So why this quaint tradition? Where do these paper hats come from? The answer is the Christmas Cracker.

A Christmas Cracker is a cardboard paper tube, wrapped in brightly coloured paper and twisted at both ends.

圣诞拉炮是用硬纸板做的纸筒，再用色彩鲜艳的彩纸包裹在外面，两端拧紧。

The answer is the Christmas Cracker.

答案就在另一项圣诞传统活动圣诞拉炮！

The loss of catalyst of the catalytic cracker for oil refinery

浅析炼油厂催化装置催化剂的损耗原因

The technical feature of FSC from Honeywell Company and its application in the catalyst cracker plant in the Company are introduced. The structure and operation of the system are described and the effect is summarized.

介绍霍尼韦尔公司故障安全控制系统FSC的技术特点以及在我厂重油催化裂化装置的应用情况，说明了该装置故障安全控制系统组成和操作界面，并总结了应用效果。

Application of New Type Slurry Oil Pump in Catalyst Cracker Units of Refinery Factory

新型油浆泵在炼厂催化裂化装置中的应用

An industrial application of MPC technique in residue catalytic cracker process control

MPC在重油催化裂化反应-再生系统控制中的应用

The aim of their efforts, an effective catalytic cracker to convert crude oil into gasoline, using a fluidised bed.

这场努力的目标，是使用流化床催化裂化器把原油转化为汽油。

Measures for Increasing Petrochemical Feedstocks in Heavy Oil Catalytic Cracker RECENT PROGRESS IN PETROCHEMICAL TECHNOLOGY

重油催化裂化装置增产石化原料的措施当代石油化工技术的进展

Safe Evaluation for Typical Defect of Weighty Oil Catalytic Cracker

重油催化再生器典型缺陷安全评定

Application of Endurance Catalyst in Heavy Oil Catalytic Cracker

Endurance催化剂在长庆石化重油催化裂化装置上的应用

Exergy analysis of heat exchanger network of heavy oil catalytic cracker unit

重催装置换热网络的火用分析

Application of vortex rapid separation technology in heavy oil catalytic cracker

应用旋流式快分技术改造重油催化裂化装置

The heavy oil catalytic cracker reduce the unit energy consumption analysis

重油催化裂化装置降低机组能耗的分析研究

Optimization Control for Cracking Severity of SRT-ⅳ Heavy Oil Cracker with VAX Computer

SRT-Ⅳ型重质油裂解炉基于VAX机的裂解深度优化控制

The main air BLOWER-GAS turbine unit for the coaxial cat cracker

同轴式催化裂化装置的主风机-烟气轮机机组

Treatment test of cyanide containing waste water from cat cracker by hydrolysis

加热水解法处理催化裂化含氰污水试验

Detection of Moving Explosive Target of Cannon Cracker on Dynamic Image Sequence

基于运动图像序列的烟花爆竹炸点目标飞行的检测

Relationship between the position of superior mesenteric artery and the posture of the nut cracker phenomenon

肠系膜上动脉方位与胡桃夹现象的体位关系

Real-time Sonographic Diagnosis of Nut Cracker Phenomenon in Children with Orthostatic Proteinuria

实时超声诊断儿童直立性蛋白尿和非肾性血尿&胡桃夹现象

Effect of posture change on asymptomatic hematuria in children with nut cracker phenomenon

体位改变对胡桃夹现象患儿血尿的影响