Zicheng Li

Publications (7)8.49 Total impact

• Article: A novel low temperature synthesis technique of sol–gel derived nanocrystalline alumina abrasive

  Zicheng Li, Aiju Zhang, Zhihong Li, Yumei Zhu, Liangjun Liu, Huiqiang Xiang
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  ABSTRACT: The effect of ball milling process, co-doped seed and two step sintering technique on the properties of sol–gel derived alumina abrasive sintered at low temperature was investigated. The results showed that ball milling time with 10h can be effective in enhancing the activity of the precursor and the microstructural uniformity of sintered alumina abrasive. A small amount of Al2O3–(NH4)3AlF6 co-doped seed addition had potential synergistic effects for reducing α-Al2O3 phase transformation temperature and improving the mechanical property of alumina abrasive. A remarkable suppression of grain growth was achieved by controlling sintering temperature with two-step sintering method. Therefore, by using ball milling process, co-doping α-Al2O3–(NH4)3AlF6 seed and two-step sintering technique, the sol–gel derived uniform nanocrystalline alumina abrasive is easily achieved at low temperature. Nanocrystalline alumina abrasive prepared at these conditions exhibited excellent mechanical properties and wear resistance compared to fused corundum abrasive and those sol–gel derived corundum abrasive with conventional sintering methods. KeywordsSynthesis–Alumina abrasive–Ball milling–Co-doped seed–Two step sintering
  Journal of Sol-Gel Science and Technology 05/2012; 57(1):24-30. · 1.63 Impact Factor
• Article: Raw materials selection applied to glass bonding for vitrified CBN grinding wheels

  Aiju Zhang, Zhihong Li, Zicheng Li, Yumei Zhu
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  ABSTRACT: In this article the selection of more appropriate raw materials applied to alumino-borosilicate glass system for vitrified cubic boron nitride (CBN) grinding wheels was investigated. The selection of raw materials had a major effect on the performance of specimens. Mechanical properties of the specimens were measured by using three-point bending strength tester and microstructure characteristics of specimens were examined by scanning electron microscopy (SEM). The results showed that the elements barium and magnesium in the form of carbonate were more beneficial to the refractoriness and fluidity of glass binder than in the form of hydrate and oxide. Moreover, the element barium in the form of carbonate was more favorable to mechanical property of glass binder than that in form of hydroxide. But magnesium carbonate was harmful to improve the mechanical property of glass binder. Therefore, selection of appropriate raw materials used in glass binder was dependent on their natural characteristic.
  Journal of Materials Science 04/2012; 43(12):4303-4308. · 2.02 Impact Factor
• Article: Two-step sintering behavior of sol–gel derived nanocrystalline corundum abrasive with MgO–CaO–SiO2 additions

  Zicheng Li, Zhihong Li, Aiju Zhang, Yumei Zhu
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  ABSTRACT: Nanocrystalline corundum abrasive with mean crystal size of less than 100nm was synthesised by sol–gel process via two-step sintering technique. A remarkable suppression of grain growth was achieved by controlling sintering temperature and taking advantage of sintering aids (MgO–CaO–SiO2) during the final stage of a two-step sintering process. The grain size of the high densification samples (>99% theoretical density) produced by two-step sintering method was about seven times less than that of the samples made by the conventional sintering technique. The microstructure of the samples was homogeneous without abnormal grain growth and the obtained corundum abrasive exhibited excellent abradability compared to conventional sintering methods.
  Journal of Sol-Gel Science and Technology 04/2012; 48(3):283-288. · 1.63 Impact Factor
• Article: Effects of hydrodynamics on the distribution of trace persistent organic pollutants and macrobenthic communities in Bohai Bay.

