期刊文献+
共找到2,629篇文章
< 1 2 132 >
每页显示 20 50 100
Risk-Balanced Routing Strategy for Service Function Chains of Cyber-Physical Power System Considering Cross-Space Cascading Failure
1
作者 He Wang Xingyu Tong +2 位作者 Huanan Yu XiaoHu Jing Bian 《Energy Engineering》 EI 2024年第9期2525-2542,共18页
Cyber-physical power system(CPPS)has significantly improved the operational efficiency of power systems.However,cross-space cascading failures may occur due to the coupling characteristics,which poses a great threat t... Cyber-physical power system(CPPS)has significantly improved the operational efficiency of power systems.However,cross-space cascading failures may occur due to the coupling characteristics,which poses a great threat to the safety and reliability of CPPS,and there is an acute need to reduce the probability of these failures.Towards this end,this paper first proposes a cascading failure index to identify and quantify the importance of different information in the same class of communication services.On this basis,a joint improved risk-balanced service function chain routing strategy(SFC-RS)is proposed,which is modeled as a robust optimization problem and solved by column-and-constraint generation(C-CG)algorithm.Compared with the traditional shortest-path routing algorithm,the superiority of SFC-RS is verified in the IEEE 30-bus system.The results demonstrate that SFC-RS effectively mitigates the risk associated with information transmission in the network,enhances information transmission accessibility,and effectively limits communication disruption from becoming the cause of cross-space cascading failures. 展开更多
关键词 Cyber-physical power system service function chain risk balance routing optimization cascading failure
下载PDF
CONSTRUCTION OF NONSYSTEMATIC LOW-DENSITY PARITY-CHECK CODES BASED ON SYMMETRIC BALANCED INCOMPLETE BLOCK DESIGN
2
作者 Lin Dengsheng Li Qiang Li Shaoqian 《Journal of Electronics(China)》 2008年第4期445-449,共5页
This paper studies the nonsystematic Low-Density Parity-Check(LDPC)codes based onSymmetric Balanced Incomplete Block Design(SBIBD).First,it is concluded that the performancedegradation of nonsystematic linear block co... This paper studies the nonsystematic Low-Density Parity-Check(LDPC)codes based onSymmetric Balanced Incomplete Block Design(SBIBD).First,it is concluded that the performancedegradation of nonsystematic linear block codes is bounded by the average row weight of generalizedinverses of their generator matrices and code rate.Then a class of nonsystematic LDPC codes con-structed based on SBIBD is presented.Their characteristics include:both generator matrices andparity-check matrices are sparse and cyclic,which are simple to encode and decode;and almost arbi-trary rate codes can be easily constructed,so they are rate-compatible codes.Because there aresparse generalized inverses of generator matrices,the performance of the proposed codes is only0.15dB away from that of the traditional systematic LDPC codes. 展开更多
关键词 Low-Density Parity-Check (LDPC) codes Nonsystematic codes Symmetric balanced Incomplete Block Design (SBIBD) Finite projective geometries
下载PDF
The Performance Evaluation System Transformation Based on Balanced Scorecard A Case Study of SEICO Company
3
作者 Li Yuling Chen Yuanhong Yu Zengbiao 《Journal of Modern Accounting and Auditing》 2012年第4期578-586,共9页
Application of Balanced Scorecard (BSC) is not so successful in China in the past few years. This paper is to represent how the company Sichuan Ertan Industrial Corporation (SEICO), design performance evaluation s... Application of Balanced Scorecard (BSC) is not so successful in China in the past few years. This paper is to represent how the company Sichuan Ertan Industrial Corporation (SEICO), design performance evaluation system to improve its efficiency and effectiveness and satisfy customers' needs with the help of BSC principles and methodology. It is found from this case study that the key steps to design performance evaluation system are to: (1) link strategy and performance measurements at company-level; (2) decompose them into all the members in all the units at all the levels of that company; and (3) tie them to an incentive plan. Those steps have not been detailed in publications by Kaplan and Norton. 展开更多
关键词 balanced scorecard (BSC) strategy map performance evaluation
下载PDF
Separate-layer balanced waterflooding development technology for thick and complex carbonate reservoirs in the Middle East
