at different vane positions and flow incidence at vane inlet was found to have a significant impact.

Plasma dynamics in an inductively coupled magnetic neutral loop discharge

Magnetic neutral loop discharges (NLDs) can be operated at significantly lower pressures than conventional radio-frequency (rf) inductively coupled plasmas (ICPs). These low pressure conditions are favourable for technological applications, in particular anisotropic etching. An ICP–NLD has been designed providing excellent diagnostics access for detailed investigations of fundamental mechanisms. Spatially resolved Langmuir probe measurements have been performed in the plasma production region (NL region) as well as in the remote application region downstream from the NL region. Depending on the NL gradient two different operation modes have been observed exhibiting different opportunities for control of plasma uniformity. The efficient operation at comparatively low pressures results in ionization degrees exceeding 1%. In this regime neutral dynamics has to be considered and can influence neutral gas and process uniformity. Neutral gas depletion through elevated gas temperatures and high ionization rates have been quantified. At pressures above 0.1 Pa, gas heating is the dominant depletion mechanism. At lower pressures neutral gas is predominantly depleted through high ionization rates and rapid transport of ions by ambipolar diffusion along the magnetic field lines. Non-uniform profiles of the ionization rate can, therefore, result in localized neutral gas depletion and non-uniform processing. We have also investigated the electron dynamics within the radio-frequency cycle using phase resolved optical emission spectroscopy and Thomson scattering. In these measurements electron drift phenomena along the NL torus have been identified.