Li_(1.5)Ga_(0.5)Ti_(1.5)PO_(4))_(3)(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explo...Li_(1.5)Ga_(0.5)Ti_(1.5)PO_(4))_(3)(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects of sintering temperature and holding time on relative density,phase composition,microstructure,bulk conductivity,and total conductivity.In the impedance test under frequency of 1-10^(6) Hz,the bulk conductivity of the samples increased with increasing sintering temperature,and the total conductivity first increased and then decreased.SEM results showed that the average grain size in the ceramics was controlled by the sintering temperature,which increased from(0.54±0.01)μm to(1.21±0.01)μm when the temperature changed from 750 to 950°C.The relative density of the ceramics increased and then decreased with increasing temperature as the porosity increased.The holding time had little effect on the grain size growth or sample density,but an extended holding time resulted in crack generation that served to reduce the conductivity of the solid electrolyte.展开更多
This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissio...This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissions of passenger cars.The dynamic behaviors of these two types of vehicles are described using cellular automata(CA)models under open boundary conditions.Numerical simulations are carried out to obtain the phase diagrams of the bus system and the trajectories of buses and passenger cars before and after the implementation of the bus holding strategy under different probabilities of passenger cars entering a two-lane mixed traffic system.Then,we analyze the flow rate,satisfaction rate,and pollutant emission rates of passenger cars together with the performance of a mixed traffic system.The results show that the bus holding strategy can effectively alleviate bus bunching,whereas it has no significant impact on the flow rate and pollutant emission rates of passenger cars;the flow rate,satisfaction rate,and pollutant emission rates of passenger cars for either the traffic system or for each lane are influenced by the bus departure interval and the number of passengers arriving at bus stops.展开更多
The aim of this study was to investigate the inter-fraction variations, patient comfort and knowledge at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). The differences in set-up that occurred between treatme...The aim of this study was to investigate the inter-fraction variations, patient comfort and knowledge at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). The differences in set-up that occurred between treatment sessions for the left sided breast patients were observed and recorded. Measurements of routine set-up variation for 24 patients were performed by matching the cone beam computed tomography (CBCT) and the planning computed tomography (CT). Scans of all five fractions per patient were used to quantify the setup variations with standard deviation (SD) in all the three directions (anterior posterior, left right, and superior inferior). The patients DIBH comfort and knowledge was also evaluated. The average translational errors for the anterior posterior (AP, z), left-right (LR, x), and Superior-inferior (SI, y) directions were 0.40 cm, 0.40 cm, and 0.40 cm, respectively. The translation variation of the three directions showed statistical significance (P < 0.05). On comfort and knowledge investigation, among all participants, 80% moderately agreed that the therapist’s instructions for operating the deep inspiration breath hold (DIBH) technique were easy to understand, and 63.33% indicated that their comfort with the DIBH technique was neutral or average. The inter-fraction variations in patients with left-sided breast cancer were qualitatively analyzed. Significant shifts between CBCT and planning CT images were observed. The daily treatment verification could assist accurate dose delivery.展开更多
Hydroxyapatite(HA)is a bio ceramic commonly utilized in bone tissue engineering due to its bioactive and osteoconductive properties.Crab shells are usually disregarded as waste material despite their significant CaCO_...Hydroxyapatite(HA)is a bio ceramic commonly utilized in bone tissue engineering due to its bioactive and osteoconductive properties.Crab shells are usually disregarded as waste material despite their significant CaCO_(3) content,and have not been widely utilized in the synthesis of HA.This study aims to synthesize and analyze HA derived from crab shells using the hydrothermal method with different durations of holding time.This study utilized precipitated calcium carbonate(PCC)derived from crab shells.With a hydrothermal reactor set at 160℃ and varying holding times of 14(HA_14),16(HA_16),and 18(HA_18)h,a PCC and(NH4)2HPO4 mixture was used to synthesize HA.The synthesis results were analyzed using scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FTIR),and X-ray diffraction(XRD)tests.This study has accomplished the synthesis of HA from crab shells.Nonetheless,the final product of synthesis still contained CaCO_(3) as an impurity.The prolonged hydrothermal holding time of 14 to 18 h resulted in a reduction of impurities while increasing the percentage of crystal weight and crystallite size of HA.Specimen CH_18 is the best-quality product generated in this study.This specimen produced HA with the highest percentage of crystal weight and crystallite size compared to the other specimens.Furthermore,specimen CH_18 exhibited the lowest concentration of impurities.The Ca/P ratio in this specimen was also the closest to 1.67.The Ca/P ratio,crystallite size,and crystal weight percentage of this specimen are 1.54,19.06 nm,and 99.1%,respectively.展开更多
