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目前日期文章:201012 (4)

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The Basics of Welding Safety

Proper welding safety starts with familiarizing yourself and other operators with the welding equipment and the manufacturer’s recommendations. Take the time to read the operator’s manual thoroughly and follow all of the safety, operation and maintenance instructions it contains. Keep the manual handy so new users can acquaint themselves with the machine. Should the operator’s manual become lost or damaged, request a new one from the manufacturer. Miller Electric and many other manufacturers provide product manuals on-line. Spanish and French language versions are available for some of the most common products.

The Well-Dressed Welder

Arc welding produces sparks and emits intense visible and invisible rays that pose several hazards to unprotected skin and eyes. When welding, adequately protect your skin. Shorts, short sleeves, open collars all leave you vulnerable to burns from both flying sparks and the arc rays. Wear only flame-resistant clothing, and button your cuffs and pockets to prevent them from catching sparks. Pants cuffs, too, can catch sparks and should be avoided.

Figure 1: The well-dressed (or safely dressed welder) no longer has to use a clumsy, ill-fitting jacket. Modern welding garments are more functional, flexible and better fitting. Note that once the welder dons the helmet, he will have no skin exposed to sparks or arc burns. A flame resistant jacket is completely buttoned, allowing no pockets or spaces for a spark to catch. A welding bandana protects the top of his head from sparks. An auto-darkening welding helmet decreases the chance for repetitive stress injury to one’s neck and can adjust to changing arc parameters conditions.

With respect to footwear, high top leather shoes offer the best protection. Tennis shoes and other cloth shoes are inadequate; they can catch a spark and smolder unnoticed and their components can melt and stick to your skin.

Always wear proper gloves when welding or handling recently welded material to protect yourself from sparks, arc burns and the heat from the workpiece. Remember, even a quick tack weld requires the use of a welding helmet and appropriate apparel (see Figure 1).

Although the above sounds obvious, a common fault among welders is not wearing the right safety equipment. While expediency is one reason often given, some welders complain that the common, one-size-fits-all apparel is too bulky, heavy and restricting and that gloves, especially in TIG applications, do not provide the necessary sensitivity and flexibility.

Figure 2: Welding gloves are now available in different styles to meet the demand of different welding applications. The medium duty MIG gloves shown here (left) offer ergonomically curved fingers and padded palm for increased comfort and rugged construction for increased longevity. The TIG gloves (bottom center) are made from goatskin, which provides excellent dexterity, comfort and durability. Metal working gloves (top center) and heavy duty MIG gloves widen the choices available to the welder.

While that may have been true in the past, leading manufacturers now offer safety apparel that address the welder’s comfort and specific needs.

"The welding industry is moving beyond the cookie cutter, one-size-fits-all idea of safety products, demanding garments that are safe from a functional standpoint, yet attractive with a better fit,” says John Swartz, welding components & consumables product manager, Miller Electric Mfg. Co.

Lightweight flame resistant cloth, pigskin leather and combinations of the two offer the welder better protection, even when welding overhead, and increased ease of movement than ever before. For additional flexibility, some jackets feature snaps for the addition of a leather bib or apron.

Gloves in small to extra-large sizes with ergonomically curved fingers are now available for specific welding processes. Heavy duty MIG/Stick gloves, medium MIG gloves and TIG gloves that provide that added dexterity and touch are just some of the recent additions to the field (see Figure 2)

Helmets

Even a brief exposure to the arc’s radiation may be damaging to your eyes, causing symptoms from a burning sensation to temporary blindness. Repeated exposure can lead to permanent injury. Always wear proper eye protection when welding or when exposed to a welding arc.

If you use a standard, fixed shade helmet, pick one that has a lens shade appropriate for your welding application. OSHA offers a guide for choosing the correct lens based on welding criteria. If your weld parameters and materials don’t vary, a fixed-shade lens may be right for you. However, if you’ll be switching processes, materials or parameters, an auto-darkening helmet may be your best solution.

Figure 3: Auto-darkening helmets provide many benefits, including increased efficiency, decreased chance for repetitive stress injury and responsiveness to changing arc quality. Attractive graphic designs promote safety while allowing the wearer to express his or her personality.

All auto-darkening helmets must meet ANSI standards, the most recent being ANSI Z87.1-2003. When an arc triggers the sensors on an auto-darkening helmet, the lens darkens in a fraction of a second. Some fixed-shade auto-darkening helmets darken to a #10 shade with a reaction time of 1/2000 to 1/3,600 of a second and are not adequate for frequent tack welds, TIG welding and other industrial applications.

Industrial grade helmets react at speeds of 1/10,000 of a second or higher to prevent eye fatigue and arc flash symptoms, and have adjustable shades settings of #9-#12 or #13. (Miller Elite auto-darkening helmets react in 1/20,000 of a second, with shade settings of #8 to #13.) Industrial grade helmets, such as the Miller Elite series, will also have adjustable sensitivity and delay controls (see Figure 3).

