柱前衍生／流动注射微柱预富集和ICP—AES法测定高纯氧化镧中痕量非

利用自合成的碳硅凝胶为吸附材料，以铜试剂（ＮａＤＤＴＣ）为柱前衍生试剂，实现了Ａｌ（Ⅲ）、Ｃｒ（Ⅵ）、Ｃｕ（Ⅱ）、Ｆｅ（Ⅲ）、Ｖ（Ｖ）流动注射（ＦＩ）微柱预富集。以稀ＨＮＯ３停流洗脱富集物，ＩＣＰ－ＡＥＳ法测定洗脱液中上述元素。在优化条件下，富集倍数近１０倍，检出限为ｎｇ／ｍＬ级，ＲＳＤ〈５．０％（ｎ＝７），方法用于高纯Ｌａ２Ｏ３中非稀土杂质测定，结果满意。     

1,3-戊二烯阳离子聚合过程中环化反应的研究

以ＡｌＣｌ３和（ＣＦ３ＳＯ３）３Ａｌ为引发剂，ＣＨ２Ｃｌ２为溶剂，在２０℃聚合了１，３ 戊二烯（ＰＤ）．对聚合物（ＰＰＤ）的结构分析表明，（ＣＦ３ＳＯ３）３Ａｌ生成的聚合物具有较高的环化度．聚合物的环化过程是通过两种机理，分子内链转移机理和阳离子引发机理，后者可以通过加入ＤｔＢＰ得到抑制．ＡｌＣｌ３引发的聚合反应中环化过程以前一种机理为主，而（ＣＦ３ＳＯ３）３Ａｌ则以后一种机理为主．通过阳离子引发的环化反应主要发生在ＰＰＤ１，２单元侧基双键上     

增效试剂对过氧化物模拟酶催化显色体系的增效作用——Fe-TPPS_4-4-AAP-苯酚衍生物-H_2O_2体系

本文以β－环糊精（β－ＣＤ）和表面活性剂为增效试剂，分别研究了它们对以Ｆｅ－ｍｅｓｏ－（四（４－磺基苯）卟啉）（Ｆｅ－ＴＰＰＳ４）为催化剂，催化过氧化氢氧化４－氨基安替比林（４－ＡＡＰ）与苯酚衍生物显色反应的速度和灵敏度的影响，发现β－ＣＤ和十二烷基苯磺酸钠（ＳＤＢＳ）对该体系具有明显的增效作用．在３×１０－３ｍｏｌ／Ｌβ－ＣＤ存在下，测定Ｈ２Ｏ２的灵敏度比文献报道的提高了１．５６倍．利用ＳＤＢＳ浓度与催化显色反应初速度的增加值之间的线性关系，建立了测定微量ＳＤＢＳ的方法     

SYNTHESIS AND CHARACTERIZATION OF NEIV PICKET FENCE CROWN－PORPHYRIN AND ITS Zn（Ⅱ），Fe（Ⅲ） COMIPLEXES

ＳＹＮＴＨＥＳＩＳＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＮＥＩＶＰＩＣＫＥＴＦＥＮＣＥＣＲＯＷＮ－ＰＯＲＰＨＹＲＩＮＡＮＤＩＴＳＺｎ（Ⅱ），Ｆｅ（Ⅲ）ＣＯＭＩＰＬＥＸＥＳ￥ＹａｎｇｄｅＷＵ，ＦａＣｈｅｎｇＱＩＡＮ，ＬｉａｎＦａｎｇＳＨＥＮａ（Ｄｅ...     

AB INITIO STUDY ON GAS-PHASE FACTION OF Ca WITH HN_3

ＡＢＩＮＩＴＩＯＳＴＵＤＹＯＮＧＡＳ－ＰＨＡＳＥＦＡＣＴＩＯＮＯＦＣａＷＩＴＨ　ＨＮ_３（ＲｏｎｇＳｈｕｎＺＨＵ；ＳｈｕＳｈａｎＤＡＩ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＹｕｎｎａｎＵｎｉｖｅｒｓｉｔｙ．Ｋｕｎｍｉｎｇ６５００９１．）ＡＢＩ?..     

