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A New Research about Pion Parton Distribution Function 被引量:1
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作者 楼立洋 阮建红 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第5期31-34,共4页
A new fit of the pion parton distribution functions is provided. Only valence quark distributions are used at a low evolution scale and are evolved with the modified Dokshitzer- Gribov-Lipatov-Altarelli-Parisi equatio... A new fit of the pion parton distribution functions is provided. Only valence quark distributions are used at a low evolution scale and are evolved with the modified Dokshitzer- Gribov-Lipatov-Altarelli-Parisi equation which is briefly introduced in this work, and the sea quark and gluon distributions are only generated by the quantum chromodynamics processes. We find that the patton distributions can explain the pion-nucleon experiments data well, and it can also be compared with the data from the leading neutron data of experiments at HERA. The momentum distributions among the partons are discussed and our results are consistent with some models. 展开更多
关键词 QCD A new Research about Pion Parton distribution Function GRS AQM
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MEASUREMENTS OF PARTICLE NUMBER SIZE DISTRIBUTIONS AND NEW PARTICLE FORMATION EVENTS DURING WINTER IN THE PEARL RIVER DELTA REGION,CHINA 被引量:1
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作者 谭浩波 银燕 +6 位作者 李菲 刘显通 陈柏纬 邓涛 邓雪娇 万齐林 吴兑 《Journal of Tropical Meteorology》 SCIE 2016年第2期191-199,共9页
Particle number size distribution(PNSD) between 10 nm and 20 μm were measured in the Pearl River Delta(PRD) region in winter 2011.The average particle number concentration of the nucleation mode(10-20 nm),Aitken mode... Particle number size distribution(PNSD) between 10 nm and 20 μm were measured in the Pearl River Delta(PRD) region in winter 2011.The average particle number concentration of the nucleation mode(10-20 nm),Aitken mode(20-100 nm),accumulation mode(100 nm-1μm) and coarse mode(1-20 μm) particles were 1 552,7 470,4 012,and 19 cm-3,respectively.The volume concentration of accumulation mode particles with peak at 300 nm accounted for over 70% of the total volume concentration.Diurnal variations and dependencies on meteorological parameters of PNSD were investigated.The diurnal variation of nucleation mode particles was mainly influenced by new particle formation events,while the diurnal variation of Aitken mode particles correlated to the traffic emission and the growth process of nucleation mode particles.When the PRD region was controlled by a cold high pressure,conditions of low relative humidity,high wind speed and strong radiation are favorable for the occurrence of new particle formation(NPF) events.The frequency of occurrence of NPF events was 21.3% during the whole measurement period.Parameters describing NPF events,including growth rate(GR) and source rate of condensable vapor(Q),were slightly larger than those in previous literature.This suggests that intense photochemical and biological activities may be the source of condensable vapor for particle growth,even during winter in the PRD. 展开更多
关键词 aerosol particle number size distribution new particle formation Pearl River Delta
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Preparation and Biological Distribution of New BATOs
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作者 Jing Tao WANG Xiang Yun WANG Yuan Fang LIU(Department of Technical Physics- Peking University, Beijing 100871)(The current address is: Institute of Photographic Chemistry, Academia Sinica, Bejing 100101) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第1期81-82,共2页
Seven new boronic acid adducts of technetium(III) tris(dioxime) (BATO) were prepared and the biodistribution in mice of Tc-99m labelled BATOs were determined. The uptake of 1.62%1D in mice heart at 2 min after injecti... Seven new boronic acid adducts of technetium(III) tris(dioxime) (BATO) were prepared and the biodistribution in mice of Tc-99m labelled BATOs were determined. The uptake of 1.62%1D in mice heart at 2 min after injection of (TcCl)-Tc-99m(MeCDO)(3)BMe indicates high myocardial extraction of this BATO. (TcCl)-Tc-99m(MeCDO)(3)BMe shows promise as a myocardial perfusion imaging agent. 展开更多
关键词 DMG Preparation and Biological distribution of new BATOs
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考虑海量分布式能源接入的配电网分布式无功控制策略 被引量:3
