己内酰胺碱性催化聚合应用于纺丝

对碱性催化的己内酰胺快速聚合应用于纺丝进行了研究,采用了合适的分子量稳定剂,控制了聚合进程,得到粘度稳定的聚合体,并且进行了连续聚合直接纺丝的扩大试验,取得了持续稳定运转的结果,纺出产品复丝,其抗张强度为5—6克/(代糸),延伸为19—25％,与水解聚合方法同类产品丝相仿。所需的聚合时间为2—2.5小时,而通常水解聚合过程则需要20—30小时以上。     

高中化学程序启发试验教材编写说明

高中化学程序启发教学实验是从1983年4、 5月间的微型试验（可行性试验）开始的。目前,两所学校的首轮试验（三年一轮）已经结束,进入追踪研究阶段。     

人胃癌细胞株转化基因的克隆和核苷酸序列的分析

本文用人胃癌细胞株BGC-823总DNA对小鼠及大鼠成纤维细胞进行转染。用分子杂交方法证明大鼠第二轮恶性转化细胞基因组中合有来自人胃癌的转化基因,它与存在于正常细胞中的原癌基因c-Ha-ras同源。以λ噬菌体EMBL 3为载体,构建大鼠第二轮转化细胞基因组文库,以人Alu重复序列和c-Ha-ras为探针,将人胃癌细胞转化基因Ha-ras从文库中克隆分离出。用M13——双脱氧法测定转化基因第一、第二外显子核苷酸序列。结果表明转化基因除了第一外显子中有一个碱基发生变化外,核苷酸序列与原癌基因完全相同。     

铂重整法制造芳烃的研究

用直馏汽油的某一馏分在装有100毫升14—20筛眼颗粒形铂重整催化剂的反应设备中,进行单程纯氢操作的铂重整反应条件试验以考察芳烃的生成与反应条件变化的关系.试验的反应条件为:溫度430—510°压力20—50大气压,空间流速1.58—6.32重量/重量/小时,氢油分子比4:1—10:1.处理所获试验数据的结果,发现芳烃生成速度γ可用下列二次反应式来关连:     

精化的1.8埃分辨率胰岛素晶体结构——晶体学修正

本文用差值Fourier技术对1.8埃分辨率胰岛素结构进行了晶体学修正。建立了一套带自动增量分析的计算程序,可进行各种(mF_o—mF_c)Fourier综合。利用这套程序修正胰岛素结构11轮,R因子从0.388降到0.210。修正期间不断监测分子的立体化学状况,并根据标准值进行调整。修正结果明显地精化了胰岛素分子的结构。以此为基础,研究分析了胰岛素二聚体的氢键体系,以及晶体中水分子与胰岛素的相互作用。     

离心分离分光光度法测定钢中氮

钢铁中含氮量的测定,除仪器方法外,目前大多采用水蒸汽蒸馏容量法。本文参考文献采用离心分离分光光度法。该法的关键是沉淀分离。但文献说法不一,也没有详细说明分离条件。因此我们着重对沉淀分离的最佳pH范围,离心分离的有关条件进行了试验研究,确定了沉淀分离的最佳pH范围为9.3—9.7。并通过加pH9.5的硼酸钠-氢氧化钠缓冲液加以控制。经两年多实践证明,此法由于不受蒸馏仪器的限制,可同时测定多个试样,比蒸馏法快速,准确度与灵敏度可达蒸馏法水平。特别适合于间断性测氮。测定范围为0.001—0.05%。通过多取或少取离心分离液可扩大到0.0005—1.25%。     

弱酸性阳离子交换树脂平衡等温线的测定

本文对国产弱酸性阳离子交换树脂的平衡特性进行了试验研究,得出不同条件下的pCa—pH、pMg—pH、pNa—pH平衡等温线,并举例说明了这些等温线的实际应用。     

准轮烷/轮烷在药物载体中的应用

准轮烷/轮烷是超分子化学领域内的一类重要成员,其结构可在外界刺激下发生改变,这一特点使其在分子机器制备方面取得了广泛的应用。近年来,由于其结构的特殊性,在药物载体领域也开始引起人们的关注。本文对近十年来准轮烷/轮烷在药物载体领域内的发展情况进行了综述,重点概述准轮烷修饰的硅纳米粒子和主体-轮烷这两类药物载体的发展历程以及各自的优缺点,最后展望了准轮烷/轮烷在药物载体领域的发展方向。     

