检索结果-南通市图书馆

测绘译丛 1992年第5期 1-14页

作者： remo.,bw 郑国忠

A formal model for ledger management systems based on contracts and temporal logic

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Blockchain(Research and Applications) 2022年第1期3卷 65-79页

作者： Paolo Bottoni Anna Labella remo.Pareschi Department of Computer Science Sapienza University of Rome00185RomaItaly Stake Lab University of Molise86100CampobassoItaly

A key component of blockchain technology is the ledger,viz.,a database that,unlike standard databases,keeps in memory the complete history of past transactions as in a notarial archive for the benefit of any future *** second-generation blockchains such as Ethereum,the ledger is coupled with smart contracts,which enable the automation of transactions associated with agreements between the parties of a financial or commercial *** coupling of smart contracts and ledgers provides the technological background for very innovative application areas,such as Decentralized Autonomous Organizations(DAOs),Initial Coin Offerings(ICOs),and Decentralized Finance(DeFi),which propelled blockchains beyond cryptocurrencies that were the only focus of first generation blockchains,such as ***,the currently used implementation of smart contracts as arbitrary programming constructs has made them susceptible to dangerous bugs that can be exploited maliciously and has moved their semantics away from that of legal *** propose here to recompose the split and recover the reliability of databases by formalizing a notion of contract modeled as a finite-state automaton with well-defined computational characteristics derived from encoding in terms of allocations of resources to actors,as an alternative to the approach based on *** complete the work,we use temporal logic as the basis for an abstract query language that is effectively suited to the historical nature of the information kept in the ledger.

关键词： Ledger Contract Database Transaction Automata theory Temporal logic

In-situ diagnostic of femtosecond laser probe pulses for high resolution ultrafast imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2021年第7期10卷 1326-1338页

作者： Chen Xie Remi Meyer Luc Froehly remo.Giust Francois Courvoisier Ultrafast Laser Laboratory Key Laboratory of Opto-electronic Information Technology of Ministry of EducationSchool of Precision Instruments and Opto-electronics EngineeringTianjin University300072 TianjinChina FEMTO-ST Institute Univ.Bourgogne Franche-ComtéCNRS15B avenue des Montboucons25030 Besançon CedexFrance

Ultrafast imaging is essential in physics and chemistry to investigate the femtosecond dynamics of nonuniform samples or of phenomena with strong spatial *** relies on observing the phenomena induced by an ultrashort laser pump pulse using an ultrashort probe pulse at a later *** years have seen the emergence of very successful ultrafast imaging techniques of single non-reproducible events with extremely high frame rate,based on wavelength or spatial frequency ***,further progress in ultrafast imaging towards high spatial resolution is hampered by the lack of characterization of weak probe *** pump–probe experiments realized within solids or liquids,because of the difference in group velocities between pump and probe,the determination of the absolute pump–probe delay depends on the sample *** addition,pulse-front tilt is a widespread issue,unacceptable for ultrafast imaging,but which is conventionally very difficult to evaluate for the low-intensity probe *** we show that a pump-induced micro-grating generated from the electronic Kerr effect provides a detailed in-situ characterization of a weak probe *** allows solving the two issues of absolute pump–probe delay determination and pulse-front tilt *** approach is valid whatever the transparent medium with nonnegligible Kerr index,whatever the probe pulse polarization and *** it is nondestructive and fast to perform,this in-situ probe diagnostic can be repeated to calibrate experimental conditions,particularly in the case where complex wavelength,spatial frequency or polarization encoding is *** anticipate that this technique will enable previously inaccessible spatiotemporal imaging in a number of fields of ultrafast science at the micro-and nanoscale.

关键词： pump polarization laser

A modified simplex method for multifactor optimization of selectivity in gas chromatography

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1995年第2期13卷 169-174页

作者： WANG, QS ZHU, CS YAN, bw NANKAI UNIV NATL LAB ELEMENTOORGAN CHEMTIANJIN 300071PEOPLES R CHINA

A computer-assisted advanced simplex method is presented for the simultaneous optimization of multifactor (stationary phase loading, carrier gas dow rate and column temperature) for separation of ten compounds in gas chromatography. A three factors factorial design was used. The method was based on a special polynomial established from fifteen preliminary runs, using resolution as the selection criterion, with connection to a general simplex method. Excellent agreement is found between the predicted data and the experimental results, and most of experiments required in the general simplex method can be omitted.

关键词： GAS CHROMATOGRAPHY STATIONARY PHASE CARRIER GAS FLOW RATE COLUMN TEMPERATURE MULTIFACTOR OPTIMIZATION

Advances in dye-sensitized solar cell

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第23期42卷 1937-1948页

作者： Jing, bw Zhang, MH Shen, T Chinese Acad Sci Inst Photog Chem Beijing 100101 Peoples R China

THE conversion of visible light to electricity using semiconductors as light absorbers has beenan important area of research for many years. In the 1970s, highly efficient photovoltaiccells based on silicon were developed (the light-to-electrical conversion efficiency≥25%),which provides energy to aircrafts. Then semiconductor liquid-junction photoelectrochemicalcell started to be investigated. Generally speaking, highly efficient liquid-junction photoelec-trochemical solar cells can be obtained by using semiconductors such as Si, GaAs and WSe.(band gap≈(1.3±0.3) eV). Conversion efficiencies over 15% have been acquired on solarcells consisting of single crystals of Si or GaAs. But the serious photocorrosion and high

关键词： dye-sensitized solar cell ruthenium complex.

