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1.
用^13C-^1H异核相关法测定并归属了2,6-二(苯并咪唑-2)吡主其钌配合物「Ru(H2Bzimpy02」^2+的^13C-NMR。由配合物与自由配体的对应碳核的化学位移差值可以分析出配合物中电荷分布的变化情况,进而得到金属离子与配体之间的相互作用微观信息。  相似文献   

2.
采用脉冲辐解动态吸收光谱法研究了Br^-2和Cl^-2自由在诱导氧化N-二异丙基磷酰化甲硫氨酸(NDM)水溶液的过程,结果表明:Br^-2和Cl^-2进攻NDM中的硫原子形成含硫三电子键NDM(S∴X)(X=Br,Cl)它们分别在400nm和390nm处有最大吸收峰,形成和衰变均呈一级反应,测定了不同条件下氧化反应的速率常数,推导了反应机理,并从分子结构观点与甲硫氨酸水溶液的Br^-2.Cl^-2  相似文献   

3.
Ba,Sr,Ca在Co/γ—Al2O3催化剂上CO氧化的作用机制(II)   总被引:2,自引:0,他引:2  
用硝酸盐水溶液等量共浸法制备了分别在750℃和900℃焙烧的系列催化剂Co-M/γ-Al2O3(M=Ca,Sr,Ba,Co3O4/Al2O3=8wt%,M/Co=15mol%)测定了CO氧化转化率,用BET表面,XRD,XPS,DTA和TPR等手段研究了助剂Ba,Sr,Ca的作用,结果表明,加入助剂后,CO完全转化温度下降了20~60℃左右,助剂的作用顺序为Ca>Sr>Ba,实验表明,750℃和9  相似文献   

4.
在HgBa2Ca2Cu3O8+δ(Hg-1223相)超导体中,我们以Pb部分代替Hg,成功地合成了(Hg,Pb)-1223相超导体,并对这些样品进行了XRD、TEM、SEM和EDX等分析。本文着重报导EMPA分析的结果:在我们最佳合成的(Hg,Pb)-1223超导样品中,正离子比为Hg:Pb:Ba:Ca:Cu=0.66:0.344:2:1.98:2.97,氧含量为8.41;以及样品的主相为(Hg,  相似文献   

5.
本文运用AES和XPS分析了不同缓蚀剂对Cu-Sn-P仿金镀层表面进行处理所形成的配合物保护膜的组成,并采用加速腐蚀实验和LSV研究了这些不同保护膜的抗腐蚀能力。结果表明:采用1=苯基-5-巯基四氮唑(PMTA)钝化处理后,不仅增强了镀层耐盐溶液和酸性气体的腐蚀能力,又不影响镀层表面的金黄色外观,其防变色效果优于苯并三氮唑(BTA)、2-巯基苯并噻唑(MBT)和2-氨基嘧啶(2-AP0。PMTA/  相似文献   

6.
此文用从头计算法,在HF,MP2,MP3水平下,使用基组6-31G,6-31+G对SiO的等电子分析SiX^m(X=Be,B,C,N,F,Ne,m=-4~+2)进行了几何优化,并计算了相应的平衡几何构型下的振动频率,对SiO分子,使用QCISD(T)方法考虑了不同水平下的电相关效应,并考虑了不同其函数6-31+G和6-311+G的影响。计算结果表明,所有分子的势能曲线都有稳定的极小值,并且键长与频  相似文献   

7.
YBa2Cu3O7-δ高温超导膜的Raman标定张鹏翔1,2,H.-U.HABERMEIER2,M.Cardona2(1云南工业大学材料科学与工程系昆明云南650051中国)(2Max-Plaud-InstitutfürFestkorperforsc...  相似文献   

