1. There is also a section on isotope dilution analysis.

2. The isotopes are measured by counting their alpha emissions; each isotope emits alpha radiation of a characteristic frequency.

3. The isotope U-235 is unstable, decaying by a process called spontaneous fission.

4. The lunar surface also contains the light isotope helium-3, which is implanted in the surface by the solar wind.

5. Isotope gastric emptying studies may be useful in clinical practice.

6. Nevertheless the association or dissociation of the lead isotope signatures for ancient glasses contributes to the overall technological picture for them.

7. A stable isotope of potassium, 9K, is converted to 39Ar by neutron bombardment of the sample to be dated.

8. Uranium has two radioactive isotopes, each of which decays to an isotope of lead and helium.

9. The oxygen isotope chemistry of the corals reflects the composition and origin of the water in which they lived.

10. A hydrogeologist and an isotope chemist provided professional advice to the ongoing geothermal resource study.

11. Woodhead etal. combine such analyses with oxygen isotope analyses, and it is variations in the latter that are particularly significant.

12. The third isotope of hydrogen, hydrogen-3 or tritium, is highly radioactive and has a very short half-life.

13. The deep-sea core oxygen isotope record is a framework for a relative chronology for the Pleistocene.

14. Measurements of the resulting isotope ratios closely approximated those found in carbonaceous chondrite meteorites.

15. Every radioactive isotope provides an independent clock for measuring geological time.

15.

16. An analogue to mineral chronometry is O isotope geothermometry.

17. Increasing the helium-3 supply would mean scaling up the production of the dangerous radioactive isotope tritium.

18. The time taken for half of the atoms of a radioactive isotope to decay is called its half-life.

19. In any organic specimen, carbon-14 is present in tiny quantities, being swamped by the more abundant isotope, carbon-12.

20. Magnox reactors produce plutonium containing about 75 percent of plutonium 239 isotope.

21. Aiding his efforts was an improved method for dating rock known as uranium-lead isotope analysis.

22. Each case has to be considered on its merits where an ambiguous answer emerges from the stable isotope data.

23. As well as decaying naturally to a stable lead isotope, U occasionally also divides in half.

24. In one path, the 40K decays to a calcium isotope, 40Ca.

25. The new ingredient in the assessment of how many deaths the Windscale cloud caused is the radioactive isotope, polonium 210.

26. She could hear the adjacent streetlight sizzling like a radioactive isotope.

27. The simplest radioactive methods are based on decay of a radioactive isotope into a stable one.

28. They include a laboratory for handling tritium, the heavy radioactive isotope of hydrogen which is a fuel for fusion reactors.

29. The dynamics of transportation of HTO (tritium water) in a simulated tea soil ecosystem were studied on simulated pollutants using isotope tracer technique.

30. Uptake, translocation, and distribution of 14C-labelled oligosaccharides in watermelon seedling were investigated by the means of radioactive isotope tracer.

31. Stable isotope labeled L - tryptophan is an application of nucleus technology in amino acids.

32. Brachytherapy, the direct application of a radioactive isotope into the tumor bed, delivers a high dose to the tumor as compared to the surrounding normal tissue.

33. Oxygen isotope variation maybe results from crystallization, degasification or hybridization of crust materials.

34. The isotope analytic technique of the agrochemical remainder is increasingly valued by people, and has made a substantial development.

35. Environmental records show that in that area the environment was extremely cold and wet during the interstage of the last glaciation(deep sea oxygen isotope stage 3).

36. Method Cellular proliferation were studied by isotope labeling technique, and the concentrations of intracellular anticancer drugs were measured by fluorospectrophotometry.

37. Centrifuge cascade hydraulics plays an important role in efficient isotope separation in gas centrifuge cascades.

38. A synthetic element produced in trace quantities by helium isotope bombardment of curium.

39. The Strontium isotope composition of marine autogenetic minerals can reflect the sea level fluctuation trend during the minerals deposited.

