The activity of non-basal slip systems and dynamic recovery at room temperature in fine-grained az31
西方批评理论考试
一、New criticism二、Formalism三、Reader-response theoryWhat Do You Think?At its most basic level, reader response criticism considers readers' reactions to literature as vital to interpreting the meaning of the text. However, reader-response criticism can take a number of different approaches. A critic deploying reader-response theory can use a psychoanalytic lens, a feminists lens, or even a structuralist lens. What these different lenses have in common when using a reader response approach is they maintain "...that what a text is cannot be separated from what it does" (Tyson 154).Tyson explains that "...reader-response theorists share two beliefs: 1) that the role of the reader cannot be omitted from our understanding of literature and 2) that readers do not passively consume the meaning presented to them by an objective literary text; rather they actively make the meaning they find in literature" (154). In this way, reader-response theory shares common ground with some of the deconstructionists discussed in the Post-structural area when they talk about "the death of the author," or her displacement as the (author)itarian figure in the text.四、StructuralismLinguistic RootsThe structuralist school emerges from theories of language and linguistics, and it looks for underlying elements in culture and literature that can be connected so that critics can develop general conclusions about the individual works and the systems from which they emerge. In fact, structuralism maintains that "...practically everything we do that is specifically human is expressed in language" (Richter 809). Structuralists believe that these language symbols extend far beyond written or oral communication.For example, codes that represent all sorts of things permeate everything we do: "the performance of music requires complex notation...our economic life rests upon the exchange of labor and goods for symbols, such as cash, checks, stock, and certificates...social life depends on the meaningful gestures and signals of 'body language' and revolves around the exchange of small, symbolic favors: drinks, parties, dinners" (Richter 809).Patterns and ExperienceStructuralists assert that, since language exists in patterns, certain underlying elements are common to all human experiences. Structuralists believe we can observe these experiences through patterns: "...if you examine the physical structures of all buildings built in urban America in 1850 to discover the underlying principles that govern their composition, for example, principles of mechanical construction or of artistic form..." you are using a structuralist lens (Tyson 197).Moreover, "you are also engaged in structuralist activity if you examine the structure of a single building to discover how its composition demonstrates underlying principles of a structural system. In the first example...you're generating a structural system of classification; in the second, you're demonstrating that an individual item belongs to a particular structural class" (Tyson 197). Structuralism in Literary TheoryStructuralism is used in literary theory, for example, "...if you examine the structure of a large number of short stories to discover the underlying principles that govern their composition...principles of narrative progression...or of characterization...you are also engaged instructuralist activity if you describe the structure of a single literary work to discover how its composition demonstrates the underlying principles of a given structural system" (Tyson 197-198).Northrop Frye, however, takes a different approach to structuralism by exploring ways in which genres of Western literature fall into his four mythoi (also see Jungian criticism in the Freudian Literary Criticism resource):1.theory of modes, or historical criticism (tragic, comic, and thematic);2.theory of symbols, or ethical criticism (literal/descriptive, formal, mythical, andanagogic);3.theory of myths, or archetypal criticism (comedy, romance, tragedy, irony/satire);4.theory of genres, or rhetorical criticism (epos, prose, drama, lyric) (Tyson 240). Peirce and SaussureTwo important theorists form the framework (hah) of structuralism: Charles Sanders Peirce and Ferdinand de Saussure. Peirce gave structuralism three important ideas for analyzing the sign systems that permeate and define our experiences:1."iconic signs, in which the signifier resembles the thing signified (such as the stickfigures on washroom doors that signify 'Men' or 'Women';2.indexes, in which the signifier is a reliable indicator of the presence of the signified(like fire and smoke);3.true symbols, in which the signifier's relation to the thing signified is completelyarbitrary and conventional [just as the sound /kat/ or the written word cat areconventional signs for the familiar feline]" (Richter 810).These elements become very important when we move into deconstruction in the Postmodernism resource. Peirce also influenced the semiotic school of structuralist theory that uses sign systems. Sign SystemsThe discipline of semiotics plays an important role in structuralist literary theory and cultural studies. Semioticians "...appl[y] structuralist insights to the study of...sign systems...a non-linguistic object or behavior...that can be analyzed as if it were a language" (Tyson 205). Specifically, "...semiotics examines the ways non-linguistic objects and behaviors 'tell' us something.For example, the picture of the reclining blond beauty in the skin-tight, black velvet dress on the billboard...'tells' us that those who drink this whiskey (presumably male) will be attractive to...beautiful women like the one displayed here" (Tyson 205). Lastly, Richter states, "semiotics takes off from Peirce - for whom language is one of numerous sign systems - and structuralism takes off from Saussure, for whom language was the sign system par excellence"五、Poststructuralism/ DeconstructionThe Center Cannot HoldThis approach concerns itself with the ways and places where systems, frameworks, definitions, and certainties break down. Post-structuralism maintains that frameworks and systems, for example the structuralist systems explained in the Structuralist area, are merely fictitious constructs and that they cannot be trusted to develop meaning or to give order. In fact, the very act of seeking order or a singular Truth (with a capital T) is absurd because there exists no unified truth.Post-structuralism holds that there are many truths, that frameworks must bleed, and that structures must become unstable or decentered. Moreover, post-structuralism is also concernedwith the power structures or hegemonies and power and how these elements contribute to and/or maintain structures to enforce hierarchy. Therefore, post-structural theory carries implications far beyond literary criticism.What Does Your Meaning Mean?By questioning the process of developing meaning, post-structural theory strikes at the very heart of philosophy and reality and throws knowledge making into what Jacques Derrida called "freeplay": "The concept of centered structure...is contradictorily coherent...the concept of centered structure is in fact the concept of a freeplay which is constituted upon a fundamental immobility and a reassuring certitude, which is itself beyond the reach of the freeplay" (qtd. in Richter, 878-879).Derrida first posited these ideas in 1966 at Johns Hopkins University, when he delivered ―Structure, Sign, and Play in the Discourse of the Human Sciences‖: "Perhaps something has occurred in the history of the concept of structure that could be called an 'event,' if this loaded word did not entail a meaning which it is precisely the function of structural-or structuralist-thought to reduce or to suspect. But let me use the term ―event‖ anyway, employing it with caution and as if in quotation marks. In this sense, this event will have the exterior form of a rupture and a redoubling‖ (qtd. in Richter, 878). In his presentation, Derrida challenged structuralism's most basic ideas.Can Language Do That?Post-structural theory can be tied to a move against Modernist/Enlightenment ideas (philosophers: Immanuel Kant, Réne Descartes, John Locke, etc.) and Western religious beliefs (neo-Platonism, Catholicism, etc.). An early pioneer of this resistance was philosopher Friedrich Nietzsche. In his essay, ―On Truth and Lies in an Extra-moral Sense‖ (1873), Nietzsc he rejects even the very basis of our knowledge making, language, as a reliable system of communication: ―The various languages, juxtaposed, show that words are never concerned with truth, never with adequate expression...‖ (248).Below is an example, adapted from the Tyson text, of some language freeplay and a simple form of deconstruction:Time (noun) flies (verb) like an arrow (adverb clause) = Time passes quickly.Time (verb) flies (object) like an arrow (adverb clause) = Get out your stopwatch and time the speed of flies as you would time an arrow's flight.Time flies (noun) like (verb) an arrow (object) = Time flies are fond of arrows (or at least of one particular arrow).So, post-structuralists assert that if we cannot trust language systems to convey truth, the very bases of truth are unreliable and the universe - or at least the universe we have constructed - becomes unraveled or de-centered. Nietzsche uses language slip as a base to move into the slip and shift of truth as a whole: ―What is truth? …truths are an illusion about which it has been forgotten that they are illusions...‖ (On Truth and Lies 250).This returns us to the discussion in the Structuralist area regarding signs, signifiers, and signified. Essentially, post-structuralism holds that we cannot trust the sign = signifier + signified formula, that there is a breakdown of certainty between sign/signifier, which leaves language systems hopelessly inadequate for relaying meaning so that we are (returning to Derrida) in eternal freeplay or instability.What's Left?Important to note, however, is that deconstruction is not just about tearing down - this is a common misconception. Derrida, in "Signature Event Context," addressed this limited view of post-structural theory: "Deconstruction cannot limit or proceed immediately to a neutralization: it must…practice an overturning of the classical opposition and a general displacement of the system. It is only on this condition that deconstruction will provide itself the means with which to intervene in the field of oppositions that it criticizes, which is also a field of nondiscursive forces" (328).Derrida reminds us that through deconstruction we can identify the in-betweens and the marginalized to begin interstitial knowledge building.六、Postmodernism七、PostcolonialismHistory is Written by the VictorsPost-colonial criticism is similar to cultural studies, but it assumes a unique perspective on literature and politics that warrants a separate discussion. Specifically, post-colonial critics are concerned with literature produced by colonial powers and works produced by those who were/are colonized. Post-colonial theory looks at issues of power, economics, politics, religion, and culture and how these elements work in relation to colonial hegemony (western colonizers controlling the colonized).Therefore, a post-colonial critic might be interested in works such as Daniel Defoe's Robinson Crusoe where colonial "...ideology [is] manifest in Crusoe's colonialist attitude toward the land upon which he's shipwrecked and toward the black man he 'colonizes' and names Friday" (Tyson 377). In addition, post-colonial theory might point out that "...despite Heart of Darkness's (Joseph Conrad) obvious anti-colonist agenda, the novel points to the colonized population as the standard of savagery to which Europeans are contrasted" (Tyson 375). Post-colonial criticism also takes the form of literature composed by authors that critique Euro-centric hegemony.A Unique Perspective on EmpireSeminal post-colonial writers such as Nigerian author Chinua Achebe and Kenyan author Ngugi wa Thiong'o have written a number of stories recounting the suffering of colonized people. For example, in Things Fall Apart, Achebe details the strife and devastation that occurred when British colonists began moving inland from the Nigerian coast.Rather than glorifying the exploratory nature of European colonists as they expanded their sphere of influence, Achebe narrates the destructive events that led to the death and enslavement of thousands of Nigerians when the British imposed their Imperial government. In turn, Achebe points out the negative effects (and shifting ideas of identity and culture) caused by the imposition of western religion and economics on Nigerians during colonial rule.Power, Hegemony, and LiteraturePost-colonial criticism also questions the role of the western literary canon and western history as dominant forms of knowledge making. The terms "first-world," "second world," "third world" and "fourth world" nations are critiqued by post-colonial critics because they reinforce the dominant positions of western cultures populating first world status. This critique includes the literary canon and histories written from the perspective of first-world cultures. So, for example, a post-colonial critic might question the works included in "the canon" because the canon does not contain works by authors outside western culture.Moreover, the authors included in the canon often reinforce colonial hegemonic ideology, such as Joseph Conrad's Heart of Darkness. Western critics might consider Heart of Darkness an effective critique of colonial behavior. But post-colonial theorists and authors might disagree with this perspective: "...as Chinua Achebe observes, the novel's condemnation of European is based on a definition of Africans as savages: beneath their veneer of civilization, the Europeans are, the novel tells us, as barbaric as the Africans. And indeed, Achebe notes, the novel portrays Africans as a pre-historic mass of frenzied, howling, incomprehensible barbarians..."八、New HistoricismIt's All Relative...This school, influenced by structuralist and post-structuralist theories, seeks to reconnect a work with the time period in which it was produced and identify it with the cultural and political movements of the time (Michel Foucault's concept of épistème). New Historicism assumes that every work is a product of the historic moment that created it. Specifically, New Historicism is "...a practice that has developed out of contemporary theory, particularly the structuralist realization that all human systems are symbolic and subject to the rules of language, and the deconstructive realization that there is no way of positioning oneself as an observer outside the closed circle of textuality" (Richter 1205).A helpful way of considering New Historical theory, Tyson explains, is to think about the retelling of history itself: "...questions asked by traditional historians and by new historicists are quite different...traditional historians ask, 'What happened?' and 'What does the event tell us about history?' In contrast, new historicists ask, 'How has the event been interpreted?' and 'What do the interpretations tell us about the interpreters?'" (278). So New Historicism resists the notion that "...history is a series of events that have a linear, causal relationship: event A caused event B; eventB caused event C; and so on" (Tyson 278).New historicists do not believe that we can look at history objectively, but rather that we interpret events as products of our time and culture and that "...we don't have clear access to any but the most basic facts of history...our understanding of what such facts mean...is...strictly a matter of interpretation, not fact" (279). Moreover, New Historicism holds that we are hopelessly subjective interpreters of what we observe.九、Feminism(1960s-present)S/heFeminist criticism is concerned with "...the ways in which literature (and other cultural productions) reinforce or undermine the economic, political, social, and psychological oppression of women" (Tyson). This school of theory looks at how aspects of our culture are inherently patriarchal (male dominated) and "...this critique strives to expose the explicit and implicit misogyny in male writing about women" (Richter 1346). This misogyny, Tyson reminds us, can extend into diverse areas of our culture: "Perhaps the most chilling example...is found in the world of modern medicine, where drugs prescribed for both sexes often have been tested on male subjects only" (83).Feminist criticism is also concerned with less obvious forms of marginalization such as the exclusion of women writers from the traditional literary canon: "...unless the critical or historical point of view is feminist, there is a tendency to under-represent the contribution of women writers" (Tyson 82-83).Common Space in Feminist TheoriesThough a number of different approaches exist in feminist criticism, there exist some areas of commonality. This list is excerpted from Tyson:1.Women are oppressed by patriarchy economically, politically, socially, andpsychologically; patriarchal ideology is the primary means by which they are keptso2.In every domain where patriarchy reigns, woman is other: she is marginalized,defined only by her difference from male norms and values3.All of western (Anglo-European) civilization is deeply rooted in patriarchal ideology,for example, in the biblical portrayal of Eve as the origin of sin and death in theworld4.While biology determines our sex (male or female), culture determines our gender(masculine or feminine)5.All feminist activity, including feminist theory and literary criticism, has as itsultimate goal to change the world by prompting gender equality6.Gender issues play a part in every aspect of human production and experience,including the production and experience of literature, whether we are consciouslyaware of these issues or not (91).Feminist criticism has, in many ways, followed what some theorists call the three waves of feminism:1.First Wave Feminism - late 1700s-early 1900's: writers like Mary Wollstonecraft (AVindication of the Rights of Women, 1792) highlight the inequalities between thesexes. Activists like Susan B. Anthony and Victoria Woodhull contribute to thewomen's suffrage movement, which leads to National Universal Suffrage in 1920with the passing of the Nineteenth Amendment2.Second Wave Feminism - early 1960s-late 1970s: building on more equal workingconditions necessary in America during World War II, movements such as theNational Organization for Women (NOW), formed in 1966, cohere feminist politicalactivism. Writers like Simone de Beauvoir (Le deuxième sexe, 1972) and ElaineShowalter established the groundwork for the dissemination of feminist theoriesdove-tailed with the American Civil Rights movementThird Wave Feminism- early 1990s-present: resisting the perceived essentialist (over generalized, over simplified) ideologies and a white, heterosexual, middle class focus of second wave feminism, third wave feminism borrows from post-structural and contemporary gender and race theories (see below) to expand on marginalized populations' experiences. Writers like Alice Walker work to "...reconcile it [feminism] with the concerns of the black community...