索尔莫炼焦厂操作13年后在生产率,生产稳定性与产品质量...

在线全文

学校读者我要写书评

暂无评论

国外炼焦化学 1989年第2期8卷 27-34页

作者： remo.,V. 王振远

Management of urethral atrophy after implantation of artificial urinary sphincter:what are the weaknesses?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2020年第1期22卷 60-63页

作者： Nathaniel H Heah Ronny bw Tan Department of Urology Tan Tock Seng Hospital308433 Singapore A dvanced Urology Mount Elizabeth Hospital228510 Singapore

The use of artificial urinary sphincter(AUS)for the treatment of stress urinary incontinence has become more prevalent,especially in the“prostate-specific antigen(PSA)-era”,when more patients are treated for localized prostate *** first widely accepted device was the AMS 800,but since then,other devices have also entered the *** efficacy has increased with improvements in technology and technique,and patient satisfaction is high,AUS implantation still has inherent risks and complications of any implant surgery,in addition to the unique challenges of urethral complications that may be associated with the ***,the unique nature of the AUS,with a control pump,reservoir,balloon cuff,and connecting tubing,means that mechanical complications can also arise from these individual *** article aims to present and summarize the current literature on the management of complications of AUS,especially urethral *** conducted a literature search on PubMed from January 1990 to December 2018 on AUS complications and their *** review the various potential complications and their *** complications are either mechanical or nonmechanical *** complications usually involve malfunction of the *** complications include infection,urethral atrophy,cuff erosion,and *** exist especially in the management of urethral atrophy,with both tandem implants,transcorporal cuffs,and cuff downsizing all postulated as potential *** complications from AUS implants are not common,knowledge of the management of these issues are crucial to ensure care for patients with these *** studies are needed to further evaluate these techniques.

关键词： artificial urinary sphincter artificial urinary sphincter complications tandem cuffs transcorporal cuffs urethral atrophy

Analytic EAM Model for the Thermodynamic Properties ofthe Disordered Solid Solution and Ordered Intermetallic Alloys of Iron Aluminides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1999年第4期15卷 336-338页

作者： Hu, WY Zhang, bw Shu, XL Huang, BY Hunan Univ Dept Appl Phys Changsha 410082 Peoples R China Cent S Univ Technol Powder Met Res Inst Changsha 410083 Peoples R China

A simple analytic embedded atom method for bcc Fe and fee Al metals is used to calculate the thermodynamic properties of the disordered solid solution and ordered intermetallic alloys of Fe aluminides. The thermodynamic properties, such as the dilute-limit heats of solution, formation enthalpies of disordered solid solutions and intermetallic compounds (Fe3Al in the D0(3) structure type, FeAl in the B2 structure type, and Fe13Al3) are in good agreement with the experimental data, and with the results calculated using the first principles and Miedema theory.

关键词： Intermetallics

Enthalpies of Formation of Binary Transition hcp Metal Based Alloys Calculated by Analytic Embedded Atom Method Model

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1999年第4期15卷 331-335页

作者： Zhang, bw Ouyang, YF Liao, SZ Jin, ZP Chinese Acad Sci Int Ctr Mat Phys Shenyang 110015 Peoples R China Hunan Educ Inst Dept Phys Changsha 410012 Peoples R China Cent S Univ Technol Dept Mat Sci & Engn Changsha 410083 Peoples R China

A simple analytic modified embedded atom method (MEAM) including a modified term for hcp metals has been developed from the MEAM applied to the fee and bcc metals. The enthalpies of formation of all binary alloy systems for eight transition hcp metals are calculated with the MEAM. The calculations are in agreement with the experimental data available and results calculated from the Miedema theory. One can conclude that our MEAM is also effective to apply to the hcp metals and their alloys.

关键词： Transition metal alloys

Biomimetic Mineralization and Degradation of Bioelectret Film in vitro

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2005年第B12期20卷 83-85页

作者：屈依丽陈治清 bw Darvell West China College of Stomatology Sichuang University Chengdu 610041 China Dental Materials Science The University of Hong Kong Hong Kong

To explore the behaviour of bioelectret film in mineralization and degradation in vitro, chitosan film was prepared and polarized in an electric field at room temperature. Polarized and unpolarized chitosan films were soaked in 1.5 × SBF （ simalated body fluid） .sohaions for 7, 14 and 28 d at 37℃. The negativelycharged surface of the bioelectret film promoted greater mineralization than did unpolarized chitosan. Apatite formarion on the surface of the films was identified by X- ray diffraction and scanning electron microscopy. Bioelectret films had a higher rate of degradation than unpolarized material in vitro （ pH 7.4, 37℃ ） in the presence of 1.5 mg/mL lysozyme aver 7 d. The electret effect facilitated the degradation of the film. After 14 d, the degradation rates of the two kinds of film were the same.

关键词： bioelectret chitosan biomimetic mineralization degradation