The French National Immunization Program was updated in 2013 for vaccination against diphtheria,tetanus,per-tussis,and poliomyelitis.Our previous findings on the evolution of age-specific booster vaccination coverage ...The French National Immunization Program was updated in 2013 for vaccination against diphtheria,tetanus,per-tussis,and poliomyelitis.Our previous findings on the evolution of age-specific booster vaccination coverage rates(VCRs)up to 2017 suggested suboptimal vaccination coverages due to the pre-2013 recommendation-residual vaccination practices.In the current analysis,we evaluated all age-specific booster VCR and distribution of age at vaccination visits in 2018.In this retrospective observational cohort study,the cumulative booster VCRs were updated at all vaccination visits up to 2018 among the people who were eligible for a booster vaccination,using a 1/97th random sample of French national healthcare reimbursement databases.The cumulative booster VCR for individuals from all age groups increased from 2017 to 2018,except for 85-years-old vaccination visit.Majority of the individuals from all age groups were vaccinated(boosted)with a vaccine containing the pertussis valence.In 2018,sharp peaks corresponding to the recommended ages for booster vaccination visits were observed for individuals aged 6,11 to 13,25,45,and 65 years.Our study reiterates suboptimal coverages in France and implies the need for booster vaccination throughout life for the protection of the population.展开更多
The daily sea surface temperature(SST)data from three kinds of different satellites of GMI,GOES and MODIS were applied to do the blend in the Southeast Pacific Ocean throughout the whole year of 2020.The coverage rate...The daily sea surface temperature(SST)data from three kinds of different satellites of GMI,GOES and MODIS were applied to do the blend in the Southeast Pacific Ocean throughout the whole year of 2020.The coverage rates of the SST of the blend result were improved highly and more stable throughout the whole year,compared with the result of the single satellite of GMI,GOES,and MODIS.The yearly average coverage rates of GMI,GOES,MODIS,and blend were 43%,48%,30%,and 76%,and their corresponding yearly average standard deviation(SD)were 4%,6%,7%,and 4%,respectively.All the coverage rates of these three satellites were low from April to September.The valid observation days calculated in the whole year over every grid were used to represent the spatial distribution patterns of the coverage rates.The spatial distribution patterns of coverage rates from GOES and MODIS were similar that their valid observation days were higher in the northwest area and lower in the south area,and those of GMI was contrary to the former two.The ranges of valid observation day was from GOES,GMI,and MODIS were 0-364,6-254,and 9-231 d,respectively.After the blend,all the observation day of every grid in the research region was enhanced(103-366 d).Especially the near shore and south area,and the minimum valid observation day increased largely from the single digits to hundreds digit.展开更多
In this study, we established a dynamic morphological model using the accumulated thermal effectiveness and photosynthetic active radiation (PAR) (A-TEP), aiming to explore the relationship between muskmelon (Cuc...In this study, we established a dynamic morphological model using the accumulated thermal effectiveness and photosynthetic active radiation (PAR) (A-TEP), aiming to explore the relationship between muskmelon (Cucumis melo L.) fruit attributes and environmental factors. Muskmelon surface color was described by parameters of red, green, blue, hue, saturation and brightness (HSI). Three characteristic parameters, gray level co-occurrence matrix (GLCM), angular second moment (ASM), entropy, contrast, and the coverage rate were used to describe the process of muskmelon fruit netting formation. ASM was not significant difference during muskmelon fruit growth. The number and deep of netting stripes gradually increased with fruit growth. Coverage rate increased rapidly for 15-30 d after pollination. The vertical and horizontal diameters of muskmelon fruit were followed a logistic curve. And root mean squared errors (RMSE) between the simulated and measured vertical and horizontal diameters were 3.527 and 4.696 mm, respectively. RMSE of red, green, blue, saturation and brightness were 0.999, 2.690, 2.992, 0.033 and 5.51, respectively, and the RMSE for entropy, contrast and coverage rates were 0.077, 0.063 and 0.015, respectively, indicating a well consistent between measured and simulated values.展开更多
