Publications (21)18.55 Total impact
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Article: Comprehensive profile of cytogenetics in 2308 Chinese children and adults with de novo acute myeloid leukemia.
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ABSTRACT: Diagnostic cytogenetic and molecular analysis is recognized as the most valuable prognostic factor in acute myeloid leukemia (AML). Among 2516 consecutive Chinese patients with de novo AML, 2308 patients had successful cytogenetic results including 61 subclasses of cytogenetic abnormalities and 27 kinds of additional cytogenetic abnormalities. The incidence of t(15;17)(q22;q12) was highest (16.7% of 2308 patients), followed by t(8;21)(q22;q22) (15.1%), trisomy 8 (5.5%), loss of Y (4.5%), trisomy 21 (2.4%), inv(16)(p13q22) or t(16;16)(p13;q22) (2.1%), etc. In comparison to children, adults had higher incidence of normal karyotype (41.5% vs. 29.1%, P<0.001) and lower incidences of t(8;21)(q22;q22) (13.4% vs. 25.8%, P<0.001), t(9;11)(p22;q23) (0.2% vs. 1.2%, P=0.001) and other 11q23 rearrangements (1.0% vs. 3.4%, P<0.001). Among 349 AML patients with t(8;21)(q22;q22), 310 (35.5%) were found in 873 patients with M2. The t(15;17)(q22;q12) was exclusively observed in 386 (71.0%) of 544 patients with M3. In 48 AML patients with inv(16)(p13q22) or t(16;16)(p13;q22), 42 (15.2%) were detected in 276 patients with M4. Our study displayed the cytogenetic characteristics in a large series of Chinese patients with de novo AML. Our results revealed the similarities and differences of cytogenetic abnormalities existing between Chinese and western AML patients.Blood Cells Molecules and Diseases 06/2012; 49(2):107-13. · 2.35 Impact Factor -
Article: A comprehensive cytogenetic classification of 1466 Chinese patients with de novo acute lymphoblastic leukemia.
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ABSTRACT: Cytogenetics and molecular cytogenetics of 1466 Chinese patients with de novo acute lymphoblastic leukemia (ALL) were studied. Cytogenetic results were available in 1175 patients. Cross-correlations of 23 subclasses of cytogenetic abnormalities were described. Childhood cases had higher incidences of normal karyotype, t(1;19), +8, 12q-, +21, +22 and high hyperdiploidy with 51-65 chromosomes, and lower incidences of t(9;22) and -5/5q- than adult ones (all p<0.05). Relationships of cytogenetic subclasses with immunophenotyping subgroups of ALL were studied. Our study presents the cytogenetic characteristics of a large series of Chinese ALL patients.Leukemia research 01/2012; 36(6):720-6. · 2.36 Impact Factor -
Article: Detection of molecular targets on the surface of CD34+CD38- bone marrow cells in myelodysplastic syndromes.
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ABSTRACT: Myelodysplastic syndrome (MDS) is a kind of clonal stem-cell disorder in which aberration within a hematopoietic stem cell (HSC) gives rise to the entire disease as in acute myeloid leukemia (AML). Studies have showed that contrasting normal stem cells, AML stem cells express CD96 and CD123, but lack of CD90, although both of them reside within the CD34(+)CD38(-) population. So far, little is known about expression of the markers on MDS HSC. In this study, we analyzed the immunophenotypic characteristics of CD34(+)CD38(-) bone marrow (BM) cells by multicolor flow cytometry in 38 patients with MDS and 10 control patients. We found that CD34(+)CD38(-) BM cells coexpressed CD13, CD33, CD117, CD133, and HLA-DR almost in all patients, but in MDS they expressed higher amounts of CD13 (79% +/- 16% vs. 36% +/- 13%, P < 0.05) and CD133 (66% +/- 20% vs. 25% +/- 13%, P < 0.05). CD90 was expressed in all control patients but just in 63% of patients with MDS. No control patients had an expression of CD2, CD5, CD7, CD44, CD96, and CD123, which expressed variable amounts in 17-53% of patients with MDS. The level of CD13 in RCMD (89% +/- 7%), RAEB-1 (88% +/- 11%), and RAEB-2 (81% +/- 13%) were obviously higher than that of RA (63% +/- 16%, P < 0.05). CD2, CD5, and CD7 were more frequently observed in RAEB or INT and HIGH-R cases. Taken together, we demonstrate MDS stem cells display deranged phenotypic abnormalities that may make them particularly difficult to eradicate using therapies targeted against surface antigens, and the percentage of cells expressing CD13 is notably higher in patients with high-grade MDS that may be a potential prognostic indicator of MDS in the future.Cytometry Part A 09/2010; 77(9):840-8. · 3.73 Impact Factor -
Article: Decreased expression of PRDM2 (RIZ1) and its correlation with risk stratification in patients with myelodysplastic syndrome.
