一种铬铁矿溶样新方法

样品用Na2 O2 -Na2 CO3 在 70 0℃用镍坩锅熔溶 ,稀硫酸提取 ,2 0 0目玻璃砂芯漏斗过滤 ,不溶物再用H2 SO4 -H3 PO4 加热溶解 ,把滤液和溶解并入 5 0 0ml容量瓶中定容 ,进行全分析 ,用此方法溶样完全 ,分析速度提高。     

奇丽施在棉花上的应用效果

每次用2 .1kg/hm2 奇丽施喷洒棉花 ,增产效果最好 ,经济效益最高。其它按增产高低依次为每次用2 .4kg/hm2、1 .8kg/hm2、1 .5kg/hm2、1 .2kg/hm2。     

高钛渣中低价钛的物相分析

本文采用HCl分离除去M_(Fe),Fe_2O_3及部份FeO,残渣以H_2SO_4-HF-H_3PO_4溶解,用硫酸高铁铵氧化低价钛,然后用K_2Cr_2O_7标准溶液滴定生成的Fe~(2+),用全铁量减去分离去的铁量对残存亚铁量进行校正。本方法具有简便,快速,重现性好的优点。     

Na_2ZnBr_4的新法合成

以NaBr和ZnBr_2为原料,用摩擦化学反应方法制备出了橄榄石型结构的Na_2ZnBr_4,和文献的方法相比,用摩擦化学反应法制备Na_2ZnBr_4简单、经济。     

蒜头果油臭氧化物的裂解方法研究

开展了蒜头果油臭氧化物的安全裂解方法的研究,考察了用O2和H2O2两种氧化剂裂解臭氧化物生成ω-羧基长链脂肪酸三甘油酯的反应条件.实验结果表明:蒜头果油臭氧化物用H202进行裂解比用Q反应条件温和,1,15.十五二酸二甲酯的得率更高.在55℃下用H2O2作为氧化剂,裂解反应2 h,1,15-十五二酸二甲酯的得率达到80.51%.     

示波极谱滴定的研究 Ⅵ.钙、锶、鋇碳酸盐混合物中鋇的快速测定

在含有20％乙醇的醋酸溶液中,用标准K_2Cr_2O_7溶液直接滴定钡,用K_2CrO_4切口的出现指示滴定终点。此法可用于钙锶钡碳酸盐混合物中钡的测定。将样品用醋酸溶解,加氨水调节溶液的酸度至pH=6,加乙醇,用标准K_2Cr_2O_7溶液直接进行滴定,方法快速准确,比现用方法优越。     

以液化天然气为冷源的超临界CO_2-跨临界CO_2冷电联供系统

为了提高超临界CO2布雷顿循环(SCO2循环)的低温余热回收效率,采用跨临界CO2循环(TCO2循环)作为底循环对再压缩式SCO2循环进行余热回收,并采用液化天然气(LNG)为冷源对工质进行冷凝,建立了以LNG为冷源的再压缩式SCO2-TCO2冷电联供系统,以同时输出电量和制冷量。对系统进行火用分析比较,并研究了关键热力参数对系统净输出功率、制冷量、系统热效率和系统火用效率的影响。结果显示:使用LNG作为冷源,降低了TCO2循环的冷凝温度,提高了低温回收热效率,系统的热效率(动力)在给定的条件下达到54.47%;提高LNG的入口温度,可以减小系统火用损;高温回热器换热效率增加,系统热效率和火用效率均增加;SCO2透平膨胀比增加,系统热效率降低,但火用效率增加;TCO2透平进口压力升高,系统热效率和火用效率均呈现先减小再升高后减小的变化趋势;随着冷凝温度升高,系统热效率降低,但火用效率先减小后增加。     

氯化钴与二甲氧基嘧啶胺配合物的合成与表征

利用氯化苄基三乙基铵为催化剂 ,改进文献方法提高了 2 -氨基 - 4,6 -二甲氧基嘧啶 (AMP)的产率。在无水乙醇中回流制得 Co Cl2 · 6 H2 O与 AMP的 1∶ 2固态配合物 ,用化学分析和元素分析确定其组成为 Co (AMP) 2 Cl2 ;用 IR,1H NMR法推测了其结构 ,中心离子 Co2 + 为 sp3 d2 杂化 ;用TG- DTG法分析了它的热稳定性 ,用 DSC法测定其熔点为 1 97.71℃ ,熔化焓为 43 .2 6 k J/mol     

