同位素

Samples of Jurassic shells, which are a portion of the collection used to the benthicassociations of Lusitanian basin, Portugal, are subjected to analysis of stable carbon isotopic composition for reconstructing palaeosalinity.

碳同位素的古盐度表明，葡萄牙卢酉塔尼亚盆地在侏罗纪时曾是一半咸水海湾，其水体含盐度低于24‰。，所以生物组合中以机会种和半咸水地方性种占优势。

Jurassic ; Lusitanian basin; carbon isotopic composition ; Paleosalinity

侏罗纪；葡萄牙卢西塔尼亚盆地；碳稳定同位素成分；古盐度

The influences of some relevant parameters on resonance ionization efficiency in the recent laser pulse time-delayed scheme were analyzed with the framework of time-dependent Schrdinger equation. As a versatile example, the feasibility of this scheme applied to lutetium isotopic analysis by Laser Resonance ionization Spectrometry was discussed.

针对宁西京教授提出激光脉冲延时方案，在含时薛定谔方程理论框架下探讨了各种参数对激光共振电离效率的影响；并以镥原子共振电离为例，探讨了该方案用于激光共振电离质谱同位素分析的可行性。

The Rhynie Chert has been radiometrically dated at 396 Ma. Plants remains show excellent cellular preservation. Three groups of plants are represented: the Rhyniophytes, the Zosterphyllophytes and a lycopod.

莱尼碎石的同位素顶年结果为 3.96亿年，其中化石植物保存有精美的细胞结构，主要的植物代表类群有莱尼蕨类，工蕨类和石松类。

Outdoor lysimeter with wheat plant growth was used to investigate the environmental fate of ^14C-labeled naphthalene in soil.

采用^14C同位素示踪技术和野外Lysimeter试验，进行了小麦种植条件下多环芳烃萘的环境归趋的定量化研究。

Cd uptake and mobility in marigold seedlings was studied by root-seperated experiment and stable istope technology.

采用水培分根实验和稳定同位素技术研究了镉在万寿菊体内的迁移和积累。

A uranium isotope with mass number 235; capable of sustaining chain reactions.

铀的同位素，原子质量数为，能进行持续的连锁反应。

In order to improve the ablation precision,efficiency and the automation of Laser Ablation System in Mass Spectrograph,the intelligentization of laser ablation system was studied in MS by taking inert gas isotope-MS as an experimental subject.

为了提高质谱仪熔样系统的熔样精度、效率和自动化程度，以惰性气体同位素质谱仪为实验对象，对熔样系统的智能化进行研究。

"For his discovery, by means of his mass spectrograph, of isotopes, in a large number of non-radioactive elements, and for his enunciation of the whole-number rule"

1922年弗朗西斯·阿斯顿英国"使用质谱仪发现了大量非放射性元素的同位素，并且阐明了整数法则"

To 6500m a.s.l.. In September 1998, an 80.36m ice core was also recovered in accumulation zone of the East Rongbuk Glacier on the northern slope of Mount Everest. The ice core was dated by seasonal variations of δ〓O (measured by Mat-Plus gas isotopic mass spectrograph with precision of 0.5‰) and major ions (measured by DX-2010 ions chromatography with precision of ng/L), together with the references of β activity peaks. Annual net accumulation was reconstructed based on the dating and density profile of the ice core.

此外，笔者还参加了1998年9月东绒布冰川80.36m冰芯的钻取工作。1999-2000年，在实验室内对上述样品进行了δ〓O测量(在中科院寒区旱区环境与工程研究所冰芯与寒区环境开放研究实验室用Mat-Plus气体稳定同位素质谱仪测量，以δ〓O平均值为-20.05‰的希夏邦马峰地区大气降水作为标准水，测量精度为0.5‰)、主要可溶性阴阳离子浓度的测定(在美国新罕布什尔大学气候变化研究中心进行，测试仪器为DX-2010型离子色谱仪，其测量精度可达ng/L)以及β活化度的测量(在美国新罕布什尔大学气候变化研究中心进行)，并以此为基础尝试重建了该冰芯的年代和净积累量。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。