[and] the survival and wholeness of her people, men and women both, and for the promotion of dialog and community as well as for the valorization of women and of all the varieties of work women perform".十、MarxismBased on the theories of Karl Marx (and so influenced by philosopher Georg Wilhelm Friedrich Hegel), this school concerns itself with class differences, economic and otherwise, as well as the implications and complications of the capitalist system: "Marxism attempts to reveal the ways in which our socioeconomic system is the ultimate source of our experience" (Tyson 277). Theorists working in the Marxist tradition, therefore, are interested in answering the overarching question, whom does it [the work, the effort, the policy, the road, etc.] benefit? The elite? The middle class? And Marxists critics are also interested in how the lower or working classes are oppressed - in everyday life and in literature.The Material DialecticThe Marxist school follows a process of thinking called the material dialectic. This belief system maintains that "...what drives historical change are the material realities of the economic base of society, rather than the ideological superstructure of politics, law, philosophy, religion, and art that is built upon that economic base" (Richter 1088).Marx asserts that "...stable societies develop sites of resistance: contradictions build into the social system that ultimately lead to social revolution and the development of a new society upon the old" (1088). This cycle of contradiction, tension, and revolution must continue: there will always be conflict between the upper, middle, and lower (working) classes and this conflict will be reflected in literature and other forms of expression - art, music, movies, etc.Though a staggering number of different nuances exist within this school of literary theory, Marxist critics generally work in areas covered by the following questions.十一、OtherGender Studies and Queer Theory (1970s-present)Gender(s), Power, and MarginalizationGender studies and queer theory explore issues of sexuality, power, and marginalized populations (woman as other) in literature and culture. Much of the work in gender studies and queer theory, while influenced by feminist criticism, emerges from post-structural interest in fragmented, de-centered knowledge building (Nietzsche, Derrida, Foucault), language (the breakdown of sign-signifier), and psychoanalysis (Lacan).A primary concern in gender studies and queer theory is the manner in which gender and sexuality is discussed: "Effective as this work [feminism] was in changing what teachers taught and what the students read, there was a sense on the part of some feminist critics that...it was still the old game that was being played, when what it needed was a new game entirely. The argument posed was that in order to counter patriarchy, it was necessary not merely to think about new texts, but to think about them in radically new ways" (Richter 1432).Therefore, a critic working in gender studies and queer theory might even be uncomfortable with the binary established by many feminist scholars between masculine and feminine: "Cixous (following Derrida in Of Grammatology) sets up a series of binary oppositions (active/passive, sun/moon...father/mother, logos/pathos). Each pair can be analyzed as a hierarchy in which the former term represents the positive and masculine and the latter the negative and feminine principle" (Richter 1433-1434).In-BetweensMany critics working with gender and queer theory are interested in the breakdown of binaries such as male and female, the in-betweens (also following Derrida's interstitial knowledge building). For example, gender studies and queer theory maintains that cultural definitions of sexuality and what it means to be male and female are in flux: "...the distinction between "masculine" and "feminine" activities and behavior is constantly changing, so that women who wear baseball caps and fatigues...can be perceived as more piquantly sexy by some heterosexual men than those women who wear white frocks and gloves and look down demurely". Moreover, Richter reminds us that as we learn more about our genetic structure, the biology of male/female becomes increasingly complex and murky: "even the physical dualism of sexual genetic structures and bodily parts breaks down when one considers those instances-XXYsyndromes, natural sexual bimorphisms, as well as surgical transsexuals - that defy attempts at binary classification".十二、精神分析Psychoanalytic Criticism (1930s-present)Sigmund FreudPsychoanalytic criticism builds on Freudian theories of psychology. While we don't have the room here to discuss all of Freud's work, a general overview is necessary to explain psychoanalytic literary criticism.The Unconscious, the Desires, and the DefensesFreud began his psychoanalytic work in the 1880s while attempting to treat behavioral disorders in his Viennese patients. He dubbed the disorders 'hysteria' and began treating them by listening to his patients talk through their problems. Based on this work, Freud asserted that people's behavior is affected by their unconscious: "...the notion that human beings are motivated, even driven, by desires, fears, needs, and conflicts of which they are unaware..." (Tyson 14-15).Freud believed that our unconscious was influenced by childhood events. Freud organized these events into developmental stages involving relationships with parents and drives of desire and pleasure where children focus "...on different parts of the body...starting with the mouth...shifting to the oral, anal, and phallic phases..." (Richter 1015). These stages reflect base levels of desire, but they also involve fear of loss (loss of genitals, loss of affection from parents, loss of life) and repression: "...the expunging from consciousness of these unhappy psychological events" (Tyson 15).Tyson reminds us, however, that "...repression doesn't eliminate our painful experiences and emotions...we unconsciously behave in ways that will allow us to 'play out'...our conflicted feelings about the painful experiences and emotions we repress" (15). To keep all of this conflict buried in our unconscious, Freud argued that we develop defenses: selective perception, selective memory, denial, displacement, projection, regression, fear of intimacy, and fear of death, among others.Id, Ego, and SuperegoFreud maintained that our desires and our unconscious conflicts give rise to three areas of the mind that wrestle for dominance as we grow from infancy, to childhood, to adulthood: ∙id - "...the location of the drives" or libido∙ego - "...one of the major defenses against the power of the drives..." and home of the defenses listed above∙superego - the area of the unconscious that houses judgement (of self and others) and "...which begins to form during childhood as a result of the Oedipus complex" (Richter 1015-1016)Oedipus ComplexFreud believed that the Oedipus complex was "...one of the most powerfully determinative elements in the growth of the child" (Richter 1016). Essentially, the Oedipus complex involves children's need for their parents and the conflict that arises as children mature and realize they are not the absolute focus of their mother's attention: "the Oedipus complex begins in a late phase of infantile sexuality, between the child's third and sixth year, and it takes a different form in males than it does in females" (Richter 1016).Freud argued that both boys and girls wish to possess their mothers, but as they grow older "...they begin to sense that their claim to exclusive attention is thwarted by the mother's attention to the。
地震的原因英语作文
地震的原因英语作文Earthquakes are one of the most powerful and destructive natural phenomena on Earth. They occur without warning and can cause widespread devastation. Understanding the causes of earthquakes is crucial for predicting and mitigating their effects. This essay will explore the scientific explanations behind the forces that trigger earthquakes.The primary cause of earthquakes is the movement of tectonic plates, which are massive slabs of solid rock that make up the Earth's lithosphere. These plates are constantly in motion, albeit very slowly, and their interactions are responsible for the majority of earthquakes. There are three main types of plate boundaries where earthquakes can occur: divergent, convergent, and transform.1. Divergent Boundaries: At divergent boundaries, two plates move away from each other. This process is known as rifting and often occurs along mid-ocean ridges. As the plates separate, magma from the mantle rises to fill the gap, creating new crust. The tension created by this process can cause earthquakes.2. Convergent Boundaries: When two plates move towards each other, they can collide, forming a convergent boundary. This can result in one plate being forced under the other in a process called subduction, or they can crumple together, forming mountain ranges. The immense pressure and stress fromthese collisions can cause the Earth's crust to rupture, resulting in earthquakes.3. Transform Boundaries: At transform boundaries, two plates slide past each other horizontally. The friction between the plates can cause them to lock together, building up stress. When the stress becomes too great, the plates can suddenly slip, releasing energy in the form of an earthquake.In addition to tectonic plate movements, earthquakes can also be caused by volcanic activity, although these are generally less powerful. The movement of magma beneath the Earth's surface can cause the crust to fracture, leading to an earthquake. Additionally, human activities, such as mining and the injection of fluids into the ground, can sometimes trigger minor earthquakes.In conclusion, the causes of earthquakes are complex and involve the dynamic interactions between the Earth's tectonic plates. Understanding these processes is essential for the development of effective earthquake early warning systems and for the design of infrastructure that can withstand the forces of these natural disasters. As our knowledge of the Earth's geology advances, so too will our ability to predict and prepare for the inevitable earthquakes that will continue to shape our planet.。
Mg–Gd–Y–Zn 稀土镁合金应变调节机制研究
第14卷 第6期 精 密 成 形 工 程收稿日期：2021–10–20基金项目：国家自然科学基金（51775135）作者简介：韩艳彬（1970—），男，博士，高级工程师，主要研究方向为镁铝合金在航空航天领域的轻量化应用。
韩艳彬1，蒋少松2，李阳2（1.中航西安飞机工业集团股份有限公司，西安 710089； 2.哈尔滨工业大学 材料科学与工程学院，哈尔滨 150001）摘要：目的 在微观尺度上研究Mg–5.4Gd–1.8Y–1.5Zn 合金的应变调节机制。
方法 将拉伸试样变形至应变为6%，采用基于互相关分析的高分辨EBSD 技术测量材料内部的刚体转动张量以及几何必需位错密度。
结果 Mg–Gd–Y–Zn 合金主要由基面<a >位错以及锥面<c +a >位错调节应变，即使在软取向晶粒内，锥面<c +a >位错也会大量出现。
当发生基面–基面位错的滑移转移与基面–锥面位错的滑移转移时，相邻两晶粒滑移系之间的Luster–Morris 因子很高（>0.78）。
结论 随着不同滑移系施密特因子的升高，晶粒内的位错密度逐渐降低。
这一反常现象可以归因于硬取向晶粒变形需消耗更多的应变能，而这部分应变能以位错密度的形式储存在晶粒内。
关键词：应变调节；稀土镁合金；HR–EBSD ；滑移转移；位错密度DOI ：10.3969/j.issn.1674-6457.2022.06.001中图分类号：TG146.2+2 文献标识码：A 文章编号：1674-6457(2022)06-0001-09Precise Measurement of Strain Accommodation in a Mg-Gd-Y-Zn AlloyHAN Yan-bin 1, JIANG Shao-song 2, LI Yang 2(1. A VIC Xi'an Aircraft Industry Group Company Ltd., Xi'an 710089, China; 2. Harbin Institute of Technology,School of Materials Science and Engineering, Harbin 150001, China)ABSTRACT: Mg-RE alloys show improved ductility compared to other classical magnesium alloys at room temperature. The present study focused on the strain accommodation mechanism in a wrought Mg-5.4Gd-1.8Y-1.5Zn alloy at the microstructural scale. For this purpose, a tensile specimen was uniaxially strained in-situ to 6%, and the lattice rotation tensor and geometrically necessary dislocation (GND) density were measured using cross-correlation-based high angular resolution electron backscatter diffraction (HR-EBSD) technique. The strain incompatibility within the Mg-Gd-Y-Zn alloy was accommodated by basal slip to-gether with pyramidal dislocation. The GND measurements via HR-EBSD showed a high occurrence of pyramidal <c +a > dis-location even in well-aligned grains. In addition, slip transfer process of the basal-basal and basal-pyramidal type was observed with high Luster-Morris factors (>0.78), in this study. The average GND density in grains tends to decrease with the Schmid factor increases. This phenomenon can be attributed to the fact that more strain energy is consumed for the hard-oriented grains, which is stored in grains in the form of dislocation density during deformation.KEY WORDS: strain accommodation; Mg-RE alloy; HR-EBSD; slip transfer; dislocation density镁及镁合金因其低密度与高比强度的特性，在航空航天以及汽车工业领域中具有广阔的应用前景[1-3]。
材料专业英语常见词汇
材料专业英语常见词汇The saying "the more diligent, the more luckier you are" really should be my charm in2006.材料专业英语常见词汇一Structure 组织Ceramic 陶瓷Ductility 塑性Stiffness 刚度Grain 晶粒Phase 相Unit cell 单胞Bravais lattice 布拉菲点阵Stack 堆垛Crystal 晶体Metallic crystal structure 金属性晶体点阵 Non-directional 无方向性Face-centered cubic 面心立方Body-centered cubic体心立方 Hexagonal close-packed 密排六方 Copper 铜Aluminum 铝Chromium 铬 Tungsten 钨Crystallographic Plane晶面 Crystallographic direction 晶向 Property性质 Miller indices米勒指数 Lattice parameters 点阵参数Tetragonal 四方的Hexagonal 六方的Orthorhombic 正交的Rhombohedra 菱方的Monoclinic 单斜的Prism 棱镜 Cadmium 镉 Coordinate system 坐 Point defec点缺陷Lattice 点阵 Vacancy 空位Solidification 结晶Interstitial 间隙Substitution 置换Solid solution strengthening 固溶强化Diffusion 扩散Homogeneous 均匀的Diffusion Mechanisms 扩散机制Lattice distortion 点阵畸变Self-diffusion 自扩散Fick’s First Law 菲克第一定律 Unit time 单位时间Coefficient 系数Concentration gradient 浓度梯度Dislocations 位错Linear defect 线缺陷Screw dislocation 螺型位错Edge dislocation 刃型位错Vector 矢量Loop 环路Burgers’vector 柏氏矢量Perpendicular 垂直于Surface defect 面缺陷Grain boundary 晶界Twin boundary 晶界 Shear force 剪应力Deformation 变形Small or low angel grain boundary 小角度晶界Tilt boundary 倾斜晶界Supercooled 过冷的Solidification 凝固Ordering process 有序化过程Crystallinity 结晶度Microstructure 纤维组织Term 术语Phase Diagram 相图Equilibrium 平衡Melt 熔化Cast 浇注Crystallization 结晶Binary Isomorphous Systems 二元匀晶相图Soluble 溶解Phase Present 存在相Locate 确定Tie line 连接线Isotherm 等温线Concentration 浓度Intersection 交点The Lever Law 杠杆定律Binary Eutectic System 二元共晶相图Solvus Line 溶解线Invariant 恒定Isotherm 恒温线Cast Iron 铸铁Ferrite 珠光体Polymorphic transformation 多晶体转变Austenite 奥氏体Revert 回复Intermediate compound 中间化合物Cementite 渗碳体Vertical 垂线Nonmagnetic 无磁性的Solubility 溶解度Brittle 易脆的Eutectic 共晶Eutectoid invariant point 共析点Phase transformation 相变Allotropic 同素异形体Recrystallization 再结晶Metastable 亚稳的Martensitic transformation 马氏体转变Lamellae 薄片Simultaneously 同时存在Pearlite 珠光体Ductile 可塑的Mechanically 机械性能Hypo eutectoid 过共析的Particle 颗粒Matrix基体Proeutectoid 先共析Hypereutectoid 亚共析的Bainite 贝氏体Martensite 马氏体Linearity 线性的Stress-strain curve 应力-应变曲线Proportional limit 比例极限Tensile strength 抗拉强度Ductility 延展性Percent reduction in area 断面收缩率Hardness 硬度Modulus of Elasticity 弹性模量Tolerance 公差Rub 摩擦Wear 磨损Corrosion resistance 抗腐蚀性Aluminum 铝Zinc 锌Iron ore 铁矿Blast furnace 高炉Coke 焦炭Limestone 石灰石Slag 熔渣Pig iron 生铁Ladle 钢水包Silicon 硅Sulphur 硫Wrought 可锻的Graphite 石墨Flaky 片状Low-carbon steels 低碳钢Case hardening 表面硬化Medium-carbon steels 中碳钢Electrode 电极As a rule 通常Preheating 预热Quench 淬火Body-centered lattice 体心晶格Carbide 碳化物Hypereutectoid过共晶Chromium 铬Manganese 锰Molybdenum 钼Titanium 钛Cobalt 钴Tungsten 钨Vanadium 钒Pearlitic microstructure 珠光体组织Martensitic microstructure 马氏体组织Viscosity 粘性Wrought 锻造的Magnesium 镁Flake 片状Malleable 可锻的Nodular 球状Spheroidal 球状Superior property 优越性Galvanization 镀锌Versatile 通用的Battery grid 电极板Calcium 钙Tin 锡Toxicity 毒性Refractory 耐火的Platinum铂Polymer 聚合物Composite 混合物Erosive 腐蚀性Inert 惰性Thermo chemically 热化学Generator 发电机Flaw 缺陷Variability 易变的Annealing 退火Tempering回火Texture 织构Kinetic 动力学Peculiarity 特性Critical point 临界点Dispersity 弥散程度Spontaneous 自发的Inherent grain 本质晶粒Toughness 韧性Rupture 断裂Kinetic curve of transformation 转变动力学曲线Incubation period 孕育期Sorbite 索氏体Troostite 屈氏体Disperse 弥散的Granular 颗粒状Metallurgical 冶金学的Precipitation 析出Depletion 减少Quasi-eutectoid 伪共析Superposition 重叠Supersede 代替Dilatometric 膨胀Unstable 不稳定Supersaturate 使过饱和Tetragonality 正方度Shear 切变Displacement 位移Irreversible 不可逆的金属材料工程专业英语acid-base equilibrium酸碱平衡 acid-base indicator酸碱指示剂 acid bath酸槽 acidBessemerconverter 酸性转炉 acid brick酸性耐火砖 acid brittleness酸洗脆性、氢脆性 acid burden酸性炉料acid clay酸性粘土 acid cleaning同pickling酸洗 acid concentration酸浓度 acid converter酸性转炉 acid converter steel酸性转炉钢 acid content酸含量 acid corrosion酸腐蚀 acid deficient弱酸的、酸不足的 acid dip酸浸acid dip pickler沉浸式酸洗装置 aciddiptank酸液浸洗槽acid drain tank排酸槽acidless descaling无酸除鳞acid medium酸性介质acid mist酸雾acid-proof paint耐酸涂料漆acid-proof steel耐酸钢acid-resistant耐酸钢acid-resisting vessel耐酸槽acid strength酸浓度acid supply pump供酸泵acid wash酸洗acid value酸值acid wash solution酸洗液acieration渗碳、增碳Acm point