Research of technique for synthesizing carbonyl diethyl malonate

Diethyl malonate being an initial raw material,processed with chlorination-replacement-desalination-vacuum rectification,is used to produce carbonyl diethyl malonate.An experiment for optimization determines that the best reaction condition was:① reaction for 7 h at 10 ℃ with mole-ratio being 2.4︰1 between chloride and raw material(diethyl malonate);② reaction for 4.5 h at 118 ℃ with mole-ratio being 1.2︰1 between the anhydrous sodium acetate and intermediate Ⅰ.The final product carbonyl diethyl malonate recovery ratio reaches up to as high as 79.12% with a purity of 96.4%,which meets the market requirement.This synthesis technique has the advantages of simple process,moderate reaction conditions,high yield and low cost,being suitable for industrial scale production.     

A representation of sl(2;C) on clifford algebra of even dimension

Under the foundation of Hermitean Clifford setting,we define the fundamental operators for complex Clifford algebra valued functions,obtain some properties of these operators,and discuss a representation of sl(2;C) on Clifford algebra of even dimension.     

Activity sequence modes for Web services and verifications

Behavior requirement expression and its satisfiability verification for composite Web services is one of the ongoing issues in service computing.In this paper,the concept of behavior specifications based on activity sequence is proposed to express one kind of behavioral requirements for composite Web services.Its basic element is activity sequence.The method to express such behavioral requirements by behavioral modes is presented.Five behavioral modes used in this method are adopted.Through mapping modes to Labeled Transition Systems(LTSs),these modes are encoded with exact operation semantics.Then,the sufficient and necessary conditions as well as the checking algorithm for satisfiability of behavioral modes are given.Finally,an example analysis is presented.The result indicates that the behavioral requirements based on activity sequence are more suitable for the case of composite Web service than those based on activity or scenario.The behavioral modes expressions are concise and the satisfiability checking is effective by the given algorithm.     

Analysis of fragrance composition in three cultivars of <Emphasis Type="Italic">Osmanthus fragrans</Emphasis> Albus group flower by gas chromatography-mass spectrometry

With supercritical CO2 fluid extraction(SCFE), essential oil was extracted from three cultivars of Xianning osmanthus. The fresh osmanthus flower was processed with a petroleum ether digestion method to produce the extractum. The yields of essential oil and extractum were 0.19 % and 0.13 % (m/m) respectively. The essential oil and fragrance composition and content extracted were analyzed with gas chromatography-mass spectrometer (GC-MS). The result showed that essential oil contained 36.99%(area/total area) of ionone, ionol and 13.11% of linalool; ionone and ionol contained in extractum were as high as up to 33.33%, while linalool up to 21.92%. Whether essential oil or extractum contains only about 40% fat acid and other ester matters. None of environmental estrogen (phthalic ester) was found in fragrance ingredients. The result also showed that the quality of O. fragrans Albus group fragrance in Xianning is better than that produced in Hangzhou and Anhui districts.     

Improved verifiability scheme for data storage in cloud computing

In Cloud computing,data and service requests are responded by remote processes calls on huge data server clusters that are not totally trusted.The new computing pattern may cause many potential security threats.This paper explores how to ensure the integrity and correctness of data storage in cloud computing with user’s key pair.In this paper,we aim mainly at constructing of a quick data chunk verifying scheme to maintain data in data center by implementing a balance strategy of cloud computing costs,removing the heavy computing load of clients,and applying an automatic data integrity maintenance method.In our scheme,third party auditor (TPA) is kept in the scheme,for the sake of the client,to periodically check the integrity of data blocks stored in data center.Our scheme supports quick public data integrity verification and chunk redundancy strategy.Compared with the existing scheme,it takes the advantage of ocean data support and high performance.     

