[Objective] Application of P and K was not reasonable in southwest rice producing area, with no effective method for guiding application of P and K. This study aimed to conduct experiments with the same N application ...[Objective] Application of P and K was not reasonable in southwest rice producing area, with no effective method for guiding application of P and K. This study aimed to conduct experiments with the same N application and different P and K application in different ecological points, to explore a scientific and efficient management method of P and K nutrients and provide guidance for application of P and K in rice production. [Method] Hybrid rice Chuanxiang9838 was used as experimental material to study the relationship among application amount of P and K, utilization rates of P and K, rice yield and rice quality in seven ecological points of four provinces (municipalities) including Sichuan, Chongqing, Yunnan and Guizhou. The application amount per hectare of P was 37.5, 75, 112.5 and 150 kg, respectively; the application amount per hectare of K was 45, 135 and 180 kg, respectively. A total of 10 treatments were set for split-plot design with three replications. [Result] Yield of Chuanxiang9838 significantly varied in different experimental locations and under different levels of P and K, interaction of ecological point and different P and K treatments varied significantly. Yield had reached the maximum in ecological point of Yunnan Binchuan and in treatment with application of N 150 kg P 75 kg K 90 kg. Efficient utilization rates of P and K varied in each ecological point, efficient application amount of P and K in Sichuan Dongpo, Sichuan Luxian, Guizhou Xiaohe and Chongqing Yongchuan was the same, while that in Sichuan Guanghan, Sichuan Zhongjiang and Yunnan Binchuan was different. The main objective of high-yield rice production was to increase the number of effective panicles per hectare and seed setting rate. Rice quality was clustered into 2 categories by locations and 6 categories by treatments. [Conclusion] Prediction models of efficient application of P and K in rice production were established, which provided guidance for high-yield rice production and rational and efficient utilization of P and K in southwest rice area.展开更多
[Objective] This study aimed to explore an optimum application amount of nitrogen for cotton cultivation. [Method] In this study, a field experiment was conducted to investigate the effects of nitrogen application amo...[Objective] This study aimed to explore an optimum application amount of nitrogen for cotton cultivation. [Method] In this study, a field experiment was conducted to investigate the effects of nitrogen application amount on the growth characteristics, boll development and lint yield of high quality cotton line FZ-1. [Result] Compared with the nitrogen level of 225 kg/hm2, the lint yield had increased by 28.46% and 18.73%, respectively, with the nitrogen application amount of 300 and 375 kg/hm2. When the nitrogen application amount had increased from 225 to 300 kg/hm2, boll number per plant, boll weight and lint yield had significantly increased. At the nitrogen level of 375 kg/hm2, however, the effects of increasing lint yield were significantly less than that at the nitrogen level of 300 kg/hm2. Compared with the nitrogen levels of 225 and 375, 300 kg/hm2 of nitrogen was the optimum application amount to improve the plant height, daily increment of plant height, number of fruit branches, number ratio of nodes to fruit branches, boll volume and seed cotton weight per boll. [Conclusion] The rational management of nitrogen is the most effective way to promote the growth and development of cotton plants, ensure high yielding ability and minimize the environmental pollution caused by the overuse of nitrogen. This study had provided a sound nitrogen application strategy for the cultivation of this high-quality cotton line in the field plantation.展开更多
[Objective] The paper was to study the nitrogen application amount and nitrogen application model for high grade hybrid rapeseed (Brassica napus L.) to get high yield. [Method] With "Youyan 599" and "Sanbei 98" ...[Objective] The paper was to study the nitrogen application amount and nitrogen application model for high grade hybrid rapeseed (Brassica napus L.) to get high yield. [Method] With "Youyan 599" and "Sanbei 98" as materials, using quadratic regression orthogonal gyration combination design, the impact of nitrogen application amount during various periods on rapeseed yield was studied. [Result] The combinations of factors to obtain the highest yield index (2 898.211 kg / hm 2 ) of "Youyan 599" were as follows: living rape fertilizer 89.27 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 101.12 kg / hm 2 , total nitrogen application amount 310.39 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12th lunar month fertilizer were 28.76%, 38.66% and 32.58%, respectively. The combinations of factors to obtain the highest yield index (2 870.14 kg/hm 2 ) of "Sanbei 98" were as follows: living rape fertilizer 120 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 37.55kg / hm 2 , total nitrogen application amount 277.55 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 43.24%, 43.24% and 13.53%, respectively. The combinations of factors to obtain the highest yield index of two combined varieties (2 813.82 kg/hm 2 )were as follows: living rape fertilizer 120 kg/hm 2 , opening fertilizer 120 kg/hm 2 , 12 th lunar month fertilizer 76.23 kg/hm 2 , total nitrogen application amount 316.23 kg/hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 37.95% , 37.95% and 24.11% , respectively. [Conclusion] The paper provided theoretical basis for high yield cultivation of high grade hybridized rapeseed.展开更多
[Objective] The aim of this study is to investigate the optimum application amount of nitrogen in Lycium barbarum based on considering the relationship between main secondary metabolites and polysaccharide.[Method]Und...[Objective] The aim of this study is to investigate the optimum application amount of nitrogen in Lycium barbarum based on considering the relationship between main secondary metabolites and polysaccharide.[Method]Under field conditions,the effects of different application amounts of nitrogen on main secondary metabolites of betaine,carotenoid and flavone of Lycium barbarum and the relationship between main secondary metabolites and polysaccharide.[Result] The main secondary metabolites of betaine,carotenoid and flavone of Lycium barbarum varied under different application amounts of nitrogen.The proper application amount of nitrogen(600-900 kg/hm2)was beneficial to the formation and accumulation of secondary metabolites such as carotenoids.Correlation analysis results showed that polysaccharide were negatively correlated with betaine,carotenoid and flavone at significant probability level.[Conclusion]Considering the relationship between the output and quality of the fruits of Lycium barbarum,the optimum nitrogen application amount should be 600-900 kg/hm2.展开更多
