{"id":47524,"date":"2023-04-22T00:14:32","date_gmt":"2023-04-22T05:14:32","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/how-to-make-ultrasound-waves\/"},"modified":"2025-01-21T07:20:42","modified_gmt":"2025-01-21T12:20:42","slug":"how-to-make-ultrasound-waves","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/vi\/how-to-make-ultrasound-waves\/","title":{"rendered":"T\u1ea1o s\u00f3ng si\u00eau \u00e2m: Nguy\u00ean l\u00fd v\u00e0 \u1ee9ng d\u1ee5ng"},"content":{"rendered":"<p>Si\u00eau \u00e2m l\u00e0 s\u00f3ng \u00e2m thanh c\u00f3 t\u1ea7n s\u1ed1 cao h\u01a1n ng\u01b0\u1ee1ng nghe c\u1ee7a con ng\u01b0\u1eddi, th\u01b0\u1eddng tr\u00ean 20kHz.  Ch\u00fang \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng r\u1ed9ng r\u00e3i trong nhi\u1ec1u l\u0129nh v\u1ef1c t\u1eeb y t\u1ebf, c\u00f4ng nghi\u1ec7p \u0111\u1ebfn nghi\u00ean c\u1ee9u khoa h\u1ecdc. V\u1eady si\u00eau \u00e2m \u0111\u01b0\u1ee3c t\u1ea1o ra nh\u01b0 th\u1ebf n\u00e0o? B\u00e0i vi\u1ebft n\u00e0y s\u1ebd \u0111i s\u00e2u v\u00e0o gi\u1ea3i th\u00edch nguy\u00ean l\u00fd v\u00e0 c\u00e1c ph\u01b0\u01a1ng ph\u00e1p t\u1ea1o ra s\u00f3ng si\u00eau \u00e2m.<\/p>\n<h3>Nguy\u00ean l\u00fd t\u1ea1o s\u00f3ng si\u00eau \u00e2m<\/h3>\n<p>S\u00f3ng si\u00eau \u00e2m, gi\u1ed1ng nh\u01b0 c\u00e1c lo\u1ea1i s\u00f3ng \u00e2m thanh kh\u00e1c, \u0111\u01b0\u1ee3c t\u1ea1o ra b\u1edfi s\u1ef1 dao \u0111\u1ed9ng c\u01a1 h\u1ecdc.  S\u1ef1 dao \u0111\u1ed9ng n\u00e0y t\u1ea1o ra c\u00e1c v\u00f9ng \u00e1p su\u1ea5t cao v\u00e0 \u00e1p su\u1ea5t th\u1ea5p lan truy\u1ec1n trong m\u00f4i tr\u01b0\u1eddng d\u01b0\u1edbi d\u1ea1ng s\u00f3ng. \u0110\u1ec3 t\u1ea1o ra s\u00f3ng si\u00eau \u00e2m, t\u1ea7n s\u1ed1 dao \u0111\u1ed9ng ph\u1ea3i \u0111\u1ee7 cao, v\u01b0\u1ee3t qu\u00e1 ng\u01b0\u1ee1ng nghe c\u1ee7a tai ng\u01b0\u1eddi.  C\u00e1c ph\u01b0\u01a1ng ph\u00e1p t\u1ea1o s\u00f3ng si\u00eau \u00e2m th\u01b0\u1eddng d\u1ef1a tr\u00ean hi\u1ec7u \u1ee9ng \u00e1p \u0111i\u1ec7n ho\u1eb7c hi\u1ec7u \u1ee9ng t\u1eeb gi\u1ea3o.<\/p>\n<h3>Hi\u1ec7u \u1ee9ng \u00e1p \u0111i\u1ec7n v\u00e0 \u1ee9ng d\u1ee5ng<\/h3>\n<p>Hi\u1ec7u \u1ee9ng \u00e1p \u0111i\u1ec7n l\u00e0 kh\u1ea3 n\u0103ng c\u1ee7a m\u1ed9t s\u1ed1 v\u1eadt li\u1ec7u (nh\u01b0 th\u1ea1ch anh, g\u1ed1m \u00e1p \u0111i\u1ec7n) t\u1ea1o ra \u0111i\u1ec7n \u00e1p khi ch\u1ecbu \u00e1p l\u1ef1c c\u01a1 h\u1ecdc v\u00e0 ng\u01b0\u1ee3c l\u1ea1i, bi\u1ebfn \u0111\u1ed5i \u0111i\u1ec7n \u00e1p th\u00e0nh dao \u0111\u1ed9ng c\u01a1 h\u1ecdc.  \u0110\u00e2y l\u00e0 nguy\u00ean l\u00fd ph\u1ed5 bi\u1ebfn nh\u1ea5t \u0111\u1ec3 t\u1ea1o ra s\u00f3ng si\u00eau \u00e2m. M\u1ed9t tinh th\u1ec3 \u00e1p \u0111i\u1ec7n \u0111\u01b0\u1ee3c \u0111\u1eb7t trong m\u1ed9t m\u1ea1ch \u0111i\u1ec7n dao \u0111\u1ed9ng, khi c\u00f3 d\u00f2ng \u0111i\u1ec7n xoay chi\u1ec1u ch\u1ea1y qua, tinh th\u1ec3 s\u1ebd dao \u0111\u1ed9ng v\u1edbi t\u1ea7n s\u1ed1 c\u1ee7a d\u00f2ng \u0111i\u1ec7n, t\u1ea1o ra s\u00f3ng si\u00eau \u00e2m.