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Spatiotemporal heterogeneity of phytoplankton diversity and its relation to water environmental factors in the southern waters of Miaodao Archipelago,China 被引量:3
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作者 ZHENG Wei LI Fen +8 位作者 SHI Honghua HUO Yuanzi LI Yan CHI Yuan GUO Zhen WANG Yuanyuan SHEN Chengcheng LIU Jian QIAO Mingyang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第2期46-55,共10页
To study the water quality influenced by the anthropogenic activities and its impact on the phytoplankton diversity in the surface waters of Miaodao Archipelago, the spatiotemporal variations in phytoplankton communit... To study the water quality influenced by the anthropogenic activities and its impact on the phytoplankton diversity in the surface waters of Miaodao Archipelago, the spatiotemporal variations in phytoplankton communities and the environmental properties of the surface waters surrounding the Five Southern Islands of Miaodao Archipelago were investigated, based on seasonal field survey conducted from November 2012 to August 2013. During the survey, a total of 109 phytoplankton species from 3 groups were identified in the southern waters of Miaodao Archipelago, of which 77 were diatoms, 29 were dinoflagellates, and 3 were chrysophytes. Species number was higher in winter(73), moderate in autumn(70), but lower in summer(31) and spring(27). The species richness index in autumn(5.92) and winter(4.28) was higher than that in summer(2.83) and spring(1.41).The Shannon-Wiener diversity index was high in autumn(2.82), followed by winter(1.99) and summer(1.92), and low in spring(0.07). The species evenness index in autumn(0.46) and summer(0.39) was higher than that in winter(0.32) and spring(0.02). On the basis of principal component analysis(PCA) and redundancy analysis(RDA), we found that dissolved inorganic nitrogen(DIN) and chemical oxygen demand(COD) in spring, COD in summer, p H in autumn, and salinity and oil pollutant in winter, respectively, showed the strongest association with the distribution of phytoplankton diversity. The spatial heterogeneity of the southern waters of Miaodao Archipelago was quite obvious, and three zones, i.e., northeastern, southwestern and inter-island water area, were identified by cluster analysis(CA) based on key environmental variables. 展开更多
关键词 Miaodao Archipelago environmental factors spatial distribution phytoplankton statistical analysis
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Distribution of chlorophyll a and some ecological factors in the Daya Bay
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作者 Huang LiangminSouth Clam Sea Institute of Oceanology, Acodemia sinica, Guangzhou, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1991年第2期311-316,共6页
The marine environment, productivity and potential biotic resources in the waters of the Daya Bay were investigated by South China Sea Institute of Oceanology, Academia Sinica from 1984 to 1986. The present paper deal... The marine environment, productivity and potential biotic resources in the waters of the Daya Bay were investigated by South China Sea Institute of Oceanology, Academia Sinica from 1984 to 1986. The present paper deals mainly with the annual variation and distribution characteristics in chlorophyll a and with some of the ecological factors involved in chlorophyll distribution within the bay. Correlation models are established and discussed. The results could be helpful for further probing into ecosystem and for the exploitation-utilization of aquatic resources in this region. 展开更多
关键词 Distribution of chlorophyll a and some ecological factors in the Daya Bay
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Development of Features for Early Detection of Defects and Assessment of Bridge Decks
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作者 Ahmed Silik Xiaodong Wang +10 位作者 Chenyue Mei Xiaolei Jin Xudong Zhou Wei Zhou Congning Chen Weixing Hong Jiawei Li Mingjie Mao Yuhan Liu Mohammad Noori Wael A.Altabey 《Structural Durability & Health Monitoring》 EI 2023年第4期257-281,共25页
Damage detection is an important area with growing interest in mechanical and structural engineering.One of the critical issues in damage detection is how to determine indices sensitive to the structural damage and in... Damage detection is an important area with growing interest in mechanical and structural engineering.One of the critical issues in damage detection is how to determine indices sensitive to the structural damage and insensitive to the surrounding environmental variations.Current damage identification indices commonly focus on structural dynamic characteristics such as natural frequencies,mode shapes,and frequency responses.This study aimed at developing a technique based on energy Curvature Difference,power spectrum density,correlation-based index,load distribution factor,and neutral axis shift to assess the bridge deck condition.In addition to tracking energy and frequency over time using wavelet packet transform,in order to further demonstrate the feasibility and validity of the proposed technique for bridge condition assessment,experimental strain data measured from two stages of a bridge in the different intervals were used.The comparative analysis results of the bridge in first and second stage show changes in the proposed feature values.It is concluded,these changes in the values of the proposed features can be used to assess the bridge deck performance. 展开更多