British Journal of Haematology 03/2010; 150(2):242-4. · 4.94 Impact Factor -
Article: Improving the Hydrophobicity and Oxidation Activity of Ti−MWW by Reversible Structural Rearrangement
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ABSTRACT: The postsynthesis treatment of Ti−MWW having the three-dimensional (3D) MWW structure with aqueous amine solutions has been carried out with the purpose to improve its hydrophobicity and catalytic activity in the liquid-phase oxidations. The treatment with piperidine (PI) or hexamethyleneimine (HMI) converted the 3D MWW structure into the corresponding lamellar precursor, which returned reversibly to the 3D MWW structure by further calcination. The treatments with other amines, however, caused a structural collapse or crystalline transfer to other phases. In the case of PI treatment, the structural conversion from 3D MWW to the MWW lamellar precursor occurred readily at 443 K at a PI/SiO2 molar ratio of >0.1 within 1 day for the Ti−MWW samples with various Si/Ti ratios. The structural interchange did not alter the amount as well as the coordination states of the Ti active sites, but removed the internal silanols by ca. 40%, leading to a defectless Ti−MWW catalyst with a more rigid and hydrophobic framework. This kind of structural rearrangement improved the catalytic activity by up to 20% in the ammoximation of ketones and also in the epoxidation of a wide range of alkenes with various molecular dimensions.03/2008; -
Article: A study of the effect of surfactants on the properties of polystyrene‐montmorillonite nanocomposites
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ABSTRACT: Polystyrene-Organo Montmorillonite (PS-MMT) nanocomposites were prepared by suspension free radical polymerization of styrene in the dispersed organophilic montmorillonite. The results of X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) indicated that exfoliated nanocomposites were achieved. The effect of organic modifiers (surfactants) on the properties of the synthesized nanocomposites was studied. It is found that polystyrene-MMT nanocomposite with 5.0 wt% of organo-MMT gave the greatest improvement in thermal stability, and polystyrene-MMT nanocomposites with 7.5 wt% of organo-MMT showed the greatest improvement in mechanical properties, compared with that of pure polystyrene (PS) in our experimental conditions. The alkyl chain length of surfactant used in fabricating organo-MMT affects the synthesized PS nanocomposites: the longer the alkyl chain length that the surfactant possesses, the higher the glass transition temperature of the PS nanocomposite, However, the organoclay in the nanocomposites seems to play a dual role: (a) as nanofiller leading to the increase of storage modulus and (b) as plasticizer leading to the decrease of storage modulus. This results in a lower storage modulus of PS-TMOMMT and PS-TMTMMT nanocomposites than that of PS-TMDMMT and PS-TMCMMT nanocomposites. Further study is needed to confirm the above hypothesis.Polymer Engineering and Science 12/2002; 43(1):214 - 222. · 1.30 Impact Factor -
Article: Thermal Stability of Quaternary Phosphonium Modified Montmorillonites
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ABSTRACT: Organically modified layered silicates (OLS) with high thermal stability are critical for synthesis and processing of polymer layered silicate nanocomposites (PLSN). In the current study, the non-oxidative thermal degradation chemistry of alkyl and aryl quaternary phosphonium-modified montmorillonites (P-MMT) was examined using TGA combined with pyrolysis/GC-MS. The morphology evolution at elevated temperature was investigated using in-situ high-temperature X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The onset decomposition temperature via TGA of these P-MMTs ranged from 190 to 230 °C. The initial degradation of the alkyl P-MMTs follows potentially two reaction pathways − β-elimination [Eβ] and nucleophilic displacement at phosphorus [SN(P)] − reflecting the multiple environments of the surfactant in the silicate. Aryl P-MMT decomposition proceeds via either a reductive elimination through a five-coordinate intermediate or radical generation through homologous cleavage of the P−phenyl bond. Overall, the interlayer environment of the montmorillonite has a more severe effect on stability of the phosphonium surfactant than previously reported for ammonium-modified montmorillonite (N-MMT). Nonetheless, the overall thermal stability of P-MMT is higher than that of N-MMT. These observations indicate that, in addition to their conventional purpose as stabilizers, phosphonium salts offer unique opportunities for melting processing polymer layered silicate nanocomposites.10/2002; -
