一、 General Properties: 1.镧系元素从57号元素镧到第71号元素镥,共十五种元素,称为镧系元素,用Ln 表示。 2.稀土元素周期表B族中的钪(Sc)钇(Y)和镧系元素在性质上都非常相似并 在矿物中共生,由于镧系收缩,Y3+离子的半径落在Er3附近,Sc3离子的半径接近于 Lu3+,所以Sc、Y可以看作镧系元素的成员在化学上把Sc、Y和镧系元素统称为 稀土元素(rare earth's' elements),用RE表示

外研版九年级英语下册Module 4 Rules and suggestions单元测试题

第一节 浸出物测定法 （Determination of Extractive） 第二节 挥发油测定法 （ Determination of Volatile Oil） 第三节 可见-紫外分光光度法 （Ultraviolet and Visible Spectrophotometry） 第四节 薄层扫描法 （ Thin Layer Chromatography Scan TLCS ） 第五节 高效液相色谱法 （High Performance Liquid Chromatograph HPLC） 第六节 气相色谱法 （Gas Chromatography GC）

Medical Virology Dept. of Medical Microbiology and Parasitology Shanghai Second Medical University Shanghai, China. E.mail:(xkguoshsmu.edu.cn)

The hyde school In 1966, Joseph W. Gauld founded the first Hyde school in Bath, Maine in response to a system of education which hebelieved was failing its children because of conflicting priorities. His search for a new approach in education led to a program that valued attitude over aptitude, effort over ability, and s character over talent

Try to find out all expressions showing graceful hands” in our text.How many times? Find out words of Mrs. Clark Pick out descriptions about ward and Mrs Clarks physical conditions

Helpful Information Telecommunications Optical fiber( the medium and the technology associated with the transmission of information as light pulses along a glass or plastic wire or fiber. Information age Information superhighway

Background information your ho their potential The hyde school In 1966, Joseph W. Gauld founded the first Hyde school in Bath, Maine in response to a system of education which hebelieved was failing its children because of conflicting priorities. His search for a new approach in education led to a program that valued attitude over aptitude, effort over ability, and s

What does a pathogen have to do? Infect (infest) a host Reproduce(replicate) itself Ensure that its progeny are transmitted to another host

Spirochetes Gram negative Long, thin, helical, motile axial filaments locomotion between peptidoglycan layer/outer membrane runs parallel