关键词 Structural health monitoring strain monitoring distribution factor wavelet packet transform
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Tissue Penetration of Capecitabine and Its Tumor-Selective Delivery of 5-FU in Advanced Breast Cancer Patients 被引量:1
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作者 叶敏 朱珠 +2 位作者 付强 孙强 茅枫 《Journal of Chinese Pharmaceutical Sciences》 CAS 2006年第3期131-138,共8页
Aim To measure the penetration of capecitabine from the plasma into tissue and to investigate the pharmacokinetics of its metabolizing into fluorouracil (5-FU) in patients with advanced breast cancer. Methods Twenty... Aim To measure the penetration of capecitabine from the plasma into tissue and to investigate the pharmacokinetics of its metabolizing into fluorouracil (5-FU) in patients with advanced breast cancer. Methods Twenty-seven patients with breast cancer received repeated doses of 1 255 mg·m^-2 of capecitabine twice daily for 7 d. Blood, tumor, and adjacent healthy tissue samples were collected. The concentrations of capecitabine and its metabolite 5-FU were determined by HPLC. The concentration-time profiles of capecitabine and 5-FU were fitted by pharmacokinetic model. The tissue distribution factors for capecitabine and 5-FU, and the AUC ratios of 5-FU to capecitabine in plasma, tumor or adjacent healthy tissue, were calculated with pharmacokinetic parameters, respectively. Results The Ka of capecitabine was 1.17 h^-1 in plasma, 0. 46 h^-1 in tumor tissue, and 0. 61 h^-1 in healthy tissue. The AUCs of capecitabine were 2. 557 1 μg·mL^-1 ·h, 1. 629 2 μg·g^-1·h and 2. 085 0 μg·g^-1· h, and T1/2 was 0. 782 3 h, 1. 528 1 h and 1. 289 6 h in plasma, tumor, and healthy tissue, respectively. The AUCs of 5-FU were 0.418 7 μg·mL^-1 h, 1.671 7 μg·g^-1·h and 1.020 8 μg·g^-1·h; the T1/2 was 0. 631 3 h ,1.204 1 h and 1.031 2 h in plasma, tumor, and healthy tissue, respectively. The tissue distribution factors of capecitabine were 0. 637 1 in tumor (AUCcap-Tumor/AUCcap-plasma) and 0. 851 4 in healthy tissue (AUCcap-HT/AUCcap-plasma . The tissue distribution factors of 5-FU were 3. 992 6 in tumor (AUC5-FU-Tumor/AUC5-FU-plasma) and 2. 438 0 in healthy tissue (AUC5-FU-HT/AUC5-FU-plasma). The AUC ratios of 5-FU to capecitabine were 0. 1637, 1. 0261, and 0. 489 5 in plasma, tumor, and healthy tissue, respectively. Conclusion The simulation curves for the disposition of capecitabine and its metabolite 5-FU in plasma and tissue basically describe the activation process of capecitabine metabolizing to 5-FU and 5-FU elimination. There are similar distributions for capecitabine in plasma, tumor, and healthy tissue. The exposure of 5-FU in tumor was found to be 3. 992 6 times greater than that in plasma and 2. 438 0 times greater than that in healthy tissue. Capecitabine may metabolize preferentially to 5- FU in tumor tissue after oral administration. 展开更多
关键词 CAPECITABINE PHARMACOKINETICS 5-FU tissue distribution factors
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Loaded multi-tooth contact analysis and calculation for contact stress of face-gear drive with spur involute pinion 被引量:9
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作者 唐进元 刘艳平 《Journal of Central South University》 SCIE EI CAS 2013年第2期354-362,共9页
The analytical method based on "Hertz theory on normal contact of elastic solids" and the numerical method based on finite element method (FEM) calculating the contact stress of face-gear drive with spur inv... The analytical method based on "Hertz theory on normal contact of elastic solids" and the numerical method based on finite element method (FEM) calculating the contact stress of face-gear drive with spur involute pinion were introduced, and their relative errors are below 10%, except edge contact, which turns out that these two methods can compute contact stress of face-gear drive correctly and effectively. An agreement of the localized bearing contact stress is gotten for these two methods, making sure that the calculation results of FEM are reliable. The loaded meshing simulations of multi-tooth FEM model were developed, and the determination of the transmission error and the maximal load distribution factor of face-gear drive under torques were given. A formula for the maximal load distribution factor was proposed. By introducing the maximal load distribution factor in multi-tooth contact zone, a method for calculating the maximal contact stress in multi-tooth contact can be given. Compared to FEM, the results of these formulae are proved to be reliable, and the relative errors are below 10%. 展开更多
