Learning large-scale spatial relationships in a maze and effects of MK-801 on retrieval in the rhesus monkey

Monkeys have strong abilities to remember the visual properties of potential food sources for survival in the nature. The present study demonstrated the first observations of rhesus monkeys learning to solve complex spatial mazes in which routes were guid

三峡永久船闸高边坡开挖三维离散元数值模拟:3-D Simulation of the Excavation of High Steep Slope of Three-Gorges Permanent Lock by Distinct Element Method

采用面一面接触的三维离散元刚性块体模型,从实测节理面中取出其中的三组,按照其倾向、倾角和节理间距将三峡永久船闸未开挖的区域划分为10~5个离散单元,通过施加力边界条件,给出了与实测初始地应力场接近的数值模拟结果；然后,分4步模拟了永久船闸的开挖过程。计算结果表明：开挖过程会引起节理面出现张开趋势,个别岩体还会沿着节理面滑移。岩体位移的不对称现象较为自然地说明了由节理引起的岩体各向异性特征。

瓦斯煤尘爆炸火焰光谱的实验研究

本文概述了瓦斯煤尘爆炸火焰光谱实验研究的重要性,我们在弱爆炸和探测器小视场角的条件下,利用自己研制的多波道仪,在一端开口的Φ200cm×2900cm大型管道里,得到了CH4、空气和煤尘的混合物在不同状态下,特征波长λ等于0.8875、1.000、1.505、2.801和4.346微米(μ)的绝对辐射强度及其有关的变化规律,对结果进行了分析讨论,并与国外实验结果进行了对比,根据测量λ=4.346μ绝对辐射强度和我们选择的黑体辐射模型,获得了爆炸火焰的温度,该项研究不仅在工业中具有重要意义,而且对燃烧和化学动力学的研究也具有参考价值。

Near-field x-ray phase contrast imaging and phase retrieval algorithm

Theoretical analyses of x-ray diffraction phase contrast imaging and near field phase retrieval method are presented. A new variant of the near field intensity distribution is derived with the optimal phase imaging distance and spatial frequency of object taken into account. Numerical examples of phase retrieval using simulated data are also given. On the above basis, the influence of detecting distance and polychroism of radiation on the phase contrast image and the retrieved phase distribution are discussed. The present results should be useful in the practical application of in-line phase contrast imaging.

透射型光折变体全息光栅对超短脉冲激光光束衍射的特性

在Kogelnik耦合波理论的基础上，考虑光栅记录介质的色散效应的影响，研究了光折变体全息光栅对不同偏振状态的超短脉冲激光光束衍射的性质，讨论了高斯型入射脉冲激光光束的谱宽与光栅的有效衍射谱宽之比不同时，衍射和透射光束的光谱宽度、时间宽度、波形和衍射效率的变化。结果表明，光栅的有效衍射谱宽受光栅参量及入射条件的影响，对衍射性质的影响很大，且在考虑光栅记录介质的色散效应时减小。当入射脉冲的偏振方向垂直于入射面时，光栅的有效衍射谱宽大于偏振方向平行于入射面的情形，衍射效率在入射脉冲宽度较大时小于偏振方向平行于

Growth, etching morphology and spectra of LiAlO2 crystal

gamma-LiAlO2 single crystal was successfully grown by Czochralski method. The crystal quality was characterized by X-ray rocking curve and chemical etching. The effects of air-annealing and vapor transport equilibration (VTE) on the crystal quality, etch pits and absorption spectra of LiAlO2 were also investigated in detail. The results show that the as-grown crystal has very high quality with the full width at half maximum (FWHM) of 17.7-22.6 arcsec. Dislocation density in the middle part of the crystal is as low as about 3.0 x 10(3) cm(-2). The VTE-treated slice has larger FWHM value, etch pits density and absorption coefficient as compared with those of untreated and air-annealed slices, which indicates that the crystal quality became inferior after VTE treatment. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

