H_(2)S is one of the most important characteristic decomposition components of SF_(6)insulated gas,and the detection of trace H_(2)S is significant for early fault diagnosis of gas insulated electrical equipment.A 157...H_(2)S is one of the most important characteristic decomposition components of SF_(6)insulated gas,and the detection of trace H_(2)S is significant for early fault diagnosis of gas insulated electrical equipment.A 1578 nm wavelength distributed feedback diode laser(DFB-DL)based cavity ring-down spectroscopy(CRDS)experimental platform is developed to monitor the concentrations of H_(2)S in SF_(6)and SF_(6)/N_(2)mixture carrier gas.The detection sensitivity is higher than 1×10^(-6).The absorption cross section parameterσis vital for calculating the concentration.With repeated experiments using standard gas samples,parameterσof H_(2)S in pure SF_(6)and SF_(6)/N_(2)mixture carrier with different mixing ratios is calibrated.Compared with the simulatedσvalues,the influence of carrier gas on the broadening of spectral profile is discussed.The variation of absorption cross sectionσwith different carrier gas mixing ratios is studied as well,so that the calculation of the concentration in the carrier gas of any mixing ratio is possible.Thus,the application of CRDS in trace component detection of gas insulated electrical equipment is promising.展开更多
In this paper, spinor and vector decompositions of SU（2） gauge potential are presented and their equivalence is constructed using a simply proposal. We also obtain the action of Faddeev nonlinear 0（3） sigma model ...In this paper, spinor and vector decompositions of SU（2） gauge potential are presented and their equivalence is constructed using a simply proposal. We also obtain the action of Faddeev nonlinear 0（3） sigma model from the SU（2） mass/ve gauge field theory, which is proposed according to the gauge invariant principle. At last, the knot structure in SU（2） Chern-Simons filed theory is discussed in terms of the Φ-mapping topological current theory, The topological charge of the knot is characterized by the Hopf indices and the Brouwer degrees of Φ-mapping.展开更多
By using the group IIIB or groupVIIB metals and modulating thecharacteristics of electric charges on carrier surface, improving the catalyst preparation processand techniques for loading the active metal components, a...By using the group IIIB or groupVIIB metals and modulating thecharacteristics of electric charges on carrier surface, improving the catalyst preparation processand techniques for loading the active metal components, a novel type SY-2 catalyst earmarked fortwo-stage hydrogenation of pyrolysis gasoline has been developed. The catalyst evaluation resultshave indicated that the novel catalyst is characterized by a better hydrogenation reaction activityto give higher aromatic yield.展开更多
An easy method for preparing CuO nanoparticles incorporated in a mesoporous structure was presented based on the thermal decomposition of a copper complex. The novel copper coordination compound of [Cu(anic)<sub>...An easy method for preparing CuO nanoparticles incorporated in a mesoporous structure was presented based on the thermal decomposition of a copper complex. The novel copper coordination compound of [Cu(anic)<sub>2</sub>]·0.75H<sub>2</sub>O (anic= 2-aminonicotinate) with the microflake morphology was synthesized through the reaction of 2-aminonicotinic acid (Hanic) and copper(II) nitrate. Using elemental analysis and Fourier transform infrared (FTIR) spectroscopy, the chemical composition of CuC<sub>12</sub>H<sub>11.5</sub>N<sub>4</sub>O<sub>4.75</sub> was proposed. Calcination process at 550 °C for 4 h transformed the microflakes into CuO nanoparticles incorporated in a mesoporous structure. The FTIR peaks assigned to 2-aminonicotinate were completely removed after calcination, confirming CuO formation. X-ray diffraction (XRD) analysis also confirmed the generation of pure and crystalline CuO. SEM showed CuO nanoparticles with the average diameter of 75 nm. The diffuse reflectance spectrum (DRS) of the CuO nanoparticles showed a band gap energy of −1.58 eV. The degradation efficiency toward rhodamine B was almost 100 % after 5 h illumination when both CuO and H<sub>2</sub>O<sub>2</sub> were utilized. The results show that the product can be used as an efficient photocatalyst for water treatment.展开更多
AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,...AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,which serve as a model for enteroendocrine L-cells,by quantitative reverse transcription-polymerase chain reaction and Western blotting before and after treatment with oleic acid.Localization of UCP2 and GLP-1 in NCI-H716 cells was assessed by immunofluorescence labeling.NCI-H716 cells were transiently transfected with a small interfering RNA(siRNA) that targets UCP2(siUCP2) or with a nonspecific siRNA using Lipofectamine 2000.The concentrations of bioactive GLP-1 in the medium were measured by enzyme linked immunosorbent assay.RESULTS:Both GLP-1 and UCP2 granules were expressed mainly in the cytoplasm of NCI-H716 cells.NCI-H716 cells that secreted GLP-1 also expressed UCP2.Time-course experiments revealed that release of GLP-1 from NCI-H716 cells into the medium reached a maximum at 120 min and remained stable until at least 180 min after treatment with oleic acid(the level of GLP-1 increased about 2.3-fold as compared with the level of GLP-1 in the control cells,P < 0.05).In an experiment to determine dose dependence,stimulation of NCI-H716 cells with ≤ 8 mmol oleic acid led to a concentration-dependent release of GLP-1 into the medium;10 mmol oleic acid diminished the release of GLP-1.Furthermore,GLP-1 secretion induced by oleic acid from NCI-H716 cells that were transfected with siUCP2 decreased to 41.8%,as compared with NCI-H716 cells that were transfected with a non-specific siRNA(P < 0.01).CONCLUSION:UCP2 affected GLP-1 secretion induced by oleic acid.UCP2 plays an important role in L-cell secretion that is induced by free fatty acids.展开更多
Objective: To investigate the influence of central administration ofneuropeptide Y-Y5 receptor antisense oligodeoxynucleotides (ODNs) on body weight, fat pads of SDrats, and the effects of white adipocytes lipolysis a...Objective: To investigate the influence of central administration ofneuropeptide Y-Y5 receptor antisense oligodeoxynucleotides (ODNs) on body weight, fat pads of SDrats, and the effects of white adipocytes lipolysis and apoptosis. Methods: Y5 receptor antisense,sense, mismatched ODNs or vehicle was intracerebroventricularly (i. c. v.) injected. Averageadipocyte area was calculated. DNA ladders were measured to evaluate adipocyte apoptosis, and RT-PCRwas used to analyse the expression of Bcl-2 and Bax gene. Results: Central administration of Y5antisense ODNs significantly decreased body weight, and average adipocyte area. DNA fragmentationwas present after electrophoresis at epididymal adipose tissue. The expression of Bcl-2 gene wasdownregulated, while the expression of Bax upregulated. Conclusion: Lipolysis and adipocyteapoptosis may be important mechanisms far 75 antisense therapy.展开更多
Loading of cocatalysts can effectively inhibit the recombination of photogenerated carriers in photocatalysts and greatly improve the photocatalytic hydrogen production rate. Cocatalysts can be deposited at the outlet...Loading of cocatalysts can effectively inhibit the recombination of photogenerated carriers in photocatalysts and greatly improve the photocatalytic hydrogen production rate. Cocatalysts can be deposited at the outlet points of electrons using a photochemical method, which is beneficial for the following photocatalytic hydrogen production reaction. H2PO2^– has been used in the photochemical reduction of transition metals because of its special properties. However, the particles formed in the presence of H2PO2^– are very large and highly crystalline, which may inhibit the activity of photocatalysts. In this study, we designed a new method for synthesizing photocatalysts by photodeposition using some other phosphates, aiming to prepare controllable weakly crystalline and small-size cocatalysts to improve the hydrogen production activity. The cocatalyst prepared using H2PO3^– as an inorganic sacrificial agent has an amorphous structure and an average size of about 10 nm. The optimal photocatalytic hydrogen production rate of the obtained Ni(OH)2/g-C3N4(4.36 wt%) is 13707.86 μmol·g^-1·h^-1, which is even higher than the activity of Pt-4.36 wt%/g-C3N4(11210.93 μmol·g^-1·h^-1). Mechanistic studies show that loading of Ni(OH)2 can efficiently accelerate the separation and transfer efficiency of photogenerated charge carriers.展开更多
