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From common biomass materials to high-performance tissue engineering scaffold: Biomimetic preparation, properties characterization, in vitro and in vivo evaluations

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Journal of Bioresources and Bioproducts 2024年第2期9卷 185-196页

作者： Zongpu Xu Fang He jing yu Zhangze yang yu Zhu Rong Liao Ruyin Lyu Mei yang Liangjun Zhu Mingying yang Institute of Applied Bioresources College of Animal SciencesZhejiang UniversityHangzhou 310058China Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province Zhejiang UniversityHangzhou 310058China Department of Neurosurgery the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

Converting common biomass materials to high-performance biomedical products could not only reduce the environmental pressure associated with the large-scale use of synthetic materials,but also increase the economic *** as a very promising candidate has drawn considerable attention owing to its abundant sources and remarkable ***,pure chitosan materials usually exhibit insufficient mechanical properties and excessive swelling ratio,which seriously affected their in vivo stability and integrity when applied as tissue engineering ***,simultaneously improving the mechanical strength and biological compatibility of pure chitosan(CS)scaffolds becomes very ***,inspired by the fiber-reinforced con-struction of natural extracellular matrix and the porous structure of cancellous bone,we built silk microfibers/chitosan composite scaffolds via ice-templating *** biomimetic strategy achieved 500%of mechanical improvement to pure chitosan,and meanwhile still maintaining high porosity(>87%).In addition,the increased roughness of chitosan pore walls by embedded silk microfibers significantly promoted cell adhesion and *** importantly,after subcutaneous implantation in mice for four weeks,the composite scaffold showed greater struc-tural integrity,as well as better collagenation,angiogenesis,and osteogenesis abilities,suggesting its great potential in biomedicine.

关键词： Chitosan Biomimetic strategy Fiber-reinforced composite Mechanical property Biocompatibility

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Application of sparse S transform network with knowledge distillation in seismic attenuation delineation

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Petroleum Science 2024年第4期21卷 2345-2355页

作者： Nai-Hao Liu yu-Xin Zhang yang yang Rong-Chang Liu jing-Huai Gao Nan Zhang School of Information and Communications Engineering Xi'an Jiaotong University School of Software Engineering Xi'an Jiaotong University PetroChina Research Institute of Petroleum Exploration and Development (RIPED) CNPC Research Institute of Exploration and Development Yumen Oilfield Company CNPC

Time-frequency analysis is a successfully used tool for analyzing the local features of seismic ***, it suffers from several inevitable limitations, such as the restricted time-frequency resolution,the difficulty in selecting parameters, and the low computational efficiency. Inspired by deep learning,we suggest a deep learning-based workflow for seismic time-frequency analysis. The sparse S transform network(SSTNet) is first built to map the relationship between synthetic traces and sparse S transform spectra, which can be easily pre-trained by using synthetic traces and training labels. Next, we introduce knowledge distillation(KD) based transfer learning to re-train SSTNet by using a field data set without training labels, which is named the sparse S transform network with knowledge distillation(KD-SSTNet).In this way, we can effectively calculate the sparse time-frequency spectra of field data and avoid the use of field training labels. To test the availability of the suggested KD-SSTNet, we apply it to field data to estimate seismic attenuation for reservoir characterization and make detailed comparisons with the traditional time-frequency analysis methods.

关键词： S transform Deep learning Knowledge distillation Transfer learning Seismic attenuation delineation

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Model gradient: unified model and policy learning in model-based reinforcement learning

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Frontiers of Computer Science 2024年第4期18卷 117-128页

作者： Chengxing JIA Fuxiang ZHANG Tian XU jing-Cheng PANG Zongzhang ZHANG yang yu National Key Laboratory for Novel Software Technology Nanjing UniversityNanjing 210023China Polixir Technologies Nanjing 210000China

Model-based reinforcement learning is a promising direction to improve the sample efficiency of reinforcement learning with learning a model of the *** model learning methods aim at fitting the transition data,and commonly employ a supervised learning approach to minimize the distance between the predicted state and the real *** supervised model learning methods,however,diverge from the ultimate goal of model learning,i.e.,optimizing the learned-in-the-model *** this work,we investigate how model learning and policy learning can share the same objective of maximizing the expected return in the real *** find model learning towards this objective can result in a target of enhancing the similarity between the gradient on generated data and the gradient on the real *** thus derive the gradient of the model from this target and propose the Model Gradient algorithm(MG)to integrate this novel model learning approach with policy-gradient-based policy *** conduct experiments on multiple locomotion control tasks and find that MG can not only achieve high sample efficiency but also lead to better convergence performance compared to traditional model-based reinforcement learning approaches.

