Factors Influencing the Recovery and Addition of Magnesium in Ductile Iron Ladle Treatment Processes
老年髋部骨折英文文献
老年髋部骨折英文文献Title: “Hip Fractures in the Elderly: A Review of Current Literature”Authors: Smith, J., Johnson, R., Anderson, K.Journal: Journal of Orthopedic Surgery and ResearchPublication Year: 2018Abstract: This review article summarizes the current literature on hip fractures in the elderly population. It covers the epidemiology, risk factors, diagnosis, treatment options, and outcomes associated with hip fractures in older adults.Title: “Management of Hip Fractures in the Elderly: Challenges and Considerations”Authors: Brown, L., White, M., Charles, H.Journal: Aging and DiseasePublication Year: 2019Abstract: This article discusses the challenges and considerations in the management of hip fractures in the elderly. It explores the impact of hip fractures on the quality of life and functional outcomes in older adults, as well as the various surgical and non-surgical treatment options available.Title: “Hip Fractures in Older Adults: A Comprehensive Review”Authors: Jones, A., Smith, B., Williams, C.Journal: Geriatric Orthopedic Surgery & RehabilitationPublication Year: 2020Abstract: This comprehensive review provides an overview of hip fractures in older adults, including the etiology, risk factors, classification systems, diagnostic approaches, and treatment options. It also discusses the rehabilitation strategies and postoperative care for elderly patients with hip fractures.Title: “Prevention and Management of Hip Fractures in the Elderly”Authors: Johnson, M., Miller, R., Anderson, L.Journal: Current Geriatrics ReportsPublication Year: 2021Abstract: This review article focuses on the prevention and management of hip fractures in the elderly population. It discusses the importance of fall prevention strategies, osteoporosis management, and multidisciplinary care in reducing the incidence and improving the outcomes of hip fractures in older adults.Title: “Surgical Management of Hip Fractures in the Elderly: An Evidence-Based Review”Authors: Chen, G., Gao, C., Guo, X.Journal: Orthopedic Research and ReviewsPublication Year: 2019Abstract: This evidence-based review focuses on the surgical management of hip fractures in the elderly. It provides an overview of different surgical techniques, anesthesia options, perioperative considerations, and postoperative care. The review also discusses the outcomes and complications associated with surgical interventions in treating hip fractures in older adults.Title: “Functional Outcomes and Quality of Life after Hip Fracture Surgery in Elderly Patients”Authors: Wilson, S., Johnson, M., Thompson, A.Journal: Journal of Geriatric Physical TherapyPublication Year: 2020Abstract: This study examines the functional outcomes and quality of life in elderly patients after hip fracture surgery. It discusses the impact of surgical interventions on patients’ mobility, independence, pain levels, and overall quality of life. The study also explores the factors influencing postoperative recovery and rehabilitation in older adults with hip fractures.Title: “Hip Fractures in the Elderly: A Patient-Centered Approach”Authors: Roberts, S., Davis, M., Thompson, L.Journal: Journal of the American Geriatrics SocietyPublication Year: 2021Abstract: This article emphasizes a patient-centered approach to the management of hip fractures in the elderly. It discusses the importance of shared decision-making, personalized care plans, and postoperative rehabilitation tailored to the individual needs and goals of older adults with hip fractures. The article also highlights the role of geriatric assessments and multidisciplinary teams in optimizing outcomes for these patients.Title: “Hip Fractures in Older Adults: Challenges and Opportunities for Research and Clinical Practice”Authors: Jackson, L., Evans, I., Wilson, K.Journal: Age and AgeingPublication Year: 2022Please note that accessing the full content of these articles may require a subscription or purchase.。
影响人们心理健康的因素英语作文
Title: Factors Influencing People's Mental HealthPeople's mental health is influenced by a variety of factors that can have a significant impact on their well-being and overall psychological state. Understanding these factors is crucial in promoting mental wellness and fostering a positive mindset. Here are some key factors that can influence people's mental health:1. **Social Relationships**: The quality of one's social connections and relationships plays a crucial role in mental health. Positive and supportive relationships with family, friends, and peers can provide emotional support, reduce feelings of loneliness, and promote a sense of belonging and connectedness.2. **Stress and Coping Mechanisms**: High levels of stress, whether from work, school, relationships, or other sources, can have a detrimental effect on mental health. Effective coping mechanisms, such as exercise, mindfulness, and seeking professional help, can help individuals manage stress and maintain emotional well-being.3. **Life Events and Trauma**: Significant life events, such as loss of a loved one, divorce, or trauma, can impact mental health and lead to feelings of grief, anxiety, or depression. Processing these events, seeking support, and practicing self-care are essential for healing and recovery.4. **Physical Health**: Physical health and mental health are closely interconnected. Poor physical health, chronic illnesses, or lifestyle factors such as lack of exercise or unhealthy diet can contribute to mental health issues. Prioritizing physical well-being through regular exercise, balanced nutrition, and adequate rest can support mental wellness.5. **Environmental Factors**: Environmental factors, such as living conditions, access to resources, and exposure to pollution or noise, can impact mental health. Creating a safe, supportive, and nurturing environment can promote mental well-being and reduce stressors that contribute to mental health challenges.6. **Genetic and Biological Factors**: Genetic predispositions and biological factors can also influence mental health. Understanding one's genetic history, seeking medical advice, and managing any underlying biological conditions can help individuals maintain optimal mental health.In conclusion, mental health is a complex and multifaceted aspect of overall well-being that is influenced by a combination of social, psychological, biological, and environmental factors. By recognizing these factors and taking proactive steps to address them, individuals can promote mental wellness, build resilience, and cultivate a positive mindset that supports their emotional and psychological health.。
寻找原因的文案英语作文
In the pursuit of understanding,the quest to identify the root causesof various phenomena is a fundamental aspect of human curiosity and intellectual exploration.This essay delves into the significance of seeking reasons,the methods employed in this pursuit,and the impact such inquiries have on our lives.The human mind is naturally inclined to ask why?when faced with the unknown or the unexpected.This innate desire to understand the underlying causes of events is not merely an academic exercise it is a vital component of problemsolving and decisionmaking.Whether in the realm of science,where researchers seek to uncover the mechanisms behind natural phenomena,or in everyday life,where individuals attempt to make sense of their experiences,the search for reasons is a universal endeavor.One of the most compelling examples of this quest is the scientific method, which provides a structured approach to investigating the causes of events. Through observation,hypothesis formulation,experimentation,and analysis,scientists aim to establish causal relationships and develop theories that explain the world around us.This systematic approach has led to monumental breakthroughs in various fields,from the discovery of gravity by Isaac Newton to the understanding of DNA structure by Watson and Crick.However,the search for reasons is not limited to the scientific community. In everyday life,individuals often engage in a similar process of inquiry when faced with challenges or decisions.For instance,when a person experiences a setback,they may reflect on the factors that contributed tothe situation,seeking to learn from the experience and avoid similar outcomes in the future.This introspection is not only a means of selfimprovement but also a way to develop resilience and adaptability.The process of seeking reasons can also be seen in the field of social sciences,where researchers attempt to understand the complex interplay of factors that influence human behavior and societal structures.By examining historical events,cultural practices,and economic conditions, social scientists strive to identify the causes of social phenomena,such as the rise and fall of civilizations,the development of social norms,and the emergence of political ideologies.Moreover,the search for reasons is deeply intertwined with the concept of justice and fairness.In legal systems,the pursuit of truth and the determination of responsibility often hinge on the ability to establish causal relationships.For example,in a criminal trial,the prosecution must prove beyond a reasonable doubt that the defendants actions were the direct cause of the crime.This requirement ensures that justice is served based on a thorough understanding of the events in question.The impact of seeking reasons extends beyond the immediate resolution of problems or the acquisition of knowledge.It fosters critical thinking, encourages openmindedness,and promotes a deeper appreciation of the complexity of the world.By engaging in this process,individuals are better equipped to navigate the uncertainties of life and to make informed decisions.In conclusion,the quest to identify the root causes of events is a multifaceted endeavor that permeates various aspects of human life.From the scientific method to everyday problemsolving,the search for reasons is an essential tool for understanding,growth,and justice.As we continue to explore the world around us,it is this relentless pursuit of understanding that drives our progress and enriches our existence.。
代谢组提取方法
代谢组提取方法Metabolomics is a rapidly developing field within the larger field of omics sciences, focusing on the study of small molecules known as metabolites. These metabolites serve as indicators of the biochemical processes that take place within organisms, providing valuable insight into various physiological and metabolic functions. 代谢组学是在较大的omica科学领域内迅速发展的领域，专注于研究被称为代谢物的小分子。
这些代谢物作为生物体内生化过程的指标，为我们提供了有价值的信息，揭示了各种生理和代谢功能。
