Effect of intermediate principal stress on strength of soft rock under complex stress states

A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/softening constitutive model based on the unified strength theory(UST) were used to simulate both the consolidated-undrained(CU) triaxial and the consolidated-drained(CD) true triaxial tests. Based on the results of the true triaxial tests simulation, the effect of the intermediate principal stress on the strength of soft rock was investigated. Finally, an example of an axial compression test for a hard rock pillar with a soft rock interlayer was analyzed using the two-dimensional finite difference code FLAC. The CD true triaxial test simulations for diatomaceous soft rock suggest the peak and residual strengths increase by 30% when the effect of the intermediate principal stress is taken into account. The axial compression for a rock pillar indicated the peak and residual strengths increase six-fold when the soft rock interlayer approached the vertical and the effect of the intermediate principal stress is taken into account.

The neural butterfly effect The injury to peripheral nerves changes the brain

Regeneration of damaged innervations in the peripheral nervous system （PNS） has been well documented in both animals and human. After injury, the damaged neurite swells and undergoes retrograde degeneration. Once the debris is cleared, it begins to sprout and restore damaged connections. Damaged axons are able to regrow as long as the perikarya are intact and have made contact with the Schwann cells in the endoneurial channel[2]. Under appropriate conditions,

Principal axes of M-DOF structures Part I:Static loading

This paper is the first in a two-part series that discusses the principal axes of M-DOF structures subjected to static and dynamic loads. The primary purpose of this series is to understand the magnitude of the dynamic response of structures to enable better design of structures and control modification devices/systems. Under idealized design conditions, the structural responses are obtained by using single direction input ground motions in the direction of the intended control devices/systems, and by assuming that the responses of the structure is decoupleable in three mutually perpendicular directions. This standard practice has been applied to both new and retrofitted structures using various seismic protective systems. Very limited information is available on the effects of neglecting the impact of directional couplings (cross effects - of which torsion is a component) of the dynamic response of structures. In order to quantify such effects, it is necessary to examine the principal axes of structures under both static and dynamic loading. This first paper deals with quantitative definitions of principal axes and “cross effects” of three-dimensional structures under static load by using linear algebra. It shows theoretically that, for three-dimensional structures, such principal axes rarely exist. Under static loading conditions, the cross effect is typically small and negligible from the viewpoint of engineering applications. However, it provides the theoretical base for subsequent quantification of the response couplings under dynamic loads, which is reported in part II of this series.

Principal axes of M-DOF structures PartⅡ:Dynamic loading

This paper is the second in a two-part series that discusses the principal axes of M-DOF structures subjected to static and dynamic loads.The primary purpose of this series is to understand the magnitude of the dynamie response of structures to enable better design of structures and response modification devices/systems.Under idealized design condi- tions,the structural responses are obtained by using single directinn input ground motions in the direction of the intended response modification devices/systems,and by assuming that the responses of the structure is deconpleable in three mutual- ly perpendicular directions.This standard practice has been applied to both new and retrofitted structures using various seis- mic protective systems.Very limited information is available on the effects of neglecting the impact of directional couplings (cross effects of which torsion is a component)of the dynamic response of structures.In order to quantify such effects,it is necessary to examine the principal axes of structures under both static and dynamic loading.In this twn-part series,the first paper is concerned with static loading,which provides definitions and fundamental formulations,with the conclusion that cross effects of a statically loaded M-DOF structure resulting from the lack of principal axes are of insignificant magnitude. However,under dynamic or earthquake loading,a relatively small amount of energy transferred across perpendicular direc- tions is accumulated,which may result in significant enlargement of the structural response.This paper deals with a formu- lation to define the principal axes of M-DOF structures under dynamic loading and develops quantitative measures to identify cross effects resuhing from the non-existence of principal axes.

Functionality of Covalent Organic Framework (COF) in Gas Storage Application: First Principal Study

Industrial growth in recent years led to air pollution and an increase in concentration of hazardous gases such as O3 and NO. Developing new materials is important to detect and reduce air pollutants. While catalytic decomposition and zeolites are traditional ways used to reduce the amount of these gases. We need to develop and explore new promising materials. Covalent organic framework (COF) has become an attractive platform for researcher due to its extended robust covalent bonds, porosity, and crystallinity. In this study, first principal calculations were performed for gases adsorption using COFs containing nitrogen and π-bonds. Different building blocks (BBs) and linkers (LINKs/LINK1 & LINK2) were investigated by means of density functional theory (DFT) calculations with B3LYP and 3-21G basis sets to calculate the binding energies of gases @COF systems. Electrostatic potential maps (ESPM), Mulliken charges and non-covalent interaction (NCI) are used to understand the type of interactions between gas and COFs fragments. O3 was found to bind strongly with COF system in comparison with NO which could make COF a useful selective material for mixed gases environment for sensing and removal application.

