Conversion of Biomass to Novel Platform Chemical γ-Valerolactone by Selective Reduction of Levulinic Acid

生物质是唯一能替代化石资源转化得到液体燃料及化学品的可再生资源,近年来,催化转化生物质制备各种平台化合物的研究受到了人们越来越广泛的关注。和乙酰丙酸(lA)一样,γ-戊内酯(gVl)也被认为是一种具有广泛应用潜能的新型生物质基平台化合物。目前,人们已经开发出多种催化剂和反应体系用于催化生物质基lA选择性还原制备gVl。根据氢源的不同可将lA制备gVl的途径概括为4种:分别以分子H2、甲酸(fA)、合成气和醇类作为氢源的途径。本文着重从氢源的差异来归纳和总结生物质基lA选择性还原制备gVl的途径及其研究进展,以期为寻找一种高效、经济、环保的gVl合成途径提供一些思路和参考。Biomass is the only renewable resources on the earth that can be converted to liquid fuels and chemicals to replace fossil resources.Recently,the catalytic conversion of biomass to platform molecules has attracted more and more attentions from the researchers worldwide.γ-Valerolactone( GVL) is regarded as a platform molecule that has extensive application potential,similar to levulinic acid( LA).Up to now,various of catalysts and reaction systems were developed and applied to the selective reduction of biomass-derived LA to GVL,and the hydrogenation of LA can be driven by various hydrogen sources,including molecule H2,formic acid( FA),syngas and alcohols.In this review,the catalytic hydrogenation routes and recent research progress for the reduction of LA are systematically summarized in view of the diversity of hydrogen sources.The future research trends of the selective reduction of LA to GVL are suggested.国家重点基础研究发展计划(973)项目(No.2010CB732201); 国家自然科学基金项目(No.201106121); 中央高校基本业务费专项资金项目(No.2010121077); 厦门大学研究生基础创新基金(No.201212G006)资

负偏置沉积法可控制备CuO多孔纳米结构薄膜

由于具有低成本、无毒、铜源丰富等优点,以及在气敏传感器、太阳能电池、光催化等领域的潜在应用前景,CuO薄膜引起了人们的广泛关注.采用射频平衡磁控溅射镀膜系统,在薄膜沉积过程中通过施加不同衬底负偏压可控制备了CuO多孔纳米结构薄膜.研究发现,所得CuO薄膜具有灵活可调的孔隙度和纳米构筑单元形貌特征,并且它们与衬底负偏压的大小密切相关;薄膜沿衬底法线方向呈柱状生长且具有显著的（111）择优取向;禁带宽度在2.0.35 eV之间可调.很明显地,传统的溅射离子轰击、再溅射理论并不适合用来解释上述负偏压效应,因此在此基础上提出了一种负偏置沉积过程中材料原子或分子在薄膜表面选择性优先沉积机制.国家自然科学基金(51501018,11574255)；江苏省自然科学基金(BK20150267,BK20141169)；江西省教育厅科技项目(GJJ161197)；江西省自然科学基金(20132BAB212005)资助

Controllable fabrication of Cu_2O porous nanostructured films by negative bias deposition method