4
作者 SONG Xinmin LI Yong +6 位作者 LI Fengfeng YI Liping SONG Benbiao ZHU Guangya SU Haiyang WEI Liang YANG Chao 《Petroleum Exploration and Development》 SCIE 2024年第3期661-673,共13页
Based on the waterflooding development in carbonate reservoirs in the Middle East,in order to solve the problem of the poor development effects caused by commingled injection and production,taking the thick bioclastic... Based on the waterflooding development in carbonate reservoirs in the Middle East,in order to solve the problem of the poor development effects caused by commingled injection and production,taking the thick bioclastic limestone reservoirs of Cretaceous in Iran-Iraq as an example,this paper proposes a balanced waterflooding development technology for thick and complex carbonate reservoirs.This technology includes the fine division of development units by concealed baffles and barriers,the combination of multi well type and multi well pattern,and the construction of balanced water injection and recovery system.Thick carbonate reservoirs in Iran-Iraq are characterized by extremely vertical heterogeneity,development of multi-genesis ultra-high permeability zones,and highly concealed baffles and barriers.Based on the technologies of identification,characterization,and sealing evaluation for concealed baffles and barriers,the balanced waterflooding development technology is proposed,and three types of balanced waterflooding development modes/techniques are formed,namely,conventional stratigraphic framework,fine stratigraphic framework,and deepened stratigraphic framework.Numerical simulations show that this technology is able to realize a fine and efficient waterflooding development to recover,in a balanced manner,the reserves of thick and complex carbonate reservoirs in Iran and Iraq.The proposed technology provides a reference for the development optimization of similar reservoirs. 展开更多
关键词 the Middle East thick carbonate reservoir vertical heterogeneity concealed baffle and barrier sealing separated development units balanced waterflooding
下载PDF
Fast and Balanced Charge Transport Enabled by Solution-Processed Metal Oxide Layers for Efficient and Stable Inverted Perovskite Solar Cells
5
作者 Jing Zhang James Mcgettrick +11 位作者 Kangyu Ji Jinxin Bi Thomas Webb Xueping Liu Dongtao Liu Aobo Ren Yuren Xiang Bowei Li Vlad Stolojan Trystan Watson Samuel D.Stranks Wei Zhang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期240-248,共9页
Metal oxide charge transport materials are preferable for realizing long-term stable and potentially low-cost perovskite solar cells(PSCs).However,due to some technical difficulties(e.g.,intricate fabrication protocol... Metal oxide charge transport materials are preferable for realizing long-term stable and potentially low-cost perovskite solar cells(PSCs).However,due to some technical difficulties(e.g.,intricate fabrication protocols,high-temperature heating process,incompatible solvents,etc.),it is still challenging to achieve efficient and reliable all-metal-oxide-based devices.Here,we developed efficient inverted PSCs(IPSCs)based on solution-processed nickel oxide(NiO_(x))and tin oxide(SnO_(2))nanoparticles,working as hole and electron transport materials respectively,enabling a fast and balanced charge transfer for photogenerated charge carriers.Through further understanding and optimizing the perovskite/metal oxide interfaces,we have realized an outstanding power conversion efficiency(PCE)of 23.5%(the bandgap of the perovskite is 1.62 eV),which is the highest efficiency among IPSCs based on all-metal-oxide charge transport materials.Thanks to these stable metal oxides and improved interface properties,ambient stability(retaining 95%of initial PCE after 1 month),thermal stability(retaining 80%of initial PCE after 2 weeks)and light stability(retaining 90%of initial PCE after 1000 hours aging)of resultant devices are enhanced significantly.In addition,owing to the low-temperature fabrication procedures of the entire device,we have obtained a PCE of over 21%for flexible IPSCs with enhanced operational stability. 展开更多
关键词 fast and balanced charge transfer inverted perovskite solar cells long-term stability low-temperature processing metal oxides
下载PDF
Unveiling evapotranspiration patterns and energy balance in a subalpine forest of the Qinghai-Tibet Plateau:observations and analysis from an eddy covariance system
6
