关于多阵列设计模式下的pad 分配问题

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

Influence of the semi-insulating GaAs Schottky pad on the Schottky barrier in the active layer

The influence of the sidegate voltage on the Schottky barrier in the ion-implanted active layer via the Schottky pad on the semi-insulating GaAs substrate was observed, and the mechanism for such an influence was proposed. (C) 1996 American Institute of Physics.

A finite-element analysis of viscoelastically damped sandwich plates

A finite element analysis associated with an asymptotic solution method for the harmonic flexural vibration of viscoelastically damped unsymmetrical sandwich plates is given. The element formulation is based on generalization of the discrete Kirchhoff theory (DKT) element formulation. The results obtained with the first order approximation of the asymptotic solution presented here are the same as those obtained by means of the modal strain energy (MSE) method. By taking more terms of the asymptotic solution, with successive calculations and use of the Padé approximants method, accuracy can be improved. The finite element computation has been verified by comparison with an analytical exact solution for rectangular plates with simply supported edges. Results for the same plates with clamped edges are also presented.

Motion simulation of annular polishing

Based on the Coulomb friction model, the frictional motion model of workpiece relating to the polishing pad was presented in annular polishing. By the dynamic analysis software, the model was simulated and analysed. The conclusions from the results were that the workpiece did not rotate steadily. When the angular velocity of ring and the direction were the same as that of the polishing pad, the angular velocity of workpiece hoicked at the beginning and at the later stage were the same as that of the polishing pad before contacting with the ring. The angular velocity of workpiece vibrated at the moment of contacting with the ring. After that the angular velocity of workpiece increased gradually and fluctuated at a given value, while the angular velocity of ring decreased gradually and also fluctuated at a given value. Since the contact between the workpiece and the ring was linear, their linear velocities and directions should be the same. But the angular velocity of workpiece was larger than that of the polishing pad on the condition that the radius of the workpiece was less than that of the ring. This did not agree with the pure translation principle and the workpiece surface could not be flat, either. Consequently, it needed to be controlled with the angular velocity of ring and the radii of the ring and the workpiece, besides friction to make the angular velocity of workpiece equal to that of the polishing pad for obtaining fine surface flatness of the workpiece. Copyright © 2007 Inderscience Enterprises Ltd.}

环形抛光中工件形状对抛光速度的影响

本文基于库仑摩擦模型，模拟了不同形状的工件在环形抛光的运动。从结果可知，（1）如果工作环处于自由转动状态，工件的角速度在环形抛光中比抛光盘的角速度大；（2）可通过控制工作环的角速度使工件和抛光盘的角速度同步。工作环的角速度依赖于工作环和工件的半径、抛光盘－工件和抛光盘－工作环的摩擦系数，以及抛光盘的角速度；（3）有尖角的工件与工作环的接触处于不连续状态，导致二者的接触状态发生变化和工件角速度的波动。

甘蓝型油菜（Brassica napus L.）花粉和柱头的发育及其与自交不亲和性的关系

作者用扫描电镜、透射电镜和组织化学方法研究了甘蓝型油菜(Brassica napus L．)花粉和柱头的发育及相互作用,得到了如下结果： 一．甘蓝型油菜具有典型的同型孢子体自交不亲和性(Homomorphic and sporophytic self-incompatibility)。自花授粉后，部分花粉粘住在乳突细胞表面，随后萌发出花粉管，花粉管生长受阻于乳突细胞，花粉管表现出各种异常形态，缠绕卷曲(Coiled pattern),顶端膨大成基足状(pad-Like swelling),花粉管二叉分枝（dichotomous branching Pollen tubes），花粉管相互连接(connections of pollen tubes），有的花粉粒还形成两个花粉管。 二．不同时期的乳突细胞的扫描电镜观察表明： 开花前6—7天 乳突细胞壁内陷，柱头中央有一沟槽; 开花前4—5天 乳突细胞被有孔的块状物覆盖; 开花前2—3天 覆盖物消失，壁表面只剩下波状纹或小凹; 开花前l - 2天 乳突细胞充分吸水膨胀，呈指状，排列疏松，细胞壁上有一些小颗粒。此时的乳突细胞已发育成熟。 三.不亲和授粉时，花粉和乳突细胞均有强烈的胼胝质荧光。 四.乳突细胞的组织化学特点：缺乏淀粉积累，细胞壁和细胞质中有过氧化物酶活性。 五.乳突细胞的超微结构特点：细胞壁分为三层，蜡质层、角质层和纤维素层。粗面内质网成群分布在细胞壁附近，并以及泡形式向细胞壁分泌物质。缺乏质体，细胞核位于乳突细胞基部，细胞中央为大液泡占据。 六.花粉的超微结构发育特点：单核花粉已发育出内壁和外壁，外壁内层不明显。细胞核位于中央。细胞质浓厚，缺乏层膜结构而积累大量淀粉粒的质体存在于细胞质中。其他细胞器不发达。两细胞花粉时期，花粉壁接受乌氏体转运的孢粉素和含油体转运的脂类物质。生殖细胞没有壁，悬浮在营养细胞的细胞质中。细胞核大，细胞质稀薄，只有一些嵴不明显的线粒体。营养细胞的核显著，细胞质浓厚，线粒体发达，质体内部的淀粉消失，转变成嗜饿小体。内质网短而粗，遍布于细胞质中，高尔基体缺乏。 七.绒毡层积极参与了花粉外壁的建成。首先，它通过分泌作用把物质（可能是蛋白质）转移到单核花粉的腔隙中或在它后期滚解后，由分布在二细胞花粉间的粗面内质网合成蛋白质，转移到花粉壁内。其次，绒毡层细胞的质体层膜形成许多造油小体，至二胞花粉时，造油小体进入壁的柱状层，参与花粉鞘形成。第三，绒毡层细胞形成许多乌氏体，花粉发育后期，乌氏体与花粉外壁接触，将孢粉素转移到花粉外壁上。

