Calculation of non－mono chromatic reflectance of Co／Sb multilayer

It is well known that the structure defects, such as the interfacial roughness, interdiffusion and chemical reaction at interface, can degrade the optical properties for soft X-ray multilayer[1—5]. For example, the interfacial rough-ness can lead to a loss of spectral reflectance, which has been investigated for many years, and number theories for the scattering of electromagnetic radiation by interfacial roughness have been formulated[6,7]. In addition, the fluc-tuation of the period can als…     

Spectroscopic study on the photophysical properties of chlorine substituted tetraphenylporphyrin-histidine and its zinc(Ⅱ)complexes

As the structural analogues of (bacterio)chlorophylls in photosynthetic organisms, porphyrins play an important role in building up artificial photosynthetic systems[13]. In natural photosynthetic pigment-protein complexes,certain amino acid residuals modulate the reactions ofcharge transfer and energy transfer via coordination andother types of interactions with chlorophyll molecules.For instance, in higher-plant photosynthetic reaction cen-ter PSⅡ, the oxidization-reduction system consistin…     

Changes in the content of eolian iron during the past 900 ka and the implications

In this study, total Fe2O3 content (Fet) in two parallel sections from the central Loess Plateau (Xifeng and Changwu) is analyzed to address the variations of eolian iron in the past 900 ka. The obtained timeseries indicate that Fet Vvalues in some glacial intervals are comparable to that of interglacial periods and its oscillations do not generally correspond to the long-term glacial-interglacial changes. Rather,it exhibits higher frequency fluctuations without detectable 100 ka period, but with a strong 20 ka period and a clear 40ka period. The combination of 20 ka and 40 ka periods suggest that eolian iron content was relatively independent of glacial-interglacial changes, but more strongly influenced by the insolation changes in the northern hemisphere. Higher iron content was observed for the S5-1 soil that is correlative to marine δ^18O stage 13. In marine records, this stage is characterized by higher δ^13C values, suggesting that the event is of global significance.     

Stress corrosion cracking and its anisotropy of a PZT ferroelectric ceramics

It is known that some types of ceramics, like Al2O3 and ZrO2, undergo stress corrosion cracking (SCC) or static fatigue fracture under static loading, ever in a rela-tively mild environment, such as moist atmosphere or water at room temperature, which leads to a time-dependent fracture[1—4]. For a transmission electron microscopy specimen of YBa2Cu3O7-x ceramics superconductor, SCC induced by residual stress can occur in an atmosphere with low moisture content[5]. For a lead zirconate ti…     

High efficient light-emitting diodes using polystyrene as matrix

High efficient polymer light-emitting diodes (PLEDs) were obtained by using a blend of conjugated polymer G-PF, a copolymer of fluorene and thiophene, and polystyrene (PS). The maximum electroluminescent (EL) efficiency of the device is 12 cd/A when G-PF/PS weight ratio is at 80/20, while that of pure G-PF device is 6.5 cd/A. Studies on photoluminescence and electroluminescence of the blends indicate that inter-chain interactions were tremendously suppressed due to the dilution effect. However, after PS concentration exceeds 20% the EL efficiency of the devices decreases with further increase of PS concentration. This may be due to the decrease of the recombination probability of electrons and holes with the excessive addition of PS insulator.     

Kinetic parameters of oscillating reaction of amino acid- BrO3^——Mn^2＋-H2SO4-acetone system

In the previous papers[1—3], the oscillating reactionusing amino acids as organic substrates was studied. Inorder to obtain information about the kinetic parameters ofoscillating reaction of amino acids in amino acid- BrO3 - ?Mn2 -H2SO4-acetone sy…     

Spectroscopic study on the photophysical properties of chlorine substituted tetraphenylporphyrin-histidine and its zinc(Ⅱ)complexes

The photophysical properties of ortho-CI,meta-CI and para-CI substituted tetraphenylporphy-rin-histidine and their zinc (II) complexes have been studied by means of steady-state absorption and fluo-rescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. For the cases of both free-base and zinc complexes, it was found that the ortho-chlorine substitution onto the phenyl rings significantly altered the fluorescence quantum yield, thefluorescence lifetime and the ratio between radiative and nonradiative deactivation rates of the porphyrin chromophore, i.e. the photophysical parameters were quite different from those of meta- and para-substituted compounds. On the other hand, however, the introduction of covalently-linked histidine did not exert much effects on the photophysical behavior of the porphyrin chromophore. The results are interpreted interms of the steric effect and the heavy-atom effect from the chlorine atoms substituted onto the phenyl rings.     

Fluorescence study on the interactions of PAMAM dendrimers and their derivatives with bovine serum albumin

The interactions of amino-terminated, and ethylenediamine core poly（amidoamine） （PAMAM） dendrimers and their derivatives with bovine serum albumin （BSA） were investigated by fluorescence spectroscopy. Experimental results showed that the fluorescence intensity of BSA decreased after the addition of different modified dendrimers, and the extent of the fluorescence quenching caused by various modified dendrimers strongly depends upon the different functional groups on their surfaces. We also investigated the influence of pH and ionic strength on the interaction between various modified dendrimers and BSA. Circular dichroism （CD） spectroscopic measurements showed that the content of α-helix structure of BSA decreased after the addition of different modified dendrimers, which indicated that dendrimers induced changes in the secondary structure of BSA.     

