可耗竭性资源从价税与累积开采量的关系研究——基于Hotelling模型的改进

提高可耗竭性资源累积开采量对解决我国资源短缺和资源开采效率低下并存的问题具有重要的意义。在增加了开采成本随累积开采量递增的假设下,本文首先对Hotelling模型做了改进。其次,运用最优控制方法,以完全竞争市场为比较基准,本文研究了垄断市场下从价税与累积开采量之间的关系。研究发现:第一,当从价税税率为零时,垄断市场下的累积开采量低于完全竞争市场下的累积开采量。第二,当从价税税率大于零时,征收从价税进一步降低了垄断市场下的累积开采量。第三,当从价税税率小于零时,征收从价税有利于提高垄断市场下的累积开采量。     

基于语义的服务资源描述模型RDF4S

在已有的语义Web服务描述框架基础上,定义了一种语义Web服务资源描述模型RDF4S,该模型从功能、接口、执行和QoS 4个层面描述服务资源的语义信息,并基于该模型提出了一个语义Web服务资源发现框架.结合旅游预订系统的一个实例,展示了RDF4S 4层语义信息的描述能力和支持发现的能力,并给出RDF4S描述模型和其他语义Web服务描述模型的比较.该工作对基于语义信息进行服务的自动发现、组合和调用具有一定的参考作用.     

四明山国家森林公园野生植物资源的开发利用与保护对策

四明山国家森林公园自然条件优越,森林覆盖率高,野生植物资源蕴藏丰富,有高等植物1226种,隶属于164科．根据用途可将它们分为食用、药用、观赏、工业用、饲料植物五大类,其中食用植物共有257种,占总数的20．96％;药用植物共有588种,占总数的47．96％;观赏植物共有383种。占31．24％：工业用植物共有342种,占总数的27．90％;饲料植物共81种,占6．60％．通过对四明山国家森林公园野生植物资源情况和利用现状的调查,提出合理开发利用园内野生植物资源的建议．同时由于人们尚未对野生植物有较好的保护意识,对一些已具商品价值的野生植物随意采集和肆意破坏,造成一些物种的不断减少,有的甚至濒临灭绝．我们就此提出一些保护对策,希望在保护前提下较好地开发利用这些野生植物资源,使这些野生植物资源得到永续利用．     

An efficient task allocation framework for scheduled data in edge based Internet of Things using hybrid optimization algorithm approach

Allocation of tasks in IoT is an integral and critical approach to finding a perfect match between scheduled tasks of a particular application and Edge-based processing devices for instant response and efficient utilization of resources to make them renewable. We need a protocol to help optimize the problem of allocating processing devices to the tasks, as task allocation is considered an NP-hard problem to prevent problems with energy consumption and response time problems. For this, a hybrid bio-inspired Swarm-based approach will improve the solution to optimize the matching of a task to a particular device. This paper proposed a Meta-heuristic algorithm to optimize Energy and Time-delay for allocating tasks to the edge-based Processing device in IoT. The proposed algorithm called the Hybrid Artificial Bee Colony whales Optimization algorithm (HAWO) is formulated by integrating Artificial Bee Colony with the Whales Optimization algorithm to overcome the search process of an Artificial Bee Colony, which converges too soon due to the local search of Employee Bee phase and Onlooker Bee phase causing the problem of looping. From the simulation results conducted in Matlab, it is observed that the integrated HAWO method shows promising results in terms of Energy and Time Delay when compared with Artificial Bee Colony and Whales Optimization algorithms separately. Also, proposed method when compared with the benchmark work shows significant improvements of 50%, 25% and 60% in terms of Energy, Time Delay and Best cost, respectively.     

Novel Synthetic Strategy for the Production of Fully Bio-Based Binders Using 2,5-Diformylfuran

In this work, resol based binders were prepared with lignin, resorcinol and the bio-based aldehydic platform chemicals 5-hydroxymethylfurfural (HMF) and 2,5-diformylfuran (DFF). In preliminary studies, the solubility and stability of DFF in aqueous-alkaline conditions was investigated. Various binders were prepared to investigate the influence of the HMF-DFF ratio and the influence of the aldehyde concentration on the molar mass, rheological properties and curing characteristics of the final binders. It is shown that significantly higher molecular weights and viscosities are obtained by using DFF instead of HMF. The properties of the final binder could also be affected by the precise choice of DFF concentration, as this resulted in higher levels of crosslinking. This work offers a novel type of fully bio-based binder that consists of non-toxic components and is therefore less hazardous than some conventional binders.     