SYNTHESES， CHARACTERIZATION AND CATALYSIS OF （dppe）Rh（μ－CO）_2M（CO）_3（M＝CR，Mo，W） CARBONYL COMPOUNDS

ＳＹＮＴＨＥＳＥＳ，ＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮ ＡＮＤ ＣＡＴＡＬＹＳＩＳ ＯＦ （ｄｐｐｅ）Ｒｈ（μ－ＣＯ）_２Ｍ（ＣＯ）_３（Ｍ＝ＣＲ，Ｍｏ，ｗ）ＣＡＲＢＯＮＹＬ ＣＯＭＰＯＵＮＤＳ￥ＣｈａｎｇＰｉｎｇＳＨＡＯ；ＪａｉｅＹｕＷＡＮＧ；ＸｉｕＺ...     

SYNTHESIS AND CHARACTERIZATION OF (PPh_3)_3Co(μ-CO)_2 V(CO)_2Cp AND (PPh_3)

ＳＹＮＴＨＥＳＩＳＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦ（ＰＰｈ_３）_３Ｃｏ（μ－ＣＯ）_２Ｖ（ＣＯ）_２ＣｐＡＮＤ（ＰＰｈ_３）ＨＰｔ（μ－ＣＯ）（μ－ＰＰｈ_２）Ｖ（ＣＯ）_２ＣｐＣｈａｎｇＰｉｎｇＳＨＡＯ（ＤａｌｉａｎＩｎｓｔｉｔｕｔｅｏｆＣｈ?..     

STUDY ON REACTION OF （μ_3－CCO_2Et）CO_2M（CO）_8（CpMe）（M＝Mo，W） WITH Na_2［Fe（CO）_4］．SYNTHESIS OF TWO KINDS OF THE NOVEL CLUSTERS EtO_2CCFeCoM（CO）_8（CpMe）H AND （OCC）FeCoM（CO）_8（CpMe）

ＳＴＵＤＹＯＮＲＥＡＣＴＩＯＮＯＦ（μ_３－ＣＣＯ_２Ｅｔ）ＣＯ_２Ｍ（ＣＯ）_８（ＣｐＭｅ）（Ｍ＝Ｍｏ，Ｗ）ＷＩＴＨＮａ_２［Ｆｅ（ＣＯ）_４］．ＳＹＮＴＨＥＳＩＳＯＦＴＷＯＫＩＮＤＳＯＦＴＨＥＮＯＶＥＬＣＬＵＳＴＥＲＳＥｔＯ_２ＣＣＦｅＣｏＭ（ＣＯ）_８...     

A FACILE TOTAL SYNTHESIS OF (±)-SELINA-3,11-DIEN-9-OL

Ａ　ＦＡＣＩＬＥ　ＴＯＴＡＬ　ＳＹＮＴＨＥＳＩＳ　ＯＦ　（±）－ＳＥＬＩＮＡ－３，　１１－ＤＩＥＮ－９－ＯＬＡＦＡＣＩＬＥＴＯＴＡＬＳＹＮＴＨＥＳＩＳＯＦ（±）－ＳＥＬＩＮＡ－３，１１－ＤＩＥＮ－９－ＯＬＬｉＪｕｎＬＩＵ；ＺｈａｏＭｉｎｇＸＩＯＮＧ；...     

原子吸收法测定环境水样中化学需氧量

在Ｈ２ＳＯ４介质中用Ｋ２Ｃｒ２Ｏ７同ＣＯＤ水样反应,反应后水相中过量的Ｃｒ（Ⅵ）以Ｃｒ２Ｏ２－７形式被ＴＯＡ萃入有机相中,而生成的Ｃｒ（Ⅲ）则留在水相,用ＡＡＳ测定有机相中的Ｃｒ（Ⅵ）或水相中的Ｃｒ（Ⅲ）都可求得ＣＯＤ含量。本法简便快速、需样量少、且测定结果同标准方法（ＣＯＤＣｒ法）一致,回收率为９８％～１０８％,平均标准偏差为３．３％。     

国内光催化研究进展简述

分1975~1985, 1985~1995和1995~2012三个时期简要介绍了国内光催化研究进展, 主要侧重于光催化材料及其改性、应用和反应机理方面的研究进展, 并指出了当前光催化领域存在的一些重要问题和未来的发展趋势, 涉及到光解水、CO₂还原、环境净化和选择性有机合成等方面.     

