With the technology support of virtual reality and ANSYS software, an example on the simulation of temperature distribution of casting system during the solidification process was provided, which took the latent heat ...With the technology support of virtual reality and ANSYS software, an example on the simulation of temperature distribution of casting system during the solidification process was provided, which took the latent heat of phase change, the conditions for convection, and the interface heat transfer coefficient into consideration. The result of ANSYS was found to agree well with the test data. This research offers an unorthodox way or ＂reverse method＂ of defining the relevant thermal physical coefficient.展开更多
The main purpose of reverse engineering is to convert discrete data pointsinto piecewise smooth, continuous surface models. Before carrying out model reconstruction it issignificant to extract geometric features becau...The main purpose of reverse engineering is to convert discrete data pointsinto piecewise smooth, continuous surface models. Before carrying out model reconstruction it issignificant to extract geometric features because the quality of modeling greatly depends on therepresentation of features. Some fitting techniques of natural quadric surfaces with least-squaresmethod are described. And these techniques can be directly used to extract quadric surfaces featuresduring the process of segmentation for point cloud.展开更多
In this study, the CaP/pDNA nanoparticles were prepared using Triton X-100/Butanol/Cyclohexane/Water reverse microemulsion system. Optimization of preparation conditions was based on evaluation of particle size by Box...In this study, the CaP/pDNA nanoparticles were prepared using Triton X-100/Butanol/Cyclohexane/Water reverse microemulsion system. Optimization of preparation conditions was based on evaluation of particle size by Box–Behnken design method. The particle sizes of the optimized CaP/pDNA nanoparticles were found to be 60.23 ± 4.72 nm, polydispersity index was 0.252 and pDNA encapsulate efficiency was more than 90%. The optimized CaP/pDNA nanoparticles have pH sensitivity and biocompatibility. Further, optimized CaP/pDNA nanoparticles showed higher transfection efficiency.展开更多
To find out and improve the flow characteristics inside the intake system of cylinder head,the application of computational fluid dynamics(CFD)in the evaluation and optimization of the reconstructed intake system base...To find out and improve the flow characteristics inside the intake system of cylinder head,the application of computational fluid dynamics(CFD)in the evaluation and optimization of the reconstructed intake system based on slicing reverse method was proposed.The flow characteristics were found out through CFD,and the velocity vector field,pressure field and turbulent kinetic energy field for different valve lifts were discussed,which were in good agreement with experimental data,and the quality of reconstruction was evaluated.In order to improve its flow characteristic,an optimization plan was proposed.The results show that the flow characteristics after optimization are obviously improved.The results can provide a reference for the design and optimization of the intake system of cylinder head.展开更多
We employ the Hirota bilinear method to systematically derive nondegenerate bright one-and two-soliton solutions,along with degenerate bright-dark two-and four-soliton solutions for the reverse-time nonlocal nonlinear...We employ the Hirota bilinear method to systematically derive nondegenerate bright one-and two-soliton solutions,along with degenerate bright-dark two-and four-soliton solutions for the reverse-time nonlocal nonlinear Schr¨odinger equation.Beyond the fundamental nondegenerate one-soliton solution,we have identified and characterized nondegenerate breather bound state solitons,with particular emphasis on their evolution dynamics.展开更多
The research was carried out for establishing a new reverse phase-HPLC stability indicating method for the quantification of Rucaparib. The experiment was determined on Waters HPLC instrument using 996 photo-diode arr...The research was carried out for establishing a new reverse phase-HPLC stability indicating method for the quantification of Rucaparib. The experiment was determined on Waters HPLC instrument using 996 photo-diode array detector. The separation was done by using symmetry C-18 ODS (25 cm × 0.46 cm internal diameter) 5 μm analytical column containing mobile phase of Phosphate buffer (0.02 M) and methanol [65:35% v/v] adjusted pH to 4.8 by adding dilute ortho phosphoric acid. The method was run at 1 ml·min<sup>-1</sup> at 286 nm detection. The drug was eluted at 5.484 min. After developing the method, it was assured for the intended use by validation which was done according to ICH Q2B guidelines. The analytical parameters checked were linearity, accuracy, repeatability, intermediate precision, limit of detection, limit of quantitation, ruggedness and robustness. It was observed that the response of the detector was linear in the range of 6 - 14 μg/ml with correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability indicating assay method was established by using the samples generated by forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative and photolytic degradation and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the analysis of quality of the rucaparib drug.展开更多
Under the background of engineering education, the result-oriented reverse instructional design method has become one of the mainstream teaching methods. Based on the reverse teaching design method, this paper integra...Under the background of engineering education, the result-oriented reverse instructional design method has become one of the mainstream teaching methods. Based on the reverse teaching design method, this paper integrates Arduino with the teaching mode and content of the robot sensor course. Taking the course of "Robot Detection Technology and Sensor" as a case and project-based teaching as a carrier, this paper studies from the aspects of hierarchical and progressive multi-dimensional teaching target matrix design, course teaching content integration and hierarchical project module division, teaching activity design based on online and offline hybrid, ideological and political education elements integrated throughout the teaching process, and the construction of diversified evaluation methods, etc., and forms a perfect project-based reverse teaching design system, which provides a reference for the specific implementation of robot engineering professional courses, with a view to providing theoretical support and reference for future research.展开更多
