Improved preprocessing methods for modulo scheduling algorithms

Instruction scheduling with an automaton-based resource conflict model is well-established for normal scheduling. Such models have been generalized to software pipelining in the modulo-scheduling framework. One weakness with existing methods is that a distinct automaton must be constructed for each combination of a reservation table and initiation interval. In this work, we present a different approach to model conflicts. We construct one automaton for each reservation table which acts as a compact encoding of all the conflict automata for this table, which can be recovered for use in modulo-scheduling. The basic premise of the construction is to move away from the Proebsting-Fraser model of conflict automaton to the Muller model of automaton modelling issue sequences. The latter turns out to be useful and efficient in this situation. Having constructed this automaton, we show how to improve the estimate of resource constrained initiation interval. Such a bound is always better than the average-use estimate. We show that our bound is safe: it is always lower than the true initiation interval. This use of the automaton is orthogonal to its use in modulo-scheduling. Once we generate the required information during pre-processing, we can compute the lower bound for a program without any further reference to the automaton.

Simulation Blocks for TOSSIM-T2"

We develop several hardware and software simulation blocks for the TinyOS-2 (TOSSIM-T2) simulator. The choice of simulated hardware platform is the popular MICA2 mote. While the hardware simulation elements comprise of radio and external flash memory, the software blocks include an environment noise model, packet delivery model and an energy estimator block for the complete system. The hardware radio block uses the software environment noise model to sample the noise floor.The packet delivery model is built by establishing the SNR-PRR curve for the MICA2 system. The energy estimator block models energy consumption by Micro Controller Unit(MCU), Radio,LEDs, and external flash memory. Using the manufacturer’s data sheets we provide an estimate of the energy consumed by the hardware during transmission, reception and also track several of the MCUs states with the associated energy consumption. To study the effectiveness of this work, we take a case study of a paper presented in [1]. We obtain three sets of results for energy consumption through mathematical analysis, simulation using the blocks built into PowerTossim-T2 and finally laboratory measurements. Since there is a significant match between these result sets, we propose our blocks for T2 community to effectively test their application energy requirements and node life times.

Spectrum sensing via universal source coding

We consider nonparametric sequential hypothesis testing when the distribution under null hypothesis is fully known and the alternate hypothesis corresponds to some other unknown distribution. We use easily implementable universal lossless source codes to propose simple algorithms for such a setup. These algorithms are motivated from spectrum sensing application in Cognitive Radios. Universal sequential hypothesis testing using Lempel Ziv codes and Krichevsky-Trofimov estimator with Arithmetic Encoder are considered and compared for different distributions. Cooperative spectrum sensing with multiple Cognitive Radios using universal codes is also considered.

Research on Q-Switched Nd : YAG laser engraving

IN this paper, the engraving process with Q-Switched Nd:YAG laser is investigated. High power density is the pre- requisition to vapor materials, and high repetition rate makes the engraving process highly efficient. An acousto- optic Q-Switch is applied in the cavity of CW 200 W Nd:YAG laser to achieve the high peak power density and the high pulse repetition rate. Different shape craters are formed in a patterned structure on the material surface when the laser beam irradiates on it by controlling power density, pulse repetition rate, pulse quantity and pulse interval. In addition, assisting oxygen gas is used for not only improving combustion to deepen the craters but also removing the plasma that generated on the top of craters. Off-focus length classified as negative and positive has a substantial effect on crater diameters. According to the message of rotating angle positions from material to be engraved and the information of graph pixels from computer, a special graph is imparted to the material by integrating the Q- Switched Nd:YAG laser with the computer graph manipulation and the numerically controlled worktable. The crater diameter depends on laser beam divergence and laser focal length. The crater diameter changes from 50 micrometers to 300 micrometers , and the maximum of crater depth reaches one millimeter.

Plasma channeling by multiple short-pulse lasers

Channeling by a train of laser pulses into homogeneous and inhomogeneous plasmas is studied using particle-in-cell simulation. When the pulse duration and the interval between the successive pulses are appropriate, the laser pulse train can channel into the plasma deeper than a single long-pulse laser of similar peak intensity and total energy. The increased penetration distance can be attributed to the repeated actions of the ponderomotive force, the continuous between-pulse channel lengthening by the inertially evacuating ions, and the suppression of laser-driven plasma instabilities by the intermittent laser-energy cut-offs.

