•hydro

hydro 发音

英：[ˈhaɪdroʊ]　　美：[ˈhaɪdrəʊ]

英：　　美：

hydro 中文意思翻译

hydro 常用词组

hydro power ─── 水力发电

hydro 短语词组

1、hydro-kinetic force ─── [医] 流体动力

2、hydro- pref. ─── 氢化的 [医] 水, ─── 氢

3、Manitoba Hydro Place ─── 马尼托巴河畔

4、hydro-exostosis ─── [医] 积水性外生骨疣

5、hydro-adenitis ─── [医] 汗腺炎

6、hydro-static force ─── [医] 流体静力

7、hydro-carbon n. ─── [有化] 碳氢化合物

8、hydro-conversion ─── [化] 加氢转化; 加氢转化作用; 加氢转换; 加氢转换作用

9、hydro-denitrification ─── [化] 加氢脱氮; 加氢脱氮作用

10、hydro-blast ─── [机] 高压水清砂机

11、tethered hydro boat ─── 系着水船

12、hydro-carbons (hydro-carbon ─── 的复数) n. [有化] 碳氢化合物

13、hydro-airplane n. ─── 水上飞机

14、hydro-denitrogenation-hydrocracking process ─── [化] 加氢脱氮-加氢裂化联合法

15、hydro-electric a. ─── 水力电气的

16、hydro-oligocythemia ─── [医] 稀血性红细胞减少

17、hydro-geology ─── [经] 水文地质学

18、hydro-electrics (hydro-electric ─── 的复数) adj. 水力电气 ─── 的

19、hydro-epigastrium ─── [医] 腹膜腹肌间积水

hydro 词性/词形变化，hydro变形

名词复数: hydros |

hydro 相似词语短语

1、hydroma ─── n.水囊瘤，水瘤

2、hydro- ─── n.电，水力电；水疗中心；家庭及工商业用电；adj.水力发电的（hydroelectric的简称）

3、hydroa ─── 水疮病

4、hydros ─── 保险粉

5、hydroid ─── adj.水螅虫的；水螅类的；水螅体的；息肉状的；n.水螅虫；水螅类生物

6、hydr- ─── 液压

7、Hydro ─── n.电，水力电；水疗中心；家庭及工商业用电；adj.水力发电的（hydroelectric的简称）

8、hydrops ─── n.积水（等于dropsy）

9、hydra ─── n.九头蛇；[无脊椎]水螅；难以根除之祸害

hydro 常见例句（双语使用场景）

1、Three- quarters of Japan's nuclear generating capacity continued to operate during the earthquake, while most of the hydro-plants failed. ─── 地震期间，日本四分之三的核电站继续运行，而大多数水电站则停止了运行。

2、Mercure Hydro Majestic, managed by the well known "Accor Hospitality" worldwide group, is the only international brand hotel in Kunming. ─── 云南海德美居酒店由著名的法国雅高国际酒店管理集团管理，是昆明唯一的国际品牌酒店。

3、Urbanization causes great changes of shape and structure of the system and influences severely the biodiversity, hydro ecosystem and visual esthetics characteristics. ─── 城市化导致了系统形态结构的巨大改变，严重影响了流域的生物多样性、水文生态过程和视觉美学特质。

4、capacity of individual power stations, many of them hydro plants, rose from a few kilowatts to over a megawatt in less than a decade. ─── 在不到十年的时间里，单个发电站的发电能力就从几千瓦上升到了几兆瓦，其中许多是水力发电站。

5、The situation can be relieved by the optimization of dispatching of hydro projects and increase of waterworks. ─── 在适当优化调度水库、泵站等水利工程以及增加、扩大一定工程规模的条件下，珠海市的缺水问题可以得到缓解。

6、Pumped hydro is the first idea. ─── 抽水机抽氢是首选想法。

7、Skin with abundant hydro can retain moisture and vivid appearance. ─── 喝饱水的肌肤，才能保持水润柔亮，神采飞扬。

8、CDM and demand of energy development in China provide an opportunity for clean energy development including small hydro power development. ─── CDM和中国能源发展需求为中国包括小水电在内的清洁能源建设带来了机遇。

9、The hydro - electric station began generating electricity in1960. ─── 1960年水电站开始发电。

10、So we are not the best place to direct your hydro power questions to, we have hardly any hydro experience. ─── 因此，我们不是最好的地方，直接您的水电问题，我们几乎没有任何水电站的经验。