关键词： reinforcement learning model-based reinforcement learning Markov decision process

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Span-based joint entity and relation extraction augmented with sequence tagging mechanism

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Science China(Information Sciences) 2024年第5期67卷 84-98页

作者： Bin JI Shasha LI Hao XU Jie yu Jun MA Huijun LIU jing yang College of Computer National University of Defense Technology

Span-based joint extraction simultaneously conducts named entity recognition(NER) and relation extraction(RE) in a text span form. However, since previous span-based models rely on span-level classifications, they cannot benefit from token-level label information, which has been proven advantageous for the task. In this paper, we propose a sequence tagging augmented span-based network(STSN), a spanbased joint model that can make use of token-level label information. In STSN, we construct a core neural architecture by deep stacking multiple attention layers, each of which consists of three basic attention *** the one hand, the core architecture enables our model to learn token-level label information via the sequence tagging mechanism and then uses the information in the span-based joint extraction; on the other hand, it establishes a bi-directional information interaction between NER and RE. Experimental results on three benchmark datasets show that STSN consistently outperforms the strongest baselines in terms of F1,creating new state-of-the-art results.

关键词： joint extraction named entity recognition relation extraction span sequence tagging mechanism

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High-chromium vanadium-titanium magnetite all-pellet integrated burden optimization and softening-melting behavior based on flux pellets

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 498-507页

作者： Bojian Chen Tao Jiang jing Wen Guangdong yang Tangxia yu Fengxiang Zhu Peng Hu School of Metallurgy Northeastern UniversityShenyang 110819China Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819China Liaoning Key Laboratory for Metallurgical Sensor and Technology Shenyang 110819China State key laboratory of vanadium and titanium resources comprehensive utilization Panzhihua 617000China

High-chromium vanadium-titanium magnetite(HVTM)is a crucial polymetallic-associated resource to be *** allpellet operation is a blast furnace trend that aims to reduce carbon dioxide emissions in the *** referencing the production data of vanadium-titanium magnetite blast furnaces,this study explored the softening-melting behavior of high-chromium vanadium-titanium magnetite and obtained the optimal integrated burden based on flux *** results show that the burden with a composition of 70wt%flux pellets and 30wt%acid pellets exhibits the best softening-melting *** comparison to that of the single burden,the softening-melting characteristic temperature of this burden composition was *** melting interval first increased from 307 to 362℃and then decreased to 282℃.The maximum pressure drop(ΔPmax)decreased from 26.76 to 19.01 *** permeability index(S)dropped from 4643.5 to 2446.8 kPa·℃.The softening-melting properties of the integrated burden were apparently *** acid pellets played a role in withstanding load during the softening *** flux pellets in the integrated burden exhibited a higher slag melting point,which increased the melting temperature during the melting *** slag homogeneity and the TiC produced by over-reduction led to the gas permeability deterioration of the single *** segregation of the flux and acid pellets in the HVTM proportion and basicity mainly led to the better softening-melting properties of the integrated burden.

关键词： high-chromium vanadium-titanium magnetite softening-melting properties all pellets integrated burden flux pellets

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Understanding livelihood vulnerability:a perspective from Western Sichuan’s ethnic rural settings

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Journal of Mountain Science 2024年第2期21卷 380-396页

作者： yu Yongqian jing Zheng WANG Yan QIU Xiaoping yang Xueting XU yun School of Geography and Resource Science Sichuan Normal UniversityChengdu 610101China Key Laboratory of land Resources Evaluation and Monitoring in Southwest Ministry of EducationSichuan Normal UniversityChengdu 610101China Sichuan County Economic Development Research Center Mianyang Normal UniversityMianyang 621000China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

To explore the livelihood status and key influencing factors of rural households in the minority areas,we collected flat data from 284 rural households in 32 villages across 12 counties of Western Sichuan from 2021 to *** conducted participatory household survey on the livelihood status of the rural households and try to identify the key factors to influence their livelihood vulnerability using multiple linear *** results showed that:the livelihood situation of the rural households is relatively *** vulnerability varies significantly with the income levels,education levels,and income *** vulnerability of farm households,categorized from low to high livelihood types,follows the sequence:non-agricultural dominant households,non-agricultural households,agricultural dominant households,and pure agricultural *** degree of damage to the natural environment,education costs,loan opportunities,the proportion of agricultural income to annual household income,and the presence of sick people in the household have significant positive effects on the livelihood vulnerability index(LVI)of rural households;while help from relatives and friends,net income per capita,household size,household education,agricultural land area,participation in industrial organizations,number of livestock,purchase of commercial houses,drinking water source,and self-supply of food have significant negative *** on the findings,we believe that local rural households operate in a complex livelihood system and recommend continuous interventions targeting key influences to provide empirical research support for areas facing similar situations.

