Ventilation (architecture)
An air handling unit is used for the heating and cooling of air in a central location (click on image for legend).
Ventilating (the V in HVAC) is the process of "changing" or replacing air in any space to provide high indoor air quality (i.e. to control temperature, replenish oxygen, or remove moisture, odors, smoke, heat, dust, airborne bacteria, and carbon dioxide). Ventilation is used to remove unpleasant smells and excessive moisture, introduce outside air, to keep interior building air circulating, and to prevent stagnation of the interior air.
Ventilation includes both the exchange of air to the outside as well as circulation of air within the building. It is one of the most important factors for maintaining acceptable indoor air quality in buildings. Methods for ventilating a building may be divided into mechanical/forced and natural types.[1]
"Mechanical" or "forced" ventilation is used to control indoor air quality. Excess humidity, odors, and contaminants can often be controlled via dilution or replacement with outside air. However, in humid climates much energy is required to remove excess moisture from ventilation air.
Kitchens and bathrooms typically have mechanical exhaust to control odors and sometimes humidity. Kitchens have additional problems to deal with such as smoke and grease (see kitchen ventilation). Factors in the design of such systems include the flow rate (which is a function of the fan speed and exhaust vent size) and noise level. If ducting for the fans traverse unheated space (e.g., an attic), the ducting should be insulated as well to prevent condensation on the ducting. Direct drive fans are available for many applications, and can reduce maintenance needs.
Ceiling fans and table/floor fans circulate air within a room for the purpose of reducing the perceived temperature because of evaporation of perspiration on the skin of the occupants. Because hot air rises, ceiling fans may be used to keep a room warmer in the winter by circulating the warm stratified air from the ceiling to the floor. Ceiling fans do not provide ventilation as defined as the introduction of outside air.
Natural ventilation is the ventilation of a building with outside air without the use of a fan or other mechanical system. It can be achieved with openable windows or trickle vents when the spaces to ventilate are small and the architecture permits. In more complex systems warm air in the building can be allowed to rise and flow out upper openings to the outside (stack effect) thus forcing cool outside air to be drawn into the building naturally through openings in the lower areas. These systems use very little energy but care must be taken to ensure the occupants' comfort. In warm or humid months, in many climates, maintaining thermal comfort solely via natural ventilation may not be possible so conventional air conditioning systems are used as backups. Air-side economizers perform the same function as natural ventilation, but use mechanical systems' fans, ducts, dampers, and control systems to introduce and distribute cool outdoor air when appropriate.
Contents
1 Definition
1.1 An example of closed ventilation
? 2 Necessity
? 3 Types of ventilation
? 4 Ventilation rate
? 5 Ventilation standards
? 6 Ventilation equipment
?
7 Natural ventilation
?8 Demand-controlled ventilation
(DCV)
?9 Local exhaust ventilation
?10 Ventilation and combustion
?11 Smoking and ventilation
?12 Problems
?13 Air Quality Procedures
?14 See also
?15 References and notes
?16 External links
edit Definition
Ventilation is the intentional movement of air from outside a building to the inside. Ventilation air, as defined in ASHRAE Standard 62.1[2] and the ASHRAE Handbook,[3] is that air used for providing acceptable indoor air quality. It mustn't be confused with vents or flues; which mean the exhausts of clothes dryers and combustion equipment such as water heaters, boilers, fireplaces, and wood stoves. The vents or flues carry the products of combustion which have to be expelled from the building in a way which does not cause harm to the occupants of the building. Movement of air between indoor spaces, and not the outside, is called transfer air.
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edit An example of closed ventilation
In commercial, industrial, and institutional (CII) buildings, and modern jet aircraft, return air is often recirculated to the air handling unit. A portion of the supply air is normally exfiltrated through the building
envelope or exhausted from the building (e.g., bathroom or kitchen exhaust) and is replaced by outside air introduced into the return air stream. The rate of ventilation air required, most often provided by this mechanically-induced outside air, is often determined from ASHRAE Standard 62.1 for CII buildings, or 62.2 for low-rise residential buildings, or similar standards.
edit Necessity
When people or animals are present in buildings, ventilation air is necessary to dilute odors and limit the concentration of carbon dioxide and airborne pollutants such as dust, smoke and volatile organic compounds (VOCs). Ventilation air is often delivered to spaces by mechanical systems which may also heat, cool, humidify and dehumidify the space. Air movement into buildings can occur due to uncontrolled infiltration of outside air through the building fabric (see stack effect) or the use of deliberate na tural ventilation strategies. Advanced air filtration and treatment processes such as scrubbing, can provide ventilation air by cleaning and recirculating a proportion of the air inside a building.
edit Types of ventilation
?Mechanical or forced ventilation: through an air handling unit or direct injection to a space by a fan. A local exhaust fan can enhance infiltration or natural ventilation, thus increasing the ventilation air flow rate.
?Natural ventilation occurs when the air in a space is changed with outdoor air without the use of mechanical systems, such as a fan. Most often natural ventilation is assured through operable windows but it can also be achieved through temperature and pressure differences between spaces. Open
windows or vents are not a good choice for ventilating a basement or other below ground structure.
Allowing outside air into a cooler below ground space will cause problems with humidity and
condensation.
?Mixed Mode Ventilation or Hybrid ventilation: utilises both mechanical and natural ventilation processes. The mechanical and natural components may be used in conjunction with each other or separately at different times of day. The natural component, sometimes subject to unpredictable
external weather conditions may not always be adequate to ventilate the desired space. The mechanical component is then used to increase the overall ventilation rate so that the desired internal conditions are met. Alternatively the mechanical component may be used as a control measure to regulate the natural ventilation process, for example, to restrict the air change rate during periods of high wind speeds.
?Infiltration is separate from ventilation, but is often used to provide ventilation air.
edit Ventilation rate
The ventilation rate, for CII buildings, is normally expressed by the volumetric flowrate of outside air being introduced to the building. The typical units used are cubic feet per minute (CFM) or liters per second (L/s). The ventilation rate can also be expressed on a per person or per unit floor area basis, such as CFM/p or CFM/ft2, or as air changes per hour.
