Water uptake by crop roots is influenced by many factors. In this study, on the basis of previous studies, root water uptake models were established with the root weight as a dependent variable from the perspective of...Water uptake by crop roots is influenced by many factors. In this study, on the basis of previous studies, root water uptake models were established with the root weight as a dependent variable from the perspective of root biomass changes according to the theory of soil water dynamics. The established models were verified and evaluated using two indicators: root-mean-square error (RMSE) and mean absolute percentage error (MAPE). The results indicated that the annual variation range of root-mean-square error (RMSE) was 0.477-1.231, with an aver- age of 0.810; the annual variation range of mean absolute percentage error (MAPE) was 1.082%-4.052%, with an average of 2.520%, suggesting that the simulation accuracy basically met the requirements. The established numerical models of root water uptake and the compiled program exhibit high simulation accuracy, which can perfectly simulate soil water dynamics during the growth period of crops under nat- ural conditions.展开更多
This paper reviews the internal influence factors of adventitious root, in- ducing oxidase activity, endogenous hormones, rooting inhibiting substances, and fu- ture research ideas are also proposed.
The root system is an important organ that plants absorb nutrients from the soil, and can synthesize the vital substances necessary for the plant. However, the study on root system is burdened with great challenges du...The root system is an important organ that plants absorb nutrients from the soil, and can synthesize the vital substances necessary for the plant. However, the study on root system is burdened with great challenges due to its underground roots. In order to further explore the research methods and techniques of plant roots, the research mainly reviewed the research methods of root system, and summarized the methods of conventional root research, such as digging method, core drilling method, container method and isotope method. The progress of CT scan method, ground penetrating radar, special environmental culture method, nucle- ar magnetic resonance method and CCD three-dimensional imaging method were reviewed. Prospects for plant root research were made according to the trends of root research methods usincl hiqh-end technolo.qy at home and abroad.展开更多
Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicid...Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the root-knot nematode parasitized on the cucumber seeding stage. It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin; while the extracts from Cibotium barometz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.展开更多
Sea surface winds are of great significance in scientific research. In the last few years,three series of scatterometers were launched to measure these winds,including the Advanced Scatterometer(ASCAT) aboard Meteorol...Sea surface winds are of great significance in scientific research. In the last few years,three series of scatterometers were launched to measure these winds,including the Advanced Scatterometer(ASCAT) aboard Meteorological Operational Satellite A(Met Op-A) and Met Op-B,Oceansat-2 Scatterometer(OSCAT),and HY-2A Scatterometer(HY-2A SCAT). Based on buoy wind data,validation and intercomparison of these scatterometers were performed. Scatterometer-derived wind and buoy wind data were collected only if the spatial difference was less than 0.1 degree and temporal difference less than 5 min. After discarding wind direction data outside five times the standard deviation,ASCAT wind products showed high accuracy in both wind speed and direction,with root-mean-square error(RMSE) 0.86 m/s and 17.97 degrees,respectively. HY-2A SCAT nearly meets the mission requirement,with RMSE for wind speed 1.23 m/s and 22.85 degrees for wind direction. OSCAT had poor performance when compared with the others. RMSE for wind speed was 1.54 m/s and 39.86 degrees for wind direction,which greatly exceeds the mission requirement of 20 degrees. In addition,the RMSE for wind direction shows a high-low pattern on buoy wind speed. However,a wind speed range from 14 to 15 m/s was found to be abnormal,and the reason remains unclear. There was no systematic dependency of both wind speed and direction residuals on buoy wind speed and cross-track location of the wind vector cells across the entire range. No seasonal variation was found for any scatterometer.展开更多
The engaged feature of a pair of gears was determined by the geometrical characteristics of their tooth surfaces. Through an analysis of gearing theory on epi-cycloidal bevel gears, the method to examine if there exis...The engaged feature of a pair of gears was determined by the geometrical characteristics of their tooth surfaces. Through an analysis of gearing theory on epi-cycloidal bevel gears, the method to examine if there exists undercut during manufacturing of epicycloidal bevel gears, the approximate formulae to calculate the gap between the convex and concave tooth surfaces in meshing so as to guarantee against the occurrence of point-contact for tooth surfaces even in maximum angle of inclination are derived in this paper. Those formula derived are simple, compact and have practical value to the design and production of epicycloidal bevel gears.展开更多
