By extending the concept of diffusion to the potential energy landscapes(PELs), we introduce the meansquared energy difference(MSED) as a novel quantity to investigate the intrinsic properties of supercooled liquids. ...By extending the concept of diffusion to the potential energy landscapes(PELs), we introduce the meansquared energy difference(MSED) as a novel quantity to investigate the intrinsic properties of supercooled liquids. MSED can provide a clear description of the “energy relaxation” process on a PEL. Through MSED analysis, we have obtained a characteristic time similar to that derived from structure analysis, namely τ_(α)^(*).Further, we establish a connection between MSED and the feature of PELs, providing a concise and quantitative description of PELs. The relaxation behavior of energy has been found to follow a stretched exponential form.As the temperature decreases, the roughness of the accessible PEL changes significantly around a characteristic temperature T_(x), which is 20% higher than the glass transition temperature T_(g) and is comparable to the critical temperature of the mode-coupling theory. More importantly, one of the PEL parameters is closely related to the Adam–Gibbs configurational entropy. The present research, which directly links the PEL to the relaxation process, provides avenues for further research of glasses.展开更多
Equations(2)and(6)and the corresponding discussion in the paper[Chin.Phys.Lett.42,056301(2025)]have been corrected.These modiffcations do not affect the results derived in the paper.
Low ionic conductivity is a major obstacle for polymer solid-state electrolytes.In response to this issue,a design concept of enhanced regional electric potential difference(EREPD)is proposed to modulate the interacti...Low ionic conductivity is a major obstacle for polymer solid-state electrolytes.In response to this issue,a design concept of enhanced regional electric potential difference(EREPD)is proposed to modulate the interaction of nanofillers with other components in the composite polymer solid-state electrolytes(CPSEs).While ensuring the periodic structure of the graphdiyne(GDY)backbone,methoxysubstituted GDY(OGDY)is prepared by an asymmetric substitution strategy,which increases the electric potential differences within each repeating unit of GDY.The staggered distributed electron-rich regions and electron-deficient regions on the two-dimensional plane of OGDY increase the free Li^(+)concentration through Lewis acid-base pair interaction.The adjacent ERRs and EDRs form uniformly distributed EREPDs,creating a continuous potential gradient that synergistically facilitates the efficient migration of Li^(+).Impressively,the OGDY/poly(ethylene oxide)(PEO)exhibits a high ionic conductivity(1.1×10^(-3)S cm^(−1))and ion mobility number(0.71).In addition,the accelerated Li^(+)migration promotes the formation of uniform and dense SEI layers and inhibits the growth of lithium dendrites.As a proof of concept,Li||Li symmetric cell and Li||LiFePO_(4)full cell and pouch cell assembled with OGDY/PEO exhibit good performance,highlighting the effectiveness of our EREPD design strategy for improving CPSEs performance.展开更多
Contact bounce of relay, which is the main cause of electric abrasion and material erosion, is inevitable. By using the mode expansion form, the dynamic behavior of two different reed systems for aerospace relays is a...Contact bounce of relay, which is the main cause of electric abrasion and material erosion, is inevitable. By using the mode expansion form, the dynamic behavior of two different reed systems for aerospace relays is analyzed. The dynamic model uses Euler-Bernoulli beam theory for cantilever beam, in which the driving force (or driving moment) of the electromagnetic system is taken into account, and the contact force between moving contact and stationary contact is simulated by the Kelvin-Voigt vis-coelastic...展开更多
A three-dimensional （3D） predictor-corrector finite difference method for standing wave is developed. It is applied to solve the 3D nonlinear potential flow equa- tions with a free surface. The 3D irregular tank is ...A three-dimensional （3D） predictor-corrector finite difference method for standing wave is developed. It is applied to solve the 3D nonlinear potential flow equa- tions with a free surface. The 3D irregular tank is mapped onto a fixed cubic tank through the proper coordinate transform schemes. The cubic tank is distributed by the staggered meshgrid, and the staggered meshgrid is used to denote the variables of the flow field. The predictor-corrector finite difference method is given to develop the difference equa- tions of the dynamic boundary equation and kinematic boundary equation. Experimental results show that, using the finite difference method of the predictor-corrector scheme, the numerical solutions agree well with the published results. The wave profiles of the standing wave with different amplitudes and wave lengths are studied. The numerical solutions are also analyzed and presented graphically.展开更多