This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Fai...This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Failure Time (AFT) model, Cox Proportional Hazards model, and Survival model, we assess the effectiveness of these models in capturing survival rates across varying gender, age groups, and treatment categories. Simulated data was used to fit the models, with model identification criteria (AIC, BIC, and R2) applied for evaluation. Results indicate that the AFT model is particularly sensitive to interaction terms, showing significant effects for older age groups (50 - 60 years) and treatment interaction, while the Cox model provides a more stable fit across all age groups. The Survival model displayed variability, with its performance diminishing when interaction terms were introduced, particularly in older age groups. Overall, while the AFT model captures the complexities of interactions in the data, the Cox model’s stability suggests it may be better suited for general analyses without strong interaction effects. The findings highlight the importance of model selection in survival analysis, especially in complex disease progression scenarios like HIV/AIDS.展开更多
The present study has been carried out on a total of 50 available plant species to assess their dust-capturing capacity and biochemical performances in and around open cast granite mine areas of Jhansi district and Bu...The present study has been carried out on a total of 50 available plant species to assess their dust-capturing capacity and biochemical performances in and around open cast granite mine areas of Jhansi district and Bundelkhand University campus treated as control site. Plant species existing under a polluted environment for a long time may be considered as potentially resistant species and recommended for green belt design in mining areas, especially to cope with dust pollution. Results showed the pollution level, especially of mining-originated dust particles holding capacity of leaves and effects of different biochemical parameters (Total Chlorophyll, Protein and Carotenoid) of existing plant species both from mining areas as well as from Bundelkhand University campus. Based on their performances, Tectona grandis L., Ficus hispida L., Calotropis procera Aiton., Butea monosperma Lam. and Ficus benghalensis L., etc. are highly tolerant species while Ficus infectoria L., Artocarpus heterophyllus Lam., Ipomoea purpurea L., Allianthus excelsa Roxb. and Bauhinia variegata L. are intermediate tolerant species. T. grandis had shown the highest dust-holding capacity (2.566 ± 0.0004 mg/cm2) whereas Albizia procera (0.018 ± 0.0002 mg/cm2) was found to be the lowest dust-holding capacity. Our findings also showed that the T. grandis and F. hispida have significant dust deposition with minimal effect of dust on their leaf chlorophyll (17.447 ± 0.019 mg/g and 14.703 ± 0.201 mg/g), protein (0.699 ± 0.001 mg/g and 0.604 ± 0.002 mg/g) and carotenoid (0.372 ± 0.003 mg/g and 0.354 ± 0.003 mg/g) content respectively among all selected plant species. Therefore, in the present investigation, plant species with high tolerance to high dust-holding capacity on their leaf surfaces are preferable for green corridors as open cast granite mines and their adjacent areas.展开更多
For eliminating the zero-order image in digital holography, a new method using the differential of the hologram intensity instead of the hologram itself for numerical reconstruction is proposed. This method is based o...For eliminating the zero-order image in digital holography, a new method using the differential of the hologram intensity instead of the hologram itself for numerical reconstruction is proposed. This method is based on digital image processing. By analyzing the spatial spectrum of the off-axis digital hologram, it theoretically proves that the zero-order image can be effectively eliminated by differential before reconstruction. Then, the detected hologram is processed in the program with differential and reconstruction. Both the theoretical analysis and digital reconstruction results show that it can effectively eliminate the large bright spot in the center of the reconstructed image caused by the zero-order image, improve the image quality significantly, and render a better contrast of the reconstructed image. This method is very simple and convenient due to no superfluous optical elements and requiring only one time record.展开更多
