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Design and control of fraction cutting for the separation of mixed alcohols from the Fischer-Tropsch aqueous by-products

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Chinese Journal of Chemical Engineering 2022年第10期50卷 143-154页

作者： Renren Zhang Yang Huang Kaitian Zheng Chunjian Xu School of Chemical Engineering and Technology State Key Laboratory of Chemical EngineeringChemical Engineering Research CenterTianjin UniversityTianjin 300072China

Since the minimum-boiling azeotropes of C2-C8 alcohols with water and high-water content(up to 95%(mass))in the Fischer-Tropsch aqueous by-products,the separation is energy-intensive and *** energy-saving strategy for the complete separation of the Fischer-Tropsch aqueous by-products has received massive attention in recent *** this study,a stripper-sidestream decanter process is proposed by exploiting homogeneous azeotropes(C2-C3 alcohols-water)and heterogeneous azeotropes(C4-C8 alcohols-water).The introduction of the stripping column for pre-dehydration avoids the revaporization of the mixture,and energy carried by the overhead vapor is conserved instead of being removed in a *** precise fraction cutting of C1-C3 alcohol-water mixture,C4-C8 alcohols,and water is realized by the sidestream distillation *** C4-C8 alcohols rich mixture withdrawn from the sidestream flows into the decanter to break the distillation boundary,where the organic phase returns to the sidestream distillation column to obtain the dehydrated C4-C8 alcohols,and the aqueous phase enters the stripping ***-state optimization based on total annual cost(TAC)minimization shows that the stripper-sidestream decanter process reduces TAC by 17.00%and saves energy by 21.27%compared with the conventional three-column distillation ***,a control structure of the process is established,and dynamic simulations show that the control structure combining a differential controller with a low-selector exhibits robust co *** study provides a novel design scheme and deepens the insights into the efficient separation of aqueous by-products of the Fischer-Tropsch synthesis.

关键词： Fischer–Tropsch synthesis Mixed alcohols Azeotrope Separation Simulation Control

Modeling Global and Local Aspects of Spatial Structure Explicitly in Land-Use Optimization: The Case of Mek'ele City, Ethiopia

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Chinese Journal of Urban and Environmental Studies 2023年第2期11卷 66-96页

作者： Ashenafi MEHARI Paolo Vincenzo GENOVESE School of Architecture Tianjin University International Center of History Critics of Architecture and Restoration of Historical Heritage (ICHCR) College of Civil Engineering and Architecture Zhejiang university

Urban spatial structure remains the center of quest and modeling. The decentralization concept is among the leading literature discourses that guide spatial analyses. In line with the decentralization discourse, the application of land-use optimization as a modeling method has grown significantly. Despite decentralization dominating the contemporary spatial analysis literature, no study so far explicitly declares an end to the centers(and subcenters). While centers(and subcenters) are alive, the land-use optimization has never taken this macro-morphological structure into consideration. This case study frames land-use optimization within the agglomeration and decentralization concepts based on the view that no single conceptual framework addresses spatial analysis sufficiently. On a theoretical level, the link is between coarse morphological assumption(basis of economic geography) and decentralization(basis of sustainable built environment). The paper blends these dual theories, one governing urban macro-morphological structures and the other governing decentralization literature. On a methodological modeling level, it blends centers and other discretized uses. Optimizing four objectives across the complete centralization through multiple centers of gravity to complete the decentralization of urban spatial structures applying Non-dominated Sorting Genetic Algorithm II, the case study findings justify the importance of explicit modeling of the macro-morphological element. It has been observed that multicenter urban forms perform well above both the single center and the dispersed scenarios. It is, therefore,argued that an appropriate approach to land-use optimization is modeling both the macro-spatial element and fine spatial elements. The result further indicates that local land-use planning regulations place the structure of city in a suboptimal state.

