Pressure Controlled Self-Assembly of High Quality Three-Dimensional Colloidal Photonic Crystals

A concise pressure controlled isothermal heating vertical deposition (PCIHVD) method is developed, which provides an optimal growing condition with better stability and reproducibility for fabricating photonic crystals (PCs) without the limitation of colloidal sphere materials and sizes. High quality PCs are fabricated with PCIHVD from polystyrene spheres with diameters ranging from 200 nm to 1 mu m. The deep photonic band gap and steep photonic band edge of the samples are most favorable for realizing ultrafast optical devices, photonic chips, and communications. This method makes a meaningful advance in the quality and diversity of PCs and greatly promotes their wide applications.

边坡稳定分析的三维Spencer法

将边坡稳定分析中的二维Spencer法拓展到了三维。该方法对所有条块满足力的平衡以及整体力矩平衡，克服了其他方法中只适用对称问题的缺点，不需已知滑动方向，还可根据滑面的几何特征，进一步得到各条块局部的稳定性系数及其潜在的滑动方向。此外，给出了该方法的实现步骤，其算法的收敛性也较好。最后以不对称问题为算例，并与其他文献中的结果进行比较，验证了该方法的可行性和有效性。

Effect of an annular pupil filter on differential confocal microscopy

Combining differential confocal microscopy and an annular pupil filter, we obtained the normalized axial intensity distribution curve of an optical system. We used the sharp slopes of the axial response curve of the optical system to measure the surface profile of a reflection grating. Experimental results prove that this method can extend the axial dynamic range and improve the transverse resolution of three-dimensional profilometry by sacrificing axial resolution. (C) 2000 Optical Society of America.

The local-field corrective effect on Rabi oscillation of ultrashort pulse excitation in semiconductor GaAs

Rabi oscillation of the thin bulk semiconductor GaAs, which takes into account the effect of the local-field correction induced by the interacting excitons, is investigated by numerically solving the semiconductor Bloch equations. It is found, for a 2 pi few-cycle pulse excitation, that two incomplete Rabi-floppings emerge due to the competition between the Rabi frequency of the incident pulse and the internal-field matrices. Furthermore, for a sub-cycle 2 pi pulse excitation a complete Rabi-flopping can occur because of the absolute phase effect. We ascribe these characteristics of the Rabi oscillation to the renormalized Rabi frequency.

Influences of phase shift on superresolution performances of annular filters

This paper investigates the influences of phase shift on superresolution performances of annular filters. Firstly, it investigates the influence of phase shift on axial superresolution. It proves theoretically that axial superresolution can not be obtained by two-zone phase filter with phase shift pi, and it gets the phase shift with which axial superresolution can be brought by two-zone phase filter. Secondly, it studies the influence of phase shift on transverse superresolution. It finds that the three-zone phase filter with arbitrary phase shift has an almost equal optimal transverse gain to that of commonly used three-zone phase filter, but can produce a much higher axial superresolution gain. Thirdly, it investigates the influence of phase shift on three-dimensional superresolution. Three-dimensional superresolution capability and design margin of three-zone complex filter with arbitrary phase shift are obtained, which presents the theoretical basis for three-dimensional superresolution design. Finally, it investigates the influence of phase shift on focal shift. To obtain desired focal shifts, it designs a series of three-zone phase filters with different phase shifts. A spatial light modulator (SLM) is used to implement the designed filters. By regulating the voltage imposed on the SLM, an accurate focal shift control is obtained.

A planar waveguide Nd : YAG laser using active Q-switching of a hybrid unstable resonator

A planar waveguide laser operating in a negative branch unstable resonator is Q-switched by an acoustooptic mod latorin anew configuration, providing effective, high-speed switching. The laser using a 200-mu m Nd:YAG core, face pumped by 10 laser diode bars, has produced 100-W output in a good beam quality at 100-kHz pulse rate, and 4.5 mJ at lower frequency with 15-ns pulse duration.

