氯化铵重量法分析步骤的简化探讨

用氯化铵重量法测定水泥及水泥熟料中二氧化硅的含量时,可简化其操作过程,即在标准法的基础上去除用氢氟酸处理残渣和比色法从滤液中回收漏失的二氧化硅这两个步骤。这种方法简单快捷,能减少因操作失误而引起的结果误差,如果能够熟练掌握实验步骤和要点,并在操作无失误的情况下,该法测定的二氧化硅的结果误差都不大于0.2%,能够满足日常分析检验的工作需要。     

Novel general procedure for the preparation of homogeneous nonionic surfactants

Homogeneous nonionic surfactants were produced by the ethoxylation of a selected unit of a homolog series. These particular products are of use for the analysis of nonionics and for the determination of surface characteristics. A new general method for the synthesis of homogeneous nonionic surfactants is described. Ethylene glycol monobenzyl ether was repeatedly reacted in Williamson synthesis (or esterified with acid chlorides in the first step), followed by hydrogenolysis with alkyl- or aralkyl alcohols, phenols, carboxylic acids, and amines. Homogeneous nonionics can be synthesized by this method, whereas the conventionally produced ones are usually inhomogeneous.     

正交试验法优化凝血酶原复合物的制备工艺

目的采用正交试验法优化凝血酶原复合物(Prothrombin complex concentrate,PCC)的制备工艺。方法取DEAE-Sephadex A-50凝胶平衡体系中的柠檬酸钠、氯化钠、pH值3因素,每因素取3水平设计正交试验;称取9等份DEAE-Sephadex A-50凝胶干粉,分别采用试验设计的平衡体系进行平衡;平衡后的凝胶分别与等量健康人去冷沉淀混合血浆混合,制备凝血酶原复合物浓缩物;测定浓缩物蛋白浓度及凝血因子Ⅱ、Ⅶ、Ⅸ、Ⅹ活性,获得4种凝血因子比活;通过正交试验直观分析及直接对比法确定较优及较差比活制备条件,对确定的条件进行验证;测定平衡体系电导率,分析正交试验中平衡体系电导率与4种凝血因子比活的相关性。结果正交试验直观分析法与直接对比法确定的凝血因子Ⅱ、Ⅶ、Ⅸ、Ⅹ较优比活凝胶平衡条件一致:柠檬酸钠0.005~0.012 mol/L,氯化钠0.06~0.10 mol/L,pH 6.9~7.2;两种方法确定的较差平衡条件不同,分别为:柠檬酸钠0.012~0.02 mol/L、氯化钠0.1~0.14 mol/L,pH 7.2~7.5及柠檬酸钠0.005~0.012 mol/L,氯化钠0.1~0.14 mol/L,pH 7.2~7.5,经实验验证,两种方法确定的较优条件比活均优于较差条件,但两种较差条件中,直接对比法确定的条件更符合实际。平衡液电导率与4种凝血因子比活之间不存在线性关系,但在不同电导率条件下,4种凝血因子比活有较大波动,电导率9.67~10.34 ms/cm,4种凝血因子比活均较高;电导率12.16~12.90 ms/cm,4种凝血因子比活均较低。结论正交试验可用于凝血酶原复合物制备工艺优化,但不同分析方法结果有一定差异。平衡体系电导率对凝血酶原复合物比活有一定影响,在工艺优化时应予注意。     

Carbon-supported cobalt catalyst for ammonia synthesis: Effect of preparation procedure

Supported cobalt catalysts were synthesised, characterised (by H₂ TPD, XRD, TEM), and tested in ammonia synthesis at 9.0 MPa (400–470 °C; H₂:N₂ = 3:1). Partly graphitised carbon of high surface area (840 m²/g), cobalt nitrate, and barium nitrate were used as a support, a precursor of the active phase, and a promoter precursor, respectively. Both cobalt dispersion in the Ba-doped catalyst and, to a greater extent, catalytic properties of the promoted Co surfaces (TOF) proved to be dependent on the unpromoted material pretreatment (reduction in H₂, subsequent calcination in air). The kinetic studies of NH₃ synthesis have shown explicitly that Ba-promoted cobalt on carbon is very active and less inhibited by the ammonia product than the commercial magnetite-based material.     