On the Structure–Odor Correlation of Muguet Aldehydes: Synthesis of 3-(4’-Isobutyl-2’-methylphenyl)propanal (Nympheal) and Four Novel Derivatives from a Hagemann’s Ester

Lilybelle and Biomuguet are currently the only renewable and biodegradable non-spermotoxic Lilial replacers. Being non-aromatic, these lack however some of the green, aquatic aspects of Lilial that are present in the captive odorant Nympheal, 3-(4-isobutyl-2-methylphenyl)propanal, which is not available from renewable resources. Therefore, the influence of the aromatic nucleus on the odor of four new hydrogenated Nympheal derivatives was investigated, which were all accessible from the isobutyl Hagemann’s ester that was synthesized in 75 % yield from isovaleraldehyde with two equivalents of ethyl acetoacetate. The respective Hagemann’s ester was alkylated with 3-bromopropanal dimethyl acetal and subjected to decarboxylative saponification, followed by hydride reduction and dehydration through the corresponding mesylate to furnish, after deprotection with formic acid, the corresponding exo- and endo-dihydro-Nympheal derivative. Full or partial hydrogenation of the central acetal-protected intermediate provided after deprotection the analogous fully saturated analogue or the cyclohexene derivative. The olfactory properties of these four novel Nympheal derivatives are discussed and rationalized by computational olfactophore models.     

传统文化融入中学化学教学——“非遗印染技艺”的教学资源开发

从染料的利用历史、传统印染工艺、印染环保创新等3个维度挖掘了非遗印染技艺的教学资源，与萃取、自然资源开发利用、还原剂、硫及其化合物、酚醇性质、配合物、电解池等化学知识结合，以印染技艺为载体将传统文化、思政教育与化学教学有机融合，落实化学学科核心素养的发展，为传统文化融入中学化学教学提供借鉴。     

Progress in Renewable Polymers from Natural Terpenes,Terpenoids, and Rosin

The development of sustainable renewable polymers from natural resources has increasingly gained attention from scientists, engineers as well as the general public and government agencies. This review covers recent progress in the field of renewable bio‐based monomers and polymers from natural resources: terpenes, terpenoids, and rosin, which are a class of hydrocarbon‐rich biomass with abundance and low cost, holding much potential for utilization as organic feedstocks for green plastics and composites. This review details polymerization and copolymerization of terpenes such as pinene, limonene, and myrcene and their derivatives, terpenoids including carvone and menthol, and rosin‐derived monomers. The future direction on the utilization of these natural resources is discussed.     

Liquid mulch based on poly(vinyl alcohol). PVA-soil interaction

This study is meant to provide a contribution in recent developments of biodegradable polymeric materials applied in agricultural practices with particular reference to the mulching segment. Special attention has been devoted to material based on renewable resources or utilization of waste products from agro-industrial activities, thus suggesting cost-effective and environmentally sound solutions to specific social needs. In the present contribution PVA solubility at room temperature has been improved by premixing with chemical additives and proteic materials. Waste materials from ethanol production by corn fermentation and from wood industries have been used as, respectively starch-based and lignocellulosic additives. The prepared formulations were applied on the soil by conventional spraying agricultural equipment. Time of permanence of the film formed on the soil was monitored as well as the effect on corn growth and yield production. Finally, in order to investigate the final fate of the PVA applied on the soil, a test was performed in lysimeters, with half of the lysimeters cropped with maize plants. PVA amount applied for the mulching test was in order of 5-10 g PVA/1 m²; under those conditions it resulted completely absorbed and no presence of PVA was recorded in the leached solutions.     

Characteristics and degradation of hybrid composite films prepared from PVA,starch and lignocellulosics

A research cooperation between USDA and the University of Pisa led to the development of several composite blends of poly(vinyl alcohol) (PVA) and lignocellulosic fibers. The cast films were prepared by blending orange fibers (OR-fibers) and PVA with and without cornstarch to yield flexible and cohesive films. To improve properties, films were also prepared by crosslinking PVA, starch and OR-fibers with hexamethoxymethylmelamine (HMMM). Films were evaluated for their thermal stability, water permeability and biodegradation. Thermal gravimetric analyses indicated the potential usefulness of such blends in several thermoplastic applications. Films were permeable to water, and retained the moisture content in the soil while retaining their integrity. Films generally biodegraded within 30 days in compost, achieving between 50-80% mineralization. Both neat PVA and blends that had been crosslinked showed comparatively slow degradation. A possible stimulating effect of lingocellulosic fillers on the biodegradation of PVA in blends has been observed.