[ Objective] The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield.cultivation of hybrid rape cuhivar Youyan 9 and Youyan 10. [ Method] The net increment cha...[ Objective] The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield.cultivation of hybrid rape cuhivar Youyan 9 and Youyan 10. [ Method] The net increment changes of individual plant fresh weight and dry matter weight of Youyan 9 and Youyan 10 with different nitrogen application treatments were studied. [ Result] The differences among average fresh weight increments of individual plant and average dry matter weight increment of individual plant with different treatments reached 0. 01 extremely significant level. Fresh weight increment and dry matter weight net increment of individual plant declined gradually with the increase of nitrogen application. In growtheourse ,fresh weight net increment of individual plant increased firstly then decreased and the maximum was in beginning flowering stage, besides that dry matter net increment increased gradually and the maximum was in mature period. The correlations among fresh net increment, dry matter weight net increment and yield net increment were positive or extremely positive. [ Conclusion] Under experimental condition, when nitrogen application was 225 kg/hm^2, hybrid rape Yanyou 9 and Yanyou 10 with low erucic,low glucosinolate could obtain high yield.展开更多
This study aimed to investigate the effects of reducing application amount of base fertilizer and increasing application time of leaf fertilizer on corn yield so as to find out the most economical fertilization way fo...This study aimed to investigate the effects of reducing application amount of base fertilizer and increasing application time of leaf fertilizer on corn yield so as to find out the most economical fertilization way for corn. On the basis of protecting environment, the economic benefits will be also increased. The results showed that the corn yield was increased with the increase of application amount of base fertilizer, and was also increased with the increase of application time of leaf fertilizer.For each time of spaying of leaf fertilizer, the corn yield was increased 258-592.5kg/hm^2 with increase amplitude ranging from 2.3%-5.6%.展开更多
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R...The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.展开更多
The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,rob...The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,robotic-assisted surgery has shown numerous advantages,including more precision,efficiency,minimal invasiveness,and safety than is possible with conventional techniques,which are research hotspots and cutting-edge trends.This article reviewed the history of medical robot development and seminal research papers about current research progress.Taking the autonomous dental implant robotic system as an example,the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.展开更多
Flexible sensors based on MXene-polymer composites are highly prospective for next-generation wearable electronics used in human-machine interfaces.One of the motivating factors behind the progress of flexible sensors...Flexible sensors based on MXene-polymer composites are highly prospective for next-generation wearable electronics used in human-machine interfaces.One of the motivating factors behind the progress of flexible sensors is the steady arrival of new conductive materials.MXenes,a new family of 2D nanomaterials,have been draw-ing attention since the last decade due to their high electronic conduc-tivity,processability,mechanical robustness and chemical tunability.In this review,we encompass the fabrication of MXene-based polymeric nanocomposites,their structure-property relationship,and applications in the flexible sensor domain.Moreover,our discussion is not only lim-ited to sensor design,their mechanism,and various modes of sensing platform,but also their future perspective and market throughout the world.With our article,we intend to fortify the bond between flexible matrices and MXenes thus promoting the swift advancement of flexible MXene-sensors for wearable technologies.展开更多
An analytic hierarchy process(AHP)was employed to assess the applicability of 18 new and superior varieties of flowers in Hefei City flower border applications.A total of 12 indicators were selected from three distinc...An analytic hierarchy process(AHP)was employed to assess the applicability of 18 new and superior varieties of flowers in Hefei City flower border applications.A total of 12 indicators were selected from three distinct aspects of adaptability,ornamental characteristics and use traits,in order to establish a comprehensive evaluation model.The results demonstrate that grade I(J≥2.685)exhibits excellent application value,encompassing six species of plants,such asHydrangeamacrophylla‘Endless Summer’;grade II(2.684≤J≤2.420)is also of notable application value,encompassing five species of plants,such asCallistemonrigidus;grade III(2.419≤J≤2.615)is of average application value,including five species of plants,such asCrocosmiacrocosmiflora;grade IV(J≤2.16)is of relatively poor application value.The evaluation results may be utilized as a theoretical reference for the promotion of new and superior varieties in the flower border of Hefei.展开更多
Background: Bilayer artificial dermis promotes wound healing and offers a treatment option for chronic wounds. Aim: Examine the clinical efficacy of bilayer artificial dermis combined with Vacuum Sealing Drainage (VSD...Background: Bilayer artificial dermis promotes wound healing and offers a treatment option for chronic wounds. Aim: Examine the clinical efficacy of bilayer artificial dermis combined with Vacuum Sealing Drainage (VSD) technology in the treatment of chronic wounds. Method: From June 2021 to December 2023, our hospital treated 24 patients with chronic skin tissue wounds on their limbs using a novel tissue engineering product, the bilayer artificial dermis, in combination with VSD technology to repair the wounds. The bilayer artificial dermis protects subcutaneous tissue, blood vessels, nerves, muscles, and tendons, and also promotes the growth of granulation tissue and blood vessels to aid in wound healing when used in conjunction with VSD technology for wound dressing changes in chronic wounds. Results: In this study, 24 cases of chronic wounds with exposed bone or tendon larger than 1.0 cm2 were treated with a bilayer artificial skin combined with VSD dressing after wound debridement. The wounds were not suitable for immediate skin grafting. At 2 - 3 weeks post-treatment, good granulation tissue growth was observed. Subsequent procedures included thick skin grafting or wound dressing changes until complete wound healing. Patients were followed up on average for 3 months (range: 1 - 12 months) post-surgery. Comparative analysis of the appearance, function, skin color, elasticity, and sensation of the healed chronic wounds revealed superior outcomes compared to traditional skin fl repairs, resulting in significantly higher satisfaction levels among patients and their families. Conclusion: The application of bilayer artificial dermis combined with VSD technology for the repair of chronic wounds proves to be a viable method, yielding satisfactory therapeutic effects compared to traditional skin flap procedures.展开更多
