Based on the correlation between certain properties of liquid and the properties of the corresponding liquid drop formed under given conditions, a liquid drop measuring device is utilized to monitor the drop formation...Based on the correlation between certain properties of liquid and the properties of the corresponding liquid drop formed under given conditions, a liquid drop measuring device is utilized to monitor the drop formation process of the liquid sample with photoelectric measuring methods. The mechanical and optical characteristic of the liquid is explored with the optical fibers from the internal of the liquid drop during its formation. The drop head capacitor is utilized to monitor the growth process of the liquid drop to gain the drop volume information related to the physical property of liquid. The unique liquid drop trace containing the integrated properties of liquid is generated, and it is proved by experiment that for different liquids their liquid drop traces are different. The analysis on liquid properties and discrimination between different liquids can be proceeded with the liquid drop trace obtained by the liquid drop measuring device.展开更多
The effective liquid drop model(ELDM)is improved by introducing an accurate nuclear charge radius formula and an analytic expression for assaulting frequency.Within the improved effective liquid drop model(IMELDM),the...The effective liquid drop model(ELDM)is improved by introducing an accurate nuclear charge radius formula and an analytic expression for assaulting frequency.Within the improved effective liquid drop model(IMELDM),the experimental cluster radioactivity half-lives of the trans-lead region are calculated.It is shown that the accuracy of the IMELDM is improved compared with that of the ELDM.At last,the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead nuclei are predicted by the IMELDM.These predictions may be useful for searching for new candidates for cluster radioactivity in future experiments.展开更多
Cluster radioactivity is studied within the generalized liquid drop model(GLDM),in which the shell correction energy,pairing energy,and cluster preformation factor are considered.The calculations show significant impr...Cluster radioactivity is studied within the generalized liquid drop model(GLDM),in which the shell correction energy,pairing energy,and cluster preformation factor are considered.The calculations show significant improvements and can reproduce the experimental data within a factor of 8.04 after considering these physical effects.In addition,the systematic trend of the cluster preformation factors is discussed in terms of the N_(p)N_(n)scheme to study the influence of the valence proton-neutron interaction and shell effect on cluster radioactivity.It is found that log10Pcis linearly related to N_(p)N_(n).This is in agreement with a recent study[L.Qi et al.,Phys.Rev.C 108,014325(2023)],in which log10Pc,obtained using different theoretical models and treatment methods than those used in this study,also had a linear relationship with N_(p)N_(n).Combined with the work by Qi et al.,this study suggests that the linear relationship between log10Pcand N_(p)N_(n)is model-independent and both the shell effect and valence proton-neutron interaction play essential roles in cluster radioactivity.An analytical formula is proposed to calculate the cluster preformation factor based on the N_(p)N_(n)scheme.In addition,the cluster preformation factors and the cluster radioactivity half-lives of some heavy nuclei are predicted,which can provide a reference for future experiments.展开更多
It is universally acknowledged that the Generalized Liquid Drop Model(GLDM)has two advantages over otherαdecay theoretical models:introduction of the quasimolecular shape mechanism and proximity energy.In the past fe...It is universally acknowledged that the Generalized Liquid Drop Model(GLDM)has two advantages over otherαdecay theoretical models:introduction of the quasimolecular shape mechanism and proximity energy.In the past few decades,the original proximity energy has been improved by numerous works.In the present work,the different improvements of proximity energy are examined when they are applied to the GLDM for enhancing the calculation accuracy and prediction ability ofαdecay half-lives for known and unsynthesized superheavy nuclei.The calculations ofαhalf-lives have systematic improvements in reproducing experimental data after choosing a more suitable proximity energy for application to the GLDM.Encouraged by this,theαdecay half-lives of even-even superheavy nuclei with Z=112-122 are predicted by the GLDM with a more suitable proximity energy.The predictions are consistent with calculations by the improved Royer formula and the universal decay law.In addition,the features of the predictedαdecay half-lives imply that the next double magic nucleus after ^(208)Pb is ^(298)Fl.展开更多
Proton radioactivity has been investigated using the effective liquid drop model with varying mass asymmetry shapes and effective inertial coefficients. An effective nuclear radius constant formula replaces the old em...Proton radioactivity has been investigated using the effective liquid drop model with varying mass asymmetry shapes and effective inertial coefficients. An effective nuclear radius constant formula replaces the old empirical one in the calculations. The theoretical half-lives are in good agreement with the available experimental data. All the deviations between the calculated logarithmic half-lives and the experimental values are less than 0.8. The root-mean-square (rms) deviation is 0.523. Predictions for the half-lives of proton radioactivity are made for elements across the periodic table. From the theoretical results, there are 11 candidate nuclei for proton radioactivity in the region Z〈51. In the region Z〉83, no nuclei are suggested as probable candidate nuclei for proton radioactivity within the selected range of half-lives studied.展开更多
