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排序方式: 共有79条查询结果,搜索用时 20 毫秒
1.
A new Schiff base hydrazone (Z)‐2‐(2‐aminothiazol‐4‐yl)‐N′‐(2‐hydroxy‐3‐methoxybenzylidene) acetohydrazide (H2L) and its chelates [VO (HL)2]·5H2O, [Cu (HL)Cl(H2O)]·2H2O and [Fe(L)Cl(H2O)2]·3H2O have been isolated and characterized using different physico‐chemical methods, for example infrared (IR), electron paramagnetic resonance (EPR), thermogravimetric analysis and DTG in the solid state, and 1H‐NMR, 13C‐NMR and UV in solution. Magnetic and UV–visible measurements proposed that the coordination environments are square pyramidal, tetrahedral and octahedral geometries for oxovanadium (IV), Cu (II) and Fe (III), respectively. The ligand acts as mono‐negative NO towards oxovanadium (IV) and Cu (II) ions, and bi‐negative ONO for Fe (III) ion. The geometries of the ligand and its complexes were performed using Gaussian 9 program with density functional theory. The EPR spectral data of oxovanadium (IV) and Cu (II) chelates confirmed the mentioned geometries. The molecular modeling was done, and illustrated bond lengths, bond angles, molecular electrostatic potential, Mulliken atomic charges and chemical reactivity for the inspected compounds. Theoretical IR and 1H‐NMR of the free ligand were calculated. Furthermore, thermodynamic and kinetic parameters for thermal decomposition steps were studied. Docking study of H2L was applied against the proteins of both bacterial strains Staphylococcus aureus and Escherichia coli, as well as the protein of xanthine oxidase as antioxidant agent by Schrödinger suite program utilizing XP glide protocol. Furthermore, antimicrobial, antioxidant and DNA‐binding activities of the compounds have been carried out. 相似文献
2.
通过水热法及沉淀法,合成了纳微尺度铜金属有机框架催化剂。通过FT-IR、TG及TEM等技术手段对其性能和结构进行了表征。系统考察了催化剂、溶剂种类及用量、反应时间等因素对异丁香酚氧化制备香草醛的影响。结果表明,用均苯三甲酸根(BTC)作配体时制备的催化剂Cu-BTC性能较佳。以Cu-BTC为催化剂、30%(质量分数)H_2O_2为氧化剂、乙腈为介质,当n(异丁香酚)∶n(H2O2)=1∶2.4时,50℃,反应8 h,异丁香酚转化率为94.4%,香草醛产率达到81.8%。纳微尺度(粒径30~300 nm)Cu-BTC催化剂体现了良好的重复使用性能,连续反应5次,异丁香酚转化率保持在90%左右。 相似文献
3.
介绍了一个综合型有机化学实验,作为一个整体项目大约安排12周时间来完成。以不含香兰素的丁香花为原料,提取其中的丁香酚来多步合成香兰素,并进行物理和化学性质检验,整个实验技术路线包含了蒸馏、合成、重结晶等多种操作,同时在纯化和结构鉴定过程中还用到红外、紫外-可见和高效液相色谱等多种大型仪器分析技术。 相似文献
4.
Temperature‐Directed Biocatalysis for the Sustainable Production of Aromatic Aldehydes or Alcohols 下载免费PDF全文
Dr. Jun Ni Yan‐Yan Gao Dr. Fei Tao Hong‐Yu Liu Prof. Ping Xu 《Angewandte Chemie (International ed. in English)》2018,57(5):1214-1217
The biosynthesis of aromatic aldehydes and alcohols from renewable resources is currently receiving considerable attention because of an increase in demand, finite fossil resources, and growing environmental concerns. Here, a temperature‐directed whole‐cell catalyst was developed by using two novel enzymes from a thermophilic actinomycete. Ferulic acid, a model lignin derivative, was efficiently converted into vanillyl alcohol at a reaction temperature at 30 °C. However, when the temperature was increased to 50 °C, ferulic acid was mainly converted into vanillin with a productivity of 1.1 g L?1 h?1. This is due to the fact that the redundant endogenous alcohol dehydrogenases (ADHs) are not active at this temperature while the functional enzymes from the thermophilic strain remain active. As the biocatalyst could convert many other renewable cinnamic acid derivatives into their corresponding aromatic aldehydes/alcohols, this novel strategy may be extended to generate a vast array of valuable aldehydes or alcohols. 相似文献
5.
通过化学键合的方法制备单壁碳纳米管包覆的四氧化三铁(Fe3O4/C N T s)磁性复合纳米粒子。首先用水热法合成磁性Fe3O4纳米粒子,并进行硅烷氨基化处理,羧基化的单壁碳纳米管通过1-(3-二甲基氨基丙基)-3-乙基碳二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)交联剂反应修饰到Fe3O4纳米颗粒表面。合成的Fe3O4/C N T s复合纳米粒子具有很高的磁响应度和很好的分散能力,是一种很好的分散固相萃取剂。本研究将合成的Fe3O4/C N T s纳米粒子用于分散固相微萃取富集牛奶中的香精添加剂,并与高效液相色谱分析联用,实现了香兰素和乙基香兰素的快速高效富集和高灵敏度检测,两者的检出限达10μg/L,回收率大于92%。本研究表明,合成的Fe3O4/C N T s磁性复合粒子是一种很好的奶制品中香兰素添加剂的样品前处理富集材料。 相似文献
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7.
Dr. Sarvesh K. Srivastava Prof. Dr. Oliver G. Schmidt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9072-9076
A proof‐of‐concept design for autonomous, self‐propelling motors towards value‐added product synthesis and separation is presented. The hybrid motor design consists of two distinct functional blocks. The first, a sodium borohydride (NaBH4) granule, serves both as a reaction prerequisite for the reduction of vanillin and also as a localized solid‐state fuel in the reaction mixture. The second capping functional block consisting of a graphene–polymer composite serves as a hydrophobic matrix to attract the reaction product vanillyl alcohol (VA), resulting in facile separation of this edible value‐added product. These autonomously propelled motors were fabricated at a length scale down to 400 μm, and once introduced in the reaction environment showed rapid bubble‐propulsion followed by high‐purity separation of the reaction product (VA) by the virtue of the graphene–polymer cap acting as a mesoporous sponge. The concept has excellent potential towards the synthesis/isolation of industrially important compounds, affinity‐based product separation, pollutant remediation (such as heavy metal chelation/adsorption), as well as localized fuel‐gradients as an alternative to external fuel dependency. 相似文献
8.
《Journal of Coordination Chemistry》2012,65(17):3108-3116
A series of transition metal–triazole derivatives have been synthesized and characterized by microanalytical, thermal, magneto-chemical, and spectral studies. The synthesized complexes were screened for biological activities. The complexes of Co(II) and Ni(II) emerged as a good antibacterial agent against Gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Bacillus subtilis, and Shigella flexneri. 相似文献
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10.
Preparative syntheses of veratraldehydeoxime esters 6–24, available fragrances produced from vanillin (1), in 82–92% yield from veratraldehydeoxime (3) were developed.
Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 558–560, November–December, 2008. 相似文献