关键词： Livelihood Vulnerability Rural households Ethnic areas

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Research on Bast Fiber Extracted from the White Bark of Three Species in the Genus Broussonetia

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Chinese Journal of Polymer Science 2024年第6期42卷 729-738页

作者： Shan-Shan Jin Si-Nong Wang Yan-Yan Huang jing-yu Zhang Peng Liu Hui yu Hong-Dong Zhang yu-Liang yang Institute for Preservation and Conservation of Chinese Ancient Books Fudan University LibraryFudan UniversityShanghai200433China State key laboratory of Molecular Engineering of polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China

Against the backdrop of a global paper resource shortage,there is a growing need to identify fast-growing tree species capable of producing long-lasting *** plant species namely Broussonetia kazinoki,Broussonetia papyrifera and hybrid paper mulberry,belong to the Broussonetia genus,were collected from China to study their white bark suitability for pulp and *** chemical composition revealed that the holocellulose content in Broussonetia kazinoki and Broussonetia papyrifera was more than 80%.The molecular weight distribution of several holocellulose/α-cellulose is observed by GPC,which allows us to better observe the changes of various components on the molecular *** yield,lignin,whiteness,and molecular weight of the pulps obtained by NaOH treatment were *** microscope was used to characterize the fiber length-width ratio and ***,the improvement of the fiber rigidity method based on the Kratky-Porod chain model makes it more theoretical and further reveals the influencing factors of fiber *** study demonstrates the high potentiality of these three species for papermaking applications.

关键词： Broussonetia genus Cellulose Alkaline pulping Kratky-Porod chain model Fiber rigidity

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Production induced fracture closure of deep shale gas well under thermo-hydro-mechanical conditions

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Petroleum Science 2024年第3期21卷 1796-1813页

作者： Shi-Ming Wei yang Xia Yan Jin Xu-yang Guo jing-yu Zi Kai-Xuan Qiu Si-yuan Chen College of Science China University of Petroleum(Beijing)Beijing102249China CNOOC Research Institute Ltd Beijing100028China The University of Hong Kong Hong Kong999077China

Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through *** multi-stage fractured horizontal well is the key to exploiting the deep shale gas ***,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas *** this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas *** we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale *** the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture *** with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the *** simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary *** creep and proppant embedment both increase the degree of fracture *** reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the ***,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield *** study is helpful to understand the mechanism of hydraulic fracture ***,it provides the theoretical guidance for maintaining the long

关键词： Shalegas Fracture closure Fluid-solid-heat coupling Discontinuous discrete fracture

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Interface optimization of graphene paper-Cu composite prepared by electrodeposition

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Journal of Iron and Steel Research International 2024年第1期31卷 64-73页

作者： jing Guo Hai-jing Wang Shuang-juan Liu Peng Zhang jing-yu Tang Wei-yang Zhang Han-jie Guo Peng-cheng Wang Cai Meng School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Advanced Technology and Materials Co. Ltd.Beijing100083China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei230027AnhuiChina

A room-temperature electrodeposition method with an organic electrolyte was developed to fabricate a HNO3-pretreated graphene paper Cu(GP'-Cu)*** improve the interfacial bonding of GP'-Cu composite,magnetron sputtering technology was used to create a"sandwich"structural gradient GP'-Cu *** selection of the intermediate transition layer metal was based on two-dimensional *** electron microscopy,X-ray photoelectron spectroscopy,and other analytical methods confirmed that the addition of an intermediate transition metal(Cr,Ni)layer reduced the gap distance and enhanced the interfacial bonding of the GP'and Cu deposited *** GP'-Ni-Cu composite exhibited the largest increase in tensile strength and *** addition,it had the highest thermal diffusivity and elongation at break among the GP'-Cu,GP'-Cr-Cu and GP'-Ni-Cu composites.

关键词： Graphene paper Two-dimensional disregistry Magnetron sputtering Metal composite

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A fungal CYP from Beauveria bassiana with promiscuous steroid hydroxylation capabilities

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Chinese Chemical Letters 2024年第5期35卷 218-222页

作者： yu Peng yue Wang Tian-Jiao Chen jing-jing Chen Jin-Ling yang Ting Gong Ping Zhu State Key Laboratory of Bioactive Substance and Function of Natural Medicines NHC Key Laboratory of Biosynthesis of Natural ProductsCAMS Key Laboratory of Enzyme and Biocatalysis of Natural DrugsInstitute of Materia MedicaChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China

Hydroxylation of steroid core is critical to the synthesis of steroid *** sp^(3) C-H hydroxylation is challenging through chemical catalysis,alternatively,fungal biotransformation offers a possible solution to this ***,mining and metabolic engineering of cytochrome P450 monooxygenases(CYPs)is usually regarded as a more eco-friendly and efficient ***,we report the mining and identification of a new steroid CYP(CYP68BE1)from Beauveria bassiana by transcriptomics,heterologous expression,in vivo and in vitro functional *** catalytic promiscuity of CYP68BE1 was explored,and CYP68BE1 showed promiscuously and catalytically versatile,which is qualified for monohydroxylation on C11α,C1α,C6βand dihydroxylation on C1β,11αand C6β,11αof six steroids,leading to the production of key steroid intermediates required in the industrial synthesis of some indispensable steroid *** dynamics simulations were performed,revealing the molecular basis of different binding orientations of CYP68BE1 with different *** discovery of CYP68BE1 offers a promising biocatalyst for enriching the steroid structural and functional diversity,which also can be applied to biosynthesize valuable steroid drug intermediates.

关键词： Fungal CYPs Steroid hydroxylase Beauveria bassiana Promiscuous biocatalyst Molecular dynamics

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