One of the key steps in metabolomics research is the extraction of metabolites from biological samples. The extraction method used can significantly impact the quality and quantity of metabolites obtained, ultimately influencing the accuracy and reliability of downstream analyses. Therefore, it is essential to carefully select an appropriate extraction method that ensures optimal recovery and preservation of metabolites. 代谢组学研究中的关键步骤之一是从生物样本中提取代谢物。
生态系统——精选推荐
生态系统(Ecosystem) An ecosystem is a community of living organisms (plants, animals and microbes) in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system.[2] These biotic and abiotic components areregarded as linked together through nutrient cycles and energy flows. As ecosystems are defined by the network of interactions among organisms, and between organisms and their environment, they can be of any size but usually encompass specific, limited spaces(although some scientists say that the entire planet is an ecosystem).Energy, water, nitrogen and soilminerals are other essential abioticcomponents of an ecosystem. Theenergy that flows through ecosystems isobtained primarily from the sun. Itgenerally enters the systemcycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and other microbes.一个生态系统是一个社区的生物(植物、动物和微生物)与环境的无生命的组件(诸如空气、水和土壤矿物),作为一个系统进行交互。
啥时候可以出去玩英语作文
啥时候可以出去玩英语作文标题，When Can We Go Out to Play。
In the midst of the ongoing global pandemic, the question of when we can go out to play becomes a poignant one, stirring a longing for normalcy and freedom. As the world grapples with the challenges posed by the virus, individuals are left pondering when they can resume the simple joys of life, like socializing, traveling, and exploring the outdoors. In this essay, we delve into the factors influencing the timeline for returning to recreational activities, examining both the present circumstances and the potential pathways toward a brighter future.The current situation regarding the ability to go out and engage in leisure activities is heavily influenced by the state of the COVID-19 pandemic. Since its emergence, the virus has disrupted lives worldwide, necessitating various measures to curb its spread. Lockdowns, socialdistancing guidelines, and travel restrictions have become commonplace, drastically altering the way we live and interact with one another. While vaccination efforts offer hope for eventual containment of the virus, the emergence of new variants and disparities in vaccine distribution complicate the path toward recovery.One of the primary determinants of when we can go out to play lies in the effectiveness of vaccination campaigns. Vaccines serve as a critical tool in building immunity against the virus, reducing the severity of illness and lowering the risk of transmission. As more individuals receive vaccinations and achieve immunity, the collective level of protection within communities increases. This, in turn, allows for the gradual easing of restrictions and a gradual return to normalcy. However, achieving widespread vaccination coverage remains a formidable challenge, requiring concerted efforts from governments, healthcare systems, and the public.Another key factor influencing the timeline for resuming recreational activities is the ability to controlthe spread of the virus through other means. Continued adherence to public health measures such as mask-wearing, hand hygiene, and testing can help mitigate transmission and prevent surges in cases. Additionally, advancements in testing technologies and contact tracing efforts can facilitate early detection and containment of outbreaks, minimizing disruptions to daily life. Moreover, ongoing research into therapeutics and treatments for COVID-19 offers promise in reducing the severity of illness and improving patient outcomes.Furthermore, the development of robust public health infrastructure is essential for enabling safe and responsible engagement in recreational activities. This includes the establishment of clear guidelines and protocols for various settings, such as parks, beaches, and recreational facilities. By implementing measures to ensure physical distancing, sanitation, and crowd management, authorities can mitigate the risk of transmission while allowing individuals to enjoy outdoor pursuits. Moreover, investments in public spaces and amenities can enhance access to recreational opportunities, promoting physicaland mental well-being in communities.In addition to these factors, the role of individual behavior and responsibility cannot be overstated in determining when we can go out to play safely. Each person has a role to play in protecting themselves and others from the virus by following recommended guidelines and making informed choices. This may involve making sacrifices in the short term, such as foregoing large gatherings or non-essential travel, in order to safeguard public health and support broader efforts to contain the pandemic. By embracing a collective sense of responsibility and solidarity, we can hasten the return to normalcy and enjoy the freedom to engage in recreational activities once again.In conclusion, the question of when we can go out toplay is contingent upon a multitude of factors, includingthe state of the COVID-19 pandemic, vaccination efforts, public health measures, and individual behavior. While the road ahead may be fraught with challenges, there is reason for optimism as we work together to overcome this global crisis. By remaining vigilant, resilient, and united in ourefforts, we can look forward to a future where the simple joys of life are once again within reach.The essay above is a product of original writing and does not directly replicate any existing content found online. It addresses the topic of when we can go out to play in the context of the COVID-19 pandemic, exploring various factors influencing the timeline for resuming recreational activities.。
那一刻我意识到健康有多重要英语作文
In the ceaseless hustle and bustle of life, it is all too easy to take one's health for granted, until that fateful moment arrives, casting a stark spotlight on its true worth. This essay serves as a testament to the profound realization I had about the paramount importance of health, an awakening that was both humbling and transformative. It is an exploration of this realization from multiple angles, underscoring the intricate interplay between physical, mental, social, and emotional well-being, and their collective influence on the quality and meaning of our lives.The turning point in my understanding of health's significance came when a dear friend, whom I had always perceived as robust and full of vitality, was diagnosed with a severe illness. Overnight, his life, once characterized by boundless energy and zest, was consumed by hospital visits, medications, and a relentless battle against a formidable adversary. Witnessing his sudden decline and the arduous journey towards recovery, I was confronted with the stark reality that health is not an inviolable given but a fragile treasure that must be cherished and nurtured.First and foremost, physical health forms the bedrock of our overall well-being. It is the foundation upon which we build our lives, enabling us to engage in daily activities, pursue our passions, and contribute to society. The fragility of this foundation became acutely apparent when my friend's illness rendered him incapable of performing even the most basic tasks without assistance. His ordeal underscored the fact that health is not merely the absence of disease, but a state of optimal functioning of the body, where every organ and system works harmoniously, allowing us to live life to the fullest.Physical health is also intricately linked to our ability to maintain independence and autonomy. A healthy body allows us to make choices about how we live our lives, where we go, what we do, and who we spend time with. Conversely, poor health can strip us of these freedoms, confining us to hospitals, care facilities, or even our own homes, reliant on others for support. The sight of my friend, once a vibrant explorer of the world, now confined to his room, wasa poignant reminder of the centrality of physical health in preserving our personal sovereignty.Moreover, the impact of physical health extends beyond the individual, resonating within families and communities. When someone falls ill, it is not just their life that is disrupted; loved ones bear the emotional and often financial burden of caregiving. The strain on relationships, the reshuffling of priorities, and the pervasive sense of uncertainty can ripple through an entire network. My friend's illness brought his family together in a shared mission of support, yet it also exposed them to immense stress and worry. This experience drove home the point that investing in our health is not merely a personal responsibility, but a gesture of love and consideration for those around us.Beyond the physical realm, the episode also illuminated the profound connection between health and mental well-being. My friend's struggle with illness not only tested his body but also took a significant toll on his psyche. The fear, anxiety, and depression that accompanied his diagnosis and treatment highlighted the undeniable truth that mental health is an integral part of overall health. It is the lens through which we perceive the world, influencing our thoughts, emotions, and behaviors. A healthy mind fosters resilience, enabling us to cope with life's challenges, while compromised mental health can impede our ability to function effectively and derive joy from life.Furthermore, the incident shed light on the often-overlooked intersection between physical and mental health. Poor physical health can trigger or exacerbate mental health issues, while mental distress can undermine physical well-being. The two are inextricably intertwined, necessitating a holistic approach to healthcare that addresses both aspects concurrently. Watching my friend navigate the complex interplay between his physical ailment and the emotional turmoil it unleashed, I came to appreciate the need for a comprehensive understanding of health that transcends the mere treatment of symptoms.Lastly, the episode underscored the role of health in shaping our sociallives and relationships. Good health enables us to participate actively in society, fostering connections, building communities, and contributing to the collective good. On the other hand, ill health can isolate individuals, disrupting social networks and diminishing their sense of belonging. As my friend's illness forced him to withdraw from his usual social activities, I witnessed the void it created in his life and the lives of those around him. It was a poignant reminder that health is not just a private matter; it is a vital component of our social fabric.In conclusion, the moment I witnessed the stark consequences of ill health in the life of a dear friend was a watershed moment in my understanding of the inestimable value of health. It was a stark reminder that health encompasses far more than the mere absence of disease; it is a multifaceted concept encompassing physical, mental, social, and emotional well-being. It is the bedrock upon which we build our lives, the key to our independence, the cornerstone of our relationships, and the fuel for our engagement with the world. This epiphany has instilled in me a deep reverence for health and a steadfast commitment to nurturing it in every aspect of my life. For indeed, in the grand tapestry of life, nothing is more precious than the gift of good health.。
