The transport process of 12C ions in water was studied with SRIM code and Geant4 toolkit. The SRIM results indicate that the transverse diffusion of 12C ion beam causes distortion of energy deposit along the beam dire...The transport process of 12C ions in water was studied with SRIM code and Geant4 toolkit. The SRIM results indicate that the transverse diffusion of 12C ion beam causes distortion of energy deposit along the beam direction. The distortion becomes more notable as the transverse diffusion increases. The simulation results of Geant4 indicate that the influence of secondary fragments on energy deposit distribution would be the main factor causing the distortion in higher energy range. In the region adjacent to the beam line where the contribution from 12C ions domi- nates, the contributions from secondary fragments are ignorable. The further from the beam axis the region locates, the larger the contributions from secondary fragments, until the contributions from secondary fragments are ignorable. The further from the beam axis the region locates, the larger the contributions from secondary fragments, until the contributions from secondary frag- ments exceed that of 12C. Among all the secondary fragments, the contributions of H, He and B ions are mostly notable. It is also found that some positron-emitting secondary fragments could be very useful for position emitting tomography (PET).展开更多
In this paper, Ti-C-N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions...In this paper, Ti-C-N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions, microstructures, and mechanical properties of the Ti-C-N films are investigated systematically by field emission scanning electron mi- croscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), grazing incident x-ray diffraction (GIXRD), Raman spectra, and nano-indentation. The results show that the nanocrystalline Ti(C,N) phase precipitates in the film from GIXRD and XPS analysis, and Raman spectra prove the presence of diamond-like carbon, indicating the formation of nanocomposite film with microstructures comprising nanocrystalline Ti(C,N) phase embedded into a diamond-like matrix. The nitrogen flow rate has a significant effect on the composition, structure, and properties of the film. The nano-hardness and elastic modulus first increase and then decrease as nitrogen flow rate increases, reaching a maximum of 34.3 GPa and 383.2 GPa, at a nitrogen flow rate of 90 sccm, respectively.展开更多
Field cultivation experiments on white sesame(Sesamum indicum L.)seeds implanted with low-energy C ion showed that different dosages of C ion implantation pro-duce different biological effects.Sesame plants in 6 diffe...Field cultivation experiments on white sesame(Sesamum indicum L.)seeds implanted with low-energy C ion showed that different dosages of C ion implantation pro-duce different biological effects.Sesame plants in 6 different dosage groups with C ion density respectively at 1×10^(11),1×10^(12),1×10^(15),5×10^(15),1×10^(16),5×10^(16)ion/cm2 were superior to the control group in plant height,leaf number,stalk diameter and leaf size.Further,sesame plants in these groups flower and seed earlier than those in the control group,and single plant yield also increased.Of all the groups,the 5×10^(15)ion/cm2 dosage group yielded the best effect,whereas the 1×10^(17)/cm^(2)dosage group showed an evident inhibitory effect of ion implantation on the germination and growth of the sesame seeds.展开更多
将醋酸镍和葡萄糖溶于水中,与氧化石墨烯(GO)水悬浮液均匀混合,在180℃下水热处理24 h,再在Ar中700℃下炭化3 h,然后在空气中300℃下煅烧3 h得到三维Ni/NiO@C/GN。结果表明,水热处理过程中葡萄糖衍生的炭层将Ni(OH)2完全包裹,并在炭化...将醋酸镍和葡萄糖溶于水中,与氧化石墨烯(GO)水悬浮液均匀混合,在180℃下水热处理24 h,再在Ar中700℃下炭化3 h,然后在空气中300℃下煅烧3 h得到三维Ni/NiO@C/GN。结果表明,水热处理过程中葡萄糖衍生的炭层将Ni(OH)2完全包裹,并在炭化过程中转化为金属Ni,部分金属Ni在空气中煅烧中被氧化为NiO。当作为锂离子电池的负极材料时,其初始容量为711.6 mA h g^(-1),300次循环后增加到772.1 mA h g^(-1)。作为对比,没有添加GO的材料的初始容量较低,仅为584.7 mA h g^(-1),300次循环后下降到148.8 mA h g^(-1)。这些结果表明炭层可以抑制Ni/NiO纳米颗粒的团聚,有效缓解锂化过程中的体积膨胀,抑制循环过程中的电极开裂。GO的加入可形成丰富的导电网络,提高导电性。较大的比表面积可增加活性位点,有利于电解液快速浸润电极材料。这些因素显著改善了Ni/NiO@C/GN负极的电化学性能。展开更多
C ^+ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon ( DLC ) film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation ,...C ^+ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon ( DLC ) film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ + ion beam- assisted deposition are improved significantly. DLC film produced by C ^+ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.展开更多
