Amorphous silicon nanoparticles in compound films grown on cold substrates for high-efficiency photoluminescence

Silicon nanoparticles have been fabricated in both oxide and nitride matrices by using plasma-enhanced chemical vapour deposition, for which a low substrate temperature down to 50 degreesC turns out to be most favourable. High-rate deposition onto such a cold substrate results in the formation of nanoscaled silicon particles, which have revealed an amorphous nature under transmission electron microscope (TEM) examination. The particle size can be readily controlled below 3.0 nm, and the number density amounts to over 10(12) cm(-2), as calculated from the TEM micrographs. Strong photoluminescence in the whole visible light range has been observed in the as-deposited Si-in-SiOx and Si-in-SiNx thin films. Without altering the size or structure of the particles, a post-annealing at 300 degreesC for 2 min raised the photoluminescence efficiency to a level comparable to the achievements with nanocrystalline Si-in-SiO2 samples prepared at high temperature. This low-temperature procedure for fabricating light-emitting silicon structures opens up the possibility of manufacturing integrated silicon-based optoelectronics.

In-situ Boron-doped Low-stress LPCVD Polysilicon for Micromechanical Disk Resonator

Polycrystalline silicon (polysilicon) has been used as an important structural material for microelectro-mechnical systems (MEMS) because of its compatibility with standard integrated circuit (IC) processes. As the structural layer of micromechanical high resonance frequency (high-f) and high quality factor (high-Q) disk resonators, the low residual stress and low resistivity are desired for the polysilicon thin films. In the present work, we investigate the effect of deposition and annealing conditions on the residual stress and resistivity for in-situ deposited low pressure chemical vapor deposition (LPCVD) polysilicon films. Low residual stress (-100 MPa) was achieved in in-situ boron-doped polysilicon films deposited at 570 degrees C and annealed at 1000 degrees C for 4 hr. The as-deposited amorphous polysilicon films were crystallized by the rapid thermal annealing and have the (111)-preferred orientation, the low tensile residual stress is expected for this annealed film, the detailed description on this work will be reported soon. The controllable residual stress and resistivity make these films suitable for high-Q and bigh-f micro-mechanical disk resonators.