Dating of sediment-hosted disseminated-type gold deposit by using ~(40)Ar/~(39)Ar laser probe: A case study of Changkeng large-scale gold deposit, China

Ore-forming age is one of the most important data in studying the genesis of mineral deposits. Dating of sedi-ment-hosted disseminated-type gold deposits, which areone of the most important types of gold deposits in theworld, is always a difficult task for ore geologists. Themajor reason is that most of the ores in this type deposit are of various siliceous and are composed of extremely fine-grained minerals, thus it will be very difficult to de-termine their ages by using conventional isotopi…     

Dating of sediment－hosted disseminated－type gold deposit by using ^40Ar／^39Ar laser probe： A case study of Changkeng large－scale gold deposit, China

Hydrothermal clay minerals that formed in the main metallogenic stage of the Changkeng disseminated-type gold deposit in central Guangdong were analyzed by the 40Ar/39Ar laser probe. The results give Ar-Ar isochron ages of 109.9 1.4 to 110.1 1.3 Ma, which are 30 to 50 Ma older than the age of silver ore bodies in the deposit. Both gold and silver mineralizations were not related to hidden granite batholith in the mining district, but probably related to evo-lution of sedimentary basins. This study shows that the 40Ar/39Ar laser probe is a sound dating tool applicable to sediment-hosted disseminated-type gold deposit.     

Aligning DNA on Si surface and cutting off by tips of atomic force microscope

DNA is a kind of promising molecule as nano-lead to build or connect nano-devices due to its stable linear structure and certain conductivity. Many methods have been applied to constructing nano-patterns by using DNA molecule. In this report it is presented that λ-DNA was aligned on Si substrate by using the free-flowing method and then imaged by an atomic force microscope (AFM). After the second liquid flow, a catenary-like pattern and a crossed network of λ-DNA were formed. In addition, the aligned λ-DNA was successfully cut off by tips of AFM.     

Analysis of the visible fracture system of coalseam in Chengzhuang Coalmine of Jincheng City,Shanxi Province

In No. 3 coalseam of Chengzhuang Coalmine of Jincheng City, there exists the visible fracture system consisting of joints, gas-expanding fractures and cleats. The gas-expanding fractures develop mainly in the bright coal sub-layer and cleats, in the vitrain and bright coal. The joints fall into two types, one developing in the coalseam and the other cutting through the whole coalseam and entering into the top and bottom rock layer. The development direction of joints is basically similar to that of gas-expanding fractures: NNE and NNW. The formation of the visible fracture system is classified as the stage of the development of cleat fissures in the coalification period, the stage of the full development of cleats and the formation of gas-expanding fractures in the second coalification period and the stage of the formation of joints by structural function. There is the spatial unhomoge-neity in three dimensions for the visible fracture system of the coal seam in Chengzhuang Coalmine: the regular distribution of the visible fractures as groups in the plane and the coal sub-layer with high permeability rate in profile. The research findings of the visible fracture system of coal seam can be applied to the drilling of the coalbed methane and to heightening the let-off efficiency of coalseam gas.     

线搜索算法映射的初步探讨

本文对线搜索算法映射进行了探讨。给出了线搜索算法的一般模型,并引入一种控制函数,借以产生一类新的非精确线搜索算法。最后讨论了带此线搜索的下降迭代法的收敛性问题。     

一种计算Vague集之间相似程度的新方法

从Vague集的直觉理解出发,提出了一种新的度量Vague集(值)之间相似度量的计算方法．与文献现有的Vague集(值)之间相似度量的方法进行比较,新方法更加合理,更接近于人的直觉理解,是一种比较理想的度量Vague集(值)之间相似程度的计算方法。     

建筑物理学科的教学探讨

对建筑物理教育与人才培养问题进行初步的探讨，主要内容包括三大部分，①科学技术的发展形成了建筑物理学科，②建筑物理与建筑设计师(包括室内设计师)的关系，③建筑物理课的设计。     

关于琴生不等式的一些加细(英文)

本文给出琴生不等式的一些加细 ,它包括若干相关结果的推广 (如正文的注释 1指出 ) 从文献上看 ,结果中出现涉及f1 ,n与fn ,n线性组合的不等式 (7)和 (8) ,在同类结果中似乎是新型 此外 ,推论 1和 2还给出了 (7)和 (8)成立的另一类型充分条件     

完全非平衡函数与分裂相对差集

引入群G到群H上的完全非平衡函数来考察G×H相对于{1}×H的分裂相对差集,证明了完全非平衡函数的存在性与对应的分裂相对差集的存在性等价.通过研究完全非平衡函数的基本性质,得到了一些结果.