Investigation on the mineralwater interactions is crucial for understanding the subsequent interfacial reactions.Currently,the hydration mechanisms of smithsonite are still obscure.In this paper,the adsorption of H_(2...Investigation on the mineralwater interactions is crucial for understanding the subsequent interfacial reactions.Currently,the hydration mechanisms of smithsonite are still obscure.In this paper,the adsorption of H_(2)O at different coverage rates on smithsonite(101)surface was innovatively investigated using density-functional theory(DFT)calculations and molecular dynamics(MD)simulations by analyzing adsorption model,interaction energy,atomic distance,density of state,electron density difference,concentration profile,radial distribution function and self-diffusion coefficient.We found that single H_(2)O preferred to be dissociated on smithsonite(101)surface via the interaction of surface Zn with the Ow of H_(2)O and H-bond between Hw of H_(2)O and surface Os.However,dissociation adsorption and molecular adsorption coexisted on the smithsonite surface at a high coverage rate of H_(2)O,and dissociation adsorption remained the main adsorption mechanism.Moreover,we found the interaction between smithsonite surface and H_(2)O was weakened as a function of H_(2)O coverage,which was because the presence of interlayer H_(2)O and different layers of H_(2)O decreased the reactivity of the smithsonite surface.The H_(2)O is mainly adsorbed on the smithsonite surface by forming three layers of H_(2)O(about 10–15Å),with the ordering degree gradually decreasing.展开更多
The eco-environmental frangibility is studied by choosing the factors of land use class change and vegetation cover rate, and the equation of eco-environmental frangibility and its evaluation system are established ba...The eco-environmental frangibility is studied by choosing the factors of land use class change and vegetation cover rate, and the equation of eco-environmental frangibility and its evaluation system are established based on remote sensing (RS) and geographic information system technology (GIS). Four different years of TM images are selected to calculate land use change grads and vegetation cover rate, and the relationship between the two factors and eco-environment frangibility index are build, taking Fuzhou as an example. The character of times change and space distribution of eco-environment frangibility are described. The result indicates the area of eco-environment frangibility increased 2.6% in Fuzhou during twelve years, and expands from the region between infield and forest land to forest land in space distribution.展开更多
The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimizat...The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimization of land use structure, to establish the ecology green equivalent mathematical model and survey the value of region green equivalent, and then assess the ecological environment situation. The results show that the ecological environment has been deteriorated in Wuhai from 2005 to 2010, so the ecological environment was poor. In order to in-crease eco-efficiency of land use, garden, urban green space and woodland area should be raised in the optimization program.展开更多
An improved cluster thermal time constant(CTTC) and surface thermal time constant(STTC) numerical model was introduced,which took into account the effect of vegetation coverage and modified the expression of net longw...An improved cluster thermal time constant(CTTC) and surface thermal time constant(STTC) numerical model was introduced,which took into account the effect of vegetation coverage and modified the expression of net longwave radiation of the canyon layer.In the case study the model was used to calculate the air temperature variation at downtown of Tianjin City.The relative error between the calculated and measured air temperatures was less than 3%.The tendency of air temperature variation was predicted when the building aspect ratio,vegetation rate,and wind speed changed respectively.It is demonstrated that when the aspect ratio of a building with south-north orientation increased,the heat island intensity at day time was mitigated;however,it became worse after sunset.The vegetation coverage rate and wind speed both had negative relationship with the urban heat island intensity.展开更多
Based on years of production practice experience, the technical measures for wind prevention and sand fixation were put forward from the causes and evolu-tion laws of sand wind, which were of great realistic significa...Based on years of production practice experience, the technical measures for wind prevention and sand fixation were put forward from the causes and evolu-tion laws of sand wind, which were of great realistic significance to improve the sand prevention work in Shandong.展开更多
All characteristics of vegetation,runoff and sediment from 1960 to 2010 in the Xiliu Gully Watershed,which is a representative watershed in wind-water erosion crisscross region in the upper reaches of the Yellow River...All characteristics of vegetation,runoff and sediment from 1960 to 2010 in the Xiliu Gully Watershed,which is a representative watershed in wind-water erosion crisscross region in the upper reaches of the Yellow River of China,have been analyzed in this study.Based on the remote sensing image data,and used multi-spectral interpretation method,the characteristics of vegetation variation in the Xiliu Gully Watershed have been analyzed.And the rules of precipitation,runoff and sediment's changes have been illuminated by using mathematical statistics method.What′s more,the influence mechanism of vegetation on runoff and sediment has been discussed by using the data obtained from artificial rainfall simulation test.The results showed that the main vegetation type was given priority to low coverage,and the