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排序方式: 共有51条查询结果,搜索用时 14 毫秒
1.
冯启峰  敖桂珍 《化学试剂》2016,(10):1011-1013
对标题化合物的合成工艺进行改进,以异喹啉为起始原料,经其5位溴代、8位硝化、加氢脱5-溴以及异喹啉环还原4步反应得到,并考察了反应时间、温度、氢气压力和催化剂对脱卤反应收率的影响。脱溴反应的最优工艺条件为反应3 h、温度23℃、氢气压力0.15 MPa、盐酸催化。该工艺路线步骤短、总收率高达32%、成本低,适合工业化生产。  相似文献   
2.
利用双表面活性剂( Tween-20和Brij-35 )保护的方法,合成并表征了一系列[Pd-Pt]/C催化剂。将其应用于喹啉催化加氢制备1,2,3,4-四氢喹啉反应中,结果表明,5wt%[Pd-Pt(1:3)]/C的催化活性最高。优化反应参数,以乙醇为溶剂,初始底物浓度为2.4mol/L,在130℃, 2.5MPa下反应50min,喹啉转化率100%,1,2,3,4-四氢喹啉选择性100%。  相似文献   
3.
以苯乙胺为原料,经乙酰化反应得乙酰苯乙胺(3),在甲基磺酸的作用下环合得1-甲基-3,4-二氢异喹啉(4),经硼氢化钠还原得1-甲基-1,2,3,4-四氢异喹啉(1)。改进了合成工艺,总收率达80.8%。  相似文献   
4.
Xingzhong Fang 《Polymer》2004,45(8):2539-2549
Cis-1,2,3,4-cyclohexanetetracarboxylic dianhydride (cis-1,2,3,4-CHDA) was synthesized. It was found that under such conditions as heating or boiling in acetic anhydride, cis-1,2,3,4-CHDA could be converted to its trans-isomer. The process of thermal isomerization was monitored by 1H NMR spectra and the mechanism of conversion was proposed. Their absolute structures of cis- and trans-1,2,3,4-CHDAs were elucidated by single crystal X-ray diffraction. The polycondensations of cis- and trans-1,2,3,4-CHDAs with aromatic diamines such as 4,4′-oxydianiline (ODA), 4,4′-methylenedianiline (MDA), 4,4′-diamino-3,3′-dimethyldiphenylmethane (DMMDA), 4,4′-bis(4-aminophenoxy)benzene (TPEQ), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) were studied. It is easy to obtain higher molecular weight polyimides from trans-1,2,3,4-CHDA using conventional one-step or two-step methods. However, higher molecular weight polyimides derived from cis-1,2,3,4-CHDA could not be prepared by the usual methods (solid content ca. 10%) owing to the trend of forming cyclic oligomers. Increasing the concentration of monomers could give higher molecular weight cis-polymers. All of the cis-polyimides were soluble at room temperature in aprotic polar solvents and phenolic solvents and some of them even soluble in chloroform and tetrahydrofuran, while the corresponding trans-polymers showed poor solubility as compared to cis-polymers. All of the polyimides showed good thermal stability with the 5% weight loss temperatures in air over 415 °C. Furthermore, polyimides derived from cis-1,2,3,4-CHDA have higher glass transition temperatures (Tgs) than corresponding trans-polyimides. The flexible polyimide films possessed a tensile modulus range of 2.1-3.6 GPa, a tensile strength range of 42-116 MPa, an elongation at break of 4-18%. These polyimides exhibited cutoffs at wavelengths around 270 nm and were entirely colorless. All the polyimides showed amorphous pattern according to Wide angle X-ray diffraction measurements. The differences of polymerization and properties were explained by the structural changes resulted from isomerism.  相似文献   
5.
