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材料进化如何改变我们生活英语作文Materials Evolution and Its Impact on Our LivesThe world we live in is constantly evolving, and the materials we use have played a significant role in shaping our everyday lives. From the ancient use of stone, wood, and clay to the modern-day advancements in technology, the evolution of materials has been a driving force behind the progress of human civilization. In this essay, we will explore how the evolution of materials has transformed our lives and the ways in which we interact with the world around us.One of the most significant impacts of materials evolution has been on the field of construction. Throughout history, the materials used in building structures have evolved from simple mud and straw to more sophisticated materials such as concrete, steel, and glass. The development of these advanced materials has allowed architects and engineers to design and construct taller, more durable, and more energy-efficient buildings. The use of steel, for example, has enabled the construction of skyscrapers that reach unprecedented heights, while the incorporation of glass has transformed the way we experience natural light and ventilation within our living and working spaces.Similarly, the evolution of materials has had a profound impact on the transportation industry. The invention of the wheel, for instance, revolutionized the way we move from one place to another, and the subsequent development of materials like rubber, metal, and plastic has led to the creation of vehicles that are more efficient, comfortable, and environmentally friendly. The introduction of lightweight and high-strength materials, such as carbon fiber, has further enhanced the performance and fuel efficiency of modern vehicles, making them more accessible and appealing to a wider range of consumers.The impact of materials evolution can also be seen in the field of healthcare. The development of new materials, such as titanium and biocompatible polymers, has enabled the creation of medical devices and implants that are more durable, less invasive, and better integrated with the human body. These advancements have significantly improved the quality of life for individuals with various medical conditions, allowing them to regain mobility, restore function, and enhance their overall well-being.Furthermore, the evolution of materials has had a significant impact on the way we communicate and access information. The invention of paper and the subsequent development of printing technologies have revolutionized the dissemination of knowledge, makinginformation more accessible to the masses. The more recent advancements in electronic materials, such as semiconductors and display technologies, have led to the creation of smartphones, tablets, and other digital devices that have become essential toolsfor communication, entertainment, and learning in our modern world.The evolution of materials has also had a profound impact on the way we produce and consume energy. The development of materials like solar cells, lithium-ion batteries, and fuel cells has enabled the creation of renewable energy sources that are more efficient, sustainable, and environmentally friendly than traditional fossil fuels. These advancements have not only reduced our reliance on non-renewable resources but also have the potential to mitigate the environmental impact of our energy consumption.In conclusion, the evolution of materials has been a driving force behind the progress of human civilization. From construction and transportation to healthcare and communication, the advancements in materials have transformed the way we live, work, and interact with the world around us. As we continue to explore new and innovative materials, it is clear that the future of our society will be shaped by the ongoing evolution of these essential building blocksof our world.。
纳米科学与技术英语Delve into the fascinating realm of nanoscience and technology, where the small scale becomes the epicenter of innovation and discovery. This field, often dubbed as the "next industrial revolution," is reshaping our understanding of materials and their applications. At the nanoscale, the properties of materials can change dramatically, offering unprecedented opportunities in medicine, electronics, and energy.Imagine a world where cancer cells are targeted with precision using nanoparticles, or where electronic devices are so small they can be integrated into fabrics or even the human body. This is the potential of nanoscience and technology, a field that is pushing the boundaries of what we thought was possible. The manipulation of matter at the atomic and molecular scale has led to the development of materials with unique properties that can be tailored for specific applications.In medicine, nanotechnology is revolutionizing drug delivery systems, allowing for more effective treatments with fewer side effects. The ability to control the release of drugs at a cellular level can lead to a more personalized approach to healthcare. Moreover, nanotechnology is also paving the way for advanced imaging techniques that can detect diseases at their earliest stages.In the world of electronics, the miniaturization of components is reaching new heights with the help of nanoscience. This has implications for the development of faster, more efficient, and more powerful computing devices. The quest for smaller, more powerful devices is not just about consumer electronics; it's also about the potential to create smart systems that can interact with their environment in new and innovative ways.Energy production and storage are also being transformed by nanotechnology. The development of nanomaterials for solar cells, batteries, and fuel cells is leading to more efficient energy conversion and storage solutions. This could be a game-changer in the quest for sustainable and clean energy sources.The exploration of nanoscience and technology is not without its challenges. Ethical considerations, environmental impacts, and the potential for misuse are all topics that must be addressed as this field continues to evolve. However, the promise of nanoscience and technology is immense, and as researchers and engineers continue to unlock its secrets, we stand on the cusp of a new era of scientific and technological advancement.。
