The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodiu...The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.展开更多
The influences of carboxymethyl starch used as stabilizer upon the stability of native cornstarchpolyvinyl alcohol blend pastes for warp sizing have been investigated. The effect of the modified starch on the paste st...The influences of carboxymethyl starch used as stabilizer upon the stability of native cornstarchpolyvinyl alcohol blend pastes for warp sizing have been investigated. The effect of the modified starch on the paste stability was evaluated in terms of the initial demixing time and the volume percentage of separated starch. The carboxymethyl starch with a series of different degrees of substitution was prepared in ethanol dispersion by varying the amount of monochloroacetic acid reacted with refined native cornstarch. The paste stability strongly depends on the modification extent and amount of carboxymethyl starch used, and on native starch content in the paste. Increase in the modification extent and/or the amount of the modified starch effectively retards the phase separation and reduces the separation extent of native cornstarch-polyvinyl alcohol blend pastes.Moreover, the mechanism and favorable modification extent of carboxymethyl starch for enhancing paste stability are also investigated and discussed.展开更多
The Migdal-Kadanoff (MK) renormalization transformation has been adopted to discuss the phase transition structures of lattice gauge theories (LGT). But it is problematic to apply it to analysing the phase behavior of...The Migdal-Kadanoff (MK) renormalization transformation has been adopted to discuss the phase transition structures of lattice gauge theories (LGT). But it is problematic to apply it to analysing the phase behavior of LGT with the action being a linear combination of fundamental and adjoint representations. For U(1) theory, i.e. compact QED, we consider the single plaquette action:展开更多
In this paper, a model is presented to correlate and predict the swelling behavior of hydrogels in aqueous solutions of electrolytes. The model is a combination of VERS-model, 'phantom network' theory and '...In this paper, a model is presented to correlate and predict the swelling behavior of hydrogels in aqueous solutions of electrolytes. The model is a combination of VERS-model, 'phantom network' theory and 'free-volume' contribution. The VERS-model is used to calculate Gibbs excess energy; 'phantom network' theory to describe the elastic properties of polymer network, and 'free-volume' contribution to account for additional difference in the size of the species. To test the model, a series of N-isopropylacrylamide based hydrogels are synthesized by free radical polymerization in oxygen-free, deionized water at 25℃ under nitrogen atmosphere. Then, the degree of swelling of all investigated gels as well as the partition of the solute between the gel phase and the surrounding coexisting liquid phase are measured in aqueous solution of sodium chloride. The model test demonstrates that the swelling behavior correlated and predicted by the model agrees with the experimental data within the experimental uncertainty. The phase transition appeared in the experiment, and the influences of the total mass fraction of polymerizable materials ζgel as well as the mole fraction of the crosslinking agent yCR on the swelling behavior of IPAAm-gels can also be predicted correctly. All these show the potential of such model for correlation and prediction of the swelling behavior of hydrogels in aqueous solutions of electrolytes.展开更多
A new low noise interface circuit for detecting weak current of micro-sensors is designed.By using the transimpedance amplifier to substitute the charge amplifier,the closed-loop circuit can avoid the phase error of t...A new low noise interface circuit for detecting weak current of micro-sensors is designed.By using the transimpedance amplifier to substitute the charge amplifier,the closed-loop circuit can avoid the phase error of the charge amplifier.Therefore,the phase compensation devices will be cancelled,because there is no phase transformation through the transimpedance amplifier.As well as,by using CCCII devices to implement the high value feedback resistor of the impedance amplifier,the noise of the I-V transformation devices is reduced,comparing with the passive resistor.The floating resistor is easy to be integrated into chips,making the integration of the interface circuit of the intelligent sensors increase.Through the simulation,the phase error of the charge amplifier is almost 9°at 2 kHz and it changes with the working frequency of the micro-sensors making the phase compensation not easy.The value of the floating resistor is 250 kΩ where the bias current is 50 μA.The noise of the active resistor is 0.037 fV2/Hz,comparing with the noise of the passive resistor,which is 4.14 fV2/Hz.展开更多