8.
对于La0.2Ba0.8-xCax(O,CO3)其中x=0.0、0.2、0.4、0.6氧化物在973K及甲烷氧化偶联(OCM)条件下,无Ca^2+的样品可用表面BaCO3和(LaO)2CO3的Raman谱及810cm^-1附近的O2^2-特征峰来表征;含Ca^2+的样品,则表现了混合碳酸盐(Ca,Ba)CO3的特征,还有位于1135cm^-1(w)和810cm^-1(w)的O2^-、O2^2-瞬时  相似文献   

9.
本文研究并比较了分别以8-羟基喹啉和巯基苯骈噻唑为萃取剂,以活性硅胶为载体的柱式萃取色谱法对环境水中Zn、Cu、Pb、Cd、Fe、Co、Ni和Mn的最佳富集和洗脱条件。  相似文献   

10.
研究具有催化活性的水解酶模型分子:三-(2-苯并咪唑甲基)胺(tris(2-benzimidazylmethyl)amine)简称NTB,与Cu,Co,Zn,三种金属离子配侠形成的配合物的紫外可见吸收光谱和荧光光谱。分析了NTB系列配合物的光说的电子跃迁,计算了不同pH值时的荧光量子产率。  相似文献   

11.
以预处理后的棉纤维为骨架,通过间接醚化法,接枝合成了2-巯基苯半螯合棉纤维(CC-MBM),研究了CC-MBM吸附重金属离子的动力学行为。实验表明,CC-MBM吸附速率快,吸附平衡时间短,吸附量随时间的变化规律遵从Langmuir方程。  相似文献   

12.
纳米纤维素碱法制备及光谱性质   总被引:3,自引:0,他引:3  
在纳米尺寸范围操控纤维素分子,由此创制出具有优异功能的新纳米材料是纤维素科学的前沿领域。纳米纤维素作为一种可再生生物材料已成为国内外研究热点,研究开发新型的简单、绿色、低能耗、快速、高效的纳米纤维素制备方法显得尤为重要。该研究采用简易可行的碱性水解法制备得到粒径较小且分散性较好的纳米纤维素。同时采用了电子显微镜、X射线粉末衍射仪和傅里叶红外光谱仪对所制备纳米纤维素进行了表征,研究了其结构与谱学性质。所制备样品为准球形纳米纤维素,颗粒尺寸约为20~40 nm,样品仍属于纤维素Ⅰ型,结晶度为79.71%,晶粒平均尺寸为3~6 nm。结果表明,碱水解法制备纳米纤维素方法具有简易可行、得率高的优点,研究可为纳米纤维素的高效制备提供一条新途径。  相似文献   

13.
In order to improve iron chelating ability and retain the activity of functional peptide, corn peptide was chelated with iron to form corn ACE inhibitory peptide-ferrous chelate (CP-Fe) treated by dual-frequency ultrasound. Furthermore, the chelating mechanism was revealed by analyzing various structural changes, and the stability was further evaluated. Under this study condition, the iron-binding capacity of corn ACE inhibitory peptide (CP) and chelate yield reached 66.39% and 82.87%, respectively. Ultrasound-treated CP exhibited a high iron chelating ability, meanwhile, chelation reaction had no significant effect on the ACE inhibition activity (82.21%) of the peptide. CP-Fe was formed by binding the peptides amino, carbonyl and carboxyl groups with Fe2+ demonstrated by Ultra-violet spectroscopy, Fourier transform infrared characterization, X-ray diffraction, energy dispersion spectrum, zeta potential, amino acid composition and other multi-angle analyses. Moreover, ultrasound-treated CP-Fe chelate exhibited porous surface and uniform nanoparticle shape. Furthermore, ultrasound-treated CP-Fe chelate exhibited an excellent stability towards various pH (retention rate ≥ 95.47% at pH 6–10), temperatures (retention rate ≥ 85.10% at 25–70 °C), and gastrointestinal digestion (retention rate 79.18%). Overall, ultrasound-treated CP-Fe chelate possessed high iron-chelating ability, ACE inhibition activity and stability. This study provides a novel synthesis method of the iron-chelating corn ACE inhibitory peptide, which is promising to be applied as iron supplements with high efficiency, bioactivity, and stability.  相似文献   

