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
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
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
The hygroscopic behaviors of atmospherically relevant multicomponent water soluble organic compounds（WSOCs） and their effects on ammonium sulfate（AS） and sodium chloride were investigated using a hygroscopicity ta...The hygroscopic behaviors of atmospherically relevant multicomponent water soluble organic compounds（WSOCs） and their effects on ammonium sulfate（AS） and sodium chloride were investigated using a hygroscopicity tandem differential mobility analyzer（HTDMA） in the relative humidity（RH） range of 5%–90%. The measured hygroscopic growth was compared with predictions from the Extended-Aerosol Inorganics Model（E-AIM） and Zdanovskii–Stokes–Robinson（ZSR） method. The equal mass multicomponent WSOCs mixture containing levoglucosan, succinic acid, phthalic acid and humic acid showed gradual water uptake without obvious phase change over the whole RH range. It was found that the organic content played an important role in the water uptake of mixed particles.When organic content was dominant in the mixture（75%）, the measured hygroscopic growth was higher than predictions from the E-AIM or ZSR relation, especially under high RH conditions. For mass fractions of organics not larger than 50%, the hygroscopic growth of mixtures was in good agreement with model predictions. The influence of interactions between inorganic and organic components on the hygroscopicity of mixed particles was related to the salt type and organic content. These results could contribute to understanding of the hygroscopic behaviors of multicomponent aerosol particles.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
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
In the context of diminishing energy resources and worsening greenhouse effect,thermoelectric materials have great potential for sustainable development due to their green and environmentally friendly characteristics....In the context of diminishing energy resources and worsening greenhouse effect,thermoelectric materials have great potential for sustainable development due to their green and environmentally friendly characteristics.Among inorganic thermoelectric materials,copper sulfide compounds have greater potential than others due to their abundant element reserves on Earth,lower usage costs,non-toxicity,and good biocompatibility.Compared to organic thermoelectric materials,the"phonon liquid-electron crystal"(PLEC)feature of copper sulfide compounds makes them have stronger thermoelectric performance.This review summarizes the latest research progress in the synthesis methods and thermoelectric modification strategies of copper sulfide compounds.It first explains the importance of the solid-phase method in the manufacture of thermoelectric devices,and then focuses on the great potential of nanoscale synthesis technology based on liquid-phase method in the preparation of thermoelectric materials.Finally,it systematically discusses several strategies for regulating the thermoelectric performance of copper sulfide compounds,including adjusting the chemical proportion of Cu_(2-x)S and introducing element doping to regulate the crystal structure,phase composition,chemical composition,band structure,and nanoscale microstructure of copper sulfide compounds,and directly affecting ZT value by adjusting conductivity and thermal conductivity.In addition,it discusses composite engineering based on copper sulfide compounds,including inorganic,organic,and metal compounds,and discusses tri-component compounds derived from sulfide copper.Finally,it discusses the main challenges and prospects of the development of copper sulfide-based thermoelectric materials,hoping that this review will promote the development of copper sulfide-based thermoelectric materials.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
Superfine Sr2CeO4:RE3+ (RE=Eu, Sm) phosphors were synthesized at relatively low temperature by a modified sol-gel method using nitrates as raw materials, ethylenediaminetetraacetic acid (EDTA) as complexing agent. Sin...Superfine Sr2CeO4:RE3+ (RE=Eu, Sm) phosphors were synthesized at relatively low temperature by a modified sol-gel method using nitrates as raw materials, ethylenediaminetetraacetic acid (EDTA) as complexing agent. Single phase phosphors could be obtained at calcination temperature above 800 °C and pH value higher than 6.4 of initial solution. The as-prepared powders consisted of uniform crotch-like grains. The preparation process was monitored by thermogravimetric and differential thermal analysis (TG-DTA) ...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
