Spatio-temporal characteristics of acoustic emission during the deformation of rock samples with compressional and extensional en-echelon faults

The spatio-temporal characteristics of acoustic emission (AE) during the deformation of rock samples with compressional and extensional en-echelon faults have been studied. The results show that the pre-existing structure can significantly influence the patterns of AE spatial distribution. With increasing of differential stress, AE events firstly cluster around the two ends of pre-existing faults inside the jog and then along the line joining the two ends. The biggish AE events often occur around one end repeatedly. The image of AE clusters indicates the direction and the area of the fracture propagation. The direction of the macroscopic fracture in extensional and compressional jogs is perpendicular and parallel to the direction of axial stress, respectively. The weakening process before the fracturing of jog area is remarkable, and one of the typical precursors for the instability is that the cumulative frequency of AE events increases exponentially. After the fracturing of the jog the frequency and releasing strain energy of AE events decrease gradually. During the friction period, there is no precursory increasing of AE activity before the big stick-slip events. The change of b value in jog shows a typical change of decreasing tendentiously returning quickly before the instability. The decrease of b value occurs in the process of stress increasing and sometime goes down to the weakening stage, and the quick increase b values appears in a short time just before the instability. The comparative analysis shows that the difference in b value due to the different structures is larger than b value variation caused by increase of the differential stress. For the same sample, the temporal sequence of AE is strongly affected by the mechanical state, and the high loading velocity corresponds to the high release rate of strain energy and low b value. Due to its lower failure strength, the broken area is sensitive to small changes in differential stress. Therefore, it offers a potential explanation for the phenomena of precursory window or sensitive point and separation of seismic source and precursors.

Mechanical analysis of en echelon structure and its significance of controlling earthquakes

The paper deals with the mechanical origin and rules of en echelon folds and their secondary fractures by means of elastic stability theory and nonlinear fracture criterion.Obtains the quantitative relations among en echelon angles of en echelon folds,ratios of boundary stresses and en echelon pitches of shear zone under an action of general boundary forces(tension shear,pure shear or compression shear).As an applied example,the paper researches the displacement field,stress field,distortion energy distribution, state of secondary fractures and energy released by fracturing of en echelon fold structure developed at the east foot of Taihang Mountain.The results of research show that maximum principal (compressive) stresses,maximum shear stresses,high value area of distortion energy are in the nuclear parts of en echelon folds.In these parts compressive fractures were easily developed in approximately parallel with fold axis.So it is verified that the secondary fracture of en echelon folds is a mechanism controlling a strong earthquake.

9例人工ECHELON股骨柄假体治疗高龄股骨转子间骨折疗效观察

目的:探讨人工ECHELON股骨柄假体治疗高龄股骨转子间骨折(Evans-Jensen IV/V型)的临床疗效。方法 9例高龄股骨转子间骨折(Evans-Jensen IV/V型)患者采用人工ECHELON股骨柄假体治疗,术后第三天下地,进行股四头肌等长等张收缩锻炼,同时使用下肢关节活动仪行功能锻炼及空气波压力治疗仪预防血栓治疗。结果:9例患者都顺利度过围手术期,伤口I/甲愈合,无下肢深静脉血栓形成、肺部感染、切口感染等情况发生。按Harris评分标准,优良率达100%。结论:用人工ECHELON股骨柄假体治疗高龄股骨转子间骨折(Evans-Jensen IV/V型),具有手术时间短,出血量少,操作简单,切口小,组织损伤小,可早期下床活动,减少并发症,提高生活质量的优点,是治疗高龄股骨转子间骨折的较好方法。

System optimization-oriented spare parts dynamic configuration model for multi-echelon multi-indenture system

In order to optimize the spares configuration project at different stages during the life cycle, the factor of time is considered to relax the assumption of the spares steady demand in multi-echelon technique for recoverable item control (METRIC) theory. According to the method of systems analysis, the dynamic palm theorem is introduced to establish the prediction model of the spares demand rate, and its main influence factors are analyzed, based on which, the spares support effectiveness evaluation index system is studied, and the system optimization-oriented spares dynamic configuration method for multi-echelon multi-indenture system is proposed. Through the analysis of the optimization algorithm, the layered marginal algorithm is designed to improve the model calculation efficiency. In a given example, the multi-stage spares configuration project during its life cycle is gotten, the research result conforms to the actual status, and it can provide a new way for the spares dynamic optimization.

