高等植物PSI ,PSII反应中心及天线系统色素蛋白复合体结构与功能的研究

一、实验证明了Cd H、Mg“在小麦类囊体膜上色素蛋白复合体的解聚和再聚合过程中，具有不同的作用。因此，二阶阳离子对激发能在光系统间的分配调节作用，可能不能仅仅用“静电现象”(Barber(1980))去解释。分析表明，在Ca2+作用下与PSII内周天线CP-47，GP-43多肽结合的L H C II和LHClb是来自间质膜区的PS I系统的。从PSI迁移到P S II的捕光色素蛋白，增加了PSII的捕光截面，从而促进了激发能有利于PsII分配。 二、Ca2*、Mg2+对小麦和菠菜类囊体膜光谱性质的影响有所差异。Ca2+对小麦类囊体膜光谱性质的影响还可以随着介质中Ca2+的消除而消除。同小麦类囊体膜相比，菠菜PSII以及LHCII更为集中在基粒区域，这可能是菠菜类囊体膜强Fv以及高F888／F735，F89H／F735比值的原因。因此，Ca2+，HgH对激发能在光系统间分配的调节作用是依赖于光系统间激发能及天线色素蛋白的分配状况的。 三、对菠菜叶中分离的PSII-RC: D1-D2-cyt b55g复合物进行的低温荧光发射光谱的研究表明，这一复合物可能具有F681和F684两种波长的低温荧光发射，但它们通常并不是同时存在，而是取决于Ca-670与Ca-680 Chla分子的相对含量的。PSII-RC内周无线GP-47，GP-43多肽的存在是D1-D2-cyt b559复合物低温荧光发射红移的原因;而D1一D2cyt b559复合物的不稳定性则与其低温荧光发射的蓝移现象有关。 从蕹菜叶中分离的Dl—D2-cyt b559复合物的F 381低温荧光发射也是由其相对含量较高的C．i-6 7 0 Chla分子的存在决定的。对蕹菜D 1一D 2-cyt b559复合物中的分析还表明，F 681的低温荧光发射直接来源于Di／D2复合物，而415nm处相对较强的吸收，则可能主要是与Pheo的存在有关的。 四、多肽分析与光谱分析的对照表明，CP-26内周天线多肽可能是PSII中F695低温荧光发射的真正来源。 五、实验分析了蔗糖密度离心分离的LHClI和PSI颗粒。结果排除了CP-27多肽（以及CP，一2 5，GP-47，CP -4 3多肽）具有F695低温荧光发射的可能，因此支持了CP-26多肽是PSII中F695低荧光发射来源的看法。对PsI颗粒的分析表明，P700的存在可能是与PSI-RC中较大的Sub-I亚基相联系的。 六、根据以上的研究结果，提出了PSI，PSII在类囊体膜上的结构模式，并对其内容进行了分析和讨论。

An New Area Function for Sharp indenter Tips in Nanoindentation

A new area function is introduced and applied to a Berkovich tip in order to characterize the contact projected area between an indenter and indented material. The function can be related directly to tip-rounding, thereby having obviously physical meaning. Nanoindentation experiments are performed on a commercial Nano Indenter XPsystem. The other two area functions introduced by Oliver and Pharr and by Thurn and Cook respectively are involved in this paper for comparison. By comparison from experimental results among different area functions, the indenter tip described by the proposed area function here is very close to the experimental indenter.

Dynamic function of damage and its implications

Dynamic function of damage is the key to the problem of damage evolution of solids. In order to understand it, one must understand its mesoscopic mechanisms and macroscopic formulation. In terms of evolution equation of microdamage and damage moment, a dynamic function of damage is strictly defined. The mesoscopic mechanism underlying self-closed damage evolution law is investigated by means of double damage moments. Numerical results of damage evolution demonstrate some common features for various microdamage dynamics. Then, the dynamic function of damage is applied to inhomogeneous damage field. In this case, damage evolution rate is no longer equal to the dynamic function of damage. It is found that the criterion for damage localization is closely related to compound damage. Finally, an inversion of damage evolution to the dynamic function of damage is proposed.

Function Innovation in Combined Surface Technologies for Metals

表面技术能够显著提高材料功能而成为工程和产品设计的重要组成部分, 但前提是表面技术必须具有可设计性。为此, 需要开拓和发展表面组合加工技术, 进行创新。该技术的内涵体现了新材料与新技术、基础研究与产业化有机结合的特点, 具有重要的价值和广阔的前景。

Barium-Functionalized Multiwalled Carbon Nanotube Yarns As Low-Work-Function Thermionic Cathodes

Barium-functionalized multiwalled carbon nanotube yarns were fabricated by drawing and twisting multiwalled carbon nanotube forests through a solution containing barium nitrate. After heat activation under vacuum, the functionalized yarns were enriched in barium oxide due to the high surface-to-volume ratio of the nanotubes. The cathodes exhibited good thermionic properties, with a work function as low as 1.73-2.06 eV and thermionic current density that exceeded 185 mA/cm(2) in a field of 850 V/5 mm at 1317 K. The barium-functionalized yarns had high tensile strength of up to 420 MPa and retained strength of similar to 250 MPa after a 2 h activation process. (C) 2008 American Institute of Physics.

Semi-weight function method on computation of stress intensity factors in dissimilar materials

Semi-weight function method is developed to solve the plane problem of two bonded dissimilar materials containing a crack along the bond. From equilibrium equation, stress and strain relationship, conditions of continuity across interface and free crack surface, the stress and displacement fields were obtained. The eigenvalue of these fields is lambda. Semi-weight functions were obtained as virtual displacement and stress fields with eigenvalue-lambda. Integral expression of fracture parameters, K-I and K-II, were obtained from reciprocal work theorem with semi-weight functions and approximate displacement and stress values on any integral path around crack tip. The calculation results of applications show that the semi-weight function method is a simple, convenient and high precision calculation method.

