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排序方式: 共有11条查询结果,搜索用时 9 毫秒
1.
利用收敛法合成了一代到四代外围带有二苯酮、核心带有降冰片二烯的芳醚树枝形聚合物, 初步研究了这些化合物的分子内光敏异构化反应. 以波长大于350 nm的光选择激发外围的二苯酮官能团引起核心处降冰片二烯基团异构化为四环烷, 随着代数的增长, 光敏异构化反应的速率逐渐加快.  相似文献   
2.
基于甲醛、苯和二氧化硫在纳米Ti3CeY2O11上的催化发光有交叉敏感现象,在3个波长处分别确定甲醛、苯和二氧化硫浓度与催化发光信号强度的响应关系,再依据发光信号强度的叠加性特征即可获取甲醛、苯和二氧化硫的准确浓度,据此建立了同时测定空气中甲醛、苯和二氧化硫的新方法.3个分析波长分别为420、535和680 nm,敏感材料表面温度为280℃,载气流速为130 mL/min.本方法对甲醛、苯和二氧化硫的检出限(3σ)分别为0.04、0.05和0.10 mg/m3,线性范围分别为0.08~75.60 mg/m3、0.10~101.40 mg/m3和0.30~115.00 mg/m3, 回收率分别为96.4%~103.7%、97.8%~102.5%和97.2%~103.3%.常见共存物,如乙醛、甲苯、硫化氢、氨、甲醇、乙醇和二氧化碳等不干扰测定.连续200 h通浓度均为50 mg/m3的甲醛、苯和二氧化硫混合气体,发光强度的相对偏差≤2%,表明此纳米级复合氧化物对甲醛、苯和二氧化硫的敏感性的寿命长.本方法充分利用了交叉敏感现象,可以实现空气中甲醛、苯和二氧化硫的在线分析.  相似文献   
3.
苯酚钾及对位取代苯酚钾的电离势   总被引:2,自引:0,他引:2  
在我们以前的研究工作中发现,酚类钾盐是很好的电荷给体,可以和顺丁烯二酸酐、三硝基苯以及醌类等电荷受体生成电荷转移(CT)络合物。表示分子的给电子能力的参数是分子的第一电离势(简称为电离势I_p)。对于苯酚的I_p值,近年来已有文献记载,但苯酚钾  相似文献   
4.
10-烃基吖啶酮的非线性光学活性研究   总被引:3,自引:0,他引:3  
随着激光技术应用的发展,非线性光学材料的研究不断深人['j,目前倍频效应和短的截止波长的倍频材料是二阶非线性光学有机材料研究的热点之一L'.现有的非线性光学有机材料,如偶氮苯、共轭烯烃与SChiff碱等类化合物,因分子具有较大的共轭长度使其吸收多处于可见光区,不适合于半导体激光等向蓝紫激光倍频"·".0'(暖酮含有大。共轭结构,分子两端同时连有吸电子基团。X一0)和推电子基团(>N-R)而发生分子内的电荷转移,使分子具有非线性光学活性"-·这类化合物结构简单,并有很好的光稳定性,且该类化合物最大紫外吸收在385~40…  相似文献   
5.
We demonstrate the characteristics of relatively low saturation intensity using co-doped Nd, Cr:YAG as saturable absorber for passively mode locking the Nd:YAG laser. The difference of the saturation intensity between Q-switched and mode-locked operation in co-doped Nd, Cr:YAG was only one to two orders of magnitude, while Cr:YAG was generally reported at a difference of five orders of magnitude. More than 80% mode locking modulation depth was achieved at an incident pump power of 4.4W, corresponding to an intracavity intensity of 6×10^4W/cm^2, using a 68cm long plano-concave cavity.  相似文献   
6.
Eight 9-benzylidene-substituted-10-methyl-9,10-dihydroacridine derivatives were synthesized from acridine as starting material and were characterized by 1H-NMR, 13C-NMR, Ms and elemental analysis. The second harmonic generation (SHG) values of these compounds were determined in powder using Nd:YAG as a laser source, as compared with urea powder, and the values of second-order polarizabilities (betaxxx), the values of the composite magnitude (betaCTmicrog) of molecular hypersusceptibilities and their moment of these compounds were obtained by the solvatochromic method under ground state for everyone. The results showed that SHG value of 10 is higher than that of urea; the betaCTmicrog of 5 (107.8 x 10(-30) esu) is lower than that of 4-nitro-N,N-dimethylaniline (30 x 10(-30) esu); the betaCTmicrog of 7 (350.8 x 10(-30) esu) and 10 (244.6 x 10(-30) esu) are higher than that of 4-nitro-N,N-dimethylaniline; the betaCTmicrog of 8 (3553 x 10(-30) esu), 11 (1187 x 10(-30) esu) and 12 (1163 x 10(-30) esu) are much more higher than that of 4-nitro-N,N-dimethylaniline. The results demonstrated that this series of compounds possesses good second-order nonlinear optical (NLO) property. The regular relationship could not be obtained between electronegativity of substituents (R) attached to benzylidene ring and SHG values or betaCTmicrog values although the Rs are different in electronegativity and should make an effect on the extent of intramolecular electron-transfer and would consequently influence SHG or betaCTmicrog. The electron-withdrawing ability of R from benzylidene ring played an important role on lambdamax of these compounds.  相似文献   
7.
The charge-transfer complexes (CTC) between a parent molecule of antipsychotic pharmaceuticals, phenothiazine, and seven unsaturated acid anhydrides, 1,4,5,8-naphtalenetetracarboxylic dianhydride, diphenic anhydride, maleic anhydride (MA), 3,4,5,6-tetrahydrophthalic anhydride (THPA), 3-hydroxy-1,8-naphthalic anhydride (HONA), 4-chloro-1,8-naphthalic anhydride (ClNA), and 1,8-naphthalic anhydride (NA) were studied using IR and UV spectroscopy. Stability constants (K) at different temperatures were measured, and based on the K's DeltaH and DeltaS were calculated. The values of electron affinity (E(A)) of anhydrides were obtained according to Mulliken's theory. The results show that phenothiazine is an excellent donor and has strong ability to complex with the carbonyl group, and the E(A) values have good linear relationships with DeltaH and K, respectively. The solvent effect on CTCs was also determined and explained. The CTC of phenothiazine-succinic anhydride (SA) was studied under the same conditions. It was deduced from the results obtained that there were two charge-accepting centers in the unsaturated acid anhydrides when they formed CTCs with phenothiazine. The first one was carbon atom of the two carbonyl groups and the second one was their -C=C- in the molecules.  相似文献   
8.
液—液相转移催化反应合成N—取代吩噻嗪   总被引:2,自引:0,他引:2  
英柏宁  吴国湘 《合成化学》1993,1(4):348-350
本文叙述以四正丁基溴化铵为相转移催化剂,液一液相转移催化合成了六个 N-取代吩噻嗪化合物。由于在方法上作了改进,所以产率均优于文献报导。  相似文献   
9.
谢周  胡琳 《合成化学》1994,2(2):151-153
由二苯甲酮合成二苯甲硫酮,再使它与月佳烯发生环加成反应,合成了两种不饱和环状硫醚,总产率74.6%。  相似文献   
10.
It becomes increasingly important to make second-order nonlinear optic (NLO) materials[1-4]. N-Hydrocarbyl-o-phenoanthrolinium salt and N-hydrocarbylacridinium salt are stable to light and heat,therefore, they are expected to be used as semi-conductor laser materials with double-frequency violet-light and blue-light (750~800 nm). Their syntheses and determination of second harmonic generation (SHG) values are in the following:  相似文献   
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