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Pre-heating temperature induced flowability and wax deposition characteristics of crude oil adding wax inhibitors

Petroleum Science 2023年第4期20卷 2468-2478页

作者： bo Yao Hao-Ran Zhu Bao-Dong yan Chuan-Xian Li Fei yang Guang-Yu sun Hong-bo Zeng College of Pipeline and Civil Engineering China University of PetroleumQingdaoShandong266580People's Republic of China Department of Chemical and Materials Engineering University of AlbertaEdmontonABT6G 1H9Canada School of Petroleum Engineering Changzhou UniversityChangzhouJiangsu213164People's Republic of China China Oil&Gas Pipeline Network Corporation Beijing100020China

This paper investigated the effects of pre-heating treatment temperatures(T_(pre))on the flowability and wax deposition characteristics of a typical waxy crude oil after adding wax *** is found that there is little difference in wax precipitation exothermic characteristics of crude oils at different T_(pre),as well as the wax crystal solubility coefficient in the temperature range of 25-30℃.For the undoped crude oil,the flowability after wax precipitation gets much improved and the wax deposition is alleviated as T_(pre)*** T_(pre)=50℃,the viscosity and wax deposition rate of crude oil adding wax inhibitors are higher than those of the undoped crude *** the T_(pre)increases to 60,70,and 80℃,the flowability of the doped crude oil are largely improved and the wax deposition is suppressed with the T_(pre)increase,but the wax content of wax deposit increases *** is speculated that,on the one hand,the T_(pre)increase helps the dispersion of asphaltenes into smaller sizes,which facilitates the co-crystallization with paraffin waxes and generates more aggregated wax crystal *** weakens the low-temperature gel structure and increases the solid concentration required for the crosslink to form the wax *** the other hand,the decrease in viscosity increases the diffusion rate of wax molecules and accelerates the aging of wax *** experimental results have important guiding significance for the pipeline transportation of doped crude oils.

关键词： Pre-heating treatment Wax inhibitor Flowability Wax deposition Waxy crude oil

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Independent N-Electron Method and High Accuracy Calculations of the Ground State Energy of the Nonrelativistic Light Atoms (3 Ne 10)

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Communications in Theoretical Physics 2001年第7期36卷 79-84页

作者： XIE yan-bo Department of Modern Physics University of Science and Technology of China Hefei 230026 China

A new method based on the independent electron-pair approximation is developed to calculate the correlation energy and the basis size truncation error. The formalisms for the nondegenerate systems are described in this paper. Because all important terms are very efficiently selected and the calculations can be separated into several parts, this new method gives very accurate results and does not require expensive computing facilities. As a test, the ground state energies (GSE) of the nonrelativistic atoms for (3 ≤ Ne ≤ 10) are calculated using this new method. The calculated results are found to be in close agreement with the most recent available version of the exact GSE which is derived from the experimental data after subtracting the contributions from the relativistic effect, QED radiative corrections, finite nucleon mass corrections, and the finite radius of the nuclear size. Those accurate results have not been reproduced for Ne ≥ 5 by any direct theoretical calculations in literatures. Since this method is not restrained to nonrelativistic or Coulomb systems, it should become powerful to study other quantum interacting systems.

关键词： correlation energy basis truncation error independent N-electron approximations Ground state Independent Energy sources Atoms Correlation energy Energy level

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A survey on high coherence visual media retargeting： recent advances and applications

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Frontiers of Computer Science 2016年第5期10卷 778-796页

作者： Weimin TAN bo yan School of Computer Science Shanghai Key Laboratory of Intelligent Information Processing Fudan University Shanghai 201203 China

The numerous works on media retargeting call for a thorough and comprehensive survey for reviewing and categorizing existing works and providing insights that can help future design of retargeting approaches and its applica- tions. First, we present the basic problem of media retarget- ing and detail state-of-the-art retargeting methods devised to solve it. Second, we review recent works on objective quality assessment of media retargeting, where we find that although these works are designed to make the objective assessment result in accordance with the subjective evaluation, they are only suitable for certain situations. Considering the subjective nature of aesthetics, designing objective assessment metric for media retargeting could be a promising area for investiga- tion. Third, we elaborate on other applications extended from retargeting techniques. We show how to apply the retarget- ing techniques in other fields to solve their challenging prob- lems, and reveal that retargeting technique is not just a simple scaling algorithm, but a thought or concept, which has great flexibility and is quite useful. We believe this review can help researchers and practitioners to solve the existing problems of media retargeting and bring new ideas in their works.

