问题 问答题 简答题

简述焊接飞溅的防止措施。

答案

参考答案:

飞溅出现的根本原因是塑性环的形成落后于金属的熔化。在焊件确定的情况下,影响焊接飞溅的因素及可采取的防止措施主要集中在以下几个方面。

1)焊前认真清理焊件表面

2)增大预压力及预压时间

3)调低焊接电流,降低加热速度

4)改换合适的焊接电极

选择题
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WELCOME

Welcome to Windsor Castle, the oldest and largest occupied castle in the world .Windsor is one the official residences (住所)of  the Queen, who sometimes stays here.

Audio tours

Free audio tours are available on leaving the Admission Centre at the start of your visit .There is a descriptive audio tour for blind and poor-sighted visitors.

Guided tours

Visitors can explore the history of the Castle through a tour of the Precincts with an expert guide. Tours depart at regular intervals throughout the day from the Courtyard and finish at the entrance to the State Apartments.

Visitors with children

For those visiting with children, a special family tour and various activities are offered during school holidays and at weekends .Please note permitted in the State Apartments. However, baby carriers are available to borrow.

St George’s Chapel

Visitors arriving at the Castle after 15:00 from March to October are advised to visit St George’s Chapel first before it closes.

Shopping

Shops offer a wide range of souvenirs designed for the Royal Collection, including books, postcards, china, jewellery, and children’s toys. Please ask at the Middle Ward shop about our home delivery service.

Refreshments

Bottled water can be purchased from the Courtyard and Middle Ward shops. From April to September ice cream is also available. Visitors wishing to leave the Castle for refreshments in the town may obtain re-entry permits from the castle shops. Eating and drinking are not permitted in the State Apartments or St George’s Chapel.

Photography and mobile phones

Non-commercial photography and filming are welcomed in the Castle. Photography, video recording and filming are not permitted inside the State Apartments or St George’s Chapel. Mobile phone must be switched off inside the State Apartments and St George’s Chapel in consideration of other visitors.

Security

As Winter Castle is a working royal palace, visitors and their belongings should get through airport style security checks. For safety and security reasons a one-way system operates along the visitor route.

小题1:A visitor can apply for a free audio tour_________.

A.in the Courtyard

B.in the State Apartments

C.at the Admission Center

D.at St George’s Chapel小题2:What is specially offered to visitors with kids?

A.A security guard.

B.A pushchair.

C.A free toy.

D.A baby carrier.小题3:Who can get re-entry permits?

A.Visitors wishing to eat outside the Castle.

B.Visitors buying gifts in the castle shops.

C.Visitors buying water from the Courtyard.

D.Visitors eating outside St George’s Chapel.小题4:Why are visitors required to turn off their mobile phones?

A.To ensure the safety of others.

B.To ensure the security of the Castle.

C.To prevent them from disturbing others.

D.To prevent the use of the built-in cameras.小题5:In the last part, a “working royal palace” refers to one ___.    

A.still being constructed

B.still used by the royal family

C.where the Queen usually works

D.where works of art are on show