The bottleneck of strontium compounds preparing from celestite is the promotion of Sr/S isolation efficiency.Low energy consumption and zero release method for isolating Sr/S in preparing Sr(OH)2 process from celestit...The bottleneck of strontium compounds preparing from celestite is the promotion of Sr/S isolation efficiency.Low energy consumption and zero release method for isolating Sr/S in preparing Sr(OH)2 process from celestite in mild condition was described.Sr element remained in precipitation with formation of Sr(OH)2,while S element entered into leachate with formation of Na2SO4.The effects of initial concentration of NaOH,conversion temperature,liquid-to-solid(L/S)ratio and conversion time on Sr/S ratio of samples for celestite conversion were systematically investigated by experiments.The results demonstrated that the efficiency of Sr/S isolation increased with the initial concentration of NaOH,L/S ratio and conversion time,and decreased with conversion temperature.The maximum conversion ratio of Sr(OH)2 was 93.88%under the optimum condition,whose Sr/S ratio of sample could reach to 41.16.It illustrated that better isolation efficiency of celestite could be achieved in alkaline treatment.The results of SEM-EDS analyses demonstrated that the conversion reaction was a dissolution-precipitation process.展开更多
基金supported in part by the National Key R&D Program of China(No.2021YFF0603100)in part by the Leading Innovation and Entrepreneurship Team in Zhejiang Province(No.2019R01014)
文摘H_(2)S is one of the most important characteristic decomposition components of SF_(6)insulated gas,and the detection of trace H_(2)S is significant for early fault diagnosis of gas insulated electrical equipment.A 1578 nm wavelength distributed feedback diode laser(DFB-DL)based cavity ring-down spectroscopy(CRDS)experimental platform is developed to monitor the concentrations of H_(2)S in SF_(6)and SF_(6)/N_(2)mixture carrier gas.The detection sensitivity is higher than 1×10^(-6).The absorption cross section parameterσis vital for calculating the concentration.With repeated experiments using standard gas samples,parameterσof H_(2)S in pure SF_(6)and SF_(6)/N_(2)mixture carrier with different mixing ratios is calibrated.Compared with the simulatedσvalues,the influence of carrier gas on the broadening of spectral profile is discussed.The variation of absorption cross sectionσwith different carrier gas mixing ratios is studied as well,so that the calculation of the concentration in the carrier gas of any mixing ratio is possible.Thus,the application of CRDS in trace component detection of gas insulated electrical equipment is promising.
基金＊The project supported by National Natural Science Foundation of China and the Doctoral Foundation of the Ministry of Education of China
文摘In this paper, spinor and vector decompositions of SU（2） gauge potential are presented and their equivalence is constructed using a simply proposal. We also obtain the action of Faddeev nonlinear 0（3） sigma model from the SU（2） mass/ve gauge field theory, which is proposed according to the gauge invariant principle. At last, the knot structure in SU（2） Chern-Simons filed theory is discussed in terms of the Φ-mapping topological current theory, The topological charge of the knot is characterized by the Hopf indices and the Brouwer degrees of Φ-mapping.
文摘By using the group IIIB or groupVIIB metals and modulating thecharacteristics of electric charges on carrier surface, improving the catalyst preparation processand techniques for loading the active metal components, a novel type SY-2 catalyst earmarked fortwo-stage hydrogenation of pyrolysis gasoline has been developed. The catalyst evaluation resultshave indicated that the novel catalyst is characterized by a better hydrogenation reaction activityto give higher aromatic yield.
基金Iran University of Science and Technology, the Research Council of Sharif University of Technology and Iran Nanotechnology Initiative Council for financial support
文摘An easy method for preparing CuO nanoparticles incorporated in a mesoporous structure was presented based on the thermal decomposition of a copper complex. The novel copper coordination compound of [Cu(anic)<sub>2</sub>]·0.75H<sub>2</sub>O (anic= 2-aminonicotinate) with the microflake morphology was synthesized through the reaction of 2-aminonicotinic acid (Hanic) and copper(II) nitrate. Using elemental analysis and Fourier transform infrared (FTIR) spectroscopy, the chemical composition of CuC<sub>12</sub>H<sub>11.5</sub>N<sub>4</sub>O<sub>4.75</sub> was proposed. Calcination process at 550 °C for 4 h transformed the microflakes into CuO nanoparticles incorporated in a mesoporous structure. The FTIR peaks assigned to 2-aminonicotinate were completely removed after calcination, confirming CuO formation. X-ray diffraction (XRD) analysis also confirmed the generation of pure and crystalline CuO. SEM showed CuO nanoparticles with the average diameter of 75 nm. The diffuse reflectance spectrum (DRS) of the CuO nanoparticles showed a band gap energy of −1.58 eV. The degradation efficiency toward rhodamine B was almost 100 % after 5 h illumination when both CuO and H<sub>2</sub>O<sub>2</sub> were utilized. The results show that the product can be used as an efficient photocatalyst for water treatment.
