The built-up effect of inorganic compounds containing more active metal ions, such as Ca^2+ , Al^3+ , Cu^2+ , and Zn^2+ , as additives adding to phosphorus-containing flame retarding systems in suppression of smok...The built-up effect of inorganic compounds containing more active metal ions, such as Ca^2+ , Al^3+ , Cu^2+ , and Zn^2+ , as additives adding to phosphorus-containing flame retarding systems in suppression of smoke was studied. The data presented herein suggested that the amount of smoke in the burning process can be better suppressed after the cotton fabric finishing with built-up system was burnt. Some general principles were identified, and the likely causes of the observed effects were analyzed according to test data.展开更多
The inhibitive action of CaSO_4 towards corrosion of aluminium in 1 mol/L HCl has been inveetigated by using fluorometrio and weight loss techniques.The results show that the inhibitor exhibits an outstanding function...The inhibitive action of CaSO_4 towards corrosion of aluminium in 1 mol/L HCl has been inveetigated by using fluorometrio and weight loss techniques.The results show that the inhibitor exhibits an outstanding function of inhibition,especially at higher tempe- ratures,and it was found to be predomiantly of cathodic rate control.Ths mechanism of inhibition and the effect of CdSO_4 on the corrosion kinetics are also discussed.展开更多
For the first time, for different organic and inorganic compounds possessing the plastic crystalline phase, a new semiempirical equation describing dependence of their fusion enthalpies on such physico-chemical quanti...For the first time, for different organic and inorganic compounds possessing the plastic crystalline phase, a new semiempirical equation describing dependence of their fusion enthalpies on such physico-chemical quantities as normal melting temperature, surface tension, molar volume and critical molar volume is received on the base of the principle of corresponding states and the energy equipartition theorem. Moreover, the proposed equation allows one to take into account the particularities of one-particle molecular rotation in the plastic crystalline phase.展开更多
For predicting the molar diamagnetic susceptibilities of inorganic compounds, a novel connectivity index ^mG based on adjacency matrix of molecular graphs and ionic parameter gi was proposed. The gi is defined as gi=...For predicting the molar diamagnetic susceptibilities of inorganic compounds, a novel connectivity index ^mG based on adjacency matrix of molecular graphs and ionic parameter gi was proposed. The gi is defined as gi=(ni^0.5-0.91)^4·xi^0.5|Zi^0.5, where Zi, ni, xi are the valence, the outer electronic shell primary quantum number, and the electronegativity of atom i respectively. The good QSPR models for the molar diamagnetic susceptibilities can be constructed from ^0G and ^1G by using multivariate linear regression (MLR) method and artificial neural network (NN) method. The correlation coefficient r, standard error, and average absolute deviation of the MLR model and NN model are 0.9868, 5.47 cgs, 4.33 cgs, 0.9885, 5.09 cgs and 4.06 cgs, respectively, for the 144 inorganic compounds. The cross-validation by using the leave-one-out method demonstrates that the MLR model is highly reliable from the point of view of statistics. The average absolute deviations of predicted values of the molar diamagnetic susceptibility of other 62 inorganic compounds (test set) are 4.72 cgs and 4.06 cgs for the MLR model and NN model. The results show that the current method is more effective than literature methods for estimating the molar diamagnetic susceptibility of an inorganic compound. Both MLR and NN methods can provide acceptable models for the prediction of the molar diamagnetic susceptibilities. The NN model for the molar diamagnetic susceptibilities appears more reliable than the MLR model.展开更多
In this paper, the radiation graft copolymer of MgO, SiO2 and-Y- molecularsieve onto organic compounds, such as methacrylate, styrene and acrylonitrile obtained by per-rndiation method were characterized by X- ray dif...In this paper, the radiation graft copolymer of MgO, SiO2 and-Y- molecularsieve onto organic compounds, such as methacrylate, styrene and acrylonitrile obtained by per-rndiation method were characterized by X- ray diffraction, pyrolysis gas chromatography, GPC and X-ray photoelectron spectroscopy.展开更多
A novel classification scheme for inorganic cluster compounds is presented based on the characteristics of their electronic structures.In the classification scheme,five distinct categories have been introduced,includi...A novel classification scheme for inorganic cluster compounds is presented based on the characteristics of their electronic structures.In the classification scheme,five distinct categories have been introduced,including Jellium clusters,Wadian clusters,electron-precise clusters,π-donor ligated metal-metal bonded clusters,and antiferro-magnetically coupled high-spin metal clusters.展开更多