Antimicrobial material is highly desired because of the increasing demand in biomedical application to prevent from the formation of biofilm.A common strategy for enhancing the antibacterial property of a metal materi...Antimicrobial material is highly desired because of the increasing demand in biomedical application to prevent from the formation of biofilm.A common strategy for enhancing the antibacterial property of a metal material is to incorporate toxic metal such as Cu and Ag.However,the reported Cu^(2+)or Ag~+released concentration from antibacterial alloys was much less than the reported minimum inhibitory ion concentrations(MIC),revealing the existence of an unknown alternative antimicrobial mechanism not relying on the toxicity of the metal ions.Herein,we proposed a new antibacterial mechanism that the antibacterial effectiveness of the different alloys is proportional to the micro-area potential differences(MAPDs)on the surface of the alloys.We designed three kinds of Ti-M(M=Zr,Ta and Au)alloys to eliminate the potential antibacterial contribution from Cu and Ag ion.We demonstrated that high MAPDs are associated with great production of reactive oxygen species(ROS),resulting in the killing effect to the biofilm known to be associated with implant infections(Staphlococcus aureus and Escherichia coli).These results provide new insights for the design of antibacterial alloys.展开更多
The nonlinear Schr?dinger equation with a Dirac delta potential is considered in this paper.It is noted that the equation can be transformed into an equation with a drift-admitting jump.Then following the procedure pr...The nonlinear Schr?dinger equation with a Dirac delta potential is considered in this paper.It is noted that the equation can be transformed into an equation with a drift-admitting jump.Then following the procedure proposed in Chen and Deng(2018 Phys.Rev.E 98033302),a new second-order finite difference scheme is developed,which is justified by numerical examples.展开更多
The valuation relation of potential difference with discharging time in Electrical Discharge Machining (EDM) is analyzed theoretically and tested and verified by experiments designed in this paper and the relation bet...The valuation relation of potential difference with discharging time in Electrical Discharge Machining (EDM) is analyzed theoretically and tested and verified by experiments designed in this paper and the relation between potential difference and spark location is induced and analyzed, and proceed by experiments under the condition of onedimension.展开更多
Global minimization algorithm is indispensable for solving protein folding problems based on thermodynamic hypothesis. A contact difference （CD） based on pseudo potential function, for simulating empirical contact p...Global minimization algorithm is indispensable for solving protein folding problems based on thermodynamic hypothesis. A contact difference （CD） based on pseudo potential function, for simulating empirical contact potential functions and testing global minimization algorithm was proposed. The present article describes a conformational sampiing and global minimization algorithm, which is called WL, based on Monte Carlo simulation and simulated annealing. It can be used to locate CD＇s globe minimum and refold extended protein structures, as small as 0. 03 nm, from the native structures, back to ones with root mean square distance（RMSD）. These results demonstrate that the global minimization problems for empirical contact potential functions may be solvable.展开更多
Global minimization algorithm is indispensable to solving the protein folding problem based upon thermodynamic hypothesis. Here we propose a pseudo potential function, contact difference(CD), for simulating empirical ...Global minimization algorithm is indispensable to solving the protein folding problem based upon thermodynamic hypothesis. Here we propose a pseudo potential function, contact difference(CD), for simulating empirical contact potential functions and testing global minimization algorithm. The present paper covers conformational sampling and global minimization algorithm called BML03, based upon Monte Carlo and simulated annealing, which is able to locate CD′s global minimum and refold extended protein structures into ones with root mean square distance(RMSD) as small as 0.03 nm from the native structures. For empirical contact potential functions, these results demonstrate that their global minimization problems may be solvable.展开更多
We consider the(2+1)-dimensional nonlinear Schrodinger equation with power-law nonlinearity under the parity-time-symmetry potential by using the Crank-Nicolson alternating direction implicit difference scheme,which c...We consider the(2+1)-dimensional nonlinear Schrodinger equation with power-law nonlinearity under the parity-time-symmetry potential by using the Crank-Nicolson alternating direction implicit difference scheme,which can also be used to solve general boundary problems under the premise of ensuring accuracy.We use linear Fourier analysis to verify the unconditional stability of the scheme.To demonstrate the effectiveness of the scheme,we compare the numerical results with the exact soliton solutions.Moreover,by using the scheme,we test the stability of the solitons under the small environmental disturbances.展开更多
