In order to avoid the interference to the primary user(PU), in this paper Cognitive Radio (CR) periodically senses the presence of PU, and during one period, CR can sense all the sub-channels based on weighed data fus...In order to avoid the interference to the primary user(PU), in this paper Cognitive Radio (CR) periodically senses the presence of PU, and during one period, CR can sense all the sub-channels based on weighed data fusion and then use all the idle channels decided by the coordinator. The local sensing time of CR is divided into multi-slots in which CR can sense any sub-channel. Through reasonably allocating the sensing slots and users by mathematic optimization, the proposed algorithm can improve the total throughput of CR. The optimization problem of the proposed scheme which seeks to maximize the throughput subject to the constraint of the detected performance of each sub-channel is proposed in order to choose the optimum local sense time and the number of the cooperative CRs. The simulation results indicate that the proposed scheme can obtain higher throughput than the conventional single-channel sense, and there are the optimum local sense time and the number of cooperative CRs to make the throughput reach maximum.展开更多
The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecologic...The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecological environment changes and even global changes.Based on field measurements,combined with Linear Regression(LR)model and Inverse Distance Weighing(IDW)method,this paper presents detailed analysis on the change history and trend of the shoreline and tidal flat in Bohai Bay.The shoreline faces a high erosion chance under the action of natural factors,while the tidal flat faces a different erosion and deposition patterns in Bohai Bay due to the impact of human activities.The implication of change rule for ecological protection and recovery is also discussed.Measures should be taken to protect the coastal ecological environment.The models used in this paper show a high correlation coefficient between observed and modeling data,which means that this method can be used to predict the changing trend of shoreline and tidal flat.The research results of present study can provide scientific supports for future coastal protection and management.展开更多
This article briefly introduces the weighing device for steel billets in front of the heating furnace of the high-speed wire rod unit,and analyzes and summarizes the problems existing in the original weighing device f...This article briefly introduces the weighing device for steel billets in front of the heating furnace of the high-speed wire rod unit,and analyzes and summarizes the problems existing in the original weighing device for steel billets in production and use.Based on on-site installation conditions,design a new weighing method,match a large range weighing sensor,upgrade the automation control of the weighing device,and remotely transmit the billet weighing data to the MES system of the group.The automatic,stable,reliable,and accurate measurement of steel billet raw materials has been achieved,providing important guarantees for the accurate measurement of production line billet and product yield.展开更多
Identification of groundwater potential areas(GPA)is important in regions facing surface water scarcity,as it assists in effective planning and utilization of groundwater for various purposes.This study employs the me...Identification of groundwater potential areas(GPA)is important in regions facing surface water scarcity,as it assists in effective planning and utilization of groundwater for various purposes.This study employs the methods of remote sensing(RS),geographic information system(GIS)model,and analytical hierarchy process(AHP),multi-criteria decision analysis(MCDA)to locate and map the prospective groundwater areas in the Kulfo-Hare watershed.Seven significant groundwater influencing factors were selected for the determination of groundwater potential in the area:Geology,land use/land cover(LULC),soil,rainfall,slope,drainage density,and lineament density.By applying a five-class classification scheme(very low,low,moderate,high,and very high),the GIS models were used to define the distribution of groundwater potential areas in terms of area coverage(km^(2)),percentage and mapping.The results show that the groundwater potential(GWP)distribution in the research region is as follows:9.7%(6035.9 ha)classified as very high GWP,29.6%(18606 ha)classified as high,24.5%(15245 ha)classified as moderate,18.1%(11431 ha)as low and 18.1%(11492 ha)very low GWP,on the basis of the weighted overlay evaluation.Although a few regions are identifies as extremely low GWP,most of the study area is characterized by very high to moderate GWP.These findings provide valuable insight for sustainable groundwater planning by the government bodies,decision-makers,and private sectors.展开更多
