With the increasing emphasis on energy conservation,emission reduction and environmental protection,the application prospect of SiC power devices is becoming more and more broad.In the high frequency application of Si...With the increasing emphasis on energy conservation,emission reduction and environmental protection,the application prospect of SiC power devices is becoming more and more broad.In the high frequency application of SiC MOSFET,the change rate of voltage and current in the turn-on and turn-off process increases with the increase of switching frequency.Also,the current and voltage spike oscillation phenomenon is gradually intensified due to the influence of circuit stray parameters.Based on the analysis of SiC MOSFET characteristics,the paper discusses the design requirements and design principles of SiC MOSFET drive circuit.Then,taking the SiC module C2M0080120D of Cree Company as an example,a driver circuit design is realized through the ACPL-355JC optocoupler driver module of Broadcom Company.The circuit not only has the characteristics of fast transmission delay and excellent performance,but also has the functions of overload and short circuit protection.The driving circuit is verified by LTspice simulation software,and the switching characteristics of SiC MOSFET under different working conditions are studied in depth.The experimental results show that the driving circuit can improve the switching time of SiC MOSFET and effectively solve the problem of current and voltage spike oscillation,which lays a foundation for the practical application of SiC MOSFET in the future.展开更多
Wind turbine is a key device to realize the utilization of wind energy,and it has been highly valued by all countries.But the mechanical gear transmission of the existing wind power device has the disadvantages of hig...Wind turbine is a key device to realize the utilization of wind energy,and it has been highly valued by all countries.But the mechanical gear transmission of the existing wind power device has the disadvantages of high vibration and noise,high failure rate,and short service time.Magneticfield modulation electromagnetic gear transmission is a new non-contact transmission method.However,the conventional modulation magnetic gear has low torque density and torque defects with largefluctuations.In order to overcome the gear transmis-sion problems of the existing semi-direct drive wind power generation machinery and improve the electromag-netic performance of the traditional magnetic gear transmission,this paper proposes a new transmission scheme of a non-contact semi-direct drive wind generator with a surface mount Halbach array modulated mag-netic gear method,and considers the electromagnetic properties of the semi-direct drive modulation magnetic gear of the wind turbine.Thefinite element software is used to construct the model of the surface-mounted Halbach array magnetic gear and the conventional gear,analyzed the distribution of magneticfield lines of the two magnetic gears,calculated the air gap magneticflux density of the inner and outer air gap,and obtained the main harmonics of the inner and outer air gap magnetic density;calculated the static torque and steady-state operating torque of the inner and outer rotors in the model,compared the air gapflux density,harmonics and torque of the magnetic gears.The simulation results show that the magneticfield modulation type mag-netic gear of the surface mount Halbach array magnetic gear method improves the magnetic induction wave-form of the inner and outer air gap,reduces the pulse torquefluctuation,and has a 60%higher static torque.Applying it to semi-direct drive wind power generation equipment not only overcomes the shortcomings of mechanical gears,but also has higher electromagnetic performance.Therefore,the surface-mounted Halbach array modulated magnetic gear can be used to replace the mechanical gearbox in the semi-direct drive wind power generation equipment.展开更多