非粮原料燃料乙醇发酵关键技术的研究

生物质燃料乙醇是一种高度清洁的交通液体燃料，是减少温室气体排放，缓解大气污染的最佳技术选择。以非粮原料生产燃料乙醇可以在进行能源生产的同时保证粮食安全，有利于产业的可持续发展。在众多的非粮原料中，甘薯是我国开发潜力最大的生物质能源作物之一。我国占世界甘薯种植总面积和产量的90％。同时，甘薯的单位面积燃料乙醇产量远大于玉米和小麦。其成本是目前酒精中最低廉的，因此利用甘薯生产乙醇是发展生物质燃料乙醇的首要选择。目前采用薯类全原料主要采用分批发酵生产乙醇，其技术水平低，发酵强度低，一般在0.7－2.5g/（L•h），乙醇浓度低，甘薯发酵乙醇为6－8％(v/v)，能耗高，环境负荷大，污染严重。针对上述问题，本文从菌株选育、原料预处理、中试放大、残糖成分分析等方面进行研究。 为了研究乙醇发酵生产规模扩大过程中，大型发酵罐底部高压条件下，CO2对酵母乙醇发酵的影响，我们通过CO2 加压的方法进行模拟试验，研究结果表明，发酵时间随压强的升高而逐渐延长，高压CO2 对乙醇发酵效率影响不大，在0.3 MPa 以下时，发酵效率均可达到90%以上。高压CO2 对发酵的抑制作用是高压和CO2 这两个因素联合作用的结果。高压CO2 条件下，酵母胞外酶和胞内重要酶类的酶活均表现出特征性。0.2 MPa 下，酶活性的变化趋势和0.1 MPa 条件下的较为一致。而0.3 MPa 下的酶活变化趋势与0.4 MPa 下的酶活更为接近。通过全基因表达分析发现在CO2 压力为0.3 MPa 下，乙醇发酵途径中多个基因表达量下调，同时海藻糖合成酶和热激蛋白基因表达量上调。 筛选耐高温的乙醇酵母菌株能够解决糖化温度和发酵温度不协调的矛盾，实现真正意义上的边糖化边发酵。高温发酵还能够降低发酵时的冷却成本，实现乙醇的周年生产。本研究筛选出一株高温发酵菌株Y-H1，进而我们对该菌株的胞外酶和胞内乙醇代谢重要酶类的酶活性进行了分析。结果表明Y-H1 能够在40 ℃条件下正常进行乙醇发酵，发酵33h，最终乙醇浓度达到10.7%（w/w），发酵效率达到90%以上。同时发酵液最终pH 在3.5 左右，显示菌株具有一定的耐酸性能力。同时观察到40 ℃下，菌株的胞外酶和胞内乙醇代谢重要酶类的酶活性发生了变化，乙醇发酵途径中关键酶基因表达下调，而海藻糖合成酶与热激蛋白基因表达量上调，这些结果为进一步研究酵母菌耐热调控机理提供了依据。 糖蜜是一种大规模工业生产乙醇的理想原料，本研究利用选育高浓度乙醇发酵菌株结合配套的发酵稳定剂，研究了糖蜜高浓度乙醇发酵情况。结果表明采用冷酸沉淀预处理糖蜜溶液，采用分批补料的发酵方式，乙醇浓度最高达到了10.26% (w/w)，发酵时间为42 h。同时观察到在糖蜜发酵中，乙醛含量与乙醇浓度存在一定的相关性。 快速乙醇发酵对于缩短乙醇生产周期、降低乙醇生产成本、减少原料腐烂损失具有重要意义。本研究诱变和筛选得到了一株快速乙醇发酵菌株10232B。在优化后的发酵条件下，采用10L 发酵罐进行分批乙醇发酵，经过18h,乙醇的最终浓度达到88.5g/L,发酵效率93.6%，平均乙醇生产速度达到4.92 g/L/h。此菌株在保持较高乙醇生产浓度的同时，拥有快速生产乙醇的能力，适合作为快速乙醇发酵生产菌种。 由于鲜甘薯具有粘度大的特点，传统液化糖化处理很难在短时间内充分糖化原料；高粘度的醪液也难以进行管道输送，容易堵塞管路；同时，也会降低后续的乙醇发酵效率。 本文采用了快速粘度分析法对鲜甘薯糊化粘度特性进行了分析，进而对预处理条件进行了研究，在最佳预处理条件下，糖化2h 后，醪液葡萄糖值最高可达99.3，粘度4.5×104 mPa.s，而采用传统糖化工艺，醪液DE 值仅为85.8，粘度大于1.0×105 mPa.s。 此预处理方法也可用于快速糖化不加水的醪液。后续的乙醇发酵试验表明，通过此预处理方法获得的糖化醪液对乙醇发酵无负面影响。 在前期已实现了实验室水平的鲜甘薯燃料乙醇快速乙醇发酵基础上，进一步将发酵规模扩大到500L，在中试水平上对甘薯乙醇发酵进行了研究。结果表明在500L 中试规模，采用边糖化边发酵（SSF）工艺，在料液比为3∶1，发酵醪液最高粘度为6×104mPa.s 条件下，发酵37h，乙醇浓度达到了12.7%（v/v），发酵效率91%，发酵强度为2.7 g/（L•h）。与目前国内的薯类乙醇发酵生产技术水平具有明显的优越性。 为研究甘薯、木薯乙醇发酵中残糖的组成，采用了高效液相色谱—蒸发光散射检测法，对乙醇发酵残糖进行了分析。结果表明，甘薯、木薯乙醇发酵残糖均为寡聚糖，主要由葡萄糖、木糖、半乳糖、阿拉伯糖和甘露糖构成。随着发酵时间延长，寡聚糖中的葡萄糖、半乳糖、甘露糖可被缓慢的水解释放。提高糖化酶量仅在一定程度上降低残糖，过量的糖化酶反而会导致残糖增加。同时发现3, 5-二硝基水杨酸法不能准确测定甘薯、木薯乙醇发酵中的残总糖含量。进一步筛选了两株残糖降解菌株，对甘薯乙醇发酵残糖的降解利用率均达到了40%以上，而且还能显著降低发酵醪液粘度。经形态学和rRNA ITS 序列分析，确定这两株菌分别属于为木霉属和曲霉属黑曲霉组。 通过对以甘薯原料为代表的非粮原料发酵技术研究开发，以期形成乙醇转化率高，能耗低，生产效率高、季节适应性好，原料适应性广，经济性强，符合清洁生产机制的燃料乙醇高效转化技术，为具有我国特色的燃料乙醇发展模式提供技术支持。 Sweet potato is one of the major feedstock for the fuel ethanol production in China. The planting area and the yield in China take 90% of the world. Sweet potato is an efficient kind of energy crops. The energy outcome per area is higher than corn or wheat. And the manufacture cost of ethanol is the lowest, compared with corn and wheat. So sweet potato is the favorable crop for the bioethanol production in China. However, the low-level fermentation technology restricts the development of ethanol production by sweet potato, including slow ethanol production rate, low ethanol concentration and high energy cost. To solve these problems, we conducted research on the strain breeding, pretreatment, pilot fermentation test and residual saccharides analysis. To study the impact of hyperbaric condition at bottom of the large fermentor on yeast fermentation, high pressure carbon dioxide (CO2) was adopted to simulate the situation. The results showed that the fermentation was prolonged with the increasing pressure. The pressure of CO2 had little impact on the ethanol yield which could reach 90% under the pressure below 0.3 MPa. The inhibition was combined by the high pressure and CO2. Under the high CO2 pressure, the extracellular and important intracellular enzyme activities were different from those under normal state. The changes under 0.1 MPa and 0.2 MPa were similar. The changes under 0.3 MPa were closer to those under 0.4 MPa. The application of thermotolerance yeast could solve the problem of the inconsistent temperature between fermentation and saccharificaton and fulfill the real simultaneous saccharification and fermentation. And it could reduce the cooling cost. A thermotolerance strain Y-H1 