Waste disposal is a major source of greenhouse gas emissions such as methane, carbon dioxide and nitrous oxide. In China, rapid economic growth and urbanization have led to increasing solid waste generation and greenh...Waste disposal is a major source of greenhouse gas emissions such as methane, carbon dioxide and nitrous oxide. In China, rapid economic growth and urbanization have led to increasing solid waste generation and greenhouse gas emissions from the waste sector. Based on the first-order decay (FOD) method recommended by the 2006 IPCC Guidelines, this paper systematically estimates China's carbon emissions from the waste sector and forecasts their peak. Results indicate that between 1981 and 2009, China's carbon emissions from the waste sector surged, possibly peaking by around 2024. In comparison with developed countries, there is a large potential to improve waste disposal in China. Industrial upgradation and waste disposal improvement will help reduce waste generation and carbon emissions from the waste sector.展开更多
A peak norm is defined for Lp spaces of E-valued Bochner integrable functions, where E is a Banach space, and best approximations from a sun to elements of the space are characterized. Applications are given to some f...A peak norm is defined for Lp spaces of E-valued Bochner integrable functions, where E is a Banach space, and best approximations from a sun to elements of the space are characterized. Applications are given to some families of simultaneous best approximation problems.展开更多
In order to further deepen the understanding of seismic wave propagation characteristics induced by the large volume airgun source,experimental data from multiple fixed excitation points in Fujian Province were used t...In order to further deepen the understanding of seismic wave propagation characteristics induced by the large volume airgun source,experimental data from multiple fixed excitation points in Fujian Province were used to obtain the equivalent single excitation high signal-to-noise ratio velocity and displacement records through linear stacking and simulation techniques.Then the peak displacements of different epicentral distances were used to calculate the equivalent magnitude of the airgun source excitation at different fixed excitation points so as to establish the attenuation relationship between equivalent magnitude,epicenter distance and velocity peak.Our results show that:①Within 270 km of epicentral distance,for the large-volume airgun’s single shot,the peak velocity range is about 700-4 nm/s,and the peak displacement range is about 200.0-0.2 nm;②The equivalent magnitude of the P-wave from the airgun source with a total capacity of 8,000 in 3 is 0.181-0.760,and the equivalent magnitude of the S-wave is 0.294-0.832.By contrast,the equivalent magnitude of the P-wave from the airgun source with a total capacity of 12,000 in 3 is 0.533-0.896,and the equivalent magnitude of the S-wave is 0.611-0.946.The S-wave energy is greater than the P-wave energy,and the excitation efficiency varies greatly with different excitation environment;③The peak velocity increases with the equivalent magnitude,and decreases with the epicentral distance.The vertical component of the P-wave peak velocity is the largest among those three components,while the S-wave has the smallest vertical component and similar horizontal components.Hence,our research can provide an important basis for the quantitative judgment of the seismic wave propagation distance using the airgun and the design of the observation system in deep exploration or monitoring with airgun.展开更多
A wide variety of near-fault strong ground motion records were collected from various tectonic environments worldwide and were used to study the peak value ratio and response spectrum ratio of the vertical to horizont...A wide variety of near-fault strong ground motion records were collected from various tectonic environments worldwide and were used to study the peak value ratio and response spectrum ratio of the vertical to horizontal component of ground motion, focusing on the effect of earthquake magnitude, site conditions, pulse duration, and statistical component. The results show that both the peak value ratio and response spectrum ratio are larger than the 2/3 value prescribed in existing seismic codes, and the relationship between the vertical and horizontal ground motions is comparatively intricate. In addition, the effect of the near-fault ground motions on bridge performance is analyzed, considering both the material nonlinear characteristics and the P-A effect.展开更多
A case of ideal fluid flow in a moving ending rigid constant diameter circular pipeline is investigated. A model of the pipeline was established based on distributed-parameter theory. The comparisons on a quotient mod...A case of ideal fluid flow in a moving ending rigid constant diameter circular pipeline is investigated. A model of the pipeline was established based on distributed-parameter theory. The comparisons on a quotient module of output and input pressure of the moving ending model and neglected ending moving model are made on the frequency response. It is revealed that the moving ending of pipeline influences largely the quotient amplitude of output and input pressure, and the peak value of frequency resonance increases with the increase of pipeline’s length.展开更多