作者 Niu Zhu Jinniu Wang +6 位作者 Dongliang Luo Xufeng Wang Cheng Shen Ning Wu Ning Zhang Binghui Tian Aihong Gai 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期175-188,共14页
Evapotranspiration is an important parameter used to characterize the water cycle of ecosystems.To under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qing... Evapotranspiration is an important parameter used to characterize the water cycle of ecosystems.To under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qinghai-Tibet Plateau,an open-path eddy covariance system was set up to monitor the forest from November 2020 to October 2021 in a core area of the Three Parallel Rivers in the Qing-hai-Tibet Plateau.The results show that the evapotranspira-tion peaked daily,the maximum occurring between 11:00 and 15:00.Environmental factors had significant effects on evapotranspiration,among them,net radiation the greatest(R^(2)=0.487),and relative humidity the least(R^(2)=0.001).The energy flux varied considerably in different seasons and sensible heat flux accounted for the main part of turbulent energy.The energy balance ratio in the dormant season was less than that in the growing season,and there is an energy imbalance at the site on an annual time scale. 展开更多
关键词 EVAPOTRANSPIRATION Energy balance Subalpine forest Three Parallel Rivers region Southeast Qinghai-Tibet Plateau
下载PDF
Coupling Coordination Analysis of Cropland Intensification and Agroecosystem Services:Evidence from Loess Plateau in Shaanxi Province,China
7
作者 FU Shaowu FU Mengyu QIU Menglong 《Chinese Geographical Science》 SCIE CSCD 2024年第3期401-419,共19页
One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroeco... One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroecosystem service,the interactive coupling and coordination among these factors remain largely unexplored.In view of this,this study performed a case study of the Loess Plateau in Shaanxi Province,China and constructed comprehensive evaluation models to quantify the cropland intensification and agroecosystem service in this area.Balance analysis and the coupling coordination degree model were used to evaluate the interactive relationship between cropland intensification and agroecosystem service,and statistical analysis and spatial autocorrelation were used to analyze the spatial characteristics and potential mechanism of the coupling coordination.Results show that both the cropland intensification and agroecosystem service in the study area were relatively low yet gradually increased from 2000 to 2020.Agroecosystem service lag was identified as the dominant unbalanced development type.Improving the supply capacity of agroecosystem services plays a key role in the balanced development of cropland in the Loess Plateau.The coupling coordination degree between cropland intensification and agroecosystem service ranges from basic coordination to serious incoordination.Therefore,cropland intensification practices in the area should be optimized to enhance this coordination degree.An upward trend was also observed in the coupling coordination degree from2000 to 2020.The withdrawal of marginal cropland in the Grain for Green program is one of the most important reasons for this trend,especially for the northern region.Around 83.6%of the high-high clusters are concentrated in the southern region of the Loess Plateau,whereas 70.5%of the low-low clusters are distributed in the northern region.These clustering characteristics are mainly attributed to the environmental suitability of these areas for agriculture and their degree of economic development. 展开更多
关键词 cropland intensification agroecosystem services balance analysis coupling coordination degree Loess Plateau China
下载PDF
Linking Perceived Risk of Public Health Emergency to Psychological Distress among Chinese College Students: The Chain Mediation Role of Balanced Time Perspective and Negative Coping Styles
8
作者 Biru Chang Shengqiang Zhu +1 位作者 Qian Xie Yanghui Dai 《International Journal of Mental Health Promotion》 2024年第8期599-610,共12页
