In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HE...In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.展开更多
Propylene is a significant basic material for petrochemicals such as polypropylene,propylene oxide,etc.With abundant propane supply from shale gas,propane dehydrogenation(PDH)becomes extensively attractive as an on-pu...Propylene is a significant basic material for petrochemicals such as polypropylene,propylene oxide,etc.With abundant propane supply from shale gas,propane dehydrogenation(PDH)becomes extensively attractive as an on-purpose propylene production route in recent years.Nitrogen-doped carbon(NC)nanopolyhedra supported cobalt catalysts were synthesized in one-step of ZIF-67 pyrolysis and investigated further in PDH.XPS,TEM and N_(2) adsorption-desorption were used to study the influence of carbonization temperature on as-prepared NC supported cobalt catalysts.The temperature is found to affect the cobalt phase and nitrogen species of the catalysts.And the positive correlation was established between Co0 proportion and space time yield of propylene,indicating that the modulation of carbonization temperature could be important for catalytic performance.展开更多
BACKGROUND A positive resection margin is a major risk factor for local breast cancer recurrence after breast-conserving surgery(BCS).Preoperative imaging examinations are frequently employed to assess the surgical ma...BACKGROUND A positive resection margin is a major risk factor for local breast cancer recurrence after breast-conserving surgery(BCS).Preoperative imaging examinations are frequently employed to assess the surgical margin.AIM To investigate the role and value of preoperative imaging examinations[magnetic resonance imaging(MRI),molybdenum target,and ultrasound]in evaluating margins for BCS.METHODS A retrospective study was conducted on 323 breast cancer patients who met the criteria for BCS and consented to the procedure from January 2014 to July 2021.The study gathered preoperative imaging data(MRI,ultrasound,and molybdenum target examination)and intraoperative and postoperative pathological information.Based on their BCS outcomes,patients were categorized into positive and negative margin groups.Subsequently,the patients were randomly split into a training set(226 patients,approximately 70%)and a validation set(97 patients,approximately 30%).The imaging and pathological information was analyzed and summarized using R software.Non-conditional logistic regression and LASSO regression were conducted in the validation set to identify factors that might influence the failure of BCS.A column chart was generated and applied to the validation set to examine the relationship between pathological margin range and prognosis.This study aims to identify the risk factors associated with failure in BCS.RESULTS The multivariate non-conditional logistic regression analysis demonstrated that various factors raise the risk of positive margins following BCS.These factors comprise non-mass enhancement(NME)on dynamic contrastenhanced MRI,multiple focal vascular signs around the lesion on MRI,tumor size exceeding 2 cm,type III timesignal intensity curve,indistinct margins on molybdenum target examination,unclear margins on ultrasound examination,and estrogen receptor(ER)positivity in immunohistochemistry.LASSO regression was additionally employed in this study to identify four predictive factors for the model:ER,molybdenum target tumor type(MT Xmd Shape),maximum intensity projection imaging feature,and lesion type on MRI.The model constructed with these predictive factors exhibited strong consistency with the real-world scenario in both the training set and validation set.Particularly,the outcomes of the column chart model accurately predicted the likelihood of positive margins in BCS.CONCLUSION The proposed column chart model effectively predicts the success of BCS for breast cancer.The model utilizes preoperative ultrasound,molybdenum target,MRI,and core needle biopsy pathology evaluation results,all of which align with the real-world scenario.Hence,our model can offer dependable guidance for clinical decisionmaking concerning BCS.展开更多
Previous studies have shown that caveolin-1 is involved in regulating the differentiation of mesenchymal stem cells.However,its role in the differentiation of human adipose mesenchymal stem cells into dopaminergic neu...Previous studies have shown that caveolin-1 is involved in regulating the differentiation of mesenchymal stem cells.However,its role in the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons remains unclear.The aim of this study was to investigate whether caveolin-1 regulates the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.We also examined whether the expression of caveolin-1 could be modulated by RNA interference technology to promote the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.The differentiation of human adipose mesenchymal stem cells into dopaminergic neurons was evaluated morphologically and by examining expression of the markers tyrosine hydroxylase,Lmx1a and Nurr1.The analyses revealed that during the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons,the expression of caveolin-1 is decreased.Notably,the downregulation of caveolin-1 promoted the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons,and it increased the expression of tyrosine hydroxylase,Lmx1a and Nurr1.Together,our findings suggest that caveolin-1 plays a negative regulatory role in the differentiation of dopaminergic-like neurons from stem cells,and it may therefore be a potential molecular target for strategies for regulating the differentiation of these cells.This study was approved by the Medical Ethics Committee of the First Affiliated Hospital of Dalian Medical University of China(approval No.PJ-KS-KY-2020-54)on March 7,2017.展开更多