由于具有低成本、无毒、铜源丰富等优点,以及在气敏传感器、太阳能电池、光催化等领域的潜在应用前景,; Cu_2O薄膜引起了人们的广泛关注.采用射频平衡磁控溅射镀膜系统,在薄膜沉积过程中通过施加不同衬底负偏压可控制备了Cu_2O多孔纳米结构薄膜.研; 究发现,所得Cu_2O薄膜具有灵活可调的孔隙度和纳米构筑单元形貌特征,并且它们与衬底负偏压的大小密切相关;薄膜沿衬底法线方向呈柱状生长且具有显著; 的(111)择优取向;禁带宽度在2.0~2.35; eV之间可调.很明显地,传统的溅射离子轰击、再溅射理论并不适合用来解释上述负偏压效应,因此在此基础上提出了一种负偏置沉积过程中材料原子或分子在薄; 膜表面选择性优先沉积机制.As one of the most common two kinds of copper oxides, cuprous oxide; (Cu_2O) is an important p-type transition metal oxide semiconductor; material. Due to the advantages of low-cost, non-toxicity and abundant; copper sources and the potential applications in the fields of gas; sensors, solar cells and photocatalysts, thin films of Cu_2O have; attracted great interest of researchers. To enhance the performances of; the above Cu_2O-based surface-sensitive devices and materials, the; researchers tend to prepare Cu_2O thin films of porous or even; nanoporous structures. However, there is still no effective method; available for the controllable fabrication of Cu_2O porous; nanostructured films (or porous nanostructure-films, short for PNFs),; which owns not only the common features of porous thin films but also; the unique properties of nanosize building units. By using a; radiofrequency balanced magnetron sputtering (MS) deposition system, in; this paper, Cu_2O PNFs were prepared on clean glass slides by applying; different negative bias voltage during film deposition. After the; preparation, a field-emission scanning electron microscope (FESEM), a; grazing-incidence X-ray diffractometer (GIXRD) and an; ultraviolet-visible (UV-Vis) spectrophotometer were applied subsequently; for the detailed characterizations of surface morphology, texture and; optical property respectively. It was observed that the as-prepared; Cu_2O PNFs exhibited flexible porosities and nanosize building units,; which were greatly dependent on the substrate negative bias voltage. In; particular, when the substrate bias voltage was kept at -50 or -150 V,; the as-prepared Cu_2O PNFs both demonstrated intriguing triangular; pyramid-like nanostructures with distinct edges and corners on the; porous film surface. Further, the side view FESEM images and the; out-of-plane GIXRD spectra demonstrated a columnar growth of the Cu_2O; PNFs with a notable preferential orientation of (111). The optical; testing results showed that the band gap of the Cu_2O PNFs obtained at; different negative bias voltages was tunable between 2.0 and 2.35 eV,; which demonstrated a little red or blue shift relative to that of bulk; Cu_2O (2.17 eV). It is expected that the traditional ion bombardment and; re-sputtering theories are not suitable for the explanation of the above; bias voltage effects. This is because the traditional ion bombardment; and re-sputtering theories were proposed to account for the bias; deposition in an unbalanced magnetron sputtering (MS) system rather than; the present balanced MS system. Further, the experimentally observed; non-linearly changed density or porosity of the Cu_2O PNFs with the bias; voltage at relatively low values and the common even surface at; relatively high values confirmed this viewpoint. Based on the above; findings and analysis, a selectively preferential deposition of material; atoms or molecules on the film surface during the negative bias; deposition was proposed. That is, when the substrate is negatively; biased, the tipcharging effect of electrons would occur on the nanoscale; rough surface of the substrate or the depositing film. The resulting; electric field near the substrate or film surface is non-uniform and; could be regarded as an assembly of many electric fields of particle or; tip charges.国家自然科学基金; 江苏省自然科学基金; 江西省教育厅科技项目; 江西省自然科学基

