ZnS/Ni_2P复合物的合成、表征及光催化性能

以ZnS微球作为前驱体,乙酸镍为镍源,白磷为磷源,采用水热法制备ZnS/Ni_2P复合物。通过XRD,FE-SEM和TEM表征得知,ZnS/Ni_2P复合物由立方相的ZnS微球和复合于微球表面的六方相Ni_2P颗粒组成,且ZnS微球由ZnS纳米颗粒组成。光催化降解染料实验测试结果显示,ZnS/Ni_2P复合物与单一的ZnS相比,催化性能得到显著改善。同时,探究了不同的ZnS与Ni_2P质量比对复合物性能的影响,结果表明Ni_2P与ZnS的相对复合比例太大或太小都会对复合物性能的提升产生不良影响,最佳ZnS:Ni_2P的质量比为4:1。     

Cyclic HIV protease inhibitors: design and synthesis of orally bioavailable, pyrazole P2/P2' cyclic ureas with improved potency

Highly potent HIV-1 protease (HIVPR) inhibitors have been designed and synthesized by introducing bidentate hydrogen-bonding oxime and pyrazole groups at the meta-position of the phenyl ring on the P2/P2' substituents of cyclic ureas. Nonsymmetrical cyclic ureas incorporating 3(1H)-pyrazolylbenzyl as P2 and hydrophilic functionalities as P2' show potent protease inhibition and antiviral activities against HIV and have good oral bioavailabilities. The X-ray structure of HIVPR.10A complex confirms that the two pyrazole rings of 10A form bidentate hydrogen bonds with the side-chain oxygen (C=O) and backbone nitrogen (N-H) of Asp30/30' of HIVPR.     

复合精炼球团中SiO2、CaO、MgO等7组分的测定

试样用混合熔剂熔融,稀盐酸浸取,定容,移取部分试液,通过控制各元素的酸度,分别用光度法测定SiO2和P;EG-TA滴定法测定CaO,EDTA滴定法测定MgO;强碱沉淀分离氟盐置换、EDTA滴定法测定TAl。另称取1份试样用三氯化铁溶解,加入过量的氢氧化钠,滤液在pH值4.5的乙酸—乙酸铵缓冲介质中,加入过量的EDTA标准溶液,在煮沸条件下与MAl络合后,以PAN为指示剂,用铜标准溶液返滴定过量的EDTA;加氟化物取代,铜标准溶液二次返滴定,计算MAl量,再换算为Al2O3量。实验确定三氯化铁浓度为8%、用量50mL及用振荡器或摇动的最佳时间为60min。该方法测定SiO2、CaO、MgO、P、Al2O3及MAl的相对偏差分别小于0.718%、2.819%、1.171%、7.143%、0.178%和1.013%,完全满足快速分析的需要。     

Structure-based design of achiral, nonpeptidic hydroxybenzamide as a novel P2/P2' replacement for the symmetry-based HIV protease inhibitors

A combination of structure-activity studies, kinetic analysis, X-ray crystallographic analysis, and modeling were employed in the design of a novel series of HIV-1 protease (HIV PR) inhibitors. The crystal structure of a complex of HIV PR with SRSS-2,5-bis[N-(tert-butyloxycarbonyl)amino]-3,4-dihydroxy-1, 6-diphenylhexane (1) delineated a crucial water-mediated hydrogen bond between the tert-butyloxy group of the inhibitor and the amide hydrogen of Asp29 of the enzyme. Achiral, nonpeptidic 2-hydroxyphenylacetamide and 3-hydroxybenzamide groups were modeled as novel P2/P2' ligands to replace the crystallographic water molecules and to provide direct interactions with the NH groups of the Asp29/129 residues. Indeed, the symmetry-based inhibitors 7 and 19, possessing 3-hydroxy and 3-aminobenzamide, respectively, as a P2/P2' ligand, were potent inhibitors of HIV PR. The benzamides were superior in potency to the phenylacetamides and have four fewer rotatable bonds. An X-ray crystal structure of the HIV PR/7 complex at 2.1 A resolution revealed an asymmetric mode of binding, in which the 3-hydroxy group of the benzamide ring makes the predicted interaction with the backbone NH of Asp29 on one side of the active site only. An unexpected hydrogen bond with the Gly148 carbonyl group, resulting from rotation of the aromatic ring out of the amide plane, was observed on the other side. The inhibitory potencies of the benzamide compounds were found to be sensitive to the nature and position of substituents on the benzamide ring, and can be rationalized on the basis of the structure of the HIV PR/7 complex. These results partly confirm our initial hypothesis and suggest that optimal inhibitor designs should satisfy a requirement for providing polar interactions with Asp29 NH, and should minimize the conformational entropy loss on binding by reducing the number of freely rotatable bonds in inhibitors.     

ICP-AES测定钒钛高炉渣中的MnO、P、V2O5、TiO2

采用电感耦合等离子体原子发射光谱法(ICP-AES法)测定钒钛高炉渣中MnO、P、V2O5、TiO2的含量,利用盐酸、硝酸、氢氟酸、高氯酸溶解钒钛高炉渣,优选适宜的仪器测定参数和最佳分析谱线,共存元素间的干扰采用谱线背景扣除的方法予以消除。实验结果表明,钒钛高炉渣中的MnO、P、V2O5、TiO2在一定浓度范围内具有良好的线性关系,相关系数在0.999以上,测定结果的相对标准偏差在0.45%~5.10%之间,加标回收率在96%~107%之间。     

矿石中SiO2、TiO2、P、Mn的联合测定

采用碱熔法处理样品,用同一母液对矿石产品中的SiO2、TiO2、P、Mn进行了联合测定。通过控制测定的酸度,各元素线性良好,测得SiO2、TiO2、P、Mn的相对标准偏差分别小于3．70％、4．00％、4．44％、1．79％。该方法用于不同含量标准物质的测定,精密度和准确度高,结果令人满意。     

X射线荧光光谱法测定萤石中CaF2、SiO2、P和S

采用熔融法制样，通过条件实验找出最佳熔融条件和测定条件，采用标准样品和合成标样绘制校准曲线，用X射线荧光光谱法测定萤石中CaF2、SiO2、P和S的含量。测量结果与标样标准值、未知试样化学分析值相符，CaF2、SiO2、P和S的相对标准偏差分别为0．19％、0．49％、7．55％和3．18％。