Acm转变点渗碳体析出温度acorn nut螺母、螺帽acoustic absorption coefficient声吸收系数acoustic susceptance声纳actifier再生器action line作用线action spot作用点activated atom激活原子activated bath活化槽activated carbon活性碳activating treatment活化处理active corrosion活性腐蚀、强烈腐蚀active area有效面积active power有功功率、有效功率active product放射性产物active resistance有效电阻、纯电阻active roll gap轧辊的有效或工作开口度active state活性状态active surface有效表面activity coefficient激活系数、活度系数actual diameter钢丝绳实际直径actual efficiency实际效率actual error实际误差actual time实时actual working stress实际加工应力actuating device调节装置、传动装置、起动装置actuating lever驱动杆、起动杆actuating mechanism 动作机构、执行机构actuating motor驱动电动机、伺服电动机actuating pressure作用压力actuation shaft起动轴actuator调节器、传动装置、执行机构acute angle锐角adaptive feed back control自适应反馈控制adaptive optimization自适应最优化adaptor接头、接合器、连结装置、转接器、附件材料科学基础专业词汇:第一章晶体结构原子质量单位 Atomic mass unit amu 原子数 Atomic number 原子量 Atomic weight波尔原子模型 Bohr atomic model 键能 Bonding energy 库仑力 Coulombic force共价键 Covalent bond 分子的构型 molecular configuration电子构型electronic configuration 负电的 Electronegative 正电的 Electropositive基态 Ground state 氢键 Hydrogen bond 离子键 Ionic bond 同位素 Isotope金属键 Metallic bond 摩尔 Mole 分子 Molecule 泡利不相容原理 Pauli exclusion principle 元素周期表 Periodic table 原子 atom 分子 molecule 分子量 molecule weight极性分子 Polar molecule 量子数 quantum number 价电子 valence electron范德华键 van der waals bond 电子轨道 electron orbitals 点群 point group对称要素 symmetry elements 各向异性 anisotropy 原子堆积因数 atomic packing factorAPF 体心立方结构 body-centered cubic BCC 面心立方结构 face-centered cubic FCC布拉格定律bragg’s law 配位数 coordination number 晶体结构 crystal structure晶系 crystal system 晶体的 crystalline 衍射 diffraction 中子衍射 neutron diffraction电子衍射 electron diffraction 晶界 grain boundary 六方密堆积 hexagonal close-packed HCP 鲍林规则 Paulin g’s rules NaCl型结构 NaCl-type structureCsCl型结构Caesium Chloride structure 闪锌矿型结构 Blende-type structure纤锌矿型结构 Wurtzite structure 金红石型结构 Rutile structure萤石型结构 Fluorite structure 钙钛矿型结构 Perovskite-type structure尖晶石型结构 Spinel-type structure 硅酸盐结构 Structure of silicates岛状结构 Island structure 链状结构 Chain structure 层状结构 Layer structure架状结构 Framework structure 滑石 talc 叶蜡石 pyrophyllite 高岭石 kaolinite石英 quartz 长石 feldspar 美橄榄石 forsterite 各向同性的 isotropic各向异性的 anisotropy 晶格 lattice 晶格参数 lattice parameters 密勒指数 miller indices 非结晶的 noncrystalline多晶的 polycrystalline 多晶形 polymorphism 单晶single crystal 晶胞 unit cell电位 electron states化合价 valence 电子 electrons 共价键 covalent bonding金属键 metallic bonding 离子键Ionic bonding 极性分子 polar molecules原子面密度 atomic planar density 衍射角 diffraction angle 合金 alloy粒度,晶粒大小 grain size 显微结构 microstructure 显微照相 photomicrograph扫描电子显微镜 scanning electron microscope SEM透射电子显微镜 transmission electron microscope TEM 重量百分数 weight percent四方的 tetragonal 单斜的monoclinic 配位数 coordination number材料科学基础专业词汇:第二章晶体结构缺陷缺陷 defect, imperfection 点缺陷 point defect 线缺陷 line defect, dislocation面缺陷 interface defect 体缺陷 volume defect 位错排列 dislocation arrangement位错线 dislocation line 刃位错 edge dislocation 螺位错 screw dislocation混合位错 mixed dislocation 晶界 grain boundaries 大角度晶界 high-angle grain boundaries 小角度晶界 tilt boundary, 孪晶界 twin boundaries 位错阵列 dislocation array位错气团 dislocation atmosphere 位错轴dislocation axis 位错胞 dislocation cell位错爬移 dislocation climb 位错聚结 dislocation coalescence 位错滑移 dislocation slip位错核心能量 dislocation core energy 位错裂纹 dislocation crack位错阻尼 dislocation damping 位错密度 dislocation density原子错位 substitution of a wrong atom 间隙原子 interstitial atom晶格空位 vacant lattice sites 间隙位置 interstitial sites 杂质 impurities弗伦克尔缺陷 Frenkel disorder 肖脱基缺陷 Schottky disorder 主晶相 the host lattice错位原子 misplaced atoms 缔合中心 Associated Centers. 自由电子 Free Electrons电子空穴Electron Holes 伯格斯矢量 Burgers 克罗各-明克符号 Kroger Vink notation中性原子 neutral atom材料科学基础专业词汇:第二章晶体结构缺陷-固溶体固溶体 solid solution 固溶度 solid solubility 化合物 compound间隙固溶体 interstitial solid solution 置换固溶体 substitutional solid solution金属间化合物 intermetallics 不混溶固溶体 immiscible solid solution转熔型固溶体 peritectic solid solution 有序固溶体 ordered solid solution无序固溶体 disordered solid solution 固溶强化 solid solution strengthening取代型固溶体 Substitutional solid solutions 过饱和固溶体 supersaturated solid solution非化学计量化合物 Nonstoichiometric compound材料科学基础专业词汇:第三章熔体结构熔体结构 structure of melt过冷液体 supercooling melt 玻璃态 vitreous state软化温度 softening temperature 粘度 viscosity 表面张力 Surface tension介稳态过渡相 metastable phase 组织 constitution 淬火 quenching退火的 softened 玻璃分相 phase separation in glasses 体积收缩 volume shrinkage材料科学基础专业词汇:第四章固体的表面与界面表面 surface 界面 interface 同相界面 homophase boundary异相界面 heterophase boundary 晶界 grain boundary 表面能 surface energy小角度晶界 low angle grain boundary 大角度晶界 high angle grain boundary共格孪晶界 coherent twin boundary 晶界迁移 grain boundary migration错配度 mismatch 驰豫 relaxation 重构 reconstuction 表面吸附 surface adsorption表面能 surface energy 倾转晶界 titlt grain boundary 扭转晶界 twist grain boundary倒易密度 reciprocal density 共格界面 coherent boundary 半共格界面 semi-coherent boundary 非共格界面 noncoherent boundary 界面能 interfacial free energy应变能 strain energy 晶体学取向关系 crystallographic orientation惯习面habit plane材料科学基础专业词汇:第五章相图相图 phase diagrams 相 phase 组分 component 组元 compoonent相律 Phase rule 投影图 Projection drawing 浓度三角形 Concentration triangle冷却曲线 Cooling curve 成分 composition 自由度 freedom相平衡 phase equilibrium 化学势 chemical potential 热力学 thermodynamics相律 phase rule 吉布斯相律 Gibbs phase rule 自由能 free energy吉布斯自由能 Gibbs free energy 吉布斯混合能 Gibbs energy of mixing吉布斯熵 Gibbs entropy 吉布斯函数 Gibbs function 热力学函数 thermodynamics function 热分析 thermal analysis 过冷 supercooling 过冷度 degree of supercooling杠杆定律 lever rule 相界 phase boundary 相界线 phase boundary line相界交联 phase boundary crosslinking 共轭线 conjugate lines相界有限交联 phase boundary crosslinking 相界反应 phase boundary reaction相变 phase change 相组成 phase composition 共格相 phase-coherent金相相组织 phase constentuent 相衬 phase contrast 相衬显微镜 phase contrast microscope 相衬显微术 phase contrast microscopy 相分布 phase distribution相平衡常数 phase equilibrium constant 相平衡图 phase equilibrium diagram相变滞后 phase transition lag 相分离 phase segregation 相序 phase order相稳定性 phase stability 相态 phase state 相稳定区 phase stabile range相变温度 phase transition temperature 相变压力 phase transition pressure同质多晶转变 polymorphic transformation 同素异晶转变 allotropic transformation相平衡条件 phase equilibrium conditions 显微结构 microstructures 低共熔体 eutectoid不混溶性 immiscibility材料科学基础专业词汇:第六章扩散活化能 activation energy 扩散通量 diffusion flux 浓度梯度 concentration gradient菲克第一定律Fick’s first law 菲克第二定律Fick’s second law 相关因子 correlation factor 稳态扩散 steady state diffusion 非稳态扩散 nonsteady-state diffusion扩散系数 diffusion coefficient 跳动几率 jump frequency填隙机制 interstitalcy mechanism 晶界扩散 grain boundary diffusion短路扩散 short-circuit diffusion 上坡扩散 uphill diffusion 下坡扩散 Downhill diffusion互扩散系数 Mutual diffusion 渗碳剂 carburizing 浓度梯度 concentration gradient浓度分布曲线 concentration profile 扩散流量 diffusion flux 驱动力 driving force间隙扩散 interstitial diffusion 自扩散 self-diffusion 表面扩散 surface diffusion空位扩散 vacancy diffusion 扩散偶 diffusion couple 扩散方程 diffusion equation扩散机理 diffusion mechanism 扩散特性 diffusion property 无规行走 Random walk达肯方程 Dark equation 柯肯达尔效应 Kirkendall equation本征热缺陷 Intrinsic thermal defect 本征扩散系数 Intrinsic diffusion coefficient离子电导率 Ion-conductivity 空位机制 Vacancy concentration材料科学基础专业词汇:第七章相变过冷 supercooling 过冷度 degree of supercooling 晶核 nucleus 形核 nucleation形核功 nucleation energy 晶体长大 crystal growth 均匀形核 homogeneous nucleation非均匀形核 heterogeneous nucleation 形核率 nucleation rate 长大速率 growth rate热力学函数 thermodynamics function 临界晶核 critical nucleus临界晶核半径 critical nucleus radius 枝晶偏析 dendritic segregation局部平衡 localized equilibrium 平衡分配系数 equilibrium distributioncoefficient有效分配系数 effective distribution coefficient 成分过冷 constitutional supercooling引领领先相 leading phase 共晶组织 eutectic structure 层状共晶体 lamellar eutectic伪共晶 pseudoeutectic 离异共晶 divorsed eutectic 表面等轴晶区 chill zone柱状晶区 columnar zone 中心等轴晶区 equiaxed crystal zone定向凝固 unidirectional solidification 急冷技术 splatcooling 区域提纯 zone refining单晶提拉法 Czochralski method 晶界形核 boundary nucleation位错形核 dislocation nucleation 晶核长大 nuclei growth斯宾那多分解 spinodal decomposition 有序无序转变 disordered-order transition马氏体相变 martensite phase transformation 马氏体 martensite材料科学基础专业词汇:第八、九章固相反应和烧结固相反应 solid state reaction 烧结 sintering 烧成 fire 合金 alloy 再结晶 Recrystallization 二次再结晶 Secondary recrystallization 成核 nucleation 结晶 crystallization子晶,雏晶 matted crystal 耔晶取向 seed orientation 异质核化 heterogeneous nucleation均匀化热处理 homogenization heat treatment 铁碳合金 iron-carbon alloy渗碳体 cementite 铁素体 ferrite 奥氏体austenite 共晶反应 eutectic reaction 固溶处理 solution heat treatment。
托福培训丨托福听力讲座结构分层解题法
托福培训丨托福听力讲座结构分层解题法朗阁托福培训中心黄蓉Vicky在托福听力考试中同学们只能听到一遍音频，由于考试涉及到各个学科，内容涉及领域广生词多，所以难免会出现在考试时某些细节信息无法准确理解的情况，而文章中的选项又常常以文中已出现的内容作为干扰，这使同学们在做题时感到非常困扰。
因此，朗阁托福培训中心的专家们通过对真题的悉心研究，总结并发现了一套行之有效的解题方法，通过托福听力文章结构类型来预测考点，并且通过文章的分层来帮助我们排除干扰选项。
首先我们从托福听力文章最为常见的并列型结构入手来进行讲解。
并列结构即在文章的一个主题下提及该主题相关的各个分支，这些分支是互相独立的并列关系。
因为这类文章的结构最为清晰，分层也最易把握，所以尤其适合刚学习分层的同学用来总结和体会分层的规律。
以TPO中的真题为例：如生物话题中TPO 17 Lecture 4关于octopus的一篇文章中，在一开头就总起叙述了章鱼的三个特性，Just like Proteus, the octopus can go through all kinds of incredible transformations. And it does this in three ways: by changing color, by changing its texture, and by changing its size and shape.接下来的文章便从color, texture, size and shape三个方面分别说明了章鱼是如何完成让人难以置信的变形而很好地伪装自己的，而文章中表示分层的句子也非常清晰。
下面我们就来看看每个并列信息之间这些表示分层的表达，并利用分层来帮助我们排除错误选项。
首先第一个层次利用For me, the most fascinating transformation is when it changes its color.展开，开始了关于color这个层次的叙述，而第二层次的展开是通过一个承上启下的句子So, that’s how octopus mimic colors. But they don’t just mimic the colors in their environment; they can also mimic the texture of objects in their environment.开始了对texture这个层次的叙述。
挤压态AZ31镁合金温热拉伸性能的各向异性
挤压态AZ31镁合金温热拉伸性能的各向异性吴国华;肖寒;周慧子;王瑞雪;程明;张士宏【摘要】The tensile properties,microstructure,appearance of fracture in five different planar directions of extruded AZ31 magnesium alloy sheets at the warm-temperature were investigated by uniaxial compression test.The results indicate that the extruded magnesium alloy sheets show high anisotropy,and the most obvious anisotropic temperature is170 ℃.With the increase of the angle between tensile direction and extrusion direction,the tensile strength increases from 217 MPa to 271 MPa,and the yield strength decreases from 174 MPa to 71 MPa.There are three deformation mechanisms of magnesium alloys at warm-temperature,which include {10-12} extension twinning,{10-11} compression twinning and base slip.The deformation mechanism is different at different stretching angles.When the angle between tensile direction and extrusion direction is less than 45°,the fracture mechanism of magnesium alloy is micropore aggregation fracture.With the increase of angle,it is the mixed fracture of toughness and brittleness,and the cleavage fracture occurs at the angle of 67.5°.%采用单向拉伸实验研究温热条件下挤压态AZ31镁合金板材5个不同方向的力学性能、显微组织、断口形貌.结果表明:挤压态镁合金力学性能具有明显的各向异性,170℃时,各向异性最明显,随着拉伸方向与挤压方向所呈角度的增大,抗拉强度从217 MPa增大到271 MPa,屈服强度却从174 MPa减小到71 MPa.镁合金在温热条件下变形机制为{10-12}拉伸孪生、{10-11}压缩孪生和{0001}基面(a)滑移;沿着不同角度拉伸时,变形机制有所不同.拉伸方向与挤压方向的角度小于45°时,挤压态镁合金表现为微孔聚集型的韧性断裂;且随着角度的增大,表现为韧-脆混合断裂,其中角度为67.5°时,镁合金以解理方式断裂.【期刊名称】《中国有色金属学报》【年(卷),期】2017(027)001【总页数】7页(P57-63)【关键词】镁合金;温热拉伸性能;孪生;断裂机制;各向异性【作者】吴国华;肖寒;周慧子;王瑞雪;程明;张士宏【作者单位】昆明理工大学材料科学与工程学院,昆明650093;昆明理工大学材料科学与工程学院,昆明650093;昆明理工大学材料科学与工程学院,昆明650093;中国科学院金属研究所,沈阳110016;中国科学院金属研究所,沈阳110016;中国科学院金属研究所,沈阳110016【正文语种】中文【中图分类】TG146.2镁合金具有低密度、高强度、电磁屏蔽效果优良及易回收等优点，常被作为轻量化结构材料应用于汽车、交通、电子等行业[1-2]。
居住空间设计英语
IntroductionResidential space design is an intricate process that transcends mere aesthetics, encompassing functionality, sustainability, emotional well-being, and the integration of advanced technologies. Crafting a high-quality, high-standard living environment necessitates a comprehensive understanding of these diverse elements and their harmonious fusion. This essay presents a multifaceted analysis of designing such spaces, delving into the key aspects that define their excellence.1. **Contextual and Site-Specific Design**A paramount aspect of high-quality residential design lies in its responsiveness to the context and site. A thorough understanding of the locale's climate, topography, cultural heritage, and urban fabric guides architects in creating homes that seamlessly blend with their surroundings. For instance, a coastal residence may incorporate large windows to capture ocean views and harness natural ventilation, while a mountain retreat may emphasize earthy materials and a low-impact footprint. Furthermore, respecting local building codes, zoning regulations, and environmental protection guidelines ensures compliance with legal standards and contributes to sustainable urban development.2. **Functional Layout and Spatial Flow**Efficient spatial planning is fundamental to achieving a high-standard living space. A well-designed layout optimizes the use of available area, ensuring that each room serves its intended purpose without feeling cramped or disconnected. The fluidity of movement between spaces is equally crucial, as seamless transitions promote a sense of spaciousness and ease of daily routines. Open-plan designs, strategic placement of transitional elements like corridors or staircases, and the careful allocation of private and communal zones contribute to an intuitive and enjoyable spatial experience.3. **Adaptive and Flexible Spaces**In today's rapidly evolving lifestyles, residential spaces must be adaptable to accommodate changing needs and preferences. High-quality design embraces flexibility through multipurpose rooms, movable partitions, and convertible furniture. Such features enable homeowners to reconfigure spaces according to their current requirements, whether it be accommodating a growing family, setting up a home office, or hosting guests. Moreover, future-proofing the design with provisions for potential extensions or renovations ensures the long-term relevance and value of the property.4. **Light, Color, and Materiality**The interplay of light, color, and material choices significantly impacts the ambiance, mood, and overall quality of a residential space. Abundant natural light not only enhances visual comfort but also improves energy efficiency and mental health. Strategic placement of windows, skylights, and light wells can maximize daylight penetration, while thoughtful selection of artificial lighting systems ensures optimal illumination during darker hours. Color schemesshould reflect the occupants' tastes and foster the desired atmosphere, be it calming neutrality, vibrant playfulness, or sophisticated elegance. Material choices should prioritize durability, sustainability, and sensory appeal, with a focus on authentic textures, eco-friendly options, and low-maintenance finishes.5. **Sustainable and Energy-Efficient Design**Environmental consciousness is a hallmark of high-quality, high-standard residential design. Architects and designers should employ passive strategies – such as orientation, insulation, shading, and natural ventilation – to minimize energy consumption for heating, cooling, and lighting. Integration of renewable energy systems, like solar panels or geothermal heat pumps, further reduces the home's carbon footprint. Water-saving fixtures, rainwater harvesting, and greywater recycling systems contribute to water conservation. Additionally, the use of locally sourced, recycled, and low-VOC materials, along with green roofs, living walls, and permeable paving, promotes biodiversity and ecological resilience.6. **Technology Integration and Smart Home Features**Incorporating cutting-edge technology enhances the functionality, convenience, and security of a high-standard residence. Smart home systems enable remote control of lighting, temperature, appliances, and security, often via voice commands or smartphone apps. Home automation can also optimize energy usage, monitor indoor air quality, and provide predictive maintenance alerts. Advanced technologies like augmented reality, virtual assistants, and AI-driven personalization can further elevate the living experience, tailoring the environment to individual preferences and routines.7. **Wellness-Oriented Design**Designing for wellness involves creating environments that positively influence physical, mental, and emotional health. This encompasses aspects such as acoustic comfort, air quality, access to nature, and opportunities for physical activity. Sound-absorbing materials, strategic placement of bedrooms away from noise sources, and dedicated quiet zones promote tranquility. Indoor plants, natural ventilation, and air purification systems enhance air quality. Incorporating features like home gyms, yoga studios, or outdoor recreational areas fosters an active lifestyle. Moreover, biophilic design principles, which connect occupants with nature through elements like greenery, natural light, and organic patterns, have been shown to reduce stress and improve overall well-being.8. **Accessibility and Universal Design**Designing residences that cater to diverse abilities and life stages demonstrates a commitment to inclusivity and high standards. Universal design principles ensure that all users, regardless of age, size, or ability, can navigate and utilize the space comfortably and independently. This includes features like level thresholds, wide doorways, non-slip flooring, accessible switches and outlets, and ample maneuvering space in bathrooms and kitchens.Thoughtful consideration of accessibility not only enhances the quality of life for residents but also increases the home's market appeal and resale value.ConclusionDesigning high-quality, high-standard residential spaces requires a holistic approach that integrates contextual sensitivity, functional efficiency, adaptability, aesthetic appeal, sustainability, technology, wellness, and inclusivity. By meticulously addressing these multifaceted aspects, architects and designers can create living environments that surpass mere shelter, offering instead sanctuaries of comfort, inspiration, and enduring value. As lifestyles continue to evolve and new design innovations emerge, the pursuit of excellence in residential space design remains a dynamic and ever-rewarding endeavor.。
文体学分析的方法
imitative word
Synaesthesia
The moan of doves in immemorial elms , And murmuring of innumerable bees.