40. The paper for the first time reports on the analytical results of hydrogen-oxygen isotope of the hot-spring water from Fujian and Jiangxi.

41. The most abundant isotope of hydrogen, H 1, with atomic mass 1.

42. An isotope of hydrogen with mass number greater than 1; deuterium or tritium.

43. Here we use an expanded marine sedimentary section from Spitsbergen to reconstruct the carbon isotope excursion as recorded in marine organic matter.

44. Its most durable isotope survives only about 200,000 years - a minute span on a stellar scale.

45. The maintenance experinence of old MAT isotope mass spectrometer has been discussed.

46. Solving the static characteristic roots of hydraulics in isotope separation centrifuge cascades is an important problem.

47. As Discovery News reports, thanks to a critical shortage last year, the price of the isotope helium-3 has skyrocketed from $150 per liter to $5,(http://) 000 per liter.

48. It would take many months of follow-up work in shore-based laboratories, including critical isotope geochronological work, to confirm our findings.

49. This article reported that 9 cases of CRF and 27 cases in good health were observed in our Department using isotope scintiscanning technique.

50. Even Francium's most stable isotope, Francium - 223 only has a half - life of 22 minutes.

51. The researchers used what's called an ion microscope to compare the amount of normal hydrogen in the moon rocks to the amount of the hydrogen isotope deuterium, which carries an extra neutron.

52. At present, radioactive isotope tracing and impulse oxygen activation are the two mostly used methods for injection profile logging in separated-zone water injectors.

53. Isotope tracer technique showed that glucosamine sulfate above can pass through the skin in vitro of test animal in a diffusion cell and osmose into subcutaneous tissue.

54. The contents concern in the development of radioactive isotope tracer energy spectrum logging device, the calibration experiment in model well, the analysis of experimental data, the data ...

55. Stable isotope ratio analysis is an effective method for the identification of fruit juice adulteration.

56. The studies on constant element, trace element, REE and lead isotope indicate that the subalkalic intrusive complex body is formed by deep crust mantle migmatization.

57. To determine the content of Chloramphenicol ( CAP ) in honey using stable isotope dilution technique.

58. Today, most cyclotrons are used either for instructional purpose or for isotope production.

59. Another isotope, lithium-6, is overabundant: there may be as much as 1000 times too much of it.

60. For instance, because it takes only 8 days for the radioactive isotope iodine-131 to decay away to half its original level of radioactivity, simply waiting should be a fix.

61. Isotope of hydrogen, chemical symbol 2H or D, atomic number 1 (But atomic weight approximately 2).

62. The city's challenge, chiefly, is to dispose of cesium-137, a radioactive isotope with a half-life of 30 years.

63. A radioactive transuranic element in the actinide series, artificially produced in trace amounts. Its longest-lived isotope is No255 with a half-life of3 minutes. Atomic number102.

64. "What it amounts to, " said Billings, "is that The Goose can convert any radioactive isotope into a stable one. It has developed the perfect defense against radiation sickness.

65. A radioactive isotope of cobalt with mass number '0 and exceptionally intense gamma-ray activity, used in radiotherapy, metallurgy, and materials testing.

66. The metabolic kinetics of branched chain amino acids (BCAA) and aromatic amino acids (AAA) in normal subjects and patients with severe viral hepatitis as studied with 4 stable isotope labeled tracers.

67. For example, by GIS thematic map and overlaying analysis every factor is visualized to administer to sample design of isotope investigation.

68. The heavy ion beam energy, as well as the charge stripping efficiency, was calculated by using the charge state stripping formula and empirical formula of stable isotope mass number .

69. The mechanism of oxygen isotope exchange between alkali feldspar and fluid is mainly dissolution reprecipitation.

70. Most of the time the fuel is uranium, artificially enriched so that 4 to 5 percent is the chain-reacting isotope uranium 235; virtually all the rest is uranium 238.