<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>V\u1eadt li\u1ec7u \u00e1p \u0111i\u1ec7n<\/th>\n<th>\u01afu \u0111i\u1ec3m<\/th>\n<th>Nh\u01b0\u1ee3c \u0111i\u1ec3m<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Th\u1ea1ch anh<\/td>\n<td>\u0110\u1ed9 \u1ed5n \u0111\u1ecbnh cao<\/td>\n<td>Hi\u1ec7u su\u1ea5t th\u1ea5p<\/td>\n<\/tr>\n<tr>\n<td>G\u1ed1m \u00e1p \u0111i\u1ec7n (PZT)<\/td>\n<td>Hi\u1ec7u su\u1ea5t cao<\/td>\n<td>\u0110\u1ed9 \u1ed5n \u0111\u1ecbnh k\u00e9m h\u01a1n th\u1ea1ch anh<\/td>\n<\/tr>\n<tr>\n<td>Polymer \u00e1p \u0111i\u1ec7n (PVDF)<\/td>\n<td>Linh ho\u1ea1t, d\u1ec5 ch\u1ebf t\u1ea1o<\/td>\n<td>Hi\u1ec7u su\u1ea5t th\u1ea5p h\u01a1n PZT<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Hi\u1ec7u \u1ee9ng t\u1eeb gi\u1ea3o v\u00e0 \u1ee9ng d\u1ee5ng<\/h3>\n<p>Hi\u1ec7u \u1ee9ng t\u1eeb gi\u1ea3o l\u00e0 s\u1ef1 thay \u0111\u1ed5i k\u00edch th\u01b0\u1edbc c\u1ee7a v\u1eadt li\u1ec7u t\u1eeb t\u00ednh khi \u0111\u1eb7t trong t\u1eeb tr\u01b0\u1eddng bi\u1ebfn thi\u00ean.  Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u1ea1o ra s\u00f3ng si\u00eau \u00e2m c\u00f4ng su\u1ea5t cao trong c\u00e1c \u1ee9ng d\u1ee5ng c\u00f4ng nghi\u1ec7p nh\u01b0 h\u00e0n si\u00eau \u00e2m, gia c\u00f4ng si\u00eau \u00e2m. M\u1ed9t cu\u1ed9n d\u00e2y \u0111\u01b0\u1ee3c qu\u1ea5n quanh m\u1ed9t v\u1eadt li\u1ec7u t\u1eeb gi\u1ea3o. Khi d\u00f2ng \u0111i\u1ec7n xoay chi\u1ec1u ch\u1ea1y qua cu\u1ed9n d\u00e2y, n\u00f3 t\u1ea1o ra t\u1eeb tr\u01b0\u1eddng bi\u1ebfn thi\u00ean l\u00e0m v\u1eadt li\u1ec7u t\u1eeb gi\u1ea3o dao \u0111\u1ed9ng, t\u1ea1o ra s\u00f3ng si\u00eau \u00e2m.<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>V\u1eadt li\u1ec7u t\u1eeb gi\u1ea3o<\/th>\n<th>\u01afu \u0111i\u1ec3m<\/th>\n<th>Nh\u01b0\u1ee3c \u0111i\u1ec3m<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Niken<\/td>\n<td>Gi\u00e1 th\u00e0nh r\u1ebb<\/td>\n<td>Hi\u1ec7u su\u1ea5t th\u1ea5p<\/td>\n<\/tr>\n<tr>\n<td>H\u1ee3p kim s\u1eaft-coban<\/td>\n<td>Hi\u1ec7u su\u1ea5t cao<\/td>\n<td>Gi\u00e1 th\u00e0nh cao<\/td>\n<\/tr>\n<tr>\n<td>Ferrite<\/td>\n<td>\u0110\u1ed9 \u1ed5n \u0111\u1ecbnh cao<\/td>\n<td>Hi\u1ec7u su\u1ea5t trung b\u00ecnh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>C\u00e1c y\u1ebfu t\u1ed1 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn s\u00f3ng si\u00eau \u00e2m<\/h3>\n<p>T\u1ea7n s\u1ed1, c\u01b0\u1eddng \u0111\u1ed9 v\u00e0 h\u00ecnh d\u1ea1ng c\u1ee7a s\u00f3ng si\u00eau \u00e2m ph\u1ee5 thu\u1ed9c v\u00e0o nhi\u1ec1u y\u1ebfu t\u1ed1, bao g\u1ed3m:<\/p>\n<ul>\n<li><strong>\u0110\u1eb7c t\u00ednh c\u1ee7a v\u1eadt li\u1ec7u t\u1ea1o s\u00f3ng:<\/strong>  V\u1eadt li\u1ec7u \u00e1p \u0111i\u1ec7n hay t\u1eeb gi\u1ea3o kh\u00e1c nhau s\u1ebd c\u00f3 hi\u1ec7u su\u1ea5t v\u00e0 t\u1ea7n s\u1ed1 c\u1ed9ng h\u01b0\u1edfng kh\u00e1c nhau.