Heavy metal-polluted soil was collected from the Pulang copper mine in Shangri-La City,Yunnan Province,Southwest China.The effects of fertilizer(organic and inorganic)and arbuscular mycorrhizal fungi(AMF)on ryegrass(L...Heavy metal-polluted soil was collected from the Pulang copper mine in Shangri-La City,Yunnan Province,Southwest China.The effects of fertilizer(organic and inorganic)and arbuscular mycorrhizal fungi(AMF)on ryegrass(Lolium multiflorum L.)growth,root morphology,mineral nutrition and cadmium(Cd)and lead(Pb)contents were investigated by pot experiments.The results showed that both fertilizer and AMF significantly ameliorated the root morphology and mineral nutrition,reduced the Cd and Pb contents,and promoted the growth of ryegrass.Among all treatments,the combined application of organic–inorganic compound fertilizer with AMF had the highest effect,resulting in increases in root length,surface area and branch number by 2.3,1.1,and 3.9 times,respectively;an 88%increase in plant biomass;a nitrogen content increase of 2.3 and 1.2 times,and phosphorus content increase of 62%and 68%in shoots and roots,respectively was also recorded as well as decreases in Cd content by 34%and 62%and Pb content by 47%and 34%in shoots and roots,respectively.Twofactor analysis showed that both fertilizer and AMF significantly promoted ryegrass growth(plant height,biomass,chlorophyll content,root length,nitrogen and phosphorus content)and reduced the Cd and Pb contents in roots,and there was a synergistic effect between them.Moreover,the nitrogen and phosphorus contents were very significantly positively correlated with the shoot and root biomasses but very significantly negatively correlated with the Cd and Pb contents of ryegrass.Thus,the application of fertilizer and AMF synergistically improved ryegrass growth on polluted soils in the copper mining area.展开更多
Spherical cobalt blue particles with good reflectivity characteristics were synthesized by spray pyrolysis. Two different spray solutions were prepared to investigate the differences in the morphology and the reflecti...Spherical cobalt blue particles with good reflectivity characteristics were synthesized by spray pyrolysis. Two different spray solutions were prepared to investigate the differences in the morphology and the reflectivity properties of cobalt blue particles. One was an aqueous solution, and the other was a polycation solution that was obtained by chemically modifying the aqueous solution with NH4OH. The cobalt blue particles prepared with the aqueous solution had an irregular morphology after heat treatment at 1000~C for 2 h. On the contrary, spherical and dense particles were obtained from the polycation solution. The spherical and dense cobalt blue particles showed remarkable improvement in reflectivity compared with that of irregular morphology particles as well as the commercial.展开更多
Hexagonal microtubes with hexagonal phase Y(OH)3 were successfully synthesized by a facile solvothermal method at 160°C for 12 h in the absence of surfactants or templates via a crystal transformation route. Sc...Hexagonal microtubes with hexagonal phase Y(OH)3 were successfully synthesized by a facile solvothermal method at 160°C for 12 h in the absence of surfactants or templates via a crystal transformation route. Scanning electron microscopy (SEM) results demonstrate that the prepared hexagonal microtubes are with a wall thickness of 50-100 nm, an outer diameter of 1 μm, and lengths going up tens of micrometers. Cubic phase Y2O3 microtubes were obtained after thermal treatment of the Y(OH)3 microtubes at 700 oC for 4 h. Eu^3+-doped Y2O3 microtubes with strong red emission at 610 nm were also prepared and their photoluminescence (PL) properties were studied. The possible mechanism for the formation of the microtubes was briefly discussed.展开更多
MnZn ferrites with the chemical formula Mn0.68Zn0.25Fe2.07O4 have been prepared by a conventional ceramic technique. Then, the effects of CuO addition on the microstructure and temperature dependence of magnetic prope...MnZn ferrites with the chemical formula Mn0.68Zn0.25Fe2.07O4 have been prepared by a conventional ceramic technique. Then, the effects of CuO addition on the microstructure and temperature dependence of magnetic properties of MnZn ferrites were investigated by characterizing the fracture surface micrograph and measuring the magnetic properties over a temperature ranging from 25 to 120 C. The results show that the lattice constant and average grain size increase with the increase of CuO concentration. When the CuO concentration is below 0.07 wt.%, the initial permeability and saturation magnetic flux density increase monotonously, and the temperature of the secondary maximum peak in the curve of initial permeability versus temperature and the lowest power loss shift to a lower temperature with the increase of CuO concentra-tion. However, excessive CuO concentration (0.07 wt.%) results in abnormal grain growth and porosity increase, which causes the initial permeability and saturation magnetic flux density decrease and the power loss increase at room temperature. Furthermore, the temperature of the secondary maximum peak in the curve of initial permeability versus temperature and the lowest power loss shift to a higher temperature.展开更多