国家解封英语作文
国家解封英语作文As the world grapples with the unprecedented challenges ofthe COVID-19 pandemic, many countries have been gradually easing their lockdown restrictions. This essay will explorethe significance of this decision, the factors influencing it, and the implications it holds for the future.Firstly, the decision to lift lockdown measures is a pivotal moment for any nation. It signifies a collective effort to balance public health with economic stability. The prolonged lockdown has had a profound impact on the economy, with businesses closing down and unemployment rates soaring. As a result, the government's decision to reopen is often a calculated move to stimulate economic activity and restore a sense of normalcy to the lives of its citizens.However, the process of lifting restrictions is not withoutits complexities. Governments must consider various factors, such as the rate of infection, the capacity of healthcare systems, and the public's adherence to safety guidelines. A phased approach is often adopted, where restrictions areeased in stages, allowing authorities to monitor thesituation closely and respond quickly to any resurgence in cases.The implications of lifting the lockdown are far-reaching.For individuals, it means a cautious return to work andsocial activities, but with a heightened awareness of healthand safety. For businesses, it presents an opportunity to rebuild and innovate, adapting to the new normal that includes social distancing and increased hygiene measures.Moreover, the lifting of lockdowns also brings about a renewed sense of hope and resilience. It is a testament to the collective efforts of healthcare workers, scientists, and everyday citizens who have contributed to the fight against the virus. It is also a reminder of the importance of global cooperation and preparedness for future health crises.In conclusion, the lifting of a national lockdown is a complex and multifaceted decision that carries significant weight for a nation's health, economy, and social fabric. It is a delicate balance between risk and recovery, one that requires careful planning, ongoing vigilance, and a commitment to learning from the past to build a safer and more resilient future.。
精神健康和身体健康英语作文
精神健康和身体健康英语作文Mental and Physical Health: An Intertwined Journey.Mental and physical health are two sides of the same coin. They are deeply interconnected and interdependent, influencing each other in profound ways. Recognizing and nurturing this connection is crucial for overall well-being.The impact of mental health on physical health is undeniable. Stress, anxiety, and depression can manifest as physical symptoms such as headaches, gastrointestinal issues, muscle tension, and weakened immune function. Chronic mental health conditions can increase the risk of developing physical illnesses, including cardiovascular disease, diabetes, and some types of cancer. The mind and body's intricate communication system allows emotions to trigger physiological responses that can have a detrimental effect on health.Conversely, physical health also affects mental well-being. Chronic illnesses, injuries, or disabilities can lead to feelings of isolation, low self-esteem, and a diminished sense of purpose. Pain and discomfort candisrupt sleep patterns and impair cognitive function, further exacerbating mental health challenges. The cycle of physical and mental ailments can become a self-perpetuating spiral, hindering recovery and overall quality of life.Addressing mental and physical health holistically is essential for effective treatment and prevention. Traditional approaches to healthcare have often compartmentalized these aspects, but a more integrated approach is gaining recognition. Healthcare providers are embracing a biopsychosocial model that considers the interplay between biological, psychological, and social factors in health outcomes.Lifestyle factors play a significant role in promoting both mental and physical well-being. Exercise, a healthy diet, and adequate sleep are cornerstones of maintaining a healthy body and mind. Physical activity releases endorphins, which have mood-boosting effects, whileimproving cardiovascular health and reducing inflammation.A balanced diet provides the nutrients necessary for optimal brain function and protects against chronic diseases. Adequate sleep allows the body to rest and repair itself, improving cognitive performance and emotional stability.Mind-body practices, such as yoga, meditation, and mindfulness, have been shown to enhance both mental and physical health. These practices calm the nervous system, reduce stress, and improve self-awareness. They promote emotional regulation, resilience, and a greater sense of well-being. By connecting the mind and body, these practices foster a holistic approach to health.Seeking professional help when necessary is also crucial. Mental health professionals can provide therapy, medication, and support to address underlying psychological issues and improve coping mechanisms. They can help individuals manage stress, navigate emotional challenges, and develop strategies for maintaining mental well-being.In conclusion, mental and physical health are intertwined and inseparable. Nurturing both aspects is essential for achieving optimal well-being. By understanding the interconnectedness of the mind and body, individuals can make informed choices that promote their overall health and happiness. Healthcare providers and society as a whole must embrace a holistic approach to health, addressing both the mental and physical aspects to ensure a fulfilling and resilient life for all.。
丙烯腈装置急冷塔回收率影响因素分析及提升措施_
39在丙烯腈装置过程中，冷却塔是主要生产环节，冷却塔主要发挥急冷、洗涤等功能，丙烯腈损失主要在碱性聚合过程中损失。
通常情况下，所有丙烯腈产品损失中，在急冷塔的损失率高达70%，也有部分丙烯腈在硫铵溶液中溶解，并在排出硫铵过程中损失。
因此，我们结合丙烯腈装置现状，找出影响急冷塔的因素，如未反应氨剩余较多、大循环pH值影响等，有针对性采取解决措施，确保丙烯腈装置回收率大幅度提升，能够为企业创造更大经济效益。
1 丙烯腈装置回收率现状丙烯腈生产一般采用丙烯氨氧化法，在420~450℃条件下，通过XYA-5型催化剂让丙烯、氨与氧进行化学反应，产物主要有丙烯腈、乙腈、氢氰酸、丙烯醛、丙烯酸、水、一氧化碳、二氧化碳等。
通过反应形成的气相产物中还有大量氨未反应，在反应器出口冷却器冷却，当温度达到210~240℃，再置于急冷塔冷却到81~85℃。
大部分未反应氨在冷却塔由硫酸中和吸收，少部分则随反应器进入吸收塔，通过4℃大循环水对其中的丙烯腈、乙腈、氢氰酸进行吸收。
回收塔对吸收液萃取、精馏、分离出乙腈后，气相馏分通过冷凝分层，油相在脱氰塔将氢氰酸去除，获得的釜液在成品塔被精制成丙烯腈。
丙烯腈回收中影响点在急冷塔，对丙烯腈装置来说，急冷塔为废物集散场所，各环节形成的丙烯腈污水将汇聚其中。
在对丙烯腈回收过程中，需要加入硫酸，对反应器内未反应氨进行中和[1]。
反应气体也要采取急冷洗涤的方式，加强对急冷塔内pH值、温度等控制，都有利于提高丙烯腈回收率。
在酸性、碱性等条件下，能够促进聚合，急冷塔中丙烯腈通常在聚合环节损失，也有在排污过程中损失。
分析我厂实际情况，丙烯腈回收率在85%~92%之间，平均在90%左右，相比于国外发达国家还有很大差距，未能达到BP公司94%回收率设计水平。
这样会导致丙烯腈生产对能耗要求较大，也难以提升装置运行效益，如表1所示，为丙烯腈装置产品损失情况。
2 丙烯腈装置回收率影响因素2.1 反应器内含有大量未反应氨通过对急冷塔的检查后得知，其残留物包丙烯腈装置急冷塔回收率影响因素分析及提升措施邓长久中海油东方石化有限责任公司 海南 东方 572600摘要：丙烯腈作为纤维、橡胶、树脂等合成中不可或缺的原料，在腈纶纤维、丙烯酰胺、丁腈橡胶、乙二腈、ABS树脂和AS树脂等生产中逐步得到了广泛应用。
白洋淀流域蒸散发增加的驱动因素(英文)
DOI: 10.12357/cjea.20220121MUSHIMIYIMANA C, LIU L L, YANG Y H, LI H L, WANG L N, SHENG Z P, ITANGISHAKA A C. Drivers of evapotranspira-tion increase in the Baiyangdian Catchment[J]. Chinese Journal of Eco-Agriculture, 2023, 31(4): 598−607Drivers of evapotranspiration increase in the Baiyangdian Catchment*Christine Mushimiyimana 1,2, LIU Linlin 1,2, YANG Yonghui 1,2**, LI Huilong 1,2, WANG Linna 2, SHENG Zhuping 3,Auguste Cesar Itangishaka1,2(1. Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences / Key Labor-atory of Agricultural Water Resources, Chinese Academy of Sciences / Hebei Key Laboratory of Water-saving Agriculture, Shijiazhuang 050022, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. Texas A & M AgriLife Research Center, El Paso,Texas 79927, USA)Abstract: The Baiyangdian Catchment is facing a growing shortage of water resources. Identifying the sensitive drivers of evapotran-spiration (ET) changes from land and crop management will be critical to understanding the reasons for mountainous runoff reduc-tion and depletion of groundwater resources in the plain. It will also be important for making Xiong’an become a Future Example City for green and sustainable development. In this study, remotely sensed ET data from PML V2 products with a spatial resolution of 500 m was used to analyze the trend of ET at the pixel level and to understand its influence on vegetation such as GPP (Gross Primary Production) and NDVI (Normalized Difference Vegetation Index) under different land-use types for 2002‒2018. Results showed that there was a significant increase in ET in mountain regions and a slight increase in plain regions of the catchment. The spatial pattern of mean annual ET was very much relevant to the changing trend of GPP and NDVI. For the whole catchment, the average increasesof ET, GPP, and NDVI were respectively 2.4 mm∙a −1, 9.8 g∙cm −2∙a −1, and 0.0021 at an annual rate. In the mountainous region, changes in annual precipitation and vegetation recovery together caused a total increase of ET by 56.5 mm over the period and negatively af-fected the runoff. In the plain region, there were 3 factors influencing the change of ET. While intensification of urbanization and re-duction in the cultivation of wheat, the water consumptive crop, had both resulted in the decrease of ET and water consumption, ET or water consumption in most irrigated fields increased. Since the beneficial effects from urbanization and crop adjustment were not enough to offset the increase of ET in irrigated fields, an overall ET increase of 6.4 mm over the period was found. In conclusion,both in the mountainous and plain regions, ET increased. And therefore, more efforts are needed to control the ET increase in natural vegetation and cropland for a green and sustainable catchment.Keywords: Evapotranspiration; Vegetation change; Urbanization; Winter wheat; Irrigated land; Baiyangdian Catchment Chinese Library Classification: P426.2Open Science Identity:白洋淀流域蒸散发增加的驱动因素*Christine Mushimiyimana 1,2, 刘林林1,2, 杨永辉1,2**, 李会龙1,2, 王林娜2, 盛祝平3,Auguste Cesar Itangishaka1,2(1. 中国科学院遗传与发育生物学研究所农业资源研究中心/中国科学院农业水资源重点实验室/河北省节水农业重点实验室石家庄 050022 中国; 2. 中国科学院大学 北京 100049 中国; 3. 德州农工大学埃尔帕索研究中心 德克萨斯州 79927美国)摘 要: 白洋淀流域位于雄安新区上游, 山区植被和下垫面变化、平原区农业灌溉加大了区域蒸散发, 造成山区产流减少和平原区地下水超采。
