查询词典 carbon 14

The cationic polyelectrolyte P (AM-DMDAAC with a certain scope of molecule weight was synthesized by controlling synthesis conditions. P is a kind of functional additive for carbon paper designed especially for proton exchange membrane fuel cell. The kinetic behavior of copolymerization of AM and DMDAAC initiated by Na2S2O8-Na2SO3 redox system in aqueous solution was studied.

通过控制合成工艺条件，合成了具有一定相对分子质量范围的阳离子聚电解质，作为质子交换膜燃料电池专用碳纸功能性添加剂，研究了过硫酸钾亚硫酸钠氧化还原引发体系水溶液聚合的动力学行为，得到的速率方程为：Rp=Kp［K2S2O8］0.55［Na2SO3］0.56［M］1.14。

The coring was successfully operated on the winter ice-cover of the lake in 2000 and the pioneer practice of the ""off-the-ice"" coring proves to be very useful and economic for taking quality cores from lakes in northern China.A multidisciplinary investigation has been carried out on core HQH4, one of the three 11-m-long cores. Results from previous investigation include lithostratigraphy, radiocarbon dating, paleoecology of Ostracoda, stable isotopic record of ostracod shells, total nitrogen and organic carbon, C/N ratio, 81 C of organic matter etc.

在对深度为11米的HQH4岩芯开展了~(14)C年代学、岩性地层学、介形类古生态及介壳稳定同位素、有机碳和总氮及C/N比值、有机碳同位素等多学科综合分析测试和研究工作的基础上，本硕士学位论文研究侧重开展了：1HQH4岩芯烧失量(Loss-on-ignition)的系统分析测定及该地层学变量的古湖泊和环境变化意义的研究；2沉水植物川蔓藻化石种子生态学特征及其在黄旗海湖泊水位重建和气候变化研究方面的重要意义的研究。

The results based on the gas, carbon isotope and water chemistry geothermometer suggest that the temperature of the deep reservoir is about 250±7℃, while the temperature ranges of the median and shallow reservoirs are 241~190℃ and 195~154℃ respectively....

气体、同位素、水化学地球化学温标显示，深层热储的温度约为 2 5 0± 7℃、中、浅层地热储温度的变化范围分别为 2 41～ 190℃和 195～ 15 4℃。根据岩浆来源 CO2 和 CH4之间的碳同位素分馏值计算，目前该区深部岩浆热源的温度应高于 5 14℃。

Organic matter less than 7000 years old can be dated using radiocarbon dating, This uses the fact that the isotope carbon-14 is found in the atmosphere and taken in by plants when they photosynthesize, and subsequently assimilated by the animals that feed on them.

在7000年以内的有机体可以用放射性碳来推测它的年代。

The result shows that the percentages of the emission, fixation and transfer amount of carbon i...

碳的排放、固定、转移量占当年吸收量的百分比分别为82.6％—84.4％、14.5％—15.7％和1.1％—1.7％，年固碳量为1.1×108—1.4×108t。

Products, the company has an annual generation capacity scale 2,750,000,000 kwh; annual production capacity of 400,000 tons of calcium carbide, PVC, 170,000 tons, 140,000 tons of caustic soda, hydrochloric acid 36,000 tons, 90,000 tons of lime nitrogen, Dicyandiamide 10,000 tons, Refining Dicyandiamide 01,500 tons, 4,000 tons of activated carbon.

产品 、规模公司年发电量27.5亿千瓦时；年产电石40万吨、聚氯乙烯17万吨、烧碱14万吨、盐酸3.6万吨、石灰氮9万吨、双氰胺1万吨、精制双氰胺0.15万吨、活性炭4000吨。

For decades, archaeologists have used a technique called carbon dating to work out how old their finds are.

几十年前，考古学家就已经开始用一项叫做碳14测年的方法来检测他们发掘的东西有多悠久。

The scientists used carbon dating to figure out how old the bone was.

科学家用碳-14年代测定法来计算这些骨骸的年代。

Libby discovered radioactive carbon element dating method and solved the puzzle of earth and human history.

利比发现的放射性碳14定年法，解答了地球与人类历史上的疑惑。

3The modified repoxy resin according to the above item(1) or (2),wherein X in the formula (1) is a hydrocarbon group having 8 to 14 carbon atoms,(4)the modified epoxy resin according to any of the above items (1) to (3),wherein the compound of the formula (1) is 1,1-bis-(4-hydroxyphenyl)-3.3.5-trimethyl-cyclohexane.

三修改repoxy树脂按上述第项或第(2)，其中X在公式(1)是烃77 有8至14个碳原子，(4)环氧树脂据上述任何第项至第(3)，其中复合配方(1) 1，1 双(4-羟基苯)-3.3.5-三甲基cy clohexane。陈丰应该没有错了

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。