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A characterization of answer sets for logic programs

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Science in China(Series F) 2007年第1期50卷 46-62页

作者： zhang MingYi zhang Ying FangZhen LiN Guizhou Academy of Sciences Guiyang 550001 China Information. Engineering School Gulzhou University Guiyang 550001 China Department of Computer Science Hong Kong University of Science and Technology Hong Kong China

Checking if a program has an answer set, and if so, compute its answer sets are just some of the important problems In answer set logic progremming. Solving these problems using Gelfond and Llfschltz＇s original definition of answer sets Is not an easy task. Alternative charaoterlzatlons of answer sets for nested logic programs by Erdem and Llfschltz, Lee and Llfschltz, and You at el. are based on the completion semantics and various notions of tlghtnese. However, the notion of tightness Is a local notion In the sense that for different answer sets there are, In general, different level mappings capturing their tlghtnese. This makes It hard to be used In the deelgn of algorithms for computing answer sets. This paper proposes a charecterization of answer sets based on sets of generetlng rules. From this charaoterlzation new algorithms are derived for computing answer sets and for performing some other reasoning teaks. As an application of the charecterlzatlon a sufficient and necessary condition for the equivalence between answer set sementics and completion semantics has been proven, and a basic theorem Is shown on computing answer sets for nested logic programs baaed on an extended notion of loop formulas. These results on tlghtnese and loop formulas are more general than that in You and Lin＇a work.

关键词： nested logic programming characterization of answer sets completion semantics tightness loop formulas

Review of Chinese atmospheric science research over the past 70 years: Atmospheric physics and atmospheric environment

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Science China Earth Sciences 2019年第12期62卷 1903-1945页

作者： Tijian WANG Taichang GAO Hongsheng zhang Maofa GE Hengchi LEI Peichang zhang Peng zhang Chunsong LU Chao LIU Hua zhang Qiang zhang Hong LIAO Haidong KAN Zhaozhong FENG Yijun zhang Xiushu QIE Xuhui CAI Mengmeng LI Lei LIU Shengrui TONG School of Atmospheric Sciences Nanjing UniversityNanjing 210023China College of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101China Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Institute of Chemistry Chinese Academy of SciencesBeijing 100190China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China School of Atmospheric Physics Nanjing University of Information Science and TechnologyNanjing 210044China National Satellite Meteorological Center China Meteorological AdministrationBeijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Department of Earth System Science Tsinghua UniversityBeijing 100084China School of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Department of Environmental Health School of Public HealthFudan UniversityShanghai 200032China Department of Atmospheric and Oceanic Sciences Fudan UniversityShanghai 200032China Department of Environmental Science College of Environmental Science and EngineeringPeking UniversityBeijing 100871China

Since the founding of the People’s Republic of China 70 years ago,the subject of atmospheric physics and atmospheric environment has developed rapidly in China,providing important support for the development of atmospheric science and guarantee for the development of national *** this paper,the general advancement of atmospheric physics and atmospheric environment in last 70 years was *** main research progress of atmospheric physics and atmospheric environment in the past 40 years of reform and opening-up was reviewed,the outstanding research achievements since the 21 st century were summarized,the major problems and challenges are pointed out,and the key directions and suggestions for future development are put forward.

关键词： Atmospheric physics Atmospheric environment Atmospheric sounding Atmospheric chemistry Atmospheric remote sensing

Association between vascular endothelial growth factor gene promoter polymorphisms and sporadic amyotrophic lateral sclerosis in a Han Chinese population Case-control study

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Neural Regeneration Research 2009年第12期4卷 1110-1115页

作者： Na Liu Nan zhang Jun zhang Liping Wang Xiaoyan zhang Wei Sui Huagang zhang Lingsong Li Dafang Chen Dongsheng Fan Department of Neurology Peking University Third Hospital Beijing 100191 China Peking University Stem Cell Research Center Beijing 100191 China Department of Epidemiology and Statistics School of Public Health Peking University Beijing 100191 China

