The wedding tradition of “something old, something new, something borrowed and something blue” has been around for hundreds of years. The tradition of carrying or wearing one of each item is said to bring luck and fortune to the newly married couple. Have you ever stopped to think what the saying really means? What is its origin and what does each item represent?

    The original saying dates back to the Victoria times and states, “something old, something new, something borrowed, something blue and a silver sixpence in your shoe.”

    Something old   A bride may wear or carry something old to represent her continued ties to her family and her old life. Many brides wear a piece of family jewelry as their old item. Some brides wear the wedding dress worn by their mother or grandmother. In many cases, something old may also be something borrowed.

    Something new   Wearing something new is supposed to represent success and hope in the bride's new life and in her marriage. If the bride purchased her wedding dress new, it may represent her new item, but any item that is new may be used. Something “new” is usually the easiest kind to fill.

    Something borrowed   The borrowed item should be something borrowed from a friend that is happily married. It is said that their happiness will rub off on you and bring lasting happiness to your marriage. Some brides borrow an item of clothing, a piece of jewelry, a handkerchief or perhaps a beaded(带珠子的) purse.

    Something blue Wearing something blue dates back to ancient times when a blue wedding dress was worn to represent purity, fidelity and love.

    Silver sixpence   Placing a silver sixpence in the bride's left shoe is said to be a symbol of wealth. This not only refers to financial wealth, but also a wealth of happiness and joy throughout her married life. Since most brides probably don't even know what a sixpence is, this part of the tradition is not used very often in modern times. However, if a bride would like to include it in her wedding, she can purchase a silver sixpence from many companies that sell bridal supplies such as garters(袜带) and invitations.

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蓝天保卫战：雾霾多发启动PM2.5监测之旅

    ①2011年入秋以来，多地频发的雾霾天气将PM2.5推向了舆论的风头浪尖。其实PM2.5由来已久，早在1997年美国便提出了PM2.5的标准。到2010年底，美国和欧盟一些国家将PM2.5纳入国标并进行强制性限制。

    ②PM2.5究竟为何物呢？“PM2.5是指大气中直径小于或等于2.5微米的颗粒物，也称为可入肺颗粒物。它的直径还不到人的头发丝粗细的1/20。但它对空气质量和能见度等有重要的影响。那PM2.5又是从何而来？ PM2.5不是凭空产生的，从工厂、燃煤到汽车尾气的工业燃烧，从树叶、藤蔓到秸秆的作物燃烧，从烹饪做饭、抽烟、甚至使用发胶的燃烧活动，都会产生PM2.5。

    ③秋冬季一直是我国雾霾多发季节，雾霾天气多发导致北京、上海等多个城市空气污染加重，甚至出现短时间的重度污染。据气象部门统计，入秋以来我国中东部地区雾霾天气确实偏多，先后共发生12次较大范围的雾霾天气过程，并具有雾霾日数多、影响范围广等特点。与常年同期相比，河北中东部、天津、安徽中东部、江苏大部、湖南西南部、广西大部和广东西部等地雾霾日数偏多5-20天，局部偏多20天以上。

    ④越小的颗粒对人体的危害越大，而且对降低能见度加重雾霾天气的作用也越大。PM2.5容易被吸入人体，而且会直接进入支气管，干扰肺部的气体交换，引发包括哮喘、支气管炎和心血管病等方面的疾病。这些颗粒还可以通过支气管和肺泡进入血液，其中的有害气体、重金属等溶解在血液中，对人体健康的伤害更大。在降低能见度上，PM2.5的作用也不可忽视。在灰霾天，PM2.5的浓度明显比平时高，PM2.5的浓度越高，能见度就越低。

    ⑤PM2.5超标对农业也有不利影响，有研究表明，灰霾天气太多，农作物减产可达25%。中国气象科学研究院副研员王亚强认为，“对农作物的影响应该是间接的，比如在污染严重的时候，会影响太阳辐射，不利农作物吸收太阳光等等。”

    ⑥据了解，在美国和澳大利亚环保部门的网站上，对于PM2.5的监测与标准的制定过程有非常详细的备忘录。美国从1997年发布标准到2000年全国监测常规化花了两三年的时间，澳大利亚2003年发布非强制标准，随后即开展全国监测。

    ⑦目前，上海、广州、南京、青岛等城市已经展开对PM2.5的监测工作。早在2000年，上海便开始了PM2.5研究和监测试点，目前技术部门主要在做技术的比对工作。广州市共设立空气质量自动监测国控点10个，各区、县级市自动监测站点28个。此外，青岛市从2012年开始在七区五市范围内启动雾霾PM2.5监测点的逐步布控。《环境空气质量标准》在基本监控项目中增设了PM2.5年均、日均浓度限值，新标准拟于2016年全面实施。

    ⑧我国污染的问题日益严重，且在极短时间内集中爆发，各种污染交织。以煤炭为主导的能源结构、快速增长的机动车数量……这些一时难以改变的现实令“打击”PM2.5格外困难。而大城市如北京、上海等减排最大的难度，就是要处理好城市发展与环境的关系。

    ⑨从1998年的北京“蓝天”计划，到2005年的首钢搬迁，北京等各大城市探索城市发展与环境保护的平衡之路一直在进行，然而要真正实现转变发展方式，调整经济结构，用绿色发展之路换蓝天，仍然任重而道远。