某类遗传环境下的两性分支过程：有关伴Y基因的灭绝概率问题

本文在文献[2]的基础上研究了另一类遗传环境下的两性分支过程（其中配对单元类型多于一种且有一种类型的配对单元数仅由雌性数嚼决定）并得到了有关它们灭绝概率的一些结果。     

离子色谱法测定2-羧乙基苯基次膦酸中的氯离子

建立离子色谱法测定2-羧乙基苯基次膦酸中氯离子的含量。样品用超纯水溶解稀释,过0.22μm滤膜;选用SH–AC–2阴离子分离柱,以30 mmol/L Na OH溶液作为淋洗液,流量为1.0 m L/min,进样体积为50μL,以抑制电导检测器测定氯离子的含量。氯离子的质量浓度在0.01~1.00 mg/L范围内与色谱峰面积线性关系良好,相关系数为0.996,氯离子的检出限(S/N=3)为1.0μg/L。测定结果的相对标准偏差小于10%(n=6),样品加标回收率为94.7%~103.5%。该方法简便、快速且灵敏,可用于2-羧乙基苯基次膦酸中氯离子的测定。     

水包油型微乳液相色谱分离激素类药物的影响因素

采用水包油型微乳液相色谱(MELC)分离了6种激素类药物(醋酸可的松、泼尼松龙、己烯雌酚、炔雌醇、醋酸氟轻松及黄体酮)。考察了微乳流动相的组成成分(包括表面活性剂的浓度、油相种类、有机添加剂种类)及固定相孔径等对分离的影响。实验得到的最佳分离条件: 色谱柱为Venusil ASB C18 (T)(粒径5 μm,孔径30 nm,250 mm×4.6 mm),微乳流动相为30 g/L十二烷基硫酸钠(SDS)-0.8%正辛烷-6.6%正丁醇,流速为0.8 mL/min,检测波长为254 nm,柱温为35 ℃。该方法可用于甾体药物及其制剂的分离鉴别以及快速测定。     

稀土金属氧化物改性整体式钌基氨合成催化剂的制备和性能的研究

研究了稀土金属氧化物La2O3，CeO2，Pr2O3，Nd2O3和Sin2O3对Ru-Bd堇青石催化剂的活性的影响。利用BET，BJH，SEM，XRD，CO化学吸附等测试手段对催化剂进行表征，并对催化剂的反应性能进行评价。SEM测试结果显示La2O3呈“虫卵状”聚集在茧青石表面，而CeO2呈立方CaF2型均匀的覆盖在堇青石表面，Ru粒子呈“孤岛状”均匀地分散在铈改性的堇青石载体表面。茧青石载体经CeO2改性后，催化剂的比表面积、比孔容积以及中、微孔数量均有所提高，孔径分布也得到了明显改善。活性数据显示，适量的稀土金属氧化物均能促进Ru-Ba/堇青石催化剂的活性，其中CeO2的改性效果最好，在10MPa，475℃，5000h^-1时CeO2改性的Ru-Ba／茧青石催化剂的氨合成转化率达到9．9％。研究了CeO2对氨浓度随温度、压力、空速变化趋势的影响。     

新型氨合成催化剂稀土总量分析

探讨了新型合成氨催化剂中稀土总量的测定方法，方法的测定线性范围为１０－５０μｇ／５０ｍＬ，灵敏度高，选择性及重现性好，简便快速，回收率９８．５－１００％，分析结果满意。     

Determination of three capsaicinoids in Capsicum annuum by pressurized liquid extraction combined with LC‐MS/MS

A new method based on pressurized liquid extraction followed by LC‐MS/MS analysis has been developed for the identification and quantification of three capsaicinoids (capsaicin, dihydrocapsaicin, and nordihydrocapsaicin) in extracts of Capsicum annuum. For the recovery of three capsaicinoids, the efficiency levels of ultrasonic‐assisted extraction, microwave‐assisted extraction, Soxhlet extraction, and pressurized liquid extraction were compared under different conditions. Pressurized liquid extraction resulted in higher yields. Pressurized liquid extractions were performed using methanol; temperature was set at 100°C and pressure at 1500 psi. LC analysis was performed on a Waters XBridge? C₁₈ column (150 × 2.1 mm, id 3.5 μm) eluted by a mobile phase of 0.1% formic acid and ACN. Data acquisition was carried out in multiple reaction monitoring transitions mode, monitoring two‐reaction monitoring transitions to ensure an accurate identification of target compounds in the samples. The proposed method is rapid, simple, and could be utilized for the routine analysis of three capsaicinoids in C. annuum samples.     

Effect of MgO promoter on Ni-based SBA-15 catalysts for combined steam and carbon dioxide reforming of methane

A series of Ni/SBA-15 catalysts with Ni contents ranging from 5 wt% to 15 wt%, as well as another series of 10%Ni/MgO/SBA-15 catalysts, in which the range of the MgO content was from 1 wt% to 7 wt%, were prepared, and their catalytic performances for the reaction of combined steam and carbon dioxide reforming of methane were investigated in a continuous flow microreactor. The structures of the catalysts were characterized using the XRD, H2-TPR and CO2-TPD techniques. The results indicated that the CO selectivity for this reaction was very close to 100%, and the H2/CO ratio of the product gas could be controlled by changing the H2O/CO2 molar ratio of the feed gas. The simultaneous and plentiful existing of steam and CO2 had a significant influence on the catalytic performance of the 10%Ni/SBA-15 catalyst without modification. After reacting at 850 °C for 120 h over this catalyst, the CH4 conversion dropped from 98% to 85%, and the CO2 conversion decreased from 86% to 53%. However, the 10%Ni/3%MgO/SBA-15 catalyst exhibited a much better catalytic performance, and after reacting for 620 h, the CO2 conversion over this catalyst dropped from 92% to around 77%, while the CH4 conversion was not decreased. Oxidation of the Ni0 species as well as carbon deposition during the reaction were the main reasons for the deactivation of the catalyst without modification. On the other hand, modification by the MgO promoter improved the dispersion of the Ni0 species, and enhanced the CO2 adsorption affinity which in turn depressed the occurring of carbon deposition, and thus retarded the deactivation process.     

Effect of O2 and H2O on the tri-reforming of the simulated biogas to syngas over Ni-based SBA-15 catalysts

A series of Ni/SBA-15 catalysts with Ni contents from 7.5 wt% to 15 wt% were prepared by impregnation method. The effect of O2 and H2O on the combined reforming of the simulated biogas to syngas was investigated in a continuous flow fixed-bed micro-reactor. The stability of the catalyst was tested at 800 ℃. The results indicated that 10 wt%Ni/SBA-15 catalyst exhibited the highest catalytic activities for the combined reforming of the simulated biogas to syngas. Under the reaction conditions of the feed gas molar ratios CH4/CO2/O2/H2O = 2/1/0.6/0.6, GHSV = 24000 ml•g{cat}-1\cdoth-1 and the reaction temperatureT = 800 ℃, the conversions of CH4 and CO2 were 92.8% and 76.3%, respectively, and the yields of CO and H2 were 99.0% and 82.0%, respectively. The catalytic activities of the catalyst did not decrease obviously after 100 h reaction time on stream.     

一类广义迭代学习控制系统的状态跟踪算法

利用迭代学习控制方法,研究了一类广义系统的状态跟踪问题.针对广义系统的分解形式,提出了一种新的迭代学习控制算法,该算法由部分D型算法和部分P型算法混合而成.给出了新算法的收敛条件,并从理论上对新算法进行了完整的收敛性分析.数值仿真结果说明了所提出的广义系统状态跟踪的迭代学习控制算法的有效性.