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1.
已完钻超深裸眼水平井侧钻技术是经济、高效开发油藏剩余油的主要手段之一,传统的磨铣钢套管开窗侧钻技术存在下入摩阻大、磨铣耗时长导致开窗失败等问题。为此,提出了基于多材质复合管柱的超深水平井裸眼井壁支撑工艺,结合中国西北油田已完钻超深裸眼水平井井况,首先,提出了基于“铝合金+碳钢”的多材质复合管柱组合及设计方法;其次,开展了基于管柱实物屈曲实验数据的管柱临界屈曲载荷计算模型适用性评价,并优选出了适合于“铝合金+碳钢”多材质复合管柱的屈曲临界载荷计算模型;最后,研究了综合考虑管柱扭矩、摩阻、刚性、井眼条件、管柱强度及材质的多材质复合管柱下入性分析方法,并利用下入性分析软件对西北油田顺北X1井、X2井、X3井、X4井复合管柱进行了下入可行性评价。该方法在X1井和X2井得到成功应用,进一步论证了该工艺现场应用的可行性。研究成果可为超深水平井裸眼井壁支撑的复合管柱设计和下入可行性评价提供理论参考。 相似文献
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针对城市区域多无人机协同物流任务分配问题, 综合考虑不同无人机性能、物流时效性、飞行可靠性等影响因素, 以经济成本、时间损失和安全风险最小为目标函数, 构建多无人机协同物流任务分配模型。因问题规模大、求解复杂度高, 设计改进的量子粒子群算法进行求解。首先,为增强粒子遍历性和多样性, 采用均匀化级联Logistic映射进行粒子初始化; 其次,为避免算法陷入局部最优解, 引入基于高斯分布的粒子变异方式; 最后,为提高算法运行效率, 运用自适应惯性权重方法对粒子赋值。仿真实验结果表明,所构建的模型能够实现任务分配多目标优化, 贴近城市区域无人机物流配送实际; 所提算法与传统量子粒子群算法和遗传算法相比, 任务分配代价分别下降了5.9%和6.3%;并进一步对参数权重设置进行分析, 当3个子目标函数权重系数分别为0.225、0.275和0.500, 种群规模为150时, 算法规划的结果最优。 相似文献
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针对从含噪原始信号中提取位置以及速度信息,经典跟踪微分器存在不能很好兼顾相位滞后和噪声放大问题、参数多,调试复杂等不足.在跟踪微分器等效线性分析基础上,提出复合形式跟踪微分器,用于电容式位移传感器位置信号跟踪以及速度信号估计,通过MATLAB\SIMULINK仿真以及实验平台测试,结果表明:在跟踪频率1 Hz、幅值1含噪声正弦信号中,复合跟踪微分器能光滑逼近原始位置信号,且能有效进行速度估计,相较于经典跟踪微分器,复合跟踪微分器跟踪相位滞后小0.03 rad,能更好兼顾跟踪信号相位滞后及速度信号噪声放大. 相似文献
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为了保障锂离子电池的使用安全,提出了基于带渐消因子的扩展卡尔曼滤波
(Fading Extended Kalman Filter,FEKF)的电池状态在线监测方法. 建立锂电池一阶等效电路模型,利用递推最小二乘法进行锂电池状态参数在线辨识,建立状态方程;引入最优渐消因子,构造FEKF,得到端电压残差;使用端电压残差序列构造χ2分布的诊断函数,计算误检率与状态参数异常阈值. 实验结果显示利用FEKF生成的残差能更早对异常状态进行告警,证明FEKF能够显著提高χ2检验对锂电池内部缓变型异常状态判断的准确率. 相似文献
7.
A broker in an open e-marketplace enables buyers and sellers to do business with each other. Although a broker plays an important role in e-marketplaces, theory and guidelines for matching between buyers and sellers in multi-attribute exchanges are limited. Therefore, a challenge for a broker’s responsibility is how to maximize a buyer’s total satisfaction degree as its goals under the consideration of trade-off between a buyer’s buying quantity and price paid to a seller, and other attributes. To solve this challenge, this paper proposes an economic model-based matching approach between a buyer’s requirements and a seller’s offers. The major contributions of this paper are that (i) a broker can model a seller’s price policy as per a buyer’s buying quantity through communication between a broker and a seller; (ii) due to each buyer’s different quantity demand, a broker models a buyer’s satisfaction degree as per a buyer’s buying quantity based on communication between a broker and a buyer; and (iii) to carry out a broker’s matching processes, an objective function and a set of constraints are generated to help a broker to maximize a buyer’s total satisfaction degree. Experimental results demonstrate the good performance of the proposed approach. 相似文献
8.
Study on the Centralization Strategy of the Blood Allocation Among Different Departments within a Hospital 总被引:1,自引:1,他引:0
By far, the researches on how to distribute blood products among different departments in hospital have not been further studied, though the problem of blood shortage and wastage that caused by improper blood allocation is severe, which may endanger patient’s lives and impose considerable costs on hospitals. In order to solve this problem, this paper mainly studies on how to distribute the blood items among different departments within a hospital and investigates the allocation approach with the novel management method by centralizing the inventory of several different departments. By integrating the blood inventory requirements of some departments, the hospital could reduce the rate of blood shortage and wastage effectively, release the pressure of the occupancy of resources and reduce the bullwhip effect of blood products. This paper illustrates the centralization principle in hospital and formulates the mixed integer programming model to work out the optimal allocation network scheme and the optimal inventory setting for every department. And the results of the numerical example demonstrate that this centralization method could considerably reduce blood shortage and wastage in hospital by about 72% and 90% respectively. Furthermore, it could decrease the total cost by about 108,540 RMB a month on blood supply chain management in the hospital and improve the effect of some certain surgeries by transfusing the fresh blood to patients. 相似文献
9.
Through molecular dynamics(MD)simulation,the dependencies of temperature,grain size and strain rate on the mechanical properties were studied.The simulation results demonstrated that the strain rate from 0.05 to 2 ns~(–1 )affected the Young’s modulus of nickel nanowires slightly,whereas the yield stress increased.The Young’s modulus decreased approximately linearly;however,the yield stress firstly increased and subsequently dropped as the temperature increased.The Young’s modulus and yield stress increased as the mean grain size increased from 2.66 to6.72 nm.Moreover,certain efforts have been made in the microstructure evolution with mechanical properties association under uniaxial tension.Certain phenomena such as the formation of twin structures,which were found in nanowires with larger grain size at higher strain rate and lower temperature,as well as the movement of grain boundaries and dislocation,were detected and discussed in detail.The results demonstrated that the plastic deformation was mainly accommodated by the motion of grain boundaries for smaller grain size.However,for larger grain size,the formations of stacking faults and twins were the main mechanisms of plastic deformation in the polycrystalline nickel nanowire. 相似文献
10.
In this paper, views of investor are described in fuzzy sets, and two fuzzy Black-Litterman models are constructed with fuzzy views and fuzzy random views respectively. In the models, expected returns and uncertainty matrix of views are redefined and the views are formulated by fuzzy approaches suitably. Then the models are tested with data from Chinese financial markets. Empirical results show that the fuzzy random views model performs the best, and both the fuzzy models are better than the traditional ones, demonstrating that the fuzzy approaches can contain more information in the views and measure the uncertainty more correctly. 相似文献