示波极谱滴定的研究——Ⅵ.钙、锶、钡碳酸盐混合物中钡的快速测定

在含有20%乙醇的醋酸溶液中,用标准 K_2Cr_2O_7溶液直接滴定钡,用 K_2CrO_4切口的出现指示滴定终点。此法可用于钙锶钡碳酸盐混合物中钡的测定。将样品用醋酸溶解,加氨水调节溶液的酸度至 pH=6,加乙醇,用标准 K_2Cr_2O_7溶液直接进行滴定,方法快速准确,比现用方法优越。     

离子液体中合成己二酸

在处于室温条件下的离子液体中,以NaW04·2H2O为催化剂,H2O2为氧化剂,用环己酮合成己二酸。讨论了离子液体用量、NaWO4·2H2O用量、H2O2用量以及回收离子液体的使用等条件对反应的影响。此法后处理简便,产品收率高（70．5％）。     

用铁粉和稀硫酸还原反萃P204中Fe3+

针对湿法炼锌过程中P204萃取除铁铁反萃困难的问题,比较铸铁板、锌板、铁粉和锌粉分别作还原剂的还原反萃效果,确定铁粉为最好的还原反萃剂;提出新的Fe^3＋反萃方法,该法以铁粉作还原剂,稀硫酸作反萃剂,在机械搅拌和强保护气氛下边还原边反萃负铁P204中的Fe^3＋;考察还原反萃时间、负载有机相中Fe^3＋含量、铁粉加入量、反应温度、反萃剂酸度对Fe^3＋还原反萃率和还原铁粉指数的影响及其与反萃液中Fe2＋的含量的关系。研究结果表明：在最优条件下,还原铁粉指数为1.087,Fe^3＋还原反萃率达73%;反萃液中Fe^2＋的质量浓度富集到61.8 g/L,可满足制备FeSO4·7H2O的要求。     

Photochemical cycling of iron in the surface ocean mediated by microbial iron(III)-binding ligands

Iron is a limiting nutrient for primary production in large areas of the oceans. Dissolved iron(III) in the upper oceans occurs almost entirely in the form of complexes with strong organic ligands presumed to be of biological origin. Although the importance of organic ligands to aquatic iron cycling is becoming clear, the mechanism by which they are involved in this process remains uncertain. Here we report observations of photochemical reactions involving Fe(III) bound to siderophores--high-affinity iron(III) ligands produced by bacteria to facilitate iron acquisition. We show that photolysis of Fe(III)-siderophore complexes leads to the formation of lower-affinity Fe(III) ligands and the reduction of Fe(III), increasing the availability of siderophore-bound iron for uptake by planktonic assemblages. These photochemical reactions are mediated by the alpha-hydroxy acid moiety, a group which has generally been found to be present in the marine siderophores that have been characterized. We suggest that Fe(III)-binding ligands can enhance the photolytic production of reactive iron species in the euphotic zone and so influence iron availability in aquatic systems.     

The type IV mucolipidosis-associated protein TRPML1 is an endolysosomal iron release channel