γ-LiAlO2晶体生长、改性和热学性质研究

采用快速提拉法生长出了透明、完整的γ-LIAlO2晶体，但是晶体的高熔点和易挥发性限制了γ-LiAlO2晶体质量．采用气相传输平衡法（vapor transport equilibration technique，VTE）工艺对晶体改性，半高宽（FWHM）值从116．9arcsec降至44．2arcsec，继续升高VTE处理温度至1300℃，FWHM值反而升高至55．2arcsec．快速提拉法生长出来晶体，[100]方向和[001]方向的热膨胀系数分别为17．2398×10^-6／K，10．7664×10

中国华中铁角蕨复合体和铁角蕨复合体几个种的生物系统学研究

本文综合形态学、孢粉学和细胞学以及等位酶分析的实验证据，阐明了中国华中铁角蕨复合体（Asplenium sarelii Hook. Complex）中两个四倍体种的起源问题，并从生物系统学的角度讨论了其中多个种的分类学问题。过去认为的四倍体的“华中铁角蕨”被证明是起源于二倍体华中铁角蕨（A. sarelii Hook.）和二倍体细茎铁角蕨（A. tenuicaule Hayata）的杂交，并被处理为新种：武当铁角蕨（A. wudangense Z.R. Wang et X. Hou, sp. nov.）。 而变异铁角蕨（A. varians Wall., Hook. et Grev.）则被认为起源于二倍体细茎铁角蕨（A. tenuicaule Hayata）和二倍体尖齿铁角蕨（A. argutum Ching）的杂交或二者同源四倍体的杂交。根据原细茎铁角蕨（A. tenuicaule Hayata）和尖齿铁角蕨（A. argutum Ching）在宏观和微观特征上的相似性，以及二者的遗传一致度（0.581～0.705），本文将这两个种处理为细茎铁角蕨（A. tenuicaule Hayata）的两个亚种：细茎亚种(ssp. tenuicaule）和尖齿亚种（ssp. argutum （Ching） Vaine, Rashbach et Reichst., ined.）。依据形态和遗传上的相似性以及各自占有一定部分重叠的分布区域，原云南铁角蕨（A. yunnanense Franch.）、宝兴铁角蕨（A. moupinense Franch.）和云南铁角蕨深裂铁角蕨变种（A. yunnanense Franch. var daraeiforme（Franch.）H. S. Kung）被处理为云南铁角蕨（A. yunnanense Franch.）的三个亚种：云南铁角蕨亚种（ssp. yunnanense）、宝兴铁角蕨亚种（ssp. moupinense （Franch.）Z. R. Wang et X. Hou, st. nov.）和深裂铁角蕨亚种（ssp. daraeiforme（Franch.）Z. R. Wang et X. Hou, st. nov.）。 同时，本文运用孢粉学、细胞学、生态学和形态学的综合手段，处理了中国铁角蕨（Asplenium trichomanes L. s. l.）的种下分类问题，划分了中国该种的四个亚种：原亚种A. trichomanes L. ssp. trichomanes，喜钙亚种A. trichomanes L. ssp. inexpectans Lovis，四倍亚种A. trichomanes L. ssp. quadrivalens D. E. Meyer emend. Lovis，粗轴亚种A. trichomanes L. ssp. pachyrachis （Christ） Lovis et Reichst.，并将一个变种：哈如变种A. trichomanes L. var. harovii Moore emend. Midle，归并入粗轴亚种ssp. pachyrahcis (Christ) Lovis et Reichst.，同时提供了它们在中国的分布情况。查阅研究PE的标本时发现一些定名为为A. trichomanes L. var. centrochinense Christ（中国变种）的模式标本碎片，因在形态上和倍性上均不同于已知分类群，认为应给予种的分类地位。

树突状细胞在AIDS灵长类动物模型疾病进程中的作用

非人灵长类动物模型在艾滋病(AIDS)发病机制、传播途径、疫苗和药物等方面的研究中具有重要作用。树突状细胞(DC)作为最重要连接先天免疫与获得性免疫的抗原递呈细胞,在AIDS发病进程中扮演着重要的角色。研究非人灵长类AIDS动物模型中DC亚群数量、表型以及功能的变化,对揭示AIDS发病机制具有十分重要的意义。该文将重点总结近些年来DC亚群在AIDS动物模型发病机制中的作用研究进展,为以后的研究提供思路。

Distracters Impair and Create Working Memory-Related Neuronal Activity in the Prefrontal Cortex