Research on Service Composition and Deployment for Pervasive Computing

普适计算（Pervasive Computing）的出现改变了传统的以计算机为中心的资源和信息获取模式，提出一种以人为本的计算方式，为人们提供随时随地、适应环境变化的资源和信息的获取方法，成为下一代网络的主流发展方向之一。普适计算具有环境异构并且动态变化的特点，在这种网络环境中信息的开发和集成打破了传统的模式，软件变服务的观点被普遍接受，并且得到了广泛的应用。因此，面向服务的计算（Service-oriented Computing）和普适计算的结合，是未来信息技术的下一阶段，也成为目前研究的热点问题。 一方面针对普适计算的特点，研究其动态变化、移动性和用户相关性等；一方面针对面向服务的计算，研究其体系结构、服务的描述、查询、组合、部署等问题。普适计算的特点决定了在该环境下的服务组合需要适应环境的动态变化；服务部署需要满足资源约束条件，提高网络资源利用率。基于研究背景以及对目前存在问题的分析，本文进行普适计算环境下服务组合及部署的研究，主要工作包括以下四个方面： （1）提出了一种规则驱动上下文相关的服务组合方法 服务组合是面向服务的计算中经典问题，研究成果包括组合模型、语言、方法和系统等，根据需求提出基于工作流、基于形式化方法、基于语义以及基于服务非功能属性等多种服务组合方法，但这些方法难以解决普适计算中的服务组合问题。因为在普适计算环境下，服务组合不仅需要满足功能性要求，而且要适应环境的异构和动态变化，能够根据环境变化自动的构建组合路径并动态的绑定服务。本文使用上下文刻画普适计算的动态变化性，提出一种基于本体的上下文模型和描述语言，并扩展服务描述，将上下文引入服务组合，提出服务组合算法，实现了规则驱动上下文相关的服务组合路径的建立。 （2）提出一种基于上下文协商的动态服务选取方法 服务组合路径建立了服务执行的先后顺序，在服务的执行期间需要动态的绑定实例，绑定服务实例过程称为动态的服务选取。考虑到普适计算中设备资源有限性以及提高网络资源利用率，本文提出一种基于上下文协商的服务选取方法。首先从已有的上下文本体中获取与动态服务选取相关的上下文，并根据其内容的不同分为用户上下文、设备上下文和服务上下文；然后给出上下文协商的约束条件，基于约束条件提出了上下文的协商算法，进行服务的选取绑定，实现动态服务组合。最后通过实验验证了算法的效率和有效性，分析了上下文数目和服务数目的变化，对服务组合成功率、资源利用率、服务选择冲突率等的影响。 （3）提出普适计算环境下的服务动态部署问题及算法 某些特定的应用（如数字家庭等）需要将服务部署在一个普适计算环境中，部署时需要考虑网络中负载均衡，提高资源利用率。本文针对普适计算中设备异构、资源有限的特点，给出组合服务动态部署问题的描述，并说明该问题是一个NP问题，提出一个启发式算法，能够在多项式时间内找到近似最优解，最后通过算法模拟和实验验证了算法的有效性以及时间性能，说明该方法适用于设备或者原子服务数目较多的普适计算环境。 （4）实现了一个服务组合原型系统 本文在国家八六三项目和国家科技攻关项目研究的基础上，实现了一个服务组合原型系统，该系统是“Web服务计算平台”的一部分，并以分布式文档管理系统为例，给出了服务组合的实现效果。Pervasive computing has been put forward to go beyond the traditional acquirements of resources and information, which based on PCs. It provides a human-centered computing pattern with information and communication technology everywhere, for everyone, at all times and becomes a mainstream of the next generation network. The main features of pervasive computing environment are ubiquitous, heterogeneous and dynamic. In this environment, the developing and integrating of information are different from the old methods, and the viewpoint that a software is a service has been accepted widely. Therefore, the integration of service-oriented computing with pervasive computing has become an active area of research. For pervasive computing, the research work includes the dynamic environment, the mobile device, user-involved, etc. For service-oriented computing, the research work includes the architecture, service description language, service finding, composition, selection, deployment, etc. This thesis puts forward an approach to service composition and deployment in pervasive computing environment. The main points of this thesis are described as follows: (1) The thesis provides an approach to ECA rules driven context-aware service composition Service composition is an important problem in service-oriented computing. The research efforts include service composition model, language, framework, etc. Many service composition methods, such as workflow-based, semantic-based, QoS-aware or context-aware, are discussed for different requirements and applications. However, in pervasive computing, service composition should not only satisfy the functional requirements but also be adapt to the heterogeneous and dynamic environment. The thesis uses context to describe the pervasive computing environment, and provides an ontology-based context modeling language and context reasoning. Based on the context description, the web ontology language for service has been extended with context. It also puts forward EAC rule driven context-aware service composition. (2) An approach to service selection based on context negotiation has been put forward Before a service instance is invoked and executed, it should be selected and bound to adapt to the pervasive computing and satisfy the user’s preferences. First, the definition of the context negotiation is given. Based on the definition, the thesis gives the constraint conditions of context negotiation. According to the constraint conditions, it presents the service composition algorithm. Furthermore, the algorithm is optimized to improve the resource utilization. Some experiments are given to validate the algorithms performance and validity. The experiment data prove that the approach presented in the thesis can be applied to context sensitive service composition in pervasive computing. (3) It discusses the service dynamic deployment method in pervasive computing Based on Liquid—an embedded and component-based system, this thesis presents a dynamic deployment problem and the algorithm of composite services for pervasive computing. First, the thesis defines the problem of dynamic deployment in the pervasive computing environment. Second, the randomized algorithm and the heuristic algorithm are given to solve the problem. Finally, the experiment data are given to analysis and compare the performance of the different algorithms. According to the method, the composite services are deployed into various embedded devices to satisfy resource requirement and improve the resource utilization. The algorithm simulation and analysis indicate that it can be applied to the pervasive computing environment with more devices or atomic services. (4) The service composition prototype is designed and implemented Based on the National High-tech Research and Development Plan of China and National Key Technologies Research and Development program, the thesis designs and implements a prototype of context-aware service composition and applies it to document management system for pervasive computing. It solves the problem that an organization manages the documents distributed in network concentratively