was isolated in our research. It gave high ethanol concentration of 10.7%（w/w）at 40 ℃ for 33 h. The ethanol yield efficiency was over 90%. At 40 ℃, the extracellular and important intracellular enzyme activities of Y-H1 showed the difference with normal state, which may indicate its physiological changes at the high temperature. Molasses is another feedstock for industrial ethanol production. By our ethanol-tolerance strain and the regulation reagents, the fermentation with high ethanol concentration was investigated. In fed-batch mode combined with cold acid deposition, the highest ethanol concentration was 10.26% (w/w) for 42h. The aldehyde concentration in fermentation was found to be related to ethanol concentration. The development of a rapid ethanol fermentation strain of Zymomonas mobilis is essential for reducing the cost of ethanol production and for the timely utilization of fresh material that is easily decayed in the Chinese bioethanol industry. A mutant Z. mobilis strain, 10232B, was generated by UV mutagenesis. Under these optimized conditions, fermentation of the mutant Z. mobilis 10232B strain was completed in just 18 h with a high ethanol production rate, at an average of 4.92 gL-1h-1 per batch. The final maximum ethanol concentration was 88.5 gL-1, with an ethanol yield efficiency of 93.6%. This result illustrated the potential use of the mutant Z. mobilis 10232B strain in rapid ethanol fermentation in order to help reduce the cost of industrial ethanol production. As fresh sweet potato syrup shows high viscosity, it is hard to be fully converted to glucose by enzymes in the traditional saccharification process. The high-viscosity syrup is difficult to be transmitted in pipes, which may be easily blocked. Meanwhile it could also reduce the later ethanol fermentation efficiency. To solve these problems, effects of the pretreatment conditions were investigated. The highest dextrose equivalent value of 99.3 and the lowest viscosity of 4.5×104 mPa.s were obtained by the most favorable pretreatment conditions, while those of 85.8 and over 1.0×105 mPa.s was produced by traditional treatment conditions. The pretreatment could also be applied on the material syrup without adding water. The later experiments showed that the pretreated syrup had no negative effect on the ethanol fermentation and exhibited lower viscosity. The fuel ethanol rapid production from fresh sweet potato was enlarged in the 500L pilot scale after its fulfillment on the laboratory level. The optimal ratio of material to water was 3 to 1 in 500L fermentor. With low-temperature-cooking (85 ℃) using SSF, the Saccharomyces cerevisiae was able to produce ethanol 97.44 g/kg for 37h, which reached 92% of theoretical yield. The average ethanol production rate was 4.06 g/kg/h. And the maximum viscosity of syrup reached 6×104mPa.s. The results showed its superiority over current industrial ethanol fermentation. The compositions of the residual saccharides in the ethanol fermentation by sweet potato and cassava were analyzed by high performance liquid chromatography coupled with evaporative light-scattering detector. The results showed that all the residual saccharides were oligosaccharides, mainly composed of glucose, xylose, galactose, arabinose and mannose. The glucose, galactose and mannose could be slowly hydrolyzed from oligosaccharides in syrup during a long period. To increase the glucoamylase dosage could lower the residual saccharides to a certain extent. However, excess glucoamylase dosage led to more residual saccharides. And the method of 3, 5-dinitrosalicylic acid could not accurately quantify the residual total saccharides content. Two residual saccharides degrading strains were isolated, which could utilize 40% of total residual saccharide and lower the syrup viscosity. With the analysis of morphology and internal transcribed spacer sequence, they were finally identified as species of Trichoderma and Aspergillus niger.

