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Behavioural equivalences of a probabilistic pi-calculus

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Science china(Information Sciences) 2012年第9期55卷 2031-2043页

作者： CHEN WeiEn,CAO YongZhi & WANG HanPin Key Laboratory of High Confidence Software Technologies,Ministry of Education of china,institute of Software,school of Electronics engineering and Computer Science,peking university,beijing 100871,china Key Laboratory of High Confidence Software Technologies Ministry of Education of China Institute of Software School of Electronics Engineering and Computer Science Peking University Beijing China

Although different kinds of probabilistic π-calculus have been introduced and found their place in quantitative verification and evaluation,their behavioural equivalences still lack a deep *** propose a simple probabilistic extension of the π-calculus,π p,which is inspired by Herescu and Palamidessi’s probabilistic asynchronous π-*** early semantics of our π p is *** generalise several classic behavioural equivalences to probabilistic versions,obtaining the probabilistic(strong) barbed equivalence and probabilistic bisimulation for π *** we prove that the coincidence between the barbed equivalence and bisimilarity in the π-calculus is preserved in the probabilistic setting.

关键词： probabilistic pi-calculus behavioural equivalence probabilistic bisimulation probabilistic barbed bisimulation

A Comparison Study between Suspension Casting Process and Low Superheat Casting Process

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 31-34页

作者： Yan Yu Qijie Thai Libo Zhang Hanqi Hu (Materials Science and engineering school, university of Science and Technology Beliing, Beding 100083, china)(Shenyang research institute of Foundry, Shenyang 110021, china) Materials Science and engineering school University of Science and Technology Beijing Beijing 100083 China Shenyang research institute of Foundry Shenyang 110021 China

Taking GCr15 bearing steel as experiment material, the effects of suspension casting process and low superheat casting process on the solidification of ingot were studied comparehvely. The results show that both suspension casting process and low superheat casting process can improve the censeal segregation and crystal structure of ingot. As the acting mechanism is different between the two kinds of processes, it is found that suspension casting process is more effective than low superheat casting process in improving the quality of ingot.

关键词： suspension casting process low superheat casting process solidification

Assessment of candidate plant DNA barcodes using the Rutaceae family

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Science china(Life Sciences) 2010年第6期53卷 701-708页

作者： LUO Kun1,2,CHEN ShiLin1,CHEN KeLi2,SONG JingYuan1,YAO Hui1,MA XinYe1,ZHU YingJie3,PANG XiaoHui1,YU Hua1,LI XiWen1,4 & LIU Zhen2 1institute of Medicinal Plant Development,peking Union medical College,Chinese Academy of medical Sciences,beijing 100193,china 2College of Pharmacy,Hubei university of Chinese Medicine,Wuhan 430061,china 3school of Bioscience and engineering,Southwest Jiaotong university,Chengdu 610031,china 4Department of Chemistry,Tsinghua university,beijing 100084,china institute of Medicinal Plant Development Peking Union Medical College Chinese Academy of Medical Sciences Beijing China College of Pharmacy Hubei University of Chinese Medicine Wuhan China school of Bioscience and engineering Southwest Jiaotong University Chengdu China Department of Chemistry Tsinghua University Beijing China

DNA barcoding is a rapidly developing frontier technology that is gaining worldwide ***,seven regions (psbA-trnH,matK,ycf5,rpoC1,rbcL,ITS2,and ITS) with potential for use as DNA barcodes were tested for their ability to identify 300 samples of 192 species from 72 genera of the family *** evaluate each barcode’s utility for species authentication,PCR amplification efficiency,genetic divergence,and barcoding gaps were *** found that the ITS2 region exhibited the highest inter-specific divergence,and that this was significantly higher than the intra-specific variation in the "DNA barcoding gap" assessment and Wilcoxon two-sample *** ITS2 locus had the highest identification efficiency among all tested *** a previous study,we found that ITS2 was able to discriminate a wide range of plant taxa,and here we confirmed that ITS2 was also able to discriminate a number of closely related ***,we propose that ITS2 is a promising candidate barcode for plant species identification.

关键词： DNA barcoding ITS2 Rutaceae identification

Effects of Vibration Technology and Polyvinyl Acetate Emulsion on Microstructure and Properties of Expanded Polystyrene Lightweight Concrete

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Transactions of Tianjin university 2009年第2期15卷 145-149页

作者：赵晓艳田稳苓姜忻良张雪松 school of Civil engineering Tianjin University Civil engineering institute Hebei University of Technology china Academy of Building research

To prevent expanded polystyrene （EPS） beads from rising up to the surface in the molding process of EPS lightweight concrete, vibration with pressure was applied and the polyvinyl acetate （PVA） emulsion was adopted to improve its mechanical properties. The mechanical properties, thermal properties and durability of EPS lightweight concrete were tested. The microstruetures of EPS lightweight concrete were observed by scanning electron microscope （SEM）. Vibration with pressure reduces the number of small cracks. The 180 d compressive strength and flexural strength increase obviously as a large amount of PVA was added. The mixed amount of PVA has no obvious influence on the thermal performance when it is not more than 10% of the cement. Vibration with pressure and surface modification of EPS beads by PVA improve the combination of EPS beads with cement stone and the mechanical properties of EPS lightweight concrete.