A series of idealized model simulations are analyzed to determine the sensitivity of model results to different configurations of the lateral boundary conditions (LBCs) in simulating mesoscale shallow convection over ...A series of idealized model simulations are analyzed to determine the sensitivity of model results to different configurations of the lateral boundary conditions (LBCs) in simulating mesoscale shallow convection over hilly terrain. In the simulations with steady thermal forcing at the model surface, a radiation condition at both boundaries is the best choice under high wind conditions, and the best results are produced when both the normal velocities and the temperature are treated with the radiation scheme in which the phase speed is the same for different variables. When the background wind speed is reasonably small, the LBC configuration with either the radiation or the zero gradient condition at both boundaries tends to make the numerical solution unstable. The choice of a constant condition at the inflow boundary and a radiation outflow boundary condition is appropriate in most cases. In the simulations with diurnal thermal forcing at the model surface, different LBC schemes are combined together to reduce spurious signals induced by the outflow boundary. A specification inflow boundary condition, in which the velocity fields at the inflow boundary are provided using the time-dependent results of a simulation with periodic LBCs over a flat domain, is tested and the results indicate that the specification condition at the inflow boundary makes it possible to use a smaller model domain to obtain reasonable results. The model horizontal domain length should be greater than a critical length, which depends on the domain depth H and the angle between gravity wave phase lines and the vertical. An estimate of minimum domain length is given by , where N and U are the background stability and wind speed, respectively, Lx is the typical gravity wavelength scale, and Zi is the convective boundary layer (CBL) depth.展开更多
Purpose With the rapid development of Phase I clinical trials for anticancer drugs in China,addressing ethical con-cerns is imperative.In order to safeguard the rights,interests,and well-being of research participants...Purpose With the rapid development of Phase I clinical trials for anticancer drugs in China,addressing ethical con-cerns is imperative.In order to safeguard the rights,interests,and well-being of research participants,this paper aims to illustrate vital ethical issues that should not be neglected by institutional review boards as well as other relevant stakeholders for Phase I clinical trials of anticancer drugs.Methods This study retrospectively collects documents on Phase I clinical trials for anticancer drugs that were sub-mitted to the Institutional Review Board at Zhejiang Cancer Hospital from 2021 to 2023.Based on Chinese and inter-national research regulations and guidelines,these documents,as well as initial and follow-up review resolutions,have been classified and analyzed.Results Given the additional risks of potentially toxic effects in Phase I clinical trials for anticancer drugs and the vul-nerability of participants enrolled with advanced cancer status,it is important to review investigator qualifica-tions,preliminary findings,research methods,inclusion and exclusion criteria in the protocol,as well as the validity and readability of informed consent.Additionally,attention should be given to follow-up reviews,particularly regard-ing safety reports and protocol deviations.Conclusion To effectively protect the rights,interests and safety of research participants.Relevant stakeholders,including sponsors,researchers,and regulatory bodies,should diligently evaluate potential risks and provision contin-gency plan to minimize the latent risk.展开更多
Ⅰ. INTRODUCTION Cerenkov radiation will be produced when the velocity of charged particles passing through a medium is faster than the phase velocity of light in the same medium. The moving direction of the radiation...Ⅰ. INTRODUCTION Cerenkov radiation will be produced when the velocity of charged particles passing through a medium is faster than the phase velocity of light in the same medium. The moving direction of the radiation photons is determined by the following formula:展开更多
The phase equilibrium relationships in the systems Sm2O3-BeO, Ho2O3-BeO and Y2O2-BeO have been studied by the quenching method together with microscopic and X-ray powder techniques as those described in detail in prev...The phase equilibrium relationships in the systems Sm2O3-BeO, Ho2O3-BeO and Y2O2-BeO have been studied by the quenching method together with microscopic and X-ray powder techniques as those described in detail in previous publications. The phase diagrams thereby constructed are presented in Fig. 1.展开更多
<正> Suppose that the 2-dimensional systems of one-parameter equations of the form for α= 0 possess a continuous family {Γ~h} of periodic orbits in an annular region of the phase plane. The study of Poincar...<正> Suppose that the 2-dimensional systems of one-parameter equations of the form for α= 0 possess a continuous family {Γ~h} of periodic orbits in an annular region of the phase plane. The study of Poincaré bifurcations of(1)_α, namely, the creation of limit cycles from some closed orbits, may be confined to the investigation of how many zeros there are in the展开更多