残留盆地分布综合地球物理研究——以大港地区为例

Macro-distribution of residual basins is a basic question in residual basin research，the main object of macro-distribution study is to build strata framework, compute thickness of residual strata and analyze characteristics of residual basins. With the guidance of the theory of integrated geology and geophysical research, the paper assembled series of methods and established the technical chart based on gravity and magnetic data, with restriction of geology, seismic and drilling data. Based on potential field data processing and analysis, forward and inverse computation, region potential field analysis and potential field separation, etc. it computed depth of gravity/magnetic basement and got strata framework. It had got effective results in the research of macro-distribution of residual basin research in the Dagang area. It did the wavelet transform of gravity/magnetic data with multi-kind of wavelet basis using a trou algorithm. From comparison of processing result and their spectral of wavelet analysis, up continuation and filter method, the wavelet approximation is better to fit the regional potential field, and it is an effective method to separate gravity/magnetic effect caused by deep geology bodies. The experiment of matching pursuit shows that te transform domain methods have great advantage in potential data analysis. From the integrated geophysical study of rock property study, gravity/magnetic basement inversion and fault system analysis of the Dagang area, it gets the strata framework and the thickness of pre-Cenozoic residual strata. Comprehensive study with gravity and magnetotelluric profile inversion and interpretation, three prospect plays of macro-distribution of residual basins are fingered out. It has great residual strata thickness in the northern part of Chengning Uplift and there is thrust fault in the deep zone and good up-Paleozoic hydrocarbon source rocks in this area. With integrated analysis, this area will be the most prospective hydrocarbon location of pre-Cenozoic residual basins.

波动方程偏移速度分析

On the subject of oil and gas exploration, migration is an efficacious technique for imagining structures underground. Wave-equation migration (WEM) dominates over other migration methods in accuracy, despite of higher computational cost. However, the advantages of WEM will emerge as the progress of computer technology. WEM is sensitive to velocity model more than others. Small velocity perturbations result in grate divergence in the image pad. Currently, Kirrchhoff method is still very popular in the exploration industry for the reason of difficult to provide precise velocity model. It is very urgent to figure out a way to migration velocity modeling. This dissertation is mainly devoted to migration velocity analysis method for WEM: 1. In this dissertation, we cataloged wave equation prestack depth migration. The concept of migration is introduced. Then, the analysis is applied to different kinds of extrapolate operator to demonstrate their accuracy and applicability. We derived the DSR and SSR migration method and apply both to 2D model. 2. The output of prestack WEM is in form of common image gathers (CIGs). Angle domain common image gathers (ADCIGs) gained by wave equation are proved to be free of artifacts. They are also the most potential candidates for migration velocity analysis. We discussed how to get ADCIGs by DSR and SSR, and obtained ADCIGs before and after imaging separately. The quality of post stack image is affected by CIGs, only the focused or flattened CIGs generate the correct image. Based on wave equation migration, image could be enhanced by special measures. In this dissertation we use both prestack depth residual migration and time shift imaging condition to improve the image quality. 3. Inaccurate velocities lead to errors of imaging depth and curvature of coherent events in CIGs. The ultimate goal of migration velocity analysis (MVA) is to focus scattered event to correct depth and flatten curving event by updating velocities. The kinematic figures are implicitly presented by focus depth aberration and kinetic figure by amplitude. The initial model of Wave-equation migration velocity analysis (WEMVA) is the output of RMO velocity analysis. For integrity of MVA, we review RMO method in this dissertation. The dissertation discusses the general ideal of RMO velocity analysis for flat and dipping events and the corresponding velocity update formula. Migration velocity analysis is a very time consuming work. Respect to computational convenience, we discus how RMO works for synthetic source record migration. In some extremely situation, RMO method fails. Especially in the areas of poorly illuminated or steep structure, it is very difficult to obtain enough angle information for RMO. WEMVA based on wave extrapolate theory, which successfully overcome the drawback of ray based methods. WEMVA inverses residual velocities with residual images. Based on migration regression, we studied the linearized scattering operator and linearized residual image. The key to WEMVA is the linearized residual image. Residual image obtained by Prestack residual migration, which based on DSR is very inefficient. In this dissertation, we proposed obtaining residual migration by time shift image condition, so that, WEMVA could be implemented by SSR. It evidently reduce the computational cost for this method.