Background:With public health emergencies(PHE)worldwide increasing,the perceived risk of PHE has been one of the critical factors influencing college students’psychological distress.However,the mechanisms by which th... Background:With public health emergencies(PHE)worldwide increasing,the perceived risk of PHE has been one of the critical factors influencing college students’psychological distress.However,the mechanisms by which the perceived risk of PHE affects college students’psychological distress are not clear.The study’s purpose was to investigate the mediation roles of deviation from a balanced time perspective(DBTP)and negative coping styles between the perceived risk of PHE and psychological distress.Methods:A convenience sampling method was used to survey 1054 Chinese college students with self-reporting.Data was collected using the Public Risk Perception Scale(PRPS),the Zimbardo Time Perspective Inventory(ZTPI),the Simplified Coping Style Questionnaire(SCSQ),the PHE Anxiety Scale,and the Chinese version of the Patient Health Questionnaire(PHQ).The associations between the perceived risk of PHE,DBTP,negative coping styles,and psychological distress were clarified using the correlation analysis.Additionally,the mediating roles of DBTP and negative coping styles between the perceived risk of PHE and psychological distress were investigated using a structural equation model.Results:The findings revealed low to moderate correlations between the variables studied.Students’perceived risk of PHE was a positive predictor of their psychological distress(b=0.219,p<0.01).DBTP and negative coping styles played chain mediation roles between them with the effect being 0.009 and a 95%Boot CI of[0.003,0.023].This chain mediation model had an excellent fit index(χ^(2)/df=4.732,CFI=0.973,TLI=0.930,RMSEA=0.048,SRMR=0.047).Conclusion:These findings showed how the perceived risk of PHE affected college students’psychological distress.Specifically,these results suggested that improving students’mental ability to switch effectively among different time perspectives depending on task features and situational considerations and reducing their negative coping styles might be effective ways to promote their mental health. 展开更多
关键词 Perceived risk of public health emergency balanced time perspective negative coping styles psychological distress college students China
下载PDF
New High-Order Numerical Methods for Hyperbolic Systems of Nonlinear PDEs with Uncertainties
9
作者 Alina Chertock Michael Herty +3 位作者 Arsen S.Iskhakov Safa Janajra Alexander Kurganov Maria Lukacova-Medvid'ova 《Communications on Applied Mathematics and Computation》 EI 2024年第3期2011-2044,共34页
In this paper,we develop new high-order numerical methods for hyperbolic systems of nonlinear partial differential equations(PDEs)with uncertainties.The new approach is realized in the semi-discrete finite-volume fram... In this paper,we develop new high-order numerical methods for hyperbolic systems of nonlinear partial differential equations(PDEs)with uncertainties.The new approach is realized in the semi-discrete finite-volume framework and is based on fifth-order weighted essentially non-oscillatory(WENO)interpolations in(multidimensional)random space combined with second-order piecewise linear reconstruction in physical space.Compared with spectral approximations in the random space,the presented methods are essentially non-oscillatory as they do not suffer from the Gibbs phenomenon while still achieving high-order accuracy.The new methods are tested on a number of numerical examples for both the Euler equations of gas dynamics and the Saint-Venant system of shallow-water equations.In the latter case,the methods are also proven to be well-balanced and positivity-preserving. 展开更多
关键词 Hyperbolic conservation and balance laws with uncertainties Finite-volume methods Central-upwind schemes Weighted essentially non-oscillatory(WENO)interpolations
下载PDF
Systematic Review:Load Balancing in Cloud Computing by Using Metaheuristic Based Dynamic Algorithms
10
作者 Darakhshan Syed Ghulam Muhammad Safdar Rizvi 《Intelligent Automation & Soft Computing》 2024年第3期437-476,共40页
Cloud Computing has the ability to provide on-demand access to a shared resource pool.It has completely changed the way businesses are managed,implement applications,and provide services.The rise in popularity has led... Cloud Computing has the ability to provide on-demand access to a shared resource pool.It has completely changed the way businesses are managed,implement applications,and provide services.The rise in popularity has led to a significant increase in the user demand for services.However,in cloud environments efficient load balancing is essential to ensure optimal performance and resource utilization.This systematic review targets a detailed description of load balancing techniques including