Quantifying Earthquake Collapse Risk of Tall Steel Moment Frame Buildings Using Rupture-to-Rafters Simulations

There is a sparse number of credible source models available from large-magnitude past earthquakes. A stochastic source model generation algorithm thus becomes necessary for robust risk quantification using scenario earthquakes. We present an algorithm that combines the physics of fault ruptures as imaged in laboratory earthquakes with stress estimates on the fault constrained by field observations to generate stochastic source models for large-magnitude (Mw 6.0-8.0) strike-slip earthquakes. The algorithm is validated through a statistical comparison of synthetic ground motion histories from a stochastically generated source model for a magnitude 7.90 earthquake and a kinematic finite-source inversion of an equivalent magnitude past earthquake on a geometrically similar fault. The synthetic dataset comprises of three-component ground motion waveforms, computed at 636 sites in southern California, for ten hypothetical rupture scenarios (five hypocenters, each with two rupture directions) on the southern San Andreas fault. A similar validation exercise is conducted for a magnitude 6.0 earthquake, the lower magnitude limit for the algorithm. Additionally, ground motions from the Mw7.9 earthquake simulations are compared against predictions by the Campbell-Bozorgnia NGA relation as well as the ShakeOut scenario earthquake. The algorithm is then applied to generate fifty source models for a hypothetical magnitude 7.9 earthquake originating at Parkfield, with rupture propagating from north to south (towards Wrightwood), similar to the 1857 Fort Tejon earthquake. Using the spectral element method, three-component ground motion waveforms are computed in the Los Angeles basin for each scenario earthquake and the sensitivity of ground shaking intensity to seismic source parameters (such as the percentage of asperity area relative to the fault area, rupture speed, and risetime) is studied.

Under plausible San Andreas fault earthquakes in the next 30 years, modeled using the stochastic source algorithm, the performance of two 18-story steel moment frame buildings (UBC 1982 and 1997 designs) in southern California is quantified. The approach integrates rupture-to-rafters simulations into the PEER performance based earthquake engineering (PBEE) framework. Using stochastic sources and computational seismic wave propagation, three-component ground motion histories at 636 sites in southern California are generated for sixty scenario earthquakes on the San Andreas fault. The ruptures, with moment magnitudes in the range of 6.0-8.0, are assumed to occur at five locations on the southern section of the fault. Two unilateral rupture propagation directions are considered. The 30-year probabilities of all plausible ruptures in this magnitude range and in that section of the fault, as forecast by the United States Geological Survey, are distributed among these 60 earthquakes based on proximity and moment release. The response of the two 18-story buildings hypothetically located at each of the 636 sites under 3-component shaking from all 60 events is computed using 3-D nonlinear time-history analysis. Using these results, the probability of the structural response exceeding Immediate Occupancy (IO), Life-Safety (LS), and Collapse Prevention (CP) performance levels under San Andreas fault earthquakes over the next thirty years is evaluated.

Furthermore, the conditional and marginal probability distributions of peak ground velocity (PGV) and displacement (PGD) in Los Angeles and surrounding basins due to earthquakes occurring primarily on the mid-section of southern San Andreas fault are determined using Bayesian model class identification. Simulated ground motions at sites within 55-75km from the source from a suite of 60 earthquakes (Mw 6.0 − 8.0) primarily rupturing mid-section of San Andreas fault are considered for PGV and PGD data.

基于电光调制的激光光谱整形技术

提出了一种新型的基于电光调制的激光光谱整形方案，该整形技术可以减轻啁啾脉冲放大系统中的增益窄化效应。傅立叶变换限的宽带种子激光脉冲通过光学展宽器线性展宽后，耦合到加载有整形电脉冲的集成波导调制器中进行整形，整形电脉冲由孔径耦合带状线电脉冲发生器产生。由于线性啁啾脉冲时间-频率的直接对应关系，在时域内对宽带种子激光脉冲整形，其光谱也得到了同样形状的整形。模拟了整形光谱形状，相应的整形电脉冲波形，分析了该整形技术的光谱整形分辨率，以及整形过程中引入的相位畸变。