Article: Study of the processing chemistry of polyimides with thermogravimetry/Fourier transform infrared/mass spectrometry techniques
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ABSTRACT: One of the fundamental aspects of the carbon fiber-reinforced, high-temperature polyimide composite AFR700B/T650-35, namely, the curing chemistry involved in the polyimide formation, was studied in real time with thermogravimetry/Fourier transform infrared (FTIR)/mass spectrometry (MS) evolved-gas analysis techniques. The off-gas reaction products identified by FTIR and MS essentially confirmed the literature polyimide curing mechanisms. However, the FTIR/MS data obtained could also accommodate a reversed curing chemistry in which the elimination of water from amide ester formation occurred first and was followed by the release of methanol from subsequent imidization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2213–2224, 2002Journal of Applied Polymer Science 03/2002; 83(10):2213 - 2224. · 1.29 Impact Factor -
Article: The characterization of organic modified clay and clay‐filled PMMA nanocomposite
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ABSTRACT: Recently, polymer–clay hybrid materials have received considerable attention from both a fundamental research and application point of view.1–3 This organic–inorganic hybrid, which contains a nanoscale dispersion of the layered silicates, is a material with greatly improved physical and mechanical characteristics. These nanocomposites are synthesized through in situ polymerization or direct intercalation of the organically modified layered silicate (OLS) into the polymer matrix. Thus, understanding the relationship between the molecular structure and the thermal stability (decomposition temperature, rate, and the degradation products) of the OLS is critical. In this study, modern thermal analysis techniques combined with infrared spectroscopy and mass spectrometry (TGA-FTIR-MS) were used to obtain information on the thermal stability and degradation products of organic modified clay. Furthermore, the thermal and mechanical properties of clay-filled PMMA nanocomposites were determined by using TGA and DSC. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1702–1710, 2002Journal of Applied Polymer Science 02/2002; 83(8):1702 - 1710. · 1.29 Impact Factor -
Article: Study of stability of high‐temperature polyimides using TG/MS technique
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ABSTRACT: The oxidative stability of the carbon fiber-reinforced composite of polyimide was examined, in real time, using the evolved gas analysis techniques. Off-gas degradation products suggested the onset temperature for chain scissions to be fairly low at about 190–220°C. Based on the off-gas products present and the trend of their release, the composite degradation mechanism appeared to be similar between 190 and 371°C, thereby marking 371°C to be the highest accelerated aging temperature for its long-term lifetime prediction. Beyond 371°C, different degradation mechanisms would apply. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1219–1227, 2002Journal of Applied Polymer Science 02/2002; 83(6):1219 - 1227. · 1.29 Impact Factor -
Article: Thermal Degradation Chemistry of Alkyl Quaternary Ammonium Montmorillonite
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ABSTRACT: The thermal stability of organically modified layered silicate (OLS) plays a key role in the synthesis and processing of polymer-layered silicate (PLS) nanocomposites. The nonoxidative thermal degradation of montmorillonite and alkyl quaternary ammonium-modified montmorillonite were examined using conventional and high-resolution TGA combined with Fourier transform infrared spectroscopy and mass spectrometry (TG−FTIR−MS) and pyrolysis/GC−MS. The onset temperature of decomposition of these OLSs was approximately 155 °C via TGA and 180 °C via TGA−MS, where TGA−MS enables the differentiation of water desorbtion from true organic decomposition. Analysis of products (GC−MS) indicates that the initial degradation of