Δu-a(x)u+b(x)u~p=0奇解的渐近性质

讨论了半线性椭圆方程Δu-a(x)u+b(x)up=0奇解的渐近性质,其中u∶Ω→R,ΩRn,n 3,n/(n-2)相似文献   

甲烷无氧芳构化催化剂的活性相生成研究

利用在线质谱分析检测了在各种催化剂上甲烷的程序升温表面反应(TPSR)过程中不同物种的行为.结果表明,MoO₃向Mo₂C的转变阻碍了甲烷的活化及其芳构化.如果这个转变过程在TPSR反应前发生,甲烷活化和苯生成的温度将大大降低(分别为760K和847K).通过比较担载在不同分子筛上钼物种的催化行为发现,甲烷的初始活化是这个反应速率的决定步骤.只有具备合适的钼价态,Bro-nsted酸性以及特殊的分子筛孔道结构的催化剂才能使甲烷芳构化反应高效进行.     

苯丙苯基化β沸石催化剂上沉积物的组成和性质

 改性β沸石是高压液相苯－丙烯异丙基化合成异丙苯反应的优良催化剂,具有催化活性高和选择性高及稳定性好等优点,已成功进行了中试．用13CNMR,IR,GC－MS,TG等手段,并结合溶剂萃取法、TPO和结构分析等方法,确定了改性β沸石催化剂上沉积物的主要成分是多异丙基苯和四氢化萘,且主要分布在沸石孔道内;同时,快速升温后恒温烧炭的效果优于慢速升温后恒温烧炭的效果．     

Determination of water states and the structural parameters of W/O microemulsions

The states of water in sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/water reverse(W/O) microemulsions system have been investigated by using Fourier transform infrared spectroscopy(FT-IR) technique. The broad peak obtained for hydroxy(O-H) of water has been resolved by least square curve-fitting. It has been observed that the water solubilized in microemul-sion droplets has four states, i.e. bound water with sulfo-group, free water, bound water with sodium counterion in the water pool of microemulsion droplets and a small amount of trapped water in the palisade layer of microemulsion droplets. The following have also been determined: the aggregation number (n), the radius of the water pool in the microemulsions(rw), the thickness of the bound water with sulfo-group(d1), the thickness of the bound water with sodium counterion(d2), the total thickness of the bound water (d) and the effective area of head groups of AOT(AAOT).     

Prospect for characterizing interacting soft colloidal structures using spin-echo small angle neutron scattering

Spin-echo small angle neutron scattering (SESANS) provides a new experimental tool for structural investigation. Due to the action of spin-echo encoding, SESANS measures a spatial correlation function in real space, as opposed to the structure factor S(Q), I(Q), in momentum (Q) space measured by conventional small angle neutron scattering. To establish the usefulness of SESANS in structural characterization, particularly for interacting colloidal suspensions, we have previously conducted a theoretical study of the SESANS correlation functions for model systems consisting of particles with uniform density profiles [X. Li, C.-Y. Shew, Y. Liu, R. Pynn, E. Liu, K. W. Herwig, G. S. Smith, J. L. Robertson, and W.-R. Chen J. Chem. Phys. 132, 174509 (2010)]. Within the same framework, we explore in the present paper the prospect of using SESANS to investigate the structural characteristics of colloidal systems consisting of particles with nonuniform intraparticle mass distribution. As an example, a Gaussian model of interacting soft colloids is used to investigate the manifestation of structural softness in a SESANS measurement. The exploration shows a characteristically different SESANS correlation function for interacting soft colloids, in comparison to that of a uniform hard sphere system. The difference arises from the Abel transform imbedded in the mathematical formalism bridging the SESANS spectra and the spatial autocorrelation function.     

研究性学习在无机化学教学中的应用

This paper introduces the attempts of inquiry learning in inorganic chemistry teaching and proposes the significances of inquiry learning. The inquiry learning has been applied in experimental teaching, case teaching, experience teaching, etc. The implementation effects of inquiry learning are showed through teaching data. The practices indicate that the inquiry learning stimulates the students' learning initiatives, strengthens the interactions between teachers and students, cultivates the students' innovation abilities and exploration spirits, and improves the teaching effects.     

6-NO2-BTAMB与钴显色反应的研究与应用

研究了6-NO2-BTAMB与钴显色反应。实验表明,在pH6.2—7.4(CH2)6N4-HCl体系中,钴与试剂定量地形成稳定的蓝绿色络合物,表观摩尔吸光系数ε650=1.18×105L·mol-1.cm-1;钴浓度在0—6μg/10mL范围内符合比耳定律。用于VB12和钴分子筛中微量钴的测定,结果令人满意。     

ICP-AES内标法测定分子筛的组成

首次通过ICP-AES仪研究了分子筛化学组成全分析的方法，采用HNO3-HF混合酸密闭溶样，用H3BO3配合F^-，分别采用内标法和基体消除法消除基体效应．将研究结果与经典方法比较表明：采用本文研究的分析方法，结果准确可靠，符合分析要求，尤其对杂原子分子筛以及金属氧化物修饰的分子筛的组成分析具有应用价值．     

催化荧光法测定痕量硒

基于稀硝酸介质中溴酸钾氧化藏红T,使其荧光猝灭,硒(Ⅳ)对此反应具有阻抑作用,使荧光强度增大,建立了催化荧光法测定痕量硒(Ⅳ)的新方法。方法检出限为0.12μg L,线性范围为0.5～10μg L。方法可用于测定水样中的硒(Ⅳ)。     

基于氧化还原体系纸芯片法对血清尿酸含量的快速检测

建立了以纸芯片为分析平台的尿酸含量快速检测方法.基于尿酸的还原性,以FeCl3为氧化剂组成氧化还原体系,以邻二氮菲为显色剂对反应产物Fe2+进行显色,根据显色强度对尿酸含量进行测定.结果 表明,当FeCl3与尿酸比例为1.6∶1,反应10 min,显色剂pH 7.4时显色最佳.显色强度(RGB值)与尿酸浓度在1.19～...