The spatiotemporal distributions of microbes in soil by different methods could affect the efficacy of the microbes to reduce the soil hydraulic conductivity.In this study,the specimens of bio-mediated sands were prep...The spatiotemporal distributions of microbes in soil by different methods could affect the efficacy of the microbes to reduce the soil hydraulic conductivity.In this study,the specimens of bio-mediated sands were prepared using three different methods,i.e.injecting,mixing,and pouring a given microbial so-lution onto compacted sand specimens.The hydraulic conductivity was measured by constant-head tests,while any soil microstructural changes due to addition of the microbes were observed by scan-ning electron microscope(SEM)and mercury intrusion porosimetry(MIP)tests.The amount of dextran concentration produced by microbes in each type of specimen was quantified by a refractometer.Results show that dextran production increased exponentially after 5-7 d of microbial settling with the supply of culture medium.The injection and mixing methods resulted in a similar amount and uniform dis-tribution of dextran in the specimens.The pouring method,however,produced a nonuniform distri-bution,with a higher concentration near the specimen surface.As the supply of culture medium discontinued,the dextran content near the surface produced by the pouring method decreased dramatically due to high competition for nutrients with foreign colonies.Average dextran concentration was negatively and correlated with hydraulic conductivity of bio-mediated soils exponentially,due to the clogging of large soil pores by dextran.The hydraulic conductivity of the injection and mixing cases did not change significantly when the supply of culture medium was absent.展开更多
Objective: To investigate the application effect of refined nursing care in the care for elderly patients with reflux esophagitis. Methods: Following the difference in nursing style, 84 cases of elderly patients with ...Objective: To investigate the application effect of refined nursing care in the care for elderly patients with reflux esophagitis. Methods: Following the difference in nursing style, 84 cases of elderly patients with reflux esophagitis admitted to our hospital from May 2022 to May 2023 were randomly grouped into a control group and a research group, with 42 cases each. The control group was given conventional nursing care and the research group was given refined nursing care. The psychological state and treatment adherence of the two groups of patients after the nursing intervention were compared. Results: After the nursing intervention, the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) scores of the research group were lower than those of the control group (P < 0.05). The treatment compliance of the research group was better than the control group (P < 0.05). Conclusion: The implementation of refined nursing care for elderly patients with reflux esophagitis exhibited a significant effect on improving the patient’s psychological state, treatment compliance, and rehabilitation.展开更多
The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a...The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.展开更多
Polymer solid-state lithium batteries(SSLB)are regarded as a promising energy storage technology to meet growing demand due to their high energy density and safety.Ion conductivity,interface stability and battery asse...Polymer solid-state lithium batteries(SSLB)are regarded as a promising energy storage technology to meet growing demand due to their high energy density and safety.Ion conductivity,interface stability and battery assembly process are still the main challenges to hurdle the commercialization of SSLB.As the main component of SSLB,poly(1,3-dioxolane)(PDOL)-based solid polymer electrolytes polymerized in-situ are becoming a promising candidate solid elec-trolyte,for their high ion conductivity at room temperature,good battery elec-trochemical performances,and simple assembly process.This review analyzes opportunities and challenges of PDOL electrolytes toward practical application for polymer SSLB.The focuses include exploring the polymerization mechanism of DOL,the performance of PDOL composite electrolytes,and the application of PDOL.Furthermore,we provide a perspective on future research directions that need to be emphasized for commercialization of PDOL-based electrolytes in SSLB.The exploration of these schemes facilitates a comprehensive and profound understanding of PDOL-based polymer electrolyte and provides new research ideas to boost them toward practical application in solid-state batteries.展开更多
Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing se...Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing seasons of 2021 and 2022 to evaluate the impacts of foliar application of iodine fertilizer on aromatic rice and to explore the optimal iodine fertilizer concentration.At the full heading stage,six different concentrations of sodium iodide solutions of 0%(CK),0.010%(T1),0.025%(T2),0.050%(T3),0.075%(T4),and 0.100%(T5)were applied to indica aromatic rice cultivars Meixiangzhan 2 and Xiangyaxiangzhan.The results showed that sodium iodide treatments significantly increased the iodine and sodium contents in both leaves and grains.Compared with the CK,the T1 and T2 treatments increased the 2-acetyl-1-pyrroline(2-AP)content in mature grains by 8.41%-101.66%and 13.58%-74.60%,respectively.Improvements in the contents of 1-pyrroline-5-carboxylic acid,proline,1-pyrroline,and methylglyoxal,as well as the activity of proline dehydrogenase were also detected.Additionally,sodium iodide treatments remarkably decreased the chalky grain rate,chalkiness area,and chalkiness degree of aromatic rice,with the T2 treatment exhibiting a 17.79%-47.42%decrease in chalkiness degree compared with the CK.Meanwhile,T1 and T2 treatments showed beneficial impacts on chlorophyll content,photosynthetic characteristics,and yield components,while T3,T4,and T5 treatments exhibited adverse effects on leaf and grain yields.The linear discriminant analysis revealed significant differences between treatments.The correlation analysis and piecewise structural equation modeling showed that the iodine and sodium influenced the photosynthetic characteristics and chlorophyll content of the leaves,thereby regulating the 2-AP biosynthesis and yield components,ultimately affecting the 2-AP content and yield.Overall,this study suggests that foliar application of 0.025%sodium iodide is an effective method to enrich the iodine content in rice grains,improve the grain aroma and appearance quality of aromatic rice,without detrimental effects on grain yield.展开更多