The potential difference between positive and negative ions was utilized to improve the homogenized dispersion of nanoscale Al_(2)O_(3) whiskers in Mg matrix composites.The Mg powders were decorated with sodium dodecy...The potential difference between positive and negative ions was utilized to improve the homogenized dispersion of nanoscale Al_(2)O_(3) whiskers in Mg matrix composites.The Mg powders were decorated with sodium dodecylbenzene sulfonate(C_(18)H_(29)NaO_(3)S,SDBS)and were introduced to the cathode group on their surface.The Al_(2)O_(3) whiskers were modified by the cetyl trimethyl ammonium bromide(C_(19)H_(42)BrN,CTAB)and were featured in the anode group.The suitable contents of CTAB and SDBS,the application atmosphere,and the type of solvents were investigated.Dispersion results showed that adding 2wt%SDBS into Mg powders and adding 2wt%CTAB into Al_(2)O_(3) whiskers pro-moted the formation of more uniformly mixed composite powders,compared to those of conventional ball milling via scanning electron micro-scopy(SEM)analysis.Meanwhile,the calculated results derived from first-principle calculations also demonstrated the stronger cohesion between Al_(2)O_(3) whisker reinforcements and Mg matrix than undecorated composite powders.After preparation by powder metallurgy,the mor-phology,grain size,hardness,and standard deviation coefficient of composites were analyzed to evaluate the dispersed efficiency.The results indicated that the modification of homogenized dispersed Al_(2)O_(3) whiskers in composites contributed to the refinement of 26%in grain size and the improvement of 20%in hardness compared with pure Mg,and the reduction of 32.5%in the standard deviation coefficient of hardness compared with the ball-milling sample.展开更多
Background: Nasal potential difference (NPD) test has long been used to assist in the diagnosis of Cystic Fibrosis (CF) and more recently as an outcome measure in clinical trials of new CF therapies. This test has als...Background: Nasal potential difference (NPD) test has long been used to assist in the diagnosis of Cystic Fibrosis (CF) and more recently as an outcome measure in clinical trials of new CF therapies. This test has also been adapted to the mouse nose. Objectives: We aimed at evaluating variability of the NPD measurements in CF patients displaying two severe CFTR mutations and in sex-matched healthy controls. NPD recorded from F508del-CF and normal wild-type mice were also compared. Methods and results: In each setting, tests were performed by a single qualified operator. In the clinical setting, the latest standardized operation protocol of the CF foundation was followed. A total of 80 tracings were obtained from 10 patients (23.2 y;range 14 to 32) and 10 healthy subjects (34 y;range 24 to 53), each tested twice, in both nostrils. Two CF and two controls were excluded from the statistical data analysis due to the presence of a single non interpretable NPD tracing (4/80, 5%). To achieve equal sample size, tests were obtained from 8 CF mice and normal wild-type. Comprehensive multivariate analysis of paired data showed a good reproducibility of NPD parameters in the clinical and the preclinical setting;lower variability was observed in mice. However, 95% repeatability limits of NPD parameters were large indicating a large measurement error, poor precision and low within-subject repeatability. In both settings, chloride secretion was shown to be the most reproducible and repeatable parameter. Conclusion: In human as in mice, NPD showed good reproducibility but limited within-subject repeatability.展开更多
BACKGROUND: The wave form, latency and wave amplitude of visual evoked potentials (VEP) are obviously affected by the stimulative parameters, physiological status of the subjects and anesthetics, thus there are greate...BACKGROUND: The wave form, latency and wave amplitude of visual evoked potentials (VEP) are obviously affected by the stimulative parameters, physiological status of the subjects and anesthetics, thus there are greater normal variations and individual differences. The features of flash VEP (F-VEP) are to be observed. OBJECTIVE: To observe and compare the differences of F-VEP latencies and wave amplitudes between eyes in rabbits, and investigate the correlation with sex and the side of eyes. DESIGN: A comparative animal experiment. SETTING: Department of Neurosurgery, General Hospital of Chinese PLA. MATERIALS: The experiment was carried out in the neurophysiological laboratory of the Institute of Neurosciences, General Hospital of Chinese PLA from September 2004 to February 2005. Thirty big-ear rabbits of clean degree, 15 males and 15 females, weighing 2.0-2.5 kg, were provided by the animal center of the General Hospital of Chinese PLA. METHODS: Viking-IV perioperative monitor and flash stimulator for special use were applied. The rabbits were anesthetized with intramuscular injection of compound ketamine. The recording electrode was placed at 3 mm anterior to exoccipital tuberosity (onion, Oz), and the reference electrode was placed at the ear edge