NiFe2O4 nanorods have been successfully synthesized via thermal treatment of the rod-like precursor fabricated by Ni-doped (x-FeOOH, which was enwrapped by the complex of citric acid and Niz~. The morphology evolutio...NiFe2O4 nanorods have been successfully synthesized via thermal treatment of the rod-like precursor fabricated by Ni-doped (x-FeOOH, which was enwrapped by the complex of citric acid and Niz~. The morphology evolution during the calcination of the precursor nanorods was investigated with transmission electron microscopy (TEM), and the phase and the magnetic properties of samples were analyzed through X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results indicated that the diameter of the NiFe204 nanorods obtained ranged between 30 and 50 nm, and the length ranged between 2 and 3 um. As the calcination temperature was up to 600℃, the coercivity, saturation magnetization, and remanent magnetization of the samples were 36.1 kA.m^-1, 27.2 A.m2.kg^-1, and 5.3 A.m2.kg^-1, respectively. The NiFe2O4 nanorods prepared have higher shape anisotropy and superior magnetic properties than those with irregular shapes.展开更多
Tricalcium silicate cement(TSC)has been widely used in dental materials because of its self-setting behavior,good bioactivity,biocompatibility,osteoinductivity,and antibacterial effect.Tricalcium silicate(C3S)powder w...Tricalcium silicate cement(TSC)has been widely used in dental materials because of its self-setting behavior,good bioactivity,biocompatibility,osteoinductivity,and antibacterial effect.Tricalcium silicate(C3S)powder was prepared by Pechini technique with a calcining temperature of 1300℃ for 3 h.The influence of liquid/powder(L/P)rate on the setting time and the mechanical property of TSC was studied.Characterization methods including XRD,FTIR,SEM-EDS,TEM,and ICP-AES were utilized to study the properties of C3S powder and its hydrated cement.The bioactivity and biocompatibility of the cement were investigated by soaking test and cell culture,respectively.The results show that the L/P rate plays an important role in the setting time and the compressive strength of TSC.The surface of TSC was covered by hydroxyapatite deposition during the immersion experiment and the cells attachment on the surface of TSC was well,which indicated that TSC has good bioactivity and biocompatibility.In addition,TSC has excellent antibacterial properties against Staphylococcus aureus.In conclusion,TSC is a promising candidate for root canal filling materials.展开更多
Fe(OH)3 precursor sol was prepared by a sol-gel method. The precursor sol was dipped onto the absorbent cotton, and gel was formed on the absorbent cotton template after the volatilization of moisture. Fe2O3 microtu...Fe(OH)3 precursor sol was prepared by a sol-gel method. The precursor sol was dipped onto the absorbent cotton, and gel was formed on the absorbent cotton template after the volatilization of moisture. Fe2O3 microtubules were synthesized after the process of self-propagation or calcination. The phase, morphology, and particle diameter of the samples were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the magnetic properties of the samples were measured using a vibrating sample magnetometer (VSM). The external diameters of Fe2O3 microtubules ranged between 8 and 13 μm, and the wall thicknesses ranged between 0.5 and 2 μm. The type of the calcination method plays a significant role in developing the Fe2O3 phase and the variation in the magnetic properties in the sol-gel template complexing method. γ-Fe2O3 was synthesized by a self-propagation method. However, α-Fe203 was synthesized after calcination at 400℃ for 2 h. The coercivity of the samples synthesized by calcination at 400℃ for 2 h after self-propagation was found to increase significantly, thereby presenting hard magnetic properties.展开更多
Hollow-structured Cu_(0.3)Co_(2.7)O_(4) microspheres have been synthesized by a simple one-pot template-free hydrothermal method with copper sulfate,cobalt acetate and ammonia as raw materials.The products were charac...Hollow-structured Cu_(0.3)Co_(2.7)O_(4) microspheres have been synthesized by a simple one-pot template-free hydrothermal method with copper sulfate,cobalt acetate and ammonia as raw materials.The products were characterized by powder X-ray diffraction,energy dispersive X-ray analysis,selected area electron diffraction,high-resolution transmission electron microscopy,scanning electron microscopy and BET measurements.The research results show that the hollow Cu_(0.3)Co_(2.7)O_(4) microspheres consist of single-crystalline nanocubes with the diameter of about 20 nm.The formation mechanism of hollow Cu_(0.3)Co_(2.7)O_(4) microspheres is suggested as Ostwald ripening in a solid-solution-solid process,and Cu_(0.3)Co_(2.7)O_(4) microspheres are mesoporous containing two pore sizes of 3.3 and 5.9 nm.The as-prepared Cu_(0.3)Co_(2.7)O_(4) sensors have optimal gas responses to 50×10^(−6) mg/m^(3) C_(2)H_(5)OH at 190℃.展开更多