阿尔金蛇绿混杂带构造岩石组合及其大地构造意义

The Alytn fault is a huge left-slip fault zone within the Asian continent, and locates such zone that is linked to main tectonic units in the western China, which makes it is very important to the tectonic framework and ore distribution in the western China. Selecting two ophiolite zones (namely Hongliugou-Lapeiquan ophiolite zone and Sulamutage ophiolite zone) respectively located within the southern and northern part of the Altyn fault and based on analysis of field geology characteristics and geochemistry, this paper recognized the rock types (mainly mafic and ultramafic rocks) within the melanges and subdivided each lithological unit based on tectonic environment. At last, this paper rebuilt the paleo-tectonic framework in the Alytn region by the method of tectonic facies and discussed its tectonic evolution with the theory of collision orogens. Combining former results with hard field observation and geochemical analysis, this paper acquired such recognitions to two ophiolte zones within the Altyn fault zone as follows: To the typical regions (Hongliugou, Lapeiquan, Mangya and Sulamutage) within the two ophiolte zones in the Altyn fault zone, this paper offered the field geology profiles. Field geology characteristics show that they are composed of melange bases (mainly abyssal flysch and carbonate rocks) and melange blocks from various tectonic environments, often with fault contact among each lithological units, belonging to typical ophiolitic melange zone. The ultramafic rocks outcropped at the Altyn region are all harzburgites. Remant grains of primary minerals have melted residual texture and elastic deformation texture under high temperature and pressure. The whole-rock analyses show their low TiO_2 contents (0.01～0.04%), low Al, Ca and high MgO contents and wide Mg~# range (89.35～95.57). Rare earth patterns have two types, namely tabacco pipe-shped and LREE-shaped, of which the former is often seen. The chondrite-nomalized Yb values of these analyses are all lower than 1. The spinels have low Ti and high Cr content and most spinels have Cr# higher than 60. All of the above characteristics show that the ultramafic rocks in the Altyn fault zone are components of metmorphic peridotites of ophiolite from depleted mantle source and most ophiolites from this zone belong to supra-subduction zone (SSZ) type ophiolite with a few mid-ocean ridge basalt (MORB) type. Geochemical analyses show that the melange blocks within the Altyn ophiolitic melange zone have different characteristics from various tectonic environments. This paper recognized such tectonic-lithological assemblages as mid-ocean basalts, oceanic island basalts, oceanic island arc tholeiites, island arc calalkaline basalts and island arc granites and inferred that these tectonic-lithological units respectively belongs to such tectonic units as ophiolites, oceanic islands and/or oceanic seamounts, oceanic island arc and a~creting arcs, which show these blocks from oceanic crust and subduction zone for the most part. For the Altyn ophiolites, the chronological data show they become new from the north to the south. Combined with the study on late slip of Altyn fault and North Qilianshan orogeny, the author inferred that the Altyn region had belonged to one part of the North Qilianshan accreting wedge-arc orogeny at paleozoic, and later huge left-slip made it locate modem site.

