Mannich reaction catalyzed by a novel catalyst under solvent-free conditions

Cai Bo Yue,Ting Feng Yi,Chuan Bing Zhu,Gang Liu 한국공업화학회 2009 Journal of Industrial and Engineering Chemistry Vol.15 No.5

An acidic catalyst [Py][CF3COO] (pyridinium trifluoroacetate) was synthesized and used in the Mannich reaction of various kinds of aromatic aldehydes, aromatic ketones and aromatic amines. b-Amino carbonyl compounds were obtained in reasonable yields when the Mannich reaction was carried out at room temperature under solvent-free conditions. The products could be separated from the catalyst simply via washing with water and after removing water, the catalyst could be recycled and reused for up to four times without noticeably decreasing in catalytic activity.

Research on Dynamic Characteristics of Hard Cutting System

Yue Caixu,Fenghuize,Cai Chunbin,Zhang Haitao,Huang Cui 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.3

Tool wear is an inevitable and continuously aggravated process in precision hard cutting. Interaction between tool wear and dynamic characteristics in cutting system makes the machining accuracy and quality of machined surface declining, which effects dynamic characteristics of cutting system deteriorated significantly. Based on this, cutter dynamic modal parameters of a specific cutting system are measured in this paper. Cutting force and change law of acceleration power spectrum are studied by experiments. Influence mechanism of tool wear on system frequency energy distribution was obtained. The cutting system dynamic characteristics are quantified by establishing simulation model. Root locus plot of non-uniform load distribution is obtained and the minimum stiffness ratio in the root locus plot is determined. The effect of tool flank wear on cutting system stability in quantitatively stable is researched.The results can provide a theoretical basis for the selection of reasonable selection of stable precision cutting conditions in different tool wear conditions.

Solving the Dynamic Correlation Problem of the Susceptible-Infected-Susceptible Model on Networks

Cai, Chao-Ran,Wu, Zhi-Xi,Chen, Michael Z. Q.,Holme, Petter,Guan, Jian-Yue American Physical Society 2016 Physical Review Letters Vol.116 No.25

Topological non-Fermi liquid

Cai, Rong-Gen,Qi, Yong-Hui,Wu, Yue-Liang,Zhang, Yun-Long American Physical Society 2017 Physical Review D Vol.95 No.12

<P>The (2 + 1)-dimensional non-Fermi liquid (NFL) has a dual description in the (3 + 1)-dimensional anti-de Sitter (AdS) spacetime. We begin with a dyonic Reissner-Nordstrom (RN) black brane background, and consider the bulk Dirac fermion field coupled with the background U(1) gauge field, as well an intrinsic axial gauge field which is induced by chiral anomaly. The axial gauge field is effectively induced from the topological term in the bulk, which would lead to nontrivial effects on the boundary NFL. We study these effects through calculating the retarded Green's functions of the dual NFL holographically, in both analytical and numerical approaches. We also obtain correlation functions in the low frequency limit at zero and finite temperatures, as well as the dispersion spectrum of the Dirac cones, Fermi arc of the surface states, which can be related with the experiment.</P>

Investigation of Eco-friendly Dyeing of Para-aramid Using Supercritical CO2

Yue Zhang,Huanda Zheng,Laijiu Zheng,Tao Cai,Fuer Zheng 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

In order to solve the problems of dyeing difficulty and serious pollution of traditional water-based dyeing of paraaramid,supercritical CO2 fluid was employed as a dyeing solvent to dye para-aramid yarn (temperatures 80-120 ℃, pressures16-24 MPa, dyeing time 15-90 min, and dye concentration 1 %-7 % o.m.f.). The K/S values reached 2.07 and 1.91 at 120 ℃,24 MPa, 60 min, 5 % o.m.f., and a CO2 flow of 20 g/min with C. I. Disperse Red 54 and C. I. Disperse Blue 79, respectively. The results proved that para-aramid yarn could be dyed in supercritical CO2 fluid. Moreover, the thermal and mechanicalproperties of dyed para-aramid yarns in supercritical CO2 showed a slightly increasing trend. The washing, rubbing, and thelight color fastness of the dyed samples were rated above 4-5, and the color fastness durability of the dyed para-aramid wasalso presented good.

Analysis of Port Hopping for Proactive Cyber Defense

Yue-Bin Luo,Bao-Sheng Wang,Gui-Lin Cai 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.2

Port hopping is a typical proactive cyber defense technology, which hides the service identity and confuses attackers during reconnaissance by constantly altering service ports. Although several kinds of port hopping mechanisms have been proposed and implemented, but it is still unknown how effective port hopping is and under what circumstances it is a viable moving target defense because the existed works are limited and they usually discuss only a few parameters. Besides, in many cases the defense effectiveness has been studied empirically. In order to have an insight into the effectiveness of port hopping, this paper introduces a quantitative analysis based on the urn model, which quantifies the probability of attacker success in terms of port pool size, number of probes, number of vulnerable services, and hopping frequency. Theoretical analysis shows that port hopping is an effective and promising proactive defense technology in thwarting cyber attacks.