关键词： Land-use optimization urban form multicenter city decentralization coarse spatial scale fine spatial scale

Phosphinic Acid/Nal Mediated Reductive Cyclization Approach for Accessing the L-1-Deoxynojirimycin Using a Two-Component Three-Centered (2C3C) Ugi Type Reaction

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Chinese Journal of Chemistry 2021年第6期39卷 1503-1510页

作者： Chandra S Azad Pratibha Shukla Mark A Olson Anudeep K Narula Institute for Molecular Design and Synthesis School of Pharmaceutical Science&TechnologyHealth Science PlatformTianjin University92 Weijin RoadNankai DistrictTianjin 300072China "Hygeia" Centre of Excellence in Pharmaceutical SciencesGuru Gobind Singh Indraprostho UniversitySector 16-CDwarkaNew Delhi 110078India Department of Chemistry Northwestern University2145 Sheridan RoodEvanstonIL 60208USA

A catalytic two-component three-centered(2C3C)Ugi-type reaction was developed for the synthesis of L-1-deoxynojirimycin(DNJ)isomers using a chiron *** new and quite mild catalytic system,comprised of phenylphosphinic ... 详细信息

关键词： Azasugars Multicomponent reactions Nitrilium ion Isocyanide Reductive cyclization

Study of an athermal infrared dual band optical system design containing harmonic diffractive element

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Chinese Science Bulletin 2003年第2期48卷 1193-1198页

作者： SUN Qiang WANG Zhaoqi LI Fengyou LIU Hongli LU Zhenwu CHEN Bo MU Guoguang Institute of Modern Optics Nankai UniversityKey Laboratory of Opt-electronic Information Science and TechnologyMinistry of EducationTianjin 300071China State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130022China

A harmonic diffractive element (HDE) is first successfully introduced to the athermal system of infrared dual band in this paper. In this system, there are only three lens and two materials, silicon and germanium. When the temperature ranges from 70℃ to 100℃ in the dual band, it can simultaneously accomplish the rectification of the longitudinal aberration in the big field of view, as well as the wave front aberration less than 1/4 wavelength. Modulation transfer function of dual band approaches or attains the diffraction limit. The calculation results show that the spec-tral properties of the HDE are between refractive and dif-fractive elements, so we can design a simple dual-band and athermal optical system by selecting the thickness and cen-tral wavelength of the HDE exactly. Compared with a con-ventional refractive optical system, this system not only re-duces the demand for high technical levels, but also has a compact structure, few elements, a high transmittance better aberrations performances and athermal character. At the same time, the use of the HDE also offers a new element for the infrared optics design.

关键词： harmonic diffraction athermal infrared dual band optical design.

Rapid and Efficient Adsorption Removal of Reactive Blue 4 from Aqueous Solution by Cross-Linked Microcrystalline Cellulose–Epichlorohydrin Polymers: Isothermal, Kinetic, and Thermodynamic Study

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Transactions of tianjin university 2021年第1期27卷 77-86页

作者： Yuanyuan Zhai Hongmei Qu Zhongxuan Li Bo Zhang Jinxi Cheng Jiaji Zhang Key Laboratory of Systems Bioengineering Ministry of EducationSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China

In this study, we modified microcrystalline cellulose by cross-linking it with epichlorohydrin to obtain a rapid and efficient adsorbent for the removal of Reactive Blue 4 dye from aqueous solution. Evidences of the cross-linking of the microcrystalline cellulose were obtained by Fourier transform infrared spectroscopy, X-ray diff raction, Brunauer–Emmett–Teller analysis, thermogravimetric analysis, and scanning electron microscopy. We investigated the eff ects of adsorbent dosage, p H, initial dye concentration, temperature, and contact time on the dye adsorption capacity. The results showed that the adsorption equilibrium time was just 20 min and the maximum adsorption capacity was 69.79 mg/g. The adsorption isotherm data fitted the Langmuir isotherm model well, and the adsorption kinetics data followed the pseudo-second-order kinetic model. The results of the thermodynamic analysis suggest that the adsorption process was spontaneous and exothermic. Recyclability experiments demonstrated the good reusability of this adsorbent. Electrostatic interaction was found to dominate the adsorption process.