In [1] and [2], the authors made a deep qualitative analysis of the equationwith the character of tangent detected phase and they mathematically provided atheoretical basis of why the phase looked loop has no look--lo...In [1] and [2], the authors made a deep qualitative analysis of the equationwith the character of tangent detected phase and they mathematically provided atheoretical basis of why the phase looked loop has no look--losing point. However,according to many practical experts, it is rather difficult to put such a phaselooked loop into practice, though it has fine properties. W. C. Lindsey [3] made a展开更多
In this paper, we use a qualitative method to study global and local bifurcations in a disturbedHamiltonian vector field approaching a Poincare map in the 3:1 resonant case. We give explicitcalculation formulas to det...In this paper, we use a qualitative method to study global and local bifurcations in a disturbedHamiltonian vector field approaching a Poincare map in the 3:1 resonant case. We give explicitcalculation formulas to determine bifurcation parameters and draw various bifurcations and phaseportraits in the phase plane.展开更多
In order to radiate E-M wave by electron or accelerate electrons by E-M wave, it is usually required to keep electrons synchronizing with the phase velocity of the E-M wave. Evanescent waves may be employed for low ph...In order to radiate E-M wave by electron or accelerate electrons by E-M wave, it is usually required to keep electrons synchronizing with the phase velocity of the E-M wave. Evanescent waves may be employed for low phase velocity. This method which requires the moving electrons to be close to a periodic structure is almost unpractical for optical frequencies. A sawtoothed wavefront has been suggested for veloc-展开更多
Expressing the perturbation optical field in terms of module and phase, using the linearized nonlinear Schrdinger equation governing the evolution of perturbations, we have deduced the analytical expressions of the mo...Expressing the perturbation optical field in terms of module and phase, using the linearized nonlinear Schrdinger equation governing the evolution of perturbations, we have deduced the analytical expressions of the modules, phases, and gain coefficients of the perturbations with zero or cut-off frequency, and studied the evolutions of the two perturbations travelling along lossless optical fibers in the negative dispersion regime. The results indicate that the phase of the perturbation with zero (or cut-off) frequency increases (or decreases) with the propagation distance monotonously and tends to its asymptotic value nπ+π/2 (or nπ) eventually. The evolution rates of the phases are closely related to the initial phase values. Although the asymptotic values of the field gain coefficients of the above mentioned two perturbations are equal to zero, and the increasing fashion of the modules is different from the familiar exponential type, it still suggests that the perturbations have a divergent nature w展开更多
基金the National Natural Science Foundation of China (No. 20025618, No. 20236010) Shanghai Municipal Education Commission of China.
文摘The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.
基金It was financially supported by Science Research Foundation of Southern Yangtze University
文摘The influences of carboxymethyl starch used as stabilizer upon the stability of native cornstarchpolyvinyl alcohol blend pastes for warp sizing have been investigated. The effect of the modified starch on the paste stability was evaluated in terms of the initial demixing time and the volume percentage of separated starch. The carboxymethyl starch with a series of different degrees of substitution was prepared in ethanol dispersion by varying the amount of monochloroacetic acid reacted with refined native cornstarch. The paste stability strongly depends on the modification extent and amount of carboxymethyl starch used, and on native starch content in the paste. Increase in the modification extent and/or the amount of the modified starch effectively retards the phase separation and reduces the separation extent of native cornstarch-polyvinyl alcohol blend pastes.Moreover, the mechanism and favorable modification extent of carboxymethyl starch for enhancing paste stability are also investigated and discussed.
基金Project supported by the Scien und of Academia Sinica
文摘The Migdal-Kadanoff (MK) renormalization transformation has been adopted to discuss the phase transition structures of lattice gauge theories (LGT). But it is problematic to apply it to analysing the phase behavior of LGT with the action being a linear combination of fundamental and adjoint representations. For U(1) theory, i.e. compact QED, we consider the single plaquette action:
基金Supported by the Scientific Research Foundation for the Returned Overseas Chineses Sehiors of State Education Ministry, Science Technology Ministry of Fujian (No. 2001Z046).