of the same side. The stimulative frequency was 1.9 Hz, and the amplifier was 50 μV; The range of wave filter was 5 Hz for high pass and 100 Hz for low pass; The average overlapping was 200 times, and the analytical time was 250 ms. MAIN OUTCOME MEASURES: Comparison of F-VEP wave forms; F-VEP latencies and wave amplitudes. RESULTS: All the 30 rabbits were involved in the analysis of results. ① Comparison of F-VEP wave forms in rabbits: The F-VEP waves mainly manifested as positive-negative-positive (PNP). The F-VEP manifestations to light stimulations were extremely similar between left and right eyes, and the wave amplitudes of both eyes were obviously increased. ② Determinations of F-VEP latencies and wave amplitudes: There were no significant differences in the latencies and wave amplitudes of F-VEP between the two groups (P > 0.05), the latencies of P1, N1 and P2 waves of left eye were (32.59±2.01), (43.85±4.35) and (66.20±8.13) ms, respectively, and the wave amplitudes of P1, N1 and P2 waves of left eye were (16.45±10.22), (7.93±3.56) and (17.62±8.18) μV. F-VEP latencies were stable with small changes, whereas amplitudes had greater changes. CONCLUSION: ① The latency and wave amplitudes F-VEP were stable with good repetition. ② The latencies and wave amplitudes had no significant differences between males and females, as well as between left and right eyes. Further investigation should be undertaken on the animal and clinical field.展开更多
An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved....An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.展开更多
This work presents a study on the use of cathodic protection as a measure against corrosion in pipelines.The cathodic protection,compliant with the API 5L standard,is implemented here by applying an impressed current,...This work presents a study on the use of cathodic protection as a measure against corrosion in pipelines.The cathodic protection,compliant with the API 5L standard,is implemented here by applying an impressed current,while carefully considering several essential variables,such as soil characteristics,the type and color of the pipeline material,as well as the placement and size of the anode.Therefore,it is crucial to optimize the location and values of anodic overflows or ground resistances to ensure a uniform distribution of potential across the entire structure.In this method,impressed current protection uses an auxiliary anode and an external direct current source to induce a current through the electrolyte and the pipeline,thus countering the resistance of the steel.This approach is advantageous as it allows for the adjustment of electrical characteristics,particularly current levels,to meet specific needs.The factors essential to the effectiveness of cathodic protection systems,which optimize the distribution of protection potential across the structure,largely depend on the precise management of ground resistances during anodic discharge,particularly the attenuation coefficient(α).These factors were studied,and the results obtained were presented and discussed based on their influence.展开更多
Objective To compare the event-related potentials （ERPs） waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and ＂...Objective To compare the event-related potentials （ERPs） waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and ＂preposition＂. Results Both verbs and prepositions elicited a negativity at the frontal site in 230-330 ms and 350-500 ms window. No difference was seen in 230-330 ms and 350-500 ms window; In difference waves, a negativity was elicited in the left and fight hemisphere at about 270-400 ms and 470-600 ms window for both open and closed-class words. Conclusion These may demonstrate that prepositions in modem Chinese are probably not a separate class from verbs and that N280 may be not a specific component for only prepositions （or closed-class words）.展开更多
A continuous and analytical surface potential model for SOI LDMOS, which accounts for automatic transitions between fully and partially-depleted statuses,is presented. The surface potential equation of the SOI de- vic...A continuous and analytical surface potential model for SOI LDMOS, which accounts for automatic transitions between fully and partially-depleted statuses,is presented. The surface potential equation of the SOI de- vice is solved by using the PSP′s accurate algorithm of surface potential,and the front and back surface potentials are obtained analytically as a function of gate and drain voltage. The formulations of inversion charge and body charge under the fully-depleted state have been modified. The continuous and analytical DC model for SOl LD- MOS is given based on PSP. The comparisons between simulation and measurements indicate that this model can predict the DC characteristics of SOI LDMOS accurately.展开更多