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作者 翟苏巍 李银银 +3 位作者 杜凡 李文云 潘凯岩 梁峻恺 《中国电力》 CSCD 北大核心 2024年第8期138-144,共7页
针对非常规安全风险对新型电力系统造成的影响,提出了考虑源荷不确定性的新型电力系统双层协同无功控制策略。以配电网网络损耗最小为目标,考虑多种调节设备约束,建立配电网无功优化模型。构建配电网分布式无功优化求解框架,外层采用自... 针对非常规安全风险对新型电力系统造成的影响,提出了考虑源荷不确定性的新型电力系统双层协同无功控制策略。以配电网网络损耗最小为目标,考虑多种调节设备约束,建立配电网无功优化模型。构建配电网分布式无功优化求解框架,外层采用自适应超松弛惩罚参数交替方向乘子法(alternating direction method of multipliers,ADMM)进行全局更新迭代求解,内层采用列与约束生成算法(column-and-constraint generation,C&CG)对各区域两阶段分布鲁棒无功优化模型求解。所提策略能有效改进分布式无功优化模型求解效率,降低网络损耗,提高新型电力系统的稳定性。 展开更多
关键词 新型电力系统 无功优化 分布鲁棒优化
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考虑灵活性的交直流混联配电网分布鲁棒优化运行 被引量:1
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作者 张振强 王宏波 +3 位作者 赵阳 范岳 李雪晴 艾欣 《电力科学与技术学报》 CAS CSCD 北大核心 2024年第2期64-73,共10页
为适应未来配电网交直流混联的配电方式、应对新能源不确定性带来的运行灵活性调节量不足问题,提出一种考虑灵活性的交直流混联配电网两阶段分布鲁棒优化运行模型。首先,在交直流混联配电网架构下,分析其灵活性资源供需关系,定义上调/... 为适应未来配电网交直流混联的配电方式、应对新能源不确定性带来的运行灵活性调节量不足问题,提出一种考虑灵活性的交直流混联配电网两阶段分布鲁棒优化运行模型。首先,在交直流混联配电网架构下,分析其灵活性资源供需关系,定义上调/下调灵活性裕度指标;其次,综合考虑系统中各类约束,构建描述配电网经济性、新能源消纳性与灵活性的优化运行模型,结合数据驱动生成的风光典型场景,采用基于综合范数距离的分布鲁棒优化方法处理风、光出力不确定性,并根据优化变量的出力特性构建两阶段分布鲁棒优化运行模型;最后,对模型进行凸性转化与求解,通过修改的33节点交直流混联配电网算例验证模型的有效性。 展开更多
关键词 交直流混联配电网 新能源不确定性 灵活性裕度指标 两阶段分布鲁棒优化
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Incremental cost analysis model of distribution network based on economic dispatch of distributed new-energy storage system
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作者 Zhuan Zhou Jiayu Bian Zhiyong Yu 《Clean Energy》 EI CSCD 2024年第2期89-103,共15页
With the implementation of China’s carbon-peaking and carbon-neutrality strategy,new energy will achieve leapfrog growth.Due to the good economics of distributed new-energy generation,it can not only save users’own ... With the implementation of China’s carbon-peaking and carbon-neutrality strategy,new energy will achieve leapfrog growth.Due to the good economics of distributed new-energy generation,it can not only save users’own investment,but also help to achieve local consumption of new energy.However,it will also bring about a series of incremental costs to the power grid.This paper first enumerates the concept,development status and scheduling mode of a distributed new-energy storage system.Based on the above,it establishes a new-energy power generation model and an energy storage system charging and discharging model,and proposes a global optimization scheduling model for a distributed new-energy storage system,considering the time-of-use electricity price and taking the lowest total operating cost of the distributed new-energy power generation system as the objective function.Finally,it proposes a distribution network incremental cost analysis model based on the penetration of distributed new energy.The calculation results show that the incremental cost of grid-connected distributed new energy is 1.0849,1.2585 and 1.3473 yuan/kWh,respectively,which indicates that the global dispatching model can optimize the power consumption structure of a distributed power generation system,and has the function of peak shaving and valley filling,but the incremental cost of the distribution network will also increase. 展开更多
关键词 distributed new energy electrochemical energy storage economic dispatch distribution network cost time-sharing price
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First record of red filament threadfin bream,Nemipterus marginatus(Valenciennes,1830)(Perciformes,Nemipteridae),from Chinese waters
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作者 宁平 吴仁协 刘静 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第6期1306-1308,共3页
We collected five specimens of threadfin bream from Beihai, Guangxi, China in March 2010. These were subsequently identified as red filament threadfin bream Nemipterus marginatus (Valenciennes, 1830), being the first ... We collected five specimens of threadfin bream from Beihai, Guangxi, China in March 2010. These were subsequently identified as red filament threadfin bream Nemipterus marginatus (Valenciennes, 1830), being the first record of this species from Chinese waters. N. marginatus is distinguished by the following characteristics: lower border of eye lies above a line from tip of snout to upper base of pectoral fin; mouth oblique, maxillary extending to lower anterior border of pupil; teeth in jaws in several rows, pointed; upper jaw with 3 to 5 pairs of small recurved canines; suborbital with straight lower edge and rounded posterior edge; pectoral fins extending to between level of anus and origin of anal fin; pelvic fins reaching to the first or second anal rays; caudal fin forked, upper lobe tails into a short reddish filament; dorsal fin bluish with a yellow margin distally and a broad yellow median band which subdivides posteriorly into 3 small bands. 展开更多
