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Liquid-phase epitaxial layer by layer brushing fabrication of metalorganic frameworks films

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Nano Research 2024年第6期17卷 5698-5704页

作者： Li-Mei chang Rui Zhai Zhi-Zhou Ma jian-Dong Huang Zhi-Gang Gu jian Zhang College of Chemistry Fuzhou UniversityFuzhou 350108China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China

Development of metal-organic framework(MOF)films is of great importance to expand their ***,we report a facile and universal method of liquid-phase epitaxial(LPE)layer by layer(LBL)brushing approach for fabricating MOF films on various substrates in a high-throughput *** MOF films preparation method offers a great prospective to cost-effectively construct films with short preparation time and little reagent ***,this LBL brushing approach has been implemented successfully to assemble various MOF films,including HKUST-1,zeolitic imidazolate framework-8(ZIF-8),Cu(bdc),and Cu_(2)(L)_(2)P(L=bdc,ndc,and cam;P=dabco and bipy).Afterwards,the classic MOF HKUST-1 and ZIF-8 films were grown on sensor chip electrode and porous fiber support for good volatile organic compounds(VOCs)selective sensing and water purification *** study demonstrates that this LBL brushing preparation method can be employed to synthesize various MOF films with a variety of characteristics to realize their sensing and separation applications.

关键词： metal-organic framework porous materials layer by layer fabrication film

Sequence structure controllable polymerization-induced self-assembly

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Science China Chemistry 2024年第1期67卷 390-397页

作者： Zi-Xuan chang Ren-Man Zhu Chun-Yan Hong Wen-jian Zhang Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Environment-Friendly Polymeric Materials of Anhui Province Anhui UniversityHefei 230601China

Polymerization-induced self-assembly(PISA)combines synthesis and self-assembly of artificial polymers in one-pot,which brings us one step closer to emulating ***,the reported PISA formulations primarily focus on developing nano-objects with new chemical compositions and rarely on structural regulation of polymers with specific ***,sequence structure controllable polymerization-induced self-assembly(SCPISA)is reported by using 7-(2-methacryloyloxyethoxy)-4-methylcoumarin(CMA)as a *** the copolymerization of 2-hydroxyethyl methacrylate(HEMA)and CMA,controlled incorporation of CMA units into the polymer chains can be realized by programmable light/heat ***-based P(HEMA-co-CMA)copolymers with the same composition but different sequence structures generate a range of ***,the morphologies of the resultant nano-objects can also be controlled by regulating the feed molar ratio of CMA and HEMA,which is similar to the conventional PISA,but the synthesis procedure is obviously simplified in *** versatility of the methodology is further demonstrated by the fabrication of different functional nano-objects with sequence structure-dependent morphologies in SCPISA systems with different functional monomers.

关键词： polymerization-induced self-assembly sequence-controlled polymers PET-RAFT polymerization

On the Quantum Cohomology of Blow-ups of Four-dimensional Quadrics

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Acta Mathematica Sinica,English Series 2024年第1期40卷 313-328页

作者： jian Xun HU Hua Zhong KE chang Zheng LI Lei SONG School of Mathematics Sun Yat-sen UniversityGuangzhou 510275P.R.China

We propose a conjecture relevant to Galkin’s lower bound conjecture,and verify it for the blow-ups of a four-dimensional quadric at a point or along a projective *** also show that Conjecture O holds in these two cases.

关键词： Quantum cohomology blow-up quadric hypersurface

Proposing a machine learning approach to analyze and predict basic high-temperature properties of iron ore fines and its factors

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Journal of Iron and Steel Research International 2024年第5期31卷 1082-1094页

作者： Qing-ke Sun Yao-zu Wang jian-liang Zhang Zheng-jian Liu Le-le Niu chang-dong Shan Yun-fei Ma Institute of Artificial Intelligence University of Science and Technology BeijingBeijing100083China School of Intelligence Science and Technology University of Science and Technology BeijingBeijing100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China

The basic high-temperature properties of iron ore play a crucial role in optimizing sintering and ore blending,but the testing process for these properties is complex and has significant lag time,which cannot meet the actual needs of ore blending.A prediction model for the basic high-temperature properties of iron ore fines was thus proposed based on a combination of machine learning algorithms and genetic ***,the prediction accuracy of different machine learning models for the basic high-temperature properties of iron ore fines was ***,a random forest model optimized by genetic algorithms was built,further improving the prediction accuracy of the *** test results show that the random forest model optimized by genetic algorithms has the highest prediction accuracy for the lowest assimilation temperature and liquid phase fluidity of iron ore,with a determination coefficient of 0.903.for the lowest assimilation temperature and 0.927 for the liquid phase fluidity after *** trained model meets the fluctuation requirements of on-site testing and has been successfully applied to actual production on site.