area of the low vegetation coverage type was reducing year by year.On the country,the area of the high vegetation coverage type was gradually increasing.In a word,vegetation conditions had got better improved since 2000 when the watershed management project started.The average annual precipitation of the river basin also got slightly increase in 2000–2010.The average annual runoff reduced by 37.5%,and the average annual sediment reduced by 73.9% in the same period.The results of artificial rainfall simulation tests showed that the improvement of vegetation coverage could increase not only soil infiltration but also vegetation evapotranspiration,and then made the rainfall-induced runoff production decrease.Vegetation root system could increases the resistance ability of soil to erosion,and vegetation aboveground part could reduce raindrop kinetic energy and splash soil erosion.Therefore,with the increase of vegetation coverage,the rainfall-induced sediment could decrease.展开更多
The areas covered by 1.5 ℃ and 2.0 ℃ warming thresholds under RCP2.6, RCP4.5, and RCP8.5 were analyzed based on 22 CMIP5 models. More than 90% of the model runs are in agreement that by the end of the 21 st century,...The areas covered by 1.5 ℃ and 2.0 ℃ warming thresholds under RCP2.6, RCP4.5, and RCP8.5 were analyzed based on 22 CMIP5 models. More than 90% of the model runs are in agreement that by the end of the 21 st century, near-surface air temperature changes over ~5%(~2%), ~40%(~18%), and ~92%(~86%)of the globe will cross the 1.5 ℃(2.0 ℃) threshold under RCP2.6, RCP4.5, and RCP8.5, respectively. Under RCP8.5, nearly the whole of North America, Europe + Russia, Africa, and Asia–Russia will cross the 1.5 ℃(2.0 ℃) threshold in ~2050(~2060), while the coverage rates over South America and Oceania are ~80%(~75%) and ~50%(~30%), respectively. The threshold-onset time(TOT) for 2 ℃ warming is earliest over Europe + Russia and North America, followed by Africa, Asia–Russia, South America, and finally Oceania under the RCP4.5 and RCP8.5 scenarios. The TOT for 1.5 ℃ is ~10–30 years ahead of that for 2.0 ℃.展开更多
Background:Despite the progress made in the control of Neglected Tropical Diseases(NTD),schistosome and soil-transmitted helminth infections are far from being effectively managed in many parts of the world.Chemothera...Background:Despite the progress made in the control of Neglected Tropical Diseases(NTD),schistosome and soil-transmitted helminth infections are far from being effectively managed in many parts of the world.Chemotherapy,the key element of all control strategies,is faced with some difficulties in terms of access to treatment.Our study aims to describe the factors involved in the success or failure of the community-directed intervention(CDI)approach through control programmes,which aims to achieve consistent high coverage at affordable and sustainable costs in endemic areas.Methods:The CDI approach was carried out from December 2007 to October 2008 in ten villages of the district of Diéma,Mali.At inclusion,each child part of the study’s sample was interviewed and submitted for a physical examination.The study focused on:data collection,treatment of the eligible population,evaluation of the treatment coverage,performance of community drug distributors(CDDs),and the involvement and perception of populations.Results:A total of 8,022 eligible people were studied with a mean coverage rate of 76.7%.Using multiple regression,it was determined that receiving praziquantel as treatment was associated with five factors:belonging to the Fulani or Moorish ethnic minority versus the Bambara/Soninke,use of the central versus the house-to-house drug distribution mode,the ratio of the population to the number of CDDs,the lack of supervision and belonging to the age group of 15 years or above(p<0.05).As well as that,it was found that the presence of parallel community-based programmes(HIV,tuberculosis)that provide financial incentives for community members discouraged many CDDs(who in most cases are volunteers)to participate in the CDI approach due to a lack of incentives.Conclusions:The findings indicate that the success of the CDI approach depends on,amongst other things,the personal characteristics of the respondents,as well as on community factors.展开更多
Acquiring vocabulary is important when studying English, as it assists in listening, speaking, reading, and writing. In this paper, we develop an English webpage corpus(EWC) and create a word frequency list using web ...Acquiring vocabulary is important when studying English, as it assists in listening, speaking, reading, and writing. In this paper, we develop an English webpage corpus(EWC) and create a word frequency list using web crawler technology. By comparing EWC word lists with the British National Corpus(BNC), we find that the BNC word frequency list possesses the feature of timeliness. We also explore primary school students' English word recognition rates by comparing the word frequency lists of several corpora, including EWC, BNC, SUBTLEX-US, and Subtitle Corpus of Children's BBC(CBBC). The results show that the word recognition rates for primary school children are relatively low in both general language and specific language register. Motivated by the experiment results, we finally propose some word-selection strategies for compiling English textbooks for Chinese primary school students.展开更多