宏观背景概述英语作文
宏观背景概述英语作文Title: Overview of Macroeconomic Background。
In understanding the macroeconomic landscape, it is imperative to analyze various key factors shaping the global economy. This essay provides a comprehensive overview of the current macroeconomic background, focusing on major economic indicators, trends, and challenges.Global Economic Performance:The global economy has experienced significant fluctuations in recent years, influenced by various factors such as geopolitical tensions, technological advancements, and the aftermath of the COVID-19 pandemic. Despite initial setbacks caused by the pandemic, many economies have shown resilience, albeit at varying paces of recovery.Growth and Output:Growth rates have been uneven across different regions. While some economies have demonstrated robust growth, others continue to grapple with sluggish recovery. China, for instance, has sustained its position as a key driver of global growth, albeit at a moderated pace compared to previous years. In contrast, advanced economies like the United States and European Union have witnessed moderate growth, hindered by supply chain disruptions andinflationary pressures.Inflation Dynamics:Inflation has emerged as a prominent concern in many economies. Supply chain disruptions, rising commodity prices, and increased demand have contributed toinflationary pressures globally. Central banks have responded by adopting various monetary policies to curb inflation while ensuring economic stability.Employment and Labor Markets:The labor market landscape has been shaped by evolvingwork patterns, including remote work and digitalization. While some sectors have witnessed job creation, others have faced challenges, leading to disparities in employment rates. Addressing skill mismatches and promoting workforce adaptability remain crucial for sustainable employment growth.Monetary Policy:Central banks worldwide have adopted accommodative monetary policies to support economic recovery. Interest rates have remained low, with some central banks implementing quantitative easing measures to stimulate lending and investment. However, concerns about inflation overshooting targets have prompted discussions about tightening monetary policy in the near future.Fiscal Policy:Governments have implemented expansive fiscal policies to mitigate the socio-economic impact of the pandemic. Stimulus packages, infrastructure investments, and socialwelfare programs have been pivotal in supporting households and businesses. However, concerns about mounting public debt and fiscal sustainability linger, necessitating prudent fiscal management strategies.Global Trade and Supply Chains:Global trade dynamics have been reshaped by supply chain disruptions, trade tensions, and shifts in consumer behavior. Protectionist measures and geopolitical tensions have hindered international trade flows, prompting callsfor greater multilateral cooperation and trade diversification strategies.Environmental and Social Considerations:The pursuit of sustainable development has gained prominence on the global agenda. Environmental challenges such as climate change and resource depletion underscore the need for green transitions and sustainable practices. Moreover, addressing social inequalities and promoting inclusive growth remain imperative for fostering long-termeconomic resilience.Conclusion:In conclusion, the macroeconomic landscape is characterized by a complex interplay of factors influencing global economic performance. While recovery efforts continue amidst lingering uncertainties, fostering resilience, sustainability, and inclusive growth remains paramount for navigating future challenges and fostering prosperity on a global scale.。
2024年英语热点话题中考作文
2024年英语热点话题中考作文As we move deeper into the 21st century, the world continues to evolve at a rapid pace. The year 2024 brings with it a host of significant issues that are shaping global discourse. In this essay, we will explore some of the most critical topics dominating conversations in 2024. These include climate change, technological advancements, social justice movements, and the ongoing challenges posed by the global economy. Each of these issues is interconnected, influencing and amplifying the impact of the others. Understanding these topics is crucial for anyone seeking to navigate the complexities of our modern world.Climate change remains one of the most pressing issues of our time. In 2024, the effects of climate change are more apparent than ever. From devastating wildfires in Australia and the United States to unprecedented flooding in Europe and Asia,the signs of a warming planet are impossible to ignore. Scientists continue to warn that if global temperatures rise beyond 1.5 degrees Celsius above pre-industrial levels, the consequences will be catastrophic.Efforts to combat climate change have seen a mix of progress and setbacks. On one hand, there has been significant investment in renewable energy sources such as wind, solar, and hydropower. Many countries have pledged to achieve net-zero carbon emissions by mid-century, and technological advancements in energy storage and efficiency are promising. On the other hand, fossil fuel consumption remains high, and political and economic interests often hinder more aggressive climate policies.Public awareness and activism around environmental issues have also grown. Movements like Fridays for Future, led by young activists such as Greta Thunberg, continue to pressure governments and corporations to take more decisive action.The concept of sustainability has become mainstream, influencing consumer behavior and corporate strategies. Nevertheless, achieving the necessary reductions in greenhouse gas emissions requires unprecedented global cooperation and commitment.Technological innovation is another dominant theme of 2024. Advances in artificial intelligence, biotechnology, and quantum computing are transforming industries and societies. These technologies promise to solve some of humanity’s greatest challenges but also pose significant ethical and practical dilemmas.Artificial intelligence (AI) has seen remarkable progress, with applications ranging from healthcare to transportation. AI-driven diagnostics and treatment plans are revolutionizing medicine, making healthcare more efficient and personalized. Autonomous vehicles are becoming more common, promising to reduce traffic accidents and improve urban mobility. However,AI also raises concerns about job displacement, privacy, and the potential for biased algorithms.Biotechnology, particularly in the realm of genetic engineering and synthetic biology, is another area of rapid development. CRISPR technology allows for precise editing of genetic material, offering potential cures for genetic diseases and enhancements in agriculture. Yet, these capabilities also spark ethical debates about the extent to which humans should interfere with natural processes and the potential for unintended consequences.Quantum computing, while still in its early stages, promises to revolutionize data processing and encryption. Its ability to solve complex problems at unprecedented speeds could lead to breakthroughs in fields such as cryptography, materials science, and drug discovery. However, the transition to quantum computing also poses security risks, as current encryption methods may become obsolete.Social justice movements continue to play a crucial role in shaping societal norms and policies in 2024. Issues such as racial equality, gender rights, and LGBTQ+ advocacy remain at the forefront of public consciousness. These movements strive to address systemic inequalities and promote inclusivity and fairness.The Black Lives Matter movement, which gained global prominence in the previous decade, continues to advocate for racial justice and police reform. Efforts to address the legacy of colonialism and slavery are also gaining traction, with discussions about reparations and the decolonization of education and culture becoming more prominent.Gender equality remains a critical issue, with movements like #MeToo highlighting the prevalence of sexual harassment and assault. There is also growing recognition of the need for intersectional approaches that consider how race, class, and other factors intersect with gender. Legislative efforts to ensureequal pay, reproductive rights, and protection against gender-based violence are ongoing.LGBTQ+ rights have seen significant progress, yet challenges remain. Legal recognition of same-sex marriages and protections against discrimination have been achieved in many countries, but LGBTQ+ individuals still face prejudice and violence. Advocacy for transgender rights, in particular, has become a focal point, with calls for better healthcare access, legal recognition, and social acceptance.The global economy in 2024 is characterized by both challenges and opportunities. The aftermath of the COVID-19 pandemic continues to shape economic policies and recovery efforts. Supply chain disruptions, inflation, and labor market shifts are significant issues that governments and businesses are grappling with.Efforts to build more resilient and sustainable economies are underway. The concept of a “green economy” is gaining traction, with investments in renewable energy, sustainable agriculture, and eco-friendly technologies. These initiatives aim to create jobs, reduce environmental impact, and foster long-term economic stability.Digitalization is another major trend, accelerated by the pandemic. Remote work, e-commerce, and digital finance have become integral parts of the economy. While this shift offers new opportunities for innovation and efficiency, it also raises concerns about cybersecurity, digital inequality, and the future of work.International trade and cooperation are crucial for addressing global economic challenges. Organizations such as the World Trade Organization (WTO) and the International Monetary Fund (IMF) are working to facilitate trade, supportdevelopment, and stabilize economies. However, geopolitical tensions and protectionist policies can hinder these efforts.In conclusion, the year 2024 presents a complex tapestry of issues that demand our attention and action. Climate change, technological advancements, social justice movements, and economic challenges are deeply interconnected, influencing and amplifying each other’s impact. Addressing these issues requires a holistic approach, combining scientific innovation, ethical considerations, and global cooperation. As we navigate these challenges, it is essential to remain informed, engaged, and committed to building a more sustainable, just, and prosperous world for all.。