Shell structures have increasingly widespread applications in biomedical ultrasound fields such as contrast agents and drug delivery,which requires the precise prediction of the acoustic radiation force under various ...Shell structures have increasingly widespread applications in biomedical ultrasound fields such as contrast agents and drug delivery,which requires the precise prediction of the acoustic radiation force under various circumstances to improve the system efficiency.The acoustic radiation force exerted by a zero-order quasi-Bessel-Gauss beam on an elastic spherical shell near an impedance boundary is theoretically and numerically studied in this study.By means of the finite series method and the image theory,a zero-order quasi-Bessel-Gauss beam is expanded in terms of spherical harmonic functions,and the exact solution of the acoustic radiation force is derived based on the acoustic scattering theory.The acoustic radiation force function,which represents the radiation force per unit energy density and per unit cross-sectional surface,is especially investigated.Some simulated results for a polymethyl methacrylate shell and an aluminum shell are provided to illustrate the behavior of acoustic radiation force in this case.The simulated results show the oscillatory property and the negative radiation force caused by the impedance boundary.An appropriate relative thickness of the shell can generate sharp peaks for a polymethyl methacrylate shell.Strong radiation force can be obtained at small half-cone angles and the beam waist only affects the results at high frequencies.Considering that the quasi-Bessel-Gauss beam possesses both the energy focusing property and the non-diffracting advantage,this study is expected to be useful in the development of acoustic tweezers,contrast agent micro-shells,and drug delivery applications.展开更多
In this research, we have improved a relaxation method for triangular meshes intended for finite element fluid simulations which contain discrete element particles. The triangle edges are treated as springs which rela...In this research, we have improved a relaxation method for triangular meshes intended for finite element fluid simulations which contain discrete element particles. The triangle edges are treated as springs which relax their lengths towards a “better” force equilibrium where the triangles are closer to equilateral shape. The actual kernel is an improved zero order integrator which is able to follow reconfigurations of the particles faster than earlier methods. The improved relaxation allows larger timesteps in the flow simulation and leads to more stable, faster mesh reconfigurations for fast moving particles in the flow. Additionally, this demonstrates how integrators of the same order zero can nevertheless have different convergence speeds towards展开更多
With derivative spectrophotometric method,the complexes of lanthanides with 2-(5-bromo-2-pyridylazo)-5-diethylaminophen- ol(5-Br-PADAP)in the presence of octylphenol poly(ethyleneg- lycol)ether(TX-100)were studied.It ...With derivative spectrophotometric method,the complexes of lanthanides with 2-(5-bromo-2-pyridylazo)-5-diethylaminophen- ol(5-Br-PADAP)in the presence of octylphenol poly(ethyleneg- lycol)ether(TX-100)were studied.It is found that the maximum absorption of fourth-order derivative spectra of the neodymium complex by 4f electron transitions is at 579(+)nm and 582(-)nm with molar derivative absorptivities of 5.2×10~3 1.mol^(-1).cm^(-1). The maximum absorption of the zero-order derivative spectra of the complexes for neodymium and praseodymium is at 580hm,the molar absorptivities are 1.47×10~5 l.mol^(-1).cm^(-1)for Nd and 1.26 ×10~5 l.mol^(-1).cm^(-1)for Pr.The component ratio of the complex is Nd:5-Br-PADAP=1:4.Beer's law is obeyed in the range of 0-3.75μg of Nd and Pr in 25ml of solution.The method has been used for the simultaneous determination of Nd and Pr in four synthetic samples and the results obtained are satisfactory.展开更多
Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects o...Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects of the diameter of the self-tapping screw and the guiding bores on the nail holding performance on different sections of Masson pine and Chinese fir dimension lumbers were mainly explored.The results showed that:(1)The nail holding strength of the tangential section was the maximum,followed by that of the radial section,and that of the cross section was the minimum.(2)The nail holding strength of Masson pine was higher than that of Chinese fir.(3)The nail holding strength grew with the increase in the diameter of self-tapping screws,but a large diameter would lead to plastic cracking of the timber,thus further affecting the nail holding strength.Masson pine and Chinese fir reached the maximum nail holding strength when the diameter of self-tapping screws was 3.5 mm.(4)Under a large diameter of screws,prefabricated guiding bores could mitigate timber cracking and improve its nail holding strength.(5)Prefabricated guiding bores were more necessary for the screw connection of Masson pine.The results obtained could provide a scientific basis for the screw connection design of Masson pine and Chinese fir timber structures.展开更多