  Binghui Zheng, Xingru Zhao, Lusan Liu, Zicheng Li, Kun Lei, Lei Zhang, Yanwen Qin, Zhifen Gan, Shizhen Gao, Lixin Jiao
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  ABSTRACT: In recent years, the rapid economic development along Bohai Bay, has brought out continuous increasing of the pollution loads in the Bohai Sea, especially by the large coastal reclamation project, Tianjin Binhai New Area. In the period of 2007-2009, we collected the sediments of the main rivers, estuaries, intertidal zone, and near-shore area of Bohai Bay, and Macrobenthos associated with the marine sediments to assess the influence of hydrodynamics in the coastal environment on the pattern of trace contaminants and the macrobenthic community. Based on data derived from these samples, the levels of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) in sediments followed the order PAHs>OCPs>PCBs>PBDEs. The higher concentrations of PCBs, OCPs, PAHs and PBDEs were found in the estuarine and near-shore environment of the Dagu Drainage River. The spatial distribution of OCPs was different to that of PCBs due to the direction of the velocity field of Bohai Bay in its old and new topography, and the higher water-solubility of OCPs than that of PCBs. The results of the Pearson correlation and the PCA indicate that the medium diameter (MD) of sediments was the predominant factor influencing the distribution of PCBs and OCPs, most sampling sites were characterized mainly by TOC of sediments and biomass of macrobenthos. The results indicate that the distribution of trace contaminants and macrobenthic community in Bohai Bay are mainly affected by the hydrodynamic conditions.
  Chemosphere 06/2011; 84(3):336-41. · 3.21 Impact Factor
• Article: [Dynamic analysis of land use and land coverage in mid-eastern China during 1988-2000].

  Ziqiang Tian, Binghui Zheng, Wenjie Wang, Zicheng Li
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  ABSTRACT: Using remote sensing (RS) and geographic information system (GIS) technologies and based on the documentary and field sampling data, this paper constructed and analyzed the 1988 and 2000 landscape maps of mid-eastern China. The mapping area of mid-eastern China was about 2.87 x 10(6) km2. With the rapid increase of economy and population, the area of farmland and town in mid-eastern China increased 10.921 x 10(5) hm2 and 13.754 x 10(5) hm2, accounted for a 2.14% and 19.25% increase, respectively from 1988 to 2000. At the same time, the forest area decreased 17.83 x 10(4) hm2, declined by 1.12%, because of the increasing demand for lumber provision and reclamation. The meadow area in 2000 increased 19.287 x 10(5) hm2, ascending 7.75%, while the coverage and quality of grassland declined, owing to the deteriorating environment. The untilled land in 2000 dropped 34.31%, contrast with 1988 by the reason of a large number of lands being exploited.
  Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 01/2005; 15(12):2297-303.
• Article: Research on consistency of identifying solitary pulmonary masses with CT

  Qiuping Wang, Gang Niu, Yun Zhang, Yongqian Qiang, Zicheng Li, Youmin Guo
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  ABSTRACT: ObjectiveTo research on consistency of identifying solitary pulmonary masses with CT.MethodsThree observers with different working backgrounds in imaging diagnosis individually interpreted the same group images of solitary pulmonary mass, by 12 indexes of objective signs. The differences in interpretation resulted in ante- and post-interpretations were assessed by the x2 test. The agreement of two interpretations from the same observer was confirmed with the kappa test. A double-blind method was adopted for analysis.ResultsThe agreement rates of ante- and post-interpreting from the three observers were respectively 82.65%(486/588) 80.27%(472/ 588) and 84.86% (499/588) while their interpreting results were generally accordant without significant difference (x2 = 4.975, df = 2, P = 0.083) however there was difference between the observer 2 and observer 3(x2 = 4.875, df = 1, P = 0.027). There were five indexes with k > 0.40 of ante-and post-interpreting results of the three observers, including clarity of nodule borderline, presence of sentus, uniformity of density, existence of cavity and calcification in pathological region, among them, the agreement rate of interpreting borderline and cavity was higher (k > 0.07); the blood vessel convergence poorer (0 < k ≤ 0.40); the other six CT signs of interpretation were slightly different.ConclusionThe ability to identify solitary pulmonary mass was inconsistent, and needs to be improved further.
  Journal of Nanjing Medical University.
• Article: Synthesis and two-step sintering behavior of sol–gel derived nanocrystalline corundum abrasives

  Zicheng Li, Zhihong Li, Aiju Zhang, Yumei Zhu
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  ABSTRACT: Nanocrystalline corundum abrasive with mean crystal size of less than 100 nm was synthesized by two-step sintering method using sol–gel process. A remarkable suppression of grain growth was achieved by controlling sintering temperature and taking advantage of sintering aids during the final stage of a two-step sintering process. The grain size of the high densification samples (>99% theoretical density) produced by two-step sintering method was about 10 times less than the samples made by the conventional sintering technique. The microstructure of the samples was homogeneous without abnormal grain growth and the sol–gel derived corundum abrasive with two-step sintering technique exhibited excellent mechanical properties and wear resistance compared to those sol–gel derived corundum abrasive with conventional sintering methods and fused corundum abrasive.
  Journal of the European Ceramic Society.