Molecular microbiological methods, such as competetive PCR, real-time PCR, denaturing gradient gel electrophoresis (DGGE) and large-scale parallel-pyrosequencing, require the extraction of sufficient quantity of high ...Molecular microbiological methods, such as competetive PCR, real-time PCR, denaturing gradient gel electrophoresis (DGGE) and large-scale parallel-pyrosequencing, require the extraction of sufficient quantity of high quality DNA from microbiologically and chemically complex matrices. Due to difficulties in the field to standardize/select the optimum DNA preservation-extraction methods in view of laboratories differences, this article attempts to present a straight-forward mathematical framework for comparing some of the most commonly used methods. To this end, as a case study, the problem of selecting an optimum sample preservation-DNA extraction strategy for obtaining total bacterial DNA from swine feces was considered. Two sample preservation methods (liquid nitrogen and RNAlater?) and seven extraction techniques were paired and compared under six quantitative DNA analysis criteria: yield of extraction, purity of extracted DNA (A260/280 and A 260/230 ratios), duration of extraction, degradation degree of DNA, and cost. From a practical point of view, it is unlikely that a single sample preservation-DNA extraction strategy can be optimum for all selected criteria. Hence, a systematic multi-criteria decision-making (MCDM) approach was used to compare the methods. As a result, the ZR Fecal DNA MiniPrepTM DNA extraction kit for samples preserved either with liquid nitrogen or RNAlater? were identified as potential optimum solutions for obtaining total bacterial DNA from swine feces. Considering the need for practicality for in situ applications, we would recommend liquid nitrogen as sample preservation method, along with the ZR Fecal DNA MiniPrepTM kit. Total bacterial DNA obtained by this strategy can be suitable for downstream PCR-based DNA analyses of swine feces.展开更多
A general weighted second order elliptic equation involving critical growth is considered on bounded smooth. domain in n-dimension space. There is the singular point for the weighted coefficients in the domain. With g...A general weighted second order elliptic equation involving critical growth is considered on bounded smooth. domain in n-dimension space. There is the singular point for the weighted coefficients in the domain. With generalized blow up method, some results are obtained for asymptotic behavior of positive solutions. This problem includes Laplacian operators as special cases.展开更多
[Objectives]This study aimed to optimize the extraction process of longan(Dimocarpus longan Lour.)leaves by multi-indicator comprehensive evaluation method.[Methods]The contents of gallic acid ethyl ester,astragalin,q...[Objectives]This study aimed to optimize the extraction process of longan(Dimocarpus longan Lour.)leaves by multi-indicator comprehensive evaluation method.[Methods]The contents of gallic acid ethyl ester,astragalin,quercetin,luteolin and kaempferol in longan leaves were determined simultaneously by HPLC.Using the multi-indicator comprehensive evaluation method,the methanol concentration,solid to liquid ratio and extraction time for extraction of longan leaves were optimized by orthogonal test.[Results]The optimal extraction process of longan leaves are as follows:methanol concentration of 100%,solid to liquid ratio of 1∶5,and extraction time of 50 min.[Conclusions]The optimized process is simple and feasible,and it can be used to determine the contents of different ingredients in longan leaves.展开更多
Medical research data are often skewed and heteroscedastic. It has therefore become practice to log-transform data in regression analysis, in order to stabilize the variance. Regression analysis on log-transformed dat...Medical research data are often skewed and heteroscedastic. It has therefore become practice to log-transform data in regression analysis, in order to stabilize the variance. Regression analysis on log-transformed data estimates the relative effect, whereas it is often the absolute effect of a predictor that is of interest. We propose a maximum likelihood (ML)-based approach to estimate a linear regression model on log-normal, heteroscedastic data. The new method was evaluated with a large simulation study. Log-normal observations were generated according to the simulation models and parameters were estimated using the new ML method, ordinary least-squares regression (LS) and weighed least-squares regression (WLS). All three methods produced unbiased estimates of parameters and expected response, and ML and WLS yielded smaller standard errors than LS. The approximate normality of the Wald statistic, used for tests of the ML estimates, in most situations produced correct type I error risk. Only ML and WLS produced correct confidence intervals for the estimated expected value. ML had the highest power for tests regarding β1.展开更多