<\/li>\n<li><strong>Thi\u1ebft k\u1ebf c\u1ee7a b\u1ed9 chuy\u1ec3n \u0111\u1ed5i:<\/strong>  H\u00ecnh d\u1ea1ng v\u00e0 k\u00edch th\u01b0\u1edbc c\u1ee7a b\u1ed9 chuy\u1ec3n \u0111\u1ed5i \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn h\u01b0\u1edbng v\u00e0 \u0111\u1ed9 t\u1eadp trung c\u1ee7a ch\u00f9m si\u00eau \u00e2m.<\/li>\n<li><strong>M\u00f4i tr\u01b0\u1eddng truy\u1ec1n s\u00f3ng:<\/strong>  T\u1ed1c \u0111\u1ed9 lan truy\u1ec1n v\u00e0 m\u1ee9c \u0111\u1ed9 suy gi\u1ea3m c\u1ee7a s\u00f3ng si\u00eau \u00e2m ph\u1ee5 thu\u1ed9c v\u00e0o m\u1eadt \u0111\u1ed9 v\u00e0 c\u00e1c \u0111\u1eb7c t\u00ednh kh\u00e1c c\u1ee7a m\u00f4i tr\u01b0\u1eddng.<\/li>\n<\/ul>\n<p>T\u00f3m l\u1ea1i, vi\u1ec7c t\u1ea1o ra s\u00f3ng si\u00eau \u00e2m d\u1ef1a tr\u00ean c\u00e1c nguy\u00ean l\u00fd v\u1eadt l\u00fd nh\u01b0 hi\u1ec7u \u1ee9ng \u00e1p \u0111i\u1ec7n v\u00e0 hi\u1ec7u \u1ee9ng t\u1eeb gi\u1ea3o.  S\u1ef1 l\u1ef1a ch\u1ecdn ph\u01b0\u01a1ng ph\u00e1p v\u00e0 v\u1eadt li\u1ec7u ph\u00f9 h\u1ee3p ph\u1ee5 thu\u1ed9c v\u00e0o \u1ee9ng d\u1ee5ng c\u1ee5 th\u1ec3 v\u00e0 y\u00eau c\u1ea7u v\u1ec1 t\u1ea7n s\u1ed1, c\u01b0\u1eddng \u0111\u1ed9 v\u00e0 h\u00ecnh d\u1ea1ng c\u1ee7a s\u00f3ng si\u00eau \u00e2m.  Vi\u1ec7c hi\u1ec3u r\u00f5 c\u00e1c nguy\u00ean l\u00fd n\u00e0y gi\u00fap ch\u00fang ta \u1ee9ng d\u1ee5ng hi\u1ec7u qu\u1ea3 c\u00f4ng ngh\u1ec7 si\u00eau \u00e2m trong nhi\u1ec1u l\u0129nh v\u1ef1c kh\u00e1c nhau.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Si\u00eau \u00e2m l\u00e0 s\u00f3ng \u00e2m thanh c\u00f3 t\u1ea7n s\u1ed1 cao h\u01a1n ng\u01b0\u1ee1ng nghe c\u1ee7a con ng\u01b0\u1eddi, th\u01b0\u1eddng tr\u00ean 20kHz. Ch\u00fang \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng r\u1ed9ng r\u00e3i trong nhi\u1ec1u l\u0129nh v\u1ef1c t\u1eeb y t\u1ebf, c\u00f4ng nghi\u1ec7p \u0111\u1ebfn nghi\u00ean c\u1ee9u khoa h\u1ecdc. V\u1eady si\u00eau \u00e2m \u0111\u01b0\u1ee3c t\u1ea1o ra nh\u01b0 th\u1ebf n\u00e0o? B\u00e0i vi\u1ebft n\u00e0y s\u1ebd \u0111i s\u00e2u v\u00e0o<\/p>\n","protected":false},"author":1,"featured_media":26473,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6406],"tags":[],"class_list":["post-47524","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","prodpage-classic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts\/47524","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/comments?post=47524"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/posts\/47524\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/media\/26473"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/media?parent=47524"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/categories?post=47524"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/vi\/wp-json\/wp\/v2\/tags?post=47524"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}