The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmi...The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min<sup>-1</sup> at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate.展开更多
An efficient hybrid time reversal（TR） imaging method based on signal subspace and noise subspace is proposed for electromagnetic superresolution detecting and imaging. First, the locations of targets are estimated b...An efficient hybrid time reversal（TR） imaging method based on signal subspace and noise subspace is proposed for electromagnetic superresolution detecting and imaging. First, the locations of targets are estimated by the transmitting-mode decomposition of the TR operator（DORT） method employing the signal subspace. Then, the TR multiple signal classification（TR-MUSIC）method employing the noise subspace is used in the estimated target area to get the superresolution imaging of targets. Two examples with homogeneous and inhomogeneous background mediums are considered, respectively. The results show that the proposed hybrid method has advantages in CPU time and memory cost because of the combination of rough and fine imaging.展开更多
Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave propagation.To obtain high-resolution imaging results,these negative effects must be considered during reverse time migration(...Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave propagation.To obtain high-resolution imaging results,these negative effects must be considered during reverse time migration(RTM).We can easily implement attenuation-compensated RTM using the constant Q viscoacoustic wave equation with decoupled amplitude attenuation and phase dispersion terms.However,the nonphysical amplitude-compensation process will inevitably amplify the high-frequency noise in the wavefield in an exponential form,causing the numerical simulation to become unstable.This is due to the fact that the amplitude of the compensation grows exponentially with frequency.In order to achieve stable attenuation-compensated RTM,we modify the analytic expression of the attenuation compensation extrapolation operator and make it only compensate for amplitude loss within the effective frequency band.Based on this modified analytic formula,we then derive an explicit time-space domain attenuation compensation extrapolation operator.Finally,the implementation procedure of stable attenuation-compensated RTM is presented.In addition to being simple to implement,the newly proposed attenuation-compensated extrapolation operator is superior to the conventional low-pass filter in suppressing random noise,which will further improve the imaging resolution.We use two synthetic and one land seismic datasets to verify the stability and effectiveness of the proposed attenuationcompensated RTM in improving imaging resolution in viscous media.展开更多
The high-frequency electromagnetic waves of ground-penetrating radar(GPR)attenuate severely when propagated in an underground attenuating medium owing to the influence of resistivity,which remarkably decreases the res...The high-frequency electromagnetic waves of ground-penetrating radar(GPR)attenuate severely when propagated in an underground attenuating medium owing to the influence of resistivity,which remarkably decreases the resolution of reverse time migration(RTM).As an effective high-resolution imaging method,attenuation-compensated RTM(ACRTM)can eff ectively compensate for the energy loss caused by the attenuation related to media absorption under the influence of resistivity.Therefore,constructing an accurate resistivity-media model to compensate for the attenuation of electromagnetic wave energy is crucial for realizing the ACRTM imaging of GPR data.This study proposes a resistivity-constrained ACRTM imaging method for the imaging of GPR data by adding high-density resistivity detection along the GPR survey line and combining it with its resistivity inversion profile.The proposed method uses the inversion result of apparent resistivity data as the GPR RTM-resistivity model for imposing resistivity constraints.Moreover,the hybrid method involving image minimum entropy and RTM is used to estimate the medium velocity at the diff raction position,and combined with the distribution characteristics of the reflection in the GPR profile,a highly accurate velocity model is built to improve the imaging resolution of the ACRTM.The accuracy and eff ectiveness of the proposed method are verified using the ACRTM test of the GPR simulated data of a typical attenuating media model.On this basis,the GPR and apparent resistivity data were observed on a field survey line,and use the GPR resistivity-constrained ACRTM method to image the observed data.A comparison of the proposed method with the conventional ACRTM method shows that the proposed method has better imaging depth,stronger energy,and higher resolution,and the obtained results are more conducive for subsequent data analysis and interpretation.展开更多
This paper presents an identification method of the scalar Preisach model to consider the effect of reversible magnetization in the process of distribution function identification.By reconsidering the identification p...This paper presents an identification method of the scalar Preisach model to consider the effect of reversible magnetization in the process of distribution function identification.By reconsidering the identification process by stripping the influence of reversible components from the measurement data,the Preisach distribution function is identified by the pure irreversible components.In this way,the simulation accuracy of both limiting hysteresis loops and the inner internal symmetrical small hysteresis loop is ensured.Furthermore,through a discrete Preisach plane with a hybrid discretization method,the irreversible magnetic flux density components are computed more efficiently through the improved Preisach model.Finally,the proposed method results are compared with the traditional method and the traditional method considering reversible magnetization and validated by the laboratory test for the B30P105 electrical steel by Epstein frame.展开更多