关键词： media retargeting quality assessment aesthet-ics enhancement image retrieval video synopsis

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Vertical Chlorophyll and Dimethylsulfide Profile Simulations in Southern Greenland Sea

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Journal of Ocean University of China 2022年第6期21卷 1565-1574页

作者： QU bo sun Wenjing School of Science Nantong UniversityNantong 226007China YK Pao School Middle School CampusShanghai 200336China

Biogenetic sulfide dimethylsulfide(DMS)plays a major role on the global climate,especially in Arctic *** simulate DMS concentration is an important *** we introduced both biogeochemical depth-averaged model G93 and its extension model-one dimensional DMS *** surface concentrations,vertical profiles of chlorophyll(CHL)and DMS are simulated using the two models within southern Greenland Sea(0°E–10°E,70°N–75°N)during year *** the input data for the models simulations,the spatial monthly mean of methodology forcings including sea surface temperature(SST),wind speed(WIND),cloud cover(CLD),sea ice concentration(ICE)and mixed layer depth(MLD)are *** 8-day time series of chlorophyll-a(CHL)are used as observation data for CHL related parameter ***ó’s imperial formula is used as the monthly DMS observation *** Genetic Algorithm technique is used for the parameter *** simulation results show that the most DMS related surface concentrations exhibit the normal distributions with peak during ***,DMS and DMSP(dimethylsulphoniopropionate)vertical profiles are obtained for July,August and September in year *** had the higher variation of subsurface concentration maximum(SCM)in July with the lower surface concentration *** had surface higher and subsurface lower profile for the all three *** also had subsurface high in *** SCM CHL diurnal variation in the subsurface also can be resulted from diurnal changes in MLD and vertical mixing variations,plus photolysis and wind-driven ventilations.

关键词： dimethylsulfide vertical profile chlorophyll biogeochemical modeling Greenland Sea

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A Feasible Zone Analysis Method with Global Partial Load Scanning for Solving Power Flow Coupling Models of CCHP Systems

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Journal of Modern Power Systems and Clean Energy 2022年第2期10卷 371-377页

作者： Pohan Chen Kai sun Chenghui Zhang bo sun the Department of Electrical Engineering Tsinghua UniversityBeijingChina the School of Control Science and Engineering Shandong UniversityJinanChina

Heat exchanger systems(HXSs)or heat recovery steam generators(HRSGs)are commonly used in 100 kW to 50 MW combined cooling,heating,and power(CCHP)*** flow coupling(PFC)is found in HXSs and is complex for researchers to *** could possibly mislead the dispatch schedule and result in the inaccurate *** is caused by the inlet and outlet temperatures of each component,gas flow pressure variation,conductive medium flow rate,and atmosphere condition *** this paper,the expression of PFC is built by using quadratic functions to fit the non!inearit>of thermal *** fitting the model,the environmental condition needs prediction,which is calculated using phase space reconstruction(PSR)Kalman *** order to solve the complex quadratic dispatch model,a hybrid following electricity load(FEL)and following thermal load(FTL)mode for reducing the dimension of dispatch model,and a feasible zone analysis(FZA)method are *** a result,the PFC problem of CCHP system is solved,and the dispatch cost,investment cost,and the maximum power requirements are *** this paper,a case in Jinan,China is *** PFC model is proven to be more precise and accurate compared with traditional models.

关键词： Combined cooling heating and power(CCHP)system renewable energy source(RES) load prediction operation strategy exergy and energy analysis power flow coupling(PFC)model.

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Longitudinal surface cracks of thin slabs

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International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 159-166页

作者： yan-hui sun You-jin Ni Hai-tao Wang Zhong-bo Xu Kai-ke Cai School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

Based on the production practice of medium carbon thin slabs in the CSP plant,the reasons and influencing factors for the formation of longitudinal cracks were investigated,and some industrial measures were taken to eliminate the *** results show that the efficient solutions to reduce longitudinal cracks are improving the performance of the mold powder,stabilizing the mold heat flux,and maintaining a proper taper of the mold during *** pouring temperature and secondary cooling also play important roles in preventing longitudinal surface cracks.

关键词： CSP thin slab medium carbon steel surface cracks

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Organic polymers achieving smart room-temperature phosphorescence

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Science China Chemistry 2019年第3期62卷 291-292页

作者： bo Zhou Dongpeng yan Beijing Key Laboratory of Energy Conversion and Storage Materials College of Chemistry Beijing Normal University

Room-temperature phosphorescence (RTP) has drawn widespread attention recently owing to the unique long-lived triplet excited states and potential applications in light-emitting diodes (LEDs)[1], optical imaging [2], photodynamic therapy [3], and information security [4]. Particularly, RTP materials can effectively utilize the triplet excitons to maximize the internal quantum yield in electroluminescent fields. However, to date, the most efficient phosphors are still limited to noble metal-containing compounds (such as iridium and platinum complexes), which have some intrinsic obstacles, such as metal scarcity and high bio-toxicity.

