清平面板堆石坝抗震分析

根据面板堆石坝的结构特点和工作条件，采用动力非线性有限元法，对清平水库面板坝进行了空库和满库条件下地震反应分析与比较、混凝土面板地震抗滑稳定分析及坝基饱和细砂层的地震液化验算，综合评价大坝的安全性．     

MSnO_3和MSn_（0．5）Zr_（0．5）O_3（M＝Sr，Ba）的水热合

本文利用水热合成方法对ＭＳｎＯ３和ＭＳｎ（０．５）Ｚｒ（０．５）Ｏ３（Ｍ＝Ｓｒ，Ｂａ）的合成进行了研究，并采用ＸＲＤ、ＳＥＭ和ＩＣＰ等方法对产物进行了表征，结果表明：在Ｍ（ＯＨ）２－ＳｎＯ２（或ＳｎＯ２＋ＺｒＯ２）－ＫＯＨ体系中，当ＫＯＨ／Ｓｎ和ＫＯＨ／（Ｓｎ＋Ｚｒ）≥３０时，２６０℃下晶化５～７天，可获得ＭＳｎＯ３和ＭＳｎ（０．５）Ｚｒ（０．５）Ｏ３纯相，在Ｍ（ＯＨ）２－（ＳｎＯ２＋ＺｒＯ２）－ＫＯＨ－Ｈ２Ｏ体系中，可通过控制介质碱度来获得ＭＳｎＯ３＋ＭＺｒＯ３混合物和ＭＳｎ（０．５）Ｚｒ（０．５）Ｏ３，并根据合成规律初步探讨了反应过程．     

Hydrothermal Synthesis of Acicular Lead Titanate Fine Powders

A pure, acicular lead titanate (PbTiO₃) fine powder with a white color has been prepared by hydrothermal synthesis. It is a new phase of PbTiO₃ with I 4 symmetry, cell parameters of a = 12.358 Å and b = 14.541 Å, and a density of 6.80 g.cm⁻³. The influences of pH (12.5 to 14.4), Pb/Ti ratio (1.0 to 1.6) in the feedstock, reaction temperature (130° to 230°C), time (0.25 to 4 h), starting materials, and additives on the formation of acicular PbTiO₃ under hydrothermal conditions have been investigated. The acicular PbTiO₃ with I 4 symmetry, referred to as the PX phase, can be converted to the perovskite-type (PE phase) of PbTiO₃ at about 605°C while its acicular morphology is essentially unchanged. The preferable conditions for preparing pure acicular PX-phase PbTiO₃ are that the pH is 13.0 to 14.0, Pb/Ti ratio is >1.3, reaction temperature is 170° to 200°C, time is 0.5 to 1.0 h, titanium butoxide (Ti[O(CH₂)₃CH₃]₄) is the starting material, and poly(vinyl alcohol) is an additive. The acicular grain of the PX phase is usually less than 100 nm in diameter and more than 1000 nm in length.     

静态水热脱铝处理对HZSM-5分子筛的结构、酸性和催化性能的影响

开发了一种静态水热脱铝的方法。HZSM-5经此法处理后,正戊烷的裂解活性增加,脱氢和芳构化性能加强。可用改变处理温度的方法来控制脱铝的程度。用XRD和吡啶吸附红外技术进行了研究。HZSM-5分子筛催化剂性能的变化用非骨架铝产生的强L酸中心来解释。     

3961连续重整催化剂性能考察

新一代高活性，高水热稳定性3961（PS－Ⅳ）型连续重整催化剂于1996年在上海石化芳烃厂400kt/a连续重整装置上首次进行工业应用试验。开工5a，催化剂跟踪分析结果表明，该剂保持了良好的物化性质和反应性能，表现为良好的比表面积稳定性和持氯能力，经过200个以上再生周期的催化剂未发现有明显的相变和金属分散度的变化。     

碱对AlMCM-41介孔分子筛合成的影响

分别用NaOH和TEAOH合成了AlMCM 4 1介孔分子筛 ,用XRD、2 7AlMASNMR、SEM、TEM、IR、N2 低温吸附和TG DTA对样品进行了表征和比较。结果表明 ,TEAOH和NaOH对AlMCM 4 1有序结构的影响不同。当硅铝原子比为 2 5或 5 0时 ,用NaOH合成的样品有序性较高 ;而当硅铝比为 15时 ,用TEAOH合成的样品有序性较高。交换成氢型AlMCM 4 1后 ,当硅铝比为 2 5或 15时 ,用TEAOH合成的样品抗水解性能优于用NaOH合成的样品 ,其酸量也较大。用TEAOH合成的样品粒度小 ,比表面积、孔径和孔体积都大于用NaOH合成的样品     

特殊α-淀粉酶的应用研究现状和前景展望

本文概述了国内外α-淀粉酶的研究和应用现状,进而阐述了特殊α-淀粉酶的特殊性及其在各种极端条件下的用途,并提出特殊α-淀粉酶的发展前景。     

液氨装置工艺计算及改造总结

介绍我公司液氯装置由活塞式氨气压缩机氨-CaCl2盐水系统改为带经济器的螺杆式氯气液化机组的工艺计算,新建装置特点以及改造后的装置在我公司运行情况和使用效果。经改造后的液氯装置每年可节约电费73万余元,同时提高了装置的安全可靠性。     

Direct synthesis and catalytic performance of ultralarge pore GaSBA-15 mesoporous molecular sieves with high gallium content

Mesoporous GaSBA-15 molecular sieves with different n_Si/n_Ga ratios have been directly synthesized using Pluronic 123 triblock polymer as a structure-directing agent by pH-adjusting method. The mesoporous materials have been characterized using ICP-AES, XRD, N₂ adsorption, ⁷¹Ga-MAS NMR, SEM and TEM. ICP-AES studies show a high amount of gallium incorporation on the silica pore walls. The structural and textural properties of calcined GaSBA-15 are characterized by XRD and N₂ adsorption. ⁷¹Ga MAS NMR results demonstrate that a high amount of tetrahedral-gallium could be substituted for Si in the framework of SBA-15. TEM and FE-SEM images show the uniform pore diameter and rope-like hexagonal mesoporous structure of GaSBA-15. These GaSBA-15 materials have been used as catalysts for vapour-phase t-butylation of 1,2-dihydroxybenzene (DHB) for selective synthesis of 4-t-butylcatechol (4-TBC) under different reaction conditions. GaSBA-15(10) gave the highest 93.2% conversion of DHB and 95.7% selectivity of 4-TBC as compared with other GaSBA-15 catalysts.     

循环加荷条件下饱和砂土液化细观数值模拟

利用离散单元法中的二维颗粒流方法(particle flow code in 2-dimension,PFC2D),通过对双轴数值试样施加循环等幅应变且控制加荷过程中试样体积(面积)不变的方法,模拟了循环加荷条件下饱和砂土的液化特性。在得到试样液化宏观力学响应的同时,分析了液化过程中内部平均接触数的变化规律。进一步研究了应变幅值、围压对数值试样液化特性的影响,并与室内试验规律进行了对比。结果表明,数值模拟能够定性地反映饱和砂土振动液化的一般规律,数值模拟得到的应变幅值、围压对试样抗液化强度的影响规律符合实际砂土室内试验规律。