电感耦合等离子体原子发射光谱(ICP-AES)法测定高温合金中5种非金属元素

研究了快速测定高温合金中5种非金属元素(As,B,P,Se,Si)的分析方法,以满足高温合金行业对非金属元素检测的需求。利用王水、氢氟酸和酒石酸对高温合金进行酸溶解,系统研究了基体元素和共存元素对分析元素谱线的光谱干扰情况,同时进行了分析谱线的选择。5种非金属元素的检出限在5.0~12.0μg/mL,5次数据的相对标准偏差(RSD,n=5)为1.1%~4.0%,各元素的加标回收率在96%~102%,方法适用于高温合金中非金属元素的测定。     

微波等离子体炬发射光谱法测定高温合金中非金属元素

研究了微波等离子体炬原子发射光谱(MPT-AES)法测定高温合金中非金属元素(As、B、P、Si)的分析方法,考察此方法对高温合金行业非金属检测需求的适应性。对镍基高温合金样品进行酸溶解处理,选择适用的微波等离子体炬分析谱线,进行检出限、精密度测定。4种非金属元素的检出限在0.03~0.12μg/mL,10次数据的相对标准偏差(RSD,n=10)为0.88%~1.9%,此方法可用于高温合金中非金属元素的测定。     

微波等离子体炬原子发射光谱法测定高温合金中非金属元素

研究了微波等离子体炬原子发射光谱(MPT-AES)法测定高温合金中非金属元素(As、B、P、Si)的分析方法,考察此方法对高温合金行业非金属检测需求的适应性。对镍基高温合金样品进行酸溶解处理,选择适用的微波等离子体炬分析谱线,进行检出限、精密度测定。4种非金属元素的检出限在0.03~0.12μg/mL,10次数据的相对标准偏差(RSD,n=10)为0.88%~1.9%,此方法可用于高温合金中非金属元素的测定。     

ICP—AES法测定含高钽镍基高温合金中的硼

采用ICP-AES法测定含高钽(4%～7%)镍基高温合金中的硼元素.通过试验探讨了镍基高温合金中基体元素,主量元素如铬、钴、钨、钼、钽、铌、铼等对硼元素分析谱线的光谱干扰情况,采用基体匹配法对基体干扰进行校正,确定了合适的分析谱线.方法的线性范围为0～4mg/L,检出限为0.0005%.测定结果的相对标准偏差为0.99%～2.60%(n-8),回收率为94.0%-97.3%.     

ICP-AES法测定镍基高温合金中的铂

采用电感耦合等离子体原子发射光谱法测定镍基高温合金中铂元素。通过实验探讨了镍基高温合金中基体元素镍,主量元素如铬、钴、铝、钼、镍、钽等对铂元素测量的干扰情况,确定了适合的分析谱线。测定结果的相对标准偏差不大于6.55%(n=6),加标回收率为94%～105%。该法可用于镍基高温合金中铂元素的测定。     

微波消解-ICP-AES法测定钴基合金中的硼

采用微波消解-ICP-AES法测定钴基合金中硼元素。通过试验探讨了钴基高温合金中基体元素,主量元素如铬、钨、钼等对硼元素分析谱线的光谱干扰情况,采用基体匹配法对基体干扰进行校正,确定了合适的分析谱线。方法的线性范围为0～8 mg/L,检出限为0.0003%。测定结果的相对标准偏差为1.88%～6.04%(n=6),回收率为92.0%～104.2%。     

电感耦合等离子体原子发射光谱法测定镍基高温合金中铬、钛、铌、铝、铁、硼的含量

在对各元素的分析谱线的选择及基体元素镍对相关元素测定的干扰作了系统研究的基础上,提出用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定镍基高温合金中铬、钛、铌、铝、铁及硼6种合金元素的方法。上述6种元素的检出限(3s/k)在0.006 9~0.13 mg.L-1范围内。取GH 33镍基高温标准样品按所提出方法分析,测定值与标准值相互一致,测得相对标准偏差值(n=10)均小于1.5%。在基体镍溶液中加入各被测元素的标准溶液做回收试验,上述6种元素的回收率在98.3%~101.0%之间。为对此方法的准确性作进一步考核,对GH 4145高温镍基合金样品进行分析,各元素的测定值与国家标准方法的测定值相符合。     

电感耦合等离子体发射光谱（ICP-OES）法测定镍-铬基高温合金GH4133B中铝、铌、钛、铬、铁

GH4133B是Ni-Cr基沉淀硬化型变形高温合金,近年来我国还没有适宜的国家检测标准,基于此对样品主要元素含量准确测定方法进行了研究和探讨。采用盐酸-硝酸体系对GH4133B镍基高温合金进行溶解,确定了盐酸和硝酸比列为8∶3,混合酸用量为11 mL,用ICP-OES法快速准确地对GH4133B镍基高温合金中铝、铌、钛、铬、铁元素含量进行测定;确定了各元素分析谱线为Al 396.152nm、Nb 309.417nm、Ti 334.941nm、Cr 267.716nm、Fe 238.204nm;建立了校准工作曲线,各元素线性相关系数均在0.999以上;优化仪器参数,消除基体干扰,测定了方法检出限,各元素检出限均小于0.003%,各元素测定结果的RSD/%在0.26%～0.47%(n=7),加标回收率在99.4%～105%。有效解决了GH4133B镍基高温合金快速有效溶解及准确测定问题。     

电感耦合等离子体光谱法测定镍基高温合金中的硅、锰、磷

建立了电感耦合等离子体光谱测定镍基高温合金中硅、锰、磷元素的方法,优化了试样前处理方法,对前处理所用酸的酸度进行不同比例试验,确定了仪器测量条件及分析谱线.在一定浓度范围内,各元素的浓度与谱线强度呈线性关系,相关系数大于0.9999.加标回收率为93.3%～106.7%,测定结果的相对标准偏差小于3.0%(n=10)....     

电感耦合等离子体发射光谱法测定铋黄铜合金中微量元素

利用ICP-AES(电感耦合等离子体发射光谱仪)研究了铋黄铜合金中铋、锑、铅、砷、铝、铁元素的测定方法,对仪器参数、分析谱线、干扰情况等因素进行了研究,确定了合适的谱线,并对铋黄铜合金进行精密度和回收实验。结果表明,相对标准偏差小于5%,回收率在94%～106%。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.