某些结构的英语读法.doc

某些结构的读法25 wt% twenty five weight percent150 oC one fifty degree centigrade(温度有华氏(Fahrenheit)和摄氏(Centigrade)两种)1/2 one half1/3 one third2/3 two thirds4/5 four fifths/ four over five1.23 one point two three0.01 zero point zero one2.X two point something= is equal to / equalsis larger thanis much greater thana = b + c a is equal to b plus ca = b - c a is equal to b minus ca = bc a is equal to b times c / a is equal to b multiplied by ca = b/ca is equal to b divided by c / a is equal to b over cx2 x square / x to the second power / x to the power twox3 x cube / x to the third power / x to the power threelognXlog x to the base na* a stara a primeaa double prime/ is parallel to常用英文化学分子式、方程式及数学式的读法Na2SO4 Sodium sulphate; C-a-two-S-O-fourMg(OH)2 magnesium hydroxide; M-g-pause-O-H-pause-twice; M-g-in brackets twiceCa2(PO4)3 2H2O calcium phosphate two hydrate; C-a-two-pause-P-O four-pause- three times-dot-two-H two-OZn(NH3)42+ tetra-ammonium zinc complex cation= give; yield; produce, form, become evolved as a gas; give off a gas is precipitated; gives X precipitate reacts reversibly Cu, D in the precence of a copper as a catalyst on heating CO32- + Ca2+ = CaCO3 a carbonate anion with a valancy of two plus a calcium cation with a valancy of two produce a calcium carbonate precipitateR R primeR” R double prime, R second primeR1 R sub one100 C one hundred degrees Centigrade+ plus; positive- minus; negative multiplied by; times/ divided by plus or minus= is equal to; equalsis identically equal to is approximately equal to( ) round brackets; parentheses square brackets bracesab a is greater than or equal to baba varies directly as blognX logX to the base nthe cubic root of xthe nth root of xx2 x square, x squared, the square of xxn X to n factors; the nth power of x; x to the power nx -8 x to the minus eighth power|x| the absolute value of xthe mean value of xthe sum of the terms indicated; summation ofx the increment of xdx differential xdy/dx the first derivative of y with respect to xintegralinfinity1/2 a half; one half2/3two thirds5/123 five over a hundred and twenty-three0.01 O point O one; zero point zero one; nought point nought one6 % 6 percent3 3 per mille2 : 3the ratio of two to threer=xdr equals x multiplied by d52=10 five times two equals tenx3/8=y2 x raised to the third power divided by eight equals y