大港千米桥地区综合地质地球物理研究

Qianmiqiao buried hill, which is a high-yield burial hill pool, was discovered at Dagang oilfield in 1998. To employ the integrated geological and geophysical research at Qianmiqiao area, it is very valuable and meaningful for the petroleum exploration of Bohai Bay Basin and even the whole country. Based on the previous results, this paper is carried out from the research on Huanghua depression, following the law, i.e. the deep part constrains the shallow, the regional constrains the local, takes the geophysical research in Qianmiqiao oilfield, discusses the formation history of burial hills, burial history, thermal history, the generated and expelling history of hydrocarbon, and migration characteristics, probes into the formation of burial hill pool. This paper uses the gravity and magnetic methods which are based on potential field, with natural sources, configures the inner structure of the earth according to the difference in the density and magnetism of the rock. The geophysical characteristics of Dagang oil field is that it is an area with positive Buge gravity anomal. The upheaval of Moho boundary is in mirror symmetry with the depression of the basin's basement. The positive and negative anomaly distributein axis symmetry, and the orientation is NNE. The thickness of the crust gradually reduces from west to east, from land to sea. The depth gradient strip of Curie surface is similar to Moho boundary, whereas their local buried depth is different. Local fractures imply that the orientation of base rock fractures is NNE-NE, and the base rock is intersected by the fractures of the same/ later term, whose orientation is NW, so the base rock likes rhombic mosaic. The results of tomography show that there exists significant asymmetry in vertical and horizontal direction in the velocity configuration of Huanghua depression. From Dezhou to Tianjin, there exits high-speed block, which extends from south to north. The bottom of this high-speed block is in good agreement with the depth of Moho boundary. Hence we can conclude that the high-speed block is actually the crystal basement. According to seismic data, well data and outcrop data, Huanghua depression can be divided into four structure layers, i.e. Pi,2-T, Ji,2-K, E, N-Q. Qianmiqiao burial hills undergo many tectonic movement, where reverse faults in developed in inner burial hill from Indosinian stage to Yanshanian stage, the normal faults extended in Himalayan stage. Under the influence of tectonic movements, the burial hills show three layers, i.e. the reverse rushing faults in buried hills, paleo-residual hill, and extended horst block. The evolution of burial hills can be divided into four stages: steady raising period from Calenonian to early Hercynian, rushing brake drape period from Indosinian to middle Yanshanian, block tilting period in early Tertiary, and heating depression period from late Tertiary to Quaternary. The basin modeling softwares BasinMod 1-D and Basin 2-D, which are made by PRA corporation, are used in this paper, according to the requirement, corresponding geological model is designed. And we model the burial history, thermal history, hydrocarbon generation and hydrocarbon expelling history of Qianmiqiao area. The results show that present bury depth is the deepest in the geological history, the sedimentary rate of Tertiary is highest and its rising rate of temperature rate is higher. During sedimentary history, there is no large erosion, and in the Tertiary, the deeper sediment was deposited in large space, therefore it is in favor of the conservation and transformation of oil and gas. The thermal research shows that the heat primarily comes from basement of the basin, present geotherm is the highest temperature in the geological history. Major source rock is the strata of ES3, whose organic is abundant, good-typed, maturative and of high-expulsive efficiency. The organic evolution of source rock of O has come to the overmature stage, the evolving time is long and the source rock can be easily destroyed. Therefore it is more difficult for the O formation source rock to form the huge accumulation of oil and gas than Es3 formation. In the research of oil assembling, we first calculated the characteristics of the fluid pressure of single well, then analyzed the distribution of the surplus fluid pressure of each formation and profile, and probe the first hydrocarbon migration situation and the distribution of pressure system of buried hill pool. In every formation, the pressure system of each burial hill has its own characteristics, e.g. high pressure or low pressure. In the research of secondary migration, the fluid potential is calculated while the relative low potential area is figured out. In Qianmiqiao area, the west margin faults have the low potential, and hence is the favorable reconnoiter belt.