Theoretical α-decay half-lives of the heaviest nuclei are calculated using the experimental Qα value. The barriers in the quasi-molecular shape path is determined within a Generalized Liquid Drop Model (GLDM) and th...Theoretical α-decay half-lives of the heaviest nuclei are calculated using the experimental Qα value. The barriers in the quasi-molecular shape path is determined within a Generalized Liquid Drop Model (GLDM) and the WKB approximation is used. The results are compared with calculations using the DensityDependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulae. The calculations provide consistent estimates for the half-lives of the α decay chains of these superheavy elements. The experimental data stand between the GLDM calculations and VSS ones in the most time.展开更多
The barrier against the spontaneous fission has been determined within the Generalized Liquid Drop Model (GLDM) including the mass and charge asymmetry, and the proximity energy. The shell correction of the spherica...The barrier against the spontaneous fission has been determined within the Generalized Liquid Drop Model (GLDM) including the mass and charge asymmetry, and the proximity energy. The shell correction of the spherical parent nucleus is calculated by using the Strutinsky method, and the empirical shape-dependent shell correction is 6mp10yed during the deformation process. A quasi-molecular shape sequence has been defined to describe the whole process from one-body shape to two-body shape system, and a two-touching-ellipsoid is adopted when the superdeformed one-body system reaches the rupture point. On these bases the spontaneous fission barriers are systematically studied for nuclei from 2a^Th to 249 Cm for different possible exiting channels with the different mass and charge asymmetries. The double, and triple bumps are found in the fission potential energy in this region, which roughly agree with the experimental results. It is found that at around Sn-like fragment the outer fission barriers are lower, while the partner of the Sn-like fragment is in the range near l^SRu where the ground-state mass is lowered by allowing axially symmetric shapes. The preferable fission channels are distinctly pronounced, which should be corresponding to the fragment mass distributions.展开更多
In this study,we systematically investigate theαdecay preformation factors,Pα,and theαdecay half-lives of 152 nuclei around Z=82,N=126 closed shells based on the generalized liquid drop model(GLDM)with Pαbeing ext...In this study,we systematically investigate theαdecay preformation factors,Pα,and theαdecay half-lives of 152 nuclei around Z=82,N=126 closed shells based on the generalized liquid drop model(GLDM)with Pαbeing extracted from the ratio of the calculatedαdecay half-life to the experimental one.The results show that there is a remarkable linear relationship between Pαand the product of valance protons(holes)Np and valance neutrons(holes)Nn.At the same time,we extract theαdecay preformation factor values of the even–even nuclei around the Z=82,N=126 closed shells from the study of Sun et al.[J.Phys.G:Nucl.Part.Phys.,45:075106(2018)],in which theαdecay was calculated by two different microscopic formulas.We find that theαdecay preformation factors are also related to NpNn.Combining with our previous studies[Sun et al.,Phys.Rev.C,94:024338(2016);Deng et al.,ibid.96:024318(2017);Deng et al.,ibid.97:044322(2018)]and that of Seif et al.,[Phys.Rev.C,84:064608(2011)],we suspect that this phenomenon of linear relationship for the nuclei around the above closed shells is model-independent.This may be caused by the effect of the valence protons(holes)and valence neutrons(holes)around the shell closures.Finally,using the formula obtained by fitting theαdecay preformation factor data calculated by the GLDM,we calculate theαdecay half-lives of these nuclei.The calculated results agree with the experimental data well.展开更多
By using the experimental approach of dropping liquid, the coupling of three anionic wetting agents with ten dust samples of sulfide ores was studied, and particularly the wetting effects of the wetting agents on the ...By using the experimental approach of dropping liquid, the coupling of three anionic wetting agents with ten dust samples of sulfide ores was studied, and particularly the wetting effects of the wetting agents on the sulfide dust influenced by factors of agent concentration and sulfate additive in the wetting agent solutions were investigated. The results show that when the solution temperature is about 20 ℃, all the selected wetting agents are effective to most dust samples, but the effect is different. Wetting agents are more effective to the dust which is difficult to be wetted. Wetting agent solution with sodium sulfate can improve the wetting ability of sulfide dust. For sodium dodecyl benzene sulfonate, the suitable concentration of sodium sulfate is 12 mmol/L. The cost of wetting agents can be reduced because the sodium sulfate is much cheaper than many surfactants. Since the dust of sulfide ores is composed of various minerals and elements, the whole effect of depressing dust should be considered while innovating a wetting agent.展开更多
A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) was demonstrated for the sensitive determination of four phenols in water samples. Under the...A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility (RSD, n=6) were in the range 5.4%-8.9% and detection limits (S/N=3) were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate (EDTA) into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.展开更多
