By introducing a knowledge production function which combines both foreign technology imports and domestic research and development （R＆D） expenditure into an endogenous technological progress model, this paper exam...By introducing a knowledge production function which combines both foreign technology imports and domestic research and development （R＆D） expenditure into an endogenous technological progress model, this paper examines the mechanism that determines enterprises＇ R＆D intensity in developing countries, and explores how factors such as technological gap, technology absorptive capacity, innovation environment and innovation ability would impact Chinese enterprises＇decision made on R＆D intensity. Our results suggest that technological gap has no significant single impact on enterprises＇R＆D intensity, but rather influences enterprises＇decision on R＆D jointly with other factors such as degree of openness and human capital. A relative fall in efficiency of technology imitation recently has a negative effect on total R＆D intensity but helps to promote enterprises＇ independent R＆D. In addition, among factors related to R＆D innovation environment, industrial R＆D intensity has a significantly positive impact on enterprises＇ independent R＆D intensity, while regional economies of scale, proportion of large enterprises and proportion of government R＆D investment have some certain negative impacts.展开更多
This paper examines the effects of ownership types on firms＇ R＆D intensity and innovation performance, using a sample of 357,857 Chinese firms from 2005-2007. This study finds considerable divergence among Chinese d...This paper examines the effects of ownership types on firms＇ R＆D intensity and innovation performance, using a sample of 357,857 Chinese firms from 2005-2007. This study finds considerable divergence among Chinese domestic enterprises in terms of R＆D intensity and innovation performance. Firms owned by the central government are the key drivers for firms＇ R＆D activities, while local government, private and foreign ownerships are negatively related to both R＆D intensity and innovation performance. Significant divergence within government ownership category and argues that China＇s institutional changes generate varied government ownership groups with different levels of resource endowment, which in turn influence firms＇ R＆D activities.展开更多
Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of bas...Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.展开更多
This article explores the effects of investment upon energy intensity by applying a unique panel data of China's 27 provinces between 2004 and 2013.In addition,it also particularly stuthes other factors,such as en...This article explores the effects of investment upon energy intensity by applying a unique panel data of China's 27 provinces between 2004 and 2013.In addition,it also particularly stuthes other factors,such as energy price,economic structure,and urbanization.The results,based on four econometric regression model results,suggest that in general,the indigenous investment on research and development is a more powerful tool to decrease China's energy intensity regardless of region disparity.The foreign direct investment(FDI) has a prominent but not persistent effect on energy intensity.However,the outward direct investment has not shown its significant impact on energy intensity.At the level of an aggregate economy and China's eastern region,the results demonstrate that FDI improves energy efficiency significantly.For the central and western provinces,FDI does not support the similar conclusion.Based on these analyses,we present the corresponding regional policies for policymakers.展开更多
The D″layer,located at the bottom of the mantle,is an active thermochemical boundary layer.The upwelling of mantle plumes,as well as possible plate subduction in the D″layer,could lead to large-scale material transf...The D″layer,located at the bottom of the mantle,is an active thermochemical boundary layer.The upwelling of mantle plumes,as well as possible plate subduction in the D″layer,could lead to large-scale material transformation and mineral deformation,which could result in significant seismic anisotropy.However,owing to limited observations and immense computational cost,the anisotropic structures and geodynamic mechanisms in the D″layer remain poorly understood.In this study,we proposed a new inversion method for the seismic anisotropy in the D″layer quantitatively with shear wave splitting intensities.We first proved the linearity of the splitting intensities under the ray-theory assumption.The synthetic tests showed that,with horizontal axes of symmetry and ray incidences lower than 30°in the D″layer(typical SKS phase),the anisotropy is well resolved.We applied the method to the measured dataset in Africa and Western Europe,and obtained strong D″anisotropy in the margins of the large low shear-wave velocity provinces and subducting slabs.The new method makes it possible to obtain D″anisotropy,which provides essential constraints on the geodynamical processes at the base of the mantle.展开更多