Sweet sorghum mutants induced by^(12)C(6+)-ion irradiation were planted under different soil salinity conditions to investigate the mechanisms maintaining the transport and spatial distribution of Na^+. The functions ...Sweet sorghum mutants induced by^(12)C(6+)-ion irradiation were planted under different soil salinity conditions to investigate the mechanisms maintaining the transport and spatial distribution of Na^+. The functions of the synergistic responses of NHX, AKT1, and SOS1 related to Na^+ accumulation were investigated in control(KFJT-CK) sorghum and KF1210-3 and KF1210-4 mutants. The results indicated that the NHX, AKT1, and SOS1 proteins in sweet sorghum are mainly involved in the transport, exclusion, and spatial distribution of Na^+,respectively. In addition to physiological parameters, we also measured the expression levels of NHX, AKT1, and SOS1 genes. The experimental results indicated that 150 m M Na Cl induced marked increases in the transcripts of NHX and SOS1 after 8 and 12 h in the KF1210-3,KF1210-4, and KFJT-CK cultivars. In contrast, however, a decrease in AKT1 was observed. On the basis of our results, we propose a model in which cooperation amongNHX, AKT1, and SOS1 facilitates Na^+ homeostasis in sweet sorghum in response to an increase in salt concentration. Accordingly, study of the regulatory mechanisms in sweet sorghum generated by carbon ion irradiation is essential for the selection of salt-tolerant cultivars.展开更多
The bare LiFePO4 and LiFePO4/C composites with network structure were prepared by solid-state reaction. The crystalline structures, morphologies and specific surface areas of the materials were investigated by X-ray d...The bare LiFePO4 and LiFePO4/C composites with network structure were prepared by solid-state reaction. The crystalline structures, morphologies and specific surface areas of the materials were investigated by X-ray diffractometry(XRD), scanning electron microscopy(SEM) and multi-point brunauer emmett and teller(BET) method. The results show that the LiFePO4/C composite with the best network structure is obtained by adding 10% phenolic resin carbon. Its electronic conductivity increases to 2.86×10-2 S/cm. It possesses the highest specific surface area of 115.65 m2/g, which exhibits the highest discharge specific capacity of 164.33 mA·h/g at C/10 rate and 149.12 mA·h/g at 1 C rate. The discharge capacity is completely recovered when C/10 rate is applied again.展开更多
We investigate the structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond(UNCD)films. Impedance spectroscopy measurements show that the impedance of diamond grains is relatively st...We investigate the structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond(UNCD)films. Impedance spectroscopy measurements show that the impedance of diamond grains is relatively stable, while that of grain boundaries(GBs)(Rb) significantly increases after the C~+ implantation, and decreases with the increase in the annealing temperature(Ta) from 650℃ to 1000℃. This implies that the C~+ implantation has a more significant impact on the conductivity of GBs. Conductive atomic force microscopy demonstrates that the number of conductive sites increases in GB regions at Ta above 900℃, owing to the formation of a nanographitic phase confirmed by high-resolution transmission electronic microscopy. Visible-light Raman spectra show that resistive trans-polyacetylene oligomers desorb from GBs at Ta above 900℃, which leads to lower Rb of samples annealed at 900 and 1000℃. With the increase in Ta to 1000℃, diamond grains become smaller with longer GBs modified by a more ordered nanographitic phase, supplying more conductive sites and leading to a lower Rb.展开更多
The microstructural study was conducted on cement and cement-slag pastes immersed in different concentrations of Mg(NO3)2 solutions utilizing ^29Si, ^27Al NMR spectroscopy and XRD techniques. The results show that t...The microstructural study was conducted on cement and cement-slag pastes immersed in different concentrations of Mg(NO3)2 solutions utilizing ^29Si, ^27Al NMR spectroscopy and XRD techniques. The results show that the hydration of both the cement and cement-slag pastes is delayed when the pastes are cured in Mg(NO3)2 solutions as compared to the pastes cured in water. Moreover, Mg^2+ ions also exhibit an decalcifying and dealuminizing effect on the C-A-S-H in cement and cement-slag pastes, and thereby decrease Ca/Si and Al[4]/Si ratios of the C-A-S-H. The dealuminization of C-A-S-H is mitigated for cement-slag paste as compared to pure cement paste. The depolymerized calcium and aluminum ions from C-A-S-H gel mainly enter the pore solution to maintain the pH value and form Al^[6] in TAH, respectively. On the other hand, Mg^2+ ions exert an impact on the intra-transition between Al^[6] species, from AFm and hydrogarnet to hydrotalcite-like phase. NO3^-ions are interstratified in the layered Mg-Al structure and formed nitrated hydrotalcite-like phase(Mg1-xAlx(OH)2(NO3)x·nH2O). Results from both ^27Al NMR and XRD data show that ettringite seems not to react with Mg^2+ ions.展开更多