非对称形态之En Echelon型地层褶皱

首次提出了具有某一种非对称构造形态的地层EnEchelon褶皱模型。文献[1]已经根据广义变分的分区原理构造连续位移函数wij和跳跃函数δij,再用Lagrange乘子算法将交界面连续条件引入到分区变分原理泛函中[1]。问题的数学描述建立了近似计算的基础[2]。结果表明非对称形态的EnEchelon型褶皱的关键因子L受双模量地基反差系数α的控制。

A FRACTAL MODEL AND ENERGY DISSIPATION FOR EN ECHELON FRACTURES

observations from the field and the taboratory show that en echelon fractures withinfracture zones have a foede1 within Ricdel structure’ The tensile fallure mecbanism of en echelonfractures can be described by the pile-ups of sbear crack-dislocations. A fractal model can be used tosimulate the Riedel within Xiedel geometry, allowing the direct rneasarement of tbe ftactal dimen sions of en echelon fractare systems. The energy dissipation of tbe en ccbe1on fracture system canbe deduced using a fracil damage evo1ution model which exptalns tbe evo1ution process of en eche lon fracture svstems. The fractal nature of the fractures can be used to dcrive an accurate estimateof total energy dissipation.

关于Echelon空间无穷矩阵序列的弱收敛

本文继研究关于echelon空间无穷矩阵变换集的有界性之后,进一步讨论echlelon空间到空间l^p(l≤p≤∞)、C、C_O的无穷矩阵序列的弱收敛性.这些工作无疑将促进对无穷矩阵代数(λ,μ)的研究.

An Integrated Multi-Echelon Model for a Sustainable Closed Loop Supply Chain Network Design

The integration of entire supply and value chain into a closed loop network is gaining more importance in recent times in order to ensure a business to be economically and environmentally sustainable with the changing trends in business and social environments, growing environmental consciousness in the society and government legislations to protect the environment as well as the business. In this context, this paper considers a multi-echelon closed loop supply chain network design with forward and reverse logistics components. An attempt has been made to develop a mixed integer non-linear programming model for this problem with different costs so that the sum of the total cost is minimized subject to different constraints pertaining to capacities of the entities of the system, demands of first customers and second customers. A generalized model is presented and then its application is illustrated using an example problem by solving the model using LINGO14. This model forms as a tool to compare future meta-heuristics to check the closeness of their solutions with corresponding optimal solutions.

An Application of Multi-echelon Inventory System Theory to Management of Equipment Maintenance

The multi echelon inventory system theory (MEIST) ,which is an important branch of inventory theory, is applied mainly in solving the problem of a multi echelon inventory and supply system. In this paper, a brief review of MEIST is given and its main points are summarized. An application is made to the decision of spares stock levels in maintenance management. The result shows that it can reduce costs of spares by using MEIST in the case of a multi echelon maintenance system.

Chinese expert consensus on echelons treatment of thoracic injury in modern warfare

The emergency treatment of thoracic injuries varies of general conditions and modern warfare. However, there are no unified battlefield treatment guidelines for thoracic injuries in the Chinese People's Liberation Army(PLA). An expert consensus has been reached based on the epidemiology of thoracic injuries and the concept of battlefield treatment combined with the existing levels of military medical care in modern warfare. Since there are no differences in the specialized treatment for thoracic injuries between general conditions and modern warfare, first aid, emergency treatment, and early treatment of thoracic injuries are introduced separately in three levels in this consensus. At Level Ⅰfacilities, tension pneumothorax and open pneumothorax are recommended for initial assessment during the first aid stage. Re-evaluation and further treatment for hemothorax, flail chest, and pericardial tamponade are recommended at Level Ⅱ facilities. At Level Ⅲ facilities, simple surgical operations such as emergency thoracotomy and debridement surgery for open pneumothorax are recommended. The grading standard for evidence evaluation and recommendation was used to reach this expert consensus.

