The Stability of Hydraulic Cylinder and Optimization Based on State Vector Matrix Transfer

液压缸由直径不同的缸体和活塞杆构成,工程上可视为承受轴向压缩的阶梯细长压杆,须进行稳定性校核.把液压缸的每段结构视作一个受压单元,受压单元中的弯矩和剪力都分别表示二维状态向量的单元矩阵,通过各单元传递矩阵相乘,获得受压状态活塞杆两端的状态向量关系,根据液压缸两端约束条件,推导液压缸稳定性普遍方程.结合MATlAb参数优化技术,获取体积约束条件下液压缸的最优尺寸,通过和rITz法计算结果、模型实验实测值比对,表明该计算结果更接近准确值.The hydraulic cylinder is composed of diverse cylindrical cases and piston rods which can be treated as a slender bar that suffers from axial compressions.So stability check must to be carried out.Each cylindrical segment was processed as a compressed unit.The bending torques and shearing forces of these units could be regarded as state vectors to solve the unit matrix.By multiplying unit transfer matrices,the correlation between state vectors of piston rod was obtained based on the constraints of hydraulic cylinder,and a generic function was deduced for cylinder stability.With integration of optimization design techniques with MATLAB,the rationale dimensions of hydraulic cylinder were obtained under volume constraint.Through comparing the results from Rits method and test,it was indicated that the calculated functional calculation results were closer to the accurate values.国家863重大项目(2008AA042501);福建省自然科学基金资助项目(2009J01259);福建省教育厅资助项目(JB08182

Selective Catalytic Hydrogenation of Cinnamaldehyde to Hydrocinnamaldehyde

采用煤质活性炭作载体,分别用HNO3、H2O2和(NH4)2S2O8进行预处理,然后用浸渍法负载PdCl2,在H2流中还原得到Pd/C催化剂,用于肉桂醛(CAL)选择加氢制氢化肉桂醛(HCAL)的反应。考查了Pd负载量,反应温度和压力对加氢反应的影响,优化了反应条件。进一步考查了助剂Fe、Co、Ni[1]对反应的影响。最终,CAL转化率为98%,HCAL选择性为88%。Coal-based activated carbon was pretreated with HNO_3,H_2O_2 and(NH_4)_2S_2O_8 before selected as support.A series of Pd/C catalysts were prepared by means of impregnation and with PdCl_2 as precursor.It was reduced in H_2 stream,and applied to selective hydrogenation of cinnamaldehyde to hydrocinnamaldehyde.Effects of Pd-loading,reaction temperature and pressure were discussed.In addition,promoters of Fe,Co,Ni were introduced to the catalysts.At last proper conditions for the reaction were found,and 88% selectivity to HCAL at 98% conversion of CAL was obtained.国家自然科学基金(No.20203014

Studies of the Mg-Al and Cation-Incorporated Hydrotalcites

研究了掺杂阳离子水滑石的制备及阳离子对水滑石性质的影响.分别制备了掺杂Zn2+、Ni2+、Fe3+型的水滑石,考察了掺杂阳离子对水滑石晶相结构、层间距、层间阴离子含量、水滑石表面形态、水滑石碱性的影响,结果表明,由于阳离子的引入,导致水滑石层间距减小及层间阴离子结合量降低,且使水滑石培烧产物电负性提高,并最终降低其碱性.以上述水滑石培烧产物作为固体碱催化剂促进苯甲醛和丙醛缩合,合成α-甲基肉桂醛,关联了水滑石培烧产物碱性与反应活性的关系.Mg-Al and cation-incorporated(containing Zn2+?Ni2+?Fe3+) hydrotalcites were synthesized and characterized. A detailed comparative analysis of structure and composition was made. Different cations influenced strongly textural parameters of hydrotalcites and the basicity of the obtained Mg-Al oxides after calcinations. With the cation incorporation, the distance of the brucite and the mount of CO2-3 as the compensating anion changed. Meanwhile the CO2-TPD was used to determine the basicity of the samples. The results showed that the basicity of the calcined hydrotalcites reduced. Finally, the activated hydrotalcite catalysts may efficiently replace homogeneous catalysts in Claisen-Schmidt condensation reaction of the benzaldehyde and propanal. And it was noteworthy that the calcined cation-type(containing Zn2+?Fe3+) hydrotalcites as catalysts did not show significant activity, in agreement with their low basicity.国家自然科学基金(20203014)资助项

Studies of the Mg-Al and cation-incorporated hydrotalcites

Mg-Al and cation-incorporated(containing Zn2+Ni2+Fe3+) hydrotalcites were synthesized and characterized. A detailed comparative analysis of structure and composition was made. Different cations influenced strongly textural parameters of hydrotalcites and the basicity of the obtained Mg-Al oxides after calcinations. With the cation incorporation, the distance of the brucite and the mount of CO32- as the compensating anion changed. Meanwhile the CO2-TPD was used to determine the basicity of the samples. The results showed that the basicity of the calcined hydrotalcites reduced. Finally, the activated hydrotalcite catalysts may efficiently replace homogeneous catalysts in Claisen-Schmidt condensation reaction of the benzaldehyde and propanal. And it was noteworthy that the calcined cation-type (containing Zn2+, Fe3+) hydrotalcites as catalysts did not show significant activity, in agreement with their low basicity

Researches on Urban Compactness Based on Grid Method： A Case Study of Tianhe District, Guangzhou

High-resolution remote sensing data of Guangzhou Tianhe district is used to extract building by object-oriented method. Then, the extracted information is used as one of basic data to identify an assessment indices system for measuring urban compactness

Impact of Urban form on Private Travel Energy Use of Typical City in China

In this paper, panel data from 2000 to 2010 of five typical city in China used to analyze the effect of population density on private travel energy use. And then, the STIRPAT model was created to estimate the effect of urban form and residents＇income on

基于情景分析的广东省建筑节能减排潜力研究

Energy consumption and greenhouse gas（GHG）emissions in construction sector of Guangdong Province in 2020 were predicted and the effects of different policy options on them were analyzed by the scenario analysis method aiming at finding the way to energy-

Analysis and Dynamic Prediction of Building Energy Consumption and GHG Emission in Guangdong Province Based on Scenario Analysis Method

Energy consumption and greenhouse gas（GHG）emissions in construction sector of Guangdong Province in 2020 were predicted and the effects of different policy options on them were analyzed by the scenario analysis method aiming at finding the way to energy-