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Quantitative studies of the regular distribution pattern for Salmonella enteritidis in the internal organs of mice after oral challenge by a specific real-time polymerase chain reaction 被引量:7
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作者 Shu-Xuan Deng An-Chun Cheng +5 位作者 Ming-Shu Wang Ping Cao Bin Yan Nian-Chun Yin Sheng-Yan Cao Zhen-Hua Zhang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第5期782-789,共8页
AIM: To identify and understand the regular distribution pattern for Salmonella enteritidis (S. enteritidis) in the internal organs of mice after an oral challenge over a 3 wk period. METHODS: Assays based on the ... AIM: To identify and understand the regular distribution pattern for Salmonella enteritidis (S. enteritidis) in the internal organs of mice after an oral challenge over a 3 wk period. METHODS: Assays based on the serovar-specific DNA sequence of S. enteritidis from GenBank, and a serovar-specific real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) were developed for the detection of S. enteritidis. We used this assay to detect genomic DNA of S. enteritidis in the blood and the internal organs, including heart, liver, spleen, kidney, pancreas, and gallbladder, from mice after oral challenge at different time points respectively.RESULTS: The results showed that the spleen was positive at 12 h post inoculation (PI), and the blood was at 14 h PI. The organism was detected in the liver and heart at 16 h PI, the pancreas was positive at 20 h PI, and the final organs to show positive results were the kidney and gallbladder at 22 h PI. The copy number of S. enteritidis DNA in each tissue reached a peak at 24-36 h PI, with the liver and spleen containing high concentrations of S. enteritidis, whereas the blood, heart, kidney, pancreas, and gallbladder had low concentrations. S. enteritidis populations began to decrease and were not detectable at 3 d PI, but were still present up to 12 d PI in the gallbladder, 2 wk for the liver, and 3 wk for the spleen without causing apparent symptoms.CONCLUSION: The results provided significant data for understanding the life cycle of S. enteritidis in the internal organs, and showed that the liver and spleen may be the primary sites for setting itself up as a commensa over a long time after oral challenge. Interestingly, it may be the first time reported that the gallbladder is a site of carriage for S. enteritidis over a 12 d period. This study will help to understand the mechanisms of action of S. enteriCdis infection in vivo. 展开更多
关键词 Fluorescence-based quantitative polymerase chain reaction Internal organs Salmonella enteritidis regular distribution pattern
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Effects of Primary and Secondary Trunk Girdling on the Status and Distribution Regularity of Nutrients in Grape
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作者 张永福 王定康 +1 位作者 莫丽玲 董翠莲 《Agricultural Science & Technology》 CAS 2016年第12期2763-2768,共6页
Objective] The study aimed to investigate the effects of primary and sec-ondary trunk girdling on the status and distribution regularity of nutrients in grape. [Method] Using grape cultivar ‘Rose Honey’ as the exper... Objective] The study aimed to investigate the effects of primary and sec-ondary trunk girdling on the status and distribution regularity of nutrients in grape. [Method] Using grape cultivar ‘Rose Honey’ as the experimental material, the ef-fects of primary and secondary trunk girdling on carbon and nitrogen nutrition, min-eral nutrition and nutrient distribution regularity in leaves and branches above the girdling wound and roots below the girdling wound were analyzed. [Result] Girdling could significantly increase non-structural carbohydrate content (such as soluble sugar and starch) in branches above the girdling wound, reduce soluble protein and total nitrogen contents, and significantly improve C/N ratio. Specifical y, the highest C/N ratio in primary girdling group and secondary girdling group was 9.04 and 5.35, respectively, but C/N ratio in control group was only 4.89 in the same period. Girdling not only significantly decreased the content of non-structural carbohydrates (such as soluble sugar and starch) in roots, but also significantly declined soluble protein and total nitrogen content, which also reduced C/N ratio in various degrees. Specifical y, the lowest C/N ratio in primary girdling group and secondary girdling group was 1.16 and 3.06, respectively, while that in control group was 3.15 in the same period. ln addition, primary girdling exerted much greater effects on carbon and nitrogen nutrition than secondary girdling. Moreover, girdling significantly de-creased the contents of phosphorus, potassium, ferrum and copper in grape leaves, branches and roots. Specifical y, primary girdling exerted greater effects on ferrum and copper contents in leaves and branches. The contents of ferrum and copper in the first batch of samples exhibited significant differences between primary girdling group and control group: ferrum content in leaves was 75.05 μg/g DW in primary girdling group and that in control group was 85.29 μg/g DW; ferrum content in branches was 76.45 ?g/g DW in primary girdling group and copper content was 7.82 μg/g DW, while ferrum and copper contents in control group were 95.96 and 10.74 μg/g DW, respectively. [Conclusion] This study provided the basis for accu-rately regulating tree nutrition and ensuring safe and effective use of girdling tech-nique in ‘Rose Honey’ production. 展开更多