The time-domain BEM was developed to analyze the dynamic stress intensity factor ( DSIF) of 3-D elastodynamic crack problems. To simulate the stress singularity along the front of a crack, eight-node isoparametric sin...The time-domain BEM was developed to analyze the dynamic stress intensity factor ( DSIF) of 3-D elastodynamic crack problems. To simulate the stress singularity along the front of a crack, eight-node isoparametric singular elements were used, and the DSIF for a semi-circular surface crack was firstly calculated based on displacement equation using the time-domain BEM formulation. The new scheme to determine the time step was brought forward. By the dynamic analysis program of time-domain BEM compiled by its, several numerical examples are presented, which demonstrate the unconditional stability and high accuracy of time-domain BEM applied to 3-D elastodynamic crack problems.展开更多
Objective:The aim of this study is to compare the effect of Vitamin D and Vitamin E supplementations,alone,and in combination,on reducing the intensity and duration of dysmenorrhea in women who were referred to the Ko...Objective:The aim of this study is to compare the effect of Vitamin D and Vitamin E supplementations,alone,and in combination,on reducing the intensity and duration of dysmenorrhea in women who were referred to the Kowsar gynecological clinics of Shahid Motahari Hospital of Urmia University of Medical Sciences.Materials and Methods:A double-blinded clinical trial was conducted on 112 women with dysmenorrhea who were randomly allocated into the four study groups.Finally,100 women complete the study and received capsules containing a placebo(n=25),1000 IU of Vitamin D(n=25),400 mg of Vitamin E(n=25),and 1000 IU of Vitamin D+400 mg of Vitamin E(n=25)every 24 h for 2 consecutive months at the beginning of the menstrual period.The pain intensity and duration among groups were compared before and after the intervention.Results:The mean menstrual pain duration in all three experimental groups(Vitamin E,Vitamin D,and the combination of them)was lower than the placebo group(all P<0.05),and the mean pain intensity scores in all three experimental groups were significantly lower than the placebo group(all P<0.05).The results(means)for all of the drugs administered at the end of the 2nd month were better than the 1st month(all P<0.01).Conclusions:Vitamin E and Vitamin D,as well as their combination,are recommended as an effective and safe treatment for the management of the complications of dysmenorrhea.展开更多
Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific attention.To quantitatively a...Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific attention.To quantitatively analyze the intensity of airblast initiated by landslides,the Wangjiayan landslide,occurred in the Wenchuan earthquake,is selected here with the landslide propagation and airblast evolution being studied using FLUENT by introducing the Voellmy rheological law.The results reveal that:(1)For the Wangjiayan landslide,its whole travelling duration is only 12 s with its maximum velocity reaching 36 m/s at t=10 s;(2)corresponding to the landslide propagation,the maximum velocity,28 m/s,of the airblast initiated by the landslide also appears at t=10 s with its maximum pressure reaching594.8 Pa,which is equivalent to violent storm;(3)under the attack of airblast,the load suffered by buildings in the airblast zone increases to 1300 Pa at t=9.4 s and sharply decreased to-7000 Pa as the rapid decrease of the velocity of the sliding mass at t=10 s,which is seriously unfavorable for buildings and might be the key reason for the destructive collapse of buildings in the airblast zone of the Wangjiayan landslide.展开更多
The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for stu...The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for studies using petrographic, geochemical and metallogenic methods. The study of macroscopic and microscopic petrography made it possible to highlight two major lithological units: 1) a volcano-plutonic unit, formed of gabbros, basalt, volcaniclastics and rhyodacite;2) a sedimentary unit (microconglomerate). From a geochemical point of view, the results obtained indicate that the plutonites are gabbro and gabbro diorite while the volcanics have compositions of basaltic andesites, rhyolite and dacites. The sediments have a litharenitic to sublitharenitic character. The metallogenic study made it possible to highlight hydrothermal alterations and metalliferous paragenesis on the formations studied. Hydrothermal alteration is characterized by the presence of carbonation, silicification, sericitization, sulfidation and to a lesser degree chloritization. Metalliferous paragenesis consists of pyrite, chalcopyrite, hematite and magnetite.展开更多
基金This study has been supported by “Research on Chinese Enterprises＇ R＆D Efficiency and Its Influencing Factors” under National Natural Science Foundation of China （70902002）, “Research on Beijing Enterprises＇ R＆D Efficiency and Its Influencing Factors： Analysis Based on Cutting-edge” under Beijing Natural Science Foundation （9102019）, together with “Program for New Century Excellent Talents in University” under the Ministry of Education and Key Project under the “211 Project” for Central University of Finance and Economics.