外文原文：Fuel Cells and Their ProspectsA fuel cell is an electrochemical conversion device. It produces electricity fromfuel (on the anode side) and an oxidant (on the cathode side), which react in the presence of an electrolyte. The reactants flow into the cell, and the reaction products flow out of it, while the electrolyte remains within it. Fuel cells can operate virtually continuously as long as the necessary flows are maintained.Fuel cells are different from electrochemical cell batteries in that they consume reactant from an external source, which must be replenished--a thermodynamically open system. By contrast batteries store electrical energy chemically and hence represent a thermodynamically closed system.Many combinations of fuel and oxidant are possible. A hydrogen cell uses hydrogen as fuel and oxygen (usually from air) as oxidant. Other fuels include hydrocarbons and alcohols. Other oxidants include chlorine and chlorine dioxide.Fuel cell designA fuel cell works by catalysis, separating the component electrons and protonsof the reactant fuel, and forcing the electrons to travel though a circuit, hence converting them to electrical power. The catalyst typically comprises a platinum group metal or alloy. Another catalytic process takes the electrons back in, combining them with the protons and oxidant to form waste products (typically simple compounds like water and carbon dioxide).A typical fuel cell produces a voltage from 0.6 V to 0.7 V at full rated load.Voltage decreases as current increases, due to several factors:•Activation loss•Ohmic loss (voltage drop due to resistance of the cell components and interconnects)•Mass transport loss (depletion of reactants at catalyst sites under high loads, causing rapid loss of voltage)To deliver the desired amount of energy, the fuel cells can be combined in series and parallel circuits, where series yield higher voltage, and parallel allows a stronger current to be drawn. Such a design is called a fuel cell stack. Further, the cell surface area can be increased, to allow stronger current from each cell.Proton exchange fuel cellsIn the archetypal hydrogen–oxygen proton exchange membrane fuel cell (PEMFC) design, a proton-conducting polymer membrane, (the electrolyte), separates the anode and cathode sides. This was called a "solid polymer electrolyte fuel cell" (SPEFC) in the early 1970s, before the proton exchange mechanism was well-understood. (Notice that "polymer electrolyte membrane" and "proton exchange mechanism" result in the same acronym.)On the anode side, hydrogen diffuses to the anode catalyst where it later dissociates into protons and electrons. These protons often react with oxidants causing them to become what is commonly referred to as multi-facilitated proton membranes (MFPM). The protons are conducted through the membrane to the cathode, but the electrons are forced to travel in an external circuit (supplying power) because the membrane is electrically insulating. On the cathode catalyst, oxygen molecules react with the electrons (which have traveled through the external circuit) and protons to form water — in this example, the only waste product, either liquid or vapor.In addition to this pure hydrogen type, there are hydrocarbon fuels for fuel cells, including diesel, methanol (see: direct-methanol fuel cells and indirect methanol fuel cells) and chemical hydrides. The waste products with these types of fuel are carbon dioxide and water.The materials used in fuel cells differ by type. In a typical membrane electrode assembly (MEA), the electrode–bipolar plates are usually made of metal, nickel or carbon nanotubes, and are coated with a catalyst (like platinum, nano iron powders or palladium) for higher efficiency. Carbon paper separates them from the electrolyte. The electrolyte could be ceramic or a membrane.Oxygen ion exchange fuel cellsIn a solid oxide fuel cell design, the anode and cathode are separated by an electrolyte that is conductive to oxygen ions but non-conductive to electrons. The electrolyte is typically made from zirconia doped with yttria.On the cathode side, oxygen catalytically reacts with a supply of electrons to become oxygen ions, which diffuse through the electrolyte to the anode side. On the anode side, the oxygen ions react with hydrogen to form water and free electrons. A load connected externally between the anode and cathode completes the electrical circuit.Fuel cell design issuesCostsIn 2002, typical cells had a catalyst content of US$1000 per-kilowatt of electric power output. In 2008 UTC Power has 400kw Fuel cells for $1,000,000 per 400kW installed costs. The goal is to reduce the cost in order to compete with current market technologies including gasoline