在硫酸-氯化钠底液中示波极谱法测定矿石含锡量的改进

硫酸-氯化钠底液法测定矿石中的锡这一方法发表在《岩石矿物分析》一书已有十年了,由于该法的结果偏低,且测量范围只适合0.1—10％锡的测定,因而未得到广泛应用。本文讨论了偏低的原因及克服办法,在此基础上扩大了方法的测量范围,含锡0.00x—xx％的样品均可测定。     

第二届全国高校计算机辅助化学教学软件交流会

1987年12月底,我系制药专业举办了一次化学实验知识竞赛,参赛对象为即将进入毕业环节学习的84级学生。我们在教学中发现许多学生对实验环节不够重视。为了使学生重视实验,我们举办了这一次实验知识竞赛。其目的还在于提高学生对实验的兴趣及操作水平,开拓知识面,并检杏实验教学的效果。这次竞赛分两轮进行:第一枪是初赛,所有报名者均参加,采用笔试形式;第二轮决赛,由第一轮的优胜者(前六名)参加,以口答为主。竞赛     

"Alpha"-, "beta"- and "delta"-anhydrodigitoxigenin

The syntheses of 3β-hydroxy-5β-carda-14, 20:22-dienolide (= «β»-anhydro-), 3β-hydroxy-5β-carda-8:14, 20:22-dienolide (= «α»-anhydro-) and «δ»-anhydro-digitoxigenin (= probably 3β-hydroxy-5β, 14β-carda-8, 20:22-dienolide) by the best ways known to date, have been described. «δ»-Anhydro-digitoxigenin represents the thermodynamically most stable isomer. In this isomer the double bond in position 8 is unaffected by hydrogenation with Pt in acetic acid; with perbenzoic acid an epoxide results from which, on hydrogenation, the double bond can be regenerated in its original position. Analogous reactions are known to occur in the 8:14-epoxides.     

化“材”为“筑”

Chemistry is a central, practical and creative discipline. The development of chemistry plays an important role in the progress of science and society, as well as the improvement of the quality of human life. This paper introduces the chemical knowledge of stone, concrete, glass and other inorganic nonmetallic building materials by the anthropomorphically story. Taking nanomaterials as an example, the prospect of building materials development in the future is put forward.     

Making "wheels" and "cubes" from triangles

[Mn(IV)Mn(II)3] triangular units directed by the presence of tripodal alcohols self-assemble in the presence of azide and acetate ligands to form either a [Mn24] "wheel" or a [Mn32] "cube".     

"Turn-on" fluorescent sensing with "reactive" probes

Chemical probes are valuable tools for the investigation of biochemical processes, diagnosis of disease markers, detection of hazardous compounds, and other purposes. Therefore, the development of chemical probes continues to grow through various approaches with different disciplines and design strategies. Fluorescent probes have received much attention because they are sensitive and easy-to-operate, in general. To realize desired selectivity toward a given analyte, the recognition site of a fluorescent probe is designed in such a way to maximize the binding interactions, usually through weak molecular forces such as hydrogen bonding, toward the analyte over other competing ones. In addition to such a supramolecular approach, the development of fluorescent probes that sense analytes through chemical reactions has witnessed its usefulness for achieving high selectivity, in many cases, superior to that obtainable by the supramolecular approach. Creative incorporations of the reactive groups to latent fluorophores have provided novel chemical probes for various analytes. In this feature article, we overview the recent progress in the development of turn-on fluorescent probes that are operating through chemical reactions triggered by target analytes. Various chemical reactions have been implemented in the development of many reactive probes with very high selectivity and sensitivity toward target analytes. A major emphasis has been focused on the type of chemical reactions utilized, with the hope that further explorations can be made with new chemical reactions to develop reactive probes useful for various applications.     

"Clickable" polymersomes

Polymersomes, composed of amphiphilic polystyrene-block-poly(acrylic acid) (PS-b-PAA), with the periphery being covered with azide groups, were used for further functionalization using "click" chemistry.