Growth characteristics of directionally solidified Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/YAG/ZrO<Subscript>2</Subscript> ternary hypereutectic <Emphasis Type="Italic">in situ</Emphasis> composites under ultra-high temperature gradient

Oxide eutectic ceramic in situ composites have attracted significant interest in the application of high-temperature structural materials because of their excellent high-temperature strength, oxidation and creep resistance, as well as outstanding microstructural stability. The directionally solidified ternary Al₂O₃/YAG/ZrO₂ hypereutectic in situ composite was successfully prepared by a laser zone remelting method, aiming to investigate the growth characteristic under ultra-high temperature gradient. The microstructures and phase composition of the as-solidified hypereutectic were characterized by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results show that the composite presents a typical hypereutectic lamellar microstructure consisting of fine Al₂O₃ and YAG phases, and the enriched ZrO₂ phases with smaller sizes are randomly distributed at the Al₂O₃/YAG interface and in Al₂O₃ phases. Laser power and scanning rate strongly affect the sample quality and microstructure characteristic. Additionally, coarse colony microstructures were also observed, and their formation and the effect of temperature gradient on the microstructure were discussed.     

Influence of Ag doping on the microstructure and electrical properties of ZnO-Bi<Subscript>2</Subscript>O<Subscript>3</Subscript>-based varistor ceramics

Silver in the form of AgNO₃ was added to ZnO-based varistor ceramics prepared by the solid-state reaction method. The effects of AgNO₃ on both the microstructure and electrical properties of the varistors were studied in detail. The optimum addition amount of AgNO₃ in ZnO-based varistors was also determined. The mechanism for grain growth inhibition by silver doping was also proposed. The results indicate that the varistor threshold voltage increases substantially along with the AgNO₃ content increasing from 0 to 1.5mol%. Also, the introduction of AgNO₃ can depress the mean grain size of ZnO, which is mainly responsible for the threshold voltage. Furthermore, the addition of AgNO₃ results in a slight decrease of donor density and a more severe fall in the density of interface states, which cause a decline in barrier height and an increase in the depletion layer.     

A cost-effective cloud leasing policy for live streaming applications

The dynamics of the globalized multimedia sources and request demands, which requires high computations and bandwidths, makes the IT infrastructure a challenge for live streaming applications. Migrating the system to a geo-distributed cloud and leasing servers is an ideal alternative for supporting large-scale live streaming applications with dynamic contents and demands. The new challenge of multimedia live streaming applications in a geo-distributed cloud is how to efficiently arrange and migrate services among different cloud sites to guarantee the distribute users’ experience at modest costs. This paper first investigates cloud leasing policies for live streaming applications and finds that there is no detailed algorithm to help live streaming applications arrange and migrate services among different cloud sites. Then, we present a quality of service (QoS) guarantee cost-effective cloud leasing policy for live streaming applications. Meanwhile, we design a genetic algorithm (GA) to deal with the leasing policy among cloud sites of diverse lease prices. Experimental results confirm the effectiveness of the proposed model and the efficiency of the involved GA.     

<Emphasis Type="Italic">a</Emphasis>-Wythoff’s game with <Emphasis Type="Italic">n</Emphasis> players

Letting a = 1 in a- Wythoff’s game introduced by Fraenkel yields Wythoff’s game which is a well-known 2-player impartial combinatorial game introduced by Wythoff in 1907. A method of solving n-player impartial games was presented by Krawec in 2012. In this paper, we employ Krawec’s function to analyze n > 2 players a-Wythoff’s game and obtain game values for all a 1. The results obtained cover n-player Wythoff’s game, a special case 1-Wythoff’s game.     

A new quantum algorithm for computing RSA ciphertext period

Shor proposed a quantum polynomial-time integer factorization algorithm to break the RSA public-key cryptosystem. In this paper, we propose a new quantum algorithm for breaking RSA by computing the order of the RSA ciphertext C. The new algorithm has the following properties: 1) recovering the RSA plaintext M from the ciphertext C without factoring n; 2) avoiding the even order of the element; 3) having higher success probability than Shor’s; 4) having the same complexity as Shor’s.