The failure mechanism of a cylindrical shell cut into fragments by circumferential detonation collision was experimentally and numerically investigated.A self-designed detonation wave regulator was used to control the...The failure mechanism of a cylindrical shell cut into fragments by circumferential detonation collision was experimentally and numerically investigated.A self-designed detonation wave regulator was used to control the detonation and cut the shell.It was found that the self-designed regulator controlled the fragment shape.The macrostructure and micro-characteristics of fragments revealed that shear fracture was a prior mechanism,the shell fractured not only at the position of detonation collision,but the crack also penetrated the shell at the first contact position of the Chapmen-Jouguet(C-J)wave.The effects of groove number and outer layer thickness on the fracture behavior were tested by simulations.When the thickness of the outer layer was 5e18 mm,it has little effect on fragmentation of the shell,and shells all fractured at similar positions.The increase of the groove number reduced the fracture possibility of the first contact position of the C-J wave.When the groove number reached 7 with a 10 mm outer layer(1/4 model),the fracture only occurred at the position of detonation collision and the fragment width rebounded.展开更多
We consider a binary dipolar Bose–Einstein condensate confined in a rotating harmonic plus quartic potential trap.The ground-state vortex structures are numerically obtained as a function of the contact interactions ...We consider a binary dipolar Bose–Einstein condensate confined in a rotating harmonic plus quartic potential trap.The ground-state vortex structures are numerically obtained as a function of the contact interactions and the dipole–dipole interaction in both slow and rapid rotation cases. The results show that the vortex configurations depend strongly on the strength of the contact interactions, the relative strength between dipolar and contact interactions, as well as on the orientation of the dipoles. A variety of exotic ground-state vortex structures, such as pentagonal and hexagon vortex lattice,square vortex lattice with a central vortex, annular vortex lines, and straight vortex lines, are observed by turning such controllable parameters. Our results deepen the understanding of effects of dipole–dipole interaction on the topological defects.展开更多
Owing to the complexity of geo-engineering seepage problems influenced by different random factors, three-dimensional simulation and analysis of the stochastic seepage field plays an important role in engineering appl...Owing to the complexity of geo-engineering seepage problems influenced by different random factors, three-dimensional simulation and analysis of the stochastic seepage field plays an important role in engineering applications. A three-dimensional anisotropic heterogeneous steady random seepage model was developed on the basis of the finite element method. A statistical analysis of the distribution characteristics of soil parameters sampled from the main embankment of the Yangtze River in the Southern Jingzhou zone of China was conducted. The Kolomogorov-Smirnov test verified the statistical hypothesis that the permeability coefficient tensor has a Gaussian distribution. With the help of numerical analysis of the stochastic seepage field using the developed model, various statistical and random characteristics of the stochastic seepage field of the main embankment of the Yangtze River in the Southern Jingzhou zone of China were investigated. The model was also examined with statistical testing. Through the introduction of random variation of the upstream and downstream water levels into the model, the effects of the boundary randomness due to variation of the downstream and upstream water levels on the variation of simulated results presented with a vector series of the random seepage field were analyzed. Furthermore, the combined influence of the variation of the soil permeability coefficient and such seepage resistance measures as the cut-off wall and relief ditch on the hydraulic head distribution was analyzed and compared with the results obtained by determinate analysis. Meanwhile, sensitivities of the hydraulic gradient and downstream exit height to the variation of boundary water level were studied. The validity of the simulated results was verified by stochastic testing and measured data. The developed model provides more detail and a full stochastic algorithm to characterize and analyze three-dimensional stochastic seepage field problems.展开更多