In this paper, we present a new method to determine the relative permittivity of periodic stratified media using the iterative time-reversal method. Based on transmission line theory, the focal peak value of iterative...In this paper, we present a new method to determine the relative permittivity of periodic stratified media using the iterative time-reversal method. Based on transmission line theory, the focal peak value of iterative time-reversal electro- magnetic waves, which contain information about the periodic stratified medium, is computed in pulse-echo mode. Using the relationship between the focal peak value and the relative permittivity of the periodic stratified medium, the relative permittivity can be obtained by measuring the focal peak value. Numerical simulations are conducted, and the results demonstrate the feasibility of the proposed approach to the measurement of the relative permittivity of a periodic stratified medium.展开更多
In this article, the seismic records of Japan's Kik-net are selected to measure the acceleration, displacement, and effective peak acceleration of each seismic record within a certain time after P wave, then a contin...In this article, the seismic records of Japan's Kik-net are selected to measure the acceleration, displacement, and effective peak acceleration of each seismic record within a certain time after P wave, then a continuous estimation is given on earthquake early warning magnitude through statistical analysis method, and Wenchuan earthquake record is utilized to check the method. The results show that the reliability of earthquake early warning magnitude continuously increases with the increase of the seismic information, the biggest residual happens if the acceleration is adopted to fit earthquake magnitude, which may be caused by rich high-frequency components and large dispersion of peak value in acceleration record, the influence caused by the high-frequency components can be effectively reduced if the effective peak acceleration and peak displacement is adopted, it is estimated that the dispersion of earthquake magnitude obviously reduces, but it is easy for peak displacement to be affected by long-period drifting. In various components, the residual enlargement phenomenon at vertical direction is almost unobvious, thus it is recommended in this article that the effective peak acceleration at vertical direction is preferred to estimate earthquake early warning magnitude. Through adopting Wenchuan strong earthquake record to check the method mentioned in this article, it is found that this method can be used to quickly, stably, and accurately estimate the early warning magnitude of this earthquake, which shows that this method is completely applicable for earthquake early warning.展开更多
Objective:The present study is to compare pharmacokinetics difference of carboplatin by using ultraselection uterine artery with by using peripheral vein in cervical cancer.Methods:Thirteen patients with locally advan...Objective:The present study is to compare pharmacokinetics difference of carboplatin by using ultraselection uterine artery with by using peripheral vein in cervical cancer.Methods:Thirteen patients with locally advanced cervical cancer who had been proved by pathobiology were randomly divided into two groups:the ultraselection uterine artery group(group A, n = 6) and the peripheral vein(group B, n = 7).Carboplatin was administered by infusing into artery or vein in both groups at the dosage of 300 mg/m2.Tissues from the cervical tumor were collected at different times after infusion in both groups and then analyzed.Results:The peak concentration of platinum in tumor tissue was about 2.79 times higher in group A than that of group B(P < 0.05).The platinum concentrations in tumor in group A reached its peak levels immediately after infusion.But, group B had delayed time.While, for the time point of 0 min, when the administration finished immediately, the platinum concentration in tumor was significantly higher when compared with group B(P < 0.05).The tumor tissue area under the concentration(AUC) of carboplatin was about 2 times higher in group A than that of group B(P < 0.05).Conclusion:We observed the pharmacological advantages of chemotherapy by using ultraselection uterine artery administration of chemotherapeutic agent carboplatin in tumor tissue which provided theoretical basis and laboratory parameters of the intra-arterial chemotherapy for gynecologic malignancy.展开更多
It is estimated that in the coming years,the rate of consumption of oil products in China will increase at an energy-saving,environmentally-friendly,and slow pace.However,the increasing speed of the demand may vary ac...It is estimated that in the coming years,the rate of consumption of oil products in China will increase at an energy-saving,environmentally-friendly,and slow pace.However,the increasing speed of the demand may vary according to the types of the products:gasoline and kerosene may be needed more while diesel may be needed less.It is also estimated that before 2020,there will be an oil products glut in the country.Export of oil products,especially diesel,will become a new norm or trend.Alternative energy forms,such as natural gas and electricity,will be developed rapidly to attain a goal of replacing 130 million tons of oil in 2030.Even with a more conservative scenario,oil demand in China is estimated to peak at either about 810 million tons or even less at 680 million tons by 2030 if the effect of alternative energy is considered.展开更多
