查询词典 lead-free

However, the principal lead is regarded as one of manifold kinds of lead in learning schools.

而校长领导被认为是学习型学校众多领导中的一种。

The effects of different lead concentration in meadow brown earth, red earth and gray limestone soil on wetland rice growth and its uptake of lead were investigated. The results showed that all treatments did not significantly change the biomass of wet...

水稻吸收的Pb与土壤中的添加Pb、总量Pb和DTPA可提取Pb含量之间均有着极显著的相关性，并由此计算了Pb的表观临界含量，其中湖北土对Pb的污染十分敏感(表观临界含量为79mgPb·kg-1)。

Rapid economic growth may lead to an overextension of resources and lead to an eventual catastrophic meltdown.

经济迅速增长可能导致资源的过度使用，并造成巨大的灾难。

Halogen ion can enter and break the phosphate glass network when they exceed certain content. The short range structure of metaphosphate and polyphosphate glasses are all built with phosphate chains. Most of lead ions still act as network modifiers, and some lead ions enter glass network to form tetrahedron or Pb-O-P linear linkages.

Br〓和F〓离子达到一定浓度时就会进入网络，使得玻璃网络发生断裂。P〓O〓含量为50mol％和40mo1％的玻璃样品结构都为链状结构，一部分pb〓离子进入玻璃网络中作为网络形成体，形成四面体或Pb-O-P键：而大部分的pb〓离子仍然作为网络修饰本。

For a long time to place dishes of water increased nitrite can lead to methemoglobinemia, or even can lead to nitrite poisoning.

长时间放置的菜水亚硝酸盐增高，会导致高铁血红蛋白血症，甚至可导致亚硝酸盐中毒。

The research team have ever fabricated the thin-film of ther mocouples by Multiple Arc Ion plating, and the contributions of the film are deviating from the target, so the Seebeck coeffcient is not in accordance with the normal thermocouples composed of Ni-Cr/Ni-Si wires, which lead to the larger error when Ni-Cr/Ni-Si wires was applied to the cuting test as compensation lead.

本课题组曾采用多弧离子镀方法制备Ni-Cr/Ni-Si薄膜热电偶，由于薄膜成分偏离标准大块Ni-Cr/Ni-Si材料，导致热电偶塞贝克系数与标准Ni-Cr/Ni-Si丝式热电偶相差较大。

Many of the countries which lead in oil production also lead in natural gas production.

许多生产石油的主要国家同时也是生产天然气的主要国家。

Then, in 1979, a well-designed study by pediatrician and psychiatrist Herbert Needleman resolved the dispute by establishing a direct correlation between the lead content of a child's teeth and bad classroom behavior. Twelve years later follow-up studies on these children found that those who had the highest lead levels in their teeth as children continued to have school problems through their last year of high school including more school failures, reading disabilities, and lower class standing.

到1979 年，由儿科医生兼精神病学家赫伯特·内德勒曼设计的一个著名实验证明不良的学习成绩与儿童牙齿中的铅含量直接相关，从而为争议下了定论12 年后对这些人的后续研究表明，当年牙齿中含铅量最高的孩子在中学毕业前一直存在学习上的问题，包括考试不合格、阅读障碍和班级排名靠后。

A new method was studied for the determination of Nickel in Lead ingot in nitre acid after the main part were separated by Lead Sulphate.

方法操作简单，精密度、准确度均可满足分析要求，适用于铅锭中0 0001%～0 005%镍量的测定。

Based on the pressure curve experiment, the physical characteristic of ore-bearing rocks of the Luoba lead-zinc deposit in the Qinling Xicheng deposit field shows small porosity, low permeability and bad link ostiole in the ore-bearing rocks series. The feature indicates that the physical characteristic of ore bearing is unfavorable for forming the Luoba lead-zinc deposit.

采用压汞分析技术对秦岭多金属成矿带西成矿田洛坝铅锌矿床含矿层各岩系的物性特征进行了研究，结果表明含矿层各岩系物性特征具有孔隙度小、渗透率低、孔喉连通性差的特点，这一特征对洛坝大型矿床的形成是极为不利的。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。