Significant progress has been made in mixed boundary-value problems associated with three-dimensional（3D） crack and contact analyses of advanced materials featuring more complexities compared to the conventional iso...Significant progress has been made in mixed boundary-value problems associated with three-dimensional（3D） crack and contact analyses of advanced materials featuring more complexities compared to the conventional isotropic elastic materials.These include material anisotropy and multifield coupling,two typical characteristics of most current multifunctional materials.In this paper we try to present a state-of-the-art description of 3D exact/analytical solutions derived for crack and contact problems of elastic solids with both transverse isotropy and multifield coupling in the latest decade by the potential theory method in the spirit of V.I.Fabrikant.whose ingenious breakthrough brings new vigor and vitality to the old research subject of classical potential theory.We are particularly interested in crack and contact problems with certain nonlinear features.Emphasis is also placed on the coupling between the temperature field（or the like） and other physical fields（e.g.,elastic,electric,and magnetic fields）.We further highlight the practical significance of 3D contact solutions,in particular in applications related to modern scanning probe microscopes.展开更多
基金supported by the National Key Research and Development Program of China (Grant No. 2022YFA1404603)by the National Natural Science Foundation of China (Grant Nos. 12274127 and 12188101)。
文摘By extending the concept of diffusion to the potential energy landscapes(PELs), we introduce the meansquared energy difference(MSED) as a novel quantity to investigate the intrinsic properties of supercooled liquids. MSED can provide a clear description of the “energy relaxation” process on a PEL. Through MSED analysis, we have obtained a characteristic time similar to that derived from structure analysis, namely τ_(α)^(*).Further, we establish a connection between MSED and the feature of PELs, providing a concise and quantitative description of PELs. The relaxation behavior of energy has been found to follow a stretched exponential form.As the temperature decreases, the roughness of the accessible PEL changes significantly around a characteristic temperature T_(x), which is 20% higher than the glass transition temperature T_(g) and is comparable to the critical temperature of the mode-coupling theory. More importantly, one of the PEL parameters is closely related to the Adam–Gibbs configurational entropy. The present research, which directly links the PEL to the relaxation process, provides avenues for further research of glasses.
文摘Equations(2)and(6)and the corresponding discussion in the paper[Chin.Phys.Lett.42,056301(2025)]have been corrected.These modiffcations do not affect the results derived in the paper.
基金supported by the National Key Research and Development Project of China(2022YFA1204500,2022YFA1204503,2018YFA0703501)the National Natural Science Foundation of China(22275115,21875274,11704024)+4 种基金the Natural Science Foundation of Shandong Province(ZR2024ZD02)Natural Science Foundation of Hebei Province(B2020201006)Hebei Province Innovation Capability Enhancement Plan Project(22567620H)Young Scholarship Funding of Shandong University.Post-graduate Innovation Fund Project of Open Laboratory Project Fund of Hebei University(HBU2025SS010)Basic Research Project of Shandong University-Xin’an Group Silicon-Based High-End New Materials Institute.
文摘Low ionic conductivity is a major obstacle for polymer solid-state electrolytes.In response to this issue,a design concept of enhanced regional electric potential difference(EREPD)is proposed to modulate the interaction of nanofillers with other components in the composite polymer solid-state electrolytes(CPSEs).While ensuring the periodic structure of the graphdiyne(GDY)backbone,methoxysubstituted GDY(OGDY)is prepared by an asymmetric substitution strategy,which increases the electric potential differences within each repeating unit of GDY.The staggered distributed electron-rich regions and electron-deficient regions on the two-dimensional plane of OGDY increase the free Li^(+)concentration through Lewis acid-base pair interaction.The adjacent ERRs and EDRs form uniformly distributed EREPDs,creating a continuous potential gradient that synergistically facilitates the efficient migration of Li^(+).Impressively,the OGDY/poly(ethylene oxide)(PEO)exhibits a high ionic conductivity(1.1×10^(-3)S cm^(−1))and ion mobility number(0.71).In addition,the accelerated Li^(+)migration promotes the formation of uniform and dense SEI layers and inhibits the growth of lithium dendrites.As a proof of concept,Li||Li symmetric cell and Li||LiFePO_(4)full cell and pouch cell assembled with OGDY/PEO exhibit good performance,highlighting the effectiveness of our EREPD design strategy for improving CPSEs performance.
文摘Contact bounce of relay, which is the main cause of electric abrasion and material erosion, is inevitable. By using the mode expansion form, the dynamic behavior of two different reed systems for aerospace relays is analyzed. The dynamic model uses Euler-Bernoulli beam theory for cantilever beam, in which the driving force (or driving moment) of the electromagnetic system is taken into account, and the contact force between moving contact and stationary contact is simulated by the Kelvin-Voigt vis-coelastic...
