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1.
高原  张茂根  王昉  王炳祥  沈健 《应用化学》2005,22(10):1096-1099
PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性  相似文献   

2.
The effect of transition metals (Cr, Mn, Fe, Co and Ni) on the hydrogenation of cinnamaldehyde over Pt/ZrO2 catalysts was studied in ethanol at 343K under 2.0MPa H2 pressure. PtCo/ZrO2 and PtFe/ZrO2 catalysts exhibit high selectivity and activity of hydrogenation for C=O (93.8% at 87.3% conversion and 83.6% at 88.6% conversion, respectively), and PtNi/ZrO2 exhibits high selectivity of hydrogenation for C=C (64.3% at 70.6% conversion). In the presence of trace H2O and NaOH, over the PtNi/ZrO2 (0.4wt%Ni) catalyst the selectivity to hydrocinnamalde hydereaches 90.6% and the conversion of cinnamaldehyde is 90.5%.  相似文献   

3.
 This paper describes the development of guidance for the equipment qualification (EQ) of analytical instruments. EQ is a formal process that provides documented evidence that an instrument is fit for its intended purpose and kept in a state of maintenance and calibration consistent with its use.  相似文献   

4.

The reaction of the title ylide {PhCOCHP(p-tolyl)3} with Pd(II), Pt(II). Hg(II), and Ag(I) in equimolar ratios using CH3CN, CH3OH, and CH2Cl2 as solvents have yielded [{(p-tolyl)3PCHCOC6H5} PdCl2]2 (I), [{(p-tolyl)3 PCHCOC6H5} PtCl2]2(2), [Hg(NO3)2 {(p-tolyl)3 PCHCOC6H5}](3), and [Ag{(p-tolyl)3 PCHCOC6H5 < eqid1 > 2]+ (4). The IR, 1H 13C, and 31P NMR together with micro analysis data of the products were obtained.  相似文献   

5.
The multiple melting behavior of poly(1,3-propylene terephthalate) (PPT) samples after isothermal crystallization from the melt was studied. The step-scan temperature-modulated differential scanning calorimetry (TMDSC) and high rate DSC were used to investigate this behavior in conjunction with standard DSC, wide-angle X-ray diffraction (WAXD) and polarizing light microscopy (PLM). The effect of PPT average molecular weight on the melting was also examined. In general multiple endotherms after isothermal crystallization of PPT were attributed to a continuous crystal perfection process during the subsequent heating scan via melting-recrystallization-remelting. Multiple melting behavior was more pronounced for the low molecular weight PPT. Step-scan TMDSC showed that extensive recrystallization occurs in PPT samples, especially after rapid isothermal crystallization. In fact two recrystallization exothermic peaks were observed. High rate DSC revealed the initial morphology generated during the isothermal step and showed that the low and middle peaks are associated with melting of primary crystals while the high temperature peak should be attributed to melting of recrystallized material.  相似文献   

6.
Diblock copolymerizations of L - or D,L -lactide (LA) with trimethylene carbonate (TMC) or 2,2-dimethyltrimethylene carbonate (2,2-DTMC) with SmMe(C5Me5)2-(tetrahydrofuran) as an initiator and triblock copolymerizations of L - or D,L -LA/cyclic carbonates/L - or D,L -LA with [Sm(C5Me5)2]2(PhCCCCPh) as an initiator generated the desired block copolymers. This article describes the comparison of biodegradabilities by proteinase K and a compost and mechanical properties between the resulting di- or triblock copolymers and random copolymers composed of L - or D,L -LA and cyclic carbonates. The scanning electron microscopic profiles of resulting polymers were measured to understand the morphological change during biodegradation. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3572–3588, 2003  相似文献   

7.
8.
Metal organic frameworks (MOFs) have attracted extensive attention in electrochemical research fields due to their high surface area and controlled porosity. Current study is design to investigate the ECL performance of the chemically modified electrode (CME) based on the bio-MOF-1, a porous zinc-adenine framework, which loaded ruthenium complex and employed for the detection of dopamine (DA). The composite material [Ru(bpy)3]2+@bio-MOF-1 (Ru-bMOF) modified carbon glassy electrode (Ru-bMOF/GCE) exhibited an excellent ECL performance having a linear co-efficient response (R2=0.9968) for 2-(dibutyl amino) ethanol (DBAE), a classical ECL co-reactant was obtained over a concentration range of 1.0×10−9 M to 1.0×10−4 M in 0.10 M pH=6.0 phosphate buffer solution (PBS). Furthermore, DA was detected based on its inhibition effect on [Ru(bpy)3]2+/DBAE system. Compared to traditional analytical methods, this method has various advantages such as simple electrode preparation, quick response, high reproducibility (RSD<2.0 %), low limit of detection (LOD=1.0×10−10 mol/L). This chemical investigated modified electrode had exploited potential for detection of DA.  相似文献   