static and dynamic load balancing algorithms.Specifically,metaheuristic-based dynamic load balancing algorithms are identified as the optimal solution in case of increased traffic.In a cloud-based context,this paper describes load balancing measurements,including the benefits and drawbacks associated with the selected load balancing techniques.It also summarizes the algorithms based on implementation,time complexity,adaptability,associated issue(s),and targeted QoS parameters.Additionally,the analysis evaluates the tools and instruments utilized in each investigated study.Moreover,comparative analysis among static,traditional dynamic and metaheuristic algorithms based on response time by using the CloudSim simulation tool is also performed.Finally,the key open problems and potential directions for the state-of-the-art metaheuristic-based approaches are also addressed. 展开更多
关键词 Cloud computing load balancing metaheuristic algorithm dynamic algorithm load balancer QOS
下载PDF
Research on the Balanced Development of Urban and Rural Compulsory Education Through Education Resource Allocation
11
作者 Kaijie Shang 《Journal of Contemporary Educational Research》 2024年第7期118-125,共8页
With the rapid development of our country’s economy,education has gradually become the focus of social attention.The problem of unbalanced distribution of urban and rural educational resources has become increasingly... With the rapid development of our country’s economy,education has gradually become the focus of social attention.The problem of unbalanced distribution of urban and rural educational resources has become increasingly prominent,urban educational resources are relatively rich,while rural educational resources are relatively scarce,and the balanced development of urban and rural compulsory education has become an urgent task.This paper mainly investigates and studies the distribution of urban and rural educational resources,discusses the unbalanced distribution of urban and rural educational resources and analyzes the reasons,and puts forward a series of corresponding solutions to promote the balanced development of urban and rural compulsory education. 展开更多
关键词 Urban and rural educational resources balanced development Educational resource allocation
下载PDF
Tilt Angle Optimality Criteria for Stand Alone PV Systems
12
作者 Mohammad Abu-Naser 《Journal of Power and Energy Engineering》 2024年第3期1-18,共18页
The conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy avai... The conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy availability varies, this criterion may not be optimal. This study explores two alternative optimization criteria focused on maximizing baseload supply potential and minimizing required storage capacity to address seasonality in energy generation. The optimal tilt angles determined for these criteria differed significantly from the standard approach. This research highlights additional factors crucial for designing solar power systems beyond gross energy generation, essential for the global transition towards a fully renewable energy-based electric grid in the future. 展开更多
关键词 Electric Grid Fixed Solar Panels Optimal PV Tilt Angle Seasonal Solar Variability Renewable Energy Supply-Demand Balance
下载PDF
Carbon fluxes and their response to environmental variables in a Dahurian larch forest ecosystem in northeast China 被引量:6
13
作者 王辉民 三枝信子 +3 位作者 祖元刚 王文杰 山本晋 近藤裕昭 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第1期1-10,共10页
The Dahurian larch forest in northeast China is important due to its vastness and location within a transitional zone from boreal to temperate and at the southern distribution edge of the vast Siberian larch forest. T... The Dahurian larch forest in northeast China is important due to its vastness and location within a transitional zone from boreal to temperate and at the southern distribution edge of the vast Siberian larch forest. The continuous carbon fluxes were measured from May 2004 to April 2005 in the Dahurian larch forest in Northeast China using an eddy covariance method. The results showed that the ecosystem released carbon in the dormant season from mid-October 2004 to April 2005, while it assimilated CO2 from the atmosphere in the growing season from May to September 2004. The net carbon sequestration reached its peak of 112 g.m^-2.month ^-1 in June 2004 (simplified expression of g (carbon).m^-2.month^-1) and then gradually decreased. Annually, the