基金supported by the Yunnan Provincial Applied Basic Research Program of China(No. KKSY201207019)
文摘A three-dimensional （3D） predictor-corrector finite difference method for standing wave is developed. It is applied to solve the 3D nonlinear potential flow equa- tions with a free surface. The 3D irregular tank is mapped onto a fixed cubic tank through the proper coordinate transform schemes. The cubic tank is distributed by the staggered meshgrid, and the staggered meshgrid is used to denote the variables of the flow field. The predictor-corrector finite difference method is given to develop the difference equa- tions of the dynamic boundary equation and kinematic boundary equation. Experimental results show that, using the finite difference method of the predictor-corrector scheme, the numerical solutions agree well with the published results. The wave profiles of the standing wave with different amplitudes and wave lengths are studied. The numerical solutions are also analyzed and presented graphically.
基金the financial support from National Natural Science Foundation of China(Nos.81071262/H1820 and 31971253/C1002)the instrumental analysis from Analytical and Testing Center,Northeastern University。
文摘Antimicrobial material is highly desired because of the increasing demand in biomedical application to prevent from the formation of biofilm.A common strategy for enhancing the antibacterial property of a metal material is to incorporate toxic metal such as Cu and Ag.However,the reported Cu^(2+)or Ag~+released concentration from antibacterial alloys was much less than the reported minimum inhibitory ion concentrations(MIC),revealing the existence of an unknown alternative antimicrobial mechanism not relying on the toxicity of the metal ions.Herein,we proposed a new antibacterial mechanism that the antibacterial effectiveness of the different alloys is proportional to the micro-area potential differences(MAPDs)on the surface of the alloys.We designed three kinds of Ti-M(M=Zr,Ta and Au)alloys to eliminate the potential antibacterial contribution from Cu and Ag ion.We demonstrated that high MAPDs are associated with great production of reactive oxygen species(ROS),resulting in the killing effect to the biofilm known to be associated with implant infections(Staphlococcus aureus and Escherichia coli).These results provide new insights for the design of antibacterial alloys.
基金supported by the National Natural Science Foundation of China(Grant Nos.11601517,61772542).
文摘The nonlinear Schr?dinger equation with a Dirac delta potential is considered in this paper.It is noted that the equation can be transformed into an equation with a drift-admitting jump.Then following the procedure proposed in Chen and Deng(2018 Phys.Rev.E 98033302),a new second-order finite difference scheme is developed,which is justified by numerical examples.
文摘The valuation relation of potential difference with discharging time in Electrical Discharge Machining (EDM) is analyzed theoretically and tested and verified by experiments designed in this paper and the relation between potential difference and spark location is induced and analyzed, and proceed by experiments under the condition of onedimension.
文摘Global minimization algorithm is indispensable for solving protein folding problems based on thermodynamic hypothesis. A contact difference （CD） based on pseudo potential function, for simulating empirical contact potential functions and testing global minimization algorithm was proposed. The present article describes a conformational sampiing and global minimization algorithm, which is called WL, based on Monte Carlo simulation and simulated annealing. It can be used to locate CD＇s globe minimum and refold extended protein structures, as small as 0. 03 nm, from the native structures, back to ones with root mean square distance（RMSD）. These results demonstrate that the global minimization problems for empirical contact potential functions may be solvable.
基金Supported by the National Natural Science Foundation of China(No.30 2 4 0 0 16)
文摘Global minimization algorithm is indispensable to solving the protein folding problem based upon thermodynamic hypothesis. Here we propose a pseudo potential function, contact difference(CD), for simulating empirical contact potential functions and testing global minimization algorithm. The present paper covers conformational sampling and global minimization algorithm called BML03, based upon Monte Carlo and simulated annealing, which is able to locate CD′s global minimum and refold extended protein structures into ones with root mean square distance(RMSD) as small as 0.03 nm from the native structures. For empirical contact potential functions, these results demonstrate that their global minimization problems may be solvable.
文摘We consider the(2+1)-dimensional nonlinear Schrodinger equation with power-law nonlinearity under the parity-time-symmetry potential by using the Crank-Nicolson alternating direction implicit difference scheme,which can also be used to solve general boundary problems under the premise of ensuring accuracy.We use linear Fourier analysis to verify the unconditional stability of the scheme.To demonstrate the effectiveness of the scheme,we compare the numerical results with the exact soliton solutions.Moreover,by using the scheme,we test the stability of the solitons under the small environmental disturbances.
