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1.
杂多配合物催化合成羧酸异戊酯的研究 总被引:2,自引:0,他引:2
杂多配合物催化合成羧酸异戊酯的研究王玉和,周百斌,关良智,王晓光,单永奎,李萍,周宏立(哈尔滨师范大学化学系哈尔滨150080)关键词杂多酸,酯化作用,异戊酯,催化羧酸异戊酯广泛用于调制各种香型的食品香料,用作溶剂、萃取剂、制革、人造丝、涂料、化妆品... 相似文献
2.
梯度淋洗离子色谱-安培检测测定苯胺类化合物 总被引:10,自引:0,他引:10
以乙腈和硫酸的混合溶液为流动相,梯度淋洗,阳离子交换分离,直流安培检测,一次进样分离2,6-甲苯二胺(2,6-TDA),2,4-甲苯二胺(2,4-TDA)、苯胺、邻甲苯胺、对氯苯胺、4,4‘-二氯基二苯甲烷(4,4‘-DADPM)、间硝基苯胺、甲萘胺等9种苯胺类化合物。方法对2,6-TDA、2,4-TDA、苯胺、邻甲苯胺、联苯胺、对氯苯胺、4、4‘-DADPM、间硝基苯胺、甲奈胺的检测限分别为3.46、7.25、4.99、7.43、21.21、16.3、2.60、201.47和22.60μg/L。 相似文献
3.
利用微波加热技术,在密闭容器内通过压力浸提、消解试样、能大大加快分析速度,本实验测定了不同煤样中的腐植酸总量,讨论了功率、时间、酸度等因素对分析结果的影响,并与标准方法相对照,用t-检验法及F-检验法检验,没有明显差异,结果令人满意,该法具有省时、省力、经济、不污染环境,宜于批量分析,便于普及推广等优点。 相似文献
4.
用可见分光光度法与等离子体发射光谱法对仙人掌果汁色素及其微量元素的含量进行了测定,仙人掌果汁色素含量达2.1% ̄3.3%,成熟果的果汁色素含量比预成熟果大。在27种被测定的元素中,除As、Be、Cd、Co、Mo、Pb,Sb,Tl等未被检出外,其余Ag,Al,B,Ba,Ca,Cr,Cu,Fe,Mg,Mn,Na,Ni,Se,V,Zn,K,P,S等均有准确测定值。成熟果与预成熟果的果汁微量元素含量无明显 相似文献
5.
肺癌患者头发中的微量元素分析 总被引:1,自引:0,他引:1
许秀娣 《广东微量元素科学》1995,2(2):53-55
分析了30例肺癌患者头发的19种微量元素,即:锌、铁、铜、钙、锰、镍,铬,钼、镉、铅,年纪最小的33岁,最大的89岁,平均年龄53.3岁,其中男22例,女8例,检测结果:肺癌患者头发微量元素锌、锰明显减低,男性肺癌病人发镍、发铬明显增高,提示肺癌的发生与人体内锌、锰的降低和镍、铬的增高有一定关系。 相似文献
6.
目前,全国已形成了国家、省、市、县四级环境监测网络,共有专业、行业监测站4800多个,其中环保系统监测站2200多个,行业监测站2600多个,国控的空气质量监测网站103个,酸雨监测网站113个,水质监测网站135个。同时,还建有噪声监测网、辐射监测网和区域监测网等。到2005年,国控环境监测网络调整为:环境空气监测网站226个,测点数793个;酸雨监测网站239个,测点数472个;水质监测网站197个;监测断面1074个;生态监测网站15个。目前,我国已制定各类国家环境标准410项,覆盖了大气、水质、土壤、噪声、辐射、农药等领域。开展了环境质量监测, 相似文献
7.