Web application fingerprint recognition is an effective security technology designed to identify and classify web applications,thereby enhancing the detection of potential threats and attacks.Traditional fingerprint r...Web application fingerprint recognition is an effective security technology designed to identify and classify web applications,thereby enhancing the detection of potential threats and attacks.Traditional fingerprint recognition methods,which rely on preannotated feature matching,face inherent limitations due to the ever-evolving nature and diverse landscape of web applications.In response to these challenges,this work proposes an innovative web application fingerprint recognition method founded on clustering techniques.The method involves extensive data collection from the Tranco List,employing adjusted feature selection built upon Wappalyzer and noise reduction through truncated SVD dimensionality reduction.The core of the methodology lies in the application of the unsupervised OPTICS clustering algorithm,eliminating the need for preannotated labels.By transforming web applications into feature vectors and leveraging clustering algorithms,our approach accurately categorizes diverse web applications,providing comprehensive and precise fingerprint recognition.The experimental results,which are obtained on a dataset featuring various web application types,affirm the efficacy of the method,demonstrating its ability to achieve high accuracy and broad coverage.This novel approach not only distinguishes between different web application types effectively but also demonstrates superiority in terms of classification accuracy and coverage,offering a robust solution to the challenges of web application fingerprint recognition.展开更多
Various mobile devices and applications are now used in daily life.These devices require high-speed data processing,low energy consumption,low communication latency,and secure data transmission,especially in 5G and 6G...Various mobile devices and applications are now used in daily life.These devices require high-speed data processing,low energy consumption,low communication latency,and secure data transmission,especially in 5G and 6G mobile networks.High-security cryptography guarantees that essential data can be transmitted securely;however,it increases energy consumption and reduces data processing speed.Therefore,this study proposes a low-energy data encryption(LEDE)algorithm based on the Advanced Encryption Standard(AES)for improving data transmission security and reducing the energy consumption of encryption in Internet-of-Things(IoT)devices.In the proposed LEDE algorithm,the system time parameter is employed to create a dynamic S-Box to replace the static S-Box of AES.Tests indicated that six-round LEDE encryption achieves the same security level as 10-round conventional AES encryption.This reduction in encryption time results in the LEDE algorithm having a 67.4%lower energy consumption and 43.9%shorter encryption time than conventional AES;thus,the proposed LEDE algorithm can improve the performance and the energy consumption of IoT edge devices.展开更多
The grain protein content(GPC)is the key parameter for wheat grain nutritional quality.This study conducted a resampling GWAS analysis using 406 wheat accessions across eight environments,and identified four previousl...The grain protein content(GPC)is the key parameter for wheat grain nutritional quality.This study conducted a resampling GWAS analysis using 406 wheat accessions across eight environments,and identified four previously reported GPC QTLs.An analysis of 87 landraces and 259 modern cultivars revealed the loss of superior GPC haplotypes,especially in Chinese cultivars.These haplotypes were preferentially adopted in different agroecological zones and had broad effects on wheat yield and agronomic traits.Most GPC QTLs did not significantly reduce yield,suggesting that high GPC can be achieved without a yield penalty.The results of this study provide a reference for future GPC breeding in wheat using the four identified QTLs.展开更多
Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In exist...Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In existing technologies,the efficiency of big data applications(BDAs)in distributed systems hinges on the stable-state and low-latency links between worker nodes.However,LMCNs with high-dynamic nodes and long-distance links can not provide the above conditions,which makes the performance of OBDP hard to be intuitively measured.To bridge this gap,a multidimensional simulation platform is indispensable that can simulate the network environment of LMCNs and put BDAs in it for performance testing.Using STK's APIs and parallel computing framework,we achieve real-time simulation for thousands of satellite nodes,which are mapped as application nodes through software defined network(SDN)and container technologies.We elaborate the architecture and mechanism of the simulation platform,and take the Starlink and Hadoop as realistic examples for simulations.The results indicate that LMCNs have dynamic end-to-end latency which fluctuates periodically with the constellation movement.Compared to ground data center networks(GDCNs),LMCNs deteriorate the computing and storage job throughput,which can be alleviated by the utilization of erasure codes and data flow scheduling of worker nodes.展开更多
基金Supported by Project of Rice Industry Technology System ConstructionGrain Production Technology Engineering Project200903002 Project~~
文摘[Objective] Application of P and K was not reasonable in southwest rice producing area, with no effective method for guiding application of P and K. This study aimed to conduct experiments with the same N application and different P and K application in different ecological points, to explore a scientific and efficient management method of P and K nutrients and provide guidance for application of P and K in rice production. [Method] Hybrid rice Chuanxiang9838 was used as experimental material to study the relationship among application amount of P and K, utilization rates of P and K, rice yield and rice quality in seven ecological points of four provinces (municipalities) including Sichuan, Chongqing, Yunnan and Guizhou. The application amount per hectare of P was 37.5, 75, 112.5 and 150 kg, respectively; the application amount per hectare of K was 45, 135 and 180 kg, respectively. A total of 10 treatments were set for split-plot design with three replications. [Result] Yield of Chuanxiang9838 significantly varied in different experimental locations and under different levels of P and K, interaction of ecological point and different P and K treatments varied significantly. Yield had reached the maximum in ecological point of Yunnan Binchuan and in treatment with application of N 150 kg P 75 kg K 90 kg. Efficient utilization rates of P and K varied in each ecological point, efficient application amount of P and K in Sichuan Dongpo, Sichuan Luxian, Guizhou Xiaohe and Chongqing Yongchuan was the same, while that in Sichuan Guanghan, Sichuan Zhongjiang and Yunnan Binchuan was different. The main objective of high-yield rice production was to increase the number of effective panicles per hectare and seed setting rate. Rice quality was clustered into 2 categories by locations and 6 categories by treatments. [Conclusion] Prediction models of efficient application of P and K in rice production were established, which provided guidance for high-yield rice production and rational and efficient utilization of P and K in southwest rice area.