(A. Tennyson : Come Dow n , O Maid)
sneak (潜行)、snoop (藐视)
音组-are
可暗示“强光或噪音”(big light or noise) : blare(喇叭等高音乐器发出的刺 耳声音)、f lare (火焰)、glare (刺目的强 光)、stare (凝视)
以- ump 结尾的系列词均与强重(heavy) 和粗笨(clumsy) 有关:
Words have weight, sound and appearance; it is only by considering these that you can write a sentence that is good to look at and good to listen to. -- Maugham(毛姆)
古老的榆树林中鸽子的呢喃, 还有成群飞舞的蜜蜂的嗡嗡声。
[m]音常常象征着低沉声，如murmur，moan， mutter，mumble，hum
1. We chip a small piece but chop a large one.
2. A slip is smaller than a slab.
Example
`John bought that new car yesterday. ↗ John bought `that new car yesterday. ↗
MachineGuarding机械安全防护
Safety begins before you even start the equipment!
Personal Protection:
• Wear PPE, such as goggles, safety shoes and leather gloves.
• Long hair should be tied back or tucked under to avoid getting caught in machinery.
When the operation of a machine or accidental contact with it can injure the operator or others in the vicinity, the hazards must be either controlled or eliminated.
Safeguards are essential for protecting workers from needless and preventable injuries.
A good rule to remember is:
Any machine part, function, or process which many cause injury must be safeguarded.
Risk Assessment Process
Gather Equipment Specifications
Determine Equipment Limitations
Catastrophic: Permanent Disabling Serious: Severe Disabling
Moderate: Significant Disabling Minor: Sligh Disabling Very Likely to Occur Likely, May Occur Unlikely, Not Likely to Occur Remote: Very Unlikely
2023年英语教学法教程知识点总结单元
FLTM: foreign language teaching methodology is a science which studies the processes and patterns of foreign language teaching, aiming at revealing the natural and laws of foreign languages.Major approaches in FLT:Grammar-translation method (deductive演绎法)Direct method (inductive归纳法)Audio-lingual methodHumanistic approaches: that emphasize the development of human values, growth in self-awareness and in the understanding of others, sensitivity to human feelings and emotions, and active student involvement in learning and in the way human learning takes palaceThe silent waySuggestopediaCommunity language learning (CLL)Total physical response method (TPR)●The natural approach(NA)●The communicative approach(CA )An approach is a set of correlative assumptions dealing with the nature of language teaching ad leaning. Approach is axiomatic. It describes the nature of the subject matter to b taught.Method is an overall plan for the orderly presentation of language material, no part of which contradicts, and all of which is based upon, the selected approach. An approach is axiomatic, a method is procedural. Within one approach, there can be many methods.A technique is implementation---that which actually takes place in a classroom. It is a particular trick, stratagem, or contrivance used to accomplish an immediate objective. Techniques must b consistent with a method, and therefore I harmony with an approach as well.Views on language:Structural view: the structural view of language sees language as a linguistic system made up of various subsystems: the sound system (phonology); the discrete units of meaning produced by sound combinations (morphology); and the system of combining units of meaning for communication (syntax).Functional view: the functional view not only sees language as a linguistic system but also means for doing things. Functional activities: offering, suggesting, advising, apologizing, etc. International view: considers language to be a communicative tool, whose main use is to build up and maintain social relations between people. Therefore, learners not only need to know the grammar and vocabulary of the language but as importantly they need to know the rules for using them in a whole range of communicative contexts.Process-oriented theories: are concerned with how the mind organizes new information such as habit formation, induction, making inference, hypothesis testing and generalization.Condition-oriented theories: emphasize the nature of the human and physical context in which language learning takes place, such as the number of students, the kind of input learners receives, and the atmosphere.Behaviorist theory, the idea of this method is that language is learned by constant repletion and the reinforcement of the teacher. Mistakes were immediately corrected, and correct utterances were immediately praised.Cognitive theory, language is not a form of behavior, it is an intricate rule-based system and a large part of language acquisition is the learning of this system.Constructivist theory, believes that learning is a process in which the learner constructs meaning based on his/her own experiences and what he/she already knows.Socio-constructivist theory, similar to constructivist theory, socio-constructivist theory emphasizes interaction and engagement with the target language in a social context based on the concept of “Zone of Proximal Development” (ZPD) and scaffolding.Ethic devotion, professional qualities and personal stylesCLT: communicative language teachingTBLT: task-based language teachingThe goal of CLT is to develop students’communicative competence, which includes both the knowledge about the language and the knowledge about how to use the language appropriately in communicative situations. P16Hedge discusses five main components of communicative competence: linguistic competence, pragmatic competence, discourse competence, strategic competence, and fluency.Howatt proposes a weak and a strong version of CLT.Weak version: learners first acquire language as a structural system and then learn how to use it in communication. --- the weak version regards overt teaching of language forms and functions as necessary means for helping learners to develop the ability to use them for communication.Strong version: language is acquired through communication. The learners discover the structural system in the process of leaning how to communicate.---regards experiences of using the language as the main means or necessary conditions for learning a language as they provide the experience for learners to see how language is used in communication.Communicative activities: P24Tasks are activities where the target language is used by the leaner for a communicative purpose (goal) in order to achieve an outcome.Four components of a task: a purpose, a context, a process, and a productTasks focus on the complete act of communication. (Purposeful & contextualized communication). Exercises focus the students’attention on the individual aspects of language, such as vocabulary, grammar or individual skills. (Focus on individual language items)Exercise-task comes halfway between tasks and exercises, consists of contextualized practice of language item.PPP: for teaching a new structure-based lesson, content lesson, presentation (introduces new vocabulary and grammatical structures), practice (the lesson moves from controlled practice to guided practice and exploitation of the texts when necessary) and production(the students are encouraged to use what they are learned and practiced to perform communicative tasks)The importance of lesson planning: 1. an unprepared teacher begins of a disastrous lesson.2. An unprepared teacher receives less trust and cooperation from the students. 3. The students are different, the time is different, and the mood is different.Lesson Planning: is a framework of a lesson in which teachers make advance decisions about what they hope to achieve and how they would like to achieve it. In other words, teachers need to think about the aims to be achieved, materials to be covered, activities to be organized, and techniques and resources to be used in order to achieve the aims of the lesson.Principles for good lesson planning: aim, variety, flexibility, learnability, and linkage. Variety: planning a number of different types of activities and where possible,introducing students to a wide selection of materials so that learning is always interesting, motivating and never monotonous for the students.Flexibility: preparing some extra and alternative tasks and activities at the class does not always go according to the plan so that teachers always have the option to cope with the unexpected situations rather than being the slaves of written plans or one methodology. Learnability:within capability of the students, not be too easy or beyond or below the students’ coping ability.Linkage: easy task followed by a comparatively difficult one, or do a series of language-focused activities to get the students prepared linguistically.Components of a lesson planning: background information, teaching aims, language content andskills, stages and procedures, teaching aids, assignments, and teacher’s after-lesson reflection.For skill-oriented lesson, focusing on developing skills, the model is applicable---pre-(reading), while-, post-. (Pre-step, while-step, post-step)Classroom management is the way teachers organize what goes on in the classroom.The role of the teacher: controller, assessor (evaluator, correcting mistakes and organizing feedback), organizer (organize and design task that students can perform in the class), prompter推进者(give appropriate prompts and give hints), participant, resource-provider, teacher’s new roles.There are rules to follow for making instructions effective.●The first is to use simple instructions and make them suit the comprehensive level of thestudents.●The second rule is to use the mother-tongue only when it is necessary.●Give students time to get used to listening to English instructions and help the make an effortto understand them.●Use body language to assist understanding and stick to it each time you teach the class. Student grouping: whole class group—same activity at the same rhythm and pace, lockstep, pair work, group work, individual studyDiscipline: refers to a code of conduct which binds a teacher and a group of students together so that learning can be more effective.Questioning in the classroom:Classification of question types: 1.closed questions and open questions 2.display questions and genuine questions 3.lower-order questions and higher-order questions 4.taxonomyClosed questions refer to those with only one s ingle correct answer while open questions may invite many different answers.Display questions are those that the answers are already known to the teacher and they are used for checking if students know the answer, too. Genuine questionsare questions which are used to find out new information and since they often reflect real context, they are more communicative. Lower-order questions refer to those that simple require recalling of information or memorization of facts while higher order questions require more reasoning, analysis, and evaluation.Simple question and difficult questionA mistake refers to a performance error that is either a random guess or an “a slip of tongue”, it’s a failure performance to a known system.An error has direct relation with the learners’language competence. Results from Lack of knowledge in the target language. Language error cannot be self-corrected no matter how much attention is paidDealing with spoken errors: tasks or activities are focusing on accuracy or fluency. Balance between accuracy-based activities and fluency-based activities..When to correct: fluency work---not to interrupt, after the student’s performance; accuracy work---need to intervene moreHow to correct: direct teacher correction, indirect teacher correction, self-correction, peer correction, whole class correction.Goal of teaching pronunciation:Consistency: the pronunciation should be smooth and naturalIntelligibility: the pronunciation should be understandable t o the listenersCommunicative efficiency: the pronunciation should help convey the meaning that is intended by the speaker.Aspects of pronunciation: besides sounds and phonetic symbols, such as stress (strong and weak form, word stress and sentence stress), intonation and rhythm (variation).Perception practice: using minimal pairs, which order, same or different? Odd and out, Completion.Production practice: listen and repeat, fill the blanks, make up sentences, use meaningful context, use picture, use tongue twisters.Grammar presentation: The deductive method, the inductive method, the guided discovery methodGrammar practice: mechanical practice and meaningful/ communicative practice.Mechanical practice: involves activities that are aimed at form accuracy. Students pay repeated attention to a key element in a structure. Substitution drill and transformation drills.Meaningful practice: focus on the production, comprehension or exchange of meaning though the students keep an eye on the way newly learned structures are used in the process. It comes after mechanical practice. (Comparatives and superlatives). Using picture prompts, using mimes or gestures as prompts, using information sheet as prompts, using key phrases or key words as prompts, using chained phrases for story telling, using created situations.What does knowing a word involve? Denotative meaning; connotative meaning; chunk/collocations; synonyms, antonyms and hyponyms; receptive and productive vocabulary.Denotative meaning of a word or a lexical item refers to those words that we use to label things as regards real objects, such as a name or a sign, etc. in the physical world. Primary meaning of a word.A connotative meaning of a word refers to the attitudes or emotions of a language user in choosing a word and the influence of these on the listener or reader’s interpretation of the word. Collocations refer to words that co-occur with high frequency and have been accepted as ways for the use of words. For instance, see, look at, watch.Hyponyms refer to words which can be grounded together under the same superordinate concept. Receptive/passive vocabulary refers to words that one is able to recognize and comprehend in reading or listening but unable to use automatically in speaking or writing. Those words that one is not only able to recognize but also able to use in speech and writing are considered as one’s productive/active vocabulary.Ways of presenting vocabulary: inductive and deductive.Ways of consolidating vocabulary: labeling; spot the difference; describe and draw; play a game; use words series; word bingo; word association; finding synonyms and antonyms; categories; using word net-work; using the internet resources for more ideas.Developing vocabulary learning strategies: review regularly, guess meaning from context, organize vocabulary effectively, use a dictionary, and manage strategy use.Principles and models for teaching listening: focus on process, combine listening with other skills (listening can be practice with not-taking, and answers, role plays, retelling, interviewing, discussions, or a writing task), focus on the comprehension of meaning, grade difficulty level appropriately, principles for selecting and using listening activities.Two approaches are frequently used to describe different processes of listening.Bottom-up model and Top-down model.Bottom-up model: 从细节入手start with sound and meaning recognitions. Listeners construct meaning of what they hear based on the sound they hear, expect the listeners have a very effective short-term memory as they have to make sense of every sound in order to figure out the meaning of words, phrase, and structures. If there are unfamiliar sounds, listeners will find it very difficult to keep up with speaker. ---recognizing sounds of words, phrases or structures.Top-down model: 着重概要listening for gist and making use of the contextual clues and background knowledge to construct meaning are emphasized. Listeners can understand better if they already have some knowledge in their mind about the topic. Such knowledge is also termedas prior knowledge or schematic knowledge---mental frameworks for various things and experience we hold in our long-term memory. ---referring meaning from broad contextual clues and background knowledge.Three teaching stages: pre-listening—warming up; while-listening---listening comprehension; post-listening---checking answers.Teaching speakingLess complex syntax, short cuts, incomplete sentences, devices such as fillers, hesitation device to give time to thinking before speaking, false start, spontaneous, time-constraint.Types of speaking: pre-communicative activities—mechanical activities; communicative activities---meaningful activities.Controlled activities, semi-controlled activities, communicative activities:Information-gap activities; dialogues and role-plays; activities using pictures; problem-solving activities; change the story; human scrabbleOrganizing speaking tasks: use small group workTeaching readingThe construction of meaning from a printed or written message.Two broad levels in the act reading.1). A recognition task of perceiving visual signals from the printed page through the eyes.2). A cognitive task of interpreting the visual information revealing the received information with the reader’s own general knowledge, and reconstructing the meaning that the writer had meant to convey.For teaching: intensive/extensive readingIn terms of methods: skimming/scanning/predictingFor reading practice: reading aloud/silent readingThe role of vocabulary in reading: sight vocabulary: words that one is able to recognizeimmediately are often referred to as sight vocabulary.Principles and models for teaching reading: bottom-up model; top-down model; interactive modelPre-reading activities: predicting (predicting based on the tile/ based on vocabulary/based on the T/F questions) setting the scene, skimming, and scanningWhile-reading activities: TD (a transition device)Reading comprehension questions: 1. questions of literal comprehension 2. Questions involving reorganization or reinterpretation 3. Questions for inference (what is implied but not explicitly stated) 4. questions for evaluation or appreciation (making judgment about what the writer is trying to do and how successful he/she is in achieving his/her purpose) 5. Questions for personal responseIntensive reading is an accuracy-oriented activity involving reading for detail; the main purpose is to learn language embedded in the reading texts, which are usually short. Extensive reading is a fluency activity. The main purpose is to achieve global understanding. Te reading texts usually contains less new vocabulary and is longer than those intended for intensive reading.Teaching writingWriting for consolidating language, writing for communication, between writing for learning and writing for communication, imaginationNot have a real communicative purpose; for language skill; a little bit communicative; communicative approach; neither restrictions in contents nor in word limit; more communicative; more motivatedCA: communication approachA Productive approach to writing 成果法/a prose model approach---fruitlessA Process approach to writing 过程法: The teacher provides to guide studentsthrough the process that they undergo when they are writing. This kind of guidance should be gradually withdrawn so that the students can finally become independent writers.Main procedures of process writing include: creating a motivation to write, brainstorming, mapping, freewriting, outlining, drafting, editing, revising, proofreading and conferencing.。
巴塞尔资本协议中英文完整版(15附录7(英文))
Non-client counterparty misperformance
Misc. non-client counterparty disputes
Vendors & Suppliers
Outsourcing
Vendor disputes
Annex 7
Detailed loss event type classification
Event-Type Category (Level 1)
Definition
Categories (Level 2)
Activity Examples (Level 3)
Internal fraud
Losses due to acts of a type intended to defraud, misappropriate property or circumvent regulations, the law or company policy, excluding diversity/ discrimination events, which involves at least one internal party.