基金the Fundamental Research Funds for the National Natural Science Foundation of China (Nos. 52101123 and 52004227)the Fundamental Research Funds for the Central Universities-Interdisciplinary Research (No. 2682021ZTPY001)the Dongguan Scitech Commissioner (No. 20211800500102)
文摘The potential difference between positive and negative ions was utilized to improve the homogenized dispersion of nanoscale Al_(2)O_(3) whiskers in Mg matrix composites.The Mg powders were decorated with sodium dodecylbenzene sulfonate(C_(18)H_(29)NaO_(3)S,SDBS)and were introduced to the cathode group on their surface.The Al_(2)O_(3) whiskers were modified by the cetyl trimethyl ammonium bromide(C_(19)H_(42)BrN,CTAB)and were featured in the anode group.The suitable contents of CTAB and SDBS,the application atmosphere,and the type of solvents were investigated.Dispersion results showed that adding 2wt%SDBS into Mg powders and adding 2wt%CTAB into Al_(2)O_(3) whiskers pro-moted the formation of more uniformly mixed composite powders,compared to those of conventional ball milling via scanning electron micro-scopy(SEM)analysis.Meanwhile,the calculated results derived from first-principle calculations also demonstrated the stronger cohesion between Al_(2)O_(3) whisker reinforcements and Mg matrix than undecorated composite powders.After preparation by powder metallurgy,the mor-phology,grain size,hardness,and standard deviation coefficient of composites were analyzed to evaluate the dispersed efficiency.The results indicated that the modification of homogenized dispersed Al_(2)O_(3) whiskers in composites contributed to the refinement of 26%in grain size and the improvement of 20%in hardness compared with pure Mg,and the reduction of 32.5%in the standard deviation coefficient of hardness compared with the ball-milling sample.
文摘Background: Nasal potential difference (NPD) test has long been used to assist in the diagnosis of Cystic Fibrosis (CF) and more recently as an outcome measure in clinical trials of new CF therapies. This test has also been adapted to the mouse nose. Objectives: We aimed at evaluating variability of the NPD measurements in CF patients displaying two severe CFTR mutations and in sex-matched healthy controls. NPD recorded from F508del-CF and normal wild-type mice were also compared. Methods and results: In each setting, tests were performed by a single qualified operator. In the clinical setting, the latest standardized operation protocol of the CF foundation was followed. A total of 80 tracings were obtained from 10 patients (23.2 y;range 14 to 32) and 10 healthy subjects (34 y;range 24 to 53), each tested twice, in both nostrils. Two CF and two controls were excluded from the statistical data analysis due to the presence of a single non interpretable NPD tracing (4/80, 5%). To achieve equal sample size, tests were obtained from 8 CF mice and normal wild-type. Comprehensive multivariate analysis of paired data showed a good reproducibility of NPD parameters in the clinical and the preclinical setting;lower variability was observed in mice. However, 95% repeatability limits of NPD parameters were large indicating a large measurement error, poor precision and low within-subject repeatability. In both settings, chloride secretion was shown to be the most reproducible and repeatable parameter. Conclusion: In human as in mice, NPD showed good reproducibility but limited within-subject repeatability.
文摘BACKGROUND: The wave form, latency and wave amplitude of visual evoked potentials (VEP) are obviously affected by the stimulative parameters, physiological status of the subjects and anesthetics, thus there are greater normal variations and individual differences. The features of flash VEP (F-VEP) are to be observed. OBJECTIVE: To observe and compare the differences of F-VEP latencies and wave amplitudes between eyes in rabbits, and investigate the correlation with sex and the side of eyes. DESIGN: A comparative animal experiment. SETTING: Department of Neurosurgery, General Hospital of Chinese PLA. MATERIALS: The experiment was carried out in the neurophysiological laboratory of the Institute of Neurosciences, General Hospital of Chinese PLA from September 2004 to February 2005. Thirty big-ear rabbits of clean degree, 15 males and 15 females, weighing 2.0-2.5 kg, were provided by the animal center of the General Hospital of Chinese PLA. METHODS: Viking-IV perioperative monitor and flash stimulator for special use were applied. The rabbits were anesthetized with intramuscular injection of compound ketamine. The recording electrode was placed at 3 mm anterior to exoccipital tuberosity (onion, Oz), and the reference electrode was placed at the ear edge of the same side. The stimulative frequency was 1.9 Hz, and the amplifier was 50 μV; The range of wave filter was 5 Hz for high pass and 100 Hz for low pass; The average overlapping was 200 times, and the analytical time was 250 ms. MAIN OUTCOME MEASURES: Comparison of F-VEP wave forms; F-VEP latencies and wave amplitudes. RESULTS: All the 30 rabbits were involved in the analysis of results. ① Comparison of F-VEP wave forms in rabbits: The F-VEP waves mainly manifested as positive-negative-positive (PNP). The F-VEP manifestations to light stimulations were extremely similar between left and right eyes, and the wave amplitudes of both eyes were obviously increased. ② Determinations of F-VEP latencies and wave amplitudes: There were no significant differences in the latencies and wave amplitudes of F-VEP between the two groups (P > 0.05), the latencies of P1, N1 and P2 waves of left eye were (32.59±2.01), (43.85±4.35) and (66.20±8.13) ms, respectively, and the wave amplitudes of P1, N1 and P2 waves of left eye were (16.45±10.22), (7.93±3.56) and (17.62±8.18) μV. F-VEP latencies were stable with small changes, whereas amplitudes had greater changes. CONCLUSION: ① The latency and wave amplitudes F-VEP were stable with good repetition. ② The latencies and wave amplitudes had no significant differences between males and females, as well as between left and right eyes. Further investigation should be undertaken on the animal and clinical field.