For residential buildings, which mostly rely on infiltration for meeting their ventilation needs, the common ventilation rate measure is the number of times the whole interior volume of air is replaced per hour, and is called air changes per hour (I or ACH; units of 1/h). During the winter, AC H may range from 0.50 to 0.41 in a tightly insulated house to 1.11 to 1.47 in a loosely insulated house.[4]
ASHRAE now recommends ventilation rates dependent upon floor area, as a revision to the 62-2001 standard whereas the minimum AC H was 0.35, but no less than 15 CFM/person (7.1 L/s/person). As of 2003,
the standards have changed to an addition of 3 CFM/100 sq. ft. (15 l/s/100 sq. m.) to the 7.5 CFM/person (3.5 L/s/person) standard.[5]
edit Ventilation standards
?In 1973, in response to the 1973 oil crisis and conservation concerns, ASHRAE Standards 62-73 and 62-81) reduced required ventilation from 10 CFM (4.76 L/S) per person to 5 CFM (2.37 L/S) per person.
This was found to be a primary cause of sick building syndrome.
?Current ASHRAE standards (Standard 62-89) states that appropriate ventilation guidelines are 20 CFM (9.2 L/s) per person in an office building, and 15 CFM (7.1 L/s) per person for schools. In
commercial environments with tobacco smoke, the ventilation rate may range from 25 CFM to 125 CFM.[6]
In certain applications, such as submarines, pressurized aircraft, and spacecraft, ventilation air is also needed to provide oxygen, and to dilute carbon dioxide for survival. Batteries in subm arines also discharge hydrogen gas, which must also be ventilated for health and safety. In any pressurized, regulated environment, ventilation is necessary to control any fires that may occur, as the flames may be deprived of oxygen.[7]
ANSI/AS HRAE (Standard 62-89) sets maximum CO2 guidelines in commercial buildings at 1000 ppm, however, OS HA has set a limit of 5000 ppm over 8 hours.[8]
Ventilation guidelines are based upon the minimum ventilation rate required to maintain acceptable levels of bioeffluents. Carbon dioxide is used as a reference point, as it is the gas of highest emission at a relatively constant value of 0.005 L/s. The mass balance equation is:
Q = G/(C i? C a)
?Q = ventilation rate (L/s)
?G = CO2 generation rate
?C i = acceptable indoor CO2 concentration
?C a = ambient CO2 concentration[9]
edit Ventilation equipment
?Fume hood
?Biological safety cabinet
?Dilution ventilation
?Room air distribution
?Heat recovery ventilation
edit Natural ventilation
Natural ventilation involves harnessing naturally available forces to supply and remove air in an enclosed space. There are three types of natural ventilation occurring in buildings: wind driven ventilation, pressure-driven flows, and stack ventilation.[10] The pressures generated by 'the stack effect' rely upon the buoyancy of heated or rising air. Wind driven ventilation relies upon the force of the prevailing wind to pull and push air through the enclosed space as well as through breaches in the building’s envelope (see Infiltration (HVAC)).
Almost all historic buildings were ventilated naturally.[11] The technique was generally abandoned in larger US buildings during the late 20th century as the use of air conditioning became more widespread. However, with the advent of advanced Building Energy Modeling (BEM) software, improved Building Automation Systems (BAS), Leadership in Energy and Environmental Design (LEED) design requirements, and improved
window manufacturing techniques; natural ventilation has made a resurgence in commercial buildings both globally and throughout the US.
The benefits of natural ventilation include:
?Improved Indoor air quality (IAQ)
?Energy savings
?Reduction of greenhouse gas emissions
?Occupant control
?Reduction in occupant illness associated with Sick Building Syndrome
?Increased worker productivity
edit Demand-controlled ventilation (DCV)
DCV makes it possible to maintain proper ventilation and improve air quality while saving energy. AS HRAE has determined that: "It is consistent with the Ventilation rate procedure that Demand Control be permitted for use to reduce the total outdoor air supply during periods of less occupancy.[citation needed]" CO2 sensors will control the amount of ventilation for the actual number of occupants. During design occupancy, a unit with the DCV system will deliver the same amount of outdoor air as a unit using the ventilation-rate procedure. However, DCV can generate substantial energy savings whenever the space is occupied below the design level.[citation needed]
edit Local exhaust ventilation
Local exhaust ventilation addresses the issue of avoiding the contamination of indoor air by specific high-emission sources by capturing airborne contaminants before they are spread into the environment. This can include water vapor control, lavatory bioeffluent control, solvent vapors from industrial processes, and dust from wood- and metal-working machinery. Air can be exhausted through pressurized hoods or through the use of fans and pressurizing a specific area.[12]
A local exhaust system is composed of 5 basic parts
1 A hood that captures the contaminant at its source
2Ducts for transporting the air
3An air-cleaning device that removes/minimizes the contaminant
4 A fan that moves the air through the system
5An exhaust stack through which the contaminated air is discharged[12]
edit Ventilation and combustion
Combustion (e.g., fireplace, gas heater, candle, oil lamp, etc.) consumes oxygen while producing carbon dioxide and other unhealthy gases and smoke, requiring ventilation air. An open chimney promotes infiltration (i.e. natural ventilation) because of the negative pressure change induced by the buoyant, warmer air leaving through the chimney. The warm air is typically replaced by heavier, cold air.
Ventilation in a structure is also needed for removing water vapor produced by respiration, burning, and cooking, and for removing odors. If water vapor is permitted to accumulate, it may damage the structure, insulation, or finishes[citation needed]. When operating, an air conditioner usually removes excess moisture from the air. A dehumidifier may also be appropriate for removing airborne moisture.
edit Smoking and ventilation
ASHRAE standard 62 states that air removed from an area with environmental toba cco smoke shall not be recirculated into ETS-free air. A space with ETS requires more ventilation to achieve similar perceived air quality to that of a non-smoking environment.
The amount of ventilation in an ETS area is equal to the amount of ETS-free area plus the amount V, where: V = DSD × VA × A/60E
?V = recommended extra flow rate in CFM (L/s)
?DSD = design smoking density (estimated number of cigarettes smoked per hour per unit area) ?VA = volume of ventilation air per cigarette for the room being designed (ft3/cig]
? E = contaminant removal effectiveness[6]
edit Problems
In hot, humid climates, unconditioned ventilation air will deliver approximately one pound of water each day for each cfm of outdoor air per day, annual average. This is a great deal of moisture, and it can create serious indoor moisture and mold problems.
