The characteristics of O＋HD （v = 0, j = 0） reaction dynamics

The analytical potential energy function of HDO is constructed at first using the many-body expansion method.The reaction dynamics of O+HD(v = 0,j = 0) in five product channels are all studied by quasi-classical trajectory(QCT) method.The results show that the long-lived complex compound HDO is the dominant product at low collision energy.With increasing collision energy,O+HD → OH+D and O+HD → OD+H exchange reactions will occur with remarkable characteristics,such as near threshold energies,different reaction probabilities,and different reaction cross sections,implying the isotopic effect between H and D.With further increasing collision energy(e.g.,up to 502.08 kJ/mol),O+HD → O+H+D will occur and induce the complete dissociation into single O,H,and D atoms.     

Electro-acupuncture promotes survival, differentiation of the bone marrow mesenchymal stem cells as well as functional recovery in the spinal cord-transected rats

Background  

Bone marrow mesenchymal stem cells (MSCs) are one of the potential tools for treatment of the spinal cord injury; however, the survival and differentiation of MSCs in an injured spinal cord still need to be improved. In the present study, we investigated whether Governor Vessel electro-acupuncture (EA) could efficiently promote bone marrow mesenchymal stem cells (MSCs) survival and differentiation, axonal regeneration and finally, functional recovery in the transected spinal cord.     

Stacking chirped pulse optical parametric amplification

Stacking chirped pulse optical parametric amplification based on a home-built Yb³⁺-doped mode-locked fiber laser and an all-fiber pulse stacker has been demonstrated. Energic 11 mJ shaped pulses with pulse duration of 2.3 ns and a net total gain of higher than 1.1 × 10⁷ at fluctuation less than 2% rms are achieved by optical parametric amplification pumped by a Q-switched Nd:YAG frequency-doubled laser, which provides a simple and efficient amplification scheme for temporally shaped pulses by stacking chirped pulse.     

Crystallization of Ge2Sb2Te5 phase—change optical disk media

In this paper, the crystallization behaviour of amorphous Ge₂Sb₂Te₅ thin films is investigated using differential scanning calorimetry), x-ray diffraction and optical transmissivity measurements. It is indicated that only the amorphous phase to face-centred-cubic phase transformation occurs during laser annealing of the normal phase-change structure, which is a benefit for raising the phase-change optical disk's carrier-to-noise ratio (CNR). For amorphous Ge₂Sb₂Te₅ thin films, the crystallization temperature is about 200℃ and the melting temperature is 546.87℃. The activation energy for the crystallization, E_a, is 2.25eV. The crystallization dynamics for Ge₂Sb₂Te₅ thin films obeys the law of nucleation and growth reaction. The sputtered Ge₂Sb₂Te₅ films were initialized by an initializer unit. The initialization conditions have a great effect on the reflectivity contrast of the Ge₂Sb₂Te₅ phase-change optical disk.     

A study on the short—wavelength and high—numerical—aperture phase—change recording

In this paper, we discuss the phase-change recording at a short-wavelength (514nm) and a high numerical aperture (0.85). Effects of recording power and pulse width on the size of the recording marks are studied. The minimum recording mark with a length of approximately 220nm has been observed. The capacity of about 17GB for a single-layer disc of a 12cm diameter can be obtained. The maximum carrier-to-noise ratio reaches 45dB at a writing power of 13--14mW.     

非双倍条件下极大奇异积分算子的估计

It is shown that the maximal singular integral operator with kernels satisfying Ho rmander＇s condition is of weak type （1,1） and L^p （1〈p〈∞） bounded without assuming that the underlying measure p is doubling. Under stronger smoothness conditions,such estimates can be obtained by using a Cotlar＇s inequality. This inequality is not applicable here and it is noticeable that the Cotlar＇s inequality maybe fails under Hormander＇s condition.     

Diode-end-pumped composite Nd:YVO4 yellow laser based on intracavity frequency-doubled self-Raman laser

We report an intracavity frequency-doubled Q-switched self-Raman yellow laser at 587 nm. A composite Nd:YVO₄ crystal was utilized as self-Raman gain medium. The maximum average output power of yellow light obtained was 1.5 W at the incident pump power of 30 W and at a repetition rate of 50 kHz, corresponding to the optical conversion efficiency of 5%. The shortest pulse width, the maximum pulse energy and the highest peak power were measured to be 5.8 ns, 46.7 μJ and 5.9 kW, respectively.     

相似非线性算子的谱相等

引进非线性算子相似的定义,证明了相似的非线性算子的谱相等。     

几种扭振复合超声变幅杆的研究

对左、右段为圆柱型、中间段为变截面杆的三段式复合扭振超声变幅杆给出了频率方程和参数计算通式据此得出中间段l2分别为指数型、类国雄型、类悬镇线型和类余弦型，而l1=l3≠0，或l1≠0；或l3≠0的各种组合复合杆的参数计算式，并算出了其参数值，给出了主要参数曲线．测试了十组典型试件的谐振频率和放大系数，实验结果与理论值基本一致，本法可组合成许多适应各种用途的扭振复合杆     

Ag-N共掺p型ZnO的第一性原理研究

采用基于密度泛函理论的第一性原理赝势法对Ag-N共掺杂ZnO体 系以及间隙N和间隙H掺杂p型ZnO: (Ag, N)体系的缺陷形成能和离化能进行了研究. 结果表明, 在Ag_Zn和N_O所形成的众多受主复合体中, Ag_Zn-N_O受主对不仅具有较低的缺陷形成能同时其离化能也相对较小, 因此, Ag_Zn-N_O受主对的形成是Ag-N共掺ZnO体系实现p型导电的主要原因. 研究发现, 当ZnO: (Ag, N)体系有额外间隙N原子存在时, Ag_Zn-N_O受主对容易与N_i形成Ag_Zn-(N₂)_{m O}施主型缺陷, 该施主缺陷的形成降低了Ag-N共掺ZnO的掺杂效率因而不利于p型导电. 当间隙H引入到ZnO: (Ag, N)体系时, H_i易与Ag_Zn-N_O受主对形成 受主-施主-受主复合结构(Ag_Zn-H_i-N_O), 此复合体的形成不仅提高了Ag_Zn-N_O受主对在ZnO中的固溶度, 同时还能使其受主能级变得更浅而有利于p型导电. 因此, H辅助Ag-N共掺ZnO可能是一种有效的p型掺杂手段. 关键词： p型ZnO 缺陷形成能 受主离化能 第一性原理