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Synthesis of Ferrocene Tertiary Amine Cyclopalladium Compounds and Its Application in Suzuki and Sonogashira Reactions  [PDF]
Qi Yuan
Open Access Library PrePrints (OALib PrePrints) , 2017, DOI: 10.4236/oalib.preprints.1200181
Abstract:
Ynones, also known as α, β-acetylenic ketones, have been widespread used in modern synthetic organic chemistry. They exist in biologically active compounds, and are used as vital building blocks in complex molecule synthesis. Consequently, a number of methodologies involving ynones have been developed to access a wide range scaffold using this simple building block. In this paper, the synthesis of a ferrocene tertiary amine cyclopalladium compounds and its application in Suzuki & Sonogashira reactions were our main works, to achieve the goal of discovering new ynones. The contents including the following three aspects: (1) The Schiff bases synthesized by ferrocene methylamine and cinnamaldehyde were underwent sodium borohydride reduction, then the corresponding cyclopalladium compounds were obtained by Mannich reaction and cyclopalladation. The structures of products were characterized by NMR spectroscopy and X-ray single crystal diffraction. (2) Suzuki coupling reactions between 3,4-dimethoxyphenylboronic acid and a series of aryl halides were studied, and several biphenyl coupling products were characterized by NMR spectroscopy. Besides, we also optimized the reaction conditions and expanded the range of substrates. (3) Sonogashira coupling reactions between phenylacetylene and series of acid chlorides were discovered, and several ynones derivatives were characterized by NMR spectroscopy. We also optimized the conditions of reaction and expanded the range of substrates.
Modularity and Dynamics of Cellular Networks
Yuan Qi,Hui Ge
PLOS Computational Biology , 2006, DOI: 10.1371/journal.pcbi.0020174
Abstract:
A WebGIS-Based Information System for Monitoring and Warning of Geological Disasters for Lanzhou City, China
Fang Miao,Qi Yuan
Advances in Meteorology , 2013, DOI: 10.1155/2013/769270
Abstract: Monitoring and warning of geological disasters accurately and in a timely fashion would dramatically mitigate casualties and economic losses. This paper takes Lanzhou city as an example and designs a Web-based system, namely the information system for geological disaster monitoring and warning (ISGDMW). Presented are its framework, key developing technologies, database, and working flow. The information system adopts a Browser/Server (B/S) structure and has three-tier architecture, combining in-situ monitoring instruments, the wireless sensor network, WebGIS techniques and the grey system theory. The framework of the ISGDMW can be divided into three categories: (1) in-situ monitoring system, it aims to monitor geological disaster sites and get state information of geological disaster sites; (2) database, manage in-situ monitoring data, antecedent field investigating data and basic data; (3) analyzing and warning system, analyze in-situ monitoring data, understand the deformation trend of the potential geological disaster, and release disaster warning information to the public. The ISGDMW allow the processes of geological disaster monitoring, in-situ monitoring data analysis, geological disaster warning to be implemented in an efficient and quick way, and can provide scientific suggestions to commanders for quick response to the possibility of geological disaster. 1. Introduction To mitigate geological disaster, we should depend on both real-time in situ data and quick response to the possibility of geological disaster. WebGIS is the integrated product of geographic information system (GIS) and internet technologies; in WebGIS, the internet technologies are connected with GIS in order to take advantage of their special characteristics, such as easy usability, use of the GIS data such as input, adjustment, manipulation, analysis, and output of geographical information and to bring out related service on the internet. Whereas previous standalone GIS had restricted application capability on the network, the WebGIS makes it possible to retrieve and analyze spatial data through the web. The internet also provides a medium for processing georelated information with no location restrictions [1]. In addition, WebGIS promotes the sharing and synthesis of multisource data and enables widespread sharing of spatial data and geosciences models [2]. Therefore, WebGIS offers a powerful and advanced approach to prevent and mitigate geological disaster, and it has played a significant role in terms of transmitting catastrophe data, analyzing the disaster condition, and
EigenNet: A Bayesian hybrid of generative and conditional models for sparse learning
Yuan Qi,Feng Yan
Computer Science , 2011,
Abstract: It is a challenging task to select correlated variables in a high dimensional space. To address this challenge, the elastic net has been developed and successfully applied to many applications. Despite its great success, the elastic net does not explicitly use correlation information embedded in data to select correlated variables. To overcome this limitation, we present a novel Bayesian hybrid model, the EigenNet, that uses the eigenstructures of data to guide variable selection. Specifically, it integrates a sparse conditional classification model with a generative model capturing variable correlations in a principled Bayesian framework. We reparameterize the hybrid model in the eigenspace to avoid overfiting and to increase the computational efficiency of its MCMC sampler. Furthermore, we provide an alternative view to the EigenNet from a regularization perspective: the EigenNet has an adaptive eigenspace-based composite regularizer, which naturally generalizes the $l_{1/2}$ regularizer used by the elastic net. Experiments on synthetic and real data show that the EigenNet significantly outperforms the lasso, the elastic net, and the Bayesian lasso in terms of prediction accuracy, especially when the number of training samples is smaller than the number of variables.