关键词 nemipterid fish new distributional note China sea
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A newly-recorded species of the genus Opopaea Simon,1892(Araneae,Oonopidae)and first description on female of Opopaea sauteri Brignoli,1974 from Taiwan,China
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作者 LI Shu-Hui TONG Yan-Feng 《蛛形学报》 2024年第1期19-29,共11页
Two species of the genus Opopaea Simon,1892 from Taiwan,China were recognized,Opopaea syarakui(Komatsu,1967)is firstly recorded from Taiwan,China and the female of Opopaea sauteri Brignoli,1974 is firstly discovered.D... Two species of the genus Opopaea Simon,1892 from Taiwan,China were recognized,Opopaea syarakui(Komatsu,1967)is firstly recorded from Taiwan,China and the female of Opopaea sauteri Brignoli,1974 is firstly discovered.Detailed diagnoses,descriptions and photomicroscopy images of the two species are provided based on specimens of both sexes. 展开更多
关键词 BIODIVERSITY new distribution taxonomy
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Particle number size distribution and new particle formation (NPF) in Lanzhou,Western China 被引量:12
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作者 Jian Gao Fahe Chai +1 位作者 Tao Wang Wenxing Wang 《Particuology》 SCIE EI CAS CSCD 2011年第6期611-618,共8页
Particle number size distribution from 10 to 10,000 nm was measured by a wide-range particle spectrometer (WPS-1000XP) at a downwind site north of downtown Lanzhou, western China, from 25 june to 19 July 2006. We fi... Particle number size distribution from 10 to 10,000 nm was measured by a wide-range particle spectrometer (WPS-1000XP) at a downwind site north of downtown Lanzhou, western China, from 25 june to 19 July 2006. We first report the pollution level, diurnal variation of particle concentration in different size ranges and then introduce the characteristics of the particle formation processes, to show that the number concentration of ultrafine particles was lower than the values measured in other urban or suburban areas in previous studies, However, the fraction of ultrafine particles in total aerosol number concentration was found to be much higher. Furthermore, sharp increase of ultrafine particle concentration was frequently observed at noon. An examination of the diurnal pattern suggests that the burst of the ultrafine particles was mainly due to nucleation process. During the 25-day observation, new particle formation (NPF) from homogeneous nucleation was observed during 33% of the study period. The average growth rate of the newly formed particles was 4.4 nm/h, varying from 1.3 to 16,9 nm/h. The needed concentration of condensable vapor was 6.1 × 10^7 cm-3, and its source rate was 1.1× 10^6 cm-3 s 1. Further calculation on the source rate of sulphuric acid vapor indicated that the average participation of sulphuric acid to particle growth rate was 68.3%. 展开更多
关键词 Lanzhou new particle formation (NPF) Number size distribution Particle growth rate Sulphuric acid
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Characterization of particle number size distribution and new particle formation in Southern China 被引量:5
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作者 Xiaofeng Huang Chuan Wang +6 位作者 Jianfei Peng Lingyan He Liming Cao Qiao Zhu Jie Cui Zhijun Wu Min Hu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第1期342-351,共10页