The multivariate linear errors-in-variables model when the regressors are missing at random in the sense of Rubin (1976) is considered in this paper. A constrained empirical likelihood confidence region for a parame...The multivariate linear errors-in-variables model when the regressors are missing at random in the sense of Rubin (1976) is considered in this paper. A constrained empirical likelihood confidence region for a parameter β0 in this model is proposed, which is constructed by combining the score function corresponding to the weighted squared orthogonal distance based on inverse probability with a constrained region of β0. It is shown that the empirical log-likelihood ratio at the true parameter converges to the standard chi-square distribution. Simulations show that the coverage rate of the proposed confidence region is closer to the nominal level and the length of confidence interval is narrower than those of the normal approximation of inverse probability weighted adjusted least square estimator in most cases. A real example is studied and the result supports the theory and simulation's conclusion.展开更多
Unmanned aerial vehicle(UAV)chemical application is widely used for crop protection,and spraying pattern is one of the most important factors that influence the chemical control efficacy.A method for UAV spraying patt...Unmanned aerial vehicle(UAV)chemical application is widely used for crop protection,and spraying pattern is one of the most important factors that influence the chemical control efficacy.A method for UAV spraying pattern measurement with partial least squares(PLS)model based spectrum analysis was proposed in this study to measure the UAV spraying pattern more accurately.The method involved the steps of fluorescent tracer solution spray and its droplets collection,the spectrum on paper strip acquiring,spectrum processing and analysis,PLS modeling.In order to verify the applicability of the method and obtain the parameters of the PLS model,UAV spraying experiments were performed in the field.Then Fluorescent tracer solution was sprayed and its droplets are collected by paper strip,and the original spectrum on paper strip obtained by a spectrometer was processed by the Savitzky-Golay and standard normalized variable(SNV)method.The prediction model of coverage rate selected as the droplet deposition parameter to measure the UAV spraying pattern,was established by using PLS method.To verify the superiority of the PLS model,a traditional linear regression(LR)model of coverage rate was established simultaneously.The results demonstrate that the method with PLS model based spectrum analysis can measure the UAV spraying pattern effectively,and PLS model has a better performance of RV2=0.94 and RMSEP=0.9446 than that of the LR model.展开更多
Glaucoma is the first leading cause of irreversible blindness worldwide with increasing importance in public health.Indicators of glaucoma care quality as well as efficiency would benefit public health assessments,but...Glaucoma is the first leading cause of irreversible blindness worldwide with increasing importance in public health.Indicators of glaucoma care quality as well as efficiency would benefit public health assessments,but are lacking.We propose three such indicators.First,the glaucoma coverage rate(GCR),which is the number of people known to have glaucoma divided by the total number of people with glaucoma as estimated from population-based studies multiplied by 100%.Second,the glaucoma detection rate(GDR),which is number of newly diagnosed glaucoma patients in one year divided by the population in a defined area in millions.Third,the glaucoma follow-up adherence rate(GFAR),calculated as the number of patients with glaucoma who visit eye care provider(s)at least once a year over the total number of patients with glaucoma in given eye care provider(s)in a specific period.Regularly tracking and reporting these three indicators may help to improve the healthcare system performance at national or regional levels.展开更多
A hybrid system proposed by three different specifications for the equipment of a tourist lodge in the headland of south-west Morocco was sized by analysing the limits of load profile constraints,such as hour-to-hour ...A hybrid system proposed by three different specifications for the equipment of a tourist lodge in the headland of south-west Morocco was sized by analysing the limits of load profile constraints,such as hour-to-hour variability(HHR),day-to-day variability(DDR)and the operating reserve rate(ROR).Based on the three-factor Doehlert matrix recommendations,the simulations employed an energy-sizing tool for hybrid renewable-energy systems.Testing was conducted with DDR at 5-30%,HHR at 10-30%and ROR at 0-20%.Under these conditions,a second-order polynomial relationship with a correlation rate of~90%was found between the net present cost(NPC)of the system,the levelized cost of electricity and the various constraint factors.The first specification,SPC(1),composed of generators and batteries,was introduced to control and validate the simulation independently of renewable energy,which showed a positive manifestation with the imposed constraints.The analysis expanded by introducing solar and wind energy resources.The SPC(2)configuration added PV modules to the SPC(1)and the SPC(3)configuration added wind turbines to SPC(2).The effect of DDR,HHR and ROR in the trials was significant by linear regression.At the same time,only DDR had a significant quadratic regression.The others,with their pairwise interactions,were insignificant.The desirability procedure made it possible to calculate the maximum limits of load profile constraint variables leading to targets of LCOE=0.41 US$/kWh and NPC=US$320080.1 of the load profile constraints:the DDR=15.47%and the HHR=26.55%at an ROR rate of 17.77%.展开更多