Research on Service Composition and Deployment for Pervasive Computing

普适计算（Pervasive Computing）的出现改变了传统的以计算机为中心的资源和信息获取模式，提出一种以人为本的计算方式，为人们提供随时随地、适应环境变化的资源和信息的获取方法，成为下一代网络的主流发展方向之一。普适计算具有环境异构并且动态变化的特点，在这种网络环境中信息的开发和集成打破了传统的模式，软件变服务的观点被普遍接受，并且得到了广泛的应用。因此，面向服务的计算（Service-oriented Computing）和普适计算的结合，是未来信息技术的下一阶段，也成为目前研究的热点问题。 一方面针对普适计算的特点，研究其动态变化、移动性和用户相关性等；一方面针对面向服务的计算，研究其体系结构、服务的描述、查询、组合、部署等问题。普适计算的特点决定了在该环境下的服务组合需要适应环境的动态变化；服务部署需要满足资源约束条件，提高网络资源利用率。基于研究背景以及对目前存在问题的分析，本文进行普适计算环境下服务组合及部署的研究，主要工作包括以下四个方面： （1）提出了一种规则驱动上下文相关的服务组合方法 服务组合是面向服务的计算中经典问题，研究成果包括组合模型、语言、方法和系统等，根据需求提出基于工作流、基于形式化方法、基于语义以及基于服务非功能属性等多种服务组合方法，但这些方法难以解决普适计算中的服务组合问题。因为在普适计算环境下，服务组合不仅需要满足功能性要求，而且要适应环境的异构和动态变化，能够根据环境变化自动的构建组合路径并动态的绑定服务。本文使用上下文刻画普适计算的动态变化性，提出一种基于本体的上下文模型和描述语言，并扩展服务描述，将上下文引入服务组合，提出服务组合算法，实现了规则驱动上下文相关的服务组合路径的建立。 （2）提出一种基于上下文协商的动态服务选取方法 服务组合路径建立了服务执行的先后顺序，在服务的执行期间需要动态的绑定实例，绑定服务实例过程称为动态的服务选取。考虑到普适计算中设备资源有限性以及提高网络资源利用率，本文提出一种基于上下文协商的服务选取方法。首先从已有的上下文本体中获取与动态服务选取相关的上下文，并根据其内容的不同分为用户上下文、设备上下文和服务上下文；然后给出上下文协商的约束条件，基于约束条件提出了上下文的协商算法，进行服务的选取绑定，实现动态服务组合。最后通过实验验证了算法的效率和有效性，分析了上下文数目和服务数目的变化，对服务组合成功率、资源利用率、服务选择冲突率等的影响。 （3）提出普适计算环境下的服务动态部署问题及算法 某些特定的应用（如数字家庭等）需要将服务部署在一个普适计算环境中，部署时需要考虑网络中负载均衡，提高资源利用率。本文针对普适计算中设备异构、资源有限的特点，给出组合服务动态部署问题的描述，并说明该问题是一个NP问题，提出一个启发式算法，能够在多项式时间内找到近似最优解，最后通过算法模拟和实验验证了算法的有效性以及时间性能，说明该方法适用于设备或者原子服务数目较多的普适计算环境。 （4）实现了一个服务组合原型系统 本文在国家八六三项目和国家科技攻关项目研究的基础上，实现了一个服务组合原型系统，该系统是“Web服务计算平台”的一部分，并以分布式文档管理系统为例，给出了服务组合的实现效果。Pervasive computing has been put forward to go beyond the traditional acquirements of resources and information, which based on PCs. It provides a human-centered computing pattern with information and communication technology everywhere, for everyone, at all times and becomes a mainstream of the next generation network. The main features of pervasive computing environment are ubiquitous, heterogeneous and dynamic. In this environment, the developing and integrating of information are different from the old methods, and the viewpoint that a software is a service has been accepted widely. Therefore, the integration of service-oriented computing with pervasive computing has become an active area of research. For pervasive computing, the research work includes the dynamic environment, the mobile device, user-involved, etc. For service-oriented computing, the research work includes the architecture, service description language, service finding, composition, selection, deployment, etc. This thesis puts forward an approach to service composition and deployment in pervasive computing environment. The main points of this thesis are described as follows: (1) The thesis provides an approach to ECA rules driven context-aware service composition Service composition is an important problem in service-oriented computing. The research efforts include service composition model, language, framework, etc. Many service composition methods, such as workflow-based, semantic-based, QoS-aware or context-aware, are discussed for different requirements and applications. However, in pervasive computing, service composition should not only satisfy the functional requirements but also be adapt to the heterogeneous and dynamic environment. The thesis uses context to describe the pervasive computing environment, and provides an ontology-based context modeling language and context reasoning. Based on the context description, the web ontology language for service has been extended with context. It also puts forward EAC rule driven context-aware service composition. (2) An approach to service selection based on context negotiation has been put forward Before a service instance is invoked and executed, it should be selected and bound to adapt to the pervasive computing and satisfy the user’s preferences. First, the definition of the context negotiation is given. Based on the definition, the thesis gives the constraint conditions of context negotiation. According to the constraint conditions, it presents the service composition algorithm. Furthermore, the algorithm is optimized to improve the resource utilization. Some experiments are given to validate the algorithms performance and validity. The experiment data prove that the approach presented in the thesis can be applied to context sensitive service composition in pervasive computing. (3) It discusses the service dynamic deployment method in pervasive computing Based on Liquid—an embedded and component-based system, this thesis presents a dynamic deployment problem and the algorithm of composite services for pervasive computing. First, the thesis defines the problem of dynamic deployment in the pervasive computing environment. Second, the randomized algorithm and the heuristic algorithm are given to solve the problem. Finally, the experiment data are given to analysis and compare the performance of the different algorithms. According to the method, the composite services are deployed into various embedded devices to satisfy resource requirement and improve the resource utilization. The algorithm simulation and analysis indicate that it can be applied to the pervasive computing environment with more devices or atomic services. (4) The service composition prototype is designed and implemented Based on the National High-tech Research and Development Plan of China and National Key Technologies Research and Development program, the thesis designs and implements a prototype of context-aware service composition and applies it to document management system for pervasive computing. It solves the problem that an organization manages the documents distributed in network concentratively