The aim of this study was to determine the nematicidal effects of some biopesticides againist root-knot nematodes (RKNs) (Meloidogyne incognita) on Bruno type kiwifruit seedlings. Research was conducted in the Ata...The aim of this study was to determine the nematicidal effects of some biopesticides againist root-knot nematodes (RKNs) (Meloidogyne incognita) on Bruno type kiwifruit seedlings. Research was conducted in the Atattirk Central Horticultural Research Institute (ACHRI, Yalova, Turkey) greenhouse during 2013-2014. Biopesticides observed in this study were: sesame oil (Devalone EC), castor oil (Ricinus communis), Myrothecium verrucaria (M. verrucaria strain AARC-0255, Inferno DF), Glomus spp. (Endomycorrhizal fungi, Endo Roots Soluble SP) and Paecilomyces lilacinus (Entomopathogenic fungi, P. lilacinus strain PL1, Bionematon SL). Nematicide Nemacur EC 400 (fenamiphos) was used as treated control (TC) and trials were set up as randomized parcel design (RPD) with seven characters and 10 replicates. Reproduction ratio was determined according to scale values in trial applications and second stage juvenile (J2) populations of M. incognita in soil. The results showed that the best nematicidal effects against RKNs were determined in castor oil (77.92% in 2013 and 73.61% in 2014) and P. lilacinus (61.03% in 2013 and 55.55% in 2014).展开更多
Although we often see references to Carnap's inductive logic even in modern literatures, seemingly its confusing style has long obstructed its correct understanding. So instead of Carnap, in this paper, I devote myse...Although we often see references to Carnap's inductive logic even in modern literatures, seemingly its confusing style has long obstructed its correct understanding. So instead of Carnap, in this paper, I devote myself to its necessary and sufficient commentary. In the beginning part (Sections 2-5), I explain why Carnap began the study of inductive logic and bow he related it with our thought on probability (Sections 2-4). Therein, I trace Carnap's thought back to Wittgenstein's Tractatus as well (Section 5). In the succeeding sections, I attempt the simplest exhibition of Carnap's earlier system, where his original thought was thoroughly provided. For this purpose, minor concepts to which researchers have not paid attention are highlighted, for example, m-function (Section 8), in-correlation (Section 10), C-correlate (Section 10), statistical distribution (Section 12), and fitting sequence (Section 17). The climax of this paper is the proof of theorem (56). Through this theorem, we will be able to overview Carnap's whole system.展开更多
As one of the largest global public health problems, cancer greatly endangers human health. Researchers have been committed to discovering anticancer drugs with high efficiency and low toxicity. Shogaol, a kind of ing...As one of the largest global public health problems, cancer greatly endangers human health. Researchers have been committed to discovering anticancer drugs with high efficiency and low toxicity. Shogaol, a kind of ingredient from ginger with high anti-tumor activity, has attracted our attention. This study was an investigation on the composition and structure-activity relationship of different analogues of shogaol, with the purpose to screen for shogaol compounds which had higher anti-tumor activity and could be easily synthesized. We chose zingerone as the starting material to synthesize shogaol through four-step reactions without protective group, as a result, 31 analogues were synthesized for anti-tumor activity detect. The biological test results showed that: the missing of the unsaturated ketone and the phenolic hydroxyl group reduced the anti-tumor activity of shogaol; the site of phenolic hydroxyl had no significant influence on the anti-tumor activity, the indicating that the larger the steric hindrance of substituent, the lower the activity, but the higher the activity of cyclobutyl substituted derivatives.展开更多
文摘Water uptake by crop roots is influenced by many factors. In this study, on the basis of previous studies, root water uptake models were established with the root weight as a dependent variable from the perspective of root biomass changes according to the theory of soil water dynamics. The established models were verified and evaluated using two indicators: root-mean-square error (RMSE) and mean absolute percentage error (MAPE). The results indicated that the annual variation range of root-mean-square error (RMSE) was 0.477-1.231, with an aver- age of 0.810; the annual variation range of mean absolute percentage error (MAPE) was 1.082%-4.052%, with an average of 2.520%, suggesting that the simulation accuracy basically met the requirements. The established numerical models of root water uptake and the compiled program exhibit high simulation accuracy, which can perfectly simulate soil water dynamics during the growth period of crops under nat- ural conditions.
文摘This paper reviews the internal influence factors of adventitious root, in- ducing oxidase activity, endogenous hormones, rooting inhibiting substances, and fu- ture research ideas are also proposed.
文摘The root system is an important organ that plants absorb nutrients from the soil, and can synthesize the vital substances necessary for the plant. However, the study on root system is burdened with great challenges due to its underground roots. In order to further explore the research methods and techniques of plant roots, the research mainly reviewed the research methods of root system, and summarized the methods of conventional root research, such as digging method, core drilling method, container method and isotope method. The progress of CT scan method, ground penetrating radar, special environmental culture method, nucle- ar magnetic resonance method and CCD three-dimensional imaging method were reviewed. Prospects for plant root research were made according to the trends of root research methods usincl hiqh-end technolo.qy at home and abroad.
基金Supported by Science and Technology Project from Shaanxi Provincial Department of EducationMajor Scientific and Technological In-novation Project of Shaanxi Province (2009ZKC08-09 )Science and Technology Project of Wenzhou (H20080045)~~
文摘Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the root-knot nematode parasitized on the cucumber seeding stage. It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin; while the extracts from Cibotium barometz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.