飞秒激光辐照K9玻璃引起的暗化和折射率变化

对不同辐照条件下近红外飞秒激光在K9玻璃内部诱导产生的暗化现象和永久性折射率改变进行了实验研究。通过辐照前后的显微镜图片、吸收光谱、电子自旋共振谱(ESR)以及激光衍射实验，分析了K9玻璃中暗化现象产生的微观过程，发现暗化是由诱导产生的空穴型色心引起的。暗化程度和折射率改变随激光强度、扫描速度、扫描行间距变化而变化。光致色心的形成与非线性电离有关。对折射率永久性改变进行了简单说明，其机理仍在探索中。

Avaliação da presença de mutações de resistência no gene da NS5B e do prognóstico da infecção pelo HCV através da IL-28B em pacientes monoinfectados com HCV no RJ

Estima-se que a prevalência global da população mundial com hepatite C é de 3%. Pouco se sabe sobre a resposta ao tratamento com respeito à resistência viral. Algumas mutações no fragmento de 109 aminoácidos da NS5B são associadas com resistência ao interferon (IFN) e ribavirina (RBV). Estudos moleculares e clínicos identificaram fatores associados com o hospedeiro e vírus relacionados associada com a resposta ao tratamento, tal como o gene que codifica a IL-28B. Este estudo foi dividido em duas fases, cujos objetivos foram caracterizar a frequência de mutações que conferem resistência ao HCV e avaliar a relevância das mutações em pacientes Respondedores (R) ou Não Respondedores (NR) ao tratamento e caracterizar geneticamente as populações sobre polimorfismos genéticos nos SNPs da IL-28B em relação ao prognóstico da resposta ao tratamento. As amostras dos pacientes foram submetidas a testes de genotipagem e carga viral. As sequências geradas foram comparadas no BLAST e no banco de dados Los Alamos HCV. Realizamos o alinhamento das sequências homólogas e as mutações identificadas. Com base no genótipo e carga viral determinamos a classificação dos pacientes de acordo com a resposta à terapia. O DNA genômico foi isolado a partir de sangue periférico para a realização da tipagem de SNPs de IL-28B. A metodologia utilizada foi de PCR em tempo real utilizando sondas TaqMan SNP específico. A análise dos dados foi realizada utilizando GraphPad Prism com qui-quadrado, risco relativo (RR), Odds Ratio (OR) e intervalo de confiança de 95%, com um nível de significância de P <0,05. Foi encontrado na primeira fase deste estudo uma taxa significativa mutações associadas ao tratamento nas amostras estudadas. A prevalência de mutações associadas à resistência ao IFN e RBV bem como a novos medicamentos antivirais localizados no fragmento de 109 aminoácidos da NS5B foi examinado em 69 indivíduos infectados naïve no Rio de Janeiro, Brasil. Na segunda fase, as mutações foram clinicamente relevantes. Desde então, procuramos observar as diferenças entre melhor ou pior prognóstico de acordo com a imunogenética que mostrou diferenciação entre os grupos R e NR ao tratamento em relação ao prognóstico da resposta terapêutica. Quando as diferenças entre as sequências da NS5B e a resposta ao tratamento foram consideradas verificou-se que associada a mutação R254K, estava a C316N que poderia conduzir a uma não resposta à terapia no genótipo 1b. Os nossos dados também suportaram forte associação de IL-28B rs12979860, com elevada probabilidade de resposta à terapia de IFN + RBV. Nossos dados evidenciam a presença de pacientes virgens de tratamento que abrigam mutações de resistência previamente descritas na literatura. A análise dos fatores preditores de resposta virológica mostrou que a predição de boa resposta ou não ao tratamento e ainda da progressão da doença é dependente de uma importante interação entre a genética viral e a do hospedeiro. Fato este importante para que no momento de avaliação de diagnóstico e conduta terapêutica, o médico possa tomar medidas apropriadas para o tratamento de cada paciente individualmente independentemente do genótipo do HCV em questão.