Message passing with relaxed moment matching
Yuan Qi,Yandong Guo
Computer Science , 2012,
Abstract: Bayesian learning is often hampered by large computational expense. As a powerful generalization of popular belief propagation, expectation propagation (EP) efficiently approximates the exact Bayesian computation. Nevertheless, EP can be sensitive to outliers and suffer from divergence for difficult cases. To address this issue, we propose a new approximate inference approach, relaxed expectation propagation (REP). It relaxes the moment matching requirement of expectation propagation by adding a relaxation factor into the KL minimization. We penalize this relaxation with a $l_1$ penalty. As a result, when two distributions in the relaxed KL divergence are similar, the relaxation factor will be penalized to zero and, therefore, we obtain the original moment matching; In the presence of outliers, these two distributions are significantly different and the relaxation factor will be used to reduce the contribution of the outlier. Based on this penalized KL minimization, REP is robust to outliers and can greatly improve the posterior approximation quality over EP. To examine the effectiveness of REP, we apply it to Gaussian process classification, a task known to be suitable to EP. Our classification results on synthetic and UCI benchmark datasets demonstrate significant improvement of REP over EP and Power EP--in terms of algorithmic stability, estimation accuracy and predictive performance.
EigenGP: Gaussian Process Models with Adaptive Eigenfunctions
Hao Peng,Yuan Qi
Computer Science , 2014,
Abstract: Gaussian processes (GPs) provide a nonparametric representation of functions. However, classical GP inference suffers from high computational cost for big data. In this paper, we propose a new Bayesian approach, EigenGP, that learns both basis dictionary elements--eigenfunctions of a GP prior--and prior precisions in a sparse finite model. It is well known that, among all orthogonal basis functions, eigenfunctions can provide the most compact representation. Unlike other sparse Bayesian finite models where the basis function has a fixed form, our eigenfunctions live in a reproducing kernel Hilbert space as a finite linear combination of kernel functions. We learn the dictionary elements--eigenfunctions--and the prior precisions over these elements as well as all the other hyperparameters from data by maximizing the model marginal likelihood. We explore computational linear algebra to simplify the gradient computation significantly. Our experimental results demonstrate improved predictive performance of EigenGP over alternative sparse GP methods as well as relevance vector machine.