关键词 GRAPE GIRDLING Tree Nutrition distribution regularity
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Distribution Regularity of Muzzle Shock-Wave Inside Protective Cover 被引量:1
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作者 WU Jun LIU Jingbo DU Yixin 《Transactions of Tianjin University》 EI CAS 2006年第B09期161-164,共4页
The injury of gunners caused by muzzle shock-wave has always been a great problem when firing inside the protective cover. The distribution regularity and personnel injury from the muzzle blast-wave were investigated ... The injury of gunners caused by muzzle shock-wave has always been a great problem when firing inside the protective cover. The distribution regularity and personnel injury from the muzzle blast-wave were investigated by both test and numerical simulation. Through the inside firing test, the changes of overpressure and noise have been measured at different measuring points in the thin-wall cover structure with different open widths and shallow covering thickness. The distribution regularity of muzzle shock-wave with different firing port widths is calculated by ANSYS/LSDYNA software. The overpressure distribution curves of muzzle shock-wave inside the structure can be obtained by comparing the test results with the numerical results. Then, the influence of open width and shallow covering thickness is proposed to give a reference to the protective design under the condition of the inside firing with the same cannon caliber. 展开更多
关键词 artillery inside firing muzzle shock-wave OVERPRESSURE distribution regularity
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Sequence boundaries and regularities in the oil-gas distribution of the low swelling slope belt in the continental rift basin 被引量:3
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作者 Xie Zongkui 《Mining Science and Technology》 EI CAS 2011年第3期419-425,共7页
Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problem... Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problems to be solved during exploration of a region. Taking the Paleogene system developed along the east slope belt of Chengdao as an example the concepts of sequence stratigraphy and sedimentary sequenc are applied. A new research method likened to a way ''to get a melon by following the vine'' is proposed to determine the direction for exploring within un-drilled or less-drilled areas. This is the process: ''the characteristics of the sequence boundary ? the forming mechanism of the stratigraphic sequence ? the conditions of oil and gas accumulation ? the distribution zones of oil and gas''. The relationship between the dynamic mechanism of stratigraphic sequence and the forming conditions for oil and gas accumulation establishes that the tectonic disturbance of the slope belt has significant responses as denudation and deposition. Above the stratigraphic sequence boundary there are large scale sand bodies of the low stand system tract (LST) that have developed in the low swelling slope belt and its deep depression. Below the sequence boundary there are the remaining sand bodies of the high stand system tract (HST). On the slope there is a convergence of mudstone layers of the extended system tract (EST) with the mudstone of the underlying strata, which constitutes the screening conditions for the reservoir of the down slope and deep depression. The distribution regularities in preferred sand bodies on the surface of the sequence boundary, and in the system tract, indicate the ordering of oil-gas deposits. From the higher stand down to the depth of the slope there are, in order, areas where exploration was unfavorable, major areas of stratigraphic overlap of oil-gas reservoirs, unconformity screened oil-gas reservoirs, and, finally, sandstone lens oil-gas reservoirs. The low swelling slope belt of Chengdao was tectonically active, which is typical for a continental rift basin. The methodology and results of the present paper are significant for the theory and practice of predicting subtle reservoir and selecting strategic areas for exploration. 展开更多
关键词 Continental rift basinLow swelling ChengdaoSequence boundary Subtle reservoirThe distribution regularity of oil and gas
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Research and Application for the Regularity of Distribution about Curvature Radius and Curvature Center of the Linkage Point Track in a Link Mechanism 被引量:2
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作者 WANG Yun-di WANG Liang-wen +1 位作者 ZHANG Hang-wei DONG Hai-jun 《International Journal of Plant Engineering and Management》 2012年第3期160-168,共9页
It is illustrated that there exists an inflection circle on the linkage rigid body by the principle of relative motion. Confirmed methods of the inflection circle, curvature radius and curvature center of the point tr... It is illustrated that there exists an inflection circle on the linkage rigid body by the principle of relative motion. Confirmed methods of the inflection circle, curvature radius and curvature center of the point track on the linkage rigid body are given in the case of the different contact type of move instantaneous center line and static instantaneous center line. The regularity of distribution of curvature radius and curvature center of the point track is researched. The identification methods called determination parameters and auxiliary vertical line of the diameter and direction of the inflection circle in the four bar mechanism are pointed out. A design method of the crane hoisting mechanism is discussed in the end of this paper. 展开更多
