查询词典 ultrafast

Objective To evaluate the value of transthoracic echocardiography and transesophageal echocardiography in diagnosing aortic dissections and compare them with ultrafast computed tomography and magnetic resonance imaging.

目的 探讨经胸超声心动图、经食管超声心动图对主动脉夹层的诊断价值，并与磁共振影像、超高速CT等影像诊断进行比较。

At the present time, their size has arrived at nanometer scale, and it approximately takes several picoseconds, or even shorter time, for free carriers to transport during such small distances. Therefore, research of carrier dynamics in silicon on shorter and shorter time scale is urgently developed. Processes on such short time scale are difficultly measured by traditional electronic method, so ultrafast spectroscopy method is the only choice of carrying out such experiments. Additionally, application of photoelectric detectors is severely influenced by laser.

近年来，硅半导体器件尺寸不断变小，目前已经缩小到了纳米尺度，载流子在这个尺度内的输运时间大约在ps量级，这促使人们需要对越来越短的时间尺度内硅的载流子动力学进行研究，传统的电子学方法很难对这么短时间尺度内发生的现象进行测量，超快光谱探测几乎成了进行这类研究的唯一测试手段。

8Ps for native and NaBH〓 chemically modified reaction centers, and the transfer process from H〓 to the final electron acceptor Q〓 occurs in about hundreds of picoseconds. On the other hand, the energy transfer from excited B was obviously slowed down in the pheophytin-exchanged RC. By considering the change of free energy of ion pair P〓Phe〓, it could be expected there might exist alternative pathway of charge separation and electron transfer in pigment-exchanged reaction center. In addition, the influence of acid environment on the ultrafast dynamics of reaction center was also experimentally observed, which shows an evident difference from that of in native RC, and further investigation should be carried out to elucidate the origination.

在色素置换后的反应中心中，以B为起点的能量传递较天然RC的情况明显减慢，约在450fs左右，考虑到置换后的反应中心中P的自由能有所提高以及其仍然保持的光化学活性，这一较慢的能量传递也可能预示着还存在着其它的能量传递通道；另外，还对酸性处理的反应中心中的超快光动力学过程进行了尝试性的研究，发现由于色素分子的聚集以及蛋白环境的改变，BChl分子的激发态动力学过程有着明显不同于天然反应中心的情况。

In recent years, size of silicon devices has been decreasing. At the present time, their size has arrived at nanometer scale, and it approximately takes several picoseconds, or even shorter time, for free carriers to transport during such small distances. Therefore, research of carrier dynamics in silicon on shorter and shorter time scale is urgently developed. Processes on such short time scale are difficultly measured by traditional electronic method, so ultrafast spectroscopy method is the only choice of carrying out such experiments. Additionally, application of photoelectric detectors is severely influenced by laser.

近年来，硅半导体器件尺寸不断变小，目前已经缩小到了纳米尺度，载流子在这个尺度内的输运时间大约在ps量级，这促使人们需要对越来越短的时间尺度内硅的载流子动力学进行研究，传统的电子学方法很难对这么短时间尺度内发生的现象进行测量，超快光谱探测几乎成了进行这类研究的唯一测试手段。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。