在仔细研辉光放电光源工作过程的基础上,在国内首先设计,制成了HGZ-Ⅱ型自动辉光放电光源。该光源除换样品外,实现抽空、进气、对光、预燃、曝光、充气、复位等摄谱全过程的自动控制。有水压、真空度、短路保护措施施和醒铃线路。设计合理,性能良好,操作简便,工作安全,可靠。程控部分的编排包括顺序控制。时序控制和条件控制。由于使用通用执行元、器件,降低了成本,提高了耐用性。为满足表层,逐层分析的需要,还专门设 相似文献
8.
超临界二氧化碳脱附固体吸附剂上卤代烃污染物研究 总被引:6,自引:0,他引:6
本文使用自制超临界流体萃取仪,考查了从活性炭、Chromosorb 102、Chromosorb105、Tenax-TA四种吸附剂上脱附1,2,3-三氯丙烷、1,3二溴丙烷、1,4-二溴丁烷、1,2,4-三氯化苯、间-二溴苯五种组分的性能。证明使用甲醇改性后CO2萃取,比单纯使用CO2萃取的效率高得多,萃取活性炭时,组分的回收率可达50%,萃取另3种吸附剂时,组分的回收率超过80%,这表明利用某些 相似文献
9.
负离子对紫精光还原和电氧化还原性能的影响冯敏辉,刘伟区,梁兆熙(中山大学高分子研究所,广州,510275)关键词紫精化合物,负离子,电氧化还原,光还原,化学还原合成了不同负离子(F-、Cl-、Br-、I-、SCN-、ClO4-)的芳基紫精聚合物,并研... 相似文献
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11.
Martin Proudmore Ji-Feng Ding Richard H. Mobbs Stephen G. Yeates Colin Price Colin Booth 《Journal of polymer science. Part A, Polymer chemistry》1995,33(10):1615-1625
Poly(hexafluoropropylene oxide), poly(HFPO), networks were prepared from functional polymers by end linking via urethane groups. The prepolymers were characterized by NMR spectroscopy and GPC. The networks were characterized by determination of the number of network chains from the shear modulus, and were snown to contain both trifunctional crosslinks and difunctional links. The properties of the networks were investigated by a range of techniques. Compared with fully-fluorinated networks formed via triazine cross-links, investigated previously, the urethane-linked networks were more readily prepared but were poorer elastomers, were less thermally stable, and were less resistant to swelling by common polar solvents. © 1995 John Wiley & Sons, Inc. 相似文献
12.
对烘烤前后南瓜籽中的化学成分进行分析并对比。采用同时蒸馏萃取装置萃取南瓜籽中的挥发性成分,采取超临界CO2萃取技术萃取南瓜籽油脂,并将其分为酸、碱、中性三个部分,用气相色谱-质谱联用方法分析其中化学成分并进行对比。结果表明,南瓜籽挥发性成分中含有多种醛类和酯类化合物,烘烤后产生了大量的烷基吡嗪,其在碱性部分中的相对含量比烘烤前提高14倍多,不饱和醛类化合物含量也有明显提高。南瓜籽油脂中的主要化学成分是油酸、亚油酸及其酯类。还含有生物活性功能成分如植物甾醇、角鲨烯和维生素E等。烘烤后除角鲨烯含量有所降低,维生素E、植物甾醇、亚麻酸等均有提高。 相似文献
13.
A series of binary and ternary rare earth complexes with para-substitued benzoic acids and 1,10-phenanthroline were synthesized. The phosphorescence spectra were measured and the lowest triplet state energies of ligands were determined, the phosphorescence lifetimes were obtained and intramolecular energy transfer mechanism between ligands was studied. The luminescence properties were also measured and were in agreement with the prediction. The energy match and intramolecular energy transfer process in these binary and ternary complexes were discussed in detail. 相似文献
14.
云南菊科中草药中铅含量特征分析 总被引:3,自引:2,他引:1
论述了云南27种菊科中草药及其水提取物中铅含量的特征。菊科植物及水提物中铅含量的频数分布为正偏态,两者的相关系数r=0.09,未呈现显著的线性相关。提取率较高的山紫苑、佩兰、木香铅实际含量低;铅含量高的叶下花、狭叶兔耳风、臭灵丹提取率又较低,减少了人体对Pb的过量摄入。 相似文献
15.
