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61.
The effect of ammonium nitrate concentration in the citric acid biosynthesis by Aspergillus niger NC-12 in single-stage continuous cultures with biomass retention was investigated. Experiments were carried out in a BIOMER
laboratory fermenter with 5 dm3 working volume. At the initial stage of each cultivation, the substrate in the bioreactor contained 1.5 g NH4NO3 dm−3. After 120 h onwards, the bioreactor was fed continuously at a constant dilution rate of 0.009 h−1. NH4NO3 concentration in the feed was varied from one culture to another, ranging between 0.5 g dm−3 and 2.5 g dm−3. Promising results were obtained when NH4NO3 concentration of 1.5 g dm−3 was used. The observed concentration of citric acid (c
P) and yield of citric acid with respect to the introduced sucrose (Y
P/S) were 117.88 g dm−3 and 78.59 %, respectively. The efficiency coefficient of citric acid biosynthesis (K
ef) was very high, amounting to 83.38.
Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May
2006. 相似文献
62.
Mingbing Zhong Prof. Dr. Xavier Pannecoucke Prof. Dr. Philippe Jubault Prof. Dr. Thomas Poisson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(46):11818-11822
Herein, the photocatalytic hydrosilylation of alkynes and alkenes under continuous flow conditions is described. By using 0.2 mol % of the developed [Cu(dmp)(XantphosTEPD)]PF6 under blue LEDs irradiation, a large panel of alkenes and alkynes was hydrosilylated in good to excellent yields with a large functional group tolerance. The mechanism of the reaction was studied, and a plausible scenario was suggested. 相似文献
63.
An improved class of Boussinesq systems of an arbitrary order using a wave surface elevation and velocity potential formulation is derived. Dissipative effects and wave generation due to a time‐dependent varying seabed are included. Thus, high‐order source functions are considered. For the reduction of the system order and maintenance of some dispersive characteristics of the higher‐order models, an extra O(μ2n+2) term (n ∈ ?) is included in the velocity potential expansion. We introduce a nonlocal continuous/discontinuous Galerkin FEM with inner penalty terms to calculate the numerical solutions of the improved fourth‐order models. The discretization of the spatial variables is made using continuous P2 Lagrange elements. A predictor‐corrector scheme with an initialization given by an explicit Runge–Kutta method is also used for the time‐variable integration. Moreover, a CFL‐type condition is deduced for the linear problem with a constant bathymetry. To demonstrate the applicability of the model, we considered several test cases. Improved stability is achieved. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
64.
在GB/T 7494–1987法的基础上将自动进样、在线萃取、在线分离技术与分光光度法相结合,测定水中阴离子表面活性剂的含量。在分析过程中利用二次萃取和分离有效除去干扰物质,提高了分析的准确度和灵敏度。标准工作曲线线性相关系数为0.999 2,检出限为0.007 mg/L,测定结果的相对标准偏差为2.0%~2.4%(n=6),加标回收率为95.0%~98.0%。连续流动注射分析法操作简单,基线稳定速度快,连续分析效果好,大大降低了氯仿对人体的危害,适合大批量水质中阴离子表面活性剂含量的分析。 相似文献
65.
We formulate a sufficient condition for the existence of a consistent price system (CPS), which is weaker than the conditional full support condition (CFS). We use the new condition to show the existence of CPSs for certain processes that fail to have the CFS property. In particular this condition gives sufficient conditions, under which a continuous function of a process with CFS admits a CPS, while the CFS property might be lost. 相似文献
66.
67.
Dr. Antoine Nitelet Dr. Damien Thevenet Dr. Bruno Schiavi Dr. Christophe Hardouin Dr. Jean Fournier Dr. Rodolphe Tamion Prof. Dr. Xavier Pannecoucke Prof. Dr. Philippe Jubault Prof. Dr. Thomas Poisson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(13):3262-3266
The copper-photocatalyzed borylation of aryl, heteroaryl, vinyl and alkyl halides (I and Br) was reported. The reaction proceeded using a new heteroleptic Cu complex under irradiation with blue LEDs, giving the corresponding boronic-acid esters in good to excellent yields. The reaction was extended to continuous-flow conditions to allow an easy scale-up. The mechanism of the reaction was studied and a mechanism based on a reductive quenching (CuI/CuI*/Cu0) was suggested. 相似文献
68.
69.
《佛山科学技术学院》2014,6(4):435-450
In the present paper, self-adjoint operator and completely continuous operator on soft inner product spaces have been introduced and some basic properties of such operators are studied. 相似文献
70.
Continuous‐Flow Microwave Synthesis of Metal–Organic Frameworks: A Highly Efficient Method for Large‐Scale Production
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Dr. Marco Taddei Daniel Antti Steitz Prof. Dr. Jeroen Anton van Bokhoven Dr. Marco Ranocchiari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3245-3249
Metal–organic frameworks are having a tremendous impact on novel strategic applications, with prospective employment in industrially relevant processes. The development of such processes is strictly dependent on the ability to generate materials with high yield efficiency and production rate. We report a versatile and highly efficient method for synthesis of metal–organic frameworks in large quantities using continuous flow processing under microwave irradiation. Benchmark materials such as UiO‐66, MIL‐53(Al), and HKUST‐1 were obtained with remarkable mass, space–time yields, and often using stoichiometric amounts of reactants. In the case of UiO‐66 and MIL‐53(Al), we attained unprecedented space–time yields far greater than those reported previously. All of the syntheses were successfully extended to multi‐gram high quality products in a matter of minutes, proving the effectiveness of continuous flow microwave technology for the large scale production of metal–organic frameworks. 相似文献