Gráficos de controle adaptativos para monitoramento de perfis

Processos de produção precisam ser avaliados continuamente para que funcionem de modo mais eficaz e eficiente possível. Um conjunto de ferramentas utilizado para tal finalidade é denominado controle estatístico de processos (CEP). Através de ferramentas do CEP, o monitoramento pode ser realizado periodicamente. A ferramenta mais importante do CEP é o gráfico de controle. Nesta tese, foca-se no monitoramento de uma variável resposta, por meio dos parâmetros ou coeficientes de um modelo de regressão linear simples. Propõe-se gráficos de controle χ2 adaptativos para o monitoramento dos coeficientes do modelo de regressão linear simples. Mais especificamente, são desenvolvidos sete gráficos de controle χ2 adaptativos para o monitoramento de perfis lineares, a saber: gráfico com tamanho de amostra variável; intervalo de amostragem variável; limites de controle e de advertência variáveis; tamanho de amostra e intervalo de amostragem variáveis; tamanho de amostra e limites variáveis; intervalo de amostragem e limites variáveis e por fim, com todos os parâmetros de projeto variáveis. Medidas de desempenho dos gráficos propostos foram obtidas através de propriedades de cadeia de Markov, tanto para a situação zero-state como para a steady-state, verificando-se uma diminuição do tempo médio até um sinal no caso de desvios pequenos a moderados nos coeficientes do modelo de regressão do processo de produção. Os gráficos propostos foram aplicados a um exemplo de um processo de fabricação de semicondutores. Além disso, uma análise de sensibilidade dos mesmos é feita em função de desvios de diferentes magnitudes nos parâmetros do processo, a saber, no intercepto e na inclinação, comparando-se o desempenho entre os gráficos desenvolvidos e também com o gráfico χ2 com parâmetros fixos. Os gráficos propostos nesta tese são adequados para vários tipos de aplicações. Neste trabalho também foi considerado características de qualidade as quais são representadas por um modelo de regressão não-linear. Para o modelo de regressão não-linear considerado, a proposta é utilizar um método que divide o perfil não-linear em partes lineares, mais especificamente, um algoritmo para este fim, proposto na literatura, foi utilizado. Desta forma, foi possível validar a técnica proposta, mostrando que a mesma é robusta no sentido que permite tipos diferentes de perfis não-lineares. Aproxima-se, portanto um perfil não-linear por perfis lineares por partes, o que proporciona o monitoramento de cada perfil linear por gráficos de controle, como os gráficos de controle desenvolvidos nesta tese. Ademais apresenta-se a metodologia de decompor um perfil não-linear em partes lineares de forma detalhada e completa, abrindo espaço para ampla utilização.

Associação entre bebidas adoçadas e consumo calórico em refeições na população brasileira.

Nas últimas décadas, tem sido observado o aumento da oferta de bebidas com elevado conteúdo calórico e com grandes quantidades de açúcar de rápida absorção. Essas bebidas adoçadas, cujo consumo tem aumentado no Brasil assim como em outras partes do mundo, são consideradas fatores de risco para obesidade e diabetes. O consumo de bebidas adoçadas pode levar ao balanço energético positivo e consequentemente ao ganho de peso. Essa associação pode ser explicada pelo mecanismo regulatório de compensação de calorias líquidas. Compensação calórica ocorre quando há redução no consumo de calorias provenientes de alimentos sólidos para compensar as calorias líquidas adicionadas à refeição ou dieta. No entanto, não há consenso em relação a evidências da compensação calórica, dificultando a elaboração de recomendações sobre essas bebidas em saúde pública. Razões para a falta de consenso incluem a diversidade de desenhos de estudos, experimentos realizados em ambientes controlados e não reais em relação ao consumo de alimentos e bebidas, e estudos com amostras pequenas ou de conveniência. Esta dissertação estudou a associação entre bebidas adoçadas e consumo calórico, verificando se calorias de bebidas adoçadas são compensadas em refeições realizadas em um ambiente pragmático. Os dados de consumo calórico de 34.003 indivíduos, com idade igual ou superior a dez anos, foram obtidos pelo Inquérito Nacional de Alimentação 2008-2009, em todo território nacional. Os participantes completaram dois registros alimentares, em dias não consecutivos da mesma semana. Foram selecionadas as refeições dos períodos café da manhã, almoço e jantar de cada indivíduo em cada um dos dias. Para cada refeição, foi calculado o valor calórico de alimentos e de bebidas adoçadas consumidos. Para testar a compensação calórica, um modelo de regressão linear multinível com efeitos mistos foi ajustado para analisar cada período. A variável reposta utilizada foi consumo calórico proveniente de alimentos e a variável explicativa foi consumo calórico de bebida adoçada na refeição. Os efeitos intra-indivíduo da bebida adoçada no consumo calórico foram estimados e interpretados. Esses efeitos são considerados não-enviesados pois são controlados pelas características constantes dos indivíduos, tendo assim o indivíduo atuando como seu próprio controle na análise. Covariadas incluídas no modelo foram variáveis da refeição: local, dia da semana, horário, consumo calórico na refeição anterior e intervalo de tempo desde a última refeição; e do indivíduo: sexo, faixa etária, categoria de Índice de Massa Corpórea e quartos de renda per capita. Efeitos aleatórios dos indivíduos e dos domicílios foram incluídos no modelo para melhor estimar a estrutura de erros de dados correlacionados. A compensação calórica foi de 42% para o café da manhã, não houve compensação no almoço e para o jantar, compensação variou de 0 a 22%, tendo interação com quartos de renda per capita. A conclusão desta dissertação é que as bebidas adoçadas não são completamente compensadas em refeições realizadas em ambiente pragmático. Assim, a redução do consumo de bebidas adoçadas em refeições pode ajudar a diminuir o consumo calórico excessivo e levar a um melhor controle do peso em indivíduos.