A novel method for determination of formaldehyde sulfoxylate, sulfite, thiocyanate, and thiosulfate in foodstuffs by ion chromatography separation with postcolumn derivation and UV detection has been developed. All sp...A novel method for determination of formaldehyde sulfoxylate, sulfite, thiocyanate, and thiosulfate in foodstuffs by ion chromatography separation with postcolumn derivation and UV detection has been developed. All species are separated at Dionex IonPac AG22A and AS22A with mobile phase of a mixture of 4.5 mmol/L sodium carbonate and 0.8 mmol/L sodium bicarbonate at a flow-rate of 1.0 mL/min. The postcolunm derivation solution was 0.24% iodine in 0.2% phosphate acid and the detection wavelength was set at 288 nm. The detection limits (LOD, signal-to-noise ratio of 3) of formaldehyde sulfoxylate, sulfite, thiocyanate, and thiosulfate were 0.004, 0.006, 0.006, and 0.007 mg/L, respectively. Within-day relative standard deviations (RSD, n = 10) of formaldehyde sulfoxylate, sulflte, thiocyanate, and thiosulfate were 3.24%, 3.76%, 2.68%, and 2.07%, respectively. The recoveries of the four anions were in the range of 67.2-116.5%.展开更多
Lithium aluminosilicate (LAS) glasses are generally difficult to prepare because of their high melting temperature. In this study, the preparation of LAS glasses was achieved at a relatively low melting temperature....Lithium aluminosilicate (LAS) glasses are generally difficult to prepare because of their high melting temperature. In this study, the preparation of LAS glasses was achieved at a relatively low melting temperature. The batch containing MgO-ZnO-LiEO- Al2O3-SiO2 was melted in a platinum crucible at 1550℃ for 2 h and was then followed by two- or three-step heat treatment processes for nucleation and crystal growth. The characterizations were carried out by differential thermal analysis, X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and UV-Vis-NIR scanning spectrophotometry. The hexagonal stuffed β-eucryptite solid solution crystallized at 840-960℃. Most of the hexagonal β-eucryptite solid solution transformed into the tetragonal β-spodumene solid solution at 1100℃. Almost all the aluminum atoms entered into the tetrahedral sites in the aluminosilicate network of the 6- eucryptite/β-quartz solid solution. All of the Al atoms did not belong to the aluminosilicate network of the β-spodumene solid solution. The glass ceramic with a mean grain size of 10-20 nm is transparent, the transmittance reaches -85% in the visible light wavelength.展开更多
In this study, chlorine decay experiments were conducted for the raw water from Nakdong River that is treated by Chllseo Water Treatment Plant (CWTP) situated in Haman, Korea as well as the effluents from sand and g...In this study, chlorine decay experiments were conducted for the raw water from Nakdong River that is treated by Chllseo Water Treatment Plant (CWTP) situated in Haman, Korea as well as the effluents from sand and granular activated carbon (GAC) filters of CWTP and fitted using a chlorine decay model. The model estimated the fast and slow reacting nitrogenous as well as organic/inorganic compounds that were present in the water. It was found that the chlorine demand due to fast and slow reacting (FRA and SRA) organic/inorganic substances was not reduced significantly by sand as well as GAC filters. However, the treated effluents from those filters contained FRA and SRA that are less reactive and had small reaction rate constants. For the effluents from microfiltration, ultrafiltration, and nanofiltration the chlorine demand because FRA and SRA were further reduced but the reaction rate constants were larger compared to those of sand and GAC filter effluents. This has implications in the formation of disinfection by products (DBPs). If DBPs are assumed to form due to the interactions between chlorine and SRA, then it is possible that the DBP formation potential in the effluents from membrane filtrations could be higher than that in the effluents from granular media filters.展开更多
The precursor of nanocrystalline ZrO2 was synthesized by solid-state reaction at low heat using ZrOCl2·8H2O,and Na2CO3·10H2O as raw materials.The nanocrystalline ZrO2 was obtained by calcining the precursor....The precursor of nanocrystalline ZrO2 was synthesized by solid-state reaction at low heat using ZrOCl2·8H2O,and Na2CO3·10H2O as raw materials.The nanocrystalline ZrO2 was obtained by calcining the precursor.The precursor and its calcined products were characterized using TG/DTA,FT-IR,XRD,and SEM.The results showed that the precursor dried at 353 K was a zirconyl carbonate compound.When the precursor was calcined at 673 K for 150min,highly crystallization ZrO2 with tetragonal structure (space group P42/nmc (137)) was obtained with a crystallite size of 24 nm.However,when the precursor was calcined at 1023 K for 150min,highly crystallization ZrO2 with monoclinic structure (space group P21/c (14)) was obtained with a crystallite size of 20 nm.The mechanism and kinetics of the thermal process of the precursor were studied using DTA and XRD techniques.Based on the Kissinger and Arrhenius equation,the values of the activation energies associated with the thermal process of the precursor were determined to be 26.80 and 566.73 kJ·mol-1 for the first and third steps,respectively.The mechanism of ZrO2 phase transition from tetragonal to monoclinic structure is the random nucleation and growth of nuclei reaction.展开更多