?Ventilation efficiency is determined by design and layout, and is dependent upon placement and proximity of diffusers and return air outlets. If they are located closely together, supply air may mix with stale air, decreasing efficiency of the HVAC system, and creating air quality problems.
?System imbalances occur when components of the HVAC system are improperly adjusted or
installed, and can create pressure differences (too much circulating air creating a draft or too little circulating air creating stagnancy).
?Cross-contamination occurs when pressure differences arise, forcing potentially contaminated air from one zone to an uncontaminated zone. This often involves undesired odors or VOCs.
?Re-entry of exhaust air occurs when exhaust outlets and fresh air intakes are either too close, or prevailing winds change exhaust patterns, or by infiltration between intake and exhaust air flows.
?Entrainment of contaminated outside air through intake flows will result in indoor air
contamination. There are a variety of contaminated air sources, ranging from industrial effluent to VOCs put off by nearby construction work.[13]
edit Air Quality Procedures
Ventilation Rate Procedure is rate based on standard, and “prescribes the rate at which ventilation air must be delivered to a space and various means to condition that air.”[14] Air quality is assessed (through CO2 measurement) and ventilation rates are mathematically derived using constants.
Indoor Air Quality Procedure “uses one or more guidelines for the specification of acceptable concentrations of certain contaminants in indoor air but does not prescribe ventilation rates or air treatment methods.”[14] This addresses both quantitative and subjective evaluation, and is based on the Ventilation Rate Procedure. It also accounts for potential contaminants that may have no measured limits, or limits are not set (such as formaldehyde offgassing from carpet and furniture).
元宵节猜灯谜闯关题及答案 2.我国西晋的第一代皇帝名字是叫曹丕吗（不是）司马炎 3.成都的市花是水仙花吗。（不是）芙蓉花 4.号称"六一居士"的古代是.欧阳修吗。（是） 5."东北三宝"中的乌拉草的优点是纤维坚韧吗（是） 6.世界上第一个空中犯罪问题的国际公约是《东京条约》（是） 9.人体最大的器官是皮肤吗？（是） 11.目前世界各国普遍实行的社会保险属于强制保险吗？（是） 12.中国电影金鸡奖奖品是高达35公分的一座造型优美的鸡形雕像，这座雕像是铸银镀金的吗？（不是）铸铜镀金 13. 小提琴协奏曲《梁山泊与祝英台》是以黄梅戏唱腔为写作素材的吗?（不是）越剧 14. 普契尼的歌剧《图兰朵》是根据法国作家的作品改编的吗? 15.人们常说的瘦西湖是西湖吗? （不是） 16."半部论语治天下"之说是由赵普开始的吗？（是） 18.秦朝开始推行郡县制度在全国设.24郡吗？（不是）36郡 19.除了黑芝麻外有白芝麻吗?（有） 20.人的眼睛能出气吗?（能） 21.皮影戏中的皮影人物一般是用胶皮制成的吗？（不是）驴皮或牛皮 22.琥珀属于有机宝石吗？（是） 24.我国最早的地理学家是.徐霞客吗？（不是）郦道元 25.金字塔是位于尼罗河的西岸吗？（是） 26.老花眼和远视眼是一回事吗?（不是） 27.植物的叶子呈绿色，是由于叶子反射绿光吗？（是） 29.无籽西瓜的繁育是通过种子吗？（是） 30.成语"不毛之地"中的"不毛"是指不生长树木吗？（不是）五谷 31.人的唾液有杀菌作用吗?（有） 32.汉代以后所指的西域是指山海关以西吗？（不是）玉门关、阳关以西 33.衣服在水中浸泡的时间越长洗得越干净吗?（.不是） 34."二锅头"酒的得名是根据生产工艺吗？（是） 37.无线电视台的电视剧传播是通过微波吗？（不是）中波 38.在生活中，正常人体的五感-视觉、听觉、触觉、嗅觉、味觉，其信息量最大的是视觉吗？（是） 39.亚麻凉席清洗后是太阳晒干吗？（不是）自然阴干 41.月球上的一天比地球上的一天长吗？（长） 42.有"非洲屋脊"之称的是乞力马扎罗山吗？（是） 1
? 源文档
必答题 1.There are _____________ stars on the flag of the US.（50） 2.How often do the Olympic Games be held?（Every four years ） 3.What kind of dog can't bark（吠）？(hot dog ) 4.The five rings of the Olympic Games has ________、________、_________、________、________ ，five colors .( red yellow blue green black) 5.__________ the longest river in the world.( Nile) 6._________________the capital of Australia.( Canberra ) 7.Which is the first day of a week ?(Sunday ) 8.Which city is called “Big Apple”?( New York ) 9.Which number is unlucky in western country ?_______(13 ) 10.You call your Grand father’s mother _____________(Great-grand mother ) 11.Mother’s Day is on _____________（On the second Sunday of May ） 12.What letter can fly ? (B) 13.“woof !woof !”It’s the sound of ___________.(dog ) 14.We have ____________ in Spring Festival. ( Lantern Festival) 15.16.The differences between “here” and “there” is _____________(the letter “T”) 17.The 2008 Olympics Games in Beijing English Slogan (口号)? （One world ,One dream ） 18.Where can we see countries without people , towns without houses