In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In...In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air.The numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation process.Experimental tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.展开更多
Objective:To examine sex reversal both by oral and by immersion using 17α-methyltestosterone on the methyltestosterone residual concentration and the organ histopathology of tilapia fish.Methods:This study used oral ...Objective:To examine sex reversal both by oral and by immersion using 17α-methyltestosterone on the methyltestosterone residual concentration and the organ histopathology of tilapia fish.Methods:This study used oral and immersion treatment methods for sex reversal of tilapia fish and used normal fish as the control and each treatment was repeated 4 times.17α-methyltestosterone at dosages of 60 mg/kg feed and 0.5 mg/L were used for oral and immersion methods,respectively.In the first step,tilapia fry were reared at 100 L aquaria,with a density of 1 fish/L for 2 months.In the next step,male tilapias were reared at happa(net cage)of(2×1×1)m3 size in the controlled pond,with a density of 30 fish/happa for 3 months.The methyltestosterone residual concentrations were analyzed by one-way analysis of variance and Duncan's multiple range tests,while organ histopathology was analyzed by descriptive method.Results:Residual concentrations in the serum of methyltestosterone-treated fish were significantly lower than that in normal fish,especially in 4-and 5-month-old tilapias with averages of less than 5μg/L,while in normal fish was more than 5μg/L.In the flesh,methyltestosterone residual concentrations showed relatively no significant differences between the oral and immersion treatment groups and methyltestosterone-treated fish remained lower compared to normal fish,except in 5-month-old tilapia.Methyltestosterone-treated tilapia exhibited histopathological changes on gill,liver,kidneys,and intestine organs.Conclusions:Sex reversal either by oral or by immersion has methyltestosterone residual concentration,but does not exceed the limits(5μg/L or 5μg/kg)of synthetic steroid on the fish body,although methyltestosterone causes histopathological changes on gill,liver,kidneys,and intestine.展开更多
A reliable and rapid laboratory procedure was developed for rapid screening of reverse osmosis(RO) membrane anti-scalants and compared with existing laboratory methods. This laboratory procedure consists of two parts ...A reliable and rapid laboratory procedure was developed for rapid screening of reverse osmosis(RO) membrane anti-scalants and compared with existing laboratory methods. This laboratory procedure consists of two parts according to the characteristics of screening RO membrane anti-scalants: preliminary screening of anti-scalants by static method and further by dynamic methods based on the result of static method. Conductivity method, critical pH method and turbidity method were selected as the methods for preliminary screening of RO anti-scalants, and drainage gradient method and dose gradient method were chosen as the dynamic methods for further screening RO anti-scalants.展开更多
Former research work about the modeling of hip joint focus on the uppersegment of femoral, and assumes the acetabulum cup is sphere concave, and the acetabulum prosthesesis semisphere. A method of acquiring the point ...Former research work about the modeling of hip joint focus on the uppersegment of femoral, and assumes the acetabulum cup is sphere concave, and the acetabulum prosthesesis semisphere. A method of acquiring the point data on the surface of the hipbone using the reverseengineering technology is presented. After analyzing the acetabulum surface fitting error, arotation ellipsoid CAD model is applied to fit the acetabulum surface, and then optimizationtechnique is used to find the geometric parameters of the model. The fitting error between thesphere and rotation ellipsoid is compared and gets the result that the fitting error of rotationellipsoid is smaller than sphere, and the rotation ellipsoid can describe the shape of theacetabulum better.展开更多
Background: After a live birth, there is much unsatisfied interest in, and unmet family planning need for contraception. Waiting at least for 24 months before attempting the next pregnancy was recommended to reduce th...Background: After a live birth, there is much unsatisfied interest in, and unmet family planning need for contraception. Waiting at least for 24 months before attempting the next pregnancy was recommended to reduce the risk of adverse maternal, perinatal and infant outcomes. The purpose of this study was to assess the determinants of long acting reversible contraception method use among mothers in extended postpartum period in Durame Town, Southern Ethiopia. Methods: A community based cross sectional study was conducted in Durame Town, Southern Ethiopia in December, 2014. Systematic random sampling technique was employed to recruit a total 460 study participants. Structured and pretested questioner was used to collect the data. Descriptive statistics was employed to characterize the study population using frequencies and proportions. Bivariate logistic regression analysis was conducted to identify all possible factors affecting utilization of LARC method. Multivariable logistic regression model was developed to control the confounding variables. Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) was computed in identifying the real factors associated with use of LARC methods. Results: In this study we found that the prevalence of LARC method use among mothers during their extended postpartum period was 36.7% (95%CI: 32.2, 41.0). The unmet family planning need of mothers in the extended postpartum period was 123 (27.9%). The odds of using LARC by literate mother were four fold higher than their counterpart illiterate mothers (AOR 4.09 95%CI: 1.68, 9.58, P value < 0.001). The odds of mother who had pervious experiences of using LARC were up to eight folds higher than mother never used LARC methods (AOR 7.84 95% CI: 3.78, 16.23, P value< 0.001). Mother who received counseling service on LARC methods during delivery was up to three times more likely to utilize the services than not counseled (AOR 3.29 95% CI: 1.53, 7.03, P value < 0.001). And odds of mothers who received counseling service on LARC during immediate postpartum period were up to five fold more likely to opt method than never got the counseling service (AOR 4.55 95 % CI: 1.94, 10.66, P value < 0.001). Conclusions: In the study area, about one third of mothers utilized LARC methods during their extended postpartum period. Another one third of mother had unmet need for family planning. Participant’s education, previous history of using LARC methods, receiving counseling services on LARC during delivery and immediate postpartum periods were found major determinant for LARC use. Educating women, providing counseling service on LARC methods during antenatal, delivery and postnatal were recommended.展开更多
Silver nanoparticles were prepared in reverse micelles of alkyl glucosides by the injection method. The TEM image showed that the obtained silver nanoparticles displayed a wide variety of shapes. The size of silver na...Silver nanoparticles were prepared in reverse micelles of alkyl glucosides by the injection method. The TEM image showed that the obtained silver nanoparticles displayed a wide variety of shapes. The size of silver nanoparticles was strongly dependent upon the kind of reducing agents, and tended to slightly increase with an increase in reaction temperature. The size of silver nanoparticles was hardly dependent upon the molar ratio of water to surfactant and the alkyl chain length of surfactants. Silver nanoparticles having various shapes were obtained at high concentration by the solid-liquid extraction method. The resultant silver colloid could be preserved for at least one month without precipitation.展开更多
The wave-operator nonlinear Schrödinger equation was introduced in the literature.Further,nonlocal space-time reverse complex field equations were also recently introduced.Studies in this area were focused on emp...The wave-operator nonlinear Schrödinger equation was introduced in the literature.Further,nonlocal space-time reverse complex field equations were also recently introduced.Studies in this area were focused on employing the inverse scattering method and Darboux transformation.Here,we present an approach to find the solutions of the wave-operator nonlinear Schrödinger equation with space and time reverse(W-O-NLSE-STR).It is based on implementing the unified method together with introducing a conventional formulation of the solutions.Indeed,a field and a reverse field may be generated.So,for deriving the solutions of W-O-NLSE-STR,it is evident to distinguish two cases(when the field and its reverse are interactive or not-interactive).In the non-interactive and interactive cases,exact and approximate solutions are obtained.In both cases,the solutions are evaluated numerically and they are displayed graphically.It is observed that the field exhibits solitons propagating essentially(or mainly)on the negative space variable,while those of the reverse field propagate on the other side(or vice versa).These results are completely novel,and we think that it is an essential behavior that characterizes a complex field system with STR.On the other hand,they may exhibit right and left cable patterns(or vice versa).It is found that the solutions of the field and its reverse exhibit self-phase modulation by solitary waves.In the interactive case,the pulses of the field and its reverse propagate in the whole space.The analysis of modulation stability shows that,when the field is stable,its reverse is unstable or both are stable.This holds whenever the polarization of the medium is selfdefocusing.展开更多
This paper discusses the inheritance and application of Chinese character reverse contrast typeface style.It begins by analyzing the visual features of Western reverse contrast typeface styles,with a focus on Caslon I...This paper discusses the inheritance and application of Chinese character reverse contrast typeface style.It begins by analyzing the visual features of Western reverse contrast typeface styles,with a focus on Caslon Italian and French Clarendon,providing a Western perspective reference for subsequent Chinese character reverse contrast typeface style designs.The paper then traces the origins of the Chinese reverse contrast style,from the calligraphy style"Lacquer Script"to the earliest printing type"フワンテール形",exploring the historical background and cultural significance of the Chinese reverse contrast style.In the methodology section of Chinese character reverse contrast typeface style design,the discussion is conducted from two dimensions:inheritance and application.In terms of inheritance,through an in-depth analysis of"Lacquer Script"and"フワンテール形"typeface style,the paper summarizes three basic theories for modern Chinese character reverse contrast typeface style design.In the application section,it examines in detail the two most influential recent typeface styles,"Ribaasu"and"Basic Artistic",outlining three directions of application:extreme horizontal stroke variations,exaggerated contrast,and diverse decorative strokes,showcasing new directions and possibilities for Chinese character reverse contrast typeface style design.This paper not only reviews the developmental history of the Chinese character reverse contrast typeface style but also analyzes the design methodology of Chinese character reverse contrast typeface style through specific case studies.展开更多
文摘With the technology support of virtual reality and ANSYS software, an example on the simulation of temperature distribution of casting system during the solidification process was provided, which took the latent heat of phase change, the conditions for convection, and the interface heat transfer coefficient into consideration. The result of ANSYS was found to agree well with the test data. This research offers an unorthodox way or ＂reverse method＂ of defining the relevant thermal physical coefficient.
