Probing the influence of the center atom coordination
你对国家的贡献作文英语
Growing up in a small town, I was always aware of the immense sacrifices and contributions made by countless individuals to the prosperity and security of our nation. It wasnt until I reached high school that I began to understand the various ways in which I, too, could contribute to my country. This realization came to me through a series of experiences that not only shaped my perspective but also ignited a passion within me to give back to the society that had nurtured me.One of the most profound experiences was when I volunteered at a local community center during my sophomore year. The center was a hub of activity, providing support and resources to those in need. I was tasked with organizing a book drive to encourage literacy among children. It was a simple task, but the impact was farreaching. Seeing the joy in the childrens eyes as they received new books, and hearing their parents express gratitude for the opportunity, was incredibly rewarding. It was then that I realized the power of small contributions to make a significant difference in peoples lives.Another pivotal moment occurred during a school trip to the capital city. We visited several historical sites, including the national museum and war memorials. The stories of bravery and sacrifice by our ancestors deeply moved me. I learned about the struggles they faced and the price they paid for our freedom and peace. This visit instilled in me a sense of responsibility towards my country and its history. It made me question how I could honor their legacy and contribute to the nations ongoing journey.As I delved deeper into understanding the various sectors of our society, I became particularly interested in environmental conservation. I joined an environmental club at school, where we organized cleanup drives, tree planting events, and awareness campaigns about the importance of sustainable living. It was during these activities that I felt a strong connection to the land and its resources. I realized that preserving our environment is not just about protecting nature its about ensuring the wellbeing of our communities and future generations.My contributions to the environment were further amplified when I participated in a nationwide recycling initiative. Our school was one of the many institutions that partnered with local businesses to collect and recycle waste. The project was a huge success, and it not only reduced the amount of waste that ended up in landfills but also educated the community about the importance of recycling. It was a small step towards creating a cleaner, greener nation, and I was proud to be a part of it.In addition to environmental efforts, I also recognized the importance of contributing to the cultural fabric of our nation. I took part in various cultural festivals and performances, showcasing our rich traditions and heritage. By doing so, I not only celebrated our diverse culture but also helped to preserve it for future generations. It was a way of acknowledging and appreciating the unique identity of our country.My journey of contributing to my country has been a continuous learning experience. It has taught me the value of community, the importance of preserving our environment, and the significance of honoring our culturalheritage. I have come to understand that every individual, regardless of their age or status, has the potential to make a difference.As I look towards the future, I am committed to continuing my contributions to my country. Whether its through volunteering, participating in community projects, or advocating for environmental and cultural preservation, I believe that every action counts. It is through these collective efforts that we can build a stronger, more vibrant, and sustainable nation.In conclusion, contributing to ones country is not limited to grand gestures or significant achievements. It is about recognizing the small ways in which we can make a difference in our communities and the world around us. It is about taking responsibility for our actions and striving to create a positive impact. As a high school student, I have had the privilege of being part of this journey, and I am excited to see where it will lead me in the years to come.。
浅析建设项目设计变更的管理策略
关键词 ：建设项 目，项 目管理 ，设计 变更
中 图 分 类 号 ：ＴＵ７２１．２
文 献 标 识 码 ：Ａ
设计变更 在建设项 目的施 工阶段经常 出现 ，尤其在 一些规模 成 施工单位的返工。
宏大 、施工条件复杂 以及设计 质量 不高 的工 程 中更是 无法避 免。
２）设计单位 发 出的变更 。设 计单 位一般 忌讳频 繁 的变 更设
析 中，对 于环境 与发展预测 、建设用地 的综合分析 与规划 、土 地最 ［３］税远友 ，周 申立 ，莫怀银 ．合 理利 用土地 的思考 ［Ｊ］．四川 师范
佳方案 的选取等均具有重要的意义 。
学院学报（自然科 学版 ），１９９６，１７（２）：３８．４２．
参 考 文 献 ：
［４］陈俊 杰，朱刘娟 ．建立动态管理的土地 管理信 息 系统 ［Ｊ］．西部
因此 ，做好建设项 目中设计变更 的管理与控 制 ，对确保工 程质量 、 变化 ，规划部 门或施工 图审查 机构对 图纸 提 出的修改要 求 ，原设
进度和投资控制以及 提高建 筑企业 的经 济效益 和建 设项 目的社 计本身 存在 漏项 、各专 业之 间的碰撞 、图纸 与现场情 况 的不 符 以
会 效 益 都 具 有 重 要 意 义 。
及 设计者对图纸其 他方面的完 善。
１ 产 生设计 变 更的主 要原 因
３）施 工单位 提出的变更 。一般 可分为三种类 型 ：ａ．真正从 工
施工图纸 的设计 变更是 进行 施工 的依据 ，也 是工程 决算 、产 程 的总体 目标考虑 提 出合 理 的、善 意的设计 变更 要求 ，如施 工单 生索赔 以及 工程交 付使用 后管理 、维修 的依 据 ，它 和原设计 图纸 位在 阅图时发现 图纸技术性错误 而提出的设计变更 ｜ｂ．通过 设计 一 起组 成一 个完 整的工程设计 ，并和原设 计具有 同等效 力 。设计 变更试 图增 加工程 量 ，制造 追加投 资和索赔 机会 ，此类 情况 往往 变更是工程施 工过 程 中为 了保证 设 计 和施 工质 量 ，完善 工 程设 出现在 一些 不正 当 的招 投 标工程 项 目中；Ｃ．结 合 自身 的施工 能 计、纠正设计错误 以及 满足施工现场 条件变化 而进行 的设计 修改 力 ，为了降低施工难度 、加 快施工进 度 而要求设 计单位 提供技 术 工作。一般有 两种形式 ：由设 计单位发 出 的设 计变 更通知单 ；由 支持 的设计 变更 。
高考英语一轮总复习 选择性必修第二册 UNIT 2 BRIDGING CULTURES
17. strengthen vi.& vt.加强;增强;巩固→ strong adj.强壮的 → strength n.体力;优点 18. competence n.能力;胜任;本领→ competent adj.有能力的;称职的 19. cooperate vi.合作;协作;配合→ cooperation n.合作;协作 20. sincerely adv.真诚地;诚实地→ sincere adj.真诚的
常用短语
1. adapt to 2. participate in 3. speak up 4. feel at home 5. engage in 6. get involved in 7. comfort zone 8. cost an arm and a leg 9. side with 10. as far as I know
Ⅲ.句型小测——高考情景仿写
1.这是我第一次参加这样有意义的活动。
It is the first time
that I have taken part in such a meaningful activity.
2.然后我向他们展示了如何沏茶。
Then I showed them how to make tea
3.The first time that she had to write an essay,her tutor explained that she must acknowledge what other people had said if she cited their ideas,but that he mainly wanted to know what she thought! 【尝试翻译】 她第一次写论文时,导师跟她解释说,如果引用别人的观点 就一定要注明,不过导师主要是想知道她自己是怎么想的。 【考点凝练】时间名词作连词
2022年12月英语四级考试真题及答案解析第3套
that it's not just parents who think teenagers are worryingly 29 from their phones—many teens
themselves do too. Fifty-four percent of the 13-to-17-year-olds surveyed said they spend too much time
30 in their phones.
Vicky Rideout, who runs a research firm that studies children's interactions with media and
technology, was not surprised by this finding. She says it's hardly 31 to teenagers. MThey are dealing
with the same challenges that adults are, as far as they are living in the 32 of a tech environment
designed to suck as much of their time onto their devices as possible,“ Rideout says.
2022年 1 2 月大学英语四级考试真题（三 ）
Part I
Writing
(30 minutes)
Directions：In this task, you are to write an essay on the necessity o f developing social skills for college students. You will have 30 minutes for the task. You should write at least 120 words but no more than 180 words.
四川理工英语第二册考试复习题
UNIT 1summaryAmericans believe so much in moving ahead that they are ____committed to___ researching, experimenting and exploring. They treat time as if it __were___ real—a precious resource. They budget it, save it, waste it, steal it, kill it, cut it, account for it and ____charge___ for it. A foreigner’s first impression _of__ the U.S. is that everyone is in a rush and often __under___ pressure. City people always appear to be ___hurrying____ to get where they are going, restlessly seeking attention or elbowing ___others____. Foreigners who miss smiles, brief conversations, or leisurely exchanges with strangers should not feel __hurt___ by this. Americans value time so __highly_____, they dislike anyone “wasting” it beyond an __appropriate__ amount. New arrivals to the States will miss the custom of social talk __during___ a business call because Americans generally __assess__ or enquire about their visitors professionally rather than socially. They start talking business very quickly; time is always __ticking___ in their heads. They work __hard__ at saving time through labor-saving devices so they communicate rapidly by fax, phone or email rather than ___through___ personal contact. The ____impersonality___ of electronic communication has __little_ to do with the significance of the matter __at___ hand. _Finishing__ a job or solving a problem rapidly in the U.S. is considered a sign of ___skillfulness__.美国人相信这么多在前进,他们致力于研究、实验和探索。
爸爸工作是大学老师的一段话英语作文
爸爸工作是大学老师的一段话英语作文全文共3篇示例，供读者参考篇1My Dad, The ProfessorEver since I was a little kid, my dad has been a university professor. Growing up, it always felt kind of cool having a dad who was an expert in his field and worked at a big university campus. Whenever we'd drive past the university, I'd feel a sense of pride knowing that's where my dad spent his days teaching and researching.Of course, being a professor isn't always as glamorous as an eight-year-old might imagine. I remember many late nights when dad would be holed up in his home office, furiously typing away at some paper or proposal until the early hours of the morning. The life of an academic is certainly not a nine-to-five gig. There were also the endless stacks of student assignments and exams to grade, which would accumulate like snowdrifts on his desk.In those earlier years, I didn't fully grasp what dad's job actually entailed. I just knew he was wicked smart and that hebasically got paid to read books and tell people about them –not a bad racket if you can get it, I figured. It wasn't until my own college years that I started to develop a deeper appreciation for the role of a professor and the multitude of responsibilities involved.Beyond teaching classes, dad also spent huge amounts of time and energy on academic research in his field of study, which centered on 18th century French literature. This could mean pouring over ancient tomes and original manuscripts, analyzing obscure texts with a microscopically-fine toothed comb, or traveling to archives and libraries across the globe to unearth some long-forgotten document.The life of the mind has always been profoundly important to my father. He has an insatiable intellectual curiosity and thirst for knowledge that I've rarely encountered in other people. In many ways, he personifies the archetypal absent-minded professor – the guy who can recite stanza after stanza of Voltaire from memory, but who occasionally misplaces his car keys orforgets to take out the trash on garbage day.Despite being brimming with brilliance, dad has always been humble and down-to-earth about his academic standing and accomplishments. Perhaps it's because he knows that in thegrand scheme of things, the work of professors and scholars is extremely niche – fascinating to a small cadre of experts, but largely unnoticed and underappreciated by society at large.There's a sense in which academic research, especially in the humanities, can feel like a self-gratifying endeavor. You spend years, decades even, diving ever-deeper into an increasingly narrow and obscure domain of knowledge. The funders, your peers, and handful of scholars around the world who understand the nuances of your ultra-specific niche might deem the work invaluable. To the other 7 billion people on the planet, it doesn't mean a whole lot.And yet, dad would surely argue that the pursuit of knowledge for its own sake has an inherent worth – that by probing the unexplored frontiers of French Enlightenment literature, he's playing a small part in piecing together a richer understanding of humanity itself. That's always been dad's mindset, and it's what has fueled his passion for teaching and researching year after year.Of course, a key part of any professor's job extends well beyond research – it's about imparting knowledge and inspiring the next generation of curious minds. While he may sometimesappear reserved and absent-minded, dad has a special gift for bringing his niche subject matter to life in the classroom.I'll never forget sitting in on one of his lectures during my junior year of college (not because I had any great interest in 18th century French literature, but rather because it was an easy way to earn some literature credits). Despite the dry-as-dust subject matter, dad had an uncanny ability to infuse life, color and energy into the dusty prose.With his disheveled wardrobe, unkempt hairstyle and utter lack of slick presentation skills, he looked more like anabsent-minded, middle-aged graduate student than aworld-renowned expert. Yet he would pace back-and-forth with frenetic energy, belaboring obscure points, cracking wry jokes, and using every square inch of the chalkboard to diagram his interpreations of the text with frenzied scribblings.Watching him teach, it was hard not to get caught up in his sheer passion and exuberance for the material. Here was a man who had achieved the academic's version of job nirvana –getting paid to devote his life's work to deeply contemplating the shades of meaning in obtuse tomes about philosophy, free will and man's relationship to nature.It probably helped that he was a white male academic from an upper-middle class background studying decidedlyupper-crust subject matter. Had he been a woman studying feminist theory or