The deformation patterns of elastic membranes under tension is called wrinkling. Wrinkling, which is caused by capillary surface tension, is called capillary wrinkling (Figure 1). In recent years wrinkling patterns...The deformation patterns of elastic membranes under tension is called wrinkling. Wrinkling, which is caused by capillary surface tension, is called capillary wrinkling (Figure 1). In recent years wrinkling patterns have drawn particular at- tention [1-11], since it can be an useful tool to infer material parameters that might otherwise be inaccessible. For exam- ple, the commonly observed tearing instability of an elastic sheet, adhered to a rigid substrate, can be used to character- ize the adhesion energy.展开更多
Preliminary analysis and calculation of liquid metal Li17Pb83 magnetohydrodynamic (MHD) pressure drop in the blanket for the FDS have been presented to evaluate the significance of MHD effects on the thermal-hydraulic...Preliminary analysis and calculation of liquid metal Li17Pb83 magnetohydrodynamic (MHD) pressure drop in the blanket for the FDS have been presented to evaluate the significance of MHD effects on the thermal-hydraulic design of the blanket. To decrease the liquid metal MHD pressure drop, Al2O3 is applied as an electronically insulated coating onto the inner surface of the ducts. The requirement for the insulated coating to reduce the additional leakage pressure drop caused by coating imperfections has been analyzed. Finally, the total liquid metal MHD pressure drop and magnetic pump power in the FDS blanket have been given.展开更多
A cold-model vertical multi-tube circulating fluidized bed evaporator was designed and built to conduct a visualization study on the pressure drop of a liquid–solid two-phase flow and the corresponding particle distr...A cold-model vertical multi-tube circulating fluidized bed evaporator was designed and built to conduct a visualization study on the pressure drop of a liquid–solid two-phase flow and the corresponding particle distribution.Water and polyformaldehyde particle(POM)were used as the liquid and solid phases,respectively.The effects of operating parameters such as the amount of added particles,circulating flow rate,and particle size were systematically investigated.The results showed that the addition of the particles increased the pressure drop in the vertical tube bundle.The maximum pressure drop ratios were 18.65%,21.15%,18.00%,and 21.15%within the experimental range of the amount of added particles for POM1,POM2,POM3,and POM4,respectively.The pressure drop ratio basically decreased with the increase in the circulating flow rate but fluctuated with the increase in the amount of added particles and particle size.The difference in pressure drop ratio decreased with the increase in the circulating flow rate.As the amount of added particles increased,the difference in pressure drop ratio fluctuated at low circulating flow rate but basically decreased at high circulating flow rate.The pressure drop in the vertical tube bundle accounted for about 70%of the overall pressure drop in the up-flow heating chamber and was the main component of the overall pressure within the experimental range.Three-dimensional phase diagrams were established to display the variation ranges of the pressure drop and pressure drop ratio in the vertical tube bundle corresponding to the operating parameters.The research results can provide some reference for the application of the fluidized bed heat transfer technology in the industry.展开更多
Magnetohydrodynamic (MHD) pressure drop in the Chinese Dual Functional Liquid Lithium-lead Test Blanket Module (DFLL-TBM) proposed for ITER is discussed in this paper. Electrical insulation between the coolant cha...Magnetohydrodynamic (MHD) pressure drop in the Chinese Dual Functional Liquid Lithium-lead Test Blanket Module (DFLL-TBM) proposed for ITER is discussed in this paper. Electrical insulation between the coolant channel surfaces and the liquid metal is required to reduce the MHD pressure drop to a manageable level. Insulation can be provided by a thin insulating coating, such as Al2O3, which can also serve as a tritium barrier layer, at the channel surfaces in contact with LiPb. The coating's effectiveness for reducing the MHD pressure drop is analysed through three-dimensional numerical simulation. A MHD-based commercial computational fluid dynamic (CFD) software FLUENT is used to simulate the LiPb flow. The effect on the MHD pressure drop due to cracks or faults in the coating layer is also considered. The insulating performance requirement for the coating material in DFLL-TBM design is proposed according to the analysis.展开更多
The densities of liquid NiCoAlCr quaternary alloys with a fixed molar ratio of Ni to Co to Al (x(Ni):x(Co):x(Al)≈73:12.15) which is close to the average value of the commercial Ni-based superalloys TMS75, INCO713, CM...The densities of liquid NiCoAlCr quaternary alloys with a fixed molar ratio of Ni to Co to Al (x(Ni):x(Co):x(Al)≈73:12.15) which is close to the average value of the commercial Ni-based superalloys TMS75, INCO713, CM247LC and CMSX-4, and the mass fraction of chromium changes from 0 to 9% were measured by a modified sessile drop method. It is found that with increasing temperature and chromium concentration in the alloys, the densities of the liquid NiCoAlCr quaternary alloys decrease, whereas the molar volume of the liquid NiCoAlCr quaternary alloys increases. And the liquid densities of NiCoAlCr quaternary alloys calculated from the partial molar volumes of nickel, cobalt, aluminum and chromium in the corresponding Ni-bases binary alloys are in good agreement with the experimental ones, i.e. within the error tolerance range the densities of the liquid Ni-based multi-component alloys can be predicted from the partial volumes of elements in Ni-based binary alloys in liquid state. The molar volume of liquid NiCoAlCr binary alloy shows a negative deviation from the ideal linear mixing and the deviation changes small with the increase of chromium concentration at the same temperature.展开更多
Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) w...Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.展开更多
A three-dimensional mathematical model,based on differential balances of mass and momentum,hasbeen developed to describe the two-phase flow of gas and liquid through the dropping zone of the blast fur-nace.Agreement b...A three-dimensional mathematical model,based on differential balances of mass and momentum,hasbeen developed to describe the two-phase flow of gas and liquid through the dropping zone of the blast fur-nace.Agreement between observed and calculated values verifies the validity of this model.On the basis of this model,various parameters for the surrounding of the dry zone of Blast FurnaceNo.I-BF of the Beijing Iron and Steel Company have been computed,from which a diagram for demar-cation of fluidization of coke and flooding of slag has been proposed.展开更多
A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene(BTX) in water...A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene(BTX) in water samples. In the microextraction procedure, a microdrop of n-decanol was delivered to the surface of the analytes’ solution, and stirred for a desired time. Following the absolute extraction, the sample vial was cooled in an ice bath for 10 min. The solidified n-decanol was then transferred into a plastic tube and melted naturally; and 1 μL of it was injected into gas chromatography for analysis. Factors relevant to the extraction efficiency were studied and optimized. The optimal experimental conditions were: 15 μL of n-decanol as extractive solvent, 30 mL of solution containing analytes, no salt, the stirring rate 400 r/min, the extraction temperature 30 °C, and the extraction time 30 min. Under those optimized conditions, the detection limit(LOD) of analytes was in a range of 0.05―0.10 ng/mL by the developed method. A good linearity(r0.99) in a calibration range of 0.01―100 μg/mL was obtained. The recoveries of the real samples at different spiked levels of BTX were in the range from 92.2% to 103.4%.展开更多
The unsteady processes of the Marangoni migration of deformable liquid drops are simulated numerically in a wider range of Marangoni number(up to Ma = 500) in the present work.A steady terminal state can always be rea...The unsteady processes of the Marangoni migration of deformable liquid drops are simulated numerically in a wider range of Marangoni number(up to Ma = 500) in the present work.A steady terminal state can always be reached,and the scaled terminal velocity is a monotonic function decreasing with increasing Marangoni number,which is generally in agreement with corresponding experimental data.The topological structure of flow field in the steady terminal state does not change as the Marangoni number increases,while bifurcation of the topological structure of temperature field occurs twice at two corresponding critical Marangoni numbers.A third critical value of Marangoni number also exists,beyond which the coldest point jumps from the rear stagnation to inside the drop though the topological structure of the temperature field does not change.It is found that the inner and outer thermal boundary layers may exist along the interface both inside and outside the drop if Ma>70.But the thickness decreases with increasing Marangoni number more slowly than the prediction of potential flow at large Marangoni and Reynolds numbers.展开更多
Drop size distribution(DSD) or mean droplet size(d32) and liquid holdup are two key parameters in a liquid–liquid extraction process. Understanding and accurately predicting those parameters are of great importance i...Drop size distribution(DSD) or mean droplet size(d32) and liquid holdup are two key parameters in a liquid–liquid extraction process. Understanding and accurately predicting those parameters are of great importance in the optimal design of extraction columns as well as mixer–settlers. In this paper, the method of built-in endoscopic probe combined with pulse laser was adopted to measure the droplet size in liquid–liquid dispersions with a pump-impeller in a rectangular mixer. The dispersion law of droplets with holdup range 1% to 24% in batch process and larger flow ratio range 1/5 to 5/1 in continuous process was studied. Under the batch operation condition, the DSD abided by log-normal distribution. With the increase of impeller speed or decrease of dispersed phase holdup, the d32 decreased. In addition, a prediction model of d32 of kerosene/deionized system was established as d32/D = 0.13(1 + 5.9φ)We-0.6. Under the continuous operation condition, the general model for droplet size prediction of kerosene/water system was presented as d32/D = C3(1 + C4φ)We-0.6. For the surfactant system and extraction system, the prediction models met a general model as d32/D = bφnWe-0.6.展开更多
基金Supported by Singapore-China Joint R&D Project (No. 003/101/04)
文摘Based on the correlation between certain properties of liquid and the properties of the corresponding liquid drop formed under given conditions, a liquid drop measuring device is utilized to monitor the drop formation process of the liquid sample with photoelectric measuring methods. The mechanical and optical characteristic of the liquid is explored with the optical fibers from the internal of the liquid drop during its formation. The drop head capacitor is utilized to monitor the growth process of the liquid drop to gain the drop volume information related to the physical property of liquid. The unique liquid drop trace containing the integrated properties of liquid is generated, and it is proved by experiment that for different liquids their liquid drop traces are different. The analysis on liquid properties and discrimination between different liquids can be proceeded with the liquid drop trace obtained by the liquid drop measuring device.
