居里夫人是如何发现镭的？为什么研究放射性在当时非常危险？
How did Marie Curie discover radium, and why was studying radioactivity so dangerous at the time?
在贝克勒尔发现铀盐放射性的基础上，居里夫妇系统测量各种矿物的放射性，发现沥青铀矿的放射性远超其中铀含量所能解释的程度，据此推断存在新的未知元素。他们用放射性本身作为示踪，经过化学分离，从数吨沥青铀矿废渣中提取出钋和镭。镭的放射性极强，衰变时放出 α、β、γ 射线，长期近距离接触会损伤 DNA 和造血系统。当时辐射的危害尚未被认识，居里夫人长期接触放射性物质，最终在1934年死于再生障碍性贫血，成为辐射工作者的先驱警示。
Building on Becquerel's discovery that uranium salts emit radiation, the Curies measured the radioactivity of many minerals and found pitchblende far more radioactive than its uranium content could explain - implying unknown elements. They then used radioactivity itself as a tracer through chemical separations, and from tonnes of pitchblende residue isolated polonium and radium. Radium is intensely radioactive, emitting alpha, beta and gamma rays that damage DNA and blood-forming tissue with prolonged proximity. Because the hazards were unknown at the time, Curie handled radioactive material for years and died of aplastic anemia in 1934 - an enduring warning to all radiation workers.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Sam Kean,《The Disappearing Spoon》Little, Brown,2010;中译《元素的盛宴》接力出版社
S. Kean, The Disappearing Spoon, Little Brown, 2010; Chinese ed. Jielie Publishing House
#居里夫人 #镭 #放射性
为什么装修新房建议测氡？
Why is testing for radon recommended in new homes?
土壤和花岗岩会释放放射性氡气，在密闭室内积累，长期吸入增加肺癌风险；加强通风可显著降低。
Soil and granite emit radioactive radon; trapped indoors it accumulates and raises lung-cancer risk—ventilation lowers it.
难度 专业 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Housecroft & Sharpe,《Inorganic Chemistry》第5版,Pearson,2018
C. E. Housecroft and A. G. Sharpe, Inorganic Chemistry, 5th ed., Pearson, 2018
#氡 #放射性 #室内
钾-氩测年法怎样测定古老岩石的年龄？
How does potassium-argon dating determine the age of ancient rocks?
放射性钾-40以约12.5亿年的半衰期通过电子俘获衰变成氩-40。含钾矿物（如长石、云母）结晶时会排出氩，此后氩-40在晶格中不断积累，因此密封良好的矿物中氩-40与钾-40的比值直接对应结晶年龄。该方法可测数百万年到数十亿年的岩石与火山灰，考古学中常与碳-14互补。
Radioactive potassium-40 decays to argon-40 by electron capture with a half-life of about 1.25 billion years. Potassium-bearing minerals such as feldspar and mica expel argon when they crystallize; afterwards argon-40 accumulates in the lattice, so in well-sealed minerals the argon-40 to potassium-40 ratio directly gives the crystallization age. The method dates rocks and volcanic ash from millions to billions of years old and complements carbon-14 dating in archaeology.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Housecroft & Sharpe,《Inorganic Chemistry》第5版,Pearson,2018
C. E. Housecroft and A. G. Sharpe, Inorganic Chemistry, 5th ed., Pearson, 2018
#钾-氩测年 #同位素地质学 #半衰期
医院的钼-锝发生器俗称“母牛”,为什么每隔一天左右就能重复淋洗出新鲜的锝-99m?
Hospital molybdenum-technetium generators are nicknamed cows — why can they be eluted repeatedly every day or so to deliver fresh technetium-99m?
钼酸根以高亲和力固定在酸性氧化铝柱上,子体高锝酸根因分配行为不同,可被生理盐水单独洗脱。子体活度按衰变动力学增长,约23小时后接近峰值,再次淋洗即得最大收率。这套周期性“挤奶”流程把短寿命核素的供应从加速器现场解放出来,支撑着绝大多数SPECT显像。
Molybdate is immobilized with high affinity on an acidic alumina column, while the daughter pertechnetate, owing to different partitioning, is washed off alone with saline. Daughter activity regrows by decay kinetics and approaches its maximum after roughly 23 hours, when a second elution gives peak yield. This periodic milking decouples short-lived nuclide supply from on-site accelerator operation and underpins most SPECT imaging.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
IAEA Technical Reports Series No. 466《Technetium-99m Radiopharmaceuticals: Manufacture of Technetium-99m Generators》,IAEA,2010
IAEA Technical Reports Series No. 466, Technetium-99m Radiopharmaceuticals: Manufacture of Technetium-99m Generators, IAEA, Vienna, 2010
#放射性核素发生器 #医用同位素
辐射剂量用什么单位衡量？西弗（Sv）是什么意思？
What unit measures radiation dose, and what does the sievert (Sv) mean?
辐射剂量常用西弗（Sv）或毫西弗（mSv）表示，它衡量电离辐射对人体造成的生物损伤大小，等于吸收剂量（戈瑞）乘以与辐射种类有关的权重因子。天然本底辐射每年约2.4毫西弗，一次胸部CT约几毫西弗，职业照射限值也以西弗为基准制定。
Radiation dose is usually quoted in sieverts (Sv) or millisieverts (mSv); it expresses the biological harm of ionizing radiation, equal to the absorbed dose (in grays) times a weighting factor that depends on the radiation type. Natural background is about 2.4 mSv per year, a chest CT delivers a few mSv, and occupational limits are also set in sieverts.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Sam Kean,《The Disappearing Spoon》Little, Brown,2010;中译《元素的盛宴》接力出版社
S. Kean, The Disappearing Spoon, Little Brown, 2010; Chinese ed. Jielie Publishing House
#辐射剂量 #西弗 #吸收剂量
同位素分馏是什么、有何用？
What is isotope fractionation and what is it for?
