Search Results

You are looking at 1 - 10 of 11 items for

  • Author or Editor: Xiang Zhang x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

SnO2 catalysts were prepared with the precipitation method by varying the pH and SnCl4 concentration. For comparison, another two SnO2 samples were also synthesized with sol–gel and combustion methods. All of the catalysts were characterized by N2-BET, XRD and H2-TPR. It was found that the CO oxidation activity of the precipitation samples increases with an increase in pH, while the CH4 oxidation activity seems unchanged. The change of the SnCl4 concentration has little influence on the activity for both CO and CH4 oxidation. The sol–gel sample has relatively higher CO but similar CH4 oxidation activity, due to its higher surface area and finer particle sizes. On the contrary, the combustion sample displays the lowest activity for both reactions, due to its extra low surface area and inert oxygen species.

Restricted access

Abstract  

The thermal curves and the enthalpy changes of the interaction between some oral sustained release preparations (Contac, Fenbid and Benza sustained release capsules) and physiological saline have been measured at 298.15 K with a MS-80 standard Calvet microcalorimeter. The curves that recorded the changes of heat effect with time have clearly shown the sustained release action and process of the above preparations. A method for examining the sustained release action of sustained release preparations can be developed from the above experiments. The principle of application and the experimental procedure of this method have been expounded, and some results of the above experiments have also been discussed.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: Li Wenxin, Yin Xinmin, Zhang Xiang, Sun Tongyu, Qing Zhi, Shizuko Ambe, Yoshitaka Ohkubo, and Fumitoshi Ambe

Abstract  

Target residues from the interaction of copper with 40MeV/nucleon 40Ar ions have been studied using thick-target, thick-catcher recoil techniques. Cross sections and average forward ranges were measured for 42 products. The data were used to obtain the mass yield distribution, the linear momentum transfer, and the excitation energy of composite systems. Comparison to similar studies for the interaction of copper with 12C ions at the same projectile energy per nucleon shows that the linear momentum transfer in central collisions depends strongly on the projectile mass.

Restricted access

Abstract  

The power-time curves of the growth of three strains of petroleum bacteria at different temperatures have been determined. A novel equation of a power-time curve has been proposed in this paper. The general formula to calculate the rate constant of the bacterial growth has been derived. The rate constants of the bacterial growth at different temperatures, the heat production per newly formed bacterium, the bacterial number at the end of the bacterial growth and the deceleration rate constant of the bacterial growth at 50.00°C, have been calculated. The optimum growth temperatures of the three strains have been obtained.

Restricted access

Abstract  

Fenton’s reagent was employed to synthesize glyoxalic acid from glyoxal. The reaction conditions were optimized in a semi-batch reactor. The mechanism and kinetics of the reaction were proposed.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: Xinmin Yin, Jinzhou Du, Xiang Zhang, Xiangke Wang, Xongxing Dai, Tongyu Sun, and Zuyi Tao

Abstract  

UO2 (NO3)2 was irradiated with a 25 MeV/nucleon40Ar ion beam. The target material irradiated was dissolved in ethyl ether, and the uranyl was removed from the back extractant 5M HNO3 saturated with NH4NO3 by means of solvent extraction with TBP in CCl4. A carrier-free multitracer solution containing 47 elements from Na to Bi and 83 radionuclides was prepared and has been applied to adsorption studies on alumina and soils.

Restricted access

Abstract

The eutectic ternary phase diagrams of some typical volatilizable energetic materials have been investigated by high pressure differential scanning calorimeter (PDSC). The ternary HX phase diagrams for TNT/TNAZ/DNTF (TTD) and TNAZ/DNTF/RDX (TDR) systems were constructed by the correlation of the apparent fusion heat with the composition (HX method). And, the ternary TX phase diagrams (the temperature dependence on composition) for the two ternary systems were constructed by calculating from the data of the five TX binary phase diagrams. The eutectic compositions (mol%) of TTD and TDR ternary systems were obtained to be 52.3/27.3/20.4 (HX method), 53.2/25.8/21.0 (TX method) and 54.9/39.6/5.5 (HX method), 55.1/42.2/2.7 (TX method), respectively. The eutectic temperatures of the ternary systems were obtained by PDSC determination and TX method calculation to be 76.5 and 76.7 °C, 47.5 and 50.2 °C, respectively. It is shown that the results obtained by two methods are in agreement and the error in measuring or calculating eutectic compositions and temperatures for the two ternary systems are within allowable ranges of ±3 mol% and ±3 °C, respectively. Moreover, by means of constructing two ternary HX phase diagrams with different fixed composition of a component and comparing the apparent fusion heat of eutectics with calculated one, the results obtained from HX method for TTD system were proved. The results showed that the gasification or volatilization of easy volatile materials could be efficiently restrained by high pressure atmosphere, and the perfectly and ideally HX ternary phase diagrams can be constructed. In comparison with TX method, HX method has as a virtue of being quick and simple, especially on constructing ternary phase diagram.

Restricted access

The forward and reverse cDNA subtractive libraries before and after the toxic effect of α-amanitin were constructed by suppression subtractive hybridization and randomly selected clones from each subtractive library were screened by PCR and dot blot hybridization. A total of 85 genes with altered expression were finally identified, with 41 genes from the forward library and 44 from the reverse library. Subsequently, the antagonistic effects of candidate traditional Chinese medicines were evaluated based on the genetic transcription levels of the genes with significant altered expression, including Catnβ, Flt3-L, IL-7r and Rpo2-4. The results indicated that Silybum marianum (L.) Gaert and Ganoderma lucidum had significant down-regulated effects on the transcription level of Catnβ that was up-regulated by α-amanitin, and the two herbs also up-regulated the transcription levels of Flt3-L and Rpo2-4. Silybum marianum (L.) had significant up-regulated effects on the IL-7r that was down-regulated by α-amanitin. These preliminary studies suggested that Silybum marianum (L.) and Ganoderma lucidum were effective antagonists against the toxicity of α-amanitin.

Restricted access

Fusarium head blight (FHB), mainly caused by Fusarium graminearum , is a very serious disease in wheat and barley production area. FHB epidemics cause yield decreases and production of mycotoxin that renders the grain useless for flour and malt products. Understanding the infection mechanism of F. graminearum plays an important role for the disease control. In present study, green fluorescence protein (GFP)-tagged were infected to wheat and barley varieties by single floret injection and screened via GFP signal. Results showed similar infection pattern of F. graminearum on both wheat and barley. Pathogen geminated in the inoculated spikelets, grew on the top of ovary or between lemma and palea, and extended towards and through rachis to the adjacent spikelets to infect the whole spike. When a spike of cultivar with FHB resistance was inoculated by F. graminearum , only the injected spikelet showed symptom at 6 days past inoculation (dpi). GFP signals indicated that F. graminearum colonized only in the inoculated spikelet and stop at the compact tissue of rachilla at 6 dpi. On the contrary, the diseased spikelets were up to 5 at 6 dpi in the spike of cultivars susceptible to FHB. F. graminearum extended through compact tissue to rachis and infected to the adjacent spikelets by spreading upward and downward to adjacent florets inter- and intra-cellularly in vascular bundles and cortical tissue of the rachis.

Restricted access