溶胶—凝胶法制备钕玻璃纤维

钕玻璃是一种重要的光学材料。它作为激光工作物质已在激光核聚变、中小能量器件、波导激光器和光纤通讯上获得重要的应用。制备钕玻璃及其纤维通常需要在高温熔融状态下进行,操作条件苛刻。溶胶-凝胶法是在较低温度下制备无机材料的新方法,目前正受到人们的重视。     

腔靶转换区辐射温度测量及定标关系

对近年来的激光腔靶实验的辐射温度作了综合分析和研究。对多种不同类型的柱型腔靶,在波长1.06μm的各种激光条件(不同的能量和脉宽)下,测量了腔靶转换区的辐射温度,并研究了辐射温度作为入腔激光能量、脉宽及腔靶转换区内表面积函数的定标关系。     

A PRELIMINARY STUDY ON THE IMPACT OF MESOSCALE IRRIGATION OVER ARID LAND ON MESOSCALE CLIMATE

The present study investigated the modification of mesoscale inhomogeneous distribu-tion of soil wetness, resulting from mesoscale irrigation over arid or semiarid lands in mid-latitude in the later summer or early autumn, on mesoscale climate under conditions withand without synoptic flow influence, using an interactive model between soil and atmo-sphere. The simulations indicated that after a mesoscale irrgation, a wet soil breeze circu-lation was thermally forced, which was, in many features, similar to that of the sea breezecirculation. The influence of synoptic flows on the structure of thermally--induced wet soilbreeze circulation was also discussed.     

电感耦合等离子体发射光谱法测定铝合金中La、Ce、Pr、Nd、Sm

利用ICP—AES仪测定稀土铝合金中微量的La、Ce、Pr、Nd、Sm。试样用酸分解,直接上机测定,对光谱干扰情况和仪器参数的选择进行了研究。实验结果和推荐值核对相符。     

天然水中微量稀土元素镧的流动注射在线预浓集ICP光谱法测定

本文采用P507萃淋树脂为固定相,应用流动注射(FI)在线预浓集技术,建立了镧的ICP发射光谱分析方法,对天然水中的微量镧进行了测定,获得满意结果。     

REACTION KINETICS OVER PRECIPITATED Fe/Mn/K CATALYST FOR THE FISCHER-TROPSCH SYNTHESIS

The kinetics of the Fischer-Tropsch Synthesis reaction is studied in an internally recycled reactor (CSTR) over a commercial, precipitated Fe/Mn/K catalyst. Kinetic data are obtained with 1 47-4.04 H2/CO feed gas over a temperature range of 265-320℃, a pressure range of 1.0-2.6 MPa, and a space velocity range of 300-800 h-1 . The kinetic model which fits the experimental data well is the same as that of the intrinsic kinetics, i.e. -RH2 CO=kPH2PCO/(PCO bPH2O, where k is the kinetic constant for the rate-determining step and b is a function of temperature only. This model may be derived by assuming that the rate-determining step is the hydrogenation of adsorbed CO according to the enol mechanism. It is found that the CO usage ratio is probably independent of synthesis gas conversion and total pressure, and the catalyst shows high water-gas-shift activity.     

Three New Diterpenoids from Euphorbia wallichii

Three new abietane diterpene lactones, 3α-hydroxyjolkinolide A (1), ent-8α, 14β-dihydroxy-13(15)-ene-16(12α)-abietanolide (2) and ent-8α,14α-dihydroxy-13(15)-ene-16(12α)-abietanolide (3) as well as a known abietane diterpene jolkinolide A (4) were isolated from the roots of Euphorbia wallichii. Their structures were elucidated on the basis of spectroscopic analysis.     

光电直读光谱法测定稀土铝合金中La,Ce,Pr,Nd,Sm ,Si,Fe,Cu

本文报道了稀土铝合金中La,Ce,Pr,Nd,Sm,Si,Fe,Cu的光电直读光谱测定，对光源的激发方式及最佳工作条件进行了选择，应用KH－5高能预火花光源，采用单向全功率放电，先冲洗3秒，然后预燃5秒，曝光10秒。各元素谱线间无干扰，。使用固体试样，样品处理简单。经试验验证该法简便快速，精密度准确度高，含量在0．001％－0．002％之间RSD＜6％，0．02％－0．3％之间RSD＜3％，标准样品的测定值与准确值吻合较好，结果令人满意。     

非球面和梯度折射率在眼光学成象中的作用

在Gullstrand-Le Grand眼模型的基础上,构造不同的眼光学模型,分别研究了角膜非球面、晶状体非球面和昌状体折射率在眼光学成象中的作用.通过比较各模型系统的Zernike标准多项式系数,分析了非球面和梯度折射率对眼光光系统各象差的影响.同时研究了不同模型调制传递函数的特性.     

等离子发射光谱法测定煤中总硫的方法研究

本文提出以ICP－AES直接测定煤中总硫。通过对样品溶液的制备、光谱干扰等方面的研究，确定了最佳分析条件，建立了以ICP－AES测定煤中总硫的方法。方法快速、准确，测定结果与国标法一致。方法回收率在96％以上，六次测定相对标准偏差小于3％。