关键词 link mechanism linkage point track instantaneous center line inflection circle determination parameters and auxiliary vertical line curvature radius curvature center distribution regularity the crane hoisting mechanism
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Analysis on Structural Control of Coal Distribution in the Northern Qaidam Basin,NW China 被引量:3
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作者 LIU Tianji WANG Tong ZHAN Wenfeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第3期690-696,共7页
The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coa... The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coalfield basement structures, features of the main faults, and the distribution of coal measures, this paper brings forward a scheme of coalfield tectonic divisional units and the definition of the coal-controlling structural styles in the northern Qaidam Basin. The structure control of the distribution of coal measures is further discussed. Several stages of regional tectonic activities since the Indosinian has led to the distribution of coal measures into the characteristics of zonation from the north to south and block from east to west. The results indicate that the structural deformations are the most intense in the front of the three uplifted belts, which are characterized by the combination of thrusts. The coal measures are uplifted to the shallow formations, and are easy to be exploited, but the scale of mines is small because of serious damages by the coal distribution. On the contrary, the stress and strain are weak in the three depressions, with the coal-controlling structural styles being mainly the thrust-fold and thrust-monocline combinations. The distribution of coals in the depressions is relatively stable. The shallower part of the depression will become the key areas for exploration and development of coal resources in the northern Qaidam Basin. 展开更多
关键词 northern Qaidam Basin tectonic units coal-controlling structural styles distribution regularity of coal measures
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Orderliness of Hydrocarbon Accumulation Distribution in Rift Basins of Eastern China 被引量:1
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作者 CAI Xiyuan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第3期779-787,共9页
The Cenozoic rift basins in eastern China show a clear temporal and spatial zonation and episodic tectonic evolution, which control their episodic hydrocarbon generation and zonal accumulation. In this paper, based on... The Cenozoic rift basins in eastern China show a clear temporal and spatial zonation and episodic tectonic evolution, which control their episodic hydrocarbon generation and zonal accumulation. In this paper, based on the study of depositional architecture, hydrocarbon migration system and dynamic evolution in the rift basins, combinations of hydrocarbon accumulation elements were analyzed using sequence stratigraphy. Hydrocarbon distribution in system tracts with different sequence orders was further studied. And we summarized stacking patterns and horizontal combination relationships for different types of reservoirs, such as lithological, tectonic-lithological, tectonic and stratigraphical reservoirs which can be observed from depression center to basin margin. The result reveals that various scales of pools exhibit significant distribution and evolution orderliness in different pool-forming units, i.e., depositional systems, plays and depressions. The regular distribution of various scales of pools is closely related to tectonic evolution and depositional filling in the rift basins. The result can be applied to the fine petroleum exploration in rift basins in eastern China. It will promote the scientific prediction and evaluation of reservoir types and their spatial distribution, lead to the active shifts of exploration targets in different zones, and thus support the stable progress of fine exploration in mature exploration areas. 展开更多
关键词 rift basin pathway system reservoir-forming element distribution regularity of hydrocarbon accumulation CENOZOIC
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Combination and distribution of reservoir space in complex carbonate rocks 被引量:2
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作者 Lun Zhao Shu-Qin Wang +4 位作者 Wen-Qi Zhao Man Luo Cheng-Gang Wang Hai-Li Cao Ling He 《Petroleum Science》 SCIE CAS CSCD 2016年第3期450-462,共13页
This paper discusses the reservoir space in carbonate rocks in terms of types,combination features,distribution regularity,and controlling factors,based on core observations and tests of the North Truva Oilfield,Caspi... This paper discusses the reservoir space in carbonate rocks in terms of types,combination features,distribution regularity,and controlling factors,based on core observations and tests of the North Truva Oilfield,Caspian Basin.According to the reservoir space combinations,carbonate reservoirs can be divided into four types,i.e.,pore,fracture-pore,pore-cavity-fracture,and pore-cavity.Formation and distribution of these reservoirs is strongly controlled by deposition,diagenesis,and tectonism.In evaporated platform and restricted platform facies,the reservoirs are predominately affected by meteoric fresh water leaching in the supergene-para-syngenetic period and by uplifting and erosion in the late stage,making both platform facies contain all the above-mentioned four types of reservoirs,with various pores,such as dissolved cavities and dissolved fractures,or structural fractures occasionally in favorable structural locations.In open platform facies,the reservoirs deposited continuously in deeper water,in an environment of alternative high-energy shoals(where pore-fracture-type reservoirs are dominant) and low-energy shoals(where pore reservoirs are dominant). 展开更多
