50 resultados para Ambler, Jaquelin, 1742-1798.
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
采用混合法研究张力腿定位的曲线形水中悬浮隧道的温度内力.分析表明,由温度升高导致隧道膨胀(或收缩)所产生的轴向力很小,主要是径向力,同时还会产生扭矩和弯矩.通过数值实验给出张力腿的水平径向力与张力腿弹簧系数、隧道曲率半径、截面抗弯刚度及圆心角之间的变化关系.计算结果表明温度内力变化复杂,两组张力腿温度内力此消彼长.
Resumo:
应用频散可控耗散格式对环形激波在圆柱形激波管内绕射、反射和聚焦的问题进行了数值模拟研究. 研究结果表明环形激波形成强烈聚焦的关键因素是环形激波在圆柱形管道中向对称轴运动时,绕射激波就不断加速而不作通常情况下的衰减;不同马赫数的环形激波绕射也产生不同马赫数及形状的准柱形激波,导致聚焦效果和位置的差异;另外,环形激波聚焦于一个点而圆柱形激波聚焦于一条线,两者有本质不同.
Resumo:
Fluorescence of Tm3+/Er3+ codoped bismuth-silica (BS) glasses and the sensitization of Ce3+ are investigated. It shows that Ce3+ codoping with Tm3+/Er3+ in BS glasses results in a quenching of Tm3+ ion emission from F-3(4) to the H-3(6) level. Consequently, the 1.47 mu m emission occurs after the population inversion between the H-3(4) and F-3(4) levels. Furthermore, the codoped glasses show the broad emission spectra over the whole S and C bands with full-width at half-maximum (FWHM) up to about 119nm, as it combines 1.55 mu m emission band of Er3+ with 1.47 mu m emission band of Tm3+ under 800nm excitation.
Resumo:
Thermal resistance and thermal rise-time are two basic parameters that affect most of the performances of a laser diode greatly. By measuring waveforms received after a spectroscope at wavelengths varied step-by-step, the spectrally resolved waveforms can be converted to calculate the thermal rise-time. Basic formulas for the spectrum variation of a laser diode and the measurement set-up by using a Boxcar are described in the paper. As an example, the thermal rise-time of a p-side up packaged short-pulse laser diode was measured by the method to be 390 mu s. The method will be useful in characterizing diode lasers and LID modules in high-power applications. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
Er3+-doped lithium-potassium mixed alkali aluminophosphate glasses belonging to the oxide system xK(2)O-(15x)Li2O-4B(2)O(3)-11Al(2)O(3)-5BaO-65P(2)O(5) are obtained in a semi-continuous melting quenching process. Spectroscopic properties of Er3+-doped glass matrix have been analysed by fitting the experimental data with the standard Judd-Ofelt theory. It is observed that Judd-Ofelt intensity parameters-Omega(t)(t=2, 4 and 6) of Er3+ change when the second alkali is introduced into glass matrix. The variation of line strength S-ed[I-4(13/2),I-4(15/2)] follows the same trend as that of the Omega(6) parameter. The effect of mixed alkali on the spectroscopic properties of the aluminophosphate glasses, such as absorption cross-section, stimulated emission cross-section, spontaneous emission probability, branching ratio and the radiative lifetime, has also been investigated in this paper.
Resumo:
本发明涉及一种大蹼铃蟾博玛津蛋白及其基因和在制药中的应用,属于生物医学领域。大蹼铃蟾博玛津蛋白是从中国两栖类动物大蹼铃蟾皮肤分泌物中分离得到的一种单链多肽,氨基酸全序列为:NH2GFPIYEIDNRPGCYVDPAERVACAGAGVTKAECKAKGCCFISARRNTIWCFKLKESADAWKCAVPMNTRVACAGAGVTPAECKGKGCCFSSYYGTV WCFKPQE-COOH)编码大蹼铃蟾博玛津蛋白的基因的cDNA由1061个核苷酸组成,编码成熟血小板活化蛋白为第67-378位核苷酸。博玛津具有诱导血小板活化、抑制胃溃疡的作用,可作为血小板聚集诱导剂和制备胃溃疡药物的应用。
Resumo:
一种抗艾滋病的药物,其中含有抗艾滋病有效量的式(Ⅰ)化合物反-1硝基2-苯硫基-乙烯用及可药用载体和/或赋形剂。$同时提供一种逆转录酶抑制剂,其中含有式(Ⅰ)化合物反-1硝基2-苯硫基-乙烯及可药用载体和/或赋形剂;式(Ⅰ)化合物反-1硝基2-苯硫基-乙烯在制备抗艾滋病药物中的应用;式(Ⅰ)化合物反-1硝基2-苯硫基-乙烯在制备逆转录酶抑制剂药物中的应用。
Resumo:
利用RAPD和ISSR两种分子标记技术,分析了丹江口水库野生赤眼鳟30个个体的遗传多样性。用11个RAPD引物对其基因组DNA进行扩增,共获得101个重复性好且谱带清晰的扩增位点,片段大小在100—3000bp之间,其中多态性位点63个,多态位点比例为62.38%;个体间遗传距离在0.1049—0.3417之间,平均为0.1742。用10个ISSR引物共检测到88个位点,其中多态性位点61个,多态位点比例为69.32%;个体间遗传距离在0.1088—0.3847之间,平均为0.1907。结果显示,丹江口水
Resumo:
通过调查滇池三个湖湾不同深度水层磷与铁的形态分布,研究三个湖湾内源磷的释放规律.结果表明,在海埂湾间隙水中,磷的释放强度远高于另外两个湖湾,根据水体中各种形态磷和铁的关系,推测出在这三个湖湾中,铁结合态磷是湖水悬浮物和沉积物中一种重要的可释放磷.
Resumo:
本研究采用RNA反义探针原位杂交技术,对vasa基因在黄鳝(Monopterusalbus)性腺发育过程中的表达情况进行了分析。结果表明:vasamRNA在Ⅰ、Ⅱ、Ⅲ期卵母细胞的胞质中均匀分布,在Ⅳ、Ⅴ期卵母细胞中vasamRNA有向胞质外周皮层迁移集中的趋势,但不明显;退化的卵粒也呈现vasamRNA阳性反应;在Ⅲ、Ⅳ期卵巢的被膜中检测到带有vasa阳性信号的细胞,这些细胞可能是待向精原细胞分化、迁移到卵巢被膜上的原始生殖细胞(Primordialgermcell,PGC),在性逆转过程中这些PGC可能
Resumo:
高温季节,在静止吋(摄食状态)的氮代谢方程式鲢为Mg=0.054W~(0.884)(毫克-氮/小时);鳙为Mg=0.073 W~(0.782)(毫克-氮/小时);氮的运动代谢量随游泳速度(s)的增大呈指数增长。氮的收支公式鲢为0.44 C_N=0.181 W~(0.61)+24/0.75{0.054-0.021(1-e~(0.2168)}W~(0.884);鳙为0.57 C_N=1.98 W~(0.61)+24/0.75{0.075-0.033(1-e~(0.1798)}W~(0.782)。以鲢和鳙对微囊
Resumo:
Clinorotation experiments were established to simulate microgravity on ground. It was found that there were obvious changes of Dunaliella salina FACHB435 cells and their metabolic characteristics during clinorotation. The changes included the increases of glycerol content, the rate of H+ secretion and PM H+-ATPase activity, and the decrease of ratio of the plasma membrane (PM) phospholipid to PM protein. These results indicated that microgravity was a stress environment to Dunaliella salina. It is deduced that it would be possible to attribute the effect of microgravity on algal cells to the secondary activation of water stress.