基金supported by the National Natural Science Foundation of China(Grant Nos.U1832120 and 11675265)S&T Program of Hebei(Grant No.236Z4601G)+4 种基金Scientific Research Foundation for the Introducing Returned Overseas Chinese Scholars of Hebei Province(Grant No.C20230360)Natural Science Foundation for Outstanding Young Scholars of Hebei Province(Grant No.A2020210012)Natural Science Foundation of Hebei Province(Grant No.A2021210010)Key Laboratory of High Precision Nuclear Spectroscopy,Institute of Modern Physics,Chinese Academy of Sciences(Grant No.IMPKFKT2021002)Key Project of Natural Science Foundation for Basic Discipline Research of Hebei Province(Grant No.A2023210064)。
文摘The effective liquid drop model(ELDM)is improved by introducing an accurate nuclear charge radius formula and an analytic expression for assaulting frequency.Within the improved effective liquid drop model(IMELDM),the experimental cluster radioactivity half-lives of the trans-lead region are calculated.It is shown that the accuracy of the IMELDM is improved compared with that of the ELDM.At last,the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead nuclei are predicted by the IMELDM.These predictions may be useful for searching for new candidates for cluster radioactivity in future experiments.
基金Supported by the National Natural Science Foundation of China(12175170)Hubei Provincial Natural Science Foundation of China(2023AFB035)+1 种基金Hunan Outstanding Youth Science Foundation(2022JJ10031)Natural Science Research Project of Yichang City(A23-2-028)。
文摘Cluster radioactivity is studied within the generalized liquid drop model(GLDM),in which the shell correction energy,pairing energy,and cluster preformation factor are considered.The calculations show significant improvements and can reproduce the experimental data within a factor of 8.04 after considering these physical effects.In addition,the systematic trend of the cluster preformation factors is discussed in terms of the N_(p)N_(n)scheme to study the influence of the valence proton-neutron interaction and shell effect on cluster radioactivity.It is found that log10Pcis linearly related to N_(p)N_(n).This is in agreement with a recent study[L.Qi et al.,Phys.Rev.C 108,014325(2023)],in which log10Pc,obtained using different theoretical models and treatment methods than those used in this study,also had a linear relationship with N_(p)N_(n).Combined with the work by Qi et al.,this study suggests that the linear relationship between log10Pcand N_(p)N_(n)is model-independent and both the shell effect and valence proton-neutron interaction play essential roles in cluster radioactivity.An analytical formula is proposed to calculate the cluster preformation factor based on the N_(p)N_(n)scheme.In addition,the cluster preformation factors and the cluster radioactivity half-lives of some heavy nuclei are predicted,which can provide a reference for future experiments.
基金Support by National Natural Science Foundation of China(10775061,11175054,11675066,11665019,11947229)the Fundamental Research Funds for the Central Universities(lzujbky-2017-ot04,lzujbky-2020-it01)Feitian Scholar Project of Gansu province。
文摘It is universally acknowledged that the Generalized Liquid Drop Model(GLDM)has two advantages over otherαdecay theoretical models:introduction of the quasimolecular shape mechanism and proximity energy.In the past few decades,the original proximity energy has been improved by numerous works.In the present work,the different improvements of proximity energy are examined when they are applied to the GLDM for enhancing the calculation accuracy and prediction ability ofαdecay half-lives for known and unsynthesized superheavy nuclei.The calculations ofαhalf-lives have systematic improvements in reproducing experimental data after choosing a more suitable proximity energy for application to the GLDM.Encouraged by this,theαdecay half-lives of even-even superheavy nuclei with Z=112-122 are predicted by the GLDM with a more suitable proximity energy.The predictions are consistent with calculations by the improved Royer formula and the universal decay law.In addition,the features of the predictedαdecay half-lives imply that the next double magic nucleus after ^(208)Pb is ^(298)Fl.
基金Supported by National Natural Science Foundation of China(11247001)Natural Science Foundation of the Higher Education Institutions of Anhui Province,China(KJ2012A083,KJ2013Z066)Anhui Provincial Natural Science Foundation(1408085MA05)
文摘Proton radioactivity has been investigated using the effective liquid drop model with varying mass asymmetry shapes and effective inertial coefficients. An effective nuclear radius constant formula replaces the old empirical one in the calculations. The theoretical half-lives are in good agreement with the available experimental data. All the deviations between the calculated logarithmic half-lives and the experimental values are less than 0.8. The root-mean-square (rms) deviation is 0.523. Predictions for the half-lives of proton radioactivity are made for elements across the periodic table. From the theoretical results, there are 11 candidate nuclei for proton radioactivity in the region Z〈51. In the region Z〉83, no nuclei are suggested as probable candidate nuclei for proton radioactivity within the selected range of half-lives studied.