基金Supported by Natural Science Foundation of China(NSFC No.30771272,31171483)the Priority Academic Development Program of Jiangsu Higher Education Institutions+1 种基金Jiangsu Innovation Project for Agriculture Science and Technology(cx(11)2054)Jiangsu Agriculture Science and Technology Support Program(SBE2010307)~~
文摘[Objective] This study aimed to explore an optimum application amount of nitrogen for cotton cultivation. [Method] In this study, a field experiment was conducted to investigate the effects of nitrogen application amount on the growth characteristics, boll development and lint yield of high quality cotton line FZ-1. [Result] Compared with the nitrogen level of 225 kg/hm2, the lint yield had increased by 28.46% and 18.73%, respectively, with the nitrogen application amount of 300 and 375 kg/hm2. When the nitrogen application amount had increased from 225 to 300 kg/hm2, boll number per plant, boll weight and lint yield had significantly increased. At the nitrogen level of 375 kg/hm2, however, the effects of increasing lint yield were significantly less than that at the nitrogen level of 300 kg/hm2. Compared with the nitrogen levels of 225 and 375, 300 kg/hm2 of nitrogen was the optimum application amount to improve the plant height, daily increment of plant height, number of fruit branches, number ratio of nodes to fruit branches, boll volume and seed cotton weight per boll. [Conclusion] The rational management of nitrogen is the most effective way to promote the growth and development of cotton plants, ensure high yielding ability and minimize the environmental pollution caused by the overuse of nitrogen. This study had provided a sound nitrogen application strategy for the cultivation of this high-quality cotton line in the field plantation.
基金Supported by Construction Project of National Rapeseed Modern Industrial Technology System (nycytx-00563)Guizhou Academy of Agricultural Sciences "Research of High Yield and High Quality Cultivation Technology for High Grade Hybrid Rapeseed with High Oil" [C ZX(2007)015]+2 种基金Department of Agriculture of Guizhou Province "Research, Promotion and Application of High Yield Cultivation Technology for Hybridized Rapeseed of New Variety Youyan 599" [QNYZZ (2009) 007]Guizhou Academy of Agricultural Sciences "Large Area Intermediate Experiment, Promotion and Application of Hybridized Rapeseed Youyan 599" [QNKZX (2009) 030]Department of Agriculture of Guizhou Province "Integrated Innovation of Seed Production Techniques and Large Area Demonstration for New High Oil Rapeseed Hybrid Variety Sanbei 98 [QKH NY (2010) 3087]~~
文摘[Objective] The paper was to study the nitrogen application amount and nitrogen application model for high grade hybrid rapeseed (Brassica napus L.) to get high yield. [Method] With "Youyan 599" and "Sanbei 98" as materials, using quadratic regression orthogonal gyration combination design, the impact of nitrogen application amount during various periods on rapeseed yield was studied. [Result] The combinations of factors to obtain the highest yield index (2 898.211 kg / hm 2 ) of "Youyan 599" were as follows: living rape fertilizer 89.27 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 101.12 kg / hm 2 , total nitrogen application amount 310.39 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12th lunar month fertilizer were 28.76%, 38.66% and 32.58%, respectively. The combinations of factors to obtain the highest yield index (2 870.14 kg/hm 2 ) of "Sanbei 98" were as follows: living rape fertilizer 120 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 37.55kg / hm 2 , total nitrogen application amount 277.55 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 43.24%, 43.24% and 13.53%, respectively. The combinations of factors to obtain the highest yield index of two combined varieties (2 813.82 kg/hm 2 )were as follows: living rape fertilizer 120 kg/hm 2 , opening fertilizer 120 kg/hm 2 , 12 th lunar month fertilizer 76.23 kg/hm 2 , total nitrogen application amount 316.23 kg/hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 37.95% , 37.95% and 24.11% , respectively. [Conclusion] The paper provided theoretical basis for high yield cultivation of high grade hybridized rapeseed.
基金Supported by Natural Science Foundation of Ningxia Hui Antonomous Region(NZ0603)Natural Science Foundation of Ningxia University(NS0506)~~
文摘[Objective] The aim of this study is to investigate the optimum application amount of nitrogen in Lycium barbarum based on considering the relationship between main secondary metabolites and polysaccharide.[Method]Under field conditions,the effects of different application amounts of nitrogen on main secondary metabolites of betaine,carotenoid and flavone of Lycium barbarum and the relationship between main secondary metabolites and polysaccharide.[Result] The main secondary metabolites of betaine,carotenoid and flavone of Lycium barbarum varied under different application amounts of nitrogen.The proper application amount of nitrogen(600-900 kg/hm2)was beneficial to the formation and accumulation of secondary metabolites such as carotenoids.Correlation analysis results showed that polysaccharide were negatively correlated with betaine,carotenoid and flavone at significant probability level.[Conclusion]Considering the relationship between the output and quality of the fruits of Lycium barbarum,the optimum nitrogen application amount should be 600-900 kg/hm2.