Layered double hydroxide(LDH)with special layered structure has been proved to have excellent hole transport capacity and good stability.Herein,we report a high efficient composite photocatalyst of CoAlLDH and BiPO4pr...Layered double hydroxide(LDH)with special layered structure has been proved to have excellent hole transport capacity and good stability.Herein,we report a high efficient composite photocatalyst of CoAlLDH and BiPO4prepared by hydrothermal and che mical adsorption(denoted as CoAl-LDH/BiPO_(4)).Phenol can be entirely degraded by 1%CoAl-LDH/BiPO_(4)under 30 min ultraviolet(UV)light irradiation,and the degradation rate constants k are 3 times and 39 times higher than that of pure BiPO_(4)and CoAl-LDH,respectively.The enhanced photocatalytic activity can be attributed to effective holes transfer from BiPO4to CoAl-LDH,which hinders the recombination of photo genera ted charge carriers.In addition,the combination of BiPO4and CoAl-LDH avoids the agglomeration of BiPO4and improves the stability of BiPO_(4).Active species capture experiments indicate that superoxide radicals(·O-_(2))are the main active species responsible for the degradation of phenol.This work provides technical approaches and research ideas for solving the photogenerated charge carrier recombination problem of photocatalyst.展开更多
In order to fully interpret and describe damage mechanics, the origin and development of fuzzy stochastic damage mechanics were introduced based on the analysis of the harmony of damage, probability, and fuzzy members...In order to fully interpret and describe damage mechanics, the origin and development of fuzzy stochastic damage mechanics were introduced based on the analysis of the harmony of damage, probability, and fuzzy membership in the interval of [0,1]. In a complete normed linear space, it was proven that a generalized damage field can be simulated through probability distribution. Three kinds of fuzzy behaviors of damage variables were formulated and explained through analysis of the generalized uncertainty of damage variables and the establishment of a fuzzy functional expression. Corresponding fuzzy mapping distributions, namely, the half-depressed distribution, swing distribution, and combined swing distribution, which can simulate varying fuzzy evolution in diverse stochastic damage situations, were set up. Furthermore, through demonstration of the generalized probabilistic characteristics of damage variables, the cumulative distribution function and probability density function of fuzzy stochastic damage variables, which show probability distribution, were modified according to the expansion principle. The three-dimensional fuzzy stochastic damage mechanical behaviors of the Longtan rolled-concrete dam were examined with the self-developed fuzzy stochastic damage finite element program. The statistical correlation and non-normality of random field parameters were considered comprehensively in the fuzzy stochastic damage model described in this paper. The results show that an initial damage field based on the comprehensive statistical evaluation helps to avoid many difficulties in the establishment of experiments and numerical algorithms for damage mechanics analysis.展开更多
The experimental realization of Rydberg dressing technology in ultracold atomic systems provides another superior platform for studying novel states of matter and macroscopic quantum phenomena.In this work,based on th...The experimental realization of Rydberg dressing technology in ultracold atomic systems provides another superior platform for studying novel states of matter and macroscopic quantum phenomena.In this work,based on the mean-field theory,we have investigated the ground-state phases of a two-component Bose–Einstein condensate with Rydberg interaction and confined in a toroidal trap.The effects of the Rydberg interaction and external potential,especially the Rydberg blockade radius,on the ground-state structure of such a system have been investigated in full parameter space.Our results show that the Rydberg blockade radius,which can be regarded as another controllable parameter,can be used to obtain a variety of ground-state phases.More interestingly,it is found that for weak Rydberg interactions,the Rydberg blockade radius breaks the spontaneous rotational symmetry of the system,leading to the formation of a discrete unit cell structure.For strongly interacting cases,it can be used to realize different orders of discrete rotational symmetry breaking.展开更多
In response to the pressing global issue of reducing carbon emissions and the crucial technical challenges of fully utilizing steel slag,researchers have been studying an accelerated carbonation process that entails t...In response to the pressing global issue of reducing carbon emissions and the crucial technical challenges of fully utilizing steel slag,researchers have been studying an accelerated carbonation process that entails the carbonation of basic oxides in steel slag to store CO_(2).However,despite its promising potential,the process has yet to see widespread industrial application.The latest research progress in the area of mineral carbonation processes,both direct and indirect,that are used to capture,utilize,and store carbon in steel slag are summarized.Given the limited scale of steel slag carbonation and the underutilized products that can be derived from it,a new research focus is proposed for examining the regulation of calcium carbonate crystal forms during carbonation using the Ca source in steel slag.Precise control of synthesis variables will help to ensure accurate control of calcium carbonate precipitation in the carbonation process.A summary of the effects of synthesis variables on CaCO_(3)crystal form and the latest research findings on controlling aragonite morphology are provided.The review is concluded with a discussion of the potential applications and future development prospects of CaCO_(3)whiskers.展开更多