In order to analyze the ice-going ship’s performance under the pack ice conditions, synthetic ice was introduced into a towing tank. A barrier using floating cylinder in the towing tank was designed to carry out the ...In order to analyze the ice-going ship’s performance under the pack ice conditions, synthetic ice was introduced into a towing tank. A barrier using floating cylinder in the towing tank was designed to carry out the resistance experiment. The test results indicated that the encountering frequency between the ship model and the pack ice shifts towards a high-velocity point as the concentration of the pack ice increases, and this encountering frequency creates an unstable region of the resistance, and the unstable region shifts to the higher speed with the increasing concentration. The results also showed that for the same speed points, the ratio of the pack ice resistance to the open water resistance increases with the increasing concentration, and for the same concentrations, this ratio decreases as the speed increases. Motion characteristics showed that the mean value of the heave motion increases as the speed increases, and the pitch motion tends to increase with the increasing speed. In addition, the total resistance of the fullscale was predicted.展开更多
Time series analysis and time domain statistics applied to the fault sonic diagnosis of the pressure hammer with artificial diamond is reported.This method with the characters of brief criterion,high accuracy and quic...Time series analysis and time domain statistics applied to the fault sonic diagnosis of the pressure hammer with artificial diamond is reported.This method with the characters of brief criterion,high accuracy and quick speed is suitable for alarming on the spot.展开更多
As a typical secondary air pollutant,surface ozone has been monitored routinely since 2013 in China.Most studies on the spatiotemporal variation of ozone have been centered around the daily maximum 8-h average,with li...As a typical secondary air pollutant,surface ozone has been monitored routinely since 2013 in China.Most studies on the spatiotemporal variation of ozone have been centered around the daily maximum 8-h average,with little attention paid to the trends of hourly ozone,especially hourly ozone exceedances.Focusing on hourly ozone exceedances and peak values,the spatiotemporal trends of hourly ozone at 77 sites in 13 cities of the Beijing-Tianjin-Hebei(BTH)region during 2017-2021 were analyzed in this study.The number of hours with exceedances(N_(H200))in 2019 was nearly three times that of 2021.On a five-year average,the percentage of cumulative NH200 in June accounted for up to 40.5%of all hourly exceedances.Cities in central Hebei Province had the highest cumulative annual N_(H200).June had the highest average hourly ozone exceeded multiples of 0.158.The top two cities with the highest average exceeded multiple were Tangshan(0.166)and Beijing(0.158).Tangshan and Xingtai ranked as the top two in terms of the mean of the 10 highest daily maximum ozone concentrations(MTDM),with 286.74 and 285.37μg m^(−3),respectively.The gap between the MTDM and the daily maximum of hourly ozone averaged over all sites had narrowed to 97.88μg m^(−3) in 2021,much lower than that in other years,which indicated that the stability and convergence of ozone pollution in BTH region had been enhanced in 2021 to some extent.展开更多
Results of several Large Eddy Simulations (LES) this article. It is shown that the vegetation can make the flow of open channel flows with non-submerged vegetation are presented in structure in the mainstream direct...Results of several Large Eddy Simulations (LES) this article. It is shown that the vegetation can make the flow of open channel flows with non-submerged vegetation are presented in structure in the mainstream direction uniform for both supercritical and subcritical flows. For subcritical flows, the LES results of the ensemble-average of time-averaged velocity distributions at four vertical sections around a single plant are in good agreement with measurements. The velocity sees double peaks at the upper and lower positions of flows. For supercritical flows, the ensemble-average velocities see some discrepancy between LES and measurement results. Some secondary flow eddies appear near the single plant, and they just locate in the positions of the double peaks in stream-wise velocity profiles. It is also found that the vegetation drag coefficient deceases as the Froude number increases.展开更多
The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling for...The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitehcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole de- formation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thick- ness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental re- sults prove the correctness of the improved formula given.展开更多