The prefrontal cortex (PFC) has a central role in working memory (WM). Resistance to distraction is considered a fundamental feature of WM and PFC neuronal activity. However, although unexpected stimuli often disrupt our work, little is known about the un

从酵母菌中获得眼镜蛇毒神经多肽菌株及其获得方法

发明为一种从酵母菌中获得眼镜蛇毒神经多肽菌株及其获得方法，主要是通过从天然眼镜蛇毒神经多肽所测定的一级结构及酵母偏爱的密码子设计的全基因序列，利用基因载体pPIczα，构建的重组质粒pPIczα－Cbt，并获得在该酵母菌中的高效表达产物。该菌株和天然眼镜蛇毒神经多肽有同样的结构和效果，可以替代天然眼镜蛇毒神经多肽，可以满足逐渐增加的市场需求，又能保护蛇资源，是一种有应用前景的菌株。

Regulation of zygotic gene activation in the preimplantation mouse embryo: Global activation and repression of gene expression

Superimposed on the activation of the embryonic genome in the preimplantation mouse embryo is the formation of a transcriptionally repressive state during the two-cell stage. This repression appears mediated at the level of chromatin structure, because it is reversed by inducing histone hyperacetylation or inhibiting the second round of DNA replication. We report that of more than 200 amplicons analyzed by mRNA differential display, about 45% of them are repressed between the two-cell and four-cell stages. This repression is scored as either a decrease in amplicon expression that occurs between the two-cell and four-cell stages or on the ability of either trichostatin A tan inhibitor of histone deacetylases) or aphidicolin tan inhibitor of replicative DNA polymerases) to increase the level of amplicon expression. Results of this study also indicate that about 16% of the amplicons analyzed likely are novel genes whose sequence doesn't correspond to sequences in the current databases, whereas about 20% of the sequences expressed during this transition likely are repetitive sequences. Lastly, inducing histone hyperacetylation in the two-cell embryos inhibits cleavage to the four-cell stage. These results suggest that genome activation is global and relatively promiscuous and that a function of the transcriptionally repressive state is to dictate the appropriate profile of gene expression that is compatible with further development.

鱼类性腺发育调控的生物技术应用前景分析

性腺是脊椎动物精卵发生的场所,是生命繁衍的关键器官.本文评述了通过调控特定基因表达与鱼类性腺发育,培育性腺发育被完全抑制的转反义GnRH基因鲤鱼、特异剔除鱼类性腺中的转植基因以及在鱼类性腺中特异表达外源基因的研究进展,认为鱼类性腺有望发展成为一种实施生物技术操纵的新型载体,并探讨了鱼类性腺发育调控在转基因鱼的遗传生态安全对策研究以及新型生物反应器的研制等方面的应用前景.

The complete mitochondrial DNA sequence and the phylogenetic position of Achalinus meiguensis (Reptilia: Squamata)

The mitochondrial genome complete sequence of Achalinus meiguensis was reported for the first time in the present study. The complete mitochondrial genome of A. meiguensis is 17239 bp in length and contains 13 protein-coding genes, 22 tRNA, 2 rRNA, and 2 non-coding regions (Control regions). On the basis of comparison with the other complete mitochondrial sequences reported, we explored the characteristic of structure and evolution. For example, duplication control regions independently occurred in the evolutionary history of reptiles; the pseudo-tRNA of snakes occurred in the Caenophidia; snake is shorter than other vertebrates in the length of tRNA because of the truncations of T psi C arm (less than 5 bp) and "DHU" arm. The phylogenic analysis by MP and BI analysis showed that the phylogenetic position of A. meiguensis was placed in Caenophidia as a sister group to other advanced snakes with the exclusion of Acrochordus granulatus which was rooted in the Caenophidia. Therefore we suggested that the subfamily Xenodermatinae, which contains A. meiguensis, should be raised to a family rank or higher rank. At the same time, based on the phylogenic statistic test, the tree of Bayesian was used for estimating the divergence time. The results showed that the divergence time between Henophidia and Caenophidia was 109.50 Mya; 106.18 Mya for divergence between Acrochordus granulatus and the other snakes of the Caenophidia; the divergence time of A. meiguensis was 103 Mya, and Viperidae diverged from the unilateral of Elapidae and Colubridae was 96.06 Mya.