文摘The French National Immunization Program was updated in 2013 for vaccination against diphtheria,tetanus,per-tussis,and poliomyelitis.Our previous findings on the evolution of age-specific booster vaccination coverage rates(VCRs)up to 2017 suggested suboptimal vaccination coverages due to the pre-2013 recommendation-residual vaccination practices.In the current analysis,we evaluated all age-specific booster VCR and distribution of age at vaccination visits in 2018.In this retrospective observational cohort study,the cumulative booster VCRs were updated at all vaccination visits up to 2018 among the people who were eligible for a booster vaccination,using a 1/97th random sample of French national healthcare reimbursement databases.The cumulative booster VCR for individuals from all age groups increased from 2017 to 2018,except for 85-years-old vaccination visit.Majority of the individuals from all age groups were vaccinated(boosted)with a vaccine containing the pertussis valence.In 2018,sharp peaks corresponding to the recommended ages for booster vaccination visits were observed for individuals aged 6,11 to 13,25,45,and 65 years.Our study reiterates suboptimal coverages in France and implies the need for booster vaccination throughout life for the protection of the population.
基金This work was supported by the National Key Research and Development Project of China(No.2019YFD0901405)the Shanghai Sailing Program(No.19YF1460000).
文摘The daily sea surface temperature(SST)data from three kinds of different satellites of GMI,GOES and MODIS were applied to do the blend in the Southeast Pacific Ocean throughout the whole year of 2020.The coverage rates of the SST of the blend result were improved highly and more stable throughout the whole year,compared with the result of the single satellite of GMI,GOES,and MODIS.The yearly average coverage rates of GMI,GOES,MODIS,and blend were 43%,48%,30%,and 76%,and their corresponding yearly average standard deviation(SD)were 4%,6%,7%,and 4%,respectively.All the coverage rates of these three satellites were low from April to September.The valid observation days calculated in the whole year over every grid were used to represent the spatial distribution patterns of the coverage rates.The spatial distribution patterns of coverage rates from GOES and MODIS were similar that their valid observation days were higher in the northwest area and lower in the south area,and those of GMI was contrary to the former two.The ranges of valid observation day was from GOES,GMI,and MODIS were 0-364,6-254,and 9-231 d,respectively.After the blend,all the observation day of every grid in the research region was enhanced(103-366 d).Especially the near shore and south area,and the minimum valid observation day increased largely from the single digits to hundreds digit.
基金supported by the National Natural Science Foundation of China (31471411)the Shanghai Agriculture Applied Technology Development Program,China ((2017)3-8-4)
文摘In this study, we established a dynamic morphological model using the accumulated thermal effectiveness and photosynthetic active radiation (PAR) (A-TEP), aiming to explore the relationship between muskmelon (Cucumis melo L.) fruit attributes and environmental factors. Muskmelon surface color was described by parameters of red, green, blue, hue, saturation and brightness (HSI). Three characteristic parameters, gray level co-occurrence matrix (GLCM), angular second moment (ASM), entropy, contrast, and the coverage rate were used to describe the process of muskmelon fruit netting formation. ASM was not significant difference during muskmelon fruit growth. The number and deep of netting stripes gradually increased with fruit growth. Coverage rate increased rapidly for 15-30 d after pollination. The vertical and horizontal diameters of muskmelon fruit were followed a logistic curve. And root mean squared errors (RMSE) between the simulated and measured vertical and horizontal diameters were 3.527 and 4.696 mm, respectively. RMSE of red, green, blue, saturation and brightness were 0.999, 2.690, 2.992, 0.033 and 5.51, respectively, and the RMSE for entropy, contrast and coverage rates were 0.077, 0.063 and 0.015, respectively, indicating a well consistent between measured and simulated values.
基金This work was supported in part by the High Performance Com-puting Center of Central South UniversityThis study was finan-cially supported by the National Natural Science Foundation of China(No.51674291).