an academic of color focusing on anti-colonial narratives, he likely would have had to work twice as hard to get half as far in the insular, privileged world of the ivory tower. Still, dad made it to the upper-echelons of his ivory tower – full professor and department chair at a prestigious research institution.I have hugely fond memories of running around theivy-covered academic buildings as a kid, attending various university functions and events with mom and dad. The cliched scenes that most people associate with elite institutions of higher learning – the hallowed libraries brimming with ancient books, the academic robes at graduation ceremonies, the Medieval-looking stone architecture covered in ivy and Renaissance statues – this was the backdrop of my childhood.At home, our house was similarly bedecked in the aesthetics and ambiance of an academic's abode. Floor-to-ceiling bookshelves lined virtually every wall, overflowing with books on every topic imaginable. Garish art posters and trippy mathematica prints covered the remaining wall space. One of myfavorite childhood possessions was dad's comically-oversized green visor, which he'd often wear while grading papers late into the night. I'd throw it on my six-year-old head and strut around pretending to be a professor myself.Fittingly, dad's workspace was perhaps the ultimate personification of the absent-minded professor lair – an utter cyclone of disarray. Stacks of books and handouts towered in every direction. Antique globes and dust-caked curios filled any remaining nook and cranny. You practically needed a machete to carve a path through the sea of scattered papers, coffee cups, and academic detritus covering every level surface.Looking back, I think a huge part of what made dad such an engaging instructor and compelling human being was his unwavering sense of childlike enthusiasm and curiosity. While most of us become world-weary adults who take life's great mysteries for granted, professors like dad cultivate the mindset of eternal students – always questioning assumptions, poking holes in conventional wisdom, and wondering "what if?" about society's bedrock narratives.It's partly what has made dad such a delightfully kooky, eccentric, and hard-to-pin-down figure. Pragmatic and conventional thinking have never been his strong suits. As he'sgotten on in years, he seems to have only further retreated into the alternately wacky and profound thought patterns of an academic's mind.Often, conversing with dad can feel like achoose-your-own-adventure novel, with his trademarkfree-associative musings leading you down an endless series of mental wormholes. What began as an innocent discussion about the morning crossword could quickly detour into a spiraling dissertation on the nature of human language, the symbolic xcode of ancient Sumerian tribes, and the existential limits of logic and reason themselves.That's just how dad's mind works - constantly questioning, theorizing, and solutioning. Even at family gatherings and social functions, you could usually find dad holding court amid a small cluster of rapt intellectuals, lecturing away about some esoteric subject with wild gesticulations and laugh-out-loud metaphors.To my childhood eyes, dad's mannerisms and eccentric fixations were endlessly entertaining and baffling. But as an adult looking back, I've come to recognize those traits as the hallmarks of a world-class teacher and true polymath. Having a professor for a dad normalized the idea of living an "life of the mind" driven by curiosity, hypotheticals, and deep study.Of course, being the son of an academic has also instilled in me a healthy skepticism of authority, credentialism, and the entire institutional knowledge-making apparatus. I've seen up close just how much knowledge gets proverbially "created" through obscure papers, conferences, and intellectual gatekeepers engaging in ideological group-think andnaval-gazing.Still, at its best, higher education plays an invaluable role in pushing the boundaries of human knowledge and understanding. And professors like my dad, for all their faults and foibles, are the engine that keeps those hallowed institutions running and propelling the great intellectual debates forward.So while the absent-minded professor might be a well-worn cliche,篇2My Father, The ProfessorAs a student, having a father who is a university professor certainly has its perks. On the one hand, it means I've been raised with a strong appreciation for education and the value of knowledge. Our home has always been filled with books on virtually every subject imaginable. From a young age, my parentsinstilled in me the importance of being a lifelong learner and keeping an open, inquisitive mind.At the same time, I've had to work hard to forge my own academic path separate from my father's sphere of influence. While he's never pushed me to follow in his footsteps, there's always been an unspoken expectation that I would take my studies seriously and perform to the best of my abilities. I'll admit, that weight on my shoulders has felt heavy at times over the years.Let me take a step back and provide some background on my dad. Professor Jonathan Richards has been teaching English literature at Hampton University for the past 25 years. His expertise lies primarily in British romantic poets like Wordsworth, Coleridge, and Keats. I still vividly remember the awestruck looks on his students' faces during those evenings when he would gather them around our living room and passionately recite poems from memory.That was my first real introduction to the idea that being an educator, especially at the university level, means so much more than just lecturing from a textbook. The truly great professors, like my dad, have a profound way of bringing their subject matter to life. They spark curiosity and inspiration in theirstudents. That visceral connection to the material is what elevates learning from a chore to an active journey of discovery.Of course, even a celebrated professor doesn't get to solely focus on the glamorous side of teaching. Throughout my childhood, I saw my dad log countless hours at home reading dense academic papers, grading essays until the wee hours, and meticulously preparing his lectures. The reality is that for every hour he spent captivating students with his theatrical in-class performances, he devoted at least triple that time behind the scenes. Becoming an expert in his field and an effective instructor required an incredible amount of commitment and personal sacrifice.My dad often talks about how fundamentally his role as a professor is one of service - to his students, to the broader community of scholars, and to the pursuit of knowledge itself. He takes immense pride in training the next generation of critical thinkers who will go on to shape our society. At the same time, he stresses that he is still very much a perpetual student himself, constantly learning from the diverse perspectives of those around him.In that sense, being an educator at the collegiate level is a lifelong endeavor where the lines between teacher and pupil areconsistently blurred. My dad described the dynamic best when he said, "My students keep me humble by revealing how much I still have to learn, while simultaneously energizing me to tirelessly seek out greater understanding through our shared journey of intellectual discovery."Quite fittingly, some of my most impactful lessons from my father didn't actually take place in the classroom. Whether it was casually discussing current events over the dinner table or him proofreading my high school essays, he always made an effort to engage me in substantive dialogue. Our conversations weren't typical superficial parent-child small talk - he treated me as an intellectual equal from a surprisingly young age.He had an uncanny ability to pivot even the most mundane topics into nuanced discussions about ethics, human nature, societal structures, and more. What started as me telling him about my day at school could quickly evolve into a spirited debate about the philosophical underpinnings of modern education models. My inquisitive young mind was constantly being challenged to analyze issues from multiple angles and question my own assumptions.Now as a university student myself, I've come to truly appreciate how my dad's approach primed me to think morecritically and articulate my thoughts with greater clarity. While the academic workload can still feel crushing at times, the skill of dissecting complex ideas was hardwired into me from an early age. More than just helping with coursework, that tenacious intellectual curiosity my father instilled within me has seeped into all facets of how I interpret the world around me.Of course, there were also instances where having a scholarly parent felt more burdensome than advantageous. Like many young people, I went through the classic "rebellious teenager" phase. However, rather than acting out in straightforward defiance, my brand of rebellion manifested more as an aversion to anything that could be remotely considered pretentious or elitist.I remember periods where I would intentionally "play dumb" around my dad's academic friends when they visited our house. I'd speak in monosyllabic grunts and shrug my shoulders at any attempted highbrow conversation. Looking back now, I realize I was instinctively pushing away from the pressure of having to live up to intellectual expectations as the daughter of a university professor.At my most extreme, I even toyed with the idea of purposely underachieving in school just to spite the family tradition ofacademic excellence. Thankfully, those misguided sentiments were relatively short-lived. As I matured, I recognized how privileged I was to be raised in an environment that valued critical thinking above all else. My momentary rebellion ultimately gave way to a re-embracing of my innate love of learning.These days, my father and I have fallen into an ideal equilibrium in our intellectually-charged relationship. We've developed a rhythm of comfortably challenging each other's ideas in a respectful manner while celebrating our unique perspectives. Our discussions are enriching without beingself-indulgent or pretentious. He treats me as a formidable intellectual equal, while still providing the occasional substantive critique to push my reasoning abilities even further.He is the first person I seek out to enjoy a rousing debate or to gain fresh insight on a complex topic I'm grappling with. More than just being my dad, he's become a trusted mentor that has helped shape how I interpret the world and my place within it as a budding scholar.At the same time, I've firmly established my own academic identity outside of the looming shadow of his prestigious career. While he laid the foundation for my intellectual passion, I'vesubsequently constructed my own unique philosophy on how to amalgamate varied schools of thought into a holistic moral framework for living an examined life. Myream disposition, while still heavily influenced by him, has taken on different shadings through my own cumulative experiences and perspectives.As I prepare for my final year of university study, I find myself simultaneously embarking on the pathway to define my own legacy. Will I follow directly in his footsteps and pursue a career as an academic? Or will I take the intellectual tools he provided and apply them through an entirely different professional avenue? Truthfully, I'm still very much undecided on what my future has in store.No matter which direction I ultimately choose, one thing is for certain - my dad's indelible impact as a world-class educator and voracious learner will forever be imprinted upon the core of who I am. His greatest accomplishment was not the decades of scholarly papers published or the legions of students he inspired. Rather, it was passing along an eternal thirst for knowledge and understanding to his own daughter.I am equally proud of dad's staggering achievements and grateful for the way he uplifted me to become my own brand of intellectual. If I'm able to leave half the profound impact on thenext generation that he did for me, I'll consider my life's journey to have been an overwhelming success.