internal combustion engines. Many companies are working on techniques to reduce cost in a variety of ways including reducing the amount of platinum needed in each individual cell. Ballard Power Systems have experiments with a catalyst enhanced with carbon silk which allows a 30% reduction (1 mg/cm2 to 0.7 mg/cm2) in platinum usage without reduction in performance.The production costs of the PEM (proton exchange membrane). The Nafion membrane currently costs €400/m². In 2005 Ballard Power Systems announced that its fuel cells will use Solupor, a porous polyethylene film patented by DSM.Water and air management (in PEMFC). In this type of fuel cell, the membrane must be hydrated, requiring water to be evaporated at precisely the same rate that it is produced. If water is evaporated too quickly, the membrane dries, resistance across it increases, and eventually it will crack, creating a gas "short circuit" where hydrogen and oxygen combine directly, generating heat that will damage the fuel cell. If the water is evaporated too slowly, the electrodes will flood, preventing the reactants from reaching the catalyst and stopping the reaction. Methods to manage water in cells are being developed like electroosmotic pumps focusing on flow control. Just as in a combustion engine, a steady ratio between the reactant and oxygen is necessary to keep the fuel cell operating efficiently.Temperature managementThe same temperature must be maintained throughout the cell in order to prevent destruction of the cell through thermal loading. This is particularly challenging as the 2H2 + O2 =2H2O reaction is highly exothermic, so a large quantity of heat is generated within the fuel cell.Durability, service life, and special requirements for some type of cells Stationary fuel cell applications typically require more than 40,000 hours of reliable operation at a temperature of -35°C to40°C, while automotive fuel cells require a 5,000 hour lifespan (the equivalent of 150,000 miles) under extreme temperatures. Automotive engines must also be able to start reliably at -30 °C and have a high power to volume ratio (typically 2.5 kW per liter).HistoryThe principle of the fuel cell was discovered by German scientist Christian Friedrich Schönbein in 1838 and published in one of the scientific magazines of thetime. Based on this work, the first fuel cell was demonstrated by Welsh scientist Sir William Robert Grove in the February 1839 edition of the Philosophical Magazine and Journal of Science, and later sketched, in 1842, in the same journal. The fuel cell he made used similar materials to today's phosphoric-acid fuel cell.In 1955, W. Thomas Grubb, a chemist working for the General Electric Company (GE), further modified the original fuel cell design by using a sulphonated polystyrene ion-exchange membrane as the electrolyte. Three years later another GE chemist, Leonard Niedrach, devised a way of depositing platinum onto the membrane, which served as catalyst for the necessary hydrogen oxidation and oxygen reduction reactions. This became known as the“Grubb-Niedrach fuel cell”. GE went on to develop this technology with NASA and McDonnell Aircraft, leading to its use during Project Gemini. This was the first commercial use of a fuel cell. It wasn't until 1959 that British engineer Francis Thomas Bacon successfully developed a 5 kW stationary fuel cell. In 1959, a team led by Harry Ihrig built a 15 kW fuel cell tractor for Allis-Chalmers which was demonstrated across the US at state fairs. This system used potassium hydroxide as the electrolyte and compressed hydrogen and oxygen as the reactants. Later in 1959, Bacon and his colleagues demonstrated a practical five-kilowatt unit capable of powering a welding machine. In the 1960s, Pratt and Whitney licensed Bacon's U.S. patents for use in the U.S. space program to supply electricity and drinking water (hydrogen and oxygen being readily available from the spacecraft tanks).United Technologies Corporation's UTC Power subsidiary was the first company to manufacture and commercialize a large, stationary fuel cell system for use as a co-generation power plant in hospitals, universities and large office buildings. UTC Power continues to market this fuel cell as the PureCell 200, a 200 kW system (although soon to be replaced by a 400 kW version, expected for sale in late 2009). UTC Power continues to be the sole supplier of fuel cells to NASA for use in space vehicles, having supplied the Apollo missions, and currently the Space Shuttle program, and is developing fuel cells for automobiles, buses, and cell phone towers; the company has demonstrated the first fuel cell capable of starting under freezing conditions with its proton exchange membrane automotive fuel cell.Fuel cell efficiencyThe efficiency of a fuel cell is dependent on the amount of power drawn from it. Drawing more power means drawing more current, which increases the losses in the fuel cell. As a general rule, the more power (current) drawn, the lower the efficiency.Most losses manifest themselves as a voltage drop in the cell, so the efficiency of a cell is almost proportional to its voltage. For this reason, it is common to show graphs of voltage versus current (so-called polarization curves) for fuel cells. A typical cell running at 0.7 V has an efficiency of about 50%, meaning that 50% of the energy content of the hydrogen is converted into electrical energy; the remaining 50% will be converted into heat. (Depending on the fuel cell system design, some fuel might leave the system