关键词 Caspian Basin Carbonate rock of platform facies Reservoir space type Reservoir type Controlling factor distribution regularity
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Spatial Pressure Distribution of Cultivated Land and the Analysis of Food Safety in Kunming City,China
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作者 PENG Er-rui WANG Sui +3 位作者 LV Xia ZHANG Jian-sheng ZHANG Chuan HAO Li-sha 《Asian Agricultural Research》 2010年第2期53-56,共4页
The social and economical condition,cultivated land resources and general situation of grain production of research area are introduced.According to relevant data of cultivated land of Kunming City in 2006,taking the ... The social and economical condition,cultivated land resources and general situation of grain production of research area are introduced.According to relevant data of cultivated land of Kunming City in 2006,taking the minimum per capita cultivated land and index model of cultivated land pressure,and combining with two conditions of per capita grain demand which are 300 kg and 400 kg,the comparative research method was used to calculate and analyze the minimum per capita cultivated land and index model of cultivated land pressure.The results show that when per capita grain demand-Gr is 300 kg,the per capita cultivated land in Kunming City has regional differences,reflects different regular patterns of spatial distribution,and presents obvious and typical radial distribution.Urban area of Kunming has the lowest point and be taken as the center,per capita cultivated land decreases progressively from suburban to the periphery;when per capita grain demand-Gr is 400 kg,under the same consumption level,cultivated land pressures of each county in Kunming City are different,and so are the driven factors;when per capita grain demand-Gr is 300 kg or 400 kg,the indexes of cultivated land pressure in Kunming are all greater than 1,cultivated land pressure is enormous,the indexes of cultivated land pressure of each county(district) have two conditions-greater than 1 and less than 2,and the reasons differ from one another.Combining with the spatial distribution characteristics of the cultivated land and food and the situation of industrial development,the countermeasures and suggestions are put forwarded to make full use of back-up cultivated land,to plan the distribution of industrial structure in each county(district) of Kunming City as a whole,to dispose cultivated land resources reasonably and so on. 展开更多
关键词 Food safety Index model of cultivated land pressure Minimum per capita cultivated land regular pattern of spatial distribution China
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Key factor analysis and model establishment of variation of rock face temperature in a deep open-pit mine 被引量:5
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作者 WANG Yuan DU Cui-feng +1 位作者 JIN Wen-bo WANG Pu-yu 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第7期1786-1798,共13页
In recent years, with the increase of the depth of open-pit mining, the pollution level has been on the rise due to harmful gases and dust occurring in the process of mining. In order to accelerate the diffusion of th... In recent years, with the increase of the depth of open-pit mining, the pollution level has been on the rise due to harmful gases and dust occurring in the process of mining. In order to accelerate the diffusion of these air pollutants, the distributed regularity of the rock face temperature which is directly related to the air ventilation in deep open-pit mines should be studied. Here, we establish the key factors influencing the rock face temperature in a deep open-pit mine. We also present an empirical model of the rock face temperature variation in the deep open-pit mine, of which the performance is interestingly high compared with that of the field test. This study lays a foundation to study the ventilation thermodynamic theory in the deep open-pit mine, which is of great importance for theoretical studies and engineering applications of solving air pollution problem in deep open-pit mines. 展开更多
关键词 deep open-pit mine distributed regularity of rock face temperature dimensional analysis nonlinear regression analysis
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Distribution regularity of downwash airflow under rotors of agricultural UAV for plant protection 被引量:2
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作者 Xin Liu Wei Zhang +2 位作者 Haiba Fu Xiaoming Fu Liqiang Qi 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2021年第3期46-57,共12页