Constructing unique and highly stable structures with plenty of electroactive sites in sodium storage materials is a key factor for achieving improved electrochemical properties through favorable sodium ion di usion k...Constructing unique and highly stable structures with plenty of electroactive sites in sodium storage materials is a key factor for achieving improved electrochemical properties through favorable sodium ion di usion kinetics. An SnS_2@carbon hollow nanospheres(SnS_2@C) has been designed and fabricated via a facile solvothermal route, followed by an annealing treatment. The SnS_2@C hybrid possesses an ideal hollow structure, rich active sites, a large electrode/electrolyte interface, a shortened ion transport pathway, and, importantly, a bu er space for volume change, generated from the repeated insertion/extraction of sodium ions. These merits lead to the significant reinforcement of structural integrity during electrochemical reactions and the improvement in sodium storage properties, with a high specific reversible capacity of 626.8 mAh g^(-1) after 200 cycles at a current density of 0.2 A g^(-1) and superior high-rate performance(304.4 mAh g^(-1) at 5 A g^(-1)).展开更多
The partial and total photorecombination cross sections of the ground-state C V ion in the KLL and KLM resonant energy regions were calculated in detail by using the Dirac atomic R-matrix code based on a fully relativ...The partial and total photorecombination cross sections of the ground-state C V ion in the KLL and KLM resonant energy regions were calculated in detail by using the Dirac atomic R-matrix code based on a fully relativistic R-matrix method. Meanwhile, the principal resonant lines in each photorecombination channel have been classified according to the calculated transition energies and probabilities from the KLL and KLM resonant states to the 1s2nl(n = 2, 3 and l = s, p, d)final states. The validity of these calculations is assessed by comparison with previously published experimental and theoretical data. The good agreement between the present calculated results and those obtained using different approaches confirms the accuracy of the present results. In addition, it is found that the damping effect can be neglected for the KLL resonant, but not for the KLM resonant.展开更多
It has been found that cold plasma is a facile and environmentally benign method for synthesizing supported metal catalysts, and great efforts have been devoted to enlarging its applications. However, little work has ...It has been found that cold plasma is a facile and environmentally benign method for synthesizing supported metal catalysts, and great efforts have been devoted to enlarging its applications. However, little work has been done to disclose the influence mechanism, which is significant for controllable synthesis. In this work, hydrogen cold plasma was adopted to synthesize a palladium catalyst supported on activated carbon (Pd/C-P) using HzPdC14 as a Pd precursor followed by calcination in hydrogen gas to remove the chlorine ions. The Pd/C-P catalyst was found to be made of larger Pd nanoparticles showing a decreased migration to the support outer surface than that prepared by the conventional thermal hydrogen reduction method (Pd/C-C). Meanwhile, the pore diameter of the activated carbon support is small (,-~4 nm). Therefore, Pd/C-P exhibits lower CO oxidation activity than Pd/C-C. It was proposed that the strong interaction between the activated carbon and PdC142-, and the enhanced metal-support interaction caused by hydrogen cold plasma reduction made it difficult for Pd nanoparticles to migrate to the support outer surface. The larger-sized Pd nanoparticles for Pd/C-P may be due to the Coulomb interaction resulting in the disturbance of the metal-support interaction. This work has important guiding significance for the controllable synthesis of supported metal catalysts by hydrogen cold plasma.展开更多
基金supported by the Fundamental Research Funds for the Central Universities of China(HEUCF101501)the Fundamental Research Funds of Harbin Engineering University of China(002150260713)
文摘The transport process of 12C ions in water was studied with SRIM code and Geant4 toolkit. The SRIM results indicate that the transverse diffusion of 12C ion beam causes distortion of energy deposit along the beam direction. The distortion becomes more notable as the transverse diffusion increases. The simulation results of Geant4 indicate that the influence of secondary fragments on energy deposit distribution would be the main factor causing the distortion in higher energy range. In the region adjacent to the beam line where the contribution from 12C ions domi- nates, the contributions from secondary fragments are ignorable. The further from the beam axis the region locates, the larger the contributions from secondary fragments, until the contributions from secondary fragments are ignorable. The further from the beam axis the region locates, the larger the contributions from secondary fragments, until the contributions from secondary frag- ments exceed that of 12C. Among all the secondary fragments, the contributions of H, He and B ions are mostly notable. It is also found that some positron-emitting secondary fragments could be very useful for position emitting tomography (PET).