unreacted, constituting an additional loss.)For a hydrogen cell operating at standard conditions with no reactant leaks, the efficiency is equal to the cell voltage divided by 1.48 V, based on the enthalpy, or heating value, of the reaction. For the same cell, the second law efficiency is equal to cell voltage divided by 1.23 V. (This voltage varies with fuel used, and quality and temperature of the cell.) The difference between these numbers represents the difference between the reaction's enthalpy and Gibbs free energy. This difference always appears as heat, along with any losses in electrical conversion efficiency.Fuel cells do not operate on a thermal cycle. As such, they are not constrained, as combustion engines are, in the same way by thermodynamic limits, such as Carnot cycle efficiency. At times this is misrepresented by saying that fuel cells are exempt from the laws of thermodynamics, because most people think of thermodynamics in terms of combustion processes (enthalpy of formation). The laws of thermodynamics also hold for chemical processes (Gibbs free energy) like fuel cells, but the maximum theoretical efficiency is higher (83% efficient at 298K) than the Otto cycle thermal efficiency (60% for compression ratio of 10 and specific heat ratio of 1.4). Comparing limits imposed by thermodynamics is not a good predictor of practically achievable efficiencies. Also, if propulsion is the goal, electrical output of the fuel cell has to still be converted into mechanical power with the corresponding inefficiency. In reference to the exemption claim, the correct claim is that the "limitations imposed by the second law of thermodynamics on the operation of fuel cells are much less severe than the limitations imposed on conventional energy conversion systems". Consequently, they can have very high efficiencies in converting chemical energy to electrical energy, especially when they are operated at low power density, and using pure hydrogen and oxygen as reactants.In practice, for a fuel cell operating on air (rather than bottled oxygen), losses due to the air supply system must also be taken into account. This refers to the pressurization of the air and dehumidifying it. This reduces the efficiency significantlyand brings it near to that of a compression ignition engine. Furthermore fuel cell efficiency decreases as load increases.The tank-to-wheel efficiency of a fuel cell vehicle is about 45% at low loads and shows average values of about 36% when a driving cycle like the NEDC (New European Driving Cycle) is used as test procedure. The comparable NEDC value for a Diesel vehicle is 22%. In 2008 Honda released a car with fuel stack claiming a 60% tank-to-wheel efficiency.Fuel cells cannot store energy like a battery, but in some applications, such as stand-alone power plants based on discontinuous sources such as solar or wind power, they are combined with electrolyzers and storage systems to form an energy storage system. The overall efficiency (electricity to hydrogen and back to electricity) of such plants (known as round-trip efficiency) is between 30 and 50%, depending on conditions. While a much cheaper lead-acid battery might return about 90%, the electrolyzer/fuel cell system can store indefinite quantities of hydrogen, and is therefore better suited for long-term storage.中文译文：燃料电池及其发展前景燃料电池是一种电化学转换装置。
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crankshaft 曲轴. piston活塞. cylinder 气缸. joint venture 合资企业. engine 发动机fuel-efficient 节能的hybrid 混合的lightweight 重量最轻的二。
chassis 底盘onboard车载的clutch 离合器. pan盘底盘. driveshaft传动轴主动轴. suspension 悬架. linkage 连杆机构.transaxle 驱动桥. turbocharger涡轮增压器.三。
block 气缸体. exhaust manifold 排气歧管.cam 凸轮. catalytic converter 催化转化器. muffer 消声器. resonator 辅助消声器. intake manifold 进气歧管. valve stem 气门杆. fuel vapor 燃油蒸气. timing chain 正时链条. fuel-injection system 燃油喷时系统srankshaft sprocket 曲轴链轮. vibration clamper 曲轴减震器. drive-belt pulley 皮带传动轮.nozzle 喷油嘴. radiator 散热器. throttle 节流阀coolant 冷却液四。
lubricant 润滑剂. shift lexer 换挡杆. synchronizer 同步器. rpm= revolutions per minute 转数/分.五。
bumper 缓冲器保险杠. shock absorber 缓冲器.减震器. fender 挡泥板. steering knwuckle 转向节. hood 车蓬引擎罩.六。
instument panel仪表板. winding 绕组. capacitor 电容器. spark plug 火花塞. condenser 电容器relay 继电器七。
电极材料英语In the realm of energy conversion and storage technologies, electrode materials play a pivotal role, influencing both performance and efficiency. As the needfor sustainable and efficient energy systems increases, the significance of electrode materials in fields like batteries, fuel cells, and supercapacitors is becoming increasingly apparent. In this article, we delve into the current status of electrode materials, exploring various types, their applications, and challenges, while alsolooking ahead to potential advancements and future trends.**Types of Electrode Materials**Electrode materials can be broadly categorized intothree types: metallic, carbon-based, and composite materials. Metallic electrodes, such as lithium, nickel,and cobalt, offer high energy densities but can suffer from issues like corrosion and dendrite formation. Carbon-based electrodes, including graphite, carbon nanotubes, and graphene, provide excellent conductivity and stability but may not offer the same level of energy density as metallics. Composite materials, which combine the benefits of bothmetallics and carbon-based materials, are being actively researched to address the limitations of both.