C群脑膜炎球菌多糖结合疫苗制备工艺的优化

目的优化C群脑膜炎球菌多糖-破伤风类毒素(Tetanus toxoid,TT)结合疫苗的制备工艺。方法分别采用衍化的降解多糖与TT结合、衍化TT与降解多糖结合和1-氰基-4-二甲基氨基吡啶.四氟化硼(CDAP)活化降解多糖后衍化再与TT结合的方法制备C群脑膜炎球菌多糖蛋白结合物PSAH-TT、PS-AHTT和PSCDAPAH-TT,并进行生化指标和抗原性检测,与溴化氰(CNBr)活化多糖衍化与TT的结合物PSCNBrAH-TT进行免疫原性比较,确定最适制备工艺,并制备2批结合疫苗,与市售疫苗进行免疫原性比较。结果 3种方法制备的多糖蛋白结合物生化指标存在差异,以PSCDAPAH-TT收率最高,且均保持了多糖的抗原性及免疫原性,并有免疫加强效应;PSCDAPAH-TT免疫2针后抗体GMT水平高于PSAH-TT和PS-AHTT,差异有统计学意义(P<0.05),3针后抗体GMT水平仍高于PSAH-TT和PS-AHTT,但差异无统计学意义(P>0.05),PSCDAPAH-TT免疫2针和3针后抗体GMT水平均高于PSCNBrAH-TT,且2针后差异有统计学意义(P<0.05),3针后差异也无统计学意义(P>0.05),但制备的2批PSCDAPAH-TT疫苗免疫2针和3针后的抗体GMT水平均明显高于市售疫苗,差异有统计学意义(P<0.05)。结论经CDAP活化降解多糖后衍化再与载体蛋白结合制备的疫苗具有较好的免疫原性。     

次氯酸钠溶液配制工序供水系统控制方案

结合庸山氯碱有限责任公司的实际情况,从硬件和软件2方面介绍了次氯酸钠配制工序供水系统的控制方案。     

Composition,preparation procedure and physical properties of linear homogeneous polyurethanes for membranes

Linear polyurethanes (PUs) were prepared in solution in two steps. In the first step, toluene‐diisocyanate (TDI) 80:20 (T) was reacted with a short‐chain poly(oxypropylene) diol (V) to obtain prepolymers characterized by various ratios of R = [T]°/[V]°. In the second step, the prepolymers were reacted with the extender 1,4‐cyclohexanedimethanol (E) with various extension ratios R_E = (R ? 1)[V]°/[E]°. The PU properties were analyzed by various techniques. In particular, the molecular weights determined by gel permeation chromatography (GPC), the thermal properties such as glass transition temperature T_g and specific heat variation ΔC_p measured by differential scanning calorimetry (DSC), the chemical composition of the PUs and the various types of hydrogen bonds present in the polymers evidenced by Fourier‐transform infrared (FTIR) spectroscopy, the monophasic structure evidenced by small‐angle X‐ray scattering (SAXS), and the existence of only one T_g confirmed that these PUs were linear, amorphous and monophasic. Positron annihilation lifetime spectroscopy (PALS) analysis showed that the mean volume of the nanoholes increased with increasing temperature, but was not dependent on the composition, as expected for a monophasic system. A stoichiometric semi‐empirical model was proposed that relates the PU blocks' micro‐composition to the R and R_E macro‐parameters, chosen for the synthesis. The polymer assumes various expressions of the general formula X? [(TV)_k? (TE)_n]_m? X for different values of the R and R_E ratios. The micro‐parameters k and m have a direct connection with the experimental mean molecular weights of the prepolymer and the polymer, respectively: n depends only on R. The model could foresee the density of hydrogen bonds and distinguished the bonds connected to either V or E, which could be shown by FTIR analysis. This paper shows that, when using stereo‐irregular diols and blends of 2,4‐ and 2,6‐TDI, non‐stereoregular PUs are obtained. If low‐molecular‐weight diols are used and R < 3.3, it is quite improbable that the PU blocks separate into macrophases and therefore monophasic amorphous PUs are obtained. Monophasic PUs can be useful for applications such as in the field of membrane gas and vapour separation. Copyright © 2005 Society of Chemical Industry     