文摘An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.
文摘This work presents a study on the use of cathodic protection as a measure against corrosion in pipelines.The cathodic protection,compliant with the API 5L standard,is implemented here by applying an impressed current,while carefully considering several essential variables,such as soil characteristics,the type and color of the pipeline material,as well as the placement and size of the anode.Therefore,it is crucial to optimize the location and values of anodic overflows or ground resistances to ensure a uniform distribution of potential across the entire structure.In this method,impressed current protection uses an auxiliary anode and an external direct current source to induce a current through the electrolyte and the pipeline,thus countering the resistance of the steel.This approach is advantageous as it allows for the adjustment of electrical characteristics,particularly current levels,to meet specific needs.The factors essential to the effectiveness of cathodic protection systems,which optimize the distribution of protection potential across the structure,largely depend on the precise management of ground resistances during anodic discharge,particularly the attenuation coefficient(α).These factors were studied,and the results obtained were presented and discussed based on their influence.
基金the National Social Science Foundation of China （No. 03BYY013） the Science Foundation of Jiangsu Province （No. QL200504）.
文摘Objective To compare the event-related potentials （ERPs） waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and ＂preposition＂. Results Both verbs and prepositions elicited a negativity at the frontal site in 230-330 ms and 350-500 ms window. No difference was seen in 230-330 ms and 350-500 ms window; In difference waves, a negativity was elicited in the left and fight hemisphere at about 270-400 ms and 470-600 ms window for both open and closed-class words. Conclusion These may demonstrate that prepositions in modem Chinese are probably not a separate class from verbs and that N280 may be not a specific component for only prepositions （or closed-class words）.
文摘A continuous and analytical surface potential model for SOI LDMOS, which accounts for automatic transitions between fully and partially-depleted statuses,is presented. The surface potential equation of the SOI de- vice is solved by using the PSP′s accurate algorithm of surface potential,and the front and back surface potentials are obtained analytically as a function of gate and drain voltage. The formulations of inversion charge and body charge under the fully-depleted state have been modified. The continuous and analytical DC model for SOl LD- MOS is given based on PSP. The comparisons between simulation and measurements indicate that this model can predict the DC characteristics of SOI LDMOS accurately.
基金supported by the National Natural Science Foundation of China(Grant 11321202)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant 20130101110120)
文摘Significant progress has been made in mixed boundary-value problems associated with three-dimensional（3D） crack and contact analyses of advanced materials featuring more complexities compared to the conventional isotropic elastic materials.These include material anisotropy and multifield coupling,two typical characteristics of most current multifunctional materials.In this paper we try to present a state-of-the-art description of 3D exact/analytical solutions derived for crack and contact problems of elastic solids with both transverse isotropy and multifield coupling in the latest decade by the potential theory method in the spirit of V.I.Fabrikant.whose ingenious breakthrough brings new vigor and vitality to the old research subject of classical potential theory.We are particularly interested in crack and contact problems with certain nonlinear features.Emphasis is also placed on the coupling between the temperature field（or the like） and other physical fields（e.g.,elastic,electric,and magnetic fields）.We further highlight the practical significance of 3D contact solutions,in particular in applications related to modern scanning probe microscopes.