Purpose. This study is to investigate the influence of acupuncture at acupoints Neiguan (PC 6) and Ximen (PC 4) on the stroke volume and the flow rate of peak value of left ventricle ejection in the patients with ...Purpose. This study is to investigate the influence of acupuncture at acupoints Neiguan (PC 6) and Ximen (PC 4) on the stroke volume and the flow rate of peak value of left ventricle ejection in the patients with coronary heart disease. Methods. 60 cases of coronary heart disease were divided into acupoint Neiguan (PC 6) group and acupoint Ximen (PC 4) group, and the stroke volume and the flow rate of peak value of left ventricle ejection were detected 3 min after manipulating needles and 20 rain after retaining needles respectively, then were compared with those before acupuncture. Results. 3 min after manipulating needles, the stroke volume and the flow rate of peak value of left ventricle ejection were enhanced in 46 cases, and 20 min after retaining needles, both the stroke volume andthe flow rate of peak value of left ventricle ejection were all enhanced in 34 cases. Conclusion. Puncturing acupoints Neiguan (PC 6) and Ximen (PC 4) could enhance the contractility of left ventricle wall, increase the stroke volume of the heart and improve the myocardial ischemia in the patients with coronary heart disease.展开更多
文摘Waste disposal is a major source of greenhouse gas emissions such as methane, carbon dioxide and nitrous oxide. In China, rapid economic growth and urbanization have led to increasing solid waste generation and greenhouse gas emissions from the waste sector. Based on the first-order decay (FOD) method recommended by the 2006 IPCC Guidelines, this paper systematically estimates China's carbon emissions from the waste sector and forecasts their peak. Results indicate that between 1981 and 2009, China's carbon emissions from the waste sector surged, possibly peaking by around 2024. In comparison with developed countries, there is a large potential to improve waste disposal in China. Industrial upgradation and waste disposal improvement will help reduce waste generation and carbon emissions from the waste sector.
文摘A peak norm is defined for Lp spaces of E-valued Bochner integrable functions, where E is a Banach space, and best approximations from a sun to elements of the space are characterized. Applications are given to some families of simultaneous best approximation problems.
基金the National Natural Science Foundation of China(41790461)
文摘In order to further deepen the understanding of seismic wave propagation characteristics induced by the large volume airgun source,experimental data from multiple fixed excitation points in Fujian Province were used to obtain the equivalent single excitation high signal-to-noise ratio velocity and displacement records through linear stacking and simulation techniques.Then the peak displacements of different epicentral distances were used to calculate the equivalent magnitude of the airgun source excitation at different fixed excitation points so as to establish the attenuation relationship between equivalent magnitude,epicenter distance and velocity peak.Our results show that:①Within 270 km of epicentral distance,for the large-volume airgun’s single shot,the peak velocity range is about 700-4 nm/s,and the peak displacement range is about 200.0-0.2 nm;②The equivalent magnitude of the P-wave from the airgun source with a total capacity of 8,000 in 3 is 0.181-0.760,and the equivalent magnitude of the S-wave is 0.294-0.832.By contrast,the equivalent magnitude of the P-wave from the airgun source with a total capacity of 12,000 in 3 is 0.533-0.896,and the equivalent magnitude of the S-wave is 0.611-0.946.The S-wave energy is greater than the P-wave energy,and the excitation efficiency varies greatly with different excitation environment;③The peak velocity increases with the equivalent magnitude,and decreases with the epicentral distance.The vertical component of the P-wave peak velocity is the largest among those three components,while the S-wave has the smallest vertical component and similar horizontal components.Hence,our research can provide an important basis for the quantitative judgment of the seismic wave propagation distance using the airgun and the design of the observation system in deep exploration or monitoring with airgun.
基金National Natural Science Foundation of China Under Grant No.50278002Dalian Nationalities University PHD Foundation Under Grant No.20066104
文摘A wide variety of near-fault strong ground motion records were collected from various tectonic environments worldwide and were used to study the peak value ratio and response spectrum ratio of the vertical to horizontal component of ground motion, focusing on the effect of earthquake magnitude, site conditions, pulse duration, and statistical component. The results show that both the peak value ratio and response spectrum ratio are larger than the 2/3 value prescribed in existing seismic codes, and the relationship between the vertical and horizontal ground motions is comparatively intricate. In addition, the effect of the near-fault ground motions on bridge performance is analyzed, considering both the material nonlinear characteristics and the P-A effect.