Employee Relations
Compensation, benefit, termination issues
Organised labour activity
Safe Environment
General liability (slip and fall, etc.)
Employee health & safety rules events
Systems
Hardware
rocol safe step矩阵防滑板安装说明书
SAFE STEP® Matrix Panels and TreadsTechnical Data & Application InstructionsDescriptionSAFE STEP®Matrix is a unique, patented anti-slip panel/tread incorporating a grid design into the near diamond hard walking surface, enabling the panel to be cut quickly and easily in situ to suit a particular layout.It also has the added benefit of antibacterial protection, incorporated into the wearing course, which provides lasting activity over the life of the SAFE STEP® Matrix.Independent tests show bacterial growth was reduced by 99.9%.Anti-Microbial Featuresq Effective over a broad spectrum of bacteria q Will not wash offq Incorporated into the surface duringmanufactureq Independently testedq Tests based on AATCC 100 method using Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus and Escherichia coli.NOTE:SAFE STEP®Matrix does not replace cleaning practices see paragraph on maintenance for cleaning requirements.Other Featuresq Easy to install q Chemical and stain resistantq Anti-slip q Light weightq Corrosion resistant q Non-conductiveq Impact resistantq Manufactured under BS EN ISO 9001 Qualitycontrolled conditionsq Tough and durableSuitable surfaces for applications includeq Kitchensq Food production areasq Rampsq Chequer plateq Problem concrete surfaces q Workstationsq Walkwaysq Open mesh catwalks q Work platformsTechnical Data (Typical)Description: Anti-slip safety flooring panel/tread withantibacterial protectionGrade: PedestrianStandard colours: Black, grey and yellowAppearance: MattOverall Thickness: 3.5-6.5mmApplication: Internal or externalROCOL Site Safety SystemsROCOL House, Swillington, Leeds, LS26 8BS, United KingdomTechnical Data (Typical) continuedPanel Size: Tread Size 1150 x 750 mm comprising of 40mm aggregated squares with 10mm channels11” (280mm) going in 1.2 metre lengths comprising of 40mm aggregated squares with 10mm channelsTRL Slip resistance values:Pendulum method (WF rubber slider)Result Potential For SlipDry 112 Extremely LowWet 92 Extremely LowOily 69 LowChemical resistance: Mild detergents, vegetable oils, diesel, lubricatingoils and greases.Our technical department can give specific advicewhere required.Weights: 5.0Kg per panel2.2Kg per treadService temperature: -20 to +80°cWeathering resistance ASTM G-53: Bacterial Resistance AATCC 100: Excellent99.9% reduction based on Salmonella, Listeria, S. aureus and E.coliImpact resistance: Panels do not chip or crack under impact from a0.9Kg steel ball dropped from a height of 2.4mAggregate dressing: BS 812 Mohs Hardness 9 Abrasion value 1.9 Polished stone value 70FixingsNote: SAFE STEP® Matrix must be fixed using a mechanical fixing systemSubstrate Fixing Type ConstructionAdhesive Timber No 14 (6mm)stainless screwYesConcrete No 14 (6mm)stainless screw &plug,YesSteel work/ chequer plate 5.5mm Self-drilling screws,M6 machinescrew, nut& washer orpop/blind rivet(4.8 x 20stainless steel)YesOpen mesh/ grating ‘W’ clamp & M6machine screw/nut& washerNoInstallationIt takes no special training to install SAFE STEP® Matrix panels and treads however it is important that these instructions are followed carefully for maximum performancePast experience has shown that the following equipment may be required for the installation of SAFE STEP® Matrix.•Fixings•Hammer•Spanner•Tape measure•Construction adhesive•Jigsaw with metal cutting blades e.g.(Bosch T118A)•Hammer action drill with masonry & metal drill bits•Screwdriver•Chalk•Spirit level (For use as a straight edge) •Pop/blind rivet gunPanels Installation1. Before fixing the SAFE STEP®Matrixpanel it is important to ensure that the surface is clean, dry, free from dust /loose material and capable of holding a mechanical fixing.ROCOL Site Safety Systems ROCOL House, Swillington, Leeds, LS26 8BS, United Kingdom2. The surface should be checked to ensureit is not worn or uneven, this can be done by placing a straight edge (e.g. spirit level) on the surface. If the surface is worn or uneven then it should be levelled before the panel is installed.3. Place panel into desired position and usingchalk mark out any cuts required.4. The panel should be cut along thechannels of the grid pattern to the desired shape using a jigsaw fitted with a metal cutting blade. NB a small manual metal cutting blade can be used for small cuts 5. Place the panel into position. (Typically 12fixings would be recommended per panel 1150 x 750mm)6. All fixing points should be positioned at theaggregate free intersections.7. If the substrate is concrete, mark the fixingpoints by drilling through the panel and marking the surface of the concrete, taking care that the panels do not move during this process. Fixings should be positioned between 300-450mm centres and 50-75mm from the panel edges. Remove panel and using a masonry bit drill the pre-marked holes to the depth of the plug.8. Insert plugs9. Where applicable apply a 5-6mm widebead of construction adhesive to the underside of the panel 50mm inside the perimeter and also in a zig zag pattern across the main body. The coverage should be 250ml of construction adhesive per 1150 x 750 mm panel.Construction adhesive is recommended to provide sound-deadening properties.10. Re-position the panel, pressing firmlydown to ensure maximum overall contact of the adhesive and immediately secure into place with the appropriate fixings. Treads Installation1. Before fixing the SAFE STEP®Matrixtread it is important to ensure that the surface is clean, dry, free from dust /loose material and capable of holding a mechanical fixing.2. The surface should be checked to ensureit is not worn or uneven, this can be done by placing a straight edge (e.g. spirit level) on the surface. If the surface is worn or uneven then it should be levelled before the tread is installed.3. Place tread into desired position and usingchalk mark out any cuts required.4. The tread should be cut along thechannels of the grid pattern to the desired shape using a jigsaw fitted with a metal cutting blade. NB a small manual metal cutting blade can be used for small cuts 5. Place the tread into position. (Typically 8fixings would be recommended per tread 1200 x 280mm)6. All fixing points should be positioned at theaggregate free intersections.7. If the substrate is concrete, mark the fixingpoints by drilling through the treadwitha metal drill bit to mark the surface of the concrete, taking care that the treads do not move during this process. Fixings should be positioned between 300-450mm centres and 50-75mm from the treadROCOL Site Safety Systems ROCOL House, Swillington, Leeds, LS26 8BS, United Kingdomedges. Remove tread and using a masonry bit drill the pre-marked holes to the depth of the plug.8. Insert plugs9. Where applicable apply a 5-6mm widebead of construction adhesive to the underside of the tread 50mm inside the perimeter and also in a zig-zag pattern across the main body. The coverage should be 150ml of construction adhesive per linear metre of tread.Construction adhesive is recommended to provide sound-deadening properties.10. Re-position the tread, pressing firmly downto ensure maximum overall contact of the adhesive and immediately secure into place with the appropriate fixings. Should you require more specific installation details please contact our technical helpline.MaintenanceSAFE STEP® Matrix panels and treads should be regularly cleaned to prevent the accumulation of oil, grease, dirt and other contaminants on the walking surface which may reduce its anti-slip properties. To clean use either of the following methods:1. Warm water with a mild detergent and astrong bristled brush.2. Pressure jet cleaning (No more than 1000psi (68 bar) and up to 80°C is recommended to avoid damage to the wearing course).After cleaning, the surface should be thoroughly rinsed with clean water and left to dry before allowing back into service.Whilst SAFE STEP®Matrix has a high resistance to solvents, oils and chemicals, it is not recommended that these substances be used as cleaning agents.Accidental spillages of such substances should be immediately removed using either of the cleaning methods above.The use of mops is not recommended due to the textured antislip surface. Health & SafetyDue to the abrasive nature of the panels and treads, gloves should be worn when handling.When cutting or drilling the panels and treads gloves, goggles and dust mask should be worn.For specific advice regarding this product please contact our technical helpline.ROCOL Site Safety Systems ROCOL House, Swillington, Leeds, LS26 8BS, United Kingdom。
牵牛花的特点和外形,颜色作文
牵牛花的特点和外形,颜色作文英文回答：The characteristics and appearance of the cowslipflower are quite distinctive. Cowslips, also known as Primula veris, are herbaceous perennial plants that belongto the Primulaceae family. They are native to Europe andcan be found in meadows, pastures, and woodland areas.One of the most notable features of the cowslip floweris its vibrant and eye-catching colors. The petals of the cowslip can range from pale yellow to a deep golden hue, creating a beautiful contrast against its dark green leaves. The flowers are trumpet-shaped and have five petals, with a delicate fragrance that adds to their appeal.In terms of size, cowslip flowers are relatively small, measuring about 1 to 1.5 inches in diameter. Despite their small size, they often grow in clusters, creating astunning display of color. The flowers bloom in spring,usually from April to May, and their presence is a sign that warmer weather is on its way.The cowslip plant itself can grow up to 8 to 12 inches in height, with a rosette of basal leaves that are oval or lance-shaped. The leaves are wrinkled and have a slightly hairy texture. The plant has a fibrous root system that helps it absorb nutrients from the soil.The cowslip flower holds cultural significance in many countries. In English folklore, cowslips were associated with fairies and were believed to bring good luck. In the language of flowers, cowslips symbolize youth, grace, and purity.中文回答：牵牛花的特点和外形非常独特。
生活中的危险英语作文
生活中的危险英语作文Navigating the Perils of Life: An Exploration of Dangers and PrecautionsThe modern world is a complex tapestry, woven with both the promise of progress and the ever-present specter of risk. As we navigate the intricate pathways of our daily lives, we are constantly confronted with potential dangers that can threaten our well-being, our safety, and even our very existence. From the mundane hazards of everyday activities to the more extraordinary threats that can arise unexpectedly, the challenges we face are numerous and multifaceted.One of the most prevalent dangers we encounter in our lives is the threat of accidents. Whether it's a slip and fall in the workplace, a car collision on the road, or a household mishap, the potential for physical harm is ever-present. These incidents can result in debilitating injuries, costly medical expenses, and even long-term disabilities that can profoundly impact an individual's quality of life. Recognizing and mitigating these risks through proper safety protocols, vigilance, and the use of protective equipment is crucial in safeguarding ourselves and our loved ones.Another significant area of concern is the prevalence of crime and violence in our communities. From petty theft to violent assaults, the specter of criminal activity can cast a dark shadow over our daily lives. The psychological toll of living in fear, the financial burden of property loss or medical bills, and the societal impact of such acts can be devastating. Addressing this threat requires a multifaceted approach, encompassing effective law enforcement, community-based initiatives, and personal safety measures.In the digital age, the realm of cybersecurity has become a critical battleground, as we navigate the ever-evolving landscape of online threats. Identity theft, data breaches, and the proliferation of malware can have far-reaching consequences, compromising our financial security, personal information, and even our digital identities. Staying vigilant, employing robust cybersecurity measures, and educating ourselves on best practices are essential in safeguarding our digital well-being.The natural world, too, can pose its own set of dangers. Natural disasters, such as earthquakes, hurricanes, floods, and wildfires, can wreak havoc on our communities, causing widespread destruction, displacement, and loss of life. Preparedness, emergency planning, and resilience in the face of these events are crucial in mitigating the impact and ensuring the safety of individuals and communities.In the realm of public health, the emergence of infectious diseases, pandemics, and environmental hazards can also present significant risks to our well-being. From the devastating effects of a global pandemic to the long-term consequences of exposure to toxic substances, these threats can have far-reaching implications for our physical, mental, and emotional health. Proactive measures, such as robust public health systems, preventive healthcare, and environmental regulations, are essential in addressing these challenges.Navigating the complexities of life's dangers requires a multifaceted approach that combines vigilance, preparedness, and a deep understanding of the risks we face. By embracing a culture of safety, fostering community resilience, and continuously adapting to the evolving landscape of threats, we can empower ourselves and our loved ones to navigate the perils of life with greater confidence and resilience. It is only through this holistic and proactive approach that we can truly safeguard our well-being and create a safer, more secure world for all.。
adams_car通讯器-推荐下载
Communicators in the Suspension Test RigThe following tables describe the input and output communicators in the suspension test rig (.__MDI_SUSPENSION_TESTRIG). In the tables, the notation:[lr] indicates that there is both a left and right communicator of the specified name, as in ci[lr]_camber_angle.s indicates a single communicator, as in cis_steering_rack_joint.Communicators in the Suspension Test RigThe communicators Belongs to theclass Form minorrolereceivesci[lr]_camber_angle parameter_real Any Camber angle value from thesuspension subsystem. Sets the correctorientation of the test rig wheels.ci[lr]_diff_tripot location any Location of the differentialci[lr]_toe_angle parameter_real any Toe angle value from the suspensionsubsystem. Sets the correct orientationof the test rig wheels.ci[lr]_suspension_mount mount any Part to which the test rig wheels canattach.ci[lr]_suspension_upright mount Any Upright part from suspensionsubsystem.ci[lr]_jack_frame mount Any Not matched (fixed to ground).ci[lr]_wheel_center location Any Location of the wheel center from thesuspension subsystem. Test rig wheelsattach to the suspension at that location. cis_driveline_active parameter_integer Any Integer value stored in the suspensiontemplate/subsystem that indicates theactivity of the drivetrain.cis_powertrain_to_body mount Any Part to which differential outputs areconstrained.cis_leaf_adjustment_steps parameter_integer Any Integer value stored in the leaf springtemplate (currently not available).cis_steering_rack_joint joint_for_motion Any Steering-rack translational joint fromthe steering subsystem.cis_steering_wheel_joint joint_for_motion Any Steering-wheel revolute joint from thesteering subsystem.cis_suspension_parameters_ARRAY array any Array used in the suspensioncharacteristic calculations; comes fromthe suspension subsystems Output Communicators in Suspension Test RigThe communicators Belongs to theclass Form minorroleoutputscos_leaf_adjustment_multiplier array Any Leaf Spring toolkit. It is currently notsupported in the standard product. cos_characteristics_input_ARRAY array Any Suspension, vehicle, and test-rigparameters array IDs used bysuspension characteristics calculationsroutines.co[l,r]_tripot_to_differential mount any Outputs the ge[lr]_diff_output parts. cos_tire_forces_array_left Array Any Outputs array of Adams IDs used bythe conceptual suspension module. cos_tire_forces_array_right array any Outputs array of Adams IDs used bythe conceptual suspension module.Communicators in the SDI Test RigThe following tables describe the input and output communicators in the SDI test rig(.