larch forest was a carbon sink that sequestered carbon of 146 g-m^-2.a^-1 (simplified expression of g (carbon).m^-2.a^-1) during the measurements. The photosynthetic process of the larch forest ecosystem was largely affected by the vapor pressure deficit (VPD) and temperature. Under humid conditions (VPD 〈 1.0 kPa), the gross ecosystem production (GEP) increased with increasing temperature. But the net ecosystem production (NEP) showed almost no change with increasing temperature because the increment of GEP was counterbalanced by that of the ecosystem respiration. Under a dry environment (VPD 〉 1.0 kPa), the GEP decreased with the increasing VPD at a rate of 3.0 μmol.m^-2.s^-1kPa -1 and the ecosystem respiration was also enhanced simultaneously due to the increase of air temperature, which was linearly correlated with the VPD. As a result, the net ecosystem carbon sequestration rapidly decreased with the increasing VPD at a rate of 5.2 μmol.m^-2.s-1.kPa^-1. Under humid conditions (VPD 〈 1.0 kPa), both the GEP and NEP were obviously restricted by the low air temperature but were insensitive to the high temperature because the observed high temperature value comes within the category of the optimum range. 展开更多
关键词 carbon balance eddy covariance method environmental effect larch forest Larix gmelinii
下载PDF
A4~12GHz Wideband Balanced MIC Power Amplifier 被引量:1
14
作者 姚小江 李滨 +2 位作者 刘新宇 陈中子 陈晓娟 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第12期1868-1871,共4页
A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz cente... A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz center frequency with an associated gain of 8.5dB and a gain flatness of + /- 0.6dB in the 4-12GHz frequency range. 展开更多
关键词 WIDEBAND Lange coupler microwave integrated circuit balanced power amplifiers
下载PDF
Effects of Balanced Fertilization on Mulberry Leaf Quality and Its Active Substance Content 被引量:1
15
作者 黄盖群 张烈 +6 位作者 殷浩 危玲 佟万红 刘刚 张建华 林超文 郭涛 《Agricultural Science & Technology》 CAS 2013年第4期635-639,644,共6页
This paper study the effect of nitrogen (N, X1), phosphorus (P, X2) and potassium (K, X3) in different amounts on crude protein, soluble sugar, total flavonoid and 1-deoxynojirimycin contents in mulberry leaves,... This paper study the effect of nitrogen (N, X1), phosphorus (P, X2) and potassium (K, X3) in different amounts on crude protein, soluble sugar, total flavonoid and 1-deoxynojirimycin contents in mulberry leaves, with mulberry trees in spring and autumn as the material and as per "3414" experimental design. The results showed that the qualities and active substance content of mulberry leaves changed from increasing to decreasing with its development; crude protein and solu-ble sugar achieved the peak on August 20; total flavonoid and 1-deoxynojirimycin was the highest on May 15. Fertilizations with N, P and K fertilizers at different amounts had significant effects on quality of mulberry leaf and content of active substances. Specifically, as fertilizer amount increased, the content of active sub- stances grew dramatically and achieved the highest at level 2 (X^2X=X~_). Based on fertilizer effect functions of objective yield, the recommended amounts of N, P and K fertilizers based on crude protein, soluble sugar, flavonoid content and DNJ in test sites were 718.46, 220.11 and 305.23 kg/hm2, when the highest of crude protein in mulberry leaf was 1 813.83 kg/hm2. When N, P and K fertilizers were recommended at 666.54, 204.41 and 243.18 kg/hm2, soluble sugar in mulberry leaf achieved the peak at 1 042.65 kg/hm2. When N, P and K fertilizers were at 675.96, 326.49 and 462.90 kg/hm2, flavonoid content achieved the maximum at 147.90 kg/hm2. When N, P and K fertilizers were at 720.9, 225.11 and 323.63 kg/hm2, DNJ content was the highest at 13.55 kg/hm2. 展开更多
关键词 MULBERRY balanced fertilization QUALITY Active substances
下载PDF
Effects of Slow-release Fertilizer and Balanced Fertilization on Nitrogen, Phosphorus and Potassium Uptake in Peppers 被引量:1
16
作者 张忠武 王建新 +4 位作者 鲁耀 段宗颜 彭荣珍 周敏 杨景华 《Agricultural Science & Technology》 CAS 2015年第7期1457-1461,共5页