11、Makes the skin tender and soft willowy, also triggers the skin hydro energy quantity, and keeps it whitening and nutrient. ─── 令肌肤水嫩、柔软有弹性，并触发肌肤水能量，令肌肤细腻透白，温润如玉。

12、The visual language includes the use of soft colors and understated graphics that helped "humanize" the brand and provided a contemporary style to Hydro's communications. ─── 作为一家挪威的公司，海特优势是它源自于这一地区向来尊重人与自然和谐相处的文化，主张将社会效益置于商业利益之上。

13、Many oil analysts expected the 24 pct stake awarded to the French oil major to go to one of its Norwegian counterparts, either Norsk Hydro or Statoil. ─── 大多数石油分析家预计,授予法国石油公司24%的股份，将会落到一家挪威公司手中,或者是挪威水电公司，或者是挪威国家石油公司。

14、Soon after, Norsk Hydro said it was bowing out. ─── 不久，海德鲁就宣布退出。

15、Furthermore, as China improved the relationship with Indochina peninsula countries in 1990s, they cooperated to construct the facilities, such as transportation, hydro power, and tourism. ─── 再者，随著中国在90年代以来与中南半岛国家关系的改善，双方合作开发湄公河流域的各项设施，如：交通运输、水电、旅游等，深化了中国大西南与东南亚区域经济的联系。

16、It reaffirmed Beijing's aim of cutting energy use by a fifth before 2010, and of doubling its reliance on renewable energy sources such as wind, hydro and nuclear power by 2020. ─── 他再确认了北京将在2010年减少五分之一的能源使用,在2020年达到使用两倍再生能源的目标,这包括了风力,水力和核能的运用.

17、Presents Hydro macroparticle urea granulation technology with fluid bed and the reasons,phenomena and harmfulness of vacuum pressure fluctuation,and discusses relative measures to solve the problem. ─── 介绍海德鲁流化床大颗粒造粒技术及该系统造粒机负压波动的形成原因、现象以及危害,并提出相应解决方案。

18、Looking out over the rooftops of crowded houses, one could see a steep foothill topped with a hydro line and a half-built apartment building in the foreground. ─── 从一排密集的房屋屋顶看过去，你能看见一个陡峭的山麓，山顶上有一排电线，山前有一幢建了一半的公寓楼。

19、Our company is an enterprise specializing in developing and producing inflatable products, hydro sports& leisure products, amusement equipment, particularly at aquatic play. ─── 公司是专门从事水上运动休闲，游乐设施，充气产品的开发、计、产、售的企业，尤其在水上游乐方面有独到之处。

20、Therefore,it is important for the catalytically hydro dechlorination of carbon tetrachloride to chloroform. ─── 因此,通过四氯化碳催化氢化脱氯生成氯仿显得尤为重要。

21、The results indicate that high failure probability of benches is primarily depended on inherent variability of strength,anti?weathering ability and hydro?physical properties of moraine soil. ─── 分析结果表明,台阶边坡破坏概率较高,主要是由冰碛土强度的固有不确定性、抗风化能力以及水理性质决定的,而边坡结构因素对其影响不显著。

22、This article describes the successful spiral case preassembly with a dummy stay ring for the manufacturing of the 550MW hydrogenerating units of Ertan Hydro Power Station. ─── 二滩水电站550MW水轮发电机组在制造过程中,采用工艺座环预装涡壳,这在国内尚属首例。

23、Through hydro and mechanical pressure the diameter of expandable tubular can be expanded. ─── 可膨胀管技术利用液压或机械方式使管材直径增大,从而保持较大的井径。

24、Hydro Gel Mask to replenish water rapidly, activate cells, diminish wrinkles, whiten and tighten the skin, strengthen skin defense, and restore skin's vitality. ─── 为肌肤注入水份，对肌肤最干燥缺水的部位发挥双倍滋润效果，并及时抚平幼纹及干纹，强化改善肤质,净化肤色，令肌肤水润。

25、To train customer's to operate by themselves utilizing the Hydro specific software for quoting and designing, developing step by step the complete customer's ability with all our product applications. ─── 培训客户通过使用海德鲁的专用软件,自行完成报价、设计工作。逐步发展并使客户完全具备应用海德鲁产品的能力。

26、Hydro polis, the world's first under water hotel. Entirely built in Germany and then assembled in Dubai , it is scheduled to be completed by 2009 after many delays. ─── 全球首个水下酒店。整个构架建造于德国、在迪拜组装而成，经过数次工期宕延后，预计于2009年峻工。