71. The stable carbon isotope composition in plant is a powerful tool for studying on carbon cycle, biogeochemistry and paleoenvironment.

72. The effect of parathion on the synthesis of protein and nucleic acid in Phaeodactylum tricornutum was studied with isotope tracing methods.

73. The lead isotope study shows that ores of the Mujiazhuang copper deposit and the host rocks contain very high radiogenic lead.

74. Provides isotope data for almost all known nuclides . From Berkeley Laboratory.

75. Then the stable carbon isotope composition of PAH series such as alkyl naphthalene and alkyl phenanthrene in crude oil samples of Tuha basin were determined on GC-IRMS.

75. is a online sentence dictionary, on which you can find nice sentences for a large number of words.

76. "What it amounts to, " said Billings, "is that The Goose can convert any radioactive isotope into a stable one..."

77. Based on the characteristics of carbon isotope and components of gas in this field, it is believed that the gas is unlikely a mixture of biogas and the lower thermogenesis natural gas.

78. It is put forward an improvement method that a laser ion source and multilayer target combining with gas jet transport method can be used on on-line isotope separator.

79. Sulfur isotope studies demonstrate that sulfur was derived from the mantle, and oxygen isotope analyses reveal that the fluid of the deposit was a mixed source of magmatic water and atmospheric water.

80. Methods Through the methods of petrochemistry and Rb, Sr, O, S isotope geology and inclusion research.

81. The meteoric origin of geothermal water in study area is evidenced by its environmental isotope composition.

82. Isotope tracing technology was used on animal experiment since 1920 s.

83. The studies on constant element, trace element, PEE and lead isotope indicate that the subalkalic intrusive complex body is formed by deep crust-mantle migmatization.

84. Because experimental condition and analytic technique have been improved, "double spike" isotopic dating method of lead isotope and analyses calc.

85. Isotope dilution mass spectrometry (IDMS) and inductively coupled plasma mass spectrometry (ICPMS) are the two most usual methods for measuring the ratio of lead isotopes.

86. Using GC/C/MS online carbon isotope analytic technic, abundant imforma- tion about single molecular carbon isotope composition can be taken from micro-samples(chromatographical scale).

87. The research on isotope mass spectrometers in China since 1980 is reviewed.

88. In a fission reaction(), the light particle (the free neutron) collides with the heavy particle (the uranium or plutonium isotope) which splits into two or three pieces.

89. Compared with common amino acids , the isotope - labeled amino acids have accordant structure and analogical property.

90. Isotope tracing and simulated ecosystem techniques were employed to study transfer, bioaccumulation and degradation of pirimicarb in aquatic ecosystem.

91. Conclusion It is not difficult to diagnose RT correctively. Cervico thoracic X ray film, radioactive isotope and CT checking can ensure the extent and character of the retrosternal part.

92. Element and isotope geochemistry of the lamprophyres veins in the Xikuangshan antimony ore deposits issystematically researched in this article, aiming at discussing genesis of lamprophyres.

93. After seven rounds of bacterium-based selection, the enrichment of each round was tested by isotope labeled ssDNA binding assay.

94. We use the rare isotope Beryllium-10, which develops in the land surface via cosmic radiation.

95. As isotope geochronology uses the elements of long half-life to determine the geological age, the half-life through out the period may be considered to be constant.

96. Some characteristics such as accumulation, transference of HTO in simulated marine ecosystem were studied with isotope tracer technique.

97. The thermal spring water has a light isotope composition in summer and a heavy isotope composition in winter.

98. The study on secondary isochron of anomalous lead is a very important problem in the common lead isotope geology.

99. The composition of gas and its isotope sampled from water, reservoir and hydrocarbon bearing inclusion can be used to research the solution and degasification process during geological time.

100. Nuclear Chemistry: radioactive chemicals, radiation chemistry, radiation chemistry, isotope chemistry, nuclear chemistry.