基金Project supported by the National Natural Science Foundation of China(Grant No.51271047)
文摘In this paper, Ti-C-N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions, microstructures, and mechanical properties of the Ti-C-N films are investigated systematically by field emission scanning electron mi- croscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), grazing incident x-ray diffraction (GIXRD), Raman spectra, and nano-indentation. The results show that the nanocrystalline Ti(C,N) phase precipitates in the film from GIXRD and XPS analysis, and Raman spectra prove the presence of diamond-like carbon, indicating the formation of nanocomposite film with microstructures comprising nanocrystalline Ti(C,N) phase embedded into a diamond-like matrix. The nitrogen flow rate has a significant effect on the composition, structure, and properties of the film. The nano-hardness and elastic modulus first increase and then decrease as nitrogen flow rate increases, reaching a maximum of 34.3 GPa and 383.2 GPa, at a nitrogen flow rate of 90 sccm, respectively.
基金This work was supported by the Country Natural Sciences Fund Subsidizes Project(No.10435020)was the project of the Undergraduate Student Scientific Research Foundation Funds in Beijing Normal University.
文摘Field cultivation experiments on white sesame(Sesamum indicum L.)seeds implanted with low-energy C ion showed that different dosages of C ion implantation pro-duce different biological effects.Sesame plants in 6 different dosage groups with C ion density respectively at 1×10^(11),1×10^(12),1×10^(15),5×10^(15),1×10^(16),5×10^(16)ion/cm2 were superior to the control group in plant height,leaf number,stalk diameter and leaf size.Further,sesame plants in these groups flower and seed earlier than those in the control group,and single plant yield also increased.Of all the groups,the 5×10^(15)ion/cm2 dosage group yielded the best effect,whereas the 1×10^(17)/cm^(2)dosage group showed an evident inhibitory effect of ion implantation on the germination and growth of the sesame seeds.
文摘将醋酸镍和葡萄糖溶于水中,与氧化石墨烯(GO)水悬浮液均匀混合,在180℃下水热处理24 h,再在Ar中700℃下炭化3 h,然后在空气中300℃下煅烧3 h得到三维Ni/NiO@C/GN。结果表明,水热处理过程中葡萄糖衍生的炭层将Ni(OH)2完全包裹,并在炭化过程中转化为金属Ni,部分金属Ni在空气中煅烧中被氧化为NiO。当作为锂离子电池的负极材料时,其初始容量为711.6 mA h g^(-1),300次循环后增加到772.1 mA h g^(-1)。作为对比,没有添加GO的材料的初始容量较低,仅为584.7 mA h g^(-1),300次循环后下降到148.8 mA h g^(-1)。这些结果表明炭层可以抑制Ni/NiO纳米颗粒的团聚,有效缓解锂化过程中的体积膨胀,抑制循环过程中的电极开裂。GO的加入可形成丰富的导电网络,提高导电性。较大的比表面积可增加活性位点,有利于电解液快速浸润电极材料。这些因素显著改善了Ni/NiO@C/GN负极的电化学性能。
基金Funded by the National Natural Science Foundation of China(No.50175041 ,50275111)
文摘C ^+ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon ( DLC ) film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ + ion beam- assisted deposition are improved significantly. DLC film produced by C ^+ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.