Principal Leadership Constructs School-based- curriculum and Shapes School Culture for Teaching and Learning: Rooting on Core Competence

Rooting on the context of accelerating and rapid societal change and global competence trend,this study explored the meaning of core competence,roles of schooling for cultivating students to be holistic person and strategies for shaping competence-oriented school campus culture.The related literature this study reviewed include the meaning of core competence,curriculum program and teaching design for oriented competence in schools,strategies to shape school culture for teaching and learning of oriented competence,and integrated comment.In order to achieve the research purposes,this study adopted the interview and document analysis to collect data.According to the literature review,interview,document analysis,result and discussion,this study proposed conclusions in the following directions:1)The meaning of core competence;2)The main point of global competence;3)School is a learning organization and learning base within competence oriented school campus;4)Principals play the roles of vision leadership,instructional leadership and curriculum leadership;5)Teachers play the roles for shaping competence oriented school campus culture;6)The strategies of shaping competence oriented school campus culture;7)The process and related factors of constructing school-based curriculum.Finally,researchers proposed reflection for this study.

Multi-wing butterfly effects on catastrophic rockslides

The catastrophic rockslide,which frequently triggers numerous severe disasters worldwide,has drawn much attention globally;however,understanding the initiation mechanism of catastrophic rockslides in the absence of typical single triggering factors related to strong seismic activity or torrential precipitation continues to be challenging within the global scientific community.This study aims to determine the mechanism of the three largest catastrophic rockslides in the eastern Tibetan Plateau,Yigong,Xinmo,and Baige,over the past 20 years using field investigation,remote sensing,and runoff analysis.Instead of the conventional driving factors of heavy rainfall and strong earthquakes,the multi-wing butterfly effects(MWBE)of climatic factors and weak earthquakes are for the first time identified as drivers of the catastrophic rockslide disasters.First,strong tectonic uplift,fast fluvial incision,high-density faults,and large regional water confluence formed the slopes in the critical regime,creating the source conditions of rockslide.Second,the MWBE of early dry-heat events and antecedent rainfall,combined with imminent weak earthquakes,initiated rockslide.Third,the delayed amplified runoff moving toward the sliding surface and lowering the strength of the locking-rock segment constituted the fundamental mechanism of the MWBE on rockslide.The catastrophic rockslide was ultimately inferred to be a nonlinear chaotic process;however,prediction and forecasting of rockslide based on the MWBE in the early stages are possible and essential.This finding presents a new perspective concerning forecasting progressive landslides.

A MODEL OF BUTTERFLY CATASTROPHE FOR ANODE EFFECT IN ALUMINA ELECTROLYSIS

A model of butterfly catastrophe is confirmed based on the matching and fitting the previous experimental data from alumina electrolysis when anode effect occurs.The complicated behaviour of the cryolite-alumina melt system with varying parameters could be generally described by this model.Therefore,the anode effect and its occurrence may be thoroughly understood.

Butterfly Effect:From U.S.Wall Street to China's A-Share Market

Right after Lehman Brothers declared bankruptcy a series of bad news came one after another.Merrill Lynch was bought out.American International Group(AIG)was handed over to the U.S.government. Washington Mutual,the largest savings bank in the U.S.,was said to be looking for a buyer.In Rus- sia,stock exchange was forced to a suspension due to a record slump in 10 years in its stock market. It seems that the end of the Moon Festival this year marked the beginning of a global financial crisis。

Butterfly Effect——The Effects That English Study Exerts on Art Learners

In the history of human beings, every choice we make is the birth of the next. Even something simple can completely reshape one's life. It's just like the Butterfly Effect—one never knows what is at the end. English study, also, may produce profound influences on the creation of art works. This passage aims at proving English study, as a disputable topic in present education in art schools, has its importance for art learners to enhance their creative thinking in the process of art creation.

A Simple Method of Measuring Vaccine Effects on Infectiousness and Contagion

The vaccination of one person may prevent another from becoming infected, either because the vaccine may prevent the first person from acquiring the infection and thereby reduce the probability of transmission to the second, or because, if the first person is infected, the vaccine may impair the ability of the infectious agent to initiate new infections. The former mechanism is referred as a contagion effect and the latter is referred as an infectiousness effect. By applying a principal stratification approach, the conditional infectiousness effect has been defined, but the contagion effect is not defined using this approach. Recently, new definitions of unconditional infectiousness and contagion effects were provided by applying a mediation analysis approach. In addition, a simple relationship between conditional and unconditional infectiousness effects was found under a number of assumptions. These two infectiousness effects can be assessed by very simple estimation and sensitivity analysis methods under the assumptions. Nevertheless, such simple methods to assess the contagion effect have not been discussed. In this paper, we review the methods of assessing infectiousness effects, and apply them to the inference of the contagion effect. The methods provided here are illustrated with hypothetical vaccine trial data.