关键词： Room-temperature widespread Organic

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Crystallizability of Poly(ε-caprolactone) Blends with Poly(vinylphenol) under Different Conditions

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Chinese Journal of Polymer Science 2014年第9期32卷 1119-1127页

作者： Tian-bo yang Xiao-li sun Zhong-jie Ren 李慧慧 Shou-ke yan State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

The intermolecular interaction between poly（vinylphenol）（PVPh） and polycaprolactone （PCL） and the crystallization behavior of PCL in PCL/PVPh blends with different compositions and under different conditions were investigated by Fourier transform infrared spectra （FTIR） and differential scanning calorimetry （DSC）. It has been shown that the PCL in the blends with different blend ratios all exists in crystalline state after solution casting, even though the crystallinity decreases with increasing PVPh content. For the melt crystallized samples, PCL in its 80/20 PCL/PVPh sample can still crystallize. The crystallinity is, however, lower than that of the solution cast sample. For blends containing 50% or 20% PCL, the as-cast samples are semicrystalline and can change to compatible amorphous state after heat treatment process. FTIR analysis shows the existence of hydrogen bonding between PCL and PVPh and the fraction of hydrogen bonds increases remarkably after heat treatment process.

关键词： Poly(vinylphenol) Polycaprolactone Polymer blends Crystallinity Hydrogen bonding.

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Protein A-based ligands for affinity chromatography of antibodies

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Chinese Journal of Chemical Engineering 2021年第2期34卷 194-203页

作者： Qinghong Shi yan sun Department of Biochemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education) Tianjin UniversityTianjin 300350China

Protein A chromatography is a key technology in the industrial production of antibodies,and a variety of commercial protein A adsorbents are available in *** stability and binding capacity of a protein A adsorbent are two key issues for successful practice of protein A *** versions of protein A adsorbents ever exhibited serious fragility to typical cleaning-in-place protocols(*** with sodium hydroxide solution),and suffered from low binding capacity,harsh elution,ligand leakage and other problems involved in industrial *** the last three decades,various techniques and approaches have been applied in the improvement of chemical stability and enhancement of binding capacity of protein A-based ligands and adsorbents for antibody *** mini-review focuses on the technical explorations in protein A-based affinity adsorbents,especially protein A-based ligands,including the efforts to increase the chemical stability by site-directed mutations and to improve the binding capacity by ligand polymerization and site-directed ***,the efforts to develop short peptide ligands based on the structure of protein A,including the biomimetic design strategies and the synthesis of peptide-mixed mode hybrid ligands are *** peptide and peptidebased hybrid ligands exhibit high affinity and selectivity to antibodies,but noteworthy differences in the binding mechanism of antibody from protein *** a result,bound antibody to the ligands could be effectively eluted under mild *** for the development of the protein A-based peptide ligands have been extensively discussed,suggesting that the ligands represent a direction for technological development of antibody purification.

关键词： Protein A Antibody Peptide ligand Rational design Protein stability Binding capacity

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a-Synuclein: A fusion chaperone significantly boosting the enzymaticperformance of PET hydrolase

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Chinese Journal of Chemical Engineering 2023年第12期64卷 18-25页

作者： Renwen Tian yan sun Department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Extensive use of polyethylene terephthalate (PET) has brought about global environmental problems. Arecently reported PET hydrolase (PETase) discovered from Ideonella sakaiensis showed high potentialfor degrading PET at moderate temperatures, but its activity and stability need further improvementfor practical applications. Herein, we proposed to use a-synuclein (aS) as a fusion chaperone and createdsix PETase-aS fusion enzymes with linkers of different types and lengths. All the fusion enzymes exhibited improved enzymatic performance, presenting 1.5 to 2.6-fold higher activity towards bis-2(hydroxyethyl) terephthalate than PETase, as well as significantly increased stabilities. Fluorescencespectroscopy indicated that the chaperone fusion tightened the overall conformation and resulted inthe opening of the substrate binding pocket, which led to the improved thermal stability and catalyticactivity of the fusion enzymes. Remarkably, one of the fusion proteins, PETase-[(GS)(EK)]10-aS, showed3.2 to 5.1 times higher PET degradation capability than PETase. The significantly boosted PET degradationperformance was not only attributed to the enhanced enzymatic activity and stability, but also possiblydue to the binding affinity of the fused aS domain for PET. These findings demonstrated that aS was aneffective fusion chaperone for significantly enhancing the enzymatic performance of PETase.

关键词： PET hydrolase a-Synuclein Fusion enzyme Stability Pollution Degradation

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