On January 17,the Chinese Association for International Understanding(CAFIU)and the Association of Bosnia-China Friendship co-hosted the webinar themed New Vision of China-Bosnia and Herzegovina Cooperation and Role o...On January 17,the Chinese Association for International Understanding(CAFIU)and the Association of Bosnia-China Friendship co-hosted the webinar themed New Vision of China-Bosnia and Herzegovina Cooperation and Role of Civil Society.展开更多
The inauguration of the secretariat of ISO/TC 341,Heat supply net work,was held in Beijing on April 11.China Urban Construction Design&Research Institute,a subordinate enterprise of China Construction Technology C...The inauguration of the secretariat of ISO/TC 341,Heat supply net work,was held in Beijing on April 11.China Urban Construction Design&Research Institute,a subordinate enterprise of China Construction Technology Consulting Co.,Ltd.(CCTC),holds the secret ariat,which is China’s first ISO secretariat for standardization in the field of housing and urban-rural development.展开更多
Objective:To analyze the application of deep inspiration breath hold technique in radiotherapy after breast-conserving surgery for left breast cancer and the improvement of cardiac dose.Methods:A total of 45 patients ...Objective:To analyze the application of deep inspiration breath hold technique in radiotherapy after breast-conserving surgery for left breast cancer and the improvement of cardiac dose.Methods:A total of 45 patients with left breast cancer treated in our hospital after breast-conserving surgery were selected,and the selection time was set from January 2020 to August 2022.All patients received radiotherapy.The right breast,heart,and lung volumes,and dose parameters of the heart,lungs,right breast,and left anterior descending coronary artery were compared under free breathing(FB)and deep inspiration breath hold(DIBH)technical modes.Results:The heart volume of the DIBH group was smaller than that of the FB group,and the left and right lung volumes were significantly larger than those of the FB group.In the DIBH group,the heart dose parameters V5,proper lung dose parameters,and left anterior descending coronary artery dose parameters were found lower than that of the FB group,and the differences were statistically significant(P<0.05).Conclusion:Compared with FB,the DIBH technique can reduce the heart’s size and increase the lung volume when used for radiotherapy after breast-conserving surgery for left breast cancer.It also reduces the dose to the heart,right lung,and left anterior descending coronary artery,thus protecting the heart and lungs.展开更多
基金funded by the National Natural Science Foundation of China(Nos.51672310,51272288,51972344)。
文摘Li_(1.5)Ga_(0.5)Ti_(1.5)PO_(4))_(3)(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects of sintering temperature and holding time on relative density,phase composition,microstructure,bulk conductivity,and total conductivity.In the impedance test under frequency of 1-10^(6) Hz,the bulk conductivity of the samples increased with increasing sintering temperature,and the total conductivity first increased and then decreased.SEM results showed that the average grain size in the ceramics was controlled by the sintering temperature,which increased from(0.54±0.01)μm to(1.21±0.01)μm when the temperature changed from 750 to 950°C.The relative density of the ceramics increased and then decreased with increasing temperature as the porosity increased.The holding time had little effect on the grain size growth or sample density,but an extended holding time resulted in crack generation that served to reduce the conductivity of the solid electrolyte.
基金Project supported by the National Natural Science Foundation of China(Grant No.52172314)the Natural Science Foundation of Liaoning Province,China(Grant No.2022-MS-150)the Special Funding Project of Taishan Scholar Engineering.
文摘This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissions of passenger cars.The dynamic behaviors of these two types of vehicles are described using cellular automata(CA)models under open boundary conditions.Numerical simulations are carried out to obtain the phase diagrams of the bus system and the trajectories of buses and passenger cars before and after the implementation of the bus holding strategy under different probabilities of passenger cars entering a two-lane mixed traffic system.Then,we analyze the flow rate,satisfaction rate,and pollutant emission rates of passenger cars together with the performance of a mixed traffic system.The results show that the bus holding strategy can effectively alleviate bus bunching,whereas it has no significant impact on the flow rate and pollutant emission rates of passenger cars;the flow rate,satisfaction rate,and pollutant emission rates of passenger cars for either the traffic system or for each lane are influenced by the bus departure interval and the number of passengers arriving at bus stops.