关键词 face gear contact stress finite element method loaded meshing simulation load distribution factor multi-tooth contact
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A novel SVPWM strategy considering neutral-point potential balancing for three-level NPC inverter 被引量:2
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作者 陈国呈 宋文祥 +1 位作者 武慧 孙承波 《Journal of Shanghai University(English Edition)》 CAS 2006年第1期53-58,共6页
This paper proposes a novel SVPWM (space vector pulse width modulation) strategy for the three-level neutral-point-clamped voltage source inverter, based on the particular disposition of all the redundant voltage ve... This paper proposes a novel SVPWM (space vector pulse width modulation) strategy for the three-level neutral-point-clamped voltage source inverter, based on the particular disposition of all the redundant voltage vectors. The new modulation approach shows superior performance for harmonic voltage and balancing control of neutral-point potential compared to the popular eight-stage centered SVPWM. It realizes suppression of inverter neutral-point potential variation by accurately modifying redundant factor of small vectors pairs, only requiring information of DC-link capacitor voltages and three-phase load currents. This is convenient to apply and is compatible of digital computer realization. Feasibility of the proposed control approach is verified by simulation and experimental results. 展开更多
关键词 neutral-point-clamped inverter neutral-point potential control SVPWM distribution factor.
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Subcellular Cd accumulation characteristic in root cell wall of rice cultivars with different sensitivities to Cd stress in soil 被引量:14
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作者 LIU Bin CHEN Li +5 位作者 CHEN Shi-bao LI Ning ZHENG Han JIN Ke PANG Huan-cheng MA Yi-bing 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第9期2114-2122,共9页
The variations of grain cadmiun(Cd) concentrations, translocation factors(TFs) of Cd from roots to shoots/grains of six rice cultivars, characterized with different Cd-sensitivities in polluted soil were studied, ... The variations of grain cadmiun(Cd) concentrations, translocation factors(TFs) of Cd from roots to shoots/grains of six rice cultivars, characterized with different Cd-sensitivities in polluted soil were studied, the selected rice cultivars were Xiangzao 17(R1), Jiayu 211(R2), Xiangzao 42(R3), Zhuliangyou 312(R4), Zhuliangyou 611(R5), and Jinyou 463(R6), respectively. The Cd subcellular distribution and Cd binding characteristics on subcellular fractions of rice root cell wall(CW) were further investigated. The results showed that the rice grain Cd contents varied significantly, with a maximum variation of 47.0% among the cultivars, the largest grain Cd content was observed with cultivar R1(Cd-sensitivity cultivar) and the smallest with R5(Cd-tolerance cultivar). The translocation factors of Cd from roots to shoots(TF_(shoot)) and roots to grains(TF_(grain)) varied greatly among the cultivars. In general, the TFgrain of the cultivars followed the order of R1〉R2〉R3〉R4〉 R6-R5. The Cd concentration(mg kg^(–1) FW) in the fraction of root CW, the fraction of cell wall removing pectin(CW-P) and the fraction of cell wall removing pectin and hemicellulose(CW-P-HC) of the cultivars generally followed the order of CW-P〉CW〉CWP-HC; the ratios of Cd concentration(mg kg–1 FW) in the fraction of CW-P to that of CW were mostly more than 1.10, while the ratios of Cd concentration in the fraction of CW-P-HC to that of CW were mostly less than 0.60, indicating that Cd was mainly stored in the hemicellulose of the root CW. The ratios of Cd of CW-P-HC to CW generally followed the descending order of R1~R2〉R3〉R4〉R5~R6 for the cultivars, which implied that hemicellulose is probably the main subcellular pool for transferring Cd into rice grain, and it restrains the translocation of Cd from shoot to the grain, especially for the Cd-tolerance cultivars(R5 and R6), the compartmentation of more Cd in hemicellulose in root CW is probably one of the main mechanisms for Cd tolerance of rice cultivars. 展开更多
关键词 cadmium rice cultivar(Oryza sativa) translocation factor subcellular distribution
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THEORETICAL INVESTIGATION ON STATE OF LOAD DISTRIBUTION AMONG CONTACT BEARINGS OF DOUBLE CIRCULAR ARC HELICAL GEARS 被引量:3
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作者 Wu Baolin (Gear Research Institute, Taiyuan University of Technology) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2000年第2期108-113,共6页