基金Supported by Natural Science Foundation of China (10775061, 10505016, 10575119)
文摘Theoretical α-decay half-lives of the heaviest nuclei are calculated using the experimental Qα value. The barriers in the quasi-molecular shape path is determined within a Generalized Liquid Drop Model (GLDM) and the WKB approximation is used. The results are compared with calculations using the DensityDependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulae. The calculations provide consistent estimates for the half-lives of the α decay chains of these superheavy elements. The experimental data stand between the GLDM calculations and VSS ones in the most time.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11175074,11120101005,11105035,and 10805061the Fundamental Research Funds for the Central Universities under Grant No.lzujbky-2012-5the Knowledge Innovation Project of the Chinese Academy of Sciences under Grant No.KJCX2-EW-N01
文摘The barrier against the spontaneous fission has been determined within the Generalized Liquid Drop Model (GLDM) including the mass and charge asymmetry, and the proximity energy. The shell correction of the spherical parent nucleus is calculated by using the Strutinsky method, and the empirical shape-dependent shell correction is 6mp10yed during the deformation process. A quasi-molecular shape sequence has been defined to describe the whole process from one-body shape to two-body shape system, and a two-touching-ellipsoid is adopted when the superdeformed one-body system reaches the rupture point. On these bases the spontaneous fission barriers are systematically studied for nuclei from 2a^Th to 249 Cm for different possible exiting channels with the different mass and charge asymmetries. The double, and triple bumps are found in the fission potential energy in this region, which roughly agree with the experimental results. It is found that at around Sn-like fragment the outer fission barriers are lower, while the partner of the Sn-like fragment is in the range near l^SRu where the ground-state mass is lowered by allowing axially symmetric shapes. The preferable fission channels are distinctly pronounced, which should be corresponding to the fragment mass distributions.
基金Supported in part by the National Natural Science Foundation of China(11205083,11505100,11705055)the Construct Program of the Key Discipline in Hunan Province,the Research Foundation of Education Bureau of Hunan Province,China(15A159,18A237)+4 种基金the Natural Science Foundation of Hunan Province,China(2015JJ3103,2015JJ2121,2018JJ3324)the Innovation Group of Nuclear and Particle Physics in USC,the Shandong Province Natural Science Foundation,China(ZR2015AQ007)the Hunan Provincial Innovation Foundation For Postgraduate(CX20190714,CX20200909)the National Innovation Training Foundation of China(201910555161)and the Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(2019KFZ10)。
文摘In this study,we systematically investigate theαdecay preformation factors,Pα,and theαdecay half-lives of 152 nuclei around Z=82,N=126 closed shells based on the generalized liquid drop model(GLDM)with Pαbeing extracted from the ratio of the calculatedαdecay half-life to the experimental one.The results show that there is a remarkable linear relationship between Pαand the product of valance protons(holes)Np and valance neutrons(holes)Nn.At the same time,we extract theαdecay preformation factor values of the even–even nuclei around the Z=82,N=126 closed shells from the study of Sun et al.[J.Phys.G:Nucl.Part.Phys.,45:075106(2018)],in which theαdecay was calculated by two different microscopic formulas.We find that theαdecay preformation factors are also related to NpNn.Combining with our previous studies[Sun et al.,Phys.Rev.C,94:024338(2016);Deng et al.,ibid.96:024318(2017);Deng et al.,ibid.97:044322(2018)]and that of Seif et al.,[Phys.Rev.C,84:064608(2011)],we suspect that this phenomenon of linear relationship for the nuclei around the above closed shells is model-independent.This may be caused by the effect of the valence protons(holes)and valence neutrons(holes)around the shell closures.Finally,using the formula obtained by fitting theαdecay preformation factor data calculated by the GLDM,we calculate theαdecay half-lives of these nuclei.The calculated results agree with the experimental data well.
文摘By using the experimental approach of dropping liquid, the coupling of three anionic wetting agents with ten dust samples of sulfide ores was studied, and particularly the wetting effects of the wetting agents on the sulfide dust influenced by factors of agent concentration and sulfate additive in the wetting agent solutions were investigated. The results show that when the solution temperature is about 20 ℃, all the selected wetting agents are effective to most dust samples, but the effect is different. Wetting agents are more effective to the dust which is difficult to be wetted. Wetting agent solution with sodium sulfate can improve the wetting ability of sulfide dust. For sodium dodecyl benzene sulfonate, the suitable concentration of sodium sulfate is 12 mmol/L. The cost of wetting agents can be reduced because the sodium sulfate is much cheaper than many surfactants. Since the dust of sulfide ores is composed of various minerals and elements, the whole effect of depressing dust should be considered while innovating a wetting agent.