**Applications of Electrode Materials**Electrode materials find applications across a range of electrochemical devices. In lithium-ion batteries (LIBs),for instance, they enable the storage and release of energy through redox reactions. In fuel cells, electrodes catalyze the conversion of chemical energy into electrical energy. Supercapacitors, on the other hand, rely on electrodes with high surface areas and conductivity to store charge rapidly. **Challenges and Future Trends**Despite their widespread use, electrode materials face several challenges. These include improving energy density, enhancing cycling stability, and reducing costs. To address these issues, researchers are exploring innovativematerials like silicon composites, sulfur cathodes, and metal oxides. These materials offer the potential forhigher energy densities and improved cycling stability, but they also come with their own set of challenges, such as volume expansion and instability.Looking ahead, the future of electrode materials islikely to be driven by the need for even more efficient and sustainable energy storage and conversion solutions. One promising trend is the development of solid-state batteries, which use solid electrolytes instead of liquid electrolytes. This innovation could lead to safer, faster-charging batteries with longer lifetimes. Another trend is the integration of electrode materials with other technologies, such as nanotechnology and artificial intelligence, to create more intelligent and adaptive energy systems.In conclusion, electrode materials are crucial to the advancement of energy conversion and storage technologies. As we move towards a more sustainable and efficient energy future, it is essential to continue exploring anddeveloping innovative electrode materials that can meet the demands of tomorrow's energy systems.**电极材料的现状与未来发展**在能源转换和储存技术领域，电极材料扮演着至关重要的角色，影响着能源系统的性能和效率。
HYDROGEN FUEL CELLSby Tom Dickerman/AHAWe are about to witness a most amazing event. Internal combustion engines (ICE’s), so abundant in the past century are about to be replaced by fuel cell systems over the next few decades. They will replace ICE’s for both vehicle power and for stationary power generation. Fuel cells will also replace batteries for small portable power supply. Hydrogen in an internal combustion engine(ICE) produces useable power at about 17 percent efficiency. A fuel cell system has about 50 percent efficiency. This makes the fuel cell about three times as efficient as an ICE! This explains the urgency to make fuel cells commercially available.The United States has spent more than $500 million in the development of highly efficient and environmentally benign fuel cells, according to Ed Gillis, the former director of fuel cell programs at the Electric Power Research Institute. While research continues, major commercialization efforts are underway at this time. Nearly every major car company in the world has invested massively in fuel cells for vehicles. Their total investment commitments now exceed two billion dollars, according to Peter Hoffman, publisher of the Hydrogen and Fuel Cell Newsletter.HOW FUEL CELLS WORKIn a typical fuel cell, hydrogen gas is supplied through a porous anode and oxygen or air is supplied through a porous cathode. An electrolyzer separates the two gases, which is a material that will not allow either of the gases to pass. On a molecular level, the hydrogen and oxygen have an affinity for each other, and would like to come together to create water (2 H2 + 02 = 2 H20).In this situation, the hydrogen atoms instantly give up their electrons, which then travel through an external circuit. The remaining parts of the hydrogen atoms are protons, which can now pass through the electrolyte, and connect with oxygen atoms. The receipt of free electrons from the external circuit allows the completion of the electrochemical reactions, as water is formed. The electrons traveling the electric circuit is electric current. Typically, a fuel cell produces about one volt when the circuit is open, which drops to a half volt when the circuit is closed and producing electrical power. For higher, more useful voltages, the fuel cells are usually stacked. One hundred cells in a stack yield about 50 volts of direct current. (DC)TYPES OF FUEL CELLSFuel cells are usually named for their electrolytes. To date five different electrolyte materials have shown potential for commercial development. The five fuel cell types have different characteristics, which make each one suitable for some applications but not others. A short description of the five types follows.ALKALINE FUEL CELLS (AFC’S)In 1839, W. R. Grove of Great Britain built the first fuel cell. He added a catalyst, potassium hydroxide, to water and put in the ends of two wires. By impressing direct electrical current, he split the water into hydrogen at one wire and oxygen at the other. This is called electrolysis of water. Then capturing both the hydrogen and oxygen, he found he could reverse the process, adding the hydrogen and oxygen at the two poles to re-create water and electric current. In this mode, he had a fuel cell.This first fuel cel l was called the alkaline fuel cell (AFC). In the 1960’s a more complex but highly reliable AFC stack was created for our manned spacecraft. AFC’s and phosphoric acid fuel cells (PAFC’S) provided essential drinking water, electricity and a little heat in the cold of outer space for the manned spacecraft Gemini, Apollo and the Space Shuttle Orbiter. Men and women could not have gone into space without them.An AFC and a PAFC from these flights are on exhibit at the National Air and Space