篇3My Father, The ProfessorEver since I was a young child, I've always admired my father's dedication to his profession as a university professor. He's not just an educator; he's a true scholar who has an unwavering passion for his field of study and a genuine desire to inspire and shape young minds.I still remember the first time I visited his office on campus. It was a cozy little nook nestled deep within the labyrinth of the university's ancient buildings, adorned with towering bookshelves that seemed to stretch towards the ceiling. The air was thick with the scent of aged leather and the faint aroma of freshly brewed coffee, a scent that has become synonymous with my father's academic sanctuary.As a child, I would often tag along with him on his occasional visits to the office, marveling at the organized chaos that surrounded him. His desk was a battlefield of papers, books, and scattered notes, each representing a fragment of the vast knowledge he had accumulated over the years. Yet, amidst theclutter, he always seemed to know exactly where everything was, as if he had crafted an intricate mental map of his domain.It was during those visits that I first witnessed the true essence of his profession. I would sit quietly in a corner, observing as he meticulously prepared his lectures, pouring over research papers and scribbling notes in the margins. His brow would furrow in deep concentration, and occasionally, he would pause to gather his thoughts, his gaze fixed on some invisible point in the distance.In those moments, I could almost sense the wheels turning in his mind, as he carefully crafted the narratives that would shape the minds of his students. It was a profound experience, witnessing the birth of knowledge first-hand, as my father wove intricate tapestries of information, intertwining facts and theories into a cohesive whole.But it wasn't just the preparation that captivated me; it was the way he transformed in front of the classroom. Gone was the pensive scholar hunched over his desk, replaced by a dynamic and engaging orator who commanded the attention of every student. His voice would rise and fall, punctuated by animated gestures and the occasional witty remark, as he guided his pupils through the depths of his subject matter.I remember sitting in on one of his lectures once, utterly mesmerized by the way he could take even the most complex concepts and distill them into digestible morsels of wisdom. It was as if he had a special gift, a unique ability to bridge the gap between the abstract and the tangible, making the seemingly impenetrable accessible to all.Yet, what truly set my father apart was his genuine interest in his students' development. He wasn't merely an imparter of knowledge; he was a mentor, a guide, and a source of inspiration for those who sought to follow in his footsteps. His door was always open, and students would flock to him, seeking advice, guidance, or simply a sympathetic ear to listen to their academic woes.I can recall countless evenings when he would return home, his briefcase brimming with papers and assignments to grade, his eyes betraying the weariness of a long day's work. But as soon as he settled into his study, that fatigue would seemingly melt away, replaced by a renewed sense of purpose as he meticulously pored over each student's work, leaving carefully crafted comments and suggestions in the margins.To my father, teaching wasn't just a job; it was a vocation, a calling that he answered with every fiber of his being. Heunderstood that his role extended far beyond the confines of the classroom, and that his influence had the potential to shape the trajectory of countless lives.As I grew older and embarked on my own academic journey, I began to appreciate the true scope of my father's impact. I would overhear snippets of conversation from former students who had gone on to achieve remarkable feats, each one crediting my father's guidance and mentorship as a pivotal factor in their success.It was then that I realized the true legacy of a great educator – a legacy that transcends the boundaries of time and space, echoing through the lives of those they have touched, reverberating through generations to come.Now, as I stand on the precipice of my own career, I find myself drawing inspiration from my father's unwavering dedication and passion. His example has instilled in me a deep respect for the pursuit of knowledge and a genuine desire to make a positive impact on the world around me.Perhaps one day, I too will have the opportunity to stand before a classroom, to ignite the flames of curiosity and understanding in the minds of eager students. And if that daycomes, I will undoubtedly draw upon the lessons I learned from the greatest professor I have ever known – my father.For it is through his tireless efforts, his unwavering commitment, and his boundless love for the pursuit of knowledge that I have come to understand the true essence of what it means to be an educator. It is a noble calling, one that demands not only a mastery of subject matter but also a genuine desire to uplift and inspire those who seek to follow in your footsteps.And while the path may be arduous and the challenges manifold, I know that I will always have the guiding light of my father's example to illuminate the way, a beacon of wisdom and inspiration that will forever burn brightly in my heart.。
TOEFL托福阅读真题整合
TOEFL托福阅读真题整合托福阅读真题1__ 31Rent control is the system whereby the local government tells building owners how much they can charge their tenants in rent. In the United States, rent controls date back to at least World War II.In 1943 the federal government imposed rent controls to help solve the problem of housing shortages during wartime. The federal program ended after the war, but in some locations, including New York City, controls continued. Under New York's controls, a landlord generally cannot raise rents on apartments as long as the tenants continue to renew their leases. In places such as Santa Monica, California, rent controls are more recent. They were spurred by the inflation of the 1970's, which, combined with California's rapid population growth, pushed housing prices, as well as rents, to record levels. In 1979 Santa Monica's municipal government ordered landlords to roll back their rents to the levels charged in 1978. Future rents could only go up by two-thirds as much as any increase in the overall price level.In any housing market, rental prices perform three functions: (1) promoting the efficient maintenance of existing housing and stimulating the construction of new housing, (2) allocating existing scarce housing among competing claimants, and (3) rationing use of existing housing by potential renters.One result of rent control is a decrease in the construction of new rental units. Rent controls have artificially depressed the most important long-term determinant of profitability —rents. Consider some examples. In a recent year in Dallas, Texas, with a 16 percent rental vacancy rate but no rent control laws, 11,000 new housing units were built. In the same year, in San Francisco, California, only 2,000 units were built. The major difference? San Francisco has only a 1.6 percent vacancy rate but stringent rent control laws. In New York City, except for government-subsidized construction, the only rental units being built are luxury units, which are exempt from controls. In Santa Monica, California, new apartments are not being constructed. New office rental space and commercial developments are, however. They are exempt from rent controls.1. What does the passage mainly discuss?(A) The construction of apartments in the United States.(B) Causes and effects of rent control(C) The fluctuations of rental prices(D) The shortage of affordable housing in the United States.2. The word They in line 9 refers to(A) the tenants(B) their leases(C) places(D) rent controls.3. Which of the following was NOT a reason for the introduction of rent controls in Santa Monica,California?(A) rapid population growth(B) inflation(C) economic conditions during wartime(D) record-high housing prices4. The phrase roll back in line 11 is closest in meaning to(A) credit(B) measure(C) vary(D) reduce5. The word stimulating in line 15 is closest in meaning to(A) experimenting with(B) identifying(C) estimating(D) encouraging6. It can be inferred that the purpose of rent control is to(A) protect tenants(B) promote construction(C) increase vacancy rates(D) decrease sales of rental units7. The word depressed in line 19 is closest in meaning to(A) saddened(B) created(C) lowered(D) defeated8. The information in the last paragraph supports which of the following statements?(A) San Francisco has eliminated its rent control laws.(B) Rent control leads to a reduction in the construction of housing units(C) Luxury apartments are rarely built when there is rent control(D) There is a growing need for government-subsidized housing.9. According to the passage , which of the following cities does NOT currently have rent controls?(A) Santa Monica(B) Dallas(C) San Francisco(D) New York City10. The word stringent in line 23 is closest in meaning to(A) straightforward(B) strict(C) expanded(D) efficient11. According to the passage , which of the following is NOT exempt from rent control?(A) Luxury apartments(B) Commercial development(C) Moderately priced apartments(D) Office space.__ 31 BDCDD ACBBB C托福阅读真题232By 1776 the fine art of painting as it had developed in western Europe up to this time had been introduced into the American colonies through books and prints, European visitors andimmigrants, and traveling colonists who brought back copies (and a few original) of old master paintings and acquaintance with European art institutions.By the outbreak of the Revolution against British rule in 1776, the status of the artists had already undergone change. In the mid-eighteenth century, painters had been willing to assume such artisan-related tasks as varnishing, gilding teaching, keeping shops, and painting wheel carriages, houses, and signs. The terminology by which artists were described at the time suggests their status: limner was usually applied to the anonymous portrait painter up to the 1760's; painter characterized anyone who could paint a flat surface. By the second half of the century, colonial artists who were trained in England or educated in the classics rejected the status of laborer and thought of themselves as artists. Some colonial urban portraitists, such as John Singleton Copley, Benjamin West, and Charles Wilson Peale, consorted with affluent patrons. Although subject to fluctuations in their economic status, all three enjoyed sufficient patronage to allow them to maintain an image of themselves as professional artists, an image indicated by their custom of signing their paintings. A few art collectors James Bowdoin III of Boston, William Byrd of Virginian, and the Aliens andHamiltons of Philadelphia introduced European art traditions to those colonists privileged to visit their galleries, especially aspiring artists, and established in their respective communities the idea of the value of art and the need for institutions devoted to its encouragement.Although the colonists tended to favor portraits, they also accepted landscapes, historical works, and political engravings as appropriate artistic subjects. With the coming of independence from the British Crown, a sufficient number of artists and their works were available to serve nationalistic purposes. The achievements of the colonial artists, particularly those of Copley, West, and Peale, lent credence to the boast that the new nation was capable of encouraging genius and that political liberty was congenial to the development of taste — a necessary step before art could assume an important role in the new republic.1. What does the passage mainly discuss?(A) European influence on colonial American painting(B) The importance of patronage to artist(C) The changing status of artists in the American colonies in the eighteenth century(D) Subjects preferred by artists in the American colonies in theeighteenth century.2. The word outbreak in line 5 is closest in meaning to(A) cause(B) beginning(C) position(D) explanation3. The word undergone in line 6 is closest in meaning to(A) led to(B) transformed(C) preferred(D) experienced4. According to the passage , before the American Revolution the main task of limners was to(A) paint wheel carriages(B) paint portraits(C) varnish furniture(D) paint flat surfaces5. I t can be inferred from the passage that artists who were trained in England(A) considered artists to be superior to painters(B) barely painted portraitists(C) were often very wealthy(D) imitated English painters6. The word consorted in line 14 is closest in meaning to(A) made decisions(B) studies(C) agreed(D) associated7. The word sufficient in line 16 is closest in meaning to(A) adequate(B) temporary(C) friendly(D) expensive8. According to the passage , artists such as Copley, West and Peal signed their paintings(A) increased the monetary value of the paintings(B) made it more difficult for other artists to copy the paintings(C) supported the artists' image of professionalism(D) distinguished colonial American artists from European artists9. The author mentions James Bowdoin III and William Byrd in line 17 as examples of which ofthe following?(A) Art gallery owners who displayed only European art(B) Art collectors who had a profound influence on American attitudes toward art(C) Artists who gave financial support to other artists(D) Patrons whose helped to encourage artisans to become artists10. With which of the following would the author be most likely to agree?(A) Countries that have not had a political revolution are unlikely to develop great art.(B) The most successful art collectors are usually artists themselves.(C) The value of colonial American paintings decreased after the Revolution.(D) Colonial artists made an important contribution to the evolving culture of the new nation.