The reaction process during synthesis of LiMn2O4 with LiOH·H2O and MnO2 was studied by means of DTA in dynamical air atmosphere, and it could be applied as an important theoretical principle for preparing Li...The reaction process during synthesis of LiMn2O4 with LiOH·H2O and MnO2 was studied by means of DTA in dynamical air atmosphere, and it could be applied as an important theoretical principle for preparing LiMn2O4. The active energies of four reaction processes were obtained with Doyle-Ozawa method and Kissinger method as follows: 66.299, 72.640, 128.11 and 113.876 kJ·mol-1, respectively. Reaction orders, frequency factors and kinetic equations of each reaction were determined by Kissinger method. XRD, SEM and TEM show that the synthesized LiMn2O4 is a pure phase, with regular appearance and higher ratio-surface.展开更多
A new hydrogen storage alloy pair, La0.6Ml0.4Ni4.7 Cr0.3-La0.2Mm0.8Ni4.35Fe0.65, was developed to serve as a bus hydride air conditioner, which utilizes the waste heat of exhaust gases of a bus as the high temperature...A new hydrogen storage alloy pair, La0.6Ml0.4Ni4.7 Cr0.3-La0.2Mm0.8Ni4.35Fe0.65, was developed to serve as a bus hydride air conditioner, which utilizes the waste heat of exhaust gases of a bus as the high temperature source. Under the operating temperature of 150-250 °C/35-40°C/15-20°C, the maximum working hydrogen capacity and the theoretical value of COPc are 4.5 and 0.74 H/mol M respectively, which can meet the practical requirements.展开更多
文摘The built-up effect of inorganic compounds containing more active metal ions, such as Ca^2+ , Al^3+ , Cu^2+ , and Zn^2+ , as additives adding to phosphorus-containing flame retarding systems in suppression of smoke was studied. The data presented herein suggested that the amount of smoke in the burning process can be better suppressed after the cotton fabric finishing with built-up system was burnt. Some general principles were identified, and the likely causes of the observed effects were analyzed according to test data.
文摘The inhibitive action of CaSO_4 towards corrosion of aluminium in 1 mol/L HCl has been inveetigated by using fluorometrio and weight loss techniques.The results show that the inhibitor exhibits an outstanding function of inhibition,especially at higher tempe- ratures,and it was found to be predomiantly of cathodic rate control.Ths mechanism of inhibition and the effect of CdSO_4 on the corrosion kinetics are also discussed.
文摘For the first time, for different organic and inorganic compounds possessing the plastic crystalline phase, a new semiempirical equation describing dependence of their fusion enthalpies on such physico-chemical quantities as normal melting temperature, surface tension, molar volume and critical molar volume is received on the base of the principle of corresponding states and the energy equipartition theorem. Moreover, the proposed equation allows one to take into account the particularities of one-particle molecular rotation in the plastic crystalline phase.
基金Project supported by the University Natural Science Foundation of Jiangsu Province (No. 04KJD150195). Acknowledgement The authors wish to express our gratitude to the referees for their value comments.
文摘For predicting the molar diamagnetic susceptibilities of inorganic compounds, a novel connectivity index ^mG based on adjacency matrix of molecular graphs and ionic parameter gi was proposed. The gi is defined as gi=(ni^0.5-0.91)^4·xi^0.5|Zi^0.5, where Zi, ni, xi are the valence, the outer electronic shell primary quantum number, and the electronegativity of atom i respectively. The good QSPR models for the molar diamagnetic susceptibilities can be constructed from ^0G and ^1G by using multivariate linear regression (MLR) method and artificial neural network (NN) method. The correlation coefficient r, standard error, and average absolute deviation of the MLR model and NN model are 0.9868, 5.47 cgs, 4.33 cgs, 0.9885, 5.09 cgs and 4.06 cgs, respectively, for the 144 inorganic compounds. The cross-validation by using the leave-one-out method demonstrates that the MLR model is highly reliable from the point of view of statistics. The average absolute deviations of predicted values of the molar diamagnetic susceptibility of other 62 inorganic compounds (test set) are 4.72 cgs and 4.06 cgs for the MLR model and NN model. The results show that the current method is more effective than literature methods for estimating the molar diamagnetic susceptibility of an inorganic compound. Both MLR and NN methods can provide acceptable models for the prediction of the molar diamagnetic susceptibilities. The NN model for the molar diamagnetic susceptibilities appears more reliable than the MLR model.
文摘In this paper, the radiation graft copolymer of MgO, SiO2 and-Y- molecularsieve onto organic compounds, such as methacrylate, styrene and acrylonitrile obtained by per-rndiation method were characterized by X- ray diffraction, pyrolysis gas chromatography, GPC and X-ray photoelectron spectroscopy.
基金supported by the Research Grants Council of Hong Kong(HKUST 16302222).
文摘A novel classification scheme for inorganic cluster compounds is presented based on the characteristics of their electronic structures.In the classification scheme,five distinct categories have been introduced,including Jellium clusters,Wadian clusters,electron-precise clusters,π-donor ligated metal-metal bonded clusters,and antiferro-magnetically coupled high-spin metal clusters.