Weak Signals and Wild Cards Leading to Transformative Disruption: A Consumer Delphi Study on the Future of e
Petri Tapio,Yuan Qi
- , 2018, DOI: 10.1177/1946756717752921
Abstract: The future of businesses is not only orchestrated by emerging trends and megatrends but also to a greater extent struck by surprising events. With the accelerating presence of high-tech innovations and smart technologies, business activities are exposed to an increasingly volatile, uncertain, complex, and ambiguous environment. Any unexpected changes in the environment could lead to the malfunction or even collapse of a company, a business, or even an industry. Discerning the seeds of change and anticipating the potential disruptions in the external environment is a precondition for avoiding potential risks and threats. The present study contributes to the conceptual and methodological discussion of disruptive transformation by identifying, analyzing, and interpreting the potential disruptive factors in the external business environment. The venture is undertaken through the lens of probing into the dynamism of China’s e-commerce industry, considering its growing influence both domestically and abroad. Any unexpected disruptions would result in a significant ripple effect on interrelated businesses, industries, and even economies. The research adopts a combined mode of qualitative and quantitative methods in the form of horizon scanning and a Consumer Delphi study. Horizon scanning collects futures signals indicating the seeds of change (i.e., weak signals) and potential disruptions (i.e., wild cards), whereas Delphi study solicits the evaluations on the degree of likelihood and impact of the collected factors from an expert panel. As a result, twenty-seven potential disruptive factors are discovered, categorized, estimated, and discussed
Research on Survivability of Mobile Ad-hoc Network  [PDF]
Yuan Zhou, Chunhe Xia, Haiquan Wang, Jianzhong Qi
Journal of Software Engineering and Applications (JSEA) , 2009, DOI: 10.4236/jsea.2009.21008
Abstract: In this paper, we analyze the survivability of Mobile Ad Hoc Network systemically and give a detailed description of the survivability issues related to the MANET. We begin our work with analyzing the requirements of survivability of ad hoc network, and then we classify the impacts that affect survivability into three categories: dynamic topology, faults and attacks. The impacts of these factors are analyzed individually. A simulation environment for the MANET towards survivability is designed and implemented as well. Experiments that under the requirements and the impacts we de-clared are done based on this environment.
Design and Strength Verification of LNG Cargo Enclosure System FSP Type  [PDF]
Zeng Ji, Yuan Bo, Feng Qi, Chen Yan
Modern Mechanical Engineering (MME) , 2019, DOI: 10.4236/mme.2019.92005
Abstract: The demand for natural gas in the world is increasing day by day. The efficient and flexible LNG becomes the preferred method for natural gas storage and transportation and has gradually entered people’s daily life. The enclosure system is the key core of LNG transport and storage vessels for storage of LNG at -163°C for isolation and thermal insulation. A new type of flat half-film prismatic LNG enclosure system has been developed for the shortcomings of the existing LNG cargo enclosure system. Through the breakthrough and mastery of key core technologies such as the overall layout and integration of the system, anti-leakage technology, liquid tank fixing technology, and large-scale friction stir welding (P-FSW) flat-line pipeline development technology, we’ll strive to fill the gap in the intelligent construction technology of large aluminum alloy tanks in China. The tank was subjected to water vapor test and numerical simulation. The results show that the structural strength of the FSP-LNG tank meets the strength check standard of IGC Code.
A Novel Modularizing Design Method of 10 kV High Voltage Switchgear for Live Maintenance  [PDF]
Yuan Yao, Xudong Ouyang, Guowei Zeng, Qi Tang, Wenyu Ma
Energy and Power Engineering (EPE) , 2020, DOI: 10.4236/epe.2020.124B001
Abstract:
Due to imperfect manufacturing technology, design defects and environmental impact, the failure rate of 10 kV switchgear is very high. For this reason, based on taken present situation of traditional switchgear and the current technical requirements for switchgear into account, a new reliable and safe modular high voltage switchgear design method is presented in this paper, which can reduce the failure rate of switchgear and improve the reliability of power supply. The electric field and temperature rise simulation model are established to check the reasonability and validity. By using the finite element software, the simulation results show that the design in this paper has a maximum temperature rise of 55 K for the main cabinet and a maximum temperature rise of 45 K for the deputy cabinet, which is far below the international standard of 70 K. The areas where the partial discharge is likely to occur within the switchgear are places such as the connection between bus-bar and cabinet, bus-bar joint and bus-bar corner. In order to avoid potential dangers, the discharge point must be located in time to prevent insulation fault of electrical equipment of the high voltage switchgear. The simulation results demonstrate that the design method in this paper greatly improve the reliability of switchgear and meets the demands of power system.
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