Polycrystalline samples of (Gd1-xCex)(2)Zr2O7+x (0 <= x <= 0.7) were synthesized by solid-state reaction using NaF as a flux at 1000 degrees C to simulate Pu-immobilization in the Gd2Zr2O7 matrix. Phase transformation and variation of the thermal expansion coefficients (TECs) and thermal conductivities (TCs) of the samples with temperature and composition were investigated. Powder X-ray diffraction (XRD) patterns show that pure Gd2Zr2O7 has a weakly ordered pyrochlore structure, whereas Ce-containing samples (i.e., the Pu-simulated solidified samples) exhibit a defect fluorite structure even if x is as low as 0.1. When x reaches 0.7, the XRD peaks of these samples widen. In the Ce 3d X-ray photoelectron spectrum (XPS) of (Gd1-xCex)(2)Zr2O7+x there are six peaks located at binding energies of 881.7, 888.1, 897.8, 900.4, 907.1, and 916.1 eV, which are almost the same as the peaks of CeO2. The Ce 3d XPS reveals that the Ce species in (Gd1-xCex)(2)Zr2O7+x are tetravalent. The TECs of (Gd1-xCex)(2)Zr2O7+x (0 <= x <= 0.7) generally increase with increasing temperature. At the same temperature, the TECs and TCs exhibit the same variation trend with the composition of the simulated solidified forms: they decrease from x = 0 to 0.1 and then linearly increase from x = 0.1 to 0.7.

Phase change in aluminoborosilicate glass and effect on leaching behavior were studied with different mass fraction of CeO2 via characterization methods of XRD, XPS, SEM and ICP-MS. The results showed that: Ir-1 glass network structure the molar ratio of quadrivalence Ce and trivalent Ce was 9.25:1. And when mass fractior(1) of CeO2 met or exceeded 7%, the cerianite began to be precipitated in glass. With mass fraction of CeO2 increasing, r(Ce) of glass decreased at first and then increased in 1 day, and showed trend to decrease in 28 day, However, in the same mass fraction of CeO2, r(Ce) gradually decreased with the prolongation of leaching time. Anq r(Ce) of the glass sample bE stabilized lower than 4 x10(-6) g.m(-2).d(-1) afcer 7 day with 9wt% CeO2. The leaching behavior was excellent. Hence, controlling CeO2 precipitated within a certain range could be superior to completely dissolving one in glass on leaching behavior.

Borosilicate glass for vitrification of high level nuclear waste (HLW) were prepared with SiO2, Al2O3, B2O3, CaO, Na2O and 5wt% CeO2 by the conventional solid-state method. The chemical durability of glass waste forms was measured by Product Consistency Test (PCT) method and the leaching rate of glass waste forms was analyzed via inductively coupled plasma mass spectra. The structure of the glass waste form was analyzed by Fourier turning infrared(FTIR). The results show that [SiO4], [BO3] and [BO4] exist in glass wasteforms and some [BO4] turns into [BO3] as B2O3 content increases. Glass matrix has the biggest glass transition temperature (T-S) and the best normalized leaching rate of Ce when doped with 15.79wt% B2O3. Glasses doped with TiO2 show better leaching resistance than those undoped, and get the best chemical stability when TiO2 content is 3wt%.

Discusses the mobile database of SQL server CE and its characteristics,analyzes in detail its RDA(Remote Data Access) and Replication data synchronization technologies,including their respective characteristics and application environment,and describes the implementation processes of two kinds of data synchronization technologies,compares which environment that is fit for these two technologies.

Discovering and selecting Web services that meets the users' requirements quickly and accurately is a research hotspot currently.Proposes a Web services discovery and selection model,which realizes QoS attributes by additional databases and extended UDDI,based on QoS and user preference.In the model,introduces QoS attributes sorting and weights to achieve the user's personalized choice,which improves the precision ratio of service.

跟踪服务是WF提供的众多基础工作流服务之一,能够对工作流运行过程中的工作流实例事件、活动事件和用户事件进行跟踪。从四个方面对WF提供的跟踪服务进行了分析和讨论,并举例说明了跟踪服务在工作流中的应用。

The effects of Al4C3 on the microstructure and performances of AZ91D alloy are studied by using SEM,EDS,EDS and DTA. It is found that a small amount Al4C3 addition to AZ91D magnesium alloy leads to the α-Mg grain size obvious decreasing,causes the eutectic microstructure morphology marked change from the fully-divorced β eutectic phase and lamellar α+β eutectic structure to honeycomb partially-divorced α+β eutectic structure,and the β-phases diminution of size and tendency to dispersed distribution. Based on the analysis of EDS,DTA and the calculation of disregistry between Al4C3 and Mg,it is found that the Al4C3 particles can act as the heterogeneous nuclei. The strength properties are significantly improved due to the microstructural refinement of AZ91D alloy,but a little change of elongation percentage,and slight increase of corrosion resistance.

Microstructure and constituent of in situ synthesized Mg-Al4C3 master alloy were analyzed with the help of DTA (differential thermal analysis),XRD(X-ray diffraction),SEM (scanning electron microscope) and EDS(energy dispersive spectrum) based on thermodynamics calculation. The results indicate that Mg-Al4C3 master alloy can be successfully synthesized by in-situ reaction at more than 700 ℃ for more than 1 h in Mg-Al-C system. In addition,formation mechanism of Al4C3 particle was expounded.