[Objectives]The antifungal protein HAS1 newly obtained was evaluated for acute toxicity safety in KM mice according to relevant national regulations,so as to eliminate people s concerns about the safety of transgenic ...[Objectives]The antifungal protein HAS1 newly obtained was evaluated for acute toxicity safety in KM mice according to relevant national regulations,so as to eliminate people s concerns about the safety of transgenic plants.[Methods]The acute toxicity of the purified protein HAS1 was observed by intragastric administration of mice,and the poisoning symptoms,poisoning degree,recovery and death were observed.[Results]No abnormal toxicity symptoms were observed in the test group,the vehicle control group and the blank control group.The main tissues and organs were not abnormal in gross anatomy.The average body weight of each group showed an increasing trend compared with before administration at 1,3,7,11 and 14 d after administration.It was found that after giving the purified protein HAS1 to KM mice at a cumulative dose of 64 mg/kg a day,no obvious toxicity was observed in the acute toxicity test,indicating that the test substance was non-toxic by oral administration.[Conclusions]This study provides a basis for further use of the protein and its coding genes.展开更多
The fractional Feynman-Kac equations describe the distributions of functionals of non-Brownian motion, or anomalous diffusion, including two types called the forward and backward fractional Feynman-Kac equations, wher...The fractional Feynman-Kac equations describe the distributions of functionals of non-Brownian motion, or anomalous diffusion, including two types called the forward and backward fractional Feynman-Kac equations, where the nonlocal time-space coupled fractional substantial derivative is involved. This paper focuses on the more widely used backward version. Based on the newly proposed approximation operators for fractional substantial derivative, we establish compact finite difference schemes for the backward fractional Feynman-Kac equation. The proposed difference schemes have the q-th(q = 1, 2, 3, 4) order accuracy in temporal direction and fourth order accuracy in spatial direction, respectively. The numerical stability and convergence in the maximum norm are proved for the first order time discretization scheme by the discrete energy method, where an inner product in complex space is introduced. Finally, extensive numerical experiments are carried out to verify the availability and superiority of the algorithms. Also, simulations of the backward fractional Feynman-Kac equation with Dirac delta function as the initial condition are performed to further confirm the effectiveness of the proposed methods.展开更多
The antifungal protein HAS1 is a new antifungal protein isolated from the genome of Bacillus subtilis HAS,which has a good inhibitory effect on various pathogenic fungi in sugarcane.This study aimed at evaluating the ...The antifungal protein HAS1 is a new antifungal protein isolated from the genome of Bacillus subtilis HAS,which has a good inhibitory effect on various pathogenic fungi in sugarcane.This study aimed at evaluating the immunological transfer reaction of the test sample through repeated skin contact by observing whether the cavy skin repeatedly exposed to purified protein HAS1 suffers from allergic reaction and how strong is the allergic reaction.The results showed that the test group and the vehicle control group exhibited no allergic reaction in the skin immediately and at 24,48 and 72 h and had an mean reaction score and a sensitization rate both of 0,so the results of the naked eye observation were both nonallergenic to cavy skin;and in the positive control group,the cavies were observed to be highly sensitized immediately after removing the drug,mildly sensitized at 24 h,and not sensitized at 48 and 72 h,which meant the skin allergy was alleviated with the observation time.It is suggested that the purified protein HAS1 is negative for cavy skin anaphylaxis test (nonallergenic to cavy skin),which provides an experimental basis for further utilization of the protein and its coding gene.展开更多
Sugarcane is an important sugar and energy crop in tropical areas. Sucrose is the main product of photosynthesis and the end accumulation carbohydrate.The sucrose accumulation mechanism in sugarcane is typical in plan...Sugarcane is an important sugar and energy crop in tropical areas. Sucrose is the main product of photosynthesis and the end accumulation carbohydrate.The sucrose accumulation mechanism in sugarcane is typical in plants. We summarized the new progresses of molecular mechanisms on sucrose accumulation in sugarcane and the genetic improvements on sugar trait by genetic modification techniques. In addition,the developments of genetic modification techniques were also concluded.展开更多