A dynamic analysis approcach to investigate the state of load distribution among contact bearings of double circular are belical gears is proposed and a computer program is developed for calculating the factor of iced... A dynamic analysis approcach to investigate the state of load distribution among contact bearings of double circular are belical gears is proposed and a computer program is developed for calculating the factor of iced distribution based on the theory of W-N gears. The changing situations of load distribution among contact bearings of the gears influenced by main issues are analyzed by a series of parametric studies. 展开更多
关键词 Double circular are belical gears State of load distribution factor of load distribution Dynamic analysis
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Sensitivity of runoff to climatic variability in the northern and southern slopes of the Middle Tianshan Mountains,China 被引量:4
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作者 ZHANG Feiyun BAI Lei +1 位作者 LI Lanhai WANG Quan 《Journal of Arid Land》 SCIE CSCD 2016年第5期681-693,共13页
Temperature and precipitation play an important role in the distribution of intra-annual runoff by influencing the timing and contribution of different water sources.In the northern and southern slopes of the Middle T... Temperature and precipitation play an important role in the distribution of intra-annual runoff by influencing the timing and contribution of different water sources.In the northern and southern slopes of the Middle Tianshan Mountains in China,the water sources of rivers are similar;however,the proportion and dominance of water sources contributing to runoff are different.Using the Manas River watershed in the northern slope and the Kaidu River watershed in the southern slope of the Middle Tianshan Mountains as case studies,we investigated the changes in annual runoff under climate change.A modified hydrological model was used to simulate runoff in the Kaidu River and Manas River watersheds.The results indicated that runoff was sensitive to precipitation variation in the southern slope and to temperature variation in the northern slope of the Middle Tianshan Mountains.Variations in temperature and precipitation substantially influence annual and seasonal runoff.An increase in temperature did not influence the volume of spring runoff;but it resulted in earlier spring peaks with higher levels of peak flow.Damages caused by spring peak flow from both slopes of the Middle Tianshan Mountains should be given more attention in future studies. 展开更多
关键词 annual runoff distribution climatic factors Kaidu River watershed Manas River watershed
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Study on spatial and temporal distribution of planktonic amphipoda in the East China Sea 被引量:4
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作者 JIANGMei WANGYunlong YUANQi CHENYaqu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2004年第2期329-336,共8页
Quantitative distribution of planktonic amphipoda in the East China Sea is analyzed and the relation with environmental factors and mackerel and scad fishing grounds is studied. The result shows that the characteristi... Quantitative distribution of planktonic amphipoda in the East China Sea is analyzed and the relation with environmental factors and mackerel and scad fishing grounds is studied. The result shows that the characteristic of biomass is great seasonal and interannual variety during the passing three decades. The distribution of planktonic amphipoda basically reflects the movement, decay and intensification of the different water systems in the survey area. 展开更多
关键词 East China Sea amphipoda biomass spatial and temporal distribution environmental factors mackerel and scad fishing grounds
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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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Surface Barrier Models of ZnO
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作者 MAYong WANGWan-lu +1 位作者 LIAOKe-jun KONGChun-yang 《Semiconductor Photonics and Technology》 CAS 2004年第1期31-34,37,共5页
For a low surface barrier, the energy band, barrier height and width of the space charge region at the surface of relatively large grains of ZnO are presented analytically on condition that the electron distribution o... For a low surface barrier, the energy band, barrier height and width of the space charge region at the surface of relatively large grains of ZnO are presented analytically on condition that the electron distribution obeys the Boltzmann statistics. It is shown that the temperature in the space charge distribution factor has an important effect on the energy band, barrier height and width of the space charge region. The depletion approximation is a model in which the temperature in the space charge distribution factor is zero. Our results are better than the depletion approximation. 展开更多
关键词 ZNO Space-charge distribution factor Energy band Surface barrier