以过氧化二苯甲酰为引发剂,使丙烯睛在涤沦(PET)纤维上接枝共聚。接枝纤维在含铜化合物,含硫还原剂溶液中反应,制备PET导电纤维。讨论了影响接枝共聚的各种因素,选择出最佳聚合条件。对该纤维的导电成份和结构以及性能进行了研究。 相似文献
16.
Tomoki Komiyama Yoko Harada Takayuki Hase Sota Mori Dr. Shinya Kimura Dr. Masashi Yokoya Prof. Dr. Masamichi Yamanaka 《化学:亚洲杂志》2021,16(13):1750-1755
Urea derivatives that were substituted with a 2-benzylphenyl group and an alkyl group functioned as low molecular weight gelators for various organic solvents and ionic liquids. Urea derivatives with long alkyl chains were effective for the gelation of polar solvents. However, they were not suitable for the gelation of non-polar solvents, whereas urea derivatives with short alkyl chains were effective. Ionic liquids were similar to polar solvents in that urea derivatives with long alkyl chains were the most effective gelators. The physical properties of the formed supramolecular gels were analyzed by dynamic viscoelasticity measurements using a rheometer. 相似文献
17.
碳苷研究 V: 用Grignard试剂合成取代苯酚中酚羟基的保护及脱保护 总被引:1,自引:0,他引:1
本文报道了一些取代苯酚的合成, 并探讨了用Grignard试剂合成取代苯酚中酚羟基的保护及脱保护的问题. 利用苄基和甲基作为酚羟基的保护基, 对文献报道的切断醚键脱保护方法进行了评价. 找到了两种新体系能在更温和条件下切断醚键的方法, 指出了它们的适用条件. 实验结果符合硬软酸碱理论. 相似文献
18.
采用溶胶-凝胶法制备了多孔氧化铝膜, 并通过DSC、TGA、SEM、N~2吸附和气体透过率测定等手段, 对膜的性能进行了表征。结果表明, 用这种方法制备的多孔氧化铝膜是一种均匀无裂痕和具有较窄孔径分布(约4nm)的膜材料。将此多孔氧化铝膜制成膜反应器后, 用于甲醇催化脱氢制甲醛的反应, 发现甲醇转化率比常规反应器有较大幅度的提高。同时首次尝试采用溶胶-凝胶法将催化活性组分直接负载到多孔氧化铝膜上, 从而得到了一种具有催化活性的多孔膜, 并考察了它的反应活性。文中对由这两种多孔膜及钯/陶瓷复合膜制成的反应器的特点进行了比较。 相似文献
19.
M. Alcolea Palafox G. Tardajos A. Guerrero-Martínez V.K. Rastogi D. Mishra S.P. Ojha W. Kiefer 《Chemical physics》2007,340(1-3):17-31
FT-IR and FT-Raman spectra of the biomolecule 5-aminouracil were recorded in the regions 400–4000 cm−1 and 10–3500 cm−1, respectively. The observed vibrational wavenumbers were analyzed and assigned to different normal modes of vibration of the molecule. Density functional calculations were performed to support wavenumber assignments of the observed bands. A comparison with the molecule of uracil was made, and specific scale factors were employed in the predicted wavenumbers of 5-aminouracil. With the purpose of study the important molecule 5-aminouracil, its equilibrium geometry and harmonic wavenumbers were calculated for the first time by the B3LYP DFT method. The vibrational wavenumbers were compared with IR and Raman experimental data. Also good reproduction of the experimental wavenumbers is obtained and the % error is very small. All the tautomeric forms of 5-aminouracil were determined and optimized. The dimer forms were also simulated. The energy, atomic charges and dipole moments were discussed and several general conclusions were underlined. 相似文献