文摘By introducing a knowledge production function which combines both foreign technology imports and domestic research and development （R＆D） expenditure into an endogenous technological progress model, this paper examines the mechanism that determines enterprises＇ R＆D intensity in developing countries, and explores how factors such as technological gap, technology absorptive capacity, innovation environment and innovation ability would impact Chinese enterprises＇decision made on R＆D intensity. Our results suggest that technological gap has no significant single impact on enterprises＇R＆D intensity, but rather influences enterprises＇decision on R＆D jointly with other factors such as degree of openness and human capital. A relative fall in efficiency of technology imitation recently has a negative effect on total R＆D intensity but helps to promote enterprises＇ independent R＆D. In addition, among factors related to R＆D innovation environment, industrial R＆D intensity has a significantly positive impact on enterprises＇ independent R＆D intensity, while regional economies of scale, proportion of large enterprises and proportion of government R＆D investment have some certain negative impacts.
基金This research is supported by National Natural Science Foundation of China （No. 71373010）.
文摘This paper examines the effects of ownership types on firms＇ R＆D intensity and innovation performance, using a sample of 357,857 Chinese firms from 2005-2007. This study finds considerable divergence among Chinese domestic enterprises in terms of R＆D intensity and innovation performance. Firms owned by the central government are the key drivers for firms＇ R＆D activities, while local government, private and foreign ownerships are negatively related to both R＆D intensity and innovation performance. Significant divergence within government ownership category and argues that China＇s institutional changes generate varied government ownership groups with different levels of resource endowment, which in turn influence firms＇ R＆D activities.
基金supported by the Natural Science Foundation of Guangdong Province,China(S2012020011043)the National High Technology Research and Development Program of China(2014AA10A605)+2 种基金the Special Fund for Agro-scientific Research in the Public Interest(201503106)Modern Agriculture Industry Technology System for Rice in Guangdong Province(2016LM1066,2017LM1066,2018LM1066)the Swiss Agency for Development and Cooperation through its funding of “Closing Rice Yield Gaps in Asia” Project(CORIGAP)
文摘Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.
基金supported by the Fundamental Research Funds for the Central Universities:[Grant Number JBK1607K05]
文摘This article explores the effects of investment upon energy intensity by applying a unique panel data of China's 27 provinces between 2004 and 2013.In addition,it also particularly stuthes other factors,such as energy price,economic structure,and urbanization.The results,based on four econometric regression model results,suggest that in general,the indigenous investment on research and development is a more powerful tool to decrease China's energy intensity regardless of region disparity.The foreign direct investment(FDI) has a prominent but not persistent effect on energy intensity.However,the outward direct investment has not shown its significant impact on energy intensity.At the level of an aggregate economy and China's eastern region,the results demonstrate that FDI improves energy efficiency significantly.For the central and western provinces,FDI does not support the similar conclusion.Based on these analyses,we present the corresponding regional policies for policymakers.
基金supported by the National Natural Science Foundations of China (No. 42174056)supported by the Deng-Feng Scholar Program of Nanjing University
文摘The D″layer,located at the bottom of the mantle,is an active thermochemical boundary layer.The upwelling of mantle plumes,as well as possible plate subduction in the D″layer,could lead to large-scale material transformation and mineral deformation,which could result in significant seismic anisotropy.However,owing to limited observations and immense computational cost,the anisotropic structures and geodynamic mechanisms in the D″layer remain poorly understood.In this study,we proposed a new inversion method for the seismic anisotropy in the D″layer quantitatively with shear wave splitting intensities.We first proved the linearity of the splitting intensities under the ray-theory assumption.The synthetic tests showed that,with horizontal axes of symmetry and ray incidences lower than 30°in the D″layer(typical SKS phase),the anisotropy is well resolved.We applied the method to the measured dataset in Africa and Western Europe,and obtained strong D″anisotropy in the margins of the large low shear-wave velocity provinces and subducting slabs.The new method makes it possible to obtain D″anisotropy,which provides essential constraints on the geodynamical processes at the base of the mantle.
