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Selective hydrodeoxygenation of guaiacol to cyclohexanol using activated hydrochar-supported Ru catalysts

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 13-22页

作者： Kaile li Shijie yu Qinghai li Yanguo Zhang Hui Zhou Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Beijing Key Laboratory of CO_(2) Utilization and Reduction TechnologyDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore117585Singapore

lignin,an abundant aromatic polymer in nature,has received significant attention for its potential in the production of bio-oils and chemicals owing to increased resource availability and environmental *** hydrodeoxygenation of guaiacol,a lignin-derived monomer,can produce cyclohexanol,a nylon precursor,in a carbon-negative and environmentally friendly *** study explored the porous properties and the effects of activation methods on the Ru-based catalyst supported by environmentally friendly and cost-effective *** selective cleavage of C_(ary)-O bonds was achieved under mild conditions(160°C,0.2 MPa H_(2),and 4 h),and alkali activation further improved the catalytic *** characterization methods revealedthat hydrothermal treatment and alkali activation relatively contributed to the excellent performance of the catalysts and influenced their porous structure and Ru dispersion.X-ray photoelectron spectroscopy results revealed an increased formation of metallic ruthenium,indicating the effective regulation of interaction between active sites and *** synergistic approach used in this study,involving the valorization of cellulose-derived hydrochar and the selective production of nylon precursors from lignin-derived guaiacol,indicated the comprehensive and sustainable utilization of biomass resources.

关键词： hydrochar guaiacol cyclohexanol activation full-component utilization

Kinematic calibration method with high measurement efficiency and robust identification for hybrid machine tools

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Chinese Journal of Aeronautics 2024年第3期37卷 468-482页

作者： liping WANG Mengyu li Guang yu Weitao li Xiangyu KONG State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipment and Control Beijing 100084China

Geometric error is the main factor affecting the machining accuracy of hybrid machine *** calibration is an effective way to improve the geometric accuracy of hybrid machine *** necessity to measure both position and orientation at each pose,as well as the instability of identification in case of incomplete measurements,severely affects the application of traditional calibration *** this study,a kinematic calibration method with high measurement efficiency and robust identification is proposed to improve the kinematic accuracy of a five-axis hybrid machine ***,the configuration is introduced,and an error model is ***,by investigating the mechanism error characteristics,a measurement scheme that only requires tool centre point position error measurement and one alignment operation is ***,by analysing the effects of unmeasured degrees of freedom(DOFs)on other DOFs,an improved nonlinear least squares method based on virtual measurement values is proposed to achieve stable parameter identification in case of incomplete measurement,without introducing additional ***,the proposed calibration method is verified through simulations and *** proposed method can efficiently accomplish the kinematic calibration of the hybrid machine *** accuracy of the hybrid machine tool is significantly improved after calibration,satisfying actual aerospace machining requirements.

关键词： Hybrid machine tool Calibration Measurement scheme Improved nonlinear least squares method Virtual measurement values

Exploring changes of precipitation extremes under climate change through global variable-resolution modeling

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Science Bulletin 2024年第2期69卷 237-247页

作者： Wei Sun Jian li Rucong yu Nina li Yi Zhang State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Tibetan Plateau Meteorology China Meteorological AdministrationChengdu 610072China Department of Atmospheric Science Yunnan UniversityKunming 650091China National Meteorological Center China Meteorological AdministrationBeijing 100081China 2035 Future Laboratory PIESAT Information Technology Co.Ltd.Beijing 100105China