the surfactant in the OLS follows a Hoffmann elimination reaction and that the architecture (trimethyl or dimethyl), chain length, surfactant mixture, exchanged ratio, or preconditioning (washing) does not alter the initial onset temperatures. Catalytic sites on the aluminosilicate layer reduce thermal stability of a fraction of the surfactants by an average of 15−25 °C relative to the parent alkyl quaternary ammonium salt. Finally, the release of organic compounds from the OLS is staged and is associated with retardation of product transfer arising from the morphology of the OLS. These observations have implications to understanding the factors impacting the interfacial strength between polymer and silicate and the subsequent impact on mechanical properties as well as clarifying the role (advantageous or detrimental) of the decomposition products in the fundamental thermodynamic and kinetic aspects of polymer melt intercalation.08/2001; -
Article: The Effect of Chlorine and Sulfur on the Composition of Ash Deposits in a Fluidized Bed Combustion System
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ABSTRACT: The major advantage of fluidized bed combustion (FBC) of fuels is the ability to absorb SO2 and HCl when limestone is used in the combustor. The combustion of high chlorine coal does generate some concerns about the possibility of chlorine-related corrosion of boiler components at high temperatures. It is believed that molten alkali salts may cause severe corrosion when they deposit on the surfaces of heat exchange tubes in a boiler. A better understanding of the effect of temperature on the deposition of alkali chloride will help find a way to convert them to harmless salts before they condense on the components of an FBC system. Furthermore, the knowledge of the distribution of sulfur and chlorine in ash under different conditions is necessary not only to understand the principle and efficiency of desulfurization by limestone, but also to evaluate the role of limestone in the capture of HCl. In this study three different fuels with different chlorine, sulfur, and alkali contents were burned in a 0.1 MWth bench scale FBC system. The effects of coal types, temperature, position, and exposure time on the composition of ash deposits were investigated by ICP-AES and XRD spectroscopy. The major compound in the ash deposits is CaSO4. The experimental results show that the operating temperature has a major effect on the condensation of alkali chloride. The absorption of HCl is favored at the lower temperatures.07/2000; -
Article: Investigation of Polycyclic Aromatic Hydrocarbons in Fly Ash from Fluidized Bed Combustion Systems
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ABSTRACT: A laboratory scale fluidized bed reactor and a bench scale 0.1 MWth fluidized bed combustor were used to study the effect of operating conditions on the formation of Polycyclic Aromatic Hydrocarbons (PAHs) in fly ash from fluidized bed combustion systems. A high volatile bituminous coal was chosen to investigate PAH emissions during the entire pyrolysis to oxygen-rich combustion process. During the experiments, the fluidized bed reactor was operated at temperatures between 700 °C and 900 °C, while the excess air ratio was varied from 0 to 1.3. An extraction and GC/MS analysis of PAHs was used in this study. Approximately 40 different PAHs were identified during the tests, of which only a few are specified by the U.S. EPA. The experimental results indicate the majority of the PAHs in the solid phase (bed and fly ash) are derived from the breakdown reactions during the processes of combustion and/or pyrolysis in a Fluidized Bed Combustion (FBC) system, although FBC systems have an efficient solid−gas mixing process and relatively long residence time. The total amount of PAHs in the fly ash was much higher than that in the raw coal and in the gas phase. Three- and four-ring aromatic compounds were the major PAHs from pyrolysis conditions, while naphthalene (two-rings) is the dominant compound in bed ash collected from oxygen-rich combustion conditions. Only naphthalene was detected in the bed ash in the FBC system. High-speed secondary air (air staging) injected into the freeboard of the FBC system is an effective method for minimizing PAH emissions, along with the other benefits including minimizing NOx and SOx emissions.04/2000; -