27、When head-dependent power output is considered, the hydro subproblem no longer becomes unit-wise and stage-wise decomposable, and therefore becomes more difficult to solve systematically. ─── 从而无需离散化任何连续变量就可以有效得到梯级水电系统的 高精度次优解。

28、Guangdong's five-year plan includes10 large projects in the transport, energy and conversion of hydro resources sectors taking total investment by the province in the period to1.1 trillion yuan. ─── 广东的“十一五”计划包括了交通、源、资源转换等方面10个大项目，广东省在“十一五”计划的总投资达到1.1万亿元。

29、The design scheme, construction and parameters of the grinding device used to repair the plane deformation of stay ring of hydro turbine at the power station are introduced, and the design gist of the grinding head system is presented. ─── 介绍了用于修磨水轮机座环平面变形的专用修磨设备的设计方案、构、数及磨头系统的设计要点。

30、China’s investments in renewables were mainly in solar heating and small hydro. ─── 中国在可再生能源方面的投资主要集中在小水电和太阳能热水器。

31、Several Clients - Small Hydro Power Plants WORK PERFORMED: Anticorrosion protection inspection. ─── 几家小型水利发电厂所做工作:负责防腐保护检测。

32、For specified projects, to train the customer's workers on site for the installation securing that process and quality results are on line with Hydro standards. ─── 对于特殊的项目，在施工现场对客户的工人进行培训，以保证施工流程和质量满足海德鲁的产品标准。

33、Ruyan Yao Minority county of Guangdong province is a poor mountain county, governing 14 townships，40 administration villages，240 nature villages，and all the towns and villages develop small hydro. ─── 广东乳源瑶族自治县是一个少数民族贫困山区县，有14个乡镇，40个行政村，240个自然村，镇镇村村都办小水电。

34、Voith Hydro Shanghai(VHS), Ltd. was established by Voith-Hydro Group and Shanghai Electric Group on Dec 12th , 1994. ─── 上海福伊特水电设备有限公司由德国福伊特水电集团与上海电气集团于1994年12月12日合资成立，1997年11月投入正式生产。

35、He said the hydro-electric project has caused conflicts over land shortages and environmental degradation caused by irrational development. ─── 他说，三峡水电站工程导致了土地缺乏的冲突矛盾和不合理开发造成的生态退化。

36、Mexia says Portugal can radically increase the production potential of both wind and hydro plants by using surplus wind energy to drive water upstream and fill hydroelectric dams. ─── 墨西阿表示，运用这些过剩的风能将水引回上游流入水力发电大坝，葡萄牙就能够极大地提高风力发电厂和水利发电厂的生产潜力。

37、The test method used here for mercury speciation was the Ontario Hydro Method. ─── 另外，较高的烟气排放温度会提高单质汞向氧化态汞转化的转化率，Hg浓度升高汞转化率下降。

38、The principle of de-excitation of THYRIPOL exciter in the Three Gorges left-bank Hydro power Plant is introduced. ─── 介绍了三峡左岸电厂THYRIPOL励磁装置的灭磁原理,详细分析了主要工况下的灭磁时序和试验录波资料,讨论了其灭磁可靠性等问题。

39、For ex-ample, the throttle of a thermal unit or the gate of a hydro unit can be adjusted to change load on that machine, and the machine will respond individually to the energy input to its prime mover. ─── 例如,调节火电机组的节流阀或水电机组的导流闸门来改变机组的负荷,而机组各自对其原动机的能量输入作出响应。

40、For specified projects, to help Technical Trainer to train the customer's workers on site for the installation securing that process and quality results are on line with Hydro standards. ─── 对于特殊的项目，帮助技术培训工程师，在施工现场对客户的工人进行培训，以保证施工流程和质量满足海德鲁的产品标准。

41、But few analysts believe it is possible to scale up hydro, nuclear, solar and wind power at such a massive rate. ─── 但只有少部分分析人士相信可以以如此快的速度发展水电，核电，太阳能和风力发电。

42、The tools string consists of flowmeter, density, hydro, pressure, temperature, GR and CCL, etc. ─── 仪器串包括流量、密度、持水、压力、温度、温度GR、CCL等。

43、Close cylinders or pressure vessels or any kind of (a) fuel tank. That is contain a liquid hydro pervert fuel is extremely dangerous. ─── 在封闭的桶子、压力容器及任何形式的油桶，都会存有液态挥发性油是有极端危险性的。