9.
Li Hua CHEN 《中国化学快报》2006,17(12):1619-1622
Recently, surface plasmon resonance (SPR) become more and more popular without the need of the label technology1-3. However, sometimes, a number of experimental artifacts complicate the final biosensor analysis4-7. The utilization of a reference surface c…  相似文献   

10.
With the accomplishment of Human Genome Project (HGP), single nucleotide polymorphism (SNP) and mutation detection in human genome are becom-ing a new researching focus. These researches can help us to understand the phenotype diversity of indi-vidual, disease susceptibility and drug resistance of different colonies. Traditional method used for muta-tion detection is slab gel electrophoresis, which re-mains labor-intensive and time-consuming because of the requirement of radioactivity or te…  相似文献   

11.
Electrochemical sensing of carcinoembryonic antigen(CEA)on a gold electrode modified by the se- quential incorporation of the mediator,thionine(Thi),and gold nanoparticles(nano-Au),through co- valent linkage and electrostatic interactions onto a self-assembled monolayer configuration is de- scribed in this paper.The enzyme,horseradish peroxidase(HRP),was employed to block the possible remaining active sites of the nano-Au monolayer,avoid the non-specific adsorption,instead of bovine serum albumin(BSA),and amplify the response of the antigen-antibody reaction.Electrochemical ex- periments indicated highly efficient electron transfer by the imbedded Thi mediator and adsorbed nano-Au.The HRP kept its activity after immobilization,and the studied electrode showed sensitive response to CEA and high stability during a long period of storage.The working range for the system was 2.5 to 80.0 ng/mL with a detection limit of 0.90 ng/mL.The model membrane system in this work is a potential biosensor for mimicking the other immunosensor and enzyme sensor.  相似文献   

12.
Cu以其优异的导电性、导热性和易加工性广泛用于工农业生产中.自然Cu的腐蚀和防腐成为人们很关注的问题.人们已经注意到,Cl-对Cu的腐蚀有影响,并进行过一些研究.但目前使用光电化学方法研究这一问题的文章尚不多见,特别是利用测量开路光电压及其瞬态波形这一现场的、无损的、灵敏的监测方法研究户对Cu电极腐蚀全过程的文章尚未见到.本文正是利用如上方法及XPS,AES方法,研究了Cl-对Cu电极腐蚀的全过程,取得了一些有意义的结果.1实验方法Cu电极用99.99%(质量分数)的Cu制成,面积约为39mm2;电极底部由Cu导线焊接引出,…  相似文献   

13.
The semiempirical zero-differential-overlap molecular orbital model which was shown in earlier papers in this series to give a good account of the charge transfer and -* spectra of Fe(II) complexes with conjugated ligands such as 2,2-bipyridyl and 1,10-phenanthroline is extended to complexes having openshell ground states, such as those of Fe(III), and to complexes of Ru(II) and Ru(III). The results are used to assign the observed charge transfer and intra-ligand absorption bands to specific orbital transitions. Observed and calculated intensities are in good agreement: reasons are advanced for the much lower intensity of the charge transfer bands in Ru(III) compared to Ru(II) complexes.  相似文献   

