轻基体中稀土氧化物的X射线荧光分析：非相干散射应用研究

本文通过研究轻元素的非相干散机机制，将非相干散射和特征线以散射归－化相结合计算表观浓度，利用强度校正模型和线性方程组的最小二乘法回归分析以及实验室标样，建立了轻基体之－Ｌｉ２ＣＯ３中少量Ｓｃ２Ｏ３，Ｙ２Ｏ３，Ｌａ２Ｏ３，Ｔｍ２Ｏ３和Ｌｕ２Ｏ３的Ｘ射线荧光分析方法，本方法测定的精密度均优于４．０％，最佳的可达２．１％。这种定时分析方法具有准确，简便，快速和多元素同时测定等优点。     

ICP-AES法同时测定氯化锂和氢氧化锂中七种杂质元素

本文报导了用ＩＣＰ－ＡＥＳ法同时测定ＬｉＣｌ和ＬｉＯＨ·Ｈ２Ｏ中７种杂质元素Ａｌ、Ｂａ、Ｃａ、Ｆｅ、Ｍｇ、Ｓｉ、Ｚｎ的分析方法。研究了基体元素锂对被测元素的基体效应，采用基体匹配法与背景扣除法进行校正。被测元素的检出限为０．１－９．４ｎｇ／ｍＬ，加标试验回收率为９２％－１０９％，当杂质元素含量为０．０００１％－０．０２８％时，相对标准偏差小于７％。方法简便、快速、准确，用于样品分析，取得了满意的结果。     

ICP－AES法直接测定高纯Eu_2O_3中14种稀土元素

建立了ＩＣＰ－ＡＥＳ测定高纯Ｅｕ２Ｏ３中１４种稀土元素的方法。用正交设计法优化仪器测量条件，实验了基体Ｅｕ２Ｏ３对被测元素的干扰和对方法测定下限的影响。１４个稀土元素的测定下限为：Ｙｂ２Ｏ３０．５μｇ·ｇ－１，Ｙ２Ｏ３１μｇ·ｇ－１，Ｄｙ２Ｏ３、Ｈｏ２Ｏ３、Ｔｍ２Ｏ３和Ｎｄ２Ｏ３５μｇ·ｇ－１，Ｇｄ２Ｏ３、Ｓｍ２Ｏ３、Ｅｒ２Ｏ３、Ｃｅ２Ｏ３、Ｐｒ６Ｏ１１和Ｌａ２Ｏ３１０μｇ·ｇ－１，Ｌｕ２Ｏ３２０μｇ·ｇ－１以及Ｔｂ４Ｏ７３０μｇ·ｇ－１。加入回收率为８８－１１２％，六次取样分析的相对标准偏差小于１１％。方法简便不经化学分离，可用于９９．９－９９．９９％Ｅｕ２Ｏ３中稀土杂质的测定或生产控制分析。     

ICP—AES法直接测定高纯Eu2O3中14种稀土元素

建立了ＩＰＣ－ＡＥＳ测定高纯Ｅｕ２Ｏ３中１４种稀土元素的方法，用正交设计法优化仪器测量条件，实验了基体Ｅｕ２Ｏ３对被测元素的干扰和对方法测定下限的影响。１４个稀土元素的测定下限为：Ｙｂ２Ｏ３０．５μｇ．ｇ＾－１，Ｙ２Ｏ３１μｇ．ｇ＾－１，Ｄｙ２Ｏ３，Ｈｏ２Ｏ３，Ｔｍ２Ｏ３和Ｎｄ２Ｏ３５μｇ．ｇ＾－１、Ｇｄ２Ｏ３、Ｓｍ２Ｏ３、Ｅｒ２Ｏ３、Ｃｅ２Ｏ３、Ｐｒ６Ｏ１１和Ｌａ２Ｏ３１０μｇ．ｇ＾－１，Ｌｕ２     

原子吸收法测定人精子中锌和铜含量的研究

本文采用石墨炉原子吸收法，以ＮＨ４ＮＯ３和Ｍｇ（ＮＯ３）２混合剂作基体改进剂，测定了人精子中微量元素铜和锌。基方法的特征质量分别为１０．００ｐｇＣｕ／０．００４４Ａ．Ｓ．，９．８０ＰｇＺ／０．００４Ａ．Ｓ；平均加收率为９７．４２％，锌为１０１．９１％，铜和锌的精密度分别是４．１％和４．０３％。     