文摘Investigation on the mineralwater interactions is crucial for understanding the subsequent interfacial reactions.Currently,the hydration mechanisms of smithsonite are still obscure.In this paper,the adsorption of H_(2)O at different coverage rates on smithsonite(101)surface was innovatively investigated using density-functional theory(DFT)calculations and molecular dynamics(MD)simulations by analyzing adsorption model,interaction energy,atomic distance,density of state,electron density difference,concentration profile,radial distribution function and self-diffusion coefficient.We found that single H_(2)O preferred to be dissociated on smithsonite(101)surface via the interaction of surface Zn with the Ow of H_(2)O and H-bond between Hw of H_(2)O and surface Os.However,dissociation adsorption and molecular adsorption coexisted on the smithsonite surface at a high coverage rate of H_(2)O,and dissociation adsorption remained the main adsorption mechanism.Moreover,we found the interaction between smithsonite surface and H_(2)O was weakened as a function of H_(2)O coverage,which was because the presence of interlayer H_(2)O and different layers of H_(2)O decreased the reactivity of the smithsonite surface.The H_(2)O is mainly adsorbed on the smithsonite surface by forming three layers of H_(2)O(about 10–15Å),with the ordering degree gradually decreasing.
基金the Department of Science and Technology of Fujian Province (2003I015)Open Foundation of State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing (WCL (02)0104)
文摘The eco-environmental frangibility is studied by choosing the factors of land use class change and vegetation cover rate, and the equation of eco-environmental frangibility and its evaluation system are established based on remote sensing (RS) and geographic information system technology (GIS). Four different years of TM images are selected to calculate land use change grads and vegetation cover rate, and the relationship between the two factors and eco-environment frangibility index are build, taking Fuzhou as an example. The character of times change and space distribution of eco-environment frangibility are described. The result indicates the area of eco-environment frangibility increased 2.6% in Fuzhou during twelve years, and expands from the region between infield and forest land to forest land in space distribution.
文摘The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimization of land use structure, to establish the ecology green equivalent mathematical model and survey the value of region green equivalent, and then assess the ecological environment situation. The results show that the ecological environment has been deteriorated in Wuhai from 2005 to 2010, so the ecological environment was poor. In order to in-crease eco-efficiency of land use, garden, urban green space and woodland area should be raised in the optimization program.
文摘An improved cluster thermal time constant(CTTC) and surface thermal time constant(STTC) numerical model was introduced,which took into account the effect of vegetation coverage and modified the expression of net longwave radiation of the canyon layer.In the case study the model was used to calculate the air temperature variation at downtown of Tianjin City.The relative error between the calculated and measured air temperatures was less than 3%.The tendency of air temperature variation was predicted when the building aspect ratio,vegetation rate,and wind speed changed respectively.It is demonstrated that when the aspect ratio of a building with south-north orientation increased,the heat island intensity at day time was mitigated;however,it became worse after sunset.The vegetation coverage rate and wind speed both had negative relationship with the urban heat island intensity.
文摘Based on years of production practice experience, the technical measures for wind prevention and sand fixation were put forward from the causes and evolu-tion laws of sand wind, which were of great realistic significance to improve the sand prevention work in Shandong.
基金Under the auspices of National Basic Research Program of China(No.2011CB403303)Innovation Scientists and Technicians Troop Construction Projects of Henan Province(No.162101510004)Foundation of Yellow River Institute of Hydraulic Research of China(No.HKY-2011-15)
文摘All characteristics of vegetation,runoff and sediment from 1960 to 2010 in the Xiliu Gully Watershed,which is a representative watershed in wind-water erosion crisscross region in the upper reaches of the Yellow River of China,have been analyzed in this study.Based on the remote sensing image data,and used multi-spectral interpretation method,the characteristics of vegetation variation in the Xiliu Gully Watershed have been analyzed.And the rules of precipitation,runoff and sediment's changes have been illuminated by using mathematical statistics method.What′s more,the influence mechanism of vegetation on runoff and sediment has been discussed by using the data obtained from artificial rainfall simulation test.The results showed that the main vegetation type was given priority to low coverage,and the area of the low vegetation coverage type was reducing year by year.On the country,the area of the high vegetation coverage type was gradually increasing.In a word,vegetation conditions had got better improved since 2000 when the watershed management project started.The average annual precipitation of the river basin also got slightly increase in 2000–2010.The average annual runoff reduced by 37.5%,and the average annual sediment reduced by 73.9% in the same period.The results of artificial rainfall simulation tests showed that the improvement of vegetation coverage could increase not only soil infiltration but also vegetation evapotranspiration,and then made the rainfall-induced runoff production decrease.Vegetation root system could increases the resistance ability of soil to erosion,and vegetation aboveground part could reduce raindrop kinetic energy and splash soil erosion.Therefore,with the increase of vegetation coverage,the rainfall-induced sediment could decrease.