ZnO nanotubes were hydrothermally synthesized and the ZNTs/CeO2 fluorescent composite were prepared by introducing nano CeO2 particles into ZnO nano-tubes via a chemical solution adsorption and annealing process. The ...ZnO nanotubes were hydrothermally synthesized and the ZNTs/CeO2 fluorescent composite were prepared by introducing nano CeO2 particles into ZnO nano-tubes via a chemical solution adsorption and annealing process. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformation infrared spectroscopy and room temperature photoluminescence measurement. Due to the interaction between Ce4+ and the surface atoms of ZnO2 nano-tubes, a photoluminescence enhancement was obser...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
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
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
Sr-doped La2Mo2O9 were prepared by solid state reaction and characterized by XRD, impedance spectroscopy and Hebb- Wagner polarization method. XRD patterns of the samples indicated that the solubility limit of Sr2＋ i...Sr-doped La2Mo2O9 were prepared by solid state reaction and characterized by XRD, impedance spectroscopy and Hebb- Wagner polarization method. XRD patterns of the samples indicated that the solubility limit of Sr2＋ in La2-xSrxM02O9 -δ was in the range of 7 mol.% to 7.5 tool.%, i.e., the maximum stoichiometric coefficient x in La2~SrxMo209_a was larger than 0.14 and less than 0.15. The cubic lattice parameter of La2 xSrxM02Og-δ （0〈x〈4） increased linearly with the content of dopant Sr2＋ increasing and the relationship could be expressed as： a=0.7154＋0.0045 lx （ram）. The total conductivities of Sr-doped La2M0209 were measured by im- pedance spectroscopy method in argon and air atmosphere, respectively. The results indicated that substituting Sr2＋ fbr La3＋ could suppress the first order phase transform ofLa2M02O9 and stabilize the cubic structure to room temperature, and tile conductivities of Sr-doped La2M02O9 were more sensitive to the change of atmosphere than that of undoped La2M02O9. The conductivity variation of Sr-doped La2M02O9 with the dopant content exhibited similar trend in air and argon atmosphere, firstly decreased and then increased with the dopant content increasing, and a minimum value appeared at x=0.1. The electronic conductivities of Sr-doped La2M02O9 were measured using Hebb-Wagner polarization method in argon atmosphere. It could be found that Sr-doping caused the increase in electronic conductivity and decrease in oxide-ion transport numbers, but the conducting species were predominantly oxide ions. And the oxide-ion transport numbers of some St-doped La2Mo2O9 samples could also reach 0.99.展开更多
Hexagonal yb3＋,Er3＋-doped NaYF4 crystals with different morphologies were synthesized by a facile hydrothermal method at 140-200 ℃. Their shape and size could be controlled by varying hydrothermal temperature, time...Hexagonal yb3＋,Er3＋-doped NaYF4 crystals with different morphologies were synthesized by a facile hydrothermal method at 140-200 ℃. Their shape and size could be controlled by varying hydrothermal temperature, time and doping effect of Ce3＋ ions. Interestingly, the products displayed hexagonal sheet, plate, crown-like prism to tube changes in the temperature range from 140 to 200 ℃. A combination of ＂diffusion-controlled growth＂ and ＂selective adsorption＂ was proposed to understand the formation of the NaYF4 crystals with well-defined shapes. NaYF4：yb3＋/Er3＋ crystals exhibited shape-dependent up-conversion （UC） luminescence under excitation of 980 nm, and their luminescence property could be tuned by doping Ce3＋ ions.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
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.
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supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (No. XDB05010400)the National Natural Science Foundation of China (Nos. 21477134, 41175119, 21473009)
文摘The hygroscopic behaviors of atmospherically relevant multicomponent water soluble organic compounds（WSOCs） and their effects on ammonium sulfate（AS） and sodium chloride were investigated using a hygroscopicity tandem differential mobility analyzer（HTDMA） in the relative humidity（RH） range of 5%–90%. The measured hygroscopic growth was compared with predictions from the Extended-Aerosol Inorganics Model（E-AIM） and Zdanovskii–Stokes–Robinson（ZSR） method. The equal mass multicomponent WSOCs mixture containing levoglucosan, succinic acid, phthalic acid and humic acid showed gradual water uptake without obvious phase change over the whole RH range. It was found that the organic content played an important role in the water uptake of mixed particles.When organic content was dominant in the mixture（75%）, the measured hygroscopic growth was higher than predictions from the E-AIM or ZSR relation, especially under high RH conditions. For mass fractions of organics not larger than 50%, the hygroscopic growth of mixtures was in good agreement with model predictions. The influence of interactions between inorganic and organic components on the hygroscopicity of mixed particles was related to the salt type and organic content. These results could contribute to understanding of the hygroscopic behaviors of multicomponent aerosol particles.
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.