基金Funds for Transformation of Scientific and Technological Achievements of Ministry of Science and Technology of China (04EFN215200268)the Nomarch Special Foundation for the Excellent Science and Technology Talents of Guizhou Province[(2005(77)]the Science and Technology Program of Guizhou Province[(2006)6001]~~
文摘[ Objective] The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield.cultivation of hybrid rape cuhivar Youyan 9 and Youyan 10. [ Method] The net increment changes of individual plant fresh weight and dry matter weight of Youyan 9 and Youyan 10 with different nitrogen application treatments were studied. [ Result] The differences among average fresh weight increments of individual plant and average dry matter weight increment of individual plant with different treatments reached 0. 01 extremely significant level. Fresh weight increment and dry matter weight net increment of individual plant declined gradually with the increase of nitrogen application. In growtheourse ,fresh weight net increment of individual plant increased firstly then decreased and the maximum was in beginning flowering stage, besides that dry matter net increment increased gradually and the maximum was in mature period. The correlations among fresh net increment, dry matter weight net increment and yield net increment were positive or extremely positive. [ Conclusion] Under experimental condition, when nitrogen application was 225 kg/hm^2, hybrid rape Yanyou 9 and Yanyou 10 with low erucic,low glucosinolate could obtain high yield.
文摘This study aimed to investigate the effects of reducing application amount of base fertilizer and increasing application time of leaf fertilizer on corn yield so as to find out the most economical fertilization way for corn. On the basis of protecting environment, the economic benefits will be also increased. The results showed that the corn yield was increased with the increase of application amount of base fertilizer, and was also increased with the increase of application time of leaf fertilizer.For each time of spaying of leaf fertilizer, the corn yield was increased 258-592.5kg/hm^2 with increase amplitude ranging from 2.3%-5.6%.
基金supported by the National Key Research and Development Program of China(No.2023YFC2907600)the National Natural Science Foundation of China(Nos.42077267,42277174 and 52074164)+2 种基金the Natural Science Foundation of Shandong Province,China(No.ZR2020JQ23)the Opening Project of State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology(No.KFJJ21-02Z)the Fundamental Research Funds for the Central Universities,China(No.2022JCCXSB03).
文摘The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.
基金supported by the National Natural Science Foundation of China[grant number 81970987].
文摘The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,robotic-assisted surgery has shown numerous advantages,including more precision,efficiency,minimal invasiveness,and safety than is possible with conventional techniques,which are research hotspots and cutting-edge trends.This article reviewed the history of medical robot development and seminal research papers about current research progress.Taking the autonomous dental implant robotic system as an example,the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.
基金The authors would like to acknowledge the support from the Natural Sciences and Engineering Research Council of Canada in the form of Discovery Grants to ARR and SS(RGPIN-2019-07246 and RGPIN-2022-04988).A.Rosenkranz greatly acknowledges the financial support given by ANID-Chile within the project Fondecyt Regular 1220331 and Fondequip EQM190057.B.Wang gratefully acknowledges the financial support given by the Alexander von Humboldt Foundation.
文摘Flexible sensors based on MXene-polymer composites are highly prospective for next-generation wearable electronics used in human-machine interfaces.One of the motivating factors behind the progress of flexible sensors is the steady arrival of new conductive materials.MXenes,a new family of 2D nanomaterials,have been draw-ing attention since the last decade due to their high electronic conduc-tivity,processability,mechanical robustness and chemical tunability.In this review,we encompass the fabrication of MXene-based polymeric nanocomposites,their structure-property relationship,and applications in the flexible sensor domain.Moreover,our discussion is not only lim-ited to sensor design,their mechanism,and various modes of sensing platform,but also their future perspective and market throughout the world.With our article,we intend to fortify the bond between flexible matrices and MXenes thus promoting the swift advancement of flexible MXene-sensors for wearable technologies.
基金by Undergraduate Innovation and Entrepreneurship Training Program of Anhui Province(S202312216042)Natural Science Key Research Project of Colleges and Universities in Anhui Province(2023AH051816)General Teaching Research Project of Anhui Province(2022jyxm665).
文摘An analytic hierarchy process(AHP)was employed to assess the applicability of 18 new and superior varieties of flowers in Hefei City flower border applications.A total of 12 indicators were selected from three distinct aspects of adaptability,ornamental characteristics and use traits,in order to establish a comprehensive evaluation model.The results demonstrate that grade I(J≥2.685)exhibits excellent application value,encompassing six species of plants,such asHydrangeamacrophylla‘Endless Summer’;grade II(2.684≤J≤2.420)is also of notable application value,encompassing five species of plants,such asCallistemonrigidus;grade III(2.419≤J≤2.615)is of average application value,including five species of plants,such asCrocosmiacrocosmiflora;grade IV(J≤2.16)is of relatively poor application value.The evaluation results may be utilized as a theoretical reference for the promotion of new and superior varieties in the flower border of Hefei.
文摘Background: Bilayer artificial dermis promotes wound healing and offers a treatment option for chronic wounds. Aim: Examine the clinical efficacy of bilayer artificial dermis combined with Vacuum Sealing Drainage (VSD) technology in the treatment of chronic wounds. Method: From June 2021 to December 2023, our hospital treated 24 patients with chronic skin tissue wounds on their limbs using a novel tissue engineering product, the bilayer artificial dermis, in combination with VSD technology to repair the wounds. The bilayer artificial dermis protects subcutaneous tissue, blood vessels, nerves, muscles, and tendons, and also promotes the growth of granulation tissue and blood vessels to aid in wound healing when used in conjunction with VSD technology for wound dressing changes in chronic wounds. Results: In this study, 24 cases of chronic wounds with exposed bone or tendon larger than 1.0 cm2 were treated with a bilayer artificial skin combined with VSD dressing after wound debridement. The wounds were not suitable for immediate skin grafting. At 2 - 3 weeks post-treatment, good granulation tissue growth was observed. Subsequent procedures included thick skin grafting or wound dressing changes until complete wound healing. Patients were followed up on average for 3 months (range: 1 - 12 months) post-surgery. Comparative analysis of the appearance, function, skin color, elasticity, and sensation of the healed chronic wounds revealed superior outcomes compared to traditional skin fl repairs, resulting in significantly higher satisfaction levels among patients and their families. Conclusion: The application of bilayer artificial dermis combined with VSD technology for the repair of chronic wounds proves to be a viable method, yielding satisfactory therapeutic effects compared to traditional skin flap procedures.
