基于多材质复合管柱的裸眼井壁支撑工艺及应用

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。     

冬枣贮藏效果与相关酶活性的相关研究

以鄂北冬枣为材料,对果实采后低温贮藏过程中相关酶活性与果实硬度进行相关分析、通径分析和灰色关联分析。分析结果表明,各相关酶活性与硬度的相关程度依次为PG、SOD、CAT、PME、POD,与果实硬度的贡献率大小依次为PG、CAT、SOD、PME、POD,与果实硬度的关联度顺序为PME、SOD、PG、CAT、POD。综合分析结果表明,PG活性、CAT活性、SOD活性为果实贮藏过程中主要的酶,在贮藏过程中对果实软化衰老起重要作用。     

General mechanisms of drought response and their application in drought resistance improvement in plants

Plants often encounter unfavorable environmental conditions because of their sessile lifestyle. These adverse factors greatly affect the geographic distribution of plants, as well as their growth and productivity. Drought stress is one of the premier limitations to global agricultural production due to the complexity of the water-limiting environment and changing climate. Plants have evolved a series of mechanisms at the morphological, physiological, biochemical, cellular, and molecular levels to overcome water deficit or drought stress conditions. The drought resistance of plants can be divided into four basic types-drought avoidance, drought tolerance, drought escape, and drought recovery. Various drought-related traits, including root traits, leaf traits, osmotic adjustment capabilities, water potential, ABA content, and stability of the cell membrane, have been used as indicators to evaluate the drought resistance of plants. In the last decade, scientists have investigated the genetic and molecular mechanisms of drought resistance to enhance the drought resistance of various crops, and significant progress has been made with regard to drought avoidance and drought tolerance. With increasing knowledge to comprehensively decipher the complicated mechanisms of drought resistance in model plants, it still remains an enormous challenge to develop water-saving and drought-resistant crops to cope with the water shortage and increasing demand for food production in the future.     

数控车床加工椭圆类非圆曲线宏程序应用

为方便加工零件上不同位置的椭圆轮廓,采用坐标系平移与坐标系旋转的方法,将给定椭圆表达式所在的原坐标系与数控车床工件坐标系建立联系.并通过实例进行粗车循环与宏程序联合编程,完成零件加工.提出的坐标系平移与坐标系旋转方法,可方便地对不同位置的椭圆轮廓在数控车床工件坐标系中建立新的表达式,该方法数学计算简单,适用于各类、不同位置非圆曲线的宏程序编写.     

基于回波预处理和相参积累的C&I干扰抑制算法

C&I(chopping and interleaving)干扰是一种针对线性调频(linear frequency modulation, LFM)雷达的典型干扰样式, 干扰子信号调频斜率与雷达发射信号相同, 利用信号处理工具分离真实回波与干扰信号难度较大。针对该问题, 以LFM相参雷达抗自卫式C&I干扰为背景, 提出基于回波预处理和相参积累的干扰抑制算法。根据估计的回波时延, 设置距离窗截取受干扰回波段, 在此基础上, 通过对回波预处理, 改变不同重复周期内假目标的快时间位置分布, 通过相参积累实现干扰抑制。仿真试验表明, 所提算法能够有效抑制强干扰背景下的C&I干扰, 干扰抑制后真实目标检测概率大幅提高, 虚假目标数量明显减少。     

Geochemistry of Clayey Aquitard Pore Water as Archive of Paleo-Environment,Western Bohai Bay

The record of paleo-environment in clayey aquitard pore water is much more effective relative to aquifer groundwater owing to the low permeability of clayey aquitard. Oxygen-18 (18O), deuterium (D), an...     

An Economic Model-Based Matching Approach Between Buyers and Sellers Through a Broker in an Open E-Marketplace

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.     

Study on the Centralization Strategy of the Blood Allocation Among Different Departments within a Hospital

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.     

磁流变液中磁性颗粒成链与团聚的临界特征分析

热运动对纳米级磁流变液系统的颗粒团聚行为和宏观流变特性扰动影响不可忽视.为研究施加外磁场后系统微结构与热运动间的关系，探讨在不同颗粒粒径情况下热运动能量在系统总能量中的占比.采用CCD设计方法，分析Monte Carlo仿真获取的颗粒位形信息，生成关于外磁场磁感应强度、颗粒粒径和体积分数的系统热耦合系数<λ>回归模型;成链团聚的临界颗粒粒径计算值比文献经验值高出约23%，证实在考虑系统内多因素的综合影响下，纳米级磁流变液具有更严格的流变现象临界发生条件.     

Effects of Strain Rate,Temperature and Grain Size on the Mechanical Properties and Microstructure Evolutions of Polycrystalline Nickel Nanowires: A Molecular Dynamics Simulation

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.