Study of the circumstance influence on the elemental distribution in ancient animal bone using μ-XRF

Elemental analysis of archaeological bone plays an important role in the study of the dietary habits of ancient animals. The elemental characteristic of diagenetic skeletons depends on the surrounding circum-stance. The study of environmental influence on the elemental concentration of ancient bone is significant. In this paper, the diagenetic influence on archaeological skeletons is analyzed by microbeam X-ray fluorescence (μ-XRF). The results show that the enamel is an excellent barrier to the diagenesis and the element Sr in bone isn’t susceptible to contamination from the buried environment.     

Experimental Verification of Left-Handed Metamaterials Composed of Coplanar Electric and Magnetic Resonators

We verified experimentally left-handed metamaterials （LHM） composed of coplanar electric and magnetic resonators. A typical LHM sample composed of coplanar resonator unit cells was fabricated, investigated and tested. The experimental results show that the tested sample has a left-handed band of width 1.4 GHz in the X band. The experimental results agree quite well with the simulation ones. Moreover, both the simulation and experimental results show that the LHM under study can automatically achieve good impedance-matching in the left-handed band.     

Bifurcation Control of Current-Mode Buck Converter via TDFC

Considering the TDFC controlled current-mode Buck converter featuring periodicity we propose a Fourier-decomposition based method for the bifurcation analysis of this system, hence the theoretical range of control gain of TDFC is determined. In addition, the power-stage experiment circuit is built and the control part is realized in a digital controller. The experimental results show that either bifurcation or chaos in the current-mode Buck converter can be controlled into the expectant period-1 orbit rapidly.     

Instrumentation of coherent X-ray imaging and the primary experimental results

Coherent X-ray microscopy has advanced towards higher-energy, more brilliant sources over the past decade since its demonstrations, and many advancements have been made towards optimizing this imaging technique. Here we present both the experimental instrument for obtaining diffraction patterns and the primary reconstruction of yeast cell 2D projection. In addition, the characteristics of the existing optics at BL29XUL of SPring-8 Facility and the method of image reconstruction are discussed.     

清明法定假日对交通量的影响研究

2008年4月4日至6日是国家新休假办法实施以来的第一个清明假日,研究其对交通量的影响对以后清明祭扫交通管理有着重要指导意义。本文通过对西安市6个公墓2008年清明假日祭扫实地观测数据以及2007年历史数据的统计分析,建立了祭扫交通量和路段饱和度分析模型以及相关的祭扫人群组成分析模型,用以研究清明法定假日对祭扫交通量的影响。以西安地区为实例进行了模型验证,结果表明清明法定假日并未使西安地区的祭扫交通量增加,但祭扫人群的组成发生了变化;对其它8个城市在2008年清明假日的祭扫人数变化情况进行了统计,得出清明假日对各地祭扫交通影响存在差异性。最后对以后的清明祭扫活动提出建议。     

Generation of multi-hollow crystalline Mo fibres

Flower-like micrometer-sized crystalline Mo fibres have been prepared by directly heating Mo powder on Mo foil, under Ar atmosphere. ED, EDX, SEM and HRTEM studies reveal that each fibre consists of a single Mo crystal containing multi-hollow cores. A one-dimensional growth mechanism, on the basis of the one-dimensional thermal flow during fibre formation, is discussed.     

Ultrafast Optical Kerr Effect of ConjugatedSilver Phenylacetylide Complex Oligomer

Conjugatedpolymerswithlargethird-orderopticalnonlinearityhavebeedfocusedfortheirpromisingpotentialsforadvancedmaterialsapplications'.Recently,investigationsoftransitionmetalwithorganicligandsystemshavebeengreatlyintensifiedduetothedelectronsincorporatedintheconjugatedsystem,whichareexpectedtoellhancethehyperpolarizability.Phenylacetyleneandthemetalphenylacetylidesplayimportantrolesinformationofuniquecoordinatedc-lusters',butitseamsthatthestudyofmetalphenylacetylides,particularlyofthesilverphen…     

Studies on Chem icalCom position ofIron-m olybdenum Cofactor fromNitrogenase by Fluorescence Analysis

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褪色光度法测定氰化物

根据ＣＮ－ 对５－（４－磺酸基苯偶氮）－８－氨基喹啉（ＳＰＡＱ）－Ｎｉ２＋ －ＣＴＭＡＢ体系的干扰褪色作用，建立了一种测定氰化物的新方法。该方法比传统方法操作简便，不需要萃取。体系λｍ ａｘ＝ ６００ｎｍ ，ε＝ ６．８８×１０４ Ｌ·ｍ ｏｌ－ １·ｃｍ － １。ＣＮ－ 含量在０～５ μｇ／２５ｍ Ｌ内符合比尔定律。方法用于环境水样中氰化物的测定。     

A Highly Sensitive Kinetic Spectrophotometric System and Its Analytical Potential for Chromatographic Detection of Metal Ions

Micelles,microemulsions.vesicles,etc.,areorganicmicroheterogeneousmedia.Useofthesemediainanalyticalreactionsfordevelopingnewkinetic-baseddeterminationsorimprovingpreviouslyestablishedkineticmethodshasbeenreported"2.Inrecentyears,amixedmicellarmediumc...