Percolation transport and magnetic transitions in a phase-separated manganite La_(0.55)Ca_(0.45)MnO_3

The structural,electronic and magnetic properties of La0.55Ca0.45MnO3 were measured.A rapid change of lattice parameters appeared around 190 K associated with the d z2 orbital ordering and charge ordering (CO) states that were reflected by both magnetization and resistivity.Great difference of magnetizations between the field-cooling (FC) and zero-field-cooling (ZFC) modes below the charge ordering temperature TCO in high magnetic field (H > 4 T) was clearly seen.A field of 5 T (threshold field) is sufficie...     

腹腔镜诊治女性不孕症50例临床研究

目的对应用腹腔镜诊治女性不孕症进行临床研究。方法 2001年9月至2009年12月,本院对女性不孕症患者行腹腔镜检查及手术的患者50例。结果在我院女性不孕症患者中,发现盆腔异常者占95.55%。继发不孕和原发不孕患者的病因构成比较差异有统计学意义(P<0.05)。结论对于药物治疗效果不佳的多囊卵巢患者来说,腹腔镜是一种有效的治疗方法。     

极坐标自动测磁装置

为了测量批量生产具有不同曲率半径的弯转磁铁,我们设计一种极坐标自动测磁装置,该装置可利用线圈或霍尔元件,对磁铁进行绝对测量和相对测量,用霍尔元件作绝对测量时,精度好于3×10~(-4),用长线圈作相对测量时,精度好于1×10~(-4),以用于检查批量生产磁铁的生产工艺的稳定性。     

化学共沉淀法制备纳米级PbTiO_3粉末

本文以Ｈ２ＴｉＯ３、Ｈ２Ｏ２、ＮＨ３、Ｐｂ（ＮＯ３）２为主要原料，用化学共沉淀法制备了纳米级ＰｂＴｉＯ３。确定了反应物Ｈ２ＴｉＯ３、Ｈ２Ｏ２、ＮＨ３的最佳摩尔比为１∶８∶２。用不同的退火温度和退火时间对样品处理得到相应粒径的纳米粉体，再由Ｘ射线和透射电镜对这些粉体进行了评估。并对反应的机理作了初步探讨。     

β—BaB_2O_4晶体的ps脉冲参量放大

本文报导用被动锁模Nd:YAG激光器的二次谐波(532nm)泵浦两块BBO晶体获得580nm～2500nm可调谐参量放大的实验研究。简并点附近能量转换效率达10％。     

Superconducting Busline Design for HT—7U Tokamak

Superconducting (SC) tokamak HT-7U has seven pairs of buslines connecting toroidal/Poloidal coils and the current leads,These SC buslines(SCBLs) share a common cryostat and are made of the calbe in conduit conductors(CICCs) arranged as a decoupling configuration.In order to reduce the heat loads conducted from the seven current leads with a capacity of 15kA during the magnets cooldown.the buslines with a much lower thermal conduction were employed in comparison with the current leads,and a special cooling loop was designed.     

非共振微波场驱动情况下的简并量子拍频激光器

本文讨论了被非共振微波场驱动的三能级原子系统在无粒子数反转时所表现的激光增益以及在无自发和受激辐射时所表现的光学吸收两种物理现象以及产生的条件。     

A Calculation of Steady Pressure Drop and an Analysis of HT—7U CICC

Under the condition of steady,the pressure drop of coolant is mainly caused by friction along the cable.in the CICC(cable-in-conduit-conductor).helium flow within the conductor consists of two parallel interconnected tubes.The velocity distribution has some differece between the central channel and conductor space.The region of Reynolds number is from 10^3 to 10^6.This paper describes the calculation of pressure drop of HT-7U CICC at various mass flows.It is assumed that the coolant flows in two parallel,rough tudes during the caclulation.     

复杂介质的折射波射线追踪

本文由二维层状介质模型出发论述了折射波逐段迭代射线追踪的原理，由于连接炮点和接收点之间的初始射线路径满足费马原理，因此其上任意连续三点之间的射线路径也满足费马原理。据此即可分别推导出透射中间点和折射点的一阶修正公式，进行折射线逐段迭代计算求出整条射线路径。将此原理推广到二维块状介质模型，用于解决复杂介质中的折射波射线追踪，推导出任意界面上折射点的一阶显式增量修正公式。避免了高次多元方程的求解，具有计算速度快，能够适用任意界面的特点。文中还指出了在块状介质模型中用逐段迭代法进行射线追踪较在层状介质中难度大的原因在于射线路径点的增、删。实例试算表明。文中所述方法是一种有效的折射波射线追踪方法。     

KCX-1型快速齿科手机消毒器

口腔齿科手机是HBV、HCV、HIV等血液传播性疾病和消化道传染病的传播媒介。采用激光泵浦光源在辐射过程中产生的瞬间高温、丰富的光谱分布的强光作为载体,对齿科手机进行快速、彻底、无损伤的消毒灭菌。