水肺英文

divediving

Scuba diving ("SCUBA" originally being an acronym for self contained underwater breathing apparatus, now widely considered a word in its own right) is a form of underwater diving in which a diver uses a scuba set to breathe underwater.Unlike early diving, which relied exclusively on air pumped from the surface, scuba divers carry their own source of breathing gas (usually compressed air), allowing them greater freedom than with an air line. Both surface supplied and scuba diving allow divers to stay underwater significantly longer than with breath-holding techniques as used in snorkelling and free-diving.According to the purpose of the dive, a diver usually moves underwater by swimfins attached to the feet, but external propulsion can come from an underwater vehicle, or a sled pulled from the surface.Early diving experimenters quickly discovered it is not enough simply to supply air to breathe comfortably underwater. As one descends, in addition to the normal atmospheric pressure, water exerts increasing pressure on the chest and lungs—approximately 1 bar (14.7 pounds per square inch) for every 33 feet (10 m) of depth—so the pressure of the inhaled breath must almost exactly counter the surrounding or ambient pressure to inflate the lungs. It generally becomes difficult to breathe through a tube past three feet under the water.[3]By always providing the breathing gas at ambient pressure, modern demand valve regulators ensure the diver can inhale and exhale naturally and virtually effortlessly, regardless of depth.Because the diver's nose and eyes are covered by a diving mask; the diver cannot breathe in through the nose, except when wearing a full face diving mask. However, inhaling from a regulator's mouthpiece becomes second nature very quickly.

Scuba diving ("SCUBA" originally being an acronym for self contained underwater breathing apparatus, now widely considered a word in its own right)[1] is a form of underwater diving in which a diver uses a scuba set to breathe underwater.[2]Unlike early diving, which relied exclusively on air pumped from the surface, scuba divers carry their own source of breathing gas (usually compressed air),[3] allowing them greater freedom than with an air line. Both surface supplied and scuba diving allow divers to stay underwater significantly longer than with breath-holding techniques as used in snorkelling and free-diving.According to the purpose of the dive, a diver usually moves underwater by swimfins attached to the feet, but external propulsion can come from an underwater vehicle, or a sled pulled from the surface.HISTORYThe first commercially successful scuba sets were the Aqualung open-circuit units developed by Emile Gagnan and Jacques-Yves Cousteau, in which compressed gas (usually air) is inhaled from a tank and then exhaled into the water adjacent to the tank. However, the scuba regulators of today, trace their origins to Australia, where Ted Eldred developed the first mouth piece regulator known as the Porpoise. This regulator was developed because patents protected the Aqua Lung's double hose design. It separated the cylinder from the demand valve giving the diver air at the same pressure surrounding his mouth, not surrounding the tank.The open circuit systems were developed after Cousteau had a number of incidents of oxygen toxicity using a rebreather system, in which exhaled air is reprocessed to remove carbon dioxide. Modern versions of rebreather systems (both semi-closed circuit and closed circuit) are still available today, and form the second main type of scuba unit, most commonly used for technical diving, such as deep diving.ETYMOLOGYThe term "SCUBA" (an acronym for self-contained underwater breathing apparatus) arose during World War II, and originally referred to United States combat frogmen's oxygen rebreathers, developed by Dr. Christian Lambertsen for underwater warfare.[3][4][5]The word "SCUBA" began as an acronym, but it is now usually thought of as a regular word—"scuba". It has become acceptable to refer to "scuba equipment" or "scuba apparatus"—examples of the linguistic RAS syndrome.TPYES OF DIVINGScuba diving may be performed for a number of reasons, both personal and professional. Most people begin through recreational diving, which is performed purely for enjoyment and has a number of distinct technical disciplines to increase interest underwater, such as cave diving, wreck diving, ice diving and deep diving.Divers may be employed professionally to perform tasks underwater. Most of these commercial divers are employed to perform tasks related to the running of a business involving deep water, including civil engineering tasks such as in oil exploration, underwater welding or offshore construction. Commercial divers may also be employed to perform tasks specifically related to marine activities, such as naval diving, including the repair and inspection of boats and ships, salvage of wrecks or underwater fishing, like spear fishing.Other specialist areas of diving include military diving, with a long history of military frogmen in various roles. They can perform roles including direct combat, infiltration behind enemy lines, placing mines or using a manned torpedo, bomb disposal or engineering operations. In civilian operations, many police forces operate police diving teams to perform search and recovery or search and rescue operations and to assist with the detection of crime which may involve bodies of water. In some cases diver rescue teams may also be part of a fire department or lifeguard unit.Lastly, there are professional divers involved with the water itself, such as underwater photography or underwater filming divers, who set out to document the underwater world, or scientific diving, including marine biology and underwater archaeology.BREATHING UNDER WATERWater normally contains the dissolved oxygen from which fish and other aquatic animals extract all their required oxygen as the water flows past their gills. Humans lack gills and do not otherwise have the capacity to breathe underwater unaided by external devices.[3] Although the feasibility of filling and artificially ventilating the lungs with a dedicated liquid (Liquid breathing) has been established for some time,[6] the size and complexity of the equipment allows only for medical applications with current technology.[7]Early diving experimenters quickly discovered it is not enough simply to supply air to breathe comfortably underwater. As one descends, in addition to the normal atmospheric pressure, water exerts increasing pressure on the chest and lungs—approximately 1 bar (14.7 pounds per square inch) for every 33 feet (10 m) of depth—so the pressure of the inhaled breath must almost exactly counter the surrounding or ambient pressure to inflate the lungs. It generally becomes difficult to breathe through a tube past three feet under the water.[3]By always providing the breathing gas at ambient pressure, modern demand valve regulators ensure the diver can inhale and exhale naturally and virtually effortlessly, regardless of depth.Because the diver's nose and eyes are covered by a diving mask; the diver cannot breathe in through the nose, except when wearing a full face diving mask. However, inhaling from a regulator's mouthpiece becomes second nature very quickly.

