Strategies of Prior-Fractionation for the Graded Utilization of Lignocellulose

木质生物质是地球上最丰富的一类生物质资源,主要由碳水化合物高分子(纤维素、半纤维素)和芳族聚合物(木质素)组成。木质纤维组分的清洁高效分离,是实; 现多元化、高值化生物精炼的重要基础。本文首先讨论了基于分级利用的组分分离技术与基于制备纤维素乙醇的预处理技术的不同之处;其次,梳理归纳了五种木质; 纤维组分优先分级分离策略:纤维素优先分离,木质素优先分离,半纤维素优先分离,木质素和半纤维素优先分离以及纤维素和半纤维素优先分离;再次,基于半纤; 维素优先分离策略,对国内相关的产业化应用进行了评述;最后,对木质生物质组分分离技术的当下定位和发展前景进行了总结与展望,以期对木质生物质的三大组; 分有较全面的价值观念和利用思路,并对木质生物质精炼技术的发展提供借鉴与参考。Lignocellulosic materials contributing the large proportion to the biomass resource are mainly composed of carbohydrate polymers (cellulose, hemicellulose), and aromatic macromolecules (lignin). Pre-fractionating lignocellulose is considered as the foundational step to establish an economical and sustainable lignocellulosic biorefinery. Firstly, the distinction between lignocellulose fractionation technologies and pretreatment methods for cellulosic ethanol production is discussed. Afterwards, five prior-fractionating strategies of lignocellulose for the biorefinery process are elaborated, including cellulose-first processing, lignin-first processing, hemicellulose-first processing, lignin & hemicellulose-first processing, and cellulose & hemicellulose-first processing. And then industrial applications of hemicellulose-first processing in our country are reviewed. Ultimately, the future perspective on lignocellulose fractionation technologies are given. The aim of this review is to provide new insights into the lignocellulosic biorefinery based on the fractionating of lignocellulose.National Natural Science Foundation of China [21676223, 21506177];; Fujian Provincial Development and Reform Commission, China [2015489];; Fundamental Research Funds for the Central Universities [20720160087,; 20720160077, 20720170062]; Natural Science Foundation of Fujian Province; of China [2016J01077, 2015J05034]; Education Department of Fujian; Province [JZ160398

Classification method of diabetes based on integration of characteristic classifier

目的:结合医用电子鼻技术,探讨糖尿病患者及其口腔呼气的气味图谱特征。方法:选择180例糖尿病患者和100例健康者,用医用电子鼻采集280例口腔呼气的气味图谱,采用基于数据特征划分的方法,用支持向量机和随机森林集成模型对糖尿病患者进行分类预测。结果:1线性核函数的支持向量机(SVM1)分类结果不是很理想,低于多项式核(SVM2)、径向基函数核(SVM3)和随机森林(RF)3种分类器,说明分类超平面显然是非线性的;2集成分类器对糖尿病患者和健康者的气味图谱特征的识别准确率可达88.04%。结论:基于特征划分的分类器集成方法预测性能明显好于单一分类器,为使用医用电子鼻进行糖尿病诊断分析提供了一种有效手段。Objective: To discuss the proi le features of oral odor of diabetic patients based on medical electronic nose technology. Methods: 180 patients of diabetes and 100 healthy people were selected, and the proi le features of oral odor of 280 volunteers were collected by using medical electronic nose. The classii cation forecasting was carried out on diabetic patients by using support vector machine(SVM) and random forest integration model based on partitioning method of data characteristics. Results: 1The classii cation result of SVM1 was not very good, which was lower than that of SVM2, SVM3 and RF, and the result showed that the classii cation hyperplane is nonlinear. 2The accurate rate of recognition of integrated classii er on diabetic patients and healthy people is 88.04%. Conclusion: The forecasting performance of classii er integration method based on feature division is superior to that of single classii er signii cantly, which provided an ef ective means for the diagnostic analysis of diabetes based on medical electronic nose.国家自然科学基金项目(No.81373552);; 福建省教育厅A类项目(No.JA14212);; 福建工程学院科研启动项目(No.GY-Z12079)~