文摘The time-domain BEM was developed to analyze the dynamic stress intensity factor ( DSIF) of 3-D elastodynamic crack problems. To simulate the stress singularity along the front of a crack, eight-node isoparametric singular elements were used, and the DSIF for a semi-circular surface crack was firstly calculated based on displacement equation using the time-domain BEM formulation. The new scheme to determine the time step was brought forward. By the dynamic analysis program of time-domain BEM compiled by its, several numerical examples are presented, which demonstrate the unconditional stability and high accuracy of time-domain BEM applied to 3-D elastodynamic crack problems.
文摘Objective:The aim of this study is to compare the effect of Vitamin D and Vitamin E supplementations,alone,and in combination,on reducing the intensity and duration of dysmenorrhea in women who were referred to the Kowsar gynecological clinics of Shahid Motahari Hospital of Urmia University of Medical Sciences.Materials and Methods:A double-blinded clinical trial was conducted on 112 women with dysmenorrhea who were randomly allocated into the four study groups.Finally,100 women complete the study and received capsules containing a placebo(n=25),1000 IU of Vitamin D(n=25),400 mg of Vitamin E(n=25),and 1000 IU of Vitamin D+400 mg of Vitamin E(n=25)every 24 h for 2 consecutive months at the beginning of the menstrual period.The pain intensity and duration among groups were compared before and after the intervention.Results:The mean menstrual pain duration in all three experimental groups(Vitamin E,Vitamin D,and the combination of them)was lower than the placebo group(all P<0.05),and the mean pain intensity scores in all three experimental groups were significantly lower than the placebo group(all P<0.05).The results(means)for all of the drugs administered at the end of the 2nd month were better than the 1st month(all P<0.01).Conclusions:Vitamin E and Vitamin D,as well as their combination,are recommended as an effective and safe treatment for the management of the complications of dysmenorrhea.
基金supported by the National Natural Science Foundation of China(42322702,42177131)。
文摘Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific attention.To quantitatively analyze the intensity of airblast initiated by landslides,the Wangjiayan landslide,occurred in the Wenchuan earthquake,is selected here with the landslide propagation and airblast evolution being studied using FLUENT by introducing the Voellmy rheological law.The results reveal that:(1)For the Wangjiayan landslide,its whole travelling duration is only 12 s with its maximum velocity reaching 36 m/s at t=10 s;(2)corresponding to the landslide propagation,the maximum velocity,28 m/s,of the airblast initiated by the landslide also appears at t=10 s with its maximum pressure reaching594.8 Pa,which is equivalent to violent storm;(3)under the attack of airblast,the load suffered by buildings in the airblast zone increases to 1300 Pa at t=9.4 s and sharply decreased to-7000 Pa as the rapid decrease of the velocity of the sliding mass at t=10 s,which is seriously unfavorable for buildings and might be the key reason for the destructive collapse of buildings in the airblast zone of the Wangjiayan landslide.
文摘The Gouméré region is located in the North-East of Côte d’Ivoire and is located in the South-West of the Bui furrow. In order to highlight the geology of the area studied, 14 samples were taken for studies using petrographic, geochemical and metallogenic methods. The study of macroscopic and microscopic petrography made it possible to highlight two major lithological units: 1) a volcano-plutonic unit, formed of gabbros, basalt, volcaniclastics and rhyodacite;2) a sedimentary unit (microconglomerate). From a geochemical point of view, the results obtained indicate that the plutonites are gabbro and gabbro diorite while the volcanics have compositions of basaltic andesites, rhyolite and dacites. The sediments have a litharenitic to sublitharenitic character. The metallogenic study made it possible to highlight hydrothermal alterations and metalliferous paragenesis on the formations studied. Hydrothermal alteration is characterized by the presence of carbonation, silicification, sericitization, sulfidation and to a lesser degree chloritization. Metalliferous paragenesis consists of pyrite, chalcopyrite, hematite and magnetite.