英语百科知识竞赛试题 对错题 一、简单题。 1、MP3是一种音乐文件的文件格式吗？是。 2、MP3的英文全称是：MPEG-Layer3 吗？是。 3、"MPC”是指多媒体计算机吗？是。 4.圣诞节的时候，除了圣诞树、圣诞礼物，圣诞大餐是不可或缺的，您知道圣诞大餐上的主菜是火鸡大餐吗？是。 5.“ＱＳＣ”是麦当劳政策：quality（质量） service（服务）clean(干净)吗？是。 6.CT是采用X射线吗？是。 7.汉语水平考试是中国为测试母语非汉语 者（包括外国人、华侨、国内少数民族人员）的汉语水平而设立的统一标准化考试。汉语水平考试的英文名称是：HSK吗？是。9。NOI是“全国信息学奥林匹克竞赛”缩写，请推断出“国际信息学奥林匹克竞赛”的缩写：IOI吗？是。
https://www.doczj.com/doc/fd1174998.html,中cn指：中文网站吗？是 11.I SEEK YOU的英文缩写是：ICQ 吗？是。 12.SARS病毒是：冠状病毒吗？是。 13.电脑中的CPU代表：中央处理器吗？是。 14.windows XP属于电脑硬件。不是。 15. windows 99是操作系统。不对 16. ADSLRAM是动态内存。不对。 17.format是格式化的命令。对。 18.域名是对的。对。 19.著名的显卡芯片制造商除了NVIDIA，ATI还有一家是SIS吗？是。 20.在DOS提示符下能执行的是以（BAK）为扩展名的文件。不对。 21.信息的基本单位是字节（Byte）。对。 22.汉字国标码是（）：GB2312－80。是。 23.《飘》的英文名是；《gone with the wind》。是 24.在互联网中，一般以“.gov”结尾的网址
一、是非题 1.一氧化碳在空气中中燃烧发出蓝色火焰，对吗？(对) 2.鲨鱼是卵生的吗？(不是胎生) 3.乌龟是世界上动物寿命最长的，对吗？(对) 4.地球自转是指地球围绕地心的运动，对吗？(不对地轴) 5.第一架望远镜是由谁发明是爱迪生发明的，对吗？(不对伽利略) 6.最早的温度计是空气温度计，对吗？(对) 7.鱼有耳朵吗？(有) 8.干冰是水凝固而成的吗？(不是是固体二氧化碳) 9.豆蔻年华是指女子十三四岁吗？(是) 10.花中四君子是梅、兰、竹、松，对吗？(不对梅、兰、竹、菊) 1.神话精卫填海上的精卫是黄帝的女儿吗？(不是炎帝) 12.古人称钱为孔方兄，对吗？(对) 13.凹凸两个字的笔画都是五笔，对吗？(对) 14.我国古代二十四史的第一部是《汉书》，是吗？(不是《史记》) 15.2000年2月有29日吗？(有) 16.蜗牛会对青菜生长产生危害吗？(会) 17.世界水日是3月21日吗？(不是是3月23日) 18.水分子是由氢、氧两种元素组成的吗？(是) 19.大熊猫和小熊猫是同一科的吗？(不是) 20.北极星是在大熊星座中吗？(不是小熊星座) 21.白兔的眼睛是黑色的吗？(不是是血液的红颜色) 22.熊猫是熊科动物吗？(不是是猫科) 3.爱因斯坦是美国科学家吗？(是) 24.月亮能发光吗？(不能反射太阳光) 25.菊花一般在春季开放，对吗？(不对在秋天) 26.目前在各种矿物质中硬度最大的是金刚石吗？(是) 27.白天天上有星星吗？(有) 28.血液在人体内循环一周需要的时间是20秒吗？(是) 29.鸟类中最小的是蜂鸟吗？(是) 30.蝙蝠是鸟吗？(不是是哺乳动物) 31.开屏的孔雀是雌孔雀吗？(不是是雄孔雀) 32.黑洞的颜色是黑色吗？(不是无颜色) 33.促进钙的吸收的是维生素D吗？(是) 34.北极有企鹅吗？( 没有只有南极有) 35.“九.一八”变是爆发于1931年吗？(是) 36.日本投降是在1949年吗？(不是是1945年) 37.相传中国古时有一种怪兽，每到除夕来伤害人命，请问这个怪兽是叫年吗？(是) 38.是爱迪生发明了白炽灯吗？(是) 39.“白雪公主”这个形象最早来自于安徒生童话，对吗？(对) 40.《西游记》中的火焰山位于印度，是吗？(不是新疆) 41.在“夸父追日”中，“夸父”是驾车追逐太阳的吗？(不是是奔跑) 42.带同种电的物体相互排斥，带异种电的物体互相吸引，对吗？(对) 43.在高大的建筑物上不需要安装避雷针，对吗？(不对) 44.灯泡内的灯丝是金属银做的吗？(不是是钨) 45.占空气体积五分之四的气体是氧气吗? (不是是氮气)
英语百科知识（10分题） 1. 英语名句“To be or not to be”来自哪一个作家？（B） A. 萧伯纳 B. 莎士比亚 C. 狄更斯 D. 培根 2. white coffee 指的是什么？ A. 白咖啡 B.纯咖啡 C. 加糖的咖啡 D. 加奶的咖啡 3．美国加利福尼亚州的别名是什么？（A） A. 黄金州 B. 阳光州 C. 常青州 D. 小麦州 4. 以下那一个英语谚语可以用来劝别人做事有耐性？（C） A. What’s done cannot be undone. B. One apple a day keeps the doctor away. C. Rome was not built in a day. D. When in Rome, do as the Romans do. 5.英国著名歌星埃尔顿.约翰Elton John通过歌曲《风中之烛》Candle in the Wind来缅怀已故的被誉为“英格兰玫瑰”的哪一位？（B） A. 玛丽莲.梦露 B. 戴安娜王妃 C. 伊丽莎白女王 D. 麦当娜 6. 成语“熟能生巧”用英语怎样表达？（D） A. It’s no use crying over the spilt milk. B. Out of sight, out of mind. C. Every coin has its two sides. D. Practice makes perfect. 7. 美国国旗星条旗上有多少颗星？（B）
A. 49 B. 50 C. 51 D. 52 8. 来自美国的餐饮连锁店KFC是以下哪一个的缩写？（C） A. Kentucky Fried Cake B. Kentucky Frying Cake C. Kentucky Fried Chicken D. Kentucky Frying Chicken 9. 英语谚语“It’s raining cats and dogs.”和以下哪一选项比较接近？（A） A. 天空正下着倾盆大雨。 B. 天气正晴朗。 C. 天上掉下很多猫和狗。 D. 天空怎么还没下雨呢？ 10. John Bull（约翰牛）和Uncle Sam（山姆大叔）分别是哪两个国家的 人的代名词？（A） A. 英国人和美国人 B. 美国人和英国人 C. 英国人和德国人 D. 美国人和德国人 11.What languages do Candians speak? (答案C ) A.English B.English and German C.English and French D. English and Spanish 12. How many Great Lakes are there inCanada? （答案A ） A. 4 B. 3 C. 5 D. 6 13. Which is the longest river in England? （答案B） A.The River Avon B. The River Thames C. The River Severn D. Changjiang River 14. How many countries does the UK consist of ? （答案C ） A. two B. three C. four D.five 15.What are the provinces called in England? （答案A）
六年级英语百科知识竞赛题 一、选择题。 （ C ）1、Our class will sweep the table.in the football match. A.打扫餐桌 B.全面亮相 C.大获全胜 （C）2、Singing songs is a piece of cake for me. A．想吃蛋糕一样B。一片蛋糕 C.小菜一碟 （A ）3.He is really a chicken. A.胆小的人 B.一只鸡 C.吃鸡肉 （ B）4、He takes to English like a duck to water. A.快乐的鸭子 B.很轻松 C.喝水的鸭子 （ B ）5.What’s the Chinese for “talk big”? A.骂人 B.吹牛 C.很大 （ B ）6.Butterflies belongs to (属于)the class of A.birds B.insects C.plants （C ）7. Sarah是班长，老师走进教室准备上课，她应该这样说：A．Sit down. B.Good morning. C.Stand up. ( A )8. 老师请你拍手，用英语该这样说： A.Clap your hands. B.Show your hands. C.Snap your fingers. ( B )9.It warms our planet.（行星），It . A.cloud B.sun C.rain ( C )10.Yao Ming is a . A.baseball plalyer B.football player C.basketball player
天鹅湖 维基百科，自由的百科全书 天鹅湖（1876） 睡美人（1889） 胡桃夹子（1892）
剧，也是所有古典芭蕾舞团的保留剧目。 ? ? ? ? ?