基金This project is supported by Research Foundation for Doctoral Program of Higher Education, China (No.98033532)
文摘The main purpose of reverse engineering is to convert discrete data pointsinto piecewise smooth, continuous surface models. Before carrying out model reconstruction it issignificant to extract geometric features because the quality of modeling greatly depends on therepresentation of features. Some fitting techniques of natural quadric surfaces with least-squaresmethod are described. And these techniques can be directly used to extract quadric surfaces featuresduring the process of segmentation for point cloud.
基金the Natural Science Foundation Committee of China for the financial support (No.81173004 and No.81202483)
文摘In this study, the CaP/pDNA nanoparticles were prepared using Triton X-100/Butanol/Cyclohexane/Water reverse microemulsion system. Optimization of preparation conditions was based on evaluation of particle size by Box–Behnken design method. The particle sizes of the optimized CaP/pDNA nanoparticles were found to be 60.23 ± 4.72 nm, polydispersity index was 0.252 and pDNA encapsulate efficiency was more than 90%. The optimized CaP/pDNA nanoparticles have pH sensitivity and biocompatibility. Further, optimized CaP/pDNA nanoparticles showed higher transfection efficiency.
基金“Strategic Cooperation of Science and Technology between Nanchong City and Southwest Petroleum University 2018” Special Fund Project,China(Nos.18SXHZ0030,18SXHZ0054)
文摘To find out and improve the flow characteristics inside the intake system of cylinder head,the application of computational fluid dynamics(CFD)in the evaluation and optimization of the reconstructed intake system based on slicing reverse method was proposed.The flow characteristics were found out through CFD,and the velocity vector field,pressure field and turbulent kinetic energy field for different valve lifts were discussed,which were in good agreement with experimental data,and the quality of reconstruction was evaluated.In order to improve its flow characteristic,an optimization plan was proposed.The results show that the flow characteristics after optimization are obviously improved.The results can provide a reference for the design and optimization of the intake system of cylinder head.
基金supported by the National Natural Science Foundation of China(Grant Nos.12261131495 and 12475008)the Scientific Research and Developed Fund of Zhejiang A&F University(Grant No.2021FR0009)。
文摘We employ the Hirota bilinear method to systematically derive nondegenerate bright one-and two-soliton solutions,along with degenerate bright-dark two-and four-soliton solutions for the reverse-time nonlocal nonlinear Schr¨odinger equation.Beyond the fundamental nondegenerate one-soliton solution,we have identified and characterized nondegenerate breather bound state solitons,with particular emphasis on their evolution dynamics.
文摘The research was carried out for establishing a new reverse phase-HPLC stability indicating method for the quantification of Rucaparib. The experiment was determined on Waters HPLC instrument using 996 photo-diode array detector. The separation was done by using symmetry C-18 ODS (25 cm × 0.46 cm internal diameter) 5 μm analytical column containing mobile phase of Phosphate buffer (0.02 M) and methanol [65:35% v/v] adjusted pH to 4.8 by adding dilute ortho phosphoric acid. The method was run at 1 ml·min<sup>-1</sup> at 286 nm detection. The drug was eluted at 5.484 min. After developing the method, it was assured for the intended use by validation which was done according to ICH Q2B guidelines. The analytical parameters checked were linearity, accuracy, repeatability, intermediate precision, limit of detection, limit of quantitation, ruggedness and robustness. It was observed that the response of the detector was linear in the range of 6 - 14 μg/ml with correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability indicating assay method was established by using the samples generated by forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative and photolytic degradation and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the analysis of quality of the rucaparib drug.
