旋转导向钻井偏心稳定器横向振动研究

旋转导向钻井偏心稳定器横向振动研究是国家863“可控(闭环)三维轨迹钻井技术”课题研究的部分内容。选取偏心稳定器的心轴作为研究对象,以偏心稳定器心轴连续梁系统的横向振动模型受力分析为基础,根据课题研究中所设计的心轴结构形式,建立了与实际情况较为接近的三铰支点的连续梁系统横向振动方程;并分析了偏心稳定器横向振动对钻井工具和钻具系统的影响,为合理进行心轴设计以及偏心稳定器样机在现场的正确使用和钻井参数的合理选择,提供了科学的理论依据和实用的计算方法。计算实例表明,当钻压范围选择在80~250kN时,215.9mm井眼钻进中的确存在19~20、61~63、162~163r/min前三阶横向共振转速区间,因此在选择钻井参数时应通过钻压与转速的配合,尽可能避开横向共振转速,以保证下部钻具组合系统及作业安全。     

SPW中自定义模块的创建与测试

SPW是一个先进的通信系统建模、仿真工具，它具有丰富的通信仿真模块和非常灵活的创建自定义模块功能。通过创建一个简单的自定义模块并对其进行功能测试，介绍了在SPW中创建及测试用户自定义模块的方法。这一实例表明，在SPW中可以将现成的模块与用户自定义模块有机结合在一起，从而大大提高了工程人员的工作效率，同时又扩展了SPW的应用领域。     

Research on Marine Boiler＇s Pressurized Combustion and Heat Transfer

The effect of pressure on combustion and heat transfer is analyzed. The research is based on the basic combustion and heat transfer theorem. A correction for the heat calculation method for pressurized furnace is made on the basis of the normal pressure case. The correction takes the effect of pressurizing into account. The results show that the correction is reasonable and the method is applicable to combustion and heat transfer of the marine supercharged boiler.     

2008北京奥运电视公用信号制作以及CCTV的投入

2008北京奥运会已圆满结束.高水准的赛亨转播给世人留下深刻印象.作者以奥运电视转播公用信号制作者的身份,介绍了2008北京奥运会电视公用信号制作的整体规模、技术特点以及BOB的管理体制以及运行模式.同时介绍了CCTV作为中国国家电视台对奥运公用信号制作的参与过程和制作水准.     

解决废钢短缺是特钢业发展的关键

随着短流程炼钢的迅速兴起，废钢消耗量急剧增加，世界范围内废钢供应已经出现了严重缺口，我国每年须从国际市场进口大量废钢才能满足钢铁生产的供需平衡，在我国废钢已成为紧缺资源，影响着我国特钢业的发展。分析了这一形势，并初步探讨了解决这一问题的方法，建立合理的废钢储备及使用体系，使废钢资源合理化流动，同时积极探寻优质的废钢代用品，以便从根本上解决我国废钢短缺问题。     

镍氢电池负极用低成本储氢合金的研究

研究了ABS型储氢合金在低Co含量条件下，随B组元替代元素Co，Al，Si等含量的变化对合金电化学性能的影响规律，同时研究了A组元中不同La／Ce比对合金电化学性能的影响情况。结果表明，随合金中Co含量的降低，合金的活化性能和放电容量得以改善，但合金的循环寿命下降也比较明显；在试验范围内，随Al元素的加入，合金的循环寿命得以改善，但材料的放电容量和活化性能均有所下降；随合金La／Ce比的降低，合金的放电容量略有下降，但其循环寿命和放电电压平台有较大提高。     

基于遗传算法的BP网络在导弹武器系统元器件贮存可靠性预测中的应用

针对目前BP神经网络在应用中,网络结构难以确定以及网络极易陷入局部解问题,用遗传算法优化神经网络的连接权和网络结构,并在遗传进化过程中引入交叉概率和变异概率与个体的适度值相联系,改进了操作算子,而且在交叉操作后又引入模拟退火机制,提高遗传算法的局部搜索能力.建立了基于改进遗传算法的BP网络贮存可靠性预测模型,并以某型导弹武器系统的元器件进行实例分析,计算结果表明,该方法预测的准确性高,且预测结果稳定.     

Development of a fuzzy decision model for manufacturability evaluation

A manufacturability evaluation decision model is formulated and analyzed based on fuzzy logic and multiple attribute decision-making under the concurrent engineering environment. The study emphasizes on the treatment of the linguistic and vagueness at the early product development stage. The study also considers the function integration of the total life cycle of a product. Hence, the integrated decision model covers the multi-level, multi-goal requirements of the products. Multiple criteria such as the goal space, the decision space, the function space, the development (i.e., product & process design) space, and the activity space, are then applied under different analysis of decision-making methods. For instances, the fuzzy multiple attribute decision-making (FMADM) combined with activity-based costing (ABC) can be used in the activity decision space. The fuzzy logic decision model can be applied in the goal decision space. The results of this study point out the importance of early decision making capability. An example of a high-pressure vessel is provided to demonstrate the proposed model for evaluating the manufacturability.     

A global output-feedback controller for stabilization and tracking of underactuated ODIN: A spherical underwater vehicle

This paper presents a method to design an output-feedback controller that simultaneously solves global asymptotic stabilization and tracking of an underactuated omni-directional intelligent navigator—a spherical underwater vehicle moving in a horizontal plane (i.e. at a constant depth). The vehicle does not have a sway actuator and has only position and orientation measurements available. The control development is based on Lyapunov's direct method, backstepping technique and use of interconnected structure of the vehicle dynamics. Numerical simulations demonstrate the results.     

Interfacial hybridization kinetics of oligonucleotides immobilized onto fused silica surfaces

Fused silica optical fibers have been used in an intrinsic mode optical configuration as biosensors for fluorescence based detection of hybridization of nucleic acids. In this work, the kinetics of hybridization of single-stranded oligonucleotides that were covalently immobilized were studied. The probe DNA was dT₂₀, and the target was Fluorescein-labeled non-complementary (dT₂₀) or complementary (dA₂₀) oligonucleotide. Chronofluorimetric monitoring of the adsorption and hybridization processes was used to investigate oligonucleotide films of different density, in different salt concentrations, at temperatures of 25 and 40 °C, with the concentration of the target DNA being 0.005–0.1 μM. Mathematical models based on first- and second-order Langmuir adsorption have been examined to describe both the adsorption and the hybridization processes. Experimental data were processed using the models, and the hybridization kinetics were calculated. Hybridization kinetics on these optical fiber DNA sensors was found to be up to three orders faster than results presented for a number of other experiments using different immobilization chemistries.