关键词： expanded polystyrene(EPS) lightweight concrete vibration with pressure polyvinyl acetate microstructure mechanical properties thermal properties

The effect of silica nanoparticle aggregates on wax dissolution in diesel oil

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Petroleum Science 2011年第2期8卷 207-210页

作者： Sun Renyuan Wang Lei Sun Chao Lin Lei Jiang Hanqiao school of Petroleum engineering China University of Petroleum Qingdao Shandong 266555 China institute of Drilling ＆ Production Technology Jidong Oilfield Tangshan Hebei 063004 China Xianhe Oil Production Plant Shengli Oilfield Dongying Shandong 257000 China school of Petroleum engineering China University of Petroleum Beijing 102249 China

In recent years, silica nanoparticle aggregates （SNPAs） have been used to decrease the injection pressure of wells in low permeability reservoirs achieving good results. In order to study the mechanisms for reduction in the injection pressure of low permeability wells by the SNPA-diesel oil system injection, the microstructure of SNPAs was observed with a transmission electron microscope （TEM）. The particle size distribution of SNPAs was also measured by the laser scattering method. The viscosities of diesel oil and SNPA-diesel oil system were measured with a capillary viscometer. The effect of SNPAs on the solubility of wax in the diesel oil was experimentally studied. The influencing factors, including temperature and SNPA concentration in diesel oil, on wax solubility were analyzed. A pore-throat film displacement model （PTFDM） was built for mechanism explanation. The microstructure and size distribution analyses show that the SNPAs are in the nanometer size range. The viscosity of the SNPA-diesel oil system is lower than that of the diesel oil. The solubility of wax in the diesel oil increases greatly due to SNPA addition, the solubility ratio reaches 7.5. The solubility of wax in diesel oil increases with increases in the concentration of SNPAs in the diesel oil and with the temperature. It is proved that the addition of SNPAs to diesel oil helps remove the wax deposited near the wellbore. This maybe one of the main mechanisms for injection pressure decreases in low permeability reservoirs.

关键词： Silica nanoparticle aggregates solubility of wax low permeability reservoir pore-throatfilm displacement model injection pressure

Progress in studies of the climate of humid period and the impacts of changing precession in early-mid Holocene

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Progress in Natural Science:Materials International 2008年第12期18卷 1459-1464页

作者： Jianbin Huang~a Shaowu Wang~a Xinyu Wen~a Bao Yang~b a Department of Atmospheric Sciences,school of Physics,peking university,beijing 100871,china b Laboratory for Desert and Desertification,Cold and Arid Regions Environmental and engineering research institute,Chinese Academy of Sciences,Lanzhou 730000,china Department of Atmospheric Sciences School of Physics Peking University Beijing 100871 China Laboratory for Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Studies on the climate of humid period and the impacts of changing precession in the early-mid Holocene are reviewed in this paper. High-resolution proxy data indicated that the African Humid Period,strong summer monsoon from the Arabian Sea to South Asia, northward migration of ITCZ (lntertropical Convergence Zone) over the northern South America,and the humid period of china appeared in 10.5-5.5 kaBP,10.0-6.0 kaBP,10.5 5.4 kaBP,and 11.0-8.0 kaBP,*** studies proved that summer inso- lation over the Northern Hemisphere increased following the changes of precession in the early Holocene,which increased the land-sea temperature contrasts,intensified the summer monsoon circulation in the Northern Hemisphere,and finally induced a humid climate over the area under the influence of summer ***,modeling results underestimated the increase of precipitation and the degree of northward extension of monsoon rain belt compared with palaeo-environmental *** discrepancies between the modeling results and the palaeo-environmental data may be associated with the changes of North Atlantic circulation,sea ice and veg- etation ***,climate of the humid period was not stable,in which several droughts were inlaid on centennial *** this review,perspectives for further studies of the climate change of the humid period in the early-mid Holocene are also proposed.