岷江柏种子的形态和发芽特征与贮藏生理动态研究

岷江柏(Cupressus chenggiana S. Y. Hu)是我国川甘地区特有的珍稀濒危乔木，一般生长在干旱的河谷区，在涵养水源和保护水 土等方面起着重要的作用。本文选择4个岷江柏种群，采用了野外调查和室内实验相结合的研究方法，调查岷江柏种群结实状况， 分析种子和球果形态特征，阐明种子发芽的基本特征，研究岷江柏种子贮藏过程中几个生理指标的动态变化特点，目的是为岷江柏 种苗繁育、自然更新能力评估以及珍稀濒危机制分析提供理论依据。研究得出如下结论：1.岷江柏球果呈椭球形，长为1.5～ 2.2cm,宽为1.5～1.9cm，质量为1.7～4.2g，球果鳞片数量为8～11片，球果内种子数量一般在40～70粒。岷江柏种子为椭圆形，长 为3.58～4.02mm，宽为3.10～3.15mm，厚为0.96～1.11mm，千粒重为3.1～3.5g。岷江柏的结实率很低，并且有显著的地理差异和 大小年差异。2. 岷江柏种子发芽温度范围是5℃～30℃,其中种子的适宜发芽温度范围是10℃～25℃。种子最适发芽温度随着贮藏 时间的增加而变化。在适宜温度范围内，种子发芽周期为20d。温度对种子的发芽势和T50有显著影响，对种子发芽率没有显著影响 ；光照有利于种子发芽；岷江柏种子的发芽特征是岷江柏保护种子资源、防止物种濒危的一种环境适应，有助于岷江柏种子提高发 芽率和幼苗的存活率。岷江柏种子是一种耐贮藏的正常性种子，在短期贮藏过程中，贮藏温度和种子含水量对于种子生理指标和种 子发芽没有显著影响。3. 岷江柏种子在短期贮藏过程中，千粒重没有显著变化；含水量都经历了先下降，再稳定的过程；粗脂肪 含量和可溶性糖含量逐渐降低；可溶性蛋白含量和丙二醛含量逐渐增加；脯氨酸含量在贮藏1～7个月时变化差异不明显，但是贮藏 7～10个月后显著增加。岷江柏种子的各个生理指标之间的相关性差异不显著。4. 岷江柏球果和种子的形态特征存在显著的地理差 异。岷江柏种子的发芽能力的地理性差异不大，种群间差异不大。岷江柏种群的地理差异由种群特征、生境特征和气候特征共同决 定。5. 在岷江柏的人工繁育中，对于刚刚采集的种子，发芽温度在15℃～25℃比较适合，其中以25℃最佳；而对于短期贮藏(4～ 10个月)后的种子，发芽温度在10℃～25℃均可，以15℃～20℃为最佳。野外播种的最适时间为4～6月，6～9月的间歇性干旱和降 水波动可能是限制岷江柏自然更新的因素之一。在短期贮藏过程中，种子可以采用常规室温贮藏，可以节约成本。Cupressus chenggiana is a specific and endangered plant in Sichuan and Gansu provinces of China, and it usually grows in dry valley and plays an important role in water supply and soil and water conservation in the dry valley of alpine and canyon region of southwest China. The research selected four Cupressus chenggiana populations and used the methods of the field investigation and the lab experiments. The fruiting characters of Cupressus chenggiana populations, the morphological characters of seeds and cones, the germination characters of seeds and the store physiological dymatics of several factors of seeds have been studied in order to give some theoretical advices on the artificial propagation and the ability of natural regeneration and the endangered principle of Cupressus chenggiana in the paper. The main results may be clarified as follows: 1. The cones of Cupressus chenggiana are ellipsoidal, length ranged from 1.5 to 2.2cm, with ranged from 1.5 to 1.9 cm, weight ranged from 1.7 to 4.2g, the number of cone squama ranged from 8 to 11, and the seed number of per cone ranged from 40 to 70. The seeds of Cupressus chenggiana are elliptical, length ranged from 3.58 to 4.02 mm, width ranged from 3.10 to 3.15 mm, thickness ranged from 0.96 to 1.11 mm, and the weight of 1000 seeds ranged from 3.1 to 3.5g. The fruiting rate of Cupressus chenggiana is very low, and the fruiting period of Cupressus chenggiana has the geographical differences and the big or small year differences. 2. Seed germination temperature is between 5℃ and 30℃, while the suited temperature is between 10℃ and 25℃. The optimum temperature of seed germination will change as the store time of seeds changes logner. The cycle of seed germination can persist 20 days in the range of the suited temperature. The germination temperatures have significant influences on the germination potential and T50, but have no significant infuluences on the germination rate. The photoperiod is in favor of seed germination. The characters of Cupressus chenggiana seed germination