纳米CaCO3微晶的晶格畸变和反常红外特性

利用TEM、SEM、X射线衍射(XRD)和Voigt函数单峰分析法讨论了纳米CaCO₃微晶结构,解释了纳米CaCO₃微晶的反常红外吸收特性,并认为微结构中的尺寸效应使得纳米CaCO₃晶格中存在较大的畸变应力,从而引起了碳酸钙微晶的红外ν₃吸收峰有约40 cm^-1的蓝移和明显窄化。     

甲烷在Mo/HZSM-5催化剂上的无氧转化─在隔离活性位上的反应

报道了无氧条件下甲烷在Ｍｏ／ＨＺＳＭ－５催化剂上转化为高碳的碳氢化合物的新途径。主要产物苯是经由乙烯聚合而成。此反应可能在两个隔离活性位上进行。乙烯作为甲烷活化的初始产物主要在分子筛外表面Ｍｏ活性位上形成,芳烃在分子筛的孔道内Ｂ酸位上形成。因此,我们认为该过程是乙烯中间产物由外表面扩散到分子筛孔道内形成芳烃。     

A Comparison of Three Heuristic Algorithms for Molecular Docking

Thed0ckingpr0cedurebetweeninhibitorsandproteinisaverys0phisticatedoptimizati0npr0blem;itisverydifficuIttocarry0utminimizati0nusinggradientmeth0dssuchasthesteepestdescentmeth0d,Gauss-Newtonmethod,whichareveryeasytofallint0theI0calpotentialwellsandverydifficultt0escapefr0mthem.S0s0meheuristicmeth0dshavebeenintr0ducedint0thestudies0fmolecuIarrec0gniti0n.Howt0chooseadequate0ptin1izationmeth0dinthed0ckingprocedureiscriticaIt0thecalcuIati0nresults.Inthispaper,wedescribetheimplementati0nandc0mpari…     

Bis-radicals (nitronyl nitroxide and imino nitroxide) Substituted Benzene with Long Alkyl Chain: Synthesis, Magnetic Study and Formation of LB film

Sincethediscovery0fthefirstgenuineorganicferr0magnet,p-nitronylphenylnitronylnitroxide(P-NPN-N)in1991',greatprogresshasbeenachievedinthefieldof0rganicferromagnetism.Bynow,morethantwentypurelyorganicferromagnetshavebeenrep0rtedsuccessiveIy'.However,theferr0magnetictransiti0ntemperature(Tc)0fthesepurely0rganicferr0magnetsarestillveryl0wwiththehighestbeing0nlyl.48K3exceptforthecharge-transfercomplexesbasedontetracyanoquinodimethane(TCNQ)andC604.Atpresentstageofresearchinthisfield,0n0nehand,e…     

FTIR study of hydrogen bonding of stearic acid with ethanol, dimethyl sulfoxide,and acetonitrile in supercritical CO_2

FTIR spectroscopy was used to study the hydrogen bonding of stearic acid with ethanol, dimethyl sulfoxide (DMSO),and acetonitrile in supercritical CO_2 at 318.15 K, and 12.5 and 16.5 MPa. The concentrations of the cosolvents range from 0—0.6 mol·L~(-1). The area percentage of absorption bands for hydrogen-bonded and nonhydrogen-bonded species was obtained from the IR spectra. The acid and the cosolvents can form hydrogen bond even when their concentrations are very low. At fixed solute concentration, the extent of hydrogenbonding increases with cosolvent concentration. At higher ethanol concentrations, it seems that one stearic acid molecule can hydrogen bond with more than one ethanol molecules simultaneously. It is seen that the strength of the hydrogen bond formed by the acid and the cosolvents is in the order: DMSO>ethanol>acetonitrile.     

丁基罗丹明B-高碘酸盐动力学催化光度法测定纳克量钌

提出了在弱酸介质中钌催化高碘酸盐氧化丁基罗丹明Ｂ（ＢＲＢ）,以光度法测定钌。催化反应速率与催化剂浓度呈线性关系的范围为０．２～１８ｎｇ／２５ｍ Ｌ,检出限为２．８×１０－ １２ ｇ／ｍ Ｌ。相对标准偏差小于１４％ 。催化反应对Ｒｕ（Ⅲ）、ＢＲＢ、ＫＩＯ４ 和Ｈ３ＰＯ４ 均为一级反应,表观活性能为４２．１２ ｋＪｍ ｏｌ－ １。探讨了反应机理。本法已用于某些岩矿和冶金产品中钌的测定。ＲＳＤ为１．０２％ ～２．２９％ ,回收率为９８．７％ ～１０２．０％     

滴定法快速测定饲料中甜菜碱

甜菜碱及其盐酸盐的结构式分别为（ＣＨ３）３Ｎ＋ＣＨ２ＣＯＯ－和（ＣＨ３）３ＮＣＨ２ＣＯＯ·ＨＣｌ,分子量分别为１１７．１１和１５３．６１。它的分析方法主要有酸碱滴定法、比色法、重量法、紫外分光光度法、薄层扫描定量法、红外光谱法、气相层析法等。前三种方法的分析原理都是基于利用沉淀剂沉淀饲料中的甜菜碱而测定,由于饲料中胆碱,氨基酸等含氮物质能与沉淀剂沉淀而产生干扰。而后四种方法需要大型的仪器设备,流程长,操作繁琐。本人在前人研究的基础上,进行了快速测定饲料中甜菜碱含量的研究。１　实验部分１．１　试剂…     

三氯锗丙酸及其衍生物自组装单分子膜的制备与表征

首次制备了三氯锗丙酸及其酯类衍生物(Cl₃GeCH₂CH₂COOC_nH_2n+1,n=0,2,4,6)在羟基化的单晶硅片上的自组装单分子膜,并利用接触角测量、椭圆偏振和光电子能谱法进行结构表征.结果表明,这类分子的自组装行为与三氯硅烷相似,组装后在基底表面形成准二维锗烷网状排布;分子链轴有一定倾斜角;膜表面润湿性随表征液体和三氯锗丙酸尾链取代基不同而不同.     

成核剂和促进剂对聚对苯二甲酸乙二酯结晶的影响

研究了一种成核剂和结晶促进剂及其混合物对聚对苯二甲酸乙二酯（ＰＥＴ）结晶过程和熔融行为的影响．结果表明,成核剂的引入降低了ＰＥＴ的结晶成核界面自由能,起到促进ＰＥＴ结晶成核的作用,从而加快了ＰＥＴ的结晶速度．而结晶促进剂对ＰＥＴ的结晶速度影响很小,不能促进ＰＥＴ的成核结晶,但能使ＰＥＴ结晶更完善,使ＰＥＴ的结晶度提高．当两者并用时,ＰＥＴ由熔体降温的结晶行为主要由成核剂控制,而成核促进剂的作用不明显．     

离子选择性电极法测定药剂中的头孢氨苄

基于头孢氨苄在０．１０ｍｏｌ／Ｌ ＮａＯＨ介质中,沸水浴降解２００ｍｉｎ后,能生成硫醇化合物,利用硫离子选择电极研究了测定头孢氨苄条件,其浓度在６．０×１０＾－５￣１×１０＾－２ｍｏｌ／Ｌ范围,电位Ｅ与浓度对数呈线性关系,并将此方法用于胶囊中头孢氨苄的测定,回收率为１０４．０％。