水肺，又叫自携式水下呼吸装置，人们潜入水中，可凭借它来自由呼吸。 19世纪30年代，由于潜水面罩的问世，人类跨出了征服水底世界的一大步。但是靠潜水面罩，人们只能潜入10米深的海水中且停留极短暂的时间，这是因为海水深度在10米左右时，水压与大气压（1.03Kg/M2）几乎相等。但每增加10米，水压就增1个大气压力。如果所呼吸的空气压力高于一般的气压，则人体血液和组织中的氮会高度浓缩；如果压力急速减低，人体器官和血管中的氮会产生毒性作用，致潜水者于死地。（图）（使用水下呼吸器的潜水员） 第二次世界大战期间，法国海军军官杰克·艾佛·古斯塔因研制水肺取得了成功而一举成史。古斯塔曾经是海军勤务官，试用过所有的潜水设备，包括手提式压缩空气瓶，都不能保证吸到压力合适的空气。经过潜心研究，他终于发明了一套送气系统，使潜水员在海底能够呼吸到与地面空气相同压力的空气。以后，古斯塔又与控制阀工程师加南合作研究。1943年加南发明呼吸器，利用煤气炉调节阀改装成呼吸器械控制阀，按需要可自动供给适当压力的空气。这样，潜水员本身的呼吸就可以靠调节空气供应量和时入肺部时气压的高低来控制，这套器械简单小巧，潜水员带上它，再穿上内有高压空气的背心就可潜至50—60米深的水中。人们凭借水肺呼吸，自由潜入水中，为人类探测水底世界又扩展了一片海域。 （图）（潜水员使用水下呼吸器的情形） 水肺经过不断改进，日臻完善。在美国的佛罗里达州，以色列、澳大利亚外海的大堡礁及英国的伦第岛和波拜克半岛等海岸，都设有使用这种呼吸装置的 “海底公园”，在那里，旅游者可尽情游览海底世界的美景。 利用这种呼吸装置，潜水员可对古代沉船进行定位，测量及打捞等工作，为海洋考古学开创了新领域。大多数水肺允许潜水员潜水2小时，因此潜水员使用它可在水下自由往来，如维修海上石油钻井平台、监察海港建筑工程、警察执行搜索任务等工作。如果长时间在海底工作，如维修海底设