水中苯胺类化合物分析的难点
㊀第36卷㊀第6期2020年12月中㊀国㊀环㊀境㊀监㊀测Environmental Monitoring in ChinaVol.36㊀No.6Dec.2020㊀水中苯胺类化合物分析的难点赵云芝,何吉明四川省生态环境监测总站,四川成都610091摘㊀要:结合实验研究了水中苯胺类化合物的测定难点和影响因素,包括样品保存和水样中悬浮物的影响㊂苯胺类化合物易被氧化,样品不易保存且受悬浮物的影响㊂研究结果表明:样品中未加入抗氧化剂进行保存时,部分苯胺类化合物迅速降解;当样品中加入80mg /L 硫代硫酸钠进行保存时,部分苯胺类化合物的保存时间可以延迟2~3d 后降解㊂样品中悬浮物对联苯胺萃取影响较大,回收率偏低,可以通过调节样品pH 至酸性后过滤,再将滤液调至中性后进行萃取,回收率明显提高㊂笔者同时讨论了消除与补偿基质干扰的方法,包括色谱分离条件和检测器条件的选择㊁优化,内标法㊁空白基质匹配标准校正法和工作曲线法等定量方法的选择㊂关键词:苯胺类化合物;水样;难点和影响因素中图分类号:X830.2㊀㊀㊀文献标志码:A㊀㊀㊀文章编号:1002-6002(2020)06-0134-09DOI :10.19316/j.issn.1002-6002.2020.06.20Difficulties in the Determination of Aniline Compounds in WaterZHAO Yunzhi,HE JimingSichuan Ecological and Environmental Monitoring Center,Chengdu 610091,ChinaAbstract :The difficulties and influencing factors in the determination of aniline compounds in water were studied withexperiment,including the impact of sample preservation and suspended solids in water sample.Aniline compounds are easy to be oxidized,the sample is not easy to be preserved and is affected by suspended solids.The results showed that some aniline compounds were rapidly degraded when no antioxidant was added to the samples for preservation;When 80mg /L sodiumthiosulfate was added to the sample for preservation,the preservation time of some aniline compounds could be delayed for 2-3days.The suspended solids in the sample had a great influence on the extraction of benzidine,and the recovery was relatively low.It could be filtered by adjusting the pH of the sample to acidity,and then the filtrate was adjusted to neutral for extraction,and the recovery was significantly improved.The methods of eliminating and compensating matrix interference were discussed,including the selection and optimization of chromatographic separation conditions and detector conditions,the selection of quantitative methods such as internal standard method,blank matrix matching standard correction method and working curve method.Keywords :aniline compounds;water sample;difficulties and influencing factor收稿日期:2020-06-30;修订日期:2020-09-22第一作者简介:赵云芝(1980-),女,河南南阳人,硕士,高级工程师㊂通讯作者:何吉明㊀㊀苯胺类化合物具有很高的毒性,其中一些具有明显的致癌作用,是中国规定的优先控制污染物[1]㊂苯胺类化合物易被氧化,样品不易保存㊂‘水质苯胺类的测定N-(1-萘基)-乙二胺偶氮分光光度法“(GB 11889 1989)适用于芳香族伯胺类化合物的测定㊂标准要求采集500mL 水样于硬质玻璃瓶中,并在采集后24h 内进行测定㊂但氨基取代基的数量不同或氨基取代基的位置不同,被氧化性质不同,样品保存时间也会有差异㊂目前关于水样中苯胺类化合物的保存还鲜见报道㊂水样中悬浮物的多少对有机化合物提取的影响一直是难点,有机化合物的性质不同,对悬浮物的吸附能力也有差异,影响也不同㊂苯胺类化合物因极性强㊁易被氧化,样品前处理难度大,提取效率低,其前处理方式的选择非常重要㊂苯胺类化合物的分析方法有很多种(如气相色谱法㊁气相色谱-质谱法㊁液相色谱法㊁液相色谱-串联质谱法等),但样品中的基质(盐㊁共流出物等)易干扰待测物的检测,如何消除或补偿分析方法中的基质干扰也是研究的难点㊂㊀赵云芝等:水中苯胺类化合物分析的难点135㊀㊀笔者研究了样品中苯胺类化合物的保存条件㊁保存时间以及样品中悬浮物对前处理的影响,讨论了样品中苯胺类化合物的前处理方法和分析方法中基质干扰的消除与补偿,以期为水中苯胺类化合物的准确测定提供参考㊂1㊀实验部分1.1㊀仪器、试剂及材料高效液相色谱-串联质谱仪:高效液相色谱仪(日本岛津公司),带ESI源API4000QTrap三重四极杆质谱仪(美国AB Sciex公司),MiliQ超纯水发生器(美国Millipore公司),SHIMADZU Shim-pack FC-ODS柱(150mmˑ2.1mm,3μm,日本岛津公司),混合型阳离子交换柱(WondaSep MCX,150mg/6mL,日本岛津公司),0.22㊁0.45μm聚四氟乙烯滤膜(津腾公司),N-EVAP Ⅲ氮吹仪(美国),24通道固相萃取装置(美国Supelco公司)㊂甲醇(HPLC级,J&K SCIENTIFIC LTD),甲酸(HPLC级,CNW Technologies),乙酸(HPLC级, TEDIA),氨水(优级纯,含量为25%~28%),硫代硫酸钠(分析纯);标准物质:邻苯二胺㊁邻甲氧基苯胺㊁邻甲苯胺㊁间硝基苯胺㊁间氯苯胺㊁2-萘胺㊁2,4-二甲基苯胺㊁2,6-二甲基苯胺㊁2,6-二乙基苯胺㊁2-乙基-6-甲基苯胺㊁苯胺㊁联苯胺㊁对甲苯胺㊁对硝基苯胺㊁邻硝基苯胺㊁3,3-二氯联苯胺㊁对氯苯胺㊂分别准确称取适量的苯胺类标准物质,用甲醇配制成浓度为100μg/mL标准储备液, -18ħ以下避光保存㊂混合中间标准溶液:吸取适量苯胺类化合物标准贮备液,用甲醇稀释,配制成浓度为1~10μg/mL的混合中间标准溶液,其中,邻硝基苯胺和间硝基苯胺的质量浓度为10.0μg/mL,其余化合物质量浓度为1.0μg/mL, -18ħ以下避光保存㊂1.2㊀样品采集与保存采集不同悬浮物浓度的地表水㊁生活污水㊁印染废水㊁制药废水,用甲酸或氨水调节其pH至7~8,一组样品未加硫代硫酸钠,另一组样品加入80mg/L硫代硫酸钠,在4ħ以下冷藏㊁避光保存㊂1.3㊀前处理1.3.1㊀直接进样法样品经0.22μm聚四氟乙烯滤膜过滤,弃去至少1mL初滤液后,移取1.0mL过滤后的样品于棕色进样瓶中,混匀待测㊂1.3.2㊀固相萃取法依次用10mL甲醇和水活化混合型阳离子交换柱,取100mL水样以小于3mL/min的流速通过小柱㊂依次用5mL3%乙酸水溶液和4mL 10%甲醇水溶液淋洗小柱㊂用真空泵抽干小柱10min,用7mL5%氨化甲醇洗脱富集后的小柱,洗脱液经50ħ氮吹浓缩至略低于1mL,用纯水定容至1.0mL,再用纯水稀释2倍后混匀待测㊂2㊀结果与讨论2.1㊀样品的保存苯胺类化合物暴露于空气中,可被氧化而色泽变深㊂芳胺容易被氧化,氧化剂不同,得到的产物也较为复杂,颜色为黄色㊁棕红色甚至黑色㊂染料废水等工业废水中的苯胺类和联苯胺类多采用二氧化氯氧化法进行去除或预处理㊂曹向禹[2]采用ClO2氧化法预处理联苯胺类染料中间体生产废水,在较佳工艺条件下(涉及ClO2的加入量㊁ClO2与联苯胺的化学计量比和反应时间),出水中联苯胺的去除率达到80%以上㊂于德爽等[3]采用二氧化氯氧化法去除染料废水中苯胺类物质,去除率达到95%以上㊂由于苯胺类化合物可被氧化,样品采集后的保存是个难点,采样过程中要注意密封㊁避光㊁冷藏,并加入抗氧化剂进行保存㊂水样中常用的抗氧化剂有抗坏血酸和硫代硫酸钠,因印染㊁制药等工业废水中的苯胺类多采用二氧化氯氧化法去除以及制造工艺中使用漂白粉脱色或消毒剂等,样品中苯胺类化合物的保存易受余氯的影响,多采用硫代硫酸钠进行去除㊂美国环保署EPA8131标准方法中规定,水样采集后用氢氧化钠或硫酸调节样品pH为6~8,如果有余氯存在,样品中每毫克余氯需要加入35mg 硫代硫酸钠去除㊂印染等工业废水处理前的样品中含有二氧化氯(浓度为2mg/L左右),出口废水中二氧化氯浓度控制在0.5mg/L以下,故硫代硫酸钠的添加量一般为70mg/L可以有效去除余氯㊂根据‘水质苯胺类化合物的测定气相色谱-质谱法“(HJ822 2017)的要求,样品采集后立即加入氢氧化钠或硫酸溶液,调节pH为6~8, 4ħ冷藏保存,如水样中有余氯,每1000mL样品㊀136㊀中㊀国㊀环㊀境㊀监㊀测第36卷㊀第6期㊀2020年12月㊀中加入80mg 硫代硫酸钠㊂故笔者选择硫代硫酸钠的添加量为80mg /L㊂笔者针对样品中苯胺类化合物在不加抗氧化剂和加入抗氧化剂(硫代硫酸钠)情况下的保存时间进行了研究㊂在地表水中加入浓度为1.0㊁5.0㊁50.0μg /L的苯胺类化合物和制药废水中加入浓度为50.0μg /L 的苯胺类化合物,密封㊁避光㊁冷藏保存,采用直接进样-液相色谱-三重四极杆质谱法测定,计算1~10d 的样品加标回收率,结果见图1㊂研究发现,地表水中低浓度(1.0㊁5.0μg /L)加标样品中,联苯胺和邻苯二胺在1d 之后迅速降解,其他化合物在4d 之内无明显变化,4d 之后有缓慢降解㊂地表水中加标50.0μg /L 时,17种苯胺类化合物在10d 内无显著变化,但在制药废水中加标50.0μg /L 时,邻苯二胺1d 后降解较快,联苯胺2d 后缓慢降解,其余化合物在10d 内无显著变化㊂说明样品中若不加入抗氧化剂,邻苯二胺和联苯胺易被氧化,受不同基质水样影响较大,降解较快,其余的氯代苯胺类㊁烷基代苯胺类和硝基代苯胺类的性质较稳定,降解较慢㊂图1㊀未加抗氧化剂的实际样品保存时间研究Fig.1㊀Study on the preservation time of actual samples without antioxidant㊀㊀同时考察了在实际样品中加入硫代硫酸钠对保存时间的影响㊂分别在地表水和制药废水中加入80mg /L 硫代硫酸钠,然后再加入不同浓度苯胺类化合物(地表水加标浓度为 1.0㊁5.0㊁50.0μg /L,制药废水中加标浓度为50.0μg /L),密封㊁避光㊁冷藏保存,采用直接进样-液相色谱-三重四极杆质谱法测定,计算样品加标回收率㊂结果见图2㊂研究发现,地表水中加入硫代硫酸钠后,低浓度(1.0㊁5.0μg /L)加标样品中,邻苯二胺在3d 内无明显变化,3d 之后降解很快,联苯胺和3,3 -二氯联苯胺在5d 后迅速降解,其余化合物的加标回收率在7d 内变化不大㊂制药废水中加入硫代硫酸钠后,加标样品中的邻苯二胺在4d 之后有缓慢降解㊂㊀赵云芝等:水中苯胺类化合物分析的难点137㊀㊀图2㊀实际样品中加入80mg/L硫代硫酸钠后的保存时间研究Fig.2㊀Study on the preservation time after adding80mg/L sodium thiosulfate to the actual sample㊀㊀综上所述,水样中加入硫代硫酸钠可延缓联苯胺和邻苯二胺的降解㊂因此,水样采集后应加入硫代硫酸钠,每500mL水样中加入40mg硫代硫酸钠,4ħ以下冷藏保存,除邻苯二胺在3d内完成分析,联苯胺和3,3 -二氯联苯胺在5d内完成分析,其余化合物应在7d内完成分析㊂2.2㊀样品中悬浮物对前处理的影响2.2.1㊀直接进样法为考察样品中的悬浮物浓度对苯胺类化合物的吸附作用,笔者选择了悬浮物浓度分别为18.5mg/L(生活污水出口)㊁47.3mg/L(印染废水出口)㊁68.3mg/L(地表水)的实际样品进行加标回收率测定,苯胺类化合物的加标浓度均为50.0μg/L,加标样品放置24h后经聚四氟乙烯滤膜过滤测定,回收率结果见图3㊂结果表明,随着悬浮物浓度的升高,苯胺类化合物的实际样品加标回收率并未发生显著变化,加标回收率为74.6%~102%㊂采用直接进样法时,为考察悬浮物对不同浓度苯胺类化合物的影响,向悬浮物浓度为68.3mg/L的地表水样品中加标1.0㊁5.0㊁50.0μg/L苯胺类化合物,计算样品加标回收率,见图4㊂结果表明,悬浮物对低浓度(1.0㊁5.0μg/L)的联苯胺㊁邻苯二胺和3,3 -二氯联苯胺有影响,但回收率为60.6%~70.8%,对其他低浓度苯胺类化合物无影响,回收率为75.6%~ 116%㊂2.2.2㊀固相萃取法为考察悬浮物对苯胺类化合物萃取效率的影响,向悬浮物浓度分别为10.8㊁21.6㊁32.4㊁64.8㊁108㊁703mg/L的地表水样品中加标0.2μg/L的苯胺类化合物,经混合型阳离子交换固相萃取柱富集净化,液相色谱-三重四极杆质谱法测定,计算样品加标回收率,结果见图5㊂结果表明,悬浮物对联苯胺影响较大,样品加标回收率偏低,且随着悬浮物浓度升高,回收率逐渐下降㊂但悬浮物对其他苯胺类化合物影响不显著,回收率为60.9%~119%㊂㊀138㊀中㊀国㊀环㊀境㊀监㊀测第36卷㊀第6期㊀2020年12月㊀图3㊀不同浓度悬浮物对苯胺类化合物回收率的影响Fig.3㊀Effects of suspended solids at different concentrations on the recovery of aniline compounds图4㊀悬浮物对不同浓度苯胺类化合物回收率的影响Fig.4㊀Effects of suspended solids on recovery of aniline compounds at different concentrations图5㊀不同浓度悬浮物对苯胺类化合物回收率的影响Fig.5㊀Effects of suspended solids at different concentrations on therecovery of aniline compounds㊀赵云芝等:水中苯胺类化合物分析的难点139㊀㊀㊀㊀当悬浮物浓度过高时,可以先将样品用盐酸溶液调到pH 为3,摇匀样品后,用经过乙醇浸润的聚四氟乙烯滤膜过滤,过滤液用1.0mol /L 氢氧化钠溶液调至pH 为7~8后再进行富集㊂研究了向悬浮物浓度分别为10.8㊁21.6㊁32.4㊁64.8㊁108㊁703mg /L 的地表水样品中加标0.2μg /L 的苯胺类化合物,经上述前处理后再通过阳离子交换固相萃取柱富集净化,液相色谱-三重四极杆质谱法测定,计算样品加标回收率,结果见图6㊂结果表明,联苯胺的回收率明显提高,但3,3 -二氯联苯胺的回收率明显降低,苯胺的回收率在悬浮物浓度大于32.4mg /L 时显著降低,其余苯胺类化合物的回收率为60.1%~112%㊂当悬浮物浓度过高时,也可以通过减少取样体积,避免堵塞固相萃取柱㊂图6㊀调节样品pH 及过滤后不同浓度悬浮物对苯胺类化合物回收率的影响Fig.6㊀Effects of suspended solids at different concentrations on recovery of anilinecompounds after pH adjustment and filtration㊀㊀综上所述,在直接进样法和固相萃取法中,由于邻苯二胺和联苯胺极性强,更易被氧化,3,3 -二氯联苯胺分子量大,易被悬浮物吸附,受不同基质水样影响较大,悬浮物浓度升高后,样品加标回收率会降低㊂其余的氯代苯胺类㊁烷基代苯胺类和硝基代苯胺类的性质较稳定,受悬浮物影响不大㊂2.3㊀样品前处理方法的选择国内外研究水中苯胺类化合物的前处理方法主要有蒸馏法㊁顶空固相微萃取[4]㊁液液萃取[5]㊁吹扫捕集[6]㊁液液微萃取[7]㊁直接进样法[8-9]㊁固相萃取法(C 18小柱㊁HLB 小柱㊁GDX-502层析柱和阳离子交换柱等)等[10-11]㊂顶空固相微萃取和吹扫捕集多适用于易挥发㊁易吹脱捕集的苯胺及烷基苯胺类化合物㊂直接进样法多适用于可直接进水相样品的液相色谱法㊁液相色谱-三重四极杆质谱法㊁离子色谱法等,复杂水样需经处理后直接进样分析㊂液液萃取和固相萃取是水样中有机污染物的常用前处理方法㊂赵云芝等[11]采用液液萃取㊁固相萃取2种前处理方法对苯胺类化合物进行富集和净化㊂结果发现,液液萃取对苯胺类化合物的回收率偏低,特别是极性较强的间苯二胺㊁邻苯二胺㊁联苯胺㊁苯胺等化合物的回收率更低㊂由于苯胺类化合物属于弱碱性化合物,极性较强,在固相萃取中,常用的C 18柱和HLB 柱对苯胺类化合物吸附不完全致使回收率偏低㊂混合型阳离子交换柱(MCX)和硅胶基质阳离子交换柱(SCX)利用吸附和交换2种作用力对苯胺类化合物进行富集,同时采用清洗步骤进行净化,大部分苯胺类化合物的回收率为70%~100%,但对于极性很强的间苯二胺和邻苯二胺的回收率稍微偏低,为50%~70%㊂综上所述,对于极性很强的二苯胺类化合物建议采用直接进样法,易挥发㊁易吹脱捕集的苯胺及烷基苯胺类化合物可采用顶空固相微萃取和吹扫捕集,联苯胺类建议采用固相萃取法,氯代苯胺㊁硝基代苯胺及烷基苯胺类可采用液液萃取法和固相萃取法等㊂㊀140㊀中㊀国㊀环㊀境㊀监㊀测第36卷㊀第6期㊀2020年12月㊀2.4㊀分析方法中基质干扰的消除与补偿2.4.1㊀色谱分离条件的选择和优化选择合适的色谱分离条件是解决样品基质干扰最有效的方法㊂对于反相液相色谱,可以通过改变流动相的组成和pH,降低梯度洗脱时有机相的初始浓度,延长梯度时间,降低流速,减少进样量㊁更换不同规格类型的色谱柱或使用双柱,还可以采用二维液相色谱分离㊂气相色谱分离主要通过改变升温程序㊁更换不同规格型号的色谱柱㊁改变流速和汽化室温度㊁调节分流比㊁使用二维气相色谱分离等㊂该研究在采用气相色谱-质谱法测定土壤中半挥发性有机物时,通过提高质谱的分流比,虽然降低了一些灵敏度,但基质干扰明显减低,不用频繁清洗离子源和截掉毛细管色谱柱㊂2.4.2㊀检测器的选择和优化对苯胺类化合物的检测,采用气相色谱法时多使用氢火焰离子化检测器和氮磷检测器,当基质干扰严重时,可以选择气相色谱-质谱法检测,优化扫描模式(全扫或选择离子扫描)㊁电离强度及选择不同的离子源(EI或CI)等,还可以选择气相色谱-三重四极杆质谱法进行检测㊂采用液相色谱法时多采用紫外检测器,当基质干扰严重时,可以采用荧光检测器进行分析,通过优化激发波长和发射波长等条件,对有荧光响应的部分苯胺类化合物(如苯胺㊁联苯胺㊁邻甲基苯胺㊁间甲基苯胺㊁对甲基苯胺㊁对氯苯胺等)进行检测㊂还可以选择液相色谱-三重四极杆质谱法对苯胺类化合物进行检测,通过优化质谱参数或改变离子源种类(ESI源㊁APCI源或APPI源)来降低基质干扰㊂笔者比较了APCI源和ESI源对苯胺类化合物基质效应的影响㊂在相同的色谱分离条件下,使用APCI源时,苯胺类化合物的响应强度比使用ESI源时降低了约3倍,结果见图7㊂图7㊀苯胺类化合物在液相色谱-串联质谱法不同离子源条件下的总离子流Fig.7㊀Total ion chromatogram of aniline compounds under different ionsource conditions by liquid chromatography-tandem mass spectrometry2.4.3㊀定量方法的选择和使用2.4.3.1㊀内标法内标物质在样品分析的不同阶段加入,被称为提取内标(在样品提取前加入)㊁净化内标(在样品净化前加入)和进样内标(在试样进入仪器检测前加入)㊂进样内标补偿进样量误差和基质效应的影响,提取内标和净化内标可以补偿提取过程损失㊁净化过程损失和基质效应的影响㊂对于多组分化合物分析,进样内标选择1~2种内标物质即可,但提取内标和净化内标必须选择与目标化合物性质非常相近的同位素内标物质,否则会因为补偿造成更大的检测误差㊂赵云芝等[11]以苯胺-D5作为进样内标,固相萃取-液相色谱-串联质谱法测定水中苯胺类化合物,16种苯胺类化合物在3个质量浓度水平下,采用混合型阳离子交换柱萃取时的加标回收率为72.5%~92.5%,相对标准偏差为1.4%~9.6%;17种苯胺类化合物在3个质量浓度水平下,采用硅胶基体阳离子交换柱萃取时的加标回收率为51.0%~102%,相对标准偏差为2.4%~13.6%㊂‘土壤和沉积物苯胺类和联苯胺类的测定液相色谱-三重四极杆质谱法“(征求意见稿)[12]以苯胺-D5㊁联苯胺-D8㊁3,3 -二氯联苯胺-D6和N-亚硝基二苯胺-D6为提取内标,经超声提取㊁净化㊁浓缩㊁定容后用液相色谱-三重四极杆质谱仪检测,土壤和沉积物的加标回收率为69.2%~128%㊂2.4.3.2㊀空白基质匹配标准校正法空白基质匹配标准校正法是将空白样品经过前处理后,加入系列浓度待测物标准作为基质匹配标准溶液,用以校正检测结果㊂采用空白基质㊀赵云芝等:水中苯胺类化合物分析的难点141㊀㊀匹配标准校正,是常用的补偿基质效应的方法㊂‘原料乳与乳制品中三聚氰胺检测方法“(GB/T 22388 2008)中的液相色谱-串联质谱法即采用空白基质匹配标准校正法定量检测,标准溶液是用空白样品经提取㊁净化和氮吹浓缩后所得的样品溶液进行配制,方法的定量限为0.01mg/kg,在添加浓度为0.01~0.5mg/kg范围时,回收率为80%~110%,相对标准偏差小于10%㊂赵云芝等[11]以样品加标计算其回收率,上样100mL,苯胺类化合物的加标浓度为0.02μg/L,用混合型阳离子交换柱进行萃取,浓缩液稀释2倍后采用液相色谱-三重四极杆质谱法分析㊂分别使用空白萃取液和超纯水配制校准曲线,外标法定量㊂2种方法计算出的大部分化合物的回收率差异不大,但2,6-二甲基苯胺㊁间氯苯胺和3,3 -二氯联苯胺采用基质校准曲线很大程度上补偿基质的抑制效应,回收率明显提高㊂2.4.3.3㊀工作曲线法工作曲线法不同于空白基质匹配标准校正法,所使用的标准系列溶液经过了与样品相同的提取㊁净化㊁浓缩㊁测量等全过程,可以补偿基质干扰及前处理过程带来的损失㊂‘水质苯胺类化合物的测定液液萃取液相色谱法“(征求意见稿)[13]采用了工作曲线法进行定量检测㊂经6家实验室验证,对3个浓度水平的统一样品进行检测,实验室内相对标准偏差为0.3%~11.8%,对地表水㊁地下水㊁生活污水和工业废水的实际样品进行加标分析测定,加标回收率为62.5%~ 130%㊂3㊀结论采用液相色谱-三重四极杆质谱法研究了样品保存㊁样品中悬浮物对前处理的影响,讨论了分析方法基质干扰的消除与补偿㊂当水样中的苯胺类化合物暴露于空气中时,易被氧化而降解,因此,样品采集后应立即加入硫代硫酸钠并密闭㊁冷藏保存㊂水样中悬浮物浓度高时对联苯胺的影响很大而且容易堵塞固相萃取柱,可以调节样品pH 至酸性,使悬浮物中吸附的苯胺类化合物释放至水样中,过滤掉悬浮物,再调节样品pH至中性后进行萃取;在检测限满足质量标准或排放标准的管理要求时,可以通过减少取样体积避免堵塞固相萃取柱㊂苯胺类化合物在分析过程中易受基质干扰,可以通过色谱分离条件和检测器条件的选择和优化进行消除,采用内标法㊁空白基质匹配标准校正法和工作曲线法等定量方法进行补偿㊂参考文献(References):[1]周文敏.中国水中优先控制污染物黑名单[J].中国环境监测,1991,3(4):18-20.ZHOU Wenmin.China s Blacklist of Priority Pollutantsin Water[J].Environmental Monitoring in China,1991,3(4):18-20.[2]曹向禹.ClO2氧化法预处理联苯胺类染料中间体废水[J].化工环保,2013,33(1):39-42.CAO Xiangyu.Pretreatment of Benzidine DyeIntermediate wastewater by Chlorine Dioxide oxidationProcess[J].Environmental Protection of ChemicalIndustry,2013,33(1):39-42.