__ 32 CBDBA DACBD托福阅读真题3__ 33Researchers in the field of psychology have found that one of the best ways to make an important decision, such as choosing auniversity to attend or a business to invest in, involves the utilization of a decision worksheet. Psychologists who study optimization compare the actual decisions made by people to theoretical ideal decisions to see how similar they are. Proponents of the worksheet procedure believe that it will yield optimal, that is, the best decisions. Although there are several variations on the exact format that worksheets can take, they are all similar in their essential aspects. Worksheets require defining the problem in a clear and concise way and then listing all possible solutions to the problem. Next, the pertinent considerations that will be affected by each decision are listed, and the relative importance of each consideration or consequence is determined. Each consideration is assigned a numerical value to reflect its relative importance. A decision is mathematically calculated by adding these values together. The alternative with the highest number of points emerges as the best decision.Since most important problems are multifaceted, there are several alternatives to choose from, each with unique advantages and disadvantages. One of the benefits of a pencil and paper decision-making procedure is that it permits people to deal with more variables than their minds can generally comprehend and remember.On the average, people can keep about seven ideas in their minds at once. A worksheet can be especially useful when the decision involves a large number of variables with complex relationships. A realistic example for many college students is the question What will I do after graduation? A graduate might seek a position that offers specialized training, pursue an advanced degree, or travel abroad for a year.A decision-making worksheet begins with a succinct statement of the problem that will also help to narrow it. It is important to be clear about the distinction between long-range and immediate goals because long-range goals often involve a different decision than short-range ones. Focusing on long- range goals, a graduating student might revise the question above to What will I do after graduation that will lead to successful career?1. What does the passage mainly discuss?(A) A tool to assist in making complex decisions.(B) A comparison of actual decisions and ideal decisions(C) Research on how people make decisions(D) Differences between long-range and short-range decision making2. The word essential in line 7 is closest in meaning to(A) introductory(B) changeable(C) beneficial(D) fundamental3. The word pertinent in line 9 is closest in meaning to(A) relevant(B) preceding(C) insightful(D) responsive4. Of the following steps, which occurs before the others in making a decision worksheet?(A) Listing the consequences of each solution(B) Calculating a numerical summary of each solution(C) Deciding which consequences are most important(D) Writing down all possible solutions5. According to decision-worksheet theory, an optimal decision is defined as one that(A) has the fewest variables to consider(B) uses the most decision worksheets(C) has the most points assigned to it(D) is agreed to by the greatest number of people6. The author develops the discussion in paragraph 1 bymeans of(A) describing a process(B) classifying types of worksheets(C) providing historical background(D) explaining a theory7. The author states that On the average, people can keep about seven ideas in their minds atonce (lines 17-18) to explain that(A) most decisions involve seven steps(B) human mental capacity has limitations(C) some people have difficulty making minor as well as major decisions(D) people can learn to keep more than seven ideas in their minds with practice8. The word succinct in line 24 is closest in meaning to(A) creative(B) satisfactory(C) personal(D) concise9. Which of the following terms is defined in the passage(A) Proponents (line 5)(B) Optimal (line 5)(C) Variables (line 17)(D) Long-range goals (line 25)10. The word it in line 24 refers to(A) worksheet(B) problem(C) distinction(D) decision11. The word revise in line 26 is closest in meaning to。
Mechanical Properties of Cu6Sn5, Cu3Sn, and Ni3Sn4 Intermetallic Compounds Measured by
Intermetallic compounds (IMCs) developed on the interface between the solder alloy and its bonding pads play a crucial role in the integrity of the solder joint, and hence the reliability of electronic packages. The Cu6Sn5, Cu3Sn, and Ni3Sn4 binary IMCs are major species in a solder system with Cu or Au/Ni/Cu pad metallizations. Ternary or multielement IMCs such as (Cul-,,Ni,)6Sn5 and (Nil-y,Cuy)3Sn4 can also be frequently found because of the adoption of various Pb-free solder alloys as well as the ease of inter-substitution of Cu and Ni due to their similar atomic sizes and lattice structures [1]. It has been identified that fracturing around the interfacial IMC layer is the primary failure induced by drop impacts in particular for Pb-free solder joints [2,3]. Characterizations of mechanical properties and strengths of IMCs in the structural [4-6] or nanomechanical regime [714] have therefore attracted great interests. In this work, we present nanomechanical properties of Cu6Sn5, Cu3Sn, and Ni3Sn4 IMCs obtained by nanoindentation incorporated with the continuous stiffness measurement (CSM) [15]. For nanoindentation of IMCs, difficulties in obtaining consistent and convergent measurement results have been pointed out by Rhee et al. [7], and data variations were attributed to specimen preparation as well as test methodologies. In most of the cases, Cu-Sn and Ni-Sn IMC samples were obtained by annealing a diffusion couple that placed Sn or a certain solder paste onto a Cu or Ni substrate. A proper annealing process should be sought in order for the IMC layers to grow
探索宇宙奥秘英语作文
探索宇宙奥秘英语作文Title: Exploring the Mysteries of the Universe。
The universe, with its vast expanse and countless wonders, has always captivated the human imagination. From ancient civilizations gazing at the stars to modern-day space exploration, humanity's quest to unravel the mysteries of the cosmos has been relentless. In this essay, we will delve into some of the key areas of exploration in the realm of astrophysics and astronomy, discussing the latest discoveries and ongoing quests for knowledge.One of the fundamental questions driving our exploration of the universe is the nature of its origins. The Big Bang theory, supported by a wealth of observational evidence, suggests that the universe began as a singularity approximately 13.8 billion years ago, expanding and evolving into the vast cosmos we see today. However, many questions remain unanswered about what triggered the Big Bang and what came before it. Scientists continue to searchfor clues that could shed light on these profound mysteries, using tools such as particle accelerators and telescopes to probe the earliest moments of the universe's existence.Another area of intense study is the search for exoplanets – planets orbiting stars outside our solar system. The discovery of thousands of exoplanets in recent years has revolutionized our understanding of planetary systems and the potential for life beyond Earth. Scientists are particularly interested in identifying exoplanetswithin the habitable zone of their host stars, where conditions may be conducive to the existence of liquidwater and, potentially, life as we know it. The development of advanced telescopes and space-based observatories has greatly expanded our ability to detect and characterize exoplanets, bringing us closer to answering the age-old question: are we alone in the universe?Exploring the mysteries of the universe also involves the study of dark matter and dark energy, two enigmatic components that make up the majority of the cosmos. Dark matter, which does not emit or interact withelectromagnetic radiation, exerts gravitational forces that influence the motion of galaxies and galaxy clusters. Despite its pervasive presence, the true nature of dark matter remains unknown, presenting one of the most profound puzzles in modern astrophysics. Similarly, dark energy, a mysterious force driving the accelerated expansion of the universe, poses another tantalizing mystery that continues to defy explanation. Understanding the properties and behavior of dark matter and dark energy is crucial to unraveling the cosmic tapestry and grasping the ultimate fate of the universe.In addition to these cosmic mysteries, scientists are also investigating the possibility of other universes beyond our own. The concept of the multiverse, which posits the existence of countless parallel universes withdifferent physical laws and properties, has gained traction in recent years, fueled by developments in theoretical physics and cosmology. While the idea of a multiverse remains speculative, it offers a fascinating glimpse into the potential diversity and complexity of reality on a cosmic scale.In conclusion, the exploration of the universe is an ongoing journey marked by discovery, wonder, and the relentless pursuit of knowledge. From probing the origins of the cosmos to searching for exoplanets and grappling with the mysteries of dark matter and dark energy, scientists are pushing the boundaries of human understanding to new heights. While many questions remain unanswered, each new revelation brings us closer to unraveling the profound mysteries that lie at the heart of existence itself. As we continue to explore the cosmos, we embark on a voyage of discovery that promises to inspire generations to come.。
苏格拉底英文介绍
Socrates maintained that true reality is knowledge, and that the only way to achieve true happiness and fulfillment is through the cultivation of Wisdom and the avoidance of ignorance
to its well being and specificity
02
The role of the philosopher
Socrates envisioned a role for philosophers in the polis, arguing
that they should participate in public affairs and seek to shape
The impact on modern logic and science
Socrates' teaching on reason and logical thinking has been highly influential in the development of modern logic and science
Introduction to Socrates in English
目录
• The Life of Socrates • Socrates' Philosophical Thought • The influence of Socrates • Socrates' Controversy and Criticism • Socrates' Legacy
跨文化交际中英汉禁忌语对比研究及语言禁忌的应对
1942019年32期总第472期ENGLISH ON CAMPUS跨文化交际中英汉禁忌语对比研究及语言禁忌的应对文/贝 玉在我国，“禁忌”一词由来已久。
早在汉朝，《后汉书·郎顗传》中云：“臣生长草野，不晓禁忌，披露肝胆，书不择言。
”许慎《说文解字》云：“禁，吉凶之忌也”。
可见 “禁”和“忌”在意思上是相近的。
不论是色气禁忌，婚嫁禁忌，还是动物禁忌，都是人们害怕给自己招来凶险而禁止接触某种事物或做出行为。
英语 taboo 一词源于波利尼西亚的汤加语(Tongan)，原意指“神圣超凡的”，后来逐渐发展为专有名词在人类学和社会学中广泛使用。
古今中外，禁忌都是各个民族文化的一个组成部分，而语言作为文化的载体，同样反映着各种文化现象，禁忌语就是其中一种。
在跨文化交际中，禁忌语对不同文化背景的人们进行有效交际造成了一定的障碍。
对禁忌语的研究与学习有助于我们丰富文化知识，开阔视野，避免不必要的误会发生，做一位成功的交际者。
一、英汉禁忌语的相似性虽然衍生于不同的背景，但中英两种文化是存在相似性的，这种相似性同样也体现在禁忌语中。
1.词的体现。
死亡一直是人们最恐惧、最不愿言说的事，因此跟死亡相关的字词带有很深的禁忌色彩，是不可随便提及的。
比如“薨”，本意是指成群的昆虫一起飞的声音；但在古代“薨”用来称诸侯或者有爵位的大官死去，也会用于 皇帝的高等级嫔妃和所生育的皇子公主，或者封王的贵族。
平头百姓也有相应的委婉语，比如“卒”。
在佛教中，和尚的死称为“坐化”，僧尼之死称为“圆寂”。
英语中有关“die”(死)的委婉表达也有很多。
“to return to dust /earth” ，尘归尘，土归土，源于上帝用泥土创造了人。
go to heaven(去天堂)、with God(和上帝在一起)等都是跟宗教文化相关。
再比如，对于女性的性别歧视也体现在两种语言的禁忌中。
中国封建社会历史漫长，汉语中有关性别歧视方面的词汇也非常丰富。
关于体育主持人的英语作文
关于体育主持人的英语作文Sports presenters play a crucial role in the world of sports broadcasting, serving as the bridge between the action on the field and the viewers at home. They are the faces and voices that bring the excitement and drama of sports events to life, captivating audiences and providing a deeper understanding of the games they cover. From live event coverage to in-depth analysis, sports presenters are the driving force behind the delivery of sports content, shaping the way fans engage with and experience their favorite teams and athletes.At the heart of a sports presenter's role is the ability to effectively communicate the nuances and intricacies of a sporting event. They must possess a deep knowledge and understanding of the rules, strategies, and historical context of the sports they cover, allowing them to provide insightful commentary and analysis that enhances the viewer's experience. Whether it's breaking down a game-changing play, highlighting the performance of a standout athlete, or providing context on the broader implications of a match or tournament, sports presenters must have the ability to conveycomplex information in a clear and engaging manner.Beyond their technical expertise, sports presenters must also possess strong communication and interpersonal skills. They are often the public face of a sports network or organization, and as such, they must be able to connect with their audience on a personal level. This involves not only the ability to speak eloquently and confidently on-air, but also the capacity to build rapport with the athletes, coaches, and other key figures they interact with during their coverage.Effective sports presenters are adept at asking the right questions, probing for deeper insights, and fostering a sense of authenticity and transparency in their interactions. They must be able to read the emotions and body language of their interview subjects, adjusting their approach to elicit the most revealing and insightful responses. This ability to establish trust and create a comfortable environment for their guests is essential in helping viewers feel more connected to the stories and narratives that unfold during a sporting event.In addition to their on-air responsibilities, sports presenters often play a crucial role in shaping the overall tone and direction of a broadcast. They work closely with producers, directors, and other members of the production team to