Knowledge of particle number size distribution(PND) and new particle formation(NPF)events in Southern China is essential for mitigation strategies related to submicron particles and their effects on regional air q... Knowledge of particle number size distribution(PND) and new particle formation(NPF)events in Southern China is essential for mitigation strategies related to submicron particles and their effects on regional air quality,haze,and human health.In this study,seven field measurement campaigns were conducted from December 2013 to May 2015 using a scanning mobility particle sizer(SMPS) at four sites in Southern China,including three urban sites and one background site.Particles were measured in the size range of15-515 nm,and the median particle number concentrations(PNCs) were found to vary in the range of 0.3× 10~4-2.2 × 10~4 cn^(-3) at the urban sites and were approximately 0.2 × 10~4 cm^(-3) at the background site.The peak diameters at the different sites varied largely from 22 to 102 nm.The PNCs in the Aitken mode(25-100 nm) at the urban sites were up to 10 times higher than they were at the background site,indicating large primary emissions from traffic at the urban sites.The diurnal variations of PNCs were significantly influenced by both rush hour traffic at the urban sites and NPF events.The frequencies of NPF events at the different sites were0%-30%,with the highest frequency occurring at an urban site during autumn.With higher SO_2 concentrations and higher ambient temperatures being necessary,NPF at the urban site was found to be more influenced by atmospheric oxidizing capability,while NPF at the background site was limited by the condensation sink.This study provides a unique dataset of particle number and size information in various environments in Southern China,which can help understand the sources,formation,and the climate forcing of aerosols in this quickly developing region,as well as help constrain and validate NPF modeling. 展开更多
关键词 Scanning mobility particle sizer(SMPS) Particle number size distribution(PND) new particle formation(NPF) Air pollution Southern China
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考虑新能源、电动汽车充电站与储能协调优化的分布鲁棒规划方法研究 被引量:7
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作者 张玮琪 王沿胜 +2 位作者 杨钊 何川 车彬 《电力系统及其自动化学报》 CSCD 北大核心 2023年第8期114-125,共12页
新能源出力的不确定性和电动汽车的无序充电给电力系统安全性带来极大挑战。首先建立确定性的风电场、光伏电站、储能设备、负荷需求响应及电动汽车充电站协调规划模型,以总成本最小化为目标。基于此,提出考虑新能源不确定性的电动汽车... 新能源出力的不确定性和电动汽车的无序充电给电力系统安全性带来极大挑战。首先建立确定性的风电场、光伏电站、储能设备、负荷需求响应及电动汽车充电站协调规划模型,以总成本最小化为目标。基于此,提出考虑新能源不确定性的电动汽车充电站与储能协调优化两阶段分布鲁棒规划模型,第1阶段最小化基础场景的投建与运行成本,第2阶段则最小化考虑不确定场景的切负荷惩罚成本期望,通过列与约束生成CCG(col⁃umn and constraint generation)算法将该两阶段模型分解成主问题和子问题反复迭代求解。最后通过算例分析验证了所提模型的有效性与实用性。 展开更多
关键词 新能源 电动汽车充电站 储能 需求响应 规划 分布鲁棒
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Light intensity distribution of a new type of contact laser scalpel
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作者 范瑾 杨昆 +2 位作者 周传清 柴新禹 任秋实 《Chinese Optics Letters》 SCIE EI CAS CSCD 2008年第12期913-915,共3页
The emergent light distribution of a new type of contact laser scalpel is measured in three different states using a light sensor. The relationship between the angle and the light intensity is analyzed. The results sh... The emergent light distribution of a new type of contact laser scalpel is measured in three different states using a light sensor. The relationship between the angle and the light intensity is analyzed. The results show that the strongest light is emitted from two sides and the front of the scalpel. The light from the front mainly plays a role of cutting. The light from two sides contributes to stanch the wound so as to remain a clear visual field during the surgery. It also helps to increase the cutting efficiency. 展开更多
关键词 Light intensity distribution of a new type of contact laser scalpel YAG type
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Upper Bounds for Ruin Probability with Stochastic Investment Return
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作者 张丽宏 《Tsinghua Science and Technology》 SCIE EI CAS 2005年第2期254-258,共5页
Risk models with stochastic investment return are widely held in practice, as well as in more challenging research fields. Risk theory is mainly concerned with ruin probability, and a tight bound for ruin ... Risk models with stochastic investment return are widely held in practice, as well as in more challenging research fields. Risk theory is mainly concerned with ruin probability, and a tight bound for ruin probability is the best for practical use. This paper presents a discrete time risk model with stochastic in- vestment return. Conditional expectation properties and martingale inequalities are used to obtain both ex- ponential and non-exponential upper bounds for the ruin probability. 展开更多
关键词 martingale new worse than used (NWU) distribution new better than used (NBU) distribution decreasing failure rate (DFR) stochastic investment return conditional expectation
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