The characteristics of argon oxygen decarburization slag(AODS)for smelting stainless steel that has been aged for 10 years were analyzed.Three types of AODSs distributed at three positions in a slag heap were sampled ...The characteristics of argon oxygen decarburization slag(AODS)for smelting stainless steel that has been aged for 10 years were analyzed.Three types of AODSs distributed at three positions in a slag heap were sampled for comparison experiments.Chemical analysis,mineral phase identification,thermogravimetric analysis,and micromorphology analysis were used to study the element migration trends and carbonation behavior of AODS after long-term aging.Sequential leaching tests were performed to study the chromium leachability of the aged AODS.The results show that during the long-term aging process,the AODS heap had undergone oxidation and carbonation,accompanied by element migration and mineralogical evolution.The surface slag had the highest degree of carbonation but the weakest chromium leachability.The chemical composition of the middle slag was the closest to that of the original slag.In the bottom steel slag,in addition to magnesium,certain depositions of other elements were present.The matrix phases in the aged slag were dicalcium silicate and merwinite,and the chromium was mainly wrapped in these matrix phases in the form of oxides,spinels,or alloys.Under the combined effects of carbonation and oxidation,the leaching characteristics of the chromium in the aged slag varied greatly depending on the location.The bottom slag had the strongest chromium leachability,and the hexavalent chromium had long-term continuous leachability.展开更多
We demonstrate experimentally the simultaneous generation and detection of two types of continuous variable nonclassical states from one type-0 phase-matching optical parametric armplification(OPA)and subsequent two r...We demonstrate experimentally the simultaneous generation and detection of two types of continuous variable nonclassical states from one type-0 phase-matching optical parametric armplification(OPA)and subsequent two ring filter cavities(RFCs).The output field of the OPA includes the baseband wo and sideband modes ω0±nωf subjects to the cavity resonance condition,which are separated by two cascaded RFCs.The first RFC resonates with half the pump wavelength wo and the transmitted baseband component is a squeezed state.The relcted fields of the first RFC,including the sideband modes ω0±wf,are separated by the second RFC,construct Einstein Podolsky-Rosen entangled state.All freedoms,including the filter cavities for sideband separation and relative phases for the measure-ments of these sidebands,are actively stabilized.The noise variance of squeezed states is 10.2 dB below the shot noise limit(SNL),the correlation variances of both quadrature amplitude-sum and quadrature phase diference for the entanglement state are 10.0 dB below the corresponding SNL.展开更多
In this paper, we focus on investigating the stochastic stability and the regime transition between the endangered state and the boom state for a time-delayed insect growth system driven by correlated external and int...In this paper, we focus on investigating the stochastic stability and the regime transition between the endangered state and the boom state for a time-delayed insect growth system driven by correlated external and internal noises. By use of the Fokker Planck equation, the method of small time delay approximation and the fast descent method, we explore in detail the joint action of noise terms and time delay on the mean reproduction and depression time for the insect population. Our investigations indicate that the pseudo-resonance phenomenon of the mean first-passage time (MFPT) occurs because of the impact of different noises and time delay. Through the numerical calculation, it is discovered that multiplicative noise can speed up the shift of the insect population from the boom state to the endangered one, while the noise correlation and time delay can propel the insect system to evolve from the endangered state to the boom state and improve the biological stability. In addition, the impact of the additive noise on the stability of the biological system depends on the positive and negative situation of the noise correlation. On the other hand, during the process of suppressing the insect explosion, it is beneficial to the pest control to amplify the association noise strength and weaken the intensities of the multiplicative, additive noises and time delay. However, during the process of eliminating the pests, it can produce nice effect on the disinsection to increase time delay, the intensities of multiplicative and additive noises and weaken the strength of noise correlation.展开更多
基金financial supports from the National Natural Science Foundation of China (No. 51875062)China Postdoctoral Science Foundation (No. 2021M700567)。
文摘In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.
基金This work is supported by the National Natural Science Foundation of China(Grant Nos.21802167,21961132026,92034302,21878331,91645108)the National Key Research and Development Program Nanotechnology Specific Project(No.2020YFA0210903).