101. According to the isotope determination data of the primary sulfide from the vein and rock, it is suggested that the vein′s sulfur source is similar to granite porphyry and quartz diorite.

102. Relations between Britain and Russia nosedived after the 2006 murder of Alexander Litvinenko with polonium-210, a rare radioactive isotope, blamed by his associates on Russian agents.

103. Zhang Y. (2002) Isotope geochronology and the age of the earth.

104. This formation has a distinct binary structure and pronounced geomorphological features as well as isotope age data. It is in erosional unconformable contact with the underlying Zhiyu Formation.

105. Water isotope technique is an important method in the field of groundwater studies, which can help to explain groundwater activity mechanism from macroscopy and microscopy.

106. The stable isotope of hydrogen, oxygen and carbon are reinterpreted. The relationship between isotope constituent and paleoenvironment is understood.

107. An isotope log of water injection profile is affected by many factors, specially the string contamination.

108. Convolution operations are performed between the calculated relative isotope abundances and the mass spectral target peak shape functions to form calculated isotope peak cluster data.

109. Wang Xianbin. 1989. Geochemistry and Cosmochemistry of noble gas isotope. Beijing:Science Press, 112 (in Chinese.

110. Measured isotope peak cluster data in a mass spectral range is obtained for a given calibration standard.

111. A naturally or artificially produced radioactive isotope of an element.

112. The research on geochemical characteristics and isotope age suggests that the deposit belongs to a magma-metasomatic pegmatite type deposit related to Fufang and Huitong granitic mass in genesis.

113. There are several ways to separate excited from unexcited molecules, thus harvesting the desired isotope.

114. According to the isotope determination data of the primary sulfide from the vein.

115. Cracked gas in high-temperature causes methane carbon isotope to heavy.

116. Finally, the effects of reversible reaction to the isotope enrichment was investigated.

117. We also bring forward a new method to recognize the different biological source for C29 sterane predominance using organic carbon isotope.

118. Caesium - 137 is a radioactive isotope, formed mainly through nuclear fission.

119. This site is a useful starting point for identifying web-based geochemistry resources in all geochemical fields, e. g. volcanology , organic, mineralogy, isotope geochemistry and cosmochemistry.

120. The isotope shifts, hyperfine structure, spontaneous emission branch ratio of the first excited level and Doppler width of the atom vapor beam were measured using laser induced fluorescence.

121. Hyperfine spectrum; Nonlinear optics; Degenerate four waves mixing; The equivalent grating; Isotope detecting.

122. In addition, carbon and nitrogen isotope and its ratio was important indicator in the riverine biogeochemistry study.

123. The Pb, S isotopic study shows that the mass migration and the fractional distillation of Pb isotope took place in the whole rock and in the cement.

124. The isotope ratio is directly used for comparing oils or gases.

125. There are differences between natural and adulterated juices in stable isotope ratio.

126. According to the clear geologic relation and information related about the isotope, the Neozoic volcanic activity can be divided into 10 stages.

127. Research on chemical components and isotope composition of carbon and hydrogen of natural gases from the Tarim basin shows that all discovered gases in this basin are thermogenic.

128. An UV nitrogen laser, which uses domestic hydrogen thyratron as switch and isotope as preionizer, is reported.

129. The geological cause of the mixed layer and its distributing characters are defined by spore pollen analysis, scanning electron microscope and C14 isotope test in this paper.

130. It is a radiological poison, specifically absorbed by bone marrow, and is used, especially the highly fissionable isotope Pu 239, as a reactor fuel and in nuclear weapons.

131. The studies of microelement, rare earth element and isotope compositions that the Huogeqi polymetallic ore field was formed in rift basin of back arc continental marging during Proterozoic Era.

132. This article briefly describes the thoughts, key points and test result of a low noise pulse amplifier used in Laser Isotope Mass Spectrometer.