44、Study of the ore-field geology and ore-controlling structure in the ore belt indicates that the stratabound plus hydro... ─── 对矿带内矿田地质和控矿构造的调查表明,本区的层控加热液改造型矿床与成矿构造关系密切。

45、Where hydro - electric stations are built,there are rich water resources. ─── 凡是建有水电站的地方，水力资源就丰富。

46、Abstract:Take use of the sediment containing the lead from the acidized copper and cadmium sediment to hydro metallurgic produce the lead acetate and lead. ─── 利用铜镉渣酸浸后的含铅废渣湿法生产醋酸铅及铅,有利于提高经济效益、改善生态环境。

47、It is an economic and energy saving way that the hot wind of hydro generator is used to power plant heating. ─── 发电机放热风用于电厂厂房采暖是一种经济节能的方法。

48、By the model test with model hydro turbine and generator units, on the condition of the steady flow, unsteady flow, and the flow state in the tailrace tunnel with sloping ceiling is understood. ─── 小波动条件下变顶高尾水洞体型对机组运行稳定性的影响;

49、A few tidal projects, such as the 42-year-old barrage at Rance in France, operate like traditional hydro schemes, in which tidal water simply rushes through turbines. ─── 几个潮汐工程象传统的水电方案那样在运转，在运转中潮汐水仅仅是冲过涡轮，比如在法国兰斯海湾的有42年之久的水坝。

50、Coordinate on going hydro power inspection projects and manage hydro power inspector team in technical aspects. ─── 协调正在执行的水电检验项目，并且对水电检验员团队进行技术管理。

51、But even before Norsk Hydro could make a firm offer, government officials in Zhaoqing, the city where Asia Aluminum's facilities were based, issued a statement saying that they weren't interested. ─── 但海德鲁都还没正式提出收购，亚洲铝业厂房所在的肇庆市政府官员就发表声明说，他们没兴趣。

52、Hou Yunpeng,Li Weili,Zhou Feng et al.Calculations of 3d temperature field in stator for large hydro generator based on 3d isoparametric element method[J].Large Electric Machine,2000,(6):14-19. ─── [4]侯云鹏,李伟力,周封,等.大型水轮发电机定子三维温度场的等参元计算[J].大电机技术,2000,(6):14-19.

53、Turkey plans to harness the waters of the Tigris and Euphrates rivers for big hydro-electric power projects. ─── 土耳其计划利用底格里斯河与幼发拉底河的水来建造大型水力发电工程。

54、A better approach is to use small scale hydro plant. ─── 一个更好的方法是使用小规模的水力发电厂。

55、Its hydraulic station provides pressure oil to the hydro cylinder, which drives the cylinder rod to push the platen move to compact Baiye. ─── 利用液压站给百叶液压机油缸供压力油，通过油缸活塞杆推动压盘移动，实现压制百叶的目的。

56、Last year, Norsk Hydro hired General Electric (GE), an American industrial giant, to build a prototype. ─── 去年，挪威水电集团聘请美国工业巨头之一的通用电气公司（GE）建造这样一个模型。

57、Prior to hydro test, check torque values again and bring them up to the torque value shown in the Bolting Specification table. ─── 在进行水压测试之前，要再次检查扭矩值，确保扭矩达到螺栓规格表上显示的扭矩值。

58、China is building a large hydro power station on the upper reaches of Yarlung Zango (Brahamputra) river and a barrage on Sutlej, which was first reported by the Hindustan Times in June last year. ─── 中国正在雅鲁藏布江（布拉马普特拉河）上游建造一座大型水电站，同时还在萨特累季河建造一座大坝，这一消息于去年六月时被《印度斯坦时报》首次披露。

59、He declined to be named because his company has been involved in several CDM hydro projects with local governments in China. ─── 他不愿意透露姓名，因为他所在的公司与中国的当地政府参与了好几个CDM水电项目。

60、Perform workshop inspection of equipments/components related to hydro power field, such as rotor, generator, distributor, guided valve, inlet valve, draft tube, embedded parts, etc. ─── 实施水电设备与零部件相关的驻厂检验，例如水轮机，发电机，活动导叶，倒水机构，进水阀门，尾水管，预埋件等等。

61、Small hydro power (SHP) is an adequate, affordable and environmental-sound energy. ─── 小水电是一种丰富、廉价和清洁的优质能源。