Field plot experiment was conducted to study the effects of two slow-re- lease fertilizers and balanced fertilization on dry matter accumulation, yield, fertilizer use efficiency, nitrogen, phosphorus and potassium up... Field plot experiment was conducted to study the effects of two slow-re- lease fertilizers and balanced fertilization on dry matter accumulation, yield, fertilizer use efficiency, nitrogen, phosphorus and potassium uptake of peppers at Jiangna Town, Yanshan County, Yunnan Province in 2011. The results showed that the dry matter accumulation in dried pepper plant, pepper yield, nitrogen, phosphorus, potassium uptake in peppers were significantly increased in all the fertilizer treat- ments, compared with those in control (no fertilizer). Compared with conventional fertilization, balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer significantly increased dried pepper economic output by 20.94%, 17.5% and 14.54%, nitrogen uptake in dried peppers by 21.53%,18.46% and 13.19%, phosphorus uptake in dried peppers by 14.08%, 15.76% and 10.44%, potassium uptake in dried peppers by 22.66%, 15.73% and 16.28%; they also in- creased nitrogen and potassium use efficiency, but reduced potassium use efficiency due to the increased potassium addition. In treatments with balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer, the nitrogen utiliza- tion was 5.84%, 7.14% and 8.33% higher and the phosphorus utilization was 3.32%, 3.27% and 2.47% higher than those in treatment with conventional fertiliza- tion. In addition, the nitrogen application could be reduced by 20%-50% by bal- anced fertilization and the two slow-release fertilizers, thereby reducing environmen- tal pollution. Slow-release fertilizers could also reduce the frequency of fertilization and labor costs. 展开更多
关键词 Slow-release fertilizer balanced fertilization Dried pepper NPK uptake Fertilizer use efficiency
下载PDF
Phosphorus Balance in the Main Crop Production Systems in Beijing Suburb——Case in Shunyi District 被引量:1
17
作者 侯勇 高志岭 马文奇 《Agricultural Science & Technology》 CAS 2011年第7期1043-1045,1070,共4页
[Objective] The research aimed to evaluate the phosphorus balances in the main crop production systems in Shunyi District of Beijing City.[Method] By using the nutrient budget method,the phosphorus balances in the mai... [Objective] The research aimed to evaluate the phosphorus balances in the main crop production systems in Shunyi District of Beijing City.[Method] By using the nutrient budget method,the phosphorus balances in the main crop production systems(field crops,orchard and open-field vegetables) in Shunyi District of Beijing City were evaluated.Moreover,the main influence elements of phosphorus surplus in the farmland were analyzed.[Result] The positive phosphorus balances were found across all three crop production systems in the study period.The amount of phosphorus surplus [491.8 kg/(hm2·a)] in vegetables production system was significantly higher than that in field crops [82.7 kg/(hm2·a)] and orchard [129.5 kg/(hm2·a)] production systems(P0.05).But the amount of phosphorus surplus between the latter two had no significant difference(P0.05).Phosphorus surpluses in the production systems of field crops and vegetables respectively presented the extremely significant and positive relationship with the phosphorus input from chemical fertilizer and organic fertilizer(r was respectively 0.987 7 and 0.970 1).The phosphorus input from chemical fertilizer and organic fertilizer in the orchard production system both presented the extremely significant and positive relationship with the phosphorus surplus in the farmland(r was respectively 0.836 3 and 0.625 2).However,the phosphorus harvested by crops didn't significantly correlated to the phosphorus surplus in the farmland for all three crop production systems(P0.05).[Conclusion] The risk of phosphorus pollution potential in all three crop production system of Shunyi Distirct was high,especially in the vegetable production system.The phosphorus surpluses in the production systems of field crops and vegetables were mainly from the inputs of chemical fertilizer and organic fertilizer,respectively.However,the inputs of chemical fertilizer and organic fertilizer both significantly affected the phosphorus surplus in the orchard production system. 展开更多
关键词 SUBURB Field crops ORCHARD Open-field vegetable Phosphorus balance
下载PDF
Establishment of a Mathematical Model for Mulberry Balanced Fertilization in Hilly Areas of Sichuan Province
18
作者 刘刚 帅小蓉 +7 位作者 张建华 殷浩 佟万红 罗春燕 黄盖群 林超文 危玲 夏庆友 《Agricultural Science & Technology》 CAS 2012年第10期2137-2141,2146,共6页