BACKGROUND： Studies have shown that vascular endothelial growth factor （VEGF） gene polymorphisms highly correlate with sporadic amyotrophic lateral sclerosis （ALS）, although this remains controversial. To date, the relationship between VEGF gene polymorphism and sporadic ALS in a Han Chinese population remains unclear. OBJECTIVE： To explore the relationship between sporadic ALS and VEGF gene promoter 7 locus polymorphisms in a Hart Chinese population, and to investigate whether this relationship exhibits gender differences. DESIGN, TIME AND SETTING： A case-control study regarding genetic association was performed at the Central Laboratory of Peking University Third Hospital from 2002 to 2006. PARTICIPANTS： A total of 93 patients, who were diagnosed with definite or probable ALS according to E1 Escorial-revised diagnostic criteria, were selected from the Outpatient Department of Neurology, Peking University Third Hospital from 2002 to 2006. All patients were from Hart populations, with no family history of ALS. In addition, 103 gender- and age-matched healthy volunteers were selected as controls. METHODS： Peripheral venous blood was collected, and whole blood genomic DNA was extracted. VEGF gene promoter 7 locus polymorphisms were analyzed by PCR using the fluorescent Taqman system. The relationship between VEGF gene promoter single nucleotide polymorphisms and ALS was analyzed using Logistic regression model analysis and was stratified according to gender. MAIN OUTCOME MEASURES： 7 VEGF gene promoter polymorphisms genotype distribution and allele frequencies. RESULTS： There were no significant differences in VEGF gene promoter 7 locus genotype distribution and allele frequency between case and control groups （P 〉 0.05）. Stratified analysis based on gender demonstrated that female Han subjects carrying the VEGF genotype -1154AA, -2549TT, -634CC genotype were more susceptible to ALS than those carrying -1154GG, -2549CC, -634GG （VEGF-1154AA： OR= 8.9, 95%CI= 1 .0-77.3, P

关键词： amyotrophic lateral sclerosis genetic polymorphisms vascular endothelial growth factor

Resource allocation based on subcarrier exchange in multiuser OFDM system

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Science China(Information Sciences) 2013年第1期56卷 184-197页

作者： WANG Ye zhang QinYu zhang NaiTong Harbin Institute of Technology Shenzhen Graduate School Communication Engineering Research Center Harbin Institute of Technology Communication Research Center

Multi-user orthogonal frequency division multiplexing(OFDM) is one of the most important techniques for next-generation wireless communication *** sum capacity and proportional fairness index are two important metrics in OFDM adaptive resource *** existing researches,the two metrics have individually yielded approximately optimal ***,as the two goals seem to contradict each other,it means that they cannot achieve optima *** paper presents a resource allocation algorithm based on subcarrier *** relaxing the fairness index,the proposed algorithm can dynamically adjust the fairness ***,By considering a criterion that minimizes the loss of sum capacity,the proposed algorithm can balance the tradeoff between fairness and sum *** contrast to existing algorithms,our proposal improves performance by approximately 30% in terms of sum capacity,at the expense of approximately 10% reduction in proportional ***,if a malicious user exists,each user in the system can obtain higher ergodic capacity compared with the conventional *** decrease the complexity,a low-complexity simplified alternative is presented,which outperforms the conventional algorithm with an increase in the number of *** numerical simulations are carried out to verify the efficiency and ***,we discuss in detail the computational complexity of the proposed algorithm.

关键词： multiuser OFDM resource allocation capacity proportional fairness computational complexity

Metafabrics for cooling under a scorching sun

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Light(Science & Applications) 2021年第11期10卷 2024-2025页

作者： Shuang zhang Department of Physics The University of Hong KongPokfulam RoadHong KongChina Department of Electrical and Electronic Engineering The University of Hong KongPokfulam RoadHong KongChina

Engineering the spectral response of composite materials in a broad range from ultraviolet to infrared can lead to a significant passive cooling *** principle is applied to the design of a novel type of metafabric for cooling the human body under direct *** cooling effect,the metafabric features other merits including superior mechanical and wetting properties.

关键词： properties. composite ultraviolet

Physical Processes Responsible for the Interannual Variability of Sea Ice Concentration in Arctic in Boreal Autumn since 1979

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Journal of Meteorological Research 2017年第3期31卷 468-475页

作者： Lei zhang Tim LI Climate Dynamics Research Center and Earth System Modeling Center International Laboratory on Climate and Environment ChangeNanjing University of Information Science & Technology Department of Atmospheric Sciences University of Hawaii

Arctic sea ice concentration （ASIC） in boreal autumn exhibits prominent interannual variability since 1979. The physical mechanism responsible for the year-to-year variation of ASIC is investigated through observational data analyses and idealized numerical modeling. It is found that the ASIC interannual variability is closely associated with the anomalous meridional circulations over the Northern Hemisphere, which is further linked with the tropical sea surface temperature （SST） forcing. A tropics-wide SST cooling anomaly leads to an enhanced meridional SST gradi- ent to the north of the equator in boreal summer, generating strengthened and northward shifting Hadley circulation over the Northern Hemisphere. Consequently, the meridional circulations are enhanced and pushed poleward, lead- ing to an enhanced descending motion at the North Pole, surrounded by an ascending motion anomaly; the surface outflow turns into easterly anomalies, opposing the mean-state winds. As a result, positive cloudiness and weakened surface wind speed emerge, which reduce ASIC through changes in the surface latent heat flux and the downward longwave radiation.