62、To gain optimization parameters of hydro turbine PID governor, this paper interprets the approach of optimization designing that uses the Particle Swarm Optimization (PSO) algorithm. ─── 为了保证获得最优水轮机PID调节器参数，本文研究了利用微粒群优化(PSO)算法进行参数优化设计的新方法。

63、Claude Burckbuchler,58, has held numerous positions within Alstom, including Managing Director of the Hydro Power business and Country President China (1996-1998). ─── 布尔布勒·克鲁德现年58岁,曾在阿尔斯通担任多个职务,包括水力发电业务部董事总经理和中国区总裁(1996-1998年)。

64、Though hydroelectric power generation uses no fuel, the initial cost to build a hydro power station is significantly higher than the initial cost of an equivalent capacity base-load or peaking type thermal power plant. ─── 尽管水力发电不需燃料,但建造水电站的费用要比建等容量基荷或填峰型火电厂的费用高得多。

65、assets owned by Hydro Tasmania have been used as a case study to develop a predictive model of costs associated with higher physical impact. ─── 资产藉着浴疗院塔斯梅尼亚拥有了已经被用当发展与较高的身体检查冲击有关的一个费用的预言性模型的一件个案研究。

66、Until Norsk Hydro's expression of interest, the only offer on the table was a management-led buyout that would have left senior debt holders recovering around 20 cents on the dollar. ─── 在海德鲁表现出兴趣前，唯一的要约就是管理层收购方向优先债券持有人提出的相当于票面价值20%的报价。

67、Georgia Tech Decision Support System (GTDSS) for reservoir management and hydro power generation is the state of the art technology for water resource management. ─── “乔治亚理工水电站水库调度与发电决策支持软件系统(GTDSS)”是一个将河流中长期径流预报技术与水库群优化调度、水资源管理集于一体的系统。

68、The premium lubricant base oil can be produced with unconverted oil from hydro cracking and/or hydrotreated solvent dewaxing oil by catalytic dewaxing. ─── 加氢裂化未转化油和／或加氢精制过的溶剂脱蜡油经催化脱蜡工艺生产高质量润滑油基础油。

69、Immigration from the Danjiangkou area for the construction of the hydro project involves people from both Hubei and Henan's Xichuan. ─── 丹江口库区移民分属湖北、河南两省，其中河南库区移民全部集中在淅川县，涉及人口16万。

70、Viewed from the constructed hydro stations in China, few examples of stress-removal of penstock and then stress testing can be gained. ─── 从国内已建成的水电站来看，对压力钢管进行消应处理并进行应力测试的例子很少，对消应后的效果说明亦缺乏资料。

71、Support for Norsk Hydro from senior debt holders -- so far silent -- isn't to be taken for granted, given that they have less to lose than the PIK note holders. ─── 优先债券持有人目前还保持沉默，鉴于他们的损失要少于实物支付债券所有者，因此不能想当然地认为他们一定会支持海德鲁。

72、There is no internationally accepted definition for "small hydro. ─── 关于“小水电”目前没有国际认可的界定。

73、The development of research on internal short circuit of generator is reviewed.New approach for research on internal faults of large turbogenerator and hydro generator is expounded. ─── 回顾了发电机内部短路研究的发展状况，阐述了大型汽轮和水轮发电机内部故障研究的最新进展和新问题。

74、This paper discusses several translations methods about hydro scientific thesis titles from English to Chinese,such as direct/free translations,adapted translation,direct plus free translation etc. ─── 叙述了水电科技论文标题英译汉的几种方法，如直译、意译、改译、直译加意译等。

75、Main Ingredients: SPA hydro essence, plant placental element, vitamin group, natural moisturizing complex, active amino acid, allantoin and essence with special flavor, etc. ─── 主要成份:SPA水疗精华、植物护发因子、维他命群、天然保湿复合物、活性氨基酸、SPA水疗因子和特殊香精等。

76、And the idea of liberating hydro from geography with small, free-standing turbines may have local applications, but maintaining such turbines is far more trouble than taking a spanner to a windmill. ─── 利用小型、自立式涡轮机水力发电，可以就地使用，但维护这些水轮机要比用扳手修理风车麻烦的多。

77、The primary train includes two gypsum bleeding pumps (one operating and one spare), discharge line to the hydro cyclone, recycling pipeline to the absorber vessel as well as hydro cyclone battery. ─── 一级脱水系统包括两台石膏排放泵（一台运行和一台备用），到水力旋流站的排放管线，到吸收塔和水力旋流站组的再循环管。

78、For the hydro optimization the best method is the stochastic dynamic programming. ─── 对于水电系统随机动态规划是最好的优化方法.