钨盐涂覆-GFAAS法测定肿瘤患者体内痕量锂

钨盐涂覆处理石墨管,大幅度提高测定锂的灵敏度。配以（ＮＨ４）２ＳＯ４基体改进剂,消除生物基体干扰。特征浓度５．５３×１０－３μｇ·ｍＬ－１／１％,回收率大于９３．７２％,相对标准偏差小于８．９３％。     

一甲基硫脲与支持电解质的阴离子在银电极上共吸附的拉曼光谱研究

本文用电化学现场表面增强拉曼散射光谱（ＳＥＲＳ）技术研究了ＭＴＵ在ＨＣｌＯ４、Ｈ２ＳＯ４和ＨＮＯ３介质中分别与一种或两种无机阴离子的共吸附行为，发现ＣｌＯ－４、ＳＯ２－４和ＮＯ－３等弱吸附无机阴离子均能被ＭＴＵ诱导物理吸附在其质子化了的氨基（ＮＨ＋３）上，这三种无机阴离子被ＭＴＵ诱导物理吸附的强弱顺序是：在电极电位位于－０．２Ｖ～－０．７Ｖ区间时，ＳＯ２－４＞ＣｌＯ－４＞ＮＯ－３，在电位位于－０．８Ｖ～－１．２Ｖ区间时，ＣｌＯ－４＞ＳＯ２－４＞ＮＯ－３。     

氧化态K—MoO3／γ—Al2O3催化剂结构的EXAFS研究

对Ｎａ２ＭｏＯ４．２Ｈ２Ｏ，ＭｏＯ３，（ＮＨ４）６Ｍｏ７Ｏ２４．４Ｈ２Ｏ等结构典型的含钼化合物及氧化态Ｋ－ＭｏＯ３／γ－Ａｌ２Ｏ３催化剂样品进行了ＥＸＡＦＳ测试，并以Ｎａ２ＭｏＯ４．２Ｈ２Ｏ为标样进行多层拟合计算，以研究各样品钼组分的配位结构。     

微波溶样—ICP／MS法测定稻中15种痕量稀土元素

本文报道采用ＨＮＯ３＋Ｈ２Ｏ２微波溶样，ＩＣＰ－ＭＳ直接测定稻中１５种稀土元素，对微波溶样和等离子体质谱测定条件进行了优化选择。选用Ｒｅ作内标可补偿基体效应。方法检出限为７．０－２５．８ｐｇ／ｍＬ，稻壳加标回收率为９５－１０５％，ＲＳＤ为２．３－４．２％，方法快速、灵敏、准确。     

石墨炉原子吸收法测定骨肿瘤患者血清中向量钻

本文建立了用石墨炉原子吸收光谱法测定血清中向量钴的方案，血清以（１＋１）ＨＮＯ３沉淀分离除去蛋白ＤＴｒｉｔｏｎＸ－１００和ＮＨ４ＶＯ３为基体改进剂，直接测定，方法简便，快速。回收率９７．６０％－１０２．１１％，ＲＳＤ〈７．２１％。     

Synthesis of 2-(1,5-diaryl-1,4-pentadien-3-ylidene)-hydrazinecarboximidamide hydrochloride catalyzed by p-dodecylbenzenesulfonic acid in aqueous media under ultrasound irradiation

Amidinohydrazone compounds are very important synthetic intermediates and can serve as versatile precursors in synthesis of many natural products and drug molecules. The use of ultrasound, p-dodecylbenzenesulfonic acid (DBSA) and water as solvent improved the synthesis of different 2-(1,5-diaryl-1,4-pentadien-3-ylidene)-hydrazinecarboximidamide hydrochlorides. The best reaction conditions for the condensation of 1,5-diphenyl-1,4-pentadien-3-one with aminoguanidine hydrochloride were as follows: 1,5-diphenyl-1,4-pentadiene-3-one (1, 1 mmol), aminoguanidine hydrochloride (1.1 mmol), DBSA (0.5 mmol), water 10 mL, reaction temperature 25-27°C, irradiation frequency 25 kHz. 2a was achieved in 94% yield within 2h. The other seven amidinohydrazones were obtained in 84-94% yield within 2-3h under the same conditions. Compared to the method involving catalysis by hydrochloric acid in refluxing EtOH, the advantages of present procedure are milder conditions, shorter reaction times, higher yields, and environmental friendly conditions, which make it a useful strategy for the synthesis of analogues.     