Museum in Washington, DC.PHOSPHORIC ACID FUEL CELLS (PAFC’s)The next fuel cell to be developed was the phosphoric acid fuel cell. PAFC’s do not require pure oxygen, but can use air at the cathode. PAFC’s are now in use for electric power generation, notably at Kaiser Hospitals, air quality offices in California, and at various sites in Japan.PAFC’s are now being developed by the DOE (and others) for trucks, buses and railroad engines. Some PAFC’s are designed to take in methanol and reform it under heat and pressure, stripping off hydrogen for the anode fuel supply.PROTON EXCHANGE MEMBRANE (PEM) FUEL CELLS,ALSO KNOWN AS POLYMER ELECTROLYTE FUEL CELLS (PEFC’S)PEM’s have only a thin plastic membrane for their electrolyte. PEM’S can be very small, with high power densities. Taking away the waste heat in a uniform continuous way, so the membrane doesn’t burn up, is a significant engineering challenge, especially for high energy/power density designs.The most reliable PEM fuel cells to date have been built by Ballard Power Systems of Vancouver, Canada. Ballard has now sold its vehicle fuel cell division to Daimler-Benz. It is also possible that Toyota or another Japanese company may be the first to mass-produce a fuel cell car. Fuel cell cars with on-board hydrogen fuel will have virtually NO emissions, except a little steam, and will be very quiet. This will be the start of anenvironmental revolution, as we begin to replace all the dirty, inefficient internal combustion engines with clean, highly efficient fuel cell engines, worldwide.SOLID OXIDE FUEL CELLS (SOFC’s)Solid oxide fuel cells, which can only operate at high temperatures, are not suited for transportation, but for stationary power. They hold the promise of high fuel efficiency, high power density and low cost.SOFC’s can be of tubular or planar construction. For tubular designs, Westinghouse has completed many hours of successful operation. Ceramatics is a leader in planar SOFC’S, which are expected to have low cost, high performance and high reliability.MOLTEN CARBONATE FUEL CELLS (MCFC’s)Energy Research Corporation (ERC) and M-C Power Corporation are making important gains toward commercialization of molten carbonate fuel cells. Stacks have been tested and small demonstration plants have been completed. ERC also completed a large two-megawatt MCFC plant for the City of Santa Clara, California. Because of operating problems, the plant is not in use. It is believed the plant may have been scaled up to far from smaller prototypes, and that intermediate sized plants should have been built first, to help resolve engineering problems of scale.MARKET ENTRY FOR FUEL CELLS.Peter Bos, President of Polydyne, Inc, has analyzed costs of manufacturing various fuel cells, and the prices buyers are willing to pay for their fuel cell applications. According to Mr. Bos, the first fuel cells to enter the market will be for high value operations.This seems to be borne out by the history of fuel cells to date. The first to develop fuel cells were NASA and the military, which were willing to pay virtually any price for the fuel cells that met their needs. Fuel cells are now being marketed to remote sites where power demand is small, but reliability is crucial, such as remote weather and pollution monitoring stations. Kaiser hospitals have decided to use fuel cell plants for primary power for hospital life support systems, which must be highly reliable. Low noise levels and low pollution near hospitals were also key factors for Kaiser.Fuel cells will also be used early on for devices such as cellular phones, laptop computers and handheld camcorders. For such uses reliability, quietness, size and weight are more important considerations that the price. Fuel cells, with their almost unlimited shelf life, will soon be replacing conventional batteries, which often go dead before they are used. Throughout the third world, small villagers are pooling their scarce money to buy two appliances: a TV set and a small diesel or gasoline engine to run it. The fuel for the generator must often be carried twenty of fifty miles from the nearest fuel station. Hereis a market for solar photovoltaics. But what about at night, or when the weather is overcast? Often villagers also carry heavy lead acid batteries to their location.This is a very likely near-term market for fuel cells. With a small electolyzer and a solar panel, hydrogen can be made and stored in a small tank. At night, a fuel cell can then be operated to generate power on demand. No more twenty-mile walks to the nearest store; no more scarce money spent for fuel.Third world countries in general are good candidates for hydrogen and fuel cell systems, because they lack the competing power grids and natural gas pipelines of the West. They also lack the entrenched corporate interests that often block development of sustainable energy systems here in America.In the near future, solar-produced clean hydrogen fuel will also be used for cooking and heating in these countries, gradually bringing to a halt the gathering of firewood, which is now decimating many areas of the Planet. Trees can be planted without fear that they will be cut for firewood. Whole continents can regrow their trees. Such a prospect is very important for the mitigation of global warming.It is no exaggeration to say that hydrogen and fuel cell systems have the potential as critical tools both to counter global warming and to reverse other environmental damage, worldwide.The fuel cell revolution is coming. Fuel cells will