文摘Propylene is a significant basic material for petrochemicals such as polypropylene,propylene oxide,etc.With abundant propane supply from shale gas,propane dehydrogenation(PDH)becomes extensively attractive as an on-purpose propylene production route in recent years.Nitrogen-doped carbon(NC)nanopolyhedra supported cobalt catalysts were synthesized in one-step of ZIF-67 pyrolysis and investigated further in PDH.XPS,TEM and N_(2) adsorption-desorption were used to study the influence of carbonization temperature on as-prepared NC supported cobalt catalysts.The temperature is found to affect the cobalt phase and nitrogen species of the catalysts.And the positive correlation was established between Co0 proportion and space time yield of propylene,indicating that the modulation of carbonization temperature could be important for catalytic performance.
文摘BACKGROUND A positive resection margin is a major risk factor for local breast cancer recurrence after breast-conserving surgery(BCS).Preoperative imaging examinations are frequently employed to assess the surgical margin.AIM To investigate the role and value of preoperative imaging examinations[magnetic resonance imaging(MRI),molybdenum target,and ultrasound]in evaluating margins for BCS.METHODS A retrospective study was conducted on 323 breast cancer patients who met the criteria for BCS and consented to the procedure from January 2014 to July 2021.The study gathered preoperative imaging data(MRI,ultrasound,and molybdenum target examination)and intraoperative and postoperative pathological information.Based on their BCS outcomes,patients were categorized into positive and negative margin groups.Subsequently,the patients were randomly split into a training set(226 patients,approximately 70%)and a validation set(97 patients,approximately 30%).The imaging and pathological information was analyzed and summarized using R software.Non-conditional logistic regression and LASSO regression were conducted in the validation set to identify factors that might influence the failure of BCS.A column chart was generated and applied to the validation set to examine the relationship between pathological margin range and prognosis.This study aims to identify the risk factors associated with failure in BCS.RESULTS The multivariate non-conditional logistic regression analysis demonstrated that various factors raise the risk of positive margins following BCS.These factors comprise non-mass enhancement(NME)on dynamic contrastenhanced MRI,multiple focal vascular signs around the lesion on MRI,tumor size exceeding 2 cm,type III timesignal intensity curve,indistinct margins on molybdenum target examination,unclear margins on ultrasound examination,and estrogen receptor(ER)positivity in immunohistochemistry.LASSO regression was additionally employed in this study to identify four predictive factors for the model:ER,molybdenum target tumor type(MT Xmd Shape),maximum intensity projection imaging feature,and lesion type on MRI.The model constructed with these predictive factors exhibited strong consistency with the real-world scenario in both the training set and validation set.Particularly,the outcomes of the column chart model accurately predicted the likelihood of positive margins in BCS.CONCLUSION The proposed column chart model effectively predicts the success of BCS for breast cancer.The model utilizes preoperative ultrasound,molybdenum target,MRI,and core needle biopsy pathology evaluation results,all of which align with the real-world scenario.Hence,our model can offer dependable guidance for clinical decisionmaking concerning BCS.
基金This work was supported by National Stem Cell Clinical Research Registered Project,No.CMR-20161129-1003(to JL)Dalian Science and Technology Innovation Fund,No.2018J11CY025(to JL).
文摘Previous studies have shown that caveolin-1 is involved in regulating the differentiation of mesenchymal stem cells.However,its role in the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons remains unclear.The aim of this study was to investigate whether caveolin-1 regulates the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.We also examined whether the expression of caveolin-1 could be modulated by RNA interference technology to promote the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.The differentiation of human adipose mesenchymal stem cells into dopaminergic neurons was evaluated morphologically and by examining expression of the markers tyrosine hydroxylase,Lmx1a and Nurr1.The analyses revealed that during the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons,the expression of caveolin-1 is decreased.Notably,the downregulation of caveolin-1 promoted the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons,and it increased the expression of tyrosine hydroxylase,Lmx1a and Nurr1.Together,our findings suggest that caveolin-1 plays a negative regulatory role in the differentiation of dopaminergic-like neurons from stem cells,and it may therefore be a potential molecular target for strategies for regulating the differentiation of these cells.This study was approved by the Medical Ethics Committee of the First Affiliated Hospital of Dalian Medical University of China(approval No.PJ-KS-KY-2020-54)on March 7,2017.
基金the National Natural Science Foundation of China No.11972018the Defense Pre-Research Joint Foundation of Chinese Ordnance Industry No.6141B012858.