? ? 在天鹅湖里，剧本可以说是举足轻重的。本来有两个差别很大的天鹅湖版本。但通常它们会被混合着上演。它们的不同在于对结局的处理。在第一个版本里，王 式的。但在著名的圣彼得堡版本里尽管结尾音乐是那么悲悲愁愁的，最后的结局却是大团圆。 施魔法的面纱》的故事，作者是卡尔·奥古斯都·姆赛斯。里面提到了离德国城市兹维考不远处有一个天鹅池塘，那有着一个关于天鹅少女的传说。当法师施法于天鹅的羽毛时，天鹅就会变成一位少女。而且这样的主题在许多其他童话里也出现过。特别是那位可怜的公主，只有一位王子的爱情才能救她。但是悲剧式的结局却是姆赛斯的首创，以前从没在别的童话中出现过。
?第一幕 王子齐格弗里德（Зигфрид）在生日前夕，其母亲告诉他，已成年的齐格弗里德要在第二天选一位新娘。而到了晚上，王子去天鹅湖捕猎天鹅。 ?第二幕 齐格弗里德遇上被罗特巴特（Ротбарт）施咒的公主奥杰塔（Одета）。她白天是天鹅，晚上却会化成一位少女。只有当某位男子真诚地爱上她时，她才能得救。齐格弗里德邀请她第二天晚上来参加舞会，并会向母亲表示，愿意娶奥杰塔为妻。 File:Swanlake2.jpg 第三幕：王子与黑天鹅 ?第三幕 各国的公主和使节都来出席齐格弗里德的生日宴会。罗特巴特也带着他的女儿奥吉莉亚（Одилия）来了。
奥吉莉亚显示的是奥杰塔的形象，只是身着黑装。齐格弗里德被迷惑并与她缔结了婚约。当齐格弗里德意识到这一切的时候，大为震惊，并立即赶往天鹅湖。 第四幕 第四幕：奥杰塔与众天鹅 王子请求奥杰塔的宽恕，而奥杰塔也原谅了他。这时罗特巴特用魔法卷起大浪，要淹死齐格弗里德。奥杰塔为了救他纵身跃入湖内。根据导演编排的不同，结尾也不一样：或者是双双逝去形成悲剧式的结尾，或者是天鹅恢复人形，王子救起公主，爱情终于战胜了
百科知识大全 题目石头城是对我国哪座城市的美称 ?(2分) 选项 A:南昌 B:南京 C:拉萨 D:西安 答案 B 题目被唐太宗李世民比作镜子的是谁？(2分) 选项 A:魏征 B:李靖 C:徐茂公 D:刘文静 答案 A 题目在中国神话中，（）发明了农业。(2分) 选项 A:后稷 B:燧人 答案 A 题目哪两种动物被称为“海洋变色龙”？(2分) 选项 A:海马和乌贼 B:乌贼和章鱼 C:章鱼和海蜇答案 B 题目联合国常任理事国共有多少个成员国?(2分) 选项 A:三 B:四 C:五 D:六 答案 C 题目体育运动篮球最早起源于:(2分) 选项 A:美国 B:中国 C:英国 D:法国 答案 A 题目世界上使用人数最多的语言是 :(2分) 选项 A:英语 B:汉语 C:西班牙语 D:法语 答案 B 题目下列名关哪一座被称为“天下第一关”?(2分) 选项 A:居庸关 B:娘子关 C:潼门关 D:山海关 答案 D 题目著名风景区九寨沟位于我国哪个省 ?(2分) 选项 A:台湾 B:云南 C:广西 D:四川 答案 D 题目吉林省抚松县被人们称为是哪种药材之乡 ?(2分) 选项 A:当归 B:人参 C:枸杞 D:田七 答案 B
题目元宵节是农历哪一天 ?(2分) 选项 A:正月初一 B:正月初二 C:正月十五 D:十二月三十 答案 C 题目请问:火车连续发出两声长鸣,这表示 :(2分) 选项 A:前进 B:停留 C:倒退 D:故障 答案 C 题目 "六畜兴旺"中的"六畜"是指猪、牛、马、羊、狗、鸡六种,其中人工驯化最早的是:(2分) 选项 A:猪 B:马 C:鸡 D:狗 答案 A 题目奥运会旗是"五色环"旗,其中黄色环代表:(2分) 选项 A:亚洲 B:欧洲 C:非洲 D:大洋洲 答案 A 题目下列哪个国家被称为"袋鼠之国 "?(C)(2分) 选项 A:索马里 B:新西兰 C:澳大利亚 D:肯尼亚 答案 C 题目下列海洋中哪一个是我国最大的海 ?(2分) 选项 A:南海 B:东海 C:黄海 D:渤海 答案 A 题目世界上海拔最高的山峰是哪一座 ?(2分) 选项 A:乔戈里峰 B:珠穆朗玛峰 C:干城章嘉峰 D:公格尔山峰 答案 B 题目世界四大洋中面积最小的是 :(2分)
企业维基很好很强大 许多IT部门都在运用维基方式处理从技术培训到项目管理的各种工作。 意大利国家电力公司（Enel）北美分公司的信息与通信技术经理Ernest Kayinamura与另一名IT经理积极采用维基(Wiki)方式，以便最终用户更容易获取各种IT材料。这是为什么？因为只有他们两个人服务全部北美的众多用户，既然维基能够减轻他们的工作负担，Kayinamura何乐而不为？ 其实这并不是什么个案，如今越来越多企业内的技术部门借助维基这种便于管理、开销又低的Web 2.0方式，以促进工作小组内部或不同部门之间的沟通。 早在1994年，就出现了第一个维基体系―WikiWikiWeb，设计者当初的设想是“维基成为切实可行的―最简单的联机数据库。” 15年过后，这个概念正深入越来越多的企业内部。业内人士表示，与免费使用的公共维基相比，企业内部的维基往往有着更多层次的结构，采用比较严格的版权管理政策确保对企业知识产权的访问，从而达到支持特定组织或部门的目标。
那些企业维基的支持者们表示，与电子邮件和较复杂的知识管理系统相比，企业维基提供了一种更简单、更自然的方式来共享信息、促进合作，完成集体任务。 减轻IT部门负担 Enel北美公司最早是在2005年启动的维基试点项目，最初他们是利用维基作为管理数据库应用开发的中心。目前它已成为一个成熟的内容管理平台，该平台让该公司的260名最终用户可以通过自助服务获取IT信息，而这些信息之前由Kayinamura领导的二人小组通过电子邮件或通过内部网络来分发。“工作量非常大。”Kayinamura说。 现在，Kayinamura的二人IT小组在使用Traction Software公司的TeamPage企业维基程序，它可以通过维基向最终用户提供各种信息，包括培训材料、计算机和手机使用政策、行业背景资料以及各种软件说明文档。 Enel在北美拥有及经营可再生能源项目，Kayinamura表示: “我们需要提供尽量多的自助服务参考材料，减轻IT部门的负担。我们为维基添加了许多资料，例如电子邮件摘要功能可以提醒员工注意任何新迈发布的内容。要是使用传统网页通知，员工去查看以往的邮件很不方便。” Kayinamura领导的IT小组还利用该平台作为放置关键
2005 in Oberwolfach