The transformations of a molecule containing two adjacent epoxide rings, 2,2-bioxirane that is, were studied over various acidic aluminosilicates (HZSM-5, HY-FAU, AlMCM-41), for the first time, In the 373–473 K temperature range, in a pulse reactor, a ring-opening–ring-enlargment reaction producing furan only occured over the zeolites and it was the predominant reaction on AlMCM-41 as well. The driving force of this transformation route is water formation via elimination from 2,2-bioxirane. Suprising is the lack of the mono- or dialdehyde, the would-be products of the cleavage of the sterically more hindered C–O bonds – an acid-catalysed reaction typical for alkyl-substituted oxiranes.  相似文献   
6.
In preparation of self‐decontamination clothing materials in high reactivities against toxic agents, photoactive benzophenone chromophoric groups were incorporated into cotton fabrics. The cotton fabrics were treated by using 4‐hydroxybenzophenone as a reagent, 1,2,3,4,‐butanetetra carboxylic acid (BTCA) as a crosslinker, and sodium hypophosphite as a catalyst. The fabric treatment was conducted by a pad‐dry‐cure method. The benzophenone chromophoric group incorporated cotton fabrics were characterized by FTIR, SEM, TGA, and so on. The results confirmed the expected structures of the benzophenone chromophoric group modified and BTCA crosslinked cotton fabrics. The treated cotton fabrics demonstrated radical reactivities and antibacterial activity under UV irradiation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007  相似文献   
7.
邱仓柏  莫卫民 《广东化工》2011,(8):3+28-3,28
2-氯-6,7-二氢喹啉培(5H)-酮是四氢喹啉是一个重要的含氮杂环化合物。文章以2-氯-5,6,7,8-四氢喹啉为原料,经氧化、酯化、水解反应后得到2.氯-5,6,7,8-四氢喹啉-8-醇,再经Anelli氧化后得到总收率为57,8%的目标产物。所得化合物的结构均经核磁和质谱确证。  相似文献   
8.
以苯肼及环戊酮为原料,以价廉易得的某A酸代替传统的无水氯化锌为催化剂,通过费舍尔反应闭环得到1,2,3,4-四氢环戊基吲哚。通过选择合适的催化剂,产品收率可高达90%,产品纯度高达94%,并且可以大大降低成本。  相似文献   
9.
A series of novel coumarin based chalcones were synthesized by the classical crossed aldol condensation reaction of 8-acetyl-1,4-diethyl-1,2,3,4-tetrahydro-7H-pyrano[2,3-g]quinoxalin-7-one and various substituted benzaldehydes. These novel ketocoumarin derivatives having a 1,4-diethyl-1,2,3,4-tetrahydroquinoxaline framework exhibited brilliant fluorescence. The novel chalcones absorbed in the range of 458-523 nm in various solvents. The wavelength of maximum absorption of these chalcones was found to be significantly longer than their simple acyl derivative known in the literature. The dyes displayed longer wavelength of absorption in the high polarity solvents compared to non-polar solvents. Thermogravimetric analysis of the chalcones revealed that the chalcones possess good thermal stability.  相似文献   
10.
以3?氨基?4(?叔丁基?NNO?氧化偶氮基)呋咱(ABAo F)为原料,经重氮化开环、肟化、氧化、氨化和硝化环化五步反应得到目标化合物1?羟基?1,2,3?三唑并[4,5?e]?5,7?二氧化?1,2,3,4?四嗪(HTTDO),总收率24.1%,采用红外光谱、核磁共振、质谱及元素分析对中间体及产物的结构进行了表征;探讨了氨化及硝化环化的反应机理;培养了HTTDO·4.5H2O的单晶,X射线衍射分析表明,其为正斜方晶系,空间群为Pna2(1),晶体密度为1.659 g·cm~(-3);利用Gaussian 09程序和Kamlet?Jacobs方程计算HTTDO理论密度为1.88 g·cm~(-3),爆速为9393 m·s-1,爆压为41.9 GPa,爆热为8010 J·g~(-1);采用差示扫描量热(DSC)研究了HTTDO的热性能:其在热分解过程中,放热剧烈,峰温最高达194.5℃。  相似文献   
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