20-02-2007, 01:54
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חבר מתאריך: 31.12.05
הודעות: 3,216
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Laser זה ראשי-תיבות של light amplification by the stimulated emission of radiation.
השם עצמו מספק רמז לגבי סכנות אפשריות (למשל, לעין). אני לא יודע מהו הסיווג (Class) הספציפי של העכבר, אבל גם אם הוא נחשב כ-"eye-safe", אני בוודאי לא הייתי נותן לפעוט בן שנתיים לצפות בלייזר שלו יותר מדי. עם זאת, נהוג לראות את Class I כבטוח מאוד.
מתוך http://en.wikipedia.org/wiki/Laser:
Laser safety
Main articles: Laser safety and Lasers and aviation safety
Even the first laser was recognized as being potentially dangerous. Theodore Maiman characterized the first laser as one Gillette; as it could burn through one Gillette razor blade. Today, it is accepted that even low-power lasers with only a few milliwatts of output power can be hazardous to a person's eyesight.
At wavelengths which the cornea and the lens can focus well, the coherence and low divergence of laser light means that it can be focused by the eye into an extremely small spot on the retina, resulting in localized burning and permanent damage in seconds or even less time. Lasers are classified into safety classes numbered I (inherently safe) to IV (even scattered light can cause eye and/or skin damage). Laser products available for consumers, such as CD players and laser pointers are usually in class I, II, or III. Certain infrared lasers with wavelengths beyond about 1.4 micrometres are often referred to as being "eye-safe". This is because the intrinsic molecular vibrations of water molecules very strongly absorb light in this part of the spectrum, and thus a laser beam at these wavelengths is attenuated so completely as it passes through the eye's cornea that no light remains to be focused by the lens onto the retina. The label "eye-safe" can be misleading, however, as it only applies to relatively low power continuous wave beams and any high power or q-switched laser at these long wavelengths will burn the cornea, causing severe eye damage.
This effect is used in a surgical treatment for detached retina: the resulting pinpoint damage heals with scarring, which "spot-welds the retina onto its backing to try to stop more detachment. |
ראשי
צ'אט
), לצד מערכת ההפעלה XP. (כמובן על כונן אחר). מתברר לי, שכשהמחשב עולה וניתנת לי אפשרות הבחירה בין שתי המערכות, אינני יכול לזוז עם החיצים ולכן אני לא יכול לבחור מבין השתיים. אציין שהמקלדת החדשה היא בחיבור USB ואני כן יכול לעשות את הבחירה במקלדת עם חיבור PS2.. כמו"כ, אני יכול להיכנס לBIOS עם המקלדת החדשה.
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