基金The first author(V.Kamchoom)acknowledges the grant(Grant No.FRB66065/0258-RE-KRIS/FF66/53)from King Mongkut’s Insti-tute of Technology Ladkrabang(KMITL)and National Science,Research and Innovation Fund(NSRF)the grant under Climate Change and Climate Variability Research in Monsoon Asia(CMON3)from the National Research Council of Thailand(NRCT)(Grant No.N10A650844)the National Natural Science Foundation of China(NSFC).
文摘The spatiotemporal distributions of microbes in soil by different methods could affect the efficacy of the microbes to reduce the soil hydraulic conductivity.In this study,the specimens of bio-mediated sands were prepared using three different methods,i.e.injecting,mixing,and pouring a given microbial so-lution onto compacted sand specimens.The hydraulic conductivity was measured by constant-head tests,while any soil microstructural changes due to addition of the microbes were observed by scan-ning electron microscope(SEM)and mercury intrusion porosimetry(MIP)tests.The amount of dextran concentration produced by microbes in each type of specimen was quantified by a refractometer.Results show that dextran production increased exponentially after 5-7 d of microbial settling with the supply of culture medium.The injection and mixing methods resulted in a similar amount and uniform dis-tribution of dextran in the specimens.The pouring method,however,produced a nonuniform distri-bution,with a higher concentration near the specimen surface.As the supply of culture medium discontinued,the dextran content near the surface produced by the pouring method decreased dramatically due to high competition for nutrients with foreign colonies.Average dextran concentration was negatively and correlated with hydraulic conductivity of bio-mediated soils exponentially,due to the clogging of large soil pores by dextran.The hydraulic conductivity of the injection and mixing cases did not change significantly when the supply of culture medium was absent.
文摘Objective: To investigate the application effect of refined nursing care in the care for elderly patients with reflux esophagitis. Methods: Following the difference in nursing style, 84 cases of elderly patients with reflux esophagitis admitted to our hospital from May 2022 to May 2023 were randomly grouped into a control group and a research group, with 42 cases each. The control group was given conventional nursing care and the research group was given refined nursing care. The psychological state and treatment adherence of the two groups of patients after the nursing intervention were compared. Results: After the nursing intervention, the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) scores of the research group were lower than those of the control group (P < 0.05). The treatment compliance of the research group was better than the control group (P < 0.05). Conclusion: The implementation of refined nursing care for elderly patients with reflux esophagitis exhibited a significant effect on improving the patient’s psychological state, treatment compliance, and rehabilitation.
基金the National Key R&D Program of China(2022YFA1203304)the Natural Science Foundation of Jiangsu Province(BK20220288)+1 种基金Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(Start-up grant E1552102)the China Postdoctoral Science Foundation(No.2023M732553).
文摘The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.
基金We express our sincere appreciation to the National Natural Science Foundation of China(No.51474113(M.Jing),22279070[L.Wang]and U21A20170[X.He])the Ministry of Science and Technology of China(No.2019YFA0705703[L.Wang]).And we would like to thank the“Explorer 100”cluster system of Tsinghua National Laboratory for Information Science and Technology for facility support.
文摘Polymer solid-state lithium batteries(SSLB)are regarded as a promising energy storage technology to meet growing demand due to their high energy density and safety.Ion conductivity,interface stability and battery assembly process are still the main challenges to hurdle the commercialization of SSLB.As the main component of SSLB,poly(1,3-dioxolane)(PDOL)-based solid polymer electrolytes polymerized in-situ are becoming a promising candidate solid elec-trolyte,for their high ion conductivity at room temperature,good battery elec-trochemical performances,and simple assembly process.This review analyzes opportunities and challenges of PDOL electrolytes toward practical application for polymer SSLB.The focuses include exploring the polymerization mechanism of DOL,the performance of PDOL composite electrolytes,and the application of PDOL.Furthermore,we provide a perspective on future research directions that need to be emphasized for commercialization of PDOL-based electrolytes in SSLB.The exploration of these schemes facilitates a comprehensive and profound understanding of PDOL-based polymer electrolyte and provides new research ideas to boost them toward practical application in solid-state batteries.
基金supported by the National Natural Science Foundation of China(Grant No.31971843)the Technology System of Modern Agricultural Industry in Guangdong Province,China(Grant No.2020KJ105)+1 种基金the Guangzhou Science and Technology Project,Guangdong Province,China(Grant No.202103000075)the Special Rural Revitalization Funds of Guangdong Province,China(Grant No.2021KJ382)。
文摘Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing seasons of 2021 and 2022 to evaluate the impacts of foliar application of iodine fertilizer on aromatic rice and to explore the optimal iodine fertilizer concentration.At the full heading stage,six different concentrations of sodium iodide solutions of 0%(CK),0.010%(T1),0.025%(T2),0.050%(T3),0.075%(T4),and 0.100%(T5)were applied to indica aromatic rice cultivars Meixiangzhan 2 and Xiangyaxiangzhan.The results showed that sodium iodide treatments significantly increased the iodine and sodium contents in both leaves and grains.Compared with the CK,the T1 and T2 treatments increased the 2-acetyl-1-pyrroline(2-AP)content in mature grains by 8.41%-101.66%and 13.58%-74.60%,respectively.Improvements in the contents of 1-pyrroline-5-carboxylic acid,proline,1-pyrroline,and methylglyoxal,as well as the activity of proline dehydrogenase were also detected.Additionally,sodium iodide treatments remarkably decreased the chalky grain rate,chalkiness area,and chalkiness degree of aromatic rice,with the T2 treatment exhibiting a 17.79%-47.42%decrease in chalkiness degree compared with the CK.Meanwhile,T1 and T2 treatments showed beneficial impacts on chlorophyll content,photosynthetic characteristics,and yield components,while T3,T4,and T5 treatments exhibited adverse effects on leaf and grain yields.The linear discriminant analysis revealed significant differences between treatments.The correlation analysis and piecewise structural equation modeling showed that the iodine and sodium influenced the photosynthetic characteristics and chlorophyll content of the leaves,thereby regulating the 2-AP biosynthesis and yield components,ultimately affecting the 2-AP content and yield.Overall,this study suggests that foliar application of 0.025%sodium iodide is an effective method to enrich the iodine content in rice grains,improve the grain aroma and appearance quality of aromatic rice,without detrimental effects on grain yield.