关键词： Iron ore Basic high-temperature property Machine learning Random forest Genetic algorithm

Solution of the Center Problem for a Class of Polynomial Differential Systems

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1685-1696页

作者： chang jian Liu Jaume Llibre Rafael Ramírez Valentín Ramírez School of Mathematics(Zhuhai) Sun Yat-sen UniversityZhuhai519086P.R.China Departament de Matemàtiques Universitat Autònoma de Barcelona08193BellaterraBarcelonaCataloniaSpain Departament d’Enginyeria Informàtica i Matemàtiques Universitat Rovira i VirgiliAvinguda dels Paiïsos Catalans 2643007TarragonaCataloniaSpain

Consider the polynomial differential system of degree m of the form x=-y(1+μ(a_(2)x-a_(1)y))+x(v(a_(1)x+a_(2)y)+Ω_(m-1)(x,y)),y=x(1+μ(a_(2)x-a_(1)y))+y(v(a_(1)x+a_(2)y)+Ω_(m-1)(x,y)),whereμandνare real numbers such that(μ^(2)+v^(2))(μ+v(m-2))(a_(1)^(2)+a_(2)^(2))≠m>2 andΩ_(m−1)(x,y)is a homogenous polynomial of degree m−1.A conjecture,stated in *** Equations 2019,suggests that whenν=1,this differential system has a weak center at the origin if and only if after a convenient linear change of variable(x,y)→(X,Y)the system is invariant under the transformation(X,Y,t)→(−X,Y,−t).For every degree m we prove the extension of this conjecture to any value ofνexcept for a finite set of values ofμ.

关键词： Center problem polynomial differential system

Biomineralization and mineralization using microfluidics:A comparison study

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 661-669页

作者： Yang Xiao Xiang He Guoliang Ma chang Zhao jian Chu Hanlong Liu Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing400045China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing400045China School of Civil Engineering Chongqing UniversityChongqing400045China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore

Biomineralization through microbial process has attracted great attention in the field of geotechnical engineering due to its ability to bind granular materials,clog pores,and seal *** minerals formed by biomineralization are generally the same as that by mineralization,their mechanical behaviors show a significant *** study aims to figure out the differences between biomineralization and mineralization processes by visualizing and tracking the formation of minerals using *** biomineralization and mineralization processes occurred in the Y-shaped sandcontaining microchip that mimics the underground sand *** from different areas in the reaction microchannel of microchips were captured to directly compare the distribution of *** size and numbers from different reaction times were measured to quantify the differences between biomineralization and mineralization processes in terms of crystal *** showed that the crystals were precipitated in a faster and more uncontrollable manner in the mineralization process than that in the biomineralization process,given that those two processes presented similar precipitation *** addition,a more heterogeneous distribution of crystals was observed during the biomineralization *** precipitation behaviors were further explained by the classical nucleation crystal growth *** present microfluidic tests could advance the understanding of biomineralization and provide new insight into the optimization of biocementation technology.

关键词： Microbially induced carbonate precipitation (MICP) Biocementation Crystal Calcium carbonate Nucleation

Mineralogical properties and co-sintering characteristics of fluxed iron ore with magnetite concentrates

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Journal of Iron and Steel Research International 2024年第2期31卷 318-328页

作者： Le-le Niu Zheng-jian Liu jian-liang Zhang Yao-zu Wang Zhen-xing Yang Si-da Li chang-dong Shan Ben Feng School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing100083China Xinxing Casting Pipe Xinjiang Co. Bayingol841300XinjiangChina