14.
鉴于含硫、氮的鳌合树脂对贵金属Au(Ⅲ)的优良亲和性,以硫代氨基脲为原料,与戊二醛直接交联合成了一种新的螯合树脂,并优化了合成条件.实验结果表明,达到最佳吸附效果的合成条件为:物料摩尔配比n(硫代氨基脲)∶n(戊二醛)为5∶4、pH值为3.3、反应温度为80℃、反应时间为6h,在优化的实验条件下合成的新型螯合树脂对金的...  相似文献   

15.
螯合棉纤维预富集流动注射在线测定痕量铅   总被引:5,自引:0,他引:5  
将自制的性能优越、成本低廉的新型吡咯烷二硫代甲酸铵螯合棉纤维(CC-APDC)作为固相富集材料,经稀硝酸洗脱液的流动注射预富集, 用石墨炉原子吸收光谱测定了痕量铅。流动注射预富集分六步完成。用稀硝酸作洗脱液,完全洗脱需0.15 mL,大大超过石墨管进样体积。实验将洗脱的前40 μL定量弃去,采用定体积取样法,将浓度最高的40 μL洗脱液加入GFAAS中,提高了测定的准确度。另外在石墨炉灰化阶段高记忆效应的消除中,将惯用的停气方式改为小流量(30 mL·min-1,富集1 min)气体原子化,使拖尾现象得到了明显的改善,且空白值低而稳定。考察了实验参数,如酸度,洗脱液浓度,洗脱速度及采样速率等)对分析性能的影响。采用螯合棉纤维作分离富集材料,选择性好,方法灵敏度高,可以在线分离干扰,采样速度50次·h-1。富集倍数15倍,检测下限0.2 μg·L-1,相对标准偏差1.4%(n=10),回收率95%~105%,样品测定结果令人满意。  相似文献   

16.
将漂白化学桉木浆(BCEP)与甲基丙烯酸缩水甘油酯(GMA)的接枝共聚产物(CPGMA)与乙二胺(EDA)反应,合成了多胺型纤维素基螯合纤维CPGMA-EDA。利用傅里叶变换红外光谱(FTIR)、固体核磁共振碳谱(13C CP/MAS NMR)和X射线衍射(XRD)对产物进行了分析。FTIR和13C CP/MAS NMR的研究结果表明,与EDA反应后,CPGMA在904 cm-1波数处的环氧基特征吸收峰基本消失,3 200~3 500 cm-1处的吸收峰因新增N—H伸缩振动而明显增宽,说明大量氨基通过开环反应被接枝到了CPGMA表面;XRD结果表明所得纤维素基螯合纤维的结晶度为48.1%,相对于原漂白化学桉木浆的结晶度下降了31.0%,说明反应不仅发生在纤维素的非结晶区,同时也发生在结晶区。  相似文献   

17.
A bipolar membrane (BPM) of carboxymethyl cellulose (CMC) and chitosan (CS) with superior performance was prepared based on the macromolecules containing metal elements. A carboxymethyl cellulose cation layer was modified by copper phthalocyanine 16-carboxylic acid (CuPc(COOH)16) to improve its ion exchange capacity as well as cation transfer rate and promote water splitting at the intermediate layer. Chitosan was crosslinked with acetyl ferrocene to prepare the anion layer. A casting method was used to prepare the BPM which showed excellent physical and chemical properties after modification. To improve the compatibility of the anion-exchange layer and cation-exchange layer, polyethylene glycol (PEG) was blended with both the CMC and CS. Scanning electron microscopy (SEM) images illustrated a structure that consisted of an anion layer and a cation layer that were closely combined with each other. The swelling results implied a proper hydrophilic performance and good shape stability in an alkali solution ([OH?]≤10 mol·L?1) of the BPM. After modification, the BPM with the metal elements exhibited good thermal stability, as shown by the thermogravimetry (TG) results. Compared with the BPM that was unmodified, both the AC impedance and the working voltage were decreased sharply. Furthermore, the modified BPM exhibited higher ion penetrability which is beneficial for its wide application.  相似文献   