基金supported by the National Key Research&Development Plan of China(No.2016YFA0602703 and No.2016YFC1401603)the special fund forthe Second Institute of Oceanography(No.JG1620)+3 种基金the National Natural Science Foundation of China(No.41705048,No.41605036 and No.41621064)Zhejiang Provincial Natural Science Foundation of China(No.LR16D060001)Sino-German cooperation in ocean and polar researchthe national-level major cultivation project of Guangdong Province(No.2014GKXM058)
文摘The areas covered by 1.5 ℃ and 2.0 ℃ warming thresholds under RCP2.6, RCP4.5, and RCP8.5 were analyzed based on 22 CMIP5 models. More than 90% of the model runs are in agreement that by the end of the 21 st century, near-surface air temperature changes over ~5%(~2%), ~40%(~18%), and ~92%(~86%)of the globe will cross the 1.5 ℃(2.0 ℃) threshold under RCP2.6, RCP4.5, and RCP8.5, respectively. Under RCP8.5, nearly the whole of North America, Europe + Russia, Africa, and Asia–Russia will cross the 1.5 ℃(2.0 ℃) threshold in ~2050(~2060), while the coverage rates over South America and Oceania are ~80%(~75%) and ~50%(~30%), respectively. The threshold-onset time(TOT) for 2 ℃ warming is earliest over Europe + Russia and North America, followed by Africa, Asia–Russia, South America, and finally Oceania under the RCP4.5 and RCP8.5 scenarios. The TOT for 1.5 ℃ is ~10–30 years ahead of that for 2.0 ℃.
文摘Background:Despite the progress made in the control of Neglected Tropical Diseases(NTD),schistosome and soil-transmitted helminth infections are far from being effectively managed in many parts of the world.Chemotherapy,the key element of all control strategies,is faced with some difficulties in terms of access to treatment.Our study aims to describe the factors involved in the success or failure of the community-directed intervention(CDI)approach through control programmes,which aims to achieve consistent high coverage at affordable and sustainable costs in endemic areas.Methods:The CDI approach was carried out from December 2007 to October 2008 in ten villages of the district of Diéma,Mali.At inclusion,each child part of the study’s sample was interviewed and submitted for a physical examination.The study focused on:data collection,treatment of the eligible population,evaluation of the treatment coverage,performance of community drug distributors(CDDs),and the involvement and perception of populations.Results:A total of 8,022 eligible people were studied with a mean coverage rate of 76.7%.Using multiple regression,it was determined that receiving praziquantel as treatment was associated with five factors:belonging to the Fulani or Moorish ethnic minority versus the Bambara/Soninke,use of the central versus the house-to-house drug distribution mode,the ratio of the population to the number of CDDs,the lack of supervision and belonging to the age group of 15 years or above(p<0.05).As well as that,it was found that the presence of parallel community-based programmes(HIV,tuberculosis)that provide financial incentives for community members discouraged many CDDs(who in most cases are volunteers)to participate in the CDI approach due to a lack of incentives.Conclusions:The findings indicate that the success of the CDI approach depends on,amongst other things,the personal characteristics of the respondents,as well as on community factors.
基金Project supported by the National Natural Science Foundation of China(Nos.61272212,61462043,and 61462045)the Graduates Innovation Fund of Jiangxi Normal University,China
文摘Acquiring vocabulary is important when studying English, as it assists in listening, speaking, reading, and writing. In this paper, we develop an English webpage corpus(EWC) and create a word frequency list using web crawler technology. By comparing EWC word lists with the British National Corpus(BNC), we find that the BNC word frequency list possesses the feature of timeliness. We also explore primary school students' English word recognition rates by comparing the word frequency lists of several corpora, including EWC, BNC, SUBTLEX-US, and Subtitle Corpus of Children's BBC(CBBC). The results show that the word recognition rates for primary school children are relatively low in both general language and specific language register. Motivated by the experiment results, we finally propose some word-selection strategies for compiling English textbooks for Chinese primary school students.