Greenhousing is a technique to bridge season gap in vegetable production and has been widely used worldwide. Calculation of water requirement of crops grown in greenhouse and determination of their irrigation schedule...Greenhousing is a technique to bridge season gap in vegetable production and has been widely used worldwide. Calculation of water requirement of crops grown in greenhouse and determination of their irrigation schedules in arid and semi-arid regions are essential for greenhouse maintenance and have thus attracted increased attention over the past decades. The most common method used in the literature to estimate crop evapotranspiration(ET) is the Penman-Monteith(PM) formula. When applied to greenhouse, however, it often uses canopy resistance instead of surface resistance. It is understood that the surface resistance in greenhouse is the result of a combined effect of canopy restriction and soil-surface restriction to water vapor flow, and the relative dominance of one restriction over another depends on crop canopy. In this paper, we developed a surface resistance model in a way similar to two parallel resistances in an electrical circuit to account for both restrictions. Also, considering that wind speed in greenhouse is normally rather small, we compared three methods available in the literature to calculate the aerodynamic resistance, which are the r_a^1 method proposed by Perrier(1975a, b), the r_a^2 method proposed by Thom and Oliver(1977), and the r_a^3 method proposed by Zhang and Lemeu(1992). We validated the model against ET of tomatoes in a greenhouse measured from sap flow system combined with micro-lysimeter in 2015 and with weighing lysimeter in 2016. The results showed that the proposed surface resistance model improved the accuracy of the PM model, especially when the leaf area index was low and the greenhouse was being irrigated. We also found that the aerodynamic resistance calculated from the r_a^1 and r_a^3 methods is applicable to the greenhouse although the latter is slightly more accurate than the former. The proposed surface resistance model, together with the r_a^3 method for aerodynamic resistance, offers an improved approach to estimate ET in greenhouse using the PM formula.展开更多
Precipitation is one of the most important indicators of climate data,but there are many errors in precipitation measurements due to the influence of climatic conditions,especially those of solid precipitation in alpi...Precipitation is one of the most important indicators of climate data,but there are many errors in precipitation measurements due to the influence of climatic conditions,especially those of solid precipitation in alpine mountains and at high latitude areas.The measured amount of precipitation in those areas is frequently less than the actual amount of precipitation.To understand the impact of climatic conditions on precipitation measurements in the mountainous areas of Northwest China and the applicability of different gauges in alpine mountains,we established a cryospheric hydrometeorology observation(CHOICE)system in 2008 in the Qilian Mountains,which consists of six automated observation stations located between 2960 and 4800 m a.s.l.Total Rain weighing Sensor(TRwS)gauges tested in the World Meteorological Organization-Solid Precipitation Intercomparison Experiment(WMO-SPICE)were used at observation stations with the CHOICE system.To study the influence of climatic conditions on different types of precipitation measured by the TRwS gauges,we conducted an intercomparison experiment of precipitation at Hulu-1 station that was one of the stations in the CHOICE system.Moreover,we tested the application of transfer functions recommended by the WMO-SPICE at this station using the measurement data from a TRwS gauge from August 2016 to December 2020 and computed new coefficients for the same transfer functions that were more appropriate for the dataset from Hulu-1 station.The new coefficients were used to correct the precipitation measurements of other stations in the CHOICE system.Results showed that the new parameters fitted to the local dataset had better correction results than the original parameters.The environmental conditions of Hulu-1 station were very different from those of observation stations that provided datasets to create the transfer functions.Thus,root-mean-square error(RMSE)of solid and mixed precipitation corrected by the original parameters increased significantly by the averages of 0.135(353%)and 0.072 mm(111%),respectively.RMSE values of liquid,solid and mixed precipitation measurements corrected by the new parameters decreased by 6%,20% and 13%,respectively.In addition,the new parameters were suitable for correcting precipitation at other five stations in the CHOICE system.The relative precipitation(RP)increment of different types of precipitation increased with rising altitude.The average RP increment value of snowfall at six stations was the highest,reaching 7%,while that of rainfall was the lowest,covering 3%.Our results confirmed that the new parameters could be used to correct precipitation measurements of the CHOICE system.展开更多