Virus-free sugarcane seedlings have improved biomass and sucrose content compared with ordinary seedlings, and sucrose invertases are key enzymes regulating sugarcane growth and sucrose accumulation. In this study, th...Virus-free sugarcane seedlings have improved biomass and sucrose content compared with ordinary seedlings, and sucrose invertases are key enzymes regulating sugarcane growth and sucrose accumulation. In this study, the differences in the expression levels of 3 invertase genes, CWI, SAI and NI, between virus- free and ordinary sugarcane seedlings were analyzed. Compared with ordinary sugarcane plants, the expression of CWI was mainly up-regulated in immature leaves and stems at elongation stage and leaves and immature internodes at maturation stage, and especially, greatly up-regulated in immature interuedes at maturation stage of virus-free plants. The expression of SAI and NI were mainly up-regnlated in leaves and immature internedes of virus-free plants at maturation stage, which might be beneficial to sugar accumulation and rapid utilization of monosaccharide in the stalks of virus-free plants. It is further indicated that virus-free treatment could significantly improve the expression of sucrose invertases at late growth period, and might facilitate the increase of plant biomass.展开更多
The sugarcane genome polyploidization can reduce the pressure of gene evolution selection,promote the fixation of fine traits,and increase the biomass and economic value of sugarcane.This paper mainly introduced the o...The sugarcane genome polyploidization can reduce the pressure of gene evolution selection,promote the fixation of fine traits,and increase the biomass and economic value of sugarcane.This paper mainly introduced the origin of the sugarcane genome,the chromosome composition,the research progress of polyploidization genetic mechanism,in the hope of providing theoretical reference for sugarcane polyploidization breeding.展开更多
Real-time satellite orbit and clock estimations are the prerequisite for Global Navigation Satellite System(GNSS)real-time precise positioning services.To meet the high-rate update requirement of satellite clock corre...Real-time satellite orbit and clock estimations are the prerequisite for Global Navigation Satellite System(GNSS)real-time precise positioning services.To meet the high-rate update requirement of satellite clock corrections,the computational efficiency is a key factor and a challenge due to the rapid development of multi-GNSS constellations.The Square Root Information Filter(SRIF)is widely used in real-time GNSS data processing thanks to its high numerical stability and computational efficiency.In real-time clock estimation,the outlier detection and elimination are critical to guarantee the precision and stability of the product but could be time-consuming.In this study,we developed a new quality control procedure including the three standard steps:i.e.,detection,identification,and adaption,for real-time data processing of huge GNSS networks.Effort is made to improve the computational efficiency by optimizing the algorithm to provide only the essential information required in the processing,so that it can be applied in real-time and high-rate estimation of satellite clocks.The processing procedure is implemented in the PANDA(Positioning and Navigation Data Analyst)software package and evaluated in the operational generation of real-time GNSS orbit and clock products.We demonstrated that the new algorithm can efficiently eliminate outliers,and a clock precision of 0.06 ns,0.24 ns,0.06 ns,and 0.11 ns can be achieved for the GPS,GLONASS,Galileo,and BDS-2 IGSO/MEO satellites,respectively.The computation time per epoch is about 2 to 3 s depending on the number of existing outliers.Overall,the algorithm can satisfy the IGS real-time clock estimation in terms of both the computational efficiency and product quality.展开更多
The BeiDou Navigation Satellite System(BDS)employs a hybrid constellation including GEO(Geosynchronous Earth Orbit),IGSO(Inclined Geosynchronous Orbit),and MEO(Medium Earth Orbit)satellites,where the GEO and IGSO sate...The BeiDou Navigation Satellite System(BDS)employs a hybrid constellation including GEO(Geosynchronous Earth Orbit),IGSO(Inclined Geosynchronous Orbit),and MEO(Medium Earth Orbit)satellites,where the GEO and IGSO satellites are critical to providing continuous and reliable Positioning,Navigation,and Timing(PNT)services in the Asia–Pacifc region.To handle the inconsistency between the satellite orbits and clocks in the broadcast ephemeris,which are determined by the Orbit Determination and Time Synchronization(ODTS)and the Two-way Satellite Time Frequency Transfer(TWSTFT)technique,respectively,we present the strategies using ground-satellite-link observations to improve the accuracy of broadcast ephemeris.The clock diferences between