基金supported by the School-Enterprise Cooperation Project“Research on the Key Technologies of Vegetation Restoration of High and Steep Slopes in Alpine Mountains(20200618)”the Yunnan Provincial Department of Education Fund Project“Research on New Technology of Ecological Protection of Weathered Rock Slopes in Alpine and High Altitude Areas in Northwest Yunnan(2021J0123)”.
文摘Heavy metal-polluted soil was collected from the Pulang copper mine in Shangri-La City,Yunnan Province,Southwest China.The effects of fertilizer(organic and inorganic)and arbuscular mycorrhizal fungi(AMF)on ryegrass(Lolium multiflorum L.)growth,root morphology,mineral nutrition and cadmium(Cd)and lead(Pb)contents were investigated by pot experiments.The results showed that both fertilizer and AMF significantly ameliorated the root morphology and mineral nutrition,reduced the Cd and Pb contents,and promoted the growth of ryegrass.Among all treatments,the combined application of organic–inorganic compound fertilizer with AMF had the highest effect,resulting in increases in root length,surface area and branch number by 2.3,1.1,and 3.9 times,respectively;an 88%increase in plant biomass;a nitrogen content increase of 2.3 and 1.2 times,and phosphorus content increase of 62%and 68%in shoots and roots,respectively was also recorded as well as decreases in Cd content by 34%and 62%and Pb content by 47%and 34%in shoots and roots,respectively.Twofactor analysis showed that both fertilizer and AMF significantly promoted ryegrass growth(plant height,biomass,chlorophyll content,root length,nitrogen and phosphorus content)and reduced the Cd and Pb contents in roots,and there was a synergistic effect between them.Moreover,the nitrogen and phosphorus contents were very significantly positively correlated with the shoot and root biomasses but very significantly negatively correlated with the Cd and Pb contents of ryegrass.Thus,the application of fertilizer and AMF synergistically improved ryegrass growth on polluted soils in the copper mining area.
文摘Spherical cobalt blue particles with good reflectivity characteristics were synthesized by spray pyrolysis. Two different spray solutions were prepared to investigate the differences in the morphology and the reflectivity properties of cobalt blue particles. One was an aqueous solution, and the other was a polycation solution that was obtained by chemically modifying the aqueous solution with NH4OH. The cobalt blue particles prepared with the aqueous solution had an irregular morphology after heat treatment at 1000~C for 2 h. On the contrary, spherical and dense particles were obtained from the polycation solution. The spherical and dense cobalt blue particles showed remarkable improvement in reflectivity compared with that of irregular morphology particles as well as the commercial.
基金support from Projects under Scientific and Technological Planning of Education Office of Jiangxi Province, China.
文摘Hexagonal microtubes with hexagonal phase Y(OH)3 were successfully synthesized by a facile solvothermal method at 160°C for 12 h in the absence of surfactants or templates via a crystal transformation route. Scanning electron microscopy (SEM) results demonstrate that the prepared hexagonal microtubes are with a wall thickness of 50-100 nm, an outer diameter of 1 μm, and lengths going up tens of micrometers. Cubic phase Y2O3 microtubes were obtained after thermal treatment of the Y(OH)3 microtubes at 700 oC for 4 h. Eu^3+-doped Y2O3 microtubes with strong red emission at 610 nm were also prepared and their photoluminescence (PL) properties were studied. The possible mechanism for the formation of the microtubes was briefly discussed.
文摘MnZn ferrites with the chemical formula Mn0.68Zn0.25Fe2.07O4 have been prepared by a conventional ceramic technique. Then, the effects of CuO addition on the microstructure and temperature dependence of magnetic properties of MnZn ferrites were investigated by characterizing the fracture surface micrograph and measuring the magnetic properties over a temperature ranging from 25 to 120 C. The results show that the lattice constant and average grain size increase with the increase of CuO concentration. When the CuO concentration is below 0.07 wt.%, the initial permeability and saturation magnetic flux density increase monotonously, and the temperature of the secondary maximum peak in the curve of initial permeability versus temperature and the lowest power loss shift to a lower temperature with the increase of CuO concentra-tion. However, excessive CuO concentration (0.07 wt.%) results in abnormal grain growth and porosity increase, which causes the initial permeability and saturation magnetic flux density decrease and the power loss increase at room temperature. Furthermore, the temperature of the secondary maximum peak in the curve of initial permeability versus temperature and the lowest power loss shift to a higher temperature.
基金the North University of China and the National Natural Science Foundation of China (No50535030) for financial support to this work
文摘NiFe2O4 nanorods have been successfully synthesized via thermal treatment of the rod-like precursor fabricated by Ni-doped (x-FeOOH, which was enwrapped by the complex of citric acid and Niz~. The morphology evolution during the calcination of the precursor nanorods was investigated with transmission electron microscopy (TEM), and the phase and the magnetic properties of samples were analyzed through X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results indicated that the diameter of the NiFe204 nanorods obtained ranged between 30 and 50 nm, and the length ranged between 2 and 3 um. As the calcination temperature was up to 600℃, the coercivity, saturation magnetization, and remanent magnetization of the samples were 36.1 kA.m^-1, 27.2 A.m2.kg^-1, and 5.3 A.m2.kg^-1, respectively. The NiFe2O4 nanorods prepared have higher shape anisotropy and superior magnetic properties than those with irregular shapes.