Because of the limited memory of the increasing amount of information in current wearable devices,the processing capacity of the servers in the storage system can not keep up with the speed of information growth,resul...Because of the limited memory of the increasing amount of information in current wearable devices,the processing capacity of the servers in the storage system can not keep up with the speed of information growth,resulting in low load balancing,long load balancing time and data processing delay.Therefore,a data load balancing technology is applied to the massive storage systems of wearable devices in this paper.We first analyze the object-oriented load balancing method,and formally describe the dynamic load balancing issues,taking the load balancing as a mapping problem.Then,the task of assigning each data node and the request of the corresponding data node’s actual processing capacity are completed.Different data is allocated to the corresponding data storage node to complete the calculation of the comprehensive weight of the data storage node.According to the load information of each data storage node collected by the scheduler in the storage system,the load weight of the current data storage node is calculated and distributed.The data load balancing of the massive storage system for wearable devices is realized.The experimental results show that the average time of load balancing using this method is 1.75h,which is much lower than the traditional methods.The results show the data load balancing technology of the massive storage system of wearable devices has the advantages of short data load balancing time,high load balancing,strong data processing capability,short processing time and obvious application.展开更多
Using Dachengqi Tang(DCQT) as a model, high performance liquid chromatography(HPLC)fingerprints were applied to optimize machine extracting process with the Box–Behnken experimental design. HPLC fingerprints were...Using Dachengqi Tang(DCQT) as a model, high performance liquid chromatography(HPLC)fingerprints were applied to optimize machine extracting process with the Box–Behnken experimental design. HPLC fingerprints were carried out to investigate the chemical ingredients of DCQT; synthetic weighing method based on analytic hierarchy process(AHP) and criteria importance through intercriteria correlation(CRITIC) was performed to calculate synthetic scores of fingerprints; using the mark ingredients contents and synthetic scores as indicators, the Box–Behnken design was carried out to optimize the process parameters of machine decocting process under high pressure for DCQT. Results of optimal process showed that the herb materials were soaked for 45 min and extracted with 9 folds volume of water in the decocting machine under the temperature of 140 1C till the pressure arrived at 0.25 MPa;then hot decoction was excreted to soak Dahuang and Mangxiao for 5 min. Finally, obtained solutions were mixed, filtrated and packed. It concluded that HPLC fingerprints combined with the Box–Behnken experimental design could be used to optimize extracting process of traditional Chinese medicine(TCM).展开更多
In the injection of pulverized coal into a blast furnace, there are some factors which affect the readout of electronic weighing system. Through analyzing the measuring errors, it is found that the main reasons are p...In the injection of pulverized coal into a blast furnace, there are some factors which affect the readout of electronic weighing system. Through analyzing the measuring errors, it is found that the main reasons are pressure fluctuations of storage tank and puffing tank. According to the interaction of pressures, a neural network based method combined with fuzzy logic is adopted to enhance the precision. Experimental results show this method is satisfactory.展开更多
The present experiment was designed to investigatethe effect of oral mungbean on the tumorogenesisin experimental mice.Hybrid mice weighing 20-22g were randomly distributed into several groups.Morpholine(0.635%)was ...The present experiment was designed to investigatethe effect of oral mungbean on the tumorogenesisin experimental mice.Hybrid mice weighing 20-22g were randomly distributed into several groups.Morpholine(0.635%)was supplemented with the basicdiet.N<sub>2</sub>NO<sub>2</sub>(0. 02%)was dissolved in drinking wateradjusted to pH7.0.Test diets were prepared by supple-ment of various levels(3%,5%,or 10%)of mungbeanwith the basic diet in addition to morpholine Same展开更多
基金Sponored by the National Natural Science Foundation of China ( Grant No. 61071104)the Fundamental Research Funds for the Central Universities( Grant No. HIT. NSRIF. 201149)
文摘In order to avoid the interference to the primary user(PU), in this paper Cognitive Radio (CR) periodically senses the presence of PU, and during one period, CR can sense all the sub-channels based on weighed data fusion and then use all the idle channels decided by the coordinator. The local sensing time of CR is divided into multi-slots in which CR can sense any sub-channel. Through reasonably allocating the sensing slots and users by mathematic optimization, the proposed algorithm can improve the total throughput of CR. The optimization problem of the proposed scheme which seeks to maximize the throughput subject to the constraint of the detected performance of each sub-channel is proposed in order to choose the optimum local sense time and the number of the cooperative CRs. The simulation results indicate that the proposed scheme can obtain higher throughput than the conventional single-channel sense, and there are the optimum local sense time and the number of cooperative CRs to make the throughput reach maximum.