ensure that the coverage aligns with the network's or organization's overall branding and messaging. This may involve making decisions about camera angles, graphics,and other visual elements that enhance the viewer's experience, as well as collaborating on the development of pre-game, halftime, and post-game segments that provide added context and analysis.The role of a sports presenter is also evolving with the changing landscape of sports media. As technology continues to advance, these professionals must adapt to new platforms and formats, embracing the opportunities presented by digital and social media to reach and engage with audiences in new and innovative ways. This may involve creating content for streaming services, curating highlights and analysis for social media, or even hosting live interactive sessions with fans, all while maintaining the same high level of expertise and professionalism that has defined their on-air work.At the same time, sports presenters must also navigate the ever-changing dynamics of the sports industry itself. They must be able to respond quickly to breaking news, unexpected events, and shifting narratives, while also maintaining a keen awareness of the broader social and cultural issues that impact the world of sports. This requires a nuanced understanding of the political, ethical, and social implications of the stories they cover, as well as the ability to approach these topics with sensitivity, objectivity, and a commitment to upholding journalistic integrity.Ultimately, the role of a sports presenter is one of immense responsibility and influence. They are the gatekeepers of sports information, the interpreters of the action, and the conduits through which fans engage with and experience the games they love. By combining their technical expertise, communication skills, and deep passion for sports, these professionals play a vital role in shaping the cultural and social significance of the athletic events they cover, leaving an indelible mark on the way we understand and appreciate the world of sports.。
关于金智秀的作文英文
关于金智秀的作文英文Title: The Enigmatic Brilliance of Kim Ji-soo。
Kim Ji-soo, a name that resonates with an air of enigma and brilliance in the realms of literature, philosophy, and cultural discourse. Often hailed as a maverick thinker anda visionary writer, Ji-soo's contributions to the literary landscape are as profound as they are enigmatic. In this exploration, we delve into the multifaceted dimensions of Kim Ji-soo's work, unraveling the layers of meaning and significance that define her legacy.At the heart of Kim Ji-soo's literary prowess lies a profound understanding of the human condition, illuminated through the prism of existentialist thought andphilosophical inquiry. Her writings delve into the depthsof human consciousness, probing the intricacies of identity, existence, and the nature of reality itself. Through her nuanced prose and evocative imagery, Ji-soo invites readers on a journey of introspection and self-discovery,challenging conventional notions of truth and perception.One of the defining characteristics of Kim Ji-soo's work is its thematic richness and philosophical depth. Whether exploring themes of love, loss, alienation, or the search for meaning, Ji-soo's writings transcend mere storytelling, offering profound insights into the complexities of the human experience. Her narratives often unfold like intricate tapestries, weaving together threads of philosophy, psychology, and mythology to create a mosaic of profound beauty and resonance.Central to Kim Ji-soo's literary oeuvre is her exploration of identity and the fluidity of selfhood. In works such as "The Mirror of Eternity" and "Echoes of the Soul," Ji-soo grapples with questions of identity and authenticity in a world defined by flux and uncertainty. Through her characters' existential journeys, she confronts the existential angst of modern existence, inviting readers to confront their own sense of self and purpose in an ever-changing world.Beyond her literary achievements, Kim Ji-soo'sinfluence extends to the realms of cultural criticism and intellectual discourse. As a keen observer of society and culture, Ji-soo's essays and commentary offer incisive analyses of contemporary issues, from the erosion of traditional values to the impact of globalization on individual identity. Her fearless engagement with controversial topics and her unwavering commitment to intellectual honesty have earned her a reputation as a thought leader and cultural icon.In the annals of literary history, Kim Ji-soo occupiesa unique and revered position as a trailblazer and visionary. Her writings continue to inspire and challenge readers across the globe, transcending cultural andlinguistic boundaries to touch the depths of the human soul. As we navigate the complexities of the modern world, Ji-soo's words serve as a guiding light, illuminating the path to greater understanding, empathy, and enlightenment.In conclusion, Kim Ji-soo's legacy as a literary luminary is a testament to the enduring power of art andideas to shape our understanding of ourselves and the world around us. Through her profound insights and evocative prose, Ji-soo invites us to embark on a journey of self-discovery and intellectual inquiry, challenging us to confront the fundamental questions that define our existence. In a world marked by uncertainty and upheaval, Ji-soo's voice remains a beacon of wisdom and clarity, reminding us of the enduring power of literature to illuminate the human experience.。
高中英语 Unit 2 单词解析 【新教材】外研版选择性必修第一册单元单词用法详解
高中英语 Unit 2 单词解析【新教材】外研版选择性必修第一册单元单词用法详解Debt refers to the amount of money that a person owes to someone else。
It can also refer to a negative XXX influence。
For example。
if you owe someone a favor。
you are in their debt。
If you XXX。
you feel a debt of XXX means that you owe a lot of money to someone and it is difficult to pay it back。
If a debt is cancelled or written off。
it means that it is no XXX the amount of debt that a person has.Pace refers to the speed at which something is done or the speed at which someone moves。
It can also refer to the distance covered by one step when walking or running。
To pace means to walk back and forth。
especially due to XXX or something means to move at the same speed as them。
If someone is off the pace。
it means that they are behind the leader in a race。
To put someone or something through their paces means to test their XXX a standard or to lead the way。
学无止境 英语作文
学无止境英语作文Title: The Pursuit of Knowledge Knows No Bounds。
In the realm of human endeavor, the quest for knowledge stands as an eternal pursuit, transcending boundaries and limitations. From the ancient scholars of Greece to the modern-day scientists probing the mysteries of the universe, the insatiable thirst for understanding propels humanity forward on a journey of discovery. In this essay, we delve into the significance of lifelong learning and its profound impact on individual growth and societal progress.First and foremost, the essence of lifelong learninglies in its ability to enrich and empower individuals. Through continuous education and self-improvement, one not only acquires new skills and knowledge but also cultivatesa broader perspective on life. In today's rapidly evolving world, where change is constant and innovation is paramount, the importance of staying abreast of new developmentscannot be overstated. By embracing a mindset of lifelonglearning, individuals equip themselves with theadaptability and resilience needed to thrive in an ever-changing landscape.Moreover, the pursuit of knowledge serves as a catalyst for personal development and fulfillment. As human beings, we are wired to seek meaning and purpose in our lives. Through learning, we embark on a journey of self-discovery, uncovering our passions, interests, and innate talents. Whether it be through formal education, hands-on experience, or intellectual exploration, each encounter with new knowledge expands our horizons and shapes our identity. In this sense, lifelong learning is not merely a means to an end but a lifelong odyssey of growth and self-realization.Furthermore, the impact of lifelong learning extendsfar beyond the individual level, exerting a profound influence on society as a whole. In an increasingly interconnected world, where global challenges require collaborative solutions, the collective pursuit of knowledge becomes imperative. Through education and shared inquiry, societies foster innovation, promote socialcohesion, and address pressing issues such as poverty, inequality, and environmental degradation. Moreover, by promoting a culture of lifelong learning, societies empower citizens to actively engage in civic life, participate in democratic processes, and contribute to the betterment of their communities.However, despite its myriad benefits, the journey of lifelong learning is not without its challenges. In a world inundated with information, navigating the sea of knowledge can be daunting. Moreover, entrenched social inequalities and systemic barriers often limit access to educational opportunities, particularly for marginalized communities.As such, ensuring equitable access to quality education and fostering a supportive learning environment for all remains a critical imperative for policymakers and educators alike.In conclusion, the pursuit of knowledge knows no bounds. From the cradle to the grave, the human quest for understanding propels us forward, shaping our identities, enriching our lives, and transforming societies. In an age defined by rapid change and uncertainty, the importance oflifelong learning cannot be overstated. By embracing a mindset of curiosity, openness, and intellectual humility, we can harness the transformative power of education to create a more just, prosperous, and sustainable world for generations to come.。
学会深入思考的英语作文
学会深入思考的英语作文Title: Mastering the Art of Critical Thinking。
In today's fast-paced world, the ability to think critically is more valuable than ever. Critical thinking goes beyond simply accepting information at face value; it involves analyzing, evaluating, and synthesizing information to form well-reasoned conclusions. In this essay, we will explore the importance of critical thinking and discuss strategies for developing this essential skill.To begin with, critical thinking is crucial for making informed decisions in both personal and professional life. In a world inundated with information, being able to discern between reliable sources and misinformation is vital. Critical thinkers are adept at questioning assumptions, examining evidence, and consideringalternative perspectives before arriving at a conclusion. This skill not only helps individuals navigate complex issues but also fosters innovation and problem-solvingabilities.One of the key components of critical thinking is the ability to ask probing questions. Instead of passively accepting information, critical thinkers actively engage with it by asking questions such as "How do we know this is true?" or "What evidence supports this claim?" By challenging assumptions and seeking evidence, individuals can develop a deeper understanding of a topic and avoid falling prey to cognitive biases.Another important aspect of critical thinking is the capacity for logical reasoning. Critical thinkers are skilled at identifying logical fallacies and inconsistencies in arguments. They are able to construct coherent arguments based on evidence and sound reasoning. Developing logical reasoning skills involves practice and exposure to a variety of arguments and viewpoints.Furthermore, critical thinking requires an open-minded approach to new ideas and perspectives. Instead of clinging to preconceived notions, critical thinkers are willing toconsider alternative viewpoints and revise their beliefs in light of new evidence. This flexibility is essential for adapting to change and fostering intellectual growth.In addition to asking questions and reasoning logically, critical thinking also involves effective communication skills. Being able to articulate one's thoughts clearly and persuasively is essential for conveying ideas and engagingin constructive dialogue. Critical thinkers are able to communicate their reasoning process effectively, which enables them to influence others and collaborate productively.So, how can one develop the skill of critical thinking? Like any skill, it requires practice and dedication. Oneway to cultivate critical thinking is to engage with challenging material that encourages deep reflection and analysis. This could involve reading thought-provoking books, engaging in debates, or solving complex problems.Furthermore, seeking out diverse perspectives and engaging with people who hold different viewpoints can helpbroaden one's thinking and foster intellectual humility. Additionally, actively seeking feedback from others and being open to constructive criticism can help identify blind spots and areas for improvement.In conclusion, mastering the art of critical thinking is essential for navigating the complexities of the modern world. By asking probing questions, reasoning logically, remaining open-minded, and honing effective communication skills, individuals can become adept critical thinkers. Through practice and dedication, anyone can develop this invaluable skill and approach life's challenges with clarity and confidence.。