__MDI_SDI_TESTRIG). In the tables, the notation [lr] indicates that there is both a left and rightcommunicator of the specified name.Input Communicators in SDI Test RigThe communicators Belongs to theclass Form minorrolereceivescis_body_subsystem mount inherit Output from the body subsystem. Itindicates the part that represents thebody.cis_chassis_path_reference marker Any Marker from the body subsystem. It isused to measure path, roll, and sidesliperror in a constant radius corneringmaneuver.cis_driver_reference marker any Marker from the body subsystem. It isused in Adams/SmartDriversimulations.cis_engine_rpm solver_variable Any Adams/Solver variable for enginerevolute speed, in rotations per minute,from the powertrain subsystem.cis_engine_speed solver_variable any Adams/Solver variable for enginerevolute speed, in radians per second,from the powertrain subsystem.cis_measure_for_distance marker Marker used to measure the distancetraveled in the forward direction of thevehicle, from the body subsystem.cis_diff_ratio parameter_real Real parameter variable for final driveratio, from the powertrain subsystem.cis_steering_rack_joint joint_for_motion front Steering-rack translational joint fromthe steering subsystem.cis_steering_wheel_joint joint_for_motion front Steering-wheel revolute joint from thesteering subsystem.cis_max_brake_value parameter_real Output from brake subsystem(maximum brake signal value).cis_max_engine_speed parameter_real Output from powertrain subsystem(maximum engine rpm value).cis_max_gears parameter_integer Output from powertrain (maximumnumber of allowed gears).cis_max_rack_displacement parameter_real Output displacement limits fromsteering subsystem. Used by theStandard Driver Interface.cis_max_rack_force parameter_real Output force limits from steeringsubsystem. Used by the StandardDriver Interface.cis_max_steering_angle parameter_real Output angle limits from steeringsubsystem. Used by the StandardDriver Interface.cis_max_steering_torque parameter_real Output from steering subsystem.cis_max_throttle parameter_real Output from powertrain (maximumvalue of throttle signal).cis_min_engine_speed parameter_real Output from powertrain subsystem(minimum engine rpm value, used forshifting strategy).cis_rotation_diff diff Output from powertrain (it is adifferential equation used to measurecrankshaft acceleration; its integral isused for engine rpm).cis_transmission_spline spline Spline for transmission gears (outputfrom powertrain: reduction ratios forevery gear).cis_transmission_input_omega solver_variable The transmission input engine variablefrom the powertrain template.cis_clutch_diff diff Clutch slip differential equation fromthe powertrain template.cis_clutch_displacement_ic solver_variable The clutch initial displacement (enginecrankshaft torque at static equilibrium)from the powertrain template.ci[lr]_front_suspension_mount mount front The hub parts (wheel carriers) fromsuspension templates (front and rear) ci[lr]_rear_suspension_mount rear The hub parts (wheel carriers) fromsuspension templates (front and rear) Output Communicators in SDI Test RigThe communicators Belongs to theclass Form minorroleoutputscos_brake_demand solver_variable Any Brake demand to the brake subsystem. cos_clutch_demand solver_variable Any Clutch demand to the powertrainsubsystem.cos_desired_velocity solver_variable any Desired velocity Adams/Solvervariable. Other subsystems canreference it.cos_initial_engine_rpm parameter_real Any Initial engine RPM real variable to thepowertrain subsystem.cos_throttle_demand solver_variable any Throttle demand to the powertrainsubsystem.cos_transmission_demand solver_variable Transmission (gear) demand to thepowertrain subsystem.cos_sse_diff1diff Differential equation computed duringquasi-static prephase, used to controlthe vehicle longitudinal dynamics. cos_std_tire_ref location X,Y,Z location of standard tirereference marker (positionedappropriately at the correct height,including 2% of road penetration).Matching Communicators with Test RigsWhen you create a template, you must meet the following conditions to ensure that an analysis willwork with your new template:2.If the template is a suspension template (for example, its major role is suspension), the template mustcontain a suspension parameters array. The suspension parameters array identifies to the suspensionanalysis how the steer axis should be calculated and whether the suspension is independent ordependent.1.The template must be compatible with other templates and with the test rigs, for example, the.__MDI_SUSPENSION_TESTRIG. The template must also contain the proper output communicators.For example, for a suspension template to be compatible with the suspension test rig, the suspensiontemplate must contain either the mount or the upright output communicators. In the following table, the notation [lr] indicates that there is both a left and right communicator of the specified name.Output Communicators in Suspension TemplatesThe communicators Belongs to theclass Form minorrolereceivesco[lr]_suspension_mount mount inherit suspension_mountco[lr]_suspension_upright mount inherit suspension_uprightco[lr]_wheel_center location inherit wheel_centerco[lr]_toe_angle parameter_real inherit toe_angleco[lr]_camber_angle parameter_real inherit camber_angle The co[lr]_suspension_mount output communicators publish the parts to which the test rig wheels should mount. As you create these communicators, ensure that you set their minor role to inherit. Bysetting the minor role to inherit, the communicator takes its minor role from the minor role of the subsystems that use your suspension template.The co[lr]_wheel_center output communicators publish the location of the wheel centers to the test rig so the test rig can locate itself relative to the suspension. As you create these types of communicators, make sure that you also leave their minor role set to inherit.The toe and camber communicators (co[lr]_toe_angle and co[lr]_camber_angle) publish, to the test rig, the toe and camber angles set in the suspension so that the test rig can orient the wheels correctly.。
滑坡英语作文翻译
滑坡英语作文翻译Title: Landslide A Natural Disaster。
A landslide, also known as landslip, is the movement of a mass of rock, debris, or earth down a slope. It is a natural disaster that can occur suddenly, often triggered by factors such as heavy rainfall, earthquakes, volcanic activity, or human activities like deforestation and construction. When a landslide happens, it can cause significant damage to property, infrastructure, and even loss of lives.The primary cause of landslides is the force of gravity acting upon the slope. When the gravitational force exceeds the strength of the materials holding the slope together, instability occurs, leading to a landslide. Rainfall, particularly heavy or prolonged rainfall, is one of the most common triggers for landslides. The water saturates the soil, increasing its weight and reducing its stability, making it more susceptible to movement.In addition to rainfall, earthquakes can also trigger landslides. The ground shaking caused by an earthquake can loosen rocks and soil, causing them to slide down slopes. Volcanic activity, such as eruptions or lava flows, can destabilize slopes by altering the composition of the land or creating new slopes.Human activities can also contribute to landslides. Deforestation, for example, removes trees and vegetation that help hold soil in place, increasing the risk of erosion and landslides. Construction activities, such as excavation or slope cutting, can weaken slopes and make them more prone to failure.The effects of landslides can be devastating. They can destroy homes, roads, bridges, and other infrastructure, disrupting communities and causing economic losses. Landslides can also result in loss of life, as people may be buried or trapped beneath the debris.Preventing landslides requires a combination ofmeasures, including land-use planning, slope stabilization, and early warning systems. Land-use planning involves identifying areas prone to landslides and implementing zoning regulations to restrict development in high-risk areas. Slope stabilization techniques, such as installing retaining walls, drainage systems, and vegetation cover, can help reduce the risk of landslides. Early warning systems, which monitor factors such as rainfall, ground movement, and seismic activity, can provide timely alerts to communities at risk, allowing them to evacuate safely.In conclusion, landslides are natural disasters that can have devastating consequences. They are often triggered by factors such as heavy rainfall, earthquakes, volcanic activity, or human activities like deforestation and construction. Preventing landslides requires a combination of measures, including land-use planning, slope stabilization, and early warning systems. By taking proactive steps to mitigate the risk of landslides, communities can reduce the impact of this destructive phenomenon.。
镁合金织构与各向异性
镁合金织构与各向异性第１５卷第１期Ｖ０１．１５Ｎｏ．１中国有色金属学报ＴｈｅＣｈｉｎｅｓｅ２００５年１月Ｊａｎ．２００５ＪｏｕｒｎａｌｏｆＮｏｎｆｅｒｒｏＢｓＭｅｔａｌｓ文章编号：１００４—０６０９（２００５）０１—０００１—１１镁合金织构与各向异性①陈振华，夏伟军，程永奇，傅定发（湖南大学材料科学与工程学院，长沙４１００８２）摘要：介绍了镁合金变形及退火织构的组分与特点，论述了在挤压、轧制、等径角挤压等塑性变形及退火过程中镁合金织构的演变规律及形成机理，分析了织构与镁合金力学性能的基本关系，探讨了合金元素、变形温度、应变速度、外加应力及晶粒度等基本因素对镁合金织构特征与各向异性的影响。
结果表明：织构对镁合金力学性能的影响，其实质是通过改变各滑移系特别是｛０００１｝［１１酌］基面滑移系的Ｓｃｈｍｉｄ因子、产生织构强化或软化而实现的。
关键词：镁合金；织构；塑性变形；各向异性；力学性能中图分类号：ＴＧｌ４６．２文献标识码：ＡＴｅｘｔｕｒｅａｎｄａｎｉｓｏｔｒｏｐｙｉｎｍａｇｎｅｓｉｕｍａｌｌｏｙｓＣＨＥＮＺｈｅｎ－ｈｕａ，ＸＩＡＷｅｉ－ｊｕｎ，ＣＨＥＮＹｏｎｇ—ｑｉ，ＦＵＤｉｎｇ—ｆａ（ＳｃｈｏｏｌｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎｇ，ＨｕｎａｎＵｎｉｖｅｒｓｉｔｙ，Ｃｈａｎｇｓｈａ４１００８２，Ｃｈｉｎａ）Ａｂｓｔｒａｃｔ：Ｔｈｅｃｈａｒａｃｔｅｒｉｓｔｉｃｓａｎｄｃｏｍｐｏｎｅｎｔｓｏｆｔｈｅｆｏｒｍａｔｉｏｎａｎｄｅｖｏｌｕｔｉｏｎｏｆｔｅｘｔｕｒｅｓｔｅｘｔｕｒｅｓｉｎｍａｇｎｅｓｉｕｍａｌｌｏｙｓｗｅｒｅｐｒｅｓｅｎｔｅｄ．Ｔｈｅｍｅｃｈａｎｉｓｍｏｆａｓｄｕｒｉｎｇｐｌａｓｔｉｃｄｅｆｏｒｍａｔｉｏｎｓｕｃｈｂｙｅｘｔｒｕｓｉｏｎ，ｒｏｌｌｉｎｇ，ｅｑｕａｌｃｈａｎｎｅｌａｎｇｌｅｔｈｅｅｆｆｅｃｔｓｏｆｔｅｘｔｕｒｅｓｏｎｅｘ—ｔｒｕｓｉｏｎｐｒｏｃｅｓｓｅｓａｎｄａｎｎｅａｌｉｎｇｗｅｒｅｒｅｖｉｅｗｅｄ，ｆｏｌｌｏｗｅｄｐｒｏｐｅｒｔｉｅｓｏｆｓｔｒａｉｎ，ｓｔｒａｉｎｔｈａｔｔｅｘｔｕｒｅｓｔｈｅａｎａｌｙｓｉｓｏｆａｓｍｅｃｈａｎｉｃａｌｍａｇｎｅｓｉｕｍａｌｌｏｙｓ．Ｔｈｅｉｎｆｌｕｅｎｃｅｓｏｆｍａｉｎｆａｃｔｏｒｓｓｕｃｈｒａｔｅａｌｌｏｙｅｌｅｍｅｎｔｓ，ｄｅｆｏｒｍａｔｉｏｎｔｅｍｐｅｒａｔｕｒｅ，ａｎｄｇｒａｉｎｓｉｚｅｏｎｔｅｘｔｕｒｅａｎｄａｎｉｓｏｔｒｏｐｙｏｆｍａｇｎｅｓｉｕｍａｌｌｏｙｓｗｅｒｅｄｉｓｃｕｓｓｅｄ．ＴｈｅｒｅｓｕｌｔｓｓｈｏｗａｆｆｅｃｔｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｍａｇｎｅｓｉｕｍａｌｌｏｙｓｍａｉｎｌｙｂｙａｌｔｅｒｉｎｇｔｈｅＳｃｈｍｉｄｆａｃｔｏｒｓｏｆａｌｌｓｌｉｐｓ，ａｓ—ｓｔｒｅｎｇｔｈｅｎｉｎｇａｎｄｓｏｆｔｅｎｉｎｇ．ｐｅｃｉａｌｌｙｂａｓａｌｓｌｉｐｓｙｓｔｅｍｓａｎｄｉｎｄｕｃｉｎｇｔｅｘｔｕｒｅＫｅｙｗｏｒｄｓ：ｍａｇｎｅｓｉｕｍａｌｌｏｙｓ；ｔｅｘｔｕｒｅ；ｐｌａｓｔｉｃｄｅｆｏｒｍａｔｉｏｎ；ａｎｉｓｏｔｒｏｐｙ；ｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓ制约变形镁合金发展的主要原因在于其较差的室温塑性变形能力，如何在较大程度上改善镁合金的塑性已成为人们关注的焦点。
怎样关爱老年人英语作文80词初三
怎样关爱老年人英语作文80词初三全文共3篇示例，供读者参考篇1How to Care for the ElderlyCaring for the elderly is an important responsibility that we should not take lightly. As people grow older, they may become more vulnerable and in need of assistance in various aspects of their lives. Here are some ways in which we can show our love and care for the elderly:1. Spend quality time with them: One of the best ways to show your love and care for the elderly is by spending time with them. Take the time to sit and chat with them, listen to their stories, and show interest in their lives. Simply being there for them can bring them a lot of happiness.2. Help them with daily tasks: As people age, they may find it more difficult to perform certain tasks, such as cooking, cleaning, or running errands. Offer your assistance to help them with these activities, and make their lives a little easier.3. Stay connected: In today's busy world, it's easy to lose touch with loved ones, especially the elderly. Make an effort tostay connected with them through phone calls, visits, or even simple gestures like sending a card or a small gift.4. Encourage physical activity: Encouraging the elderly to stay active and exercise regularly can have a positive impact on their physical and mental well-being. Help them find activities that they enjoy, such as walking, gardening, or yoga.5. Show patience and understanding: As people age, they may experience changes in their health or behavior. It's important to show patience and understanding in these situations, and to offer support and comfort when needed.6. Ensure their safety and well-being: Make sure that the elderly have a safe and comfortable living environment. Take steps to prevent accidents and injuries, and stay alert to any signs of health problems that may require medical attention.7. Respect their independence: While it's important to care for the elderly, it's also crucial to respect their independence and autonomy. Allow them to make their own decisions and choices whenever possible, and provide assistance only when needed.In conclusion, caring for the elderly is a meaningful and rewarding endeavor that can make a big difference in their lives. By showing love, patience, and support, we can help the elderlyfeel valued and appreciated, and ensure that they enjoy a happy and fulfilling life. Let's make an effort to care for the elderly in our communities and show them the love and respect they deserve.篇2How to Care for the ElderlyCaring for the elderly is an important responsibility that we should all take seriously. As people get older, they may require more assistance and support in their daily lives. Here are some ways to show love and care for the elderly:1. Spend quality time with them: One of the best ways to show your love and care for the elderly is to spend quality time with them. Listen to their stories, play games with them, or simply sit and chat with them. This can help them feel valued and appreciated.2. Help with daily tasks: Many elderly people may have difficulty with daily tasks such as cooking, cleaning, or running errands. Offer to help out with these tasks to make their lives easier and more comfortable.3. Show respect and patience: It's important to show respect and patience when interacting with the elderly. Remember thatthey may have different needs and limitations, so it's important to be understanding and compassionate.4. Encourage physical activity: Encouraging the elderly to stay active can have numerous health benefits. Encourage them to go for walks, do light exercises, or participate in activities that they enjoy.5. Provide emotional support: As people age, they may face feelings of loneliness or isolation. Providing emotional support and being there to listen can make a big difference in their overall well-being.6. Keep them connected: Help the elderly stay connected with friends and family members. Whether it's through phone calls, video chats, or in-person visits, staying connected can help alleviate feelings of loneliness.7. Ensure their safety and well-being: It's important to ensure the safety and well-being of the elderly. Make sure their living environment is safe and comfortable, and encourage them to seek medical help if needed.In conclusion, caring for the elderly is a noble and important task that requires love, patience, and understanding. By following these tips, you can show your love and care for theelderly in a meaningful and impactful way. Let's all do our part to ensure that our elderly loved ones feel valued and supported.篇3How to Care for the ElderlyCaring for the elderly is an important aspect of our society. They have contributed so much to our lives and deserve to be treated with respect and kindness. Here are some ways to show our love and care for the elderly:1. Spend time with them: One of the best ways to show love and care for the elderly is to spend quality time with them. Whether it's having a meal together, going for a walk, or simply sitting and chatting, being present and attentive to their needs is a great way to show you care.2. Listen to them: The elderly have a wealth of wisdom and stories to share. Take the time to listen to them, ask about their experiences and opinions, and show that you value their knowledge and insight.3. Help with practical tasks: As people age, they may find it harder to carry out everyday tasks. Offer to help with shopping, cleaning, cooking, or other practical tasks to make their lives easier and more comfortable.4. Show patience and understanding: Aging can bring a lot of physical and emotional challenges. Show patience and understanding towards the elderly, especially when they may be feeling frustrated, anxious, or lonely.5. Keep them engaged: Encourage the elderly to stay active and engaged with activities that interest them. This could be anything from reading, puzzles, gardening, or even learning a new skill or hobby.6. Show affection: A simple hug, kiss, or hand-holding can goa long way in showing your love and care for the elderly. Physical touch can be reassuring and comforting, especially for those who may feel lonely or isolated.7. Respect their preferences: Everyone has different preferences and needs. Respect the elderly's choices and wishes, whether it's about food, activities, or daily routines.8. Ensure their safety: Make sure that the elderly are living ina safe and secure environment. Install handrails, non-slip mats, and ensure that their living space is well-lit and clutter-free to prevent accidents.9. Stay connected: Keep in touch with the elderly regularly, through phone calls, visits, or video chats. Let them know that you are thinking of them and care about their well-being.10. Seek professional help if needed: If the elderly need medical or emotional support, don't hesitate to seek professional help. Make sure they have access to healthcare services, counseling, or other support systems that they may need.In conclusion, caring for the elderly is an important responsibility that we should all take seriously. By showing love, respect, and kindness towards the elderly, we can make a positive impact on their lives and create a more compassionate and caring society.。
建议他通过做运动来强身健体作文英语翻议
建议他通过做运动来强身健体作文英语翻议全文共3篇示例，供读者参考篇1Staying Fit Through ExerciseHey man, it's your buddy here. I wanted to talk to you about something really important - your health. I know, I know, you're probably thinking "Here he goes again, nagging me about my lifestyle choices." But hear me out, because this isn't just another lecture. This is me, your friend, giving you some real talk about why you need to start taking your fitness seriously.Let's be honest, we're not getting any younger. Those days of eating whatever we wanted and never gaining a pound are long gone. Nowadays, it feels like just looking at a cheeseburger puts an extra inch on my waistline. And I know you've been feeling it too – the sluggishness, the lack of energy, the constant feeling of being out of shape.But it doesn't have to be this way, dude. We can turn things around, and it all starts with making exercise a regular part of our lives. I'm not talking about becoming hardcore gym rats or anything like that (unless you're into that sort of thing, nojudgment). Just simple, consistent physical activity can work wonders for our overall health and well-being.Think about it – when was the last time you felt truly energized, ready to take on the world? For me, it's been way too long. But I've started incorporating regular exercise into my routine, and let me tell you, the difference is night and day. After a good workout, I feel alive, like I can conquer anything that comes my way. And the best part? That feeling of accomplishment and pride in taking care of myself – it's addictive in the best possible way.And it's not just about the physical benefits, either. Exercise has been shown to do wonders for our mental health too. You know how sometimes we get caught up in our own heads, overthinking everything and stressing ourselves out? A good sweat session can be the perfect antidote to that. It's like hitting a reset button on our minds, allowing us to come back feeling refreshed, focused, and ready to tackle whatever life throws our way.But don't just take my word for it. Look at all the successful people out there who swear by the power of exercise. CEOs, athletes, celebrities – they all make time for it because they knowhow crucial it is for peak performance. And let's be real, we could all use a little more peak performance in our lives, am I right?So, what do you say, buddy? Are you ready to join me on this fitness journey? It doesn't have to be anything crazy – we can start small, with just a few sessions a week. Maybe we could even make it a thing, hitting the gym or going for a run together. Not only would it hold us accountable, but it would also give us a chance to catch up and have some good old-fashioned bro time.And who knows, maybe once we start feeling the benefits of regular exercise, we'll get inspired to take things to the next level. We could start trying different workout styles, like yoga or kickboxing, or