introduced the self-concordant functions which are useful in the analysis of Newton's method. [8] References 1. "The George B. Dantzig Prize". 2000. Retrieved December 12, 2014. 2. "Yurii Nesterov". 2009. Retrieved June 4, 2014. 3. Nesterov, Yurii. Introductory lectures on convex optimization : A basic course(PDF). ISBN 978-1402075537. 4. Bubeck, Sebastien (April 1, 2013). "ORF523: Nesterov’s Accelerated Gradient Descent". Retrieved June 4, 2014. 5. Bubeck, Sebastien (March 6, 2014). "Nesterov's Accelerated Gradient Descent for Smooth and Strongly Convex Optimization". Retrieved June 4, 2014. 6. "The Zen of Gradient Descent". 7. Nesterov, Yurii; Arkadii, Nemirovskii (1995). Interior-Point Polynomial Algorithms in Convex Programming. Society for Industrial and Applied Mathematics. ISBN 0898715156. 8. Boyd, Stephen P.; Vandenberghe, Lieven (2004). Convex Optimization(pdf). Cambridge University Press. ISBN 978-0-521-83378-3. Retrieved October 15, 2011. External links Official website (https://www.uclouvain.be/32349.html) This article contains text translated from French Wikipedia Retrieved from "https://https://www.doczj.com/doc/fd1174998.html,/w/index.php? title=Yurii_Nesterov&oldid=712596518" Categories: Living people Belgian mathematicians Université catholique de Louvain faculty1956 births Soviet mathematicians This page was last modified on 30 March 2016, at 01:04. Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia? is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
百科知识竞赛 卷一 一、选择题 1、的"山"是指:(B) A泰山B、太行山C沂蒙山D、恒山 2、史书《资治通鉴》是属于哪一类体例的历史?(C) A纪传体B、纪事本末体C编年体D国别体 3、著有"农村三部曲"的著名作家是:(B) A巴金B、茅盾C郭沫若D、欧阳山 4、唐代诗人有称“诗圣”的杜甫“诗仙”的白等，你可知道被人颂称“诗魔”的是谁?(A) A、白居易 B、王维 C、禹锡 D、商隐 5、我国煤炭资源主要集中在哪些省市?(B) A、、新疆 B、、蒙 C、、新疆 6、阿姆斯特朗是乘哪个飞船成功登月的? ( A) A 阿波罗11号B阿波罗12号C和平号D爱国者6号 7、古代六艺，"礼、乐、射、御、书、数"中的"御"是指：(D) A骑马B杂技C射箭D驾车. 8、我们平时常说“如果冬天来了，春天还会远吗?”请问这句名言出自于英国的哪位作家?(C) A、雨果 B、拜论 C、雪莱 D、普斯金
9、白菜属于_________科(C) A.豆科 B.菊科 C.十字花科 D.蔷薇科 10、奥林匹克运动会的发源地是:(B) A古罗马B古希腊C古代中国D古巴比伦 11、我国境最早的人类是:(B) A.人 B.元谋人 C.山顶洞人 D.丁村人 12、下列哪个国家不是联合国常任理事国之一?(D) A.英国 B.法国 C.中国 D.德国 13、色盲患者最普遍的不易分辨的颜色是什么?(A) A.红绿 B.蓝绿 C.红蓝 D.绿蓝 14、天下第一书"《兰亭集序》是哪一位古代书法家的杰作?(C) A.旭 B.王献之 C.王羲之 D.芝 15、中国面积最大的省份是哪一个?(B) A. B.新疆C. D. 16、"知天命"代指什么年纪?(D) A.二十岁 B.七十岁 C.三十岁 D.五十岁 17、请问:火车连续发出两声长鸣,这表示:(C) A.前进 B.停留 C.倒退 D.故障 18、轮船发出六声短笛,这是表示什么呢?(D) A.倒退 B.避让 C.转弯 D.遇险 19、"隐形飞机"是指什么样的飞机?(D) A.肉眼看不见 B.飞行太高看不见 C.体积太小 D.雷达测不到
Wiki简介 Wiki一词来源于夏威夷语的“wee kee wee kee”,原本是“快点快点”的意思,被译为“维基”或“维客”。 一种多人协作的写作工具。Wiki站点可以有多人（甚至任何访问者）维护，每个人都可以发表自己的意见，或者对共同的主题进行扩展或者探讨。 Wiki指一种超文本系统。这种超文本系统支持面向社群的协作式写作，同时也包括一组支持这种写作的辅助工具。有人认为，Wiki系统属于一种人类知识网格系统，我们可以在Web的基础上对Wiki文本进行浏览、创建、更改，而且创建、更改、发布的代价远比HTML文本小；同时Wiki系统还支持面向社群的协作式写作，为协作式写作提供必要帮助；最后，Wiki的写作者自然构成了一个社群，Wiki系统为这个社群提供简单的交流工具。与其它超文本系统相比，Wiki有使用方便及开放的特点，所以Wiki系统可以帮助我们在一个社群内共享某领域的知识。 Wiki发明者是一位Smalltalk程序员沃德·坎宁安(Ward Cunningham)。 由于wiki可以调动最广大的网民的群体智慧参与网络创造和互动，它将成为WEB3.0时代不可逆转的一大趋势。 Wiki与Blog的区别 Wiki站点一般都有着一个严格的共同关注，Wiki的主题一般是明确的坚定的。Wiki 站点的内容要求着高度相关性。最其确定的主旨，任何写作者和参与者都应当严肃地遵从。