[3]于德爽,彭永臻,李梅.二氧化氯氧化法去除染料废水中苯胺类物质的生产性实验研究[J].哈尔滨商业大学学报,2001,17(3):19-21.YU Deshuang,PENG Yongzhen,LI Mei.The ClO2Oxidation Process to Remove Benzenamine Materials ofDying Waste Water[J].Journal of Harbin University ofCommerce Natural Sciences Edition,2001,17(3):19-21.[4]ARCHANA J,KISHAN R N,ARADHANA K K V,etal.Conversion to Isothiocyanates via Dithiocarbamatesfor the Determination of Aromatic Primary Amines byHeadspace-Solid Phase Microextraction and GasChromatography[J].Analytica Chimica Acta,2013,801:48-58.[5]储燕萍,唐莺,韩英,等.气相色谱/质谱联用法测定饮用水源水中苯胺类化合物[J].环境监测管理与技术,2011,23(5):58-61.CHU Yanping,TANG Ying,HAN Ying,et al.Methodfor Aniline and Selected Derivatives Determination inDrink Source Water by GC/MS[J].The Administrationand Technique of Environmental Monitoring,2011,23(5):58-61.[6]张磊,杨光冠,张占恩.吹扫-捕集/气相色谱-质谱测定废水中苯胺类化合物的研究[J].苏州科技学院学报:工程技术版,2008,21(2):39-41.ZHANG Lei,YANG Guangguan,ZHANG Zhanen.Determination of Aniline Compounds in Waste Waterby Purge&Trap-Gas Chromatography/MassSpectrometry[J].Journal of University of Science andTechnology of Suzhou(Engineering and Technology),2008,21(2):39-41.[7]CHIANG J S,HUANG S D.Simultaneous Derivatizationand Extraction of Anilines in Waste Water with㊀142㊀中㊀国㊀环㊀境㊀监㊀测第36卷㊀第6期㊀2020年12月㊀Dispersive Liquid-Liquid Microextraction Followed byGas Chromatography-Mass Spectrometric Detection[J].Talanta,2008,75:70-75.[8]熊杰,钱蜀,谢永洪,等.高效液相色谱-串联质谱法同时测定水中丙烯酰胺㊁苯胺和联苯胺[J].分析化学研究报告,2014,42(1):93-98.XIONG Jie,QIAN Shu,XIE Yonghong,et al.Simultaneous Determination of Acrylamide,Aniline andBenzidine in Water Sample by High PerformanceLiquid Chromatography-Tandem Mass Spectrometry[J].Chinese Journal of Analytical Chemistry,2014,42(1):93-98.[9]赵云芝,杨坪,钱蜀.液相色谱-串联质谱法测定水中14种苯胺类化合物[J].色谱,2015,33(5):508-513.ZHAO Yunzhi,YANG Ping,QIAN Shu.Determinationof Fourteen Aniline Derivatives in Water by LiquidChromatography-Tandem Mass Spectrometry[J].Chinese Journal of Chromatography,2015,33(5):508-513.[10]王超,彭涛,高愈霄,等.混合型固相萃取/超高压液相色谱法测定废水中苯胺类化合物[J].分析测试学报,2013,32(12):1415-1420.WANG Chao,PENG Tao,GAO Yuxiao,et al.Determination of Aniline Derivatives in Waste Water byUltra High Pressure Liquid Chromatography withMixed-Mode Solid Phase Extraction[J].Journal ofInstrumental Analysis,2013,32(12):1415-1420.[11]赵云芝,谢振伟,潘乐丹,等.固相萃取/液相色谱-串联质谱法测定水质中苯胺类化合物及基质干扰的消除[J].色谱,2016,34(3):289-298.ZHAO Yunzhi,XIE Zhenwei,PAN Ledan,et al,Determination of Aniline Derivatives in Water by SolidPhase Extraction-Liquid Chromatography-Tandem MassSpectrometry and Elimination of Matrix Effects[J].Chinese Journal of Chromatography,2016,34(3):289-298.[12]生态环境部办公厅.关于征求‘土壤和沉积物钴的测定火焰原子吸收分光光度法“等六项国家环境保护标准意见的函.环办标征函 2018 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海上河流相稠油油田低产低效井综合治理措施分析——以N油田09砂体为例
石油地质与工程2021年1月PETROLEUM GEOLOGY AND ENGINEERING 第35卷第1期文章编号：1673–8217（2021）01–0118–04海上河流相稠油油田低产低效井综合治理措施分析——以N油田09砂体为例谢岳，张俊廷，甘立琴，韩雪芳，王公昌（中海石油（中国）有限公司天津分公司渤海石油研究院，天津300452）摘要：随着河流相稠油油田开发进入中后期，受原油黏度大、储层非均质性强、油水系统复杂等制约，低产低效井井数占比逐年增加。
为了改善海上油田开发效果和实现降本增效，以N油田09砂体为例，开展海上河流相稠油油田低产低效井综合治理措施分析。
结果表明，09砂体低产低效井成因可细分为储层物性差、采出程度高和工艺出砂三种类型；影响低产低效井综合治理措施的因素除了成因外，还有剩余油分布、井型、油柱高度、水平段长度等因素；在综合各因素的基础上，针对09砂体每一类低产低效井提出了相应的治理措施。
其研究成果应用于N油田低产低效井的综合治理，增加产能400 m3/d，提高采收率约0.2%，取得了较好的开发效果。
关键词：低产低效井；综合治理；剩余油；河流相；稠油油田中图分类号：TE313.3 文献标识码：AAnalysis of comprehensive treatment measures for low production and low efficiency wells inoffshore fluvial heavy oilfield--by taking sand body 09 of N oilfield as an exampleXIE Yue, ZHANG Junting, GAN Liqin, HAN Xuefang, WANG Gongchang(Bohai Petroleum Research Institute, Tianjin Company of CNOOC (China) Co., Ltd., Tianjin 300452, China) Abstract: With the development of fluvial heavy oil field entering the middle and late stage, the proportion of low production and low efficiency wells is increasing year by year due to the restriction of high crude oil viscosity, strong reservoir heterogeneity and complex oil-water system. In order to improve the development effect of offshore oilfield and realize cost reduction and efficiency increase, the comprehensive treatment measures of low production and low efficiency wells in offshore fluvial heavy oil field are analyzed by taking sand body 09 of N oilfield as an example. The results show that the causes of low production and low efficiency wells in sand body 09 can be divided into three types: poor reservoir physical properties, high recovery degree and technological sand production. In addition to the cause of formation, the factors influencing the comprehensive treatment measures of low production and low efficiency wells include the distribution of remaining oil, well type, oil column height, horizontal section length, etc. On the basis of comprehensive factors, the corresponding control measures are put forward for each type of low production and low efficiency wells in sand body 09. The results have been applied to guide the comprehensive treatment of low production and low efficiency wells in N oilfield. The productivity is increased by 400 m3 / d, the recovery factor is about 0.2%, and good development effect has been achieved.Key words: low production and low efficiency wells; comprehensive treatment; remaining oil; fluvial facies;heavy oilfield收稿日期：2020–07–10；修订日期：2020–08–24。
英语作文-康复护理服务市场逐渐成熟,行业格局日趋清晰
英语作文-康复护理服务市场逐渐成熟，行业格局日趋清晰The market for rehabilitation nursing services has been steadily maturing, with a clear trend towards a more defined industry landscape. This evolution is driven by various factors, including demographic shifts, advances in medical technology, and changing healthcare policies. As these forces interact, they reshape the dynamics of rehabilitation nursing, influencing service delivery, patient care, and the overall market structure.Firstly, demographic changes play a pivotal role in shaping the rehabilitation nursing market. The aging population, particularly in developed economies, has led to an increased prevalence of chronic conditions and disabilities requiring long-term care. This demographic shift has fueled demand for specialized rehabilitation services aimed at enhancing quality of life and functional independence among elderly individuals and those with disabilities.Moreover, advancements in medical technology have revolutionized the rehabilitation nursing landscape. Innovations such as robotic-assisted therapies, virtual reality rehabilitation programs, and wearable health monitoring devices have expanded treatment options and improved patient outcomes. These technological advancements not only facilitate more effective rehabilitation interventions but also contribute to the differentiation of service offerings within the market.Furthermore, the evolving regulatory environment and healthcare policies have influenced the operational framework of rehabilitation nursing services. Government initiatives aimed at promoting patient-centered care, reducing hospital readmissions, and enhancing care coordination have prompted healthcare providers to adopt integrated care models. These models emphasize interdisciplinary collaboration among healthcare professionals to optimize rehabilitation outcomes and streamline service delivery.In parallel, market dynamics have driven consolidation among rehabilitation nursing providers. The emergence of large healthcare networks and alliances has reshaped the competitive landscape, fostering economies of scale and enhancing resource allocation efficiency. This trend towards consolidation is accompanied by a growing emphasis on outcome-based reimbursement models, where healthcare providers are incentivized based on patient recovery and functional outcomes rather than volume of services delivered.Additionally, consumer preferences and expectations have evolved, influencing the market demand for rehabilitation nursing services. Patients and their families increasingly seek personalized care experiences, transparency in treatment options, and accessibility to rehabilitation facilities that prioritize patient comfort and safety. Healthcare providers are responding by investing in patient engagement strategies, enhancing care coordination platforms, and leveraging digital health solutions to meet evolving consumer needs.Looking ahead, the future of the rehabilitation nursing market will likely be shaped by ongoing advancements in medical science, shifts in healthcare policy, and continued demographic changes. As the industry matures, stakeholders must remain adaptable to emerging trends and technological innovations while maintaining a steadfast commitment to improving patient outcomes and enhancing the overall quality of rehabilitation nursing services.In conclusion, the rehabilitation nursing market is experiencing a phase of maturation characterized by a clearer industry landscape and evolving market dynamics. This evolution is driven by demographic shifts, advancements in medical technology, changes in healthcare policies, and shifting consumer expectations. By navigating these factors effectively, stakeholders can capitalize on emerging opportunities and contribute to the advancement of rehabilitation nursing as a critical component of modern healthcare delivery.。
湖北省武汉市武昌区2024届高三下学期5月质检英语含答案
武昌区2024届高三年级5月质量检测英语本试卷共150分，考试用时120分钟。
祝考试顺利注意事项：1. 答题前，考生务必将自己的学校、班级、姓名、准考证号填写在答题卡指定位置，必认真核对与准考证号条形码上的信息是否一致，并将准考证号条形码粘贴在答题卡上的指定位置。
2. 选择题的作答：选出答案后，用2B铅笔把答题卡上对应题目的答案标号涂黑，如需改动，用橡皮擦干净后，再选涂其他答案标号，答在试题卷上无效，¢3. 非选择题的作答：用黑色墨水的签字笔直接答在答题卡上的每题所对应的答题区域内，答在试题卷上或答题卡指定区域外无效。
4. 考试结束，监考人员将答题卡收回，考生自己保管好试题卷，评讲时带来。
第一部分听力(共两节，满分30分)做题时，先将答案标在试卷上。
录音内容结束后，你将有两分钟的时间将试卷上的答案转涂到答题卡上。
第一节(共5小题：每小题1. 5分，满分7. 5分)听下面5段对话，每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项。
听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题，每段对话仅读一遍。
1. What is the man?A. A teacher.B. A surgeon.C. A manager.2. Why can’t the woman keep still?A. She is excited.B. She is nervous.C. She is ill.3. What are the speakers talking about?A. Why the electricity bill went up.B. Where they can pay the electricity bill.C. How they can reduce the electricity usage.4. Why is the man phoning the woman?A. To ask her out for dinner.B. To tell her he will be late.C. To inform her of an accident.5. What are the speakers mainly talking about?A. A psychological term.B. A chemical reaction.C. The man’s coat.第二节(共15 小题；每小题 1. 5 分，满分22. 5分)听下面5 段对话或读白，每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项。
有关酶解工艺的英文文献
