本文目录一览：
- 1、喷头PY-5035和水泵机组65BP-55什么意思
- 2、聚苯乙烯的单体是什么
- 3、c++问题，不能导出名字为title的txt文件，求大神帮忙解决。。。
- 4、平面上有两点A(-1,0),B(1,0),点P在圆周（x-3)^2+(y-4)^2=4上，求使AP^2+BP^2最小值时点P的坐标
喷头PY-5035和水泵机组65BP-55什么意思
你了解喷头PY-5035和水泵机组65BP-55什么意思，不知道你说的喷头是不是喷淋管道的喷头，用于消防的喷头设计标注一般为喷头温级68度，喷头流量为系数K=80。不知道你喷头用于什么方面，PY是喷头的型号，5035是喷头的流量或者是其他方面的标示。水泵机组65BP是水泵机组立式65口径，55是水泵的吸水扬程高度。
聚苯乙烯的单体是什么
这是REACH注册过程中必需要出具的物质CAS编号.下面是聚苯乙烯的CAS号和他的一些基本信息.有关REACH方面的问题可以问我13771066122.
CAS: 9003-53-6
分子式: C8H8(unspec.)
沸点: 212℃
中文名称: 聚苯乙烯树脂
乙烯基苯均聚物
苯乙烯乳胶
泡沫聚苯乙烯
聚苯乙烯橡胶微球
聚苯乙烯
英文名称: Polystyrene resin
Benzene, ethenyl-, homopolymer
PS resin
168n15
3a
454h
475u
666u
686e
825tv
825tv-ps
a 3-80
afcolene
afcolene 666
afcolene s 100
atactic polystyrene
bactolatex
bakelite smd 3500
basf iii
bdh 29-790
ethenyl-benzen homopolymer
bextrene xl 750
bicolastic a 75
bicolene h
bio-beads s-s 2
bp-klp
bsb-s 40
bsb-s-e
bustren
bustren k 500
bustren k 525-19
bustren u 825
bustren u 825e11
bustren y 3532
bustren y 825
cadco 0115
carinex gp
carinex hr
carinex hrm
carinex sb 59
carinex sb 61
carinex sl 273
carinex tgx/mf
copal z
cosden 550
cosden 945e
denka qp3
diarex 43g
diarex hf 55
diarex hf 55-247
diarex hs 77
diarex ht 190
diarex ht 500
diarex ht 88
diarex ht 88a
diarex ht 90
diarex yh 476
dorvon
dorvon fr 100
dow 1683
dow 360
dow 456
dow 665
dow 860
dow mx 5514
dow mx 5516
dylark 250
dylene
dylene 8
dylene 8g
dylene 9
dylite f 40
dylite f 40l
edistir rb
esbrite
esbrite 2
esbrite 4
esbrite 4-62
esbrite 500hm
esbrite 8
esbrite g 10
esbrite g-p 2
esbrite lbl
escorez 7404
estyrene 4-62
estyrene 500sh
estyrene g 15
estyrene g 20
estyrene g-p 4
estyrene h 61
ethenylbenzene homopolymer
fc-my 5450
fg 834
foster grant 834
gedex
hf 10
hf 55
hf 77
hh 102
hhi 11
hi-styrol
hostyren n
hostyren n 4000
hostyren n 4000v
hostyren n 7001
hostyren s
ht 88
ht 88a
ht 91-1
ht-f 76
it 40
k 525
kb (polymer)
km (polymer)
koplen 2
kr 2537
krasten 052
krasten 1.4
krasten sb
lacqren 506
lacqren 550
latex
ls 061a
ls 1028e
lustrex
lustrex h 77
lustrex hh 101
lustrex hp 77
lustrex ht 88
mx 4500
mx 5514
mx 5516
mx 5517-02
n 4000v
napst
nbs 706
oligostyrene
owispol gf
pelaspan 333
pelaspan esp 109s
piccolastic
piccolastic a
piccolastic a 25
piccolastic a 5
piccolastic a 50
piccolastic a 75
piccolastic c 125
piccolastic d
piccolastic d 125
piccolastic d 150
piccolastic d-100
piccolastic e 100
piccolastic e 200
piccolastic e 75
poligostyrene
polyco 220ns
polyflex
polystrol d
polystyrene
polystyrene bw
polystyrene latex
polystyrene nanoparticles
polystyrene polymer latex
polystyrol
printel's
prx 1195