基金supported by the Natural Science Foundation of China under Grant Nos.10771017 and 11071022Key Project of MOE,PRC under Grant No.309007
文摘The multivariate linear errors-in-variables model when the regressors are missing at random in the sense of Rubin (1976) is considered in this paper. A constrained empirical likelihood confidence region for a parameter β0 in this model is proposed, which is constructed by combining the score function corresponding to the weighted squared orthogonal distance based on inverse probability with a constrained region of β0. It is shown that the empirical log-likelihood ratio at the true parameter converges to the standard chi-square distribution. Simulations show that the coverage rate of the proposed confidence region is closer to the nominal level and the length of confidence interval is narrower than those of the normal approximation of inverse probability weighted adjusted least square estimator in most cases. A real example is studied and the result supports the theory and simulation's conclusion.
基金This study was supported by Zhang Ruirui's Beijing Nova Program(No.Z181100006218029)National Natural Science Foundation of China(31601228)+1 种基金BAAFS'Innovation Ability Construction Program 2018(No.KJCX20180424)National Key R&D Program of China(2016YFD0200701-2).
文摘Unmanned aerial vehicle(UAV)chemical application is widely used for crop protection,and spraying pattern is one of the most important factors that influence the chemical control efficacy.A method for UAV spraying pattern measurement with partial least squares(PLS)model based spectrum analysis was proposed in this study to measure the UAV spraying pattern more accurately.The method involved the steps of fluorescent tracer solution spray and its droplets collection,the spectrum on paper strip acquiring,spectrum processing and analysis,PLS modeling.In order to verify the applicability of the method and obtain the parameters of the PLS model,UAV spraying experiments were performed in the field.Then Fluorescent tracer solution was sprayed and its droplets are collected by paper strip,and the original spectrum on paper strip obtained by a spectrometer was processed by the Savitzky-Golay and standard normalized variable(SNV)method.The prediction model of coverage rate selected as the droplet deposition parameter to measure the UAV spraying pattern,was established by using PLS method.To verify the superiority of the PLS model,a traditional linear regression(LR)model of coverage rate was established simultaneously.The results demonstrate that the method with PLS model based spectrum analysis can measure the UAV spraying pattern effectively,and PLS model has a better performance of RV2=0.94 and RMSEP=0.9446 than that of the LR model.
基金funded by Wenzhou Medical University R&D Fund,No.QTJ13009Health Innovation Talents in Zhejiang Province(2016).No.25.
文摘Glaucoma is the first leading cause of irreversible blindness worldwide with increasing importance in public health.Indicators of glaucoma care quality as well as efficiency would benefit public health assessments,but are lacking.We propose three such indicators.First,the glaucoma coverage rate(GCR),which is the number of people known to have glaucoma divided by the total number of people with glaucoma as estimated from population-based studies multiplied by 100%.Second,the glaucoma detection rate(GDR),which is number of newly diagnosed glaucoma patients in one year divided by the population in a defined area in millions.Third,the glaucoma follow-up adherence rate(GFAR),calculated as the number of patients with glaucoma who visit eye care provider(s)at least once a year over the total number of patients with glaucoma in given eye care provider(s)in a specific period.Regularly tracking and reporting these three indicators may help to improve the healthcare system performance at national or regional levels.
文摘A hybrid system proposed by three different specifications for the equipment of a tourist lodge in the headland of south-west Morocco was sized by analysing the limits of load profile constraints,such as hour-to-hour variability(HHR),day-to-day variability(DDR)and the operating reserve rate(ROR).Based on the three-factor Doehlert matrix recommendations,the simulations employed an energy-sizing tool for hybrid renewable-energy systems.Testing was conducted with DDR at 5-30%,HHR at 10-30%and ROR at 0-20%.Under these conditions,a second-order polynomial relationship with a correlation rate of~90%was found between the net present cost(NPC)of the system,the levelized cost of electricity and the various constraint factors.The first specification,SPC(1),composed of generators and batteries,was introduced to control and validate the simulation independently of renewable energy,which showed a positive manifestation with the imposed constraints.The analysis expanded by introducing solar and wind energy resources.The SPC(2)configuration added PV modules to the SPC(1)and the SPC(3)configuration added wind turbines to SPC(2).The effect of DDR,HHR and ROR in the trials was significant by linear regression.At the same time,only DDR had a significant quadratic regression.The others,with their pairwise interactions,were insignificant.The desirability procedure made it possible to calculate the maximum limits of load profile constraint variables leading to targets of LCOE=0.41 US$/kWh and NPC=US$320080.1 of the load profile constraints:the DDR=15.47%and the HHR=26.55%at an ROR rate of 17.77%.