14.
A voltammetric method based on a combination of incorporated Nafion, single-walled carbon nanotubes and poly(3-methylthiophene) film-modified glassy carbon electrode (NF/SWCNT/PMT/GCE) has been successfully developed for selective determination of dopamine (DA) in the ternary mixture of dopamine, ascorbic acid (AA) and uric acid (UA) in 0.1M phosphate buffer solution (PBS) pH 4. It was shown that to detect DA from binary DA-AA mixture, the use of NF/PMT/GCE was sufficient, but to detect DA from ternary DA-AA-UA mixture NF/SWCNT/PMT/GCE was required. The later modified electrode exhibits superior electrocatalytic activity towards AA, DA and UA thanks to synergic effect of NF/SWCNT (combining unique properties of SWCNT such as high specific surface area, electrocatalytic and adsorptive properties, with the cation selectivity of NF). On the surface of NF/SWCNT/PMT/GCE AA, DA, UA were oxidized respectively at distinguishable potentials of 0.15, 0.37 and 0.53 V (vs. Ag/AgCl), to form well-defined and sharp peaks, making possible simultaneous determination of each compound. Also, it has several advantages, such as simple preparation method, high sensitivity, low detection limit and excellent reproducibility. Thus, the proposed NF/SWCNT/PMT/GCE could be advantageously employed for the determination of DA in real pharmaceutical formulations.  相似文献   

15.
建立了同时分离测定异丙醇胺(IPA)、三异丙醇胺(TIPA)、N-甲基二乙醇胺(MDEA)、N,N-二甲基二乙醇胺(DMAE)和6种阳离子的离子色谱法。色谱柱为TSKgelSuperIC-CR阳离子交换柱,流动相为冠醚(2.0mmol/L)、甲基磺酸(2.2mmol/L)、L-组氨酸(0.5mmol/L)混合溶液,流速为0.5mL/min,抑制电导检测。DMAE、MDEA、TIPA、IPA的检出限分别为0.48、36.9、47.04和1.39μg/L;样品中DMAE、MDEA、TIPA、IPA平均回收率为103.15%,95.48%,97.64%,92.41%。方法具有简单、快速、灵敏、抗干扰等优点,用于测定脱硫液中的DMAE、MDEA、TIPA和IPA,结果令人满意。  相似文献   

16.
The use of injectable materials is a simple approach for drug delivery and tissue repair, in, e.g. minimally invasive surgery applications. If these materials are used past their glass transition temperature and have a low viscosity, they will be able to flow while delivered in situ. Whether these materials are to be used as low viscosity drug carriers or further crosslinked for tissue repair, there is a need for a better understanding of their handling properties. In this study, oligo(trimethylene carbonate) (oTMC) and oligo[D,L‐lactide‐co‐(ε‐caprolactone)] (oDLLA‐co‐CL) of various molecular weights within a relevant injectability range were synthesized via ring‐opening polymerization. The materials were comparatively characterized by 1H NMR spectroscopy, differential scanning calorimetry, gel permeation chromatography, and rheological measurements. After comparing the viscosities and molecular weights of the materials, it was concluded that oDLLA‐co‐CLs were, generally, better suited as an injectable in situ crosslinking network, whereas oTMCs were found to be better candidates as injectable drug carriers. This study provides useful data and guidelines on the use of these and other similar oligomers intended for injectable implants. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

17.
本文研究了HA—2型大孔吸附剂用于血液灌流治疗流行性出血热并发急性肾衰,观察其血液相容性及疗效。  相似文献   

18.
Methyl methacrylate (MMA), acrylic acid (AAc), and vinyl acetate (VAc) were graft copolymerized onto Himachali wool in an aqueous medium by using vanadium oxyacetyl acetonate as initiator. Graft copolymerization was studied at 45, 55, 65, and 75°C for various reaction periods. The percentage of grafting was determined as functions of concentration of monomers, concentration of initiator, time, and temperature. The maximum percentage of grafting with each monomer occurred at 55°. Several grafting experiments were carried out in the presence of various additives which include HNO3, DMSO, and pyridine. Nitric acid was found to promote grafting of MMA. All these additives had adverse effects on grafting of VAc and AAc. MMA, VAc, and AAc were found to differ in reactivity toward grafting and followed the order MMA > AAc > VAc.  相似文献   

19.
20.
庚醛与顺丁烯二酸二乙酯进行游离基加成反应得到庚酰丁二酸二乙酯(3),3脱羧得到γ-酮酸乙酯(4),4在碱性条件下环化为2-戊基-1,3-环戊二酮(5),5与重氮甲烷反应得到2-戊基-3-甲氧基环戊-2-烯酮(6),6与丙二酸二甲酯反应得到(7),7水解、脱羧和酯化得到[2-戊基-3-酮-1-环戊烯]基乙酸甲酯(8),8氢化得到二氢茉莉酮酸甲酯。  相似文献   

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