Nonlinear state estimation for fermentation process using cubature Kalman filter to incorporate delayed measurements☆

State estimation of biological process variables directly influences the performance of on-line monitoring and op-timal control for fermentation process. A novel nonlinear state estimation method for fermentation process is proposed using cubature Kalman filter (CKF) to incorporate delayed measurements. The square-root version of CKF (SCKF) algorithm is given and the system with delayed measurements is described. On this basis, the sample-state augmentation method for the SCKF algorithm is provided and the implementation of the proposed algorithm is constructed. Then a nonlinear state space model for fermentation process is established and the SCKF algorithm incorporating delayed measurements based on fermentation process model is presented to implement the nonlinear state estimation. Finally, the proposed nonlinear state estimation methodology is applied to the state estimation for penicillin and industrial yeast fermentation processes. The simulation results show that the on-line state estimation for fermentation process can be achieved by the proposed method with higher esti-mation accuracy and better stability.     

Cellulose nanofibers prepared from TEMPO‐oxidation of kraft pulp and its flocculation effect on kaolin clay

Cellulose nanofibers were prepared using TEMPO/NaBr/NaClO oxidation of kraft pulp and successive ultrasonic treatment, and the properties were characterized by conductimetric titration, X‐ray diffraction, and atomic force microscopy. The resulting product was then applied as an anionic microparticle to constitute a microparticulate system with cationic polyacrylamide (CPAM), to induce the flocculation of the kaolin clay suspension. The flocculation effect was evaluated by determining the relative turbidity of clay suspension. The results showed that the obtained cellulose nanofibers had cellulose I structure with higher crystallinity than that of the kraft pulp, and their cross‐sectional dimension was in the range of 3–5 nm. They had more negative zeta potential at neutral and alkaline conditions. It was found that the microparticulate system showed high flocculation effect on kaolin clay at a very low level of nanofiber addition, and a high shear level after CPAM addition was helpful for the flocculation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40450.     

燃烧前CO2捕集技术在IGCC发电中的应用

由于整体煤气化联合循环（IGCC）发电本身的技术特点,使得其非常适合于进行燃烧前CO₂捕集。针对IGCC特点,提出了一种MDEA脱酸气结合湿法氧化法硫回收的燃烧前CO₂捕集流程。通过模拟计算,验证了流程的可行性。将其与IGCC发电系统集成,对比计算了有无燃烧前CO₂捕集的IGCC系统供电效率等相关参数,燃烧前CO₂捕集使IGCC供电效率降低约10个百分点。分析指出了导致包含燃烧前CO₂捕集的IGCC供电效率降低的3个因素：蒸汽消耗、燃料化学能损失和新增动力设备电耗,并据此确定了今后的优化方向。     

羧甲基-β-环糊精的制备及表征

在碱性介质条件下,以β-环糊精(β-CD)和一氯乙酸为原料,通过亲核取代反应得到羧甲基-β-环糊精(CM-β-CD),并用红外光谱和核磁共振对其进行了表征。考察了反应时间、反应温度和反应物配比对制备产物取代度的影响,结果表明:一氯乙酸与β-CD的物质的量比为10∶1时,在65℃时,反应7 h,可得到取代度3.66的羧甲基-β-环糊精。     

分子印迹技术在水中污染物处理中的应用及发展

分子印迹聚合物具有选择性高,特异性强等特点,能从复杂基质中选择性的去除目标物,在多污染体系中有重要的发展潜力和应用前景。综述了近些年来分子印迹在水污染处理中的应用和研究进展,并对目前存在的问题进行了探讨。     

添加惰性物配煤炼焦的研究进展

添加惰性物质配煤炼焦是降低配煤炼焦成本以及扩大炼焦煤资源的有效途径。概述了在成焦过程中,惰性物与配合煤中活性组分相互作用的结焦机理,总结了添加焦粉和无烟煤炼焦的研究及应用现状,提出了配合煤中添加惰性物最为关键的是配入量和粒度。展望了添加惰性物配煤炼焦在焦化行业的应用前景。     

室内甲醛污染控制技术研究进展

综述了吸附法、植物净化法、空气负离子技术、化学反应法、光催化法以及热催化氧化法等室内甲醛污染控制技术。其中,热催化氧化法尤其是室温催化氧化法在不用外加光源和热源情况下即可催化甲醛完全氧化,便于集成到空气净化器或通风空调系统中,适用范围广,被认为是空气净化技术发展的趋势,具有广阔的发展空间和应用前景。催化剂作为室温催化氧化技术的核心,开发高效稳定、廉价易得的室温应用催化剂将成为室内甲醛污染控制技术的重点研究方向。     

Experimental and numerical investigation of sands and Geldart A biomass co-fluidization

This article investigated the fluidization of sands and small Geldart A biomass mixtures. The mixture fluidized like Geldart A type particles with a uniform bed expansion regime before bubbling. The video recorded color distance between pure sands and sands–biomass mixtures was used to estimate the sands–biomass mixing. The coarse-grained computational fluid dynamics–discrete element method with a hybrid drag model which couples the Syamlal–O'Brien drag and a filtered drag can capture the mixing while the simulation with Gidaspow drag predicted a segregated bed. The simulations were further validated with experimental measured pressure drops. The time averaged pressure drop equals the weight of the bed material, however, its fluctuation is about three times of the bed material fluctuation.     

Synthesis, properties and applications of nanoscale nitrides, borides and carbides

Nanoscale nitrides, borides and carbides are a fascinating type of materials, which have aroused tremendous and continuous research interest for decades owing to their special mechanical, electrical, optical, photoelectronic, catalytic properties and widespread uses. In this feature article, recent developments and breakthroughs in the synthesis, properties and applications of nanometre scale nitrides (BN, Si(3)N(4), GaN, noble nitrides), borides (LnB(6), LnB(2), Fe(3)BO(5), LiMBO(3)) and carbides (carbon, SiC, TiC, NbC, WC) were briefly reviewed in sequence of their different dimensions (1D, 2D and 3D). In particular, our latest advances in the "autoclave route" fabrication of nanoscale nitrides, borides, and carbides were highlighted. The challenges, issues and perspectives of the synthetic methodologies and potential applications concerning the above-mentioned materials were also briefly discussed.     

农地乐52．25％乳油防治甜菜夜蛾田间药效试验与示范

试验结果表明,农地乐 ５２．２５ＥＣ防治甜菜夜蛾速效性好于对照药剂抑太保和除尽,药后 １ｄ的防效,１０００、６６７倍液达 ８０％以上,５００倍液达 ９０％以上。药后 ７ｄ的防效,１０００、６６７倍液为 ９１．４％～９３．３％,与抑太保 １０％乳油 １０００倍液相当;５００倍液为 ９６．７％,与除尽相当。农地乐 ５２．２５ ＥＣ防治甜菜夜蛾的持效期为 ７～８天。农地乐对作物安全。示范面积２．１× １０３ｈｍ２,平均防 效达 ８５％以上。农地乐 ５２．２５ ＥＣ已成为冀东防治甜菜夜蛾的首选药剂。