文摘The aim of this study was to investigate the inter-fraction variations, patient comfort and knowledge at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). The differences in set-up that occurred between treatment sessions for the left sided breast patients were observed and recorded. Measurements of routine set-up variation for 24 patients were performed by matching the cone beam computed tomography (CBCT) and the planning computed tomography (CT). Scans of all five fractions per patient were used to quantify the setup variations with standard deviation (SD) in all the three directions (anterior posterior, left right, and superior inferior). The patients DIBH comfort and knowledge was also evaluated. The average translational errors for the anterior posterior (AP, z), left-right (LR, x), and Superior-inferior (SI, y) directions were 0.40 cm, 0.40 cm, and 0.40 cm, respectively. The translation variation of the three directions showed statistical significance (P < 0.05). On comfort and knowledge investigation, among all participants, 80% moderately agreed that the therapist’s instructions for operating the deep inspiration breath hold (DIBH) technique were easy to understand, and 63.33% indicated that their comfort with the DIBH technique was neutral or average. The inter-fraction variations in patients with left-sided breast cancer were qualitatively analyzed. Significant shifts between CBCT and planning CT images were observed. The daily treatment verification could assist accurate dose delivery.
基金funded the World Class Research(WCR)Grant of Universitas Diponegoro with Contract Number 357-36/UN7.D2/PP/IV/2024.
文摘Hydroxyapatite(HA)is a bio ceramic commonly utilized in bone tissue engineering due to its bioactive and osteoconductive properties.Crab shells are usually disregarded as waste material despite their significant CaCO_(3) content,and have not been widely utilized in the synthesis of HA.This study aims to synthesize and analyze HA derived from crab shells using the hydrothermal method with different durations of holding time.This study utilized precipitated calcium carbonate(PCC)derived from crab shells.With a hydrothermal reactor set at 160℃ and varying holding times of 14(HA_14),16(HA_16),and 18(HA_18)h,a PCC and(NH4)2HPO4 mixture was used to synthesize HA.The synthesis results were analyzed using scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FTIR),and X-ray diffraction(XRD)tests.This study has accomplished the synthesis of HA from crab shells.Nonetheless,the final product of synthesis still contained CaCO_(3) as an impurity.The prolonged hydrothermal holding time of 14 to 18 h resulted in a reduction of impurities while increasing the percentage of crystal weight and crystallite size of HA.Specimen CH_18 is the best-quality product generated in this study.This specimen produced HA with the highest percentage of crystal weight and crystallite size compared to the other specimens.Furthermore,specimen CH_18 exhibited the lowest concentration of impurities.The Ca/P ratio in this specimen was also the closest to 1.67.The Ca/P ratio,crystallite size,and crystal weight percentage of this specimen are 1.54,19.06 nm,and 99.1%,respectively.
文摘This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Failure Time (AFT) model, Cox Proportional Hazards model, and Survival model, we assess the effectiveness of these models in capturing survival rates across varying gender, age groups, and treatment categories. Simulated data was used to fit the models, with model identification criteria (AIC, BIC, and R2) applied for evaluation. Results indicate that the AFT model is particularly sensitive to interaction terms, showing significant effects for older age groups (50 - 60 years) and treatment interaction, while the Cox model provides a more stable fit across all age groups. The Survival model displayed variability, with its performance diminishing when interaction terms were introduced, particularly in older age groups. Overall, while the AFT model captures the complexities of interactions in the data, the Cox model’s stability suggests it may be better suited for general analyses without strong interaction effects. The findings highlight the importance of model selection in survival analysis, especially in complex disease progression scenarios like HIV/AIDS.