the ODTS and TWSTFT techniques are used for correcting the radial orbit component to derive the refned orbits,which are used to generate the refned broadcast ephemeris.The test results show the precision of the refned orbits is improved by 50–60%in the 3-h to 12-h predicted arcs for the GEO satellites,and by 40–50%for the IGSO satellites.Moreover,the validation using satellite laser ranging observations shows the mean precision of the refned broadcast ephemeris is improved by 27%compared to the original one.Applying the proposed strategies in the BDS Operational Control Segment(OCS),the time evolution of BDS Single Point Positioning(SPP)in the period from Jan.2016 to April 2021 is evaluated.The SPP accuracy is improved from 1.94,2.06 and 3.29 m to 1.39,1.85,and 2.39 m in the north,east,and up components,respectively.Further update with the inclusion of BDS-3 satellites improve the corresponding SPP precision to 0.68,0.70 and 1.91 m.展开更多
Ratiometric probes facilitate quantitative studies via self-calibration and are cherished for bioimaging.Often,a small probe-product spectral separation leads to crosstalk,but the rational development of ratiometric p...Ratiometric probes facilitate quantitative studies via self-calibration and are cherished for bioimaging.Often,a small probe-product spectral separation leads to crosstalk,but the rational development of ratiometric probes with zero probe-product crosstalk remains challenging.Harnessing the recent progress on photophysical modulation of xanthenoid fluorochromes,we propose a powerful and versatile probe design principle,that is,“bridging-group modification,”and developed totalROX,a robust probe for monitoring the total cellular oxidative capacity.展开更多
Addressing global challenges such as energy sustainability,food security,and environmental conservation requires innovative agricultural solutions.Modern sugarcane(Saccharum hybrid)is a crucial crop that contributes n...Addressing global challenges such as energy sustainability,food security,and environmental conservation requires innovative agricultural solutions.Modern sugarcane(Saccharum hybrid)is a crucial crop that contributes not only to the sugar industry but also to bioenergy systems.Beyond its traditional role,sugarcane supports global food security,environmental sustainability,and economic empowerment of farmers.Over 80%of the worldwide sugarcane production is dedicated to sugar,a dietary staple(OECD-FAO,2024).The remaining 19%aid biofuel production,with sugarcane accounting for 24%of the global ethanol feedstock by 2033.As a C4 plant,sugarcane efficiently captures atmospheric carbon and acts as an important carbon sink.Additionally,sugarcane cultivation can lower local temperatures by nearly 1°C compared to pastures/natural vegetation(Loarie et al.,2011).Economically,sugarcane is a high-value cash crop,generating$43 billion annually in Brazil alone(Voora et al.,2023).展开更多
基金the phased achievements of the postgraduate practice innovation project(SJCX22_1479)in Jiangsu Province.
文摘With the increasing emphasis on energy conservation,emission reduction and environmental protection,the application prospect of SiC power devices is becoming more and more broad.In the high frequency application of SiC MOSFET,the change rate of voltage and current in the turn-on and turn-off process increases with the increase of switching frequency.Also,the current and voltage spike oscillation phenomenon is gradually intensified due to the influence of circuit stray parameters.Based on the analysis of SiC MOSFET characteristics,the paper discusses the design requirements and design principles of SiC MOSFET drive circuit.Then,taking the SiC module C2M0080120D of Cree Company as an example,a driver circuit design is realized through the ACPL-355JC optocoupler driver module of Broadcom Company.The circuit not only has the characteristics of fast transmission delay and excellent performance,but also has the functions of overload and short circuit protection.The driving circuit is verified by LTspice simulation software,and the switching characteristics of SiC MOSFET under different working conditions are studied in depth.The experimental results show that the driving circuit can improve the switching time of SiC MOSFET and effectively solve the problem of current and voltage spike oscillation,which lays a foundation for the practical application of SiC MOSFET in the future.
基金supported by the National Natural Science Foundation of China(Grant No.51765020)the Natural Science Foundation of Jiangxi Province(Grant No.20161BAB206153).