关键词： Microcrystalline cellulose Cross-linking Epichlorohydrin Adsorption Reactive Blue 4 Wastewater

STEADY STATE MOTIONS OF SHALLOW ARCH UNDER PERIODIC FORCE WITH 1:2 INTERNAL RESONANCEON THE PLANE OF PHYSICAL PARAMETERS

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Applied Mathematics and Mechanics(English Edition) 1998年第7期19卷 625-635页

作者：毕勤胜陈予恕 Department of Mechanics Tianjin University Tianjin P. R. China

The bifurcation dynamics of shallow arch which possesses initial deflection under periodic excitation for the case of 1:2 internal resonance is studied in this paper. The whole parametric plane is divided into several different regions according to lire types of motions; then the distribution of steady state motions of shallow arch on the plane of physical parameters is obtained. Combining with numerical method, the dynamics of the system in different regions, especially in the Hopf bifurcation region, is studied in detail. The rule of the mode interaction and the route to chaos of the system is also analysed at the end.

关键词： shallow arch internal resonance steady state motion bifurcation chaos

Violet/blue photoluminescence from CeO_2 thin film

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Chinese Science Bulletin 2003年第2期48卷 1198-1200页

作者： CHAI Chunlin, YANG Shaoyan, LIU Zhikai, LIAO Meiyong & CHEN Nuofu Key Laboratory of Semiconductor Material Science, Institute of Semi-conductors, Chinese Academy of Sciences, Beijing 100083, China Key Laboratory of Semiconductor Material Science Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

CeO2 thin film was fabricated by dual ion beam epitaxial technique. The violet/blue PL at room temperature and lower temperature was observed from the CeO2 thinfilm. After the analysis of crystal structure and valence in the compound was carried out by the XRD and XPS technique, it was inferred that the origin of CeO2 PL was due to theelectrons transition from Ce4f band to O2p band and thedefect level to O2p band. And these defects levels were lo-cated in the range of 1 eV around Ce4f band.

关键词： cerium dioxide thin film PL violet/blue.

USING WAVELET TRANSFORM TO STUDY THELIPSCHITZ LOCAL SINGULAR EXPONENTIN WALL TURBULENCE

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Applied Mathematics and Mechanics(English Edition) 1998年第10期19卷 983-990页

作者：姜楠王振东舒玮 Department of Mechanics Tianjin University Tianjin Laboratory for Nonlinear Mechanics of Continuous Media Institute of Mechanics Academia Sinica Beijing P. R. China

In this paper, wavelet,transform is introduced to study the Lipschitz local singular exponent for characterising the local singularity behavior of fluctuating velocity in wall turbulence. I, is found that the local singular exponent is negative when the ejections and sweeps of coherent structures occur in a turbulent boundary layer.

关键词： wavelet transform coherent structure Lipschitz local singular exponent

Color-image retrieval based on fuzzy correlation

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Science in China(Series F) 2004年第3期47卷 295-300页

作者： ZHAIHongchen LIANGYanmei MUGuoguang KeyLaboratoryofOpto-electronicInformationScienceandTechnologyofEducation MinistryofEducationofChina.Tianjin300071China JointInstituteofNankaiuniversityandtianjinuniversity:InstituteofModernOptics NankaiUniversityTianjin300071China

We report a method of color-image retrieval based on fuzzy correlation, inwhich α-cut relations in fuzzy set theory are applied to defining color match and heightmatch of color peaks for synthesizing fuzzy correlation of two color histograms, and RGBspace is partitioned into six sub-regions in the experiment for the regional colorcomparisons. Experimental results show that the efficiency of the color-image retrievalcan be effectively improved by this approach.

关键词： color—image retrieval color histogram fuzzy correlation