英语作文写教师的伟大事迹
英语作文写教师的伟大事迹The Great Deeds of Teachers。
Teachers are the unsung heroes of society, tirelessly working behind the scenes to mold and shape the minds of the future generation. Their dedication, sacrifice, and unwavering commitment to their students make them true beacons of light in an often tumultuous world. In this essay, we will explore some of the great deeds performed by teachers and the profound impact they have on individuals and communities alike.First and foremost, teachers possess the remarkable ability to ignite a spark of curiosity and passion for learning in their students. Through their innovative teaching methods, engaging lesson plans, and genuine enthusiasm for their subject matter, they inspire young minds to explore new ideas, ask probing questions, and strive for excellence. Whether it's through hands-on experiments in the science lab, thought-provokingdiscussions in the classroom, or immersive experiences in the great outdoors, teachers have a unique talent for making learning come alive.Moreover, teachers serve as mentors, guides, and role models for their students, imparting not only academic knowledge but also invaluable life lessons and skills. They teach resilience in the face of adversity, compassion for others, and the importance of integrity and honesty. Beyond the confines of the classroom, teachers often go above and beyond to support their students in times of need, offering a listening ear, words of encouragement, and practical assistance to help them overcome obstacles and reach their full potential.In addition to their roles as educators and mentors, teachers play a vital role in fostering a sense of community and belonging within schools. By creating a supportive and inclusive learning environment where every student feels valued, respected, and accepted, they lay the foundation for academic success and personal growth. Through extracurricular activities, volunteer initiatives,and collaborative projects, teachers encourage collaboration, teamwork, and empathy, instilling in their students the values of cooperation and solidarity that are essential for building a better world.Furthermore, teachers often make significant sacrifices in their personal lives to ensure the success and well-being of their students. They spend countless hours outside of school preparing lesson plans, grading assignments, and attending professional development workshops to continually improve their craft. They invest their own time, resources, and energy to provide enriching learning experiences and opportunities for their students, often putting their own needs and desires on hold in the process.Finally, the impact of a great teacher extends far beyond the classroom and can ripple through the lives of countless individuals for years to come. Many people can look back on their formative years and pinpoint aparticular teacher who made a lasting impression on them, inspiring them to pursue their passions, overcome obstacles, and achieve their dreams. Whether it's a former student whogoes on to become a successful entrepreneur, a groundbreaking scientist, or a compassionate humanitarian, the influence of a dedicated teacher can be felt in every aspect of their lives.In conclusion, teachers perform countless acts of greatness each and every day, shaping the future one student at a time. From igniting a love of learning to providing guidance and support, fostering a sense of community, making sacrifices, and leaving a lasting legacy, the contributions of teachers to society are immeasurable. As we celebrate their achievements and express ourgratitude for their tireless dedication, let us neverforget the profound impact they have on the lives of individuals and communities around the world.。
科学和品德的英语作文
科学和品德的英语作文Title: The Interplay between Science and Ethics。
In the ever-evolving landscape of human knowledge and endeavor, the realms of science and ethics stand as two pillars that shape our understanding of the world and our actions within it. While science delves into the empirical exploration of phenomena and the pursuit of knowledge, ethics provides the moral compass guiding our conduct and decisions. The intricate interplay between these two domains is crucial for navigating the complexities of our modern society.First and foremost, science, with its methodological rigor and empirical inquiry, uncovers the mysteries of the universe, advancing our understanding of nature and technology. From unraveling the genetic code to probing the depths of space, scientific endeavors have revolutionized human existence, offering solutions to pressing challenges and enriching our lives in countless ways. However, theethical dimension becomes indispensable in determining the responsible use and application of scientific discoveries.Ethics serves as the guardian of moral principles, ensuring that scientific progress aligns with human values and societal welfare. The ethical considerations surrounding scientific research encompass a broad spectrum of issues, including the protection of human rights, environmental sustainability, and the equitabledistribution of resources. For instance, the development of genetic engineering raises profound ethical questions regarding the manipulation of life and the potential consequences for future generations. Similarly, advances in artificial intelligence prompt reflections on the ethical implications of autonomy, privacy, and accountability.Moreover, the ethical dimension of science extends beyond the research laboratory to encompass the broader social and cultural context. Science does not operate in a vacuum but within a framework of values, norms, and power dynamics that shape its trajectory. The ethical responsibility of scientists entails not only adherence toprofessional codes of conduct but also active engagement with diverse stakeholders to address ethical dilemmas and foster inclusive decision-making processes.Furthermore, the relationship between science andethics is dynamic and reciprocal, with each domain influencing and informing the other. Ethical considerations may influence the direction of scientific inquiry, prompting researchers to prioritize certain lines of investigation or to adopt precautionary measures in the face of uncertain risks. Conversely, scientific knowledge can shed light on ethical debates, providing empirical evidence and critical insights that inform ethical reasoning and policy-making.In navigating the interface between science and ethics, education plays a pivotal role in fostering ethical awareness and critical thinking among scientists and the broader public. By integrating ethics into scientific training and curriculum, future generations of researchers can develop a nuanced understanding of the ethical dimensions of their work and cultivate a sense ofresponsibility towards the ethical implications of their research.In conclusion, the interplay between science and ethics is intrinsic to the pursuit of knowledge and the advancement of human civilization. While scienceilluminates the mysteries of the universe and empowers us with technological prowess, ethics guides our moral deliberations and ensures that scientific progress serves the common good. By fostering dialogue, collaboration, and ethical reflection, we can harness the transformative potential of science to create a more just, sustainable, and compassionate world.。
以穿透力为话题的作文600字
以穿透力为话题的作文600字英文回答：In the tapestry of life, the power of penetration serves as an indispensable thread, weaving its transformative influence through the fabric of our existence. It is the ability to pierce through obstacles, uncover hidden truths, and forge a path towards enlightenment.As humans, we are endowed with a natural drive to penetrate the veil of ignorance. From the dawn of civilization, we have sought knowledge and understanding, relentlessly probing the mysteries of the world around us. Through scientific inquiry, philosophical contemplation, and artistic expression, we have endeavored to penetrate the depths of our own minds and the complexities of the universe.Penetration transcends the realm of physical barriers.It encompasses the ability to pierce through emotional and psychological obstacles that hinder our growth and fulfillment. When we confront our fears, delve into our vulnerabilities, and embrace uncomfortable truths, we penetrate the walls that have confined us. This process of self-discovery is essential for personal transformation and the attainment of true freedom.Additionally, penetration can manifest in the realm of communication. Effective communication requires the ability to convey ideas and emotions with clarity and conviction. By penetrating the listener's mind, we can foster understanding, inspire change, and forge meaningful connections.In essence, the power of penetration is the ability to pierce through limitations and access the boundless possibilities that lie within ourselves and the world. Itis a force that drives human progress, empowers personal growth, and illuminates the path towards a brighter future.中文回答：穿透力在生命中扮演着至关重要的角色，它编织成不可或缺的线索，深深影响着我们的存在。
谁对谁有重大影响英语作文
谁对谁有重大影响英语作文Title: Significant Influences Between Individuals。
In the intricate tapestry of human interactions,certain relationships bear significant influence, shaping destinies, perspectives, and actions. Whether through mentorship, friendship, or familial bonds, these influences leave indelible marks on individuals. Let us delve into some notable instances where one individual profoundly impacts another.Firstly, the mentor-mentee relationship stands as a quintessential example of profound influence. History brims with instances where mentors, through their wisdom and guidance, have sculpted the paths of their protégés. Take, for instance, the bond between Socrates and Plato. Socrates, with his probing inquiries and philosophical acumen, profoundly influenced Plato's worldview and philosophical doctrines. Plato, in turn, immortalized his mentor's teachings, thereby perpetuating Socrates' intellectuallegacy through his dialogues and treatises.Friendship, too, serves as a crucible for profound influence. Consider the friendship between J.R.R. Tolkien and C.S. Lewis, two literary titans whose bond transcended mere camaraderie. Their intellectual exchanges and shared love for mythology and storytelling fueled each other's creativity, giving rise to masterpieces like "The Lord of the Rings" and "The Chronicles of Narnia." Through their friendship, they not only enriched each other's lives but also left an enduring imprint on the landscape of fantasy literature.Furthermore, familial relationships wield unparalleled influence over individuals. The parent-child dynamic, in particular, lays the groundwork for a lifetime of influence. From childhood to adulthood, parents mold their children's values, aspirations, and character. The profound impact of parental influence is evident in the life of Albert Einstein, whose father's encouragement of intellectual pursuits during his formative years laid the foundation for his groundbreaking contributions to theoretical physics.Moreover, the sway of influence extends beyond conventional relationships to encompass encounters with strangers or distant figures. Consider the impact of historical figures like Mahatma Gandhi or Nelson Mandela, whose ideologies and actions continue to inspiregenerations long after their passing. Through their courage, resilience, and unwavering commitment to justice, they have kindled flames of hope and catalyzed social change on a global scale.In conclusion, the fabric of human existence is woven with threads of influence that bind individuals together in myriad ways. Whether through mentorship, friendship,familial bonds, or encounters with distant figures, the exchange of ideas, values, and experiences shapes destinies and leaves an indelible mark on the tapestry of life. As we navigate the complex web of relationships, let us recognize and cherish the profound influences that enrich our lives and shape our collective journey.。