文摘Wind turbine is a key device to realize the utilization of wind energy,and it has been highly valued by all countries.But the mechanical gear transmission of the existing wind power device has the disadvantages of high vibration and noise,high failure rate,and short service time.Magneticfield modulation electromagnetic gear transmission is a new non-contact transmission method.However,the conventional modulation magnetic gear has low torque density and torque defects with largefluctuations.In order to overcome the gear transmis-sion problems of the existing semi-direct drive wind power generation machinery and improve the electromag-netic performance of the traditional magnetic gear transmission,this paper proposes a new transmission scheme of a non-contact semi-direct drive wind generator with a surface mount Halbach array modulated mag-netic gear method,and considers the electromagnetic properties of the semi-direct drive modulation magnetic gear of the wind turbine.Thefinite element software is used to construct the model of the surface-mounted Halbach array magnetic gear and the conventional gear,analyzed the distribution of magneticfield lines of the two magnetic gears,calculated the air gap magneticflux density of the inner and outer air gap,and obtained the main harmonics of the inner and outer air gap magnetic density;calculated the static torque and steady-state operating torque of the inner and outer rotors in the model,compared the air gapflux density,harmonics and torque of the magnetic gears.The simulation results show that the magneticfield modulation type mag-netic gear of the surface mount Halbach array magnetic gear method improves the magnetic induction wave-form of the inner and outer air gap,reduces the pulse torquefluctuation,and has a 60%higher static torque.Applying it to semi-direct drive wind power generation equipment not only overcomes the shortcomings of mechanical gears,but also has higher electromagnetic performance.Therefore,the surface-mounted Halbach array modulated magnetic gear can be used to replace the mechanical gearbox in the semi-direct drive wind power generation equipment.
基金Supported by National Natural Science Foundation(31471555)National Key Research and Development Project(SQ2018YFD020024)
文摘[Objectives]The antifungal protein HAS1 newly obtained was evaluated for acute toxicity safety in KM mice according to relevant national regulations,so as to eliminate people s concerns about the safety of transgenic plants.[Methods]The acute toxicity of the purified protein HAS1 was observed by intragastric administration of mice,and the poisoning symptoms,poisoning degree,recovery and death were observed.[Results]No abnormal toxicity symptoms were observed in the test group,the vehicle control group and the blank control group.The main tissues and organs were not abnormal in gross anatomy.The average body weight of each group showed an increasing trend compared with before administration at 1,3,7,11 and 14 d after administration.It was found that after giving the purified protein HAS1 to KM mice at a cumulative dose of 64 mg/kg a day,no obvious toxicity was observed in the acute toxicity test,indicating that the test substance was non-toxic by oral administration.[Conclusions]This study provides a basis for further use of the protein and its coding genes.
基金Project supported by the National Natural Science Foundation of China(Grant No.11471262)Henan University of Technology High-level Talents Fund,China(Grant No.2018BS039)
文摘The fractional Feynman-Kac equations describe the distributions of functionals of non-Brownian motion, or anomalous diffusion, including two types called the forward and backward fractional Feynman-Kac equations, where the nonlocal time-space coupled fractional substantial derivative is involved. This paper focuses on the more widely used backward version. Based on the newly proposed approximation operators for fractional substantial derivative, we establish compact finite difference schemes for the backward fractional Feynman-Kac equation. The proposed difference schemes have the q-th(q = 1, 2, 3, 4) order accuracy in temporal direction and fourth order accuracy in spatial direction, respectively. The numerical stability and convergence in the maximum norm are proved for the first order time discretization scheme by the discrete energy method, where an inner product in complex space is introduced. Finally, extensive numerical experiments are carried out to verify the availability and superiority of the algorithms. Also, simulations of the backward fractional Feynman-Kac equation with Dirac delta function as the initial condition are performed to further confirm the effectiveness of the proposed methods.
基金Supported by National Natural Science Foundation(31471555)National Key Research and Development Project(SQ2018YFD020024)
文摘The antifungal protein HAS1 is a new antifungal protein isolated from the genome of Bacillus subtilis HAS,which has a good inhibitory effect on various pathogenic fungi in sugarcane.This study aimed at evaluating the immunological transfer reaction of the test sample through repeated skin contact by observing whether the cavy skin repeatedly exposed to purified protein HAS1 suffers from allergic reaction and how strong is the allergic reaction.The results showed that the test group and the vehicle control group exhibited no allergic reaction in the skin immediately and at 24,48 and 72 h and had an mean reaction score and a sensitization rate both of 0,so the results of the naked eye observation were both nonallergenic to cavy skin;and in the positive control group,the cavies were observed to be highly sensitized immediately after removing the drug,mildly sensitized at 24 h,and not sensitized at 48 and 72 h,which meant the skin allergy was alleviated with the observation time.It is suggested that the purified protein HAS1 is negative for cavy skin anaphylaxis test (nonallergenic to cavy skin),which provides an experimental basis for further utilization of the protein and its coding gene.