基金supported by the National Natural Science Foundation of China (41602205, 42293261)the China Geological Survey Program (DD20189506, DD20211301)+2 种基金the Special Investigation Project on Science and Technology Basic Resources of the Ministry of Science and Technology (2021FY101003)the Central Guidance for Local Scientific and Technological Development Fund of 2023the Project of Hebei University of Environmental Engineering (GCY202301)
文摘The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecological environment changes and even global changes.Based on field measurements,combined with Linear Regression(LR)model and Inverse Distance Weighing(IDW)method,this paper presents detailed analysis on the change history and trend of the shoreline and tidal flat in Bohai Bay.The shoreline faces a high erosion chance under the action of natural factors,while the tidal flat faces a different erosion and deposition patterns in Bohai Bay due to the impact of human activities.The implication of change rule for ecological protection and recovery is also discussed.Measures should be taken to protect the coastal ecological environment.The models used in this paper show a high correlation coefficient between observed and modeling data,which means that this method can be used to predict the changing trend of shoreline and tidal flat.The research results of present study can provide scientific supports for future coastal protection and management.
文摘This article briefly introduces the weighing device for steel billets in front of the heating furnace of the high-speed wire rod unit,and analyzes and summarizes the problems existing in the original weighing device for steel billets in production and use.Based on on-site installation conditions,design a new weighing method,match a large range weighing sensor,upgrade the automation control of the weighing device,and remotely transmit the billet weighing data to the MES system of the group.The automatic,stable,reliable,and accurate measurement of steel billet raw materials has been achieved,providing important guarantees for the accurate measurement of production line billet and product yield.
文摘Identification of groundwater potential areas(GPA)is important in regions facing surface water scarcity,as it assists in effective planning and utilization of groundwater for various purposes.This study employs the methods of remote sensing(RS),geographic information system(GIS)model,and analytical hierarchy process(AHP),multi-criteria decision analysis(MCDA)to locate and map the prospective groundwater areas in the Kulfo-Hare watershed.Seven significant groundwater influencing factors were selected for the determination of groundwater potential in the area:Geology,land use/land cover(LULC),soil,rainfall,slope,drainage density,and lineament density.By applying a five-class classification scheme(very low,low,moderate,high,and very high),the GIS models were used to define the distribution of groundwater potential areas in terms of area coverage(km^(2)),percentage and mapping.The results show that the groundwater potential(GWP)distribution in the research region is as follows:9.7%(6035.9 ha)classified as very high GWP,29.6%(18606 ha)classified as high,24.5%(15245 ha)classified as moderate,18.1%(11431 ha)as low and 18.1%(11492 ha)very low GWP,on the basis of the weighted overlay evaluation.Although a few regions are identifies as extremely low GWP,most of the study area is characterized by very high to moderate GWP.These findings provide valuable insight for sustainable groundwater planning by the government bodies,decision-makers,and private sectors.