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Probing the influence of the center atom coordination structure in iron phthalocyanine multi-walled carbon nanotube-based oxygen reduction reaction catalysts by X-ray absorptionfine structure spectroscopyYingxiang Peng a,Zhipan Li a,Dingguo Xia b,Lirong Zheng c,Yi Liao a,Kai Li a,Xia Zuo a,*a Department of Chemistry,Capital Normal University,Beijing100048,PR Chinab College of Engineering,Peking University,Beijing100871,PR Chinac Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing100049,PR Chinah i g h l i g h t s g r a p h i c a l a b s t r a c tThe pentacoordinate FePc electro-catalysts are prepared by a micro-wave method.XAFS technique reveals the connec-tion of molecular structure and ORR activity.The coordination geometry of FePc is closer to square pyramidal structure by XANES.A smaller radius of phthalocyanine ring can be obtained in FePc e Py/ MWCNTs byEXAFS.a r t i c l e i n f oArticle history:Received21February2015Received in revised form15April2015Accepted27April2015Available online15May2015Keywords:Iron-phthalocyanineMulti-walled carbon nanotubesMicrowave synthesisOxygen reduction reaction PentacoordinateX-ray absorptionfine structure spectroscopy a b s t r a c tThree different pentacoordinate iron phthalocyanine(FePc)electrocatalysts with an axial ligand(pyridyl group,Py)anchored to multi-walled carbon nanotubes(MWCNTs)are prepared by a microwave method as high performance composite electrocatalysts(FePc e Py/MWCNTs)for the oxygen reduction reaction (ORR).For comparison,tetracoordinate FePc electrocatalysts without an axial ligand anchored to MWCNTs(FePc/MWCNTs)are assembled in the same way.Ultraviolet e visible spectrophotometry(UV e Vis),Raman spectroscopy(RS),and high-resolution transmission electron microscopy(HRTEM)are used to characterize the obtained electrocatalysts.The electrocatalytic activity of the samples is measured by linear sweep voltammetry(LSV),and the onset potential of all of the FePc e Py/MWCNTs electrocatalysts is found to be more positive than that of their FePc/MWCNTs counterparts.X-ray photoelectron spectroscopy(XPS)and X-ray absorptionfine structure(XAFS)spectroscopy are employed to elucidate the relationship between molecular structure and electrocatalytic activity.XPS indicates that higher concentrations of Fe3þand pyridine-type nitrogen play critical roles in determining the electro-catalytic ORR activity of the samples.XAFS spectroscopy reveals that the FePc e Py/MWCNTs electro-catalysts have a coordination geometry around Fe that is closer to the square pyramidal structure,a higher concentration of Fe3þ,and a smaller phthalocyanine ring radius compared with those of FePc/ MWCNTs.©2015Elsevier B.V.All rights reserved.*Corresponding author.E-mail address:zuoxia@(X.Zuo).Contents lists available at ScienceDirect Journal of Power Sourcesjournal ho mep age:/locate/jpowsour/10.1016/j.jpowsour.2015.04.1580378-7753/©2015Elsevier B.V.All rights reserved.Journal of Power Sources291(2015)20e281.IntroductionCathode catalysts for the oxygen reduction reaction(ORR) are regarded as the chief technology for the improvement of direct methanol fuel cells(DMFCs).Although platinum(Pt)and its alloys are the most effective cathode catalysts for DMFCs[1], the practical applications of DMFCs are still limited by the prohibitive cost,poor durability,and scarce reserves of Pt and Pt-based precious metals[2e5].For the sustainable commer-cialization of DMFCs,low-cost,non-precious metal catalysts such as transition metal N4-macrocycles,especially metal phthalocyanine(MPc)macrocyclic catalysts[6e10],have been considered as a suitable alternative to Pt and its alloys for the ORR.Particularly,iron phthalocyanine(FePc)complexes have been shown to exhibit excellent ORR activity compared with that of MPc complexes with other central metals[11].However, the wide application of FePc is limited by its low electric con-ductivity in acidic media and its instability for the ORR[8,13]. To improve the poor conductivity of MPc complexes,various carbon materials(CM)have been mixed with MPc complexes (MPc/CM)to enhance the overall electrochemical performance of the resulting composite materials[8,9,11,12,14e18],such as single-walled carbon nanotubes(SWCNTs)[8,16],multi-walled carbon nanotubes(MWCNTs)[12,17],and graphene(GR)[18]. Additionally,one traditional approach used to enhance the ac-tivity of FePc/CM-type non-precious metal catalysts involves a high temperature pyrolysis process[19e21].High-temperature pyrolysis can improve the activity and durability of FePc/CM-type catalysts fabricated by complex preparation methods. Accordingly,the molecular structures of the catalysts and the catalytic mechanism are obviously unpredictable[22],which make it difficult to rationally design FePc/CM-type catalysts for ORR.Another approach has seen the design of non-pyrolyzed pentacoordinate FePc electrocatalysts anchored to pyridine-functionalized carbon nanotubes,which are inspired by the unique feature of the active site in cytochrome c oxidase[23]. However,the reason the ORR electrocatalytic activity of pen-tacoordinate FePc electrocatalysts is better than that of tetra-coordinate FePc electrocatalysts has not been fully revealed. Therefore,the development of a method for identifying the mechanism of ORR in these catalysts is of crucial importance to the research and development of non-precious metal catalysts for DMFC applications.The key factors influencing catalytic activity and stability depend on the molecular-scale structures,such as the coordi-nation structures and geometric structures of the active site.X-ray absorptionfine structure(XAFS)spectroscopy,which in-volves X-ray absorption near edge structure(XANES)and extended X-ray absorptionfine structure(EXAFS)measure-ments,may be used to reveal the correlation between the electrocatalytic activity and the coordination structures and geometric structures of FePc/CM-type catalysts.XANES can provide data related to the oxidation states and the coordina-tion geometry of the center metal atom[24,25],while EXAFS is a powerful tool that can provide chemical speciation data such as local crystal structure,bond distance,and coordination number[26e30].In this work,three pentacoordinate FePc electrocatalysts (FePc e Py/MWCNTs)were prepared by a microwave method.For comparison,three tetracoordinate FePc electrocatalysts(FePc/ MWCNTs)were fabricated in the same way.XAFS spectroscopy and X-ray photoelectron spectroscopy(XPS)were used to reveal how the molecular-scale structures affect the ORR electrocatalytic ac-tivity in these catalysts.2.Experimental2.1.Catalyst preparation2.1.1.Pyridine-functionalized MWCNTs(Py/MWCNTs)by diazonium salt reactionBefore synthesis of the electrocatalysts,MWCNTs(0.01g,outer diameter¼6e13nm,length¼2.5e20m m,Sigma Aldrich)were purified with a concentrated HCl solution for5days and then refluxed for5h.The purified MWCNTs were thoroughly washed with water and acetone,and then dried in a vacuum at80 C overnight.In a typical synthesis[23],NaNO2(0.07mol)was dissolved in 7mL of H2O,and then cooled to0 C in an ice bath.4-aminopyridine(4-AP,0.07mol)was dissolved in5mL of 4mol LÀ1HCl,and then also cooled to0 C.The NaNO2solution was then added to the4-AP solution.The mixture was maintained at0 C in an ice bath and stirred for30min,after which a yellow reaction mixture was obtained.After that,the purified MWCNTs (0.1g)were dispersed in200mL of N,N-dimethylformamide (DMF)using a bath sonicator for2.5h,and then cooled to0 C. The yellow reaction mixture of NaNO2and4-AP was added to the MWCNTs solution while the temperature was maintained at0 C. The mixture was reacted at0 C for3h and then stirred at room temperature for15h.The resulting product(Py/MWCNTs)was obtained byfiltering and washing with2mol LÀ1HCl,2mol LÀ1 NaOH,water,and acetone until thefiltrate was colorless.Finally, the obtained Py/MWCNTs were dried in a vacuum at80 C overnight.2.1.2.Synthesis of pentacoordinate electrocatalysts of FePc e Py/ MWCNTsTo prepare the electrocatalysts,1,2-dicyanobenzene(0.5mmol), anhydrous ferric chloride(0.125mmol)and Py/MWCNTs(0.01g) were dispersed in3mL of N,N-dimethyl ethanolamine(DMEA). After stirring for20min,the mixture was placed in a microwave reactor and heated to120 C at150W for8min.After cooling to room temperature,the reaction mixture was transferred to aflask containing50mL ethanol and was refluxed for1h.The obtained precipitate wasfiltered,washed with anhydrous methanol, acetone,2%hydrochloric acid,and doubly distilled water until the filtrate was colorless,andfinally dried in a vacuum at80 C over-night.The obtained catalysts are hereafter denoted as mononuclear FePc e Py/MWCNTs(m-FePc e Py/MWCNTs).Binuclear FePc e Py/MWCNTs(b-FePc e Py/MWCNTs)were ob-tained using the same method and conditions described above, except that the1,2-dicyanobenzene(0.5mmol)was changed to a mixture of1,2-dicyanobenzene(0.195mmol)and1,2,4,5-tetracyanobenzene(0.033mmol).Poly FePc e Py/MWCNTs(p-FePc e Py/MWCNTs)were obtained as above except that the1,2-dicyanobenzene(0.5mmol)was changed to1,2,4,5-tetracyanoquinodimethane benzene(0.5mmol).2.1.3.Synthesis of tetracoordinate FePc/MWCNTs electrocatalystsThe same procedures as described above except with MWNCTs instead of Py/MWCNTs were used to synthesize m-FePc/MWCNTs, b-FePc/MWCNTs,and p-FePc/MWCNTs.2.2.Electrocatalytic property measurementsElectrochemical measurements were performed on an SP-200 electrochemical workstation(Bio-Logic SA)with a standard three-electrode system using O2-saturated0.5mol LÀ1H2SO4so-lution at room temperature.A glassy-carbon(GC)disk(diameter 4mm)was used as the working electrode,while a gauze platinumY.Peng et al./Journal of Power Sources291(2015)20e2821electrode(Pt)and a mercury/mercurous sulfate electrode(Hg/ Hg2SO4)with saturated K2SO4solution were used as the counter and reference electrodes,respectively.To prepare the working electrode,the surface of the GC wasfirst polished with alumina powder.The catalyst ink was prepared by mixing5mg of the catalyst with1mL of ethanol containing25m L of Nafion®solution (2wt.%),followed by ultrasonic treatment for0.5h.Then,10m L of the ink was deposited onto the surface of the GC electrode and dried at room temperature for30min.The cyclic voltammetry(CV) testing system wasfirst established before investigating the ORR catalytic activity of the electrocatalysts.All CV tests were per-formed betweenÀ0.6and0.6V(vs.Hg/Hg2SO4)in O2-saturated electrolyte with a potential scan rate of20mV sÀ1.The ORR curves of the FePc/MWCNTs and Pt/C(Pt,nominally20%on carbon black; Alfa Aesar,USA)were obtained using linear sweep voltammetry (LSV)with a rotating disk electrode(RDE)system(1600rpm)and a potential range fromÀ0.9to0.4V at a scan rate of5mV sÀ1.Our synthetic strategy and the electrochemical measurement results for the electrocatalysts are shown in Scheme1.2.3.Characterization of physical parametersRaman spectra(RS)measurements were recorded on a Raman imaging microscope system(Renishaw Corporation)with an excitation wavelength of632.8nm.Ultraviolet and visible spec-trophotometry(UV e Vis)was performed using a UV-2550UV e vi-sible spectrophotometer(Shimadzu Corporation,Japan).The morphology and microstructure of the synthesized catalyst mate-rials were investigated by high-resolution transmission electron microscopy(HRTEM;FEI Tecnai F20,Japan).The chemical states and the amount of nitrogen contained in the catalysts were analyzed by XPS(Thermo ESCALAB250,UK).Determination of the Fe content in the electrocatalysts was performed by inductively coupled plasma mass spectrometry(ICP-MS;7500-Ce,Agilent).The electronic structure and local geometry of the Fe in the catalysts were investigated by XAFS(BSRF synchrotron facility).The Fe K-edge spectra were measured influorescence mode using a double-crystal Si(111)monochromator.XAFS spectroscopy consists of two parts,the X-ray absorption near edge structure(XANES)and the extended X-ray absorptionfine structure(EXAFS).The XAFS data were analyzed using the Athena software package.3.Results and discussion3.1.Raman spectroscopy of MWCNTs and Py/MWCNTsRaman spectroscopy(RS)is the most direct and nondestructive technique for investigating the structural changes ofcarbon Scheme1.The synthetic strategy and the electrochemical measurement results for the electrocatalysts.Y.Peng et al./Journal of Power Sources291(2015)20e2822materials [31].The Raman spectra of Py/MWCNTs on sheet glass were collected by micro-Raman spectroscopy at an excitation wavelength of 514nm.For comparison,the spectra of pristine MWCNTs were also collected under the same conditions.As shown in Fig.1,the D band located at 1325cm À1corresponds to sp 3hy-bridized carbons in the hexagonal framework of the nanotube walls,and the G band around 1592cm À1is assigned to the char-acteristic tangential modes of the nanotube walls [32].The in-tensity of the D band in the Py/MWCNTs (I D :I G ¼1.88:1)was clearly lower than that of the MWCNTs (I D :I G ¼1.28:1),which indicates that there were more sp 3hybridized carbons in the Py/MWCNTs than in the MWCNTs.In other words,the Py groups were connected to the MWCNTs through covalent functionalization by the diazo-nium salt reaction.Moreover,the presence of the characteristic vibrational peaks (648,994,1048,and 2983cm À1)[33]of the pyridine ring in the spectrum of the Py/MWCNTs further con firmed the above conclusion.3.2.Morphology and structure of FePc e Py/MWCNTs and FePc/MWCNTsUsing dimethyl sulfoxide (DMSO)as the solvent,FePc e Py/MWCNTs and FePc/MWCNTs electrocatalysts were characterized by UV e Vis.As shown in Fig.2,the Q-band absorption peaks of MPc compounds were observed in the visible region (651e 696nm)[34],indicating that FePc had been formed in the FePc e Py/MWCNTs and FePc/MWCNTs electrocatalysts.As shown in Fig.2(A e C),the Q-bands of FePc e Py/MWCNTs were red-shifted compared with those of FePc/MWCNTs (m-FePc e Py/MWCNTs,655nm >m-FePc/MWCNTs,651nm;b-FePc e Py/MWCNTs,666nm >b-FePc/MWCNTs,662nm;p-FePc e Py/MWCNTs,696nm >p-FePc/MWCNTs,691nm).This suggests that the lowest unoccupied mo-lecular orbitals (LUMO)of FePc e Py/MWCNTs had lower energy than those of FePc/MWCNTs,indicating that the FePc e Py/MWCNTs were more inclined to donate electrons owing to the introduction of Py groups.The morphology of FePc e Py/MWCNTs and FePc/MWCNTs was examined by HRTEM.The FePcs were found to be coated onto the surface of the Py/MWCNTs or the MWCNTs in all FePc e Py/MWCNTs and FePc/MWCNTs