青蒿素研究进展

青蒿素是目前治疗疟疾的特效药。本文对自青蒿素发现以来的最新研究进展进行了比较详尽的综述。内容包括: 青蒿素的发现及历史, 青蒿素的来源, 青蒿素的全合成,青蒿素的生物合成, 青蒿素衍生物以及植物组织培养生产青蒿素。     

Reactions in droplets in microfluidic channels

Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet-based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights.     

Recent Advances in Analytical Methodology for in vivo Electrochemistry in Mammals

Electrochemistry is one of the most advanced techniques for monitoring neurochemical activities in the living brain because electrochemical approaches bear the advantageous features of high spatial and temporal resolutions, which facilitate its tremendous potential in investigating the highly spatially heterogeneous brain system and the fast dynamics of neurochemical activities. On the other hand, since brain is the most complicated organ in the sense of its numerous kinds of neurochemical species, high selectivity is always required for any analytical methods that approach the brain. In this review, we will discuss various electrochemical methodologies to achieve selective detection of neurochemicals in mammalian brain and the strategies developed mainly by our group towards selective monitoring of both electrochemically active and inactive neurochemicals. At the end, we will discuss possible solutions towards brain mapping of neurochemical species and combination of neurochemical detection strategy with electrophysiology as the direction of future development of electroanalysis in living brain.     

乙基香兰素研究前景

报导了近几十年来国内外关于乙基香兰素的研究进展与动态,并简单介绍了本文作者在该方面所取得的研究成果,参考文献33篇。     

Gemini表面活性剂合成进展*

系统总结了近百种Gemini表面活性剂的合成路线和方法,并且按照其结构特点分门别类地进行比较和归纳,对今后Gemini表面活性剂的合成发展方向提出了一些看法,这对促进此类新颖表面活性剂的工业化进程将具有指导意义。     

Interpretation of inorganic arsenic metabolism in humans in the light of observations made in vitro and in vivo in the rat

The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (As_i). In order to document the methylation process in humans, the kinetics of As_i, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of As_i. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As₂O₃) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of As_i metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of As_i uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems.     

Trends in education in analytical chemistry

Summary At the session of the WPAC of Fechem on education in analytical chemistry it was concluded that it is now essential to include chemometrics and basic knowledge of computers in all courses on analytical chemistry.

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Tendenzen in der analytisch-chemischen Ausbildung

Zusammenfassung Bei einer Tagung der WPAC über die Lehre auf dem Gebiet der analytischen Chemie wurde bei der Betrachtung neuer Aspekte festgestellt, daß vor allem Chemometrie und Grundkenntnisse in Computertechnik in die Ausbildung aufgenommen werden sollten.

     

钙与人体及临床

钙是宏量元素，是人体中含量较高的元素之一，体内99％的钙构成骨骼和牙齿以及维持骨骼结构，1％的钙调节人体重要生理功能。钙的含量过高或过低都与许多疾病有关，只有保持一种平衡状态，才能使机体处于正常环境。     

AGET ATRP in the Presence of Air in Miniemulsion and in Bulk

Summary: The recently developed initiation system, activators generated by electron transfer (AGET), is used in atom transfer radical polymerization (ATRP) in the presence of a limited amount of air. Ascorbic acid and tin(II ) 2‐ethylhexanoate are used as reducing agents in miniemulsion and bulk, respectively. An excess of reducing agent consumes the oxygen present in the system and, therefore, provides a deoxygenated environment for ATRP. ATRP of butyl acrylate is successfully carried out in miniemulsion and in the presence of air. During polymerization the radical concentration remains constant. The polymerization reaches over 60% monomer conversion after 6 h, which results in polymers with a predetermined molecular weight = 14 000 g · mol⁻¹ and a low polydispersity ( = 1.23). AGET ATRP of styrene is also successful in bulk in the presence of air, as evidenced by linear semi‐logarithmic kinetics, which leads to polystyrene with an of 13 400 g · mol⁻¹ and a low polydispersity index ( = 1.14).

Appearance of miniemulsion before and after the reducing agent ascorbic acid was added (left); and GPC traces representing molecular weights during the AGET ATRP of BA in miniemulsion in the presence of air (right).