be the engines/generators of choice for all uses in the twenty-first century. To paraphrase Lee Iacocca, we can lead or we can follow, or we can just get out of the way.FUEL CELL QUIZ1.FIVE TYPES OF FUEL CELLS ARE NEARING COMMERCIALIZATION.NAME THREE.a)ALKALINEb)ACIDc)SOLID OXIDEd)MOLTEN CARBONATEe)PROTON EXCHANGE MEMBRANE THREE COMPANIES THAT ARE RESEARCHING/DEVELOPING FUELCELLS.a)BALLARDb)DAIMLER-BENZc)WESTINGHOUSEd)M-C CORPORATIONe)TOYOTAf)CERAMATECg)ENERGY RESEARCH CORPORATION3.WHAT IS THE EFFICIENCY OF AN INTERNAL COMBUSTION ENGINE?a)17 PERCENT4.WHAT IS THE TYPICAL EFFICIENCY OF A FUEL CELL SYSTEM?a)50 PERCENT TWO APPLICATIONS FOR FUEL CELLS. WHICH ARE LIKELY TO BEEARLY ADOPTERS?a)CAMCORDERSb)LAPTOP COMPUTERSc)BATTERIESd)CELL PHONESe)REMOTE SITE APPLICATIONS6.IS HYDROGEN A FUEL?a)YES7.IS HYDROGEN COMMON IN NATURE?a)YES-MOST ABUNDANT ATOM IN THE UNIVERSE8.WHAT ARE ADVANTAGES OF A FUEL CELL OVER AN INTERNALCOMBUSTION ENGINE?a)THREE TIMES THE EFICIENCYb)NO DEPLETION OF FOSSIL FUELSc)NO AIR POLLUTIONd)NO CONTRIBUTION TO GLOBAL WARMING9.HOW CAN FUEL CELLS HELP TO MITIGATE GLOBAL WARMING?a)BY REPLACING FOSSIL FUELS, ELIMINATING THEIR CO2 EMISSIONSb)BY REPLACING THE USE OF FIREWOOD, STOPPING THE CUTTING OFTREES, WHICH SEQUESTER CARBON。
在火星生存很难的英语Surviving on Mars: The Challenges and Potential Solutions.Venturing beyond Earth and establishing a sustainable human presence on Mars has long been a captivating aspiration for space exploration. However, the Martian environment poses formidable challenges that must be overcome to make this vision a reality. From the planet's thin atmosphere and extreme temperatures to its lack of liquid water and protection from harmful radiation, surviving and thriving on Mars requires ingenuity, technological advancements, and a comprehensive understanding of the planet's unique characteristics.The Challenges.Thin Atmosphere and Extreme Temperatures: Mars' atmosphere is incredibly thin, with a surface pressure only about 1% of Earth's. This lack of atmospheric pressureresults in extreme temperature variations, ranging from a scorching 70°C (158°F) during the day to a bone-chilling -63°C (-81°F) at night. Such drastic temperature fluctuations pose significant challenges for maintaining a stable and habitable environment for humans.Lack of Liquid Water: Mars is a remarkably arid planet, with no surface liquid water currently present. Water is essential for human survival, and its absence on Mars necessitates the development of innovative water extraction and recycling systems.Harmful Radiation: The Martian surface is exposed to high levels of cosmic and solar radiation due to its thin atmosphere and weak magnetic field. These radiations can be harmful to human health, increasing the risk of cancer and other adverse effects. Radiation shielding and protective measures are crucial for safeguarding astronauts on Mars.Dust Storms and Atmospheric Phenomena: Mars is prone to frequent and intense dust storms that can engulf the entire planet, blocking out sunlight and causing widespreaddisruption. These storms can reduce visibility, affect power generation, and pose respiratory hazards to humans.The Potential Solutions.Habitat Design and Thermal Management: To mitigate the challenges posed by Mars' thin atmosphere and extreme temperatures, habitats must be designed with advanced thermal insulation and temperature control systems. Pressurized modules can provide a breathable atmosphere and protection from temperature extremes, while airlocks and environmental control systems maintain a comfortable and livable interior.Water Extraction and Recycling: Water extraction technologies are essential for long-term human presence on Mars. Methods such as extracting water from the Martian atmosphere, subsurface ice, or mineral hydrates offer potential solutions to the water scarcity problem. Recycling and purification systems can also minimize water consumption and maximize its availability.Radiation Shielding: Providing adequate radiation shielding is paramount to protect astronauts from harmful radiation exposure. Habitats and spacesuits can be equipped with materials such as water, regolith, or composite shielding panels to absorb and deflect radiation. Advanced radiation detection and monitoring systems are also necessary to assess radiation levels and minimize risks.Dust Mitigation and Atmospheric Management: To address the challenges posed by dust storms, dust mitigation strategies such as electrostatic dust collectors or air filtration systems can be employed to minimize their impact on habitats and equipment. Atmospheric management systems can also be implemented to filter and purify the air, removing dust particles and other contaminants.Energy Generation and Power Management: Sustainable energy generation is crucial for powering habitats, life support systems, and exploration vehicles on Mars. Solar panels and nuclear reactors are potential sources of energy, while fuel cells and batteries can provide backup power during periods of darkness or reduced solar intensity.Food Production and Resource Utilization: Establishing a sustainable food production system is essential for long-term survival on Mars. Controlled environment agriculture (CEA) techniques can be employed to grow crops in enclosed and controlled environments, utilizing artificial lighting, hydroponics, and aeroponics. In-situ resource utilization (ISRU) technologies can also be used to extract and utilize Martian resources, such as water, oxygen, and building materials, reducing