文摘The present study has been carried out on a total of 50 available plant species to assess their dust-capturing capacity and biochemical performances in and around open cast granite mine areas of Jhansi district and Bundelkhand University campus treated as control site. Plant species existing under a polluted environment for a long time may be considered as potentially resistant species and recommended for green belt design in mining areas, especially to cope with dust pollution. Results showed the pollution level, especially of mining-originated dust particles holding capacity of leaves and effects of different biochemical parameters (Total Chlorophyll, Protein and Carotenoid) of existing plant species both from mining areas as well as from Bundelkhand University campus. Based on their performances, Tectona grandis L., Ficus hispida L., Calotropis procera Aiton., Butea monosperma Lam. and Ficus benghalensis L., etc. are highly tolerant species while Ficus infectoria L., Artocarpus heterophyllus Lam., Ipomoea purpurea L., Allianthus excelsa Roxb. and Bauhinia variegata L. are intermediate tolerant species. T. grandis had shown the highest dust-holding capacity (2.566 ± 0.0004 mg/cm2) whereas Albizia procera (0.018 ± 0.0002 mg/cm2) was found to be the lowest dust-holding capacity. Our findings also showed that the T. grandis and F. hispida have significant dust deposition with minimal effect of dust on their leaf chlorophyll (17.447 ± 0.019 mg/g and 14.703 ± 0.201 mg/g), protein (0.699 ± 0.001 mg/g and 0.604 ± 0.002 mg/g) and carotenoid (0.372 ± 0.003 mg/g and 0.354 ± 0.003 mg/g) content respectively among all selected plant species. Therefore, in the present investigation, plant species with high tolerance to high dust-holding capacity on their leaf surfaces are preferable for green corridors as open cast granite mines and their adjacent areas.
基金The Natural Science Foundation of Jiangsu Province (No.BK2006102)the National Natural Science Foundation of China(No.10772086)
文摘For eliminating the zero-order image in digital holography, a new method using the differential of the hologram intensity instead of the hologram itself for numerical reconstruction is proposed. This method is based on digital image processing. By analyzing the spatial spectrum of the off-axis digital hologram, it theoretically proves that the zero-order image can be effectively eliminated by differential before reconstruction. Then, the detected hologram is processed in the program with differential and reconstruction. Both the theoretical analysis and digital reconstruction results show that it can effectively eliminate the large bright spot in the center of the reconstructed image caused by the zero-order image, improve the image quality significantly, and render a better contrast of the reconstructed image. This method is very simple and convenient due to no superfluous optical elements and requiring only one time record.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.81527901,11604361,and 91630309)。
文摘Shell structures have increasingly widespread applications in biomedical ultrasound fields such as contrast agents and drug delivery,which requires the precise prediction of the acoustic radiation force under various circumstances to improve the system efficiency.The acoustic radiation force exerted by a zero-order quasi-Bessel-Gauss beam on an elastic spherical shell near an impedance boundary is theoretically and numerically studied in this study.By means of the finite series method and the image theory,a zero-order quasi-Bessel-Gauss beam is expanded in terms of spherical harmonic functions,and the exact solution of the acoustic radiation force is derived based on the acoustic scattering theory.The acoustic radiation force function,which represents the radiation force per unit energy density and per unit cross-sectional surface,is especially investigated.Some simulated results for a polymethyl methacrylate shell and an aluminum shell are provided to illustrate the behavior of acoustic radiation force in this case.The simulated results show the oscillatory property and the negative radiation force caused by the impedance boundary.An appropriate relative thickness of the shell can generate sharp peaks for a polymethyl methacrylate shell.Strong radiation force can be obtained at small half-cone angles and the beam waist only affects the results at high frequencies.Considering that the quasi-Bessel-Gauss beam possesses both the energy focusing property and the non-diffracting advantage,this study is expected to be useful in the development of acoustic tweezers,contrast agent micro-shells,and drug delivery applications.
