¿óÎï²ÄÁÏÏÖ´ú²âÊÔ¼¼Êõ ½²Òå - ͼÎÄ ÏÂÔر¾ÎÄ

ͼ4£­20 (3) È¥µô±³¾°

ͼ4£­20 (4) ±ê×¢·åλ

ͼ4£­20 (5) ͼÆױȽÏ

41

4 ÑÜÉäÊý¾ÝµÄ»ñµÃ ÑÜÉäÊý¾Ý: ÃæÍø¼ä¾à(d)£¬ÑÜÉäÇ¿¶È(I)

µ«ÓÉÓÚÎÞ·¨ÕæÕý»ñµÃ¾ø¶ÔµÄÑÜÉäÇ¿¶ÈÊý¾Ý£¬ÒòΪ²»Í¬µÄ¾§Ìå³ß´ç¡¢²»Í¬µÄ¹âÔ´ÌØÕ÷¡¢²»Í¬µÄÒÇÆ÷ÖÖÀ࣬Ëù»ñµÃµÄʵ²âÑÜÉäÇ¿¶ÈÊÇÍêÈ«²»¿É±È½ÏµÄ£¬Òò´ËÔڼǼÑÜÉäÇ¿¶ÈµÄʱºò£¬°´Ïà¶ÔÇ¿¶È¼Ç¼£¨I/Io)¡£ ÕÕÏà·½·¨£ºµÃµ½Ò»Õŵ°Ýͼ£¬²¢´ÓµÂ°Ýͼ¿ÉÒÔ»ñµÃÈçÏÂÊý¾Ý£º £¨1£© d°´¼ÆËã»ñµÃ£¨²¼À­¸ñ·½³Ìʽ£©

£¨2£© I/IoÓÃÄ¿²âµÄ·½·¨¹À¼ÆµÃµ½ÒÔÏÂÖµ£¨±í4£­2£©

±í4£­2 I/IoÓÃÄ¿²âµÄ·½·¨¹À¼Æ

ÑÜÉäÒÇ·½·¨£ºµÃµ½Ò»ÕÅÑÜÉäͼÆ×ͼ£¨Í¼4£­21£©£¬²¢¾­¹ý´¦ÀíÒÔºóͬʱµÃµ½Ò»ÕÅÊý¾Ý±í£¨±í4£­3£©¡£

ͼ4£­21 ÑÜÉäͼÆ×ͼ

±í4£­3 ÑÜÉäÊý¾Ý±í

42

4 ÑÜÉäÏßÌõµÄÖ¸±ê»¯ Ö¸±ê»¯·½·¨£º

µÈÖᾧϵ¡¢Öм¶¾§×壨ËÄ·½¡¢Ð±·½¡¢Áù·½£©Ò»°ã¿ÉÒÔ¾­¹ý¼ÆËãµÄ·½·¨£¬¸ù¾Ý·ÛÄ©ÑÜÉäµÄÊý¾Ý¿ÉÒÔÇó³ö¸÷ÑÜÉäÏßµÄÖ¸Êý£»

µÍ¼¶¾§×壨µ¥Ð±¡¢Èýб£©ÔòÒ»°ãÎÞ·¨¼ÆËã³ö£¬±ØÐë´Óµ¥¾§½á¹¹·ÖÎöµÃ³ö¡£ ÏÂÃæ¾ÙÀý˵Ã÷ º¬Ò壺Çó³ö¸÷ÑÜÉäÏßÌõµÄÑÜÉäÖ¸Êý Ó¦Óãº1£©Ó÷ÛÄ©ÑÜÉä·¨¼ÆË㾧°û²ÎÊý

2£©¼ø¶¨ÑÜÉäÏßÌõÖÐÓÐÎÞÔÓÏߣ¬¼´È·¶¨ÊÇ·ñº¬ÔÓÖÊ 3£©È·¶¨Ò»Ð©ÓëÎïÖʽṹÓйصÄÐÅÏ¢

ÀýÈ磺µÈÖᾧϵ£¬¸ù¾ÝÃæÍø¼ä¾àµÄ¼ÆË㹫ʽ£º

ÓÐ (h2+k2+l2)= a2/d2

µÈÖᾧϵ£¬µ±¾§°û´óСÒÑ֪ʱ£ºÀýÈç a =6.2921?£¬¼ÆËãµÃ±í4£­4

±í4£­4 µÈÖᾧϵ£¬µ±¾§°û´óСÒÑ֪ʱ£¬¼ÆËãÃæÍø¼ä¾à

µÈÖᾧϵ£¬µ±¾§°û´óСδ֪ʱ£ºÓó¢ÊÔ·¨£¨±í4£­5£©

±í4£­5µÈÖᾧϵ£¬µ±¾§°û´óСδ֪ʱÓó¢ÊÔ·¨¼ÆËãÃæÍø¼ä¾à

43

ÆäËû¾§Ïµ£¬ÓÉÓÚδ֪µÄ²ÎÊýÔö¶à£¬ÔÚ¾§°û²ÎÊýÒÑÖªµÄÇé¿öÏÂÉпɽøÐÐÖ¸±ê»¯£¬ÔÚÍêȫδ֪µÄÇé¿öÏ£¬¶ÔÓڱȽϸ߶ԳÆÐԵģ¬»¹¿ÉÒÔ¼ÆËã³öÖ¸±êÊýÖµ£¬¶ø¶ÔÓڶԳƵ͵ÄÔò»ù±¾ÎÞ·¨¼ÆËã¡£ ÑÜÉäÖ¸ÊýµÄÓ¦Ó᪡ªÈ·¶¨¿Õ¼ä¸ñ×ÓÀàÐÍ (µÈÖáΪÀý) ¸ù¾Ý²»Í¬¸ñ×ÓÀàÐ͵ÄÏû¹â¹æÂÉ£¨±í4£­6£©£º

±í4£­6 ²»Í¬¸ñ×ÓÀàÐ͵ÄÏû¹â¹æÂÉ ´æÔÚµÄhklÑÜÉä ÎÞÑÜÉäЧӦµÄhkl ԭʼ¸ñ×ÓP È«²¿ ÎÞ ÌåÐĸñ×ÓI h+k+l=żÊý h+k+l=ÆæÊý ÃæÐĸñ×ÓF h,k,lÈ«Ææ»òȫż h,k,lÆ桢ż»ìÔÓ £¨h2+k2+l2) = Á¢·½Ô­Ê¼£º1, 2, 3, 4, 5, 6, 8, 9¡­ (ȱ7,15,23µÈ) Á¢·½ÌåÐÄ£º2, 4, 6, 8, 10, 12, 14, 16, 18¡­ Á¢·½ÃæÐÄ£º3, 4, 8, 11, 12, 16, 19, 29¡­

F P

44