轻、重同位素因质量差在物理化学过程中比例出现微小改变；可用于气候记录（¹⁸O/¹⁶O）与代谢示踪。
Light and heavy isotopes shift in ratio during physico-chemical processes due to mass differences; used in climate records (¹⁸O/¹⁶O) and metabolic tracing.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Sam Kean,《The Disappearing Spoon》Little, Brown,2010;中译《元素的盛宴》接力出版社
S. Kean, The Disappearing Spoon, Little Brown, 2010; Chinese ed. Jielie Publishing House
#分馏 #同位素 #示踪
居里夫人为什么能从几吨矿渣里提炼出镭？
Why could the Curies extract radium from tons of ore residue?
他们利用镭化合物与钡化合物性质相近难分离的特点，反复结晶富集，最终从沥青铀矿残渣中得到极少量氯化镭。
Because radium resembles barium, they repeatedly crystallized to enrich it, finally isolating a tiny amount of radium chloride from uranium-ore waste.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Housecroft & Sharpe,《Inorganic Chemistry》第5版,Pearson,2018
C. E. Housecroft and A. G. Sharpe, Inorganic Chemistry, 5th ed., Pearson, 2018
#居里 #镭 #放射性
碳-14 测年法依据什么原理,为什么它的适用上限大约只有五万年?
On what principle does radiocarbon dating rest, and why is its useful limit only about fifty thousand years?
宇宙射线在中层大气产生 C-14,经氧化成为 CO2 进入碳循环,生物体存活期间体内 C-14/C-12 比值与环境一致;死亡后不再交换,C-14 按 5730 年半衰期指数衰减。测定残留放射性或用加速器质谱计数原子即可反推年代。经过约十个半衰期后剩余信号只剩初始值的千分之一左右,本底与污染误差已超过可分辨范围,故上限约为五万年。
Cosmic rays produce C-14 in the mid-atmosphere; oxidized to CO2 it mixes through the carbon cycle, so living organisms track the ambient C-14/C-12 ratio. After death, exchange stops and C-14 decays exponentially with a 5730-year half-life; residual beta activity or accelerator mass spectrometry atom counting then dates the sample. After roughly ten half-lives only ~0.1% of the original signal remains, at which point background and contamination dominate — hence the ~50,000-year ceiling.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
W. F. Libby 1949 年 Science 论文《Age determination by radiocarbon content》
W. F. Libby et al., "Age determination by radiocarbon content: world-wide assay of natural radiocarbon", Science, 1949
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1126/science.109.2827.227：Age Determinati
#碳十四测年 #放射性衰变
高放废液为什么通常固化成硼硅酸盐玻璃长期封存，而不是蒸干后装进不锈钢罐直接储存？
Why is high-level liquid waste usually immobilized as borosilicate glass for long-term disposal rather than simply evaporated and kept in stainless-steel tanks?
直接蒸发得到的是易溶于水的盐饼，一旦接触水体核素便迅速浸出，加上罐体腐蚀与衰变热累积，长期裸存风险极高。硼硅玻璃以SiO₄四面体共价网络为骨架，Na₂O降低熔点便于连续浇注，B₂O₃提升热稳定性并抑制失透；Cs⁺、Sr²⁺作为网格改体离子嵌入网络空隙，锕系与氧配位并入骨架，核素靠化学键合而非简单包裹被固定，浸出率比煅烧盐低几个数量级，产物致密体积小，可直接转入地质处置。
Straight evaporation leaves water-soluble salts that release radionuclides the moment groundwater arrives, while canister corrosion and decay heat compound the hazard year after year. Borosilicate glass builds on a covalent network of SiO4 tetrahedra: Na2O lowers the melting point for continuous casting and B2O3 improves thermal stability while suppressing devitrification. Cs+ and Sr2+ sit as network-modifying cations in the interstices and actinides coordinate into the framework, so nuclides are locked by chemical bonding instead of mere encapsulation; leach rates fall orders of magnitude below calcined salts, and the dense compact product passes straight to geological disposal.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
I. W. Donald,《Waste Immobilization in Glass and Ceramic Based Hosts》,John Wiley & Sons,2010 (DOI: 10.1002/9781444319354)
I. W. Donald, 'Waste Immobilization in Glass and Ceramic Based Hosts', John Wiley & Sons, 2010, DOI: 10.1002/9781444319354
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1002/9781444319354
#硼硅玻璃 #核废料固化 #核素浸出
碳-14 测年怎么工作？
How does carbon-14 dating work?
活体不断与环境交换 ¹⁴C，死后停止；依其约 5730 年的半衰期测剩余量来推算年代，上限约数万年。
Living things exchange ¹⁴C with the environment and stop at death; measuring the remaining ¹⁴C against its ~5730-year half-life dates samples up to tens of thousands of years.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Sam Kean,《The Disappearing Spoon》Little, Brown,2010;中译《元素的盛宴》接力出版社
S. Kean, The Disappearing Spoon, Little Brown, 2010; Chinese ed. Jielie Publishing House
#碳14 #测年 #同位素