method of qos-aware service components composition

在面向服务的架构中,如何利用已有的服务构件组装成新的服务成为当前此领域的一个研究热点.该文以构件化嵌入式操作系统Liquid为背景,给出了一种基于QoS的服务构件组合方法,在满足组合服务的功能需求同时,满足其QoS需求.文章详细给出了所涉及的服务模型、QoS模型以及构件选择基本算法.为使此服务构件组合方法适应于动态变化的系统环境,该文进一步对构件选择基本算法进行优化,给出了构件选择的启发和协商算法.最后通过实验,比较和分析三种算法的性能

approach to dynamic service composition based on context negotiation

普适计算的计算环境和交互信息动态变化,为了提供适时适地的服务,服务组合除了满足用户的需求之外,还要适应环境的变化.以面向普适计算的分布式文档管理系统为例,提出一种基于上下文协商的动态服务组合方法,适应普适计算环境下资源动态变化的特点,同时满足用户对服务的需求.首先定义上下文和带有上下文信息的服务模型;然后给出服务和设备以及服务和用户之间的上下文协商约束条件,根据约束条件提出基本算法实现服务动态组合,并对基本算法进行优化;最后通过原型系统和实验验证算法的性能和有效性,并通过实验数据分析上下文对于服务组合的影响.实验数据说明:提出的方法能够应用在普适计算环境中上下文敏感的服务组合问题上,提高服务组合的动态适应性和网络资源利用率