文摘The failure mechanism of a cylindrical shell cut into fragments by circumferential detonation collision was experimentally and numerically investigated.A self-designed detonation wave regulator was used to control the detonation and cut the shell.It was found that the self-designed regulator controlled the fragment shape.The macrostructure and micro-characteristics of fragments revealed that shear fracture was a prior mechanism,the shell fractured not only at the position of detonation collision,but the crack also penetrated the shell at the first contact position of the Chapmen-Jouguet(C-J)wave.The effects of groove number and outer layer thickness on the fracture behavior were tested by simulations.When the thickness of the outer layer was 5e18 mm,it has little effect on fragmentation of the shell,and shells all fractured at similar positions.The increase of the groove number reduced the fracture possibility of the first contact position of the C-J wave.When the groove number reached 7 with a 10 mm outer layer(1/4 model),the fracture only occurred at the position of detonation collision and the fragment width rebounded.
基金Project supported by the Sichuan Province Education Department Key Natural Science Fund,China(Grant No.17ZA339)the Chongqing Research Program of Basic Research and Frontier Technology,China(Grant No.cstc2014jcyjA50016)the National Natural Science Foundation of China(Grant No.61504016)
文摘We consider a binary dipolar Bose–Einstein condensate confined in a rotating harmonic plus quartic potential trap.The ground-state vortex structures are numerically obtained as a function of the contact interactions and the dipole–dipole interaction in both slow and rapid rotation cases. The results show that the vortex configurations depend strongly on the strength of the contact interactions, the relative strength between dipolar and contact interactions, as well as on the orientation of the dipoles. A variety of exotic ground-state vortex structures, such as pentagonal and hexagon vortex lattice,square vortex lattice with a central vortex, annular vortex lines, and straight vortex lines, are observed by turning such controllable parameters. Our results deepen the understanding of effects of dipole–dipole interaction on the topological defects.
基金supported by the National Natural Science Foundation of China (Grant No. 50379046)the Doctoral Fund of the Ministry of Education of China (Grant No. A50221)
文摘Owing to the complexity of geo-engineering seepage problems influenced by different random factors, three-dimensional simulation and analysis of the stochastic seepage field plays an important role in engineering applications. A three-dimensional anisotropic heterogeneous steady random seepage model was developed on the basis of the finite element method. A statistical analysis of the distribution characteristics of soil parameters sampled from the main embankment of the Yangtze River in the Southern Jingzhou zone of China was conducted. The Kolomogorov-Smirnov test verified the statistical hypothesis that the permeability coefficient tensor has a Gaussian distribution. With the help of numerical analysis of the stochastic seepage field using the developed model, various statistical and random characteristics of the stochastic seepage field of the main embankment of the Yangtze River in the Southern Jingzhou zone of China were investigated. The model was also examined with statistical testing. Through the introduction of random variation of the upstream and downstream water levels into the model, the effects of the boundary randomness due to variation of the downstream and upstream water levels on the variation of simulated results presented with a vector series of the random seepage field were analyzed. Furthermore, the combined influence of the variation of the soil permeability coefficient and such seepage resistance measures as the cut-off wall and relief ditch on the hydraulic head distribution was analyzed and compared with the results obtained by determinate analysis. Meanwhile, sensitivities of the hydraulic gradient and downstream exit height to the variation of boundary water level were studied. The validity of the simulated results was verified by stochastic testing and measured data. The developed model provides more detail and a full stochastic algorithm to characterize and analyze three-dimensional stochastic seepage field problems.
基金supported by the National Key Research and Development Program of China [2019YFC1904500]National Natural Science Foundation of China [52270115, 21878331, 21777080]Science Foundation of China University of Petroleum, Beijing [2462019QNXZ05, 2462020YXZZ018]
文摘Layered double hydroxide(LDH)with special layered structure has been proved to have excellent hole transport capacity and good stability.Herein,we report a high efficient composite photocatalyst of CoAlLDH and BiPO4prepared by hydrothermal and che mical adsorption(denoted as CoAl-LDH/BiPO_(4)).Phenol can be entirely degraded by 1%CoAl-LDH/BiPO_(4)under 30 min ultraviolet(UV)light irradiation,and the degradation rate constants k are 3 times and 39 times higher than that of pure BiPO_(4)and CoAl-LDH,respectively.The enhanced photocatalytic activity can be attributed to effective holes transfer from BiPO4to CoAl-LDH,which hinders the recombination of photo genera ted charge carriers.In addition,the combination of BiPO4and CoAl-LDH avoids the agglomeration of BiPO4and improves the stability of BiPO_(4).Active species capture experiments indicate that superoxide radicals(·O-_(2))are the main active species responsible for the degradation of phenol.This work provides technical approaches and research ideas for solving the photogenerated charge carrier recombination problem of photocatalyst.