18.
我国生物质能源产业近年来得到快速发展,但对能源草的研究还处于初级阶段,如果能建立全面的能源植物木质素、纤维素、半纤维素的近红外预测模型数据库,将有助于优良品种的筛选、能源植物能用性能的评价及生物质能源产业在线控制。本研究采用傅里叶变换近红外光谱(FT-NIR)技术结合偏最小二乘法(PLSR)建立了荻、南荻、奇岗、芒四种芒属能源植物品质指标(纤维素,半纤维素,木质素和灰分)近红外预测模型,并在此基础上研究了样本粒度对模型的影响。研究结果表明:(1)四种芒属能源植物茎秆中纤维素,半纤维素和木质素含量误差均方根(RMSECV)分别为1.35%(R2=0.88),0.39%(R2=0.91)和0.35%(R2=0.80),叶片中纤维素,半纤维素和木质素含量误差均方根(RMSECV)分别为0.72%(R2=0.88),0.85%(R2=0.85)和0.44 (R2=0.87),所建的纤维素,半纤维素和木质素的近红外校准模型在预测未知样品含量时效果较好,但灰分含量预测效果不理想;(2)2和0.5 mm粒度样品所建近红外模型均满足样品检测精度要求,但考虑到时间和人工成本,建议在工厂对能源植物原料品质进行分析时,采用2 mm样品建模。  相似文献   

19.
Developing biodegradable and biocompatible products to replace non-biodegradable petrochemical products is of great importance for supplementing rapidly diminishing oil resources and reducing environmental pollution. Based on this belief, the goal of this research was to introduce a green/clean procedure to prepare an aerogel using biodegradable cellulose as feedstock and renewable choline butyrate as solvent. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) were used to investigate the morphology, chemical structure and thermostability. The results indicated that the cellulose aerogel possessed a porous structure which was composed of randomly oriented cellulose sheets. The cellulose aerogel had an amorphous structure compared to the original cellulose (cellulose I), and displayed good thermal stability.  相似文献   

20.
Nonoptimal classroom acoustical conditions directly affect speech perception and, thus, learning by students. Moreover, they may lead to voice problems for the instructor, who is forced to raise his/her voice when lecturing to compensate for poor acoustical conditions. The project applied previously developed simplified methods to predict speech intelligibility in occupied classrooms from measurements in unoccupied and occupied university classrooms. The methods were used to predict the speech intelligibility at various positions in 279 University of British Columbia (UBC) classrooms, when 70% occupied, and for four instructor voice levels. Classrooms were classified and rank ordered by acoustical quality, as determined by the room-average speech intelligibility. This information was used by UBC to prioritize classrooms for renovation. Here, the statistical results are reported to illustrate the range of acoustical qualities found at a typical university. Moreover, the variations of quality with relevant classroom acoustical parameters were studied to better understand the results. In particular, the factors leading to the best and worst conditions were studied. It was found that 81% of the 279 classrooms have "good," "very good," or "excellent" acoustical quality with a "typical" (average-male) instructor. However, 50 (18%) of the classrooms had "fair" or "poor" quality, and two had "bad" quality, due to high ventilation-noise levels. Most rooms were "very good" or "excellent" at the front, and "good" or "very good" at the back. Speech quality varied strongly with the instructor voice level. In the worst case considered, with a quiet female instructor, most of the classrooms were "bad" or "poor." Quality also varies with occupancy, with decreased occupancy resulting in decreased quality. The research showed that a new classroom acoustical design and renovation should focus on limiting background noise. They should promote high instructor speech levels at the back of the classrooms. This involves, in part, limiting the amount of sound absorption that is introduced into classrooms to control reverberation. Speech quality is not very sensitive to changes in reverberation, so controlling it for its own sake should not be a design priority.  相似文献   

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