Wiki的协作是针对同一主题作外延式和内涵式的扩展，将同一个问题谈得很充分很深入。Blog是一种无主题变奏，一般来说是少数人（大多数情况下是一个人）的关注的蔓延。一般的Blog站点都会有一个主题，凡是这个主旨往往都是很松散的，而且一般不会去刻意地控制内容的相关性。 Wiki非常适合于做一种“All about something”的站点。个性化在这里不是最重要的，信息的完整性和充分性以及权威性才是真正的目标。Wiki由于其技术实现和含义的交织和复杂性，如果你漫无主题地去发挥，最终连建立者自己都会很快的迷失。Blog注重的是个人的思想（不管多么不成熟，多么地匪夷所思），个性化是Blog的最重要特色。Blog 注重交流，一般是小范围的交流，通过访问者对一些或者一篇Blog文章的评论和交互。 Wiki使用最多也最合适的就是去共同进行文档的写作或者文章/书籍的写作。特别是技术相关的（尤以程序开发相关的）FAQ，更多的也是更合适地以Wiki来展现。Blog也有协作的意思，但是协作一般是指多人维护，而维护者之间可能着力于完全不同的内容。这种协作在内容而言是比较松散的。任何人，任何主体的站点，你都可以以Blog方式展示，都有它的生机和活力。从目前的情况看，Wiki的运用程度不如Blog的广，但以后会怎样，还有待观察，毕竟Wiki是一个共享社区。 Wiki发展历史 Wiki的历史还不长，无论是Wiki概念自身，还是相关软件系统的特性，还都在热烈的讨论中；所以怎样的一个站点才能称得上是一个Wiki系统还是有争议的。与Wiki相关最近出现的技术还有blog，它们都降低了超文本写作和发布的难度。这两者都与内容管理系统关系紧密。第一个Wiki 网站诞生于1995年，由沃德·坎宁安(Ward Cunningham)创建
英语百科知识竞赛
宜宾学院 素质拓展项目 之 英语百科知识竞赛 策 划 书 主办方：宜宾学院校团委 承办方：外国语学院素质拓展部 二〇一四年十月二十八日
一、活动名称：英语百科知识竞赛 二、活动主题：开拓眼界搏击英语 三、活动目的：本次英语百科知识竞赛旨在提高宜宾学院同学的英 语技能，增强学生学习英语的能力，拓宽学生的知识面，培养学生对各类英语知识的兴趣，活跃英语的学习氛围，在比赛中国充分挖掘同学们的潜能，为今后对于英语的运用打下良好的基础。 四、参赛对象：宜宾学院全体学生 五、报名时间:11月15—20号 六、比赛时间：11月29日周六14：30 七、比赛地点：3教A座202 八、比赛形式：比赛分专业组和非专业组。非专业组（除外国语学 院）各学院各派一支由三人组成的代表队；专业组队伍由报名选手抽签决定分组。 九、奖项设置：专业组和非专业组各设置团队奖和个人奖，团队奖 有冠军、亚军和季军三个奖项；个人奖有第一、二、三名各1人，优秀奖1名。 十、一般规则： 1.本次比赛采用现场竞赛，现场评比，现场颁奖的方式进行。 2.比赛试题分为必答题、选答题、抢答题、风险题四种形式。 3.比赛先以团队形式答题，后以个人进行角逐。
4.竞赛中若发生名次并列情况，由并列队或并列人加赛一题进行抢 答，继续加赛一题，直至名次决出。 5.主持人提出问题后，若答题者为听清，可要求主持人重复一遍（抢 答题例外） 6.参赛者回答结束之后要说“回答完毕”，回答不出要说“放弃” 十一、比赛具体规则: 第一环节：必答题 1.每支队伍由抽签决定答题顺序，依次答题，每组十道题。 2.答题总时间为30秒。队员答题时，必须10秒之内作答，超过 10秒不回答或中停顿超过10秒，被视为放弃。组内成员可以讨论。 3.每题10分，答对加10分，答错或不答不扣分。 4.在答题时间内，每组有一次向支持人求助的机会，即排除一个错 误答案一次。 5.每组答完十道题后第一环节结束，由工作人员统计分数。分数最 低的三组淘汰。 第二环节：抢答题。 1.总共是10道题。每题10分。答对加10分，答错或超时、违规扣 10分。 2.由主持人直接读题，原则上在主持人读完题说开始后，各代表队方
Early in the 19th century, about 60 million bison lived on the Great Plains in North America. They were central to the existence of the Plains people. Then from 1830 to 1889 they neared extinction, with less than 1,000 still roaming. Today, they are a protected animal and there are well over 200,000 living in protected areas and ranches. · I live in North America, however, I have some close relatives in Europe. · I live in plains regions. I am able to survive cold winters. ·I roam out in the open on the Great Plains of North America, mostly in protected areas and private ranches. · I have a massive head, a hump over my front shoulders and sharply pointed horns. · I have a thick coat of dark brown and black hair. · I am about 6.5 feet (2 meters) tall and about 9-12 feet (2.7-3.7 meters) long. · I'm quite heavy. I can weigh 1800-2400 pounds (850-1100 kg). · I eat lots leaves and lots of grass. ·I have help getting protection now, because I was near extinction. But I do have horns and I usually hang out in a group with my friends. · I first came to North American in prehistoric times when I crossed the Bering Strait land bridge from Eurasia. 