文摘Molecular microbiological methods, such as competetive PCR, real-time PCR, denaturing gradient gel electrophoresis (DGGE) and large-scale parallel-pyrosequencing, require the extraction of sufficient quantity of high quality DNA from microbiologically and chemically complex matrices. Due to difficulties in the field to standardize/select the optimum DNA preservation-extraction methods in view of laboratories differences, this article attempts to present a straight-forward mathematical framework for comparing some of the most commonly used methods. To this end, as a case study, the problem of selecting an optimum sample preservation-DNA extraction strategy for obtaining total bacterial DNA from swine feces was considered. Two sample preservation methods (liquid nitrogen and RNAlater?) and seven extraction techniques were paired and compared under six quantitative DNA analysis criteria: yield of extraction, purity of extracted DNA (A260/280 and A 260/230 ratios), duration of extraction, degradation degree of DNA, and cost. From a practical point of view, it is unlikely that a single sample preservation-DNA extraction strategy can be optimum for all selected criteria. Hence, a systematic multi-criteria decision-making (MCDM) approach was used to compare the methods. As a result, the ZR Fecal DNA MiniPrepTM DNA extraction kit for samples preserved either with liquid nitrogen or RNAlater? were identified as potential optimum solutions for obtaining total bacterial DNA from swine feces. Considering the need for practicality for in situ applications, we would recommend liquid nitrogen as sample preservation method, along with the ZR Fecal DNA MiniPrepTM kit. Total bacterial DNA obtained by this strategy can be suitable for downstream PCR-based DNA analyses of swine feces.
文摘A general weighted second order elliptic equation involving critical growth is considered on bounded smooth. domain in n-dimension space. There is the singular point for the weighted coefficients in the domain. With generalized blow up method, some results are obtained for asymptotic behavior of positive solutions. This problem includes Laplacian operators as special cases.
基金National Natural Science Foundation of China(81560691)Special Fund Project for Innovation Driven Development of Guangxi(Gui Ke AA17202046)+7 种基金Open Program for Construction of TCM Pharmacy Doctor Station in Guangxi University of Chinese Medicine(201410-06)The First-Class Subject of Traditional Chinese Medicine(Ethnic Pharmacy)in Guangxi(Gui Jiao Ke Yan[2018]No.12)Program of Collaborative Innovation Center of Zhuang and Yao Medicine(Gui Jiao Ke Yan[2013]No.20)Program of Key Laboratory of Zhuang and Yao Medicine[Gui Ke Ji Zi[2014]No.32]The Eighth Batch of Special Experts Project of Guangxi Zhuang Autonomous Region(Study on Quality Standard of Zhuang&Yao Medicine,[2019]No.13)High-level Talent Team Cultivation Program of"Qihuang Project"of Guangxi University of Chinese Medicine(2018002)High Level Innovation Team and Excellent Scholar Program of Guangxi Universities(Gui Jiao Shi Fan[2019]No.52)Guangxi One Thousand Young and Middle-aged College and University Backbone Teachers Cultivation Program(Gui Jiao Ren[2019]No.5).
文摘[Objectives]This study aimed to optimize the extraction process of longan(Dimocarpus longan Lour.)leaves by multi-indicator comprehensive evaluation method.[Methods]The contents of gallic acid ethyl ester,astragalin,quercetin,luteolin and kaempferol in longan leaves were determined simultaneously by HPLC.Using the multi-indicator comprehensive evaluation method,the methanol concentration,solid to liquid ratio and extraction time for extraction of longan leaves were optimized by orthogonal test.[Results]The optimal extraction process of longan leaves are as follows:methanol concentration of 100%,solid to liquid ratio of 1∶5,and extraction time of 50 min.[Conclusions]The optimized process is simple and feasible,and it can be used to determine the contents of different ingredients in longan leaves.