represent a kind of environmental adaptability to protect the seed sources and endangered species, and it can give help to increase the germination rate of seeds and the livability of seedings. The seeds of Cupressus chenggiana are a kind of orthodox seeds that can endure the long time storage. In the short time storage, the store temperatures and the moisture contents of seeds have no significant infuluences on the physiological factors and the germination of seeds, but the store time has significant influences on the physiological factors of seeds. 3. In the short store course of Cupressus chenggianna seeds, the 1000 seed weight has no significant variation; The moisture content descends at the beginning of the storage, but has no significant variation later; The crude fat content and the soluble sugar content descend gradually; The soluble protein content and MDA content increase gradually; The praline content has no significant variation after 1～7 months storage, but increase significantly after 7～10 months storage. The correlations of different physiological factors are not significant. 4. The morphological characters of cones and seeds of four populations exist significant differences. The germination of Cupressus chenggiana seeds has no significant geographical variation. The geographical variation of Cupressus chenggiana populations can be ascribed to the population characters, climate and environment. 5. In the course of artificial propagation of Cupressus chenggiana, it is favored that the germination temperature of newly collected seeds is between 15℃ and 25℃, while the optimum temperature is 25℃. After the short storage ranged from 4 months to 10 months, it is favored that the germination temperature is between 10℃ and 25℃, while the optimum temperature is ranged from 15℃ to 20℃. The field sowing optimum time is between April and June, and the interval drought and fallrain fluctuation between July and September may be one of the reasons that restrict natural regeneration of Cupressus chenggiana. In the short storage, seeds can be stored in the condition of room temperature.

Commissioning of electron cooling in CSRm

A new generation electron cooler has started operation in the heavy ion synchrotron CSRm which is used to increase the intensity of heavy ions. Transverse cooling of the ion beam after horizontal multi-turn injection allows beam accumulation at the injection energy. After optimization of the accumulation process an intensity increase in a synchrotron pulse by more than one order of magnitude has been achieved. In given accumulation time interval of 10 seconds, 108particles have been accumulated and accelerated to the final energy. The momentum spread after accumulation and acceleration in the 10−4 range has been demonstrated in six species of ion beams. Primary measurements of accumulation process varying with electron energy,electron beam current, electron beam profile, expansion factor and injection interval have been performed.The lifetimes of ion beams in the presence of electron beams were roughly measured with the help of DCCT signal.