文摘In this paper, a model is presented to correlate and predict the swelling behavior of hydrogels in aqueous solutions of electrolytes. The model is a combination of VERS-model, 'phantom network' theory and 'free-volume' contribution. The VERS-model is used to calculate Gibbs excess energy; 'phantom network' theory to describe the elastic properties of polymer network, and 'free-volume' contribution to account for additional difference in the size of the species. To test the model, a series of N-isopropylacrylamide based hydrogels are synthesized by free radical polymerization in oxygen-free, deionized water at 25℃ under nitrogen atmosphere. Then, the degree of swelling of all investigated gels as well as the partition of the solute between the gel phase and the surrounding coexisting liquid phase are measured in aqueous solution of sodium chloride. The model test demonstrates that the swelling behavior correlated and predicted by the model agrees with the experimental data within the experimental uncertainty. The phase transition appeared in the experiment, and the influences of the total mass fraction of polymerizable materials ζgel as well as the mole fraction of the crosslinking agent yCR on the swelling behavior of IPAAm-gels can also be predicted correctly. All these show the potential of such model for correlation and prediction of the swelling behavior of hydrogels in aqueous solutions of electrolytes.
基金Sponsored by the National High Technology Research Development Plan of China(Grant No.2008AA042201)
文摘A new low noise interface circuit for detecting weak current of micro-sensors is designed.By using the transimpedance amplifier to substitute the charge amplifier,the closed-loop circuit can avoid the phase error of the charge amplifier.Therefore,the phase compensation devices will be cancelled,because there is no phase transformation through the transimpedance amplifier.As well as,by using CCCII devices to implement the high value feedback resistor of the impedance amplifier,the noise of the I-V transformation devices is reduced,comparing with the passive resistor.The floating resistor is easy to be integrated into chips,making the integration of the interface circuit of the intelligent sensors increase.Through the simulation,the phase error of the charge amplifier is almost 9°at 2 kHz and it changes with the working frequency of the micro-sensors making the phase compensation not easy.The value of the floating resistor is 250 kΩ where the bias current is 50 μA.The noise of the active resistor is 0.037 fV2/Hz,comparing with the noise of the passive resistor,which is 4.14 fV2/Hz.
基金The first author was supported by an Overseas Research ScholarshipThis work was supported by the National Natural Science Foundation of China under Grant No.40233031.
文摘A series of idealized model simulations are analyzed to determine the sensitivity of model results to different configurations of the lateral boundary conditions (LBCs) in simulating mesoscale shallow convection over hilly terrain. In the simulations with steady thermal forcing at the model surface, a radiation condition at both boundaries is the best choice under high wind conditions, and the best results are produced when both the normal velocities and the temperature are treated with the radiation scheme in which the phase speed is the same for different variables. When the background wind speed is reasonably small, the LBC configuration with either the radiation or the zero gradient condition at both boundaries tends to make the numerical solution unstable. The choice of a constant condition at the inflow boundary and a radiation outflow boundary condition is appropriate in most cases. In the simulations with diurnal thermal forcing at the model surface, different LBC schemes are combined together to reduce spurious signals induced by the outflow boundary. A specification inflow boundary condition, in which the velocity fields at the inflow boundary are provided using the time-dependent results of a simulation with periodic LBCs over a flat domain, is tested and the results indicate that the specification condition at the inflow boundary makes it possible to use a smaller model domain to obtain reasonable results. The model horizontal domain length should be greater than a critical length, which depends on the domain depth H and the angle between gravity wave phase lines and the vertical. An estimate of minimum domain length is given by , where N and U are the background stability and wind speed, respectively, Lx is the typical gravity wavelength scale, and Zi is the convective boundary layer (CBL) depth.
基金The research belongs to the project“influencing factors and countermeasures of clinical research ethical cognition implementation of medical researchers in the context of scientific research innovation”,financed by Zhejiang Provincial Medical Health Science and Technology Project 2022,No.2022KY643.