文摘A single-drop liquid phase micro-extraction procedure using 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) was demonstrated for the sensitive determination of four phenols in water samples. Under the optimized conditions, the linear range of proposed method was excellent in the range of 0.5-100 μg·L^-1, the reproducibility (RSD, n=6) were in the range 5.4%-8.9% and detection limits (S/N=3) were 0.3, 0.3, 0.5 and 0.5 μg·L^-1 for 2, 4-dichlorophenol, 2-naphthol, 2-nitrophenol and 4-chlorophenol, respectively. The experimental results indicated that the effect of complex matrices natural water samples could be resolved with addition of sodium ethylene diamine tetracetate (EDTA) into the samples. Excellent spiked recoveries were achieved for these four phenols ranged from 86.2%-114.9 %. All these facts demonstrated that the proposed method with merits of low cost, simplicity and easy operating would be a competitive alternative procedure for the determination of such compounds at trace level.
文摘The deformation patterns of elastic membranes under tension is called wrinkling. Wrinkling, which is caused by capillary surface tension, is called capillary wrinkling (Figure 1). In recent years wrinkling patterns have drawn particular at- tention [1-11], since it can be an useful tool to infer material parameters that might otherwise be inaccessible. For exam- ple, the commonly observed tearing instability of an elastic sheet, adhered to a rigid substrate, can be used to character- ize the adhesion energy.
基金This work was supported by the National Natural Science Foundation of China No.10175067 and No.10175068
文摘Preliminary analysis and calculation of liquid metal Li17Pb83 magnetohydrodynamic (MHD) pressure drop in the blanket for the FDS have been presented to evaluate the significance of MHD effects on the thermal-hydraulic design of the blanket. To decrease the liquid metal MHD pressure drop, Al2O3 is applied as an electronically insulated coating onto the inner surface of the ducts. The requirement for the insulated coating to reduce the additional leakage pressure drop caused by coating imperfections has been analyzed. Finally, the total liquid metal MHD pressure drop and magnetic pump power in the FDS blanket have been given.
基金supported by the open foundation of State Key Laboratory of Chemical Engineering (SKL-ChE-18B03)the Municipal Science and Technology Commission of Tianjin (No. 2009ZCKFGX01900)
文摘A cold-model vertical multi-tube circulating fluidized bed evaporator was designed and built to conduct a visualization study on the pressure drop of a liquid–solid two-phase flow and the corresponding particle distribution.Water and polyformaldehyde particle(POM)were used as the liquid and solid phases,respectively.The effects of operating parameters such as the amount of added particles,circulating flow rate,and particle size were systematically investigated.The results showed that the addition of the particles increased the pressure drop in the vertical tube bundle.The maximum pressure drop ratios were 18.65%,21.15%,18.00%,and 21.15%within the experimental range of the amount of added particles for POM1,POM2,POM3,and POM4,respectively.The pressure drop ratio basically decreased with the increase in the circulating flow rate but fluctuated with the increase in the amount of added particles and particle size.The difference in pressure drop ratio decreased with the increase in the circulating flow rate.As the amount of added particles increased,the difference in pressure drop ratio fluctuated at low circulating flow rate but basically decreased at high circulating flow rate.The pressure drop in the vertical tube bundle accounted for about 70%of the overall pressure drop in the up-flow heating chamber and was the main component of the overall pressure within the experimental range.Three-dimensional phase diagrams were established to display the variation ranges of the pressure drop and pressure drop ratio in the vertical tube bundle corresponding to the operating parameters.The research results can provide some reference for the application of the fluidized bed heat transfer technology in the industry.
基金Anhui Provincial Natural Science Foundation of China(No.070413085)Anhui Education Department Natural Science Foundation of China(No.2006KJ264)
文摘Magnetohydrodynamic (MHD) pressure drop in the Chinese Dual Functional Liquid Lithium-lead Test Blanket Module (DFLL-TBM) proposed for ITER is discussed in this paper. Electrical insulation between the coolant channel surfaces and the liquid metal is required to reduce the MHD pressure drop to a manageable level. Insulation can be provided by a thin insulating coating, such as Al2O3, which can also serve as a tritium barrier layer, at the channel surfaces in contact with LiPb. The coating's effectiveness for reducing the MHD pressure drop is analysed through three-dimensional numerical simulation. A MHD-based commercial computational fluid dynamic (CFD) software FLUENT is used to simulate the LiPb flow. The effect on the MHD pressure drop due to cracks or faults in the coating layer is also considered. The insulating performance requirement for the coating material in DFLL-TBM design is proposed according to the analysis.