基金Supported by Natural Science Foundation of Hainan Province(20163124)National Nonprofit Institute Research Grant(ITBB140503)Natural Science Foundation of China(No.31371687)
文摘Sugarcane is an important sugar and energy crop in tropical areas. Sucrose is the main product of photosynthesis and the end accumulation carbohydrate.The sucrose accumulation mechanism in sugarcane is typical in plants. We summarized the new progresses of molecular mechanisms on sucrose accumulation in sugarcane and the genetic improvements on sugar trait by genetic modification techniques. In addition,the developments of genetic modification techniques were also concluded.
基金Supported by"863"Program(2013AA102604-1)Natural Science Foundation of Hainan Province(20163124)+1 种基金Basal Research Fund for Central Public-interest Scientific Institute(ITBB140503)Earmarked Fund for China Agriculture Research System(CARS-20-2-5)
文摘Virus-free sugarcane seedlings have improved biomass and sucrose content compared with ordinary seedlings, and sucrose invertases are key enzymes regulating sugarcane growth and sucrose accumulation. In this study, the differences in the expression levels of 3 invertase genes, CWI, SAI and NI, between virus- free and ordinary sugarcane seedlings were analyzed. Compared with ordinary sugarcane plants, the expression of CWI was mainly up-regulated in immature leaves and stems at elongation stage and leaves and immature internodes at maturation stage, and especially, greatly up-regulated in immature interuedes at maturation stage of virus-free plants. The expression of SAI and NI were mainly up-regnlated in leaves and immature internedes of virus-free plants at maturation stage, which might be beneficial to sugar accumulation and rapid utilization of monosaccharide in the stalks of virus-free plants. It is further indicated that virus-free treatment could significantly improve the expression of sucrose invertases at late growth period, and might facilitate the increase of plant biomass.
基金Supported by National High-tech R&D Program of China(863 Program)Project of Natural Science Foundation of Hainan Province(20163124)Special Project of Fundamental Research Funds for Central Public Welfare Research Institutes(ITBB2015RC04 & ITBB2015ZY12)
文摘The sugarcane genome polyploidization can reduce the pressure of gene evolution selection,promote the fixation of fine traits,and increase the biomass and economic value of sugarcane.This paper mainly introduced the origin of the sugarcane genome,the chromosome composition,the research progress of polyploidization genetic mechanism,in the hope of providing theoretical reference for sugarcane polyploidization breeding.
基金the project“Early-Warning and Rapid Impact Assessment with real-time GNSS in the Mediterranean(EWRICA)”Funded by the Federal Ministry of Education and Research,Germany.
文摘Real-time satellite orbit and clock estimations are the prerequisite for Global Navigation Satellite System(GNSS)real-time precise positioning services.To meet the high-rate update requirement of satellite clock corrections,the computational efficiency is a key factor and a challenge due to the rapid development of multi-GNSS constellations.The Square Root Information Filter(SRIF)is widely used in real-time GNSS data processing thanks to its high numerical stability and computational efficiency.In real-time clock estimation,the outlier detection and elimination are critical to guarantee the precision and stability of the product but could be time-consuming.In this study,we developed a new quality control procedure including the three standard steps:i.e.,detection,identification,and adaption,for real-time data processing of huge GNSS networks.Effort is made to improve the computational efficiency by optimizing the algorithm to provide only the essential information required in the processing,so that it can be applied in real-time and high-rate estimation of satellite clocks.The processing procedure is implemented in the PANDA(Positioning and Navigation Data Analyst)software package and evaluated in the operational generation of real-time GNSS orbit and clock products.We demonstrated that the new algorithm can efficiently eliminate outliers,and a clock precision of 0.06 ns,0.24 ns,0.06 ns,and 0.11 ns can be achieved for the GPS,GLONASS,Galileo,and BDS-2 IGSO/MEO satellites,respectively.The computation time per epoch is about 2 to 3 s depending on the number of existing outliers.Overall,the algorithm can satisfy the IGS real-time clock estimation in terms of both the computational efficiency and product quality.