镱掺杂TiO_2光催化剂的制备工艺研究

采用溶胶凝胶法制备了镱掺杂TiO2纳米光催化剂,并通过XRD、IR和BET对样品进行表征。在紫外光照射下,以罗丹明B为光催化目标降解物,考察了催化剂的光催化性能。结果表明:Yb/TiO2比纯TiO2具有更好的光催化活性。制备Yb/TiO2光催化剂的最佳条件是:n(Yb)/n(Ti)为1.0%,HAc为3mL,溶液pH值为1.4,PEG为0.5g,湿凝胶陈化时间为2d,干燥时间为12h,干凝胶煅烧温度为600℃,煅烧时间为3h,此条件下制备出的Yb/TiO2能使罗丹明B的降解率达到88.9%。结构表征说明掺镱二氧化钛粉体降低了TiO2的颗粒粒径,增加了比表面积,提高了光催化活性。     

A simplified procedure for the quantitative extraction of lipids from brain tissue

A method is described for the quantitative extraction of lipid from brain tissue with chloroform/methanol (C/M) that eliminates secondary purification of the lipid extract by dextran-gel chromatography or aqueous washing of the organic extract. Nonlipid substances that generally contaminate C/M lipid extracts are separated by pre-extraction of the tissue with dilute (0.25%) aqueous acetic acid. The residual tissue is extracted twice with 40 volumes of C/M (1∶1, v/v). Approximately 97% of the lipid is recovered in these extractions. A third extraction which yields ca. 1% more lipid is performed if the process is discontinued at this stage in a shortened version of the method. The remainder of the lipid is recovered after treatment of the tissue with 1 N HCl by two additional extractions, the first with 40 volumes of C/M (1∶2, v/v) and the second with 40 volumes of methanol. The method, which was demonstrated with pig brain, gave a complete extraction of the lipid, including gangliosides, free of nonlipid substances.     

A rapid and quantitative procedure for the preparation of methyl esters of butteroil and other fats

A simple and convenient method for the quantitative preparation of methyl esters of fatty acids from glyceride fats and oils is described. The procedure, using potassium methylate as catalyst and a heating interval of 2 min at 65C in a closed vial, is applicable to fats containing both low and high molecular weight fatty acids such as butteroil. The methyl esters of samples ranging from a few mg to 30 mg are isolated by CS₂ extraction and a TLC technique. A similar procedure using sulfuric acid in methanol as catalyst is described for the conversion of free fatty acids to methyl esters. For the routine analysis by GLC of fats and oils such as lard, tallow, soybean, cottonseed oil or butteroil, no isolation of the methyl ester is required. A CS₂ extraction carried out in the reaction vial allows the GLC analysis immediately after the reaction period (2 min). Presented at the AOCS Meeting, Philadelphia, October 1966. E. Utiliz. Ees. Dev. Div., ABS, USDA.     

Arylmercury compounds I. A general procedure for the preparation of diarylmercury compounds by symmetrisation reactions

A process for the preparation of disubstituted organomercurials was studied. The reaction is summarised by the following equation: where Ar = aryl and × = different anions. Instead of ammonia and EDTA other amines and chelating agents were also used. Only those chelating agents that have virtually the same structural features as EDTA were found to have the same effect. Various amines could be used instead of ammonia. The reaction can be carried out in water or in mixtures of organic solvents and water.     

无血清培养基培养Vero细胞制备狂犬病病毒工艺的建立

目的建立无血清培养基(virus production-serum-free medium,VP-SFM)培养Vero细胞制备狂犬病病毒CTN-1V株的工艺。方法分别采用VP-SFM和含5%牛血清DMEM于方瓶中培养Vero细胞制备狂犬病病毒CTN-1V株,比较无血清培养基培养不同代次Vero细胞间及无血清与含血清培养基培养Vero细胞间制备的狂犬病病毒滴度及效力。将2 g/L微载体cytodex-1加至250 ml spinner flask中,加入Vero细胞,37℃培养3 d,按MOI=0.02接种狂犬病病毒CTN-1V株,检测病毒收获液的病毒滴度及效力,每天显微镜下观察细胞生长情况,计算细胞比生长速率。结果无血清培养基培养不同代次Vero细胞制备狂犬病病毒的滴度和效力差异无统计学意义(P0.05);无血清和含血清培养基培养Vero细胞制备狂犬病病毒的滴度差异无统计学意义(P0.05),但无血清培养基培养Vero细胞制备狂犬病病毒效力明显高于含血清的培养基(P0.05)。搅拌瓶微载体系统培养Vero细胞制备狂犬病病毒,细胞贴壁均匀,生长良好,收获病毒液的平均病毒滴度为6.50 lg FFU/ml,平均病毒效力为6.77 IU/ml。结论初步建立了微载体系统无血清培养Vero细胞制备狂犬病病毒的工艺,为无血清规模化制备狂犬病疫苗奠定了基础。     