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Parametric message passing-based relative navigation in joint tactical information distribution system 被引量:1
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作者 Nan Wu Bin Li +2 位作者 Hua Wang Liang Hou Jingming Kuang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第1期81-89,共9页
Relative navigation is a key feature in the joint tactical information distribution system(JTIDS).A parametric message passing algorithm based on factor graph is proposed to perform relative navigation in JTIDS.Firs... Relative navigation is a key feature in the joint tactical information distribution system(JTIDS).A parametric message passing algorithm based on factor graph is proposed to perform relative navigation in JTIDS.First of all,the joint posterior distribution of all the terminals' positions is represented by factor graph.Because of the nonlinearity between the positions and time-of-arrival(TOA) measurement,messages cannot be obtained in closed forms by directly using the sum-product algorithm on factor graph.To this end,the Euclidean norm is approximated by Taylor expansion.Then,all the messages on the factor graph can be derived in Gaussian forms,which enables the terminals to transmit means and covariances.Finally,the impact of major error sources on the navigation performance are evaluated by Monte Carlo simulations,e.g.,range measurement noise,priors of position uncertainty and velocity noise.Results show that the proposed algorithm outperforms the extended Kalman filter and cooperative extended Kalman filter in both static and mobile scenarios of the JTIDS. 展开更多
关键词 joint tactical information distribution system(JTIDS) relative navigation parametric message passing factor graph.
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Is China’s Economic Growth Profitled or Wage-led?——A Theoretical Inquiry and Empirical Study on the Impact of Labor Share on Growth
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作者 刘盾 施祖麟 林玳玳 《China Economist》 2015年第3期83-99,共17页
The paper makes a comparative review and evaluation of different theories on impacts of the distribution of labor and capital income on economic growth as well as criticism of the mainstream theories and suggests usin... The paper makes a comparative review and evaluation of different theories on impacts of the distribution of labor and capital income on economic growth as well as criticism of the mainstream theories and suggests using Bhaduri-Marglin model as the theoretical basis for relevant research. By formulating the econometric model and analyzing time series data from 1978 to 2012, the paper makes an empirical research into the impact of labor share on economic growth in China. It has discovered that the positive effect of labor share on consumption demand growth in China outweighs its negative effect on investment and net export growth, concluding that growth in China is wage-led at present. That may mean that (1) increasing labor share promotes growth and the goals of equality and efficiency supports each other," (2) the demand and optimizing structure" lies in regulation tools. key to "stabilizing growth, expanding domestic establishing a set of pro-labor institution and 展开更多
关键词 labor share labor-capital distribution factors income distribution economicgrowth wage-led growth effective demand
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Chain Rule for Extracting Resilience Procurement Costs from Locational Marginal Prices
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作者 Yifei Wang Tong Zhu +2 位作者 Tiancong Chen Mohammad Shahidehpour Qingshan Xu 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第3期1342-1355,共14页
Power system resilience procurement costs in N-k contingencies have gained more prominence as number of extreme events continues to increase.A chain rule is presented in this paper for extracting resilience procuremen... Power system resilience procurement costs in N-k contingencies have gained more prominence as number of extreme events continues to increase.A chain rule is presented in this paper for extracting resilience procurement costs from a fully decomposed locational marginal price(LMP)model.First,power transfer distribution factor(PTDF)matrices with AC power flow(i.e.,AC-PTDF)are determined.AC-PTDF and AC-LODF(line outage distribution factor)equations are derived for N-k contingencies and a fully decomposed LMP model is developed where generation and transmission security components are established for specific contingencies.Furthermore,resilience procurement costs can be measured at different buses for the proposed security components.Impact of N-k contingencies on resilience procurement costs at specific buses can be determined as proposed security components will gain more insight for resilience procurement in power systems.The modified IEEE 6-bus and 118-bus systems are adopted to verify effectiveness of the proposed resilience procurement method. 展开更多
