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971.
In this work, solid-phase microextraction coupled with gas chromatography–mass spectrometry was developed to determine trace levels of nitrobenzene compounds in water and soil samples. Graphene was chosen as the extraction material and its composite was coated on a stainless steel wire through sol–gel technique for the solid phase microextraction. The key parameters influencing the extraction efficiency were optimized. Under the optimal conditions, the linearity for the compounds was observed in the range of 0.02–15.0 mg/L for water samples, and 0.2–60.0 mg/kg for soil samples, with the correlation coefficients(r) of 0.9966–0.9987. The limits of detection of the method were 0.0025–0.005 mg/L for water samples, and 0.02–0.04 mg/kg for soil samples. The recoveries for the spiked samples were in the range of 72.0%–113.2%, and the precision, expressed as the relative standard deviations, was less than 12.1%. 相似文献
972.
聚合物电致发光材料成型加工简便、可大面积生产,可应用于大面积平板显示及固体照明器件。与红、绿光聚合物发光材料相比,蓝光聚合物电致发光材料在发光性能、材料寿命等方面仍然存在较大差距,这成为全色显示的瓶颈。通过在聚合物主链上引入大体积的取代基或侧链、形成具有三维空间共轭效应的支化结构或能量可转移的主客体结构等,来改善溶解性和光物理性能等,从而得到发光效率高、色纯度好、热力学性能优异且材料加工性能良好的蓝光聚合物电致发光材料。本文从材料设计的角度简要介绍了国内外蓝光聚合物发光材料的主要研究进展。 相似文献
973.
To exploit an effective adsorbent to separate hydrogen and methane, microporous titanium silicate molecular sieve NaETS-4 was synthesized and modified by strontium. The adsorption characteristics and diffusion behaviors of the prepared titanosilicate molecular sieve were studied by concentration pulse chromatography. And the effects of ion-exchange and dehydration temperature on adsorbent structure and gas diffusion were also discussed. The results showed that the thermal stability and Henry's Law constants were enhanced and micropore diffusivity decreased after exchanging Na+ with Sr2+. With the increase of dehydration temperature, Henry's Law constant and micropore diffusivity of CI-I4 decreased in both NaETS-4 and SrETS-4. While for 1-12 in SrETS-4, the increase of Henry's Law constant and the decrease of diffusion rate can be attributed to the shrinks of pore diameter resulting from the relocation of Sr2+. Correspondingly, the kinetic selectivity of H2/CH4 reached 8.91 indicating its potentiality in separating H2 and CH4. 相似文献
974.
黄油中8种类固醇激素的液相色谱/串联质谱检测 总被引:1,自引:0,他引:1
建立了黄油中雌酮、α-雌二醇、β-雌二醇、雌三醇、睾酮、表睾酮、孕酮和丙酸睾酮8种类固醇激素的凝胶渗透色谱(GPC)-液相色谱/串联质谱(LC-MS/MS)检测方法。样品用乙酸乙酯-环己烷(1∶1,V/V)提取,提取液经GPC柱净化除脂,GPC浓缩液采用C18色谱柱(100 mm×2.0 mm i.d.,3.0μm)分离,以乙腈和水为流动相进行梯度洗脱,电喷雾电离多反应监测模式进行定性和定量分析。8种类固醇激素以基质匹配外标法定量,药物在1.0~20.0μg/kg线性范围内相关系数(r)均大于0.999;方法检出限(S/N=3)为0.04~0.30μg/kg,定量限LOQs(S/N=10)为1.0μg/kg;添加水平为1.0,2.0,4.0μg/kg时,回收率范围在64.1%~110%之间;相对标准偏差(RSD)小于11%。结果表明,本方法准确、可靠,满足黄油中8种类固醇激素的检测分析要求。 相似文献
975.
A new mixed-valence cyanide-bridged complex, Br3Fe(μ-NC)RuBr(dppm)2(dppm = bis(diphenylphosphino)methane), was obtained through the reaction between trans-(dppm)2ClRuCN and FeBr3. Its crystal structure was characterized. Electronic absorption spectra indicate the existence of metal-to-metal charge transfer(MMCT) and this complex is Class Ⅱ mixed valence complexes according to the classification of Robin and Day. Magnetic analysis shows it is paramagnetic. 相似文献
976.
