松香产品中重质松节油成分的气相色谱/质谱法分析

利用水汽蒸馏提取法富集了松香产品中残留的重质松节油,经气相色谱／质谱联机分析,发现其主要由１９种单萜和倍半萜化合物组成,全部为香味物质（未知物除外）。为提高松香产品的品质和开发利用松香重质松节油提供了依据。     

布里渊放大器中Stokes光的高增益放大

微小Stokes信号光在布里渊放大器中得到放大,当Stokes信号光强度为015mj时,增益系数达到67。Stokes光增益决定于Stokes信号光强度及放大池中泵光与Stokes光的耦合程度,小信号Stokes光将得到较大的增益,并能得到较好的相位共轭效果     

Identification of wheat varieties using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and an artificial neural network

A novel tool for variety identification of wheat (Triticum aestivum L.) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness of this novel method with respect to various experimental parameters has been tested. The results can be summarised: (i) With this approach 97% of the wheat varieties can be classified correctly with a corresponding correlation coefficient of 1.0, (ii) The method is fast since the time of extracting gliadins from flour can be reduced to 20 min without significant decrease in overall performance, (iii) The storage of flour or extracts under standard conditions does not influence the classification ability (i. e. the generalisation ability) of the method, and (iv) The classification obtained is not influenced by the identity of the operator making the analysis. This study demonstrates that a combination of an ANN and MALDI-TOFMS analysis of the gliadin fraction provides a fast and reliable tool for the variety identification of wheat. Copyright 1999 John Wiley & Sons, Ltd.     

A SEMI-MICROSCOPIC MODEL FOR ACOUSTICAL ACTIVITY

In this paper we suggest a semi-microscopic model to describe the phenomenon of acoustical activity and to extend the point group symmetry consideration first given by Portigal and Burstein[1].     

Motion of Solitons in Deoxyribonucleic Acid (DNA) Double Helices with Dissipation

Under the first-order approximation, the general soliton solution of the plane base rotator model is obtained using the direct perturbation method, when taking the dissipation interaction in the DNA double helices dynamics into consideration. The stability condition of system leads to a relation among the soliton velocity, the coupling constants and the damping factor. It imposes limits to the maximum value of the soliton velocity and energy. An estimation of the value of the dissipation factor is given using recently published experimental data. Some practical problems such as the energy transmission and the semiconservative replication of B-DNA are discussed in detail.     

考虑裂隙间相互作用情况下围压卸荷过程应力应变关系

岩体的稳定性和变形特性主要决定于裂隙，同时裂隙间的相互作用对岩体的稳定和变形产生显著的影响。裂隙岩体在加载和卸荷条件下的力学特性有显著的区别。为此本文首次利用位错模型法结合叠加原理研究在围压卸荷条件下裂隙间的相互作用对岩体的变形的影响问题。文中推导了考虑裂隙间的相互作用情况下裂隙岩体围压卸荷过程的应力应变关系及应力强度因子表达式，且进行了数值计算。     

治疗胃炎伴糜烂蒙药中多种微量元素的ICP-AES法测定

蒙药含有多种氨基酸和丰富的微量元素,特别是人体必需的微量元素含量相对高,而对人体有害的重金属元素含量相对低。采用微波消解ICP-AES法同时测定了治疗胃炎伴糜烂组合蒙药(1#:如达-6、2#:巴特日-7(Ⅱ))中Ca、Mg、Al、Fe、Mn、Sr、Cu、Zn、Pb等15种微量元素。加标回收率在94.9%~106.2%之间,相对标准偏差RSD≤3.2%,检出限在≤0.009μg/L。实验结果表明:1#、2#为不同类型的蒙药,其微量元素含量有所不同。     

手性流动相HPLC法拆分对羟基苯甘氨酸对映体的研究

将β-环糊精、羟丙基-β-环糊精作为手性流动相添加剂,系统地研究了D,L对羟基苯甘氨酸在RP-HPLC系统中的拆分。分别考察了手性流动相的种类,手性试剂β-环糊精的浓度,流动相的pH,修饰剂的种类及浓度,色谱柱温度等对拆分效果的影响,以-βCD为手性流动相添加剂,建立了-βCD手性流动相分离对羟基苯甘氨酸对映体的方法。结果表明:用ODS柱(250 mm×4.6 mmi.d.),以V(甲醇-β环糊精)∶V(pH 4.5磷酸盐缓冲液)=30∶70为流动相,流速0.2 mL/min,柱温25℃,检测波长为230 nm时对羟基苯甘氨酸对映体得到了良好的基线分离,分离度可达1.71。     

矿物在煤粉中的分布规律研究

本文采用浮沉法研究了矿物在煤粉中的分布规律.结果发现,密度级别反映了矿物在煤粉中存在状态.随着密度级别提高,无烟煤煤粉中有机显微组分种类和含量不发生变化,烟煤煤粉中镜质组含量下降,惰质组含量升高,壳质组含量较低,略呈下降趋势,而褐煤煤粉中镜质组含量升高,壳质组含量下降,而惰质组含量几乎不发生变化,所有煤粉中无机矿物种类分布规律相似,内在矿物均以粘土矿物为主,以黄铁矿为辅,而外在矿物种类齐全,但仍以粘土矿物为主.无烟煤和高灰分烟煤煤粉中矿物几乎均匀存在于各密度级别中,而中等灰分的烟煤煤粉中矿物以独立存在为主,而褐煤中矿物与有机质均匀交织在一起.