文摘Medical research data are often skewed and heteroscedastic. It has therefore become practice to log-transform data in regression analysis, in order to stabilize the variance. Regression analysis on log-transformed data estimates the relative effect, whereas it is often the absolute effect of a predictor that is of interest. We propose a maximum likelihood (ML)-based approach to estimate a linear regression model on log-normal, heteroscedastic data. The new method was evaluated with a large simulation study. Log-normal observations were generated according to the simulation models and parameters were estimated using the new ML method, ordinary least-squares regression (LS) and weighed least-squares regression (WLS). All three methods produced unbiased estimates of parameters and expected response, and ML and WLS yielded smaller standard errors than LS. The approximate normality of the Wald statistic, used for tests of the ML estimates, in most situations produced correct type I error risk. Only ML and WLS produced correct confidence intervals for the estimated expected value. ML had the highest power for tests regarding β1.
基金funded by the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(FIRI2016-07)
文摘Greenhousing is a technique to bridge season gap in vegetable production and has been widely used worldwide. Calculation of water requirement of crops grown in greenhouse and determination of their irrigation schedules in arid and semi-arid regions are essential for greenhouse maintenance and have thus attracted increased attention over the past decades. The most common method used in the literature to estimate crop evapotranspiration(ET) is the Penman-Monteith(PM) formula. When applied to greenhouse, however, it often uses canopy resistance instead of surface resistance. It is understood that the surface resistance in greenhouse is the result of a combined effect of canopy restriction and soil-surface restriction to water vapor flow, and the relative dominance of one restriction over another depends on crop canopy. In this paper, we developed a surface resistance model in a way similar to two parallel resistances in an electrical circuit to account for both restrictions. Also, considering that wind speed in greenhouse is normally rather small, we compared three methods available in the literature to calculate the aerodynamic resistance, which are the r_a^1 method proposed by Perrier(1975a, b), the r_a^2 method proposed by Thom and Oliver(1977), and the r_a^3 method proposed by Zhang and Lemeu(1992). We validated the model against ET of tomatoes in a greenhouse measured from sap flow system combined with micro-lysimeter in 2015 and with weighing lysimeter in 2016. The results showed that the proposed surface resistance model improved the accuracy of the PM model, especially when the leaf area index was low and the greenhouse was being irrigated. We also found that the aerodynamic resistance calculated from the r_a^1 and r_a^3 methods is applicable to the greenhouse although the latter is slightly more accurate than the former. The proposed surface resistance model, together with the r_a^3 method for aerodynamic resistance, offers an improved approach to estimate ET in greenhouse using the PM formula.
基金funded by the National Natural Sciences Foundation of China(42171145,41690141,41971041,42101120)the Joint Research Project of Three-River Headwaters National Park,Chinese Academy of Sciences and Qinghai Province,China(LHZX-2020-11).
文摘Precipitation is one of the most important indicators of climate data,but there are many errors in precipitation measurements due to the influence of climatic conditions,especially those of solid precipitation in alpine mountains and at high latitude areas.The measured amount of precipitation in those areas is frequently less than the actual amount of precipitation.To understand the impact of climatic conditions on precipitation measurements in the mountainous areas of Northwest China and the applicability of different gauges in alpine mountains,we established a cryospheric hydrometeorology observation(CHOICE)system in 2008 in the Qilian Mountains,which consists of six automated observation stations located between 2960 and 4800 m a.s.l.Total Rain weighing Sensor(TRwS)gauges tested in the World Meteorological Organization-Solid Precipitation Intercomparison Experiment(WMO-SPICE)were used at observation stations with the CHOICE system.To study the influence of climatic conditions on different types of precipitation measured by the TRwS gauges,we conducted an intercomparison experiment of precipitation at Hulu-1 station that was one of the stations in the CHOICE system.Moreover,we tested the application of transfer functions recommended by the WMO-SPICE at this station using the measurement data from a TRwS gauge from August 2016 to December 2020 and computed new coefficients for the same transfer functions that were more appropriate for the dataset from Hulu-1 station.The new coefficients were used to correct the precipitation measurements of other stations in the CHOICE system.Results showed that the new parameters fitted to the local dataset had better correction results than the original parameters.The environmental conditions of Hulu-1 station were very different from those of observation stations that provided datasets to create the transfer functions.Thus,root-mean-square error(RMSE)of solid and mixed precipitation corrected by the original parameters increased significantly by the averages of 0.135(353%)and 0.072 mm(111%),respectively.RMSE values of liquid,solid and mixed precipitation measurements corrected by the new parameters decreased by 6%,20% and 13%,respectively.In addition,the new parameters were suitable for correcting precipitation at other five stations in the CHOICE system.The relative precipitation(RP)increment of different types of precipitation increased with rising altitude.The average RP increment value of snowfall at six stations was the highest,reaching 7%,while that of rainfall was the lowest,covering 3%.Our results confirmed that the new parameters could be used to correct precipitation measurements of the CHOICE system.
