Laser-diode-pumped Cr4+,Nd3+: YAG with self-Q-switched laser output of 1.4 W

By use of a laser diode as a pump source, a self-Q-switched laser from a Cr,Nd:YAG crystal is demonstrated. The output Q-switched traces are very stable, the threshold pump power is 3.5 W, the pulse duration is 50 ns, and the slope efficiency is as high as 20%. In addition, the pulse width remains constant while the pulse repetition rate Varies with pump power. (C) 2000 Optical Society of America OCIS codes: 140.0140, 140.2020, 140.3380, 140.3480, 140.3540, 140.3580.

Opioid Withdrawal for 4 Days Prevents Synaptic Depression Induced by Low Dose of Morphine or Naloxone in Rat Hippocampal CA1 Area In Vivo

The formation of memory is believed to depend on experience- or activity-dependent synaptic plasticity, which is exquisitely sensitive to psychological stress since inescapable stress impairs long-term potentiation (LTP) but facilitates long-term depression (LTD). Our recent studies demonstrated that 4 days of opioid withdrawal enables maximal extents of both hippocampal LTP and drug-reinforced behavior; while elevated-platform stress enables these phenomena at 18 h of opioid withdrawal. Here, we examined the effects of low dose of morphine (0.5 mg kg(-1), i.p.) or the opioid receptor antagonist naloxone (1 mg kg(-1), i.p.) on synaptic efficacy in the hippocampal CA1 region of anesthetized rats. A form of synaptic depression was induced by low dose of morphine or naloxone in rats after 18 h but not 4 days of opioid withdrawal. This synaptic depression was dependent on both N-methyl-D-aspartate receptor and synaptic activity, similar to the hippocampal long-term depression induced by low frequency stimulation. Elevated-platform stress given 2 h before experiment prevented the synaptic depression at 18 h of opioid withdrawal; in contrast, the glucocorticoid receptor (GR) antagonist RU38486 treatment (20 mg kg(-1), s.c., twice per day for first 3 days of withdrawal), or a high dose of morphine reexposure (15 mg kg(-1), s.c., 12 h before experiment), enabled the synaptic depression on 4 days of opioid withdrawal. This temporal shift of synaptic depression by stress or GR blockade supplements our previous findings of potentially correlated temporal shifts of LTP induction and drug-reinforced behavior during opioid withdrawal. Our results therefore support the idea that stress experience during opioid withdrawal may modify hippocampal synaptic plasticity and play important roles in drug-associated memory. (C) 2009 Wiley-Liss, Inc.

紫茎泽兰精油各馏份对4种仓库害虫的杀虫活性

：用紫撬泽兰精油的20℃～150。C，150℃一200℃，20．0℃，230℃．230屯。300℃和300℃以上馏协，分剐以 稚．簦嘴，L的熏蒸浓爰楚理米象、玉采象、簿豆象牵蚕熹象，螬幕表磷凄5争犍静中，娃15。℃～200℃馏傍转荣虫活性 最高，其洗是20℃一150℃和200℃～230气馏份，而300℃以上馏份的杀虫活性靛低。进一步的生测结装表明．150屯一 200℃增傍对米象、玉来氧、绿黛象和善豆象24h的l(葡分莉为15 5li4，17．8124，培．0302和16．2671mg／Lo

1 x 4 Ge-on-SOI PIN Photodetector Array for Parallel Optical Interconnects

High-quality Ge film was epitaxially grown on silicon on insulator using the ultrahigh vacuum chemical vapor deposition. In this paper, we demonstrated that the efficient 1 4 germanium-on-silicon p-i-n photodetector arrays with 1.0 mu m Ge film had a responsivity as high as 0.65 A/W at 1.31 mu m and 0.32 A/W at 1.55 mu m, respectively. The dark current density was about 0.75 mA/cm(2) at 0 V and 13.9 mA/cm(2) at 1.0 V reverse bias. The detectors with a diameter of 25 mu m were measured at 1550 nm incident light under 0 V bias, and the result showed that the 3-dB bandwidth is 2.48 GHz. At a reverse bias of 3 V, the bandwidth is about 13.3 GHz. The four devices showed a good consistency.

Submicrosecond rearrangeable nonblocking silicon-on-insulator thermo-optic 4 X 4 switch matrix

A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4 X 4 switch matrix is designed and fabricated. A spot-size converter is integrated to reduce the insertion loss, and a new driving circuit is designed to improve the response speed. The insertion loss is less than 10 dB, and the response time is 950 us. (c) 2007 Optical Society of America

半导体可饱和吸收镜自启动的Kerr锁模Cr~(4+)∶YAG激光器

采用传统的X型像散腔,利用一块精心设计的半导体可饱和吸收镜(SESAM)做启动元件,实现了自启动的Kerr锁模Cr4+∶YAG激光器.输出脉冲的最窄脉宽小于80 fs,脉冲重复频率为120 MHz,脉冲峰值功率可以达到100 W以上.

GaAs/Al（0.4）Ga（0.6）As多量子肼红外探测器光吸收计算

于2010-11-23批量导入

电子与类铍N~(3+)和O~(4+)离子碰撞激发截面的相对论扭曲波计算

采用全相对论扭曲波方法,系统地计算了类铍N3+和O4+离子从基态到2s2p和2p2的各激发态以及从亚稳态到2p2各激发态的电子碰撞激发截面,详细地讨论了靶态的关联效应对激发截面的影响.结果表明:对于2s-2p的单电子激发,在低能碰撞时,靶态的电子关联效应起非常重要的作用,且使得激发截面降低;而高能碰撞时,靶态波函数的描述对连续态波函数的影响比较小,对激发截面影响也比较小.对于2s2-2p2的双电子激发,其中基态2s21S0到J=0的2p23P0,1S0的激发截面较大,其主要原因是末离子态波函数与基组态波函数的混合,但是其他几个激发的激发截面较小.

C~(4+)离子与金属表面碰撞引起的X射线产生截面的研究

<正>离子与原子碰撞物理学是利用离子与原子相互作用,通过测量碰撞产物的状态及碰撞产物之间的相关性来研究碰撞机制和过程的一门学科。测量碰撞后的各种反应产物及其截面数据,对于天体物理、重离子物理、受控热核聚变、材料科学、粒子加速器技术及激光技术等许多研究领域都有十分重要的意义。

用1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮从硝酸中萃取痕量钍

用1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮(PMBP)为萃取剂,~(234)Th作示踪剂,完成了在硝酸介质中痕量钍溶剂萃取行为的研究。在~(234)Th萃取效率与酸度、萃取剂浓度、平衡时间等依赖关系的条件实验的基础上,获得了萃取钍的最佳条件。使用改进的PMBP萃取钍的流程,从~(18)O离子辐照过的铀靶中分离钍,钍样品的γ射线单谱显示绝大部分反应产物和大量铀的去除是满意的。