基金Project(NCET-05-0764) supported by the Program for New Century Excellent Talent in Universityproject(2004527) supported by SRF for ROCS, SEM
文摘The densities of liquid NiCoAlCr quaternary alloys with a fixed molar ratio of Ni to Co to Al (x(Ni):x(Co):x(Al)≈73:12.15) which is close to the average value of the commercial Ni-based superalloys TMS75, INCO713, CM247LC and CMSX-4, and the mass fraction of chromium changes from 0 to 9% were measured by a modified sessile drop method. It is found that with increasing temperature and chromium concentration in the alloys, the densities of the liquid NiCoAlCr quaternary alloys decrease, whereas the molar volume of the liquid NiCoAlCr quaternary alloys increases. And the liquid densities of NiCoAlCr quaternary alloys calculated from the partial molar volumes of nickel, cobalt, aluminum and chromium in the corresponding Ni-bases binary alloys are in good agreement with the experimental ones, i.e. within the error tolerance range the densities of the liquid Ni-based multi-component alloys can be predicted from the partial volumes of elements in Ni-based binary alloys in liquid state. The molar volume of liquid NiCoAlCr binary alloy shows a negative deviation from the ideal linear mixing and the deviation changes small with the increase of chromium concentration at the same temperature.
基金Supported by the National Natural Science Foundation of China (No.: 29676042)
文摘Extensive experimental work on hysteresis in a c℃urrent gas-liquid upflow packed bed was carried out with three kinds of packings and the air-water system. However, only when packed with small glass beads ((1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.
文摘A three-dimensional mathematical model,based on differential balances of mass and momentum,hasbeen developed to describe the two-phase flow of gas and liquid through the dropping zone of the blast fur-nace.Agreement between observed and calculated values verifies the validity of this model.On the basis of this model,various parameters for the surrounding of the dry zone of Blast FurnaceNo.I-BF of the Beijing Iron and Steel Company have been computed,from which a diagram for demar-cation of fluidization of coke and flooding of slag has been proposed.
基金Supported by the National Natural Science Foundation of China(No.21105088)the Program for Science and Technology Projects of the Education Department of Fujian Province,China(No.JA10211)
文摘A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene(BTX) in water samples. In the microextraction procedure, a microdrop of n-decanol was delivered to the surface of the analytes’ solution, and stirred for a desired time. Following the absolute extraction, the sample vial was cooled in an ice bath for 10 min. The solidified n-decanol was then transferred into a plastic tube and melted naturally; and 1 μL of it was injected into gas chromatography for analysis. Factors relevant to the extraction efficiency were studied and optimized. The optimal experimental conditions were: 15 μL of n-decanol as extractive solvent, 30 mL of solution containing analytes, no salt, the stirring rate 400 r/min, the extraction temperature 30 °C, and the extraction time 30 min. Under those optimized conditions, the detection limit(LOD) of analytes was in a range of 0.05―0.10 ng/mL by the developed method. A good linearity(r0.99) in a calibration range of 0.01―100 μg/mL was obtained. The recoveries of the real samples at different spiked levels of BTX were in the range from 92.2% to 103.4%.
基金supported by the National Natural Science Foundation of China(10972225)
文摘The unsteady processes of the Marangoni migration of deformable liquid drops are simulated numerically in a wider range of Marangoni number(up to Ma = 500) in the present work.A steady terminal state can always be reached,and the scaled terminal velocity is a monotonic function decreasing with increasing Marangoni number,which is generally in agreement with corresponding experimental data.The topological structure of flow field in the steady terminal state does not change as the Marangoni number increases,while bifurcation of the topological structure of temperature field occurs twice at two corresponding critical Marangoni numbers.A third critical value of Marangoni number also exists,beyond which the coldest point jumps from the rear stagnation to inside the drop though the topological structure of the temperature field does not change.It is found that the inner and outer thermal boundary layers may exist along the interface both inside and outside the drop if Ma>70.But the thickness decreases with increasing Marangoni number more slowly than the prediction of potential flow at large Marangoni and Reynolds numbers.
基金Supported by the National Natural Science Foundation of China(NSFC)(21636004)the National Safety Academy Foundation(U1530107)the National Basic Research Program of China(2012CBA01203).
文摘Drop size distribution(DSD) or mean droplet size(d32) and liquid holdup are two key parameters in a liquid–liquid extraction process. Understanding and accurately predicting those parameters are of great importance in the optimal design of extraction columns as well as mixer–settlers. In this paper, the method of built-in endoscopic probe combined with pulse laser was adopted to measure the droplet size in liquid–liquid dispersions with a pump-impeller in a rectangular mixer. The dispersion law of droplets with holdup range 1% to 24% in batch process and larger flow ratio range 1/5 to 5/1 in continuous process was studied. Under the batch operation condition, the DSD abided by log-normal distribution. With the increase of impeller speed or decrease of dispersed phase holdup, the d32 decreased. In addition, a prediction model of d32 of kerosene/deionized system was established as d32/D = 0.13(1 + 5.9φ)We-0.6. Under the continuous operation condition, the general model for droplet size prediction of kerosene/water system was presented as d32/D = C3(1 + C4φ)We-0.6. For the surfactant system and extraction system, the prediction models met a general model as d32/D = bφnWe-0.6.