关键词 Line outage distribution factors locational marginal price power system resilience power transfer distribution factor security components
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Influence of fuel mass load,oxygen supply and burning rate on emission factor and size distribution of carbonaceous particulate matter from indoor corn straw burning 被引量:4
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作者 Guofeng Shen Miao Xue +13 位作者 Siye Wei Yuanchen Chen Bin Wang Rong Wang Huizhong Shen Wei Li Yanyan Zhang Ye Huang Han Chen Wen Wei Qiuyue Zhao Bin Li Haisuo Wu Shu Tao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2013年第3期511-519,共9页
The uncertainty in emission estimation is strongly associated with the variation in emission factor (EF),which could be influenced by a variety of factors such as fuel properties,stove type,fire management and even ... The uncertainty in emission estimation is strongly associated with the variation in emission factor (EF),which could be influenced by a variety of factors such as fuel properties,stove type,fire management and even methods used in measurements.The impacts of these factors are complicated and often interact with each other.Controlled burning experiments were conducted to investigate the influences of fuel mass load,air supply and burning rate on the emissions and size distributions of carbonaceous particulate matter (PM) from indoor corn straw burning in a cooking stove.The results showed that the EFs of PM (EFPM),organic carbon (EFOC) and elemental carbon (EFEC) were independent of the fuel mass load.The differences among them under different burning rates or air supply amounts were also found to be insignificant (p 〉 0.05) in the tested circumstances.PM from the indoor corn straw burning was dominated by fine PM with diameter less than 2.1 μm,contributing 86.4%±3.9% of the total.The size distribution of PM was influenced by the burning rate and air supply conditions.On average,EF PM,EF OC and EF EC for corn straw burned in a residential cooking stove were (3.84±1.02),(0.846±0.895) and (0.391±0.350) g/kg,respectively.EF PM,EF OC and EF EC were found to be positively correlated with each other (p 〈 0.05),but they were not significantly correlated with the EF of co-emitted CO,suggesting that special attention should be paid to the use of CO as a surrogate for other incomplete combustion pollutants. 展开更多
关键词 indoor corn straw burning emission factor size distribution influencing factor
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Robust N−k Security-constrained Optimal Power Flow Incorporating Preventive and Corrective Generation Dispatch to Improve Power System Reliability
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作者 Liping Huang Chun Sing Lai +3 位作者 Zhuoli Zhao Guangya Yang Bang Zhong Loi Lei Lai 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2023年第1期351-364,共14页
As extreme weather events have become more frequent in recent years,improving the resilience and reliability of power systems has become an important area of concern.In this paper,a robust preventive-corrective securi... As extreme weather events have become more frequent in recent years,improving the resilience and reliability of power systems has become an important area of concern.In this paper,a robust preventive-corrective security-constrained optimal power flow(RO-PCSCOPF)model is proposed to improve power system reliability under N−k outages.Both the short-term emergency limit(STL)and the long-term operating limit(LTL)of the post-contingency power flow on the branch are considered.Compared with the existing robust corrective SCOPF model that only considers STL or LTL,the proposed ROPCSCOPF model can achieve a more reliable generation dispatch solution.In addition,this paper also summarizes and compares the solution methods for solving the N−k SCOPF problem.The computational efficiency of the classical Benders decomposition(BD)method,robust optimization(RO)method,and line outage distribution factor(LODF)method are investigated on the IEEE 24-bus Reliability Test System and 118-bus system.Simulation results show that the BD method has the worst computation performance.The RO method and the LODF method have comparable performance.However,the LODF method can only be used for the preventive SCOPF and not for the corrective SCOPF.The RO method can be used for both. 展开更多
关键词 Benders cut bender decomposition line outage distribution factor N−k security criterion optimal power flow power system reliability RESILIENCE robust optimization
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Spatial and temporal variation of haze in China from 1961 to 2012 被引量:13
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作者 Rui Han Shuxiao Wang +4 位作者 Wenhai Shen Jiandong Wang Kang Wu Zhihua Ren Mingnong Feng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第8期134-146,共13页