To investigate the feasibility of co-sintering of fluxed iron ore with magnetite concentrates, the mineralogical properties of a novel fluxed iron ore were studied using particle size analysis, microscopic morphology characterization, and X-ray diffraction Rietveld analysis. Following that, the experiments for granulation performance and basic sintering characteristics were designed under seven different fluxed iron ore ratios, and the integrated ranking of different fluxed iron ore ratios was determined using gray relation analysis. Finally, the results of the industrial trails were combined with the feasibility analysis. Test and experimental results show that the fraction of the fluxed iron ore particles larger than 0.5 mm can account for more than 48%, and the particles have two morphologies: spherical-rough and flaky-smooth. Ca elements are found in the form of calcite (CaCO3. and dolomite (CaMg(CO3.2). The average particle size of granules and powder removal rate can be improved from 2.50 to 3.16 mm and 3..60% to 24.20%, respectively, with the increase in the fluxed iron ore ratio. Furthermore, the fluxed iron ore can improve assimilability and liquid fluidity of magnetite concentrates. In terms of overall granulation performance and sintering characteristics, the fluxed iron ore ratios are graded from best to worst as follows: 12%, 15%, 9%, 18%, 21%, 6% and 3.. The industrial trails show that when the fluxed iron ore ratio is increased, the beneficial effect of the superior sintering characteristics of the fluxed iron ore itself is ideally balanced with the negative effect of the lower amount of additional CaO at 12% ratio, and thus, it is feasible to bring the fluxed iron ore into production at a level of roughly 12%.

关键词： Fluxed iron ore Magnetite concentrate Granulation performance Sintering characteristics Gray relation analysis

Research on Reservoir Landslide Thrust Based on Improved Morgenstern-Price Method

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Journal of Earth Science 2024年第4期35卷 1263-1272页

作者： Xuan Wang Xinli Hu chang Liu Lifei Niu Peng Xia jian Wang Jiehao Zhang Faculty of Engineering China University of GeosciencesWuhan430074China

The curve of landslide thrust plays a key role in landslide *** commonly used transfer coefficient method(TCM)and Morgenstern-Price method(MPM)are *** does not take into account the moment balance between *** MPM considers the moment balance,the calculation is complex,and it does not consider that the force between slices may be less than zero at the back edge of the *** rationality and feasibility of the improved MPM are verified by calculating the landslide stability coefficient and landslide thrust at different reservoir water *** paper studies the law of landslide thrust when the reservoir water level changes,and discusses the determination of design thrust,to provide a certain theoretical basis for the design of reservoir landslides.

关键词： reservoir transfer coefficient method Morgenstern-Price landslide thrust design thrust landslides

Mechanical behavior of 2G NPR bolt anchored rock samples under static disturbance loading

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Journal of Mountain Science 2024年第7期21卷 2494-2516页

作者： WANG Jiong jianG jian WANG Siyu chang Yiwen LIU Peng HE Manchao CHENG Shuang State Key Laboratory for Tunnel Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China

The deep mining of coal resources is accompanied by severe environmental challenges and various potential engineering *** implementation of NPR(negative Poisson's ratio)bolts are capable of controlling large deformations in the surrounding rock *** paper focuses on studying the mechanical properties of the NPR bolt under static disturbance *** deep nonlinear mechanical experimental system was used to study the mechanical behavior of rock samples with different anchored types(unanchored/PR anchored/2G NPR anchored)under static disturbance *** whole process of rock samples was taken by high-speed camera to obtain the real-time failure characteristics under static disturbance *** the same time,the acoustic emission signal was collected to obtain the key characteristic parameters of acoustic emission such as acoustic emission count,energy,and *** deformation at the failure of the samples was calculated and analyzed by digital speckle *** findings indicate that the failure mode of rock is influenced by different types of *** peak failure strength of 2G NPR bolt anchored rock samples exhibits an increase of 6.5%when compared to the unanchored rock *** cumulative count and cumulative energy of acoustic emission exhibit a decrease of 62.16%and 62.90%,*** maximum deformation of bearing capacity exhibits an increase of 59.27%,while the failure time demonstrates a delay of 42.86%.The peak failure strength of the 2G NPR bolt anchored ones under static disturbance load exhibits an increase of 5.94%when compared to the rock anchored by PR(Poisson's ratio)*** cumulative count and cumulative energy of acoustic emission exhibit a decrease of 47.16%and 43.86%,*** maximum deformation of the bearing capacity exhibits an increase of 50.43.,and the failure time demonstrates a delay of 3.%.After anchoring by 2G NPR bolt,anchoring support effectively reduces the risk of damage caused by s

关键词： Anchored rock samples Static disturbance load Acoustic emission characteristics Digital speckle Negative Poisson's ratio