水溶液中PbS纳米晶生长过程的原位光谱检测

为了研究纳米晶在溶液中的生长规律,设计并实现了一个能够实时监测纳米晶生长的原位透射光谱系统。利用该系统对PbS纳米线和纳米点在水相中生长过程进行了原位光谱检测,发现十二烷基硫酸钠对PbS纳米晶的定向生长起了非常重要的作用。     

一类全纯映射族的系数估计

在~$\mathbb{C}^n$ 中的单位多圆柱上和一般复 ~Banach 空间的单位球上引入正规化全纯映射族~$\mathcal{M}_g$. 考虑~满足条件~$(Df(x))^{-1}f(x)\in \mathcal{M}_g$ 的正规化局部双全纯映射~$f$~(其中~$x=0$ 是~$f(x)-x$ 的 ~$k+1$ 阶零点) 并得到其 系数估计. 所得结果统一和推广了许多已知结论.     

双连环递推数列通项的求解策略

两个数列的连环递推，我们称之为“双连环递推”，其一般特征是：两个数列的通项由它们的首项和两个相互联系、相互制约、相互依存的递推关系联合限制给出。     

关注一元二次不等式中的范围问题

含参数的一元二次不等式中求范围问题是近年来高考和其他选拔性考试的常见题型,它综合考查了二次函数、二次方程、二次不等式的主要内容,并且与二次不等式恒成立及二次不等式有解联系密切,本文举例介绍几种常见问题,以期抛砖引玉.……     

世界各地数学奥林匹克试题摘编

１．ｐ，ｑ是正整数，ｆ是正实数集合到正实数集的一个映射，使得对于任意的正实数ｘ，ｙ，有ｆ（ｘｆ（ｙ））＝ｘｐｙｑ①求证：ｑ＝ｐ２．证取ｘ＝１ｙ，代入①得ｆ（ｙ）＝ｙｑｐ（ｆ（１））１ｐ②再取ｙ＝１，代入②得ｆ（１）＝１，由②得ｆ（ｙ）＝ｙｑｐ③∴ｆ（...     

结构描述符正交化及典型相关分析在饱和醇、醚质谱分类中的应用

结构描述符正交化及典型相关分析在饱和醇、醚质谱分类中的应用;饱和醇醚;模式识别;质谱分类变量;块变量;典型相关分析     

RELATIONSHIP BETWEEN THE CHANGES OF THE FAST PHASE OF MILLISECOND DELAYED LIGHT EMISSION AND THE PROTON RELEASED BY THE OXIDATION OF WATER

The phosphorylation uncouplers suppressing the proton gradient across the thylakoidmembrane can also affect the fast phase of millisecond delayed light emission (ms-DLE) atflash light intensity strong enough to saturate the Hill reaction. At the concentration ofsame uncoupling degree, nigericin decreases the fast phase DLE much more than NH_4Cl.Omitting the terminal acceptor in the reaction mixture or adding DBMIB to inhibit PQ oxi-dation diminishes the slow phase DLE and affects the fast phase slightly, while DCMU orHOQNO which inhibits electron transport between PSII and PQ, diminishes both phases ofms-DLE. These results indicate that the proton gradient responsible for the enhancement ofthe fast phase DLE is more intimately linked to the thylakoid membrane, and is mainlyrelated to the proton release from water oxidation and not to the turnover of plastoquinone.     

转基因水稻表达的Bt毒蛋白Cry I Ab溶液构象的研究

用荧光光谱法研究了毒蛋白Cry I Ab在溶液中的构象。结果表明，pH值增大时，毒蛋白的荧光强度也增大，至pH=11时荧光强度已达最大值；甲醇、乙醇及异丙醇等有机溶剂引起毒蛋白荧光发射波长蓝移和荧光强度增大，至有机溶剂的浓度超过某一阈值后荧光发射波长不再蓝移；丙酮能完全猝灭毒蛋白Cry I Ab的荧光，丙烯酰胺能猝灭Cry I Ab86%的荧光，而KI对毒蛋白的荧光无猝灭作用，由此推断Cry I Ab的大部分色氨酸残基位于分子表面富含负电荷的区域中。     

A CLUSTER COMPOUND WITH DI-ENDOXYGEN LIGANDS——THE CRYSTAL AND MOLECULAR STRUCTURE OF [Fe(MOS_4O)_2][N(C_2H_5)_4]3

[Fe(MoS_4O)_2] [N(C_2H_3)_4]_3 cluster compound with di-end-oxygen ligands has been prepared and characterized by the X-ray diffraction method. The compound crystallizes in a monoclinic space group P2_1/n with lattice parameters a=13.019(4), b=16.959(5), c=18.234(5), β=97.34(2)(°), Z=4. The final agreement factors are R=0.0740, Rw=0.0598. The terminal bond length, Mo-S_t and bridged one, MO-S_b for the compound are much longer than the counterpart without end-oxygen ligand. It possibly suggests that low valence of molybdenum and smaller electronegativity of sulphur than oxygen lead to the charge transfer as S→Mo→O.