文摘In this research, we have improved a relaxation method for triangular meshes intended for finite element fluid simulations which contain discrete element particles. The triangle edges are treated as springs which relax their lengths towards a “better” force equilibrium where the triangles are closer to equilateral shape. The actual kernel is an improved zero order integrator which is able to follow reconfigurations of the particles faster than earlier methods. The improved relaxation allows larger timesteps in the flow simulation and leads to more stable, faster mesh reconfigurations for fast moving particles in the flow. Additionally, this demonstrates how integrators of the same order zero can nevertheless have different convergence speeds towards
文摘With derivative spectrophotometric method,the complexes of lanthanides with 2-(5-bromo-2-pyridylazo)-5-diethylaminophen- ol(5-Br-PADAP)in the presence of octylphenol poly(ethyleneg- lycol)ether(TX-100)were studied.It is found that the maximum absorption of fourth-order derivative spectra of the neodymium complex by 4f electron transitions is at 579(+)nm and 582(-)nm with molar derivative absorptivities of 5.2×10~3 1.mol^(-1).cm^(-1). The maximum absorption of the zero-order derivative spectra of the complexes for neodymium and praseodymium is at 580hm,the molar absorptivities are 1.47×10~5 l.mol^(-1).cm^(-1)for Nd and 1.26 ×10~5 l.mol^(-1).cm^(-1)for Pr.The component ratio of the complex is Nd:5-Br-PADAP=1:4.Beer's law is obeyed in the range of 0-3.75μg of Nd and Pr in 25ml of solution.The method has been used for the simultaneous determination of Nd and Pr in four synthetic samples and the results obtained are satisfactory.
基金funded by the National Natural Science Foundation of China (32160348)Forestry Science and Technology Research Project of Guizhou Forestry Bureau (J[2022]21 and[2020]C14)+1 种基金Department Program of Guizhou Province ([2020]1Y128)the Cultivation Project of Guizhou University of China ([2019]37).
文摘Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects of the diameter of the self-tapping screw and the guiding bores on the nail holding performance on different sections of Masson pine and Chinese fir dimension lumbers were mainly explored.The results showed that:(1)The nail holding strength of the tangential section was the maximum,followed by that of the radial section,and that of the cross section was the minimum.(2)The nail holding strength of Masson pine was higher than that of Chinese fir.(3)The nail holding strength grew with the increase in the diameter of self-tapping screws,but a large diameter would lead to plastic cracking of the timber,thus further affecting the nail holding strength.Masson pine and Chinese fir reached the maximum nail holding strength when the diameter of self-tapping screws was 3.5 mm.(4)Under a large diameter of screws,prefabricated guiding bores could mitigate timber cracking and improve its nail holding strength.(5)Prefabricated guiding bores were more necessary for the screw connection of Masson pine.The results obtained could provide a scientific basis for the screw connection design of Masson pine and Chinese fir timber structures.
文摘On January 17,the Chinese Association for International Understanding(CAFIU)and the Association of Bosnia-China Friendship co-hosted the webinar themed New Vision of China-Bosnia and Herzegovina Cooperation and Role of Civil Society.
文摘The inauguration of the secretariat of ISO/TC 341,Heat supply net work,was held in Beijing on April 11.China Urban Construction Design&Research Institute,a subordinate enterprise of China Construction Technology Consulting Co.,Ltd.(CCTC),holds the secret ariat,which is China’s first ISO secretariat for standardization in the field of housing and urban-rural development.
文摘Objective:To analyze the application of deep inspiration breath hold technique in radiotherapy after breast-conserving surgery for left breast cancer and the improvement of cardiac dose.Methods:A total of 45 patients with left breast cancer treated in our hospital after breast-conserving surgery were selected,and the selection time was set from January 2020 to August 2022.All patients received radiotherapy.The right breast,heart,and lung volumes,and dose parameters of the heart,lungs,right breast,and left anterior descending coronary artery were compared under free breathing(FB)and deep inspiration breath hold(DIBH)technical modes.Results:The heart volume of the DIBH group was smaller than that of the FB group,and the left and right lung volumes were significantly larger than those of the FB group.In the DIBH group,the heart dose parameters V5,proper lung dose parameters,and left anterior descending coronary artery dose parameters were found lower than that of the FB group,and the differences were statistically significant(P<0.05).Conclusion:Compared with FB,the DIBH technique can reduce the heart’s size and increase the lung volume when used for radiotherapy after breast-conserving surgery for left breast cancer.It also reduces the dose to the heart,right lung,and left anterior descending coronary artery,thus protecting the heart and lungs.