辐射加热金X光再发射时间测量

利用星光Ⅱ三倍频激光打双盘靶，研究了辐射加热材料的Ｘ光发射时间。激光脉冲能量４０～６０Ｊ、脉冲宽度６００～７００ｐｓ。通过两台时间关联的亚千Ｘ光能谱仪分别监测双盘靶初、次级发射Ｘ光谱，给出了辐射加热次级Ｘ光再发射时间。     

Status of the standard solar model prediction of solar neutrino fluxes

The Standard Solar Model (BP04) predicts a total ⁸B neutrino flux that is 17.2% larger than that measured in the salt phase of the SNO detector (and if it is significant, it will indicate oscillation to sterile neutrinos). Hence, it is important to examine in detail the uncertainties (and values) of inputs to the BP04. Currently, the largest fractional uncertainty is due to the new evaluation of the surface composition of the Sun. We examine the nuclear input on the formation of solar ⁸B [S ₁₇(0)] and demonstrate that it is still quite uncertain due to the ill-known slope of the measured astrophysical cross section factor and thus illdefined extrapolation to zero energy. This yields an additional reasonable uncertainty due to extrapolation of _−3.0 ^+0.0 eV b ( _−14% ^+0% ). Since a large discrepancy exists between measured as well as predicted slopes, the value of S ₁₇(0) is dependent on the choice of data and theory used to extrapolate S ₁₇(0). This situation must be alleviated by new measurement(s). The “world average” is driven by the Seattle result owing to the very small quoted uncertainty, which we, however, demonstrate to be an overestimated accuracy. We propose more realistic error bars for the Seattle results based on the published Seattle data. The text was submitted by the author in English.     

闪光灯泵浦的Nd:KGd(WO4)2激光器

报道了用闪光灯泵浦的掺钕的钨酸钆镓(Nd³⁺:KGd(WO₄)₂激光器.在重复频率1Hz,脉宽120μs的灯泵下,测量了不同透过率下激光输出能量,获得最大输出能量384mJ,斜率效率1.0%,外推阈值0.54J.在调Q运行时,Nd:KGW晶体的斜率效率为0.16%,最大输出能量46mJ.     

DIRICHLET BOUNDARY VALUE PROBLEMS FOR SECOND-ORDER QUASI-LINEAR DIFFERENTIAL EQUATIONS WITH CHANGING SIGN NONLINEARITIES

This paper is concerned with the existence of positive solutions of two-point Dirichlet singular and nonsingular boundary problems for second-order quasi-linear differential equations with changing sign nonlinearities.     

1β—Methyl Carbapenem中间体的合成

综述了１β－Ｍｅｔｈｙｌ Ｃａｒｂａｐｅｎｅｍ中间体的合成方法，重点强调了如何构筑１位β构型的甲基。参考文献３７篇。     

Raman mapping and in situ SERS spectroelectrochemical studies of 6-mercaptopurine SAMs on the gold electrode

The self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) were formed at the roughened polycrystalline gold surfaces in acid and alkaline media. The time-dependent Raman mapping spectral analysis in conjunction with the quantum calculations for the vibrational modes using ab initio BLYP/6-31G method suggested that both of the resulted 6MP SAMs adopted the same adsorption mode through the S atom of pyrimidine moiety and the N7 atom of the imidazole moiety anchoring the gold surface in a vertical way. The in situ surface-enhanced Raman scattering spectroelectrochemical experiment was conducted to examine the stability of the SAMs at various bias potentials. It was found that the detaching process of the 6MP SAMs from the surface involved one electron reduction as the voltage was applied at ca. 0.7 V vs a standard calomel electrode.     

High-yield solvothermal formation of magnetic CoPt alloy nanowires

One-dimensional (1D) magnetic nanomaterials have attracted much attention recently because of their applications in magnetic recording and spintronics. Nevertheless, it remains a challenge to prepare free-standing magnetic nanowires in high yield. This Communication reports the successful high-yield synthesis of an interesting 1D ferromagnetic CoPt alloy by direct decomposition of platinum acetylacetonate and cobalt carbonyl compound in ethylenediamine solvent through a solvothermal reaction. The CoPt alloy nanowires obtained have a tunable diameter of 10-50 nm and a length along the longitudinal axis of up to several microns, depending on crystallization temperature and reaction time. A unique formation mechanism involving coarsening and ripening under solvothermal conditions was discovered. This research opens new opportunities in synthesizing nanomaterials through low-temperature solvothermal processes.