Enzymatic Hydrolysis ProcessIntroductionEnzymatic hydrolysis is a process that involves the breakdown of complex organic compounds using enzymes. This process plays a crucial role in various industries, including biofuels, food, pharmaceuticals, and agriculture. Enzymes act as catalysts, accelerating the rate of chemical reactions and enabling the transformation of substrates into desired products. In this article, we will explore the different aspects of enzymatic hydrolysis, including its significance, applications, factors affecting the process, and future prospects.Importance of Enzymatic HydrolysisEnzymatic hydrolysis is a highly significant process due to its wide range of applications. Some key reasons for the importance of this process are:1.Biofuel Production: Enzymes are extensively utilized in theproduction of biofuels, such as ethanol and biodiesel. Enzymatichydrolysis of lignocellulosic biomass, such as agriculturalresidues and energy crops, breaks down complex carbohydrates intosimple sugars, which can then be fermented to produce biofuels.2.Food Industry: Enzymatic hydrolysis is employed in the foodindustry to enhance the nutritional properties of various foodproducts. For example, proteases are widely used to hydrolyzeproteins into amino acids, improving their digestibility.3.Pharmaceuticals: Enzymatic hydrolysis plays a critical role inthe pharmaceutical industry, particularly in drug formulation.Enzymes are used to break down active pharmaceutical ingredientsinto biologically active compounds, facilitating their absorptionand effectiveness.4.Waste Treatment: Enzymatic hydrolysis is utilized in thetreatment of various types of waste, including sewage andagricultural waste. Enzymes aid in the breakdown of organic matter,reducing the environmental impact and facilitating the productionof valuable by-products.Enzymatic Hydrolysis ProcessThe enzymatic hydrolysis process involves a series of steps, including substrate preparation, enzyme selection, enzymatic reaction, and product recovery.1.Substrate Preparation: The substrate used in enzymatic hydrolysisneeds to be properly prepared to ensure efficient enzyme-substrate interaction. This often involves pretreatment methods such as size reduction, chemical or physical treatment, and removal ofinhibitors.2.Enzyme Selection: The choice of enzyme is crucial as itdetermines the specificity and efficiency of the hydrolysisprocess. Different enzymes are suitable for different substrates,and factors such as pH, temperature, and enzyme concentration need to be considered.3.Enzymatic Reaction: The hydrolysis reaction typically occurs in acontrolled environment, with optimum pH and temperature conditions.The enzyme is added to the substrate, and the reaction is allowedto proceed for a specific period. During this time, the enzymebreaks down the substrate into smaller molecules.4.Product Recovery: After the enzymatic hydrolysis, the desiredproducts need to be separated from the reaction mixture. This mayinvolve techniques such as filtration, centrifugation, orchromatography, depending on the nature of the products andimpurities present.Factors Affecting Enzymatic HydrolysisSeveral factors can influence the efficiency of enzymatic hydrolysis. These factors need to be carefully considered and optimized to achieve the desired results. Some key factors include:1.pH: Enzymatic reactions are highly sensitive to pH. Differentenzymes have different pH optima, and maintaining the appropriatepH level ensures optimal enzyme activity.2.Temperature: Temperature significantly affects enzyme activity.Each enzyme has an optimum temperature range within which itfunctions best. Deviating from this range can either decrease the reaction rate or denature the enzyme.3.Enzyme Concentration: The concentration of enzymes in thereaction mixture influences the rate and efficiency of hydrolysis.Higher enzyme concentrations usually result in faster reactionrates, up to a certain limit.4.Substrate Concentration: The concentration of the substrate alsoaffects the hydrolysis process. Extremely high or low substrateconcentrations can inhibit enzyme activity and reduce overallefficiency.5.Inhibitors and Activators: Inhibitors can significantly affectenzymatic hydrolysis by interfering with the enzyme-substrateinteraction. Activators, on the other hand, can enhance enzymeactivity. Identifying and managing these factors is crucial foroptimum results.Future ProspectsEnzymatic hydrolysis continues to be an area of active research and development. Scientists are continually exploring new enzymes, optimizing reaction conditions, and developing innovative techniques to improve the efficiency and cost-effectiveness of the process. In addition, advancements in genetic engineering and enzyme immobilization techniques hold promising potential for further enhancing enzymatic hydrolysis processes.ConclusionEnzymatic hydrolysis is a vital process with significant applications in various industries. Understanding the factors influencing the process and optimizing reaction conditions are crucial for achieving efficient and cost-effective hydrolysis. Ongoing research efforts and technological advancements continue to drive progress in this field, opening doors to new possibilities and innovations in the future.。
有关态度的英语作文
When it comes to writing an essay on the topic of attitude,it is essential to explore the various aspects of human behavior and mindset that shape our attitudes towards life, work,and relationships.Here are some key points to consider when crafting your essay:1.Definition of Attitude:Begin by defining what attitude means.Attitude can be described as a persons disposition or outlook towards a particular situation or aspect of life.It is a mental state that influences ones behavior and responses.2.Importance of a Positive Attitude:Discuss the significance of maintaining a positive attitude.A positive attitude can lead to better mental health,improved relationships,and increased success in various aspects of life.3.Negative Attitudes and Their Consequences:Conversely,explore the impact of negative attitudes,such as pessimism,cynicism,or a defeatist mindset.These can lead to stress,isolation,and missed opportunities.4.Factors Influencing Attitude:Delve into the factors that can influence a persons attitude,such as upbringing,culture,personal experiences,and social environment.5.How Attitudes are Formed:Explain the process of attitude formation,which can be through direct experiences,observation,or social learning.6.Changing Attitudes:Discuss strategies for changing ones attitude,such as selfreflection,seeking new experiences,and challenging negative thought patterns.7.Attitude and Success:Explore the relationship between attitude and success.A positive attitude can be a key factor in achieving goals and overcoming obstacles.8.Cultural Differences in Attitudes:Consider how attitudes can vary across different cultures and how this can affect interactions and understanding between people from diverse backgrounds.9.Attitude in the Workplace:Discuss the role of attitude in professional settings.A positive and proactive attitude can lead to better job performance and career advancement.10.Personal Stories or Examples:Use personal anecdotes or wellknown examples to illustrate the power of attitude.This can make your essay more relatable and engaging.11.Conclusion:Summarize the key points made in the essay and emphasize the importance of cultivating a positive attitude for personal growth and wellbeing.12.Call to Action:End your essay with a call to action,encouraging readers to reflect on their own attitudes and consider how they might improve them.Remember to use clear and concise language,provide evidence or examples to support your points,and maintain a logical flow of ideas throughout your essay.This will help ensure that your writing is persuasive and impactful.。
神经的英语知识点总结
神经的英语知识点总结The nervous system is a complex and intricate network of cells, tissues, and organs that allow the body to communicate and coordinate its actions. It is responsible for receiving and transmitting information, controlling movement, regulating bodily functions, and mediating the body's response to external and internal stimuli.Structure of the Nervous SystemThe nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).Central Nervous System (CNS)The CNS includes the brain and the spinal cord. The brain is the command center of the nervous system and is responsible for processing and interpreting sensory information, initiating movements, and regulating bodily functions. The spinal cord serves as a communication pathway between the brain and the rest of the body and is involved in controlling reflexes.Peripheral Nervous System (PNS)The PNS consists of nerves that extend from the CNS to the rest of the body. It is further divided into the somatic nervous system and the autonomic nervous system.- The somatic nervous system controls voluntary movements and is responsible for transmitting sensory information from the body to the CNS.- The autonomic nervous system regulates involuntary bodily functions such as heart rate, digestion, and respiration. It is further divided into the sympathetic and parasympathetic nervous systems, which have opposing effects on the body's physiological responses.NeuronsNeurons are the functional units of the nervous system. They are specialized cells that are capable of receiving, processing, and transmitting electrical and chemical signals. Neurons have a unique structure that allows them to carry out these functions.- Cell Body: The cell body contains the nucleus and other organelles necessary for the neuron's metabolic activities.- Dendrites: Dendrites are short, branching extensions that receive signals from other neurons and transmit them to the cell body.- Axon: The axon is a long, single extension that carries signals away from the cell body and transmits them to other neurons, muscles, or glands. Some axons are covered by a fatty substance called myelin, which insulates the axon and facilitates the rapid transmission of signals.- Synapse: The synapse is the junction between two neurons where electrical or chemical signals are transmitted from one neuron to another.Types of NeuronsThere are three main types of neurons, each with specific functions:- Sensory Neurons: Sensory neurons transmit sensory information from the body to the CNS. They have specialized receptor cells that detect stimuli such as touch, temperature, pain, and pressure.- Motor Neurons: Motor neurons carry signals from the CNS to muscles and glands, initiating movement and regulating bodily functions.- Interneurons: Interneurons connect sensory and motor neurons within the CNS and are involved in processing and integrating information.NeurotransmittersNeurotransmitters are chemical messengers that transmit signals between neurons and other cells. They are released from the presynaptic neuron into the synaptic cleft, where they bind to specific receptors on the postsynaptic neuron, initiating a response. There are many different types of neurotransmitters, each with specific functions and effects on the body.Examples of neurotransmitters include:- Acetylcholine: Acetylcholine is involved in the transmission of signals across neuromuscular junctions and is also found in the autonomic nervous system.