Synthesis of Compact ZSM-5 Zeolite Membrane by Adding the Promoter NaCl

[中文文摘]报道了一种添加氯化钠低温条件下合成出具有纳米尺寸的ZSM 5分子筛 ,并以其为晶种预吸附在多孔氧化铝载体上 ,再通过添加成膜促进剂氯化钠二次水热合成制备出高度致密ZSM 5分子筛膜的新方法 .通过考察添加的钠离子浓度对成膜的影响 ,认为在一定浓度范围内钠离子能够促进成膜 .SEM结果也验证了这一结论 ,分子筛膜主要是由孪生聚晶分子筛组成 .渗透结果显示 ,当添加量为x =10 0 (Al2 O3 ∶84SiO2 ∶10Na2 O∶xNaCl∶15TPABr∶3 5 0 0H2 O)时 ,在室温和 0 .1MPa的条件下 ,H2 /C3 H8的理想选择性最大值 2 3 .7,温度提高到 2 0 0℃时的选择性下降为 9.4,但仍然高于努森扩散值 (4 .69) ,表明该膜具有高度的完整性。[英文文摘]The compact ZSM-5 membranes was synthesized on porous alumina substrates by pre-coating nanosized ZSM-5 seeds and then employing the twice hydrothermal synthesis with adding the promoter NaCl. Effect of Na + concentration on the formation of membrane was investigated in this work, indicating that adding a certain mount of NaCl can boost the growth of zeolite crystals on the substrates, thus forming the compact membrane consisted of highly intergrown crystals. The separating performance of zeolite membranes indicated that using a mixture with a composition of Al2O3∶84SiO2 ∶10Na2O∶100NaCl ∶15TPABr∶3500H2O as synthesis gel , the ideal selectivity of H2/ C3H8 could reach a maximum value of 23. 7 at room temperature and pressure difference of 0. 1 MPa , and the permselectivity decreased to 9. 4 at testing temperature of 200 ℃, which is still higher than the corresponding Knudsen diffusion value (4. 69) , suggesting that the membrane synthesized by this method was defect-free.国家重点研究发展规划基金 (No.G1999022401 ); 国家自然科学基金(No.K16161 )资助项目

Effect of Exogenous Nitric Oxide Donor Sodium Nitroprusside on Stomatal Movement in Leaves of Mangrove Plant Aegiceras corniculatum

探索一种用材简单、操作方便、真实性强的观察红树植物桐花树叶片气孔的制片技术,并利用该技术研究不同浓度、不同处理时间的一氧化氮(nO)供体硝普钠(SOdIuM nITrOPruSSIdE,SnP)对桐花树气孔开闭的影响,探讨了nO调控的气孔运动与外源CA2+的关系以及nO与H2O2在调节气孔运动过程中的关系。结果表明:在搅碎法、指甲油印迹法、牛皮胶印迹法三种观察气孔方法中,牛皮胶印迹法是观察气孔开度变化的最佳方法。nO能够诱导桐花树气孔快速关闭,且表现出明显的时间效应与浓度效应。nO导致的气孔关闭与CA2+的参与有密切关系,nO与H2O2存在明显的协同效应,可以促进气孔关闭。The aim of the present paper was to find out a simple and easy-to-go method to observe the stomatal movement of a mangrove plant Aegiceras corniculatum.The new method was used to study the following areas, inculing the effect of exogenous nitric oxide (NO) on the leaf stomatal movement under different concentrations and different treated time, the effect of Ca2+ in the regulation of stomatal movement induced by exogenous NO, the interactional effect between NO and H2O2 in the regulationb of stomatal movement.The results suggested that the oxhide pastern print was the best way to observe stomatal movement of A.corniculatum compared with the blender method and the nail enamel print method.The stomatal closure induced by NO was associated with Ca2+ in dose dependent manner.It was also proved that a rapid stomatal closure could be co-induced by NO and H2O2 in A.corniculatum guard cells.国家自然科学基金项目(30770192;30670317);厦门大学“新世纪优秀人才支持计划”项目(X07115);湖北民族学院博士启动基金项

NaA型分子筛膜的合成及分离性能的研究

在自制的片状多孔陶瓷载体上 ,通过多次原位水热晶化合成出NaA型分子筛膜 .通过扫描电子显微镜观测 ,发现在某些区域 ,小颗粒的NaA型分子筛以非常紧密的形式畸晶孪生在一起 ,其致密度远好于由分子筛晶粒松散无规律堆积而形成的膜排列方式 .此类膜生长形式可能是获取致密无缺陷型分子筛膜的一种途径 .单组分及双组分气体渗透测试结果表明 ,在所合成的分子筛膜上 ,晶粒间隙孔可能是主要的膜扩散通道 ,可凝聚气体异丁烷因发生毛细管凝聚现象而具有高于氢及甲烷的真实选择透过

A DDA Calculation on the Optical Properties of Silver Nanorods

【中文文摘】利用离散偶极近似 (Discretedipoleapproximation ,简称DDA)的方法 ,从理论上对粒子的形状、尺寸及周围介质等因素对银纳米粒子 ,特别是银纳米棒的光学性质的影响进行了较系统的研究 .计算表明 ,置于空气中的棒状银纳米粒子的光学性质与其形状密切相关 ,纵向表面等离子体共振吸收峰的位置随纳米棒长径比的增加呈现线性红移关系 .给出了空气中银纳米棒纵向表面等离子体共振吸收峰的位置随长径比变化的DDA拟合公式 .如果将金属纳米粒子置于折射率更高的介电环境中 ,其纵向等离子体共振吸收峰的位置进一步呈现线性红移关系 .合成的银纳米粒子的TEM图像及相关的UV VIS消光光谱显示DDA计算结果与实验值相当一致 .DDA算法与Mie′s理论在计算球状银纳米粒子的消光系数时给出很接近的结果 ,这表明用DDA的方法来分析银的光学性质是准确可靠的 ;而DDA算法对银纳米棒消光特性的成功拟合则表明 ,该算法相对Gans′理论而言 ,在研究纳米粒子的光学性质时具有更广的适用性及更高的准确性 . 【英文文摘】The optical properties of metal nanoparticles are quite different from those of the bulk materials mainly due to the collective oscillations of their conduction electrons known as the surface plasmon resonance (SPR), which is strongly dependent on the particle shape and size, and the dielectric properties of the local environment where the nanoparticles are embedded in. Based on the discrete dipole approximation (DDA) method, we studied the optical properties of silver nanorods with different aspect ratios ...Project supported by the National Natural Science Foundation of China (2 0 2 2 80 2 0,2 0 0 2 10 0 2