文摘In the context of diminishing energy resources and worsening greenhouse effect,thermoelectric materials have great potential for sustainable development due to their green and environmentally friendly characteristics.Among inorganic thermoelectric materials,copper sulfide compounds have greater potential than others due to their abundant element reserves on Earth,lower usage costs,non-toxicity,and good biocompatibility.Compared to organic thermoelectric materials,the"phonon liquid-electron crystal"(PLEC)feature of copper sulfide compounds makes them have stronger thermoelectric performance.This review summarizes the latest research progress in the synthesis methods and thermoelectric modification strategies of copper sulfide compounds.It first explains the importance of the solid-phase method in the manufacture of thermoelectric devices,and then focuses on the great potential of nanoscale synthesis technology based on liquid-phase method in the preparation of thermoelectric materials.Finally,it systematically discusses several strategies for regulating the thermoelectric performance of copper sulfide compounds,including adjusting the chemical proportion of Cu_(2-x)S and introducing element doping to regulate the crystal structure,phase composition,chemical composition,band structure,and nanoscale microstructure of copper sulfide compounds,and directly affecting ZT value by adjusting conductivity and thermal conductivity.In addition,it discusses composite engineering based on copper sulfide compounds,including inorganic,organic,and metal compounds,and discusses tri-component compounds derived from sulfide copper.Finally,it discusses the main challenges and prospects of the development of copper sulfide-based thermoelectric materials,hoping that this review will promote the development of copper sulfide-based thermoelectric materials.
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.
基金Project supported by the National Natural Science Foundation of China (10776014)High-Tech Foundation of Jiangsu Province (BG2007047)
文摘Superfine Sr2CeO4:RE3+ (RE=Eu, Sm) phosphors were synthesized at relatively low temperature by a modified sol-gel method using nitrates as raw materials, ethylenediaminetetraacetic acid (EDTA) as complexing agent. Single phase phosphors could be obtained at calcination temperature above 800 °C and pH value higher than 6.4 of initial solution. The as-prepared powders consisted of uniform crotch-like grains. The preparation process was monitored by thermogravimetric and differential thermal analysis (TG-DTA) ...
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 supported by the Natural Science Foundation of Tianjin Province (09JCYBJC04200)
文摘ZnO nanotubes were hydrothermally synthesized and the ZNTs/CeO2 fluorescent composite were prepared by introducing nano CeO2 particles into ZnO nano-tubes via a chemical solution adsorption and annealing process. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformation infrared spectroscopy and room temperature photoluminescence measurement. Due to the interaction between Ce4+ and the surface atoms of ZnO2 nano-tubes, a photoluminescence enhancement was obser...
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.
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supported by National Natural Science Foundation of China (50604002)
文摘Sr-doped La2Mo2O9 were prepared by solid state reaction and characterized by XRD, impedance spectroscopy and Hebb- Wagner polarization method. XRD patterns of the samples indicated that the solubility limit of Sr2＋ in La2-xSrxM02O9 -δ was in the range of 7 mol.% to 7.5 tool.%, i.e., the maximum stoichiometric coefficient x in La2~SrxMo209_a was larger than 0.14 and less than 0.15. The cubic lattice parameter of La2 xSrxM02Og-δ （0〈x〈4） increased linearly with the content of dopant Sr2＋ increasing and the relationship could be expressed as： a=0.7154＋0.0045 lx （ram）. The total conductivities of Sr-doped La2M0209 were measured by im- pedance spectroscopy method in argon and air atmosphere, respectively. The results indicated that substituting Sr2＋ fbr La3＋ could suppress the first order phase transform ofLa2M02O9 and stabilize the cubic structure to room temperature, and tile conductivities of Sr-doped La2M02O9 were more sensitive to the change of atmosphere than that of undoped La2M02O9. The conductivity variation of Sr-doped La2M02O9 with the dopant content exhibited similar trend in air and argon atmosphere, firstly decreased and then increased with the dopant content increasing, and a minimum value appeared at x=0.1. The electronic conductivities of Sr-doped La2M02O9 were measured using Hebb-Wagner polarization method in argon atmosphere. It could be found that Sr-doping caused the increase in electronic conductivity and decrease in oxide-ion transport numbers, but the conducting species were predominantly oxide ions. And the oxide-ion transport numbers of some St-doped La2Mo2O9 samples could also reach 0.99.
基金Project supported by the National Natural Science Foundation of China(20671029,21271062Major State Basic Research Development Program of China(2013CBA01700)
文摘Hexagonal yb3＋,Er3＋-doped NaYF4 crystals with different morphologies were synthesized by a facile hydrothermal method at 140-200 ℃. Their shape and size could be controlled by varying hydrothermal temperature, time and doping effect of Ce3＋ ions. Interestingly, the products displayed hexagonal sheet, plate, crown-like prism to tube changes in the temperature range from 140 to 200 ℃. A combination of ＂diffusion-controlled growth＂ and ＂selective adsorption＂ was proposed to understand the formation of the NaYF4 crystals with well-defined shapes. NaYF4：yb3＋/Er3＋ crystals exhibited shape-dependent up-conversion （UC） luminescence under excitation of 980 nm, and their luminescence property could be tuned by doping Ce3＋ ions.
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%.
