曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
safety glass is tempered glass that breaks into small grains, rather than into sharp pieces.
safety valve (pressure system component). A pressure relief valve used on containers holding a
compressible fluid under pressure. If the pressure inside the container becomes excessive, the safety valve
will pop off its seat and relieve the excess pressure.
safety wire. Soft wire used to secure fasteners (bolts, pins, and clips) so they will not vibrate loose in
operation. Safety wire (also called lockwire) is made of galvanized low-carbon steel, annealed stainless
steel, or brass.
sailplane (aircraft type). A high-performance glider. Sailplanes normally have a high-aspect-ratio wing,
are lightweight, and very strong. Sailplanes glide so well that they ride upward on rising air currents. They
can stay airborne for hours and can travel long distances.
Saint Elmo’s fire (meteorology). A discharge of static electricity often seen on airplanes flying through
stormy weather. Static electricity from the clouds collects on the airplane structure and discharges from
sharp points in the form of visible light.
sal ammoniac. A name commonly used for ammonium chloride. Ammonium chloride is one of the
components of the moist-paste electrolyte used in carbon-zinc flashlight batteries.
salient pole (electrical machine). A field pole of an electrical generator or motor that has its own pole
shoe protruding radially inward from the field frame. A field coil is wound around this pole shoe. Salient
poles are often used instead of distributed poles which do not have separate pole shoes.
Printed from Summit Aviation's Computerized Aviation Reference Library, 2/7/2007
Page 501
salt. A product of a chemical reaction in which a metal displaces the hydrogen in an acid. If sulfuric acid
(H2SO4) reacts with sodium hydroxide (NaOH), sodium sulfate (Na2SO4) and water (H2O) are produced.
Sodium sulfate is a salt. The food seasoning called “salt” is sodium chloride (NaCl).
samarium. A pale gray, rare-earth, metallic chemical element. Samarium’s symbol is Sm, its atomic
number is 62, and its atomic weight is 150.35. Samarium is used in laser technology and as an ingredient in
infrared-absorbing glass.
sandbag (sheet-metal-working tool). A heavy canvas or leather bag filled with sand. A sandbag is used to
shape sheet metal parts by forming a depression in the sand and hammering the metal into it with a
soft-face mallet.
sand casting (metal forming). A method of casting metal parts in a mold made of sand. A pattern that
duplicates the part to be molded is made of wood and is covered with a special casting sand that contains a
resin to bind it together.
The mold is separated along a special parting line, and the pattern is removed. The mold is put
back together, and the cavity is poured full of molten metal. When the metal cools, the sand is broken away
from the molded part. Sand casting is less expensive than permanent-mold casting.
sanding coat (finishing system). A coat of heavy-bodied surfacer material sprayed over a surface to be
painted. After the sanding coat has thoroughly dried, it is sanded to give a smooth surface over which the
subsequent coats of finishing material are applied.
sandpaper. An abrasive paper made by bonding grains of sharp sand to the surface of a piece of paper.
Sandpaper is used for abrading (wearing away) rough surfaces or unwanted material.
sandwich construction. A type of laminated structure used where high strength, light weight, and rigidity
are required. One commonly used type of sandwich construction is made of a fiberglass or metal
honeycomb core bonded between two sheets of resin-impregnated fiberglass or metal.
Santa Ana (meteorology). A hot, dry, foehn wind, generally from the northeast or east, occurring west of
the Sierra Nevada Mountains, especially in the pass and river valley near Santa Ana, California.
satellite. An object that rotates in an orbit around a larger object. Today, man-made satellites rotate in
orbits around the earth for the purposes of observation and communication.
satin-weave fabric. Fabric in which the warp threads pass under one fill thread and over several more.
Satin-weave fabrics are used when the lay-up must be made over complex shapes.
Printed from Summit Aviation's Computerized Aviation Reference Library, 2/7/2007
Page 502
saturable reactor (electrical component). A type of electrical transformer whose core permeability is
varied to control the current flowing in its secondary winding. A control winding carrying direct current is
wound over the transformer core. When no current flows through the control winding, the permeability of
the core is high, and the transformer has enough inductive reactance to decrease the secondary current.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
航空术语词典Dictionary of Aeronautical Terms 下(34)