制备工艺对炭/石墨密封材料性能及其结构的影响

以改性的填料（二次焦）为骨料炭,中温煤沥青为黏结剂来制备炭/石墨密封材料,考察了材料制备工艺条件对材料机械强度、开孔率以及微观结构的影响。研究表明,与传统的炭/石墨密封材料制备工艺相比,利用改性后的骨料炭所制备的炭/石墨材料具有较高的机械强度和相对均匀的孔径分布。此外,随着二次焦热处理温度的升高,最终材料的体积密度和机械强度增大,开孔率降低。当二次焦热处理温度升高到540℃时,最终所得材料的抗压和抗弯强度分别达到210.0MPa和67MPa,开孔率为19.3%。炭/石墨材料经浸渍金属Cu后,Cu颗粒在利用传统工艺制备的材料中的尺寸相对较大,且存在局部聚集或团聚,而在利用二次浆涂工艺制备的材料中则呈细网状结构且均匀分布。     

Inelastic response of copolyurethane elastomers with varying soft segment molecular weights and preparation procedure

A family of thermoplastic polyurethane elastomers (TPUs) based on the soft segment poly(oxytetramethylene) (PTMO₂₀₀₀ and PTMO₁₀₀₀) were synthesized by the one‐shot and prepolymer methods. Two hard segments were chosen, 4,4′‐methylenebis(phenyl isocyanate) (MDI) (non‐crystallizable) and 4,4′‐dibenzyl diisocyanate (DBDI) (crystallizable). Microphase separation and crystallinity were investigated using small‐angle X‐ray scattering and wide‐angle X‐ray scattering, and dynamic viscoelastic properties were also determined. An increased hard phase degree of crystallinity was primarily achieved by use of DBDI instead of MDI, regardless of the preparation procedure and soft segment molecular weight. An increase of the molecular weight leads to an increase in phase separation and to a decrease in hysteresis. For the DBDI based polymers, a lower soft segment molecular weight resulted in an increase in crystallinity. The DBDI series of TPUs obtained by the one‐shot and prepolymer methods showed higher hysteresis and residual elongations compared with the corresponding materials achieved with MDI. Although the materials varied widely in response to first loading, regardless of the preparation procedure, they displayed remarkable reproducibility and commonality in cyclic responses within the maximum strain envelope. The thermomechanical experiments revealed a better thermal behavior with increase of the soft segment molecular weight from PTMO₁₀₀₀ to PTMO₂₀₀₀.© 2013 Society of Chemical Industry     

玻璃软化点温度的简易计算方法

采用Excel添加趋势线的方法进行玻璃软化点温度的计算.与用最小二乘法进行线性拟合计算相比,该方法计算公式极少,简单易学,方便实用.     

K2FeO4的简化制备法及其对印染废水的处理

采用简化双碱法制备K2FeO4,以NaOH代替了部分KOH,省去了除杂、干燥程序,降低了制备的成本,克服了难以大规模制备、储运的弱点。将简化法制备的K2FeO4用于处理印染厂废水,pH为6～9,投加35 mg/L的K2FeO4和4 mg/L的PAM,可以达到较好的处理效果,其中色度、SS去除率超过95%,COD、BOD5去除率超过60%,同时提高了废水的可生化性。     

A novel procedure in the galvanic deposition of Zn alloys for the preparation of large area Ni and Ni-Co surfaces

A new methodology for the electrodeposition of Ni-Zn and Ni-Co-Zn alloys that prevents zinc being in contact with the substrate and allows total elimination of this metal during alkaline leaching is fully described. This is achieved by a careful control of the plating bath composition during the electrolysis. The resulting coatings show a multilayer structure and the desirable concentration profile for all the metallic species involved, as revealed by SEM and EDX analyses. The electrochemical active area of the deposits after leaching of the zinc was measured by cyclic voltammetry. They were of the order of 1100 and 4400 times the geometric area for Ni and Ni-Co, respectively. These highly porous structures are very active for hydrogen evolution in alkaline solutions, showing extremely low overpotentials for relatively high current densities, as well as good stability for long term operation. Other possible applications for these structures are briefly discussed.