查询词典 helium

Helium has an atomic number of 2, which means that helium has two protons and two electrons.

氦的原子数为2，此意即氦有二个质子和二个电子。

At the end of the process a carbon core of the star will be surrounded by a shell where helium is still being fused into carbon, which in turn is surrounded by and envelope where hydrogen is converted into helium.

该过程结束时碳的星核会被一层仍然在进行氦聚变为碳的壳层包围，而在这个氦-碳聚变层的外面还包围着一层由氢-氦聚变层。

A vivid example of this: in the two deuterium nuclei polymerization into a helium-4 nucleus, it seems quality is not conservation, is the quality of helium-4 nucleus does not mean that two of the deuteron and quality.

这个例子生动地说明：在2个氘原子核聚合成1个氦4原子核时，似乎质量并不守恒，也就是氦4原子核的质量并不等于2个氘核质量之和。

An experiment on near threshold double ionization of helium impacted with 106 eV electron has been performed by using the newest developed reaction microscope. In this experiment the momenta of all products after double ionization of helium were measured and the five fold differential cross section was obtained for emitted electrons.

利用最新发展起来的适用于低能电子入射的反应显微成像谱仪，对电子轰击He原子近阈值的双电离过程进行了研究，实验测量了反应后4个粒子的全部动量，获得了五重微分截面及出射粒子间的关联信息。

He population analysis proved the interaction between helium atom and V was electrovalent bond. The helium had the stronger attractive to the vanadium atom which was in lattice site.

i-He(o2)体系在四种Ti-He体系(两种八面体和两种四面体)中具有最低的能量，单点能为-6481.4287eV，Ti-He(t1)次之，单点能为-6480.3876eV，在Ti-He体系中氦原子嵌入到o2位置具有更趋稳定的结构。

To compare the effect of helium-oxygen mixtures containing 80%helium or 60%helium on vital capacity and related index.

比较含80%氦和含60%氦的氦氧混合气体对肺活量及其相关指标的影响。

To master the liquid helium transfer method correctly is of a great important sig-nificance in economy for reduction of the liquid helium precool amount, full use of the liquidhelium cool amount and increase of the transfer efficiency of liquid helium In this paper the construction and use demands of the liquid helium transfer tubes,liquidhelium precool and transfer methods are presented.

正确掌握液氦输送方法，对减少液氦预冷量、充分利用氦气冷量和提高液氦输送效率有着十分重要的经济意义。

The hot helium temperature follows HTR-10's nuclear power changes slowly, and there is a large coupling between them, so the RPHHT system adopts cascade control, the minor loop is fast, and the major loop is hot helium temperature control loop whose dynamic response is slow; there is also a large coupling between main helium loop and steam-water loop, and both the main steam temperature measure signal and the heating process of the once-through steam generator are delayed, therefore, the MHFMST applies cascade control, the minor is main helium flow control loop whose dynamic response is fast, and the major is the main steam temperature control loop whose dynamic response is slow.

本文运用机理建模法，建立了HTR-10系统动态控制模型，然后进行了动态性能仿真，将堆芯用集中参数表示，冷却剂按一维流动处理；直流蒸汽发生器按二回路工质不同的相分为预热段、蒸发段和过热段，建立了三环节控制模型，得到HTR-10系统控制模型；仿真结果与数值计算结果对比表明，本文所建立的控制模型，能近似地反映HTR-10的动态特性，适合设计控制系统。

I used the homemade ECDL to measure the 2S-3D two photon transition spectrum of Helium , the advantages are that the expense of homemade ECDL is cheap and have good output power. At the same time, I used the electronic part can be got in the market to manufacture a pulse generator in the experiment, the pulse generator can control the output frequency, the pulse width, the relative phase and also can simultaneously control four sets of systems or instruments need the TTL pulse control. The advantage is that the cost of the pulse generator is cheap and the pulse generator is stable. To isolate the magnetic field I used the magnetic foil to helium cell. I also built a gas discharge system, the switch sequence of this system can be controlled by the pulse generator. Finally I built a detecting system can measure the helium energy state. It is cheap and can be combined with the comb laser system in my laboratory.

本实验是利用一台自制的外腔雷射系统来量测2S-3D的氦原子双光子跃迁，其优点在於自制的外腔雷射之费用非常便宜，也有不错的输出功率，同时在实验中我利用市售的电子零件制作了一台脉冲产生器，可控制输出的频率、脉冲宽度以及相对的相位，且可同时控制四套需要TTL脉冲控制的系统或仪器，优点除了便宜之外，也非常稳定；为了隔绝磁场，利用了磁场隔绝金属箔，我也在实验室中建立了一组气体放电系统，其系统可以用脉冲产生器来控制开关时序，最后，我建造了一个氦原子能阶的量测系统，而且费用低廉，可与本实验室的另外一门研究光梳雷射系统做结合。

I used the homemade ECDL to measure the 2S-3D two photon transition spectrum of Helium , the advantages are that the expense of homemade ECDL is cheap and have good output power. At the same time, I used the electronic part can be got in the market to manufacture a pulse generator in the experiment, the pulse generator can control the output frequency, the pulse width, the relative phase and also can simultaneously control four sets of systems or instruments need the TTL pulse control. The advantage is that the cost of the pulse generator is cheap and the pulse generator is stable. To isolate the magnetic field I used the magnetic foil to helium cell. I also built a gas discharge system, the switch sequence of this system can be controlled by the pulse generator. Finally I built a detecting system can measure the helium energy state.

本实验是利用一台自制的外腔雷射系统来量测2S-3D的氦原子双光子跃迁，其优点在於自制的外腔雷射之费用非常便宜，也有不错的输出功率，同时在实验中我利用市售的电子零件制作了一台脉冲产生器，可控制输出的频率、脉冲宽度以及相对的相位，且可同时控制四套需要TTL脉冲控制的系统或仪器，优点除了便宜之外，也非常稳定；为了隔绝磁场，利用了磁场隔绝金属箔，我也在实验室中建立了一组气体放电系统，其系统可以用脉冲产生器来控制开关时序，最后，我建造了一个氦原子能阶的量测系统，而且费用低廉，可与本实验室的另外一门研究光梳雷射系统做结合。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。