关键词： Arctic sea ice variability interannual variability tropical forcing meridional circulations

当归补血汤辅助治疗糖尿病肾病临床疗效的Meta分析

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中国全科医学 2021年第27期24卷 3477-3483页

作者：程丽颖王梦玺张翥邵凤民河南中医药大学河南省郑州市450000 南京中医药大学江苏省南京市210029 阜外华中心血管病医院河南省郑州市451464

背景过度的炎性反应及肾纤维化是糖尿病肾病(DN)进展为终末期肾病(ESRD)的关键环节,但目前西医对DN的常规治疗在抗炎、抗纤维化方面效果不显著。临床应用当归补血汤作为抗炎、抗纤维化辅助治疗DN的疗效显著,但缺乏循证依据。目的系统研... 详细信息

背景过度的炎性反应及肾纤维化是糖尿病肾病(DN)进展为终末期肾病(ESRD)的关键环节,但目前西医对DN的常规治疗在抗炎、抗纤维化方面效果不显著。临床应用当归补血汤作为抗炎、抗纤维化辅助治疗DN的疗效显著,但缺乏循证依据。目的系统研究当归补血汤在DN辅助治疗中的疗效和安全性。方法计算机检索中国知网、万方数据知识服务平台、维普网、中国生物医学文献数据库、PubMed、The Cochrane Library、EMBase、中国临床试验注册中心(ChiCTR)、***,检索时间为建库至2020年12月。筛选关于当归补血汤辅助治疗DN的临床随机对照试验,其中对照组施以常规综合治疗,试验组在对照组基础上配合当归补血汤加减。采用Cochrane风险偏倚评估工具进行文献质量评价,并提取文献数据。采用RevMan 5.4软件进行统计学分析。结果共纳入文献10篇,包括879例患者。Meta分析结果显示,试验组总有效率高于对照组〔相对危险度(RR)=1.18,95%CI(1.10,1.28),P0.05〕。结论当归补血汤辅助治疗DN的临床疗效显著,具有良好的安全性。

关键词：糖尿病肾病当归补血汤治疗结果 Meta分析

Uncertainty in Projection of Climate Extremes:A Comparison of CMIP5 and CMIP6

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Journal of Meteorological Research 2021年第4期35卷 646-662页

作者： Shaobo zhang Jie CHEN State Key Laboratory of Water Resources&Hydropower Engineering Science Wuhan University299 Bayi RoadWuchang DistrictWuhan 430072 Hubei Provincial Key Lab of Water System Science for Sponge City Construction Wuhan UniversityWuhan 430072

Climate projections by global climate models(GCMs)are subject to considerable and multi-source *** study aims to compare the uncertainty in projection of precipitation and temperature extremes between Coupled Model Intercomparison Project(CMIP)phase 5(CMIP5)and phase 6(CMIP6),using 24 GCMs forced by 3 emission scenarios in each phase of *** this study,the total uncertainty(T)of climate projections is decomposed into the greenhouse gas emission scenario uncertainty(S,mean inter-scenario variance of the signals over all the models),GCM uncertainty(M,mean inter-model variance of signals over all emission scenarios),and internal climate variability uncertainty(V,variance in noises over all models,emission scenarios,and projection lead times);namely,T=S+M+*** results of analysis demonstrate that the magnitudes of S,M,and T present similarly increasing trends over the 21 st *** magnitudes of S,M,V,and T in CMIP6 are 0.94-0.96,1.38-2.07,1.04-1.69,and 1.20-1.93 times as high as those in *** CMIP5 and CMIP6 exhibit similar spatial variation patterns of uncertainties and similar ranks of contributions from different sources of *** uncertainty for precipitation is lower in midlatitudes and parts of the equatorial region,but higher in low latitudes and the polar *** uncertainty for temperature is higher over land areas than oceans,and higher in the Northern Hemisphere than the Southern *** precipitation,T is mainly determined by M and V in the early 21 st century,by M and S at the end of the 21 st century;and the turning point will appear in the 2070 *** temperature,T is dominated by M in the early 21 st century,and by S at the end of the 21 st century,with the turning point occuring in the 2060 *** relative contributions of S to T in CMIP6(12.5%-14.3%for precipitation and 31.6%-36.2%for temperature)are lower than those in CMIP5(15.1%-17.5%for precipitation and 38.6%-43.8%for temperature).By contrast,the re

关键词： climate projection uncertainty uncertainty contribution Coupled Model Intercomparison Project(CMIP)phase 5(CMIP5)and phase 6(CMIP6) extreme precipitation and temperature

Moments of integral-type downward functionals for single death processes

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Frontiers of Mathematics in China 2020年第4期15卷 749-768页

作者： Jing WANG Yuhui zhang School of Mathematical Sciences Beijing Normal UniversityLaboratory of Mathematics and Complex SystemsMinistry of EducationBeijing 100875China School of Mathematics and Statistics Yili Normal UniversityYili 835000China

We get an explicit and recursive representation for high order moments of integral-type downward functionals for single death ***,main results are applied to more general integral-type downward functionals.

关键词： Single death process integral-type functional moment