A modeling approach for fuzzy programming with echelon form membership functions

In order to solve fuzzy mathematical programming with soft constraints,the initial models must first be converted into crisp models.Membership functions are employed to describe the fuzzy right-hand side parameters needed to achieve this conversion.In some cases,echelon form membership functions(EFMFs)are required to depict the actual fuzzy situation.However,due to their discrete properties,fuzzy programming problems with such membership functions cannot be modeled by traditional methods.Motivated by these challenges,this paper introduces a novel absolute value representation modeling approach to formulate fuzzy programming using EFMFs.This approach can translate a discrete model to a continuous one which can then be easily solved.Finally,by means of a numerical example,the effectiveness of our new approach is demonstrated.

Magnetic pressure in electromagnetic tube forming with echelon coil

The effects of geometrical characteristics of echelon coil on the magnetic pressure distribution and their contribution to the final shape of parts were focused and investigated through experiments and numerical simulation using FEM software ANSYS. The results show that the geometrical characteristics of echelon coil play a key role in controlling the magnetic pressure acting on the tube. They show a hump-like distribution near the interface between bigger diameter region and transition region of echelon coil, and affect the final shape of tubular parts then. With the reduction of relative diameter, the magnetic pressure in smaller diameter region decreases and its distribution gradient in transition region increases. With the augment of relative length, the magnetic pressure increases in bigger diameter region, while it almost remains constant in smaller diameter region, and the gradient in transition region enhances sharply. The distribution of magnetic pressure in the axial direction of tube agrees well with the profile of specimen.

Attaching Importance to the Training of Young Researchers and Promoting the Echelon Construction of the Research Institute

This paper analyzes the current situation of training young scientific and technological talents,attracting talents and making good use of talents in Changli Fruit Tree Research Institute of Hebei Academy of Agricultural and Forestry Sciences.There are some problems,such as lack of talent recruitment planning,and lack of follow-up training mechanism.This paper puts forward some measures,such as formulating a scientific recruitment plan,making a follow-up plan for talent training,building an ability-and performance-oriented evaluation mechanism for scientific and technological talents,so as to attach importance to the training of young scientific research talents and promote the echelon construction of the research institute.

bv、bv_0到p阶Echelon空间矩阵变换的形式

本文讨论了ｂｖ，ｂｖ０到ｐ阶ｅｃｈｅｌｏｎ空间无穷矩阵变换的形式。并因此得到ｂｖ，ｂｖ０到空间Ｉ＾ｐ无穷矩阵变换的形式。

人工ECHELON及MP股骨柄假体治疗高龄股骨转子间骨折早期疗效观察

目的:探讨人工ECHELON股骨柄假体及MP股骨柄假体治疗早期高龄股骨转子间骨折(Evans-Jensen IV/V型)的临床疗效。方法:选取2013年01月至2018年3月于我科行髋关节置换的18例大于75岁以上的高龄股骨转子间骨折(Evans-Jensen IV/V型),其中9例患者采用人工ECHELON股骨柄假体治疗,9例患者采用人工MP股骨柄假体治疗,对2组临床疗效展开对比,记录两组患者术后Harris评分、手术时间、出血量,并在均在术后第一天指导患者进行股四头肌等长等张收缩锻炼,第三天下地,同时使用下肢关节活动仪行功能锻炼联合空气波压力治疗仪预防血栓治疗。结果:18例患者在围手术期内无不良反应,伤口I/甲愈合,无下肢深静脉血栓形成、肺部感染、切口感染等情况发生。按Harris评分标准,优良率达100%,MP假体组在手术时间、出血量及手术难度方面有优势,但价格昂贵。结论:用人工ECHELON股骨柄假体及MP假体治疗高龄股骨转子间骨折(Evans-Jensen IV/V型),均可在早期下床活动,降低并发症发生率,提高患者的生活质量。MP股骨柄假体具有便于调整前倾角及肢体长度的优势,是治疗高龄股骨转子间骨折的较好方法。