HIV-1 C亚型密码子优化gp120基因重组腺病毒载体的构建及表达

目的 构建含有HIV-1 C亚型gp120基因重组腺病毒载体,并在293细胞中表达gp120蛋白.方法 PCR扩增,获得HIV-1 C亚型gp120片段,定向克隆入腺病毒转移载体pTrack-CMV,线性化后转化至含有腺病毒骨架载体pAd-easy-1的大肠埃希菌BJ5183,获得重组子prAd-gp120,PacⅠ酶切纯化后转染293细胞,包装成复制缺陷型重组腺病毒vAd-gp120.结果 经PCR、酶切及DNA测序,插入片段大小、方向正确,获得了具有感染力的vAd-gp120重组腺病毒;通过Western 印迹检测,重组腺病毒在293细胞中表达出分子量为120 kD的蛋白.结论 成功构建了含有HIV-1 C亚型gp120基因重组腺病毒载体,并获得该基因的表达.

Revision of the labeonine genus Sinocrossocheilus (Teleostei : Cyprinidae) from South China

Sinocrossocheilus was recently diagnosed by Su et al. (2003) as consisting of nine species, i.e. S. bamaensis, S. guizhouensis, S. liuchengensis, S. longibullus, S. tridentis, S. microstomatus, S. nigrovittatus, S. labiatus, and S. papillolabrus. It is actually a catch-all genus that is composed of some species misidentified from Pseudocrossocheilus and Hongshuia. Sinocrossocheilus is here redefined based mainly on the details of the lower lip morphology; it is easily separated from all other Asian Labeonini genera in possessing a lower lip with its median lobe modified into a densely papillated, greatly protruded, crescentic fold and a papillose, slightly protruded, triangular fleshy pad which is posteriorly continuous with the mental region. Two species are recognized in this genus: S. guizhouensis and S. labiatus. Detailed redescriptions are given for the two species. All remaining species do not fit with the new definition of Sinocrossocheilus; six species, i.e. S. papillolabrus, S. nigrovittatus, S. bamaensis, S. longibullus, S. liuchengensis, and S. tridentis, should be moved to Pseudocrossocheilus and S. microstomatus to Hongshuia.

Description of a new genus and two new species of labeonine fishes from South China (Teleostei : Cyprinidae)

A new genus and two new species are described from the Pearl River drainage in Guangxi Province, South China. Hongshuia, new genus, can be distinguished from all other Asian genera of the Labeonini by having a lower lip with its median lobe modified into a round, fleshy plate peripherally greatly protruded so as to form a ring-like fold that is posteromedially continuous with the mental region, and centrally sunken so as to form a round, flat, fleshy pad. This genus is distinct from all other Asian labeonine genera of the Garrina except for one newly described species of Parasinilabeo ( P. longibarbus), Pseudocrossocheilus, and Sinocrossocheilus, in the presence of well-developed maxillary barbels. Hongshuia differs from the above three genera in the lower lip morphology, and further from both Pseudocrossocheilus and Qianlabeo in the number of pharyngeal tooth rows and from Sinocrossocheilus in the colour pattern. Two new species, H. banmo and H. paoli, differ in the distribution density and degree of development of papillae on the rostral fold, depth of indentations on the distal edge of the rostral fold, presence or absence of papillae on the lower lip, size and shape of tubercles on the tip of the snout and anterior portion of the lachrymal, length, position and colour pattern of the dorsal fin, and snout length.