TRPML1 (mucolipin 1, also known as MCOLN1) is predicted to be an intracellular late endosomal and lysosomal ion channel protein that belongs to the mucolipin subfamily of transient receptor potential (TRP) proteins. Mutations in the human TRPML1 gene cause mucolipidosis type IV disease (ML4). ML4 patients have motor impairment, mental retardation, retinal degeneration and iron-deficiency anaemia. Because aberrant iron metabolism may cause neural and retinal degeneration, it may be a primary cause of ML4 phenotypes. In most mammalian cells, release of iron from endosomes and lysosomes after iron uptake by endocytosis of Fe(3+)-bound transferrin receptors, or after lysosomal degradation of ferritin-iron complexes and autophagic ingestion of iron-containing macromolecules, is the chief source of cellular iron. The divalent metal transporter protein DMT1 (also known as SLC11A2) is the only endosomal Fe(2+) transporter known at present and it is highly expressed in erythroid precursors. Genetic studies, however, suggest the existence of a DMT1-independent endosomal and lysosomal Fe(2+) transport protein. By measuring radiolabelled iron uptake, by monitoring the levels of cytosolic and intralysosomal iron and by directly patch-clamping the late endosomal and lysosomal membrane, here we show that TRPML1 functions as a Fe(2+) permeable channel in late endosomes and lysosomes. ML4 mutations are shown to impair the ability of TRPML1 to permeate Fe(2+) at varying degrees, which correlate well with the disease severity. A comparison of TRPML1(-/- )ML4 and control human skin fibroblasts showed a reduction in cytosolic Fe(2+) levels, an increase in intralysosomal Fe(2+) levels and an accumulation of lipofuscin-like molecules in TRPML1(-/-) cells. We propose that TRPML1 mediates a mechanism by which Fe(2+) is released from late endosomes and lysosomes. Our results indicate that impaired iron transport may contribute to both haematological and degenerative symptoms of ML4 patients.     

酞菁铁的模板合成及其对氧还原的电催化性能

针对直接甲醇燃料电池阴极常用的铂基催化剂易中毒、选择性差等问题,以Fe2＋为模板剂控制合成了酞菁铁配合物催化剂.红外光谱测试表明,Fe2＋与酞菁中的N形成了配键.研究结果表明,随着温度的升高,酞菁铁对氧还原反应的电催化活性逐渐增强,且对甲醇氧化反应无催化活性,证明酞菁铁具有较好的催化选择性.     

硫铁矿烧渣水热法合成形貌可控的氧化铁

以硫铁矿烧渣硫酸浸出液与氨水反应制备的Fe(OH)3胶体为前驱体,采用水热法合成不同形貌的氧化铁粒子。在中性介质中考察反应温度、物质的量比(n(Fe2+)/n(Fe3+))、水热体系总Fe浓度及晶种量对水热法氧化铁物相、形貌和粒径的影响。采用X线衍射仪、扫描电镜、透射电镜及选择区域电子衍射对水热产物物相和形貌进行研究。研究结果表明:反应温度为230℃,n(Fe2+)/n(Fe3+)为0.1以及水热体系总Fe浓度为1.25 mol/L和晶种量为2 g时,水热产物为片状α-Fe2O3粒子;控制上述其他条件不变,当温度在140～260℃时,随着温度的升高,水热法产物由α-FeOOH相向α-Fe2O3相转变,α-Fe2O3粒子形貌由球形向小圆饼状和片状依次转变;当n(Fe2+)/n(Fe3+)在0～0.12时,随着n(Fe2+)/n(Fe3+)的增加,水热产物由α-Fe2O3相向α-Fe2O3和Fe3O4相转变,α-Fe2O3粒子形貌由球形逐渐向片状转变,其粒径由小变大;当水热体系中总Fe浓度为0.625 mol/L和1.875 mol/L时,水热法氧化铁分别为不均一形貌和球形;当没有加入晶种及晶种量为6 g时,水热...     

Speciation of iron in atmospheric particulate matter by EXAFS

In the atmospheric particulate matter (PM), fractions with a particle size of less than 10 μm (PM10) or evenless than 2.5 μm (PM2.5) in aerodynamic diameter can be inhaled into human body and cause serious health problems[1,2]. The influence of the PM on health is not only related to elemental concentrations, but also to its chemical speciation. The study on elemental speciation in atmospheric PM is significant for evaluating toxicity of PM and providing information about the formation a…     

