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881.
通过对13种植物生长调节剂的试验,建立了用于筛选植物生长调节剂的生物检测方法,该方法第1步采用萝卜、黄瓜、小麦、油菜4种幼苗生长法联合筛选,第2步采用萝卜子叶扩张法、黄瓜子叶生根法联合筛选,这样能保证有生长调节剂活性的化合物在普筛中不被漏筛,而且方法简便,测试周期短。 相似文献
882.
C. Ratsch C. Anderson R. E. Caflisch L. Feigenbaum D. Shaevitz M. Sheffler C. Tiee 《Applied Mathematics Letters》2003,16(8):1165-1170
We adapt the level-set method to simulate epitaxial growth of thin films on a surface that consists of different reconstruction domains. Both the island boundaries and the boundaries of the reconstruction domains are described by different level-set functions. A formalism of coupled level-set functions that describe entirely different physical properties is introduced, where the velocity of each level-set function is determined by the value of the other level-set functions. 相似文献
883.
A.B.El-Rayes AbdEl-MoneimA.Mohamed HamdyM.AbouGabal 《数学物理学报(B辑英文版)》2003,23(3):321-327
A target is assumed to move according to a Brownian motion on the real line. The searcher starts from the origin and moves in the two directions from the starting point.The object is to detect the target. The purpose of this paper is to find the conditions under which the expected value of the first meeting time of the searcher and the target is finite,and to show the existence of a search plan which made this expected value minimum. 相似文献
884.
两参数齐次独立增量过程在原点的局部性质 总被引:2,自引:0,他引:2
Adler曾经给出了两参数独立增量过程的特征函数的一般形式.本文对齐次情形给出了更具体的表达式,引进了累积量的概念.在此基础上,研究了比值X(s,t)/st在原点的分布,单调过程在原点的局部性质以及任意过程在原点的局部增长.由此得到了Brown单和不包含高斯分量的过程在原点的局部增长. 相似文献
885.
Global asymptotic stability of a two species competitive system with stage structure and harvesting 总被引:3,自引:0,他引:3
Xinyu SONG Lansun CHEN Department of Mathematics Xinyang Teachers College Henan China Institute of Mathematics Academy of Mathematics System Sciences Chinese Academy of Sciences Beijing China 《Communications in Nonlinear Science & Numerical Simulation》2001,6(2)
Introduction' There have recently appeared in the literature several mathematical models of stagestructured population growth, i. e., models which take into account the faCt that individuals in a population may belong to one of two classes, the immatures and the matureslllZI.Cannibalism has been observed in a great variety of species, including a number of fish species.Cannibalism models of various types have also been investigatedI3"l. In these models, the ageto maturity is represented by a… 相似文献
886.
田范基 《数学物理学报(B辑英文版)》2001,21(3)
We consider the random power serie8aoIw(z) = ZX.(w)z", (1)n =Owhere {Xn} is a 8equence of complex random variables in a probability spare (Q, F, P).Lemma 1 Supose that {Xn) is independent ai1d that there exists a positive coustallt crsuch thatVn 2 l, o'a: = a'ElXn l' S E'lX.l < oo. (2)Then for w e n, there exists a natural nunther N(w) a.s. such that for n > N(w)IXn(w)l 5 nrrn. (3)If {X.* } is any subsequence Of {X.}, thenP (ltL(lXn*l 2;rru*) = l. (4)Proof When ny = 0,X. = 0 a.s. … 相似文献
887.
本文研究了一类矩阵方程组解的秩的范围.利用矩阵的奇异值分解以及Frobenius范数的特征,得到了解的极值秩以及解的通式,并就这些问题的特殊情况进行了讨论,得到了一些结果. 相似文献
888.
A new organic compound of bis-glycine maleate was synthesized in the alkaline medium of 10% ammonium hydroxide solution. The bulk single crystals of Bis-Glycine Maleate (BGM) have been grown by slow cooling method. The grown crystals were characterized by employing single crystal and powder X-ray diffraction, Fourier transform infrared, optical absorption spectral studies and thermo gravimetric analysis. The microhardness studies confirmed that the BGM has a fairly high Vicker’s hardness number value (41 kg mm−2) in comparison to other organic NLO crystals. Second harmonic generation efficiency of the crystal measured by Kurtz–Perry powder method using Nd:YAG laser is found to be comparable to that of potassium dihydrogen phosphate (KDP). Frequency dependent dielectric studies were carried out along the major growth axis. 相似文献
889.
Toshinori Taishi Hideaki Ise Yu Murao Takayuki Osawa Masashi Suezawa Yuki Tokumoto Yutaka Ohno Keigo Hoshikawa Ichiro Yonenaga 《Journal of Crystal Growth》2010,312(19):2783-2787
Oxygen-containing germanium (Ge) single crystals with low density of grown-in dislocations were grown by the Czochralski (CZ) technique from a Ge melt, both with and without a covering by boron oxide (B2O3) liquid. Interstitially dissolved oxygen concentrations in the crystals were determined by the absorption peak at 855 cm−1 in the infrared absorption spectra at room temperature. It was found that oxygen concentration in a Ge crystal grown from melt partially or fully covered with B2O3 liquid was about 1016 cm−3 and was almost the same as that in a Ge crystal grown without B2O3. Oxygen concentration in a Ge crystal was enhanced to be greater than 1017 cm−3 by growing a crystal from a melt fully covered with B2O3; with the addition of germanium oxide powder, the maximum oxygen concentration achieved was 5.5×1017 cm−3. The effective segregation coefficients of oxygen in the present Ge crystal growth were roughly estimated to be between 1.0 and 1.4. 相似文献
890.
Yongzheng Wang Jing LiJiyang Wang Shujuan HanYongjie Guo 《Journal of Crystal Growth》2010,312(19):2779-2782
Neodymium phosphate single crystals, NdPO4, have been grown by a flux growth method using Li2CO3-2MoO3 as a flux. The as-grown crystals were characterized by X-ray powder diffraction(XRPD), differential thermal analysis (DTA) and thermogravimetric analysis (TG) techniques. The results show that the as-grown crystals were well crystallized. The crystal was stable over the temperature range from 26 to 1200 °C in N2. The specific heat of NdPO4 crystal at room temperature was 0.41 J/g °C. The absorption and the fluorescence spectra of NdPO4 crystal were also measured at room temperature. 相似文献