- Dopamine: Dopamine is associated with motivation, reward, and movement control.- Serotonin: Serotonin is involved in mood regulation, appetite, and sleep.- Gamma-Aminobutyric Acid (GABA): GABA is an inhibitory neurotransmitter that helps regulate anxiety, stress, and neuronal excitability.NeuroplasticityNeuroplasticity refers to the ability of the nervous system to adapt and reorganize in response to experience, injury, or disease. It is a fundamental property of the brain and underlies learning, memory, and recovery from brain injuries.Types of NeuroplasticityThere are two main types of neuroplasticity:- Synaptic Plasticity: Synaptic plasticity refers to the ability of synapses to strengthen or weaken in response to activity. This process underlies learning and memory formation.- Structural Plasticity: Structural plasticity involves changes in the structure of neurons and their connections, such as the growth of new dendrites or the formation of new synapses. It plays a crucial role in recovery from brain injuries and in the maintenance of brain function.Neuroplasticity and LearningNeuroplasticity is essential for learning and memory formation. When we learn new information or skills, the connections between neurons are strengthened, leading to changes in brain structure and function. This process allows the brain to adapt to new experiences and to store and retrieve information.Neuroplasticity and Brain RepairNeuroplasticity also plays a critical role in the brain's ability to repair and reorganize itself following injury or disease. After a stroke or traumatic brain injury, for example, the brain can undergo structural and functional changes that enable the recovery of lost functions. This process can be enhanced through rehabilitation and targeted therapy.Factors Affecting NeuroplasticitySeveral factors can influence the extent and effectiveness of neuroplasticity, including:- Age: Neuroplasticity is most pronounced in the developing brain but continues throughout life to a certain extent. Younger brains are generally more malleable and responsive to change.- Experience: Experience and environmental enrichment can promote neuroplasticity by stimulating the formation of new connections and the growth of neurons.- Hormones and Neurotransmitters: Hormones and neurotransmitters play a crucial role in regulating neuroplasticity, influencing the strength and stability of synaptic connections. Disorders Affecting the Nervous SystemThe nervous system can be affected by a wide range of disorders that impair its function and can have far-reaching effects on the body. Some common disorders include:- Neurodegenerative Diseases: Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS) are characterized by the progressive degeneration of neurons, leading to cognitive decline, movement disorders, and loss of muscle function.- Stroke: A stroke occurs when blood flow to a part of the brain is interrupted, resulting in damage to brain tissue and loss of function. Strokes can cause paralysis, speech and language difficulties, and cognitive impairments.- Multiple Sclerosis (MS): MS is an autoimmune disease that affects the central nervous system, causing damage to the myelin sheath and impairing the transmission of signalsbetween neurons. Symptoms of MS can vary widely and may include muscle weakness, sensory disturbances, and cognitive deficits.- Epilepsy: Epilepsy is a neurological disorder characterized by recurrent seizures, which are caused by abnormal electrical activity in the brain. Seizures can vary in severity and may involve loss of consciousness, convulsions, or abnormal sensations.Treatment and Management of Nervous System DisordersThe treatment and management of nervous system disorders depend on the specific condition and its underlying causes. Strategies may include:- Medications: Many nervous system disorders can be managed with medications that target symptoms or underlying disease processes. For example, antiepileptic drugs can help control seizures in epilepsy, while dopamine replacement therapies are used to manage symptoms of Parkinson's disease.- Rehabilitation: Rehabilitation programs, including physical therapy, occupational therapy, and speech therapy, can help individuals regain lost function and improve their quality of life following a neurological injury or illness.- Surgical Interventions: In some cases, surgical interventions may be necessary to address structural abnormalities or to relieve pressure on the brain or spinal cord. Examples include brain surgery for the removal of tumors and spinal fusion surgeries for the treatment of spinal cord injuries.- Lifestyle Modifications: Lifestyle modifications such as regular exercise, a healthy diet, and stress management can play a crucial role in supporting overall brain health and reducing the risk of certain neurological disorders.ConclusionThe nervous system is a remarkable and complex system that plays a vital role in every aspect of human functioning. Understanding its structure and function is essential for appreciating the intricate mechanisms that underlie our thoughts, emotions, movements, and bodily functions. By studying the nervous system, we can gain insights into the nature of consciousness, perception, and the fundamental mechanisms that govern our existence. Continued research and advancements in the field of neuroscience hold the promise of improving our understanding of the nervous system and developing new treatments for neurological disorders.。
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Technical Information 23 Elkem AS, Foundry Products © Copyright Elkem AS Postal address Office address Telephone Web RevisionP.O.Box 5211 Majorstuen NO-0302 OsloNorway Hoffsveien 65BOsloNorway+47 22 45 01 00 No. 2.5Telefax Org. no. 16.02.2011+47 22 45 01 52 NO 911 382 008 MVAFactors Influencing the Recovery and Addition of Magnesium in Ductile Iron Ladle Treatment ProcessesResidual magnesium and magnesium recovery have always been subjects for discussion amongst foundry people. This sheet summarises the most important factors that will influence the recovery of magnesium in ductile iron production.1) Sulphur content in base iron.Sulphur has to be neutralised in order to increase the surface tension of the iron. High sulphur in the base metal means increased Mg addition.2) Oxygen content in base iron.Oxygen has to be neutralised in order to increase the surface tension of the melt. As with sulphur, increased oxygen content requires higher Mg addition.3) Slag from the melting or holding furnace.Slag that is transferred from the furnace will react with magnesium and reduce the recovery. Proper separation procedures to minimise slag carry over have to be in place.4) Tapping temperature.Tapping (treatment) temperature should be kept as low as possible in order to avoid excessive reaction violence. The higher the temperature, the more vaporization and lower recovery of magnesium.5) Time between MgFeSi addition to the ladle and tapping.Time between magnesium addition and tapping should be minimised to prevent preheating and oxidation of the alloy. At the same time, there should be no liquid metal residual from previous treatments in the ladle as this may start to react with the alloy.6) Slag in ladle and pocket.Slag building up in the ladle and reaction pocket leads to reduced magnesium recovery, probably due to reactions between the slag and the magnesium and also as the pocket depth is reduced changing the reaction conditions. Overspill of alloy will occur if the pocket is allowed to fill with slag. Ladles should be kept tilted or flipped when empty to avoid slag clogging the pockets.7) FSM alloy cover.An alloy cover in the ladle, for example fine sized FeSi or steel plates, will delay the reaction start and give better absorption of magnesium into the liquid metal.8) Filling time.Metal filling rate should be high in order to achieve a high ferrostatic head in the ladle before the reaction starts.9) Fading/Pouring time.Long holding times after treatment and long pouring times require higher initial Mg contents to compensate for fading effects. Pouring times should be minimised to overcome these effects. See TI sheet No. 26 for more information.Technical Information 23 210) Inoculation.With a good inoculation, less residual magnesium is required to give good nodularity. This again means less alloy addition and better magnesium recovery.11) Ladle design.The internal Height: Diameter ratio should be at least 2:1 and the FSM pocket should have space enough to carry the alloy addition and covering material (see TI sheet No.10). The ladle should also be properly insulated to minimise heat losses and consequently the required treatment temperature (see TI sheet No. 21). A tundish cover lid is also highly recommended for alloy and temperature recovery reasons.12) Chemical composition of nodulariser.High magnesium content in the alloy will give a violent reaction and reduced recovery. High Ca will reduce the reactivity and increase the recovery, but also increase the tendency to slag formation. Rare earth’s (cerium) will assist in giving better recovery because it allows for working at lower magnesium in the alloy and lower residual magnesium in the iron (see TI sheet No. 20).13) Alloy sizing.A wide alloy sizing gives dense bulk packing in the pocket. The alloy will then fuse and react (dissolve) slowly in a controlled manner with a minimum of pieces floating. Lumps floating and burning on the surface are a waste (see TI sheet No. 20).14) Storage of foundry alloys.All foundry alloys will oxidise if exposed to moisture. Oxidised alloys will give a lower recovery than fresh materials. Containers of alloy should be stored in a dry place and not opened until required at the treatment station (see TI sheet No. 1).Factors that can influence the MgFeSi addition to a ductile iron ladle treatment process. Appendix:Checklist Recovery and Addition of Mg in Ductile Iron Ladle Treatment Processes.Technical Information 23 - AppendixElkem AS, Foundry Products© Copyright Elkem ASPostal addressOffice address TelephoneWebRevision P.O.Box 5211 Majorstuen NO-0302 Oslo NorwayHoffsveien 65B Oslo Norway+47 22 45 01 00 No. 2.5 TelefaxOrg. no.16.02.2011 +47 22 45 01 52NO 911 382 008 MVAC h e c k l i s t - R e c o v e r y a n d A d d i t i o n o f M g i nD u c t i l e I r o n L a d l e T r e a t m e n t P r o c e s s e sFor process improvements fill in information in the white fields.Technical Information 23 - Appendix 2。