Article: The Effect of Sulfur Dioxide on the Formation of Molecular Chlorine during Co-Combustion of Fuels
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ABSTRACT: This project was designed to evaluate the combustion performance of and emissions from a fluidized bed combustor during the combustion of mixtures of high sulfur and/or high chlorine coals and municipal solid waste (MSW). The effect of sulfur dioxide on the formation of molecular chlorine during co-combustion of fuels was examined in this study. Sulfur dioxide was shown to be an effective inhibitor for the formation of molecular chlorine through the Deacon Reaction and, subsequently, the formation of chlorinated organics. Theoretically, co-firing high sulfur coals with MSW will decrease the possibility of polychlorodibenzodioxin/furan (PCDD/F) formation during the combustion process. A mixture of coal and PVC pellets was burned in a 0.1 MWth bench-scale fluidized bed system at WKU and no detectable amounts of chlorinated organics were found in the flue gas and bed ash. The results from this study indicated the practical effects of using coal as a combustion support fuel when burning MSW.03/2000; -
Article: Characterization of the ash deposits from AFBC system using thermal techniques
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ABSTRACT: Deposit formation is considered as an important problem challenging the improvement of coal-combustion performance. Deposits usually result from the thermal decomposition of coal-borne mineral matter followed by impact and adhesion along the hot gas pathway. Several ash deposit samples collected from the heat exchange tube in the Atmospheric Fluidized Bed Combustor (AFBC) at Western Kentucky University, were used in the present study. The SDT-MS and XRD techniques were employed to examine the sample composition and the mechanism responsible for the deposit formation. This work especially concentrated on the investigation of the chlorine containing species and the behavior of chlorine during the heat treatment. It was proved that the alkali or alkali earth chloride would vaporize significantly under the tested condition, and these compounds were likely responsible for the deposit formation.Thermochimica Acta - THERMOCHIM ACTA. 01/2000; 357(1):231-238. -
Article: Behavior of Chloride during Coal Combustion in an AFBC System
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ABSTRACT: Two 1000-h burns were conducted with the 12-in. (0.3 m) laboratory AFBC system at Western Kentucky University. Operating conditions similar to those used at the 160-MW AFBC system at the TVA Shawnee Steam Plant located near Paducah, KY, were used. A low-chlorine (0.012% Cl and 3.0% S) western Kentucky No. 9 coal and a high-chlorine (0.28% Cl and 2.4% S) Illinois No. 6 coal were used in this study. Four different metal alloys [carbon steel C1020 (0.18% C and 0.05% Cr), 304 SS (18.39% Cr and 8.11% Ni), 309 SS (23.28% Cr and 13.41% Ni), and 347 SS (18.03% Cr and 9.79% Ni)] were exposed uncooled in the freeboard area at the entrance to the convective pass, where the metal temperature was approximately 900 K. A two-phase investigation was carried out in order to study the fate of chlorine during coal combustion in an AFBC system and to study the susceptibility of boiler components to corrode in combustion gases containing hydrogen chloride. As determined from emission and ash studies, the temperature in an AFBC system plays a key role in the retention of chloride, which is more favorable at low operating temperatures. A small amount of scale failure was observed on the other three samples in both test runs. On the basis of the SEM-EDS mapping results, there was no localized chloride distribution observed on the surface of the coupons, either in the scale failure area nor on the rest of the metal part. Some trace amount of chloride was found but was evenly distributed on the surface of the coupons. There was no concentration of chloride on the spot of scale failure. The scale failure might be due to sulfur attack and/or the effect of erosion. Further study with higher chlorine-content coals for more conclusive information is needed.02/1999; -
Article: Highly efficient and selective production of epichlorohydrin through epoxidation of allyl chloride with hydrogen peroxide over Ti-MWW catalysts