ps 1 (polymer)
ps 2
ps 2 (polymer)
ps 200
ps 209
ps 454h
ps 5 (polymer)
ps-b
psb-c
psb-s
psb-s 40
psb-s-e
psv-l
psv-l 1
psv-l 1s
psv-l 2
py2763
r 3
r 3612
rexolite 1422
rhodolne
s 173
sb 475k
sd 188
shell 300
smd 3500
sps 600
srm 705
srm 706
st 30ul
st 90
sternite 30
sternite st 30vl
stryon 686
styrafoil
styragel
styrene polymers
styrex c
styrocell pm
styrofan 2d
styroflex
styrofoam
styrolux
styron 440a
styron 470a
styron 475
styron 475d
styron 492
styron 666
styron 666k27
styron 666u
styron 666v
styron 678
styron 679
styron 683
styron 685
styron 690
styron 69021
styron gp
styron ps 3
styron t 679
styropian
styropian fh 105
styropol ht 500
styropol ibe
styropol jq 300
styropol ka
tc 3-30
tgd 5161
tmde 6500
toporex 500
toporex 550-02
toporex 830
toporex 850-51
toporex 855-51
trolitul
trycite 1000
u625
ubatol u 2001
ucc 6863
up 1
up 2
up 27
upm
upm508l
upm703
vestolen p 5232g
vestyron
vestyron 114-12
vestyron 512
vestyron mb
vestyron n
vinamul n 710
vinamul n 7700
vinyl products r 3612
vinylbenzene polymer
x 600
poly(styrene)
polymeric beads,expandable
Benzene,ethenyl-,homopolymer
MALDI validation set polystyrene Mp 500-70'000certified according to DIN
Polystrene Standard 88'000
Polystrene Standard broad 206'000
Polystrene Standard broad 350'000
Polystyrene solution
Polystyrene latex microsphere,1micron
Polystyrene latex microsphere,2micron
Polystyrene latex microsphere,0.05micron
Polystyrene latex microsphere,0.10micron
Polystyrene latex microsphere,0.20micron
Polystyrene latex microsphere,0.50micron
Polystyrene latex microsphere,4.5micron
Polystyrene latex microsphere,6.0micron
Polystyrene latex microsphere,10.0micron
Polystyrene latex microsphere,15.0micron
Polystyrene latex microsphere,20.0micron
Polystyrene latex microsphere,25.0micron
Polystyrene latex microsphere,0.75micron
Polystyrene latex microsphere,45.0micron
Polystyrene latex microsphere,75.0micron
Polystyrene latex microsphere,90.0micron
Polystyrene latex microsphere,1micron,dry form
Polystyrene latex microsphere,fluorescent,6.0micron
Polystyrene,atactic
Polystyrene,M.W.ca 100,000
c++问题，不能导出名字为title的txt文件，求大神帮忙解决。。。
我在linux系统下编译可以生成
Analyses of Biguanides and Related Compounds in Biological and Environmental Samples by HPLC.txt
可能是这个名字太长了，windows下不支持这么长的名字？
你试试换个固定文件名看能不能输出
平面上有两点A(-1,0),B(1,0),点P在圆周（x-3)^2+(y-4)^2=4上，求使AP^2+BP^2最小值时点P的坐标
设P点坐标(x,y)，P在圆周上，所以P满足(x-3)²+(y-4)²=4
PA²=(x+1)²+y² PB²=(x-1)²+y²
PA²+PB²=2x²+2y²+2
把圆的方程展开x²-6x+9+y²-8y+16=4→ x²+y²+1=6x+8y-20
PA²+PB²=4(3x+4y-10)
∵3x+4y≥2√12xy=4√3xy且当3x=4y时
∴代入圆的方程得P(21/5,28/5)