文摘A case of ideal fluid flow in a moving ending rigid constant diameter circular pipeline is investigated. A model of the pipeline was established based on distributed-parameter theory. The comparisons on a quotient module of output and input pressure of the moving ending model and neglected ending moving model are made on the frequency response. It is revealed that the moving ending of pipeline influences largely the quotient amplitude of output and input pressure, and the peak value of frequency resonance increases with the increase of pipeline’s length.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61071031,61107018,and 61201089)the Research Fund for the Doctoral Program of Higher Education of China(Grant Nos.20100185110021 and 20120185130001)+2 种基金the Program for Changjiang Scholars and Innovation Team in University,China(Grant No.IRT1113)the Natural Science Foundation of the Higher Education Institutions of Anhui Province(Grant No.KJ2013Z287)Fundamental Research Fund for the Central Universities(Grant No.ZYGX2011YB018)
文摘In this paper, we present a new method to determine the relative permittivity of periodic stratified media using the iterative time-reversal method. Based on transmission line theory, the focal peak value of iterative time-reversal electro- magnetic waves, which contain information about the periodic stratified medium, is computed in pulse-echo mode. Using the relationship between the focal peak value and the relative permittivity of the periodic stratified medium, the relative permittivity can be obtained by measuring the focal peak value. Numerical simulations are conducted, and the results demonstrate the feasibility of the proposed approach to the measurement of the relative permittivity of a periodic stratified medium.
文摘In this article, the seismic records of Japan's Kik-net are selected to measure the acceleration, displacement, and effective peak acceleration of each seismic record within a certain time after P wave, then a continuous estimation is given on earthquake early warning magnitude through statistical analysis method, and Wenchuan earthquake record is utilized to check the method. The results show that the reliability of earthquake early warning magnitude continuously increases with the increase of the seismic information, the biggest residual happens if the acceleration is adopted to fit earthquake magnitude, which may be caused by rich high-frequency components and large dispersion of peak value in acceleration record, the influence caused by the high-frequency components can be effectively reduced if the effective peak acceleration and peak displacement is adopted, it is estimated that the dispersion of earthquake magnitude obviously reduces, but it is easy for peak displacement to be affected by long-period drifting. In various components, the residual enlargement phenomenon at vertical direction is almost unobvious, thus it is recommended in this article that the effective peak acceleration at vertical direction is preferred to estimate earthquake early warning magnitude. Through adopting Wenchuan strong earthquake record to check the method mentioned in this article, it is found that this method can be used to quickly, stably, and accurately estimate the early warning magnitude of this earthquake, which shows that this method is completely applicable for earthquake early warning.
基金Supported by a grant from the Nature Sciences of Guangdong Province(No. 06024389).
文摘Objective:The present study is to compare pharmacokinetics difference of carboplatin by using ultraselection uterine artery with by using peripheral vein in cervical cancer.Methods:Thirteen patients with locally advanced cervical cancer who had been proved by pathobiology were randomly divided into two groups:the ultraselection uterine artery group(group A, n = 6) and the peripheral vein(group B, n = 7).Carboplatin was administered by infusing into artery or vein in both groups at the dosage of 300 mg/m2.Tissues from the cervical tumor were collected at different times after infusion in both groups and then analyzed.Results:The peak concentration of platinum in tumor tissue was about 2.79 times higher in group A than that of group B(P < 0.05).The platinum concentrations in tumor in group A reached its peak levels immediately after infusion.But, group B had delayed time.While, for the time point of 0 min, when the administration finished immediately, the platinum concentration in tumor was significantly higher when compared with group B(P < 0.05).The tumor tissue area under the concentration(AUC) of carboplatin was about 2 times higher in group A than that of group B(P < 0.05).Conclusion:We observed the pharmacological advantages of chemotherapy by using ultraselection uterine artery administration of chemotherapeutic agent carboplatin in tumor tissue which provided theoretical basis and laboratory parameters of the intra-arterial chemotherapy for gynecologic malignancy.
文摘It is estimated that in the coming years,the rate of consumption of oil products in China will increase at an energy-saving,environmentally-friendly,and slow pace.However,the increasing speed of the demand may vary according to the types of the products:gasoline and kerosene may be needed more while diesel may be needed less.It is also estimated that before 2020,there will be an oil products glut in the country.Export of oil products,especially diesel,will become a new norm or trend.Alternative energy forms,such as natural gas and electricity,will be developed rapidly to attain a goal of replacing 130 million tons of oil in 2030.Even with a more conservative scenario,oil demand in China is estimated to peak at either about 810 million tons or even less at 680 million tons by 2030 if the effect of alternative energy is considered.