基金Supported by Grant from the National Natural Science Foundation of China,No. 30771039
文摘AIM:To investigate whether uncoupling protein 2(UCP2) affects oleic acid-induced secretion of glucagonlike peptide-1(GLP-1) in L-cells.METHODS:mRNA and protein expression of UCP2 were analyzed in human NCI-H716 cells,which serve as a model for enteroendocrine L-cells,by quantitative reverse transcription-polymerase chain reaction and Western blotting before and after treatment with oleic acid.Localization of UCP2 and GLP-1 in NCI-H716 cells was assessed by immunofluorescence labeling.NCI-H716 cells were transiently transfected with a small interfering RNA(siRNA) that targets UCP2(siUCP2) or with a nonspecific siRNA using Lipofectamine 2000.The concentrations of bioactive GLP-1 in the medium were measured by enzyme linked immunosorbent assay.RESULTS:Both GLP-1 and UCP2 granules were expressed mainly in the cytoplasm of NCI-H716 cells.NCI-H716 cells that secreted GLP-1 also expressed UCP2.Time-course experiments revealed that release of GLP-1 from NCI-H716 cells into the medium reached a maximum at 120 min and remained stable until at least 180 min after treatment with oleic acid(the level of GLP-1 increased about 2.3-fold as compared with the level of GLP-1 in the control cells,P < 0.05).In an experiment to determine dose dependence,stimulation of NCI-H716 cells with ≤ 8 mmol oleic acid led to a concentration-dependent release of GLP-1 into the medium;10 mmol oleic acid diminished the release of GLP-1.Furthermore,GLP-1 secretion induced by oleic acid from NCI-H716 cells that were transfected with siUCP2 decreased to 41.8%,as compared with NCI-H716 cells that were transfected with a non-specific siRNA(P < 0.01).CONCLUSION:UCP2 affected GLP-1 secretion induced by oleic acid.UCP2 plays an important role in L-cell secretion that is induced by free fatty acids.
基金Supported by grant from National Natural Science Foundation (39870362)Natural Science Foundation of Education Committee of Jiangsu Province (98KJB320002).
文摘Objective: To investigate the influence of central administration ofneuropeptide Y-Y5 receptor antisense oligodeoxynucleotides (ODNs) on body weight, fat pads of SDrats, and the effects of white adipocytes lipolysis and apoptosis. Methods: Y5 receptor antisense,sense, mismatched ODNs or vehicle was intracerebroventricularly (i. c. v.) injected. Averageadipocyte area was calculated. DNA ladders were measured to evaluate adipocyte apoptosis, and RT-PCRwas used to analyse the expression of Bcl-2 and Bax gene. Results: Central administration of Y5antisense ODNs significantly decreased body weight, and average adipocyte area. DNA fragmentationwas present after electrophoresis at epididymal adipose tissue. The expression of Bcl-2 gene wasdownregulated, while the expression of Bax upregulated. Conclusion: Lipolysis and adipocyteapoptosis may be important mechanisms far 75 antisense therapy.
文摘Loading of cocatalysts can effectively inhibit the recombination of photogenerated carriers in photocatalysts and greatly improve the photocatalytic hydrogen production rate. Cocatalysts can be deposited at the outlet points of electrons using a photochemical method, which is beneficial for the following photocatalytic hydrogen production reaction. H2PO2^– has been used in the photochemical reduction of transition metals because of its special properties. However, the particles formed in the presence of H2PO2^– are very large and highly crystalline, which may inhibit the activity of photocatalysts. In this study, we designed a new method for synthesizing photocatalysts by photodeposition using some other phosphates, aiming to prepare controllable weakly crystalline and small-size cocatalysts to improve the hydrogen production activity. The cocatalyst prepared using H2PO3^– as an inorganic sacrificial agent has an amorphous structure and an average size of about 10 nm. The optimal photocatalytic hydrogen production rate of the obtained Ni(OH)2/g-C3N4(4.36 wt%) is 13707.86 μmol·g^-1·h^-1, which is even higher than the activity of Pt-4.36 wt%/g-C3N4(11210.93 μmol·g^-1·h^-1). Mechanistic studies show that loading of Ni(OH)2 can efficiently accelerate the separation and transfer efficiency of photogenerated charge carriers.
基金Project(2015-GX-108A)supported by Qinghai Provincial Science and Technology Support Program,China
文摘The bottleneck of strontium compounds preparing from celestite is the promotion of Sr/S isolation efficiency.Low energy consumption and zero release method for isolating Sr/S in preparing Sr(OH)2 process from celestite in mild condition was described.Sr element remained in precipitation with formation of Sr(OH)2,while S element entered into leachate with formation of Na2SO4.The effects of initial concentration of NaOH,conversion temperature,liquid-to-solid(L/S)ratio and conversion time on Sr/S ratio of samples for celestite conversion were systematically investigated by experiments.The results demonstrated that the efficiency of Sr/S isolation increased with the initial concentration of NaOH,L/S ratio and conversion time,and decreased with conversion temperature.The maximum conversion ratio of Sr(OH)2 was 93.88%under the optimum condition,whose Sr/S ratio of sample could reach to 41.16.It illustrated that better isolation efficiency of celestite could be achieved in alkaline treatment.The results of SEM-EDS analyses demonstrated that the conversion reaction was a dissolution-precipitation process.