Synchronization of modified Chua's circuit with x vertical bar x vertical bar function

This paper considers the chaos synchronization of the modified Chua's circuit with x vertical bar x vertical bar function. We firstly show that a couple of the modified Chua systems with different parameters and initial conditions can be synchronized using active control when the values of parameters both in drive system and response system are known aforehand. Furthermore, based on Lyapunov stability theory we propose an adaptive active control approach to make the states of two identical Chua systems with unknown constant parameters asymptotically synchronized. Moreover the designed controller is independent of those unknown parameters. Numerical simulations are given to validate the proposed synchronization approach.

Self-consistent kinetic modeling of electron distribution function in a low-pressure inductively coupled plasma

Based upon the spatially inhomogeneous Boltzmann equation in two-term approximation coupled with electromagnetic and fluid model analysis for the recently developed inductively coupled plasma sources, a self-consistent electron kinetic model is developed. The electron distribution function, spatial distributions of the electron density and ionization rate are calculated and discussed.

Quantum and variational monte-carlo interaction potentials for li2 (x1-sigma-g+)

Optimized trial functions are used in quantum Monte Carlo and variational Monte Carlo calculations of the Li₂(X ¹Σ⁺_g) potential curve. The trial functions used are a product of a Slater determinant of molecular orbitals multiplied by correlation functions of electron—nuclear and electron—electron separation. The parameters of the determinant and correlation functions are optimized simultaneously by reducing the deviations of the local energy E_L (E_L  Ψ⁻¹_THΨ_T, where Ψ_T denotes a trial function) over a fixed sample. At the equilibrium separation, the variational Monte Carlo and quantum Monte Carlo methods recover 68% and 98% of the correlation energy, respectively. At other points on the curves, these methods yield similar accuracies.

Magnetostatic configuration of a confined magnetic-flux tube

In this paper an isolated magnetic flux tube confined in stratified atmosphere is studied for slender and axisymmetric model. The functions of the pressure, density, and temperature are expanded as a Taylor series of magnetic surface function psi. Several models of an isolated magnetic flux tube confined in a stratified atmosphere are constructed, and the external pressure of the stratified atmosphere decreases reasonably with increasing height. The distribution of thermal dynamic quantities and the magnetic pressure in the flux tube are also obtained.

Optimization of tried wave-function in quantum monte-carlo method

A method for optimizing tried wave functions in quantum Monte Carlo method has been found and used to calculate the energies of molecules, such as H-2, Li-2, H-3+, H-3 and H-4. Good results were obtained.

Statistical-theory of multiphoton excitation of polyatomic-molecules based on the wigner function

This paper is aimed at establishing a statistical theory of rotational and vibrational excitation of polyatomic molecules by an intense IR laser. Starting from the Wigner function of quantum statistical mechanics, we treat the rotational motion in the classical approximation; the vibrational modes are classified into active ones which are coupled directly with the laser and the background modes which are not coupled with the laser. The reduced Wigner function, i.e., the Wigner function integrated over all background coordinates should satisfy an integro-differential equation. We introduce the idea of ``viscous damping'' to handle the interaction between the active modes and the background. The damping coefficient can be calculated with the aid of the well-known Schwartz–Slawsky–Herzfeld theory. The resulting equation is solved by the method of moment equations. There is only one adjustable parameter in our scheme; it is introduced due to the lack of precise knowledge about the molecular potential. The theory developed in this paper explains satisfactorily the recent absorption experiments of SF6 irradiated by a short pulse CO2 laser, which are in sharp contradiction with the prevailing quasi-continuum theory. We also refined the density of energy levels which is responsible for the muliphoton excitation of polyatomic molecules.

An automatic imaging spectroscopic ellipsometer for characterization of nano-film pattern on solid substrate

In order to characterize the physical and spatial properties of nano-film pattern on solid substrates, an automatic imaging spectroscopic ellipsometer (ISE) based on a polarizer - compensator - specimen - analyzer configuration in the visible region is presented. It can provide the spectroscopic ellipsometric parameters psi (x, y, lambda) and Delta (x, y, lambda) of a large area specimen with a lateral resolution in the order of some microns. A SiO2 stepped layers pattern is used to demonstrate the function of the ISE which shows potential application in thin film devices' such as high-throughput bio-chips.

The gated integration technique for the accurate measurement of the autocorrelation function of speckle intensities scattered from random phase screens

A new approach based on the gated integration technique is proposed for the accurate measurement of the autocorrelation function of speckle intensities scattered from a random phase screen. The Boxcar used for this technique in the acquisition of the speckle intensity data integrates the photoelectric signal during its sampling gate open, and it repeats the sampling by a preset number, in. The average analog of the in samplings output by the Boxcar enhances the signal-to-noise ratio by root m, because the repeated sampling and the average make the useful speckle signals stable, while the randomly varied photoelectric noise is suppressed by 1/ root m. In the experiment, we use an analog-to-digital converter module to synchronize all the actions such as the stepped movement of the phase screen, the repeated sampling, the readout of the averaged output of the Boxcar, etc. The experimental results show that speckle signals are better recovered from contaminated signals, and the autocorrelation function with the secondary maximum is obtained, indicating that the accuracy of the measurement of the autocorrelation function is greatly improved by the gated integration technique. (C) 2006 Elsevier Ltd. All rights reserved.