赣南葛粉中微量元素含量的测定

目的测定赣南葛粉样品中微量元素的含量。方法采用火焰原子吸收光谱法测定赣南7种葛粉中Mg、Fe、Mn和Zn 4种微量元素的含量。结果标准加入法的回收率为94.9%～104.1%,10次平行测定结果的相对标准偏差RSD均介于0.13%～1.79%。此法灵敏度高,操作简便快速,结果准确,重现性好。赣南葛粉样品富含Mg、Fe、Mn和Zn元素;不同产地不同品种赣南葛粉的微量元素含量差异明显,即使同一产地不同品种赣南葛粉的微量元素含量也有差异。结论该研究可为葛粉资源的进一步开发利用提供参考。     

赣南离子吸附型稀土矿床成矿特征概述

赣南是我国离子型稀土资源的主产区之一,其成矿母岩分布广,成矿条件优越,稀土配分类型多样。本文从成矿背景和矿床分布规律,成矿母岩和矿体赋存特征,以及矿石中稀土的赋存状态和配分类型等方面较为详细地总结了赣南稀土矿床成矿地质特征。     

Determination of Six Trace Elements in Gannan Orange by AAS

将赣南脐橙经硝酸和高氯酸消化后,在样品中加入氯化镧作为释放剂以消除共存离子的干扰,采用火焰原子吸收光谱法测定了Ca、Mn、Zn、Fe、Cu和Pb元素的含量.结果表明,标准加入法的回收率为96.58％～104.31％,10次平行测定结果的相对标准偏差RsD均小于2％.该法灵敏度高、操作简便快速,结果准确,重现性好.可见赣南脐橙中各元素含量差异显著,其中Ca的含量比较丰富,Mn、Fe和Zn的含量中等,含有人体必需的微量元素,而对身体有害的元素如Pb含量却相当低,这说明赣南脐橙具有一定的药用和经济价值,为进一步探讨赣南脐橙开发利用提供实际依据.     

火焰原子吸收光谱法测定赣南脐橙中6种微量元素含量

将赣南脐橙经硝酸和高氯酸消化后，在样品中加入氯化镧作为释放剂以消除共存离子的干扰，采用火焰原子吸收光谱法测定了Ca、Mn、Zn、Fe、Cu和Pb元素的含量。结果表明，标准加入法的回收率为．96．58％～104．31％，10次平行测定结果的相对标准偏差RSD均小于2％。该法灵敏度高、操作简便快速，结果准确，重现性好。可见赣南脐橙中各元素含量差异显著，其中ca的含量比较丰富，Mn、Fe和zn的含量中等，含有人体必需的微量元素，而对身体有害的元素如P11含量却相当低，这说明赣南脐橙具有一定的药用和经济价值，为进一步探讨赣南脐橙开发利用提供实际依据。     

简论加强化学科技伦理教育的重要意义

化学科学与人类生活密不可分,对人类的可持续发展至关重要。若科技与伦理的关系不和谐,必定会影响到整个人类社会发展的和谐性。化学作为一门重要的自然科学,化学科技伦理在当前科技伦理教育中的重要地位日益突出,在教学中加强化学科技伦理教育具有非常重要的意义。     

赣南清溪离子吸附型稀土矿元素迁移富集特征研究

离子吸附型稀土矿床是中国特有的稀土资源。对这一类型矿床及周边的地质环境,风化壳中稀土进行研究具有较高的产学研价值。本文通过对中国赣南典型稀土矿区花岗岩风化壳进行元素地球化学分析,并结合相关地球化学参数与图解,结果表明：研究区成矿花岗岩风化壳形成于强化学风化条件,发育成熟度高,处于晚期去Si阶段;稀土元素地球化学参数显示,风化壳整体的稀土配分特征主要继承于成矿母岩;稀土元素主要以离子交换态在风化剖面中迁移,并受pH值、微生物活动、氧化还原条件等多种因素控制。     

赣南鼢鼠骨骼中7种微量元素含量的测定

目的赣南鼢鼠骨骼经硝酸、高氯酸消化后,在样品中加入氯化镧作为释放剂以消除共存离子的干扰,方法采用火焰原子吸收光谱法对赣南鼢鼠骨骼中7种微量元素ca、cu、Mn、Fe、zn、Pb、和Mg进行了测定。结果赣南鼢鼠全骨中7种元素含量依次为ca,Fe,zn,Mn,cu,Mg,Pb,同一元素在不同骨骼分布不均,头骨最丰富,除zn、Mn外,同一元素在不同部位骨骼的含量存在显著差异,结论此种方法灵敏度高,操作简便快速,结果准确,重现性好,说明赣南鼢鼠终生虽营地下生活,但骨骼微量元素含量依然丰富,并不表现出缺乏的现象。     

基础研究与今日中国化学

强调基础研究在人类文明、社会进步和科技发展中的重要地位和作用 ,介绍我国近年来基础研究取得的重要进展 ,呼吁在基础研究中大力倡导创新文化 ,提出了目前化学界面临的一些问题     