黄瓜白粉病抗机制的细胞化学及形态学上探讨

黄瓜白粉病[Sphaerotheca fuligenea [Schlecht] Poll]是瓜类尤其是温室瓜类的主要病害之一。本工作用光学显微镜、扫描电镜、透射电镜细胞化学方法，在不同层次上探索抗病和感病寄主，黄瓜，对黄瓜白粉病的不同反应。实验结果如下： 1. 从外观上观察，抗病和感病品种在接种七天后就表现明显的病症差异。在抗病品种上白粉发生较少，感病的则白粉甚多。 2. 从光学显微镜下发现，在抗病品种叶子上，白粉病孢子萌发率虽然比感病的高，但是以后在菌丝生长及产生孢子梗能力上却比感病品种的弱。 3. 从扫描电镜中观察到，接种两天后，抗病品种叶片上，病菌孢子有的菌丝生长不良，至第三天，有的菌丝顶端发生弯曲、变形、甚至降解。而在感病品种上则未见此现象。 4. 从透射电镜的细胞化学定位来看，接种四天后，抗病品种具较高的过氧化物酶活性，酶活性增高的部位是在表皮细胞、叶肉细胞壁、乳突、膜包体(membrane-bound body)和过氧化物体。在感病品种的乳突中，穿透钉壁及外围一圈上缺少过氧化物酶和多酚氧化酶活性，而在抗病品种中则具有酶活性。糖蛋白的相对量在感病品种中较抗病的为多。在感病品种中主要分布在表皮细胞相互连接的壁上和表皮与栅栏细胞连接的壁上以及穿透处附近的表皮细胞外壁。 在电镜下我们观察到还有一些细胞学上差异，即在抗病品种上，有的附着胞不能穿透细胞壁，部分穿透细胞壁后不能穿透乳突，甚至穿透乳突后也不能发育成吸器或发育不良;而在感病品种则一般吸器发育良好。基于以上的实验结果，我们认为过氧化物酶和多酚氧化酶活性可能与壁木质化有关，本质化的细胞壁可作为抵御病原侵入的屏障。糖蛋白则可能与病原和寄主的识别有关。看来黄瓜白粉病抗病机理似是多因素的协调和组合而起作用。

硅基蓝—紫光发光材料及其制备工艺

本发明涉及一种新型硅基蓝一紫光发光材料及其制备工艺，该发光材料是在单晶硅基片层上设有发光层，在发光层上设有薄膜保护层；其制备工艺是先将单晶硅片在高温加气氛下进行热处理；然后将预处理后的单晶硅片注入离子进行掺杂；再用高能重离子对掺杂硅片进行辐照；本发明的性能稳定且发光效率较高，可发出蓝一紫光；其制备工艺代替了传统工艺。

Accelerated evolution of the pituitary adenylate cyclase-activating polypeptide precursor gene during human origin

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide abundantly expressed in the central nervous system and involved in regulating neurogenesis and neuronal signal transduction. The amino acid sequence of PACAP is extremely conserved across vertebrate species, indicating a strong functional constraint during the course of evolution. However, through comparative sequence analysis, we demonstrated that the PACAP precursor gene underwent an accelerated evolution in the human lineage since the divergence from chimpanzees, and the amino acid substitution rate in humans is at least seven times faster than that in other mammal species resulting from strong Darwinian positive selection. Eleven human-specific amino acid changes were identified in the PACAP precursors, which are conserved from murine to African apes. Protein structural analysis suggested that a putative novel Deuropeptide might have originated during human evolution and functioned in the human brain. Our data suggested that the PACAP precursor gene underwent adaptive changes during human origin and may have contributed to the formation of human cognition.

云南保山猪线粒体DNA D loop区序列初步分析

为了解云南保山猪(Baoshan pig)的遗传多样性及其遗传背景，我们测定了19个个体线粒体DNA Dloop高变区1 1 5 363 - 1 5 801片段序列438帅。检测到1。种单倍型，包括8个多态位点，其中5次T/ C转换、1次G/ A转换、1次G/ C颠换和1次A/ T颠换，其A.T.GX碱基的平均含量分别为35.4%.26.9%.13.2%和24.5 %,A+ T含量(62 .3)明显高于G+ C含量(37 .7 %)。对于保山猪的保种及其持续利用有着重要的理论指导意义。