Molecular analysis of silver crucian carp (Carassius auratus gibelio Bloch) clones by SCAR markers

Random amplified polymorphic DNA (RAPD) molecular markers specific for one, two or three clones have been identified from five gynogenetic clones of silver crucian carp (Carassius auratus gibelio Bloch) using RAPD markers developed earlier. In this study, three RAPD markers (RA1-PA, RA2-EF and RA4-D) produced by Opj-1, and two RAPD DNA fragments (RA3-PAD and RA5-D) produced by Opj-7, were selected for molecular cloning and sequencing. Sequence data indicated that there were identical 801-bp nucleotide sequences in the shared marker RA1-PA cloned respectively from clones P and A, and the shared marker RA2-EF (which was cloned from clones E and F), were also of identical 958-by nucleotide sequences. The nucleotide sequences of the shared marker RA3-PAD fragments were also similar for 1181 by among clones P, A and D. The specific fragment RA4-D was composed of 628 bp, and the fragment RA5-D from clone D contained 385 nucleotides. According to the nucleotide sequences, we designed and synthesized five pairs of sequence characterized amplified regions (SCAR) primers to identify the specific fragments in these gynogenetic clones of silver crucian carp. Only individuals from clones P and A amplified a specific band using a pair of SCI-PA primers synthesized according to the marker RA1-PA sequences, whereas no products were detected in individuals from clones D, E and F. The PCR products amplified using SC2-EF and SC3-PAD primers were as expected. Furthermore, the pair of SC4-D primers amplified specific bands only in individuals from clone D, although weak bands could be produced in all individuals of the five clones when lower annealing temperatures were used. However, an additional pair of SC5-D primers designed from the RA5-D marker sequences could amplify a DNA band in individuals from clones P, A and D, and the same weak band was produced in clone E, whereas no products were detected in individuals from clone F. Searches in GenBank revealed that the 385-bp DNA fragment from RA5-D was homologous to the 5' end of gonadotropin I beta subunit 2 gene and growth hormone gene. No homologous sequences were found for other markers in GenBank. The SCAR markers identified in this study will offer a powerful, easy, and rapid method for discrimination of different clones and for genetic analyses that examine their origins and unique reproductive modes in crucian carp. Furthermore, they will likely benefit future selective breeding programs as reliable and reproducible molecular markers. (C) 2001 Elsevier Science B.V. All rights reserved.

干旱对不同抗旱性冬小麦旗叶光合及主茎干物质转运的影响

以冬小麦品种长武134(抗旱性强)和陕253(抗旱性弱)为材料,研究干旱对旗叶净光合速率和叶绿素含量、主茎及其组成节间花前积累干物质的转运及其对穗粒重贡献的影响。结果表明,干旱条件下长武134主茎穗粒重降幅小于陕253;干旱缩短了小麦花后旗叶光合速率高值持续期(PAD)和叶绿素含量缓降期(RSP),长武134受影响程度较小。长武134除穗下节外,其余各节间及茎杆干物质转运量及对籽粒贡献率降幅均大于陕253;干旱提高了陕253穗下节和倒二节干物质转运率,降低了倒三节和下部节干物质转运率,茎杆干物质转运率无明显变化;长武134除穗下节外其余各节间及茎杆干物质转运率均明显低于对照,而且距离穗部越远的节位降低幅度越大。上述结果表明,干旱条件下不同节位干物质转运能力变化与距离穗远近有关,花前茎杆干物质转运并不能补偿籽粒产量的损失,花后旗叶光合功能期延长是小麦抗旱高产的主要原因。

干旱对不同冬小麦旗叶光合产物供应能力的影响

研究干旱对小麦旗叶光合产物供应能力的影响,揭示小麦抗旱高产的生理机制,为提高小麦的抗旱能力及高产稳产提供理论依据。【方法】在防雨池栽培条件下,以旱地冬小麦品种长武134(抗旱性强)和水地冬小麦品种陕253(抗旱性弱)为试材,以适宜水分处理为对照(CK,土壤含水量为田间持水量的70%～75%),研究干旱处理(土壤含水量为田间持水量的50%～55%)对不同冬小麦旗叶光合产物供应速率(净光合速率和蔗糖合成能力)和供应持续期的影响。【结果】与对照相比,干旱处理降低了冬小麦灌浆中后期旗叶净光合速率,缩短了净光合速率高值持续期(PAD),其中长武134降幅较小,净光合速率较高;干旱处理提高了冬小麦灌浆初期旗叶的蔗糖磷酸合成酶(SPS)活性,其中长武134增幅较大,且在灌浆中后期依然能保持相对较高的蔗糖供应能力;干旱处理缩短了冬小麦叶绿素含量缓降期(RSP),提高了丙二醛(MDA)含量,加速了旗叶的衰老,缩短了光合产物的供应持续期,其中长武134受干旱影响较小;干旱处理降低了冬小麦灌浆中后期主茎穗粒质量积累量及其速率,其中长武134降幅较小。【结论】干旱条件下,抗旱品种长武134旗叶在灌浆中后期可维持较高的光合产物...

光子晶体的微腔特性

为了设计一种高品质因子的光子晶体微腔和研究单缺陷光子晶体微腔谐振模波长随晶格常数的变化规律,使用时域有限差分法（difference time-domain method）和基于Baker算法的Padé近似方法计算了半导体材料上空气孔阵列光子晶体微腔的谐振模波长和品质因子.得到的新型光子晶体微腔的品质因子达246510,单缺陷光子晶体微腔模波长随晶格常数α和孔半径r的近似为线性变化关系