Adjustable sensitivity is useful when welding at low amperages, especially TIG, when the light isn’t as bright as other processes. Adjustable delay controls how long the lens remains darkened after the arc stops. When tack welding, a short delay may be desired, while a longer delay may be desirable after welding at very high temperatures. Even when not activated, the lens provides UV/IR protection and usually has a light state of a #3 or #4 shade, which is relatively easy to see through.

Auto-darkening helmets provide some other important benefits also. With a fixed-shade helmet, the welder positions the gun, torch or electrode and then jerks his head down to bring the helmet into place. This may lead to neck injury through the repeated motion, especially for welders who perform a series of tack welds. For the novice or person who welds infrequently, the jerking action can cause him to move out of position and lead to a weld defect. An auto-darkening helmet allows the welder to keep the helmet in place while positioning the electrode, leading to better positioning and relieving some of the stress from the welder’s neck.

Work Environment

You must also protect others in the welding area. Use a weld screen to ensure passersby will not be subjected to the arc flash.

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假如我說
I was ____ not talking about you.
(我完完全全不是在說你)
那麼該填哪個好呢?

(absolutely/totally/definitely)

maow大大講的不完全正確

以這句來說
應該填absolutely
absolutely就是中文的"絕對"
用來加強情緒的表達
=>我絕對不是在說你
absolutely在這裡也可以全等於completely
表示談話的內容"完全沒有涉及到你"
=>我完全沒有在講你
兩種解釋都通

totally雖然中文翻成"完全"
但其英文本意並不是這樣

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易混詞辨析

 

1 . affect , effect , influence , impact

本組詞都有“影響”的意思,但分別有一些用法上的不同。 affect 意為“影響”,強調產生不好的影響或結果effect 意為“招致、產生、促成”,著重強調影響所產生的結果influence 意為“影響、對……有作用”,強調對人或物的性格、行為或看法產生潛移默化的作用或影響impact 除了有“影響”之外,還有“衝擊,撞擊”的意思。

Will the government policy be affected ( changed ) by the appointment of a new minister? 政府政策是否會因為任命了一位新部長而受影響

The climate affected the amount the rainfall .氣候影響了雨量。

The new minister hopes to effect ( produce ) changes in the government's policy .這位新部長希望改變政府的政策。

Influenced by her family , Mary became a teacher after graduation .受家庭影響,瑪麗畢業後當了老師。

I heard a noise of metal impacting on stone .我聽到了金屬碰撞石頭的聲音。

2 . wage , salary , pay

本組詞都有“工資、薪水”的意思,但在具體的使用中有一些差別。 wage [ 常 pl . ] 一般指體力勞動者或非技術工人的“薪水、工資”,通常按小時或用計件的方法結算,按周發給salary [U/C] 一般指腦力勞動者技術工人的工資,通常按年計算,按月發給,可稱為“年薪”或“月薪”; pay [U] 包括工資、軍餉、津貼、酬勞等,可代替本組其他兩個詞。

Money earned every week is called a weekly wage .每週掙的錢稱為週薪。

His wages have gone up .他漲了工資。

How much salary does the job pay? 這個工作的薪水是多少?

He doesn't like the job , but the pay is good .他不喜歡這個工作,但工資很高。

3 . declinerefuserejectdeny

本組詞都有“拒絕”的意思,但在不同的語境中可表達不同的語氣和程度。 decline 常用詞,表示有禮貌或婉轉地“謝絕”他人的邀請或幫助,後可接名詞、代詞、或動詞,後接動詞不定式時,語義較強,相當於 refuserefuse 常用詞,表示“拒絕”某種請求,不接受”某種提供,強調不情願,可後接名詞、代詞、或動詞不定式,與 decline 不同的是此詞可以人為賓語,而 decline 不可以如 You shouldn't have refused him 為正確表達,此處的 refuse 不能換成 decline ; reject 意為“拒絕”,語氣強烈、堅決,多用於正式場合,如外交或商業談判等,指拒絕不接受不合理的要求沒有價值或所嫌棄的東西、意見或請求,帶有“駁回、丟 棄、不能接受其條件”等含義; deny 正式用語,表示“拒絕給予、拒絕……的要求”,使人根本不能得到某物或不允許某種事情或行為發生,後多接雙賓語間接賓語為人,直接賓語為所拒絕給予的事 物。

We invited them to our party , but they declined politely .我們邀請他們參加我們的聚會,但他們禮貌地謝絕了

Bill angrily declined to discuss the matter .比爾憤怒地拒絕討論此事。

後接動詞不定式時語義較強,相當於 refuse

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  1. abacus
  2. abandon
  3. abase
  4. abashed
  5. abate
  6. abbreviate
  7. abdicate
  8. abdomen
  9. abduct

10. aberrant

11. abet

12. abeyance

13. abhor

14. abhorrent

15. abide

16. abiding

17. abject

18. abjure

19. ablution

20. abnegate

21. abnormal

22. abode

23. abolition

24. abolitionist

25. abominable

26. abominate

27. aboriginal

28. abortive

29. abound

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