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231.
Zheng-Zhong Lin Rui-hu Wang Lei Han Rong Cao 《Journal of solid state chemistry》2004,177(7):2494-2498
The indium(III)-organic compound [In(HBtc)2(4,4′-bpy)](4,4′-Hbpy)(H2O)0.5 (Btc=1,3,5-benzenetricarboxylate, 4,4′-bpy=4,4′-bipyridine) has been synthesized under hydrothermal condition and characterized by IR, fluorescent spectroscopy, TGA and single-crystal X-ray diffraction analyses. The compound crystallizes in monoclinic, space group P2(1)/c, a=17.0884(2) Å, b=12.28390(10) Å, c=17.9456(4) Å, β=104.1920(10)°, V=3652.03(10) Å3, Z=4, R1=0.0572 and wR2=0.1116 [I>2σ(I)]. All the indium atoms in the compound are hepta-coordinated and link 1,3,5-benzenetricarboxylate forming a 2-D layer structure with rhombus grids. 相似文献
232.
Cao Ning-Jun Xu Qin Chen Chee-Shan Gong C. S. Chen L. F. 《Applied biochemistry and biotechnology》1994,(1):521-530
Cellulose gel with < 10% of crystallinity was prepared by treatment of microcrystalline cellulose, Avicel, with zinc chloride
solution at a ratio of zinc chloride to cellulose from 1.5 to 18 (w/w). The presence of zinc ions in the cellulose gels enhanced
the rate of hydrolysis and glucose yield. The evidence obtained from X-ray diffraction, iodine absorption experiments; and
Nuclear Magnetic Resonance spectra analysis suggested the presence of zinc-cellulose complex after Avicel was treated with
zinc chloride. Zinc-cellulose complex was more susceptible to hydrolysis than amorphous cellulose. Under the experimental
condition, cellulose gels with zinc ions were hyrolyzed to glucose with 95% theoretical yield and a concentration of 14% (w/v)
by cellulases within 20 h. The same gel was hydrolyzed by acid to glucose with 91.5% yield and a concentration of 13.4% (w/v). 相似文献
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Xylan is the major component of hemicellulose, which consists of up to one-third of the lignocellulosic biomass. When the
zinc chloride solution was used as a pretreatment agent to facilitate cellulose hydrolysis, hemicellulose was hydrolyzed during
the pretreatment stage. In this study, xylan was used as a model to study the hydrolysis of hemicellulose in zinc chloride
solution. The degradation of xylose that is released from xylan was reduced by the formation of zinc-xylose complex. The xylose
yield was >90% (w/w) at 70°C. The yield and rate of hydrolysis were a function of temperature and the concentration of zinc
chloride. The ratio of zinc chloride can be decreased from 9 to 1.3 (w/w). At this ratio, 76% of xylose yield was obtained.
When wheat straw was pretreated with a concentrated zinc chloride solution, the hemicellulose hydrolysate contained only xylose
and trace amounts of arabinose and oligosaccharides. With this approach, the hemicellulose hydrolysate can be separated from
cellulose residue, which would be hydrolyzed subsequently to glucose by acid or enzymes to produce glucose. This production
scheme provided a method to produce glucose and xylose in different streams, which can be fermented in separated fermenters. 相似文献
235.
To improve the reproducibility, stability, and sensitivity of bismuth film electrode (BiFE), we studied the performances of a mixed coating of two cation‐exchange polymers, Nafion (NA) and poly(sodium 4‐styrenesulfonate) (PSS), modified glassy carbon BiFE (GC/NA‐PSS/BiFE). The characteristics of GC/NA‐PSS/BiFE were investigated by scanning electron microscopy and cyclic voltammetry. Various parameters were studied in terms of their effect on the anodic stripping voltammetry (ASV) signals. Under optimized conditions, the limits of detection were 71 ng L?1 for Cd(II) and 93 ng L?1 for Pb(II) with a 10 min preconcentration. The results exhibited that GC/NA‐PSS/BiFE can be a reproducible and robust tool for monitor of trace metals by ASV rapidly and environmentally friendly, even in the presence of surface‐active compounds. 相似文献
236.
Herein, we describe the detailed synthesis of Ag/Au core-shell nanoparticles, the surface-functionalization of these particles with thiolated oligonucleotides, and their subsequent use as probes for DNA detection. The Ag/Au core-shell nanoparticles retain the optical properties of the silver core and are easily functionalized with thiolated oligonucleotides due to the presence of the gold shell. As such, the Ag/Au core-shell nanoparticles have optical properties different from their pure gold counterparts and provide another “color” option for target DNA-directed colorimetric detection. Size-matched Ag/Au core-shell and pure gold nanoparticles perform nearly identically in DNA detection and melting experiments, but with distinct optical signatures. Based on this observation, we report the development of a two-color-change method for the detection and simultaneous validation of single-nucleotide polymorphisms in a DNA target using Ag/Au core-shell and pure gold nanoparticle probes. 相似文献
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[reaction: see text] Two readily prepared catalysts have been developed for the hydroamination of alkynes by 1,1-disubstituted hydrazines. The catalyses are facile with terminal alkynes and some internal alkynes. If the hydrazine bears an aryl group, Fischer cyclization can occur in a one-pot procedure. In addition, reactions with acetylene to produce a plethora of hydrazones are described. Catalytic reactions involving acetylene and substituted hydrazines are complete in less than 2 h at room temperature and 1 atm of pressure. 相似文献