基金Project(2019JJ50797)supported by Hunan Provincial Natural Science Foundation of China。
文摘Tricalcium silicate cement(TSC)has been widely used in dental materials because of its self-setting behavior,good bioactivity,biocompatibility,osteoinductivity,and antibacterial effect.Tricalcium silicate(C3S)powder was prepared by Pechini technique with a calcining temperature of 1300℃ for 3 h.The influence of liquid/powder(L/P)rate on the setting time and the mechanical property of TSC was studied.Characterization methods including XRD,FTIR,SEM-EDS,TEM,and ICP-AES were utilized to study the properties of C3S powder and its hydrated cement.The bioactivity and biocompatibility of the cement were investigated by soaking test and cell culture,respectively.The results show that the L/P rate plays an important role in the setting time and the compressive strength of TSC.The surface of TSC was covered by hydroxyapatite deposition during the immersion experiment and the cells attachment on the surface of TSC was well,which indicated that TSC has good bioactivity and biocompatibility.In addition,TSC has excellent antibacterial properties against Staphylococcus aureus.In conclusion,TSC is a promising candidate for root canal filling materials.
基金the North University of China for the support given for carrying out this work under projects from the National Natural Science Fundation of China(Nos.20571066 and 20871108)
文摘Fe(OH)3 precursor sol was prepared by a sol-gel method. The precursor sol was dipped onto the absorbent cotton, and gel was formed on the absorbent cotton template after the volatilization of moisture. Fe2O3 microtubules were synthesized after the process of self-propagation or calcination. The phase, morphology, and particle diameter of the samples were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the magnetic properties of the samples were measured using a vibrating sample magnetometer (VSM). The external diameters of Fe2O3 microtubules ranged between 8 and 13 μm, and the wall thicknesses ranged between 0.5 and 2 μm. The type of the calcination method plays a significant role in developing the Fe2O3 phase and the variation in the magnetic properties in the sol-gel template complexing method. γ-Fe2O3 was synthesized by a self-propagation method. However, α-Fe203 was synthesized after calcination at 400℃ for 2 h. The coercivity of the samples synthesized by calcination at 400℃ for 2 h after self-propagation was found to increase significantly, thereby presenting hard magnetic properties.
基金Project(51202066)supported by the National Natural Science Foundation of ChinaProject(NCET-13-0784)supported by the Program for New Century Excellent Talents in University of China。
文摘Hollow-structured Cu_(0.3)Co_(2.7)O_(4) microspheres have been synthesized by a simple one-pot template-free hydrothermal method with copper sulfate,cobalt acetate and ammonia as raw materials.The products were characterized by powder X-ray diffraction,energy dispersive X-ray analysis,selected area electron diffraction,high-resolution transmission electron microscopy,scanning electron microscopy and BET measurements.The research results show that the hollow Cu_(0.3)Co_(2.7)O_(4) microspheres consist of single-crystalline nanocubes with the diameter of about 20 nm.The formation mechanism of hollow Cu_(0.3)Co_(2.7)O_(4) microspheres is suggested as Ostwald ripening in a solid-solution-solid process,and Cu_(0.3)Co_(2.7)O_(4) microspheres are mesoporous containing two pore sizes of 3.3 and 5.9 nm.The as-prepared Cu_(0.3)Co_(2.7)O_(4) sensors have optimal gas responses to 50×10^(−6) mg/m^(3) C_(2)H_(5)OH at 190℃.
基金supported by National Natural Science Foundation of China(No.20775070) Zhejiang Provincial Natural Science Foundation of China(No.Y507252)+1 种基金Zhejiang Qianjiang Project of Science and Technology for Competent People(No.2008R10028) Zhejiang Provincial Analysis and Testing Foundation of China(No.2007F70061)
文摘A novel method for determination of formaldehyde sulfoxylate, sulfite, thiocyanate, and thiosulfate in foodstuffs by ion chromatography separation with postcolumn derivation and UV detection has been developed. All species are separated at Dionex IonPac AG22A and AS22A with mobile phase of a mixture of 4.5 mmol/L sodium carbonate and 0.8 mmol/L sodium bicarbonate at a flow-rate of 1.0 mL/min. The postcolunm derivation solution was 0.24% iodine in 0.2% phosphate acid and the detection wavelength was set at 288 nm. The detection limits (LOD, signal-to-noise ratio of 3) of formaldehyde sulfoxylate, sulfite, thiocyanate, and thiosulfate were 0.004, 0.006, 0.006, and 0.007 mg/L, respectively. Within-day relative standard deviations (RSD, n = 10) of formaldehyde sulfoxylate, sulflte, thiocyanate, and thiosulfate were 3.24%, 3.76%, 2.68%, and 2.07%, respectively. The recoveries of the four anions were in the range of 67.2-116.5%.