The purpose of this study is to analyze the climatic characteristics and long-term spatial and temporal variations of haze occurrence in China. The impact factors of haze trends are also discussed. Meteorological data... The purpose of this study is to analyze the climatic characteristics and long-term spatial and temporal variations of haze occurrence in China. The impact factors of haze trends are also discussed. Meteorological data from 1961 to 2012 and daily PM10 concentrations from2003 to 2012 were employed in this study. The results indicate that the annual-average hazy days at all stations have been increasing rapidly from 4 days in 1961 to 18 days in 2012. The maximum number of haze days occur in winter(41.1%) while the minimum occur in summer(10.4%). During 1961-2012, the high occurrence areas of haze shifted from central to south and east regions of China. The Beijing-Tianjin-Hebei(Jing-Jin-Ji) region, Shanxi,Shaanxi, and Henan Province are the high occurrence areas for haze, while the Yangtze River Delta(YRD) and the Pearl River Delta(PRD) have become regions with high haze occurrences in the last 25 years. Temperature and pressure are positively correlated with the number of haze days. However, wind, relative humidity, precipitation, and sunshine duration are negatively correlated with the number of haze days. The key meteorological factors affecting the formation and dissipation of haze vary for high and low altitudes, and are closely related to anthropogenic activities. In recent years, anthropogenic activities have played a more important role in haze occurrences compared with meteorological factors. 展开更多
关键词 China Haze Spatial distribution Interannual trend Meteorological factors Anthropogenic activities
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Development of the applicability of simplified Henry’s method for skewed multicell box-girder bridges under traffic loading conditions 被引量:1
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作者 Iman MOHSENI A.R.Khalim RASHID 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2012年第12期915-925,共11页
Concrete precast multicell box-girder(MCB) bridges combine aesthetics with torsional stiffness perfectly.Previous analytical studies indicate that currently available specifications are unable to consider the effect o... Concrete precast multicell box-girder(MCB) bridges combine aesthetics with torsional stiffness perfectly.Previous analytical studies indicate that currently available specifications are unable to consider the effect of the twisting moment(torsional moment) on bridge actions.In straight bridges the effect of torsion is negligible and the transverse reinforced design is governed by other requirements.However,in the case of skewed bridges the effect of the twisting moment should be considered.Therefore,an in-depth study was performed on 90 concrete MCB bridges with skew angles ranging from 0° to 60°.For each girder the bridge actions were determined under the American Association of State Highway and Transportation Officials(AASHTO) live load conditions.The analytical results show that torsional stiffness and live load positions greatly affected the bridges' responses.In addition,based on a statistical analysis of the obtained results,several skew correction factors are proposed to improve the precision of the simplified Henry's method,which is widely used by bridge engineers to predict bridge actions.The relationship between the bending moment and secondary moments was also investigated and it was concluded that all secondary actions increase with an increase in skewness. 展开更多
关键词 Distribution factor Live loads Skewed bridges Grillage analysis
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Analysis of Rolling Pressure in Asymmetrical Rolling Process by Slab Method 被引量:13
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作者 TIAN Yong GUO Yan-hui WANG Zhao-dong WANG Guo-dong 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2009年第4期22-26,38,共6页
The plane strain asymmetrical rolling was analyzed using slab method. The contact arc was replaced by parabola, and the constant surface friction status was adopted during the analysis. The deformation area was divide... The plane strain asymmetrical rolling was analyzed using slab method. The contact arc was replaced by parabola, and the constant surface friction status was adopted during the analysis. The deformation area was divided into three zones according to the direction of the friction. Then, the three zones were studied, respectively. A rolling force model and a rolling torque model were developed based on the analysis, and they were used to analyze the influ- ence of asymmetrical rolling factors on deformation area and unit pressure if they had good precision which was determined by comparing the calculated results with the measured ones. 展开更多
关键词 asymmetrical rolling slab method asymmetrical factor specific pressure distribution
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