Effective Education in a College in Bangladesh: From Managerial to Transformational Leadership

This paper is a study on the compulsion of transformational leadership from the part of the principal of this era when the demography of the students are changing exponentially, when the globe is experiencing massive changes in methods and techniques in educational process but the institutions remain the same as its ethics and operational strategies. The time is eloping when an educational head earns praises due to their prominence and performance in managerial functioning. But this paper tends to focus on several persisting challenges in these educational institutions like huge gap between teacher-student ratio, students’ increasing technological oriented learning, teachers’ lack of knowledge of multimedia class operation, girls’ little rate of enrolment in higher level of education, early marriage of school going girls and ensuring quality education to girls as per the demand of SDG 4 by 2030. This paper fosters the idea that a transformational head of the institution can be successful in this chase of challenges as he involves everyone to activities in order to reach goal. He works with the other members as a team member and thus a challenge of an institution turns to be liability to all.

Study on dynamic response of high speed train window glass under tunnel aerodynamic effects

Purpose-This paper aims to analyze the bearing characteristics of the high speed train window glass under aerodynamic load effects.Design/methodology/approach-In order to obtain the dynamic strain response of passenger compartment window glass during high-speed train crossing the tunnel,taking the passenger compartment window glass of the CRH3 high speed train onWuhan-Guangzhou High Speed Railway as the research object,this study tests the strain dynamic response and maximum principal stress of the high speed train passing through the tunnel entrance and exit,the tunnel and tunnel groups as well as trains meeting in the tunnel at an average speed of 300 km$h-1.Findings-The results show that while crossing the tunnel,the passenger compartment window glass of high speed train is subjected to the alternating action of positive and negative air pressures,which shows the typical mechanic characteristics of the alternating fatigue stress of positive-negative transient strain.The maximum principal stress of passenger compartment window glass for high speed train caused by tunnel aerodynamic effects does not exceed 5 MPa,and the maximum value occurs at the corresponding time of crossing the tunnel groups.The high speed train window glass bears medium and low strain rates under the action of tunnel aerodynamic effects,while the maximum strain rate occurs at the meeting moment when the window glass meets the train head approaching from the opposite side in the tunnel.The shear modulus of laminated glass PVB film that makes up high speed train window glass is sensitive to the temperature and action time.The dynamically equivalent thickness and stiffness of the laminated glass and the dynamic bearing capacity of the window glass decrease with the increase of the action time under tunnel aerodynamic pressure.Thus,the influence of the loading action time and fatigue under tunnel aerodynamic effects on the glass strength should be considered in the design for the bearing performance of high speed train window glass.Originality/value-The research results provide data support for the analysis of mechanical characteristics,damage mechanism,strength design and structural optimization of high speed train glass.

Administrative Decisions/Practices that Make the School Effective

The purpose of this work is to develop a model of effective educational administration and leadership through the conceptual definition of educational administration and the understanding of the concept of leadership in school.In particular,the educational administration will be identified and demarcated and its basic functions that are vital for the smooth operation,development and efficiency of educational organizations will be identified.Then,the concept of leadership will be analyzed,the modern models and forms in which it can be practiced in schools will be presented and the basic differences between leadership and administration will be captured.Finally,the concept of school effectiveness will be analyzed and effective ways of administration and leadership at school level will be listed,emphasizing the skills that an effective principal of a modern school unit must have.

Lack of Evidence for Local Adaptation of the Endangered Karner Blue Butterfly to Its Sole Larval Hostplant—The Wild Lupine

Local adaptation is an important process that drives the evolution of populations within species, and it can be generally expressed by the higher fitness of individuals raised in their native habitats versus in a foreign location. The influence of local adaptation is especially prominent in species that subsist in small and/or highly isolated populations. This study evaluated whether the federally endangered Karner blue butterfly, Lycaeides melissa samuelis (Lepidoptera: Lycaenidae) is locally adapted to its exclusive larval host plant, the wild lupine (Lupinus perennis). To test for local adaptation, individuals from a laboratory-raised colony were reared on wild lupine plants from populations belonging to either their native (Indiana) or a foreign (Michigan and Wisconsin) region. For this purpose, lupine plants from the different populations were grown in a common garden in growth chambers, and one Karner blue larva was placed on each plant. Fitness traits related to growth and development were recorded for each butterfly across populations. Days from hatching to pupation and eclosion showed gender-specific significant differences across wild lupine populations and plant genotypes (within populations). The percent survival of butterflies (from hatching to eclosion) also differed among plants from different populations. These results indicate that wild lupine sources can affect some developmental traits of Karner blue butterflies. However, growth-related traits, such as pupal and adult weight of individuals reared in plants from native populations did not differ from those of foreign regions. The apparent absence of local adaptation to wild lupine suggests that, at least, some individuals of this species could be translocated from native populations to foreign reintroduction sites without experiencing decreased fitness levels. However, future studies including more populations across the geographical range of this butterfly are recommended to evaluate other environmental factors that could influence adaptation on a wider spatial scale.