even sign up for a local sports league. The possibilities are endless when you've got a solid foundation of fitness to build upon.Look, I get it – changing habits is tough, especially when it comes to something as fundamental as our daily routines. But think about how amazing it would feel to finally shed those extra pounds, to have more energy and confidence, to really start living our best lives. Isn't that worth pushing through the initial discomfort and making some sacrifices?At the end of the day, it all comes down to priorities. We can either keep coasting along, letting our health slowly deteriorate,or we can take control and make a conscious decision to invest in ourselves. And honestly, what could be more important than that?So, what do you say, buddy? Are you ready to get fit and start feeling like the best versions of ourselves? I'll be right there with you, every step of the way. Let's do this, man – for our health, for our happiness, and for the chance to finally feel like we're living life to the fullest.Your friend,[Your Name]篇2Title: Get Fit Through ExerciseDear friend,I know you've been feeling a bit down lately about your health and fitness levels. Believe me, I totally get it. With all the demands of school, work, family, and social life, it can be really tough to find the time and motivation to exercise regularly. But I'm writing to you today to encourage you to make a change and incorporate physical activity into your daily routine. Trust me, the benefits of exercise are absolutely worth the effort.Let's start with the obvious: exercise is crucial for maintaining a healthy body weight and preventingobesity-related health issues like heart disease, diabetes, and certain cancers. I know you've been self-conscious about the extra pounds you've put on lately, and exercise is the most effective way to burn calories and shed those unwanted pounds. But it's not just about looking good on the outside – regular exercise also strengthens your cardiovascular system, improves muscle tone and flexibility, and boosts your overall energy levels. Imagine how much better you'll feel when you're not constantly feeling sluggish and out of shape!But the benefits of exercise go far beyond just physical health. Did you know that it can also have a profound impact on your mental well-being? Exercise releases endorphins, those natural feel-good chemicals in your brain, which can improve your mood and reduce symptoms of anxiety and depression. In our increasingly stressful world, having a healthy outlet to relieve tension and clear your mind is absolutely invaluable.And let's not forget about the cognitive benefits of exercise. Regular physical activity has been shown to improve memory, concentration, and overall brain function. As students, we could definitely use all the help we can get in that department, am Iright? Exercise can also boost your self-confidence andself-esteem, as you start to feel better about your body and your ability to accomplish physical goals.Now, I know what you're thinking: "But I don't have time to go to the gym every day!" And that's totally understandable. But here's the thing – you don't have to engage in intense workouts or join a fancy gym to reap the benefits of exercise. Even small changes in your daily routine can make a big difference.For example, you could start by taking the stairs instead of the elevator whenever possible. Or you could go for a brisk walk during your lunch break or after dinner. Alternatively, you could try some simple bodyweight exercises like push-ups, squats, and lunges right in your own living room. The key is to find activities that you actually enjoy and that fit seamlessly into your lifestyle.And don't forget about the social aspect of exercise. Why not invite some friends to join you for a game of basketball, a hike in the local park, or even just a leisurely bike ride around the neighborhood? Not only will you be getting in some physical activity, but you'll also be strengthening your social connections, which are so important for overall happiness and well-being.I know that starting a new exercise routine can be intimidating, especially if you're not used to being active. Butremember, Rome wasn't built in a day. Start small and gradually increase the intensity and duration of your workouts as you become more comfortable. And don't be too hard on yourself if you slip up or miss a few days – just get back on track as soon as you can.Ultimately, the decision to make exercise a priority is up to you. But I truly believe that incorporating physical activity into your life will not only improve your physical health, but also your mental and emotional well-being. You deserve to feel your best, and exercise is a proven way to achieve that.So, what do you say, my friend? Are you ready to take the first step towards a healthier, happier you? I'll be right there with you, cheering you on every step of the way. Let's do this together!Your friend,[Your Name]篇3Title: The Road to Fitness: Embracing Exercise for a Healthier LifeDear friend,I hope this letter finds you well. I wanted to take a moment to share my thoughts and experiences regarding physical fitness and the transformative power of exercise. As someone who has witnessed firsthand the incredible benefits of an active lifestyle, I cannot emphasize enough the importance of making exercise a part of your daily routine.Let's start with the obvious: exercise is crucial for maintaining a healthy body weight and reducing the risk of obesity-related illnesses such as heart disease, stroke, and type 2 diabetes. However, the advantages of regular physical activity extend far beyond just weight management. Exercise has been proven to have a profound impact on our overall well-being, both physically and mentally.Physically, exercise strengthens our cardiovascular system, improves muscle tone and flexibility, and enhances our endurance levels. It's like giving our bodies a tune-up, ensuring that all the intricate systems are operating at their optimal levels. Regular exercise can even help to alleviate chronic pain conditions, such as lower back pain and arthritis, by improving joint mobility and reducing inflammation.But the benefits of exercise aren't limited to just the physical realm. There is a wealth of scientific evidence that highlights thepositive impact of exercise on our mental health as well. Regular physical activity has been shown to reduce symptoms of anxiety and depression, boost mood and self-esteem, and improve cognitive function and memory. It's like a natural antidepressant and mood enhancer, without the potential side effects of medication.Personally, I can attest to the transformative power of exercise on my own life. Just a few years ago, I found myself stuck in a sedentary lifestyle, feeling lethargic, and lacking motivation. It wasn't until I decided to take control of my health and incorporate exercise into my daily routine that I experienced a remarkable shift.At first, it was challenging to find the time and energy to exercise regularly. But as I persisted, I noticed a gradual improvement in my overall energy levels, mood, and confidence. The endorphins released during exercise became my natural high, leaving me feeling invigorated and accomplished after each workout session.Moreover, the discipline and dedication required to maintain an exercise routine spilled over into other aspects of my life. I found myself becoming more productive, focused, and betterable to manage stress. It was as if exercise had unlocked a hidden reservoir of resilience and determination within me.Now, I can't imagine my life without regular physical activity. Whether it's going for a brisk walk, hitting the gym, or participating in a group fitness class, exercise has become an integral part of my daily routine, a sacred ritual that nourishes my body, mind, and spirit.Friend, I understand that starting an exercise routine can be daunting, especially if you've been inactive for a long time. The thought of stepping into a gym or lacing up your running shoes can be intimidating. But I implore you to take that first step, no matter how small it may seem.Start slowly and gradually increase the intensity and duration of your workouts. Seek out activities that you genuinely enjoy, whether it's swimming, cycling, dancing, or joining a local sports team. The key is to find something that you look forward to and that doesn't feel like a chore.Remember, consistency is key. While it may be tempting to embark on an overly ambitious fitness regimen, it's essential to adopt a sustainable approach that you can realistically maintain over time. Consistency breeds habit, and habit breeds lifestyle change.Surround yourself with a supportive network of friends, family, or a fitness community that can encourage and motivate you along your journey. Having accountability partners can make a world of difference when the going gets tough.Lastly, be patient and celebrate your progress, no matter how small. Improving your physical fitness is a journey, not a destination. There will be setbacks and challenges along the way, but if you persevere and remain dedicated, the rewards will be immeasurable.Friend, I urge you to embrace the power of exercise and take control of your health and well-being. The road ahead may be challenging, but the benefits – improved physical health, mental clarity, and an overall sense of vitality – are well worth the effort. Trust me; your future self will thank you for taking this step towards a healthier, happier life.Wishing you the best of luck on your fitness journey,[Your Name]。
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Acta Materialia 51(2003)2055–2065The activity of non-basal slip systems and dynamic recovery at room temperature in fine-grained AZ31B magnesiumalloysJ.Koike a,∗,T.Kobayashi a ,T.Mukai b ,H.Watanabe b ,M.Suzuki a ,K.Maruyama a ,K.Higashi caDepartment of Materials Science,Tohoku University,Sendai 980-8579,JapanbDepartment of Mechanical Engineering,Osaka Municipal Technical Research Institute,Joto-ku,Osaka 536-8553,Japan cDepartment of Metallurgy and Materials Science,Osaka Prefecture University,Sakai,Osaka 599-8531,JapanReceived 14March 2002;accepted 20December 2002AbstractFine-grained alloys of Mg-3Al-1Zn-0.2Mn in wt.%(AZ31B)were obtained by an equal-channel angular extrusion technique and subsequent annealing at elevated temperatures.Tensile tests were performed at room temperature at a strain rate of 1x10-3s -1.The alloys exhibited an apparent steady-state deformation region and a large tensile elongation of 47%.The deformed microstructure at an elongation of 2%indicated substantial cross-slip to non-basal planes induced by plastic compatibility stress associated with grain boundaries.The non-basal segment of dislocations was found to consist of 40%of the total dislocation density at a yield anisotropy factor of only 1.1instead of an expected value of 100obtained from single-crystal experiments.The deformed microstructure at an elongation of 16%indicated recovered regions within twins as well as untwinned matrices.These results indicate that dynamic recovery can occur in Mg alloys at room temperature.2003Acta Materialia Inc.Published by Elsevier Science Ltd.All rights reserved.Keywords:Magnesium;Mechanical properties;Microstructure;Dislocations1.IntroductionMg and its alloys have been perceived to have poor ductility and poor cold workability.There-fore,practical Mg alloys having complicated shapes are often produced by casting routes with no or minimal mechanical processing.However,∗Corresponding author.Tel./fax:+81-22-217-7325.E-mail address:koikej@material.tohoku.ac.jp (J.Koike).1359-6454/03/$30.00 2003Acta Materialia Inc.Published by Elsevier Science Ltd.All rights reserved.doi:10.1016/S1359-6454(03)00005-3most of the cast Mg alloys exhibit a tensile elong-ation of only a few percent,making them mechan-ically less reliable than other alloys for structural applications.Also,the size of cast pieces is limited by solidification speed.If ductility could be improved to an extent that shape forming becomes possible near ambient temperature,large structural components of Mg alloys could be produced at substantially lower cost and could be utilized for much wider applications,such as automobile parts.The poor ductility of Mg alloys has been attri-2056J.Koike et al./Acta Materialia51(2003)2055–2065buted to highly anisotropic dislocation slip behavior.Critical resolved shear stresses(CRSS) have been reported for three different slip systems in single crystal Mg[1–4].According to the reported data,the CRSS of a basal slip system at room temperature is approximately1/100those of non-basal slip systems on prismatic and pyramidal planes.Therefore,plastic deformation in polycrys-talline alloys has been thought to occur almost entirely by basal slip.If this is the case,the basal slip system provides only two independent slip sys-tems,far fewer than the necessaryfive independent systems for homogeneous deformation.On the other hand,some cast alloys exhibit a reasonable ductility with a tensile elongation of more than 10%at room temperature[5].In a recent study using an equal-channel-angular extrusion(ECAE) technique,Yamashita et al.reported the effects of grain size on tensile elongation[6].They found that elongation-to-failure increased up to15% when grain size was reduced from400to17µm. Mukai et al.also applied the ECAE technique to a Mg-3Al-1Zn-0.2Mn(AZ31B)alloy to further reduce the grain size to1µm.After annealing,this alloy exhibited a tensile elongation of more than 40%at room temperature[7].Such large elong-ation values cannot be expected if the basal slip system is the sole mechanism of plastic defor-mation.Moreover,the grain-size dependence of tensile elongation suggests that the effects of grain boundaries may play an important role in defor-mation at room temperature.The purpose of the present work is to understand characteristic deformation mechanisms of polycry-stalline alloys and to provide satisfactory interpret-ation of a large tensile ductility in the ECAE-pro-cessed alloys of AZ31B.We focused on investigating the evolution of deformation micro-structure with increasing tensile strain.Obtained results indicated that cross-slipping of a dislo-cations to non-basal planes was significantly active as a result of grain-boundary compatibility stresses and that dynamic recovery took place during ten-sile deformation.Thesefindings deviate substan-tially from traditional views of deformation mech-anisms and yield phenomena in Mg alloys and may pave a way for shape forming at ambient tempera-ture.2.Experimental procedureSamples were AZ31B Mg alloys having a chemical composition of Mg-3Al-1Zn-0.2Mn in wt.%.An ECAE process was carried out at473K for eight passes using a die with a90°channel.The ECAE-processed samples were annealed at573K for24h,followed by cooling to room temperature. Crystallographic texture distribution of the annealed sample was examined by an X-ray dif-fractometer(XRD)from two cross-sectional planes,one cut parallel to the extrusion direction and the other cut perpendicular to the extrusion direction.Tensile tests were performed at room temperature at a constant cross-head speed.Initial strain rate was set at1x10-3s-1.Tensile direction was parallel to the extrusion direction of the ECAE process.The microstructure was observed by a trans-mission electron microscope(TEM)after annealing,and after deformation to2%and to 16%.TEM samples were prepared by cutting the deformed samples perpendicular to the tensile axis. The cut disks were mechanically ground to less than100µm in thickness,followed by dimple-grinding the disk center to less than20µm in thickness.Finally,the samples were ion-milled to perforation at an ion accelerating voltage of3kV. Two types of TEM experiments were performed in several grains of different orientations.For thefirst type of experiment,Kikuchi diffraction patterns were taken from these grains at a sample tilt angle of0°.In this condition,an incident electron beam was parallel to the tensile axis.Analysis of the pat-terns provided the crystallographic orientation of the tensile axis as well as the direction of possible slip planes and slip directions for each grain.From the obtained orientation data,Schmid factors for the possible slip systems were calculated.Then,the following relation was used to estimate yield ani-sotropy[8]m NBSm BSϭm NBS sm BS sϭt NBSt BS.Here,s is the externally applied stress;t is the critical resolved shear stress;and m is the Schmid factor.The subscripts of NBS and BS represent,2057J.Koike et al./Acta Materialia 51(2003)2055–2065respectively,a non-basal slip system and a basal slip system.In the second type of TEM experiment,samples were tilted in such a way that the incident beamdirection was aligned parallel to either the [011¯0]direction or the [2¯110]direction.In this condition,the basal planes were set parallel to the incident electron beam direction.Dislocations in a basal-slip system could then be easily distinguished from those in a non-basal slip ly,dislo-cations parallel to a basal-plane trace were in the basal-slip system,whereas other dislocations were in the non-basal slip system.The length of dislo-cation segments in both basal and non-basal slip systems was measured from the TEM images to provide quantitative information of dislocation density in each slip system.3.Results3.1.Initial microstructure and mechanical propertiesFig.1shows XRD scans of a longitudinal sec-tion and a transverse section of theECAE-pro-Fig.1.X-ray diffraction scan of the annealed sample.Longi-tudinal and transverse scans correspond to diffraction from par-allel planes and perpendicular planes to the ECAE extrusion direction byECAE.Fig.2.TEM bright-field image of the annealed sample.cessed and annealed sample.Three peaks in an angle range of 30–40°correspond,from the low-angle side,to prism (101¯0),basal (0002),and pyr-amidal (101¯1)planes,respectively.The longitudi-nal and the transverse sections exhibit no notice-able difference in the relative intensities among the three peaks.This indicates that the texture distri-bution in the annealed sample is homogeneous.Fig.2shows a TEM bright-field image.Average grain size,determined by a linear interception method applied for several images at a lower mag-ni fication,is found to be 6.5±0.4µm.The dislo-cation density is extremely low.Fig.3shows a typical result of a tensile test at room temperature.Note that a clear yield phenomenon can be