Antimasking aspects of harp seal (Pagophilus groenlandicus) underwater vocalizations

Underwater sounds are very important in social communication of harp seals (Pagophilus groenlandicus) because they are the main means of long- and short-distance communication. Individual harp seals must try to avoid being masked and emit only those calls that will benefit them. Underwater vocalizations of harp seals were recorded during the breeding season. The physical characteristics associated with antimasking attributes of 16 call types were examined. Rising frequency or increasing amplitude within calls were not common. Most of the calls ended abruptly (range 145-966 dB/s), but call onset was more gradual. At high calling rates (95.1-135 calls/min) there were significantly more calls overlapping temporally than at medium (75.1-95 calls/min) or low (35-75 calls/min) calling rates, but even at the highest calling rates, 79.1% of the calls were not overlapped. When 2, 3, or 4 calls overlapped, there were significantly fewer frequency separations of less than 1/3 octave than would be expected by chance. This is important because sounds that are separated by less than 1/3 octave likely mask each other. When 2-4 calls are occurring simultaneously, only 4.5% to 14.2% are masked by virtue of being within 1/3 octave from their nearest neighbor. None of the overlappping calls was of the same type. This suggests that the seals are actively listening to each other's calls and are not randomly using the different call types. Harp seals use frequency and temporal separation in conjunction with a wide vocal repertoire to avoid masking each other.     

Experimental study of the effects of pulsed Doppler sample volume size and position on the Doppler spectrum

With a pulsed Doppler system, the recorded Doppler spectrum is expected to vary depending upon the sample volume size relative to the diameter of the vessel, the position of the sample volume in the vessel and the velocity profile. In the in vitro experiments described in this paper, the velocity profile was kept constant by using steady parabolic flow in a flow model. As the Doppler sample volume size and position were changed, the maximum variations of quantitative measurements from the Doppler spectrum were determined. The maximum, mean and mode frequencies and spectral broadening index (SBI) were affected by the position of the sample volume but to a lesser degree by its length (1.5-5.0 mm) relative to the 9.5 mm beam path length across the tube. When the centre of the Doppler sample volume was moved within the central 25% of the tube, the maximum variations were as follows: maximum frequency 3-5%, mean frequency 8-9%, mode frequency 8-9% and SBI 16-18%, where the range indicates the effect of increasing the sample volume size. Based on these results obtained under steady flow conditions in vitro, it is concluded that quantification of pulsed Doppler spectra may be feasible if the sample volume is positioned within the central 25% of the vessel.     

倍频YAG泵浦脉冲钛宝石激光器设计与激光运转

用10ns倍频YAG激光泵浦实现了Ti~(3+):Al_2O_3激光运转,最大输出能量可达37mJ,能量转换效率40%,斜率效率59%,量子效率80%,泵浦阈值0.5～1.2J/cm~2,在662～938nm波长范围内实现了连续调谐.     

交换纤维柱分离ICP-AES测定高纯氧化镱中La、Nd、Eu和Gd

以强酸型离子交换纤维柱分离富集高纯Yb₂O₃中La,Nd,Eu和Gd等痕量杂质元素,并用Optima 5300 DV ICP-AES测定分离富集后的这4种元素。供试纤维对Yb的动态吸附容量为134 mg·g-1,4.0 g纤维柱的分离条件为：pH 3.00的试液以1.0 mL·min-1流速上柱后,分离柱先以流速为1.5 mL·min-1的pH 3.00 HNO₃溶液80 mL预淋洗,再以同样流速pH 5.00的0.01 mol·L-1 EDTA铵溶液淋洗。结果表明：10 mg Yb与各为0.100 μg的La,Nd,Eu和Gd能达到基线分离;分离含100 mg Yb的试液后,在杂质富集液中Yb的残留浓度仅为0.017 1 μg·mL-1。 研究显示,当待测试液中Yb₂O₃的浓度小于100 μg·mL-1(如Yb 87.8 μg·mL-1)时,它对测定La,Nd,Eu和Gd等杂质元素的基体干扰可以忽略不计。富集倍数分别为La₂O₃ 3.68×105,Nd₂O₃ 4.20×105,Eu₂O₃ 3.82×105,Gd₂O₃ 4.01×105。方法检出限分别为La₂O₃ 0.005 0 pg·mL-1,Nd₂O₃ 0.014 pg·mL-1,Eu₂O₃ 0.001 8 pg·mL-1,Gd₂O₃ 0.008 2 pg·mL-1。本方法已用于99.99% Yb₂O₃样品中4种稀土杂质的测定,标准加入的平均回收率分别为La₂O₃ 94.2%,Nd₂O₃ 107%,Eu₂O₃ 97.8%,Gd₂O₃ 102%,RSD (%, n=5)分别为La₂O₃ 6.2,Nd₂O₃ 5.9,Eu₂O₃ 7.3,Gd₂O₃ 2.5,校正曲线不需进行Yb的基体匹配,分析周期为4 h。     