Understanding the responses of precipitation extremes to global climate change remains limited owing to their poor representations in models and complicated interactions with multi-scale *** we take the record-breaking precipitation over China in 2021 as an example,and study its changes under three different climate scenarios through a developed pseudo-global-warming(PGW)experimental framework with 60-3 km variable-resolution global ensemble *** to the present climate,the precipitation extreme under a warmer(cooler)climate increased(decreased)in intensity,coverage,and total amount at a range of 24.3%-37.8%(18.7%-56.1%).With the help of the proposed PGW experimental framework,we further reveal the impacts of the multi-scale system interactions in climate change on the precipitation *** the warmer climate,large-scale water vapor transport converged from double typhoons and the subtropical high marched into central China,enhancing the convective energy and instability on the leading edge of the transport *** a result,the mesoscale convective system(Mcs)that directly contributed to the precipitation extreme became stronger than that in the present *** the contrary,the cooler climate displayed opposite changing characteristics relative to the warmer climate,ranging from the large-scale systems to local environments and to the *** summary,our study provides a promising approach to scientifically assess the response of precipitation extremes to climate change,making it feasible to perform ensemble simulations while investigating the multi-scale system interactions over the globe.

关键词： Precipitation extreme Climate change Pseudo-global-warming experiment Variable-resolution modeling Multi-scale system interaction

Multi-omics analysis of human tendon adhesion reveals that ACKR1-regulated macrophage migration is involved in regeneration

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Bone Research 2024年第2期12卷 390-406页

作者： Xinshu Zhang Yao Xiao Bo Hu Yanhao li Shaoyang Zhang Jian Tian Shuo Wang Zaijin Tao Xinqi Zeng ning-ning liu Baojie li Shen liu Department of Orthopaedics Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine600 Yishan RdShanghai 200233PR China Section of Spine Surgery Department of OrthopaedicsChangzheng HospitalNaval Medical UniversityShanghai 200003PR China Bio-X Institutes Key Laboratory for the Genetics of Developmental and Neuropsychiatric DisordersMinistry of EducationShanghai Jiao Tong UniversityShanghai 200241PR China Department of Orthopaedics Wuxi Ninth People’s Hospital Affiliated to Soochow UniversityWuxi 214062PR China State Key Laboratory of Systems Medicine for Cancer Center for Single-Cell OmicsSchool of Public HealthShanghai Jiao Tong University School of MedicineShanghai 200025China

Tendon adhesion is a common complication after tendon injury with the development of accumulated fibrotic tissues without effective anti-fibrotic therapies,resulting in severe *** are widely recognized as a fibrotic trigger during peritendinous adhesion ***,different clusters of macrophages have various functions and receive multiple regulation,which are both still *** our current study,multi-omics analysis including single-cell RNA sequencing and proteomics was performed on both human and mouse tendon adhesion tissue at different stages after tendon *** transcriptomes of over 74000 human single cells were *** results,we found that SPP1^(+)macrophages,RGCC^(+)endothelial cells,ACKR1^(+)endothelial cells and ADAM12^(+)fibroblasts participated in tendon adhesion ***,despite specific fibrotic clusters in tendon adhesion,FOLR2^(+)macrophages were identified as an antifibrotic cluster by in vitro experiments using human ***,ACKR1 was verified to regulate FOLR2^(+)macrophages migration at the injured peritendinous site by transplantation of bone marrow from Lysm-Cre;R26R^(tdTomato) mice to lethally irradiated Ackr1^(-/-)mice(Ackr1^(-/-)chimeras;deficient in ACKR1)and control mice(WT chimeras).Compared with WT chimeras,the decline of FOLR2^(+)macrophages was also observed,indicating that ACKR1 was specifically involved in FOLR2^(+)macrophages *** together,our study not only characterized the fibrosis microenvironment landscape of tendon adhesion by multi-omics analysis,but also uncovered a novel antifibrotic cluster of macrophages and their *** results provide potential therapeutic targets against human tendon adhesion.