A new mixed-valence heterometal cluster Mo8VW2VIO26(C5H5N)8·2H2O has been synthesized under solvothermal conditions and characterized by X-ray single-crystal diffraction, IR, UV-vis and XPS spectroscopy. The title compound crystallizes in the triclinic system, space group P1 with a = 11.708(3), b = 12.018(4), c = 13.316(4) , a = 112.184(4), β = 97.844(4), r = 110.043(3)o, V = 1551.9(8) 3 and Z = 1 at 293(2) K. The final full-matrix least-squares refinement converged to R = 0.0414 for 4460 observed unique reflections with I 2σ(I) and w R = 0.1290 for all data(5352) and S = 1.015. In addition, its thermal stability and fluorescent property have also been investigated. 相似文献
977.
Haihua Xiao Pingliang Li Jinhui Hu Ruixia Li Limin Wu Dongcai Guo 《Applied biochemistry and biotechnology》2014,172(4):2188-2196
The reaction of 5,5′-(pyridine-2,6-diyl)bis(4-amino-3-mercapto-1,2,4-triazole) with various aromatic aldehydes in acetic acid yielded the corresponding 5,5′-(pyridine-2,6-diyl)bis(4-arylideneamino-3-mercapto-1,2,4-triazole) derivatives. The structures of the synthesized compounds as well as their intermediates were confirmed by elemental analysis, infrared spectra, 1H NMR spectra and mass spectra studies. All the synthesized title compounds were screened for their antibacterial activities, and the preliminary results revealed that some of them showed good activities against Escherichia coli and Pseudomonas aeruginosa. 相似文献
978.
Bo Xiao Xiaoyan Chi Li Zhang Huige Qu Yujing Liu Xiaojie Wang Juhua Zhou 《Applied biochemistry and biotechnology》2014,173(8):2129-2139
Efficient expression of target protein is one of strategies for gene therapy or vaccine design. Many studies showed that codon optimization could enhance the expression of target proteins. In this paper, a target sequence of about 1.26 kb encoding the major capsid protein VP6 of grass carp reovirus (GCRV) and an optimized counterpart were synthesized and inserted into vectors for expressing VP6. The final constructs (named as pcDV6G and pcDV6YG) were transfected in Ctenopharyngodon idellus kidney (CIK) cells. The fluorescence analysis and the Western blot results showed that the gene fragment was transfected and expressed in CIK cells successfully. Although the qRT-PCR results showed no difference at the messenger RNA (mRNA) levels between the different versions of vp6 in the indicated stages, the enzyme-linked immunosorbent assay (ELISA) results showed that the protein level of VP6 expressed by pcDV6YG was higher than that by pcDV6G in the indicated hours. Taken together, these results suggest that the enhanced expression of GCRV VP6 in CIK cells by relative sequence optimization may be a good choice for making DNA vaccine against GCRV. 相似文献
979.
Xiubing Li Junjie Xiao Xi Wang Chunwang Yi Shengpei Su 《Colloid and polymer science》2014,292(12):3243-3249
The pH-responsive inclusion complexation of comblike triblock polymer, P2VP-b-PPEOMA-b-P2VP, with α-cyclodextrin (α-CD) was studied. The triblock polymer was prepared by reversible addition–fragmentation chain transfer polymerization (RAFT) and formed inclusion complexes (ICs) after selective threading of the PEO segment of the triblock polymer through the cavities of α-CD units. For comparison, PPEOMA homopolymer was prepared, and the inclusion complexation with α-CD was also studied. The formed ICs were characterized by XRD and 1H NMR. The results revealed that P2VP-b-PPEOMA-b-P2VP can form ICs with α-CD even when forming micelles, and the introduction of P2VP had a great influence on the solution property and the stoichiometry of EO to CD of the inclusion complexes depending on the concentration and the pH of the solution. 相似文献
980.