译文 野牛——地图上涂绿色的地方是我的家 有趣的常识： 早在十九世纪，约六千万野牛生活在北美大草原上。它们曾是草原人民的生活中心。然而从1830年到1889年，它们濒临灭绝，只有1000只野牛尚存。今天，它们是保护动物，并且超过20万只野牛很好地生活在保护区和农场。 · 我生活在北美，然而，我有一些近亲在欧洲。 · 我生活在草原地区，我能在寒冷的冬天生存。
到紧张和有压力，让您不想再参与维基，那么就忘掉这些规则，做您自己的事儿吧!”（“If rules make you nervous and depressed，and not desirous of participating in the wiki，then ignore them entirely and go about your business.”）但令人惊奇的是，虽然如此，维基却至今依然是一个很有组织、很规范的系统。[10] 处理破坏 与此同时，一些恶 英语维基百科上观看到的对于条目文章的修改 意的修改行为也会被限制。对破坏行为进行监督和纠正也并不是什么难事，用户只需查看修改的清单就可在几分钟（甚至几秒钟）内发现这些破坏行为，然后点击撤销按钮就可以回到被破坏之前的状态，这就比较利于维基社区对质量的掌控。 2004年11月1日前一期的《新闻周刊》引用英国艾塞克斯一位维基百科迷（他曾对1000多个词条的正确性进行网上监督）的话说：“合著百科全书的想法也许是有些疯狂，但它的自控却很好。” 4参与团队 维基媒体基金会 维基百科
维基百科基金会 是由属于非营利组织的维基媒体基金会负责托管与资助，同时维基媒体基金会还管理包括维基词典与维基教科书等与维基百科相关的计划。维基媒体基金会的经营主要是依赖公众或者企业的捐赠和补助金，其中重要的捐助者包括有美国投资家华伦·巴菲特、前美国总统吉米·卡特、维珍集团首席执行官理查德·布兰森爵士、亚马逊公司创办人杰夫·贝佐斯、Craigslist创办人克雷格·纽马克（Craig Newmark）等。[14] 管理人员 维基百科社区已经创建了“各式各样的官僚体系”，其中为了能够有效掌握维基百科中条目的编辑修改动向，使得许多语言版本的维基百科陆续由志愿担任管理人员者组织“明确的权力结构”。这些志愿协助管理工作的“管理员”往往在维基百科社区中也是拥有良好信誉的编辑用户，在成为有部分特权的“管理员”之后便拥有能力删除页面、封锁正在被破坏的文章或者是社区严重争执时删除污辱性对话，甚至也能够停止违规用户的编辑权利。不过“管理员”的权力行使者要在于编辑部分的行使，期望能够阻止用户对于维基百科的破坏性编辑，而对于普通的编辑用户实质上并无管辖权力。此外，管理员在决策决定这一方面也并未享有任何特殊权力 用户团队 维基百科是由全球无数志愿学者、玩家、学生等等有知识的人共同建筑的，该 英语维基百科仲裁委员会的介绍页面 计划的参与者叫做维基百科人。直至如今，参与者的人数仍在不断增加，特别是受到良好教育的人士。事实上，维基百科不能说是一种技术，而是一种创造性运用技术的方式，但对一种先进技术来说，能把它用好其实是最重要的事情。[15]维基百科本身有三个引人注意的特点，这些特点使维基百科与传统的百科全书有所区别：[15] 首先，维基百科将自己定位为一个包含人类所有知识领域的百科全书，而不是一本词典、在线的论坛或其他任何东西。其次，维基百科允许大众的广泛参与，它是一个协作计划。另外，维基百科是一部内容开放的百科全书，它允许任何第三
A组 1、What is English equivalent（对应词）of 世界贸易组织( C ) 2、What is English equivalent of 世界卫生组织(B) （解析：WHO is world health organization.) 3、What is English equivalent of 国内生产总值(A) 4、What is English equivalent of 国际奥委会(A) （解析：FIFA：国际足球联盟） 5、What is English equivalent of 药品生产质量管理规范(D) B组 1、Translate the sentence"All that glitters（闪烁；闪耀）is not gold." into Chinese. (发光的并不一定都是金子。） 2、Translate the sentence "A lazy youth ,a lousy （非常糟的；极坏的）age.''into Chinese. （少壮不努力，老大徒伤悲。） 3、Translate the sentence "All time is no time when it is past." into Chinese. （光阴一去不复返。） 4、Translate the sentence"Failure is the mother of success."into Chinese. （失败乃成功之母。） 5、Translate the sentence"A thousand-li journey is started by taking the first step.'' into Chinese. （千里之行，始于足下。） C组 1、Translate the sentence "Man struggles upwards; water flows downwards.''into Chinese. （人往高处走，水往低处流。） 2、Translate the sentence''Genius（天才）is one percent inspiration and ninety-nine percent