samples.Fig.3(A)and (B)display the morphology of p-FePc/MWCNTs and p-FePc e Py/MWCNTs,respec-tively.In Fig.3(A),FePcs with a thickness of about 4e 7nm were attached to the surface of the MWCNTs by p e p interactions.When the MWCNTs were combined with FePcs through pyridyl groups after modi fication by the diazonium salt reaction,the FePcs had a thickness of approximately 5e 8nm (Fig.3(B)).3.3.Electrocatalytic properties of FePc e Py/MWCNTs and FePc/MWCNTs towards ORRFig.4shows the polarization curves of linear sweep voltam-mograms (LSV)measured for FePc e Py/MWCNTs,FePc/MWCNTs and Pt/C (Pt,nominally 20%on carbon black;Alfa Aesar,USA)in O 2-saturated 0.5mol L À1H 2SO 4at room temperature.Fig.4(A)pre-sents the results for the mononuclear electrocatalysts,and in-dicates that the onset potential (0.72V vs.NHE)and diffusion limiting current (3.3mA cm À2)of m-FePc e Py/MWCNTs are more positive than those of m-FePc/MWCNTs (0.53V,1.8mA cm À2).Fig.4(B)and (C)show the results obtained for the binuclear elec-trocatalysts and poly electrocatalysts,respectively,from which the same observations can be made,where the onset potential and diffusion-limiting current of FePc e Py/MWCNTs are more positive (b-FePc e Py/MWCNTs,0.71V, 2.6mA cm À2>b-FePc/MWCNTs,0.60V,1.2mA cm À2;p-FePc e Py/MWCNTs,0.78V,3.2mA cm À2>p-FePc/MWCNTs,0.71V,2.7mA cm À2).In conclusion,the introduc-tion of Py groups in FePc e Py/MWCNTs was bene ficial to their ORR activity.As shown in Fig.4(D),the onset potential and diffusion-limiting current of p-FePc e Py/MWCNTs (0.78V, 3.2mA cm À2,respectively)approached those of Pt/C (0.87V and 3.5mA cm À2,respectively).It is important for the electrocatalysts to exhibit long-term stability.The stability of the poly electrocatalysts and Pt/C was evaluated by a chronoamperometric approach [35].Fig.5shows the current versus time (i e t)plots for p-FePc e Py/MWCNTs,p-FePc/MWCNTs and Pt/C over 48h.The p-FePc e Py/MWCNTs exhibited the least current loss of 14.8%after 48h,and the p-FePc/MWCNTs showed a current loss of 20.5%after 48h.In contrast,Pt/C showed poor stability with a current loss of 64.9%after 48h.In other words,these results indicate that p-FePc e Py/MWCNTs have good ORR stability compared with p-FePc/MWCNTs and Pt/C.The methanol tolerance of the cathode electrocatalyst has become a signi ficant factor since the electrocatalysts were devel-oped for DMFCs.Hence,the methanol tolerance measurement of p-FePc e Py/MWCNTs was evaluated in an O 2-saturated solution of 0.5mol L À1H 2SO 4containing 1mol L À1of methanol [36].Fig.6shows the methanol tolerance of the p-FePc e Py/MWCNTs.For comparison,the data of p-FePc/MWCNTs and Pt/C are presented in Fig.S5(A)and (B).There is little activity loss in the p-FePc e Py/MWCNTs,which suggests an excellent tolerance to methanol poisoning.3.4.X-ray photoelectron spectroscopy analysisXPS was performed to verify the composition of the investigated catalysts.The atomic compositions of FePc e Py/MWCNTs and FePc/MWCNTs are listed in Table 1.ICP-MS was also performed to con firm the Fe content of all electrocatalysts,and the results are included in Table 1.In particular,the Fe2p spectra were used to provide further explanation for the ORR activity of all the FePc e Py/MWCNTs and FePc/MWCNTs samples.The Fe content of FePc e Py/MWCNTs was higher than that of FePc/MWCNTs (m-FePc e Py/MWCNTs >m-FePc/MWCNTs;b-FePc e Py/MWCNTs >b-FePc/MWCNTs;p-FePc e Py/MWCNTs >p-FePc/MWCNTs).Considering the ORR results mentioned above,we can conclude that FePc e Py/MWCNTs demonstrate better electrocatalytic properties when their iron content is high.To further explore how the iron content in fluences the ORR activity,Fig.7shows the high-resolution Fe2p XPS spectra of the FePc e Py/MWCNTs and FePc/MWCNTs samples.Two bands could be observed for all samples,which correspond to lower energy (Fe2p 3/2)and higher energy (Fe2p 1/2)asymmetric bands origi-nating from spin e orbital splitting [37].The standard Fe2p 3/2/Fe2p1/Fig.1.Raman spectra of MWCNTs (solid line)and Py/MWCNTs (dotted line).Y.Peng et al./Journal of Power Sources 291(2015)20e 28232signals for Fe 2þand Fe 3þare located at 709.2eV/722.8eV and 711.2eV/724.8eV,respectively [37].All of the fitting parameters are listed in Table 2.It can be concluded that there was more Fe 3þpresent in FePc e Py/MWCNTs than in FePc/MWCNTs:m-FePc e Py/MWCNTs (Fe 2þ:Fe 3þ¼1:2.865)>m-FePc/MWCNTs (Fe 2þ:Fe 3þ¼1:1.326);b-FePc e Py/MWCNTs (Fe 2þ:Fe 3þ¼1:1.905)>b-FePc/MWCNTs (Fe 2þ:Fe 3þ¼1:1.326);p-FePc e Py/MWCNTs (Fe 2þ:Fe 3þ¼1:1.114)>p-FePc/MWCNTs (Fe 2þ:Fe 3þ¼1:0.709).With regard to the ORR results mentioned above,we can conclude that a higher concentration of Fe 3þin FePc e Py/MWCNTs is favorable for ORR activity [38].It has been proposed that the chemical states and amount of nitrogen in a catalyst in fluence on its ORR activity [39e 42].Fig.8presents the high-resolution N1s XPS spectra of the FePc e Py/MWCNTs and FePc/MWCNTs samples.According to the literature [43e 45],the N1s XPS spectra were decomposed into four peaks at binding energies of 398.6±0.3eV,399.5±0.3eV,401.3±0.3eV,and 403.3±0.3eV,assigned to pyridinic e N,pyrrolic e N,graph-itic e N,and pyridine e N-oxide,respectively.The relative concen-trations of each of the nitrogen species are listed in Table 3.Analyzing the results in Fig.8(A),it is clear that the pyridinic e N concentration of m e PcFe-Py/MWCNTs (11.41%pyridinic e N)was increased in comparison with that of the m-PcFe-MWCNTs sample (4.19%pyridinic e N).The same conclusion was obtained for the other electrocatalysts (Fig.8(B)and (C)):FePc e Py/MWCNTs had a higher pyridinic e N concentration (b-FePc e Py/MWCNTs,32.79%pyridinic e N >b-FePc/MWCNTs, 2.17%pyridinic e N;p-FePc e Py/MWCNTs,57.56%pyridinic e N >p-FePc/MWCNTs,40.69%pyridinic e N),which is why the FePc e Py/MWCNTs (Fe e N 5)sam-ples exhibited higher electrocatalytic activity than that of the FePc/MWCNTs (Fe e N 4).Combined with the electrochemical results,it can be inferred that the introduction of pyridinic e N in the FePc e Py/MWCNTs electrocatalysts played a critical role in deter-mining their electrocatalytic ORR activity and the stability of their Fe e N x macrocycles [46].3.5.XANES and EXAFS analysesTo further determine the effect of the atomic coordination and geometric structures of the iron in FePc e Py/MWCNTs and FePc/MWCNTs on their ORR activity,XAFS measurements were carried out using a synchrotron radiation light source.The normalized K-edge XANES spectra of the electrocatalysts are shown in Fig.9,and the insets are enlargements of the pre-edge peak at 7114eV.The small pre-edge peak at 7114eV is assigned to a dipole-forbidden but quadrupole-allowed 1s /3d transition,typical for square-pyramidal Fe(III)complexes [47].In other words,the presence of a strong small pre-edge peak at 7114eV indicates that the coordi-nation geometry around Fe is closer to the square pyramidal structure.As indicated in Fig.9(A e C),the FePc e Py/MWCNTs elec-trocatalysts had a stronger pre-edge peak at 7114eV compared with that of the FePc/MWCNTs electrocatalysts,whichindicatesFig.2.UV e vis absorption spectra of DMSO solutions of the mononuclear (A),binuclear (B),and poly electrocatalysts(C).Fig.3.HRTEM images of p-FePc/MWCNTs (A)and p-FePc e Py/MWCNTs (B).Y.Peng et al./Journal of Power Sources 291(2015)20e 2824that the diazonium salt reaction introduced more five-coordinate structures into the FePc e Py/MWCNTs.The small pre-edge peak was weak for the FePc/MWCNTs electrocatalysts,which may have been caused by some impurity atoms (such as oxygen atoms)be-tween the phthalocyanine structure and the MWCNTs.However,when pyridine groups were introduced as an axial ligand anchored between the phthalocyanine structure and the MWCNTs,the small pre-edge peak intensity of the FePc e Py/MWCNTs electrocatalysts was increased.As a result,the increased amount of N ligand had a major in fluence on oxygen reduction performance.The likely reason for this is that after transferring electrons to oxygen,the iron atoms need to replenish their lost electrons through the MWCNTs.Meanwhile,the aromatic structure and small molecular size of pyridine favor fast electron transfer from MWCNTs to FePc for ORR.Moreover,the white-line-peak observed for the FePc e Py/MWCNTs electrocatalysts was stronger than that of the FePc/MWCNTselectrocatalysts (m-FePc e Py/MWCNTs >m-FePc/MWCNTs;b-FePc e Py/MWCNTs >b-FePc/MWCNTs;p-FePc e Py/MWCNTs >p-FePc/MWCNTs)after the introduction of the pyridine group.TheFig.4.The LSV curves of mononuclear (A),binuclear (B),poly electrocatalysts (C),and poly electrocatalysts and Pt/C (D)at room temperature in 0.5mol L À1H 2SO 4solution saturated with O 2.The LSV technique was applied at a rotation rate of 1600rpm and a scan rate of 5mV s À1.Fig.5.Chronoamperometric responses (percentage of current retained against oper-ation time)of p-FePc e Py/MWCNTs,p-FePc/MWCNTs,andPt/C.Fig.6.The LSV curves for p-FePc e Py/MWCNTs at a rotation rate of 1600rpm in O 2-saturated 0.5mol L À1H 2SO 4with and without 1mol L À1methanol.Table 1Atomic compositions of FePc e Py/MWCNTs and FePc/MWCNTs (the data of XPS and the data of ICP-MS).SimpleThe data of XPS The data of ICP-MS C1s (%)N1s (%)O1s (%)Fe2p (%)Fe (wt%)Fe (%)m-PcFe/MWCNTs 90.22 2.73 6.670.38 1.740.386m-PcFe e Py/MWCNTs 82.44 5.0412.120.40 1.760.403b-PcFe/MWCNTs 81.98 6.8310.700.49 2.110.481b-PcFe e Py/MWCNTs 77.409.3012.740.56 2.400.554p-PcFe/MWCNTs 78.9314.22 6.280.57 2.540.580p-PcFe e Py/MWCNTs69.7420.179.490.602.630.613Y.Peng et al./Journal of Power Sources 291(2015)20e 2825increased intensity of the white-line peak means a higher con-centration of Fe 3þ[48],which is consistent with the Fe2p XPS data.Fig.10shows the Fe K-edge Fourier transform EXAFS spectra of FePc e Py/MWCNTs and FePc/MWCNTs.The first strong peak at 1.4Å(before phase-shift correction)was caused by backscattering from the four N atoms.The second peak at 2.3Åwas caused by back-scattering from the eight carbon atoms of the pyrrole ring bonded to nitrogen [49].As shown in Fig.10(A),the radius of the firstandFig.7.Fe2p XPS spectra of mononuclear (A),binuclear (B),and poly electrocatalysts (C).Table 2Fe2p quadrature component spectra results.SimplePeak 1-Fe(II)(%)Peak 2-Fe(III)(%)Peak 3-Fe(II)(%)Peak 4-Fe(III)(%)m-PcFe-MWCNTs 25.76(709.7eV)30.49(712.5eV)17.22(721.2eV)26.53(724.3eV)m-PcFe e Py/MWCNTs 0.609(709.30eV)46.92(711.5eV)25.27(722.2eV)27.20(725.5eV)b-PcFe-MWCNTs 32.17(710.4eV)28.96(712.9eV)17.36(722.3eV)21.50(724.8eV)b-PcFe e Py/MWCNTs 19.81(708.9eV)39.82(711.1eV)14.62(722.1eV)25.75(725.6eV)p-PcFe-MWCNTs 22.74(708.8eV)35.84(711.3eV)20.32(721.4eV)21.10(724.6eV)p-PcFe e Py/MWCNTs31.51(708.8eV)32.61(711.2eV)15.89(721.4eV)19.99(724.1eV)Fig.8.N1s XPS spectra of mononuclear (A),binuclear (B),and poly electrocatalysts (C).Table 3Relative concentrations of nitrogen species in the electrocatalysts determined by XPS.SimplePyridinic (%)Pyrrolic (%)Graphitic (%)Pyridine-oxide (%)m-PcFe-MWCNTs 4.19(398.5eV)82.19(399.8eV)13.61(400.9eV)0(402.3eV)m-PcFe e Py/MWCNTs 11.41(398.8eV)42.83(399.8eV)42.05(400.8eV) 3.71(402.3eV)b-PcFe-MWCNTs 2.17(398.6eV)59.42(399.8eV)38.46(400.9eV)0(402.6eV)b-PcFe e Py/MWCNTs 32.79(398.7eV)63.30(399.6eV) 3.91(400.7eV)0(402.4eV)p-PcFe-MWCNTs 40.69(398.6eV)48.08(399.5eV)11.24(400.3eV)0(402.3eV)p-PcFe e Py/MWCNTs57.56(398.7eV)39.75(399.7eV)2.69(401.0eV)0(402.5eV)Y.Peng et al./Journal of Power Sources 291(2015)20e 2826second peak of FePc e Py/MWCNTs (m-FePc e Py/MWCNTs)was smaller than that of FePc/MWCNTs (m-FePc/MWCNTs),which means that the phthalocyanine rings of FePc e Py/MWCNTs had a smaller radius compared with those of FePc/MWCNTs.The same conclusion can be formed from Fig.10(B)and (C),which compare the spectra obtained for b-FePc/MWCNTs and p-FePc/MWCNTs,respectively.Considering the above ORR electrocatalytic property results,we can infer that FePc e Py/MWCNTs (with axial Py groups anchored on MWCNTs)having a smaller phthalocyanine ring radius will exhibit excellent electrocatalytic properties towards the ORR.4.ConclusionsIn summary,three FePc e Py/MWCNTs and three FePc/MWCNTswere successfully prepared using a microwave synthesis method.The LSV results demonstrated that the introduction of Py groups to FePc e Py/MWCNTs was bene ficial for improving their catalytic ORR activity.Furthermore,p-FePc e Py/MWCNTs exhibited excel-lent long-term stability and tolerance to methanol poisoning compared with p-FePc/MWCNTs and Pt/C.Meanwhile,XPS anal-ysis indicated that the higher concentrations of Fe 3þand pyridine-type nitrogen play key roles in determining the ORR activity of such catalysts.Furthermore,XANES and EXAFS analyses revealed that the five-coordinate structures (FePc e Py/MWCNTs)intro-duced by the diazonium salt reaction showed excellent electro-catalytic activity for ORR because the coordination geometry around Fe was closer to square pyramidal planar,and because they had a higher concentration of Fe 3þand a phthalocyanine ring skeleton structure of smaller radius.Our present findings are ex-pected to be signi ficant to the future design and preparation of ORRcatalysts.Fig.9.Fe K-edge XANES spectra of mononuclear (A),binuclear (B),and poly electro-catalysts(C).Fig.10.Fe K-edge Fourier transforms EXAFS spectra of mononuclear (A),binuclear,(B)and poly electrocatalysts (C).Y.Peng et al./Journal of Power Sources 291(2015)20e 2827。