astm2000 m5ca 710 z1 z2是什么意思 橡胶美国ASTM标准（谁帮我解答一下下面一串数字）
z1z2=(x1+iy1)(x2+iy2)=x1x2-y1y2+i(x2y1+x1y2)，
所以Re(z1z2)就是z1z2的实部，即为x1x2-y1y2。
这你们在哪，。，就只看自己逆袭逆袭就是那种那你想你先拿着卡卡那你息怒息怒辛苦再看看呢，你，你行吗在卡卡；想。，。你，那些那你上哪弄上哪。，你那手机声卡在卡卡
轴承Z2等级是表示噪音级别，一般使用于深沟球轴承。只是特定转速和使用环境下的一个噪音标准。单个轴承的的振动有Z1、Z2、Z3、Z4四个等级，振动值由Z1—Z4逐渐减小。
深沟球轴承是滚动轴承中最为普通的一种类型。基本型的深沟球轴承由一个外圈，一个内圈、一组钢球和一组保持架构成。 深沟球轴承类型有单列和双列两种，深沟球结构还分密封和开式两种结构，开式是指轴承不带密封结构，密封型深沟球分为防尘密封和防油密封。
外语是美国人的母语，美国人说英语那么轻松，中国人不懂的不知道说什么？中国人说母语 ，不懂中国语言的也是白听了，所以要想英语学的好，孩子在几个月时都可以学，而这个学不是教他跟你学着说，可以放英语歌曲，英语动画，家长们也可以说些简单的给宝宝听，孩子每天接触英语，学的英语就快，跟同年的孩子比，他会更好，上学阶段会很轻松，这样就更加没有厌烦感。加油…`加油…加由…加油…拼搏………::…冲冲冲冲冲:……拼搏…冲冲冲:为什么呢??
不知道什么意思
求橡胶高手回答 ASTM D2000 M2GE506,B37,Z1,Z2j 是什么意思~
该标准第五页，9. Line Call-Outs，有清楚的说明。
Understanding the ASTM D2000 (SAE Recommended Practice J200)
By Dale T. McGrosky
"Standard Classification System for Rubber Products in Automotive Applications"
ASTM D2000 was introduced to provide engineers with a classification system for commercially available rubber materials and to provide a simple designation method called the "Line call-out." Although the title specifies automotive application it is not limited to only the automotive industry. In fact several industries benefit from this standard.
ASTM D2000-90 2BG710 B14 B34 EF11 EF21 EO14 EO34 F17 K11
Lets breakdown the "Line call-out" above.
"ASTM D2000" is the reference number for this standard.
"-90" is the revision year of the document. The latest revision year should always be used.
Now we get to the nitty gritty of the line call-out.
"M" states that the units of measure are SI (International Standard of Units). If the line call-out doesn't have the "M" them the "Inch-Pound Units" are to be used.
Lets Jump ahead one step and skip "2" for now.
"BG" - The first letter, "B", is the designation for Type (resistance to heat aging) as shown in table 1. The second letter, "G", is the designation for Class (resistance to swelling in oil) as shown in Table 2. Put these two designation together and you can use table X1.1 in the ASTM D2000 specification to see what basic elastomers are used. According to Table X1.1, BG is "NBR polymers, urethanes."
Type Test Temperature
A 70°C (158°F)
B 100°C (212°F)
C 125°C (257°F)
D 150°C (302°F)
E 175°C (347°F)
F 200°C (392°F)
G 225°C (437°F)
H 250°C (482°F)
J 275°C (527°F)
Table 1
Class Volume Swell, max
A no requirement
B 140%
C 120%
D 100%
E 80%
F 60%
G 40%
H 30%
J 20%
K 10%
Table 2, Tested for 70 hrs @ temperature from
table 1 in ASTM Oil No 3.
Lets go back to "2" now.
"2" represents the grade of rubber. The grades available are shown on table 6 of the ASTM D2000 specification. The grades available are dependent on the hardness and tensile strength for the particular Type and Class material. Table 6 also shows the basic requirements of the rubber like hardness, tensile strength, elongation, heat ages properties and oil immersion, compression set (Does heat aged & oil immersion sound familiar?--Type and Class "BG"). Grade 1 indicates that only the basic requirements are required and no suffix requirements are permitted. But well get to suffix requirements in a minute.
"7" represents the hardness. In this case 7 = 70 Durometer Shore "A"
"10" represents the tensile strength. Remember the "M" from before? Here's were it comes in.
M2BG710 = 10 MPa tensile strength minimum -- SI Units
2BG710 = 1015 psi tensile strength minimum -- Inch-Pound Units
Starting to get the picture? Lets continue with the next step, the suffix requirements.
Grades other than 1 are used to to show deviations or additional requirements other than the basic requirements and are listed as "Suffix Requirements."
Each suffix requirement has a suffix letter(s) and a suffix number. The suffix letter represents the test required. The meaning of each suffix letter is shown in table 3.
Suffix Letter Test Required
A Heat Resistance
B Compression Set
C Ozone or Weather Resistance
D Compression-Deflection Resistance
EA Fluid Resistance (Aqueous)
EF Fluid Resistance (Fuels)
EO Fluid Resistance (Oils and Lubricants)
F Low Temperature Resistance
G Tear Resistance
H Flex Resistance
J Abrasion Resistance
K Adhesion
M Flammability Resistance
N Impact Resistance
P Staining Resistance
R Resilience
Z Any Special Requirements
Table 3, Suffix letter meanings
The sare a two digit number. The first number indicates the test method and the second number indicates the temperature of the test. table 4 in the ASTM D2000 manual shows each suffix requirement.
So lets recap the Suffix Requirements.
For each Type and Class of material there are a set of basic requirements: heat ages properties, tensile strength, elongation, oil immersion in ASTM Oil No 3 and compression set. For grades of material other than 1 there are additional requirements or deviations from the basic requirements that are shown as Suffix Requirements. Each suffix requirements is a group of letters and numbers that tell what test, the test method and temperature of the test to be performed.
Please note that you do not need to meet ALL the suffix requirements for a particular material . The suffix requirements are picked based on the qualities needed to meet the service requirements of the material. For example, you may not be particularly interested in the fluid resistance tests if the material you are picking is going to be used in an application were it will only see compressed air. If there is a special requirement that you need to meet the suffix letter "Z" is used to note them. These requirements need to be specified in detail.
I hope this helps you to understand the ASTM D2000 Manual. I highly recommend that you have this manual on hand.
ASTM D2000(参考号码)-90（年代） M5（国际标准单位）B（热形变参数，图表1）G（油膨胀参数，图表2）614B14E014E034F16 （依次类推）
这是原文，希望你可以看懂，并对你有帮助。需要翻译的话，Hi我。