A Hybrid Life-Cycle Analysis and Two-Stage Stochastic Programming Model for Low-Carbon Management upon Urban Water Resources

Wencong Yue,Yanpeng Cai,Linyu Xu,Xumei Wang,Qiangqiang Rong,Lin Liu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.6

Due to population growth and economic development, water demands for municipal, industrial, and agricultural users are increasing. It is a challenging and critical issue in water resources system to properly allocate and utilize water resources to satisfy the goals of different stakeholders and greenhouse gases mitigation. In this study, a hybrid life-cycle analysis and two-stage stochastic programming model was proposed to analyze the water-allocation strategies based on complicated urban water resource system. The hybrid model can effectively assess the low-carbon performance of an urban water resources system in the framework of life-cycle analysis. The environmental impacts and GHGs reduction of urban water resources were firstly considered as the objective and constraint for solving the water allocation problems. The results indicated that the first-stage solutions of surface water conveyance of Dalian could be [3.83×108, 8.25×108] in 2015, and [3.83×108, 9.21×108] in 2020; Meanwhile, the first-stage solutions of surface water conveyance of Dalian could be [4.26×108, 8.68×108] in 2015, and [5.35×108, 10.7×108] in 2020.

Snapshot of Technology Business Incubators in China

Nasir Mahmood,Cai Jianfeng,Farhan Jamil,Hina Munir,Jintao LU,Mustafa Khan,Yue Cai 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.7

In the contemporary world, the production of suitable goods and commodities and business developments, the business technology incubators are considered important for the inception of new ideas and combining them with the available resources. Similarly, business and technology incubators are considered a backbone to accelerate the innovation and new business development structure of national economies. The business incubators in China are flourishing by leaps and bounds since the mid of 1990s. This paper aims to explore the performance of technology business incubator in china. In this study the incubator data which was compiled by Ministry of Science and Technology (MOST) China was taken for performance evaluation in china. The performance of incubator in 2002 and in 2012 was assessed by comparison of total number of tenants, total income of tenants, number of graduated tenants and number of employees of tenants, further, in 2012 the association of number of invention patent with the accumulated number of tenants obtained investment and finance is assessed, and this paper also presents the graduated firms number every year in China. These results show that the performance of technology incubators is increased during the last decade.

Business Incubators: Boon or Boondoggle for SMEs and Economic Development of Pakistan

Nasir Mahmood,Cai Jianfeng,Farhan Jamil,Jawad Karmat,Mustafa Khan,Yue Cai 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.4

In this age of technological development, business incubation system is an important tool, for the government to implement and facilitate technological innovation and entrepreneurship development. An effective business incubation system renders an important role in the nourishment of local, national and regional economies by producing employment opportunities & development of SMEs. This study presents evidence that suggests business incubators are important for economic development especially for developing countries like Pakistan. A comprehensive survey was carried out to analyze the current functional status of business incubators, along with the services provided by those incubators, with their success & shortcoming links with incubation system in Pakistan. The importance of business incubators for the promotion of entrepreneurship, development and technological innovation, addressed with an assessment of the needs of Pakistan economy. This is followed with an evaluation of the requirements to be dealt before incubators can leave the desired effects on the improvements of the entrepreneurship and technological innovation. Finally, the findings reveal implications for the future development programme of business incubators in Pakistan with the policy recommendation.

Ozone and Daily Mortality Rate in 21 Cities of East Asia: How Does Season Modify the Association?

Chen, Renjie,Cai, Jing,Meng, Xia,Kim, Ho,Honda, Yasushi,Guo, Yue Leon,Samoli, Evangelia,Yang, Xin,Kan, Haidong Oxford University Press 2014 American Journal of Epidemiology Vol.180 No.7

<P>Previous studies in East Asia have revealed that the short-term associations between tropospheric ozone and daily mortality rate were strongest in winter, which is opposite to the findings in North America and Western Europe. Therefore, we investigated the season-varying association between ozone and daily mortality rate in 21 cities of East Asia from 1979 to 2010. Time-series Poisson regression models were used to analyze the association between ozone and daily nonaccidental mortality rate in each city, testing for different temperature lags. The best-fitting model was obtained after adjustment for temperature in the previous 2 weeks. Bayesian hierarchical models were applied to pool the city-specific estimates. An interquartile-range increase of the moving average concentrations of same-day and previous-day ozone was associated with an increase of 1.44% (95% posterior interval (PI): 1.08%, 1.80%) in daily total mortality rate after adjustment for temperature in the previous 2 weeks. The corresponding increases were 0.62% (95% PI: 0.08%, 1.16%) in winter, 1.46% (95% PI: 0.89%, 2.03%) in spring, 1.60% (95% PI: 1.03%, 2.17%) in summer, and 1.12% (95% PI: 0.73%, 1.51%) in fall. We found significant associations between short-term exposure to ozone and higher mortality rate in East Asia that varied considerably from season to season with a significant trough in winter.</P>