In order to increase mulberry leaf yield and production efficiency in hilly areas of Sichuan Province through scientific fertilization,"3414",a quadratic regression design for modern fertilization,was employed to si... In order to increase mulberry leaf yield and production efficiency in hilly areas of Sichuan Province through scientific fertilization,"3414",a quadratic regression design for modern fertilization,was employed to simulate the regression relationship between mulberry leaf yield and major fertilizer elements including nitrogen(N),phosphor(P) and potassium(K) among which mulberry leaf yield was the objective function and N,P and K were the regulatory factors to fertilization level.As a result,7 types of ternary,binary and monadic quadratic fertilizer effect functions of N,P and K fertilizer elements were established.The weight of fertilizer factors in the optimal mulberry leaf yield obtained by various types of functions was in decreasing order of KPKPNPKNKNNP,and the weight of fertilizer factors in the ratio of leaf yield to input was in decreasing order of K〉PK〉NPK〉P〉NK〉NP〉N.To be specific,the ternary quadratic fertilizer effect function(Y=20 313+0.25X1+43.48 X2+34.47X3-0.01X1^2-0.14X2^2-0.06X3^2+0.05X1X2+0.02X1X3-0.07X2X3,in which X1,X2 and X3 indicate the fertilizer factors N,P and K,respectively) was a model containing all factors,thereby being a recommended fertilization program for mulberry field.Single factor effect analysis indicated that K fertilizer had the highest influence on mulberry leaf yield and ratio of leaf yield to input.Therefore,among all the simulation functions,the monadic quadratic fertilizer effect function of K fertilizer factor(Y=25 002.27+44.728X3-0.084X32) leads to the optimal leaf yield and maximum ratio of leaf yield to input.By using the optimal fertilization program with 600 kg/hm2 N,210 kg/hm2 P2O5 and 254.33 kg/hm2 K2O,the optimal economic leaf yield obtained is 30 945.00 kg/hm2,the cost of fertilizer input is 4 403.65 yuan/hm2,and the ratio of leaf yield to input is as high as 17.57.After verification by production practices,the recommended fertilization indicators in the optimal mulberry fertilization program can provide reference for the construction of high-yield mulberry field in hilly areas of Sichuan Province. 展开更多
关键词 MULBERRY High yield balanced fertilization Fertilizer effect function
下载PDF
Multisensory mechanisms of gait and balance in Parkinson’s disease:an integrative review
19
作者 Stiven Roytman Rebecca Paalanen +4 位作者 Giulia Carli Uros Marusic Prabesh Kanel Teus van Laar Nico I.Bohnen 《Neural Regeneration Research》 SCIE CAS 2025年第1期82-92,共11页
Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have ... Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases. 展开更多
关键词 aging BALANCE encephalography functional magnetic resonance imaging GAIT multisensory integration Parkinson’s disease positron emission tomography SOMATOSENSORY VESTIBULAR visual
下载PDF
Joint eigenvalue estimation by balanced simultaneous Schur decomposition
20
作者 付佗 高西奇 《Journal of Southeast University(English Edition)》 EI CAS 2006年第4期445-450,共6页
The problem of joint eigenvalue estimation for the non-defective commuting set of matrices A is addressed. A procedure revealing the joint eigenstructure by simultaneous diagonalization of. A with simultaneous Schur d... The problem of joint eigenvalue estimation for the non-defective commuting set of matrices A is addressed. A procedure revealing the joint eigenstructure by simultaneous diagonalization of. A with simultaneous Schur decomposition (SSD) and balance procedure alternately is proposed for performance considerations and also for overcoming the convergence difficulties of previous methods based only on simultaneous Schur form and unitary transformations, it is shown that the SSD procedure can be well incorporated with the balancing algorithm in a pingpong manner, i. e., each optimizes a cost function and at the same time serves as an acceleration procedure for the other. Under mild assumptions, the convergence of the two cost functions alternately optimized, i. e., the norm of A and the norm of the left-lower part of A is proved. Numerical experiments are conducted in a multi-dimensional harmonic retrieval application and suggest that the presented method converges considerably faster than the methods based on only unitary transformation for matrices which are not near to normality. 展开更多
关键词 direction of arrival multi-dimensional harmonic retrieval joint eigenvalue simultaneous Schur decomposition balance algorithm
下载PDF
上一页 1 2 132 下一页 到第
使用帮助 返回顶部