基金supported by the National Natural Science Foundation of China(Grant No51109118)the China Postdoctoral Science Foundation(Grant No20100470344)+1 种基金the Fundamental Project Fund of Zhejiang Ocean University(Grant No21045032610)the Initiating Project Fund for Doctors of Zhejiang Ocean University(Grant No21045011909)
文摘In order to fully interpret and describe damage mechanics, the origin and development of fuzzy stochastic damage mechanics were introduced based on the analysis of the harmony of damage, probability, and fuzzy membership in the interval of [0,1]. In a complete normed linear space, it was proven that a generalized damage field can be simulated through probability distribution. Three kinds of fuzzy behaviors of damage variables were formulated and explained through analysis of the generalized uncertainty of damage variables and the establishment of a fuzzy functional expression. Corresponding fuzzy mapping distributions, namely, the half-depressed distribution, swing distribution, and combined swing distribution, which can simulate varying fuzzy evolution in diverse stochastic damage situations, were set up. Furthermore, through demonstration of the generalized probabilistic characteristics of damage variables, the cumulative distribution function and probability density function of fuzzy stochastic damage variables, which show probability distribution, were modified according to the expansion principle. The three-dimensional fuzzy stochastic damage mechanical behaviors of the Longtan rolled-concrete dam were examined with the self-developed fuzzy stochastic damage finite element program. The statistical correlation and non-normality of random field parameters were considered comprehensively in the fuzzy stochastic damage model described in this paper. The results show that an initial damage field based on the comprehensive statistical evaluation helps to avoid many difficulties in the establishment of experiments and numerical algorithms for damage mechanics analysis.
基金supported by the National Natural Science Foundation of China under Grants No.12005125,No.12105365,12175129the Key Research Program of Frontier Sciences of Chinese Academy of Sciences under Grant No.ZDBS-LY-7016+2 种基金Shaanxi Fundamental Science Research Project for Mathematics and Physics under Grant No.22JSY034Scientific Research Program Funded by Shaanxi Provincial Education Department Program No.23JP020the Youth Innovation Team of Shaanxi Universities。
文摘The experimental realization of Rydberg dressing technology in ultracold atomic systems provides another superior platform for studying novel states of matter and macroscopic quantum phenomena.In this work,based on the mean-field theory,we have investigated the ground-state phases of a two-component Bose–Einstein condensate with Rydberg interaction and confined in a toroidal trap.The effects of the Rydberg interaction and external potential,especially the Rydberg blockade radius,on the ground-state structure of such a system have been investigated in full parameter space.Our results show that the Rydberg blockade radius,which can be regarded as another controllable parameter,can be used to obtain a variety of ground-state phases.More interestingly,it is found that for weak Rydberg interactions,the Rydberg blockade radius breaks the spontaneous rotational symmetry of the system,leading to the formation of a discrete unit cell structure.For strongly interacting cases,it can be used to realize different orders of discrete rotational symmetry breaking.
基金support from Hebei Province Central Guidance Local Science and Technology Development Fund Project(236Z3803G)Innovative Research Group Project of Natural Science Foundation of Hebei Province(E2022209093)+1 种基金Science and Technology Project of Hebei Education Department(QN2021116)National Natural Science Foundation of China(No.52274333).
文摘In response to the pressing global issue of reducing carbon emissions and the crucial technical challenges of fully utilizing steel slag,researchers have been studying an accelerated carbonation process that entails the carbonation of basic oxides in steel slag to store CO_(2).However,despite its promising potential,the process has yet to see widespread industrial application.The latest research progress in the area of mineral carbonation processes,both direct and indirect,that are used to capture,utilize,and store carbon in steel slag are summarized.Given the limited scale of steel slag carbonation and the underutilized products that can be derived from it,a new research focus is proposed for examining the regulation of calcium carbonate crystal forms during carbonation using the Ca source in steel slag.Precise control of synthesis variables will help to ensure accurate control of calcium carbonate precipitation in the carbonation process.A summary of the effects of synthesis variables on CaCO_(3)crystal form and the latest research findings on controlling aragonite morphology are provided.The review is concluded with a discussion of the potential applications and future development prospects of CaCO_(3)whiskers.