133. A radioactive, inert, gaseous isotope of radon a half - life of 3.92 seconds.

134. Each element has at least one isotope with unstable nuclei that can undergo radioactive decay.

135. System stability (Ss) is one of the most important specifications of the Isotope mass spectrometer (IMS). It influences the quality of the data detected by the IMS directly.

135. try its best to collect and create good sentences.

136. Carbon isotope in soil carbonates is an important paleoclimate data carrier.

137. The mineral - fluid oxygen isotope exchange in granitic rocks is mainly a non - equilibrium one in open system.

138. Noble gas isotope has been widely used to identify sources of natural gas.

139. In this paper, we made use of silver-staining detection method instead of isotope labelling method for AFLP analysis in maize cauliflower and tomato.

140. A radioactive isotope of cobalt emits penetrating gamma rays that are used in radiation therapy.

141. Objective:To develop a method for determining the metabolites of nitrofuran antibiotics in aquatic products by HPLC-MS/MS using isotope internal standard dilution technique.

142. This paper analysed the carbon and oxygen isotope composition of brachiopods fossils from the Devonian Period in Sichuan Province.

143. But this isotope is radioactive and decays about six times faster than does uranium 238, which indicates that the fissile fraction was much higher in the distant past.

144. The first samples were made through a nuclear reaction involving fusion of an isotope of californium , 249 Cf , with one of oxygen, 18 O.

145. Combined diagnosis by abdominal X-Ray, serum AFP assay , liver ultrasound and isotope scan, arteriogram and CT may be helpful in the identification of the tumor nature.

146. BEIJING - Trace levels of radioactive isotope cesium-137 and cesium-134 were detected in the air of 13 of the Chinese mainland's 31 provincial-level regions on Monday, up from eight regions on Sunday.

147. On-line system was developed to gauge film thickness using isotope, by which the problem of difficulty in measuring wide film thickness was resolved.

148. The adding of stable isotope of iodine to the dissolver can improve the removal of 131I.

149. The isotope of uranium with mass number235, fissionable with slow neutrons.

150. The decomposition reaction of the complex anisole·BF3 is indispensable during the separation of boron-10 isotopes by chemical isotope exchange distillation between BF3 and the complex anisole·BF3.

151. Those radioactive elements are N-16 the radioactive isotope (or version) of nitrogen (air).

152. What's more, it detected comparatively high levels of the isotope deuterium in Venus'upper atmosphere.

153. The importation of the radioactive isotope,(http:///isotope.html) radiation equipment and other radioactive materials should come up to applicable state regulations.

154. Why meteoritic oxygen isotope ratios are significantly different from those on Earth has mystified scientists for years.

155. The method of determining Ni, Cu and Pbi n urine with isotope dilution mass spectrometry ( IDMS ) is described.

156. However, this modality does not allow differentiation of inflammatory from lymphomatous lesions, and normal thymus may take up the isotope as well.

157. The meteorite, which recently fell to the tropical island in Pacific Ocean, proved to be the present well of the thinnest radioactive isotope!

158. The isotope analysis of minim lead in the gold dust has special meaning.

159. In either case, the accelerated particle impacts a target material, potentially knocking free protons or neutrons and making a new element or isotope.

160. The oldest aeolian deposit on terrace T 2 is loess L 1, corresponding to oxygen isotope time MIS 2.

161. This indium isotope was created at the same time as the earth.

162. Cosmochemistry is the study of the chemicals found within the Solar System , including the origins of the elements and variations in the isotope ratios.

163. In this core, the vertical distributions of dinoflagellate cyst, organic carbon, carbon isotope and biogenic silica were studied.

164. Therefore, von Blanckenburg, and the GFZ geoscientist, Dr. Hella Wittmann, have analysed this "cosmogenic" isotope in the sand of the Swiss Alps rivers and, thus, in the direct products of erosion.

165. An isotope of carbon known as carbon-14 would also be stable, as would a form of oxygen, so the organic reactions necessary for life would be possible.

166. Intraband electronic interaction has bigger influence on isotope effect than interband electronic interaction.