79、It is distributed alon g the Pangxidong -Jinshan fault system,and composed mainly of hydro thermally altered deformed rocks an d quartz veins. ─── 地质地球化学研究结果表明,该矿床是中低温蚀变构造岩型银金矿床。

80、After analysis of the structure and work principle of hydro cylinder drived weight hammer impactor, a mathematical model was set up. ─── 分析了液压缸驱动重锤式碎石机冲击器的结构及其工作原理，建立了该液压冲击器的数学模型。

81、BOAT, CAT, DEEPVEE, ECO, ECOTEAM, ELECTRIC, F1E1KG, FSRH, FSRO, FSROX, FSRV, HYDRO, MARINE, MODEL, MONO, NITRO, OUTRIGGER, R/... ─── 2003"发现之旅杯"全国航海模型锦标赛地点：褔建厦门日期：2003年11月1日至2003年11月5日项目：开幕表演赛员：南京郑和外语学...

82、A company/institution qualified for both power generation (thermal or hydro) and power transmission engineering design may apply for the qualification for power industry-wide engineering design. ─── 同时具备发电专业（火力发电或水力发电）及送电专业工程设计资质，即可申请电力全行业工程设计资质。

83、It called for more hydro power in Sichuan and said electricity was being diverted from other regions to supply the southwestern province. ─── 宝石即使落在泥潭里，仍是一样可贵液压升降机；尘土纵然扬到天上心理咨询，还是没有价值。（贾比尔）

84、For prototype test and vibration source analysis on abnormal vibration of3# hydro generating set at Tianshengqiao first cascaded power station, it is useful to find out the vibration source by finite element computation for upper bracket. ─── 对天生桥一级电厂3#组上机架异常振动进行了真机实测及原因分析,得到的结果是:振动过大的主要原因是发电机转子质量不平衡,次要原因是机组轴线不直。

85、"Chinese hydro dams will be affected as well . . . several projects are being requested for review for exactly the same reasons, " he said. ─── 他说：“中国的水电项目也会受影响……有些项目被要求接受审核的理由完全相同。”

86、Prior to hydro test, check torque values again and bring them up to the torque value shown in the Bolting Specification table. ─── 在进行水压测试之前，要再次检查扭矩值，确保扭矩达到螺栓规格表上显示的扭矩值。

87、Three major renewable sources are: wind, solar, and hydro. ─── 三大主要的可再生能源是：风能，太阳能以及水能。

88、For civil engineering in Canada, he says, hydro engineering and municipal engineering would be just two of the many knowledge requirements. ─── 他说，对加拿大的土木工程来说，水利工程和工民建只是众多的教育要求中的两项。

89、For the low head hydro power station,the diameter of turbine will be relatively large, and the rated speed will be very low as well if the rated net head is lower than 10m. ─── 在低水头电站中 ,设计水头在 10m以下时 ,水轮机的转轮直径相对较大 ,而机组的转速相对很低。

纯氢气会燃烧吗？

纯氢气在有氧状态下能燃烧。

1、常温常压下，氢气是一种极易燃烧，无色透明、无臭无味且难溶于水的气体。氢气是世界上已知的密度最小的气体，氢气的密度只有空气的1/14，即在0 ℃时，一个标准大气压下，氢气的密度为0.089g/L。所以氢气可作为飞艇、氢气球的填充气体（由于氢气具有可燃性，安全性不高，飞艇现多用氦气填充）。氢气是相对分子质量最小的物质，主要用作还原剂。

2、氢气 (H2) 最早于16世纪初被人工制备，当时使用的方法是将金属置于强酸中。1766–1781年，亨利·卡文迪许发现氢元素，氢气燃烧生成水(2H2+O2点燃=2H2O)，拉瓦锡根据这一性质将该元素命名为 “hydrogenium”（“生成水的物质”之意，"hydro"是“水”，"gen"是“生成”，"ium"是元素通用后缀）。19 世纪50 年代英国医生合信(B.Hobson）编写《博物新编》(1855 年）时，把"hydrogen"翻译为“轻气”，意为最轻气体。

3、工业上一般从天然气或水煤气制氢气，而不采用高耗能的电解水的方法。制得的氢气大量用于石化行业的裂化反应和生产氨气。氢气分子可以进入许多金属的晶格中，造成“氢脆”现象，使得氢气的存储罐和管道需要使用特殊材料（如蒙耐尔合金），设计也更加复杂。