利用分频与反演提高地震资料信噪比与分辨率方法研究

This thesis mainly talks about the wavelet transfrom and the frequency division method. It describes the frequency division processing on prestack or post-stack seismic data and application of inversion noise attenuation, frequency division residual static correction and high resolution data in reservoir inversion. This thesis not only describes the frequency division and inversion in theory, but also proves it by model calculation. All the methods are integrated together. The actual data processing demonstrates the applying results. This thesis analyzes the differences and limitation between t-x prediction filter and f-x prediction filter noise attenuation from wavelet transform theory. It considers that we can do the frequency division attenuation process of noise and signal by wavelet frequency division theory according to the differences of noise and signal in phase, amplitude and frequency. By comparison with the f-x coherence noise, removal method, it approves the effects and practicability of frequency division in coherence and random noise isolation. In order to solve the side effects in non-noise area, we: take the area constraint method and only apply the frequency division processing in the noise area. So it can solve the problem of low frequency loss in non-noise area. The residual moveout differences in seismic data processing have a great effect on stack image and resolutions. Different frequency components have different residual moveout differences. The frequency division residual static correction realizes the frequency division and the calculation of residual correction magnitude. It also solves the problems of different residual correction magnitude in different frequency and protects the high frequency information in data. By actual data processing, we can get good results in phase residual moveout differences elimination of pre-stack data, stack image quality and improvement of data resolution. This thesis analyses the characters of the random noises and its descriptions in time domain and frequency domain. Furthermore it gives the inversion prediction solution methods and realizes the frequency division inversion attenuation of the random noise. By the analysis of results of the actual data processing, we show that the noise removed by inversion has its own advantages. By analyzing parameter's about resolution and technology of high resolution data processing, this thesis describes the relations between frequency domain and resolution, parameters about resolution and methods to increase resolution. It also gives the processing flows of the high resolution data; the effect and influence of reservoir inversion caused by high resolution data. Finally it proves the accuracy and precision of the reservoir inversion results. The research results of this thesis reveal that frequency division noise attenuation, frequency residual correction and inversion noise attenuation are effective methods to increase the SNR and resolution of seismic data.

花岗岩风化土微观结构及其工程地质特性研究

Saprolite is the residual soil resulted from completely weathered or highly weathered granite and with corestones of parent rock. It is widely distributed in Hong Kong. Slope instability usually happens in this layer of residual soil and thus it is very important to study the engineering geological properties of Saprolite. Due to the relic granitic texture, the deformation and strength characteristics of Saprolite are very different from normal residual soils. In order to investigate the effects of the special microstructure on soil deformation and strength, a series of physical, chemical and mechanical tests were conducted on Saprolite at Kowloon, Hong Kong. The tests include chemical analysis, particle size analysis, mineral composition analysis, mercury injection, consolidation test, direct shear test, triaxial shear test, optical analysis, SEM & TEM analysis, and triaxial shear tests under real-time CT monitoring.Based on the testing results, intensity and degree of weathering were classified, factors affecting and controlling the deformation and strength of Saprolite were identified, and the interaction between those factors were analyzed.The major parameters describing soil microstructure were introduced mainly based on optical thin section analysis results. These parameters are of importance and physical meaning to describe particle shape, particle size distribution (PSD), and for numerical modeling of soil microstructure. A few parameters to depict particle geometry were proposed or improved. These parameters can be used to regenerate the particle shape and its distribution. Fractal dimension of particle shape was proposed to describe irregularity of particle shapes and capacity of space filling quantitatively. And the effect of fractal dimension of particle shape on soil strength was analyzed. At the same time, structural coefficient - a combined parameter which can quantify the overall microstructure of rock or soil was introduced to study Saprolite and the results are very positive. The study emphasized on the fractal characteristics of PSD and pore structure by applying fractal theory and method. With the results from thin section analysis and mercury injection, it was shown that at least two fractal dimensions Dfl(DB) and Df2 (Dw), exist for both PSD and pore structure. The reasons and physical meanings behind multi-fractal dimensions were analyzed. The fractal dimensions were used to calculate the formation depth and weathering rate of granite at Kowloon. As practical applications, correlations and mathematical models for fractal dimensions and engineering properties of soil were established. The correlation between fractal dimensions and mechanical properties of soil shows that the internal friction angle is mainly governed by Dfl 9 corresponding to coarse grain components, while the cohesion depends on Df2 , corresponding to fine grain components. The correlations between the fractal dimension, friction angle and cohesion are positive linear.Fractal models of PSD and pore size distribution were derived theoretically. Fragmentation mechanism of grains was also analyzed from the viewpoint of fractal. A simple function was derived to define the theoretical relationship between the water characteristic curve (WCC) and fractal dimension, based on a number of classical WCC models. This relationship provides a new analytical tool and research method for hydraulic properties in porous media and solute transportation. It also endues fractal dimensions with new physical meanings and facilitates applications of fractal dimensions in water retention characteristics, ground water movement, and environmental engineering.Based on the conclusions from the fractal characteristics of Saprolite, size effect on strength was expressed by fractal dimension. This function is in complete agreement with classical Weibull model and a simple function was derived to represent the relationship between them.In this thesis, the phenomenon of multi-fractal dimensions was theoretically analyzed and verified with WCC and saprolite PSD results, it was then concluded that multi-fractal can describe the characteristics of one object more accurately, compared to single fractal dimension. The multi-fractal of saprolite reflects its structural heterogeneity and changeable stress environment during the evolution history.