关键词： Holocene Humid period Precession Summer monsoon

Ca2+ sparks and Ca2+ glows in superior cervical ganglion neurons

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Acta Pharmacologica Sinica 2006年第7期27卷 848-852页

作者： Li-jun YAO~(2,3,4) Gang WANG~(3,4) Kun-fu OU-YANG~3 Chao-liang WEI~3 Xian-hua WANG~3 Shi-rong WANG~3 Wei YAO~3 Hong-ping HUANG~3 Jian-hong LUO~2 Cai-hong WU~3 Jie LIU~3 Zhuan ZHOU(3,5) He-ping CHENG~(3,5)2 Department of Neurobiology,Zhejiang university school of Medicine,Hangzhou 310031,china 3 institute of Molecular Medicine and State Key Laboratory of Biomembrane engineering,peking university,beijing 100871,china Department of Neurobiology Zhejiang University School of Medicine Hangzhou China institute of Molecular Medicine and State Key Laboratory of Biomembrane engineering Peking University Beijing China

Aim:Ca2+release from the endoplasmic reticulum（ER）is an integral component ofneuronal Ca2+*** present study is to investigate properties of localCa2+release events in superior cervical ganglion（SCG）***:Pri-mary cultured SCG neurons were prepared from neonatal rats（P3-P7）.Low con-centration of caffeine was used to induce Ca2+release from the ER Ca2+store,andintracellular Ca2+was recorded by high-resolution line scan confocal imaging andthe Ca2+indicator ***:Two populations of local Ca2+release eventswith distinct temporal characteristics were evoked by 1.5 mmol/L caffeine near thesurface membrane in the soma and the neurites of SCG *** eventssimilar to classic Ca2+sparks lasted a few hundreds of milliseconds,whereas long-lasting events displayed duration up to tens of *** somatic andneurite sparks were of 0.3-and 0.52-fold increase in local Fluo-4 fluorescence,*** Ca2+glows were brighter（ΔF/F0approximately 0.6）,butwere highly confined in *** half maximum of full duration of neurite sparkswas much longer than those in the soma（685 vs 381 ms）.Conclusion:Co-exist-ence of Ca2+sparks and Ca2+glows in SCG neurons indicates distinctive localregulation of Ca2+release *** local Ca2+signals of variable,site-specifictemporal length may bear important implications in encoding a"memory"of thetrigger signal.

关键词： superior cervical ganglion neurons Ca2+ sparks ryanodine receptors caffeine

Estimating fisheye camera parameters from homography

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Science china(Information Sciences) 2012年第9期55卷 2119-2127页

作者： ZHU HaiJiang 1,YANG Ping 2 & LI ShiGang 3 1 school of Information Science and Technology,beijing university of Chemical Technology,beijing,100029,china 2 National institute of Metrology,100013,beijing,china 3 Department of Electrical and Electronic engineering,Tottori university,680-8552,Koyama,Tottori,Japan school of Information Science and Technology Beijing University of Chemical Technology Beijing China National institute of Metrology Beijing China Department of Electrical and Electronic engineering Tottori University Koyama Tottori Japan

This paper presents a method to linearly estimate fisheye camera model parameters from the homography induced by the space plane between two fisheye *** homography is firstly calculated by using four feature points,instead of three points on the same line,in the fisheye *** the constraint on the model parameters of fisheye camera can be derived from the homography under the assumption that fisheye camera model is a polynomial *** the model parameters for different order polynomials are *** proposed technique requires only multiple fisheye images to include a planar scene and need not a priori knowledge of 3D coordinate of the planar *** results with synthetic data and real fisheye images demonstrate the validity of our *** method can also be extended to fisheye image of other planar scene excluding the planar calibration object.

关键词： homography parameter estimation fisheye camera

Ultrasonic Frequency Fast-Convert Pulse Plasma Spraying Power Supply Topology

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稀有金属材料与工程 2011年第S4期40卷 297-301页

作者： Zhang Wei1,Qi Bojin1,Xu Haiying21school of Mechanical engineering and Automation,BeiHang university,beijing 100191,china2beijing Aeronautical Manufacturing Technology research institute,beijing 100024,china BeiHang Univ Sch Mech Engn & Automat Beijing 1000191 Peoples R China beijing Aeronaut Mfg Technol Res Inst Beijing 100024 Peoples R China

Considering the high DC current and high pulse frequency characteristic of ultrasonic frequency fast-convert pulse plasma spraying process,a special power supply topology was proposed,which was composed of the mutual independent base current circuit and peak current *** current circuit was consisted of four parallel direct current power supplies,which was not only to meet the requirements of high power output,but also improved the reliability of power *** on the Boost circuit topology,a peak current circuit was designed,which could reduce effectively the output inductance influence and output ultrasonic frequency pulse high current with fast-convert rising and falling *** on the above techniques,the Ultrasonic frequency fast-convert pulse plasma spraying power supply was *** can output 5-1000A base current,0-250A peak current,and the pulse current frequency band is 20-100kHz,10%～80% duty ratio and pulse current change rate over 50A/μs.

关键词： Ultrasonic frequency pulse Fast-convert Plasma spraying