基金Supported by the National Natural Science Foundation of China(Nos.U1406404,41331172,61361136001)the National High Technology Research and Development Program of China(863 Program)(No.2013AA09A505)
文摘Sea surface winds are of great significance in scientific research. In the last few years,three series of scatterometers were launched to measure these winds,including the Advanced Scatterometer(ASCAT) aboard Meteorological Operational Satellite A(Met Op-A) and Met Op-B,Oceansat-2 Scatterometer(OSCAT),and HY-2A Scatterometer(HY-2A SCAT). Based on buoy wind data,validation and intercomparison of these scatterometers were performed. Scatterometer-derived wind and buoy wind data were collected only if the spatial difference was less than 0.1 degree and temporal difference less than 5 min. After discarding wind direction data outside five times the standard deviation,ASCAT wind products showed high accuracy in both wind speed and direction,with root-mean-square error(RMSE) 0.86 m/s and 17.97 degrees,respectively. HY-2A SCAT nearly meets the mission requirement,with RMSE for wind speed 1.23 m/s and 22.85 degrees for wind direction. OSCAT had poor performance when compared with the others. RMSE for wind speed was 1.54 m/s and 39.86 degrees for wind direction,which greatly exceeds the mission requirement of 20 degrees. In addition,the RMSE for wind direction shows a high-low pattern on buoy wind speed. However,a wind speed range from 14 to 15 m/s was found to be abnormal,and the reason remains unclear. There was no systematic dependency of both wind speed and direction residuals on buoy wind speed and cross-track location of the wind vector cells across the entire range. No seasonal variation was found for any scatterometer.
文摘The engaged feature of a pair of gears was determined by the geometrical characteristics of their tooth surfaces. Through an analysis of gearing theory on epi-cycloidal bevel gears, the method to examine if there exists undercut during manufacturing of epicycloidal bevel gears, the approximate formulae to calculate the gap between the convex and concave tooth surfaces in meshing so as to guarantee against the occurrence of point-contact for tooth surfaces even in maximum angle of inclination are derived in this paper. Those formula derived are simple, compact and have practical value to the design and production of epicycloidal bevel gears.
文摘The aim of this study was to determine the nematicidal effects of some biopesticides againist root-knot nematodes (RKNs) (Meloidogyne incognita) on Bruno type kiwifruit seedlings. Research was conducted in the Atattirk Central Horticultural Research Institute (ACHRI, Yalova, Turkey) greenhouse during 2013-2014. Biopesticides observed in this study were: sesame oil (Devalone EC), castor oil (Ricinus communis), Myrothecium verrucaria (M. verrucaria strain AARC-0255, Inferno DF), Glomus spp. (Endomycorrhizal fungi, Endo Roots Soluble SP) and Paecilomyces lilacinus (Entomopathogenic fungi, P. lilacinus strain PL1, Bionematon SL). Nematicide Nemacur EC 400 (fenamiphos) was used as treated control (TC) and trials were set up as randomized parcel design (RPD) with seven characters and 10 replicates. Reproduction ratio was determined according to scale values in trial applications and second stage juvenile (J2) populations of M. incognita in soil. The results showed that the best nematicidal effects against RKNs were determined in castor oil (77.92% in 2013 and 73.61% in 2014) and P. lilacinus (61.03% in 2013 and 55.55% in 2014).
文摘Although we often see references to Carnap's inductive logic even in modern literatures, seemingly its confusing style has long obstructed its correct understanding. So instead of Carnap, in this paper, I devote myself to its necessary and sufficient commentary. In the beginning part (Sections 2-5), I explain why Carnap began the study of inductive logic and bow he related it with our thought on probability (Sections 2-4). Therein, I trace Carnap's thought back to Wittgenstein's Tractatus as well (Section 5). In the succeeding sections, I attempt the simplest exhibition of Carnap's earlier system, where his original thought was thoroughly provided. For this purpose, minor concepts to which researchers have not paid attention are highlighted, for example, m-function (Section 8), in-correlation (Section 10), C-correlate (Section 10), statistical distribution (Section 12), and fitting sequence (Section 17). The climax of this paper is the proof of theorem (56). Through this theorem, we will be able to overview Carnap's whole system.
文摘As one of the largest global public health problems, cancer greatly endangers human health. Researchers have been committed to discovering anticancer drugs with high efficiency and low toxicity. Shogaol, a kind of ingredient from ginger with high anti-tumor activity, has attracted our attention. This study was an investigation on the composition and structure-activity relationship of different analogues of shogaol, with the purpose to screen for shogaol compounds which had higher anti-tumor activity and could be easily synthesized. We chose zingerone as the starting material to synthesize shogaol through four-step reactions without protective group, as a result, 31 analogues were synthesized for anti-tumor activity detect. The biological test results showed that: the missing of the unsaturated ketone and the phenolic hydroxyl group reduced the anti-tumor activity of shogaol; the site of phenolic hydroxyl had no significant influence on the anti-tumor activity, the indicating that the larger the steric hindrance of substituent, the lower the activity, but the higher the activity of cyclobutyl substituted derivatives.