the need for supplies from Earth.Medical Care and Health Monitoring: A comprehensive healthcare system is necessary to ensure the well-being of astronauts on Mars. Advanced medical equipment, telemedicine capabilities, and trained medical personnel can provide essential care and support in remote and challenging conditions. Continuous health monitoring and screening are also crucial for detecting and addressing any potential health issues.Psychological and Social Support: Surviving on Mars requires not only technological solutions but alsopsychological and social support systems. Isolation, confinement, and the unique challenges of a Martian environment can affect astronauts' mental and emotional health. Establishing robust communication channels, providing opportunities for socialization and recreation, and fostering a sense of community are essential for maintaining their well-being.Conclusion.Establishing a sustainable human presence on Mars is an ambitious and complex endeavor that requires overcoming numerous challenges. By leveraging technological advancements, innovative solutions, and a comprehensive understanding of the Martian environment, we can mitigate these challenges and pave the way for future human exploration and settlement on the Red Planet. Embracing the spirit of ingenuity, collaboration, and perseverance will be instrumental in making the vision of living and thriving on Mars a reality.。
J Power SourcesIntroductionJ Power Sources refers to the sources of power used in different applications. Power sources are essential for providing the necessary energy for various devices and systems to operate. The type of power source used depends on the specific requirements and constraints of the application. This document provides an overview of different J power sources, their advantages, disadvantages, and applications.1. BatteriesBatteries are one of the most common types of power sources used in numerous applications. They convert chemical energy into electrical energy. Batteries are portable, have a high energy density, and can be easily replaced when depleted. They are widely used in portable electronic devices such as smartphones, laptops, and smartwatches. They are also extensively used in automotive applications.Advantages of Batteries:•Portability•High Energy Density•Wide Range of Applications•Easy ReplacementDisadvantages of Batteries:•Limited Lifespan•Disposal and Recycling Challenges•Costly to Manufacture2. Fuel CellsFuel cells are electrochemical devices that convert the chemical energy from a fuel into electrical energy through a chemical reaction. They can use a variety of fuels, including hydrogen, methane, methanol, and more. Fuel cells are highly efficient and can operate continuously if supplied with fuel. They are used in various applications, including transportation, power plants, and portable power sources.Advantages of Fuel Cells:•High Efficiency•Environmentally Friendly (if hydrogen-based)•Continuous Operation with Fuel SupplyDisadvantages of Fuel Cells:•High Initial Cost•Limited Fuel Availability•Complex Refueling Infrastructure3. Solar PowerSolar power utilizes the energy from the sun to generate electricity. Photovoltaic (PV) cells convert sunlight directly into electrical energy. Solar power is a renewable and clean energy source. It is widely used in residential, commercial, and industrial applications for generating electricity and providing power to various devices.Advantages of Solar Power:•Renewable and Environmentally Friendly•Low Operating Costs•Long LifespanDisadvantages of Solar Power:•Dependence on Sunlight (Weather Conditions)•High Initial Installation Cost•Requires a Large Surface Area4. Wind PowerWind power harnesses the kinetic energy from the wind and converts it into electrical energy using wind turbines. Wind power is another renewable and clean energy source. It is commonly used in large-scale wind farms to generate electricity for communities and cities. It can also be utilized on a smaller scale for residential and commercial applications.Advantages of Wind Power:•Renewable and Environmentally Friendly•Scalable for Small or Large Applications•Low Operational CostsDisadvantages of Wind Power:•Dependence on Wind Availability•Potential Noise Pollution•Visual Impact on Landscapes5. Hydroelectric PowerHydroelectric power is generated by utilizing the gravitational force of falling or flowing water. It is one of the oldest and most widely used renewable energy sources. Hydroelectric power plants can range from small-scale installations tolarge-scale dams that generate electricity for entire regions. It is a reliable and clean energy source.Advantages of Hydroelectric Power:•Renewable and Environmentally Friendly•Reliable Power Generation•Water Storage and Flood ControlDisadvantages of Hydroelectric Power:•Limited Availability of Suitable Sites•Disruption of Aquatic Ecosystems•Initial Construction CostConclusionJ Power Sources play a crucial role in powering various applications. Batteries, fuel cells, solar power, wind power, and hydroelectric power are just a few examples of power sources used in different scenarios. Each power source has its unique advantages and disadvantages, making them suitable for specific applications. The choice of power source depends on factors such as energy requirements, portability, environmental impact, availability, and cost. As technology advances, there is a continuous search for more efficient and sustainable power sources to meet the growing energy demands of our society.。