基于能量转化机制的岩石强度的演化机理研究

针对岩石强度的演化机理是提高强度准则计算精度与适用性的前提,基于能量转化是物质物理过程的本质属性,弹性应变能是材料破坏的内在机理,通过试验与理论研究,探究了围压、中间主应力及泊松比对岩石强度演化规律的影响.结果表明:岩石破坏与应力状态及岩石变形特性有关,忽略泊松比的影响是中间主应力效应提出的理论依据,并指出围压效应与中间主应力效应忽略变形影响,既与试验结果不一致,又是据此建立的强度理论精度较差的内在原因.岩石强度的演化是围压、中间主应力及泊松比共同作用的结果,并据此研究了静水应力状态下材料破坏特性、围压区间性及三轴拉伸强度恒大于三轴压缩强度条件.理论及试验表明,体现了围压、中间主应力及泊松比影响的强度理论具有较高计算精度与适用性.研究成果对于精准地描述岩石破坏特性,建立普遍适用的强度理论具有重要意义.

生物电化学厌氧消化的应用现状与研究进展

调研了近年来报道的生物电化学厌氧消化经典案例,梳理了该系统的构型及工作原理;讨论了其解抑增效潜能及机理;分析了外加电压、电极材料及布置间距等对系统强化效果的影响.目前,生物电化学厌氧消化系统通常可将厌氧消化甲烷产率产量提高0.15~8.6倍,提升沼气中的甲烷含量至原来的1.2~1.6倍.外加电极及电压造成的功能微生物富集和电子高效传递是系统性能强化的主要原因.有鉴于此,电压和电极材料是系统效能的主要影响因素.该系统的规模化运行受到经济性制约,后期探索间歇供电、新能源供电、峰谷电等用电策略或形式;研发利于微生物富集但不易结垢的电极材料,创新电极组件摆放或嵌入型式等可能对该系统的工程化应用具有重要促进作用.

Equivalence of the Aharonov-Bohm and Dirac Monopole Potentials

The Aharonov-Bohm effect (experimentally verified) constitutes an undubitable proof of the non local nature of quantum mechanics and of the gauge character of the electromagnetic interaction. On the other hand, the existence of a Dirac monopole (not yet experimentally confirmed) leads to the quantization of the electric charge. Both phenomena can be mathematically described in the context of fiber bundle theory. Using this approach, we briefly review the mutual determination of the corresponding connections ωA−B, ωDand potentials AA−B±, AD±. This mathematical result gives an additional theoretical support to present day active search of the magnetic charge.

城市主干路交通隔离栏设置对驾驶人规避效应的影响

为探究城市主干路交通隔离栏的设置对驾驶人规避效应的影响,利用无人机采集了3处设置了交通隔离栏与2处未设置交通隔离栏的主干路的车辆行驶数据、行车环境与交通量,根据车道与交通隔离栏横向距离对车道进行了分类,明确了交通隔离栏影响下的驾驶行为特性与规避效应形成机制.研究结果表明,不同车道内的轨迹偏移量存在着显著差异性,目标车道偏移中心相对频率峰值大于零,其他车道则在-0.1~0.1 m范围内波动.车道区域对轨迹偏移的影响最大,其次为相邻车道交通量、速度、标线与交通隔离栏的组合类型.交通隔离栏的设置会造成驾驶人的规避效应,减少了左偏与对向来车的冲突,从而规范了行车轨迹,控制了行车速度,在出口和入口分别减速约5.1%和19.3%.但不良的设施与标线的组合形式易引起规避效应过量而致使轨迹向右偏移过大(大于0.85 m)而侵占其他车道,增加行车风险.当交通隔离栏底座与车道边线间距大于15 cm(单边)时,规避效应所带来的影响处于最佳水平.

数字经济发展、FDI与碳排放强度

促进经济低碳转型和构建双循环发展格局是我国当前面临的重大焦点问题.作为助推经济发展的重要引擎,数字经济能否促进低碳发展?基于2011—2020年中国30个省份面板数据从投入、产出角度测度数字经济发展水平,运用Tobit模型和门槛模型实证研究数字经济发展对碳排放强度的影响及FDI对上述关系的调节作用.研究表明:数字经济发展对碳排放强度有显著抑制作用,且FDI增强了数字经济发展的降碳效应;数字经济发展与FDI对碳排放强度均存在单一门槛效应.本文为理解数字经济的碳排放影响提供了新的分析视角,也为促进经济社会发展全面绿色转型、构建双循环新发展格局提供了政策启示.