关键词： tendon analysis landscape

Insight into the adsorption behavior and mechanism of trace impurities from H_(2)O_(2) solution on functionalized zirconia by tuning the structure of amino groups

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 83-94页

作者： yu Meng Yitong Wang Guozhu li Guozhu liu li Wang Key Laboratory for Green Chemical Technology of Ministry Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Primary,secondary and tertiary amino-functionalized zirconia(ZrO_(2)-NH_(2),ZrO_(2)-NH and ZrO_(2)-N)was synthesized by the postgrafting method for the adsorption removal of typical metallic ions,phosphate and total oxidizable carbon from a real H_(2)O_(2) ***_(2)-NH_(2),ZrO_(2)-NH and ZrO_(2)-N exhibited similar pore sizes and sequentially increased zeta *** adsorption results of single and binary simulated solutions showed that the removal efficiency increased in the order of Fe^(3+)>Al^(3+)>Ca^(2+)>Na^(+).There is competitive adsorption between metallic ions,and Fe^(3+) has an advantage over the other metals,with a removal efficiency of 90.7%.The coexisting phosphate could promote the adsorption of metallic ions,while total oxidizable carbon had no effect on *** adsorption results of the real H_(2)O_(2)solution showed that ZrO_(2)-NH_(2) exhibited the best adsorption affinity for metallic ions,as did phosphate and total oxidizable carbon,with a total adsorption capacity of 120.9 mg·g_(-1).Density functional theory calculations revealed that the adsorption process of metallic ions involves electron transfer from N atoms to metals and the formation of N-metal bonds.

关键词： adsorption metallic ion phosphate total oxidizable carbon zirconia H_(2)O_(2)

Deformation and stability of the seawall,considering the strength uncertainty of cement mixing piles

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 483-501页

作者： yuansheng yu lingling li Xiangmiao KONG Chengyuan li Zhen GUO Key Laboratory of Offshore Geotechnics and Material of Zhejiang Province College of Civil Engineering and ArchitectureZhejiang UniversityHangzhou310058China Hainan Institute Zhejiang UniversitySanya572000China ninghai Highway and Transportation Management Center Ningbo315600China ninghai Traffic Engineering Construction Management Institute Ningbo315600China

The cement mixing (CM) pile is a common method of improving soft offshore ground. The strength growth of CM piles under complex conditions is affected by many factors, especially the cement and moisture contents, and shows significant uncertainty. To investigate the stochasticity of the early strength of CM piles and its impact on the displacement and stability of a seawall, a series of laboratory tests and numerical analyses were carried out in this study. Vane shear tests were conducted on the cement-solidified soil to determine the relationships between the undrained shear strength s_(u) of the cement soil curing in the seawater and the cement content a_(c), as well as the in situ soil moisture content w. It can be inferred that the 24 h undrained shear strength follows a normal distribution. A numerical model considering the random CM pile strength was established to investigate the deformation of the seawall. Due to the uncertainty of CM pile strength, the displacement of the seawall demonstrates a certain discreteness. The decrease of the mean undrained shear strength of CM piles causes a corresponding increase in the average displacement of the seawall. When the mean strength of CM piles is lower than a certain threshold, there is a risk of instability. Furthermore, the heterogeneity of the strength within an individual CM pile also has an impact on seawall displacement. Attention should be paid to the uncertainty of CM pile strength to control displacement and stability.

关键词： Construction uncertainty Cement mixing(CM)pile Strength of cement soil Seawall stability Random finite element method(RFEM) Monte Carlo simulation(MCS)

The pseudospectrum and spectrum (in)stability of quantum corrected Schwarzschild black hole

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Science China(Physics,Mechanics & Astronomy) 2024年

作者： li-Ming Cao Jia-ning Chen liang-Bi Wu li-Bo Xie yu-Sen Zhou Peng Huanwu Center for Fundamental Theory Interdisciplinary Center for Theoretical Study and Department of Modern Physics University of Science and Technology of China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCAS

In this study,we investigate the pseudospectrum and spectrum (in)stability of quantum corrected Schwarzschild black ***,we use the hyperboloidal framework to cast the quasinormal mode (QNM) problem into an eigenvalue problem associated with a non-selfadjoint operator,and then the spectrum and pseudospectrum are ***,the invariant subspace method is exploited to improve the computational efficiency for *** investigation into the spectrum(in)stability entails two main *** the one hand,we calculate the spectra of the quantum corrected black hole,then by the means of the migration ratio,the impact of the quantum correction effect on the Schwarzschild black hole has been *** results indicate that the so-called“migration ratio instability”will occur for small black holes with small angular momentum number *** the eikonal limit,the migration ratios remain the same for each *** the other hand,we study the spectrum(in)stability of the quantum corrected black hole by directly adding some particular perturbations into the effective potential,where perturbations are located at the event horizon and null infinity,*** are two interesting observations under the same perturbation energy ***,perturbations at infinity are more capable of generating spectrum instability than those at the event ***,we find that the peak distribution can lead to the instability of QNM spectrum more efficiently than the average distribution.

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Understanding of the structural evolution of catalysts and identification of active species during CO_(2) conversion

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Chinese Chemical Letters 2024年第4期35卷 17-30页

作者： li li Fanpeng Chen Bohang Zhao Yifu yu Department of Chemistry School of ScienceInstitute of Molecular PlusTianjin UniversityTianjin 300072China

Converting CO_(2) into value-added chemicals and fuels through various catalytic methods to lower the atmospheric CO_(2) concentration has been developed to be a crucial means to alleviate the energy shortage and ameliorate the ever-fragile environment status. However, the complexity of the CO_(2) conversion reaction and the strong reduction conditions lead to the inevitable structural evolution, making it difficult for the prior design of suitable catalytic materials. Herein, to guide the rational design of efficient catalysts,we will be centered on the thermal, electro, and photo-induced structural evolution and active species identification during the CO_(2) conversion, including the in situ/operando characterization techniques monitoring the activation, steady, and deactivation stage of the catalysts as well as the inherent restructuring mechanism towards active species. Besides, the future challenges and opportunities on the merits of combining the structural evolution with the adsorbed intermediates recognized by ultra-fast spectroscopic techniques, simultaneously, the combination of theoretical simulation and the results of in situ experiments will also be addressed. This review can not only guide the identification of real active species, but also provide an approach to design the specific active species towards CO_(2) conversion, rather than only focusing on activity, for the purpose of practical industrial application.

关键词： CO_(2) Structural evolution Active species In situ Operando

Oxidation resistant low-alloyed Ti alloys with good ductility

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Rare Metals 2024年第8期43卷 3921-3936页

作者： Meng li Zhang-Zhi Shi Jun-Yi Xu Fu-Zhi Dai Xiang-Min li Zi-lin li Lu-ning Wang Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advance Metals and MaterialsSchool of Materials Science and Engineering University of Science and Technology Beijing Institute of Materials Intelligent Technology Liaoning Academy of Materials

Oxidation resistance enhancement of pure Ti often comes at the cost of reduced ductility,which is frequently the problem through alloying with sole Al,Si,W,Mo and *** overcome the short coming of single element alloying,this paper proposes a multi-element low-alloying strategy to take advantage of synergistic effects and resolve the conflict between oxidation resistance and *** demonstrates that the addition of a small quantity of Ta（0.51wt%） can boost both oxidation resistance and ductility in comparison to pure ***,the combined addition of a small amount（0.54 wt%） of Ta,Nb and Si not only preserves good ductility of pure Ti,but also reduces mass gains to 14%-67% of pure Ti during 100 h oxidation at 650-850℃ in *** indicates even better oxidation resistance than that obtained through the use of Ta,Nb,or Nb+Ta *** Ta+Nb+Si alloying creates an oxide layer that is less porous and more resistant to stratification and ***,a 3-μm N-rich layer can form in the Ti substrate beneath the oxide scale,in which phase transformation generates coherent Ti2N with（0001）Tias the habit plane,with N atoms prefers to diffuse along ■ than along [0001]*** completely transformed Ti2N region or partially transformed Ti+Ti2N region can effectively impede oxygen ***,the multielement low-alloying strategy is promising for enhancing both oxidation resistance and mechanical properties of metallic materials in the future.

关键词： Ti alloys Multi-element Co-alloying Oxidation resistance Mechanical properties