文摘Under the background of engineering education, the result-oriented reverse instructional design method has become one of the mainstream teaching methods. Based on the reverse teaching design method, this paper integrates Arduino with the teaching mode and content of the robot sensor course. Taking the course of "Robot Detection Technology and Sensor" as a case and project-based teaching as a carrier, this paper studies from the aspects of hierarchical and progressive multi-dimensional teaching target matrix design, course teaching content integration and hierarchical project module division, teaching activity design based on online and offline hybrid, ideological and political education elements integrated throughout the teaching process, and the construction of diversified evaluation methods, etc., and forms a perfect project-based reverse teaching design system, which provides a reference for the specific implementation of robot engineering professional courses, with a view to providing theoretical support and reference for future research.
文摘The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min<sup>-1</sup> at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate.
基金supported by the National Natural Science Foundation of China(6130127161331007)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(2011018512000820120185130001)the Fundamental Research Funds for Central Universities(ZYGX2012J043)
文摘An efficient hybrid time reversal（TR） imaging method based on signal subspace and noise subspace is proposed for electromagnetic superresolution detecting and imaging. First, the locations of targets are estimated by the transmitting-mode decomposition of the TR operator（DORT） method employing the signal subspace. Then, the TR multiple signal classification（TR-MUSIC）method employing the noise subspace is used in the estimated target area to get the superresolution imaging of targets. Two examples with homogeneous and inhomogeneous background mediums are considered, respectively. The results show that the proposed hybrid method has advantages in CPU time and memory cost because of the combination of rough and fine imaging.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2021QNLM020001)the Major Scientific and Technological Projects of Shandong Energy Group(No.SNKJ2022A06-R23)the Major Scientific and Technological Projects of CNPC(No.ZD2019-183-003).
文摘Intrinsic attenuation of the earth causes energy loss and phase distortion in seismic wave propagation.To obtain high-resolution imaging results,these negative effects must be considered during reverse time migration(RTM).We can easily implement attenuation-compensated RTM using the constant Q viscoacoustic wave equation with decoupled amplitude attenuation and phase dispersion terms.However,the nonphysical amplitude-compensation process will inevitably amplify the high-frequency noise in the wavefield in an exponential form,causing the numerical simulation to become unstable.This is due to the fact that the amplitude of the compensation grows exponentially with frequency.In order to achieve stable attenuation-compensated RTM,we modify the analytic expression of the attenuation compensation extrapolation operator and make it only compensate for amplitude loss within the effective frequency band.Based on this modified analytic formula,we then derive an explicit time-space domain attenuation compensation extrapolation operator.Finally,the implementation procedure of stable attenuation-compensated RTM is presented.In addition to being simple to implement,the newly proposed attenuation-compensated extrapolation operator is superior to the conventional low-pass filter in suppressing random noise,which will further improve the imaging resolution.We use two synthetic and one land seismic datasets to verify the stability and effectiveness of the proposed attenuationcompensated RTM in improving imaging resolution in viscous media.
基金supported by the National Natural Science Foundation of China (No.41604102)the Guangxi Natural Science Foundation project (No.2020GXNSFAA159121).
文摘The high-frequency electromagnetic waves of ground-penetrating radar(GPR)attenuate severely when propagated in an underground attenuating medium owing to the influence of resistivity,which remarkably decreases the resolution of reverse time migration(RTM).As an effective high-resolution imaging method,attenuation-compensated RTM(ACRTM)can eff ectively compensate for the energy loss caused by the attenuation related to media absorption under the influence of resistivity.Therefore,constructing an accurate resistivity-media model to compensate for the attenuation of electromagnetic wave energy is crucial for realizing the ACRTM imaging of GPR data.This study proposes a resistivity-constrained ACRTM imaging method for the imaging of GPR data by adding high-density resistivity detection along the GPR survey line and combining it with its resistivity inversion profile.The proposed method uses the inversion result of apparent resistivity data as the GPR RTM-resistivity model for imposing resistivity constraints.Moreover,the hybrid method involving image minimum entropy and RTM is used to estimate the medium velocity at the diff raction position,and combined with the distribution characteristics of the reflection in the GPR profile,a highly accurate velocity model is built to improve the imaging resolution of the ACRTM.The accuracy and eff ectiveness of the proposed method are verified using the ACRTM test of the GPR simulated data of a typical attenuating media model.On this basis,the GPR and apparent resistivity data were observed on a field survey line,and use the GPR resistivity-constrained ACRTM method to image the observed data.A comparison of the proposed method with the conventional ACRTM method shows that the proposed method has better imaging depth,stronger energy,and higher resolution,and the obtained results are more conducive for subsequent data analysis and interpretation.