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ABSTRACT: The catalytic properties of Ti-MWW in the epoxidation of allyl chloride (ALC) with hydrogen peroxide to epichlorohydrin (ECH) were studied by comparing these properties with those of TS-1, Ti-MOR, and Ti-Beta. Issues concerning the stability and reuse of Ti-MWW were also considered. The investigation on various reaction parameters showed that Ti-MWW is an active and selective catalyst for ALC epoxidation. Ti-MWW prefers aprotic solvents, such as acetonitrile and acetone, over protic alcohols, which is favorable for suppressing the formation of solvolysis byproducts. ALC conversion and ECH selectivity were both as high as 99% on Ti-MWW. 3-Chloro-1,2-propanediol and other heavy byproducts with high boiling points had a negative effect on ALC conversion for both TS-1 and Ti-MWW. A novel secondary synthesis caused a structural rearrangement of the Ti-MWW framework and then improved its stability.Journal of Catalysis. 246(1):205-214. -
Article: Postsynthesis and catalytic properties of metallosilicates structurally analogous to MCM-56
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ABSTRACT: A novel postsynthesis method for preparing various metallosilicates structurally analogous to MCM-56 has been developed. Highly crystalline MCM-56 zeolites were postsynthesized readily from corresponding MWW type lamellar precursors by a simple acid treatment at controllable temperatures. The titanosilicate analogue, Ti-MCM-56, thus obtained has been characterized by various techniques and applied to the liquid-phase oxidation of alkenes in comparison to three-dimensional (3D) Ti-MWW and Ti-Beta. Ti-MCM-56 with an open external surface showed a much higher activity for bulky molecules than Ti-MWW.Studies in Surface Science and Catalysis. -
Article: Post-conversion of MWW lamellar precursors into metallosilicates with large porosity
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ABSTRACT: Two postsynthesis methods for preparing metallosilicates with larger porosity from MWW lamellar precursors have been developed. The alkoxysilylation of MWW precursor with Me2Si(OEt)2 (DMES) led to interlayer expanded zeolites (IEZ), MWW-IEZ, while a mild acid treatment on the lamellar precursors resulted in MCM-56 analogues. Ti-MWW-IEZ and Ti-MCM-56 thus prepared, maintaining the basic structure of the MWW zeolite, turned to be superior to three-dimensional (3D) Ti-MWW in the epoxidation of a wide range of bulky alkenes.Studies in Surface Science and Catalysis. -
Article: Thermal characterization of organically modified montmorillonite
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ABSTRACT: Polymer/organically modified layered silicate (PLS) nanocomposites are a new class of filled polymers with ultrafine phase dimensions. They offer an outstanding combination of stiffness, strength and weight that is difficult to attain separately from the individual components. Additionally, the nanoscopic phase distribution as well as synergism between polymer and the layered silicate result in additional properties, such as flame retardency, enhanced barrier properties and ablation resistance, which are not observed in either component. These nanocomposites are synthesized by blending the organically modified layered silicate (OLS) into the polymer melt. Thus, understanding the relationship between the molecular structure and the thermal stability (decomposition temperature, rate, and the degradation products) of the organic modification of the layered silicate is critical. During this study, modern thermal analysis techniques combined with infrared spectroscopy and mass spectrometry (TGA–FTIR–MS) were used to obtain information on the thermal stability and degradation products. The effect of chemical variation (alkyl chain length, number of alkyls, and unsaturation) of organic modifiers on the thermal stability of the organically exchanged montmorillonite are discussed. A range of interesting results is observed, however, not all are currently understandable.Thermochimica Acta.
Top co-authors
Top Journals
Institutions
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2010–2012
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Huazhong University of Science and Technology
Wuhan, Hubei, China
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2002
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Western Kentucky University
- Department of Chemistry
Bowling Green, KY, USA
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