Structure and reactivity of a mononuclear non-haem iron(III)-peroxo complex

Oxygen-containing mononuclear iron species--iron(III)-peroxo, iron(III)-hydroperoxo and iron(IV)-oxo--are key intermediates in the catalytic activation of dioxygen by iron-containing metalloenzymes. It has been difficult to generate synthetic analogues of these three active iron-oxygen species in identical host complexes, which is necessary to elucidate changes to the structure of the iron centre during catalysis and the factors that control their chemical reactivities with substrates. Here we report the high-resolution crystal structure of a mononuclear non-haem side-on iron(III)-peroxo complex, [Fe(III)(TMC)(OO)](+). We also report a series of chemical reactions in which this iron(III)-peroxo complex is cleanly converted to the iron(III)-hydroperoxo complex, [Fe(III)(TMC)(OOH)](2+), via a short-lived intermediate on protonation. This iron(III)-hydroperoxo complex then cleanly converts to the ferryl complex, [Fe(IV)(TMC)(O)](2+), via homolytic O-O bond cleavage of the iron(III)-hydroperoxo species. All three of these iron species--the three most biologically relevant iron-oxygen intermediates--have been spectroscopically characterized; we note that they have been obtained using a simple macrocyclic ligand. We have performed relative reactivity studies on these three iron species which reveal that the iron(III)-hydroperoxo complex is the most reactive of the three in the deformylation of aldehydes and that it has a similar reactivity to the iron(IV)-oxo complex in C-H bond activation of alkylaromatics. These reactivity results demonstrate that iron(III)-hydroperoxo species are viable oxidants in both nucleophilic and electrophilic reactions by iron-containing enzymes.     

由铁鳞制备纳米氧化铁可见光光催化剂

以铁鳞为原料,采用水热法成功制备不同形貌的纳米Fe2 O3光催化剂。探讨了不同浓度的盐酸、液固比及反应时间对铁鳞浸出规律的影响。系统研究了铁鳞浸出液的纯度对于水热法制备纳米Fe2 O3的微观形貌和光催化性能的影响。结果表明：8 g铁鳞与150 mL浓度为3 mol·L-1的盐酸溶液在100℃回流反应2 h,铁鳞的浸出率达到约93%且浸出液纯度较高。浸出液中的杂质离子改变了纳米Fe2 O3的微观形貌和晶体的择优生长方向。另外,以铁鳞为原料制备出的纳米Fe2 O3可见光光催化性能较好,光降解罗丹明B溶液60 min后,其降解率可达87%左右。     

Crystal structure of the non-haem iron halogenase SyrB2 in syringomycin biosynthesis

Non-haem Fe(II)/alpha-ketoglutarate (alphaKG)-dependent enzymes harness the reducing power of alphaKG to catalyse oxidative reactions, usually the hydroxylation of unactivated carbons, and are involved in processes such as natural product biosynthesis, the mammalian hypoxic response, and DNA repair. These enzymes couple the decarboxylation of alphaKG with the formation of a high-energy ferryl-oxo intermediate that acts as a hydrogen-abstracting species. All previously structurally characterized mononuclear iron enzymes contain a 2-His, 1-carboxylate motif that coordinates the iron. The two histidines and one carboxylate, known as the 'facial triad', form one triangular side of an octahedral iron coordination geometry. A subclass of mononuclear iron enzymes has been shown to catalyse halogenation reactions, rather than the more typical hydroxylation reaction. SyrB2, a member of this subclass, is a non-haem Fe(II)/alphaKG-dependent halogenase that catalyses the chlorination of threonine in syringomycin E biosynthesis. Here we report the structure of SyrB2 with both a chloride ion and alphaKG coordinated to the iron ion at 1.6 A resolution. This structure reveals a previously unknown coordination of iron, in which the carboxylate ligand of the facial triad is replaced by a chloride ion.     

铁胁迫对大豆POD和EST同工酶的影响

采用垂直聚丙烯酰胺凝胶电泳,研究了2个品种的大豆--浙春3号和1601在不同时期、不同浓度铁胁迫下过氧化物酶(POD)同工酶和酯酶(EST)同工酶的变化情况.结果表明,浙春3号的2种同工酶酶谱的变化基本一致,随铁浓度的增加酶带数和强度都有所增加;而1601的2种同工酶,在高浓度铁处理时,酶带数和强度都减少.2个大豆品种不同时期的POD和EST同工酶酶谱对铁胁迫的反应也有差异.不同品种大豆的同工酶酶谱的变化,与其对铁胁迫的抗性有关.