基金supported by the National Natural Science Foundation of China under Grant 52007102,52207012by the State Key Laboratory of Reliability and Intelligence of Electrical Equipment under Grant EERIKF2021015。
文摘This paper presents an identification method of the scalar Preisach model to consider the effect of reversible magnetization in the process of distribution function identification.By reconsidering the identification process by stripping the influence of reversible components from the measurement data,the Preisach distribution function is identified by the pure irreversible components.In this way,the simulation accuracy of both limiting hysteresis loops and the inner internal symmetrical small hysteresis loop is ensured.Furthermore,through a discrete Preisach plane with a hybrid discretization method,the irreversible magnetic flux density components are computed more efficiently through the improved Preisach model.Finally,the proposed method results are compared with the traditional method and the traditional method considering reversible magnetization and validated by the laboratory test for the B30P105 electrical steel by Epstein frame.
基金the National Natural Science Foundation of China(Grant No.51964022).
文摘In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air.The numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation process.Experimental tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.
文摘Objective:To examine sex reversal both by oral and by immersion using 17α-methyltestosterone on the methyltestosterone residual concentration and the organ histopathology of tilapia fish.Methods:This study used oral and immersion treatment methods for sex reversal of tilapia fish and used normal fish as the control and each treatment was repeated 4 times.17α-methyltestosterone at dosages of 60 mg/kg feed and 0.5 mg/L were used for oral and immersion methods,respectively.In the first step,tilapia fry were reared at 100 L aquaria,with a density of 1 fish/L for 2 months.In the next step,male tilapias were reared at happa(net cage)of(2×1×1)m3 size in the controlled pond,with a density of 30 fish/happa for 3 months.The methyltestosterone residual concentrations were analyzed by one-way analysis of variance and Duncan's multiple range tests,while organ histopathology was analyzed by descriptive method.Results:Residual concentrations in the serum of methyltestosterone-treated fish were significantly lower than that in normal fish,especially in 4-and 5-month-old tilapias with averages of less than 5μg/L,while in normal fish was more than 5μg/L.In the flesh,methyltestosterone residual concentrations showed relatively no significant differences between the oral and immersion treatment groups and methyltestosterone-treated fish remained lower compared to normal fish,except in 5-month-old tilapia.Methyltestosterone-treated tilapia exhibited histopathological changes on gill,liver,kidneys,and intestine organs.Conclusions:Sex reversal either by oral or by immersion has methyltestosterone residual concentration,but does not exceed the limits(5μg/L or 5μg/kg)of synthetic steroid on the fish body,although methyltestosterone causes histopathological changes on gill,liver,kidneys,and intestine.
文摘A reliable and rapid laboratory procedure was developed for rapid screening of reverse osmosis(RO) membrane anti-scalants and compared with existing laboratory methods. This laboratory procedure consists of two parts according to the characteristics of screening RO membrane anti-scalants: preliminary screening of anti-scalants by static method and further by dynamic methods based on the result of static method. Conductivity method, critical pH method and turbidity method were selected as the methods for preliminary screening of RO anti-scalants, and drainage gradient method and dose gradient method were chosen as the dynamic methods for further screening RO anti-scalants.
基金This project is supported by China Post Doctor Science FoundationShanghai Jiaotong University-Shanghai Second Medical University Cooperation Foundation.
文摘Former research work about the modeling of hip joint focus on the uppersegment of femoral, and assumes the acetabulum cup is sphere concave, and the acetabulum prosthesesis semisphere. A method of acquiring the point data on the surface of the hipbone using the reverseengineering technology is presented. After analyzing the acetabulum surface fitting error, arotation ellipsoid CAD model is applied to fit the acetabulum surface, and then optimizationtechnique is used to find the geometric parameters of the model. The fitting error between thesphere and rotation ellipsoid is compared and gets the result that the fitting error of rotationellipsoid is smaller than sphere, and the rotation ellipsoid can describe the shape of theacetabulum better.
