镶嵌型乳胶粒子的合成

以苯乙烯、甲基丙烯酸甲酯、丙烯腈等单体或它们的混合物为硬单体,天然胶乳为弹性组分,经多步种子乳液聚合法制得了在天然胶乳的粒子上镶嵌硬聚合物相的互穿网络型乳胶粒子.考察了十二烷基硫酸钠、十二烷基苯磺酸钠、壬基酚聚氧乙烯醚、油酸等乳化体系,过硫酸钾、过氧化苯甲酰热引发体系及异丙苯过氧化氢-四乙烯五胺、叔丁基过氧化氢-四乙烯五胺等氧化还原引发体系对聚合反应的影响.研究了交联剂用量对互穿结合率、溶胶含量的影响及溶胀时间、硬单体组成、乳化剂种类对乳胶粒子形态的影响,确定了适宜的聚合配方和工艺条件.透射电镜观察乳粒形态结果表明,单一使用极性或非极性单体,仅得到核-壳结构乳液,而采用不同极性单体复合、溶胀、互穿,得到的是镶嵌硬聚合物型乳粒结构.     

3-羟基丁酸的气相色谱分析

采用ＢＦ３－ＣＨ３ＯＨ酯化衍生法,以正辛酸作内标,建立了３－羟基丁酸、巴豆酸、３羟基丁醛、巴豆醛等混合体系中３－羟基丁酸的气相色谱分析方法,利用标准样对照并结合质谱分析确定了化学合成３－羟基丁酸反应混合物的组成。该法线性范围为０．４０～１６０．６７ｇ／Ｌ,相关系数为ｒ＝０．９９９５。方法快速、简单、重现性好,并用于化学合成３－羟基丁酸反应混合物的分析,结果令人满意。     

原位合成分子筛多孔层毛细管柱的制备与性能考察

在毛细管内壁,原位合成了Ｎａ－Ａ型分子筛,成功制备出一类新型分子筛多孔尾毛细管柱。和涂渍相比,原位合成法在毛细管内壁形成的分子筛层更加均匀、致密度、更能体现出分子筛对低碳烃的分离特性,实验表明用超短毛细管柱即可对低碳烃进行良好的分离。     

确定金属酶及模拟络合物中金属离子氧化态的一种方法——键价和分析

在生物化学领域中弄清金属酶活性中心的结构和氧化态是至关重要的。“键价和分析”是根据金属 配体键长数据确定固体中金属离子氧化态的一种方便可行的方法 ,它已用于金属蛋白、金属酶以及高温超导体中金属氧化态的指派。本文拟介绍该方法的要点及其实际应用。     

DBC-偶氮肿-锇-溴酸钾催化光度法测定微量锇

酸性介质中Os(Ⅳ)对溴酸钾氧化DBC-偶氮肿的褪色反应有明显的催化作用,据此反应建立了微量娥的催化光度分析法,锇在1.0-20.0μg·L-1符合比耳定律.反应在水相中进行,灵敏度高,简便快速,用于贵金属精矿中娥的测定,结果满意.     

Fluorescence Turn-On Analysis of Trace Protein Based on Carbon Nanodots and Hybridization Chain Reaction

In this work, an ultrasensitive method for trace protein detection based on fluorescent carbon nanodots and hybridization chain reaction (HCR) is designed. Generally, the synthesized bright carbon nanodots are conjugated with two hairpin-structured DNA probes, respectively, which act as subsequent HCR fuel strands. Since single-stranded parts of DNA probes could be easily absorbed on graphene oxide (GO) nanosheets, fluorescence emission of carbon nanodots is effectively quenched via fluorescence resonance energy transfer. However, in the presence of target protein, the aptamer sequence in another hairpin-structured DNA probe specially interacts with target and the hairpin is opened. A single-stranded region is thus exposed, which initiates HCR by coupling with the DNA fuel strands on carbon nanodots. The formed HCR product displays a rigid, long double-stranded structure, which facilitates the release of carbon nanodots from GO surface. As a result, fluorescence of carbon nanodots is recovered and initial concentration of target protein can be estimated. This protein detection method shows a favorable linear response with a low limit of detection (2.3 fg mL⁻¹). Furthermore, it is highly selective and capable of detecting target in biological fluids like serum samples, which demonstrates the promising applications of this method.     