The Size and Shape Effects on the Optical Properties of Gold Nanoparticles

【中文文摘】纳米尺度的金属及半导体呈现出特殊的光学、电学及磁学性质,采用近年发展起来的离散偶极近似(DDA)的方法,我们分析了金纳米粒子的尺寸及形状对其光学性质的影响。粒子周围介质的影响在文中亦作了分析。计算结果显示,金纳米粒子的等离子体吸收带同时受到粒子尺寸和形状的影响,但来自形状的影响更为明显。与米氏理论及扩展的甘氏理论相比较,DDA方法在粒子尺寸不再远小于入射光波长的时候更准确,并能应用于任何形状的纳米粒子。理论计算与实验结果能较好的吻合。 【英文文摘】Metals and semiconductors exhibit unusual optical, electronic, and magnetic properties at the nanometer scale. Based on the newly developed method, discrete dipole approximation (DDA), the dependence of the optical properties of the gold nanoparticles on the size and shape was analyzed. The effects of the surrounding medium were also taken into consideration in the calculation. The calculated results show that the plasmon absorption band depends on both the size and shape of the gold noanoparticles. However , the influence of the shape is more significant . Compared to the Mieps theory and the extension , Gansp theory , the DDA method is more accurate when the dimensions of the particles are not much smaller than the wavelength of the incident light and can be applied to particles of any shape. The theoretical results are in good agreement with the experimental data.国家自然科学基金项目,批准号为 :20003008,2983306

预涂布晶种法合成无缺陷A型分子筛膜的研究

采用一种颗粒度约为 2 0 0 nm的胶态 A型分子筛为晶种源 ,对晶种层进行特殊的蒸气处理后 ,进一步采取原位水热晶化法 ,在多孔氧化铝载体表面制备出 A型分子筛膜 .膜分子筛以特殊的孪生聚晶形式生长在一起 ,可有效地消除晶粒间隙 ,形成致密的分子筛膜层 .晶化反应液的碱度对 A型分子筛膜的质量影响很大 ,低碱度更有利于 A型分子筛膜的生长 .在对分子筛膜进行高温活化处理过程中产生一些缺陷孔 ,降低了膜气体分离性

Promotional Effects of Ni and Mg on the Preferential Oxidation of CO over Carbon Nanotube-Supported Pt Catalyst

采用共浸渍法制备了nI和Mg促进的碳纳米管载PT催化剂(PT-nI-Mg/CnT),考察了其对CO优先氧化的催化性能.结果表明,PT,nI和Mg在CnT表面发生了相互作用,可能存在合金纳米粒子,从而显著改善了催化剂CO优先氧化的催化性能.添加适量nI可提高CO的转化率,而加入适量Mg则有助于改善CO2的选择性.当PT,nI和Mg同时负载时,优化后所得的催化剂5%PT-5%nI-5%Mg/CnT在100°C对富H2气体中CO选择氧化的转化率为100%,CO2的选择性为53.7%;该催化剂在140°C下连续反应24H,催化活性稳定.A carbon nanotube-supported Pt catalyst promoted by Ni and Mg(Pt-Ni-Mg/CNT) was prepared by the co-impregnation method for preferential oxidation of CO in H2-rich gas.The results of X-ray diffraction, H2 temperature-programmed reduction, transmission electron microscopy, and energy dispersive spectroscopy indicated that Pt interacted with Ni and Mg on CNT surface and might form alloy nanoparticles to some extents, which in turn markedly improved the catalytic performance of preferential oxidation of CO in H2-rich gas.The results of performance tests showed that CO conversion at low temperatures could be effectively enhanced by adding a proper amount of Ni, while the selectivity was improved by adding a proper amount of Mg.When Ni and Mg were added simultaneously, the 5%Pt-5%Ni-5%Mg/CNT catalyst showed CO conversion of 100% and selectivity for CO2 of 53.7% in a H2-rich stream at 100 °C.The catalytic performance did not change obviously during 24 h of run at 140 °C.国家重点基础研究发展计划(973计划;2009CB939804);福建省科技重大专项前期项目(2009HZ10102