observed at a stress of 118MPa.WithincreasingFig.3.Stress –strain curve of the annealed sample at room temperature at a strain rate of 1x10-3s -1.2058J.Koike et al./Acta Materialia 51(2003)2055–2065strain,flow stress increases rapidly,followed by an apparent steady-state region identi fied by a nearly constant stress.Failure occurs at an elongation of 47%in this sample.Similar stress –strain curves can be consistently obtained for five other samples with an average yield stress of 115±6MPa and an average elongation-to-failure of 42±5%.3.2.Yield anisotropy and dislocation activity in 2%-elongated sampleBefore the deformation microstructure is shown,the magnitude of the yield anisotropy factor is presented first for all examined grains.The direc-tions of the tensile axes of the examined grains were determined by analyzing Kikuchi diffraction patterns at a sample tilt angle of 0°.Fig.4shows the tensile-axis directions,indicated by circles inaFig.4.A standard stereographic projection of Mg.Each dot corresponds to the plane normal to the third order.Numbered filled circles indicate the tensile directions,represented by their plane normals,of the examined grains listed in Table 1.Table 1Schmid factors of basal slip and non-basal slip systems for six examined grains having tensile directions indicated in Fig.4.Values in parentheses are yield anisotropy factors Grain No.Schmid factor (yield anisotropy factor)(0001)͗112¯0͘{101¯0}͗112¯0͘{112¯2}͗112¯3͘100.43(ϱ)0.33(ϱ)20.10.42(3.81)0.38(3.45)30.10.42(2.47)0.37(2.18)40.10.45(3.46)0.48(3.69)50.40.31(0.69)0.40(0.89)60.40.36(0.82)0.39(0.89)standard triangle of the Mg hcp stereographic pro-jection.Here we use plane –pole indices to indicate the tensile ly,the [hkil]direction refers to the normal direction of the (hkil)ing this indexing scheme,analysis of Kikuchi patterns and calculation of Schmid factors could be performed easily.A total of seven grains was examined and their Schmid factors are listed in Table 1for representative slip systems of basal,prism,and pyramidal types.Yield anisotropy fac-tors are also listed in parentheses.In order to exam-ine the effects of the yield anisotropy factor on dis-location activity,the type and density of dislocations were investigated in all the listed samples.Among these,three representative cases,Nos.1,3and 6,are shown in Figs.5–7,respect-ively.All TEM images in Figs.5–7were taken under two-beam diffraction conditions using different diffraction vectors,g ,as indicated by arrows in the figures.No twins are observed in this sample.Based on the g țb criterion,all dislocations are vis-ible in (a).Dislocations having the a Burgers vec-tor are out of contrast in (b).Dislocations having the c Burgers vector are out of contrast in (c).The basal plane is aligned parallel to the incident beam direction,so that the basal plane can be seen edge-on.The basal-plane trace is indicated in each fig-ure.Under this condition,straight dislocation seg-ments lying parallel to the basal trace are in the basal-slip system.Otherwise,dislocations are in the non-basal slip systems.In Fig.5,the tensile direction is [011¯0],parallelJ.Koike et al./Acta Materialia51(2003)2055–20652059Fig.5.TEM bright-field image of the grain1of the2%-elongated sample taken by a two-beam diffraction condition.The diffraction vector is indicated by an arrow.A common basal-plane trace for the threefigures is indicated by a white line in(c).Fig.6.TEM bright-field image of grain3of the2%-elongated sample.A common basal-plane trace for the threefigures is indicated by a black line in(c).Fig.7.TEM bright-field image of grain5of the2%-elongated sample.A common basal-plane trace for the threefigures is indicated by a black line in(c).2060J.Koike et al./Acta Materialia51(2003)2055–2065to the basal plane.Dislocations are visible in all three images taken under different two-beam con-ditions.Nearly all dislocation segments are not par-allel to the basal-plane trace.These results indicate that a major deformation mechanism in this grain is non-basal slip of a+c dislocations,which is in agreement with the large yield anisotropy factor listed in Table1.In Fig.6,the tensile direction is [549¯2].The yield anisotopy factor is merely2.5 for a+c pyramidal slip and2.2for a prism slip. Dislocations are invisible in(b)where g=0002. Thus,all the dislocations have Burgers vectors of the a type.Notice that the majority of dislocation segments are parallel to the basal-plane trace. However,the basal dislocation segments extend out of the basal-plane trace.These results indicate that the dislocations in this grain can cross-slip from the basal plane to non-basal planes.These cross-slipping dislocations are of a screw type with their Burgers vector being a.The activity of non-basal slip segments is surprising for the small yield anisotropy factors of2.5and2.2.In Fig.7,the tensile direction is[112¯2],and in this case the yield anisotropy factor is less than1.0.Dislocation seg-ments are straight and parallel to the basal-plane trace,and are out of contrast when g=0002. Therefore,only the basal slip system with the a Burgers vector is mainly active in this grain. Fig.8summarizes the results shown in Figs.5–7,including the other samples listed in Table1. The length of dislocation segments is measured by counting the number of intersecting points with a given number of parallel grid lines for the basal-slip system and for the non-basal slip system.The measured dislocation density values were scattered within±8%,based on repetitive counting of vari-ous regions of the image.The corresponding error bars are provided for the data points in thefigure. Types of Burgers vectors are also included in the figure.The vertical axis of thefigure indicates the ratio of the dislocation density of either basal or non-basal system to the total dislocation density, and the horizontal axis indicates the yield ani-sotropy factor.Thefigure shows that non-basal a +c dislocations are active only when the yield ani-sotropy factor satisfies the prescribed condition of more than100based on the single crystal data.On the other hand,non-basal a dislocations areunex-Fig.8.The ratio of non-basal(r NBS)or basal(r BS)dislo-cation density to the total dislocation density(r TOTAL)as a function of the yield anisotropy factor for the six examined grains listed in Table1in a2%-elongated sample.Plotted dislo-cation types are basal a dislocations,non-basal a dislocations, and non-basal a+c dislocations.Non-basal planes for a and a+c dislocations are tentatively assigned as in Table1,and the yield anisotropy factors are calculated accordingly. pectedly active with a small yield anisotropy fac-tor.When the yield anisotropy factor is increased to1.1and higher,40%of the a dislocation seg-ments can slip on non-basal planes by cross slip.3.3.Microstructure of16%-elongated sample Fig.9shows a TEM image of the16%-elon-gated sample.Twin formation is observed in this sample.Since the dislocation density is very high, we did not attempt to determine dislocation types.A twinned region is magnified in Fig.9(a),and a schematic drawing of the microstructure is shown in Fig.9(b).Solid and dotted lines correspond to structural boundaries where diffraction contrast abruptly changes when the sample is continuously tilted.The boundary types are determined by ana-lysing Kikuchi diffraction patterns shown in Fig.9 (c).The diffraction patterns are numbered to indi-cate the corresponding regions in the images.Indi-ces of major Kikuchi lines are analysed and indi-cated in thefigures.It should be noticed that Kikuchi lines in the regions2and4are much sharper than the regions1and3.Since Kikuchi lines increase their sharpness with decreasing lat-tice strain,the regions2and4are considered to be less strained than the other regions1and3.It2061J.Koike et al./Acta Materialia 51(2003)2055–2065Fig.9.The microstructure of 16%-elongated sample.(a)TEM bright-field image of a representative area.(b)Schematic dia-gram to indicate boundaries.Numbers on the side of dotted lines are misorientation angles between adjacent grains.Index on the side of solid lines are twin interface index.(c)Kikuchi diffraction patterns from the same numbered area in (b)and (c).is highly unlikely to observe such a drastic strain inhomogeneity at the strain of 16%,unless dynamic recovery takes place.The boundary types are determined by analysing the Kikuchi patterns.The solid boundaries sur-rounding the region 3are twin boundaries with theinterface plane index of (11¯01).The dotted line separating regions 3and 4are a small-angle boundary with a misorientation angle of 3.6°.Although its diffraction pattern is not shown here,another dotted line above the twin interface is also a small-angle grain boundary with a misorientation angle of 2.6°.The formation of twins and small-angle boundaries is frequently observed in other parts of this sample.The types of twin interfacesare not limited to (11¯01),but (11¯02)interfaces are also observed.4.Discussionpatibility stress and activation of non-basal slip systemsIn large-grained pure Mg and Mg alloys,twin-ning is observed from the early stage of plastic deformation and serves as an additional defor-mation mechanism to basal dislocation slip in order to satisfy the von-Mises criterion.In contrast,the fine-grained AZ31alloys investigated in the present work exhibit no noticeable twinning after deformation of 2%and exhibit some twinning after deformation of 16%.The difference in twinning tendency between the large-grained Mg samples and the fine-grained AZ31alloys is consistent with the fact that twinning becomes increasingly dif fi-cult with decreasing grain size [9].Then,additional dislocation mechanisms are needed in place of twinning in the fine-grained AZ31alloys.Cross-slip of a dislocations from basal to non-basal planes is observed at an elongation of 2%at a yield anisotropy factor of as small as 1.1.To date,non-basal dislocation slip has been considered to occur when the tensile axis is aligned nearly parallel to the basal planes so as to make resolved shear stress for basal slip nearly zero.Even when stress con-centration arises near grain boundaries and triple junctions,its magnitude in polycrystalline alloys is generally little more than ten times applied stress [10].This level of stress concentration would reduce the yield anisotropy factor to activate non-basal slip to approximately 10from a single crystal value of 100.Yet,the reduced value of 10is still larger by an order of magnitude than the value determined experimentally in the present work.In this section,we will discuss the activity of non-basal slip in terms of grain-size dependent com-patibility stress at grain boundaries.The effects of compatibility stress at grain boundaries have been investigated in detail in vari-ous bi-crystal samples.Hook and Hirth [11]reported that elastic compatibility stress can acti-vate secondary slip systems in Fe-3%Si.Meyer and2062J.Koike et al./Acta Materialia51(2003)2055–2065Ashworth[12]proposed that microyielding occursby elastic compatibility stress near grain bound-aries,forming workhardened layers.They utilized this model to explain the Hall-Petch relationship.In the case of Mg,however,elastic constants arehighly isotropic.For example,elastic anisotropy factors of Mg are C11/C33=0.96,C12/C13= 1.20,and CЈ/C44=1.02[13].Therefore,elastic compatibility stress can be neglected in Mg alloys.In contrast,plastic heterogeneity is very strong inMg alloys and may give rise to a large plastic com-patibility stress.The effects of plastic compatibility stress near a bi-crystal grain boundary have been investigated mainly in cubic metals[14–17]and in some cases in hcp Zn[18]and WC-Co[19]. Activation of the secondary slip systems by plastic compatibility stress has been well-established by the previous studies.A large plastic compatibility stress can thus be expected near grain boundaries of Mg alloys.Fig.10shows a schematic drawing to explainthe compatibility effects on the activation of non-basal glide systems in Mg alloys.Let us consider two separate grains of Mg under uniaxial tensile stress as shown in(a).Basal planes are oriented at 45°to the tensile axis in both grains,but are tilted by90°across the grain boundary.If only the basal slip systems are operated,two grains are deformed to a diamond shape as shown in(b).If the two deformed grains are to be bonded at a grain bound-ary,additional shear stresses(compatibility stresses)are needed,as indicated by arrows in(c), and activate the non-basal slip systems.This sug-gests that the basal slip systems cannot operate near grain boundaries unless the non-basal glide systems become active;otherwise,fracture would occur along grain boundaries.Since the density of mobile dislocations is expected to increase rapidly at this point,a clear stress-drop phenomenon appears as exemplified in Fig.3.Although twinning may be induced by compati-bility stress,the formation of interfaces requires anextra driving force.The energy of twin interfaces is,as described later,significantly large in Mg. This leads to the increasing difficulty in twin nucleation with decreasing grain size.For this rea-son,in a well-annealed andfine-grained alloy under the effects of the compatibility stress,we Fig.10.Schematic drawing of stressed bicrystals:(a)before deformation,(b)deformed condition without bonding along a grain boundary,and(c)Possible stress state in order to maintain contact between two grains along a grain boundary. consider that dislocation slip on basal and non-basal planes occurs before twinning occurs.Note that the non-basal a dislocations observed in the present work are not sufficient to ensure homo-geneous deformation;activation of a+c dislo-cations is still necessary to satisfy the von-Mises condition.In the2%-elongated sample,the a+c dislocations were actually observed but only in the limited grains having their basal planes parallel to the tensile axis.One possibility is that the a+c dislocations are activated by further deformation of2063 J.Koike et al./Acta Materialia51(2003)2055–2065more than2%.The a+c dislocations would thenbring about a rapid work hardening together withthe cross-slipping of a dislocations.Obara et al.[2] reported that in a single crystal Mg the a+c dislo-cations tend to dissociate to a and c segments.They attributed the observed work hardening to the formation of the immobile c dislocation segments.Whenflow stress increases to a certain level,twin-ning occurs as an additional deformation mech-anism even in afine-grained alloy.The role oftwinning in the present work is further discussed in the next section.Meanwhile,we will discusshow far from grain boundaries the compatibilitystress can influence dislocation slip in polycrystals. Margolin and Stanescu[20]measured the lengthof slip lines for the primary and secondary systemsin polycrystalline b Ti-Mn alloys.They found that the average length of the secondary slip linesadjacent to grain boundaries is approximately10µm,regardless of the variation of grain size from 49–94µm.In the present alloy,grain size is6.5µm.Cross-slip to non-basal planes is observed in the entire region of examined grains.The observed results can be explained if we consider that the dis-tance of the grain-boundary affected region in thepresent alloy is on the same order as the value reported by Margolin and Stanescu.The present observation suggests the following scenario with regard to yield stress and an apparent elastic deformation region of polycrystalline Mg alloys.We consider that plastic yielding can occur in the grain interior at a very small stress of several MPa.This marks microscopic yielding.Its appear-ance and magnitude in stress-strain curves depend on the grain size;i.e.the volume in which basal slip can occur without the influence of the compati-bility rge-grained alloys are expected to facilitate basal slip more easily than small-grained alloys,thus exhibiting a clear microscopic yielding at a very low stress.Therefore,a strong yield ani-sotropy in Mg prevents a large number of basal dislocations from slipping,rapidly increasingflow stress to a sufficiently high level to activate twin-ning for large-grained alloys but to activate non-basal slip systems forfine-grained alloys.This would mark macroscopic yielding,which has been often taken as a yield stress by many researchers. Thus,an apparently elastic portion of stress-strain curve before reaching the macroscopic yield stress is not a truly elastic portion;rather,it is a rapidly work-hardened region caused by the limited slip of basal dislocations under the influence of grain-boundary compatibility.In fact,in our separate work in AZ31[21],this portion of stress–strain curves before reaching a proof stress is strongly dependent on both strain rate and grain size; namely,on the extent of grain-boundary compati-bility effects.Accurate interpretation of yield phenomenon is extremely important when creep, fatigue,and damping experiments are performed. Further work is necessary to differentiate the microscopic and the macroscopic yield stresses and to understand their grain-size and texture depen-dence.4.2.Dynamic recovery and the role of twinning The microstructure of the16%-elongated sample showed recovered regions in the deformed matrix as well as within some twins.These results indicate that dynamic recovery can take place in Mg alloys during room-temperature deformation.Note that in the stress–strain curve(Fig.3)work hardening is followed by an apparently steady-state deformation behaviour with a nearly constantflow stress.Gen-erally,such a steady-state deformation is con-sidered to occur at elevated temperatures by a dynamic balance between hardening and softening effects.A supporting evidence of dynamic recov-ery was reported by Conrad and Robertson[22]in a single crystal Mg.They found that strain-harden-ing coefficient takes a constant value at defor-mation temperatures of78–203K,but at higher deformation temperatures,including room tem-perature,the coefficient was found to decrease with increasing deformation temperature.They attri-buted the softening to a recovery process.In another report,by Miller[23],creep was claimed to occur at room temperature.Although this report may turn out to lend further support for the occurrence of dynamic recovery at room tem-perature,the results should be interpreted carefully. To summarize the report,constant-load creep tests were performed up to100h at room temperature in die-cast AZ91alloys.Stress level was varied in the range of60–180MPa,including a0.2%proof。