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Access control is often a system enabling authorities to control use of areas and resources inside a given physical facility or computer-based information system. Access control is, actually, a typical, everyday phenomenon. For example, a lock on the car door is essentially a kind of access control. The PIN over a bank's ATM method is another way of access control. Even nightclub bouncers, standing in front of your door, are another illustration of (perhaps) a much more primitive mode of access control. Using an access control mechanism is essential when persons seek to secure confidential, important, or sensitive information and equipment.
Note that the epoxy adhesive curing speed varies depending on temperature. At higher temperatures it dries faster, but has less resistance and firmness. During the winter you might also leave a few minutes in double boiler pots, and try to take certain temperature (never to be more than 30 degrees at all), like too cold, the information becomes more complicated, thus a viscous mix.
Space probe according to the detection of object is divided into lunar probe, probe and interplanetary spacecraft, small body such as a space probe to leave the speed of the earth must be large enough to overcome or get rid of the earth's gravity, realize the deep space flight. The probe orbits the heliocentric elliptical orbit (double-cut orbit) that is tangent to the earth's orbit and the planet's orbit, and may meet the target planet; Increase speed to change the orbit, flew to target the planet can shorten the time in order to ensure the detector fly the double track to the planetary orbits and tangent with the target when the target planets also run to it, must be chosen in the earth and the target planet at a particular moment of relative position detector. Detector can fly around the star, the use of planetary gravitational fields accelerate continuous multiple planets orbit the significant characteristic of space probe is, flying in space for long time, the ground cannot real-time remote control, so must have the ability of autonomous navigation; To fly outside the solar system, away from the sun, solar arrays, and nuclear energy systems; It is necessary to adopt special protective structure to withstand very severe space environment. Landing or walking on the surface of the moon or planet requires some special form of structure
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