STEM教育与博物馆结合的路径分析*

结合教育部、国家文物局《关于利用博物馆资源开展中小学教育教学的意见》,提出STEM教育与博物馆结合的4条路径。1借鉴优质案例,注重本土发展借鉴他馆优质案例,进行STEM教育案例设计的迁移创新。为实现本土发展,可融入地方性科技、文化资源,讲好中国故事,如北京博物馆可开展模拟故宫建筑修复活动,江西博物馆可开展模拟陶瓷制作活动,四川博物馆可开展模拟脸谱制作、古法制盐等活动。     

赣南信丰风化壳淋积型稀土矿的吸附特性

风化壳淋积型稀土矿体吸附特性对于提高原地浸矿稀土浸取率具有重要意义。通过筛分获得不同粒径的风化壳淋积型稀土矿样,测试各粒径矿样的离子相稀土品位、比表面积、表面形貌以及矿物成分等,分析稀土离子在矿体中的吸附特性。研究结果表明:赣南信丰类型的稀土矿体中矿物成分有高岭石、钾长石、石英、电气石、白云母等,这5种主要矿物成分的总质量比重达到90.13%,不同矿物成分的粒度有明显的差异,小粒径矿样中高岭石和白云母的含量增加,矿样的稀土离子吸附量与高岭石等黏土矿物的含量成正相关;基于稀土离子在矿体颗粒表面凹坑的单位面积吸附量与孔径和粒径成对数正态分布,建立了稀土离子吸附量与矿体颗粒表面凹坑孔径之间关系的分析模型,运用该模型计算得到赣南信丰类型的有效吸附孔径为2.0~20.0 nm。     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.     

Review and patents and literature

The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed.     

Ground- and excited-state aromaticity and antiaromaticity in benzene and cyclobutadiene

The aromaticity and antiaromaticity of the ground state (S 0), lowest triplet state (T 1), and first singlet excited state (S 1) of benzene, and the ground states (S 0), lowest triplet states (T 1), and the first and second singlet excited states (S 1 and S 2) of square and rectangular cyclobutadiene are assessed using various magnetic criteria including nucleus-independent chemical shifts (NICS), proton shieldings, and magnetic susceptibilities calculated using complete-active-space self-consistent field (CASSCF) wave functions constructed from gauge-including atomic orbitals (GIAOs). These magnetic criteria strongly suggest that, in contrast to the well-known aromaticity of the S 0 state of benzene, the T 1 and S 1 states of this molecule are antiaromatic. In square cyclobutadiene, which is shown to be considerably more antiaromatic than rectangular cyclobutadiene, the magnetic properties of the T 1 and S 1 states allow these to be classified as aromatic. According to the computed magnetic criteria, the T 1 state of rectangular cyclobutadiene is still aromatic, but the S 1 state is antiaromatic, just as the S 2 state of square cyclobutadiene; the S 2 state of rectangular cyclobutadiene is nonaromatic. The results demonstrate that the well-known "triplet aromaticity" of cyclic conjugated hydrocarbons represents a particular case of a broader concept of excited-state aromaticity and antiaromaticity. It is shown that while electronic excitation may lead to increased nuclear shieldings in certain low-lying electronic states, in general its main effect can be expected to be nuclear deshielding, which can be substantial for heavier nuclei.     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Syntheses and structures of P-anilino-P-chalcogeno- and P-anilino-P-iminodiazasilaphosphetidines and their group 12 and 13 metal compounds

The P-anilino-P-chalcogeno(imino)diazasilaphosphetidines [Me(2)Si(mu-N(t)Bu)(2)P=E(NHPh)] (E = O (3), S (4), Se (5), N-p-tolyl (6)) were synthesized by oxidizing the P-anilinodiazasilaphosphetidine [Me(2)Si(N(t)Bu)(2)P(NHPh)] (2) with cumene hydroperoxide, sulfur, selenium, and p-tolyl azide, respectively. The lithium salt of 4 reacted with thallium monochloride to produce ([Me(2)Si(mu-N(t)Bu)(2)P=S(NPh)-kappaN-kappaS]Tl)(7), which features a two-coordinate thallium atom. Treatment of 4-6 with AlMe(3) gave the monoligand dimethylaluminum complexes ([Me(2)Si(mu-N(t)Bu)(2)P=E(NPh)-kappaN-kappaE]AlMe(2)) (E = S (8), Se (9), N-p-tolyl (10)), respectively. In these complexes the aluminum atom is tetrahedrally coordinated by one chelating ligand and two methyl groups, as a single-crystal X-ray analysis of 8 showed. A 2 equiv amount of 4-6 reacted with diethylzinc to produce the homoleptic diligand complexes ([Me(2)Si(mu-N(t)Bu)(2)P=E(NPh)-kappaN-kappaE](2)Zn)(E = S (11), Se (12), N-p-tolyl (13)). A crystal-structure analysis of 11 revealed a linear tetraspirocycle with a tetrahedrally coordinated, central zinc atom.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...