基金supported by the Program of Shanghai Academic Research Leaderthe National Key R&D Program of China(No.2018YFB0504300)+2 种基金Key R&D Program of Guangdong province(No.2018B030325001)the National Natural Science Foundation of China(No.11673050)the Key Program of Special Development funds of Zhangjiang National Innovation Demonstration Zone(Grant No.ZJ2018-ZD-009).
文摘The BeiDou Navigation Satellite System(BDS)employs a hybrid constellation including GEO(Geosynchronous Earth Orbit),IGSO(Inclined Geosynchronous Orbit),and MEO(Medium Earth Orbit)satellites,where the GEO and IGSO satellites are critical to providing continuous and reliable Positioning,Navigation,and Timing(PNT)services in the Asia–Pacifc region.To handle the inconsistency between the satellite orbits and clocks in the broadcast ephemeris,which are determined by the Orbit Determination and Time Synchronization(ODTS)and the Two-way Satellite Time Frequency Transfer(TWSTFT)technique,respectively,we present the strategies using ground-satellite-link observations to improve the accuracy of broadcast ephemeris.The clock diferences between the ODTS and TWSTFT techniques are used for correcting the radial orbit component to derive the refned orbits,which are used to generate the refned broadcast ephemeris.The test results show the precision of the refned orbits is improved by 50–60%in the 3-h to 12-h predicted arcs for the GEO satellites,and by 40–50%for the IGSO satellites.Moreover,the validation using satellite laser ranging observations shows the mean precision of the refned broadcast ephemeris is improved by 27%compared to the original one.Applying the proposed strategies in the BDS Operational Control Segment(OCS),the time evolution of BDS Single Point Positioning(SPP)in the period from Jan.2016 to April 2021 is evaluated.The SPP accuracy is improved from 1.94,2.06 and 3.29 m to 1.39,1.85,and 2.39 m in the north,east,and up components,respectively.Further update with the inclusion of BDS-3 satellites improve the corresponding SPP precision to 0.68,0.70 and 1.91 m.
基金supported by the National Natural Science Foundation of China(nos.21822805,21908065,31871430,81802979,818800585,and 8180032537)Young Medical Talents Training Program of Shanghai(2018)+3 种基金the Commission of Science and Technology of Shanghai Municipality(no.18430711000)the Australian National Health and Medical Research Council(nos.APP1126091 and APP1125794)the Science and Technology Commission of Shanghai Municipality for the Shanghai International Cooperation Program(18430711000)the China Postdoctoral Science Foundation(nos.2019M651427 and 2020T130197),W.Yang acknowledges the financial support of the innovative research team of high-level local universities in Shanghai.
文摘Ratiometric probes facilitate quantitative studies via self-calibration and are cherished for bioimaging.Often,a small probe-product spectral separation leads to crosstalk,but the rational development of ratiometric probes with zero probe-product crosstalk remains challenging.Harnessing the recent progress on photophysical modulation of xanthenoid fluorochromes,we propose a powerful and versatile probe design principle,that is,“bridging-group modification,”and developed totalROX,a robust probe for monitoring the total cellular oxidative capacity.
文摘Addressing global challenges such as energy sustainability,food security,and environmental conservation requires innovative agricultural solutions.Modern sugarcane(Saccharum hybrid)is a crucial crop that contributes not only to the sugar industry but also to bioenergy systems.Beyond its traditional role,sugarcane supports global food security,environmental sustainability,and economic empowerment of farmers.Over 80%of the worldwide sugarcane production is dedicated to sugar,a dietary staple(OECD-FAO,2024).The remaining 19%aid biofuel production,with sugarcane accounting for 24%of the global ethanol feedstock by 2033.As a C4 plant,sugarcane efficiently captures atmospheric carbon and acts as an important carbon sink.Additionally,sugarcane cultivation can lower local temperatures by nearly 1°C compared to pastures/natural vegetation(Loarie et al.,2011).Economically,sugarcane is a high-value cash crop,generating$43 billion annually in Brazil alone(Voora et al.,2023).