基金This work was financially supported by the Ministry of Education of China (No.KB20026)
文摘Lithium aluminosilicate (LAS) glasses are generally difficult to prepare because of their high melting temperature. In this study, the preparation of LAS glasses was achieved at a relatively low melting temperature. The batch containing MgO-ZnO-LiEO- Al2O3-SiO2 was melted in a platinum crucible at 1550℃ for 2 h and was then followed by two- or three-step heat treatment processes for nucleation and crystal growth. The characterizations were carried out by differential thermal analysis, X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and UV-Vis-NIR scanning spectrophotometry. The hexagonal stuffed β-eucryptite solid solution crystallized at 840-960℃. Most of the hexagonal β-eucryptite solid solution transformed into the tetragonal β-spodumene solid solution at 1100℃. Almost all the aluminum atoms entered into the tetrahedral sites in the aluminosilicate network of the 6- eucryptite/β-quartz solid solution. All of the Al atoms did not belong to the aluminosilicate network of the β-spodumene solid solution. The glass ceramic with a mean grain size of 10-20 nm is transparent, the transmittance reaches -85% in the visible light wavelength.
文摘In this study, chlorine decay experiments were conducted for the raw water from Nakdong River that is treated by Chllseo Water Treatment Plant (CWTP) situated in Haman, Korea as well as the effluents from sand and granular activated carbon (GAC) filters of CWTP and fitted using a chlorine decay model. The model estimated the fast and slow reacting nitrogenous as well as organic/inorganic compounds that were present in the water. It was found that the chlorine demand due to fast and slow reacting (FRA and SRA) organic/inorganic substances was not reduced significantly by sand as well as GAC filters. However, the treated effluents from those filters contained FRA and SRA that are less reactive and had small reaction rate constants. For the effluents from microfiltration, ultrafiltration, and nanofiltration the chlorine demand because FRA and SRA were further reduced but the reaction rate constants were larger compared to those of sand and GAC filter effluents. This has implications in the formation of disinfection by products (DBPs). If DBPs are assumed to form due to the interactions between chlorine and SRA, then it is possible that the DBP formation potential in the effluents from membrane filtrations could be higher than that in the effluents from granular media filters.
基金financially supported by the National Natural Scientific Foundation of China (No.201161002)
文摘The precursor of nanocrystalline ZrO2 was synthesized by solid-state reaction at low heat using ZrOCl2·8H2O,and Na2CO3·10H2O as raw materials.The nanocrystalline ZrO2 was obtained by calcining the precursor.The precursor and its calcined products were characterized using TG/DTA,FT-IR,XRD,and SEM.The results showed that the precursor dried at 353 K was a zirconyl carbonate compound.When the precursor was calcined at 673 K for 150min,highly crystallization ZrO2 with tetragonal structure (space group P42/nmc (137)) was obtained with a crystallite size of 24 nm.However,when the precursor was calcined at 1023 K for 150min,highly crystallization ZrO2 with monoclinic structure (space group P21/c (14)) was obtained with a crystallite size of 20 nm.The mechanism and kinetics of the thermal process of the precursor were studied using DTA and XRD techniques.Based on the Kissinger and Arrhenius equation,the values of the activation energies associated with the thermal process of the precursor were determined to be 26.80 and 566.73 kJ·mol-1 for the first and third steps,respectively.The mechanism of ZrO2 phase transition from tetragonal to monoclinic structure is the random nucleation and growth of nuclei reaction.
基金financially supported by the Liaoning Province Natural Science Foundation under contract No.9810300702the Northeastern University Ph.D.Thesis Funds Project.
文摘The reaction process during synthesis of LiMn2O4 with LiOH·H2O and MnO2 was studied by means of DTA in dynamical air atmosphere, and it could be applied as an important theoretical principle for preparing LiMn2O4. The active energies of four reaction processes were obtained with Doyle-Ozawa method and Kissinger method as follows: 66.299, 72.640, 128.11 and 113.876 kJ·mol-1, respectively. Reaction orders, frequency factors and kinetic equations of each reaction were determined by Kissinger method. XRD, SEM and TEM show that the synthesized LiMn2O4 is a pure phase, with regular appearance and higher ratio-surface.
文摘A new hydrogen storage alloy pair, La0.6Ml0.4Ni4.7 Cr0.3-La0.2Mm0.8Ni4.35Fe0.65, was developed to serve as a bus hydride air conditioner, which utilizes the waste heat of exhaust gases of a bus as the high temperature source. Under the operating temperature of 150-250 °C/35-40°C/15-20°C, the maximum working hydrogen capacity and the theoretical value of COPc are 4.5 and 0.74 H/mol M respectively, which can meet the practical requirements.