基于激光熔覆的绿色再制造技术研究

为了实现轴类零件的修复,搭建基于激光熔覆技术的绿色再制造系统,该系统由功率为6kW的CO2激光器、四轴工作台、送粉机构、数控系统等硬件设备和激光绿色再制造系统驱动软件组成。以轴类为典型零件、Ni60A合金粉末为熔覆材料,对激光绿色再制造工艺技术进行研究。通过研究分析激光功率、熔覆速度、送粉量、熔覆间距等主要参数对熔覆层高度、宽度和熔覆层质量等的影响情况,获得了轴类零件激光修复的最佳工艺参数组合,实现基于激光熔覆的绿色再制造技术在生产实践中的应用。

南海大陆边缘地壳结构与盆地形成机制--以珠江口－琼东南盆地为例

South China Sea is located in the convergence of Eurasian plate, the Pacific Ocean plate and Indian Ocean-Australia plate. The total area is about 3,500,000 km2, the geologic structure is complicated, and the structure line cut off reciprocal is the marginal sea taking form by that the seafloor spreads during the middle Oligocene. South China Sea continental margin have developed more than 10 large oil-gas bearing basins and a number of medium-small sized basins. These basins contain abundant mineral resources such as oil & gas. The marginal deepwater area in the north part of South China Sea has become our country’s strategic energy prospecting frontier. The deepwater area of Zhujiangkou and Qiongdongnan basins is the research target in this thesis. The thesis studied deep structure and the earth dynamics of the north part of South China Sea margin, and these researches provide scientific basis for oil-gas resources strategic investigation and valuation in deepwater sea area of north part slope of South China Sea. In order to develop the research of rebuilding velocities and density architecture of earth shell in region of interest, in marginal deepwater area in the north part of South China, we adopted 14 long-cable seismic reflection profile data of 3556.41 kilometers in total, the gravity measurement data along profiles (3851.44 kilometers in total), the magnetic observation along profiles (3838.4 kilometers in total) and depth measurement along profile, the logging data of 11 wells in project, the interpreted fault parameter and preexisting geologic and geophysical research achievement. This thesis has carried out concretely studying research as follows: 1. Overlay-velocity data sampling and analysis, interval velocity calculation, time-depth conversion, model building of earth shell velocity and layering character of earth shell are studied on 14 deep sections. Velocity structure in region of interest has revealed: Changchang is the sag with thinnest crust in Qiongdongnan basin; the sedimentary thickness lowers gradually from north to south, and the thickness change from west to east is milder. The sags’ sedimentary velocities in Qiongdongnan basin have obvious demarcation. The velocity of the 8000 meters sedimentary rocks is 4700 m/s in Shunde sag and Baiyun sag, and is the lowest; at that depth, the velocity very different in Liwan sag and Baiyun sag, which is about 800m/s. 2. Extracting gravity data and building of initial crust density model along the section; With Bouguer gravity anomaly data as constraint, revising density distributes of initial model, and building the crust density model. 3. With crust velocity and density as constraint, correcting the effect of thermobaric field and constructing constitution structure of rock in region of interest. By this research, we known that rocks in Zhujiangkou upper crustal layer are chiefly granite-gneiss, quartzite, granodiorite and basalt, however, rocks in Qiongdongnan basin upper earth shell are chiefly composed of granite-gneiss, quartzite, granodiorite, diorite and basalt. 4. Synthetically crust velocity and density structure, gaining expanding factor on crust and entire crust along section. The result is indicated: the expanding factor in every sag rises from northwest to southeast, which have reflected thinning characteristic of crust from continent to ocean. Intra-crustal deformation degree in Changchang and Ledong-Lingshui sag is bigger than that in Songnan-Baodao sag. Entire crust extension factor in Changchang and Songnan-Baodao sag is greater than that in Ledong-Lingshui sag, which can make an explanation of frequently event and longer heating process in middle-east of Qiongdongnan basin. 5. Synthesize multidisciplinary information to discuss the earth dynamics significance of discordogenic seismic profile in deepwater area of Zhujiangkou and Qiongdongnan basins.