Sixth-order variants of Chebyshev–Halley methods for solving non-linear equations

In this paper, we present a family of new variants of Chebyshev–Halley methods with sixth-order convergence. Compared with Chebyshev–Halley methods, the new methods require one additional evaluation of the function. The numerical results presented show that the new methods compete with Chebyshev–Halley methods.     

CombinedB → X s Ψ andB → X s ν c decays as a test of factorization

We calculate the inclusive decaysB → X _s Ψ andB → X _s ν _c using factorization assumption. To investigate the bound state effect of the decaying B meson in these inclusive decays we take into account the motion of theb quark using a Gaussian momentum distribution model. The resulting correction to free quark decay approximation is around 6% at most. Utilizing a potential model evaluation of the ratio of the decay constantsf _νc ²/f _Ψ ², it is shown that the ratioR = Γ(B → X _sν_c)/Γ(B → X_sΨ) can be used a possible test of factorization assumption.     

碘冉酸阴离子桥联双核铜（Ⅱ）配合物的合成与磁性

碘冉酸阴离子桥联双核铜（Ⅱ）配合物的合成与磁性孟祥军寇会忠邹国彰廖代正姜宗慧＊王耕霖（南开大学化学系天津３０００７１）关键词碘冉酸，Ｃｕ（Ⅱ），双核配合物，合成，磁性１９９６－０８－２０收稿，１９９６－１１－１８修回国家自然科学基金资助项目随着生物无...     

Catalyst Kinetics Analytical Method Study of Ruthenium

Color reactions are used to determine ruthenium utilizing spectrophotometer, but the process need high temperature, long time pyrogenation and miscellaneous extraction and it contaminates the enviroment. As the sensitive degree and simple apparatus of catalyst kinetics analytical method, it was extensively attentcd. The fundmental principle means to determinn a certain chemistry reaction rate accelerated by homogeneous catalyst and determine substantial content using the function of the numerical value of of its and the catalyst concentration. Color acid double azo-reagents (chloro-phosphor group, arsenic group and carboxylic acid group) are sensitive color reagent determining uranium and thorium of lanthanon, but the report is few that it is used to determine ruthenium. Since 1990s, the author studied that the ruthenium was possessed evident catalysis to the fade reaction of oxidant (KIO4, KBrO3) oxidating color acid double azo-reagent in acitidy medium and provided the catalyst kinetics analytical method to determine trace ruthenium.sensitive degree was increased 1 ～2 amount than color reaction. The reaction as:The original concentration of color acid double azo-reagents is A. The instantaneous absorbency after t reaction time is At. In homogeneous catalyst reaction: log(A0/At) = KCRu3+t. Reaction time t is invarible, so log(A0/At) = K' CRu3+t.Color acid double azo-reagents, such as: chlor-azochlorphosphor(CPA-TC),bromic-azochlorphosphor (CPA-TB), DBS-azochlorphosphor(DBS-CPA), DBC-azochlorphosphor (DBC-CPA), DBOK-azochlorpho sphor (DBOK-CPA), p-iodineazochlorphosphor(CPA-PI),p-acetylazochlorphosphor (CPA-PA), azochlorpho sphorⅢ(CPAⅢ), chlor-azoarsenic (TC-AsA),bromic-azoarsenic (TB-AsA), DBS-azoarsenic(DCS-AsA), DCS-azoarsenic(DCS-AsA),azoarsenicⅢ(AsAⅢ), bromicnityrlazoarsenic (DBN-AsA), P-acetylcarboxy lazo-p,P-acetylcarboxylazo, were utilized in catalyst kinetics system. The author obtains the satisfactory results that color acid double azo-rea gents was utilized to determine ruthenium of noble metal mine.