文摘Because of the limited memory of the increasing amount of information in current wearable devices,the processing capacity of the servers in the storage system can not keep up with the speed of information growth,resulting in low load balancing,long load balancing time and data processing delay.Therefore,a data load balancing technology is applied to the massive storage systems of wearable devices in this paper.We first analyze the object-oriented load balancing method,and formally describe the dynamic load balancing issues,taking the load balancing as a mapping problem.Then,the task of assigning each data node and the request of the corresponding data node’s actual processing capacity are completed.Different data is allocated to the corresponding data storage node to complete the calculation of the comprehensive weight of the data storage node.According to the load information of each data storage node collected by the scheduler in the storage system,the load weight of the current data storage node is calculated and distributed.The data load balancing of the massive storage system for wearable devices is realized.The experimental results show that the average time of load balancing using this method is 1.75h,which is much lower than the traditional methods.The results show the data load balancing technology of the massive storage system of wearable devices has the advantages of short data load balancing time,high load balancing,strong data processing capability,short processing time and obvious application.
基金financially supported by Longhua Medical Project (LYTD-14)the National Special Research Foundation of TCM (No.201007010)
文摘Using Dachengqi Tang(DCQT) as a model, high performance liquid chromatography(HPLC)fingerprints were applied to optimize machine extracting process with the Box–Behnken experimental design. HPLC fingerprints were carried out to investigate the chemical ingredients of DCQT; synthetic weighing method based on analytic hierarchy process(AHP) and criteria importance through intercriteria correlation(CRITIC) was performed to calculate synthetic scores of fingerprints; using the mark ingredients contents and synthetic scores as indicators, the Box–Behnken design was carried out to optimize the process parameters of machine decocting process under high pressure for DCQT. Results of optimal process showed that the herb materials were soaked for 45 min and extracted with 9 folds volume of water in the decocting machine under the temperature of 140 1C till the pressure arrived at 0.25 MPa;then hot decoction was excreted to soak Dahuang and Mangxiao for 5 min. Finally, obtained solutions were mixed, filtrated and packed. It concluded that HPLC fingerprints combined with the Box–Behnken experimental design could be used to optimize extracting process of traditional Chinese medicine(TCM).
文摘In the injection of pulverized coal into a blast furnace, there are some factors which affect the readout of electronic weighing system. Through analyzing the measuring errors, it is found that the main reasons are pressure fluctuations of storage tank and puffing tank. According to the interaction of pressures, a neural network based method combined with fuzzy logic is adopted to enhance the precision. Experimental results show this method is satisfactory.
文摘The present experiment was designed to investigatethe effect of oral mungbean on the tumorogenesisin experimental mice.Hybrid mice weighing 20-22g were randomly distributed into several groups.Morpholine(0.635%)was supplemented with the basicdiet.N<sub>2</sub>NO<sub>2</sub>(0. 02%)was dissolved in drinking wateradjusted to pH7.0.Test diets were prepared by supple-ment of various levels(3%,5%,or 10%)of mungbeanwith the basic diet in addition to morpholine Same