基金supported by the Science and Technology Service Network Initiative(STS)program of the Chinese Academy of Sciences(CAS)(KFJ-EW-STS-086)the National Natural Science Foundation of China(No.11275171)+1 种基金the CAS‘‘Light of West China’’ Program(Nos.29Y506020 and 29Y406020)the Youth Innovation Promotion Association of CAS(No.2015337)
文摘Sweet sorghum mutants induced by^(12)C(6+)-ion irradiation were planted under different soil salinity conditions to investigate the mechanisms maintaining the transport and spatial distribution of Na^+. The functions of the synergistic responses of NHX, AKT1, and SOS1 related to Na^+ accumulation were investigated in control(KFJT-CK) sorghum and KF1210-3 and KF1210-4 mutants. The results indicated that the NHX, AKT1, and SOS1 proteins in sweet sorghum are mainly involved in the transport, exclusion, and spatial distribution of Na^+,respectively. In addition to physiological parameters, we also measured the expression levels of NHX, AKT1, and SOS1 genes. The experimental results indicated that 150 m M Na Cl induced marked increases in the transcripts of NHX and SOS1 after 8 and 12 h in the KF1210-3,KF1210-4, and KFJT-CK cultivars. In contrast, however, a decrease in AKT1 was observed. On the basis of our results, we propose a model in which cooperation amongNHX, AKT1, and SOS1 facilitates Na^+ homeostasis in sweet sorghum in response to an increase in salt concentration. Accordingly, study of the regulatory mechanisms in sweet sorghum generated by carbon ion irradiation is essential for the selection of salt-tolerant cultivars.
基金Project(50672024) supported by the National Natural Science Foundation of ChinaProject(06FJ2006) supported by the Applied Basic Research of Hunan Province, China
文摘The bare LiFePO4 and LiFePO4/C composites with network structure were prepared by solid-state reaction. The crystalline structures, morphologies and specific surface areas of the materials were investigated by X-ray diffractometry(XRD), scanning electron microscopy(SEM) and multi-point brunauer emmett and teller(BET) method. The results show that the LiFePO4/C composite with the best network structure is obtained by adding 10% phenolic resin carbon. Its electronic conductivity increases to 2.86×10-2 S/cm. It possesses the highest specific surface area of 115.65 m2/g, which exhibits the highest discharge specific capacity of 164.33 mA·h/g at C/10 rate and 149.12 mA·h/g at 1 C rate. The discharge capacity is completely recovered when C/10 rate is applied again.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50972129 and 50602039)the International Science Technology Cooperation Program of China(Grant No.2014DFR51160)+3 种基金the National Key Research and Development Program of China(Grant No.2016YFE0133200)European Union’s Horizon 2020 Research and Innovation Staff Exchange(RISE)Scheme(Grant No.734578)One Belt and One Road International Cooperation Project from the Key Research and Development Program of Zhejiang Province,China(Grant No.2018C04021)Xinmiao Talents Program of Zhejiang Province,China(Grant No.2017R403078)
文摘We investigate the structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond(UNCD)films. Impedance spectroscopy measurements show that the impedance of diamond grains is relatively stable, while that of grain boundaries(GBs)(Rb) significantly increases after the C~+ implantation, and decreases with the increase in the annealing temperature(Ta) from 650℃ to 1000℃. This implies that the C~+ implantation has a more significant impact on the conductivity of GBs. Conductive atomic force microscopy demonstrates that the number of conductive sites increases in GB regions at Ta above 900℃, owing to the formation of a nanographitic phase confirmed by high-resolution transmission electronic microscopy. Visible-light Raman spectra show that resistive trans-polyacetylene oligomers desorb from GBs at Ta above 900℃, which leads to lower Rb of samples annealed at 900 and 1000℃. With the increase in Ta to 1000℃, diamond grains become smaller with longer GBs modified by a more ordered nanographitic phase, supplying more conductive sites and leading to a lower Rb.