文摘Background: After a live birth, there is much unsatisfied interest in, and unmet family planning need for contraception. Waiting at least for 24 months before attempting the next pregnancy was recommended to reduce the risk of adverse maternal, perinatal and infant outcomes. The purpose of this study was to assess the determinants of long acting reversible contraception method use among mothers in extended postpartum period in Durame Town, Southern Ethiopia. Methods: A community based cross sectional study was conducted in Durame Town, Southern Ethiopia in December, 2014. Systematic random sampling technique was employed to recruit a total 460 study participants. Structured and pretested questioner was used to collect the data. Descriptive statistics was employed to characterize the study population using frequencies and proportions. Bivariate logistic regression analysis was conducted to identify all possible factors affecting utilization of LARC method. Multivariable logistic regression model was developed to control the confounding variables. Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) was computed in identifying the real factors associated with use of LARC methods. Results: In this study we found that the prevalence of LARC method use among mothers during their extended postpartum period was 36.7% (95%CI: 32.2, 41.0). The unmet family planning need of mothers in the extended postpartum period was 123 (27.9%). The odds of using LARC by literate mother were four fold higher than their counterpart illiterate mothers (AOR 4.09 95%CI: 1.68, 9.58, P value < 0.001). The odds of mother who had pervious experiences of using LARC were up to eight folds higher than mother never used LARC methods (AOR 7.84 95% CI: 3.78, 16.23, P value< 0.001). Mother who received counseling service on LARC methods during delivery was up to three times more likely to utilize the services than not counseled (AOR 3.29 95% CI: 1.53, 7.03, P value < 0.001). And odds of mothers who received counseling service on LARC during immediate postpartum period were up to five fold more likely to opt method than never got the counseling service (AOR 4.55 95 % CI: 1.94, 10.66, P value < 0.001). Conclusions: In the study area, about one third of mothers utilized LARC methods during their extended postpartum period. Another one third of mother had unmet need for family planning. Participant’s education, previous history of using LARC methods, receiving counseling services on LARC during delivery and immediate postpartum periods were found major determinant for LARC use. Educating women, providing counseling service on LARC methods during antenatal, delivery and postnatal were recommended.
文摘Silver nanoparticles were prepared in reverse micelles of alkyl glucosides by the injection method. The TEM image showed that the obtained silver nanoparticles displayed a wide variety of shapes. The size of silver nanoparticles was strongly dependent upon the kind of reducing agents, and tended to slightly increase with an increase in reaction temperature. The size of silver nanoparticles was hardly dependent upon the molar ratio of water to surfactant and the alkyl chain length of surfactants. Silver nanoparticles having various shapes were obtained at high concentration by the solid-liquid extraction method. The resultant silver colloid could be preserved for at least one month without precipitation.
文摘The wave-operator nonlinear Schrödinger equation was introduced in the literature.Further,nonlocal space-time reverse complex field equations were also recently introduced.Studies in this area were focused on employing the inverse scattering method and Darboux transformation.Here,we present an approach to find the solutions of the wave-operator nonlinear Schrödinger equation with space and time reverse(W-O-NLSE-STR).It is based on implementing the unified method together with introducing a conventional formulation of the solutions.Indeed,a field and a reverse field may be generated.So,for deriving the solutions of W-O-NLSE-STR,it is evident to distinguish two cases(when the field and its reverse are interactive or not-interactive).In the non-interactive and interactive cases,exact and approximate solutions are obtained.In both cases,the solutions are evaluated numerically and they are displayed graphically.It is observed that the field exhibits solitons propagating essentially(or mainly)on the negative space variable,while those of the reverse field propagate on the other side(or vice versa).These results are completely novel,and we think that it is an essential behavior that characterizes a complex field system with STR.On the other hand,they may exhibit right and left cable patterns(or vice versa).It is found that the solutions of the field and its reverse exhibit self-phase modulation by solitary waves.In the interactive case,the pulses of the field and its reverse propagate in the whole space.The analysis of modulation stability shows that,when the field is stable,its reverse is unstable or both are stable.This holds whenever the polarization of the medium is selfdefocusing.
文摘This paper discusses the inheritance and application of Chinese character reverse contrast typeface style.It begins by analyzing the visual features of Western reverse contrast typeface styles,with a focus on Caslon Italian and French Clarendon,providing a Western perspective reference for subsequent Chinese character reverse contrast typeface style designs.The paper then traces the origins of the Chinese reverse contrast style,from the calligraphy style"Lacquer Script"to the earliest printing type"フワンテール形",exploring the historical background and cultural significance of the Chinese reverse contrast style.In the methodology section of Chinese character reverse contrast typeface style design,the discussion is conducted from two dimensions:inheritance and application.In terms of inheritance,through an in-depth analysis of"Lacquer Script"and"フワンテール形"typeface style,the paper summarizes three basic theories for modern Chinese character reverse contrast typeface style design.In the application section,it examines in detail the two most influential recent typeface styles,"Ribaasu"and"Basic Artistic",outlining three directions of application:extreme horizontal stroke variations,exaggerated contrast,and diverse decorative strokes,showcasing new directions and possibilities for Chinese character reverse contrast typeface style design.This paper not only reviews the developmental history of the Chinese character reverse contrast typeface style but also analyzes the design methodology of Chinese character reverse contrast typeface style through specific case studies.