Research on Three-Echelon Inventory Model and Algorithm for Valuable Spare Parts in Weapon Equipment

According to the current situation of repair and supply for valuable spare parts in the weapon equipment of the PLA,using the research results of the repairable spare parts inventory theory,an inventory model of the valuable spare parts in three-echelon repair and supply system is established by expanding the classical METRIC model and theory,and the genetic algorithm is utilized to solve the model.In the algorithm,the chromosome representation and initial population production,the crossover and mutation operators are designed.By using an example,a simulation analysis is carried out to verify the model's correctness.

Capacity Configuration of Energy Storage Systems for Echelon Utilization Based on Accelerated Life Test in Microgrids

Retired power battery construction energy storage systems(ESSs)for echelon utilization can not only extend the remaining capacity value of the battery,and decrease environmental pollution,but also reduce the initial cost of energy storage systems.In this paper,an ESS constructed of retired power batteries for echelon utilization in microgrids(MGs)is considered.Firstly,considering the influence of different discharge depths on the battery life cycle,the correlation equation between the state of charge(SOC)and the state of health(SOH)is established.Secondly,the accelerated life test method,based on the inverse power law coefficient equation,is proposed,and it is used to evaluate the reliability of the ESS.Finally,according to the SOC characteristics,the dynamic security margin of the ESS is established.The life cycle cost,supply-demand balance and ESS balanced control are comprehensively considered,and the location and capacity of energy storage in MGs are determined.It is simulated using the IEEE-RTS 24 node system;the results show that the investment cost of the ESS is reduced and the operational life is prolonged.

梯次推进:论学校铸牢中华民族共同体意识教育的一体化建设

教育作为继往开来、培基铸魂的基础工程,为中华民族共同体建设发挥着夯实基础、筑牢根基的重要作用。学校构建以铸牢中华民族共同体意识为主线的一体化教育体系格局,既要理论与实践相结合,更要遵循青少年心理发展和成长规律,形成不同学段纵向螺旋上升、不同学科横向融合贯通和不同部门协同发力的“一体化”教育网络。以“铸牢中华民族共同体意识”为导向的一体化育人体系,使教学、育人、管理体系有序衔接。要遵循学生心理发展并注重学生认知能力的梯次性,使教育内容循序渐进推进;以不同区域“试点引领、示范带动、以点带面”的形式,解决教育发展的不均衡问题;深入推进各学科融通、各学段贯穿的课程体系,实现教材和课程的一体化设计;通过梯次发挥全员、全过程、全方位育人的作用,深化“大思政”育人格局和“三全育人”综合改革工作。基于“四个维度”的梯次推进,助推学校铸牢中华民族共同体意识教育的内涵式发展。学校铸牢中华民族共同体意识就要一步一级逐渐提升,按照梯次推进的理念不断积累以达千里之远。

机械刻划层分结构铝膜刀具磨损研究

掌握机刻光栅刀具磨损机理是稳定制备大面积光栅的关键,由镀制工艺决定的具有层分结构铝膜是机刻光栅的首选膜坯。为获取光栅机械刻划过程中层分构铝膜对金刚石刻划刀具磨损影响规律,首次开展层分构铝膜力学性能测试与刀具刻划磨损规律研究,采用纳米压痕实验测得层分构铝膜硬度与弹性模量分别为0.48 GPa与65.2 GPa,满足Hall-Petch强化理论。据此,首次运用Deform 3D有限元分析软件建立层分构铝膜模型,将刻深位置设置在铝膜层分界面位置,分别对刻深在2μm与4μm的单层与4层铝膜进行刻划仿真后发现,分层膜界面对于其应力传递影响作用明显,且刻深突破第一、二层铝膜界面时,该界面对于应力传递的阻碍作用消失;不同刻深刻划单层和4层铝膜时刀具磨损形式与磨损部位大体相同,但刻划4层铝膜时刀具磨损较小,与后续机刻试验结果相符。