FEM Simulations and Optimization about Residual Stresses in Coating Structures with Functionally Graded Materials Layer

An elasto-plastic finite element method is developed to predict the residual stresses of thermal spraying coatings with functionally graded material layer. In numerical simulations, temperature sensitivity of various material constants is included and mix

Numerical Simulation of Transient Thermal Field and Residual Stress in Laser Melting Process

以激光熔凝表面强韧化处理为背景,应用空间弹塑性有限单元和高精度数值算法同时考虑材料组织性能的变化模拟工件的温度场及残余应力,研究激光熔凝加工中瞬时温度场及残余应力数值模拟,同时考虑相变潜热及相变塑性的影响,用算例验证了模型的正确性,给出了不同时刻温度场分布及残余应力分布。

Thermal Residual Stresses in Particulate Composites and Its Toughening Effect

In this paper, an accurate formula for calculating the thermal residual stress field in a particle-reinforced composite are presented. Numerical examples are given to show r-variations of the thermal residual stresses. The increase in fracture toughness of matrix predicted by the thermal residual stress field is compared well with the experimentally measured increase.

Scheme Construction with Numerical Flux Residual Correction (NFRC) and Group Velocity Control (GVC)

For simulating multi-scale complex flow fields like turbulent flows, the high order accurate schemes are preferred. In this paper, a scheme construction with numerical flux residual correction (NFRC) is presented. Any order accurate difference approximation can be obtained with the NFRC. To improve the resolution of the shock, the constructed schemes are modified with group velocity control (GVC) and weighted group velocity control (WGVC). The method of scheme construction is simple, and it is used to solve practical problems.

Ocean Waves Propagating over a Porous Seabed: Residual and Oscillatory Mechanisms

Two mechanisms for the wave-induced pore pressures in a porous seabed, i.e. oscillatory and residual excess pore pressures, have been observed in laboratory experiments and field measurements. Most previous investigations have focused on one of the mechanisms individually. In this paper, an analytical solution for the wave-induced residual pore pressure, which is not available yet, is derived, and compared with the existing experimental data. With the new solution, a parametric analysis is performed to clarify the applicable ranges of two mechanisms. Then, a simplified approximation for the prediction of wave-induced liquefaction potential is proposed for engineering practice.

The autocorrelation of speckles in deep Fresnel diffraction region and characterizations of random self-affine fractal surfaces

This paper studies the correlation properties of the speckles in the deep Fresnel diffraction region produced by the scattering of rough self-affine fractal surfaces. The autocorrelation function of the speckle intensities is formulated by the combination of the light scattering theory of Kirchhoff approximation and the principles of speckle statistics. We propose a method for extracting the three surface parameters, i.e. the roughness w, the lateral correlation length xi and the roughness exponent alpha, from the autocorrelation functions of speckles. This method is verified by simulating the speckle intensities and calculating the speckle autocorrelation function. We also find the phenomenon that for rough surfaces with alpha = 1, the structure of the speckles resembles that of the surface heights, which results from the effect of the peak and the valley parts of the surface, acting as micro-lenses converging and diverging the light waves.