文摘Purpose With the rapid development of Phase I clinical trials for anticancer drugs in China,addressing ethical con-cerns is imperative.In order to safeguard the rights,interests,and well-being of research participants,this paper aims to illustrate vital ethical issues that should not be neglected by institutional review boards as well as other relevant stakeholders for Phase I clinical trials of anticancer drugs.Methods This study retrospectively collects documents on Phase I clinical trials for anticancer drugs that were sub-mitted to the Institutional Review Board at Zhejiang Cancer Hospital from 2021 to 2023.Based on Chinese and inter-national research regulations and guidelines,these documents,as well as initial and follow-up review resolutions,have been classified and analyzed.Results Given the additional risks of potentially toxic effects in Phase I clinical trials for anticancer drugs and the vul-nerability of participants enrolled with advanced cancer status,it is important to review investigator qualifica-tions,preliminary findings,research methods,inclusion and exclusion criteria in the protocol,as well as the validity and readability of informed consent.Additionally,attention should be given to follow-up reviews,particularly regard-ing safety reports and protocol deviations.Conclusion To effectively protect the rights,interests and safety of research participants.Relevant stakeholders,including sponsors,researchers,and regulatory bodies,should diligently evaluate potential risks and provision contin-gency plan to minimize the latent risk.
文摘Ⅰ. INTRODUCTION Cerenkov radiation will be produced when the velocity of charged particles passing through a medium is faster than the phase velocity of light in the same medium. The moving direction of the radiation photons is determined by the following formula:
文摘The phase equilibrium relationships in the systems Sm2O3-BeO, Ho2O3-BeO and Y2O2-BeO have been studied by the quenching method together with microscopic and X-ray powder techniques as those described in detail in previous publications. The phase diagrams thereby constructed are presented in Fig. 1.
基金Project supported by the Science Fund of Academia Sinica
文摘<正> Suppose that the 2-dimensional systems of one-parameter equations of the form for α= 0 possess a continuous family {Γ~h} of periodic orbits in an annular region of the phase plane. The study of Poincaré bifurcations of(1)_α, namely, the creation of limit cycles from some closed orbits, may be confined to the investigation of how many zeros there are in the
文摘In [1] and [2], the authors made a deep qualitative analysis of the equationwith the character of tangent detected phase and they mathematically provided atheoretical basis of why the phase looked loop has no look--losing point. However,according to many practical experts, it is rather difficult to put such a phaselooked loop into practice, though it has fine properties. W. C. Lindsey [3] made a
基金The project supported by the National Natural Science Foundation of China
文摘In this paper, we use a qualitative method to study global and local bifurcations in a disturbedHamiltonian vector field approaching a Poincare map in the 3:1 resonant case. We give explicitcalculation formulas to determine bifurcation parameters and draw various bifurcations and phaseportraits in the phase plane.
文摘In order to radiate E-M wave by electron or accelerate electrons by E-M wave, it is usually required to keep electrons synchronizing with the phase velocity of the E-M wave. Evanescent waves may be employed for low phase velocity. This method which requires the moving electrons to be close to a periodic structure is almost unpractical for optical frequencies. A sawtoothed wavefront has been suggested for veloc-
基金This work was supported by the Chinese Institute of Engineering Physics and the National Natural Science Foundation of China (No. 10176019)
文摘Expressing the perturbation optical field in terms of module and phase, using the linearized nonlinear Schrdinger equation governing the evolution of perturbations, we have deduced the analytical expressions of the modules, phases, and gain coefficients of the perturbations with zero or cut-off frequency, and studied the evolutions of the two perturbations travelling along lossless optical fibers in the negative dispersion regime. The results indicate that the phase of the perturbation with zero (or cut-off) frequency increases (or decreases) with the propagation distance monotonously and tends to its asymptotic value nπ+π/2 (or nπ) eventually. The evolution rates of the phases are closely related to the initial phase values. Although the asymptotic values of the field gain coefficients of the above mentioned two perturbations are equal to zero, and the increasing fashion of the modules is different from the familiar exponential type, it still suggests that the perturbations have a divergent nature w