基金All the authors acknowledge the support of this study by the National Natural Science Foundation of China(Nos.51704119 and 51574108)the Key Research and Development Project of Tangshan(No.19140205F).
文摘The characteristics of argon oxygen decarburization slag(AODS)for smelting stainless steel that has been aged for 10 years were analyzed.Three types of AODSs distributed at three positions in a slag heap were sampled for comparison experiments.Chemical analysis,mineral phase identification,thermogravimetric analysis,and micromorphology analysis were used to study the element migration trends and carbonation behavior of AODS after long-term aging.Sequential leaching tests were performed to study the chromium leachability of the aged AODS.The results show that during the long-term aging process,the AODS heap had undergone oxidation and carbonation,accompanied by element migration and mineralogical evolution.The surface slag had the highest degree of carbonation but the weakest chromium leachability.The chemical composition of the middle slag was the closest to that of the original slag.In the bottom steel slag,in addition to magnesium,certain depositions of other elements were present.The matrix phases in the aged slag were dicalcium silicate and merwinite,and the chromium was mainly wrapped in these matrix phases in the form of oxides,spinels,or alloys.Under the combined effects of carbonation and oxidation,the leaching characteristics of the chromium in the aged slag varied greatly depending on the location.The bottom slag had the strongest chromium leachability,and the hexavalent chromium had long-term continuous leachability.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11654002,11804207,11874250,and 11804206)the National Key Research and Development Program of China(Grant No.2016YFA0301401)+1 种基金the Program for Sanjin Scholar of Shanxi Province,the Key Research and Development Program of Shanxi(Grant No.201903D111001)the Fund for Shanxi 1331 Project Key Subjects Construction,the Program for Outstanding Innovative Teams of Higher Learning In-stitutions of Shanxi,and the Natural Science Foundation of Shanxi Province(Grant No.201801D221006).
文摘We demonstrate experimentally the simultaneous generation and detection of two types of continuous variable nonclassical states from one type-0 phase-matching optical parametric armplification(OPA)and subsequent two ring filter cavities(RFCs).The output field of the OPA includes the baseband wo and sideband modes ω0±nωf subjects to the cavity resonance condition,which are separated by two cascaded RFCs.The first RFC resonates with half the pump wavelength wo and the transmitted baseband component is a squeezed state.The relcted fields of the first RFC,including the sideband modes ω0±wf,are separated by the second RFC,construct Einstein Podolsky-Rosen entangled state.All freedoms,including the filter cavities for sideband separation and relative phases for the measure-ments of these sidebands,are actively stabilized.The noise variance of squeezed states is 10.2 dB below the shot noise limit(SNL),the correlation variances of both quadrature amplitude-sum and quadrature phase diference for the entanglement state are 10.0 dB below the corresponding SNL.
基金This project was supported by the National Natural Science Foundation of China (Grant Nos.61773012 and 61371114)Six Talent Peaks Foundation Project of Jiangsu Province (Grant No.JY-082)+2 种基金Jiangsu Provincial "Qing-Lan Engineering" Foundation Project, the Jiangsu Provincial Key Laboratory of Networked Collective Intelligence under (Grant No. BM2017002)China Postdoctoral Science Foundation Funded Project (Project No.2016KI591737)the Doctoral Research Startup Project of Jiangsu University of Science and Technology, China (Grant No.1052931704).
文摘In this paper, we focus on investigating the stochastic stability and the regime transition between the endangered state and the boom state for a time-delayed insect growth system driven by correlated external and internal noises. By use of the Fokker Planck equation, the method of small time delay approximation and the fast descent method, we explore in detail the joint action of noise terms and time delay on the mean reproduction and depression time for the insect population. Our investigations indicate that the pseudo-resonance phenomenon of the mean first-passage time (MFPT) occurs because of the impact of different noises and time delay. Through the numerical calculation, it is discovered that multiplicative noise can speed up the shift of the insect population from the boom state to the endangered one, while the noise correlation and time delay can propel the insect system to evolve from the endangered state to the boom state and improve the biological stability. In addition, the impact of the additive noise on the stability of the biological system depends on the positive and negative situation of the noise correlation. On the other hand, during the process of suppressing the insect explosion, it is beneficial to the pest control to amplify the association noise strength and weaken the intensities of the multiplicative, additive noises and time delay. However, during the process of eliminating the pests, it can produce nice effect on the disinsection to increase time delay, the intensities of multiplicative and additive noises and weaken the strength of noise correlation.