基金Funded by National Natural Science Foundation of China(Nos.51778513,51402003,51578004)China Ministry of Science and Technology(No.2015CB655101)
文摘The microstructural study was conducted on cement and cement-slag pastes immersed in different concentrations of Mg(NO3)2 solutions utilizing ^29Si, ^27Al NMR spectroscopy and XRD techniques. The results show that the hydration of both the cement and cement-slag pastes is delayed when the pastes are cured in Mg(NO3)2 solutions as compared to the pastes cured in water. Moreover, Mg^2+ ions also exhibit an decalcifying and dealuminizing effect on the C-A-S-H in cement and cement-slag pastes, and thereby decrease Ca/Si and Al[4]/Si ratios of the C-A-S-H. The dealuminization of C-A-S-H is mitigated for cement-slag paste as compared to pure cement paste. The depolymerized calcium and aluminum ions from C-A-S-H gel mainly enter the pore solution to maintain the pH value and form Al^[6] in TAH, respectively. On the other hand, Mg^2+ ions exert an impact on the intra-transition between Al^[6] species, from AFm and hydrogarnet to hydrotalcite-like phase. NO3^-ions are interstratified in the layered Mg-Al structure and formed nitrated hydrotalcite-like phase(Mg1-xAlx(OH)2(NO3)x·nH2O). Results from both ^27Al NMR and XRD data show that ettringite seems not to react with Mg^2+ ions.
基金the National Natural Science Foundation of China (Grant No. 21701144)the China Postdoctoral Science Foundation (Grant Nos. 2016M592303 and 2017T100536)
文摘Constructing unique and highly stable structures with plenty of electroactive sites in sodium storage materials is a key factor for achieving improved electrochemical properties through favorable sodium ion di usion kinetics. An SnS_2@carbon hollow nanospheres(SnS_2@C) has been designed and fabricated via a facile solvothermal route, followed by an annealing treatment. The SnS_2@C hybrid possesses an ideal hollow structure, rich active sites, a large electrode/electrolyte interface, a shortened ion transport pathway, and, importantly, a bu er space for volume change, generated from the repeated insertion/extraction of sodium ions. These merits lead to the significant reinforcement of structural integrity during electrochemical reactions and the improvement in sodium storage properties, with a high specific reversible capacity of 626.8 mAh g^(-1) after 200 cycles at a current density of 0.2 A g^(-1) and superior high-rate performance(304.4 mAh g^(-1) at 5 A g^(-1)).
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274254,U1332206,and U1331122)the International Scientific and Technological Cooperative Project of Gansu Province,China(Grant No.1104WCGA186)
文摘The partial and total photorecombination cross sections of the ground-state C V ion in the KLL and KLM resonant energy regions were calculated in detail by using the Dirac atomic R-matrix code based on a fully relativistic R-matrix method. Meanwhile, the principal resonant lines in each photorecombination channel have been classified according to the calculated transition energies and probabilities from the KLL and KLM resonant states to the 1s2nl(n = 2, 3 and l = s, p, d)final states. The validity of these calculations is assessed by comparison with previously published experimental and theoretical data. The good agreement between the present calculated results and those obtained using different approaches confirms the accuracy of the present results. In addition, it is found that the damping effect can be neglected for the KLL resonant, but not for the KLM resonant.
基金supported by National Natural Science Foundation of China (Grant Nos. 11505019, 21673026)Dalian Youth Science and Technology Project (Grant No. 2015R089)
文摘It has been found that cold plasma is a facile and environmentally benign method for synthesizing supported metal catalysts, and great efforts have been devoted to enlarging its applications. However, little work has been done to disclose the influence mechanism, which is significant for controllable synthesis. In this work, hydrogen cold plasma was adopted to synthesize a palladium catalyst supported on activated carbon (Pd/C-P) using HzPdC14 as a Pd precursor followed by calcination in hydrogen gas to remove the chlorine ions. The Pd/C-P catalyst was found to be made of larger Pd nanoparticles showing a decreased migration to the support outer surface than that prepared by the conventional thermal hydrogen reduction method (Pd/C-C). Meanwhile, the pore diameter of the activated carbon support is small (,-~4 nm). Therefore, Pd/C-P exhibits lower CO oxidation activity than Pd/C-C. It was proposed that the strong interaction between the activated carbon and PdC142-, and the enhanced metal-support interaction caused by hydrogen cold plasma reduction made it difficult for Pd nanoparticles to migrate to the support outer surface. The larger-sized Pd nanoparticles for Pd/C-P may be due to the Coulomb interaction resulting in the disturbance of the metal-support interaction. This work has important guiding significance for the controllable synthesis of supported metal catalysts by hydrogen cold plasma.