bypass

A bypass is a road or highway that avoids or "bypasses" a built-up area, town, or village, to let through traffic flow without interference from local traffic, to reduce congestion in the built-up area, and to improve road safety. A bypass specifically designated for trucks may be called a truck route. If there are no strong land use controls, buildings are often built in town along a bypass, converting it into an ordinary town road, and the bypass may eventually become as congested as the local streets it was intended to avoid. Petrol stations, shopping centres and some other businesses are often built there for ease of access, while homes are often avoided for noise and pollution reasons.

A flood bypass is a region of land or a large man-made structure that is designed to convey excess flood waters from a river or stream in order to reduce the risk of flooding on the natural river or stream near a key point of interest, such as a city. Flood bypasses, sometimes called floodways, often have man-made diversion works, such as diversion weirs [堰] and spillways, at their head or point of origin. The main body of a flood bypass is often a natural flood plain. Many flood bypasses are designed to carry enough water such that combined flows down the original river or stream and flood bypass will not exceed the expected maximum flood flow of the river or stream.

Bypass surgery refers to a class of surgeries involving rerouting a tubular body part. Vascular bypass surgery such as coronary artery [冠状动脉] bypass surgery is a heart operation. Cardiopulmonary bypass is a technique used in coronary artery bypass surgery. 体外循环是一种用于冠状动脉搭桥手术的技术。

cardio-: relating to the heart. pulmonary: relating to the lungs.

Cardiopulmonary bypass (CPB) is a technique in which a machine temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the patient's body. The CPB pump itself is often referred to as a heart–lung machine or "the pump". Cardiopulmonary bypass pumps are operated by perfusionists. CPB is a form of extracorporeal circulation. Extracorporeal membrane oxygenation is generally used for longer-term treatment. corporeal: 身体的。

CPB mechanically circulates and oxygenates blood for the body while bypassing the heart and lungs. It uses a heart–lung machine to maintain perfusion to other body organs and tissues while the surgeon works in a bloodless surgical field. The surgeon places a cannula in the right atrium, vena cava, or femoral vein to withdraw blood from the body. Venous blood is removed from the body by the cannula and then filtered, cooled or warmed, and oxygenated before it is returned to the body by a mechanical pump. The cannula used to return oxygenated blood is usually inserted in the ascending aorta, but it may be inserted in the femoral artery, axillary artery, or brachiocephalic artery (among others).

体外循环在绕过心脏和肺的同时，为身体进行机械循环和充氧。它使用心肺机来维持对其他身体器官和组织的灌注，而外科医生在一个不流血的外科领域工作。外科医生在右心房、腔静脉或股静脉中放置一个套管，以从体内抽取血液。静脉血通过套管从体内取出，然后过滤、冷却或加热，并在通过机械泵返回体内之前进行充氧。用于回流含氧血液的套管通常插入升主动脉，但也可以插入股动脉、腋动脉或头臂动脉（等等）。

In telecommunications, the term bypass has these meanings:
The use of any telecommunications facilities or services that circumvents those of the local exchange common carrier.
An alternate circuit that is routed around equipment or a system component.

In the United States, wireline telephone companies are divided into two large categories: long-distance (interexchange carrier, or IXCs) and local (local exchange carrier, or LECs). This structure is a result of 1984 divestiture of then-regulated monopoly carrier American Telephone & Telegraph (AT&T). Local telephone companies at the time of the divestiture are also known as Incumbent Local Exchange Carriers (ILEC).

Bleach bypass, also known as skip bleach or silver retention, is a chemical effect which entails either the partial or complete skipping of the bleaching function during the processing of a color film. By doing this, the silver is retained in the emulsion along with the color dyes. The result is a black-and-white image over a color image. The images usually have reduced saturation and exposure latitude, along with increased contrast and graininess. It usually is used to maximum effect in conjunction with a one-stop underexposure.

六级/考研单词: bypass, interfere, designate, lorry, seldom, convert, gasoline, ease, pollute, convey, excess, divert, artery, lung, oxygen, pump, circulate, tissue, vessel, filter, insert, ascend, telecommunications, carrier, alternate, equip, component, unite, monopoly, incumbent, bleach, skip, silver, entail, dye, saturate, latitude, conjunction