分光光度法测定利福平磺丁基醚-β-环糊精包合物

建立测定利福平磺丁基醚-β环糊精包合物中利福平含量的方法。采用分光光度法测定含量,测定波长为474nm。利福平在474nm处有最大吸收,在9.786—39.14μg/mL,范围内与吸光度呈良好的线性关系,回归方程为:A=0.01 72C+0.0025(r=0.9998);平均回收率为99.87%(n=9),RSD为0.24%;日内RSD分别为0.81%、0.43%、0.57%(n=5);日间RSD分别为1.06%、1.21%、1.53%(n=3);测得3批样品的含量分别为25.33%、25.98%、25.76%。本法准确、简便、迅速,适用于利福平磺丁基-β-环糊精包合物中利福平含量的测定。     

ICP－AES法测定钒酸钇晶体中的掺杂稀土元素铒和铕的含量

本文用硫酸溶解样品，以ＩＣＰ－ＡＥＳ法对钒酸钇晶体中掺杂稀土元素铒和铕进行测定，取得满意结果，回收率分别是９８％－１０４％和９６％－１０５％；相对标准偏差３％以内。文中选择了相宜的内标元素并研究了硫酸浓度和基体浓度对被测元素的谱线强度的影响。     

Correlation between short-term and long-term radon measurements

In selected kindergartens and schools, long-term average indoor air radon concentrations were measured by two-month exposure of etched track detectors. Short-term average concentrations were obtained from 7-10 day continuous radon recordings during the exposure of etched track detectors. Only in about 1/3 of cases both averages did agree within +/- 20%; otherwise they differ considerably. The assumption that short-term results can substitute for long-term data, which is sometimes made to correct radon exposure estimated on the basis of concentrations obtained by etched track detectors, should therefore be treated with caution.     

水体的温度变化对测定溶解有机物浓度的影响

用激光诱导荧光(LIF)方法研究了水体的温度变化对溶解有机物(DOM)发射荧光强度的影响。随着温度的增加,DOM的荧光强度和水的拉曼散射强度不断降低。在20～75 ℃范围之内,对归一化荧光强度与温度关系曲线进行线性拟合,计算出归一化荧光强度随温度升高的变化梯度平均值为-5.24×10-4 ℃-1,根据归一化荧光强度与浓度的关系,给出了所测DOM的浓度随着温度升高的平均下降速率为-3.45×10-3 (mg·L-1)·℃-1。因此,在这一温度范围内测量时,假设归一化荧光强度不变,则温度变化将引起DOM浓度最大为8.45%的相对变化。     

Diamond Composites with TiC,SiC and Ti 3 SiC 2 Bonding Phase

The problems connected with producing diamond composites with 30 wt.% of bonding phase in form of: SiC, TiC, and Ti 3 SiC 2 are presented in the paper. Increasing the fraction of the bonding phase within the composite generally helps to reduce internal stresses. Composites were sintered at pressure 8.0 - 0.2 GPa and temperature of 2070 - 50 K using the Bridgman type high pressure apparatus. Interactions in the diamond-SiC, the diamond-TiC, and the diamond-Ti 3 SiC 2 systems were studied by means of transmission electron microscope (TEM) and X-ray diffraction. Density was measured pycnometrically. The wear resistance studies of these composites were carried out using pin - on disc type laboratory equipment. Hardness was measured with Vickers apparatus. Results of measurements of physical and mechanical properties are reported.