基金financially supported by the National Natural Science Foundation of China(Grant No.51639004)
文摘In order to analyze the ice-going ship’s performance under the pack ice conditions, synthetic ice was introduced into a towing tank. A barrier using floating cylinder in the towing tank was designed to carry out the resistance experiment. The test results indicated that the encountering frequency between the ship model and the pack ice shifts towards a high-velocity point as the concentration of the pack ice increases, and this encountering frequency creates an unstable region of the resistance, and the unstable region shifts to the higher speed with the increasing concentration. The results also showed that for the same speed points, the ratio of the pack ice resistance to the open water resistance increases with the increasing concentration, and for the same concentrations, this ratio decreases as the speed increases. Motion characteristics showed that the mean value of the heave motion increases as the speed increases, and the pitch motion tends to increase with the increasing speed. In addition, the total resistance of the fullscale was predicted.
文摘Time series analysis and time domain statistics applied to the fault sonic diagnosis of the pressure hammer with artificial diamond is reported.This method with the characters of brief criterion,high accuracy and quick speed is suitable for alarming on the spot.
基金supported by the National Key Research and Development Program of China[grant number 2022YFC3700705]。
文摘As a typical secondary air pollutant,surface ozone has been monitored routinely since 2013 in China.Most studies on the spatiotemporal variation of ozone have been centered around the daily maximum 8-h average,with little attention paid to the trends of hourly ozone,especially hourly ozone exceedances.Focusing on hourly ozone exceedances and peak values,the spatiotemporal trends of hourly ozone at 77 sites in 13 cities of the Beijing-Tianjin-Hebei(BTH)region during 2017-2021 were analyzed in this study.The number of hours with exceedances(N_(H200))in 2019 was nearly three times that of 2021.On a five-year average,the percentage of cumulative NH200 in June accounted for up to 40.5%of all hourly exceedances.Cities in central Hebei Province had the highest cumulative annual N_(H200).June had the highest average hourly ozone exceeded multiples of 0.158.The top two cities with the highest average exceeded multiple were Tangshan(0.166)and Beijing(0.158).Tangshan and Xingtai ranked as the top two in terms of the mean of the 10 highest daily maximum ozone concentrations(MTDM),with 286.74 and 285.37μg m^(−3),respectively.The gap between the MTDM and the daily maximum of hourly ozone averaged over all sites had narrowed to 97.88μg m^(−3) in 2021,much lower than that in other years,which indicated that the stability and convergence of ozone pollution in BTH region had been enhanced in 2021 to some extent.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10972163, 51079102)the State Water Pollution Control and Management of Major Special Science and Technology (Grant No. 2008ZX07104-005)the Fundamental Rsearch Funds for the Central Universities (Grant N0. 2104001)
文摘Results of several Large Eddy Simulations (LES) this article. It is shown that the vegetation can make the flow of open channel flows with non-submerged vegetation are presented in structure in the mainstream direction uniform for both supercritical and subcritical flows. For subcritical flows, the LES results of the ensemble-average of time-averaged velocity distributions at four vertical sections around a single plant are in good agreement with measurements. The velocity sees double peaks at the upper and lower positions of flows. For supercritical flows, the ensemble-average velocities see some discrepancy between LES and measurement results. Some secondary flow eddies appear near the single plant, and they just locate in the positions of the double peaks in stream-wise velocity profiles. It is also found that the vegetation drag coefficient deceases as the Froude number increases.
基金Sponsored by National Natural Science Foundation of China(50974039)
文摘The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitehcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole de- formation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thick- ness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental re- sults prove the correctness of the improved formula given.
文摘Purpose. This study is to investigate the influence of acupuncture at acupoints Neiguan (PC 6) and Ximen (PC 4) on the stroke volume and the flow rate of peak value of left ventricle ejection in the patients with coronary heart disease. Methods. 60 cases of coronary heart disease were divided into acupoint Neiguan (PC 6) group and acupoint Ximen (PC 4) group, and the stroke volume and the flow rate of peak value of left ventricle ejection were detected 3 min after manipulating needles and 20 rain after retaining needles respectively, then were compared with those before acupuncture. Results. 3 min after manipulating needles, the stroke volume and the flow rate of peak value of left ventricle ejection were enhanced in 46 cases, and 20 min after retaining needles, both the stroke volume andthe flow rate of peak value of left ventricle ejection were all enhanced in 34 cases. Conclusion. Puncturing acupoints Neiguan (PC 6) and Ximen (PC 4) could enhance the contractility of left ventricle wall, increase the stroke volume of the heart and improve the myocardial ischemia in the patients with coronary heart disease.