基金supported in part by the National Science Foundation of China under Grants U22B2027,62172297,62102262,61902276 and 62272311,Tianjin Intelligent Manufacturing Special Fund Project under Grant 20211097the China Guangxi Science and Technology Plan Project(Guangxi Science and Technology Base and Talent Special Project)under Grant AD23026096(Application Number 2022AC20001)+1 种基金Hainan Provincial Natural Science Foundation of China under Grant 622RC616CCF-Nsfocus Kunpeng Fund Project under Grant CCF-NSFOCUS202207.
文摘Web application fingerprint recognition is an effective security technology designed to identify and classify web applications,thereby enhancing the detection of potential threats and attacks.Traditional fingerprint recognition methods,which rely on preannotated feature matching,face inherent limitations due to the ever-evolving nature and diverse landscape of web applications.In response to these challenges,this work proposes an innovative web application fingerprint recognition method founded on clustering techniques.The method involves extensive data collection from the Tranco List,employing adjusted feature selection built upon Wappalyzer and noise reduction through truncated SVD dimensionality reduction.The core of the methodology lies in the application of the unsupervised OPTICS clustering algorithm,eliminating the need for preannotated labels.By transforming web applications into feature vectors and leveraging clustering algorithms,our approach accurately categorizes diverse web applications,providing comprehensive and precise fingerprint recognition.The experimental results,which are obtained on a dataset featuring various web application types,affirm the efficacy of the method,demonstrating its ability to achieve high accuracy and broad coverage.This novel approach not only distinguishes between different web application types effectively but also demonstrates superiority in terms of classification accuracy and coverage,offering a robust solution to the challenges of web application fingerprint recognition.
基金This work was supported by the National Science and Technology Council,Taiwan,under Project NSTC 112-2221-E-029-015.
文摘Various mobile devices and applications are now used in daily life.These devices require high-speed data processing,low energy consumption,low communication latency,and secure data transmission,especially in 5G and 6G mobile networks.High-security cryptography guarantees that essential data can be transmitted securely;however,it increases energy consumption and reduces data processing speed.Therefore,this study proposes a low-energy data encryption(LEDE)algorithm based on the Advanced Encryption Standard(AES)for improving data transmission security and reducing the energy consumption of encryption in Internet-of-Things(IoT)devices.In the proposed LEDE algorithm,the system time parameter is employed to create a dynamic S-Box to replace the static S-Box of AES.Tests indicated that six-round LEDE encryption achieves the same security level as 10-round conventional AES encryption.This reduction in encryption time results in the LEDE algorithm having a 67.4%lower energy consumption and 43.9%shorter encryption time than conventional AES;thus,the proposed LEDE algorithm can improve the performance and the energy consumption of IoT edge devices.
基金supported by the“Integration of Two Chains”Key Research and Development Projects of Shaanxi Province“Wheat Seed Industry Innovation Project”,Chinathe Key R&D of Yangling Seed Industry Innovation Center,China(Ylzy-xm-01)。
文摘The grain protein content(GPC)is the key parameter for wheat grain nutritional quality.This study conducted a resampling GWAS analysis using 406 wheat accessions across eight environments,and identified four previously reported GPC QTLs.An analysis of 87 landraces and 259 modern cultivars revealed the loss of superior GPC haplotypes,especially in Chinese cultivars.These haplotypes were preferentially adopted in different agroecological zones and had broad effects on wheat yield and agronomic traits.Most GPC QTLs did not significantly reduce yield,suggesting that high GPC can be achieved without a yield penalty.The results of this study provide a reference for future GPC breeding in wheat using the four identified QTLs.
基金supported by National Natural Sciences Foundation of China(No.62271165,62027802,62201307)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030297)+2 种基金the Shenzhen Science and Technology Program ZDSYS20210623091808025Stable Support Plan Program GXWD20231129102638002the Major Key Project of PCL(No.PCL2024A01)。
文摘Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In existing technologies,the efficiency of big data applications(BDAs)in distributed systems hinges on the stable-state and low-latency links between worker nodes.However,LMCNs with high-dynamic nodes and long-distance links can not provide the above conditions,which makes the performance of OBDP hard to be intuitively measured.To bridge this gap,a multidimensional simulation platform is indispensable that can simulate the network environment of LMCNs and put BDAs in it for performance testing.Using STK's APIs and parallel computing framework,we achieve real-time simulation for thousands of satellite nodes,which are mapped as application nodes through software defined network(SDN)and container technologies.We elaborate the architecture and mechanism of the simulation platform,and take the Starlink and Hadoop as realistic examples for simulations.The results indicate that LMCNs have dynamic end-to-end latency which fluctuates periodically with the constellation movement.Compared to ground data center networks(GDCNs),LMCNs deteriorate the computing and storage job throughput,which can be alleviated by the utilization of erasure codes and data flow scheduling of worker nodes.