In the plant protection spray operation of UAVs,the process of droplet from formation to sedimentation target is affected by airflow,easy to form uneven deposition.Accurately description of rotor downwash flow field,c... In the plant protection spray operation of UAVs,the process of droplet from formation to sedimentation target is affected by airflow,easy to form uneven deposition.Accurately description of rotor downwash flow field,clarification of velocity vector distribution at different heights of the UAV rotor flow field,simulation of the flow field with high precision,which are the prerequisites for accurately analyzing the droplet deposition distribution in rotor downwash flow field.Based on CFD method,the detail of rotor flow field was numerically calculated.Taking LTH-100 single-rotor agricultural UAV as the research object,the three-dimensional solid model of UAV was established,the Reynolds average N-S equation was used as the control equation and the RNGκ-εas the turbulence model to simulate the flow field of UAV in hover and lateral wind conditions,the wind velocity distribution at different altitudes of rotor downwash flow field was studied.The simulation results of the hover state showed that:In the flow field,the peak velocity appears in a circular distribution below the distal axis of the rotor.With the decrease of height,the peak velocity distribution area showed a tendency to expand gradually after small shrinkage;When the distance from the rotor was not more than 1.5 m,the downwash flow field presented an axisymmetric distribution based on the rotor axis,and the variation rate of velocity in the peak velocity was basically the same,turbulence in downwash flow field made the flow field more complex when the distance from rotor was larger than 2.0 m.On this basis,the optimal flight altitude of UAV is 1.5 m.Wind velocity test of the flow field was carried out on a rotor test bench,wind velocities at four altitudes of 0.5 m,1.0 m,1.5 m and 2.0 m were measured to verify the coincidence between the simulated and measured values.The test results showed that:the relative error between the measured and simulated values at four measurement heights were between 0.382-0.524,and the overall average relative errors was 0.430,which verified the confidence level of simulated values for measured values.When the lateral wind velocity was 3 m/s,4 m/s and 5 m/s,the simulation results showed that:The distribution trend of airflow velocity at the same altitude in lateral-wind flow field with different wind speeds was similar;When the lateral wind speed was 5 m/s,the coupling field formed by the lateral wind and rotor airflow cannot reach the height of 2 m below the rotor.The results of this study can provide more accurate environmental conditions for theoretical analysis of droplet deposition regularity in the flow field,and also provide methodological guidance for the related research on rotor flow field of multi-rotor UAV. 展开更多
关键词 aviation plant protection downwash flow field distribution regularity numerical simulation single-rotor UAV
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Study on copper complexing ligand concentrations in several China's coastal waters
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作者 GONG Haidong ZHANG Zhengbin LIU Chunying LIU Liansheng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第1期64-77,共14页
Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regulari... Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows: Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complex- ing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China's coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly. 展开更多
关键词 copper complexing ligand concentrations China' s coastal waters distribution regularity RELATIONSHIP
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多区域互联电-气耦合系统分散协调分布鲁棒优化调度 被引量:15
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作者 张亚超 谢仕炜 朱蜀 《电力系统自动化》 EI CSCD 北大核心 2022年第19期31-42,共12页
电力、天然气等异质能流的深度耦合和互补协调,使得面向可再生能源消纳的多区域互联电-气耦合系统成为未来能源互联网发展的重要方向。在此背景下,综合考虑风电出力、燃气机组耗气量及配电网间联络线交互能流等多重不确定因素,提出基于... 电力、天然气等异质能流的深度耦合和互补协调,使得面向可再生能源消纳的多区域互联电-气耦合系统成为未来能源互联网发展的重要方向。在此背景下,综合考虑风电出力、燃气机组耗气量及配电网间联络线交互能流等多重不确定因素,提出基于多主体自治决策的多区域综合能源系统分散协调优化调度框架。首先,针对配电网,建立基于风电出力模糊集的分布鲁棒优化调度模型,并结合对偶理论和线性决策规则将该半无限优化问题转化为线性规划问题。其次,建立天然气网的二阶锥规划模型,并根据燃气机组耗气量不确定集检验其在配电网中备用配置的可行性。然后,分析多区域互联系统中能量流的解耦机制,采用一种基于平行正则化的交替方向乘子法对多区域电-气耦合系统分散协调调度模型进行求解。最后,通过算例验证了所提模型及求解方法的有效性和实用性。 展开更多
关键词 多区域电-气耦合系统 综合能源系统 多重不确定性 分布鲁棒优化 分散协调 平行正则化
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WIND SPEED DISTRIBUTION REGULARITY AND WIND REDUCTION EFFECT OF SHELTER NET
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作者 张翼 宋兆民 卫林 《Science China Chemistry》 SCIE EI CAS 1987年第11期1211-1222,共12页
Wind speed distribution regularities in a shelter mesh (S. M.) have been deduced from the wind speed distribution in the sheltered area of a single shelter beh (S. B.).The components of a wind vector in a mesh follow ... Wind speed distribution regularities in a shelter mesh (S. M.) have been deduced from the wind speed distribution in the sheltered area of a single shelter beh (S. B.).The components of a wind vector in a mesh follow the error function distribution model or the logarithmic model of 2-variable power function.The wind vector itself follows the vector composition model of these models.We can calculate the wind speed distribution and wind reduction effect of a mesh under the conditions of any shelter-belt characteristics, any size and shape of a mesh and any wind inclination angle with this model. The results of our field model experiment are in better agreement with the theoretically calculated results. 展开更多
关键词 WIND SPEED distribution regularITY AND WIND REDUCTION EFFECT OF SHELTER NET
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