生物体系中电子转移机理的研究Ⅱ: 分子间电子转移及 电子供、受体间不同基 团的影响

利用自编程序MOPAC-ET中AM1方法,及KT(Koopman'sTheorem)法,研究了二苯负离子体系的分子间电子转移现象,计算了其电子供、受体在不同距离下的V~A~B及它们之间的相关性,另外,还对两苯环间不同介入基团对电子转移的影响做了初步研究,发现不同的介入基团存在着较大的差异。     

模糊优化相对增量比准则摄动梯度投影算法

首先根据非线性规划最优解的ＫＴ条件，给出一种含参数不等式约束的非线性规划最优解的存在条件，建立相对增量比与较优解的概念，应用摄动梯度投影方法，针对工程优化设计中具有模糊约束非线性规划的模糊优化问题，构造了一种相对增量比准则摄动梯度投影的普通优化算法，为求解模糊优化问题提供了一种新的途径。     

KTB iron mineralogy at iridium deficient layers revealed by Mössbauer spectroscopy

Mössbauer spectroscopic studies of two sedimentary layers from Petriccio section in Gubbio formation are presented. It is found that these layers have almost the same iron phases nanophase hematite and phyllosilicate and with the same compositions as those in the Cretaceous-Tertiary Boundary (KTB) in Petriccio. The two layers also show enhancement in the siderophile elements such as Cr, Ni, Fe, Ca etc. to that found in the KTB layer. The two layers are well separated from the KTB layer, 128 and 149 cm below this layer, and show no enhancement of iridium. From the data it is suggested that the two layers also represent some kind of impact by extraterrestrial (ET) bolides.     

植物激素对海带孢子体发生的影响

采用析因试验设计,对影响海带孢子体发生的主要环境因子进行优化,筛选出温度8℃、光强30umol-m^-2·s^-1、光时12h的最佳环境条件．基于此条件,对吲哚乙酸（IAA）、赤霉素（GA,）、脱落酸（ABA）、激动素（KT）和矮壮素（CCC）等5种植物激素进行了初步筛选,结果表明0．1mg·L^-1IAA、2．0mg·L^-1KT对海带孢子体的发生有显著促进作用,0．5mg·L“IAA及0．1、0．5、1．0mg·L^-1ABA抑制孢子体的发生,GA3、CCC无显著的影响．采用拉丁方区组设计,对具有显著促进作用的KT进行浓度筛选,获得了促进孢子体发生的最佳浓度4mg·L^-1．在此条件下,孢子体于第5天发生,第16天发生率达94．2％±2．0％,孢子体发生显著加快．此外,孢子体发生与细胞增殖呈异速生长关系,并且连续光照斜率高于短光照,表明短光照更适合孢子体的发生．     

Zr^4＋对KTP晶体结构畸变性的影响

采用高温固相反应法合成了掺杂Zr^4＋的KTP晶体。用XRD对烧成产品的物相进行了系统的分析,用最小二乘法对样品的晶胞参数进行了计算,系统分析了掺Zr^4＋对晶胞参数的影响。随着掺杂Zr^4＋浓度的增加,晶胞参数明显增大,KTP中八面体畸变的程度会更高。     

Melting of mesoscopic lattices of magnetic fluid thin film subjected to perpendicular fields

Applying a magnetic field on the magnetic fluid thin film perpendicularly, leads a phase separation that is concentrated in particles separating from a dilute phase. The concentrated phase forms cylindrical columns that construct two-dimensional lattices. This kind of artificial lattice is a novel mesoscopic system and has been explored with optical microscope, CCD, and digital imaging analysis. We explore the ordering evolution of the two-dimensional extraordinary lattice by varying the applied field. The ordering of these lattices is analyzed in terms of translational and bond-orientation correlation functions to address the two-dimensional melting.     

高温超导体中磁场诱导的能量耗散行为的转变

高温超导体在强电方面应用的关键问题是如何克服磁通运动所造成的能量损耗。由于存在极强的各向异性,短的相干长度和小的磁通钉扎势,因此与磁通运动紧密相关的混合态相图变得很复杂,文章综述了根据一系列灵敏的电磁测量所观察到的磁场诱导的能量耗散行为的转变。     

Critical properties of XY model on two-layer Villain－ferromagnetic lattice

We investigate phase transitions of the XY model on a two-layer square lattice which consists of a Villain plane (J) and a ferromagnetic plane (I), using Monte Carlo simulations and a histogram method. Depending on the values of interaction parameters (I,J), the system presents three phases: namely, a Kosterlitz－Thouless (KT) phase in which the two planes are critical for I predominant over J, a chiral phase in which the two planes have a chiral order for J predominant over I and a new phase in which only the Villain plane has a chiral order and the ferromagnetic plane is paramagnetic with a small value of chirality. We clarify the nature of phase transitions by using a finite size scaling method. We find three different kinds of transitions according to the values of (I,J): the KT transition, the Ising transition and an XY-Ising transition with ν=0.849(3). It turns out that the Ising or XY-Ising transition is associated with the disappearance of the chiral order in the Villain plane.